Inhibitory effect of peak 2-4 of uremic middle molecules on platelet aggregation

It is well-known that uremic patients present prolonged bleeding times as a common complication. Factors responsible for this disorder have been extensively investigated. In order to elucidate the possible role of uremic middle molecules as responsible for the bleeding tendency observed in uremia, we have studied the effect on platelet aggregation of middle molecules obtained from uremic plasma by Sephadex and ion-exchange chromatography. Our results show that some purified middle molecular fractions have a specific inhibitory activity on platelet aggregation and suggest an important role for these compounds in the pathogenesis of uremic bleeding.

Serum micronutrient levels in relation to gastric pathology

As part of an ongoing cohort study of gastric cancer precursors in Nariño, Colombia, blood levels of ascorbic acid, vitamin E, retinol, pre-albumin, retinol binding protein and carotenoids were measured and correlated with histopathologic findings of gastric biopsies. Carotene levels in both sexes and vitamin E levels in males were significantly lower in subjects with gastric dysplasia than in subjects with normal mucosa and subjects with less advanced gastric lesions (chronic atrophic gastritis and intestinal metaplasia). No other significant correlations were found.

Tracheal versus pulmonary deposition and clearance of inhaled Pasteurella haemolytica or Staphylococcus aureus in mice

The aim of this investigation was to do a comparative study on the deposition and clearance of inhaled bacteria between the lungs and tracheae of mice exposed to aerosols of bacteria. Two hundred and eighty-eight mice were divided into four groups (n = 72) and exposed to aerosols of Pasteurella haemolytica or Staphylococcus aureus in four replicates. The numbers of bacteria were determined in the trachea and lungs of mice sacrificed 0, 2, 4, 8, 12, 24, 48 and 72 hours postexposure. Results indicated that bacterial deposition was greater in lungs than in tracheae. No significant (p greater than 0.05) difference was observed between P. haemolytica and S. aureus clearance rates. Although bacteria were rapidly eliminated from the whole respiratory tract, bacterial clearance was significantly (p less than 0.002) faster in tracheae than lungs. A significant (p less than 0.05) replicate effect was also observed.

Pulmonary recruitment of neutrophils and bacterial clearance in mice inoculated with aerosols of Pasteurella haemolytica or Staphylococcus aureus

Pulmonary alveolar macrophages are considered to be the main phagocytic cell of the pulmonary defense mechanism. However recent studies indicate that neutrophils may also participate in the defense against inhaled bacteria. The aim of this investigation was to study in mice the correlation between numbers of phagocytic cells in the bronchoalveolar space and the pulmonary clearance of bacteria. White mice were exposed to aerosols of Pasteurella haemolytica (n = 129) or Staphylococcus aureus (n = 129) in three different experimental replicates. Another group of mice (n = 22) was sham exposed to an aerosol of sterile phosphate buffered solution in a single replicate. Animals were sacrificed at various times postaerosolization. The numbers of neutrophils and alveolar macrophages in lung lavages and the pulmonary bacterial clearance rates were determined and statistically analysed. No significant differences (p greater than 0.05) were observed in the rates of pulmonary clearance between the two genera of bacteria, but P. haemolytica had a significant (p less than 0.05) replicate effect. The number of alveolar macrophages was not significantly affected by either bacteria or phosphate buffered solution. Exposure to P. haemolytica resulted in dramatic, significant (p less than 0.01) but transient increases in neutrophils in the bronchoalveolar space as well as a significant (p less than 0.01) increase in the weights of lung. The correlation between neutrophils and clearance was positive for P. haemolytica but negative for S. aureus. These results indicate that both species of bacteria are rapidly eliminated from the lung despite a rather different cellular response.

Interaction of low density lipoproteins with arterial proteoglycans. The role of charge and sialic acid content

The interaction of low density lipoproteins (LDL) with chondroitin sulfate-rich arterial proteoglycans appears to be initiated by coulombic interactions that lead to insoluble complexes. Once formed, large LDL aggregates are held together by non-polar associations. The irreversible formation of LDL proteoglycans aggregates was evaluated for different LDL preparations by definition of an avidity coefficient (Ar) using a Langmuir isotherm. LDL from different subjects, when tested against the same lipoprotein-complexing proteoglycan (LCP), gave Ar values ranging from 1-9 X 10(6) L/M. High avidity values were associated to lipoproteins with apparent isoelectric points above 6.5. These lipoproteins show low sialic acids content. The content of N-acetyl and N-acetyl,O-acetyl sialic acid was found inversely correlated with the avidity coefficient for the arterial LCP. Reductions of 42% on the LDL sialic acid content, by neuraminidase treatment, induced a 10-fold increment in their avidity for the lipoprotein complexing proteoglycan. The results indicate that at low ionic strength and physiological Ca2+-concentration and pH, the surface charge of LDL is an important modulator of the interaction with the arterial proteoglycan. Sialic acid, perhaps because of its exposure at the LDL surface, plays a determinant role in the in vitro association of LDL with the polyanionic proteoglycans. It is possible that in the intima-media the sialic residues of LDL and its balance of surface charges will control part of the interactions with the proteoglycans of the extracellular matrix.

Lung lesions in bovine fetuses aborted by Brucella abortus

Considering the poor facilities available for microbiological diagnosis in some countries where Brucella abortus is a frequent cause of bovine abortion, a study was conducted to determine if isolation of B. abortus from an aborted bovine fetus could be predicted from a detailed histological study of the formalized lung. Thirty-nine samples of B. abortus positive and 20 negative fetal samples were examined for the presence of 14 different pulmonary lesions. Differences in the frequency of observed lesions between the positive and negative groups, were determined by odds ratios and chi square statistic. The confidence of the prediction was calculated by means of the logistic computer model. The frequency of eight lung lesions was found to be significantly (p less than 0.05) different between the groups; nevertheless, these lesions were not specific enough to be able to incriminate B. abortus as the cause of abortion.

Energy/protein ratio in natural-ingredient diets for weanling rats. II. Energy and protein retention and efficiency of retention

A 3 x 3 factorial experiment was carried out, in which natural ingredient diets formulated at 3 digestible energy levels (DE) (100, 90 and 80% of NRC, 1978 recommendations) and at 3 energy: protein ratios (EPR) (63, 71 and 79 kJ DE/g crude protein (CP)) were fed to 8 weanling male Wistar rats/group. Half of these animals were sacrificed at the end of the 6-week experimental period and their body composition analyzed. Retentions of protein and energy were assessed by difference from a similar group of 8 rats killed and analyzed at the beginning of the experiment. No interaction was found between the 2 factors studied. Main results showed a decrease in intake and retention of both energy and protein, without affecting the efficiency of retention when energy level of diets was reduced by 20%. An increase in the EPR of the diets led to a decrease in protein intake and to an increase in efficiency of protein retention, without affecting the amount retained. No changes in body composition, nor in composition of live weight gains were found as a result of treatments. It is concluded that a 10% reduction in DE level of the diet is of no consequence, and that an EPR of 79 kJ/g leads to more efficient use of the dietary protein without detrimental effects over any other nutritional indicator.

Energy/protein ratio in natural ingredient diets for weanling rats

The effect of 3 levels of Digestible Energy (DE; 100, 90 and 80% of NRC Recommendations) and 3 different Energy/Protein ratios (EPR; 63, 71 and 79 kJ DE/g Crude Protein [CP]) were studied in a 3 X 3 factorial design using 8 weanling rats per group and diets formulated with natural ingredients. A 20% reduction in DE level decreased significantly energy and protein intake and daily weight gain, and increased the feed intake/body weight gain ratio without affecting protein or energy conversion ratios. Wider values of EPR brought about a decrease in protein intake and CP/body weight gain ratio, with no effect on feed and energy intakes, conversion ratios, nor weight gain. At the protein levels used, energy but not protein concentration of diet, determined growth rate; with the natural ingredient diets used, up to 10% reduction in DE level may be compensated for; wider EPR values led to more efficient utilization of dietary protein.

ApoLDL: evidence for an aggregating system of heterogeneous subunits

The protein moieties of low density lipoprotein (LDL) (d 1.019-1.063 g/ml) and subfractions: I (d 1.018-1.023 g/ml), II (d 1.023-1.028 g/ml), III (d 1.028-1.034 g/ml), and IV (d 1.034-1.052 g/ml) were obtained by a mild delipidation procedure involving attachment of LDL to an ionic-exchange column and a gradient of the non-ionic detergent Brij-36T (J. Lipid Res. 1979. 20: 631.). The apoLDL, eluted in the presence of 6 M urea, 0.1% SDS, or 4 M guanidine-HCl and analyzed by pore-gradient polyacrylamide gel electrophoresis and high performance gel exclusion chromatography, appeared to be made up of several polypeptide components with molecular weights between 250,000 and 14,000. The complex pattern was observed in the apoprotein of LDL subfractions I to IV; however the distribution of the most prominent components was different for each density range. These results, those from immunoelectrophoresis, N-terminal analysis, and measurements of tetramethylurea-soluble apoproteins discounted the possibility that the presence of bands with molecular weights below 250,000 could be caused by contamination with VLDL or HDL or nonspecific proteolysis. Delipidation of subfractions I to IV with organic solvents produced, on the other hand, simple patterns of highly aggregated apoLDL subfractions, where most of the protein had molecular weights above 250,000. The more disaggregated apoLDL preparations were those obtained from LDL rapidly isolated by single-spin centrifugation in KBr gradients, from fresh plasma immediately mixed with EDTA, phenylmethyl sulfonylfluoride, and chloramphenicol. ApoLDL fractionated by single-pore polyacrylamide gel electrophoresis appeared to be a system of heterogeneous antigens unevenly distributed on the different polypeptide components. These results, and those obtained by peptide maps of tryptic hydrolyzates from the major constituents, suggest that apoLDL is made of several polypeptides of different lengths with similar repetitive sequences but with some dissimilar segments specific for the major protein constituent of LDL. These polypeptides show a high tendency to form multiple aggregates with size distribution dependent on the preparation history.-Socorro, L., F. López, A. López, and G. Camejo. ApoLDL: evidence for an aggregating system of heterogeneous subunits.

[Coma states induced by craniocerebral injuries in children. Review of 20 cases]

From a total of three-hundred and fifty-six children admitted into the Department of Pediatrics at the Hospital Clínico of the University of Granada during of period of two years, twenty cases that needed admittance in critical pediatrics care unit are revised. Organic etiology that provoked coma, time of appearance, intensity, evolution, complications and short term outcome are analysed. A comparison is made of the incidences and prognosis of this type of coma with that of other authors presenting therapeutic outline carried. Two large evolutive groups; one which consisted of nine patients which entered into coma immediately after injury. The second group includes those patients which had lucid period before entering into coma. Following conclusions have been withdrawn: Severity and duration of coma does not have a definite relationship with the existence of a mass-lesion. Presence of an associated--mass-lesion is a sign of grave prognosis. For a good therapeutic response the following approaches are necessary: Immediate assistance monitoring and periodic or systematic maintenance of extracranial variants diagnostic, and treatment of the primary causing factor.

[Use of human albumin and dextran-70 in extracorporeal circulation. Postoperative function of blood platelets (author's transl)]

Human albumin and dextran 70 were used as volume expanders in extracorporeal circulation in two homogeneous series of patients. Comparative results were statistically processed. No significant differences were observed either to early postoperative bleeding or needed volume of transfused blood. Postoperative complications neither developed in the two groups of patients. The total number of platelets showed a 50 percent decrease in relation to basal extraction figures and those after immediate heparin neutralization. Results of platelet function tests were similar in both series, except for a statistical significant decrease in ADP-induced platelet aggregation in the group with dextran 70. Such decrease, however, was not followed by an increase of postoperative bleeding. Thus, dextran 70 has showed to be a valuable substitute for human albumin in extracorporeal circulation.

[Complete triploidy in a liveborn premature (author's transl)]

Authors describe the clinical, pathological and cytogenetic data of a polymalformed premature with a complete a triploidy 69,XXY). This rare condition (30 cases in the literature) may be suspected in a premature with broad posterior fontanella, eye and ear anomalies, syndactily between IV and III fingers/toes, intersexual status and mielomeningocele. Frequently the placenta presents a molar or micromolar degeneration.

[Ultrastructural study of the basal cells of the prostatic gland]

The ultrastructure of basal cell in canine and bovine prostate is studied. In the canine prostate only one type of basal cell could be specified, however in the bovine prostate type I and type II basal cells could be described. Canine basal cell and bovine type I have similar characteristic and never reach the alveolar lumen whereas bovine type II basal cell is columnar in shape, has numberous mitochondria in the apical pole and ocassionally reaches the alveolar lumen. Type II is a clearly defined intermediate cell between type I and secretory elements. All types of basal cells in both species have ultrastructural features which correspond to those of undifferentiated stem cells.

[Ultrastructure of the secretory cells of the bovine prostatic gland: a possible secretion mechanism]

An ultrastructural study of the secretory cells of the Bovine Diseminated Prostatic Gland has been carried out. The main features of the glandular epithelium are described. The suggested mechanism of secretion is compared with those studied in other mammals. The proposed mechanism involves the formation of primary and secondary protrusions and accompanying isolating membrane systems. This process can be visualized in three different ultrastructural phases.