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Biomedical subjects

P Kolm

Publications and source records attributed to P Kolm.

At least 55 records · Page 3Linked to original sources
PubMed1994

Fertilization efficiency of morphologically abnormal spermatozoa in assisted reproduction is further impaired by antisperm antibodies on the male partner's sperm.

OBJECTIVE: To investigate the influence of antisperm antibodies on the sperm surface on the outcome of IVF and GIFT. DESIGN: Matched controlled retrospective review of two large series. SETTING: Reproductive endocrine divisions of two level-three academic centers. PATIENTS: Twenty-nine male factor patients (38 IVF cycles) showing positive antisperm antibodies on the sperm by immunobead test treated by IVF at the Norfolk program and 56 similar patients (57 cycles) treated by GIFT at the Tygerberg program. Twenty-nine male factor patients (29 IVF cycles) with negative antisperm antibodies screening matched by wife's stimulation protocol and baseline semen analysis characteristics were used as controls in Norfolk; 56 GIFT patients (56 GIFT cycles) matched similarly were the Tygerberg controls. Study and control groups were divided according to sperm morphology pattern in normal, good, and poor prognosis subgroups for comparison. MAIN OUTCOME MEASURES: Fertilization rate of preovulatory oocytes used in IVF in Norfolk and of GIFT supernumerary preovulatory oocytes in Tygerberg; total and term pregnancy rates (PRs) and abortion rates. RESULTS: Fertilization rate was significantly lower in the IVF (41.9% +/- 2.8%) as well as in the GIFT (26.8% +/- 3.8%) (mean +/- SE) study groups than in the respective control groups (73.1% +/- 3.9% and 61.8% +/- 3.9%). Total and term PRs in IVF per cycle (21.1% +/- 6.6%; 13.2% +/- 5.5%) and per transfer (23.5% +/- 7.4%; 14.7% +/- 6.1%), and in GIFT (25.0% +/- 5.8%; 19.6% +/- 5.3%) in the study groups were also lower when compared with their control counterparts (IVF per cycle: 62.1% +/- 6.2% and 41.4% +/- 6.0%; IVF per transfer: 41.9% +/- 2.0% and 27.9% +/- 1.9%; GIFT: 31.6% +/- 6.2% and 28.1% +/- 6.0%), but the difference did not reach statistical significance. Abortion rates were similar in the IVF study group (37.5% +/- 17.1%) and its control groups (39.9% +/- 11.5%). The abortion rate in the GIFT study group was 14.3% +/- 9.4%, and no abortions were recorded in the control group (not significant). CONCLUSIONS: The presence of antisperm antibodies on the sperm surface per se impairs the outcome of assisted reproduction, mainly in terms of fertilization rate of preovulatory oocytes, and possibly in terms of total and term PRs. This holds true regardless of the impact of other semen parameters, particularly the morphology of the sperm within the semen sample.

Abortion, Spontaneous↗
PubMed1994

Hypothalamo-pituitary effects of RU486: inhibition of progesterone-induced hyperprolactinaemia.

Monkeys given oestrogen priming at physiological levels for at least 1 week become hyperprolactinaemic upon the addition of physiological progesterone administration. Here, using RU486, we test whether that this oestrogen/progestin-induced hyperprolactinaemia results from classical progesterone actions at the hypothalamo-pituitary level. Blood samples were collected daily from study day 1-67. Each monkey (n = 2) received daily injections of 25 micrograms/kg oestradiol benzoate, i.m., on study days 5-60. Progesterone-filled silastic capsules (3 cm) were inserted on study day 14 and removed on day 53. On study days 39-45, each monkey received RU486 (25 mg/day, p.o.). Serum samples were stored at -20 degrees C until assayed for prolactin, oestradiol, progesterone and RU486 by radioimmunoassay. Hyperprolactinaemia was induced in all three monkeys upon insertion of progesterone capsules. Prolactin concentrations fell sharply during RU486 treatment to nadirs some 10-fold less than prior to RU486 treatment. The time series was modelled by the Box-Jenkins autoregressive-integrated moving average (ARIMA) method with progesterone producing a gradual increase in prolactin concentrations and RU486 producing a sudden decrease. Statistically significant effects of progesterone and RU486 were found. Thus, the addition of progesterone to an oestrogenized milieu significantly increased prolactin concentrations, and RU486 fully reversed this effect. This evidence indicates that the progesterone-induced hyperprolactinemia in an oestrogenized milieu results from classical progesterone effects.

Animals↗
PubMed1993

Double-blind placebo controlled randomized trial of indomethacin on urodynamic values measured by radionuclide imaging.

The effect of the prostaglandin synthetase inhibitor, indomethacin on urodynamic values measured by radionuclide imaging was studied in 17 men in a double-blind placebo controlled randomized trial. Measurements were made of voiding time, time for 50% emptying, average flow rate, ejection fraction, post-void residual urine volume, voided volume, and total bladder volume. Statistical analyses indicated no placebo-indomethacin differences between the two groups. Although prostaglandins are thought to contribute to the act of micturition by maintenance of bladder tone and contractility, our studies indicate that a standard dose of the prostaglandin inhibitor, indomethacin, did not affect the voiding component of bladder function. Patients need not discontinue prostaglandin inhibitors and other non-steroidal anti-inflammatory drugs with such effects prior to urodynamic testing.

Aged↗
PubMed1993

Prostate-specific antigen to determine progression-free survival after radiation therapy for localized carcinoma of prostate.

Prostate-specific antigen (PSA) levels after radiation therapy will more precisely and objectively identify the presence of persistent prostate carcinoma. We determined the impact of PSA marker levels on progression-free status for 123 patients treated by interstitial implantation (I-125) and 311 patients treated by external beam therapy (XRT) who have been followed for a median of 109 and 51 months, respectively. Actuarial progression-free survival curves were calculated, using standard clinical criteria, and then recalculated, using PSA marker criteria. Sera obtained twelve months or more after the initiation of XRT and twenty-four months or more after the date of I-125 were used for determination of PSA levels. Using normal PSA level (by Hybritech assay < or = 4.0 ng/mL) as the criterion for progression-free status for patients treated by XRT, 35 percent of patients with Stage A2, 20 percent of patients with Stage B1 or B2, and 10 percent of patients with Stage C tumor were progression-free at ten years. The progression-free survival by clinical criteria for Stage A2 and 65 percent, B1 was 40 percent, B2 was 35 percent, and C was 25 percent. Using undetectable PSA level (< or = 0.5 ng/mL) as the criterion, less than 10 percent of patients were progression-free at ten years, regardless of stage, grade; and treatment modality. This information should not be interpreted as indicating that radiation is ineffective therapy for prostate cancer, since clinical control of the disease among men in their eighth decade is a more practical goal than marker control. However, PSA monitoring after radiation therapy and after any local therapy for prostate cancer will provide more precise information on the success of that therapy in ablating disease.

Actuarial Analysis↗
PubMed1993

Deoxyribonucleic acid cytometric analysis of prostate core biopsy specimens: relationship to serum prostate specific antigen and prostatic acid phosphatase, clinical stage and histopathology.

We describe a sampling method of obtaining fresh prostate cells that yields adequate numbers of cells for flow cytometric deoxyribonucleic acid (DNA) analysis and produces histograms of good resolution. Exfoliated cells from 204 prostate biopsy wash specimens obtained by agitation of biopsy cores in saline were fixed and stained for DNA analysis. The mean percentage of hyperdiploid cells was statistically different between the pathologically benign and malignant specimens (p < 0.0001). Hyperdiploid cells of 22% or more exhibited a high degree of specificity for the malignant specimens with only a 1.4% (1 of 69 benign specimens) false-positive rate. However, sensitivity was only 41% (25 of 59 malignant specimens were associated with a flow cytometry analysis of 22% or greater hyperdiploid cells) because of the high false-negative rate (59%, 35 of 59). The percentage of hyperdiploid cells correlated statistically with increasing prostate specific antigen (PSA) levels and approached significance with Gleason grade but did not correlate with prostatic acid phosphatase or clinical stage. When the amount of hyperdiploid cells was 22% or more and serum PSA level was greater than 4.0 ng./ml. a 95% chance of a malignant biopsy was predicted. This result was greater than that predicted by a PSA elevation alone. Only a 5% chance of a malignant biopsy was present for patients with less than 22% hyperdiploid cells and 4.0 ng./ml. or less serum PSA, a decrease over either method separately. This method of DNA assessment permits prospective categorization of tumors by ploidy without interfering with histological assessment. The prognostic importance of ploidy analysis awaits further clinical followup.

Acid Phosphatase↗
PubMed1992

Six-year survival after coronary thrombolysis and early revascularization for acute myocardial infarction.

Six-year follow-up was conducted in a consecutive series of 192 patients receiving thrombolytic therapy for acute myocardial infarction (AMI) with ST-segment elevation. Cardiac catheterization was performed within a day, and patients with an open infarct artery routinely had early revascularization: 99 (67%) underwent coronary bypass surgery and 18 (12%) coronary angioplasty. With this treatment strategy, 6-year cardiac mortality was 14.5%, 6% (12 patients) in hospital and 9% (16 patients) for survivors of hospitalization. Multivariate analysis showed that predictors of cardiac death among survivors of hospitalization were a closed infarct artery at catheterization (p less than 0.01), diabetes (p less than 0.01) and anterior myocardial infarction (p = 0.01). A subset of 146 patients underwent radionuclide angiography before hospital discharge; for them, predictors of mortality were a closed infarct artery at catheterization (p less than 0.01), anterior wall AMI (p = 0.02), and Killip class III to IV on admission (p less than 0.06). Left ventricular ejection fraction was not a significant predictor of mortality for this subset of patients.

Aged↗
PubMed1992

Intussusception reduction 1991: an international survey of pediatric radiologists.

A detailed survey of intussusception reduction practices at the International Pediatric Radiology '91 meeting in Stockholm yielded 78 responses from radiologists representing 21 countries on six continents. Results indicates a striking lack of conscensus on basic technical issues such as the type of contrast material or reducing agent, the pressure limits for reduction, the use of balloon-tip tubes, the role of sedation, manipulation of the abdomen during reduction, and duration of symptoms beyond which reduction would not be attempted. For example, while gas reduction has been strongly promoted in the literature during the late 1980's, only 34.7% of the respondents indicated that this was their principle choice of reducing agent. Among technique choices which produced significant correlations with outcome, it is noteworthy that pooled data suggest an eightfold increase in perforations among those using gas rather than liquid for reduction. Also, although 53.8% of respondents use parenteral sedation at least part of the time, those who reported using it regularly had significantly lower success rates than all other radiologists. This study provides a current sampling of international opinion in a subject of importance to all pediatric radiologists; and by linking the response with reported outcomes suggests opportunities for further investigation.

Child↗
PubMed1991

Racial pigmentation and the cutaneous synthesis of vitamin D.

The varying epidermal melanin content that produces racial pigmentation determines the number of photons that reach the lower (malpighian) cellular layers, where vitamin D3 synthesis takes place. We investigated the effect of racial pigmentation on vitamin D3 formation, stimulating the process with a fixed dose of UVB radiation (wavelengths, 290 to 320 nm). Vitamin D nutritional status was further assessed measuring serum 25-hydroxyvitamin D and the most active serum metabolite, 1,25-dihydroxyvitamin D. Experimental subjects were young (third decade of life) and healthy, representing the white, Oriental (East Asian), Indian (South Asian), and black races. Basal serum vitamin D3 levels were similar among groups, ranging from 2.3 +/- 0.6 nmol/L (mean +/- SEM) for blacks to 3.4 +/- 1.0 nmol/L for Indians. Following whole-body exposure to 27 mJ/cm2 of UVB, there was a significant racial group effect on serum vitamin D3 levels. Post-UVB levels were significantly higher in whites (31.4 +/- 4.4 nmol/L) than in Indians or blacks (12.8 +/- 2.9 and 9.1 +/- 2.1 nmol/L, respectively), while the levels in Orientals (27.8 +/- 4.4 nmol/L) differed significantly from those in blacks and Indians but not in whites. Race had only a marginal effect on serum 25-hydroxyvitamin D, with higher levels in whites than in blacks (69.9 +/- 12.7 vs 29.7 +/- 6.2 nmol/L). Serum 1,25-dihydroxyvitamin D and vitamin D binding protein levels were similar in all groups. We conclude that while racial pigmentation has a photoprotective effect, it does not prevent the generation of normal levels of active vitamin D metabolites.

Adult↗
PubMed1989

Alzheimer patient evaluation and the mini-mental state: item characteristic curve analysis.

To develop a tool for precisely assessing dementia severity, items should be selected according to their relationship to the overall progression of the disease. Using an item characteristic curve analysis (ICC), items were examined from the Folstein Mini-Mental State Exam (MMSE), a useful clinical tool for evaluating dementia. MMSE data were available for 86 patients who met DSM-III criteria for primary degenerative dementia -- possible or probable Alzheimer's disease (AD). A logistic regression analysis of the probability of correct performance on an item, given the total MMSE score, yielded statistics for difficulty and discrimination. These statistics were interpreted respectively as indicators of the point in the progression of the illness at which the mental function tested by that item is lost and the rapidity of that loss. The data indicated a systematic progression of the development of symptoms in AD related to decline of memory function. Temporal orientation was lost before spatial and object orientation, and recollection of words was lost before ability to repeat them. ICC can help to delineate the loss of mental functions during the course of AD.

Aged↗
PubMed1989

Wound complications after median sternotomy. Relationship to internal mammary grafting.

Case histories of 2582 patients requiring median sternotomy for coronary artery bypass grafting between January 1982 and August 1986 were retrospectively reviewed. Only saphenous vein grafts were used in 230 patients, one mammary artery graft was used in 1626 patients, and both mammary arteries were used in 726 patients. The relationship of potential risk factors and wound complication was evaluated. The overall incidence of wound complications was 0.81%-0.43% in the saphenous vein graft group, 0.49% in the single mammary group, and 1.65% in the bilateral mammary group. Graft type and a number of potential risk factors were analyzed in a logistic regression analysis to determine significant predictors of wound complications. The results indicated that pneumonia, obesity, reexploration, use of the intraaortic balloon pump, and diabetes were significant risk factors contributing to the probability of wound complications. Bilateral mammary grafting was significantly associated with the increased probability of a wound complication developing. Bilateral mammary grafting increased the chance of wound complication nearly five times that of saphenous vein grafting and three times that of single mammary grafting. Mammary artery grafts have been shown to achieve greater long-term patency than saphenous vein grafts, and their continued use is encouraged. However, the potential for increased wound problems should be considered along with other significant preoperative risk factors such as insulin-dependent diabetes, chronic pulmonary disease, and obesity.

Bacteria↗
PubMed1988

Endothelial regulation of cyclic GMP and vascular responses in hypertension.

The mechanism whereby endothelial modulation of drug-induced vascular responses might change during hypertension was examined. Acetylcholine (ACh) (1 microM) induced maximal relaxation of aortic ring segments with intact endothelium from both Wistar-Kyoto, normotensive rats (WKY) and spontaneously hypertensive rats (SHR) at 5 to 6 weeks of age. At 15 to 18 weeks of age the relaxation response to ACh was reduced in rings from both SHR and WKY (to a greater extent in SHR) and was attenuated even more in the deoxycorticosterone acetate (DOCA)-salt hypertensive rat. The contractile responses of aortic preparations to norepinephrine (NE) (0.1 microM) were similar between 5-6-week-old and 15-18-week-old WKY, but were increased in 15-18-week-old SHR compared to 5-6-week-old SHR. Endothelial cell removal increased contractile responses to NE to a greater extent in WKY than SHR but this did not affect that seen in DOCA-salt hypertensive rats. Methylene blue treatment increased contractions of aortic rings with intact endothelium from 15-18-week-old WKY and SHR to the level detected in rubbed arteries, but it did not affect the NE-induced constriction of intact aortic rings from DOCA-salt hypertensive rats. Basal cyclic GMP concentrations in intact aortic rings were not different between SHR and WKY at 5 to 6 weeks of age. The basal aortic cyclic GMP was unchanged in WKY at 15 to 18 weeks of age, but decreased in SHR and in DOCA-salt hypertensive rats of the same age.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗
PubMed1987

Comparing self- and supervisor evaluations: a different view.

Studies comparing self- and supervisor evaluations of performance during medical training have generally indicated a lack of congruence between the two sets of ratings. A possible explanation is that supervisors may make evaluations on the basis of an overall impression whereas self-evaluations are more sensitive to differences between performance in different areas. Support for this explanation was indicated by consistently higher correlations among supervisor ratings of 13 performance areas for first-year residents. Support was also indicated by separate factor analyses of supervisor and self-ratings of 13 areas, in that two factors were identified for supervisors whereas there were three for self-ratings. It was concluded that the data supported the notion that self-ratings were more discriminating than supervisors' in evaluating resident performance across a number of performance areas.

Analysis of Variance↗
PubMed1986

Alteration of 6-phosphofructo-1-kinase isozyme pools during heart development and aging.

The nature of 6-phosphofructo-1-kinase isozyme pools in fetal, neonatal, young adult (3 months), and aged (30 months) rat hearts was studied using chromatographic and immunological techniques. Furthermore, the changing subunit composition of each isozyme pool was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis on 6% slab gels and by immunoblotting with subunit-specific antibodies. Although all three subunit types were expressed in heart throughout life, total activity and the nature of the isozyme pools varied during neonatal development and in aged heart. In fetal heart, the complex tetramers containing all three subunits appeared to be the major isozyme types. As the heart matured to the young adult stage, the M-type subunit increased over 6-fold; whereas the changes in the other two subunits were considerably less. These data indicate that during neonatal heart maturation the isozymic pools progressively exhibited increased amounts of the tetrameric forms containing two or more M-type subunits. In aged heart relative to the young adult (3 months) heart, the total activity and proportion of M-type subunit in the isozymes were decreased; and consequently, the amounts of the M-rich isozymes were decreased. The shifts in the types of isozymes during heart maturation and subsequent aging were primarily due to changes in availability of the M-type subunit to participate in random assembly of the tetrameric isozymes.

Aging↗
PubMed1986

Relative accuracy of the diagnostic components of noninvasive carotid arterial tests: a comparison of pulsed Doppler arteriography and spectrum analysis.

Pulsed Doppler ultrasonography (UA), sound spectrum analysis, and subjective interpretation of the audible signal are valuable methods for assessing carotid arterial disease; however, the relative contribution of each in making a diagnosis is disputed. To investigate this issue, 258 noninvasive carotid studies with measured x-ray comparisons were reviewed. Internal carotid spectra, UA images, and images combined with the technician's comments were each interpreted blindly by three independent readers. Percentage of stenosis was categorized into six groups: 0, 1% to 24%, 25% to 49%, 50% to 74%, 75% to 99%, and 100%. Each reader's assessment of the individual noninvasive components and his overall reading of the complete study were compared with x-ray findings and with those of the other two readers. The readings of the three observers were consistent within each diagnostic component (p less than 0.001). For each reader, the technician's comments significantly improved the accuracy of ultrasonic imaging alone (p less than 0.001). Spectrum analysis was as good as the image plus technician's comments and, for two of three readers, was better than the image alone (p less than 0.001).

Angiography↗
PubMed1986

Endothelial modulation of vascular relaxation to nitrovasodilators in aging and hypertension.

Blood vessel responses to relaxant drugs have been reported to change with aging and with the development of hypertension. In view of the requirement of endothelial cells for the activity of many relaxant drugs, we examined the role of the endothelium in the relaxation response of vascular tissue. Aortic and mesenteric ring segments from normotensive and hypertensive rats, ages 5 to 6, 15 to 18 and 30 to 31 weeks, were examined for relaxation to sodium nitroprusside, sodium nitrite, atrial natriuretic factor and 8-bromo-cyclic GMP. Relaxation responses to the nitrovasodilators were reduced progressively with aging in ring segments of Wistar-Kyoto rats (WKYs) and spontaneously hypertensive rats (SHRs) with intact endothelium; however, intact SHR ring preparations displayed less relaxation to nitrovasodilators at 15 to 18 and 30 to 31 weeks than those of WKYs. Rubbed (endothelium denuded) ring preparations displayed greatest relaxation to nitrovasodilators with no difference being observed between SHR and WKY preparations at any age tested. Relaxation to atrial natriuretic factor and 8-bromo-cyclic GMP was not different between rubbed and unrubbed ring segments or between SHRs and WKYs, indicating no detectable impairment of the overall relaxation response in the vascular smooth muscle of SHRs. These results suggest that the total functional capacity of vascular smooth muscle to relax to nitrovasodilators is not changed with aging or hypertension. However, the endothelial cells exert modulatory influences upon the vascular smooth muscle to reduce overall responsiveness to nitrovasodilators, an effect that is enhanced with aging and the development of genetic hypertension.

Aging↗
PubMed1985

The impact of legal medicine education on medical students' attitudes toward law.

Physicians' negative attitudes toward law and the legal system derive in part from the physician's lack of understanding of basic legal principles relating to medical practice. Required legal medicine education at the medical school level offers a vehicle for changing these attitudes while at the same time clarifying physicians' rights and responsibilities under the law. The authors in this study assess the impact of required curriculum programming in legal medicine at Southern Illinois University School of Medicine on medical students' attitudes toward law and the legal system. A total of 80 students completed a survey instrument prior to and immediately following required instruction in legal medicine. This instrument enabled the authors to gather information regarding students' attitudes toward law and the legal system as well as students' perceptions of ther medical/legal knowledge. The results suggest that legal medicine education has a favorable impact on the attitudes of medical students toward law and the legal system.

Attitude of Health Personnel↗