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Biomedical subjects

W C Hop

Publications and source records attributed to W C Hop.

At least 199 records · Page 11Linked to original sources
PubMed1995

Decremental follicle-stimulating hormone and dominant follicle development during the normal menstrual cycle.

OBJECTIVE: To study the relationship between decreasing serum FSH levels in the follicular phase of the normal menstrual cycle and follicle development by means of transvaginal sonography and E2 production. DESIGN: Daily blood samples were taken and transvaginal sonography was performed every other day in 16 normal regularly cycling female volunteers. MAIN OUTCOME MEASURE: Serum levels of FSH, LH, E2, and P and follicle diameter by transvaginal sonography. RESULTS: A distinct variability in individual maximal early follicular phase FSH plasma levels was observed (range 4.4 to 11.2 mIU/mL [conversion factor to SI unit, 1.000]). Differences in maximum FSH levels did not correlate with other endocrine or sonographic follicular phase characteristics. The follicular phase FSH decrease (from median 6.6 to 2.9 mIU/mL [conversion factor to SI unit, 1.000]) took place between cycle day 5 and 13 and was linear (0.5 +/- 0.05 mIU/mL per day; mean +/- SD). A significant correlation was found between serum FSH decrease and E2 increase. The day of sonographic appearance of a dominant follicle (median cycle day 8) did correlate with the first rise of the E2 plasma concentration. CONCLUSIONS: The present study suggests that even in women exhibiting normal ovarian function a 2.5-fold difference in FSH threshold concentrations for follicle recruitment does occur. Moreover, the magnitude of decrease in serum FSH concentrations during the follicular phase affects dominant follicle E2 production. The sonographic appearance of the dominant follicle is associated with a rise in serum E2 levels.

Adult↗
PubMed1995

Ceftazidime pharmacokinetics in preterm infants: effect of postnatal age and postnatal exposure to indomethacin.

1. The effects of postnatal age and postnatal exposure to indomethacin on the pharmacokinetic parameters of ceftazidime (CAZ) were investigated in 23 preterm infants (gestational age 28.7 +/- 1.7 weeks; weight 1086 +/- 311 g) on day 3 and day 10 after birth. 2. CAZ (25 mg kg-1) was administered by intravenous bolus injection. Blood samples were drawn from an arterial catheter at 0, 0.5, 1, 2, 4, 8, and 12 h after the dose and CAZ concentrations in serum were determined by h.p.l.c. CAZ pharmacokinetics followed a one-compartment open model. 3. The glomerular filtration rate (GFR) of all infants was studied by means of the 24 h continuous inulin infusion technique. 4. The total body clearance of CAZ (34.7 +/- 9.2 vs 50.6 +/- 19.6 ml h-1, P < 0.05; 30.7 +/- 5.9 vs 41.6 +/- 9.0 ml h-1 kg-1, P < 0.05) and GFR (0.72 +/- 0.11 vs 0.91 +/- 0.15 ml min-1, P < 0.05) increased, whereas the apparent volume of distribution (425 +/- 147 vs 352 +/- 108 ml, P < 0.05; 363 +/- 59 vs 292 +/- 44 ml kg-1, P < 0.005) and the elimination half-life (8.7 +/- 2.8 vs 5.0 +/- 0.9 h, P < 0.005) decreased significantly between day 3 and day 10 after birth. Clearance of CAZ increased with increasing GFR (r = 0.81, P < 0.001). 5. In infants with postnatal exposure to indomethacin the changes in CAZ pharmacokinetics were markedly reduced. 6. These results indicate that the dosage regimen of CAZ should be adjusted after the first week of life except in infants who were postnatally exposed to indomethacin.

Age Factors↗
PubMed1994

Doppler colour flow imaging of fetal intracerebral arteries relative to fetal behavioural states in normal pregnancy.

In 14 normally developing term fetuses, the relationship between the blood flow velocity waveforms at cerebral arterial level (internal carotid artery, anterior, middle and posterior cerebral artery) and fetal behavioural states was studied using Doppler colour flow imaging. Behavioural state dependent changes in absolute flow velocities occurred in all vessels, except for the middle cerebral artery. These changes suggest preferential blood flow to the left heart resulting in increased flow to the cerebrum during fetal behavioural state 2F (active sleep) when compared with fetal behavioural state 1F (quiet sleep). The middle cerebral artery supplies the neocerebrum. This developing part of the cerebrum does not seem to take part in the regulation of fetal behaviour. In the internal carotid artery, an inverse relationship between peak systolic velocity and fetal heart rate could be established, which can be explained by a shorter rapid filling phase at raised fetal heart rate according to the Frank-Starling Law.

Behavior↗
PubMed1994

Changes in long term prognosis for breast cancer in a Dutch cancer registry.

OBJECTIVES: To assess whether the long term survival of patients with breast cancer has changed with time. DESIGN: Population based descriptive study. SETTING: Eindhoven Cancer Registry in south east Netherlands. SUBJECTS: 2052 patients with first primary breast cancer diagnosed between 1955 and 1974. MAIN OUTCOME MEASURES: Overall survival and relative survival. RESULTS: Overall survival was 35% (727 patients) after 10 years, 21% (267) after 20 years, and 15% (25) after 30 years. The corresponding relative survival rates were 43%, 34%, and 34%, respectively. Survival improved from 1955 onwards for all ages and all tumour stages. Improvement was observed in both overall and relative survival. Prognosis was strongly related to the stage at diagnosis in the first 10 years of follow up but independent of stage after 10 years. Survival of patients still alive after 19 years became similar to that of the general female population. CONCLUSIONS: Both short and long term survival improved considerably in all age groups. This improvement was most marked for patients who were diagnosed with a localised tumour. Patients who survive for 19 years may be considered cured.

Adult↗
PubMed1994

[Reconstruction of the digestive tract using a free small intestine interpositional graft following total larynx-pharynx extirpation. Follow-up results].

OBJECTIVE: To evaluate the results of pharyngo-oesophageal reconstruction after pharyngolaryngectomy using a free jejunal interposition graft. DESIGN: Retrospective study. SETTING: University Hospital Dijkzigt, Rotterdam. PATIENTS AND METHODS: Between 1982 and 1992, 59 selected patients (median age 63 years) undergoing laryngopharyngectomy for cancer had the continuity of the upper gastrointestinal tract restored by use of a free jejunal autograft. Twenty-three (36%) had had no previous treatment and received post-operative radiotherapy. Eight patients had laryngeal tumour recurrence after irradiation and in 28 (48%) patients pre-operative radiotherapy had been administered. RESULTS: Follow-up ranged from 1-127 months (mean 37 months). Graft necrosis secondary to vascular problems initially occurred in 5 patients. In four cases the jejunum was successfully replaced by another segment and in one patient a gastric transposition was performed. Fistulas occurred in eight patients of whom four required surgery. The mortality rate was 8.5%. After discharge 6 patients were reoperated on for dysphagia due to stricture formation. In four cases the distal or proximal anastomosis was revised and in the other two patients the graft was replaced, by another segment and by a colonic autograft, respectively. One year after operation 85% of the patients reported an adequate swallowing function and a normal oral intake. The overall 5-year survival rate of this selected group of patients was 42%, for those without primary lymph node involvement 66%. All patients with primary locoregional metastasis died within a period of 34 months after operation. CONCLUSION: Reconstruction of the upper alimentary tract after a laryngopharyngectomy with a free jejunal autograft appears to be a relatively safe procedure with an acceptable mortality and morbidity and, in patients without local lymph node involvement, good long-term results.

Adult↗
PubMed1994

[Intra-abdominal adhesions and foreign-body granulomas following earlier laparotomy].

OBJECTIVE: To determine the prevalence of foreign body granulomas in intra-abdominal adhesions in patients subjected to relaparotomy. DESIGN: Cross-sectional. SETTING: University Hospital Rotterdam-Dijkzigt, the Netherlands. METHOD: From July 1991 to September 1992, 119 patients were subjected to relaparotomy. Presence, distribution and quality of adhesions were scored during the relaparotomy and adhesion samples were taken for histological examination. RESULTS: Adhesions were present in 94% of the patients; they were most frequently attached to small bowel (83%) and omentum (78%). The number of adhesions was significantly smaller in patients with a history of only one minor operation than in those with one major or multiple laparotomies. Foreign body granulomas were found in 22% of the patients with adhesions. These were caused by suture material (19%) or starch glove powder (6%); a combination of both occurred in 3% of the patients. When granulomas were present, the median interval between present and most recent laparotomy was significantly shorter than when no granulomas were found. In patients with adhesions who had had the previous operation less than 6 months previously, granulomas were present in 71%. In contrast, 13% of the patients operated upon longer than 6 months previously had granulomas. CONCLUSIONS: In young adhesions foreign body granulomas occur in large percentages of the cases. This suggests that the intra-abdominal presence of foreign material is an important cause of adhesion formation. Therefore, intra-abdominal contamination with suture material and glove powder should be avoided.

Cross-Sectional Studies↗
PubMed1994

Minimal effects of E. coli and Erwinia asparaginase on the coagulation system in childhood acute lymphoblastic leukemia: a randomized study.

A randomized study was done in twenty newly diagnosed children with acute lymphoblastic leukemia. Ten children were treated with Escherichia coli L-asparaginase, and ten with Erwinia chrysanthemi L-asparaginase. L-asparaginase (ASP) treatment started halfway during ALL-induction treatment with vincristine, prednisone, daunorubicin and intrathecal methotrexate. The mean activated partial thromboplastin time (APTT) level in all children demonstrated a significant fall (P < 0.001) from 28.25 sec at diagnosis to 23.0 sec at the start of ASP treatment. In this same time interval, the mean fibrinogen level declined markedly from 3 g/l to 1.2 g/l (P < 0.001), probably due to prednisone therapy. The APTT stayed shortened during ASP therapy, whereas the hypofibrinogenemia recovered significantly faster in the Erwinia group (P < or = 0.01). Factors (F) II, V, VII and X stayed within the normal range, while F VIII and F IX were elevated. During the entire period of induction therapy, the ATIII activity remained within the normal range in both treatment groups. The protein C values, however, demonstrated a steady decline from 140% at start of ASP treatment to a mean of 81% and 93%, respectively, at the end of the ASP therapy in the E. coli and Erwinia group. Five of the ten children treated with E. coli ASP demonstrated protein C levels below 70% at the end of ASP therapy, opposed to none of the Erwinia treated patients (P = 0.03). We suggest that the effect of ASP resulting in decreased coagulation factor synthesis is in part counterbalanced by the effect of prednisone on the coagulation system, when ASP is administered at the end of ALL induction treatment. The overall effect of ASP either of E. coli or of Erwinia on the hemorrhagic system reveals a slight imbalance towards thrombosis, mainly because of a gradual decrease in protein C activity. This imbalance is less pronounced in the Erwinia group.

Asparaginase↗
PubMed1994

High fat, low carbohydrate, enteral feeding in patients weaning from the ventilator.

OBJECTIVE: To study whether high fat, low carbohydrate enteral nutrition could reduce VCO2 in patients during ventilator support and weaning from the ventilator in order to facilitate the weaning process. DESIGN: prospective, randomized controlled study. SETTING: Medical ICU of a university hospital. PATIENTS: 32 ventilator-dependent patients with a prospect of weaning from mechanical ventilation. INTERVENTIONS: high fat feeding administered to 15 patients and standard isocaloric feeding administered to 17 patients, both in a dosage of 1.5 times basal metabolic rate. MEASUREMENTS AND RESULTS: Respiratory and metabolic measurements were obtained both during mechanical ventilation and weaning procedures. High fat feeding was associated with significantly lower RQ values compared with standard feeding; the mean (+/- SEM) RQ values during mechanical ventilation amounted to 0.91 +/- 0.01 and 1.00 +/- 0.02 and during weaning to 0.72 +/- 0.02 and 0.86 +/- 0.02 for high fat and standard nutrition respectively (both p-values < 0.001). High fat feeding reduced the CO2-excretion both during mechanical ventilation and weaning, but only the decrease during weaning proved to be significant; the mean (+/- SEM) CO2-excretion amounted to 0.177 +/- 0.010 and 0.231 +/- 0.011 1/min STPD for the high fat and standard feeding respectively (p < 0.01). No significant differences were found in the PaCO2 during weaning between the two feeding groups. CONCLUSION: High fat, low carbohydrate enteral feeding significantly reduced the RQ values in ventilated patients with decreases in VCO2, but in this study failed to reduce PaCO2 during weaning from the ventilator.

Analysis of Variance↗
PubMed1994

Prognostic significance of tissue polypeptide-specific antigen (TPS) in patients with advanced non-small cell lung cancer.

In this study, we evaluated the prognostic value of the tumour marker, tissue polypeptide-specific antigen (TPS), in 203 patients with non-small cell lung cancer (NSCLC), and related this to several other known prognostic factors. TPS was significantly correlated with lactate dehydrogenase (LDH), gamma-glutamyltranspeptidase and alkaline phosphatase, and the median level of TPS in patients with stage 4 disease was significantly higher as compared to stage 3A and 3B disease. In the univariate analysis, performance status, stage of disease, LDH, alkaline phosphatase, a histology of undifferentiated large cell carcinoma and TPS all had a statistically significant association with survival. Multivariate analysis showed that stage of disease, performance status, histology and TPS were the most important prognostic factors. TPS has prognostic significance for survival in patients with advanced NSCLC, independent from performance status and stage of disease.

Adult↗
PubMed1994

Parameters of prostate volume and shape in a community based population of men 55 to 74 years old.

Parameters of prostate volume and shape were determined in a community based population of 502 men 55 to 74 years old who had not undergone a previous prostate operation and did not suffer from prostatic cancer. The volumes of the total prostate and of the central relatively hypoechoic area of the prostate were determined. Of all men in this age range 95% had a total prostate volume of more than 20 cm3. Moderate correlations between age and both volume measurements were found (r = 0.26, p < 0.0001 and r = 0.34, p < 0.0001, respectively). The percentage increase per year of central hypoechoic volume (3.5%) was higher than that of total prostatic volume (2%). The average doubling time of total prostatic volume and volume of the central hypoechoic prostate was calculated to be 35 and 20 years, respectively. The roundness of the prostate as expressed by width-to-height ratio at the largest transverse section of the prostate correlated poorly with age (r = -0.13, p = 0.004). The average total prostate volumes as measured by transrectal ultrasound were 21 to 28% higher than reported average volumes measured at autopsy in men in the same age range.

Age Factors↗
PubMed1994

Improved prognosis of breast cancer since 1970 in south-eastern Netherlands.

Despite many new advances in breast cancer therapy since the 1970s, there are only few reports on improved prognosis in a general population. A follow-up of more than 10 years is rarely reported, and a differentiation according to stage of the disease or between follow-up intervals is seldom made. Our purpose was to assess whether prognosis of primary breast cancer improved in patients diagnosed between 1970 and 1984 in south-eastern Netherlands, and to distinguish between different stages and follow-up intervals. Data from 4,467 breast cancer patients diagnosed between 1970 and 1984 were derived from the population-based Eindhoven Cancer Registry. Follow-up was attained up to 1 July 1991. Relative survival rates, as the ratio of the observed to the expected rates, were calculated. In a multivariate analysis a change in prognosis over time was computed with adjustment for age and stage; this was done separately for 5 year follow-up intervals. The relative survival rates were 69% after 5 years, 55% after 10 years and 50% after 20 years. Relative survival, after adjustment for age, was strongly related to the stage of the disease in the first 5 years of follow-up, less markedly between 5 and 10 years, and to a small, borderline significant, extent after 10 years of follow-up. Relative survival rates increased markedly over time, during the whole interval of follow-up. This increase was apparent in all age groups and in all stages, except for those with distant disease at diagnosis. The observed improvement in survival is unlikely to be explained by the increased use of adjuvant chemo- and hormonal therapy. Other factors, such as a change in the natural history of the disease in this period, cannot be ruled out.

Adult↗
PubMed1994

Blood transfusions and local tumor recurrence in colorectal cancer. Evidence of a noncausal relationship.

OBJECTIVE: The authors analyzed the effect of blood transfusions on the pattern of colorectal cancer recurrence. BACKGROUND: Retrospective studies suggest that blood transfusions are associated with a poor prognosis in patients who undergo operations for colorectal malignancies. In a previously published, randomized trial, it was investigated whether autologous blood transfusions could overcome this putative detrimental effect. However, this did not appear to be the case. METHODS: In the current study, the authors analyzed the patterns of recurrence in 420 patients who underwent curative operations for colorectal cancer. RESULTS: Patients who did not require transfusions (N = 143) had significantly better disease-free survival than those who did need transfusions (N = 277); percentages at 4 years were 73% and 59%, respectively (p = 0.001). No difference was found between both groups in comparing cumulative percentages of patients having metastases; percentages at 4 years were 25% in the group that did not undergo transfusion and 27% in the transfused group. The percentage of cases having local recurrence, however, was significantly increased (p = 0.0006) in the transfused group as compared with the group that did not undergo transfusion; percentages at 4 years were 20% and 3%, respectively. The groups of patients receiving only allogeneic, only autologous, or both types of transfusions all had a significantly higher incidence of local recurrence than the patients who did not receive transfusions, but no differences were found between these three groups. CONCLUSIONS: These findings suggest that the association between blood transfusions and prognosis in colorectal cancer is a result of the circumstances that necessitate transfusions, leading to the development of local recurrences, but not of distant metastases.

Aged↗
PubMed1994

Doppler colour flow imaging of fetal intracerebral arteries and umbilical artery in the small for gestational age fetus.

OBJECTIVE: To assess with Doppler colour flow imaging whether a brain-sparing effect is present in all cerebral arteries of the circle of Willis in the small for gestational age fetus, to determine which cerebral flow velocity parameter is most discriminating in this pathological condition, and to relate this parameter to the umbilical artery pulsatility index. DESIGN: Prospective, cross-sectional, matched case-control study. SETTING: Academic department of obstetrics and gynaecology. SUBJECTS: Twenty-eight small for gestational age fetuses and 28 normal controls at 24 to 38 weeks of gestation. INTERVENTIONS: Blood flow velocity waveforms from the umbilical and fetal intracerebral arteries were studied with Doppler colour flow imaging for measurement of peak systolic, end-diastolic and time averaged velocities, and calculation of the pulsatility index. MAIN OUTCOME MEASURES: Comparison of intracerebral and umbilical artery waveform parameters between small for gestational age fetuses and controls. RESULTS: Acceptable flow velocity waveforms were obtained in the intracerebral circulation in more than 85%. In small for gestational age fetuses, all intracerebral arteries displayed reduced downstream impedance. The end-diastolic velocities of the middle and anterior cerebral artery are the most discriminative factors between small for gestational age fetuses and controls. The highest sensitivity was reached for the umbilical artery pulsatility index. CONCLUSIONS: Doppler colour flow imaging allows easy identification of fetal intracerebral arterial vasculature. Whereas for the intracranial vasculature, the end-diastolic blood flow velocities in the anterior and middle cerebral artery are the most sensitive parameters discriminating between small for gestational age and controls, umbilical artery pulsatility index remains the best indicator for the small for gestational age fetus.

Adolescent↗
PubMed1994

Diagnostic value of anti-Candida enolase antibodies.

An immunodominant antigen with enolase enzyme activity was purified and used for the development of an assay to detect antibodies directed against this antigen in sera from patients with either invasive candidiasis or Candida colonization. The Au enzyme-linked immunosorbent assay established with the Candida enolase antigen was able to discriminate significantly between invasive candidiasis and colonization in both immunocompetent and immunodeficient groups of patients. The test had a sensitivity of 50% and a specificity of 86% in the immunocompetent patient group. In the immunodeficient patient group, a sensitivity of 53% and a specificity of 78% were established. Antibody levels determined by a counterimmunoelectrophoresis assay with the same set of sera resulted in a better sensitivity for sera from the immunocompetent patient group but a lower specificity, i.e., 80 and 29%, respectively. The counterimmunoelectrophoresis assay of sera from the immunodeficient patient group was not able to discriminate significantly between invasive candidiasis and colonization. With the use of more serum from each patient, the sensitivity of the antibody detection assays increased, while the specificity was maintained. The increase, however, was not statistically significant. Combining the results of the antibody assays with antigen titers obtained by the Cand-Tec assay did not improve the predictive value with respect to invasive candidiasis, as determined by multivariance regression analysis. Furthermore, it was demonstrated by performance of Western blots (immunoblots) that sera from patients as well as a rabbit antiserum cross-reacted with the Candida enolase and baker's yeast enolase enzyme. However, by tandem crossed immunoelectrophoresis it was demonstrated that the antibodies were directed toward different epitopes of the antigen.

Antibodies, Viral↗
PubMed1994

Dysplasia and aneuploidy as markers of malignant degeneration in Barrett's oesophagus. The Rotterdam Oesophageal Tumour Study Group.

The role of dysplasia and aneuploidy as markers in columnar epithelium for malignant degeneration in Barrett's oesophagus was compared in a case control study comprising 38 patients with benign Barrett's oesophagus and 50 patients with Barrett's oesophagus associated with adenocarcinoma. Tissue specimens of columnar epithelium were reviewed for the presence of specialised columnar epithelium and the grade of dysplasia. Ploidy was determined using the method for formalin fixed paraffin wax embedded tissue described by Hedley. There was no significant difference in the frequency of specialised columnar epithelium between both groups. Dysplasia was found more often in columnar epithelium associated with adenocarcinoma compared with benign Barrett's oesophagus (p < 0.001). Multivariate analysis using logistic regression showed an increased risk of malignancy in Barrett's oesophagus in case of dysplasia (odds ratio 9.4, p = 0.003 for mild dysplasia and 33.1, p < 0.001 for moderate or severe dysplasia). Ploidy was not statistically significantly correlated with dysplasia. Aneuploidy or increased G2/tetraploidy proved to be an independent risk factor for younger patients (age < 65 years: odds ratio 44.7, p = 0.003). In conclusion, dysplasia and aneuploidy or increased G2/tetraploidy in columnar epithelium are independent risk factors for malignant degeneration. Patients with these risk factors should be offered a more intensive screening programme.

Adult↗
PubMed1994

Effects of prenatal exposure to betamethasone and indomethacin on the glomerular filtration rate in the preterm infant.

The effects of gestational age (GA), body weight, and prenatal exposure to betamethasone and indomethacin on the glomerular filtration rate (GFR) on d 3 of life in preterm infants were studied. GFR measurements were performed in 147 preterm infants with a GA between 23.4 and 37.0 wk by means of the continuous inulin infusion technique. Mean GFR values increased significantly with GA (r = 0.60, p < 0.001) and with body weight (r = 0.44, p < 0.001). Multivariate analysis indicated that GA was the most important determinant for this increase. Prenatal exposure to indomethacin resulted in significantly lower GFR values (-0.15 +/- 0.03 mL/min, p < 0.001) at d 3 after birth. Prenatal administration of betamethasone and indomethacin significantly (p < 0.001) increased the GFR in comparison with exposure to indomethacin alone to levels not different than those seen in patients who were not prenatally exposed to betamethasone or indomethacin. GFR measurements were repeated in 40 preterm infants on d 10 after birth. During this 7-d period, a significant increase in GFR values (0.17 +/- 0.03 mL/min, p < 0.001) was detected. This postnatal increase in GFR values was independent of GA and was not influenced by prenatal exposure to betamethasone or indomethacin. We conclude that prenatal exposure to betamethasone or indomethacin exerts significant effects on the renal function of preterm infants in the first days of life.

Betamethasone↗
PubMed1994

Plain film diagnosis in intussusception.

In early childhood intussusception a characteristic gas pattern is often visible on plain radiographs which can be used for diagnosis. To test this hypothesis, radiographs of 163 children with intussusception, and as many controls, were reviewed. By using multivariable analysis, it appeared that five out of seven parameters (reduced amount of gas in the jejunum; lateralization of the ileum; indiscernible caecum; reduced amount of feces in the colon; and visibility of the intussusceptum) had discriminatory value. For each parameter a weighting (in points) was derived and the patients were classified: the higher the score the more likely that an intussusception was present. A sensitivity of 90% and a specificity of 90% were obtained.

Cecum↗