Distinct Nuclear Membrane Research Articles

Morphologic appearance of peripheral blood cells from Zovawk pigs (Sus scrofa domesticus) visualized by transmission electron microscopy.

Ultrastructural information regarding the peripheral blood cells of local (Zovawk) pigs from Mizoram, India, is not available in the scientific literature. The present study was designed to reveal the fine structural details of the blood cells from these local pigs using a transmission electron microscope (TEM). Blood samples were collected from 12 healthy Zovawk pigs of either sex and processed according to a standard protocol. Processed blood samples were then sent to the All India Institute of Medical Sciences, New Delhi, for further processing and imaging under TEM. Different types of blood cells were viewed under TEM, and different characteristics of these cells were assessed. In the present study, erythrocytes are elongated, biconcave, and nucleated without cytoplasmic organelles. Neutrophils are round with 2-5 lobed nuclei surrounded by cytoplasm with an indistinct bilayered nuclear membrane. The cytoplasm is packed with membrane bound round, oval, and elongated cytoplasmic granules. Eosinophils areround to oval with 2-3 lobed nuclei with distinct nuclear membranes. Basophils are spherical and contained small, medium, and large electron-dense granules. Lymphocytes are small, medium, and large and contained all cellular components. Monocytes are irregularly spherical with slight nuclear indentations. The platelets are elongated, oval, or rounded, with a few pseudopods at the cell surface. From the present study, we can conclude that the ultrastructural morphology of blood cells from Zovawk pigs resembles those of other domestic animals. However, a few differences have been observed.

Shaping the Landscape of Eukaryotic Gene Expression: Horizontal Gene Transfer

Horizontal gene transfer (HGT) in prokaryotes refers to the movement of genes and genetic information between two organisms. This usually results in the spread of antibiotic resistance genes among bacteria. Vertical gene transfer(VGT), on the other hand, refers to the flow of genetic information from parents to offsprings. Until recently, HGT was an exclusive prerogative of the prokaryotes. These are obvious due to the distinct nuclear membrane enclosure of eukaryote genomes that are shielded from outside interferences. VGT can cross species barriers and may even allow the transmission of genes across the kingdoms of life. HGT is now an emerging idea in eukaryotic genomes, challenging previous assertions that HGT is restricted to prokaryotes. It is now accepted that HGT can profoundly influence host metabolic pathways and alter gene expressions even in eukaryotes. HGT, is also fundamentally important during development, origin of human diseases, such as cancer, and neurodegenerative disorders. It may also influence therapeutic outcome by promoting resistant phenotypes. HGT is recently documented in prokaryote to eukaryote HGT is the tardigrade case though an analysis of a draft tardigrade genome suggested that HGT contributed to up to ~17 % of the gene. Further analysis performed after whole genome pair-wise alignments between human genome as well as 53 vertebrate genomes, it was observed that nearly 1500 human genome regions involving 642 known genes, most of which are enriched with ion binding to be conserved with non-mammals than with most mammals. This indicated horizontal gene transfer is more common than we expected in the human genome.
 It’s a matter of time or maybe a tip of iceberg to know the full extent and implications of HGT. Surprisingly its seems that the eukaryotic genome has many more ways to update itself to vastly expand its repertoire of expression and usability. HGT is just another feather in the crown.

G protein‐coupled receptor 37L1 participates in epigenetic gene regulation in human renal proximal tubule cells

G protein‐coupled receptors (GPCRs) in the kidney regulate the reabsorption of essential nutrients, ions, and water from the glomerular filtrate. Abnormality in the renal luminal sodium transport plays an important role in the pathogenesis of essential hypertension. There are a growing number of GPCRs and their interacting protein components that are localized on the nuclear membrane or within the nucleus, where they retain their signaling functions. In most cases, nuclear GPCRs are constitutively expressed on the nuclear membrane. The functions of these nuclear GPCRs are not well understood. Recently we showed that G protein‐coupled receptor 37L1 (GPR37L1), expressed on the apical membrane of renal proximal tubules (RPT), regulates luminal sodium transport and blood pressure via modulating NHE3 function. However, the GPR37L1 signaling pathway in the RPT has not been studied. Co‐immunoprecipitation (Co‐IP), combined with mass spectrometry analyses, revealed the association of GPR37L1 with nuclear import proteins: IPO7, IPO8, KPNA2, KPNB1; nuclear export proteins: XPO1 and XPO7; nuclear pore complex proteins: NUP210; kinases involved in signaling: mTOR, PRKDC, IRS4; and a DNA (Cytosine‐5‐)‐Methyltransferase 1 (DNMT1) in the GPR37L1 protein complex. Immunoblot analyses of nuclear preparations from the human RPT cells (hRPTCs) confirmed the presence of GPR37L1 in the nucleus. Confocal fluorescence imaging of hRPTCs expressing GPR37L1 tagged with green fluorescence protein (GPR37L1‐GFP) showed distinct nuclear membrane expression of GPR37L1. Association of GPR37L1 with mTOR, PRKDC, and DNMT1 proteins was confirmed by Co‐IP followed by immunoblot analyses. Overexpression of GPR37L1 in hRPTCs increased the phosphorylation of PI3, and AKT and decreased the expression of DNMT1, and NHE3 promoter methylation. Our data show that GPR37L1 signals via the PI3K/AKT/mTOR pathway to decrease the expression of DNMT1. Decreased DNMT1 function reduces CpG methylation on the NHE3 promoter that in turn increases NHE3 transcription. This is the first report showing the direct role of a nuclear GPCR in the regulation of renal sodium transport through epigenetic gene regulation.Support or Funding InformationR56DK116828: Prasad Konkalmatt

Abstract P2037: G Protein-Coupled Receptor 37l1 is Localized on the Nuclear Envelope

G protein-coupled receptors (GPCRs), expressed on the plasma membrane, interact with various types of ligands, which trigger a cascade of signal transduction events leading to different intracellular responses that in turn manifest in physiological changes. Some GPCRs also reside and exert signals from intracellular organelles such as nucleus, endoplasmic reticulum, and Golgi apparatus. Recently, we reported that G protein-coupled receptor 37L1 (GPR37L1) is expressed in the apical membrane of renal proximal tubule cells (RPTCs) and participates in luminal sodium transport and blood pressure regulation by regulating the renal expression of NHE3. However, the mechanism by which GPR37L1 regulates NHE3 expression and function in the RPTC has not been studied. Tandem affinity purification of GPR37L1, combined with mass spectrometry analyses, revealed the association of GPR37L1 with mediators of nuclear importing proteins, such as RAN-GTPase, importin-5, and importin-7. In silico analyses of GPR37L1 amino acid sequence revealed the presence of a potential nuclear localization signal at the N-terminus. Confocal fluorescence imaging of RPTCs expressing GPR37L1 tagged with green fluorescence protein (GPR37L1-GFP) showed distinct nuclear membrane expression of GPR37L1. In addition, fluorescence imaging of nuclei isolated from the RPTCs expressing GPR37L1-GFP showed the expression on the nuclear envelope. Immunoblot analyses confirmed the presence of GPR37L1 in the nuclear protein prepared from the RPTCs expressing GPR37L1-GFP. The purity of the nuclear protein preparations was confirmed by the presence of histone deacetylase 2, a marker for nuclear protein, the absence of Na,K-ATPase, a marker for plasma membrane, and the absence of calnexin, a marker for endoplasmic reticulum. Our results show that GPR37L1 also resides on the nuclear envelope and may play a critical role in the regulation of the expression of genes responsible for maintaining normal electrolyte balance and blood pressure.

Pathomorphological studies and detection of bovine papilloma viruses in wart-like lesions/growths in reticulum of buffaloes

The present investigation was carried out to study the pathomorphology of wart-like lesions/growths in reticulum of buff aloes and their association with different bovine papilloma virus (BPV) types. A total of 19 tissue samples of reticulum were included in this study. Grossly, single to multiple, pin-head to pea-nut sized, sessile, pedunculated, dome shaped and mushroom-like growths with thickened reticular pillars were observed. Histopathologically, these were diagnosed as fibropapilloma, papilloma, hyperplasia and reticulitis. Ultrastructurally, the pleomorphic spinocytes containing variable shaped nuclei with scanty heterochromatin and distinct nuclear membrane were observed. PCR revealed presence of BPV-1, -2 and-5 DNA alone or their mixed infections. Quantitative real-time PCR revealed varying amount of viral DNA copy numbers of BPV-1, -2 and-5. Immunostaining for Ki-67 in fibropapilloma cases varied with random distribution of the immunopositive cells. As compared to basal cells; more number of Ki-67 immunopositive cells was observed in suprabasal cells. Cyclooxygenase-2 (COX-2) expression showed cytoplasmic staining with occasional membrane staining, especially in koilocytes. The stromal inflammatory cells in reticulitis associated cases were also moderately positive for COX-2 immunostaining. In conclusion, BPV-1, -2 and-5 were associated either alone or their mixed infections with reticular wart-like lesions/growths in buffaloes. The basal and suprabasal cells of the reticular fibropapilloma were cellular proliferation sites. In conclusion, the present investigation revealed that the growths/wart-like lesions occurring in the reticulum of slaughtered buffaloes are associated with infection of BPV-1, -2 and-5, as DNA of these viruses were detected in such cases.

Comparison of diagnostic accuracy between CellprepPlus® and ThinPrep® liquid‐based preparations in effusion cytology

Liquid-based cytology (LBC) is being increasingly used for body fluid specimens and has improved diagnostic accuracy when compared to conventional smears. We compared the diagnostic accuracy and cellular morphologic features between CellprepPlus® LBC and ThinPrep® LBC in effusion cytology. One hundred and eighty body fluid specimens, consisting of 119 pleural fluid specimens, 59 peritoneal fluid specimens, and 2 pericardial fluid specimens, were obtained from 166 patients. Equal volumes of body fluid from each specimen were used in the CellprepPlus® and ThinPrep® preparations. Sensitivity, specificity, and positive and negative predictive values were evaluated. In addition, we selected 16 specimens from patients with metastatic adenocarcinoma, confirmed them by both LBC preparations, and measured the size of the nucleus in the tumor cells in these specimens. The sensitivity of the CellprepPlus® and ThinPrep® methods was 73.1% and 50.0%, respectively. The specificity and positive predictive values were 100% for both LBC methods, and the negative predictive values of the CellprepPlus® and ThinPrep® methods were 90.9% and 83.3%, respectively. The average nuclear size of the tumor cells was calculated as 20.87 μm using the CellprepPlus® method and 15.08 μm using the ThinPrep® method (P < 0.05). The CellprepPlus® method provided better diagnostic accuracy of effusion cytology compared to the ThinPrep® method and revealed the characteristic morphological features of tumor cells, including large and hypochromatic nuclei, prominent nucleoli, distinct nuclear membranes, and high cellularity.

Epithelioid Inflammatory Myofibroblastic Sarcoma

Inflammatory myofibroblastic tumor (IMT) is a mesenchymal neoplasm of intermediate biological potential, which may recur and rarely metastasize. Pathologic features do not correlate well with behavior. Approximately 50% of conventional IMTs harbor ALK gene rearrangement and overexpress ALK, most showing diffuse cytoplasmic staining. Rare IMTs with a distinct nuclear membrane or perinuclear pattern of ALK staining and epithelioid or round cell morphology have been reported. These cases pursued an aggressive clinical course, suggesting that such patterns may predict malignant behavior. We describe 11 cases of IMT with epithelioid morphology and a nuclear membrane or perinuclear pattern of immunostaining for ALK. Ten patients were male and 1 was female, ranging from 7 months to 63 years in age (median, 39 y). All tumors were intra-abdominal; most arose in the mesentery or omentum, measuring 8 to 26 cm (median, 15 cm). Six tumors were multifocal at presentation. The tumors were composed predominantly of sheets of round-to-epithelioid cells with vesicular nuclei, large nucleoli, and amphophilic-to-eosinophilic cytoplasm. In all cases, a minor spindle cell component was present. Nine tumors had abundant myxoid stroma. In 7 cases neutrophils were prominent and in 3 cases lymphocytes were prominent. Plasma cells were often absent. Median mitotic rate was 4/10 HPF; 6 tumors had necrosis. By immunohistochemistry, all tumors were positive for ALK, 9 tumors showing a nuclear membrane staining pattern and 2 tumors showing a cytoplasmic pattern with perinuclear accentuation. Other positive markers were desmin (10 of 11), focal smooth muscle actin (4 of 8), and CD30 (8 of 8). All tumors were negative for MYF4, caldesmon, keratins, EMA, and S-100. Fluorescence in situ hybridization was positive for ALK gene rearrangement in 9 cases, and in 3 cases tested, a RANBP2-ALK fusion was detected by reverse transcription polymerase chain reaction. Ten patients underwent surgical resection; 1 patient was inoperable. Follow-up was available for 8 patients and ranged from 3 to 40 months (median, 13 mo). All patients experienced rapid local recurrences; 4 patients had multiple recurrences. Eight patients were treated with postoperative chemotherapy; 2 patients received additional radiotherapy. Two patients also developed metastases (both patients developed metastases to the liver; 1 patient developed metastases to the lung and lymph nodes as well). Thus far, 5 patients died of disease, 2 patients are alive with disease, and 1 patient, treated with an experimental ALK inhibitor, has no evidence of disease. In summary, the epithelioid variant of IMT with nuclear membrane or perinuclear ALK is a distinctive intra-abdominal sarcoma with a predilection for male patients. Unlike conventional IMT, abundant myxoid stroma and prominent neutrophils are common. These tumors pursue an aggressive course with rapid local recurrences and are frequently fatal. We propose the designation "epithelioid inflammatory myofibroblastic sarcoma" to convey both the malignant behavior of these tumors and their close relationship with IMT.

Isolated spermatogonia protrude active pseudopodia in vitro

When dispersed spermatogenic cells obtained by enzymatic digestion from prepuberal mice, adult male mice, nonazoospermic men and normospermic men were observed live using Normarski optics, it was found that, respectively, 47.4%, 1.4%, 5.1%, and 2.4% of them protruded active pseudopodia. These cells were 8 to 10 mum in diameter, had a high N/C ratio, and had one to two prominent nucleoli that were close to a distinct nuclear membrane. They showed low alkaline phosphatase activities and homogeneous nuclear immunoreactive patterns using gamma-H2AX, which suggests that they were spermatogonia.

P-987: Recognizing pseudopodia as an identifier for isolated spermatogonia

P-987: Recognizing pseudopodia as an identifier for isolated spermatogonia

Ultrastructural changes in the testis and epididymis of rats following treatment with the benzene chromatographic fraction of the chloroform extract of the seeds of Carica papaya.

The benzene chromatographic fraction of the chloroform extract of the seeds of Carica papaya at a dose of 10 mg/rat/day for 150 days, which has shown a total inhibition of motility, reduced sperm count and infertility, was tested to de fi ne the mode of action at the subcellular level in the testis and epididymis. The ultrastructure of the testis of the treated animals revealed no appreciable changes in the subcellular characteristics. The mechanism of protein synthesis as well as steroidogenesis were evident in the Sertoli cells while the spermatogonia, spermatocytes and spermatids, both round and elongated, depicted a prominent nucleus, distinct nuclear membrane and cytoplasmic characteristics indicating normal germ cell differentiation. The principal cells of the cauda epididymis were characterized by the presence of well-de fi ned rough endoplasmic reticulum, mitochondria, Golgi bodies and secretary granules, suggesting active secretory functions. The absorptive function of the cauda epididymis was evidenced by the presence of numerous vesicles and multivesicular bodies adjacent to stereocilia. It is concluded that the inhibition of sperm motility by the drug could be due to other epididymal factors rather than the subcellular characteristics of testis and epididymis.

Ultrastructural aspects of the oesophageal and reproductive systems of the equine parasite Strongylus vulgaris

The ultrastructure of the dorsal oesophageal gland ampulla and its relationship with the oesophagus, oesophageal ultrastructure, and control mechanisms in oesophageal activity were studied. Terminal ducts of the sub-ventral glands open through the oesophageal crown at the base of the buccal cavity. The terminal duct of the dorsal oesophageal gland running through the dorsal gutter opens to the exterior at the rim 'groove' of the buccal capsule. The posterior oesophageal region is clavate and the cuticle of the lumen folds to form outlet valves, 'valvulae'. An inconspicuous oesophago-intestinal valve (three lobes) connects oesophagus and intestine and is visualized in the open and shut position. In the female reproductive tract, with the exception of the uterus, the cells lie on a thick, irregular (convoluted) basal lamina. The apical plasma membrane of the uterus, and seminal receptacle, extend into the lumen by microvilli-like projections with which spermatozoa make intimate contact. The lumen of the uterus is filled with oocytes, fertilized and unfertilized. Testicular cells have two parts linked by a rachis. Spermatocytes are elongated with a large nucleus, distinct nuclear membrane, and many granules. The apical membrane of the rachis forms long microvilli-like projections with balloon-like tips. The amoeboid spermatozoa contain membrane specializations, a nucleus devoid of a membrane, and are enclosed by a pseudopodial-like extension.

Atypical Glandular Cells of Undetermined Significance in Cervical Smears After Conization

To evaluate the cytologic features of atypical glandular cells of undetermined significance (AGUS) smears following conization through a comparison with adenocarcinoma in situ (AIS) smears. Fifty cervical smears, diagnosed as AGUS based on groups of crowded glandular cells that raised the possibility of AIS, from 38 patients who had conization and 24 AIS smears, histologically confirmed, from 17 patients were reviewed. Subsequent follow-up biopsies or hysterectomies in 38 patients were evaluated. Nuclear atypia was a more reliable feature than architectural structure in differentiating postcone effect from AIS on cytology. The predominant cytologic features of the postcone smears were crowded glandular cells with a high nuclear/cytoplasmic ratio and relatively small, hyperchromatic nuclei with rather finely granular and uniformly dispersed chromatin, less distinct nuclear membranes, less frequent mitosis and presence of endometrial-type stromal cells in the background. The architecture of the crowded cells in the postcone smears was sometimes similar to that of AIS. No AIS or high grade squamous intraepithelial lesion histology was encountered in follow-up biopsies or hysterectomy specimens. The cytologic features distinguishing AGUS from AIS may be helpful in identifying the postcone effect. Since it is important to avoid miscalling the postcone effect as AIS, it is recommended that one check for a previous history of a cone biopsy.

Peripheral primitive neuroectodermal tumour of the cervix

Peripheral primitive neuro-ectodermal tumours (PNET) of the cervix are very rare. Here, we report the clinical, pathological, immunohistochemical and genetic features of a case of a PNET located in the cervix. Hysterectomy revealed a cervical tumour. On microscopic examination, a vaguely lobular arrangement of uniformly appearing neoplastic cells, with round to oval nuclei, distinct nuclear membranes and a clear, moderately glycogen-rich cytoplasm was seen. Cells stained positive for LEU 7, S 100, monoclonal NSE and particularly for MIC2. Neurogenic differentiation was also seen by electron microscopic examination. The genetic hallmark of PNET, a 22q12 rearrangement was demonstrated by fluorescence in situ hybridisation experiments, supporting the diagnosis. Awareness of the existence of primary PNET of the cervix is important to avoid confusion with other tumours of the cervix.

Cytologic features of colonic adenocarcinoma. Differences between primary and metastatic neoplasms.

To evaluate cytologic differences between primary and metastatic specimens of colonic adenocarcinoma. Fifty colonic brushings of primary adenocarcinoma of the colon and 50 specimens of metastatic colonic adenocarcinoma were examined. The latter included fine needle aspirates of lung, liver and other sites and bronchial brushings. In contrast to primary colonic adenocarcinomas, which typically showed large, hyperchromatic nuclei, many cases of metastatic colonic adenocarcinoma showed nuclei with fine, delicate chromatin and distinct nuclear membranes. Often occurring in conjunction with those two features were prominent nucleoli and thin internuclear pseudochannels separating adjacent nuclei. Other features noted in occasional metastatic cases but only rarely in primary specimens were small tumor cell size, uniformity and cohesiveness. The features delicate chromatin, distinct nuclear membranes and prominent nucleolus, with the occasional presence of thin internuclear pseudochannels, may be viewed as constituting a secondary cytologic pattern of colonic adenocarcinoma to complement the basic classic pattern of elongated cell shape; hyperchromatic, cigar-shaped nuclei; nucleoli; molding of nuclei; palisaded or glandular arrangement; and necrosis. Varying states of preservation and degeneration may explain many of these differences.

Ultrastructural Characteristics of Glioblastoma Multiforme

The ultrastructural studies of Glioblastoma multiforme was carried out from tissue obtained from human intracranial neoplasms obtained in Madras Institute of Neurology.Light microscopy showed a highly cellular neoplasm with areas of sinusoidal necrosis palisaded by spongioblasts. The malignant cells exhibited hyperchromatism, pleomorphism, bizarre nuclei and there were marked endothelial proliferations. Mono nuclear cell aggregates are also seen.Ultrastructurally Glioblastoma multiforme exhibited great variation in size and shape of cells. In the main, the cells were off moderate size with ovoid nuclei and fine chromatin distributed evenly throughout the nucleus. Nucleoli were prominent and here also the two distinct nuclear membranes could be easily be made out. Fine pores were seen in the nuclear membranece.The cytoplasm was relatively lucent and showed various organelles such as mitochondria, Golgi apparatus and elements of the rought endoplasmic reticulum in moderate numbers. The endoplasmic reticulum was dilated in many regions and numerous electron dense bodies could also be seen.

The mesokaryote [formula omitted] lacks nucleosomes

The dinoflagellate Gyrodinium cohnii has a distinct nuclear membrane but apparently lacks histones associated with its chromatin. Approximately 13% of the nuclear DNA is rapidly digested by micrococcal nuclease to acid soluble fragments and not to nucleosomal sized fragments as in the typical eukaryote. Moreover in the electron microscope the chromatin of G. cohnii appears as a thin filament of 40–60 Å in width without regularly spaced nucleosomes. These observations support the view that the dinoflagellates exhibit characteristics of both prokaryotes and eukaryotes.

Breakdown of the germinal vesicle in bovine oocytes cultivated in vitro.

Breakdown of the germinal vesicle (GV) was studied in bovine follicular oocytes cultivated in vitro. The intact GV of control oocytes did not correspond to the findings in porcine oocytes (GV I). Instead it was characterized by a nuclear membrane and a few chromocenters in finely granular nucleoplasm (GV II). After two and three hours of cultivation, GV III predominated (50% and 64% respectively). Faintly-staining chromatin and after a longer interval in the form of filaments also appeared round the chromocenters. After four hours, 35.8% of the oocytes were still at stage GV III but the GV of 46.6% of the oocytes already contained filamentous bivalents (GV IV). After five hours, GV IV (59.7%) was typical, with a less distinct nuclear membrane and condensing bivalents. GV breakdown was completed in 30.4% of the oocytes after five hours of cultivation and in 92.5% after six hours.

Extraskeletal neoplasm resembling Ewing's sarcoma.

This article reviews the pathologic features and the behavior of 39 small, round, or oval cell sarcomas occurring in the soft tissues and considered histologically indistinguishable from Ewing's sarcoma of bone. The tumors affected chiefly young adults (median age 20 years) and most commonly involved the soft tissues of the lower extremity and the paravertebral region. Microscopically, they consisted of solidly packed small, round, or ovoid cells of great uniformity, arranged in sheets or lobules separated by strands of fibrous connective tissue. The nucleus of the tumor cells contained finely divided chromatin, a distinct nuclear membrane, and frequently a minute nucleolus. The scanty ill-defined cytoplasm contained varying amounts of glycogen. Sometimes the histologic picture was dominated by a "peritheliomatous" pattern, or by large areas of necrosis or hemorrhage. Followup data ranging from 1 month to 14 years were available in 35 of the 39 cases (93%). Of these, 13 were alive and 22 had died. In the majority of the fatal cases, the clinical course was rapid; metastatic lesions developed within a few months after the primary tumor was excised. The lungs and the skeleton were the two most common sites of metastasis. Cure may be achieved by wide local excision of the tumor at an early stage of the disease, combined with radiation therapy and chemotherapy.

Fine structure of quiescent and germinating aeciospores of Cronartium fusiforme.

Aeciospores of the long-cycle heteroecious rust fungus, Cronartium fusiforme, were found to have an extremely thick cell wall with striking spicules protruding from it. The wall was readily degraded by commercial chitinase, but spicules were unaffected. Quiescent spores contained two nuclei with distinct nuclear membranes possessing many pores. Numerous membrane-bounded lipid bodies were found both in wild-type orange and in white mutant aeciospores. An abundance of irregularly ovoid mitochondria was present in quiescent spores. After glutaraldehydeosmium fixation, the surface of the mitochondria appeared to be covered with ribosomes or microtubules in a paracrystalline array, whereas after permanganate fixation only smooth outer mitochondrial membranes were noted. The latter fixative revealed abundant vesicular endoplasmic reticulum in the spore. Spores incubated at 20 C on agar produced one to five distinct germ tubes within 65 to 180 min. These thin-walled tubes exhibited varying degrees of branching, and reached a total hyphal length of 300 to 500 mu prior to rupturing. Emergence of germ tubes took place through a pore in the spore wall and appeared to be mainly a physical flowing of cytoplasm from the spore into the germ tube without division of nuclei or other cell organelles. On completion of germination, the protoplasm of the germ tube contained both nuclei and nearly all of the other spore contents. Mitochondria had smooth outer membranes, were greatly elongated, and possessed distinct longitudinal cristae. A limited amount of rough endoplasmic reticulum was arranged parallel to the germ tube wall. Other organelles seen in germ tubes were lipid bodies, concentric membrane figures, and numerous ribosomes. Lipid bodies appeared smaller and fewer in number than in quiescent spores.

Studies on Tricercomonas Intestinalis (Wenyon and O'Connor, 1917)

Summary Tricercomonas intestinalis of Wenyon and O'Connor, 1917, has been found and described for the second time in the United States. The study of the flagellate from this case furnishes the following morphological features in addition to those previously reported. This intestinal parasite of man is a small flagellate measuring 4 to 10µ in length and 3 to 6 µ in width. It may be ovoid or rounded, but under favorable conditions it shows a caudal protoplasmic protuberance, which makes the organism priform in shape when viewed from the side. One side is flattened and the other convex. The nucleus, ovoid or rounded, is situated in the anterior end. It has a round or ovoid karyosome and distinct nuclear membrane. Two blepharoplasts are present lying between the nucleus and the flattened side. The anterior blepharoplast gives origin to the 3 anterior flagella. The posterior blepharoplast gives rise to the posterior recurrent flagellum that is adherent to the protoplasm of the body and caudal protoplasmic process, and then emerges as a free fibril. It is stronger than the anterior flagella. Tricercomonas intestinalis cysts measure 6 to 8µ in length and 3.5 to 5µ in width. They are ovoid in shape and possess 1, 2 or 4 nuclei. Binucleate cysts predominated. Tricercomonas intestinalis was cultured for three weeks in a medium composed of whole egg slants covered with a mixture of Locke's solution (8 parts) and human serum (1 part); it is called the L. E. S. (Locke-egg-serum) medium. The flagellate divides by binary fission with the nucleus passing through changes somewhat similar to those found in metazoan mitosis. This paper, with that of Lynch (5) establishes the validity of the genus and species of Tricercomons intestinalis as separate and distinct from that of Enteromonas hominis.