[Functional and morphological characteristics of coronary vessels in varying degree of coronary perfusion].

Limitation of coronary perfusion of different degree induces inhomogeneous changes in resistance of vessels in the hypoperfusing zone: an adequate dilatory regulatory reaction may be followed by an increase in resistance of the coronary vessels. An active component of diastolic coronary resistance used to analyze vascular reactions, rate and character of changes in resistance under conditions of coronary perfusion as well as histological and electron-microscopic estimation of the vascular wall state testify to reversibility and active character of the observed changes in coronary resistance including its increase. This increase is pathogenetically significant as it may induce further development of the coronary perfusion disorder.


[Aging-related characteristics of the secretory response of the stomach to stimulation of its mechanoreceptors].

Age peculiarities of the gastric secretory response to the mechanical stimulation have been studied in thirty-one healthy subjects aged 60-79 and ten healthy subjects aged 20-35 (a control group). The secretory response of the gastric glands to mechanical distention of the stomach with 600 ml of water is found to decrease with aging. No changes in gastrin concentration in plasma during balloon distention have been revealed, so this confirms the hypothesis that stimulation of acid secretion by distention is mediated by reflexes without participation of the gastrin mechanism. Distention of the stomach with 800 ml of water induces significant inhibition of the acid output in subjects aged over 60. The mechanism of this reaction is not clear yet and needs further investigation.


[Effect of vibration on gamma-aminobutyric acid metabolism in the brain in various functional conditions of the adrenal cortex].

The low-frequency vibration during 30 min (20 Hz, A = 0.4 mm) has been studied for its influence on the level of components of the GABA system and dicarbonic ++amino acids in male rats at hypo- and hyperfunction of the adrenal cortex. It is shown that under these conditions of the experiment the GABA level and glutamate-decarboxylase activity increase. Hyperfunction of the adrenal cortex against the background of vibration causes a relatively less pronounced increase in the GABA content, than the vibration alone or against the background of inhibition of adrenocortical function in the organism.


[Participation of cholecystokinin and pentagastrin in the regulation of the liver blood supply and oxygen consumption].

Cholecystokinin and pentagastrin cause predominantly the dilatation of mesenterial, intrahepatic arterial and portal vessels. The short-term amplitude-expressed changes in the vascular blood flow followed by less intensive long-term ones are observed. The amplitude of short-term reactions in these vascular regions is different and depends on the place of hormone injections. Cholecystokinin and pentagastrin in the same series of experiments decrease and increase the oxygen consumption by the liver depending on its functional state. It is supposed that correction of the oxygen supply of hepatocytes by the action of pentagastrin is realized due to changes in the blood flow in the liver artery, and under the cholecystokinin effect it is made by the change of the oxygen extraction.


[Effect of extremely low frequency magnetic fields on time-related pattern of metabolism of thiol groups and products of lipid peroxidation in the brain of mice].

The influence of extremely low-frequency magnetic fields on lipid peroxidation products and total thiol groups in the brain of mongrel mice has been investigated. Certain changes in time organization and interrelation of the studied processes under the effect of the magnetic field depending on frequency are shown.


[Biological mechanism of long-term effect of alternating electric field on the development of mice].

The method of principal components has been used for the quantitative analysis of 50 histomorphological indices of physiological state of white mice males subjected to the action of the alternating electric field in dynamics of their postnatal development. The theoretical analysis of the results obtained permits supposing that the alternating electric field disturbs proliferation and differentiation under its chronic action on the organism of mammals.


[Diphasic effect of thyrotropin on the uptake and absorption of iodine-131 by thyroid cell culture].

The studies were performed on the primary culture of thyroid cells of newborn pigs. It was shown that thyroid-stimulating hormone (TSH) within the first 12th of its action inhibited uptake and organification of iodine-131. A negative influence of TSH on 131I uptake was retained both with its simultaneous introduction into the culture medium and with 30 min interval as well as when conducting experiments on the 1st, 3d, 5th and 7th days of cultivation. Previous 72h incubation with TSH sufficient for activation of all the links of iodine transport caused an increase in 131I uptake and organification.


[Age-related characteristics of triglyceride, secondary lipid peroxidation products and alpha-tocopherol levels in the tissues of female rats].

The content of triglycerides, secondary lipid peroxidation products and alpha-tocopherol closely related by complex functional interactions has been studied in the blood plasma, erythrocytes, liver and brain of rat females of all the age groups. The results obtained confirm an essential difference of vitamin E content in the tissues of rat females as against that in tissues of males. It may be a result of susceptibility of these parameters to endocrinic effects and of a particular functional role of alpha-tocopherol in females.


The determination of nitrate in cured meat products. A comparison of the HPLC UV/VIS and Cd/spectrophotometric methods.

A comparison of the traditional spectrophotometric method, with prior application of a reducing Cd column, and a high performance liquid chromatography method with an anion exchanging column for the determination of nitrate in spiced Spanish sausage, was carried out. Both methods demonstrated a high correlation. The chromatographic method proved more precise, reproducible and appropriate for routine work.


Deoxynivalenol in wheat and maize flour reference materials. 2. Preparation and certification.

The preparation of four cereal reference materials (two wheat and two maize) and the certification of their 4-deoxynivalenol (DON) contents is described. The materials were prepared and certified within the BCR programme of the Commission of the European Community as part of a broad activity to improve accuracy and agreement of measurements of importance in food and agriculture. Reference material RM 379 was prepared from naturally contaminated wheat four blended with 'blank' material to achieve the desired DON content. The reference material RM 378 was prepared from naturally contaminated maize identified as containing approximately the desired DON content. Details are given of the milling, blending and packaging procedure, and the checks to ensure homogeneity and stability of the materials. The reference materials RM 396 and 377 were similarly prepared from the blank wheat and maize samples respectively. The certification exercise was carried out by five laboratories (with a further two to three laboratories providing supporting data) using a variety of extraction and clean-up procedures with either high performance liquid chromatography (HPLC) or gas chromatography (GC) as the determinative stages. Wheat RM 379 was certified as containing DON at a level of 673 +/- 21 micrograms/kg and wheat RM 396 as containing less than 50 micrograms/kg. Maize RM 378 was certified as containing DON at 425 +/- 38 micrograms/kg and maize RM 377 as containing less than 50 micrograms/kg. The materials are intended for the verification of methods used to determine DON in cereal samples.


Alternative fatty food simulants for migration testing of polymeric food contact materials.

The amounts of substances migrating from plastics into foodstuffs with high fat contents are in most cases higher than in foodstuffs with water contents. This increase in migration commonly is due to the higher solubility of the migrating organic compounds in fat compared to water. The increase in migration is not necessarily due to an increase in the substance's diffusion coefficient due to interactions between the fat and the plastic as is often assumed. Ethanol is a good simulant for fatty foods because it has little interaction with many plastics, e.g. polyolefins, migrants are readily soluble in it, and because it is easy to work with analytically. The utilizable limits of ethanol and ethanol/water mixtures as food simulants are developed from the physical background of diffusion. The use of ethanol and ethanol/water mixtures is supported by published experimental migration results.


Determination of total non-sulphonated aromatic amines in soft drinks and hard candies by reduction and derivatization followed by high-performance liquid chromatography.

Utilizing elements of methodology developed previously for food colours, total free and bound non-sulphonated aromatic amines (NSAA) were determined in commercial samples of soft drink beverages and hard candies. Bound amines in the samples were reduced using sodium dithionite, then total NSAA were extracted into chlorofom, transferred to aqueous acid solution and diazotized with sodium nitrite before coupling with 2-naphthol-3,6-disulphonic acid, disodium salt (R-salt). The coloured derivatives were analysed using reversed-phase ion pair high-performance liquid chromatography (HPLC) and an absorbance detector set at 512 nm. Solid phase extraction cartridges were utilized for extraction and clean-up of the food colours present in the sample, and the concentration of each dye was determined quantitatively using HPLC and absorbance detector wavelengths of 426, 516 or 625 nm. Levels of total NSAA were compatible with those observed previously in food colours. Commercial soft drinks were found to contain (expressed in terms of total free plus bound NSAA in the beverage) 0.19-12.6 ng/ml of aniline, 0.83-8.25 ng/ml 1-naphthylamine and 0.62-1.12 ng/ml 2-naphthylamine. Levels of 0.66-9.15 ng/g of aniline and 2.48-10.6 ng/g 1-naphthylamine were found in commercial samples of hard candies. Bound NSAA in hard candies appeared to survive the manufacturing process. Recoveries averaged 96.9% for tartrazine and 89.6-97.2% for the bound amines when hard candies were prepared in the laboratory.


Practical gloving and handwashing regime for dental practice.

The debate concerning the re-use of gloves in dental practice continues, despite the fact that recent guidelines on cross-infection control recommend that a new pair of gloves should be used for each patient. Whichever policy for glove use is adopted, it is important to take the maximum possible precautions in hand care. This paper presents a practical regimen for hand/glove washing which is simple, quick and effective. The importance of establishing a hand-care regimen in dental practice is emphasised.


A method for the determination of methyl carbamate and ethyl carbamate in wines.

A method is described for the simultaneous determination of methyl carbamate (MC) and ethyl carbamate (EC) in wines that is based on: (a) extraction of the sample with dichloromethane using an extraction tube or an alumina-Celite column, (b) concentration of the extract to a small volume, and (c) determination by gas-liquid chromatography-thermal energy analyser (N-mode). The method is highly sensitive (1-2 ng/ml), accurate (recoveries greater than 80%), and precise (CV, 5-10%). Nineteen of 27 samples of wines analysed contained traces (up to 2.7 ng/ml) of MC, and most contained EC (up to 70 ng/ml). Wines treated in the laboratory with 200 ppm dimethyl pyrocarbonate (DMPC)-a cold sterilant recently approved for use in wines-indicated that such a treatment may increase the MC contents of the wines to 10 ng/ml. Additional studies suggested that formation of MC in DMPC-treated wines is dependent on both pH and ammonia content of the wines. The identity of MC in a few selected samples was confirmed by gas-liquid chromatography-high resolution (10 K) mass spectrometry. The natural low levels of MC found in these wines are not considered to pose a risk to human health.


Determination of butyltin, cyclohexyltin and phenyltin compounds in beers and wines.

Butyl- cyclohexyl- and phenyltin compounds were extracted from enzymically-hydrolysed wine and beer samples with 0.05% tropolone in pentane. Methyl derivatives were made by Grignard reaction for determination by gas chromatography-atomic absorption spectrometry. Wine and beer samples contained less than 0.1 to 160 nl/ml of butyltins from an undetermined source of contamination. GC-MS confirmation of butyltins also detected phenyltin, and di- and tricyclohexyltin compounds at levels less than the GC-AAS based method detection limits of 0.05-0.13 ng Sn/mL.


The evaluation in the Ames test of the mutagenicity of tetrahydro-beta-carboline-3-carboxylic acids from smoked foods.

This paper reports the evaluation of five tetrahydro-beta-carboline carboxylic acids, formed from the interaction of woodsmoke carbonyls and tryptophan, for mutagenicity in the Ames test. Three of the compounds tested have been detected recently in smoked foods at levels in the micrograms/kg or mg/kg range. None of the compounds induced mutagenicity in TA 97, TA 98 or TA 100 strains of Salmonella typhimurium either with or without prior activation. However, tetrahydro-beta-carboline-3-carboxylic acid, and to a lesser extent 1-methyl-tetrahydro-beta-carboline-3-carboxylic acid were toxic to the strains of Salmonella typhimurium used. The inability of these beta-carbolines to induce mutation contrasts markedly with the mutagenicity of some beta-carbolines found in grilled meat products.


Lamellocyte differentiation in Drosophila larvae parasitized by Leptopilina.

The presence of Leptopilina heterotoma or Leptopilina boulardi eggs in the hemocoel of a Drosophila melanogaster larva induces the differentiation of lamellocytes, the blood cells that encapsulate foreign objects. L. boulardi eggs are encapsulated by the newly differentiated lamellocytes, but L. heterotoma eggs are not. The induced lamellocytes in host larvae with L. heterotoma eggs undergo the same destructive morphological changes as reported previously for lamellocytes present in melanotic tumor mutant larvae at the time of parasitization. Thus, the virus-like particles produced by the L. heterotoma female to protect its eggs from encapsulation do not block the differentiation of lamellocytes, but rather destroy lamellocytes whenever they are present in the hemocoel.


Agglutinin activity in Pacific oyster (Crassostrea gigas) hemolymph following in vivo Vibrio anguillarum challenge.

Hemolymph from the Pacific oyster (Crassostrea gigas) contains lectins that agglutinate horse (Gigalin E) and human (Gigalin H) erythrocytes. The gigalins also agglutinate bacteria, including Vibrio anguillarum, and were adsorbed from oyster hemolymph at different temperatures by living, heat-killed, and freeze-dried V. anguillarum cells. Baseline activities of the two gigalins were established by measuring their activities in oyster hemolymph over a period of 4 years. A normal distribution of Gigalin H activity (mean titer 139) was found, whereas the distribution of Gigalin E activity in the same samples was skew (mean titer 512). No covariance was observed between the two agglutinin activities. Increased lectin activity above this baseline was found in oysters exposed for varying time intervals to V. anguillarum at different seasons and temperatures over a period of 2 years. Such exposure resulted in an increase in activity (titer) of four- to nine-fold for Gigalin E and three- to seven-fold for Gigalin H when compared with controls, and in augmentation in the hemolymph of a protein with the same electrophoretic mobility as affinity-purified oyster lectins (gigalins). Challenge with either living or heat-killed bacteria resulted in a significant increase of Gigalin E activity, whereas results for Gigalin H were variable. Oysters challenged with bacteria were observed to filter normally with open shells during the experiments. Also, no increase was found in hemolymph calcium that could indicate anoxia following bacterial challenge (0.49 +/- 0.004 mg mL-1) compared to unexposed oysters (0.50 +/- 0.001 mg mL-1). Increase in the concentration of free amino acids in oyster hemolymph was observed following exposure to bacteria (15.05 mM) and anaerobiosis (13.51 mM) compared to controls (9.06 mM), and changes (in mol %) of individual amino acids differed considerably between hemolymph from animals challenged with bacteria and animals kept anaerobic. The augmented lectin activity in oyster hemolymph, following in vivo exposure to increased bacteria in the seawater, suggests their involvement in enhancing bacterial clearance and defense in the oyster.


Characterization of anti-hapten antibodies generated in vitro by channel catfish peripheral blood lymphocytes.

Secondary in vitro stimulation of channel catfish peripheral blood lymphocytes with haptenated T-dependent antigen (TNP-KLH) elicited large numbers of hapten-specific Ab-producing cells and relatively high levels (10-96 micrograms/mL) of TNP-specific Ab in the culture medium. These in vitro generated Abs were compared to in vivo generated Abs from the serum of the same fish with respect to covalent structure, affinity, and isotypic composition of heavy and light chains. SDS-PAGE analysis under both reducing and nonreducing conditions revealed that the in vitro Abs were structurally similar to the serum Abs. Similarly, in vitro pulse-labeled Abs also exhibited the eight band profile characteristic of channel catfish serum Abs when run under nonreducing denaturing conditions. Scatchard analysis of equilibrium dialysis data revealed that the affinities of the culture- and serum-derived Abs were quite similar, that is, exhibited association constants of approximately 2.0 x 10(6) M-1. However, it was routinely observed that the in vitro generated Abs exhibited somewhat fewer binding sites per molecule than those derived from serum. The use of murine monoclonal Abs specifically for different isotypes of channel catfish heavy and light chains demonstrated that the isotypic composition of the culture- and serum-derived fish anti-TNP Abs were similar; exceptions occurred with cultures producing lower levels of Abs. These results strongly suggest that channel catfish in vitro Ab responses closely reflect what normally occurs in vivo.


Changes in the thymus and spleen of the turtle Mauremys caspica after testosterone injection: a morphometric study.

To confirm a possible role of sex hormones in governing the seasonal variations affecting the reptilian lymphoid organs, a morphometric analysis was carried out on the thymus and spleen of turtles, Mauremys caspica, intraperitoneally injected with a single dose of testosterone propionate (TP) at the third week of June when physiological levels of testosterone are low. At 4 and 6 weeks, control turtles show an apparent lymphocyte mobilization both from thymus and spleen with a decrease in the percentage of thymic cortex, numbers of cortical lymphocytes, and mitotic index, but increased numbers of medullary lymphocytes. In the thymic cortex of treated turtles, there is a decrease in the same parameters but they occur in the first 2 weeks, whereas the medullary lymphocytes also undergo reduction at 4 and 6 weeks. In addition, the number of reticuloepithelial cells per area unit decreases at 2 weeks in the thymic cortex of treated turtles. These results are discussed from the point of view of a biphasic effect of testosterone on turtle lymphoid organs: In the first weeks, the changes observed could be attributed to the high levels of testosterone; after 4 and 6 weeks, variations are dependent both on long-term effects of testosterone and on those induced by the high values of corticosterone occurring in summer.


Phorbol ester/calcium ionophore activate fish leukocytes and induce long-term cultures.

This study documents that phorbol ester (TPA) and calcium ionophore (A23187) in combination are potent mitogens for channel catfish peripheral blood leukocytes (PBL), stimulating both catfish T and B cells. Unlike T-cell responses to Concanavalin A (ConA), these responses to TPA/A23187 did not appear to require monocytes and were not strongly inhibited by low culture temperature. These results support the notion that catfish lymphocytes utilize the bifurcating phosphatidylinositol bisphosphate second-messenger system for transmembrane signaling during the activation process, as do mammalian lymphocytes. Furthermore, it was unexpectedly found that TPA/A23187 stimulation of normal catfish PBL reproducibly (greater than or equal to 95%) resulted in the generation of long-term leukocyte cultures that did not require restimulation or the addition of exogenous factors for continued proliferation. These TPA/A23187-induced leukocyte cultures were refractory to cloning and appeared to contain 10-40% monocytes and 50-80% putative T cells with no detectable B cells or neutrophils.


MHC dosage effects on primary immune organ development in the chicken.

Immune development in vertebrates is thought to be influenced by many factors including genotype. We used the Trisomic avian model to probe for influences of the major histocompatibility complex (MHC) on the development of the primary immune organs. Chickens were produced having two, three, and four copies of the MHC-encoding microchromosome. Studies of growth, immune organ development and structure, and lymphocyte populations were performed at three post-hatching time points. Chickens with three and four MHC copies (trisomic and tetrasomic) exhibited reduced overall growth and had smaller bursae and thymuses compared to disomic controls. However, the fold reductions in immune organ weights were much greater than for body weights. Histological analysis of the immune organs revealed dramatic alterations in follicular composition in tetrasomic bursae compared to disomic controls. No obvious alterations were observed in thymic and splenic histology of tetrasomics. Studies of organ lymphocyte numbers revealed a sharp reduction in bursal and thymic lymphocyte counts of trisomic and tetrasomic chickens. Based on these results, it appears that MHC dosage modulates, in a targeted fashion, the cellularity of the primary immune organs through an extended period in differentiation of B and T lymphocytes.


Thrombocytopenia in the HELLP syndrome is not due to platelet-associated IgG (PAIgG).

The presence of membrane-bound and circulating platelet-associated IgG (PAIgG) in nine pregnant women with hemolysis, elevated liver enzymes, and low platelet count (HELLP syndrome) was investigated. The reference group consisted of 21 patients with chronic idiopathic thrombocytopenic purpura (ITP). In the majority of patients with ITP, thrombocytopenia results from the binding of PAIgG to the platelet membrane with subsequent platelet destruction. In none of the patients with HELLP syndrome membrane-bound or circulating PAIgG was found. By contrast, membrane-bound and circulating PAIgG was detected in 15 of the 21 cases of chronic ITP (71.4%). These findings suggest that platelet destruction in patients with HELLP syndrome does not result from the binding of PAIgG to the platelet membrane. Therefore, the treatment of thrombocytopenia in this syndrome with immunosuppressants (e.g., corticosteroids), as in chronic ITP, does not seem appropriate.


Purine metabolism and B-lymphocyte development in the chicken bursa of fabricius.

The activity of three enzymes involved in the salvage pathway of purine nucleosides--purine nucleoside phosphorylase (PNP), xanthine dehydrogenase (XDH), and hypoxanthine-guanine phosphoribosyl transferase (HGPRT)--was investigated in cellular fractions of the chicken bursa of Fabricius differentially enriched in epithelial cells or lymphocytes. Markedly increasing levels of PNP and XDH were observed along with the enrichment in epithelial cells together with a slight, though significant, decrease in HGPRT activity. By contrast, a dramatic fall in PNP and XDH activities was detected along with the enrichment in lymphocytes together with a slight, though significant, increase in HGPRT activity. This sharply different distribution of the three enzymes, all sharing hypoxanthine as a substrate, clearly indicates that lymphocytes preferentially channel hypoxanthine into the salvage and interconversion pathways, phosphorylating it to IMP, while epithelial cells rapidly catabolize such a purine base to uric acid. Moreover, epithelial cells, unlike lymphocytes, are able to retain high intracellular levels of both hypoxanthine and inosine. These results support the possibility that epithelial cells contribute to the normal development of bursal lymphocytes by supplying such actively proliferating cells with purine rings and at the same time by preventing them from accumulating potentially toxic high levels of purine nucleotides being able to rapidly eliminate excess hypoxanthine as uric acid from the bursa environment into the bloodstream.


Effects of AFB1 embryonic exposure on chicken mononuclear phagocytic cell functions.

Effects of embryonic exposure to aflatoxin-B1 (AFB1) on the postnatal development of chicken mononuclear phagocytic system function was examined. Single exposure of 6-d chick embryos to 0.1, 0.5, and 1 micrograms AFB1 in 10 microL acetone was employed. Control embryos received 10 microliters solvent and sham-treated controls included embryos with a hole in the egg shell with no compound added. Aflatoxin B1 exposure caused a dose-related increase in embryonic mortality. After hatch, no differences were observed in body weight gain among treatment groups. The incidence of circulating thrombocytes was reduced in chicks exposed to the highest AFB1 dose with enhancement in monocyte and lymphocyte cell populations. Birds exposed to 1 microgram AFB1 recruited fewer macrophages in the peritoneal cavity after i.p. Sephadex elicitation along with reduced substrate adherence potential of peritoneal exudate cells. Similarly, macrophages from 0.5 and 1 micrograms AFB1-treated birds had depressed phagocytic potential. These results suggest that long-term immune depression of macrophage-mediated functions can occur following embryonic exposure to AFB1.


Ultrastructural localization of a soluble antigen in the chicken Harderian gland.

The relationship between plasma cells, macrophages, B and T cells, dendritic cells, and epithelium in the chicken Harderian gland have been studied by means of ultrastructural localization of the horseradish peroxidase following local immunization. After 5 d, peroxidase activity was found in vesicles located in macrophages and immature plasma cells. On day 7, peroxidase-antiperoxidase complexes were found in vesicles of the epithelial cells lining the secondary ducts and the acini, in the lumina of the ducts, and on the surface of lymphocytes located among these epithelial cells. Dendritic cells showing peroxidase activity on their surface were seen in the subepithelial lymphoid tissue and in the lymphoid follicles. On day 9, peroxidase activity was found as iccosomes on the surface of dendritic cells and lymphoblasts. These results indicate that immature plasma cells in the Harderian gland can take up antigen and may have a role in presenting it to T cells. Further, our results suggest that intraepithelial lymphocytes might be involved in antigen transportation from the epithelium to the subepithelial lymphoid tissue.


Monoclonal enzyme immunoassay measurement of estradiol and progesterone receptors in in vitro fertilization and spontaneous cycles.

So far, the few studies performed on endometrial steroid receptors in in vitro fertilization (IVF) cycles have been carried out by the dextran-coated charcoal (DCC) method. Despite widespread efforts to standardize the DCC assay method, assay results still vary and thus, data obtained in IVF cycles are controversial. In the present article, late luteal estradiol (E2) and progesterone (P) receptor (R) levels were measured by a new monoclonal enzyme immunoassay (EIA) method in endometrial samples obtained from 21 patients in an IVF program who received no embryo transfer (ET) after ovarian stimulation with follicle-stimulating hormone/human menopausal gonadotrophin/human chorionic gonadotrophin under pituitary suppression with buserelin. Plasma levels of E2, P and prolactin (PRL) were measured in three blood samples collected in the midluteal phase. Results were compared with those obtained in a control group of 21 spontaneous cycles. E2, P and PRL were significantly higher in stimulated than in spontaneous cycles. The level of E2R was decreased in endometrium in IVF stimulated cycles, but PR remained unchanged.


The endometrial biopsy as a predictive factor of pregnancy rate in women with unexplained infertility.

To investigate whether or not there is any relation between endometrial morphology and subsequent pregnancy rate, 47 couples with unexplained infertility were followed up for 3 years after they had had an endometrial biopsy. Each woman had an LH-timed endometrial biopsy performed in the luteal phase of the cycle. The biopsy was dated chronologically according to the luteinizing hormone (LH) surge and histologically using morphometric criteria. None of the women received any form of treatment in the endometrial biopsy cycle. Of 47 women with unexplained infertility, 36 (76.6%) (Group I) had 'in phase' endometrial development and 11 (23.4%) (Group II) had retarded endometrium. Women with normal endometrial development had a higher pregnancy rate than women with retarded endometrial development (50% vs. 9%; P less than 0.02). The fecundability during treatment cycles was higher in Group I than in Group II (0.051 vs. 0.008; P less than 0.05). In women with 'in phase' endometrium, treatment increased the monthly probability of conception (0.051 vs. 0.006; P less than 0.001). A precisely timed endometrial biopsy should be considered as part of the investigations for women with unexplained reproductive failure, to help determine prognosis.


Uterine horn replacement in the rat using denervated and devascularized jejunum.

In the hope of identifying suitable material for reconstructive tubal and uterine surgery, the authors have replaced a portion of the uterine horns of two groups of Wistar rats (n = 10) with normal (VAS group) or with denervated and devascularized jejunal grafts (NVAS group). All grafted horns stayed patent. No pregnancy was observed in the uterine horns operated on. The light microscopic appearance of the grafts was studied and compared by ANOVA. Three months after surgery in the VAS group, the number (51.4 +/- 9.5) and height (309.8 +/- 44.7 microns, P less than 0.05) of the villus, the Lieberkühn cripts height (156.9 +/- 34.9 microns) and the number of goblet cells per cript (7.2 +/- 1.2, P less than 0.05) had decreased in relation to their corresponding control jejunal fragments (57.7 +/- 5.4; 345.1 +/- 18.0 microns; 192.2 +/- 40.8 micron; 12.4 +/- 1.9, respectively). Three months after surgery, the intestinal structure was maintained in the anastomosis areas of the NVAS group, therefore the mucus production of the jejunal-graft mucosa was not completely eliminated. No villus or crypts were observed, but a monostratified cubic-cell-type epithelium at the NVAS jejunal graft mid-portion, along 58.1 +/- 12.9% of the total length of the intestinal graft. Under this epithelium a connective tissue, like a non-glandular submucosa, was apparent.


Formation of brown bodies in the coelomic cavity of the earthworm Eisenia fetida andrei and attendant changes in shape and adhesive capacity of constitutive cells.

The formation of brown bodies in the coelomic cavity may result from an aggregation of coelomocytes around offending foreign cells such as bacteria, gregarines, incompatible graft fragments, and altered self structures such as setae or necrotic muscle cells. The initial nodule rapidly increases in volume by aggregation of new coelomocytes and various waste particles. When a brown body has reached a diameter of 1-2 mm, its external cells flatten and lose their adhesiveness toward free coelomocytes or waste particles and its pigment rapidly darkens. Brown bodies play an important role in homeostasis.


Rhabdomyoma of the vagina.

A case of vaginal rhabdomyoma in 35-year-old healthy woman is presented. The lesion, a pedunculated polyp measuring 1.2 cm in diameter, was located in the anterior wall of the vagina. This is an extremely rare entity that pursues a benign course. Light and immunohistochemical features are commented and selected literature briefly reviewed.


Pregnancy in primary biliary cirrhosis.

A 34-year-old multigravid woman with symptomatic primary biliary cirrhosis (PBC) of the liver had a successful pregnancy. A healthy baby was born prematurely at 36 weeks of gestation. Six months prior to the conception of this pregnancy, stage III PBC had been diagnosed. Portal hypertension and liver cirrhosis had not developed. It is uncommon for pregnancy to occur in the presence of PBC. In the case presented, the outcome of pregnancy was good and the liver function had not been significantly affected by the pregnancy.


Organization of perinatal care within the European community.

A survey on the infrastructure and organization of maternity and neonatal services in the European Community has been conducted within the framework of the European Community Concerted Action Project 'New Methods for Perinatal Surveillance'. Objectives were to provide a basis for comparative evaluation of perinatal studies, to achieve a better understanding of differences in national perinatal services and to identify problem areas in provision of perinatal care. Data concern general maternal statistics, structure of maternity services and organization of maternity and neonatal services. Similarities between the perinatal services of the countries surveyed outweigh local deficiencies in some aspects of care and organization. Information tabulated in this survey can serve as a stimulant to reach a better understanding of current health care for pregnant mothers and their newborns within the European Community.


What cervical dilatation rate during active labour should be considered abnormal?

The present study tested the common notion of slow labour that only dilatation rates of 1 cm/h and above lead to normal (intervention free) delivery. We examined all primiparous spontaneous term labours cared for in our hospital over a 1 year period when a protocol for intervention in the case of slow dilation rate was not in place. Of 505 consecutive singleton labours, 105 (20.6%) progressed at an overall cervical dilatation rate of less than 1 cm/h. However, only those progressing at 0.5 cm/h and less (n = 52 or 10.3% of the total) had significantly increased rates of oxytocin usage and of caesarean section. The data suggest that there may be a more conservative definition of slow labour.


Blood flow velocity waveforms of the middle cerebral artery and abnormal neurological evaluations in live-born fetuses with absent or reverse end-diastolic flow velocities of the umbilical arteries.

We studied 37 fetuses with absent or reverse end-diastolic flow velocities (AREDFV) of the umbilical arteries with respect to the mode of delivery, fetal acidosis, resistance index of the middle cerebral arteries, and abnormal neurological evaluation at the time of discharge from the department of pediatrics. A control group with normal umbilical artery flow velocity waveforms was matched for gestational age. Fetuses with AREDFV were delivered almost exclusively by cesarean section, in most cases due to fetal distress. Metabolic changes with decreased base excess values were found more often in fetuses with AREDFV, but no difference could be detected with respect to severe fetal acidosis. The number of fetuses with abnormal neurological evaluations during the first 6 months of life was significantly higher in cases with AREDFV than in the control group. More than two thirds of the fetuses with AREDFV showed an abnormal blood flow velocity waveform of the middle cerebral arteries with elevated end-diastolic flow velocities. The combination of extreme premature delivery before 28 weeks of gestation, severe idiopathic respiratory distress syndrome, and a resistance index of the middle cerebral arteries under the 5th percentile seems to be a risk factor for early neurological morbidity in fetuses with AREDFV. Premature delivery of fetuses with AREDFV--as we did during our study in order to prevent intra-uterine death or fetal asphyxia--should therefore be critically regarded in cases under 28 weeks of gestational age and abnormal flow velocity waveforms of the middle cerebral arteries.


A practical approach to identification of susceptibility genes for IDDM.

Of all the common diseases that have a genetic component, IDDM is probably the most tractable to the experimentalist. Large numbers of nuclear multiplex families are available, which can be stored as permanent cell lines; diagnosis is relatively unambiguous; and a mouse strain, the NOD, spontaneously develops autoimmune IDDM similar to the human disorder. In addition, the resolution and accessibility of the human genome map has been revolutionized by the discovery and widespread application of the PCR, particularly the amplification of short, tandemly repeated segments of DNA called microsatellites, which display high levels of allelic polymorphism. With these reagents, the stage is set for dissection of the genetic factors that control the pathophysiology of IDDM.


Ambulatory blood pressure in type I diabetes mellitus. Comparison to presence of incipient nephropathy in adolescents and young adults.

AMBP measurements were obtained at 20-min intervals during the day and at 60-min intervals during the night in 38 adolescents and young adults (12-25 yr old) with type I diabetes, and in 36 healthy, nondiabetic control subjects of comparable age. The group of patients with elevated AER (greater than 15 micrograms/min) had higher mean 24-h sBP, dBP, and BPB (defined as the prevalence of systolic readings greater than 130 mm Hg or diastolic readings greater than 85 mm Hg) compared with both the group of patients with type I diabetes and AER less than 15, and the control group. The normal diurnal variation in BP and BPB was observed in the control group and the group with type I diabetes and AER less than 15, whereas the nocturnal decrease observed in the group with type I diabetes and AER greater than 15 was not statistically significant. Elevations in AMBP of the patient group with AER greater than 15 were reflected in random BP measurements. Even though the mean random BP measurements of all groups were within the normal range for age, the mean random sBP and dBP of the type I diabetes patients with AER greater than 15 was higher than both the control group and the group with type I diabetes and AER less than 15. The GFR, determined by the clearance of 99Tc-DTPA, was associated negatively with measures of AMBP and AER in the group with AER greater than 15.(ABSTRACT TRUNCATED AT 250 WORDS)


Comparison of peripheral and portal (via the umbilical vein) routes of insulin infusion in IDDM patients.

Twelve subjects with insulin-dependent diabetes mellitus were treated using continuous subcutaneous insulin infusion (CSII) and intraportal insulin infusion (IPII) via the umbilical vein for 4 mo. Glucose control improved in both CSII and IPII groups, but a decrease in glucose and HbAIc was more rapid and more significant in the IPII group than in CSII, even though insulin requirement was lower during IPII than CSII (40 +/- 2 vs. 50 +/- 2 U/day, P less than 0.05). The insulin plasma fasting levels were different (88 +/- 10.7 in the IPII group vs. 263 +/- 23 pM in CSII, P less than 0.001). High plasma levels of lactate, pyruvate, alanine, cortisol, and growth hormone were decreased in both groups, with their full normalization only in the IPII group. Glucagon concentrations were low in both groups at the beginning of the study (30.0 +/- 4.1 in the CSII group and 32.3 +/- 1.8 ng/L in IPII); they were equalized to control values in the IPII group and were low in the CSII group at the study's end (46.0 +/- 3.7 in IPII vs. 31.7 +/- 3.1 ng/L in CSII, P less than 0.05. We conclude that intraportal administration of insulin via the umbilical vein at rates of 0.01-0.05 U.kg-1.hr-1 reduces plasma levels of glucose, three carbon precursors, cortisol, and growth hormone by a direct action on the liver, and the hepatic action of peripherally administered insulin is manifested only when the infusion rate is increased to 0.1-0.3 U.kg-1.hr-1.(ABSTRACT TRUNCATED AT 250 WORDS)


Variation in sorbitol accumulation and polyol-pathway activity in cultured human proximal tubule cells.

The polyol pathway is present in tissues of several organs where its activation may participate in the development of diabetic complications. We measured the accumulation of polyol-pathway intermediates in HPT cells isolated from 21 different human kidneys from nondiabetic individuals. When exposed to 27.5 mM glucose in the growth media, cells isolated from approximately 75% of individuals (accumulators) accumulated sorbitol within 1-4 days, whereas 25% (nonaccumulators) accumulated only negligible amounts, even when the period of exposure was extended to 2 wk. Surprisingly, measurement of the activities of the polyol-pathway enzymes showed no difference in the levels of either AR or SDH between accumulators and nonaccumulators, even when the conversion of galactose to galactitol was used to measure AR activity in intact cells independently of SDH. Measurement of sorbitol in the growth media indicated that nonaccumulators were not releasing sorbitol into the growth media. Fructose levels in the conditioned growth media were 4 times higher in the sorbitol-accumulating cells. Together, these results indicate that the tendency of cells from an individual to accumulate significant amounts of sorbitol may reflect the cells' ability to metabolize sorbitol in steps subsequent to the polyol pathway.


A new method for quantification of islets by measurement of zinc content.

The ability to quantify the yield of pancreatic islet tissue after isolation is important for interlaboratory comparisons and for the assessment of islet yield prior to clinical transplantation. Because pancreatic islets contain a much higher concentration of zinc than other tissues, we investigated the analysis of zinc as a measure of islet tissue yield. Rat islets of standard diameter 250 microns were handpicked into samples containing 10-80 islets. The zinc content was measured by EAAS and showed a linear correlation with islet number. A zinc binding fluorescent dye, TSQ, was investigated as a way of simplifying the zinc measurement for routine use. Samples of 10-80 islets of 250 microns were sonicated in 3 ml zinc-free water, 0.18 mumol TSQ was added, and the TSQ-zinc fluorescence was measured at 480 nm. A linear correlation was observed. Exocrine contamination up to 50% barely affected the results. Islet zinc content also was shown to be correlated linearly with islet number for freshly isolated human islets. Measurement of zinc by TSQ fluorescence is a rapid, cheap, and objective measure of islet tissue content.


Effects of oleate and insulin on glucose uptake, oxidation, and glucose transporter proteins in rat adipocytes.

We examined effects of Na oleate on glucose uptake, glucose transporter protein concentrations, and glucose oxidation in isolated adipocytes from fed rats. Na oleate increased basel 14C-glucose uptake in a dose-dependent manner (+42% with 1.0 mM, +79% with 2.8 mM Na oleate), but had no statistically significant effect on insulin-stimulated glucose uptake. Insulin (100 nM) resulted in a redistribution of GLUT4 protein concentration from the LDM fraction (-42%) to the PM fraction (+266%) but did not affect the distribution of GLUT1. Na oleate had no effect on basal or insulin-stimulated concentrations of GLUT1 or GLUT4 proteins in the PM or LDM fractions. Na oleate (2.8 mM) had no statistically significant effect on basal glucose oxidation, but inhibited insulin-stimulated glucose oxidation by 48% (P less than 0.01). In summary, Na oleate inhibited insulin-stimulated glucose oxidation and stimulated basal glucose uptake in isolated adipocytes without affecting PM or LDM distribution of GLUT1 or GLUT4 proteins. We conclude that the stimulatory effect of Na oleate on basal glucose uptake in adipocytes may be mediated by changes in the intrinsic activity of the glucose transporters.


Impaired insulin-mediated skeletal muscle blood flow in patients with NIDDM.

Patients with non-insulin-dependent diabetes mellitus (NIDDM) exhibit decreased rates of skeletal muscle insulin-mediated glucose uptake (IMGU). Because IMGU is equal to the product of the arteriovenous glucose difference (AVG delta) across and blood flow (F) into muscle (IMGU = AVG delta x F), reduced tissue permeability (AVG delta) and/or glucose and insulin delivery (F) can potentially lead to decreased IMGU. The components of skeletal muscle IMGU were studied in six obese NIDDM subjects (103 +/- 9 kg) and compared with those previously determined in six lean (weight 68 +/- 3 kg), and six obese (94 +/- 3 kg) with normal glucose tolerance. The insulin dose-response curves for whole body and leg muscle IMGU were constructed using the combined euglycemic clamp and leg balance techniques during sequential insulin infusions (range of serum insulin 130-80,000 pmol/L). In lean, obese, and NIDDM subjects, whole body IMGU, femoral AVG delta, and leg IMGU increased in a dose-dependent fashion over the range of insulin with an ED50 of 400-500 pmol/L in lean, 1000-1200 pmol/L in obese, and 4000-7000 pmol/L in NIDDM subjects (P less than 0.01 lean vs. obese and NIDDM). In lean and obese subjects, maximally effective insulin concentrations increased leg blood flow approximately 2-fold from basal with an ED50 of 266 pmol/L and 957 pmol/L, respectively (P less than 0.01 lean vs. obese). In contrast, leg F did not increase from the basal value in NIDDM subjects (2.7 +/- 0.1 vs. 3.5 +/- 0.5 dl/min, NS).(ABSTRACT TRUNCATED AT 250 WORDS)


Noninvasive detection of cardiac sympathetic nervous dysfunction in diabetic patients using [123I]metaiodobenzylguanidine.

The association between clinical autonomic dysfunction and myocardial MIBG accumulation was investigated. The study groups comprised 6 male diabetic patients with autonomic neuropathy (ANP+ group), 6 male diabetic patients without autonomic neuropathy (ANP-group), and 6 male nondiabetic control subjects. The mean age was comparable in all groups, and the subjects had no evidence of coronary heart disease. Reduced heart-rate variation in a deep-breathing test was used as a criterion for autonomic neuropathy. Immediately after injection, the peak net influx rate of MIBG to myocardium was significantly (P less than 0.05) reduced in both diabetic groups. At 6 hr after MIBG injection, the MIBG uptake of the myocardium was significantly (P less than 0.05) smaller in the ANP+ group than in the control group. In the ANP- group, the MIBG uptake of the myocardium was between that of the ANP+ group and that of the control group. Our data show that reduced myocardial MIBG accumulation is associated with autonomic dysfunction in diabetic patients, but it can occur to a lesser extent also in diabetic patients without apparent autonomic neuropathy. The measurement of the myocardial MIBG accumulation is a promising new method to detect cardiac sympathetic nervous dysfunction in diabetic patients.


A rapid and sensitive radioimmunoassay for the measurement of proinsulin in human serum.

RIA methodology is used widely to measure proinsulin in human serum. However, some RIAs lack the sensitivity necessary to quantify proinsulin in unextracted serum and require long incubation periods. We developed an RIA with a sensitivity of 3.5 pM that permits the routine measurement of proinsulin in less than 48 h. This was accomplished by using a nonequilibrium binding reaction at room temperature and PEG-assisted second antibody precipitation as the method for separating bound and free proinsulin. We obtained a specific antiproinsulin antibody by absorbing the initial goat antiserum with human C-peptide-agarose. Proinsulin produced 50% displacement of tracer at 25.6 pM, whereas both human insulin and C-peptide failed to displace tracer at concentrations as high as 1 microM. We evaluated several cleaved derivatives of proinsulin for cross-reactivity with the antibody. B-chain-C-peptide cleaved derivatives (less than or equal to 50% cross-reactivity) were more potent than A-chain-C-peptide cleaved derivatives (less than 5% cross-reactivity). However, all derivatives cleaved in the region from 56-60 failed to cross-react with the antiserum. These data indicate that a major antigenic determinant is present on the C-peptide region of proinsulin adjacent to the A-chain-C-peptide junction. After administration of an oral glycemic challenge, the mean fasting serum concentration of proinsulin in normal adults rose from 4.1 +/- 0.28 to 23.6 +/- 3.8 pM. We found a significant difference in the proinsulin concentrations in 6 adults before and after a glycemic challenge when two different antibodies were used in the RIA.(ABSTRACT TRUNCATED AT 250 WORDS)


Diminished glomerular capillary hydraulic conductivity precedes morphologic changes in experimental diabetes mellitus in the rat.

Glomerular ultrafiltration coefficient, Kf, is diminished in established diabetic nephropathy. To determine whether Kf is decreased because of a decrease in capillary area, A, and or in hydraulic conductivity, Lp, glomerular Kf and morphometric parameters were measured, and Lp was calculated in glomeruli of young rats with STZ-induced DM and in control rats. STZ was administered to Fischer 344 rats that weighted 50-75 g; glomeruli were examined after 3 or 5 mo of DM, and their structure and function was compared with that of control rats. The effects of insulin or of an ACEI, enalapril, also were assessed after 3 or 5 mo. Growth of DM rats was markedly impaired, and their ratio of kidney weight to body weight was increased. Ccr was proportional to rat weight, and the ratio of Ccr to body weight was not different in DM and control rats. At 3 mo, average volume of glomeruli isolated from DM rats was less than that of glomeruli from control rats. In contrast, glomerular volume after 5 mo was equal in DM and control rats. No increase in GBM thickness or mesangial volume was observed, nor was any decrease seen in GBM area in DM rats at 5 mo. Kf was lower in DM rats than controls after 3 mo, but not after 5 mo. The Lp of DM and control glomeruli did not differ at 3 mo, but was lower in DM at 5 mo. Insulin therapy improved somatic growth and increased kidney and glomerular size in DM rats; the kidney weight/body weight ratio remained elevated.(ABSTRACT TRUNCATED AT 250 WORDS)


Growth of neonatal islet transplants in the spontaneously diabetic BB/Wor rat.

We have previously shown that culture-isolated neonatal islets are able to survive both rejection and the recurrence of autoimmunity in the spontaneously diabetic BB/Wor rat. In trials designed to demonstrate the MHC restriction of the autoimmune response in this model, we discovered that neonatal islet grafts from diabetic BB rats appeared larger than grafts from nondiabetic controls. This study was undertaken to quantify the mass difference seen in this original study and to determine the characteristics of graft growth in more highly controlled trials. Grafts from diabetic animals in the original study were significantly larger than those from nondiabetic animals (81 +/- 36 vs. 238 +/- 216 micrograms, P = 0.01). These findings were supported by results from a second series of experiments, in which the mean growth index of grafts from diabetic animals was 7.25 +/- 4.91, whereas that from nondiabetic animals was 2.5 +/- 1.15 (P = 0.011). Three animals in this study were reversed of hyperglycemia: two had normal and one had a subdiabetic ip GTTs. These three rats received 97, 317, and 408 micrograms of islet tissue that increased in mass to 1790, 3270, and 4107 micrograms, respectively. Nuclear/total cell area percentages were the same in diabetic and nondiabetic grafts (P = 0.76), suggesting that the increase in mass was attributable primarily to proliferation rather than hypertrophy. Limited studies that use BrDU incorporation support this conclusion.(ABSTRACT TRUNCATED AT 250 WORDS)


Insulin treatment, endogenous insulin concentration, and ECG abnormalities in diabetic Pima Indians. Cross-sectional and prospective analyses.

The prevalence and incidence of CHD, defined by ECG abnormalities according to the Tecumseh criteria for Minnesota Codes, were determined in Pima Indians greater than or equal to 25 yr of age. In a cross-sectional analysis, the age-sex-adjusted prevalence (+/- SE) of ECG abnormalities was higher in 1454 NIDDM patients (6.86 +/- 0.65%) than in 1696 nondiabetic subjects (3.23 +/- 0.63%; prevalence rate ratio = 2.12; 95% CI 1.39-3.25). In a prospective analysis, the age-sex-adjusted incidence (+/- SE) of ECG abnormalities was higher in 824 NIDDM patients (12.77 +/- 1.67) than in 935 nondiabetic subjects (5.93 +/- 1.43 cases/1000 person-yr; incidence rate ratio = 2.15; 95% CI 1.26-3.69). The prevalence of ECG abnormalities in insulin-treated NIDDM patients was significantly higher than in NIDDM patients not treated with insulin (age-sex-adjusted OR = 2.83; 95% CI 1.84-4.33); and this association persisted when adjusted for other factors such as sBP, BMI, duration of diabetes, serum cholesterol concentration, and oral hypoglycemic agents (OR = 2.12; 95% CI 1.34-3.37). In the prospective analysis, the incidence of ECG abnormalities in NIDDM patients treated with insulin was higher than in those NIDDM patients not treated with insulin, but, when controlled for age, sex, duration of diabetes, and oral hypoglycemic agents in a proportional-hazards model, the relationship with insulin treatment was not statistically significant (incidence rate ratio = 1.36; 95% CI 0.80-2.31). This suggests that insulin treatment may be a marker of more severe diabetes, and that factors associated with clinical indications for insulin treatment, rather than insulin treatment per se, are related causally to CHD. On the other hand, endogenous fasting and 2-h postload serum insulin concentrations were not associated with ECG abnormalities among 761 NIDDM patients not treated with insulin nor among 1226 nondiabetic subjects. Furthermore, in the prospective study, neither endogenous fasting nor 2-h postload serum insulin was associated with the subsequent development of ECG abnormalities in NIDDM patients or nondiabetic subjects.


Total body fat content and fat topography are associated differently with in vivo glucose metabolism in nonobese and obese nondiabetic women.

In this study, total body fat content and fat topography were related to glucose metabolism in the basal and insulin-stimulated states in 18 nonobese and 18 obese premenopausal nondiabetic women. All subjects received a euglycemic insulin (20 mU.min-1.m2) clamp study in combination with [3-3H]-D-glucose infusion and indirect calorimetry to quantitate total body glucose uptake, glucose oxidation, and nonoxidative glucose disposal. Total body fat content was determined with tritiated water, whereas body fat distribution was estimated from the WHR, the STR, and the VSR (measured by magnetic resonance imaging). In the postabsorptive state, total body glucose utilization, glucose oxidation, and nonoxidative glucose disposal rates were similar in nonobese and obese women, whereas during the insulin clamp all three metabolic parameters were reduced significantly in the obese group. In nonobese women, total body fat content was related inversely to both total and nonoxidative glucose disposal during the insulin clamp, whereas no relationship was found between glucose metabolism (total, oxidative, and nonoxidative) and WHR, STR, or VSR. In contrast, in obese women, no relationship was observed between total body fat content and any measure of insulin-mediated glucose metabolism. However, both WHR and VSR were related inversely to total, oxidative, and nonoxidative glucose disposal rates during the insulin clamp. These results suggest that total body fat content and body fat topography are associated differently with insulin-mediated glucose metabolism in nonobese and obese women. In the nonobese women, total body fat mass appears to be a primary determinant of tissue sensitivity to insulin, whereas in obese women, body fat topography exerts a more dominant effect.


Identification and characterization of aldose reductase in cultured rat mesangial cells.

Although the enhanced activity of the polyol pathway has been detected in diabetic glomeruli, the intraglomerular localization of this pathway has not yet been well defined. In this study, we attempted to identify aldose reductase, a key enzyme of the polyol pathway, in cultured rat mesangial cells and to characterize the properties of this enzyme using enzymological and immunological methods. When the aldose reductase (DL-glyceraldehyde-reducing) activity was analyzed in mesangial cell extract, the Lineweaver-Burk plot showed concave downward curvature, and the Michaelis constant was 0.83 mM DL-glyceraldehyde, and this activity was noncompetitively inhibited by an aldose reductase inhibitor, ICI-128,436. The enzyme activity was enhanced by the addition of sulfate ion and partially suppressed by barbital. The enzyme cross-reacted with the antisera against rat lens and testis aldose reductases on Ouchterlony plate, and migrated to the region of molecular weight of about 36,500 Da on Western blotting. The presence of aldose reductase mRNA was also confirmed by Northern analysis using cDNA for rat aldose reductase, 10Q. From these results, it was concluded that the aldose reductase may exist in rat glomerular mesangial cells and may play a role in the development of diabetic glomerulopathy, though the coexistence of aldehyde reductase(s) may not be fully ruled out.


Markedly reduced beta-cell function does not result in insulin resistance in islet autografted dogs.

Autotransplantation of islets of Langerhans has resulted in long-term normoglycemia in pancreatectomized dogs. This canine model is useful in evaluating both the progress of islet transplantation and the effect of a reduced islet mass upon the determinants of glucose tolerance: i.e., insulin secretion, insulin sensitivity, and glucose effectiveness. To determine the effect of a reduced islet mass on these factors, we measured the acute insulin response to arginine (AIRa) and glucose (AIRg), the slope of glycemic potentiation of AIRa (SP), insulin sensitivity (Sl), and glucose effectiveness (SG) in control (CN), diabetic (DM), and pancreatectomized dogs rendered normoglycemic with transplanted autografts of islets of Langerhans (TX). Normal fasting plasma glucose (FPG) (TX 4.7 +/- 0.2 mM; CN 4.9 +/- 0.1 mM; P greater than 0.05) was maintained despite a markedly reduced insulin secretion in TX (AIRa 24%, AIRg 15%, and SP 11% of CN). All measures of insulin secretion were significantly correlated (SP vs. AIRg, r = 0.80, P less than 0.0001; AIRa vs. AIRg, r = 0.92, P less than 0.0001) across all animals, but none of the measures of secretion were significantly correlated with either the number of islets transplanted or time posttransplant (P greater than 0.10). Insulin sensitivity was normal in islet autografted dogs (TX: 136 +/- 12 min-1/(nmol/ml); CN: 101 +/- 11 min-1/(nmol/ml), P greater than 0.05) but SG was reduced (TX: 1.93 +/- 0.28 x 100 min-1; CN: 3.53 +/- 0.35 x 100 min-1, P less than 0.05), as determined by the minimal-model method. In diabetic animals (FPG = 16.1 +/- 1.3 mM), insulin secretion was negligible by all measures (P greater than 0.05), and was associated with insulin resistance (Sl = 28 +/- 8 min-1/(nmol/ml)) and reduced SG (1.72 +/- 0.11 x 100 min-1). These studies indicate that across a range of insulin secretion in dogs, the secretagogues arginine and glucose provide similar estimates of beta-cell function. This markedly reduced beta-cell function does not result in insulin resistance when fasting normoglycemia is maintained, but is associated with a decrease in glucose action at basal insulin.


An ELISA for antibodies to recombinant glutamic acid decarboxylase in IDDM.

To detect serum antibodies to GAD in subjects with IDDM, three recombinant mBGAD 67 peptides encompassing the full-length protein were used in an ELISA. In this study 7 of 9 (78%) preclinical IDDM subjects (ICA+ first-degree relatives of a person with IDDM) and 6 of 13 (46%) recent-onset IDDM subjects, but no subjects with Graves' disease (n = 10) or scleroderma (n = 10), nor healthy nondiabetic control subjects (n = 10) had antibodies that reacted with one or more of the recombinant mBGAD peptides. We found no preferential reactivity with any recombinant peptide. Although only 3 preclinical subjects and 1 recent-onset subject had antibodies to all three mBGAD peptides, the results indicate that mBGAD 67 contains at least three B-cell autoepitopes. Compared with an immunoprecipitation assay of native human brain GAD, the ELISA detected 5 of 6 (83%) preclinical and 6 of 6 (100%) recent-onset IDDM subjects. The ELISA should facilitate screening to evaluate the role of autoimmunity to GAD in the development of IDDM.


Banting Lecture: glucose turnover. A key to understanding the pathogenesis of diabetes (indirect effects of insulin).

This article is divided into two parts. A retrospective overview summarizes some of the work that provided the framework and tools of the more recent studies. The five novel areas of research are related to the indirect effects of insulin. Regulation of plasma glucose is of central importance in health and diabetes. Understanding this precise regulation requires sensitive isotope dilution methods that can measure the rates at which glucose is produced by the liver and used by the tissues on a minute-to-minute basis. Validation studies indicated that the non-steady-state tracer method yields reasonable results when the specific activity of plasma glucose does not change abruptly. During hyperinsulinemic glucose clamps, the decrease in specific activity of glucose can be prevented by the MSTI. During exercise, the decrease of specific activity can be only in part ameliorated by step-tracer infusion. Depancreatized dogs are used extensively as a model of selective insulin deficiency, because dog stomach secretes physiological amounts of glucagon. This strategy can avoid injections of somatostatin, which can have other affects in addition to the suppression of insulin and glucagon. In human diabetes, in addition to an increase of glucose production, there is also an increase in glucose cycling in the liver. In animal models of diabetes, mild NIDDM, and in glucose intolerance, the percentage of increments of glucose cycling are much larger than those of glucose production. We hypothesize, therefore, that measurements of glucose cycling can be used as an early marker of glucose intolerance. Application of different tracer strategies and use of the depancreatized dog as a model of diabetes, we investigated the importance of the indirect effects of insulin in the pathogenesis of diabetes. 1) Because, in the treatment of IDDM, insulin is administered by the peripheral routes we compared the relative importance of hepatic and peripheral effects of insulin in regulating the rate of glucose production. Experiments were performed in depancreatized dogs that were initially maintained at moderate hyperglycemia (10 mM) with subbasal portal insulin infusion. During the experimental period, insulin was infused either peripherally or portally at 0.9 mU.kg-1.min-1. In addition, peripheral infusions were also given at 0.45 mU.kg-1.min-1. We concluded that when suprabasal insulin levels are provided to moderately hyperglycemic depancreatized dogs, the suppression of glucose production is more dependent on peripheral than portal insulin concentrations. This indirect effect of insulin may be mediated by limitation of the flow of precursors and energy substrates for gluconeogenesis and/or by suppressive effect of insulin on glucagon secretion.(ABSTRACT TRUNCATED AT 400 WORDS)


Lilly Lecture: syndromes of insulin resistance. From patient to gene and back again.

The syndromes of insulin resistance are a group of clinically diverse disorders, and our understanding of their molecular pathogenesis has advanced in parallel with our understanding of the structure of the insulin receptor and the mechanism of insulin action. The most straightforward progress has related to defining the role of both anti-receptor antibodies and mutations in the insulin receptor gene in causing these disorders. Despite this progress, the cause of severe target cell resistance in patients without defects in the receptor locus remains unknown, and we are limited in our ability to relate specific molecular defects in insulin signalling to in vivo phenotypes, such as those relating to growth and development and function of adipose tissue and muscle. Answers to these questions may ultimately be explained by the existence of multiple species of insulin receptors expressed in different tissues, brought about by alternative splicing and receptor hybrids, and by divergent pathways of insulin signalling with different consequences for specific tissues. The possibility that the insulin receptor and GLUT4 may be candidate genes for inherited insulin resistance in NIDDM has been addressed with the aid of genetic screening techniques such as SSCP. Currently, the loci have not been implicated in studies in most patients. Transgenic methodologies will be powerful tools for pursuit of unanswered questions in the field of insulin resistance in coming years.


Gastric and colorectal cancer in the rural Indian subcontinent: a survey of patients attending mission hospitals.

37 missionaries working in India, Nepal, Pakistan, Bangladesh and Bhutan completed questionnaires regarding their clinical practice during the year 1980. Information was collected on the frequency of both gastric and colorectal cancers. More than 500,000 out-patients were reviewed and over 100,000 inpatients treated. A total of 291 gastric tumours and 169 colorectal carcinomas were diagnosed. Surgery was performed in 82% of the hospitals but only 36% had a histology service. In India and Pakistan there was no significant difference between the incidence of gastric and colorectal neoplasms. The relative risk of developing gastric rather than colorectal cancer in Bangladesh was 8 (95% confidence limits 4.5-14.2) and in Nepal the relative risk was 4 (95% confidence limits 2.0-7.0). A significant variation in the occurrence of cancer was observed between countries. Nepal had the highest and Pakistan the lowest numbers of both gastric and colorectal tumours. It seems likely that local environmental factors, such as diet, play a significant role in the development of these tumours.


Influence of pirenzepine on gallbladder contraction in man induced by sham feeding or an intraduodenal meal.

Pirenzepine, an M1 muscarinic receptor antagonist, was tested for its ability to antagonize sham feeding- and intraduodenal fatty meal-stimulated gallbladder contraction in man. Intravenously administered pirenzepine abolished sham feeding-induced gallbladder contraction. Pirenzepine also inhibited contraction induced by intraduodenal meal, but this inhibition was of a lesser magnitude than the inhibition of sham feeding-induced contraction. The results demonstrate that the cephalic phase of gallbladder contraction is probably mediated by M1 muscarinic receptors while the duodenal phase of gallbladder contraction is partially mediated by M1 receptors.


Repeated upper gastrointestinal hemorrhage caused by metachromatic leukodystrophy of the gall bladder.

A 27-year-old man with metachromatic leukodystrophy (MLD) of the adult type had developed repeated severe gastrointestinal (GI) bleeding. During endoscopic retrograde cholangiography (ERC), hemobilia was observed on two occasions. The definite diagnosis was obtained by a biopsy specimen taken from the lumen of the gall bladder during ERC, demonstrating large masses of metachromatic material inside the gall bladder. Upon cholecystectomy, papillomatosis of the gall bladder was found virtually obliterating the lumen of the gall bladder. A blood clot was observed at the angle of the cystic duct; histologic examination revealed diffuse hemorrhage into the stroma of the gall bladder. The patient is without upper GI hemorrhage since 3 years. In patients with MLD and upper GI bleeding, one should, therefore, be aware of the gall bladder as a possible source of hemorrhage.


Multicenter double-blind trial of gabexate mesylate (FOY) in unselected patients with acute pancreatitis.

A multicenter, randomized, double-blind trial was carried out to evaluate the efficacy of gabexate mesylate (FOY) in acute pancreatitis. One hundred unselected patients were randomly allocated into two groups: 51 were assigned to receive FOY (12 mg/kg/day as continuous intravenous infusion for a minimum of 4 days and a maximum of 12 days), and 49 were allocated to placebo. The groups were comparable in demographic, clinical and biochemical parameters, etiology of pancreatitis, and disease severity, which was generally mild. Gallstones were the main etiological factor. All patients received fluid and electrolyte replacement, analgesia and nasogastric suction for at least 48 h after admission. Experimental therapy was initiated no later than 12 h after the beginning of symptoms. The results showed no statistically significant differences between the two groups with respect to the evolution of clinical and biochemical parameters, analgesic requirements, development of complications, hospitalization time or mortality at completion of the trial. In conclusion, early treatment with FOY does not appear to have any demonstrable beneficial effects in acute pancreatitis.


Human gastric alcohol dehydrogenase: in vitro characteristics and effect of cimetidine.

The presence of at least two types of alcohol dehydrogenase has been demonstrated in surgical specimens from the human stomach. One isoenzyme has a Km of approximately 1-2 mM for ethanol comparable to that of class I alcohol dehydrogenase isoenzyme as defined for the liver. This isoenzyme can also be detected by immunohistology using a polyclonal rabbit antibody against human liver class I alcohol dehydrogenase. The other isoenzyme of alcohol dehydrogenase has a much lower affinity to ethanol (greater than 300 mM), but with activities that become significant at ethanol concentrations of more than 100 mM commonly present in the human stomach. Cimetidine was found to be a noncompetitive inhibitor of gastric alcohol dehydrogenase at concentrations as low as 1 mM in vitro. Since the human gastric alcohol dehydrogenase is responsible for the first-pass metabolism of ethanol, its inhibition by cimetidine may explain the reduced first-pass metabolism of alcohol which is associated with elevated ethanol blood concentrations seen after cimetidine therapy.


Prevalence of pancreatitis in liver diseases of various etiologies: an analysis of 107,754 adult autopsies in Japan.

The frequency of acute and chronic pancreatitis is 3.3 and 2.1%, respectively, in 107,754 adult autopsies in Japan. Acute pancreatitis is highly associated with liver diseases of various etiologies such as subacute hepatitis (16.1%), fulminant hepatitis (13.5%), biliary cirrhosis (10.5%), cholangiocarcinoma (8.6%) and postnecrotic cirrhosis (7.1%). Chronic pancreatitis is also closely related to various liver diseases. It is suggested that the portal venous stasis in liver diseases may predispose the patients to develop pancreatitis regardless of the etiology of liver diseases.


Intermediate filaments and epithelial differentiation of male rat embryonic gonad.

The presence and distribution of desmin, vimentin, cytokeratin, and laminin in the gonads of developing male rat embryos (11-17 days) were studied by immunocytochemistry. The findings were correlated with morphological changes of the cells and with the formation of basement membranes, as determined by electron microscopy. The surface epithelial and subepithelial cells of the meesonephros in the prospective gonadal region contained desmin. At the onset of gonadal development, vimentin appeared in the somatic cells of the thickening surface epithelium, which formed the gonadal ridge. Desmin disappeared and cytokeratins appeared in the Sertoli precursor cells at the inception of their epithelial differentiation. Simultaneously, the prospective Sertoli cells became polarized during their assembly into epithelial cell aggregates; the aggregates then fused and formed elongated testicular cords. The epithelial cell differentiation was accompanied by a deposition of basement membrane material around the cords and by an increase of desmin in the cells immediately around the cords. With further differentiation of the testicular cords, some cytokeratins from the Sertoli cells, but not from the cells of the rete cords, disappeared. On the other hand, other cytokeratin polypeptides and vimentin remained in the fetal Sertoli cells. The surface cell layer slowly differentiated towards a proper epithelium after the basic formation of the testicular cords and interstitium. Desmin and vimentin persisted in the interstitial cells throughout the entire study period. The early differentiation of the gonad is apparently under a general sex-independent initiation program. The developmental changes in intermediate filaments offer an opportunity for the further analysis of their general role in early organogenesis. In light of the genetic theory of testicular differentiation, the functions of the regulatory factor(s) include specific organization of cord cells, histological organization into looping cords rather than separated follicles, and male development of the interstitium, surface epithelium and tunica albuginea.


Patterns of immunocytochemically detected Z-DNA in the recrudescing testicular epithelium of the Turkish hamster (Mesocricetus brandti).

Z-DNA has been considered a labile but essential structural form of DNA in recombination and gene expression, two significant activities in mammalian seminiferous epithelium. The present study has utilized the recrudescing testes of Mesocricetus brandti to study in detail the potential Z-DNA sites in specific testicular cell types as detected by an immunoprobe. Testicular regression was physiologically induced by modifying environmental photoperiods and/or temperature. Partial atrophy of seminiferous epithelium occurred in all experimental groups but Sertoli cells persisted throughout regression. Recrudescence of testicular activity was marked in all experimental groups by characteristic sequences of reappearance of potential Z-DNA sites to a final positive or negative mature state of the cell type. It is suggested that Z-DNA is a functionally important from of DNA in many cell types of the active seminiferous epithelium of the Turkish hamster, and perhaps other mammals.


Characterization of bep1 and bep4 antigens involved in cell interactions during Paracentrotus lividus development.

We have identified and partially characterised two antigens, extracted with 3% butanol, from Paracentrotus lividus embryos dissociated at the blastula stage, and encoded by the cDNA clones previously described as bep1 and bep4 (bep-butanol extracted proteins). The cDNA fragments containing the specific central portions of bep1 and bep4 were expressed as MS2 polymerase fusion proteins in Escherichia coli. These two fusion proteins, called 1C1 (bep1) and 4A1 (bep4), were injected subcutaneously into rabbits and the corresponding polyclonal antibodies generated. Western blot analysis of proteins, extracted with 3% butanol, from sea urchin embryos at the blastula stage (b.e.p.), established that both antibodies recognize two 33 KDa proteins. Reducing and non-reducing electrophoretic conditions show that both antibodies against bep1 and bep4 related proteins react also with a protein band of a molecular weight 66 KDa, indicating that these two antigens probably exist as dimers. Immunolocalization with anti 1C1 and 4A1 antibodies shows the presence of the related antigens also on the cell surface. Fab fragments of the polyclonal antibodies against 1C1 and 4A1 inhibited reaggregation of sea urchin embryonic cells, dissociated from blastula stage embryos. This prevention of reaggregation indicates that these proteins probably play a role in cell interaction during sea urchin embryonic development.


Trypsinogen-activation peptides in experimental rat pancreatitis: prognostic implications and histopathologic correlates.

Intrapancreatic activation of trypsinogens is believed to occur either as a cause or a consequence of acute pancreatitis and to be associated with the more severe forms of the disease. Trypsinogen-activation peptides (TAPs) were measured in plasma, urine, and ascites of rats (n = 54) assigned to different pancreatitis-inducing regimens reproducing the entire spectrum of severity. Compared with survivors, nonsurvivors at 9 hours had significantly higher TAP levels in plasma at 3 hours (P = 0.0001), urine (peak, 1-4 hours) (P = 0.004), and ascites (P = 0.0001) after death. Stepwise discriminant analysis showed that TAP in urine and plasma were the most accurate predictors of outcome (88.2% of animals) compared with other routine laboratory parameters. Morphometric analysis showed that the best histopathologic correlates of TAP elevation were acinar necrosis and intrapancreatic hemorrhage. In a second series of experiments using a homogeneous technique of induction producing pancreatitis with a mortality of 55% at 48 hours, plasma TAP level at 3 hours (cutoff, 0.5 nmol/L) and/or urinary TAP level (peak, 1-6 hours; cutoff, 25 nmol/L) accurately predicted outcome in 85% of animals. It is concluded that the TAP assay gives an accurate early prediction of outcome in different pancreatitis models and correlates best with acinar necrosis and hemorrhage.


Possible induction of fatty acid cyclo-oxygenase in lipopolysaccharide-stimulated rat Kupffer cells.

In response to stimulation with lipopolysaccharide, isolated rat Kupffer cells released increased amounts of prostaglandin E2, prostaglandin D2, 6-keto-prostaglandin F1 alpha, and thromboxane B2. There was a lag of 2-6 hours before a significant release of these metabolites into the medium was detected. Nonstimulated Kupffer cells converted exogenous arachidonic acid to prostaglandins and thromboxane B2, and a major product was prostaglandin D2. Twenty-four hours after stimulation with lipopolysaccharide, Kupffer cells produced approximately 7 times more prostaglandin E2 and 2 times more prostaglandin D2, 6-keto-prostaglandin F1 alpha; and thromboxane B2 than nonstimulated cells. Western immunoblotting of microsomal proteins prepared from the stimulated rat Kupffer cells showed a 70-kilodalton component that was immunoreactive with a polyclonal anticyclo-oxygenase antibody. The intensity of the band increased with the time of the lipopolysaccharide stimulation. These results suggest that the accelerated arachidonate metabolism in lipopolysaccharide-stimulated rat Kupffer cells might be attributed to an induction of the cyclo-oxygenase enzyme.


Bile acid transport in the anhepatic rat.

Hepatocyte dysfunction eventually results in the loss of canalicular bile formation. Without canalicular flow, intestinal bile acid may originate from plasma by reverse transport. Anhepatic rats with preserved intestinal function permit evaluation of such transport. In the present study, plasma taurocholate clearance was markedly decreased in anhepatic rats. The relative proportion of free cholate increased with time. Peripheral tissues contained virtually only cleared taurocholate, but the intestinal contents were mainly free cholate. This indicates the intestinal contents as the source of the plasma cholate and shows an equilibrium between intestinal and plasma bile acid even without bile flow. The enteral administration of an anion exchange resin to anhepatic rats increased intestinal bile acid recovery and decreased the bile acid recovery in tissue. Plasma bile acid concentration was decreased and fractional loss increased threefold, confirming the anhepatic plasma-intestine bile acid equilibrium. However, the enhanced plasma clearance produced by the resin was less than 1% of the fractional loss found in the intact rat. These data show a very limited bile acid flux between intestine and plasma without bile flow, which could be modestly influenced by an intestinal bile acid sequestrant.


Characterization of spontaneous and ethanol-induced gastric damage in cirrhotic rats.

Cirrhosis was induced in Sprague-Dawley rats via ligation of the common bile duct. Changes in gastric blood flow and mucosal architecture were examined. Using an ex vivo gastric chamber preparation, the susceptibility of the cirrhotic gastric mucosa to injury by 20% ethanol was also examined. The gastric mucosa of cirrhotic animals was abnormal, even before ethanol administration. The macroscopically visible damage in these animals ranged from superficial hyperemia to epithelial sloughing. These gastric lesions were similar in appearance to the gastropathy described in cirrhotic patients, including "cherry-red spots" and areas of generalized erythema. Cirrhotic rats had a lower resting gastric transmucosal potential difference than control rats, and their gastric mucosa was also significantly more susceptible to damage by topical ethanol application. Ethanol administration caused a significant increase in gastric blood flow in control rats, whereas it significantly decreased gastric blood flow in cirrhotic rats. This lack of a reactive hyperemic response in cirrhotic rats may be responsible for the increased susceptibility of the gastric mucosa to ethanol-induced damage.


Thiamine transport by basolateral rat liver plasma membrane vesicles.

Hepatic thiamine transport is thought to be a saturable, Na(+)- and energy-dependent process. However, the transport of this organic cation has not been examined in experimental models that allow direct characterization of carrier-mediated processes. Recently, a sinusoidal organic cation/H+ antiport was identified, using N1-methylnicotinamide as a marker. To determine whether thiamine is a substrate for this antiport, the characteristics of thiamine uptake were examined in rat liver basolateral membrane vesicles. An inwardly directed Na+ gradient had no effect on thiamine uptake as compared with an identical K+ gradient. An outwardly directed H+ gradient stimulated thiamine uptake as compared with pH-equilibrated conditions, and H(+)-dependent uptake was not the result of an H+ diffusion potential. Identical pH gradients stimulated uptake under voltage-clamped conditions, consistent with electroneutral thiamine/H+ exchange. Unlabeled intravesicular thiamine trans-stimulated [3H]thiamine uptake. Choline and imipramine cis-inhibited thiamine/H+ exchange; a series of other organic cations and thiamine analogues had no effect. Carrier-mediated [3H]thiamine uptake showed two saturable systems. In conclusion, a thiamine/H+ antiport is present on the sinusoidal membrane, distinct from Na+/H+ and NMN+/H+ exchange.


Glycerol interference in serum lipase assay falsely indicates pancreas injury.

The measurement of serum lipase activity has been shown to be a very sensitive and specific marker for the diagnosis of pancreatic injury. Two case reports are presented showing that glycerol ingested coincidentally in the formulation of several medications taken therapeutically and given in the emergency room causes a falsely elevated serum lipase activity when measured on the Kodak Ektachem 700 clinical analyzer (Eastman Kodak Co., Rochester, NY). The transient but falsely elevated serum lipase activity could potentially affect the differential diagnosis of patients by the admitting physician.


Successful dissolution of cholesterol gallstone during treatment with pravastatin.

This case report describes a 51-year-old hypercholesterolemic male patient who had a large solitary cholesterol gallstone. The patient was treated with the 3-hydroxy 3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor pravastatin, 40 mg/day. After 3 months of therapy, serum cholesterol level normalized (7.7 mmol/L before and 5.2 mmol/L during treatment), and biliary cholesterol saturation index decreased from 1.3 before to 0.8 during treatment. Repeatedly performed ultrasonography showed complete gallstone dissolution. Pravastatin may be valuable in the nonsurgical treatment of cholesterol gallstone disease particularly when there is an additional indication for HMG-CoA reductase inhibitors because of hypercholesterolemia.


Gastrointestinal food hypersensitivity: basic mechanisms of pathophysiology.

Gastrointestinal symptoms occur in a large number of patients with food allergies. Immediate hypersensitivity mechanisms may give rise to the nausea, vomiting, abdominal pain, and diarrhea experienced by these patients. However, there are limited human data about the pathophysiological basis for these symptoms. Most of the available information comes from a variety of animal models. This article reviews the literature using models of intestinal food hypersensitivity, as well as human studies, that have contributed to our understanding of the pathophysiological mechanisms in gastrointestinal food hypersensitivity.


Complementary peptide to the carboxyl-terminal tetrapeptide of gastrin.

Codons of noncoding DNA strands for peptides have been found to code for amino acids with hydropathic properties opposite to those of the native peptides. Synthetic peptides, designated as complementary peptides, with amino acid sequences coded by noncoding DNA strands of several peptide hormones have been shown to bind the native peptides. In some instances, antibodies to these complementary peptides have shown agonist or antagonist properties of the native hormones. In this study a peptide was synthesized based on codons complementary to messenger RNA for the carboxyl-terminal gastrin tetrapeptide. This complementary peptide bound radiolabeled human gastrin (G17). Antibodies to the complementary peptide competitively inhibited the binding of 125I-gastrin by canine fundic mucosal membrane preparations. These antibodies also showed gastrin agonist properties in that they stimulated canine gastric mucosal parietal cell [14C]aminopyrine uptake, used as an index of stimulation of gastric acid secretion. Competitive inhibition of 125I-gastrin binding by membrane receptors for gastrin and stimulation of [14C]-aminopyrine uptake by antibodies to the complementary peptide for the gastrin tetrapeptide are consistent with their recognition, binding, and occupancy of gastrin receptors.


Enterohepatic circulation is essential for regular cycling of duodenal migrating motor complexes in dogs.

The role of enterohepatic circulation and specific bile acids in the initiation and caudad migration of duodenal migrating motor complexes (MMCs) was investigated in conscious dogs. All dogs had spontaneous duodenal MMCs that migrated to the terminal ileum when bile flow was intact. During the first 3 days after total external biliary diversion, no MMCs originated in the duodenum. Instead, all MMCs originated in the jejunum and migrated to the ileum. During the next 4 days of total external biliary diversion, 81% of the MMCs originated in the jejunum and 19% in the duodenum. When normal bile flow was restored after 9 days of total external biliary diversion, regular duodenal MMCs resumed after a delay of 126 +/- 27 minutes. Perfusion of individual bile acids or dogs' own bile, but not saline or alkaline solution, into the duodenum or perfusion of dogs' own bile directly into the ileum during total external biliary diversion restarted duodenal MMCs with a time lag of about 2 hours. The authors conclude that intact enterohepatic circulation is essential for the initiation of regular duodenal MMCs.


Helicobacter pylori infection and gastric function in patients with chronic idiopathic dyspepsia.

Helicobacter pylori infection, histological features of the gastric mucosa, and gastric motor and secretory functions were evaluated in 45 consecutive patients with chronic idiopathic dyspepsia. H. pylori infection was found in 60% of dyspeptic patients, compared with 33% of 15 healthy controls (P = 0.1). No difference was detected in basal or stimulated gastric acid secretion between dyspeptic patients and healthy controls. Gastric emptying was significantly (P less than 0.01) delayed in dyspeptic patients compared with healthy controls when standardized for age and sex. Delayed gastric emptying was associated with a low frequency of H. pylori infection, female gender, and young age. Epigastric pain or burning and postprandial fullness were, respectively, more severe in patients with H. pylori infection (P less than 0.02) and in those with delayed gastric emptying (P less than 0.01). These findings support the existence of separate subsets of patients with chronic idiopathic dyspepsia. Despite the presence of overlaps, there appear to be partially different functional derangements and clinical features in different subgroups of dyspeptic patients.


Effect of acute hyperglycemia on esophageal motility and lower esophageal sphincter pressure in humans.

The effect of acute hyperglycemia on esophageal motility and lower esophageal sphincter pressure (LESP) was investigated. Esophageal manometry was performed for 120 minutes in seven healthy volunteers on two separate occasions during euglycemia and during hyperglycemia with blood glucose levels stabilized at 15 mmol/L. At 90 minutes, motility was stimulated with edrophonium chloride (0.08 mg/kg intravenously). Pancreatic polypeptide (PP) secretion was determined as an indirect measure of vagal-cholinergic tone. During hyperglycemia the LESP decreased significantly (P less than 0.05) from 20.1 +/- 1.6 mm Hg to 10.7 +/- 0.6 mm Hg; plasma PP levels were also significantly (P less than 0.05) decreased during hyperglycemia. Edrophonium induced significant (P less than 0.05) increases in LESP and PP levels in both experiments. However, LESP and PP levels after edrophonium stimulation remained significantly (P less than 0.05) reduced during hyperglycemia compared with euglycemia. During hyperglycemia a significant (P less than 0.05) increase in peristaltic wave duration and a decrease in peristaltic velocity were observed in the distal part of the esophagus. It is concluded that blood glucose levels affect esophageal motility, acute hyperglycemia reduces LESP and impairs esophageal motility under both basal and edrophonium-stimulated conditions, and hyperglycemia reduces plasma PP levels, suggesting impaired vagal-cholinergic activity during hyperglycemia.


Proliferation assay of human gastric remnant by bromodeoxyuridine and flow cytometry.

The cell kinetics of gastric epithelium were studied by bromodeoxyuridine (BrdU) and flow cytometry in seven patients with remnant stomachs reconstructed with a Billroth type II procedure and in 25 patients with whole stomachs. Each patient received an intravenous injection of BrdU (200 mg/m2) 6 hours before surgery. Fresh specimens obtained from the lesser curvature, greater curvature, and stomal areas in the cases of remnant stomachs and from the antrum and fundus in the case of whole stomachs were studied. The BrdU labeling index was higher in the stomal area of the gastric remnant than in other areas, and DNA synthesis time was shortened in the stomal area of the gastric remnant (P less than 0.01) but not in other areas. The turnover time of the mucosa in the stomal area was 4.1 +/- 1.2 days, significantly shorter (P less than 0.01) than in other areas (7.6 +/- 2.3 to 8.2 +/- 1.2 days). The present study showed that the cell proliferation was extremely rapid in the stomal area of the gastric remnant, suggesting that this enhanced turnover of epithelial cells may assist in promoting carcinogenesis in the stomal area of the gastric remnant.


Ileocolonic transit does not change after right hemicolectomy.

The role of the human ileocolonic junction in the transit of solid contents through the entire gut was evaluated. Eight patients, well compensated after right hemicolectomy for localized colon cancer, and eight age-matched healthy controls were enrolled. Scintigraphic transit was quantified after subjects ingested a mixed meal containing 111In-labeled Amberlite beads (average diameter, 1 mm; Sigma Chemical Co., St. Louis, MO). Gastric emptying was initially faster in the postoperative group, but overall emptying was not different from controls; small bowel transit also did not differ between the groups. In patients in whom the distal ileum, ileocolonic sphincter, and proximal colon were absent, isotopes moved from small to large bowel in a manner that was qualitatively and quantitatively no different from that of controls. Major episodes of coloileal reflux could not be identified in either group. After hemicolectomy, the residual transverse colon, and to a lesser degree the descending colon, were able to store solid residue, although in lesser amounts than the unoperated large bowel. The ileocolonic sphincter in humans appears to play only a minor role, at most, in ileocolonic transit, and the colon remaining after right hemicolectomy stores residue so that bowel habits are not greatly disturbed.


Inhibition of rat methylbenzylnitrosamine metabolism by dietary zinc and zinc in vitro.

Methylbenzylnitrosamine is an esophageal-specific carcinogen in the rat, and the incidence of methylbenzylnitrosamine-induced esophageal carcinoma is increased by dietary zinc deficiency. Methylbenzylnitrosamine requires activation by cytochrome P-450 to be mutagenic; the present study examined the role of dietary zinc deficiency and the in vitro addition of zinc on the cytochrome P-450-dependent microsomal metabolism of methylbenzylnitrosamine. Dietary zinc deficiency significantly increased the cytochrome P-450-dependent esophageal and hepatic microsomal metabolism of methylbenzylnitrosamine. These changes occurred without alteration in the specific content of total microsomal cytochrome P-450 of the esophagus or liver. The addition of zinc in vitro, at concentrations found in normal tissues, irreversibly inhibited the esophageal and hepatic cytochrome P-450-dependent microsomal metabolism of methylbenzylnitrosamine. These results suggest that physiological levels of zinc may be an endogenous inhibitor of methylbenzylnitrosamine metabolism. Dietary zinc deficiency appears to reduce this inhibition of cytochrome P-450 activity, resulting in an increase in carcinogen activation.


Helicobacter pylori in Hispanics: comparison with blacks and whites of similar age and socioeconomic class.

Helicobacter pylori infection is twice as frequent in blacks as in whites. It has been postulated that the apparent increase in susceptibility to H. pylori infection in blacks might have a genetic basis. A case-control seroepidemiologic study of H. pylori prevalence was performed in 108 healthy Hispanic volunteers. Eighty-nine Hispanics were matched (1:1:1) with blacks and whites for age and socioeconomic status. There was an inverse correlation between H. pylori infection and educational level that remained after logistic regression analysis adjusting for age and sex. The adjusted prevalence of H. pylori infection was almost identical in Hispanics and blacks and significantly higher than in whites. Because Hispanics do not constitute a race, the increased prevalence of H. pylori in Hispanics and blacks is unlikely to be genetic. It is speculated that the unrecognized bias is a reflection of a generation cohort phenomenon related to the generational distance from very low socioeconomic status, i.e., the prevalence of H. pylori in Hispanics and blacks is currently lower than that of their parents but higher than that of the white population, which has experienced higher socioeconomic status for several generations.


The distribution of spinal and vagal sensory neurons that innervate the esophagus of the cat.

The distribution of spinal and vagal neurons that convey sensory information from the distal smooth muscle esophagus is poorly documented. Therefore, sensory cell bodies were retrogradely labeled by injecting fast blue into the striated and smooth muscle of the esophageal body and into the lower esophageal sphincter of the cat. The maximum distribution of spinal sensory neuron labeling was found in the following dorsal root ganglia: C1-T8 (striated muscle); C5-L2 (smooth muscle), and T1-L3 (lower esophageal sphincter). Vagal sensory neurons in the nodose ganglion were found to have a crude topographic layout. The total number of vagal sensory neurons labeled by injection into the three esophageal areas was greater than the number of spinal neurons labeled (809.7 +/- 166.1 vs. 328.9 +/- 53.4; mean +/- SEM; n = 12; P less than 0.005). It is concluded that spinal sensory neurons of the esophagus are segmentally arranged. Accordingly, each level of the esophagus has a distinct but overlapping sensory projection to the spinal cord, and afferents from all parts of the esophagus overlap the known spinal distribution of cardiac afferents.