Vestibular and cochlear efferent neurons in the monkey identified by immunocytochemical methods

Attempts were made to identify vestibular (VEN) and cochlear (CEN) efferent neurons in the squirrel monkey using retrograde transport of horseradish peroxidase (HRP) and immunocytochemical methods. HRP implants in the ampulla of the lateral semicircular duct retrogradely labeled cells of VEN bilaterally and some cells of CEN. VEN located lateral to the rostral part of the abducens nucleus formed a compact collection of cells, all of which were immunoreactive only to antisera for choline acetyltransferase (ChAT). CEN, identified by immunoreactivity to ChAT were located at the hilus of the lateral superior olive (LSO), along the lateral border of the LSO and sparsely near lateral parts of the ventral trapezoid nucleus (VTN). A small number of cells and fibers near the border of the VTN and lateral to the LSO were immunoreactive for leucine enkephalin (L-ENK). Fibers immunoreactive for L-ENK also were identified in the hilus of the LSO. No cells of the superior olivary complex were immunoreactive for antisera to ChAT, L-ENK, substance P, gamma-aminobutyric acid or glutamic acid decarboxylase. Cells of VEN and CEN can be identified by their immunoreactivity to ChAT, and some cells and fibers of CEN also contain L-ENK.

Expression of biologically active human interleukin 1 subpeptides by transfected simian COS cells

"Interleukin 1" (IL-1) is a term used to describe the family of macrophage-derived proteins that mediate many immune and inflammatory reactions. We have previously described the molecular cloning and sequencing of the cDNA encoding the predominant (neutral) form of human IL-1, which has been designated IL-1 beta. We report here that transfection of simian COS cells with this cDNA clone results in the transcription of IL-1 mRNA and the synthesis of antibody-neutralizable intracellular IL-1 biological activity. In addition, selective deletion of regions of the IL-1 cDNA judged not to be essential for function, on the basis of conserved sequence homology, resulted in localization of a "core" region responsible for a majority of the biological activity. These results permit mapping the active site of IL-1 to a peptide of 6970 molecular weight located within the carboxyl third (between Met-136 and Gln-197) of the IL-1 precursor.

A crossed polaroid-pinhole device

The study describes the use of a pinhole device in which the light-absorbing area surrounding the holes is varied by polarizing filters. The study demonstrates that a pinhole aperture of 1.6-1.8 mm in diameter with polaroids crossed at 90 degrees will allow a visual acuity equal to or better than 20/40 in the face of refractive errors of 1, 2, and 3 diopters. The study next evaluates the effects of pinholes of different sizes and the polarizing components crossed at angles less than 90 degrees. The study concludes by showing that polaroids crossed at between 75 degrees and 85 degrees allow a greater depth of focus, a larger visual field, and greater illumination than traditional pinhole devices.

Interaction of estrogen receptor isoforms with immobilized monoclonal antibodies

High-performance liquid chromatography was performed to separate the various isoforms of estrogen receptor from human breast cancer, based on size (high-performance size-exclusion chromatography) and surface charge (high-performance ion-exchange chromatography) properties. The ability of these isoforms to interact with the monoclonal antibodies was assessed. All isoforms exhibited similar immunodeterminant sites, but when they are bound to [125I]iodoestradiol-17 beta (IE), only 30% binding of the radioactive complex to the immobilized monoclonal antibodies was observed. However, the mass of the receptor recognized by the antibody bead, via the estrogen receptor-enzyme immunoassay (ER-EIA), was always significantly higher. This was true for both fractionated and non-fractionated cytosols, suggesting that non-ligand binding forms, such as precursors and products of the estrogen receptor, were also recognized; or the ligand was only selecting for a particular conformer(s); or the monoclonal antibody on the bead recognized other proteins associated with estrogen receptor. Ion-exchange fractionation of unlabeled receptor showed loss of immunodeterminant sites. However, size-exclusion fractionation did not show this effect. Diethylstilbestrol, a competitor of IE binding, showed marked stability of receptor recognized by ER-EIA during both size-exclusion and ion-exchange chromatography. Limited trypsin treatment of the receptor caused the loss of immunodeterminant sites without altering the ligand binding sites. Thus, proteolysis of estrogen receptors in cytosols of human breast cancer could easily lead to underestimation by ER-EIA. Although the components with immunodeterminant sites recognized by ER-EIA were always eluted with the ligand-binding isoforms of the estrogen receptor, our data suggest that the concentration of the protein having the epitope associated with the monoclonal antibody is unequal to that recognized by the steroid ligand. We conclude that application of ER-EIA to clinical assays of estrogen receptors clearly needs further clarification.

High density lipoprotein subpopulations in chronic liver disease

Severe liver disease may be associated with a reduction in plasma concentration of high density lipoprotein and an impairment of plasma cholesterol esterification. These changes were confirmed in two patients with severe acute on chronic alcoholic liver disease. In five additional patients with biopsy-proven clinically compensated cirrhosis, there was minimal reduction in concentration of plasma cholesteryl esters; there was, however a reduction of the plasma high density lipoprotein concentration to only 48 to 66% of normal. The particle size distribution of high density lipoprotein in these five patients was determined by gradient gel electrophoresis. The high density lipoprotein2 subfraction was preserved. The high density lipoprotein3 subfraction, however, was markedly changed with a reduction in the normal particles of radius 4.3 m and an accentuation of smaller particles of radius 3.9 m; in two patients, these smaller particles were the major high density lipoprotein subpopulation. Further investigations of this finding of a distinctive distribution of high density lipoprotein subpopulations in patient with chronic liver disease may provide new insights into high density lipoprotein metabolism.

Hemodynamics after autogenous, interpositional grafting in small arteries

This investigation initiates the quantitative, hemodynamic assessment of interpositional grafts in small rat arteries. The left femoral arteries in 16 Sprague-Dawley rats were transected at two levels, and were then repaired using interrupted suturing technique. This effectively provided an ideally sized and histologically matched interposition graft. The 20-MHz PUDVM method was used to measure blood velocities, and derive values for vessel lumen area, temporal mean of the spatial mean velocity (Vsm), and volumetric flows. Measurements were completed distal to the interposed graft. Variables were quantitated in the preoperative and at the 5-, 15-, and 30-minute postoperative intervals. Statistical analysis of data indicated that the interpositional grafting procedure resulted in increased vessel lumen area and decreased Vsm, but, importantly, volumetric flow (about 8.20 ml/min) remained unchanged. This study demonstrated that, although hemodynamic characteristics are altered, volumetric flow can be restored after an experimental, interpositional grafting procedure in small arteries.

The origin and innervation of the adductor pollicis muscle

A gross dissection of twenty human adductor pollicis muscles indicated an extensive origin of both the transverse and oblique heads. The origins included the second, third, and fourth metacarpal bones and the capitate, trapezoid, and trapezium bones. Soft tissue origins included intermetacarpal ligaments and the anterior fascia of palmar interosseous muscles. An interfascicular dissection of the deep branch of the ulnar nerve within the substance of the adductor pollicis muscle revealed three distinct patterns of terminal branching to the transverse and oblique heads, and to the first dorsal interosseous muscle.

Does phenobarbital protect against trimethyltin-induced neuropathology of limbic structures?

Because of the similarity in the pattern of limbic sites damaged by both compounds, it has been suggested that trimethyltin (TMT) may be an excitotoxin like kainic acid (KA). KA produces seizures which eventually result in neuronal damage similar to that found in epilepsy. Anticonvulsants reduce both the seizures and pathology associated with KA. Because TMT may also produce seizures, we undertook to determine whether or not some of the TMT-induced limbic neuropathology could result from seizure activity. To do this, a single dose of TMT chloride (either 7.5 or 15 mg/kg) was given per os to rats, and then phenobarbital (30 mg/kg) was administered subcutaneously in repeated doses. Treatment with phenobarbital did not prevent pathologic changes in the hippocampus, dentate gyrus, and pyriform or prepyriform cortex. Since phenobarbital did not protect against TMT-induced neuronal damage, as it has been reported by others to protect against KA-induced damage, the present findings suggest that these two toxicants probably produce hippocampal pathology via different mechanisms and that the TMT-induced pathologic changes do not require sustained electrical seizure activity.

Histopathology of microvenous repair

The histopathology of microvascular repair was investigated in the femoral vein of the rat. Previous microvascular repair studies have primarily involved arteries, giving little insight to similar processes in veins. In our study, 36 rats with an average weight of 440 gm were randomly assigned to experimental groups of 1 hour, 24 hours, 2 weeks, and 4 weeks after repair. Histological evaluation of the suture site included the use of light, scanning electron, and transmission electron microscopy. Endothelial loss was observed in all 1-hour specimens. Extensive inflammatory response appeared in 2-hour specimens. Re-endothelialization of the intima was achieved in all animals by the 2-week time interval. At 4 weeks, the animals exhibited evidence of medial regeneration of smooth muscle cells. This was predominantly occurring between adjacent suture sites. Minimal subintimal hyperplasia was localized at the suture site itself in both 2- and 4-week specimens.

The dorsal tegmental nucleus: an axoplasmic transport study

The afferent and efferent connections of the dorsal tegmental nucleus (DTN) were studied in the rat using axoplasmic transport techniques. Horseradish peroxidase (HRP) and Fast Blue were injected stereotaxically into either pars centralis or pars ventromedialis of the DTN, two subdivisions of the nucleus with distinctive connections. The pars centralis is reciprocally connected with the ipsilateral lateral mammillary and interpeduncular nuclei; these projections constitute the major afferent and efferent systems of the DTN. Commissural fibers from the corresponding pars centralis and intrinsic fibers systems are massive and form a complex fiber meshwork within the subnucleus. The prepositus hypoglossi nucleus (ipsilateral) and supragenualis nuclei (bilateral) also project to the pars centralis. Smaller numbers of afferent fibers arise from the lateral habenular nucleus, the posterior hypothalamus and the brainstem reticular formation. The pars ventromedialis of the DTN receives diverse inputs which include the septal nuclei, diagonal band of Broca, preoptic area, anterior and lateral hypothalamus, lateral and medial habenular nuclei, medial mammillary nucleus and many nuclei of the brainstem reticular formation. Based on the differences of connections and cytoarchitecture between the pars centralis and the pars ventromedialis, the pars ventromedialis may be an entity separate from the dorsal tegmental nucleus.

The natural history of colorectal carcinoma in adolescents

The symptoms, histology, extent, and course of disease of 24 adolescents with colorectal carcinoma who were admitted to St. Jude Children's Hospital between 1964 and 1980 are presented. Twenty of the patients were referred between October 1974 and June 1980. Most patients presented with vague abdominal complaints. Twenty-one of the 24 patients had poorly differentiated mucin-producing adenocarcinoma. Extensive disease at diagnosis and unresponsiveness to medical management was reflected in the eight-month median survival from diagnosis. Only two of the 24 patients survive free of disease 15 and 130 months from diagnosis. Two other patients survive with disease at four and 24 months.

Peripheral blood blast cell progenitors in human preleukemia

Progenitors of blast cell colonies have been identified in acute leukemia. The peripheral blood of 18 of 25 patients with preleukemic states yielded low numbers of blast cell colonies, and the colony-forming cells were in an active proliferative state when assessed using short-term exposure to tritiated thymidine. The clinical significance of blast cell colonies is uncertain, but we suggest that further analysis of this cultural abnormality may lead to a better understanding of mechanisms and management in preleukemia.

The effects of cyclophosphamide, azathioprine, and 6-mercaptopurine on oocyte and follicle number in C57BL/6N mice

Cyclophosphamide, azathioprine and 6-mercaptopurine were studied for oocyte and follicle toxicity in a murine ovarian toxicity assay system. Seven days after a single treatment with cyclophosphamide (100 mg/kg ip), 63% of the primordial follicles and 0% of the growing or large follicles and their oocytes were destroyed in four week old C57BL/6N mice. Treatment with azathioprine (100 mg/kg/day ip x 9 days) or 6-mercaptopurine (100 mg/kg/day ip x 9 days) suppressed weight gain and increased mortality but had no effect on the number of oocytes or follicles in these mice. These data are consistent with previous observations on the effects of cyclophosphamide, azathioprine and 6-mercaptopurine on human ovarian toxicity. This suggests that the murine ovarian toxicity assay system may be useful in evaluating xenobiotics, including drugs, for human ovarian toxicity.

Primary malignant tumors of the stomach in children

Primary malignant tumors of the stomach are rare in children. During the years 1952--1977, eight children were seen at Childrens Hospital of Los Angeles with primary malignant tumors of the stomach. The patients were between the ages of 20 mo and 17 hr and included 5 males and 3 females. The series consisted of 3 malignant lymphomas, 2 adenocarcinomas, 2 leiomyosarcomas, and 1 rhabdomyosarcoma of the stomach. Three patients are living and five are dead. Clinical histories, treatment and pathologic findings are described along with a review of the literature and recommendations for the management of primary gastric malignancies in children.

The kinetics of in vitro reoxidation and reduction of the inter heavy--light chain disulfide bond in an unusual murine immunoglobulin G myeloma protein lacking inter-heavy chain disulfide bonds

After 5 years of subcutaneous transfer in Balb/C mice, our MOPC 173 myeloma tumour line (originally an IgG2a,κ H2L2-producer) exclusively synthesized an unusual IgG2b,κ protein lacking inter-heavy (H) chain disulfide bonds. This protein was designated MOPC 173B. On sodium dodecyl sulfate – polyacrylamide gel electrophoresis, it migrated with an apparent molecular weight of 77 000; following complete reduction and alkylation, the mobilities of its constituent H and light (L) chains were found to differ slightly from those of MOPC 173 H2L2. MOPC 173B was serologically identical to another typical IgG2b,κ myeloma protein, MOPC 195, and peptide mapping studies showed that it possessed only the inter H–L disulfide bond characteristic of typical IgG2b,κ proteins. In a nondissociating solvent, the sedimentation coefficient of the protein was 6.3S even at concentrations as low as 0.2 mg/ml, indicating that noncovalent interactions existed between two half-molecule subunits. Since this unusual IgG myeloma protein contained only a single category of interchain disulfide bridge, the inter H–L bond, it was an ideal model system for characterization of the kinetics of formation and reduction of interchain disulfide bonds. The kinetics of the glutathione-catalyzed reoxidation of the inter H–L disulfide bridge in MOPC 173B followed an apparent second-order rate equation. In contrast, reduction of its inter H–L bridge under anaerobic conditions with dithioerythritol in excess, was strictly a first-order process and not a simple reversal of the reoxidation. These studies provide the basis for the more complex mathematical models that describe the reoxidation and reduction of typical immunoglobulin molecules.

Glucose effect on respiration: possible mechanism for capacitation in guinea pig spermatozoa

Guinea pig sperm respiration was determined in minimal capacitation medium (MCM) with different energy sources. The ZO2 observed for spermatozoa suspended in media containing pyruvate and lactate was 35.7 +/- 5.9, pyruvate alone, 27.9 +/- 3.8 and D-glucose alone 3.4 +/- 1.1. When D-glucose was added to spermatozoa rapidly respiring in media containing pyruvate as the only exogenous energy source, an immediate suppression in respiration was observed. Further reduction was caused by continued addition of D-glucose. Fructose and mannose also produced a suppression in respiratory rate. However, lactose, fucose, sucrose, L-glucose, and galactose did not alter the respiratory rate. The suppression of respiration by metabolizable sugars is paralleled by a suppression of acrosome reaction in guinea pig spermatozoa. The possibility that suppression of respiration is the mechanism for retardation of capacitation and the subsequent acrosome reaction by D-glucose and other metabolizable sugars is suggested.

Effects of Aureomycin on bile acids in rats

Primary BA's secreted into the duodenum are extensively altered by bacteria in the large intestine. Such changes are not found in GF animals. As a result, GF rats reabsorb BA much more efficiently than do CV controls, and BA and cholesterol pools are higher in GF than CV rats. This indicates the importance of the intestinal flora in the homeostasis of cholesterol metabolism. Antibiotics can affect the extent to which BA's are altered by bacteria. In some cases, the antibiotic treatment also affects cholesterol levels in serum or liver. We have found that treatment of CV rats for only 5 days with low levels of Aureomycin (0.85 micron) led to a predominance of omega-MC over HDC in the feces at 10 days after withdrawal of the antibiotic. This reduced the usual HDC/omega-MC ratio from approximately 2.0 to 0.9 or less. These rats were also found to have liver cholesterol levels modestly elevated over those of controls. In other experiments the decrease in hyodeoxycholate/omega-muricholate ratio was found to persist for at least 90 days after discontinuation of treatment. Later experiments carried out with Aureomycin and with penicillin revealed the possible existence of a resistance factor to Aureomycin. A significant lowering of the hyodeoxycholate/omega-muricholate ratio was now found only with antibiotic concentrations 10 to 100 times greater than those used previously. Possible implications of the persistence of antibiotic effects, as measured by changes in fecal BA's, include effects on vitamin metabolism, colon cancer, and cholesterol metabolism.

Effect of autoclaving of a lactose-containing diet on cholesterol and bile acid metabolism of conventional and germ-free rats

Feeding of lactose in amounts comparable to the adult human intake in developed countries (6% of diet, and in later studies 10%) had no major effect on cholesterol and bile acid metabolism of germ-free and conventional rats. However, when lactose-containing casein-starch diets were sterilized by autoclaving, changes in intestinal and/or fecal bile acids were found. Both germ-free and conventional rats demonstrated some increase in intestinal beta-muricholic acid concentrations ascribable to the mere presence of lactose in the diet. Autoclaving of the diet produced additional changes, especially in the fecal bile acid pattern of conventional rats. Here the ratio between the beta-muricholic-derived secondary bile acids hyodeoxycholic and omega-muricholic acids changed from the usual 5:3 to approximately 1:10, with omega-muricholic acid becoming the major fecal bile acid. These changes point to a notable effect of lactose-derived products, formed during steam-sterilization, on the microbial modification of intestinal bile acids in the lower gut. Similar changes have been observed after oral administration of aureomycin and other, unrelated antibiotics that inhibit growth of gram positive organisms.

Effect of dietary lactose at levels comparable to human consumption on cholesterol and bile acid metabolism of conventional and germfree rats

In recent years, the use of milk products and the concomitant intake of lactose have been tentatively linked to the etiology of cardiovascular disease. An effect of lactose on the microbial modification of acid and neutral sterols has been suggested. In the present study lactose intake, ranging up to 30% of total diet increased beta-muricholic (beta-MC) but not cholic acid concentrations in conventional (CV) rat small intestine to the extent that at the 20% and 30% intake level, the intestinal cholic: beta-MC ratio approached that in germ-free (GF) rats. Total intestinal bile acid (BA) content increased by approximately 1/3, but remained at less than half the value found in GF rats. At lactose intake levels within a range corresponding to the consumption of dairy products often recommended for adult man (5% to 10%) only moderate changes in intestinal, and little change in fecal BA were found during and after the 3 months experimental period. Intestinal beta-MC was increased in the presence and in the absence of an intestinal microflora. Experiments with GF rats fed 10% lactose or 10% maltose indicated that this increase is evoked similarly by both carbohydrates. The slight increase in serum cholesterol levels seen with disaccharide feeding, which became evident only in the GF rats, was again not specific for lactose. No influence was found of lactose feeding on liver cholesterol values. Comparison of CV rats fed nonsterile and radiation-sterilized lactose-containing diets suggested that this mode of sterilization has only a minor influence on the resulting data. When GF experiments are to be incorporated, sterilazation of diet by irradiation with 3.5 to 4.0 X 10(6) Rad is preferable to autoclaving. The present data indicate that no major effect specifically related to a normal dietary intake of lactose on cholesterol and BA metabolism of the adult rat could be demonstrated for the duration of these experiments.