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Biomedical subjects

R Ma

Publications and source records attributed to R Ma.

At least 163 records · Page 9Linked to original sources
PubMed1987

Cell culture compared with broth for detection of Trichomonas vaginalis.

Trichomonas vaginalis can be grown in cell culture. We studied the growth kinetics of T. vaginalis in McCoy cell culture compared with that in a conventional broth medium (Diamond TYI-S-33 medium supplemented with 10% heat-inactivated bovine serum [TYI]). In the presence of McCoy cells and two parts cell culture medium to one part TYI, a peak concentration of 2 X 10(6) to 6 X 10(6) T. vaginalis per ml was consistently achieved with inocula as low as three T. vaginalis cells per ml. Without cells, this medium did not support growth of T. vaginalis. T. vaginalis in TYI in 1-ml vials with or without McCoy cells demonstrated poor growth. In tubes containing 10 ml of TYI, inocula grew to 2 X 10(6) to 6 X 10(6) T. vaginalis per ml, but at least 3 X 10(3) T. vaginalis per tube was required to initiate growth. Thus, in vitro, cell culture was more sensitive than TYI broth in detecting low numbers of T. vaginalis. In a subsequent clinical comparison of broth and cell culture for isolation of T. vaginalis from 188 vaginal specimens and 21 urethral specimens from men, the results were in agreement for 206 specimens (98.6%). There were no situations in which culture was negative and a saline preparation showed motile trichomonads. For women, using a positive culture as the indicator of true positivity, the sensitivity of detection of T. vaginalis was 83% with the Pappenheim stain and 77% with saline preparations. These studies show that cell culture can be used for isolation of T. vaginalis from clinical specimens; it gave results comparable to those of broth culture for the group of mainly symptomatic women. Further studies should be performed to determine its utility in clinical populations such as asymptomatic women and men with and without symptoms, in which T. vaginalis is more likely to be present in low numbers.

Animals↗
PubMed1987

Chemoattraction of infective larvae of Ancylostoma braziliense to rodent plasmas and to salts.

Infective larvae of Anyclostoma braziliense were tested for orientational response to rat plasma, to mouse plasma, to rat plasma fractions, and to salts. A high percentage of larvae accumulated at sources of rat plasma, mouse plasma, rat plasma diffusate, concentrated rat plasma dialysate, and some salts, notably sodium chloride. Because sodium chloride is present at an effective concentration in mammalian plasma, and because this salt may form a gradient between the blood and the skin surface, sodium chloride from the blood may direct the penetrating larvae through host's skin. Preliminary tracking of the larvae in gradients of rat plasma and of sodium chloride suggests that orientation to sources of these attractants was via a taxis, possibly a klinotaxis, whereas accumulation at these sources was via a klinokinesis.

Ancylostoma↗
PubMed1968

Initiation of deoxyribonucleic acid synthesis after thymine starvation of Bacillus subtilis.

Evidence for premature initiation of deoxyribonucleic acid (DNA) replication after thymine starvation of Bacillus subtilis W23T(-) is presented, based on (i) increase in the number of ade(+) relative to met(+) transformants yielded by the DNA isolated from cultures after starvation (the ade(-) marker being near the origin of replication, whereas met(-) is close to the terminus), and (ii) increase in both the initial rate and final level of tritiated thymine incorporation in the presence of chloramphenicol after release from starvation. The marker ratio data agree quantitatively with the hypothesis that the initiation is induced only on one arm of each chromosome which was replicating prior to starvation.

Bacillus subtilis↗
PubMedDate not supplied

Simplified techniques in rat heterotopic small bowel transplantation.

AIM: Establish a simplified heterotopic small bowel transplantation (SBT) in the rat. METHODS: Ninety pairs of male Wistar rats were used as donors and recipients. The whole small intestine with a vascular pedicle composed of superior mesenteric artery (SMA) and portal vein (PV) was harvested as the graft. Revascularization was accomplished by end-to-side anastomosis between donor SMA and recipient infrarenal aorta and cuffed end-to-end anastomosis between donor PV and left renal vein of recipient. The distal end of graft was exteriorized to form an enterostoma. RESULTS: Average time of an operation was 130 minutes and the mean warm ischemia time of grafts was 30 minutes. The technical success rate of this model was 100% and 7-day survival was 95.6% (86/90). CONCLUSION: This simplified technique was effective and practical to improve the outcome of rat heterotopic SBT.

Animals↗
PubMedDate not supplied

Effects of ulinastatin on postoperative systemic inflammatory response of recipients of rat small bowel transplantation.

AIM: We sought to evaluate the effects of ulinastatin on postoperative systemic inflammatory responses of recipients of rat small bowel transplantations (SBT). METHODS: Twenty-four recipients of rat heterotopic SBT were randomly divided into a control group and a treated group. Ulinastatin (50,000 U/kg(-1)/d(-1)) was injected intravenously 30 minutes before graft revascularization. Measured variables included plasma concentrations of tumor necrosis factor (TNF), interleukin (IL)-6, and C-reactive protein (CRP) on postoperative days 1 and 3. RESULTS: Administration of ulinastatin attenuated the postoperative increases in plasma concentrations of TNF, IL-6, and CRP. CONCLUSION: Ulinastatin attenuated the postoperative systemic inflammatory response of rat recipients of SBT.

Animals↗
PubMedDate not supplied

Body-size corrections for in vivo neutron activation analysis.

Differences in body size and shape can cause large variances in the results of in vivo neutron activation analysis. Preliminary body-size correction data were obtained for the delayed-gamma neutron activation facility (DGNA) at Brookhaven National Laboratory (BNL), based on phantom standards of different sizes, used in combination with computer simulations on the effect of different body sizes.

Body Composition↗
PubMedDate not supplied

Total body chlorine: calibration of the in vivo neutron activation measurement.

Total body chlorine (TBCI), used to estimate the extracellular space, is measured by delayed-gamma neutron activation (DGNA) using the reaction 37Cl(n, gamma)38Cl, at Brookhaven National Laboratory. During the calibration process, we noticed that different values were obtained when different amounts of Cl were placed in the phantom. This non-linear relationship is due to the thermal neutron flux suppression by the thermal neutron capture reaction 35Cl(n, gamma)36Cl. Monte Carlo simulations confirm the results of phantom measurements showing an inverse relationship between the Cl content in the phantom and the gamma-ray yield per gram Cl. Thus, it is important to calibrate the DGNA system for TBCl using phantom standards containing an amount of Cl close to that expected in the individual undergoing measurement.

Body Composition↗