PubMed Health⌕ Search

Biomedical subjects

R Singer

Publications and source records attributed to R Singer.

At least 127 records · Page 7Linked to original sources
PubMed1980

Brachymesophalangia V in Hottentot and "Cape Colored" children in Namibia (South West Africa) and South Africa.

In order to determine the incidence of Brachymesophalangia V, an inspectional and metrical analysis was made of radiographs of 67 Nama-speaking Hottentots aged 2 to 17.5 years, and 210 Rehoboth Basters (in Namibia) and Cape Colored children (near Cape Town) aged 1.5 to 21 years. None of the children displayed cone-shaped epiphysis or early union, and none showed Brachymesophalangia V. It was confirmed that the incidence of Brachymesophalangia V is considerably higher in Mongoloid populations than in Caucasoid or Negroid groups, including Hottentots.

Adolescent↗
PubMed1980

Some properties of acid and alkaline phosphatase in seminal fluid and isolated sperm.

Activities of acid and alkaline phosphatases were examined in spermatozoa isolated from 177 semen samples differing in sperm counts. Alkaline phosphatase was also determined in seminal fluid. The enzymes were assayed using disodium p-nitrophenyl phosphate as substrate and were studied with respect to susceptibility to various concentrations of tartrate (acid) and to heat (alkaline). Electrophoretic separation of alkaline phosphatase from seminal fluid was performed using an Helena apparatus. The results showed that acid phosphatase activity in spermatozoa decreased with increase in sperm densities and that elevation of tartrate from 0.028 to 0.17 M usually correlated an inhibition of the enzyme from 72% to 78% (mean values). Alkaline phosphatase was very low in sperm and generally below the sensitivity of the method used. Activity of alkaline phosphatase in seminal fluid showed a tendency to increase with the increase in sperm counts, but the significance of differences between groups was not statistically valid. Exposure of seminal fluid to 55 degrees C for 16 min resulted in enzyme inactivation of about 90% and in this respect the alkaline phosphatase resembles the enzyme of bone origin. The electrophoretic pattern, however, did not confirm this view and the type of alkaline phosphatase in seminal fluid is not clear.

Acid Phosphatase↗
PubMed1980

Properties of spermatozoa from normospermic and oligospermic human semen fractionated on columns of discontinuous gradients of albumin.

One hundred and twenty-eight samples of human semen, divided into four groups according to sperm counts, were fractionated on two types of columns of discontinuous gradients of bovine serum albumin (3%, 15%, or 7.5%, 17.5%). In addition to morphology and motility, protein and DNA contents of spermatozoa as well as microscopical pictures of their sediments were examined in order to assess sperm sensitivity to damage in the course of common isolation procedures. The proportions of morphological normalcy and motility grades within the groups were higher in the bottom column fractions than in the middle ones; both showing prevalence over parent semen. Motility percentages were also higher in the bottom than in middle fractions, but no prevalence over parent semen was observed. Protein and DNA contents of spermatozoa were similar in the two fractions within the same group. Comparison between groups revealed an increase in percentages of normal morphology and motility and a decrease in protein and DNA with elevation of sperm density. Microscopic examinations revealed similar degrees of contamination in both fractions which were more abundant in oligospermia than in normospermia. It is suggested that sperms with better morphology and motility are as sensitive to common laboratory procedures as cells of lower quality originating from the same specimen.

Cell Fractionation↗
PubMed1979

Progress in the diagnosis of craniofacial injuries and tumours by computer tomography.

This paper tries to demonstrate the diagnostic possibilities and limitations of CT in the facial skeleton. Our results stem from the examination of benign and malignant processes in 250 patients. This paper should demonstrate the different characteristics of the pictures obtained by CT and conventional polytomography. The main purpose of CT is not the diagnosis of fractures - here pluridirectional tomography is far superior - but the demonstration of space-occupying processes of benign and malignant tumours. CT cannot presently be applied to the investigation of different histopathological lesions.

Diagnosis, Differential↗
PubMed1979

Use of dermal flaps about the breasts during major reconstruction.

During major breast surgery, we have achieved superior results by securing a dermal flap to the chest wall. This technique has been used successfully for the past three years with improvement in breast contour, prevention of ptosis, and less pronounced scarring than is produced by techniques of the past.

Breast↗
PubMed1979

Rhytidectomies in office operating rooms.

We report our experiences in 100 consecutive face lifts done in a well-equipped office operating room, and we believe the results answer the question about the safety of face lifts being done in this manner in a carefully screened population. With the application of our preoperative criteria for patient selection, the complication rate in these outpatients compares favorably with the reported rates in inpatient series of face lifts. Patient satisfaction has been higher, we feel.

Adult↗
PubMed1979

Acid phosphatase activity in human semen.

Acid phosphatase activity was examined in normal and abnormal human semen of individuals not suffering from testosterone deficiency. No differences in enzymatic activity between the examined groups were observed. The presence of tartaric acid caused an inhibition of about 95% of enzymatic activity.

Acid Phosphatase↗
PubMed1979

High sperm densities and the quality of semen.

Thirty semens with sperm densities above 200 million per milliliter from patients with fertility disorders were examined for volume, motility, vitality, and morphology of spermatozoa, and for fructose content as well as for percentile decreases with time of activity and viability. In addition, blood levels of follicle stimulating hormone, luteinizing hormone, testosterone, and prolactin were estimated. Percentages of motility, vitality, and morphological normality, motility grades, and percentile decreases in both activity and viability were found to be comparable with those of oligospermic specimens. On the average, volume of semens were lower by about 30% than in normo- and oligospermia. 42% of the investigated semens had low fructose values (below 1 mg/ml). In about 60% of patients the prolactin levels were low (2-5 ng/ml). Follicle stimulating hormone, luteinizing hormone, and testosterone were either within normal range or slightly decreased. Despite the above abnormalities, the overall numbers of "normal" spermatozoa per ejaculate were not inferior to those usually present in normospermic specimens, suggesting that factors of presently unknown nature, involved in regulation of both proliferation and spermatogenesis, might be responsible for fertility disorders in these conditions.

Follicle Stimulating Hormone↗
PubMed1979

Sensitivity of human spermatozoa to various isolation procedures: differences in relation to sperm counts.

The aim of the present work was to examine the sensitivity of human spermatozoa from oligospermic and normospermic semen samples to manipulations in the course of isolation by generally used procedures. To this end we performed protein and DNA estimations in spermatozoa isolated by procedures differing in rigorousness (washings with Ringer's buffer and a medium containing ficoll) as well as microscopic examinations of washed sediments. The results showed that the washed sediments contained, in addition to spermatozoa, materials containing protein and DNA, possibly deriving from the breakage of sperm cells. These materials increased in amount with the decrease of original sperm counts. We suggest that abnormal spermatozoa, whose percentage usually increases with the severity of oligospermia, are more sensitive to damage than the normal ones.

Buffers↗
PubMed1978

[The effect of the shape of aluminum oxide-ceramic implants on its staying power in the dog mandible].

Investigations were carried out on implants of Al2O3 ceramic as secondary single toothe replacement in the lower jaw of young Beagle test dogs. Two basically different forms with altogether 7 variations were tested: the first three types of implants had conical roots and a further 4 had cylindrical roots. Common to all 7 types was an implantation shoulder which was tested for its ability to conduct the masticatory force via the cortical substance to the mandibular bone. All implants are at least under indirect masticatory strain; type 80-40-027-00 was directly under strain: part of the implant, shaped like a premolar protrudes through the gum directly into the oral cavity. Preliminary results show that cylindrical root shapes stood the test well. Their length was of no great importance. Conical root shapes without special provision of retention are not suitable. Firm positioning of the implant during introduction is of prime importance. A cortically placed implantation shoulder is not suitable for the conduction of the masticatory pressure into the mandibular bone in dogs.

Aluminum Oxide↗