Biomedical subjects
R S Thompson
Publications and source records attributed to R S Thompson.
A comparison of Doppler ultrasound waveform indices in the umbilical artery--I. Indices derived from the maximum velocity waveform.
Various Doppler waveform indices have been used for assessment of the fetal circulation. Comparisons were made to show what relations exist between the indices, and to identify any differences or difficulties which might arise from using one as opposed to another in clinical practice. Both normal pregnancy and cases of fetal growth failure were studied. Indices were obtained from the maximum velocity envelope of the umbilical artery waveform using a curve fitting technique. The values were very reproducible for all indices. The FHR, which varied over the entire normal range, did not significantly affect the values of any index. The downstream impedance indices calculated included the AB ratio, pulsatility index (PI) and Pourcelot ratio. These all gave very closely correlated results for normals but discrepancies occurred in the at risk group, where values were elevated. This could be attributed to differences in the underlying distributions. The indices suggested for cardiac contractility were not as closely related to each other, and moreover the differences between them showed no clear pattern. None of the indices varied independently of the others. The rising slope, which is by definition related to the PI, was more highly correlated with the downstream indices than the relative flow rate index.
A comparison of Doppler ultrasound waveform indices in the umbilical artery--II. Indices derived from the mean velocity and first moment waveforms.
Umbilical artery Doppler recordings in both normal pregnancy and cases of fetal growth failure were processed by computer. Representative waveforms for the maximum velocity, mean velocity and first moment were obtained after ensemble averaging and correction for thump filtering. The same set of indices, which included the AB ratio, pulsatility index, rising slope and relative flow rate index, were calculated for each of the waveforms. The results were compared to identify differences which might arise in clinical practice if a waveform other than the usual (maximum velocity) was used. The ratio of the mean to the maximum velocity, which gives an indication of the velocity profile, was shown to be very error prone. The reproducibility of the mean velocity and first moment indices was inferior to that of the maximum velocity indices. The results from the different waveforms were highly correlated for normals for most indices. However, in the growth retarded group there was a tendency for the mean velocity and first moment indices to classify as normal studies classified as abnormal by the maximum velocity index. The values of indices derived from the first moment waveform were generally larger than the maximum and mean velocity values. For the relative flow rate index, where results were often different to the general trend, the values were more nearly equal.
Maximizing compliance with hemoccult screening for colon cancer in clinical practice.
A factorial design randomized controlled trial to test several clinically feasible strategies primary-care practitioners may use in routine practice to increase patient participation in occult blood testing for colorectal cancer is reported. Three compliance-enhancing intervention strategies (physician/nurse talk, and/or reminder postcard, and/or reminder phone call) were introduced. Patient health beliefs were examined as compliance predictors. High compliance levels were seen in all intervention groups, with a mean of 89% compared with 68% in controls. An interactive talk by the physician or nurse increased compliance by 12-13%. The reminder postcard was the most effective single intervention. It increased compliance by 24-25%, achieving 92.7% overall compliance, and appeared to be cost-effective. Patient health beliefs were of minimal value in predicting compliance in this study.
Quantification of liver and kidney phosphofructokinase by radioimmunoassay in fed, starved and alloxan-diabetic rats.
A newly developed specific radioimmunoassay was used to quantify phosphofructokinase protein directly and independently of assayable activity in liver and kidney cytosol of normal fed, starved and alloxan-diabetic rats. In the fed state, liver phosphofructokinase concentration was 0.096 microM and the kidney enzyme was 0.086 microM (mumol/kg of tissue). In the starved state (24h), liver and kidney phosphofructokinase concentrations decreased by 30%. Prolonged starvation up to 72h did not further decrease enzyme concentration. In liver, total enzyme content during starvation declined by more than 50%, secondary also to a decrease in liver weight. In the alloxan-diabetic rats, there was a 22% decrease in enzyme protein concentration in liver and kidney. Total enzyme content per liver actually decreased much more (46%), because diabetes also resulted in a decrease in liver size. In conjunction with assayable activity measurements, the results of the radioimmunoassay allowed us to calculate the apparent specific activity of the enzyme. The specific activity of the kidney enzyme was 2-3 times that of the liver. Little or no change in specific activity of the liver or kidney enzyme occurred as a result of starvation or chemically induced diabetes. Tissue enzyme concentrations of phosphofructokinase unequivocally reconcile the ultimate results of changing rates of synthesis and degradation and are useful data in the design of spectrophotometric, kinetic, aggregation-disaggregation and other studies.
Changes in physician behavior and cost savings associated with organizational recommendations on the use of "routine" chest X rays and multichannel blood tests.
Group Health Cooperative (GHC) of Puget Sound is a prepaid health plan with 285,000 enrollees and 340 physicians. In 1978 a "criterion analysis" approach was instituted to develop medical staff recommendations about preventive care. By 1979, two recommendations evolved discouraging the "routine" use of: (a) chest X rays (CXR) and (b) multichannel blood tests (MCBT) in asymptomatic adults at "routine" physical exams. An extensive educational campaign was conducted to change physician behavior in use of these tests. Usage patterns were measured both before and after the recommendations and educational programs. A fivefold fall in "nonindicated" use of CXR and a 1.5-fold fall in MCBT occurred. A cost savings of $166,582 (annually) resulted from this diminution in "nonindicated" testing. The decision-making process and educational campaign technology hold promise for GHC's preventive medicine program in the future. These results may have applicability to other health care organizations.
Evaluation of initial implementation of an organized adult health program employing family nurse practitioners.
An organized program for periodic health evaluation of adults was instituted at one Group Health Cooperative Clinic (A) using a fixed exam schedule and two family nurse practitioners (FNPs), working in a team with six family practitioners, to perform as many of the examinations as possible. We evaluated the effects of the FNP program at Clinic A in terms of six specific objectives, comparing it with the preexisting conventional pattern in another clinic (B). The evaluation showed 1) diminished waiting times at Clinic A; 2) no diminution in quality of examinations performed by FNPs; 3) lesser unit costs in Clinic A; 4) no indication of higher overall postexam outpatient utilization or costs for those examined by FNPs; 5) greater patient satisfaction at Clinic A than Clinic B, and for those examined by FNPs, compared with those examined by physicians (MDs); 6) only 17 per cent of FNP time was spent on health evaluations and met one half the overall demand at Clinic A; 7) FNPs made day-to-day practice qualitatively more complex for some MDs; and 8) different staffing ratios are probably necessary when FNPs are teamed with family physicians rather than internists.
The effects of prenatal diethylstilbestrol exposure on the genitalia of pubertal Macaca mulatta. II. Male offspring.
In order evaluate the potential embryotoxic and fetotoxic effects of in utero diethylstilbestrol (DES) exposure on the developing offspring, 19 pregnant rhesus monkeys were administered 1 mg/day DES orally beginning on either day 19 (group I), 100 (group II) or 130 (group III) or gestation and termination on the day of natural birth or cesarean section. Five of ten male offspring are alive at 7 years of age. At 4 1/2 years of age, three of these five offspring exhibited one or more abnormalities of the external genitalia, including testicular hypoplasia, preputial adhesions and undescended testes. Semen analysis following rectal electroejaculation and testicular biopsies at 5 1/2 years of age confirmed two cases of testicular hypoplasia. Semen evaluation, testicular biopsies and analysis of serum testosterone levels at 6 1/2 years of age indicated normal testicular morphology and function in all DES-exposed males as compared with colony controls. Our study, therefore, suggests that DES may affect maturation of the reproductive tract as indicated by a delay in the normal breakdown of preputial adhesions in addition to gross and microscopic evidence of testicular hypoplasia during the postpubertal period between 4 1/2 and 5 1/2 years of age. Further observations on breeding performance and fertility are required to evaluate the long-term effects of DES in this species.
Approaches to prevention in an HMO setting.
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The effects of prenatal diethylstilbestrol (DES) exposure on the genitalia of pubertal Macaca mulatta. I. Female offspring.
Nineteen pregnant female rhesus monkeys (Macaca mulatta) received 1 mg/day diethylstilbestrol (DES) over three time periods during gestation: day 21 to delivery (group I), day 100 to delivery (group II) and day 130 to delivery (group III). Seven females and five males of a total of 20 offspring are presently alive at 5 1/2 years of age; one female died at 5 years of age. No deaths have been shown to be treatment related. In female offspring, menstruation began at about 2 1/2 years of age, was irregular for approximately one and one-half to two years and then became regular. Vaginal ridging and/or cervical hooding have been observed in seven of the eight DES-exposed females, and three had histologically demonstrable vaginal adenosis. None of the anomalies was related to a specific treatment period, for they appeared in all treatment groups, nor did they occur in the age-matched controls. Furthermore, none of the animals, either treated or control, showed any evidence of adenocarcinoma. Therefore, exposure of Macaca mulatta females to DES in utero appears to be teratogenic, but thus far no carcinogenicity has been observed. Reports in humans indicate that adenocarcinoma is an additional manifestation of prenatal exposure to DES; also, treatment effects appear to be more commonly observed in individuals exposed during the early stages of gestation. From this viewpoint, the rhesus monkey is a potentially valuable model for the study of vaginocervical anomalies and adenosis, but it is premature to consider it a suitable model for the study of adenocarcinoma.
Recovery of midcycle human follicular oocytes: correlation of their morphology with endomethrial and follicular histology.
The ovarian follicles of 23 of 33 women undergoing elective pelvic laparotomy during menstrual cycle days 11 to 17 were aspirated by a low-vacuum device. The study compared the ovulatory status of women in midcycle with the health of the oocytes obtained, and determined the frequency of recovery of mature oocytes without the preadministration of exogenous hormones. Maturing or mature oocytes were obtained from 22% and nonmature oocytes from 48% of the 23 women. Sixty per cent of the women in each of the maturing or mature and nonmature groups were postovulatory as judged by evaluation of the endometrial and ovarian tissue recovered. Furthermore, 20% of the maturing or mature oocytes and 65% of the nonmature oocytes showed a moderately heavy amount of cytoplasmic degeneration, which was independent of ovulatory status. Therefore, it is concluded that, because of the relatively low rate of return of oocytes, the frequent postovulatory status of patients in midcycle, and uncertainty about the viability of the oocytes so obtained, women not stimulated by exogenous hormones are ill-suited for recovery of maturing or mature follicular oocytes for in vitro fertilization studies.
Anti-implantation action of a medicated intrauterine delivery system (MIDS).
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Anomalous patterns of mammalian oocyte maturation and fertilization.
This report illustrates some of the errors that may occur during in vivo and in vitro maturation and fertilization of mammalian ova, considers the possible mechanisms accounting for their occurrence, and discusses their functional consequences. Included in the description are anomalies of oocyte and follicular development, i.e., multinucleated oocytes, polyovular follicles, and aberrations of zona pellucida formation. Also considered are deviations from the normal process of oocyte maturation such as chromosomal anomalies, development of abnormal nuclear structures (subnuclei), inhibition of polar body formation and abberations of polar body structure. Anomalies of the process of fertilization such as polyspermia, sperm penetration into polar bodies, and development of multinucleated blastomers in two-cell embryos are also described.
Azulene analogs of pharmacological agents III: acute toxicity and local anesthetic activity of azulylamides and azulenecarboxamides.
This paper describes the acute toxicity of two azulylamides and six azulenecarboxamides and the nerve conduction-inhibiting properties of some of these compounds. The azulene derivatives are compared to their benzenoid prototypes, lidocaine and procainamide, as part of a continuing investigation of the biological properties of nonbenzenoid aromatic compounds.
Laparoscopic recovery of mature human oocytes.
This report provides a detailed description of a method by which mature or maturing human oocytes can safely be recovered by follicular aspiration during laparoscopy. By combining gonadotropin administration with laparoscopic recovery, oocytes which have resumed or completed meiotic division can be obtained for study without subjecting the patient to more hazardous surgical procedures. Fifteen oocytes were obtained from sixteen patients. On electron microscopic examination, four were found to have extruded polar bodies and were therefore classified as mature. Daily rather than intermittent administration of HMG, larger HMG dose, longer HCG aspiration intervals, and controlled aspiration pressures appeared to be the factors which produced the best yield of mature oocytes.
Phagocytosis of supernumerary spermatozoa by two-cell embryos.
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Fertilization of mouse ova in vitro: an electron microscopic study.
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Letter: Racemic epinephrine in croup.
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