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Biomedical subjects

W C Hop

Publications and source records attributed to W C Hop.

At least 289 records · Page 16Linked to original sources
PubMed1989

Cerebral Doppler ultrasound of the human fetus.

Maximal flow velocity waveforms were recorded in the internal carotid artery (ICA), middle cerebral artery (MCA), posterior cerebral artery (PCA) and anterior cerebral artery (ACA) in 55 normal pregnancies and 14 complicated by intrauterine growth retardation between 25 and 41 weeks gestation. In normal pregnancy, acceptable flow velocity waveforms were obtained in the ICA in 89%, in the MCA in 91%, in the PCA in 58% and in the ACA in 64%. A decrease in pulsatility was observed in all four intracranial arteries during the latter weeks of gestation. In growth-retarded pregnancies, pulsatility in all vessels was significantly reduced compared with normal pregnancy, suggesting participation of all major intracranial arteries in a brain-sparing effect in the presence of chronic fetal hypoxia.

Blood Flow Velocity↗
PubMed1989

Risk factors in outpatient extracorporeal shock wave lithotripsy.

At present, outpatient extracorporeal shock wave lithotripsy (ESWL) is practiced in many centers for the treatment of urinary calculi. The safety of outpatient treatment is difficult to assess, no appropriate indications and criteria for patient selection have been established. In a retrospective study 1,203 patients, treated with ESWL using the Dornier HM-3 lithotriptor for the first time over the year 1986, were evaluated to analyze possible risk factors for outpatient ESWL. By multivariate analysis various pretreatment factors were investigated for their relation with complications arising from ESWL therapy. It was shown that stone size and sex of the patient were the strongest determining factors. In the present study a low-risk group (5% complications) could be identified, suitable for outpatient treatment, corresponding to 74% of the patient population. The remaining patients (26%) are at higher risk (18% complications) and should be considered for hospital treatment.

Ambulatory Care↗
PubMed1989

Fetal cardiac and peripheral arterial flow velocity waveforms in intrauterine growth retardation.

Maximum flow velocity waveforms were studied at the cardiac level (ascending aorta, pulmonary artery, and ductus arteriosus) and at the peripheral level (fetal internal carotid artery, descending aorta, umbilical artery, and maternal uteroplacental artery) in 25 patients with intrauterine growth retardation and 25 normal control subjects matched for gestational age and maternal parity. Gestational age ranged from 27 to 35 weeks (median, 30 weeks). All flow velocity waveforms were obtained with a mechanical sector scanner combined with a pulsed and continuous Doppler system with a carrier frequency of 3.5 and 3.0 MHz. Normal pregnancy was characterized by low fetal and placental vascular resistances. The peak systolic velocity in the ascending aorta was significantly higher compared with the pulmonary artery. In patients with intrauterine growth retardation, reduced end-diastolic flow velocities were documented in fetal descending aorta, umbilical artery, and maternal uteroplacental artery, reflecting raised umbilical placental and uteroplacental vascular resistances. Raised end-diastolic flow velocities were observed at the cerebral level, reflecting reduced cerebral vascular resistance ("brain sparing" effect). Reduced peak systolic flow velocities documented at the cardiac level may be secondary to reduced volume flow, increased valve or vessel size, or raised afterload. The noninvasive nature of this study did not allow differentiation between these variables.

Adolescent↗
PubMed1988

Consequences of blood loss on growth of artificial metastases.

Previous studies have shown that lung metastases from a nonimmunogenic sarcoma (LS175) in BN (homozygous for RTln) rats were stimulated by blood transfusions. Enhanced growth was also observed after abdominal surgery combined with allogeneic blood transfusions while syngeneic blood transfusions had no effect. These experimental findings have been confirmed in retrospective clinical studies. The allogeneic blood transfusion effect may be avoided in cancer patients by autologous blood transfusions although this implies blood donation before surgery. The aim of the present study was to investigate the effect of blood loss before surgery on formation ('take') of lung colonies, and on the outgrowth of established metastases in the BN rat model. These aspects of tumour behaviour were also investigated in rats undergoing surgery, or receiving blood transfusion, or both, after blood loss. The results indicate that blood loss has a profound stimulating effect on the growth of established metastases, but not on the 'take' of tumour cells. This stimulating effect was also present when blood loss was combined with surgery, while previously surgery alone was found to have no effect. Allogeneic and syngeneic transfusions in combination with blood loss both had a strong stimulating effect on growth of established lung metastases. The results indicate that blood loss may be an important factor in determining the outcome of metastatic growth.

Animals↗
PubMed1988

Factors influencing the outcome of successive IVF treatment cycles in attaining a follicular puncture.

An analysis has been made on data from 576 cycles in 300 patients regarding the chances of various superovulation protocols attaining a puncture in successive cycles. The cumulative proportion of patients with at least one successful stimulation increased from 77% at the first attempt, to 98% at the fifth attempt. Of the 576 stimulations, 440 (76%) resulted in a puncture. Age, the number of ovaries and the reaction to superovulation induction contribute to the outcome of a cycle, the chances being lowest for older individuals with one ovary and an inadequate reaction in the first treatment cycle. Changing the treatment protocol did not improve the outcome in subsequent gonadotrophin-induced cycles, even if combined with clomiphene citrate. Reasons for cancellation did not tend to recur, although the incidence of dominance and premature stimulation was significantly higher in patients aged greater than 35 years. Age-dependent chances of success were calculated.

Adult↗
PubMed1988

Association of high plasma prorenin with diabetic retinopathy.

Plasma prorenin, but not renin, is elevated in long-standing diabetes mellitus. Nephropathy and autonomic neuropathy have been implicated as causes. However, we found no arteriovenous difference in prorenin across the kidney, despite high levels of circulating prorenin and a very low renal plasma flow, in five diabetics with combined end-stage nephropathy and proliferative diabetic retinopathy. Moreover, plasma prorenin was normal in 16 non-diabetics with autonomic neuropathy. The presence of a high level of prorenin was closely associated with the presence of diabetic retinopathy, particularly the proliferative type, in 223 consecutive patients. This association was independent of insulin requirements, metabolic control and of the presence of nephropathy or neuropathy. These data are evidence that part of the elevated plasma prorenin in diabetics is produced by an extrarenal source and that perhaps the eye affected by diabetic retinopathy is that source.

Blood Pressure↗
PubMed1988

Fetal internal carotid and umbilical artery blood flow velocity waveforms as a measure of fetal well-being in intrauterine growth retardation.

Maximal flow velocity waveforms were recorded on one occasion from the umbilical artery (UA) and fetal internal carotid artery (ICA) in 240 normal pregnancies and 44 cases of intrauterine growth retardation between 26 and 39 wk of gestation. In normal pregnancy the mean UA pulsatility index (PI) decreased from 1.14 (SD: +/- 0.13) at 26-27 wk of gestation to 0.78 (SD: +/- 0.15) at 38-39 wk. The corresponding decrease in ICA PI was from 1.63 (SD: +/- 0.19) to 1.31 (SD: +/- 0.21). Mean values of UA PI for normal pregnancies were linearly related to gestational age; for ICA PI this relation appeared to be quadratic. Normal limits according to age were constructed by estimated means +/- 2 SD. In intrauterine growth retardation, the UA PI was increased (greater than 2 SD) in 80% of cases, ICA PI was reduced (greater than 2 SD) in only 45%. The outcome of fetuses with intrauterine growth retardation, as expressed by fetal heart rate abnormality, Apgar score at 1 min, and umbilical cord pH, was significantly related to the UA PI but not to the ICA PI.

Blood Flow Velocity↗
PubMed1987

Tobramycin in patients with cystic fibrosis. Adjustment in dosing interval for effective treatment.

The efficacy of the dosing regimen of tobramycin was investigated in 28 patients with cystic fibrosis who had an acute exacerbation of chronic pulmonary infection with Pseudomonas aeruginosa. The initial dose of tobramycin was 3.3 mg/kg of body weight three times daily (ie, 10 mg/kg/day). A highly significant relationship was found between the serum concentration of tobramycin before the dose and the change in the forced expiratory volume in one second (FEV1), both measured on the tenth day of treatment (rs = 0.75; p less than 0.001). In nine of the 16 patients who had a six-hour serum concentration of 1 mg/L or less on the tenth day of treatment, the eight-hour dosing interval of tobramycin was shortened to achieve a serum concentration of tobramycin of about 1 mg/L before the dose. In the other seven patients, the dosage of tobramycin was not changed. On the 20th day, seven of the nine patients in whom the dosing interval was shortened exhibited an increase in FEV1 of 20 percent or more. Such an increase was observed only in one of the seven patients in whom the dosing interval was not reduced (p less than 0.05). We conclude that individualizing the dosage of tobramycin in patients with cystic fibrosis results in a better clinical outcome.

Acute Disease↗
PubMed1985

Grading of prostatic cancer (I): An analysis of the prognostic significance of single characteristics.

This paper contains the first part of an attempt to quantitate the impact on prognosis of various parameters used in grading of prostatic cancer. Out of 346 patients of Elmer Belts series, 113 were identified whose tumors showed homogeneity with respect to single characteristics of a total of 12 parameters applied for grading in Mostofi's system. By this procedure it was possible to eliminate the possible influence on prognosis of the presence of several tumor formations within the same tumor. By using overall and intercurrent death corrected survival as end points, the impact of each of the 12 parameters on prognosis was studied. Only the architecture of the tumor (the parameter "glands"), variation in size and shape of the nucleus (anaplasia), and grade significantly influenced overall survival. In addition, corrected survival was significantly dependent on the amount of tumor seen and on the presence of mitoses. Subsequently, an attempt was made to replace "grade" by single parameters which had been shown previously to be of prognostic significance. It turned out that this was not possible. Grade is largely dependent on architecture and nuclear pleomorphism, but neither one of these parameters alone can reproduce "grade." Multivariate analysis was next used to further determine the prognostic weight of the individual parameter, and, if possible, to construct a new, more efficient grading system. These results will be reported separately [8]. It is unknown at the present time what the impact of several architectural formations within the same tumor on prognosis may be. The number of different formations found ranges from 1 to 4 in this material; 668 different formations belonging to 346 tumors were graded. The results of this analysis will be reported in part two of this series of papers [7].

Cell Nucleolus↗
PubMed1985

Grading of prostatic cancer: II. The prognostic significance of the presence of multiple architectural patterns.

This second report in a series of three deals with the prognostic importance of the presence of multiple, histologically identifiable architectural patterns in prostatic carcinomas. In the previous paper three of 12 parameters studied were identified as being prognostically significant in patients with single architectural patterns (formations) present in their tumors. The three parameters are nuclear anaplasia, architecture ("glands"), and mitoses, if present. The questions of whether "the worst part of a tumor determines prognosis" or "the presence of differentiated formations improves prognosis" are investigated by applying these parameters to patients with multiple tumor formations. Overall and corrected survival served as parameters. It was shown that the parameters shown to be of importance for prognosis in tumors with single formations also have significant influence in patients with multiple formations. The worst formation determines prognosis, but patients with poorly differentiated tumors do significantly worse if their tumor is homogeneous. The presence of better-differentiated formations improves the prognosis of the worst formation. The observations made are discussed in view of the histopathogenesis of prostatic cancer.

Cell Nucleus↗
PubMed1985

Grading of prostatic cancer: III. Multivariate analysis of prognostic parameters.

This work is based on the two previous publications which are concerned with grading prostatic carcinoma. In the present communication the technique of multivariate analysis is applied to quantify the prognostic importance of parameters which were earlier identified as contributing in a significant manner to grading. The results of this analysis are used to construct a scoring system which differentiates five significantly different prognostic groups. When compared to the results of grading, the new system is shown to be superior. The large group of 228 patients with G2 tumors can be split into three groups, each with a significantly different prognosis. The correlation of the scoring system to local tumor extension (pT category) is described. Recommendations for grading of prostatic carcinoma resulting from this work are the following: Only three independent parameters are of significance for grading prostatic cancer: tumor architecture, nuclear anaplasia, and the presence or absence of mitoses. The combination of these parameters in a scoring system identifies five separate prognostically different groups. The separation achieved by this new system is superior to conventional grading and is suggested for grading prostatic cancer.

Humans↗
PubMed1984

Treatment of metastatic breast cancer patients with different dosages of megestrol acetate; dose relations, metabolic and endocrine effects.

Megestrol acetate (MA) is of therapeutic value in breast cancer patients. This study was designed to evaluate the effects of different dosages of MA on endocrine events potentially influenced by the drug in relation to plasma level of MA and clinical effects in patients with advanced breast cancer. Eighteen postmenopausal patients were randomly distributed over six groups to receive daily 90, 180 or 270 mg of MA (niagestin) orally in a cross-over study consisting of 3 periods of 6 weeks. Complete remission was observed in 1 patient, partial remission in 9, no change in 4 and failure in 4 patients. During the 18 weeks of treatment plasma levels of MA gradually increased, irrespective of the dose administered. Significant rises of the basal and TRH-stimulated plasma PRL and basal insulin levels were observed, whereas LH and FSH, estradiol, SHBG and the pituitary-adrenal axis were suppressed. None of these metabolic effects showed a correlation with the clinical response. We concluded that treatment of metastatic breast cancer with 180 mg MA/day is effective and causes minimal adverse effects.

Administration, Oral↗
PubMed1984

Prognostic scoring using cytomorphometry and lymph node status of patients with breast carcinoma.

Applying morphometry on FNA smears may lead to meaningful prognostic subgrouping of breast carcinomas. A statistical analysis of the cytomorphometric and clinical data of 73 patients with breast carcinoma was performed. By multivariate analysis, taking into account various prognostic factors, it was shown that variations in nuclear area and the presence of axillary metastases were the most important prognosticators. By weighing these factors a prognostic score was obtained. According to that score the patients were classified into 4 score groups: the decreasing survival with increasing score was evident. The prognostic score was also related to the metastasis-free period. This prognostic scoring is relatively easy to perform, and can be done in routine pathology laboratories.

Aged↗