Cardiac metastases from a squamous cell lung carcinoma in the absence of local recurrence - a unique case

OBJECTIVE

Metastatic tumors of the heart are much more frequent than primary tumors. In this paper, we present the uncommon case of heart metastases of a squamous cell lung carcinoma.

CASE REPORT

The study is a description of a unique case of cardiac metastases from lung cancer in the absence of local recurrence. The patient had a squamous cell lung carcinoma and underwent pulmonectomy two years before, followed by four cycles of chemotherapy.

RESULTS

We report this case to raise the awareness of cardiac manifestations of neoplastic diseases that are usually underdiagnosed.

CONCLUSIONS

According to our knowledge, there is no such case described in the literature. Heart metastases are significantly underdiagnosed. Although the survival prognosis is very poor, earlier diagnosis could provide the chance to start the treatment and to prolong patients' life.

A single-institution retrospective analysis of the differences between 7th and 8th edition of the UICC TNM staging system in patients with advanced lung cancer

OBJECTIVE

The TNM (Tumor, Node, Metastasis) classification of Union for International Cancer Control is a system describing the anatomical extent of the solid tumors that leads to staging and decision on the type of treatment. The latter TNM system (2017) as compared to the previous version (2010) has brought numerous changes. Our aim was to examine whether significant changes in the new TNM edition have altered the components of the TNM classification in patients and the stage of the disease to which they are ascribed.

PATIENTS AND METHODS

The study is retrospective and is based on radiological examination reports and case reports of 100 patients of the Department of Pneumonology, Allergology and Oncology of the Medical University in Lublin, Poland. One hundred randomly selected patients, who were hospitalized at the Clinic between 2013 and 2018 with primary lung cancer were enrolled in the study. The chi-square test, Mann-Whitney U test, Kruskal-Wallis test and an appropriate post-hoc test were used in statistical analysis.

RESULTS

It was calculated that the T descriptor evaluated as per TNM in revision 8th in comparison to revision 7th changed in 41% of patients, the M descriptor - in 29% of patients, which resulted in change in staging in 11 patients. In spite of this scale amendments, only three patients could be treated differently because of the change in the stage of the disease.

CONCLUSIONS

Changing the treatment method, including withdrawal from surgery, can help avoid unnecessary treatment, but on the other hand, may potentially reduce the patient's chances of survival by depriving them of the possibility of radical treatment.

Lipophilic components and evaluation of the cytotoxic and antioxidant activities of

The chemical composition of the lipophilic fractions of Impatiens glandulifera Royle and I. noli-tangere L. were analyzed by gas chromatography-mass spectrometry (GC-MS)., The study focused on the fatty acids, triterpenoids and sterols in the leaves, roots and seeds. Most of the identified compounds are new for these species. a-linolenic, oleic and palmitic acids were the most abundant in the fatty acid fractions, β-amyrin and 5a-lup-20(29)-en-3β-ol in the triterpenoid fractions, and β-sitosterol, spinasterol and chondrillasterol in the sterol fractions. The fatty acid and triterpenoid fractions showed strong antioxidant activity, similar to positive controls. Moreover, the triterpenoid fraction from I. noli-tangere seeds significantly inhibited HL-60 human leukemia cells. Other fractions showed moderate cytotoxicity. The present study suggests that I. glandulifera and I. noli-tangere are good source of omega-3 fatty acids, and they might be considered as antioxidant and chemopreventive agents.

A New Enzyme Immunoassay for Soluble Fibrin in Plasma, with a High Discriminating Power for Thrombotic Disorders

Fibrin formation is a multistep process initiated by thrombin. At first thrombin converts fibrinogen to fibrin molecules which in vivo form soluble complexes with fibrinogen. Soluble fibrin is considered to be an early biochemical marker for intravascular fibrin formation and impending thrombotic events, such as deep venous thrombosis (DVT), pulmonary embolism (PE) and disseminated intravascular coagulopathy (DIC).

A new enzyme immunoassay (EIA) was developed on the basis of a monoclonal antibody directed against a fibrin specific neo-epitope located on the gamma-chain of fibrinogen; γ-(312-324). In addition, it was possible to prepare a lyophilized reference material of thrombin-generated soluble fibrin, that allowed for full antigen recovery after reconstitution with buffer. Assay conditions, e.g. solid phase-Ig concentration and buffer composition, sample and conjugate dilution, and incubation times were optimised.

The present assay was found to be specific (no interference of homologous antigens) and reproducible (intra-assay CV 4-8%, inter-assay CV 4-9%), and therefore highly suited for measuring soluble fibrin levels in a plasma milieu. The median normal value for soluble fibrin was determined in plasma samples obtained from apparently healthy volunteers (n = 81) and found to be 0.040 μg/ml, with a range (10-90 percentiles) of 0.026-0.059 μg/ml.

A retrospective study showed that soluble fibrin levels were highly significantly increased in patients with a confirmed diagnosis of DIC (median 1.042 μg FEU/ml, range 0.160-2.319 μg/ml, n = 21, P <0.0001 vs normal), PE (median 0.527 μg FEU/ml, range 0.084-1.234 μg/ml, n = 29, P <0.0001 vs normal) and DVT (median 0.126 μg FEU/ml, range 0.059-0.878 μg/ml, n = 36, P <0.0001 vs normal), as determined by the Mann-Whitney U-Test.

Upper Extremity Lymphedema After Axillary Lymph Node Dissection: Prospective Lymphoscintigraphic Evaluation

This prospective study was designed to evaluate changes in upper extremity lymphatic drainage after ALND in comparison to the preoperative status using lymphoscintigraphy. The study enrolled 44 women (mean age: 57.95; range: 35-80) with a new diagnosis of unilateral invasive breast carcinoma who had been scheduled to undergo ALND. This was a substudy of the physiotherapeutic project, in which subjects after ALND were randomized into 4 groups treated with: 1) rehabilitation exercises; 2) manual lymphatic drainage; 3) pneumatic compression pump; and 4) education only. Clinical evaluation which included arm measurements and lymphoscintigraphy was performed in every subject before surgery and 3 times after surgery (1-6 weeks, 1 and 2 years after ALND). Follow-up was completed in 44 subjects at 1 year and in 32 subjects at 2 years. Lymphedema diagnosis was made in 4 subjects 1 year after ALND (9%) and in 8 subjects 2 years after ALND (25%). Among them, respectively, only 50% and 62% noticed and reported lymphedema. Quantitative analysis of lymphoscintigrams and photoplethysmography results did not reveal upper extremities lymphatic transport and/or venous function impairment after the ALND procedure. Qualitative analysis of lymphoscintigrams revealed most commonly disappearance of previously functional lymph nodes and appearance of dermal backflow in subjects who developed lymphedema. Conversely, appearance of functional lymph nodes in different locations after ALND may indicate protection from development of upper extremity lymphedema.

Transgene delivery to endothelial cultures derived from porcine carotid artery ex vivo

Carotid artery disease is a widespread cause of morbidity and mortality. Porcine models of vascular disease are well established in vivo, but existing endothelial systems in vitro (e.g. human umbilical vein endothelial cells, rat aortic endothelial cultures) poorly reflect carotid endothelium. A reliable in vitro assay would improve design of in vivo experiments and allow reduction and refinement of animal use. This study aimed (1) to develop ex vivo endothelial cultures from porcine carotid and (2) to test whether these were suitable for lentivector-mediated transgene delivery. Surplus carotid arteries were harvested from young adult female Large White pigs within 10 min post-mortem. Small sectors of carotid artery wall (approximately 4 mm×4 mm squares) were immobilised in a stable gel matrix. Cultures were exposed to HIV-derived lentivector (LV) encoding a reporter transgene or the equivalent integration-deficient vector (IDLV). After 7-14 days in vitro, cultures were fixed and labelled histochemically. Thread-like multicellular outgrowths were observed that were positive for endothelial cell markers (CD31, VEGFR2, von Willebrand factor). A minority of cells co-labelled for smooth muscle markers. Sensitivity to cytotoxic agents (paclitaxel, cycloheximide, staurosporine) was comparable to that in cell cultures, indicating that the gel matrix permits diffusive access of small pharmacological molecules. Transgene-expressing cells were more abundant following exposure to LV than IDLV (4.7, 0.1% of cells, respectively). In conclusion, ex vivo adult porcine carotid artery produced endothelial cell outgrowths that were effectively transduced by LV. This system will facilitate translation of novel therapies to clinical trials, with reduction and refinement of in vivo experiments.

Resident phenotypically modulated vascular smooth muscle cells in healthy human arteries

Vascular interstitial cells (VICs) are non-contractile cells with filopodia previously described in healthy blood vessels of rodents and their function remains unknown. The objective of this study was to identify VICs in human arteries and to ascertain their role. VICs were identified in the wall of human gastro-omental arteries using transmission electron microscopy. Isolated VICs showed ability to form new and elongate existing filopodia and actively change body shape. Most importantly sprouting VICs were also observed in cell dispersal. RT-PCR performed on separately collected contractile vascular smooth muscle cells (VSMCs) and VICs showed that both cell types expressed the gene for smooth muscle myosin heavy chain (SM-MHC). Immunofluorescent labelling showed that both VSMCs and VICs had similar fluorescence for SM-MHC and αSM-actin, VICs, however, had significantly lower fluorescence for smoothelin, myosin light chain kinase, h-calponin and SM22α. It was also found that VICs do not have cytoskeleton as rigid as in contractile VSMCs. VICs express number of VSMC-specific proteins and display features of phenotypically modulated VSMCs with increased migratory abilities. VICs, therefore represent resident phenotypically modulated VSMCs that are present in human arteries under normal physiological conditions.

Axillary lymph nodes and arm lymphatic drainage pathways are spared during routine complete axillary clearance in majority of women undergoing breast cancer surgery

Alterations in axillary lymph nodes (ALNs) after complete axillary lymph node dissection (ALND) in comparison to the preoperative status were evaluated using lymphoscintigraphy performed preoperatively and 1-6 weeks after surgery in 30 women with a new diagnosis of unilateral, invasive breast carcinoma. Analysis of lymphoscintigrams revealed that ALNs after surgery were present in 26 of 30 examined women. In comparison to preoperative status, they were visualized in the same location (12 women), in the same and additionally in different locations (9 women), or only in different locations (4 women). No lymph nodes were visualized in one woman and lymphocoele were in 4 women. Thus, after ALND, a variable number of axillary lymph nodes remain and were visualized on lymphoscintigraphy in the majority of women. The classical ALND, therefore, does not allow complete dissection and removal of axillary nodes with total disruption of axillary lymphatic pathways, accounting in part for the variable incidence and severity of lymphedema after the procedure.

Interstitial cells from rat middle cerebral artery belong to smooth muscle cell type

It is now established that non-contractile cells with thin filopodia, also called vascular interstitial cells (VICs), are constitutively present in the media of many, if not all, blood vessels. The aim of this study was to determine the type of cell lineage to which arterial VICs belong using immunocytochemical, and real-time and reverse transcription PCR (RT-PCR). Using RT-PCR, we compared gene expression profiles of single VICs and smooth muscle cells (SMCs) freshly dispersed from rat middle cerebral artery. Both VICs and SMCs expressed the SMC marker, smooth muscle myosin heavy chain (SM-MHC), but did not express fibroblast, pericyte, neuronal, mast cell, endothelial or stem cell markers. Freshly isolated VICs also did not express c-kit, which is the marker for interstitial cells of Cajal in the gastrointestinal tract. Immunocytochemical labelling of contractile proteins showed that VICs and SMCs expressed SM-MHC similarly to the same degree, but VICs in contrast to SMCs had decreased expression of alpha-SM-actin and very low or no expression of calponin. Real-time RT-PCR was consistent with immunocytochemical experiments and showed that VICs had four times lower gene expression of calponin comparing to SMCs, which may explain VICs' inability to contract. VICs had greater expression than SMCs of structural proteins such as non-muscular beta-actin and desmin. The results obtained suggest that VICs represent a subtype of SMCs and may originate from the same precursor as SMCs, but later develop filopodia and a non-contractile cell phenotype.

[Eros, Thanatos and a cloned child]

The paper discusses and confirms the opinion that modern Western European culture is characterised by a high level of fear of death, which shows all features of a thanatic crisis. This is a consequence of wearing-out of culture-made means used to alleviate the fear induced by human finity. In this situation, modern societies put more and more hope in supported procreation and cloning of Homo sapiens as methods of reducing thanatic fears.

Nuclear liver glycoproteins at different stages of chicken embryo development

In order to examine whether the patterns of nuclear and chromatin glycoproteins change during development the glycoproteins of foetal and adult chicken liver were investigated. Nuclear and chromatin proteins from both sources were separated by SDS-PAGE, transferred onto Immobilon-P transfer membrane or nitrocellulose and tested for concanavalin A (Con A), Galanthus nivalis agglutinin (GNA) and Aleuria aurantia agglutinin (AAA) binding. Results revealed a similarity in the profiles of nuclear and chromatin glycoproteins recognized by Con A from 14-, 16-, 18-day foetal and adult chicken liver. Generally GNA and AAA reacted more weakly with glycoproteins from foetal liver compared with the same glycoproteins from adult liver.

Cross-reactivity of TNP immune effector T cells that mediate contact hypersensitivity and inflammatory bowel disease in the mouse

BACKGROUND

Experiments were aimed to test the cross-reactivity of immune Th1 cells that mediate contact hypersensitivity (CHS) or inflammatory bowel disease (IBD) to TNP in the mouse.

METHODS

CBA/J mice were immunized either epicutaneously or intrarectally with TNP and after appropriate time intervals were challenged with antigen in a crossed manner. The CHS reaction was measured by the ear swelling test. IBD was quantified by increase of colon weight and myeloperoxidase level. Both reactions were confirmed histologically. In passive-transfer experiments, mesenteric lymph node cells of animals sensitized intrarectally and peripheral lymph node and spleen cells of mice immunized epicutaneously were used. In some experiments, before being immunized mice were made either unresponsive to the TNP hapten by induction of suppressor T cells, or resistant to suppression after induction of upregulatory T cells.

RESULTS

Irrespective of the mode of sensitization upon appropriate challenge with antigen all mice developed a good CHS reaction as well as significant IBD. This cross-reactivity could be passively transferred by immune cells. In mice in which antigen-specific down- or upregulatory cells were induced before sensitization both CHS and IBD to TNP were modulated accordingly.

CONCLUSION

TNP hapten deposited on skin or on mucosal surfaces induces effector cells that recognize antigen independent of its tissue localization, and produce a local inflammatory reaction. TNP-specific up- and downregulatory cells, shown before to regulate the CHS reaction, similarly modulate the generation and development of hapten-induced IBD.

A new enzyme immunoassay for soluble fibrin in plasma, with a high discriminating power for thrombotic disorders

Fibrin formation is a multistep process initiated by thrombin. At first thrombin converts fibrinogen to fibrin molecules which in vivo form soluble complexes with fibrinogen. Soluble fibrin is considered to be an early biochemical marker for intravascular fibrin formation and impending thrombotic events, such as deep venous thrombosis (DVT), pulmonary embolism (PE) and disseminated intravascular coagulopathy (DIC). A new enzyme immunoassay (EIA) was developed on the basis of a monoclonal antibody directed against a fibrin specific neo-epitope located on the gamma-chain of fibrinogen; gamma-(312-324). In addition, it was possible to prepare a lyophilized reference material of thrombin-generated soluble fibrin, that allowed for full antigen recovery after reconstitution with buffer. Assay conditions, e.g. solid phase-Ig concentration and buffer composition, sample and conjugate dilution, and incubation times were optimised. The present assay was found to be specific (no interference of homologous antigens) and reproducible (intra-assay CV 4-8%, interassay CV 4-9%), and therefore highly suited for measuring soluble fibrin levels in a plasma milieu. The median normal value for soluble fibrin was determined in plasma samples obtained from apparently healthy volunteers (n = 81) and found to be 0.040 microg/ml, with a range (10-90 percentiles) of 0.026-0.059 microg/ml. A retrospective study showed that soluble fibrin levels were highly significantly increased in patients with a confirmed diagnosis of DIC (median 1.042 microg FEU/ml, range 0.160-2.319 microg/ml, n = 21, P<0.0001 vs. normal). PE (median 0.527 microg FEU/ml, range 0.084-1.234 microg/ml, n = 29, P<0.0001 vs normal) and DVT (median 0.126 microg FEU/ml, range 0.059-0.878 microg/ml, n = 36, P<0.0001 vs. normal), as determined by the Mann-Whitney U-Test.

CCK receptors in release of pancreatic polypeptide (PP) in dogs

Pancreatic polypeptide (PP) is released after ingestion of protein-fat meals and following administration of some gut hormones (CCK and bombesin), but the hormonal contribution to the physiological release of PP has not been elucidated. We used specific and potent CCK-receptor antagonist, L-364,718, administered intravenously in a dose of 0.5 mumol/kg or intraduodenally in a dose of 2 mumol/kg to assess the role of CCK in the release of PP. Exogenous CCK-8 infused intravenously in gradually increasing doses (12.5-400 pmol/kg/hr) caused a dose-dependent increase in plasma PP from basal 28 +/- 4 pM to 136 +/- 18 pM, and this PP increase was completely suppressed by both intravenous and intraduodenal administration of L-364,718. Meat feeding caused a dramatic increase in plasma PP from a basal level of 26 +/- 4 pM to a peak of about 190 +/- 32 pM, and the pretreatment with intravenous or intraduodenal L-364,718 reduced this PP increase by about 60%. Duodenal perfusion with oleate (0.12-4.0 mmol/hr) or L-Trp (0.12-4.0 mmol/hr) also increased plasma PP, reaching, respectively, 180 +/- 28 pM and 76 +/- 6 pM. Pretreatment with intravenous or intraduodenal L-364,718 completely abolished the plasma PP responses to oleate and L-Trp. Bombesin (100 pmol/kg/hr) raised plasma PP to the level similar to that achieved by meat feeding and L-364,718 given intravenously or intraduodenally blocked completely these plasma PP increments.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of helodermin, VIP and PHI in pancreatic secretion and blood flow in dogs

Helodermin, VIP and PHI, which share a high degree of homology with secretin, have been identified in the gut but their physiological role is unknown. In this study 3 series of tests were carried out to determine the actions of helodermin, VIP and PHI on pancreatic secretion in 6 conscious dogs and amylase release from the dispersed canine pancreatic acini and to correlate the alterations in pancreatic secretory and circulatory effects in 24 anesthetized dogs. Helodermin, VIP and PHI infused i.v. in graded doses (12.5-200 pmol/kg.h) resulted in a dose-dependent increase in pancreatic HCO3 secretion reaching, respectively, 100%, 7% and 2% of secretin maximum. When combined with constant dose infusion of CCK-8 (100 pmol/kg.h), helodermin but not VIP or PHI augmented dose-dependently the HCO3 secretion. When added in various concentrations (10(-10)-10(-5)M) to the incubation medium of dispersed pancreatic acini only helodermin but not VIP or PHI increased dose-dependently amylase release reaching about 50% of CCK-8 maximum. In anesthetized dogs, the pancreatic blood flow (PBF) measured by electromagnetic blood flowmetry showed an immediate and dose-dependent increase following the injections of various doses of helodermin, VIP, PHI and secretin, the peak blood flow preceding by about 1 min the peak secretory stimulation. This study shows that helodermin resembles secretin in its potent pancreatic HCO3 stimulation but differs from VIP or PHI which are poor secretagogues but potent vasodilators. We conclude that if tested peptides are released in the gut, helodermin, like secretin, may be involved in the hormonal stimulation of exocrine pancreas, whereas VIP and PHI may serve mainly as vasodilators in the pancreatic circulation.

Comparison of telenzepine, pirenzepine and atropine on gastric acid and pepsin secretion in response to histamine, pentagastrin, bethanechol, sham-feeding and feeding

This study was designed to compare gastric antisecretory effects of telenzepine, a new antimuscarinic agent, with those of pirenzepine and atropine in dogs. None of these antimuscarinics affected gastric acid secretion induced by histamine but all of them caused a dose-dependent inhibition of acid secretion from the gastric fistula (GF) and Heidenhain pouches (HP) stimulated by pentagastrin and bethanechol, telenzepine being 5-9 times more potent than pirenzepine and equipotent with atropine. All antimuscarinics were also effective inhibitors of acid responses to sham feeding and ordinary feeding. The inhibitory effect of telenzepine and pirenzepine were not accompanied by any major alterations in plasma gastrin or somatostatin but those of atropine were related to significant increase in plasma gastrin and to significant decrease in plasma somatostatin levels, suggesting the involvement of M2 receptors in the cholinergic control of these hormones. All three antimuscarinics were effective inhibitors of pepsin secretion induced both from the GF and HP by all secretagogues used. Neither telenzepine nor pirenzepine administered in various doses affected the heart rate while atropine caused a significant increase in heart rate confirming that the former agents are selective M1 receptor antagonists. This study provides evidence that telenzepine is more potent than pirenzepine in the inhibition of gastric secretion induced by pentagastrin, bethanechol, sham-feeding and ordinary feeding and that, unlike atropine, it does not increase plasma gastrin responses to meat feeding. In fact, telenzepine and pirenzepine alike reduced plasma gastrin concentrations under these conditions. No influence of these antimuscarinics on plasma somatostatin levels was observed.

Effects of non-peptidal CCK receptor antagonist (L-364,718) on pancreatic responses to cholecystokinin, gastrin, bombesin, and meat feeding in dogs

Postprandial pancreatic secretion results from the interaction of neural and hormonal factors but their contribution to the net postprandial secretion is unknown. Recent description of highly specific and potent cholecystokinin (CCK) receptor antagonists allows the determination of the physiological role of CCK in the postprandial pancreatic secretion. In six dogs with chronic pancreatic fistulae, the blockade of CCK receptors by non-peptidal agent (L-364,718) caused little change in basal pancreatic secretion, but decreased significantly (p less than 0.05) by about 60% the pancreatic protein response to meat feeding and virtually abolished the pancreatic responses to CCK-8 and bombesin. The pancreatic protein responses to pentagastrin, reaching about 37% of CCK maximum, was also significantly reduced but this effect was less pronounced than that observed in tests with CCK-8 or bombesin stimulation. In contrast, cholinergically stimulated pancreatic secretion, reaching about 40% of CCK maximum, was unaffected by L-364,718. Cholecystokinin antagonism also failed to affect the postprandial and bombesin induced increments in plasma CCK and gastrin concentrations, but significantly reduced the PP responses to CCK-8 bombesin and meat feeding possibly as a result of the removal of the CCK mediated release of PP. We conclude that CCK plays a crucial role in the mediation of the postprandial and bombesin induced pancreatic secretion and in the PP release.

Effect of cholecystokinin receptor antagonist on pancreatic responses to exogenous gastrin and cholecystokinin and to meal stimuli

Exocrine pancreatic response to food is believed to result from the interaction of neural and hormonal factors, but their contribution in the net postprandial secretion is unknown. Recent description of a highly specific and potent cholecystokinin (CCK)-receptor antagonist permitted the evaluation of the physiologic role of CCK in postprandial pancreatic secretion. In dogs with chronic pancreatic fistula, CCK antagonism caused little alteration in sham feeding- or urecholine-induced pancreatic protein secretion, but reduced by approximately 60% the pancreatic protein response to a gastrointestinal meal and virtually abolished the pancreatic responses to duodenal perfusion with amino acids or oleate and to exogenous CCK, but not to secretin or neurotensin. The pancreatic protein responses, particularly to lower doses of gastrin, were also reduced by CCK-receptor antagonist, but no changes in the responses to secretin or neurotensin were detected. Cholecystokinin antagonism also significantly reduced the pancreatic polypeptide responses to CCK, gastrin, and the gastrointestinal meal, possibly due to removal of the CCK-mediated release of pancreatic polypeptide. We conclude that CCK plays a crucial role in the mediation of the gastrointestinal phase, but not the cephalic phase, of pancreatic secretion.

Transplacental stimulation of functional and morphologic fetal rabbit lung maturation: effect of thyrotropin-releasing hormone

We investigated the effect of maternally administered thyrotropin-releasing hormone on functional and morphologic fetal lung maturation. Thyrotropin-releasing hormone (40 micrograms/kg/day) or the vehicle was injected intravenously into the New Zealand White rabbit does on days 25, 26, and 27 of gestation. On day 27 of pregnancy, the does were killed and the fetuses were delivered. The functional pulmonary maturity was assessed by pressure-volume hysteresis while morphologic maturity was assessed by histologic techniques. Enhanced functional and morphologic fetal lung maturation was noted in animals treated with thyrotropin-releasing hormone when compared with controls. An important role of thyrotropin-releasing hormone in fetal lung maturation is proposed.

The fetal heart insulin receptor responds differently to varying plasma insulin concentrations

We investigated in vivo the effect of varying plasma concentrations of insulin on the 28- and 30-day-old fetal rabbit heart insulin receptors using plasma membranes. Alloxan induced maternal diabetes (n = 5) associated with fetal hyperglycemia and mild hyperinsulinemia (59.80 +/- 8.10 microU/ml versus a control of 26.25 +/- 3.70, p less than 0.01) increased the insulin receptor number from a control (30 d) of 168 +/- 1.01 to 320 +/- 34 X 10(10)/mg protein (p less than 0.01). Fetal administration of 1.0 U of insulin (n = 4) resulting in normoglycemia and moderately high plasma insulin concentrations (103.3 +/- 34.63 microU/ml versus a control of 13.72 +/- 1.60, p less than 0.05) did not alter the insulin receptor number (28 d). On the other hand fetal administration of 2.0 U of insulin (n = 4) resulting in hypoglycemia and severely high plasma insulin concentrations (288.3 +/- 51 microU/ml versus a control of 13.72 +/- 1.60, p less than 0.01) decreased the insulin receptor number from a control (28 d) of 200 +/- 23 to 82 +/- 23 X 10(10)/mg protein (p less than 0.01). The receptor affinity remained constant. We conclude that the downregulation (decrease) of the fetal heart insulin receptors in vivo is not a physiologic but a pharmacologic effect of insulin.

Properties of antisera against lymphocytes of nude mice

The activity of rabbit antisera against nu/nu BALB/c lymphocytes was estimated in vivo and in vitro. It was found that anti-lymphocyte serum (ALS) against nu/nu lymph node cells suppressed the alloantigen reaction and the spontaneous rosette-forming cell (sRFC) or plaque-forming cell (PFC) formation for T-dependent (sheep red blood cells) and T-independent (lipopolysaccharide) antigens. ALS against nu/nu spleen cells affected only the sRFC and PFC for T-independent antigen. The former serum exhibited a high cytotoxicity for the suspensions enriched or depleted in B cells, while the latter was more cytotoxic for the suspension enriched in B cells. This may indicate that ALS anti-nu/nu spleen cells is specific for B lymphocytes, and ALS anti nu/nu lymph node cells is directed not only to B cells but also to a subpopulation of T lymphocytes. It may suggest the existence of a subpopulation of T lymphocytes in nu/nu lymph node cells.