Different Phases Of Maturation Research Articles

Pre- and postnatal developmental exposure to the polychlorinated biphenyl mixture aroclor 1221 alters female rat pituitary gonadotropins and estrogen receptor alpha levels

Polychlorinated-biphenyls (PCBs) are industrial compounds, which were widely used in manufacturing of electrical parts and transformers. Despite being banned in 1979 due to human health concerns, they persist in the environment. In humans and experimental model systems, PCBs elicit toxicity in part by acting as endocrine-disrupting chemicals (EDCs). Aroclor 1221 (A1221) is a weakly estrogenic PCB mixture known to alter reproductive function in rodents. EDCs can impact hormone signaling at any level of the hypothalamic-pituitary-gonadal (HPG) axis, and we investigated the effects of A1221 exposure during the prenatal and postnatal developmental periods on pituitary hormone and steroid receptor expression in female rats. Examining offspring at 3 ages, postnatal day 8 (P8), P32 and P60, we found that prenatal exposure to A1221 increased P8 neonate pituitary luteinizing hormone beta (Lhb) mRNA and LHβ gonadotrope cell number while decreasing LH serum hormone concentration. No changes in pituitary hormone or hormone receptor gene expression were observed peri-puberty at P32. In reproductively mature rats at P60, we found pituitary follicle stimulating hormone beta (Fshb) mRNA levels increased by prenatal A1221 exposure with no corresponding alterations in FSH hormone or FSHβ expressing cell number. Estrogen receptor alpha (ERα) mRNA and protein levels were also increased at P60, but only following postnatal A1221 dosing. Together, these data illustrate that exposure to the PCB A1221, during critical developmental windows, alters pituitary gonadotropin hormone subunits and ERα levels in offspring at different phases of maturation, potentially impacting reproductive function in concert with other components of the HPG axis.

Seasonal Variation in the Nutritional Composition of Fishes in Tuticorin, Southeast Coast of India

Background: The nutritional quality of fish is very important for human consumers. The consumption of fish provides important nutrients to a large number of people worldwide and makes a very significant contribution to nutrition. The purpose of the study was to investigate the proximate composition of economically important marine water fish.
 Methods: The present work was conducted between March 2016 and February 2017, investigated the seasonal variations in the contents of protein, lipid, carbohydrate, ash and moisture in six fish species namely Sardinella fimbriata, Stolephorus commersonnii, Epinephelus areolatus, Carangoides chrysophrys, Gazza achlamys and Parupeneus indicus. The fish samples were collected from the fish market of Tuticorin. The proximate compositions of the samples were analysed according to standard AOAC methods.
 Results: Remarkable seasonal variations are found in the levels of the parameters studied in the six selected species. In all the seasons, Epinephelus areolatus is characterized by the highest moisture and ash contents, and Carangoides chrysophrys by the highest protein and carbohydrate contents, whereas Sardinella fimbriata contains more lipids. Except for moisture content all other nutrient compositions are high during the monsoon and post-monsoon periods. During summer the nutrient contents decrease due to breeding activities involving maturation of gonads, and after the breeding season the nutrient contents again show a rising trend. The seasonal variations in nutrient composition in fish are related to the cycle of maturation and depletion of gonads. Different phases of maturation are associated with marked quantitative fluctuations of each nutrient in different fishes.
 Conclusion: Based on the current finding, it is concluded that fishes are very good sources of protein, carbohydrates, ash, and lipids and that the biochemical constituents of the body tissues of fishes fluctuate during different seasons. The results suggested that the consumption of those fish species contributed to human health. Finally, this research work might help to understand the changes in nutritional values of some commercial fishes in various seasons and will assist in identifying the proper fish harvesting period.

Improving Interpretation of Biopsies During Microsurgical Testicular Sperm Exploration in Azoospermic Patients: Use of Davidson’s Fluid

Background: Histological interpretation of testicular biopsies in the investigation of infertility in men with azoospermia requires adequate tissue fixation to preserve the nuclear and cytoplasmic detail, as well as the architectural organisation of germ cells in different phases of maturation within seminiferous tubules. Research Aims/Objectives: The aim of the study was to assess the histomorphological quality of testicular biopsies using Davidson’s fluid (DF) as fixative and compare it to standard 10% neutral buffered Formalin. Methodology: Concurrent testicular biopsies from the same testis from patients undergoing microsurgical testicular sperm exploration (m-TESE) were separately fixed in DF and Formalin and processed for histological examination. Histological parameters including sloughing of cells, cytoplasmic shrinkage of seminiferous tubular cells, nuclear chromatin detail, cytoplasmic graininess and overall clarity of morphological detail were graded on a scale of 0 to 4 (0=none, 1=minimal, 2=slight, 3=moderate, 4=marked). The effect of DF on biopsy diagnoses was assessed by comparison with corresponding Formalin fixed biopsy diagnoses. Results/Findings: 87 testicular biopsies from 27 patients were examined. DF fixation resulted in significantly less luminal sloughing of cells (1.59±1.34 vs. 3.44±0.83, p = [Formula: see text] 0.00001), less cytoplasmic shrinkage of seminiferous tubular cells (1.58±1.11 vs. 3.11±1.07, p = [Formula: see text] 0.00001), better nuclear chromatin detail (3.06±0.91 vs. 1.92±0.48, p = [Formula: see text] 0.00001), less cytoplasmic graininess (2.11±0.96 vs. 2.86±0.87, p = 0.0014) and better overall clarity of morphological detail than Formalin fixation (3.14±0.69 vs. 2.14±0.58, p = [Formula: see text] 0.00001). The diagnostic concordance between DF fixed and Formalin fixed biopsies was 90.8%. Conclusions: This study supports the use DF as a superior alternative fixative to Formalin for histological assessment of testicular biopsies.

Improving interpretation of biopsies during microsurgical testicular sperm exploration in azospermic patients: use of Davidson's fluid.

Histological interpretation of testicular biopsies in the investigation of infertility in men with azoospermia requires adequate tissue fixation to preserve the nuclear and cytoplasmic detail, as well as the architectural organisation of germ cells in different phases of maturation within seminiferous tubules. The aim of the study was to assess the histomorphological quality of testicular biopsies using Davidson's fluid (DF) as fixative and compare it to standard 10% neutral buffered formalin. Concurrent testicular biopsies from the same testis from patients undergoing microsurgical testicular sperm exploration (m-TESE) were separately fixed in DF and formalin and processed for histological examination. Histological parameters including sloughing of cells, cytoplasmic shrinkage of seminiferous tubular cells, nuclear chromatin detail, cytoplasmic graininess and overall clarity of morphological detail were graded on a scale of 0-4 (0, none; 1, minimal; 2, slight; 3, moderate; 4, marked). The effect of DF on biopsy diagnoses was assessed by comparison with corresponding formalin fixed biopsy diagnoses. Eighty-seven testicular biopsies from 27 patients were examined. DF fixation resulted in significantly less luminal sloughing of cells (1.59±1.34 vs 3.44±0.83, p≤0.00001), less cytoplasmic shrinkage of seminiferous tubular cells (1.58±1.11 vs 3.11±1.07, p≤0.00001), betternuclear chromatin detail (3.06±0.91 vs 1.92±0.48, p≤0.00001), less cytoplasmic graininess (2.11±0.96 vs 2.86±0.87, p=0.0014) and better overall clarity of morphological detail than formalin fixation (3.14±0.69 vs 2.14±0.58, p≤0.00001). The diagnostic concordance between DF fixed and formalin fixed biopsies was 90.8%. This study supports the use of DF as a superior alternative fixative to formalin for histological assessment of testicular biopsies.

Vitrification technique for female germinative tissue cryopreservation and banking.

ObjectiveTo report on a device designed for the vitrification of germinative tissue, and a systematic vitrification/warming protocol.MethodsWe obtained six fragments of cortical germinative tissue from a human ovary. We randomly chose two fragments and sent them to histological analysis. We vitrified four test samples and stored them for one week in liquid nitrogen (LN), and warmed one week later. We sent the vitrified/warmed fragments to the pathology laboratory, where they analyzed them morphologically under an optical microscope (10-40X). They analyzed the nuclear and cytoplasmic characteristics of the follicular cells, luteal layer, and stroma. The primordial and primary follicles in the fresh and vitrified/warmed fragments were counted and compared with the Mann-Whitney test (p<0.05).ResultsThere were ovarian follicles in different phases of maturation in both fresh and vitrified/warmed fragments, with a predominance of healthy-looking primordial and primary follicles. In the test fragments, the fusocellular architecture supporting the stromal cells exhibited some foci of edema, and were associated with cells with hydropic degeneration, with cytoplasmic fragmentation and eosinophilia. However, there were no signs of tissue necrosis or autolysis. There was no statistically significant difference between the number of follicles found in the control and test tissue fragments (p>0.05).ConclusionsThere were no significant morphological changes between fresh and vitrified/warmed germinative tissue. The vitrification device and protocol tested were effective in the preservation of human follicles, and should be considered for the banking germinative tissue for the restoration of fertility of women who are submitted to life-saving sterilizing treatments.

Morphological and molecular aspects of sclerotial development in the phytopathogenic fungus Sclerotinia sclerotiorum

Sclerotinia sclerotiorum (Lib.) de Bary produces a resistance structure called sclerotium, which guarantees its survival in soil for long periods. Morphological and melanization aspects during sclerotial development were evaluated by microscopy and qRT-PCR techniques. S. sclerotiorum produces sclerotia with different phases of maturation and melanization during growth in PDA medium. Using scanning electron microscopy we observed that there are no structural differences in the three stages of formation of melanized and non-melanized sclerotium. Through histochemical analysis we observed that the melanized sclerotium accumulates more glycogen and produces less protein than non-melanized sclerotia. Melanin was most commonly found in the rind of melanized sclerotia, and the highest concentration of lipofucsins was found in non-melanized sclerotia. These molecules are products of the lipid peroxidation pathway and are associated with oxidative stress during differentiation in fungi. The expression of histidine kinase (shk) and adenylate cyclase (sac) genes in melanized and non-melanized sclerotiawere also evaluated. The higher gene expression of shk and lesser expression of sac in non-melanized sclerotiais an indication of the participation of cell signaling in the development of these structures. The higher expression of polyketide synthase (pks), tyrosinase (tyr) and laccase (lac) in non-melanized sclerotia suggested that S. sclerotiorum can use the DHN and L-dopa pathways to produce melanin. Expression studies of the enzymes chitin synthase and glucan synthase suggest that this process occurs along with the formation of melanin. This is interesting since polysaccharides, such as chitin and β-1,3-glucan, serve as a scaffold to which the melanin granules are cross-linked.

Condrolipoma na orelha de um cão

Background: Lipoma is defined as a tumor composed of mature adipocytes, identical to the cells that form normal adult fat. Other elements may also be present, such as cartilaginous tissue. Chondrolipoma is characterized by the presence of differentiated cartilage islands spread within a typical lipoma, in which mucin and collagen can be observed around isles of chondrocytes. This condition affects mainly middle-aged or elderly dogs as well as elderly humans. In the scientific literature, chondrolipomas have not yet been described on the ear of dogs. Therefore, this study aimed to report a case of chondrolipoma on the ear of a dog and its histopathological and histochemical description.Case: A female, 10-year-old, Labrador retriever dog was admitted to the Veterinarian Hospital of the Federal University of Paraíba (UFPB), Areia, Brazil. The dog was presented with an ulcerated pendulous nodule on the ear, with a clinical evolution of approximately 7 months. A biopsy sample was taken and submitted to the Veterinary Histopathology Laboratory of the UFPB. Macroscopic evaluation revealed a pendulous and firm nodule, with a round apex, measuring 1.3cm in diameter. The epidermis covering the nodule exhibited an ulcer of 0.5cm in length. The nodule exhibited resistance to cutting and the surface was dark red with hard areas in the center. Sample was fixed in 10% formalin and routinely processed for histology, embedded in paraffin, and stained with hematoxylin and eosin (HE), alcian blue (AB), Masson’s trichrome (MT), and periodic acid-Schiff (PAS). Histopathological evaluation revealed that the nodule was encapsulated, formed by adipocytes of variable sizes. Adipocytes were well-differentiated and the nodule was defined as lipoma. Within the lipoma there was proliferation of chondrocyte islands in a bluish basophilic matrix. Adjacently, abundant fibrous connective tissue was found intertwined with blood vessels. Some vessels exhibited red blood cells in the vicinity, indicating hemorrhage. The epidermis covering the nodule was slightly acanthotic and moderately hyperkeratotic. MT staining marked the fibrous tissue in blue. AB staining revealed blue areas confirming the presence of mucin around cartilage islands. PAS staining revealed the presence of glycogen between mesenchymal cells, which included chondrocytes.Discussion: The diagnosis of chondrolipoma was concluded with the presence of a well-differentiated lipoma, randomly intertwined with cartilage islands, which were also well-differentiated and spread within a typical lipoma. Additionally, the presence of mucin and collagen around the isles of chondrocytes facilitated the diagnosis. Chondrocytes presented different phases of maturation. The case described here exhibited microscopic characteristics that were similar but somewhat different to those previously reported by other authors, in considering that the nodule was encapsulated, and did not exhibit cell atypia or mineralization in the cartilage islands. Most studies published used PAS and Masson’s trichrome staining techniques to confirm the diagnosis of chondrolipoma. However, alcian blue also aids in diagnosing this condition. The tumor developed for months before the dog was taken to a veterinarian, when it finally became ulcerated, which characterized it as non-invasive. Chondrolipoma is a benign tumor, which does not induce metastasis and once excised does not exhibit recurrence. In veterinary medicine, the presence of cartilage within a lipoma is a rare event.

White matter maturation of normal human fetal brain. An in vivo diffusion tensor tractography study

We demonstrate for the first time the ability to determine in vivo and in utero the transitions between the main stages of white matter (WM) maturation in normal human fetuses using magnetic resonance diffusion tensor imaging (DTI) tractography. Biophysical characteristics of water motion are used as an indirect probe to evaluate progression of the tissue matrix organization in cortico-spinal tracts (CSTs), optic radiations (OR), and corpus callosum (CC) in 17 normal human fetuses explored between 23 and 38 weeks of gestation (GW) and selected strictly on minimal motion artifacts. Nonlinear polynomial (third order) curve fittings of normalized longitudinal and radial water diffusivities (Z-scores) as a function of age identify three different phases of maturation with specific dynamics for each WM bundle type. These phases may correspond to distinct cellular events such as axonal organization, myelination gliosis, and myelination, previously reported by other groups on post-mortem fetuses using immunostaining methods. According to the DTI parameter dynamics, we suggest that myelination (phase 3) appears early in the CSTs, followed by the OR and by the CC, respectively. DTI tractography provides access to a better understanding of fetal WM maturation.

Amenities, Affluence, and Ideology: Comparing Rural Restructuring Processes in the US and Norway

In this paper we analyse how conceptions of nature and rural space, combined with broader structural influences—particularly rural restructuring and neoliberal ideology—impact community development in rural amenity areas. Building on qualitative data (in-depth interviews, photo-elicitation, and participant observation), the paper applies interactional theory of community to analyse the amenity-based restructuring narratives of two rural communities: Bayfield County in Wisconsin, USA, and Hitra/Frøya in Norway. Three primary conclusions are drawn: 1) while amenity-led development occurs because of rural contrast, the trappings of urban life are growing in importance; 2) consumption may be the driving force behind growth and change in many ‘post-productivist’ rural areas, but landscapes are actively produced to capitalize upon local amenities; and 3) the study areas are in different phases of maturation, where Norwegian social attitudes about land seem to be shifting from a ‘traditional’ mentality towards a more ‘American’ mentality.

Evaluation of distracted mandibular bone using computed tomography scan and ultrasonography: technical note

Distraction osteogenesis is considered an important reconstruction armamentarium in the management of mandibular deformities and deficiency disorders. The duration of the consolidation period is still a debatable issue among the clinicians. Evaluation of the newly formed bone is the cornerstone for terminating the consolidation period safely. The aim of this study is to find a more conservative protocol for the evaluation of callus distraction by monitoring bone healing using two different examination tools: ultrasonography and dental CT. Four adult patients (three women and one man) underwent mandibular distraction (using two intraoral and two extraoral devices). The latency period was 5-7 days and the distraction was at a rate of 2 mm per day, with 12-14 weeks of consolidation. All patients were evaluated during activation, 3 months, 6 months and 1 year post-distraction. Evaluation included clinical examination, plain radiographs, CT and ultrasonography examinations. Ultrasonographic examination of the healing callus revealed four different phases of maturation. These phases were similar to the degree of tissue calcification as measured by CT. Tissue density across the distraction wound at the time of distractor removal (12-14 weeks) was equal to or less than one-third of normal bone density. Clinical monitoring of mandibular distraction wounds can be successfully achieved through frequent use of ultrasonographic examinations. Standardization of ultrasonography based on CT findings will expand the reliability of ultrasound in monitoring callus maturation. An algorithm for evaluation of distraction wound healing is suggested.

Induction of endotoxin tolerance in rat bone marrow cells by in vivo infusion of tumor necrosis factor.

To determine in a rat model whether a low-dose infusion of tumor necrosis factor (TNF) affects the production of the inflammatory cytokines TNF and interleukin (IL)-6, the immunosuppressive factor prostaglandin E2 (PGE2), and complement component C3 (C3) by isolated bone marrow-adherent and -nonadherent cells, cultured in the presence of lipopolysaccharide, a component of bacterial endotoxin. Randomized, controlled animal study. Research laboratory of a university medical center. Sprague-Dawley rats (n = 18), 250 to 275 g. Animals received a continuous infusion of one of the following three treatments for 4 days: a) TNF in saline containing bovine serum albumin; b) saline containing bovine serum albumin; and c) saline alone. After infusion, isolated bone marrow cells were cultured for 1 day and 3 days, with and without lipopolysaccharide (1 microgram/mL); culture supernatants were assayed for TNF, IL-6, PGE2, and C3. TNF infusion caused a decrease in the in vitro production of TNF, IL-6, and PGE2 by the lipopolysaccharide-stimulated adherent and nonadherent bone marrow cells. This tolerance to lipopolysaccharide stimulation was present after both 1 day and 3 days of culture. TNF infusion caused an increase in C3 production by the nonadherent cells. The production of TNF by adherent cells from saline-infused or bovine serum albumin-infused animals (controls) was greater in 3-day cultures compared with 1-day cultures, whereas the production of IL-6 and PGE2 was less. These results indicate that TNF infusion caused cells in the bone marrow to be tolerant to lipopolysaccharide stimulation or that TNF infusion programmed the cells to become tolerant to lipopolysaccharide stimulation on differentiation and/or maturation. The results also indicate that bone marrow cells may be regulated by TNF (probably indirectly) at different phases of maturation and/or differentiation with respect to the production of different mediators. Although TNF is considered to be an inflammatory cytokine, at low concentrations it may be an important down-regulator of the inflammatory response.

Synthesis and secretion of von Willebrand factor and fibronectin in megakaryocytes at different phases of maturation.

Our goals have been to define the biochemical characteristics of megakaryocytes during maturation that are critical for platelet assembly and release into the circulation and to introduce biochemical markers for megakaryocytes. To achieve these goals, we have studied fibronectin (FN) and von Willebrand factor (vWF), which are large adhesive proteins that are synthesized by megakaryocytes, stored in alpha granules, and thought to have a fundamental role in hemostasis. The study demonstrated that vWF is primarily synthesized in mature megakaryocytes, which synthesized 7.5 times more vWF than immature megakaryocytes. Brefeldin A, which blocks the exit of proteins from the rough endoplasmic reticulum (RER), inhibited the formation of vWF multimers but did not affect the synthesis of monomers and dimers in mature megakaryocytes. These data are consistent with the formation of vWF dimers in the RER and the assembly of vWF multimers in the trans- and post-golgi. The synthesis of both the 260-kD and 275-kD pro-vWF was detected. However, the synthesis of 275-kD pro-vWF and 220-kD mature vWF was only evident after 2 hours, suggesting that the transit time of nascent vWF through the RER is about 2 hours. Constitutive secretion of vWF was demonstrated in megakaryocytes. About 14.5% and 4.6% of synthesized vWF was secreted by mature and immature megakaryocytes, respectively. In contrast, the synthesis of FN monomers and dimers was established in immature megakaryocytes, and their synthesis in mature megakaryocytes was very similar. Constitutive secretion of FN was not seen in megakaryocytes. Brefeldin A did not inhibit the synthesis of FN dimers; thus, formation of FN dimers occurs in the RER. The demonstration that vWF and FN are synthesized at different phases of megakaryocyte maturation and that only vWF is constitutively secreted by megakaryocytes provides new information relevant to alpha granule formation and possibly bone marrow matrix assembly.

The Acylation of Megakaryocyte Proteins: Glycoprotein IX Is Primarily Myristoylated While Glycoprotein Ib Is Palmitoylated

The acylation of megakaryocyte proteins was studied with special emphasis on the myristoylation and palmitoylation of the glycoprotein (GP) Ib complex. Guinea pig megakaryocytes were purified and separated into subpopulations at different phases of maturation. Cells were incubated with [3H]myristate, [3H]palmitate, or [3H]acetate to study endogenous protein acylation. Cycloheximide was used to distinguish between cotranslational and posttranslational acylation and hydroxylamine to distinguish between thioester and amide linkages. After incubations, delipidated proteins or GPIb complex subunits, immunoprecipitated with PG-1, AN-51 or FMC-25 monoclonal antibody, were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and assessed by fluorography. Radiolabeled fatty acids bound to GPIX and GPIb were also analyzed by high pressure liquid chromatography (HPLC) and scintillation spectrometry. With [3H]myristic acid and [3H]acetate, GPIX was found to be a major myristoylated protein in megakaryocytes and CHRF-288 cells. Myristic acid was linked to GPIX by an amide bond, and this process occurred cotranslationally. With [3H]acetate, GPIb was primarily palmitoylated, but with [3H]myristate, GPIb was acylated with about equal mounts of myristic acid and palmitic acids. Both fatty acids were linked to GPIb by thioester bonds, and acylation was posttranslational. The myristoylation of GPIX while the palmitoylation of GPIb occurred throughout megakaryocyte maturation. Myristoylation and palmitoylation may have different functions relevant to the assembly of the GPIb complex in megakaryocytes.

Distribution of the extracellular matrix proteins tenascin, fibronectin, and vitronectin in fetal, infant, and adult human spleens.

Using immunohistochemistry, we investigated the distribution of the extracellular matrix (ECM) glycoproteins tenascin, fibronectin, and vitronectin in fetal [16-24 gestational weeks (GW)], infant (40 GW), and adult human spleens to clarify the presence of these proteins during different phases of maturation. In the red and white pulp, tenascin and fibronectin were constant components of the reticular fibers from the age of 18 GW onwards, whereas vitronectin was seen only in adult spleens. The immunohistochemical staining patterns of tenascin and fibronectin remained unchanged at different fetal ages. Ring fibers, which are modified basement membranes around venous sinuses, became visible relatively late, and in adult spleens they contained both tenascin and vitronectin but lacked fibronectin. The composition of the ring fibers is therefore clearly different from that of ordinary basement membranes, which have not been reported to contain tenascin or vitronectin. The rapidly increasing number of reticular fibers in the spleen at the age of approximately 18 GW corresponds with the beginning of lymphatic colonization. Reticular fibers, rich in ECM glycoproteins, form a framework to which cells can migrate and attach. We suggest that the composition of these fibers might be important for lymphatic colonization and function of the spleen.

Developmental Regulation of β‐Thymosins in the Rat Central Nervous System

HPLC analysis of guanidinium hydrochloride extracts of neonatal and adult rat brain revealed a polypeptide that is present in high concentration in the immature nervous system, but whose levels decline dramatically in the adult. This polypeptide has been isolated and its complete amino acid sequence determined by gas-phase Edman degradation following specific chemical and enzymatic cleavages. The molecule is identified as thymosin beta 10, a member of a multigene family that encodes a structurally conserved series of small acidic polypeptides of uncertain function. Thymosin beta 10 is present in the developing nervous system as early as embryonic day 9. Levels subsequently increase to peak values between embryonic day 15 and postpartum day 3, before falling to adult values (about a 20-fold reduction) by postpartum day 14. The elevated levels of thymosin beta 10 in fetal and neonatal brain correlate with high levels of thymosin beta 10 mRNA, whereas the low values of the polypeptide in the adult and juvenile are mirrored by an approximate 15-fold reduction in specific mRNA. In comparison, the levels of thymosin beta 4 polypeptide, a homologue of thymosin beta 10, only decline by about 20% during the same developmental period. However, the mRNA encoding thymosin beta 4 is elevated in fetal brain, and its levels decrease approximately four-fold to a stable value around the time of birth. The reason for this discrepancy between thymosin beta 4 protein and mRNA levels is unknown. Thymosin beta 10 can also be detected by HPLC in fetal liver, where levels are approximately 5% of those in brain. In liver, thymosin beta 10 also declines following birth. It is concluded that beta-thymosin expression (as measured by steady-state mRNA and polypeptide levels) is both up- and down-regulated during different phases of maturation of the mammalian nervous system.

Characterization of Guinea Pig Megakaryocyte Subpopulations at Different Phases of Maturation Prepared With a Celsep Separation System

We introduce a new method for preparing subpopulations of guinea pig megakaryocytes (MK). MK, partially purified by a density gradient, were separated according to size by sedimentation, starting as a monolayer, in an albumin gradient at unit gravity. Twenty-two fractions were collected. Cells were cytocentrifuged, ploidy was assessed by microdensitometry, and small MK were identified with anti-von Willebrand factor (vWF) immunoglobulin. Immaturity was assessed by uptake of 3H thymidine and synthesis of proteoglycans from 35S sulfate. About 88% of cells in fractions 2 through 18 were MK, of which 90% were viable. Fractions containing the largest cells were composed of 98% stage III and IV MK; fractions with the smallest cells contained up to 80% stage I and II MK. Six MK classes were isolated: immature cells, both stage I and II cells, at either the 8N, 16N or 32N ploidy class; mature cells, both stage III and IV cells, at either the 8N, 16N or 32N ploidy class. The fractions were pooled into three groups: (a) 8% of MK in group 1, fractions 2 through 11, were immature, and group 1 was composed of 92% of 16N and 32N mature classes; (b) 29% of MK in group 2, fractions 12 through 15, were immature, and group 2 was composed of 52% 16N mature, 24% 16N immature, and 13% 8N mature classes; 67% of MK in group 3, fractions 16 through 18, were immature, and group 3 contained 51% 8N immature, 14% 16N immature, and 18% mature 16N classes. The mean protein content of the three groups was 1.251, 0.624, and 0.284 mg/10(6) MK, respectively. Nine percent of cells in group 3 but no cells in group 1 took up large amounts of 3H thymidine. The synthesis of high-molecular-weight (high-mol-wt) proteoglycans in group 3 and synthesis of lower mol wt proteoglycans in groups 1 and 2 provided further evidence for differences in MK maturity. Thus, the method can isolate MK subpopulations that are viable and can be used to investigate the biochemical characteristics of MK at different phases of maturation.

Characterization of guinea pig megakaryocyte subpopulations at different phases of maturation prepared with a Celsep separation system

We introduce a new method for preparing subpopulations of guinea pig megakaryocytes (MK). MK, partially purified by a density gradient, were separated according to size by sedimentation, starting as a monolayer, in an albumin gradient at unit gravity. Twenty-two fractions were collected. Cells were cytocentrifuged, ploidy was assessed by microdensitometry, and small MK were identified with anti-von Willebrand factor (vWF) immunoglobulin. Immaturity was assessed by uptake of 3H thymidine and synthesis of proteoglycans from 35S sulfate. About 88% of cells in fractions 2 through 18 were MK, of which 90% were viable. Fractions containing the largest cells were composed of 98% stage III and IV MK; fractions with the smallest cells contained up to 80% stage I and II MK. Six MK classes were isolated: immature cells, both stage I and II cells, at either the 8N, 16N or 32N ploidy class; mature cells, both stage III and IV cells, at either the 8N, 16N or 32N ploidy class. The fractions were pooled into three groups: (a) 8% of MK in group 1, fractions 2 through 11, were immature, and group 1 was composed of 92% of 16N and 32N mature classes; (b) 29% of MK in group 2, fractions 12 through 15, were immature, and group 2 was composed of 52% 16N mature, 24% 16N immature, and 13% 8N mature classes; 67% of MK in group 3, fractions 16 through 18, were immature, and group 3 contained 51% 8N immature, 14% 16N immature, and 18% mature 16N classes. The mean protein content of the three groups was 1.251, 0.624, and 0.284 mg/10(6) MK, respectively. Nine percent of cells in group 3 but no cells in group 1 took up large amounts of 3H thymidine. The synthesis of high-molecular-weight (high-mol-wt) proteoglycans in group 3 and synthesis of lower mol wt proteoglycans in groups 1 and 2 provided further evidence for differences in MK maturity. Thus, the method can isolate MK subpopulations that are viable and can be used to investigate the biochemical characteristics of MK at different phases of maturation.

Flow cytometric quantification of rat spermatogenic cells after hypophysectomy and gonadotropin treatment.

DNA flow cytometry was evaluated as a tool to analyze stage-specific changes that occur in absolute cell numbers in the testes. Hypophysectomy was selected as a model system for perturbing testicular cell types, since the cytological sequelae of this treatment post-hypophysectomy in the rat are well documented in the literature. Rat spermatogenic cells in stages II-V, VII, and IX-XIII of the seminiferous epithelial cycle (as defined by Leblond and Clermont, 1952) were quantified in numbers per standard length of seminiferous tubule by DNA flow cytometry after hypophysectomy and subsequent gonadotropin treatment. In agreement with previous histological studies, we found that acrosome- and maturation-phase spermatids disappeared from the seminiferous epithelium after 17 days post-hypophysectomy, whereas meiosis and early spermiogenesis continued at least 164 days. The number of meiotic cells and round spermatids gradually decreased after hypophysectomy. Changes were observed as early as Day 6 post-hypophysectomy. Treatment with human chorionic gonadotropin (hCG) alone maintained most cell numbers within normal limits, and follicle-stimulating hormone (FSH) was needed in addition to hCG to maintain the normal number of cells with the amount of DNA contained in primary spermatocytes and spermatogonia in G2/M-phase (4C) in stages IX-XIII and elongated spermatids (1C') in stages II-V of the epithelial cycle. The absolute numbers of spermatogenic cells at different phases of maturation provide a useful reference for quantitative studies of spermatogenesis. Pathological changes in the seminiferous epithelium can be detected and quantified by DNA flow cytometry.

Age-dependent effects of cyproterone acetate (CA) on growth and peripheral hormones in the male rat

A longitudinal study was carried out to see the effects of CA (20mg/kg b.w.) given s.c. daily to male Wistar rats during their multiphase sexual development between age day 20 and day 90.Blood was collected from the same animals at regular intervals, and plasma concentrations of LH,FSH,T,DHA,GH,insulin,Somatomedin (SM) and T4 together with body weight were examined. In the CA-treated animals body weight and its velocity were suppressed. When CA was withdrawn at different phases of maturation, catch-up growth was observed at all time-points except age day 80. The CA-treated animals showed multiple effects on their hormonal levels; FSH being increased at all time-points, LH increment after day 30 then increasing and DHA increasing after day 30. Following the withdrawal of CA, all peripheral hormones, except GH, recorded non - malization. The reversibility of growth suppression induced by CA is age-dependent and therefore has wider clinical implication. In contrast to the findings in humans, the antigonadotropic effect of CA seen in prepubertal animals was later overcome by antiandrogenic effect.

Seasonal changes in the biochemical composition of the freshwater cat-fish, Wallagonia attu (Bloch.)

Seasonal changes in the various biochemical constituents of muscle, liver and gonads were studied in the cat-fish, W. attu. Distinct phases of high and low fat accumulation occurred in each tissue. Moisture in different tissues showed marked seasonal variations which were related inversely to the changes in the amount of fat. Seasonal fluctuation in protein was less pronounced in muscle and liver while in ovaries these were fairly well defined. Protein values in all the tissues were generally low during the winter. Ash content showed little variations in the three tissues. The seasonal cycles of various constituents in each tissue were correlated with the cycle of maturation and depletion of gonads. Different phases of maturation were associated with marked quantitative fluctuations of each ingredient in different tissues.