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Biomedical subjects

K Langer

Publications and source records attributed to K Langer.

At least 91 records · Page 5Linked to original sources

The lack of discriminant seminal and endocrine variables in the partners of fertile and infertile women.

Seminal and endocrinological investigations were done on 50 fertile men whose wives became pregnant spontaneously (Group I), on 100 men from our fertility clinic whose wives conceived after treatment of the couple (Group II) and in 100 infertile men whose wives failed to become pregnant even after 5-year treatment of the couple (Group III). Patients with azoospermia were excluded. While there were no significant differences in the mean sperm density and total sperm count of the men from all three groups, mean sperm motility and sperm morphology were significantly better (p less than 0.001) in both Group I and Group II men than in the infertile Group III men. The mean serum LH and FSH concentrations were significantly lower in Group I than in the two other groups. However, there were no differences between Groups II and III. The mean serum concentrations of prolactin, testosterone, and estradiol were similar in all three groups. Based on semen and hormone data, stepwise multiple discriminant analysis could allocate 80% of the Group I men correctly, whereas only 50% of Groups II and III could be correctly classified. Although overall differences in sperm motility and morphology as well as in serum gonadotrophin concentrations were noted, no specific seminal or hormonal variable could be identified as being of value in predicting the fertility of an individual man.

Adult↗

[Sonographic determination of residual urine].

A method to determine residual urine volume by ultrasonotomography has been developed. In 206 patients the greatest horizontal and the greatest sagittal area of the urinary bladder were measured using a B-Mode real time scanner and the volume of the bladder was calculated from these two parameters. Then the bladder was emptied with a catheter and the determined volume was compared with the calculated volume. Applying the statistical method of multiple regression analysis a nomogram was computed for direct reading of the calculated residual urine volume. Using this ultrasonic method the bladder volume determination is highly reliable and due to its advantages (e.g. no risk of infection and urethral injury, quick, simple and inexpensive) it has replaced the catheter method for assessing residual urine volume at our institution.

Humans↗

Ultrasonic assessment of residual urine volume.

A new method to assess residual urine volume using ultrasound has been developed. By measuring the areas of the bladder in both longitudinal and transverse directions the amount of residual urine volume can be estimated with a degree of accuracy comparable to the catheterisation method. A nomogram containing relevant urine volume determinations has been computed by applying the statistical method of multiple regression analysis in more than 200 cases studied. We find this nomogram to be easy to work with, and due to the advantages of ultrasonic assessment (e.g., there is no risk of infection, it is atraumatic, and it is quick), this approach may be recommended as a suitable method for routine practice in lieu of the catheterisation method.

Humans↗

Reproductive functions in young fathers and grandfathers.

Testicular functions were investigated in 23 grandfathers [60--88 yr old; 67 +/- 7.8 (mean +/- SD)], i.e. men with fertility proven earlier in life. They were recruited from a nonpatient population and led an active life, most of them with a permanent partner. The grandfathers were compared with a group of 20 unrelated healthy fathers, 24--37 years old (29.2 +/- 3.2). Whereas sperm density was higher in the older group, there were no significant differences in ejaculate volume and sperm morphology between the younger and older men. Sperm motility and seminal fructose, however, decreased with age. The fertilizing capacity of sperm as assessed in the heterologous ovum penetration test using zona pellucida-free hamster eggs did not decrease significantly with age. Whereas the basal serum testosterone and estradiol levels were not different between the younger and older men, the response to 2 days of hCG stimulation decreased significantly with age. This decrease was observed in older men whether they had frequent or infrequent sexual activity. Basal serum LH and FSH levels were elevated in the older men. The LH response to GnRH stimulation relative to basal; values was significantly reduce, while FSH responses did not change with age. We conclude that sperm counts and fertilizing capacity of sperm are not negatively influenced by old age, at least not in men with sustained sexual activity. However, the pituitary as well as the testis show signs of decreased endocrine reserve capacity in old age.

Adult↗

[Effects of a partial exchange transfusion with Fluosol DA 20% on healthy pigs].

In 9 animals 500 ml of blood was replaced with 500 ml of Fluosol DA 20%. An average of 19.2 ml per kg body weight of emulsion, i.e. 3.883 gm per kg body weight of fluorocarbons was given. On the eighth day following exchange transfusion the animals were killed and tissue samples taken from liver and lung for electron microscopy and chemical analysis. Biochemical parameters were measured in central venous blood prior to transfusion and on the 2nd, 3rd, 6th and 8th days. One animal died on the sixth day of study, hence only the results obtained from the remaining 8 animals were analysed. On removing the lungs a marked firmness of consistency and failure to collapse was noted. Electron microscopy revealed numerous phagocytic cells packed with foam-like substance, partly occluding the pulmonary capillaries. On chemical analysis a residue of 23.95 mg fluorocarbon per gm of lung tissue was found. Acid-base analysis of central venous blood showed a compensated respiratory acidosis on the 6th and 8th day. The hepatic reticulo-endothelial system was found to be laden with numerous vacuoles, to such a degree that the sinusoids were all practically fully occluded. Neither cell necrosis nor inflammatory reactions were observed.

Acid-Base Equilibrium↗

Evidence for valine intolerance in patients with cirrhosis.

Valine (62.5 mg per kg), leucine (70 mg per kg) and equal amounts of the calcium salts of the corresponding keto acids, i.e., alpha-ketoisovaleric acid (KIVA) and alpha-ketoisocaproic acid (KICA) were orally administered to patients with cirrhosis and to control subjects. Valine or leucine ingestion increased serum valine and leucine levels and the corresponding keto acids, KIVA and KICA, in cirrhotics and controls. KIVA or KICA ingestion increased serum KIVA and KICA concentrations within a few minutes associated with a rise in valine and leucine. In cirrhotics, administration of valine or KIVA resulted in significantly higher serum valine or KIVA concentrations than in control subjects. The clearance of valine and KIVA from blood was also delayed in cirrhotic patients. No such differences were observed after leucine or KICA ingestion. It is suggested that cirrhotics have a diminished tolerance for valine. Since the tolerance for KIVA, but not KICA, is also impaired, it appears that cirrhotics have a derangement in one or more metabolic steps distal to the branched-chain keto acid dehydrogenase.

Administration, Oral↗

Heterologous ovum penetration test and seminal parameters in fertile and infertile men.

Sperm penetration rates in the heterologous ovum penetration test were correlated with results of routine semen analysis in 30 fertile and 50 infertile men. There was no difference in penetration rates when comparing infertile men with normal and abnormal seminal parameters, nor was any difference seen between fertile (15-83%) and infertile men (8-83%). Of the 22 infertile men with normal seminal characteristics, seven had partners with no discernible reproductive dysfunction. The penetration rates of these men (38-81%) did not differ from those of fertile men. Stepwise regression analysis of seminal characteristics, with penetration as the dependent variable, indicated that sperm count and morphology are the most important seminal parameters for fertility assessment. Discrimination analysis revealed that sperm numbers and morphologic variables provide significant information for discriminating between fertile men and infertile men with normal or abnormal seminal characteristics. Sperm penetration and motility were not indicated as important factors. The present data suggest that, in unselected male patients seeking reproductive evaluation, the sperm penetration assay did not yield any additional information on the cause of infertility.

Adult↗

Development of an intravenous glutamine supply through dipeptide technology.

Glutamine is considered as semi-essential amino acid during catabolic stress. Due to its chemical instability in aqueous solutions during heat sterilization and long term storage, it could not be added to infusion solutions so far. In contrast, the dipeptide glycl-L-glutamine exhibits all properties needed for use as glutamine derivative in parenteral nutrition. It is freely soluble in water and does not decompose during heat sterilization. The peptide undergoes rapid enzymatic hydrolysis after infusion. This results in perfect utilization. Glycyl-L-glutamine is already produced in large amounts by chemical synthesis techniques. Both chemical and optical purity of the dipeptide can be controlled by modern chromatographic methods. Glamin, a newly developed complete amino acid solution, contains 20 g of glutamine per liter in form of glycyl-L-glutamine. Since no additional free glycine is added, no imbalances are created by the amino-terminal amino acid of the peptide structure.

Dipeptides↗

Gelatin nanoparticles by two step desolvation--a new preparation method, surface modifications and cell uptake.

A new two-step desolvation method for manufacturing gelatin nanoparticles was developed. After the first desolvation step, the low molecular gelatin fractions present in the supernatant were removed by decanting. The high molecular fractions present in the sediment were redesolved and then desolvated again at pH 2.5 in the second step. The resulting particles can then be easily purified by centrifugation and redispersion. The different fractions obtained during the process were analysed by gel permeation chromatography (GPC). Based on these results, it can be concluded that the molecular weight of gelatin has a decisive influence on the stability of the manufactured gelatin nanoparticles. In addition, two fluorescent dyes (Texasred and fluoresceinamine) were coupled to the nanoparticles for cell uptake studies. The fluorescent nanoparticles showed a high uptake into monocytes/macrophages.

Cells, Cultured↗