Development of the diffuse endocrine system in the chicken proventriculus

The development of endocrine cells in the chicken proventriculus has been investigated using light- and electron-microscopy in conjunction with silver and immunocytochemical techniques. The first morphologically detectable endocrine cells were found in 5-day-old embryos by electron microscopy. From the 9th to the 13th day, endocrine cells in contact with the lumen of the organ could be detected both by electron and light (silver impregnation) microscopy. The number of open-type endocrine cells progressively decreased and the number of closed-type increased after this stage. Until the 16th day, endocrine cells were located exclusively in the luminal epithelium, but afterwards they appeared in progressively greater numbers in the compound glands. After hatching, long cytoplasmic processes could be seen in the endocrine cells. Immunoreactivities to regulatory substances appeared in the following order: serotonin (day-14), avian pancreatic polypeptide, glucagon and somatostatin (day-16), bombesin and neurotensin (day-18), and finally, met-enkephalin (day-21).

Erythropoietin treatment in allogeneic BMT accelerates erythroid reconstitution: results of a prospective controlled randomized trial

Twenty-eight allogeneic BMT patients (16 with acute leukemia, 12 with chronic myeloid leukemia) were included in a single center, prospective, randomized, controlled trial to assess the value of recombinant human erythropoietin (rh-Epo) in this setting. rh-Epo was administered through a central venous catheter as a single bolus injection (days 0-7: 100 U/kg/d; days 7-30: 150 U/kg/d). No secondary effects to rh-Epo treatment were detected. An earlier appearance of reticulocytes and a diminished need of red blood cells (RBCs) transfusions were observed in patients who were treated with rh-Epo (4 units vs 12 units; p < 0.05). The time to unsupported platelets above 25 x 10(9)/l was less in patients treated with rh-Epo than in control patients (19 days vs 31; p < 0.05), and they received significantly fewer platelet transfusions (36 units vs 138.5; p < 0.05). Our results show that rh-Epo treatment is capable of accelerating the erythroid reconstitution and decreasing the need for RBC transfusions. A beneficial effect on platelet reconstitution is also suggested, but further studies are necessary to confirm this point.

Regulation of somatostatin and growth hormone-releasing factor by gonadal steroids in fetal rat hypothalamic cells in culture

The mechanism underlying the sexually dimorphic pattern of growth hormone (GH) secretion in the rat has not been clearly elucidated. In the present study, we assayed the possible direct effect of gonadal steroids on both somatostatin (SS) and growth hormone-releasing factor (GRF) in fetal rat hypothalamic cells in culture. Hypothalamic cells, obtained by mechanical dispersion, were maintained as monolayer cultures in serum-supplemented medium. After 20 days in culture, cells were incubated with serum free medium containing testosterone (T, 10, 20, 40 ng/dl) or estradiol (E, 0.1, 1, 10 ng/dl) for 48 h. At the end of the experiments, immunoreactive SS (IR-SS) and immunoreactive GRF (IR-GRF) were measured by specific radioimmunoassays (RIAs) in media and cell extracts. After 48 h of incubation with testosterone, somatostatin in both media and cells was significantly reduced. On the contrary, this treatment lead to a dose-dependent increase in media and cell GRF content. When cells were incubated with estradiol for 48 h, a significant inhibition in medium SS release was observed, whereas intracellular SS slightly increased at the highest concentration of 10 ng/dl. Estradiol treatment resulted in an inconsistent decrease in media and cells IR-GRF. Our results indicate that both SS and GRF are under the influence of testosterone and estradiol acting at the hypothalamic level, and furthermore suggest that at this stage of brain development, gonadal steroids may regulate GH secretion through their ability to modulate hypothalamic SS and GRF.

[Rhombencephalitis caused by Listeria monocytogenes]

The observation of an abscess in the brain stem and cerebellum due to Listeria monocytogenes is presented. The patient was a 55 year old diabetic, alcoholic, gastrectomized male in whom a febrile and meningeal syndrome developed. Three days later he had a progressive unilateral dysfunction of the cranial nerves. The cerebrospinal fluid showed pleocytosis of the polymorphonuclear cells, an increase in proteins and low glucose in relation with the glycemia. No parenchymatous lesion was observed upon emergency computerized tomography. Magnetic resonance imaging showed a hyper-signal lesion in the brain stem and cerebellum with a contrast enhancement in ring. Following antibiotic treatment the clinical evolution of the patient was favorable with slight focal sequelae persistent at discharge. A review of the epidemiology, clinical manifestations and treatment of this infection is carried out.

Anatomical study of the bronchial system and major blood vessels of the chicken lung (Gallus gallus) by means of a three-dimensional scale model

The bronchial and vascular patterns of the chicken lung, from specimens age 8-10 days, have been studied by serial, paraffin sections of the whole organ. According to the histological structure, the bronchial system consists of three airway types: primary bronchus or mesobronchus, secondary bronchi, and tertiary bronchi or parabronchi. The mesobronchus gives rise to three sets of secondary bronchi: four dorsomedial, four dorsal, and three lateral ones. The total number of secondary bronchi is 11, which is less than the number reported in adult birds by other authors until now. Nevertheless, the number and distribution of the major vessels, arteries and veins are in basic agreement with previous descriptions.

[Biologic markers in multiple sclerosis (I). Clinical correlations]

Seven biological markers were studied in a population of 236 patients (144 females, 92 males) with multiple sclerosis as was the relation with the different degrees of diagnostic certainty (Rose and Poser scales), the time of evolution and number of bouts of the disease. The IgG concentrations, IgG ratio and the quantification of the intrathecal IgG synthesis by the Tourtellotte formula isolatedly constituted the most sensitive biological markers for the diagnosis of multiple sclerosis. Altogether, the determination of the number of cells, IgG and the IgG ratio achieved diagnostic sensitivity of 94% for defined multiple sclerosis. The IgG ratio was the most closely related biological marker related with the number of bouts and the time of evolution of the disease.

Fractionated TBI and methotrexate-cyclosporin do not seem to increase relapses in BMT for first chronic phase CML patients: results of a single centre study

Fractionated total body irradiation (FTBI) and methotrexate-cyclosporin A(MTX-CSA) have been found useful in reducing interstitial pneumonia (IP) and acute graft-versus-host-disease (GVHD) in bone marrow transplantation patients, but an increase in relapse rate has been observed by some authors when these strategies are used. To evaluate this relapse risk, we performed a retrospective analysis in 24 consecutive first chronic phase chronic myeloid leukemia patients who received an HLA-identical non-T cell-depleted graft in a single institution. All were conditioned with cyclophosphamide plus FTBI (12 Gy in six fractions delivered twice daily for 3 days) (CY-FTBI) and received MTX-CSA as GVHD prophylaxis. Serial hematologic and cytogenetic bone marrow analysis were performed at least three times (days +30, +100, +360) and at variable intervals thereafter in long-term survivors. Actuarial probabilities of developing IP and acute GVHD greater than or equal to II were respectively 5.9% and 44.2%, with a GVHD-associated mortality of 33%. Four-year actuarial relapse and disease-free survival rates were 7.7% and 48.2% respectively. No exclusively cytogenetic relapses were observed. Our results suggest that CY-FTBI and MTX-CSA are not associated with an increase in relapse rate in 1CP-CML patients.

Allogeneic bone marrow transplantation for high risk acute lymphoblastic leukemia. Results from a single institution

We present our experience with bone marrow transplantation (BMT) in 30 consecutive patients with high risk acute lymphoblastic leukemia. With a median follow-up of 4 years the disease-free survival (DFS) was 44% for the whole group, with a significant difference between patients in first or second complete remission (CR 1 and 2, as one group), compared with patients with more advanced disease (greater than CR2), 69.5% versus 15.4% (p less than 0.01). The main cause of BMT failure was leukemic relapse, with a relapse rate of 15% for patients in CR 1 and 2 and of 77% for patients with greater than CR2 (p less than 0.01). Among patients with active disease at BMT those who had 15% blast cells or less in the marrow fared better than those with more advanced disease or extramedullary relapse. Transplant-related death was 17%. Graft-versus-host disease (GVHD) was associated with an antileukemic effect; the DFS for patients with acute and/or chronic GVHD was better than for patients with no GVHD at all.

[A study of some pathogenic factors of Salmonella typhi]

30 strains isolated from clinical cases and a laboratory induced R-mutant or S typhi were studied. The synthesis of Colicin V, Siderophores, hydroxamate and phenolate (Aerobactin and Enterochelin) were investigated using biological assays. All strains were positive for Enterochelin but only strains 6586 and 4448 were positive for Aerobactin. An 80 kD receptor for enterochelin was found in the outer membrane of strains. Only strains 4448, 635 and 4693 produced Colicin V. Plasmid related antibiotic resistance was demonstrated in 7 strains and was considered "cryptic" in 3 others. The LD50 for mice ranged from 2.7 x 10(4) to 1 x 10(9) bacteria per ml. The presence of pathogenic factors was not related to the LD50.

[Rupture of the interventricular septum in acute myocardial infarct]

Ventricular septal rupture in patients with acute myocardial infarction is not a common complication. It was found in 20 patients of 4298 admitted to the coronary care unit of the Instituto Nacional de Cardiología Ignacio Chávez from January 1980 to March 1991. The diagnosis was made by right heart catheterization if 85%, by echocardiography in 35% and by postmortem study in 15% of the patients. Mortality was 70%. In all patients the functional class worsened after the rupture, from class I to III or IV. There were not significant differences in mortality in relation to risk factors, or hemodynamic findings. Mortality was higher in older patients, females and patients with anterior myocardial infarction. Angiographic studies did not increase mortality and are necessary to establish an early surgical treatment.

[Lack of predictive power of cerebrospinal fluid calcitonin and serotonin concentrations for the intensity of postoperative pain and the duration of analgesia after subarachnoid morphine administration]

Based on the important relationship of calcitonin and serotonin with narcotic drugs at the level of the central nervous system and with the modulating mechanisms of pain sensation, we have studied whether central baseline levels of these modulators possess a predictive value for the assessment of the intensity and duration of narcotic spinal analgesia. Therefore, intradural levels of calcitonin an serotonin were measured in 18 patients who underwent and infraumbilical laparotomy with intradural anesthesia with bupivacaine associated with 0.5 mg of morphine. There was no statistically significant correlation between the levels of calcitonin and serotonin with the age, weight, height, sex, values of analogic visual scale 2, 4, 6, 12 and 24 hours after lumbar punction, and duration of the analgesia. Even though a correlation exists in experimental models, our results indicate that baseline values of modulators calcitonin and serotonin lack of predictive value for the assessment of the degree and duration of narcotic spinal analgesia.

Identification of natural killer (NK) cells in lesions of human cutaneous graft-versus-host disease: expression of a novel NK-associated surface antigen (Kp43) in mononuclear infiltrates

We performed an immunohistochemical analysis of skin biopsies from 13 allogeneic bone marrow transplant (BMT) recipients, undergoing either acute graft-versus-host-disease (aGVHD, n = 8) or chronic GVHD (cGVHD, n = 5). A panel of different monoclonal antibodies (MoAb) was employed including anti-CD2, -CD3, -CD4, -CD8, -CD11b, -CD16, -CD56, and -CD57, as well as a recently described reagent (HP-3B1) specific for a novel natural killer (NK)-associated cell-surface antigen (Kp43). Our data indicate that in aGVHD lesions the proportions of CD2+ cells often exceeded those detected with anti-CD3 MoAb. Double labeling confirmed the presence of CD2+ CD3- lymphocytes and suggested the coexpression in some cells of CD2 and CD11b. When MoAb specific for non-lineage-restricted NK-associated markers were employed, anti-CD56 and -CD57 occasionally stained variable numbers of lymphocytes (means = 14.6% of mononuclear cells in 0.05 mm2, range less than 1-48% and means = 10.3%, range 2-25%, respectively), whereas no CD16+ lymphocytes were observed. In contrast, most samples consistently displayed substantial proportions of Kp43+ cells (means = 32.8%, range 12-63%), which appeared CD3- and were mainly located at the dermoepidermal junction. On the other hand, sections from most (four of five) cGVHD lichenoid lesions analyzed displayed lower proportions of Kp43+ and CD56+ cells. Our data point out the interest of the anti-Kp43 MoAb to identify NK cells in aGVHD lesions, suggesting their pathogenetic participation.

[Nutritional support in liver transplantation]

Given the malnutrition present in patients suffering from advanced hepatic illness, as well as the implications of this in the post-hepatic transplant period, a study was made of various biochemical parameters (prealbumin, retinol-bound protein, zinc, magnesium, cholesterol and amino acid pattern) as indicators of the nutritional condition of a series of 15 patients who underwent hepatic transplants and required total parenteral nutrition (TPN) during the first 10 post-transplant days. Before the transplants were carried out, all the patients studied showed a decrease in all evaluated parameters. Ten days after the transplant, and having been fed parenterally during this time, the different parameters corrected themselves, with the exception of cholesterol. TPN, administered with enrichment of branched amino acids by 35%, practically normalized the plasma amino acid pattern.

Effect of different MCT/LCT ratios on protein synthesis in injured rats fed parenterally

The effect of the lipidic composition of the diet on the proteic synthesis of the male Sprague-Dawley rats fed parenterally for four days has been studied. All animals received identical nitrogen and caloric intake, but the ratio of medium to long-chain triglycerides (MCT/LCT) varied: group 1, control (0/100); group 2 (30/70); group 3 (50/50) and group 4 (70/30). Hepatic and jejunal protein synthesis were determined with L-(1-14C)-leucine. In groups 1, 3 and 4 muscle protein synthesis was measured with L-(3,4-3H)-phenylalanine. In liver, there were no significant differences in the fractional synthesis rate among the groups. In jejunum, the control group showed a higher fractional synthesis rate with statistically significant differences among the groups. In muscle, group 3 presented the highest fractional synthesis rate with statistically significant differences (p less than 0.05).

[Percutaneous surgery in renal lithiasis. Current indications]

The indiscriminate use of extracorporeal shock waves in the treatment of urinary calculi has changed the place of percutaneous surgery in the treatment of renal lithiasis. The authors analyse current indications of PCN highlighting stone size. In their view, calculi greater than 2 cm warrant treatment by PCN since only 15-20% of patients are completely stone-free following a single session of ESWL. Attention is focussed on the staghorn calculus and the percutaneous approach. They describe the difficulty encountered in the fragmentation of the cystine calculus owing to its hardness and discuss the difficulties that may arise when using the percutaneous approach in patients with coexisting renoureteral conditions, in the treatment of lithiasis in children and in the obese patients.

Isolation and evolutionary analysis of a RepFVIB replicon of the plasmid pSU212

We have isolated at least two different replication regions from pSU401, a Tn802 insertion derivative of the IncFVI plasmid pSU212. One of the replication regions (RepFVIB) is highly homologous to the RepFIIA replicon of IncFII plasmids, and thus belongs to the RepFIIA family. We have also cloned the incompatibility determinant (incFVI) and the copy number control gene (cop) from RepFVIB and determined their nucleotide sequences. The analysis of the sequences supports the idea of a modular evolution of RepFIIA plasmids.

Immunocytochemical and ultrastructural characterization of endocrine cells in chicken proventriculus

The endocrine cells of the chicken proventriculus were investigated immunocytochemically, using the peroxidase-antiperoxidase technique on paraffin and semithin sections for light microscopy, and immunogold staining in osmium-fixed material for electron microscopy. The fixation procedure also allowed a detailed ultrastructural investigation. Twenty-three antisera were tested and 7 immunoreactive cell-types were identified: D-cells containing somatostatin-like peptide; EG-cells immunoreactive to anti-glucagon, anti-GLP1 and anti-neurotensin; NT-cells labelled only with anti-neurotensin; BN-cells containing bombesin-like material; ENK-cells showing met-enkephalin immunoreactivity; EC-cells reactive to anti-serotonin; and APP-cells positive to anti-avian pancreatic polypeptide. In addition, enterochromaffin-like (ECL) cells, were also detected by electron microscopy. The presence of ENK-cells and the ultrastructure of these and NT-cells are described for the first time in chicken proventriculus, and glucagon. GLP1 and neurotensin are shown to be colocalized in the EG-cells.

Interferon alpha treatment of accelerated-phase chronic myeloid leukemia in relapse after bone marrow transplantation: a case with complete cytogenetic and molecular remission

We describe here a patient with Philadelphia-positive chronic myeloid leukemia who had a hematologic and cytogenetic relapse after bone marrow transplantation. A diagnosis of accelerated phase was made when an additional malignant clone was detected. This clone was probably derived from the primitive Philadelphia clone, with duplication and rearrangement of the Philadelphia chromosome. The patient was treated with interferon alpha 2a and experienced a complete cytogenetic and molecular remission, with full reconstitution of the donor marrow.

Uremic platelets have a functional defect affecting the interaction of von Willebrand factor with glycoprotein IIb-IIIa

Uremic patients have an impaired platelet function that has been related to membrane glycoprotein (GP) abnormalities. Using a perfusion system, we have studied the interaction of normal and uremic platelets with vessel subendothelium (SE) under flow conditions. Reconstituted blood containing washed platelets, purified von Willebrand factor (vWF) (1 U/mL), and normal washed red blood cells was exposed to de-endothelialized rabbit segments for 10 minutes at two different shear rates (800 and 1,600 seconds-1). In some experiments a monoclonal antibody to the GPIIb-IIIa complex (EDU3) was added to the perfusates. With normal platelets, the percentage of the vessel covered by platelets (%CS) was 23.1% +/- 3.7% at 800 seconds-1 and 30% +/- 4.3% at 1,600 seconds-1. Platelets were observed in contact or forming monolayers on vessel SE. EDU3 inhibited the spreading of normal platelets. The %CS (11.1% +/- 3.3%) was statistically decreased (P less than .01) and most of the platelets were observed in contact with the vessel surface. These data indicate that, under flow conditions, the interaction of vWF with GPIIb-IIIa can support the spreading of normal platelets in the absence of exogenous fibrinogen. Under the same experimental conditions, the interaction of uremic platelets with SE was markedly impaired at both shear rates studied (P less than .01 v normal platelets). The presence of EDU3 did not modify the interaction of uremic platelets. These results confirm the impairment of the platelet adhesion observed in uremic patients. Furthermore, they indicate the presence of a functional defect in the interaction of vWF with GPIIb-IIIa. The fact that perfusions with normal and uremic platelets in the presence of an antibody to the GPIIb-IIIa complex did not show any differences gives indirect evidence on a functionally normal interaction vWF/GPIb in uremic patients.

[Critical analysis of the routine use of the direct antiglobulin test in 22,517 cross-matching tests]

Routine performance of the direct antiglobulin test (DAT) in pretransfusion testing (PT) is controversial. To evaluate its usefulness, we review the positive DATs found in 22,517 PT performed in our center in the last five years. DAT was positive in 330 PT (1.4%). Eluate studies gave information, not obtained from the rest of PT, in 6 cases. DAT predictive value is low (1.8% of the positive DATs, 0.02% of all PT). Although this predictive value is low, we keep on follow including DAT in PT but we have reduced eluate studies to 1) positive DAT of untransfused patients (to get information of the DAT prior to transfusion and to detected autoimmune haemolytic anaemias) and 2) positive DAT of previously transfused patients with previous negative DAT or changes in its reactivity (for the prompt detection of clinically significant antibodies).

Characterization of the RepFVII replicon of the haemolytic plasmid pSU233: nucleotide sequence of an incFVII determinant

We have isolated a replication region (designated RepFVII) from the IncFVII plasmid, pSU233. Hybridization experiments showed that RepFVII has high homology to the RepFIII replicon of the plasmid pSU316 and, therefore, that pSU233 is another member of the RepFIIA family. We have also located the incompatibility gene (incFVII) from RepFVII. The analysis of its sequence revealed the same organization described for several other replicons belonging to the same family.

[Pulmonary thromboembolism: clinical characteristics and diagnostic and therapeutic approaches]

In the present study the variability and diagnostic meaning of clinical features and common laboratory investigations were evaluated in a series of 220 patients with pulmonary thromboembolism (PTE) diagnosed by clinical means. The patients were classified into the two following groups: group I consisted of 102 critical patients admitted to an intensive care unit; group II consisted of 118 less-severely ill patients admitted to an ordinary hospital ward. Although clinical and laboratory features were nonspecific, the association of thrombotic risk factors in 88% of the patients permitted us to suspect the diagnosis of PTE within the initial three days in 71%. Chest radiogram was normal in 48%, ECG was normal in 32%, and contrast phlebography did not demonstrate phlebothrombosis in 16.4% of cases. The presumptive diagnosis was earlier (4 +/- 2 days) in group I than in group II patients (8 +/- 5 days) (p less than 0.01), and there was a significantly higher frequency of thoracic symptoms, hypoxemia, hypocapnia and radiologic and electrocardiographic abnormalities in group I patients. Chest radiogram and ECG were normal in only a small minority of these patients (9 and 7%, respectively). Overall mortality rate was 9.4% (20 patients, 14 from group I and 6 from group II). In 10 patients, all from group I, death took place within the first 72 hours after the diagnosis.

Comparative subcellular distribution of apyrase from animal and plant sources. Characterization of microsomal apyrase

1. Apyrase (ATP: diphosphohydrolase) has been found in the microsomal fraction of rat salivary gland, mammary gland and uterus. 2. This enzyme, already described in plant tissue, is mainly present as a soluble polypeptide in tubers of Solanum tuberosum. 3. A fraction of this enzyme is associated with the microsomal fraction with a higher specific activity than the soluble one, for either ATP or ADP as substrate. 4. Apyrase bound to microsomes from rat and potato tissues was characterized in its substrate specificity and effect of inhibitors. 5. The Km values for ATP and ADP, optimum pH and metal ion requirement were determined. 6. A characteristic common to the microsomal and soluble apyrases is the stimulatory effect of a potato activator protein of soluble plant apyrase. 7. The microsomal-bound apyrase from rat and potato tissues were solubilized and subjected to size-exclusion chromatography. 8. The mammary gland and salivary gland apyrases eluted as molecular aggregates, in contrast to the uterus and potato enzyme.

Histological and immunocytochemical study of the endocrine pancreas of the lizard Podarcis hispanica Steindachner, 1870 (Lacertidae)

The endocrine pancreas of the lizard Podarcis hispanica is described using light and electron microscopy. The endocrine pancreas of this reptile is located throughout the spleen side of the organ and consists of islet-like structures, small groups of two to five cells, and single scattered endocrine cells. The endocrine cells, including the islet-like structures, are not discrete units; on the contrary, they are intermingled with the endocrine component, both forming the glandular units. The endocrine islet-like structure shows a peculiar pseudoacinar pattern. The tridimensional reconstruction allows us to recognize the true structure of the glandular units. They are made up of two or three tubules closely arranged around a blood vessel, the endocrine component being disposed in the facing aspects of the tubules, around the vessel. Silver methods, Giemsa, and peroxidase-antiperoxidase techniques for light microscopy, immunogold, and routine methods for electron microscopy were used to demonstrate the regulatory peptide-producing cells present in the endocrine pancreas. Four major pancreatic endocrine cells, immunolocalized with the light and electron microscope, have been described: glucagon-containing cells (granules of 440 nm in diameter), insulin cells (400 nm), somatostatin cells (610 nm), and pancreatic polypeptide-containing cells (460 nm).

Brucella outer membrane lipoprotein shares antigenic determinants with Escherichia coli Braun lipoprotein and is exposed on the cell surface

In an enzyme-linked immunosorbent assay (ELISA), purified Brucella abortus and Escherichia coli peptidoglycan-linked lipoproteins gave a strong cross-reaction with sera from rabbits hyperimmunized with the heterologous lipoprotein. When smooth E. coli cells were used as ELISA antigens, the immunological cross-reaction was not observed unless the cells were treated to remove lipopolysaccharide and other outer membrane components. In contrast, intact cells from smooth strains of B. abortus and Brucella melitensis bound anti-lipoprotein immunoglobulin G, and the controls performed by ELISA showed that this reaction was not due to antibodies to the lipopolysaccharide, group 3 outer membrane proteins, or porins. Electron microscopy of cells labeled with antilipoprotein serum and protein A-colloidal gold showed specific labeling of smooth cells from both B. abortus and B. melitensis, even though unspecific labeling by nonimmune serum was observed with rough B. abortus. These results confirm the close similarity between E. coli and Brucella peptidoglycan-linked lipoproteins and show that, in contrast to E. coli, the lipoprotein of B. abortus and B. melitensis is partially exposed on the surface of smooth cells.

Giemsa stain applied to deplasticized sections to identify pancreatic islet cells

A new application of the Giemsa stain to demonstrate endocrine cells in deplasticized sections of Epon embedded material is described. Its application to the pancreas of Rana temporaria is illustrated. The technique does not require postfixation with OsO4 and is easily performed in 30 min. It allows the easy identification of three types of endocrine cells (A, B, and D). A cells, preferentially located at the islet periphery, stain purple-blue. B cells, which occupy the interior of the islet, display a lilac color. D cells give a strong purple color; they are located both in the periphery of the islets and scattered among acinar cells. Positive identification of the cell types was made by immunocytochemistry and electron microscopy.

Defective platelet adhesion on vessel subendothelium in uremic patients

Bleeding time, platelet retention on glass beads, and ristocetin-induced platelet agglutination (RIPA) in platelet-rich plasma were simultaneously determined for 20 patients with chronic renal failure and previous hemorrhagic history. In seven patients chosen at random out of a group of 16 in whom the three tests were abnormal, RIPA of uremic-isolated platelets in presence of normal platelet-poor plasma (PPP) and of normal platelets in presence of patient PPP were performed. In all cases, the first assay showed diminished agglutination, suggesting a platelet defect; however, uremic PPP did not inhibit the agglutination of normal platelets. In the same patients, the interaction of platelets with subendothelium was evaluated using Baumgartner's perfusion method. The subendothelial surface covered by platelets was significantly decreased in experiments with uremic whole blood when compared to normal controls. The interaction of platelets with subendothelium was also decreased when perfusions were carried out with platelet-plasma mixtures containing either normal washed platelets and uremic PPP or uremic washed platelets and normal PPP. These results show an impaired platelet adhesion caused both by a platelet and a plasmatic abnormality. Since uremic PPP decreased the adhesion of normal platelets to subendothelium but did not inhibit RIPA, it seems probable that the plasmatic defect could result in a defective binding between vWF and subendothelium. The influence of the red cell count on the platelet adhesion to subendothelium was reconfirmed by comparing perfusions of reconstituted blood with hematocrit values of 20% to 23% and 40% to 45%. In summary, a defective platelet adhesion to subendothelium has been postulated in uremic patients, caused by platelet and plasmatic alterations that are influenced by a low hematocrit.

Glucose and ketone bodies production in hepatocytes isolated from fetuses at term--I. Effect of maternal fasting

The effect produced by maternal fasting on glucose and ketone bodies production has been studied in hepatocytes isolated from fetal rat. Maternal fasting produces a decrease in the weight of fetal liver. Maternal fasting produces a decrease in glucose production, both from endogenous substrates and adding lactate (10 mM) to the incubation medium. Maternal fasting produces an increase in ketone bodies production, both from endogenous substrates and adding acetate (5 mM) to the incubation medium.

Glucose and ketone bodies production in hepatocytes isolated from fetuses at term--II. Effect of maternal adrenalectomy

Glucose and ketone bodies production has been studied in hepatocytes isolated from fetuses at term of fed and fasted adrenalectomized mothers. Maternal adrenalectomy diminishes the fetal liver weight. This effect is increased when the adrenalectomized pregnant rat is fasted for the last 2 days of gestation. Maternal adrenalectomy diminishes glucose production in hepatocytes isolated from fetuses at term. This diminution is markedly greater when the adrenalectomized pregnant rat is fasted for the last 48 hr of gestation. Maternal adrenalectomy diminishes ketone bodies production in hepatocytes isolated from fetuses at term.