Biomedical subjects
R White
Publications and source records attributed to R White.
Spontaneous contractions of dispersed vascular muscle in cell culture.
Dispersed vascular muscle cells from chick omphalomesenteric vessels maintained in primary cell culture contracted spontaneously. Six methods which produced contracting isolated muscle cells are described and compared. The combination of dispersion method and culture conditions to produce contracting muscle cells was more critical for vascular than for heart muscle. These findings of continuing pacemaker function demonstrate that functional integrity of isolated vascular muscle cells is possible to maintain. Further indication of the full functional state of the isolated vascular muscle cells was demonstrated by the sensitivity to norepinephrine at a physiological concentration (0.1 muM). Spontaneous contraction frequencies were similar to the range found in situ, and spontanious or norepinephrine-induced contractions had time courses corresponding to intact vessel contractions. This is the first report that isolated vascular muscle cells in primary cell culture retain functional characteristics found in situ and are suitable for pharmacological characterization of individual muscle cells.
Pregnancy during the hysterogram cycle.
Because of potential mutagenic effects of radiation on the soon-to-be fertilized ovum, we questioned whether we should advise against conception during the cycle in which a hysterosalpingogram is performed. Our results do not suggest any increase in the incidence of spontaneous abortion or congenital anomalies in these patients. Therefore, we see no need to advise against conception during the cycle in which a hysterosalpingogram is performed.
Some political influences surrounding the Nurses Registration Act 1919 in the United Kingdom.
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Sturt College of Advanced Education. The school of health profession.
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Coral-algal associations: capacity for producing and sustaining elevated oxygen tensions in situ.
Net oxygen production during photosynthesis by all plants requires adaptation to intracellular O2 tensions in excess of 0.21 ATA. The symbiotic association of zooxanthellae (algae) in the tissues of many actinozoans and hydrozoans (corals and anemones) suggests such an adaptation in these tissues as well, and raises the question as to degree. Oxygen production by zooxanthellae in a single coral head of Montastrea cavernosum was monitored daily in situ in a closed, recirculating 15-liter system. The net photosynthetic activity repeatedly raised the PO2 to more than 0.5 ATA, indicating that even higher tensions existed in the coral's tissues in order to cause this increase and suggesting that coral tissue may represent another example of an oxygen-adapted tissue.
Mouse satellite DMA in noncentromeric heterochromatin of cultured cells.
Specific chromosomes in several mouse lines have interstitial C-bands. In situ hybridization studies indicate that these interstitial bands contain typical mouse satellite DNA.
The effect of vaginal lubricants on sperm motility in vitro.
Apart from the documentation of the spermicidal effects of KY Jelly and Surgilube, little information about the effect of vaginal lubricants on sperm motility has been available. Fifteen substances utilizable as vaginal lubricants were therefore tested for their effect on sperm motility in vitro. Petroleum jelly and glycerin had minimal detrimental effects on motility and apparently are the lubricants of choice when an infertility problem exists.
Genetic heterozygosity in unreplicated bacteriophage lambda recombinants.
Bacteriophage crosses using density-labeled parents have been carried out under conditions restricting DNA synthesis. The parental material and genetic contributions to progeny manifesting recombination within a genetic interval sufficiently short to exhibit high negative interference have been examined. The unreplicated products of recombination isolated as phage particles appear to contain long continuous heteroduplex regions which are heterozygous for the closely linked markers. Recombination between closely linked markers seems to be the consequence of the removal of base-pair mismatches that are present within the heteroduplex regions. This localized reduction of heterozygosity within the heteroduplex regions that join the parental components of recombinant DNA molecules can account for high negative interference.
Lipiarmycin, a new antibiotic from Actinoplanes III. Mechanism of action.
In vivo, at low concentrations (less than or equal to 1 mug/ml), the antibiotic lipiarmycin specifically inhibits RNA synthesis in Bacillus subtilis. At a much higher concentration (100 mug/ml), syntheses of other macromolecules such as DNA and protein also appear to be suppressed. In vitro, the antibiotic caused 50% inhibition of DNA-dependent RNA-polymerase from B. subtilis at a concentration of 0.6 mug/ml and of that E. coli at 5 approximately 8 mug/ml. The activity of Escherichia coli DNA-polymerase I is inhibited 50% at 55 approximately 65 mug/ml. Lipiarmycin prevent ribonucleoside triphosphate polymerization only if added prior to the association between RNA-polymerase and DNA, and does not affect the elongation rate of RNA chains at concentrations up to 100 mug/ml. At that concentration, however, the antibiotic immediately blocks the polymerization of deoxyribonucleotide triphosphates catalyzed by DNA-polymerase I.
Improved renal allograft survival using the mixed lymphocyte culture for selection of nonidentical living related donors.
Our results concur with earlier published work, by other groups, showing that LRD-recipient pairs with low MLC stimulation usually have better and more prolonged graft success than do those with higher stimulation. Specific HL-A compatibilities or incompatibilities did not seem to affect these results, nor did the presence of an increased number of common loci, short of increasing the apparent chromosome compatibility. The presence of pre-transplant cytotoxic antibodies, in patients with a high MI, however, may unfavorably affect the LRD transplant. The overall results of our LRD transplant experience is shown in Figure 1, and superimposed upon Figure 2, is the current extrapolation of data showing MLC stimulation and haplotype success. Thus, it appears that graft survival may be improved and more closely approach the levels seen in a full-house, diplotype match, by using the MLC results in considering patients for transplantation. Not all patients with a high MLC, however, (see table) reject their grafts and it is impossible to predict pre-transplant who will develop specific allograft enhancement. Before the MI becomes a specific criteria for transplant selection, additional studies of patient stimulation in MLC should be done. Suppression of stimulation by donor cells in autologous serum, as compared to the response to unrelated controls, might provide pre-transplant clues to the presence of enhancing factors. Such studies could provide an index that would be more meaningful than the MI in AB sera alone. Since overall results from both our series and from the Transplant Registry continue to indicate better long term graft survival for LRD than for cadaver transplants, and since the evidence suggests that a successful transplant offers a patient a better quality of life, as well as decreased morbidity and mortality compared to concomitant time spent on hemodialysis, continued LRD transplants with high MI is warranted in some circumstances with the patient's understanding of the overall outcome and backgrouns. Until in vitro tests can be more predictive of individual rather than statistical graft success, the patient with an LRD and a high MI should be given a complete explanation of the probabilities for success or failure, and he and the donor allowed to make an informed decision. The following are guidelines that we proposed for the selection of LRD transplants: 1. Availability and willingness. 2. Medical and psycho-social clearance. 3. ABO compatibility. 4. Negative direct crossmatch. 5. HL-A diplotype or haplotype. 6. MI less than 10 if possible, with or without HL-A antibodies. 7. MI greater than 10 with no HL-A antibodies, if possible. 8. MI greater than 10, with HL-A antibodies, if both donor and recipient clearly understand the enhanced chance for failure.
Direct measurement of total dissolved gas pressure.
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Cerebral lipofucsinosis induced with tellurium: electron dispersive X-ray spectrophotometry analysis.
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Effects of serum proteins on pulmonary surfactants in vitro: evidence of a protective mechanism in pulmonary edema.
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The effects of marijuana on human sleep patterns.
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