Inflammation induced by tumor-associated nerves promotes resistance to anti-PD-1 therapy in cancer patients and is targetable by interleukin-6 blockade

While the nervous system has reciprocal interactions with both cancer and the immune system, little is known about the potential role of tumor associated nerves (TANs) in modulating anti-tumoral immunity. Moreover, while peri-neural invasion is a well establish poor prognostic factor across cancer types, the mechanisms driving this clinical effect remain unknown. Here, we provide clinical and mechniastic association between TANs damage and resistance to anti-PD-1 therapy. Using electron microscopy, electrical conduction studies, and tumor samples of cutaneous squamous cell carcinoma (cSCC) patients, we showed that cancer cells can destroy myelin sheath and induce TANs degeneration. Multi-omics and spatial analyses of tumor samples from cSCC patients who underwent neoadjuvant anti-PD-1 therapy demonstrated that anti-PD-1 non-responders had higher rates of peri-neural invasion, TANs damage and degeneration compared to responders, both at baseline and following neoadjuvant treatment. Tumors from non-responders were also characterized by a sustained signaling of interferon type I (IFN-I) - known to both propagate nerve degeneration and to dampen anti-tumoral immunity. Peri-neural niches of non-responders were characterized by higher immune activity compared to responders, including immune-suppressive activity of M2 macrophages, and T regulatory cells. This tumor promoting inflammation expanded to the rest of the tumor microenvironment in non-responders. Anti-PD-1 efficacy was dampened by inducing nerve damage prior to treatment administration in a murine model. In contrast, anti-PD-1 efficacy was enhanced by denervation and by interleukin-6 blockade. These findings suggested a potential novel anti-PD-1 resistance drived by TANs damage and inflammation. This resistance mechanism is targetable and may have therapeutic implications in other neurotropic cancers with poor response to anti-PD-1 therapy such as pancreatic, prostate, and breast cancers.

Histopathologic features predictive of metastasis and survival in 230 patients with cutaneous squamous cell carcinoma of the head and neck and non-head and neck locations: a single-center retrospective study

BACKGROUND

Staging systems for cutaneous squamous cell carcinoma (cSCC) produce inconsistent risk stratification.

OBJECTIVE

The aim of this study was to identify further prognostic parameters for better stratification.

METHODS

We retrospectively analysed the prognostic significance of clinicopathologic parameters of 230 patients who underwent primary excision of invasive cSCC of the head and neck (n = 115) and non-head and non-neck (n = 115) locations. In addition to known high-risk features, we analysed tumour nest shape, invasion pattern, lymphoid response pattern and tumour budding.

RESULTS

On multivariable analysis, lymphovascular invasion (LVI) and high tumour budding predicted worse disease-specific survival, and ulceration, LVI and high tumour budding predicted worse overall survival. Only ulceration was independently associated with risk of nodal metastasis.

CONCLUSION

High tumour budding, LVI and ulceration are independently associated with poor outcome in cSCC and may be used to refine cSCC prognostic stratification, which is crucial to optimize clinical decision and to identify patients who are more likely to benefit from more aggressive interventions or clinical trials.

Comparison of performance indicators of MGIT primary culture to assess the impact of implementation of ISO 15189:2012 standards

Performance indicators are key component and plays a major role for monitoring and continuous quality improvement of the test results. The NABL certificate of accreditation is issued in accordance with the standard ISO 15189:2012 requirements. As part of the accreditation process, the laboratory has acquired knowledge and implemented the quality system procedures. Present study analyzed the impact of the accreditation process on the "performance indicators" of MGIT primary culture and found that performance indicators have been improved significantly after implementation of NABL for almost all indicators which clearly indicate the importance of accreditation and implementation of quality procedures for reliability of valid test results.

An unusual case of unresolving tunnel infection in a patient on continuous ambulatory peritoneal dialysis

Atypical mycobacteria remain a rare cause of peritoneal dialysis catheter-related tunnel infection (TI) and poses serious risk because of the resistant nature to most antibiotic therapy. Non-tubercular mycobacterial infections lead to chronicity requiring peritoneal dialysis catheter removal. We report an 82-year-old male, with diabetic nephropathy who had a coinfection with Staphylococcus hominis and Mycobacterium abscessus who presented with pus discharge at exit site and TI. He was treated with relocation of the extraperitoneal part of the catheter with a new exit site without catheter removal and multidrug mycobacterial therapy.

Spitzoid melanoma with histopathological features of ALK gene rearrangement exhibiting ALK copy number gain: a novel mechanism of ALK activation in spitzoid neoplasia

Spitzoid neoplasms pose diagnostic difficulties because their morphology is not consistently predictive of their biological potential. Recent advances in the molecular characterization of these tumours provides a framework by which they can now begin to be categorized. In particular, spitzoid lesions with ALK rearrangement have been specifically associated with a characteristic plexiform growth pattern of intersecting fascicles of amelanotic spindled melanocytes. We report the case of an 87-year-old man with a 3-cm nodule on his mid-upper back comprised of an intradermal proliferation of fusiform amelanotic melanocytes arranged in intersecting fascicles with occasional peritumoral clefts. Immunohistochemical studies demonstrated diffuse, strong expression of SOX10 and S100 by the tumour cells and diffuse, weak-to-moderate cytoplasmic positivity for anaplastic lymphoma kinase (ALK), suggestive of ALK rearrangement. Fluorescence in situ hybridization revealed no ALK rearrangements but instead revealed at least three intact ALK signals in 36% of the tumour cells, confirming ALK copy number gain. To our knowledge, this is the first reported case of a plexiform spitzoid neoplasm exhibiting ALK copy number gain instead of ALK rearrangement. This case suggests that ALK copy number gain is a novel mechanism of ALK activation but with the same characteristic histopathological growth pattern seen among ALK-rearranged spitzoid neoplasms.

Pruritic arthropod bite-like papules in T-cell large granular lymphocytic leukaemia and chronic myelomonocytic leukaemia

T-cell large granular lymphocytic leukaemia (T-LGLL) is a clinically indolent mature T-cell neoplasm characterized by a monoclonal population of CD3+ CD8+ cytotoxic T cells, which usually presents as neutropenia, anaemia and thrombocytopenia. Chronic myelomonocytic leukaemia (CMML) is a clonal haematopoietic disorder with features of both a myeloproliferative neoplasm and myelodysplastic syndrome (MDS). Patients with CMML exhibit a persistent peripheral blood monocytosis in addition to myelodysplastic features. Because of the rarity of T-LGLL, its cutaneous manifestations are poorly documented, but include vasculitis, vasculopathy, persistent ulcerations, generalized pruritus and disseminated granuloma annulare. Various types of skin lesions have been observed in patients with CMML and reportedly occur in approximately 10% of cases. We report the extraordinary case of a patient with MDS who developed T-LGLL, and subsequently the MDS progressed to CMML. The patient then developed diffuse arthropod bite-like papules and intractable pruritus.

Variants of katG, inhA and nat genes are not associated with mutations in efflux pump genes (mmpL3 and mmpL7) in isoniazid-resistant clinical isolates of Mycobacterium tuberculosis from India

To understand the impact of efflux pump genes such as mmpL3 and mmpL7 on isoniazid (INH) resistance and to correlate with presence or absence of mutations in essential genes of INH resistance (katG, inhA, and nat) in clinical isolates of Mycobacterium tuberculosis (M. tuberculosis). One hundred (75 resistant and 25 sensitive) clinical isolates of M. tuberculosis from India were selected for the study. The presence of mutations in specific regions of katG, inhA, and nat, efflux pump genes (mmpL3 and mmpL7) associated with INH resistance were analyzed using multiplex allele-specific polymerase chain reaction (MAS-PCR) and DNA sequencing methods, respectively. Substitution mutation AGC-ACC at codon 315 of the katG gene was detected in 65% of resistant isolates. Mutation (C-T at nucleotide position 15) in the inhA promoter region was seen in 22% of resistant isolates. Silent mutation (GGA to GGG) at codon 207 in the nat gene was found in three resistant isolates. No mutations were found in either of the efflux genes (mmpL3 and mmpL7) in any of the isolates. Of the 75 resistant isolates analyzed, 74% had mutation in katG and inhA genes. Thus, this report suggests that the role of mmpL3, mmpL7 and nat genes in INH resistance should not be overestimated in comparison to the primary contribution by katG and inhA in clinical isolates of M. tuberculosis. Further, this concise report is the first of its kind to our knowledge, to show the influence of efflux genes on INH resistance in relation to katG and inhA in clinical isolates of M. tuberculosis.

Mineral bone disease in maintenance hemodialysis patients: Association with morbidity and mortality

There is a paucity of data on mineral bone disease in maintenance hemodialysis (MHD) patients from India. This retrospective analysis was undertaken on 858 (males: 599; females: 259) patients from two medical centers on MHD from 1998 to 2010. Age, gender, months on dialysis, hours per session of dialysis, hemoglobin, serum calcium, inorganic phosphorus, intact parathyroid hormone (iPTH), urine output, erythropoietin dosage per week, blood sugar, blood pressure, urea reduction rate, gain in fluid and fluid removed per session, serum albumin, alkaline phosphatase, vitamin D level, supplemental vitamin D and use of phosphate binder for therapy were documented. Overall, 191 patients died (22%) during the observation period. There was an 86% patient survival rate at 1 year on dialysis and an overall predicted 3-year survival rate of 78%. A relatively higher iPTH (P = 0.012), a need for vitamin D supplementation (P = 0.003), less hours on dialysis per session (P = 0.046) and a non-vegetarian diet (P = 0.022) were significantly associated with mortality.

Rare occurrence of fatal Candida haemulonii peritonitis in a diabetic CAPD patient

A 68-year-old diabetic chronic kidney disease patient on continuous ambulatory peritoneal dialysis for two years developed Candida haemulonii peritonitis without any predisposing factors. There is no effective treatment for this fungus. A peritoneal biopsy showed morphological changes of acute inflammation and chronicity.

A non-surgical approach for male germ cell mediated gene transmission through transgenesis

Microinjection of foreign DNA in male pronucleus by in-vitro embryo manipulation is difficult but remains the method of choice for generating transgenic animals. Other procedures, including retroviral and embryonic stem cell mediated transgenesis are equally complicated and have limitations. Although our previously reported technique of testicular transgenesis circumvented several limitations, it involved many steps, including surgery and hemicastration, which carried risk of infection and impotency. We improved this technique further, into a two step non-surgical electroporation procedure, for making transgenic mice. In this approach, transgene was delivered inside both testes by injection and modified parameters of electroporation were used for in-vivo gene integration in germ cells. Using variety of constructs, germ cell integration of the gene and its transmission in progeny was confirmed by PCR, slot blot and immunohistochemical analysis. This improved technique is efficient, requires substantially less time and can be easily adopted by various biomedical researchers.

Effect of long-term castration on serum biochemistry in rhesus monkeys

BACKGROUND

Testicular failure has an effect on normal physiology. To address this issue, an experimental non-human primate model of long-term castrated rhesus monkey was chosen for this study to evaluate the influence of castration on various biochemical parameters.

METHODS

Nine castrated rhesus monkeys were evaluated for changes in body weight, serum testosterone, and serum biochemical parameters as compared to those in non-castrated macaques.

RESULTS

Castration caused statistically significant changes in body weight, biochemical analytes, and testosterone levels. Body weight and testosterone levels were decreased, and there were increase in alanine aminotransferase, cholesterol, serum bilirubin, phosphorous, alkaline phosphatase, urea and a decrease in serum protein, uric acid, creatinine, and triglycerides.

CONCLUSIONS

This study provided essential baseline information on biochemical variables due to the effect of castration associated with declining levels of testosterone, as data are not readily accessible from the existing body of scientific literature on non-human primates.

Constant Temperature Microfeature Embossing with Slowly Crystallizing Polymers

A new microfeature embossing method utilizing a slowly crystallizing mechanism was investigated to eliminate thermal cycling, as needed in standard hot embossing. Poly(ethylene terephthalate) was used as a model system for demonstration. Due to its slow crystallization, amorphous PET film can be made by melt casting onto a chilled roll. The resulting amorphous film was embossed at a constant temperature of 180°C for a period of time comparable to or longer than the polymer's half-time of crystallization. During constant-temperature embossing, the film is softened first, caused by rubber softening of the amorphous phase, and is then hardened, resulting from the crystallization of the amorphous phase at the same embossing temperature. Since the embossed film is hardened under the constant mold temperature, no cooling is needed. Selected micro features, including circular microchannels and high aspect ratio microribs, were consistently patterned using a total cycle time about 40s. The embossed films were characterized using DSC and rotational rheometry to elucidate the physical mechanism for softening and hardening the polymer during constant-temperature embossing.

Retrieval of Mycobacterium tuberculosis cultures suspended in phosphate buffered saline

One hundred and twenty-seven of 130 isolates of Mycobacterium tuberculosis, suspended in phosphate buffered saline (PBS) and stored at ambient conditions in the laboratory for 14days, and another 55 of 60 cultures, suspended as above, transported from reference laboratories within 7days, were successfully retrieved on LJ medium. Considering the maximum retrieval of M. tuberculosis, use of PBS can be explored further for transportation of M. tuberculosis cultures across laboratories.

Protocol for long duration whole body hyperthermia in mice

Hyperthermia is a general term used to define the increase in core body temperature above normal. It is often used to describe the increased core body temperature that is observed during fever. The use of hyperthermia as an adjuvant has emerged as a promising procedure for tumor regression in the field of cancer biology. For this purpose, the most important requirement is to have reliable and uniform heating protocols. We have developed a protocol for hyperthermia (whole body) in mice. In this protocol, animals are exposed to cycles of hyperthermia for 90 min followed by a rest period of 15 min. During this period mice have easy access to food and water. High body temperature spikes in the mice during first few hyperthermia exposure cycles are prevented by immobilizing the animal. Additionally, normal saline is administered in first few cycles to minimize the effects of dehydration. This protocol can simulate fever like conditions in mice up to 12-24 hr. We have used 8-12 weeks old BALB/Cj female mice to demonstrate the protocol.

Assessment of panel slides prepared by phenol ammonium sulphate and NALC methods for proficiency testing

BACKGROUND

Existing methods for the preparation of panel slides necessitate handling high-grade acid-fast bacilli positive sputum samples.

OBJECTIVE

To compare panel slides prepared using the phenol ammonium sulphate sediment (PhAS) method with those prepared using the N-acetyl-L-cysteine (NALC) method in proficiency testing.

METHODS

Pooled sputum specimens of known smear-positives and -negatives were divided into two parts: one part was used for preparing panel slides using the NALC method and the other using PhAS, a non-hazardous method. Respectively 413 and 384 smears of different grades were prepared in three batches using the PhAS and NALC methods. Smear grade and quality were recorded by 121 microscopists during proficiency testing in different states. Agreement between reference and reported results was analysed using the kappa test.

RESULTS

The overall agreement was 96% for the PhAS method and 91% for the NALC method. There were 37 errors using the NALC method compared to 21 for the PhAS method (P < 0.223). Smear quality was equally good in both methods; however, the cell count was significantly higher in the PhAS than in the NALC method.

CONCLUSION

The PhAS method, a non-hazardous procedure with good-quality smears, may be further explored for the preparation of panel slides.

Recovery of Mycobacterium tuberculosis from Löwenstein-Jensen media contaminated with other organisms

Growth of contaminating organisms along with Mycobacterium tuberculosis on Löwenstein-Jensen (LJ) medium is common. However, there is no documented evidence on the decontamination procedure adopted in mycobacteriology laboratories to recover M. tuberculosis from the contaminants grown on LJ medium. At the National Institute for Research in Tuberculosis, of 1048 LJ slopes with M. tuberculosis received from intermediate reference laboratories, 98 (9%) were contaminated. Of these, 87 (89%) M. tuberculosis cultures were retrieved after decontamination with 1% cetrimide. The use of cetrimide as a decontaminating agent to retrieve M. tuberculosis cultures grown with contaminants is documented.

Effect of dietary β carotene on cerebral aneurysm and subarachnoid haemorrhage in the brain apo E-/- mice

Atherosclerosis will lead to stenosis/occlusion in the lumen of various arteries of living body. This can lead various conditions including myocardial infarction, cerebral infarction/aneurysm and peripheral artery disease. Ang II is believed to be an important regulatory peptide involved in maintaining cardiovascular homeostasis and pathogenesis of various cardiovascular diseases. Matrix metalloproteinase's (MMPs), adhesion molecules and plasminogen systems are involved in the inflammatory reaction of various blood vessels as well as pathogenesis of cerebro vasuclar disease in apo E(-/-) mice during angiotensin II injection. The present study analyses the role of ang II in development of cerebral aneurysm and also evaluated the mRNA levels of MMPs, adhesion molecules, plasminogen systems and peroxisome proliferators-associated receptors in the brain of apo E(-/-) mouse during the progression of cerebral aneurysm and ischemic conditions. Also, this study evaluates the role of dietary β carotene on cerebrovascular disease. Serum total cholesterol (TC), Low density lipoprotein (LDL) and triglyceride (TG) levels were significantly increased in angiotensin II treated animals and further β carotene supplementation reduces TC but does not affect the triglyceride and LDL levels. Circulating levels of macrophages were significantly increased in angiotensin treated animals and further beta carotene supplementation significantly reduced the circulating macrophages. Cerebro meningeous aneurysm, subarachnoid haemorrhage, multiple foci of infarction, necrosis and infiltration of inflammatory cells were observed in the cerebral hemispheres of ang II treated animals, however, infarction size were reduced and no aneurysm, inflammatory foci was observed in β carotene treated animals. Real time analysis showed down regulation of mRNA levels of MMP 2, uPA, PAI, PPAR-A, MCSF1 and up regulation of tPA and MCP-1 in the brain during the progression of cerebral aneurysm and β carotene supplementation to bring to normal expression levels of all the candidate genes for cerebrovascular diseases. Based on above results, Ang II may induced cerebral aneurysm, ischemia/infarction on brain through RAS system by down regulating the mRNA levels of MMP 2, uPA, PAI, PPAR-A, MCSF1 and up regulating tPA and MCP-1 and β carotene attenuates the disease condition and bring down to normal expression levels of above genes.

Potassium channel opening: a subtle two-step

Voltage-gated K(+) channels undergo a voltage-dependent conductance change that plays a key role in modulating cellular excitability. While the Open state is captured in crystal structures of Kv1.2 and a chimeric Kv1.2/Kv2.1 channel, the Close state and the mechanism of this transition are still a subject of debate. Here, we propose a model based on mutagenesis combined with measurements of both ionic and gating currents which is consistent with the idea that the Open state is the default state, the energy of the electric field being used to keep the channel closed. Our model incorporates an 'Activated state' where the bulk of sensor movement is completed without channel opening. The model accounts for the well characterized electrophysiology of the 'V2' and 'ILT' mutations in Shaker, where sensor movement and channel opening occur over distinct voltage ranges. Moreover, the model proposes relatively small protein rearrangements in going from the Activated to the Open state, consistent with the rapid transitions observed in single channel records of Shaker type channels at zero millivolts.

A mouse model for luminal epithelial like ER positive subtype of human breast cancer

Background

Generation of novel spontaneous ER positive mammary tumor animal model from heterozygous NIH nude mice.

Methods

Using brother-sister mating with pedigree expansion system, we derived a colony of heterozygous breeding females showing ER-Positive tumors around the age of 6 months. Complete blood picture, differential leukocyte count, and serum levels of Estrogen, Alanine amino transferase (SGPT), Aspartate amino transferase (SGOT), total protein and albumin were estimated. Aspiration biopsies and microbiology were carried out. Gross pathology of the tumors and their metastatic potential were assessed. The tumors were excised and further characterized using histopathology, cytology, electron microscopy (EM), molecular markers and Mouse mammary Tumor Virus – Long Terminal Repeats (MMTV LTR) specific RT-PCR.

Results

The tumors originated from 2^ndor 5^thor both the mammary glands and were multi-nodulated with variable central necrosis accompanied with an accumulation of inflammatory exudate. Significant increases in estrogen, SGPT, SGOT and neutrophils levels were noticed. Histopathologically, invasive nodular masses of pleomorphic tubular neoplastic epithelial cells invaded fibro-vascular stroma, adjacent dermis and subcutaneous tissue. Metastatic spread through hematogenous and regional lymph nodes, into liver, lungs, spleen, heart and dermal lymphatics was observed. EM picture revealed no viral particles and MMTV-negativity was confirmed through MMTV LTR-specific RT-PCR. High expression of ER α, moderate to high expression of proliferating cell nuclear antigen (PCNA), moderate expression of vimentin and Cytokeratin 19 (K19) and low expression of p53 were observed in tumor sections, when compared with that of the normal mammary gland.

Conclusion

Since 75% of human breast cancer were classified ER-positive and as our model mimics (in most of the characteristics, such as histopathology, metastasis, high estrogen levels) the ER-positive luminal epithelial-like human breast cancer, this model will be an attractive tool to understand the biology of estrogen-dependant breast cancer in women. To our knowledge, this is the first report of a spontaneous mammary model displaying regional lymph node involvement with both hematogenous and lymphatic spread to liver, lung, heart, spleen and lymph nodes.

Strobilocercus fasciolaris infection with hepatic sarcoma and gastroenteropathy in a Wistar colony

Tapeworm cysts were identified in liver of Wistar rats and it induced fibrosarcoma in liver and gastroenteropathy in stomach and intestine. The tapeworm larva was confirmed as Strobilocercus fasciolaris by PCR linked mitochondrial DNA sequencing. Light microscopy, special staining (masson trichrome) and immunoflouresence supported the diagnosis of fibrosarcoma. Infiltration of plasma cells, macrophages and eosinophils were observed in the liver section. Gastric mucosal hyperplasia, dilation of gastric glands with secretion, intestinal mucosal cell hyperplasia, proliferation of duodenal submucosal glands were confirmed by light microscopy and supported by PAS, AB staining. The concomitant development of hepatic sarcoma and gastroenteropathy by larvae of Taenia taeniaeformis (S. fasciolaris) infection is very rare and is the first reported case in Wistar rats to our knowledge.

Follicle-stimulating hormone-independent functions of primate Sertoli cells: potential implications in the diagnosis and management of male infertility

CONTEXT

FSH is known to augment the production of essential germ cell (Gc) survival factors, lactate and estradiol, by Sertoli cells (Sc) of 18-d-old pubertal rats. However, the failure of gonadotropin and androgen treatment to initiate spermatogenesis in testis of some infertile men bearing Sc and Gc is intriguing. The role of FSH in regulation of lactate and estradiol production by primate Sc is currently unknown.

OBJECTIVE

The objective of the study was to determine the role of FSH in regulating lactate and estradiol production by primate Sc.

METHODS

Gc differentiation was initiated in male juvenile rhesus monkeys by pulsatile administration of GnRH for 4-5 wk. Sc from these pseudopubertal monkeys and pubertal rats were cultured. Production of lactate and estradiol in response to FSH and 8-bromoadenosine-cAMP was evaluated. Inhibin-betaB expression, cAMP production, and cell proliferation were also assayed.

RESULTS

Unlike Sc from pubertal rats, Sc from pseudopubertal monkeys constitutively aromatized testosterone to estradiol and produced large amounts of lactate without FSH stimulation. Increasing doses of recombinant monkey FSH or 8-bromoadenosine-cAMP failed to augment lactate production, although they significantly augmented proliferation of Sc. Production of cAMP and expression of inhibin-betaB mRNA were also remarkably augmented by recombinant monkey FSH.

CONCLUSIONS

These results suggest that lactate and estradiol production by monkey Sc is not governed by FSH, as previously thought based on studies of rat Sc. Thus, in a clinical situation, assessment of such gonadotropin-independent functions of Sc may be obligatory for the diagnosis and management of certain forms of idiopathic male infertility.

Granulosa theca cell tumor with luteoma in the ovary of a bonnet monkey (Macaca radiata)

A mass was identified on the left caudal region of the abdomen in a 13-year-old bonnet monkey (Macaca radiata). The mass was excised and diagnosed as granulosa theca cell tumor accompanied with luteoma based on the microscopic findings. Morphologically it appeared pink, round, firm multilobulated measured approximately 5 x 3 x 2.5 cm in dimension. Histologically the luteoma composed of polyhedral cells with pale strained vacuolated cytoplasm, centrally located nuclei with distinct cytoplasmic borders. Granulosa theca cell tumor appeared as densely packed spindle shaped fusiform cells arranged in interlacing bundles and whorled pattern with neoplastic cells appearing irregular shaped solid sheets. The concomitant development of granulosa theca cell tumor with luteoma in a single ovary is very rare and is the first reported case in a bonnet macaque to our knowledge.

Sebaceous gland adenoma in a rhesus monkey (Macaca mulatta)

A tumor mass was identified below the shoulder region of a 5-year-old male rhesus monkey (Macaca mulatta). The mass was excised and diagnosed as sebaceous gland adenoma based on the microscopic findings. Morphologically it appeared as an elevated, dome-shaped, circumscribed mass of 3.6 x 2.8 x 3.2 cm in dimension with tan speckled color. Histologically, the tumor was composed of mature, sebaceous cells (sebocytes), basal cells arranged in a mass of irregular shapes and sizes, with a characteristic appearance of poly or multilobular structure. Sebocytes were well differentiated with foamy cytoplasm in the center of the lobules and poorly or undifferentiated densely staining basal cells in the periphery of the lobules. Cellular changes in the adjacent lymph node included hyperplasia of plasma cells, macrophages and lymphoid elements with typical mitosis.

Differential expression of putative transbilayer amphipath transporters

The aminophospholipid translocase transports phosphatidylserine and phosphatidylethanolamine from one side of a bilayer to another. Cloning of the gene encoding the enzyme identified a new subfamily of P-type ATPases, proposed to be amphipath transporters. As reported here, mammals express as many as 17 different genes from this subfamily. Phylogenetic analysis reveals the genes to be grouped into several distinct classes and subclasses. To gain information on the functions represented by these groups, Northern analysis and in situ hybridization were used to examine the pattern of expression of a panel of subfamily members in the mouse. The genes are differentially expressed in the respiratory, digestive, and urogenital systems, endocrine organs, the eye, teeth, and thymus. With one exception, all of the genes are highly expressed in the central nervous system (CNS); however, the pattern of expression within the CNS differs substantially from gene to gene. These results suggest that the genes are expressed in a tissue-specific manner, are not simply redundant, and may represent isoforms that transport a variety of different amphipaths.

A comparison of somatic chromosomal instability in tissue culture regenerants from Medicago media Pers

Two cultivars (Heinrichs, Reaver) and two breeding lines (Br1, Le1) from Medicago media were cultured in a media protocol consisting of a high concentration 2,4-D induction step. Regenerants were produced from all four stocks. Representative samples from each regenerant population along with the corresponding control population were cytologically analyzed for chromosomal and pollen abnormalities. While numerical changes in chromosome numbers were found in all regenerant populations, there was considerable variation between the four stock groups. Heteroploidy was observed for both hypo and hyper aneuploid regenerants, but there were no differences in pollen stainability between hypo and hyper aneuploid regenerants and 'euploid' regenerants. Tissue culture regenerants generally produced a lower pollen stainability percent as compared to control populations grown from seeds. Gross and cryptic changes in chromosomes, or hormonal carry over effects or both were considered causes for poor pollen stainability in tissue culture regenerants. Cytological analyses indicate that the cultivar might play an important role in the cytological stability or instability of regenerant populations. Exploitation of this naturally existing situation to produce 'euploid' regenerants for field experiments and to obtain gross cytological stability in somaclones is discussed.