Adjacent Tubules Research Articles

Histological Study of Development Structure of Testis and Epididymis in Gazelle Gazelle Subgutturosa

Objective: The aim of this study for focused the light on the development structure of the testis of gazelle. Materials and Method: 10 healthy male gazelle were used to study the histology structure of testis (5 pre- Puberty and 5 post- Puberty). Results: The testis is surrounded by a thick, irregular connective tissue capsule. Each lobule of the testis is composed of seminiferous tubules and interstitial tissue, and trabecular and interlobular septa divide the lobules apart. Neighboring the seminiferous tubules are Sertoli cells and spermatogenic cells. From spermatogenic cells, spermatozoa are produced. The first spermatogonia are small, spherical cells with black, spherical nuclei that reside on the basement membrane. Spermatogonia were earliest stages of the spermatogenic cells. Larger cells with frequently distinct chromatin are called primary spermatocytes. Secondary spermatocytes are rare because of their quick second meiotic division and the haploid spermatids that follow. Spermatids are round, pale-nucleated cells that are grouped close to the lumen of the seminiferous tubule. Prostatogenic cells outnumber Sertoli cells in the body. Oval or triangular in shape, the nucleus has a light coloration. In the connective tissue separating adjacent tubules, Leydig cells are present. Lines the epididymis are pseudostratified epithelium. Extensions of the cytoplasm into the lumen are called stereocilia. In different proportions, there is circular smooth muscle, and a connective tissue lamina propria supports the epithelium. The rete testis is connected to the ductus epididymidis by the efferent ductules, which are convolutions of tubules. Numerous valved veins were visible in the tunica albuginea, which covered the initial ascending portion of the epididymal head. Cuboidal epithelium was lining extratesticular rete testis. Three different cell types; migrating, basal, and columnar had epithelial membranes lining the efferent ductules. Many columnar, non-ciliated cells with many cytoplasmic vacuoles and tiny granules lined the epithelium of the first segment of the efferent ductules. Conclusion: In post-puberty age, the structure of the gazelle's testis exhibited a pattern resembling that of other ruminants; the seminiferous tubules contain adult sperm and a broad lumen.

#2781 Renal cortical necrosis—a rare cause of acute kidney injury

Abstract Background and Aims Renal cortical necrosis (RCN) is a rare and catastrophic cause of acute kidney injury (AKI). It is characterized by ischemic destruction of all the elements of renal cortex due to marked reduction in renal arterial perfusion of renal cortex due to vascular spasm and microvascular injury. It can be patchy or diffuse depending upon the cause and extent of hypoperfusion. Snake bite is rare cause of RCN. Incidence of RCN following snake bite has been reported to be as high as in 25% of the bitten patients to <1%. Lack or delay in receiving anti snake venom (ASV) has been observed to be a contributing factor in development of RCN following snake bite. Method A 45-year-old female had an unknown bite on foot while returning to home at twilight. She had intense pain at site of bite with slight ooze of blood. Overnight she had vomiting and pain abdomen. Subsequently she developed progressive fall in urine output and dyspnoea. After about 36 hours of bite at the time of admission in hospital she had anuria, prolonged whole blood clotting time, tachypnoea, hypoxemia and required oxygen (O2) to maintain normal O2 saturation. She was given two doses of polyvalent ASV 6 hours apart which corrected her coagulation defect. Investigations showed: haemoglobin—9 gm/dl, total leucocyte count—18700/mcl, platelet—1.15 lakh/mcl, blood urea—88 mg/dl and serum creatinine—10.5 mg/dl. She was managed with haemodialysis and supportive care. Even after 3 weeks of onset of AKI, she had anuria so a kidney biopsy was done. Results kidney biopsy on light microscopy examination showed 9 glomeruli; 8 revealing global tuft necrosis along with necrosis of adjacent tubules and vasculature and necrotic process affected around 60% of sampled cortical area consistent with cortical necrosis (Fig. 1). She was continued with haemodialysis support and urine output and pre-dialysis serum creatinine were monitored. Her urine output after 3 months of onset of AKI is around one litre per day but her pre-dialysis serum creatinine stays in the range of 9-10 mg/dl and so she continues to receive biweekly haemodialysis. Conclusion In our index case, there was delay in getting ASV which may have contributed to development of RCN. So, early treatment of snake bite is important to prevent this catastrophic complication.

Polycystic Kidney in Adult Guinea Pig: A Case Report

Polycystic kidney disease (PKD) is a genetic or acquired disorder characterized by progressive distension of multiple tubular segments, manifested by fluid accumulation, and growth of non-neoplastic epithelial cells. A male, 2.5 years old, Dunkin Hartley guinea pig, which was kept as a retired breeder in a lab animal facility, TANUVAS, was found dead and subjected for necropsy. History of dullness, depression, anorexia and emaciation was reported. Grossly, both the kidneys were enlarged with multiple, variable sized, spherical transparent cysts with clear fluid. The gall bladder was slightly enlarged with thick bile and a few small, black coloured stones. The tissue samples were fixed in 10% neutral buffered formalin and processed through paraffin embedding technique. Histopathological examination of kidney revealed multiple, variable sized cysts mostly in the cortical areas and the cyst wall was lined by flattened epithelium. Partial to complete loss of glomerular tufts, glomerulosclerosis, tubular epithelial cells degeneration and necrosis were also observed. Some cysts were filled with eosinophilic fluid. Interstitial areas revealed the presence of mononuclear cells infiltration. The basement membrane which supported the cyst wall showed mild thickening by special staining like Masson’s trichrome and Periodic Acid Schiff. Liver showed multifocal, periportal fibrosis with mononuclear cells infiltration and bile duct hyperplasia. Lungs revealed pulmonary congestion, emphysema and bronchiolar epithelial cell degeneration with peribronchiolar mononuclear cells infiltration. Presence of multiple cysts with degenerative changes in adjacent tubules and glomeruli of both the kidneys might have lead to the death of the animal.

A Multitubular Kidney-on-Chip to Decipher Pathophysiological Mechanisms in Renal Cystic Diseases.

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a major renal pathology provoked by the deletion of PKD1 or PKD2 genes leading to local renal tubule dilation followed by the formation of numerous cysts, ending up with renal failure in adulthood. In vivo, renal tubules are tightly packed, so that dilating tubules and expanding cysts may have mechanical influence on adjacent tubules. To decipher the role of this coupling between adjacent tubules, we developed a kidney-on-chip reproducing parallel networks of tightly packed tubes. This original microdevice is composed of cylindrical hollow tubes of physiological dimensions, parallel and closely packed with 100–200 μm spacing, embedded in a collagen I matrix. These multitubular systems were properly colonized by different types of renal cells with long-term survival, up to 2 months. While no significant tube dilation over time was observed with Madin-Darby Canine Kidney (MDCK) cells, wild-type mouse proximal tubule (PCT) cells, or with PCT Pkd1+/- cells (with only one functional Pkd1 allele), we observed a typical 1.5-fold increase in tube diameter with isogenic PCT Pkd1-/- cells, an ADPKD cellular model. This tube dilation was associated with an increased cell proliferation, as well as a decrease in F-actin stress fibers density along the tube axis. With this kidney-on-chip model, we also observed that for larger tube spacing, PCT Pkd1-/- tube deformations were not spatially correlated with adjacent tubes whereas for shorter spacing, tube deformations were increased between adjacent tubes. Our device reveals the interplay between tightly packed renal tubes, constituting a pioneering tool well-adapted to further study kidney pathophysiology.

A little walk between Early Jurassic sponges and corals: A confusing morphological convergence

Hispaniastraea Turnšek et Geyer, 1975 is a unique coral genus from the Early Jurassic Epoch (Liassic). Corals of this genus are characterised by a highly dominant major septum and a set of eleven minor septa that are very short or even abortive. Initially discovered in Spain, new samples of this genus were depicted from Morocco by Beauvais in 1980; however, this genus was interpreted as a synonym of Pseudoseptifer Fischer, 1970, a chaetetid sponge (i.e., a sponge with siliceous spicules embedded in a calcareous skeleton). The skeleton of Pseudoseptifer is composed of adjacent tubules that increase by fissiparity by means of a pseudoseptum. Based on the study of new material sampled from the Lower Jurassic of Morocco and Southern France, we highlight the coexistence and legitimacy of both genera (i.e., Pseudoseptifer and Hispaniastraea), which therefore constitutes a fine example of morphological convergence between separate phyla. Although the living tissues and microstructures of the skeleton differ between the sponge and coral genera, the distinction from fossil material is challenging, especially if material is diagenetically altered. Herein, we recommend a set of key characters to distinguish these genera and propose a systematic revision of the genus Hispaniastraea. The synonymy between the two original species, Hispaniastraea murciana and H. ramosa is established and a new species, Hispaniastraea ousriorum, is described. Finally, a new family, the Hispaniastraeidae (Order Hexanthiniaria?), is erected for these distinctive corals, which are unique in the history of this group.

Germ Cell Neoplasia in Situ and Preserved Fertility Despite Suppressed Gonadotropins in a Patient With Testotoxicosis

Testotoxicosis is an autosomal-dominant, male-limited disorder. Activating mutations in the luteinizing hormone receptor gene (LHCGR) cause high autonomous testosterone secretion, resulting in early-onset peripheral precocious puberty. Little is known about long-term consequences of testotoxicosis. We present a rare case of a patient followed for 25 years with two remarkable outcomes: preserved fertility and germ cell neoplasia in situ (GCNIS). He presented with precocious puberty at 10 months of age and was diagnosed with testotoxicosis due to a de novo heterozygous Asp578Tyr mutation in LHCGR. Testicular biopsy in childhood showed Leydig cell hyperplasia with altered cell maturation. From infancy throughout adulthood, elevated testosterone and estradiol, low inhibin B and anti-Müllerian hormone, and completely suppressed follicle-stimulating hormone and luteinizing hormone were noted. Height acceleration and advanced bone age resulted in a reduced final height. Semen analysis revealed ongoing spermatogenesis, and the patient fathered a child by natural conception. Ketoconazole treatment decreased circulating testosterone in childhood, supported by experimental suppression of testosterone production in his adult testis tissue cultured ex vivo. At 25 years of age, ultrasound revealed a testicular tumor, identified as a Leydig cell adenoma, but unexpectedly with GCNIS present in adjacent seminiferous tubules. The case illustrates that absence of gonadotropins but high intratesticular testosterone concentration is sufficient for spermatogenesis and to allow fatherhood. Our study is also the first description, to our knowledge, of GCNIS in a patient with testotoxicosis. We recommend regular clinical examination and ultrasonic evaluation of the testes in these patients due to potential increased risk of malignancy.

The Effect of Mobile Phone Exposure on the Testicular Structure of the Pubertal and the Adult Male Albino Rat

Introduction: Nowadays, mobile phones (MP) have become indispensable devices in our daily life. The electromagnetic waves and biological effects of MP have recently become a crucial subject in scientific studies. As men usually put MP in standby position most of the day in their pockets close to their testes, the assessment of consequences of MP handling on the male reproductive function seems to be of great importance. Electromagnetic exposure has been found to alter the reproductive endocrine hormones and gonadal function in both the pre-pubertal and the adult rats. Other studies declared that prolonged MP use has been associated with a delay in the onset of puberty.Aim of work: To study the histological structure of the testis of both pubertal and adult male albino rats, upon exposure to MP.Material and Methods: Forty male albino rats were used in this study, twenty pubertal, aging 6-8 weeks and weighing 140-160 gm, and twenty adult, aging 4-6 months and weighing 200 - 250 gm. Group I (Control Group): composed of twenty rats that were left without mobile exposure and were used as control. It was further subdivided into: Group IA (Control Pubertal Group): consisted of ten pubertal rats. Group IB (Control Adult Group): consisted of ten adult rats. Group II (Mobile Group): composed of twenty rats that were exposed to MP during calling for 1 month. It was further subdivided into: Group IIA (Mobile Pubertal Group): consisted of ten pubertal rats. Group IIB (Mobile Adult Group): consisted of ten adult rats. At the end of the experiment, the testis specimens were collected and processed for light microscopic and immunohistochemical examination and morphometric studies were also done.Results: Histological examination of the testis sections of the mobile pubertal group stained with Hx. & E showed multiple focal areas of rupture of basement membrane, decrease in the height of epithelial lining of seminiferous tubules with poor discrimination between its spermatogenic stages. Semithin sections revealed multiple areas of patchy depletion of germinal epithelium and some of the existing spermatogenic cells appeared with pyknotic nuclei. An increase in the number of Leyding cells was observed in the interstitial tissue. Immunohistochemical examination for Caspase III showed positively stained cells revealing marked apoptosis. On the other hand, examination of testis sections of the mobile adult group stained with Hx. & E. showed distortion in some seminiferous tubules. Multiple areas of degeneration were noted close to the basement membrane in many tubules. The thickness of the germinal epithelium was relatively decreased with areas of patchy depletion observed among the spermatogenic cells Moreover, some tubules showed disturbance of their normal architecture with almost complete loss of discrimination of their spermatogenic stages . Secretions were noticed in the interstitial tissue with notable adhesion of adjacent tubules. In semithin section Sertoli cells and spermatogonia were few in number .Some primary spermatocytes appeared distorted in shape. Vacuolation in between the seminiferous layers was evident, along with areas of complete depletion from cellular content. An increase in the number of Leydig cells was observed in the interstitial tissue. Immuno-histochemical examination for Caspase III showed positively stained cells revealing evident apoptosis.Conclusion: Affection of the seminiferous epithelium following mobile waves’ exposure and the more marked affection observed in the pubertal rats in our study, may be considered as a danger alarm for the widely spread and increasing use of mobile phones among pubertal teenage males. Therefore, further studies regarding this age group in human and the possible protective agents against harmful waves are highly recommended.

Primary Testicular Failure: An Overview

Primary testicular failure (PTF) or hypergonadotropic hypogonadism refers to conditions where testes fail to produce sperm despite adequate hormonal support. Primary testicular failure is major cause of non-obstructive azoospermia and oligospermia. It affects approximately 1% of all men and 10% of those seeking fertility evaluations [1]. Non-obstructive azoospermia i.e. defect in spermatogenesis can be primary (testicular pathology) or secondary (pathology outside testes; mostly hypothalamo-pituitary axis or pretesticular). The pre-testicular (hypogonadotropic hypogonadism) causes of azoospermia may be defined as extragonadal endocrine disorder originating in the pineal, hypothalamus, pituitary, or adrenals, which have an adverse effect on spermatogenesis through aberrant hormonal action. The testicular (hypergonadotropic hypogonadism/ primary testicular failure) causes of azoospermia are primary defects of the testes. Primary testicular failure is classified into four distinct subtypes viz., sertoli cell only syndrome (SCOS), germ cell/maturation arrest (GCA/MA), hypospermatogenesis (HS) and tubular fibrosis (TF) according to histopathology/cytology findings although accurate categorization is only possible by multiple testicular biopsies/fine needle aspiration cytology (FNAC). However, often one may find differences in subtypes between testes viz., SCOS in one side and tubular fibrosis in other side or any other combinations and these cases are usually labeled as mixed group. In addition many patients may present as complete germinal cell aplasia in some tubules whereas complete spermatogenesis in adjacent tubules (focal germinal cell aplasia) or some tubules with sertoli cells only/hyaline sclerosis and other tubules with complete spermatogenesis or any combinations. This categorization should be considered as a description of histopathologic phenotypes of spermatogenic failure, and not as manifestations of disease entities. Sometimes, patients may present as hypospermatogenesis/maturation arrest initially and later as sertoli cell only syndrome/testicular fibrosis over a period of few years hence diagnosis may change with time. Sertoli cell only syndrome or germ cell aplasia applies to a testis, in which germ cells at any stage are absent, but the tubular architecture is not affected by fibrosis, and supporting cells continue to be present. Sertoli cells play a central role in development of a functional testis, and hence in the expression of a male phenotype. Sertoli cell only syndrome is a common finding of non-obstructive azoospermia. It is a histopathologic phenotype of spermatogenic failure and described first by Castillo et al. [2], in complete germ cell aplasia, the tubules are reduced in diameter, contain only sertoli cells and no other cells involved in spermatogenesis are present. The primordial germ cells either do not migrate from the yolk sac into the future gonads or do not survive in the seminiferous tubules. Germ cell aplasia can also be focal with a variable percentage of tubules containing germ cells, but even in these tubules, spermatogenesis is often have limited activity [3] and hence, should be categorized as hypospermatogenesis. Maturation/Germ Cell arrest is the interruption of normal germ cell maturation at a specific cell stage including spermatogonia, spermatocyte or spermatid level. In hypospermatogenesis all the stages of spermatogenesis are present in some or all tubules, but they are reduced in number. Tubular fibrosis presents as thickening of peritubular membrane and hyaline deposition on basement membrane with absence of germ cells and sertoli cells.

PO-0786 Prenatal Diagnosis Of Glomerulocystic Kidney Disease Due To Mutation Hnf 1b. Importance Of Genetic Test

Background HNF 1B is a key factor for the normal development of the kidney and pancreas transcription. Mutations affecting the gene encoding this factor are related to different phenotypes of renal disease among glomerulocystic kidney disease (GCKD) is included. GCKD is entity characterised by glomerular cysts with dilatation of the Bowman space and adjacent tubules. Methods Case report: Male patient, 7 years old, with renal cystic disease prenatal diagnosis of bilateral cortical cysts distribution. Unrelated parents, mother with IgA nephropathy, no alterations of hepatic metabolism or glucose. At birth, had very enlarged kidneys with increased echogenicity and loss of cortico medullary differentiation without other extrarenal findings. The disease has slowly evolved, with increased number of cysts, always cortical distribution. No impairment of renal function, normal BP. Genetic study was performed. Results Heterozygous mutation HNF 1B was identified (c. 1-?_1674+del), consisting of the deletion in one of its complete gene alleles. Neither parent is a carrier of the mutation. Conclusions The demonstration of de novo gene mutation in this patient confirms the aetiology of cystic disease. The test is very useful because it allows early diagnosis, non-invasive, allows estimating a prognosis and genetic counselling to the family.

Acute oxalate nephropathy induced by oral high-dose vitamin C alternative treatment.

A 59 year-old woman presented for abdominal pain, fatigue and decreased urine output. Eight months before she underwent a hysterectomy with bilateral salpingo-oophorectomy for a uterine leiomyosarcoma but was diagnosed 6 months later with local recurrence. She refused radiotherapy and palliative chemotherapy but rather preferred alternative treatment with oral high-dose vitamin C. Acute renal failure (ARF) was diagnosed (creatinine 166 versus 48 µmol/L 2 months before) and urinalysis revealed abundant calcium oxalate. Abdominal scan did not reveal renal obstruction. Renal biopsy showed extensive tubular calcium oxalate crystal deposition with some degree of acute tubular injury and mild interstitial inflammation with eosinophils (Figures 1 and ​and2).2). She denied any ethylene glycol ingestion and she was not known for bypass surgery or malabsorption. Hemodialysis treatments were initiated to increase creatinine and for hypervolemia but unfortunately, her condition slowly deteriorated. After 3 weeks of hemodialysis, the patient's renal function has not recovered and she was finally transferred to palliative care unit. Oxalate nephropathy is mostly seen with ethylene glycol intoxication, malabsorption or in primary hyperoxaluria. Vitamin C is metabolized into oxalate and can induce ARF by precipitation of calcium oxalate in renal tubules when excessive dose is taken. The patient reported that she was taking over 4 g of vitamin C daily during 30 consecutive days. Our case combined to recently published papers [1–3] underline the importance for clinicians to increase their awareness about this potential but easily preventable complication in patients taking high-dose vitamin C as alternative treatment. Fig. 1. Intra-tubular deposition of calcium oxalate crystals (white arrows) and acute tubular injury in adjacent tubules. H&E ×20. Fig. 2. Birefringent calcium oxalate crystals under polarized light. H&E ×20.

Structure, stability, and motion of dislocations in double-wall carbon nanotubes

In this paper, a novel double-wall carbon nanotube (DWCNT) with both edge and screw dislocations is studied by using the molecular dynamics (MD) method. The differences between two adjacent tubule indexes of armchair and zigzag nanotubes are determined to be 5 and 9, respectively, by taking into account the symmetry, integrality, and thermal stability of the composite structures. It is found that melting first occurs near the dislocations, and the melting temperatures of the dislocated armchair and zigzag DWCNTs are around 2600 K—2700 K. At the pre-melting temperatures, the shrink of the dislocation loop, which is comprised of edge and screw dislocations, implies that the composite dislocation in DWCNTs has self-healing ability. The dislocated DWCNTs first fracture at the edge dislocations, which induces the entire break in axial tensile test. The dislocated DWCNTs have a smaller fracture strength compared to the perfect DWCNTs. Our results not only match with the dislocation glide of carbon nanotubes (CNTs) in experiments, but also can free from the electron beam radiation under experimental conditions observed by the high resolution transmission electron microscope (HRTEM), which is deemed to cause the motion of dislocation loop.

"Mixed germ cell testicular tumor" in an adult female

The androgen insensitivity (testicular feminization) syndrome was described by Morris in phenotypic females with 46XY karyotype, presenting with primary amenorrhea, adequate breast development, and absent or scanty pubic or axillary hair. Gonads consist usually of seminiferous tubules without spermatogenesis. These patients have a 5–10% risk of developing germ cell tumors, usually after the complete development of secondary female sexual characteristics. We hereby report a case considered as a female with married life of 15 years, who was operated for severe abdominal pain. Phenotype characters were that of female. Microscopic examination of the tumor from the abdomen revealed germinoma and yolk sac tumor with adjacent seminiferous tubules. Karyotyping showed 46XY. Final diagnosis of malignant mixed germ cell tumor in androgen insensitivity syndrome was made. Surveillance may be the most appropriate option when these conditions are initially diagnosed in adulthood to prevent development of germ cell tumors.

Modeling Calcium Dynamics in Realistic Rabbit Ventricular Myocytes with Several Transverse Tubules

Calcium signaling in cardiomyocytes is strongly influenced by the topology of the sarcolemma (SL) and the distribution of sarcolemmal proteins, including the L-type calcium channel (LCC) and sodium-calcium exchanger (NCX). Peculiar to mammalian ventricular cardiomyocytes are sarcolemmal invaginations called transverse tubules (TT) exhibiting high densities of LCC clusters that trigger Ca2+ release from the sarcoplasmic reticulum (SR). Prior studies of pharmacologically-disabled SR release in rabbit ventricular myocytes have demonstrated that sub-micrometer resolution details of the SL geometry shape local Ca2+ dynamics and suggest a feedback between cytosolic [Ca2+] and SL ion channel and transporter activity. Here we investigate the hypothesis that the ordered spatial arrangement of TT and coupling between adjacent tubules leads to an organized Ca2+ transient. Moreover, we compare Ca2+ transients arising from clustered or continuously-distributed trigger fluxes for the propensity to produce Ca2+ waves. Our findings are that 1) the arrangement of TTs promotes a faster rise in [Ca2+] transversely relative to the longitudinal direction of cardiomyocytes and 2) clustering of SL transporters along the TT promotes an axially-uniform calcium transient. These results evidence contribution of structural detail at sub-micrometer resolution to excitation-contraction coupling and anomalous Ca2+ dynamics underlying cardiac arrhythmias.Supported by NBCR (NIH grant 2 P41 RR08605), NIH GM31749, NSF MCB-0506593, MCA93S013, Center for Theoretical Biological Physics, Howard Hughes Medical Institute, SDSC, W. M. Keck foundation, Richard A. and Nora Eccles Fund for Cardiovascular Research.

Purinergic signalling

The Chief Editor of Acta Physiologica earned his degree at the ‘I. Physiologisches Institut’ in Heidelberg. He is right now writing these lines in Hessische Str. 3–4 in Berlin. Who cares? And what does this have to do with purines in physiology, a topic so hot that our journal dedicated a whole issue to it (Fredholm & Verkhratsky 2010)? Little did I know at the time in Heidelberg that the enormous desk I was sitting at had once been the desk of Albrecht Karl Martin Leonhard Kossel (Had I known, our laboratory dogs would probably not have been allowed to relieve their bowels there as often). Kossel discovered the nitrogenous compounds purine and pyrimidine in the resolvent of the nucleic acid. He separated two different purines: adenine and guanine and three different pyrimidines: thymine (separated firstly), cytosine and uracil (Anon 2007, http://www.nobelkepu.org.cn/english/physiology/134556.shtml). For this, Kossel was awarded the Nobel Prize in 1910. In the late 19th century, Kossel joined the famous physiologist Emil Du Bois-Reymond in Berlin. And as you may already anticipate, their laboratory was situated in the building I am now sitting. Looking out of the window to the left, the previous Chemistry Department appears. There, in the Chemistry Department, once sat Hermann Emil Fischer, who coined the name ‘purine’ (purum uricum) in 1884 and was awarded the Nobel Prize in 1902. Finally, in 1929, Hans Karl Heinrich Adolf Lohmann discovered ATP. Naturally, his office in Berlin was just down the hall. Realizing all this can cause acute academic insignificance syndrome! Also in 1929, Alan Drury and Albert Szent-Györgyi proposed that purines are signalling molecules. Geoffrey Burnstock, the man who built the concept of adenosine triphosphate (ATP) as a transmitter molecule, and contributed to the special issue in Acta Physiologica (Burnstock et al. 2010), was born, naturally, in 1929. Purinergic signalling is a true strength of Acta Physiologica (Oxford). As pointed out by Fredholm & Verkhratsky (2010), only water is involved in a higher number of chemical reactions than ATP. Given its high concentration in the cytosol, it does not surprise that ATP acts also as a signalling molecule. When cells take harm, surrounding ATP concentration increases. ATP then acts as an extracellular signal, such as in the gut (Kaunitz & Akiba 2011) or in the fish gill when hypotonic shock occurs. In this situation, epithelial release of ATP and NaCl secretion is stimulated via purinergic receptors (Marshall 2011). Interestingly, specific ATP sensitive receptors, such as the dorsal root ganglion neurones, inhibit cAMP by a G protein-coupled pathway, suggesting a neuronal expression of a plasmalemmal cAMP receptor (Mamenko et al. 2010). ATP seems so fundamental that even neural stem cell migration involves this pathway (Grimm et al. 2010). Adenosine is a second basic purinergic signalling molecule acting almost universally in the organism (Aliagas et al. 2010, Nilsson et al. 2010, Ribeiro & Sebastiúo 2010, Wang et al. 2010, Yang et al. 2010). It results from ATP degradation. Any increase in energy consumption and, hence, ATP hydrolysis will increase cytosolic adenosine concentration. Adenosine signals ATP breakdown, intra- or extracellularly, thereby providing crucial information for complex organisms and may even help regulate apoptosis (Mlejnek & Dolezel 2010). In addition to adenosine, uridine adenosine tetraphosphate (Jankowski et al. 2005, Tolle et al. 2010, Schuchardt et al. 2011), diadenosine tetraphosphate (Schluter et al. 1994, Hoyle & Pintor 2010) and UDP have important roles as signalling molecules (Harden et al. 2010). All these purines are important for cardiovascular physiology (Hansen et al. 2010, Andersen et al. 2011) and pathophysiology (Waldenstrom et al. 2010). Take for instance the kidney, which is a crucial organ for blood pressure control (Guyton 1991). The kidney controls blood pressure by regulating volume and electrolytes, among other mechanisms. ATP supplies the energy to the plasma membrane pumps. Thus, it does not surprise that electrolyte reabsorption is regulated by purinergic receptors (Novak 2011), which help control renal perfusion (Dahl et al. 2011) and sodium homeostasis (Jankowski et al. 2011). In particular, it seems that the renal medulla and its blood supply by the vasa recta determine the long-term blood pressure (Cowley et al. 1995, Makino et al. 2002, Mattson 2003). It seems that nucleotides released from adjacent tubules play an important role in determining vasa recta blood flow (Crawford et al. 2011). To close the circle, Burnstock’s interests in purinergic signalling started as he took up his first postdoctoral post with Feldberg (Burnstock 2009). Of course Feldberg’s laboratory was here in the Physiological Institute in Berlin (Hessische Str. 3–4). Sadly, he was dismissed in 1933 during the Nazi purge of Jewish scientists and only thanks to the aid of Hill, he could relocate to Britain’s National Institute for Medical Research where he welcomed the young Burnstock.

Renal tubular Fas ligand mediates fratricide in cisplatin-induced acute kidney failure

Cisplatin, a standard chemotherapeutic agent for many tumors, has an unfortunately common toxicity where almost a third of patients develop renal dysfunction after a single dose. Acute kidney injury caused by cisplatin depends on Fas-mediated apoptosis driven by Fas ligand (FasL) expressed on tubular epithelial and infiltrating immune cells. Since the role of FasL in T cells is known, we investigated whether its presence in primary kidney cells is needed for its toxic effect. We found that all cisplatin-treated wild-type (wt) mice died within 6 days; however, severe combined immunodeficiency (SCID)/beige mice (B-, T-, and natural killer-cell-deficient) displayed a significant survival benefit, with only 55% mortality while exhibiting significant renal failure. Treating SCID/beige mice with MFL3, a FasL-blocking monoclonal antibody, completely restored survival after an otherwise lethal cisplatin dose, suggesting another source of FasL besides immune cells. Freshly isolated primary tubule segments from wt mice were co-incubated with thick ascending limb (TAL) segments freshly isolated from mice expressing the green fluorescent protein (GFP) transgene (same genetic background) to determine whether FasL-mediated killing of tubular cells is an autocrine or paracrine mechanism. Cisplatin-stimulated primary segments induced apoptosis in the GFP-tagged TAL cells, an effect blocked by MFL3. Thus, our study shows that cisplatin-induced nephropathy is mediated through FasL, functionally expressed on tubular cells that are capable of inducing death of cells of adjacent tubules.

Alterations in Ca2+ Sparks and T-Tubules Promote Slowed, Dyssynchronous Ca2+ Release in Failing Cardiomyocytes

In heart failure, cardiomyocytes exhibit slowing of the rising phase of the Ca2+ transient which contributes to the impaired contractility in this condition. We investigated the underlying mechanisms in a murine model of congestive heart failure (CHF). Myocardial infarction (MI) was induced by left coronary artery ligation, and at 10 weeks post-MI, mice exhibited symptoms of CHF including reduced cardiac function and increased lung weight. Cardiomyocytes were isolated from viable regions of the septum, and septal myocytes from SHAM-operated mice served as controls. Confocal line-scan imaging revealed a slowed rate of rise of Ca2+ transients (fluo-4 AM, 1 Hz) in CHF cells, which largely resulted from spatially non-uniform Ca2+ release. Ca2+ sparks recorded in resting myocytes were also slower to peak in CHF than SHAM (11.5±0.6 ms vs 9.5±0.6 ms, P<0.05) and longer lasting (FWHM=24.5±0.7 ms vs 21.6±1.0 ms, P<0.05). The mean increase in these measurements resulted from a sub-population of sparks in CHF cells with very long rise times but small amplitudes. Local Ca2+ transients (width=2 μm) measured at the same coordinates as these sparks were also slow to rise, indicating that altered Ca2+ spark kinetics contributed to the dyssynchronous Ca2+ release pattern in CHF. As well, di-8-ANEPPS staining revealed disorganized T-tubular structure in failing myocytes, which is also known to promote Ca2+ release dyssynchrony. Specifically, we observed irregular gaps between adjacent tubules where Ca2+ release was markedly delayed, occurring only after Ca2+ diffusion from regions where tubules were present. Thus, slowed and dyssynchronous Ca2+ release in failing myocytes results from a combination of altered ryanodine receptor function and T-tubule disorganization. We suggest that the sub-population of slow, small amplitude Ca2+ sparks in CHF may represent ryanodine receptors which are functionally uncoupled from their neighbours.

Detection of dentinal cracks using contrast-enhanced micro-computed tomography

A new technique using contrast enhanced micro-computed tomography (micro-CT) was developed to improve the ability to detect dentinal cracks in teeth and assess associated risks to oral health. Extracted, whole human molars that exhibited visual evidence of external cracks following extraction and machined, partially fractured elephant dentin specimens were labeled by BaSO 4 precipitation and imaged by micro-CT. Contrast-enhanced micro-CT was demonstrated in vitro to enable non-destructive, 3-D imaging of the presence, morphology and spatial location of dentinal cracks in whole human molars and machined specimens. BaSO 4 staining provided enhanced contrast for the detection of cracks that could not be detected prior to staining. Backscattered SEM micrographs showed that BaSO 4 was precipitated on the surfaces of dentinal cracks and within adjacent tubules. The new methods demonstrated in this study are expected to be useful for clinical and scientific studies investigating the etiology and treatment of dentinal cracks in teeth.

Myxidium scripta n. sp. identified in urinary and biliary tract of Louisiana-farmed red-eared slider turtles Trachemys scripta elegans

During a necropsy investigation of a mortality event occurring at a turtle farm in Assumption Parish, Louisiana, spores of a myxozoan were identified in the renal tubules in 3 of 6, the gall bladder lumen in 2 of 6, and the bile ductule in 1 of 6 red eared slider turtles Trachemys scripta elegans. In total, myxozoa were identified in 4 of 6 turtles. In 1 turtle, renal tubules contained numerous mature spores, had epithelial hyperplasia, granulomatous transformation, compression of adjacent tubules and interstitial lymphocytic nephritis. The genus of myxozoan was Myxidium, based on spore morphology in cytological preparations, in histologic section, and by electron microscopy. In cytological preparation the spores had mean dimensions of 18.8 x 5.1 microm and a mean polar capsule dimension of 6.6 x 3.5 microm. Electron microscopy showed renal tubules contained plasmodia with disporoblasts with spores in various stages of maturation. Ultrastructure of mature spores demonstrated a capsule containing 2 asymmetrical overlapping valves and polar capsules containing a polar filament coiled 6 to 8 times and surrounded by a membrane composed of a double layer wall. The small subunit rDNA gene sequence was distinct from all other Myxidium species for which sequences are available. Additionally, this is the first Myxidium species recovered from a North American chelonian to receive genetic analysis. Although T. s. elegans is listed as a host for Myxidium chelonarum, this newly described species of Myxidium possessed larger spores with tapered ends; thus, we described it as a new species, Myxidium scripta n. sp. This report documents a clinically significant nephropathy and genetic sequence from a Myxidium parasite affecting a freshwater turtle species in North America.

Kidney Biopsy Findings in a Patient With Fever, Bilateral Pulmonary Infiltrates, and Acute Renal Failure

Kidney Biopsy Findings in a Patient With Fever, Bilateral Pulmonary Infiltrates, and Acute Renal Failure

Altered expression of progesterone receptors in testis of infertile men

Progesterone has been implicated in the process of spermatogenesis. This study aimed to investigate the association of progesterone receptor (PR) expression with spermatogenesis in the testis of infertile men. PR mRNA and protein were assessed by in-situ hybridization and immunohistochemistry in testicular biopsies obtained from 18 infertile men. The extent of spermatogenesis was assessed by Johnsen scoring. None of the patients included in the study had Yq microdeletions. PR expression was almost undetectable in all the testicular sections displaying Sertoli cell only (SCO) or arrest at spermatogonia. Weak cytoplasmic expression was observed in biopsies showing arrest at different stages of meiosis. In biopsies displaying spermatogenesis up to the round spermatid stages, PR expression was observed in both nucleus and cytoplasm of different cell types at intensity lower than that detected in normal biopsies. Normal PR expression was observed in biopsies demonstrating hypospermatogenesis. In biopsies showing mixed phenotypes, the tubules with SCO or spermatogonia arrest showed absence of PR expression; normal PR expression was observed in adjacent tubules showing complete spermatogenesis. Semi-quantitative assessment of PR expression and Johnsen scores in the testicular biopsies of infertile men demonstrating different phenotypes indicated a direct relationship between PR expression and extent of spermatogenesis.