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PubMed1992

Selection bias in genetic-epidemiological studies of cleft lip and palate.

The possible impact of selection bias in genetic and epidemiological studies of cleft lip and palate was studied, using three nationwide ascertainment sources and an autopsy study in a 10% sample of the Danish population. A total of 670 cases were identified. Two national record systems, when used together, were found suitable for ascertaining facial cleft in live births. More than 95% ascertainment was obtained by means of surgical files for cleft lip (with or without cleft palate) without associated malformations/syndromes. However, surgical files could be a poor source for studying isolated cleft palate (CP) (only a 60% and biased ascertainment), and they cannot be used to study the prevalence of associated malformations or syndromes in facial cleft cases. The male:female ratio was 0.88 in surgically treated cases of CP and was 1.5 in nonoperated CP cases, making the overall sex ratio for CP 1.1 (95% confidence limits 0.86-1.4) The sex ratio for CP without associated malformation was 1.1 (95% confidence limits 0.84-1.6). One of the major test criteria in CP multifactorial threshold models (higher CP liability among male CP relatives) must be reconsidered, if other investigations confirm that a CP sex-ratio reversal to male predominance occurs when high ascertainment is achieved.

Cleft Lip↗
PubMed1993

Transposition of the great arteries with intact ventricular septum. Arterial switch repair in patients 21 days of age or older.

Since 1985 we have performed arterial switch repair for infants with simple transposition of the great arteries (with intact or virtually intact ventricular septum) who were younger than 2 months of age. As of December 1990, a total of 118 arterial switch operations had been performed for transposition of the great arteries with intact ventricular septum. Although correction is usually performed in the first 14 days of life, 18 infants had operations at or after 21 days (range 21 to 118 days; mean 38 days). Fourteen of 18 patients had echocardiographic or catheter evidence (or both) of low left ventricular pressure at the time of operation. None of these patients had preliminary pulmonary artery banding. Mortality was 5.6% (1 of 18 patients, confidence limit 0.8% to 17%) for the older group versus 0% (0 of 100 patients; confidence limit, 0% to 1.8%) for patients less than 21 days of age. The single death occurred in a 22-day old, 1.8 kg premature baby, probably as a result of a problem with a coronary anastomosis. One patient required a left ventricular assist device for 2 days after the operation. These data suggest that with appropriate perioperative management and support, the arterial switch procedure can be safely carried out as a primary procedure for patients up to the age of 1 month and probably up to the age of 2 months.

Age Factors↗
PubMed2005

Economic evaluation of a randomized trial comparing Helicobacter pylori test-and-treat and prompt endoscopy strategies for managing dyspepsia in a primary-care setting.

BACKGROUND: In western European countries, most dyspeptic patients are initially managed by their general practitioners (GPs), who use a range of strategies to manage dyspepsia. We performed an economic analysis of a Helicobacter pylori test-and-treat strategy versus a prompt endoscopy approach in a primary care setting. METHODS: Data were used from the Strategy: Endoscopy versus Serology (SENSE) study, performed in The Netherlands from 1998 to 2001. Patients were randomized to a prompt endoscopy (n = 105) or test-and-treat (n = 118) group. Follow-up lasted 1 year. Adverse events were not recorded in the SENSE study. Health care costs were based on the total amount of dyspepsia-related drugs used, the number of dyspepsia-related GP visits, the number of diagnostic tests, and the number of dyspepsia-related referrals to specialists. The use of medical resources was calculated as standardized costs for 1999, recorded as euros. (On December 31, 1999, 1.00 Euro = 1.00 US dollar.) Quality of life was measured at inclusion and 1 year later, using the RAND-36 questionnaire. To calculate quality-adjusted life-years (QALYs), we transformed the individual scores of the RAND-36 into 1 overall score, the Health Utilities Index Mark 2, which introduced a limitation to the study. An incremental cost-effectiveness ratio (ICER) was calculated. The 95% confidence limits were calculated using a parametric bootstrap method with angular transformation. All cost data were analyzed from a third-party payer perspective. RESULTS: The total costs per patient were 511 Euros, with 0.037 QALY gained per patient, in the test-and-treat group, and 748 Euros, with 0.032 QALY gained per patient, in the endoscopy group (between groups, P < 0.001 and P = NS, respectively). The point estimate of the ICER indicated that the test-and-treat strategy yielded cost savings and QALYs gained. Parametric bootstrap confidence limits indicated cost savings per QALY gained in 75.7% of the bootstrap simulations. CONCLUSION: This analysis of data from the SENSE1026 study suggests that the H pylori test-and-treat strategy was more cost-effective than prompt endoscopy in the initial management of dyspepsia in general practice, from the perspective of a third-party payer.

Adult↗
PubMed2005

Paired observations of refractive error after cataract surgery.

PURPOSE: To quantify the design effect if pairing between eyes is ignored when reporting refractive outcome following cataract surgery. METHODS: A retrospective review was conducted of biometry prediction error in 612 patients who had bilateral phacoemulsification with intraocular lens (IOL) implantation. The levels of uncertainty (confidence interval and variance) of the estimates for the biometry prediction error were compared when intra-cluster correlation between ocular measurements of paired eyes within each patient was either taken into account or ignored. The design effect (the ratio of the two variances) was calculated. RESULTS: The correlation between the two eyes was weak, as indicated by the intra-cluster correlation coefficient of 0.22 (confidence limits 0.15-0.30). The mean biometry prediction error was 0.73 dioptres (D) and the 95% confidence limits for the mean in the two situations were similar at 0.69-0.76D and 0.69-0.77D, respectively. The variance of the biometry prediction error if pairing of eyes was ignored (0.00033D) was slightly less than if pairing was taken into account (0.00041D). This yielded a design effect of 1.2. CONCLUSIONS: A high correlation between data collected from pairs of eyes is not inevitable. If data on both eyes are used to estimate biometry prediction error, the usual statistical procedures will underestimate the standard errors and the variance, but the effect will be trivial and the confidence intervals only negligibly smaller. The maximum variance is expected to be 1.2 times higher than that given by simple statistical methods that ignore the pairing of eyes.

Biometry↗
PubMed1990

[Spontaneous variability in ischemic episodes during everyday conditions. Role of ST-Holter monitoring in assessment of therapy].

To analyze the daily spontaneous variability of ischemic ST-segment changes and to derive criteria for statistical documentation of a therapeutic antiischemic effect, in 30 patients with coronary artery disease, with the aid of Holter monitoring the frequency of episodes E1 and E2 during everyday activities without medication was registered for two consecutive 24-hour periods. The spontaneous variability of the ischemic episodes of an individual patient was defined as the frequency distribution of the respective percent changes [(E2-E1)/E1].100 = (E2/E1-1).100 from day to day. To fit the curve to a normal distribution, logarithmic transformation was performed: [formula: see text] where i designates the number of patients. The constant 0.01 serves to correct for the event of episode frequency = 0. From the standard deviation sd of this logarithmic quotient, by retransformation, the one- and two-sided confidence limits K for the percent spontaneous variability are derived from the equation K = -(10-z alpha.sd-1).100; z alpha = 1.65 or 1.96. A statistically significant therapeutic effect can be assumed if, on paired comparison of 24-hour registrations with and without treatment, the limits are exceeded. Possible aggravation by the drug must be ruled out with the one-sided confidence interval. From the standard deviation sd, the standard deviation sd/square root of n for the collective of n = 5 ... to n = 30 patients was calculated and, analogously to the individual patient, the corresponding one- and two-sided 95% confidence limits for a significant therapeutic effect are defined.(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗
PubMed1994

Serum parathormone profile during surgical treatment of hyperfunctioning parathyroid adenoma: a multicompartmental model.

Patterns of intact parathyroid hormone (iPTH) elimination and subsequent recovery of parathyroid function were studied in seven patients undergoing surgical removal of solitary hyperfunctioning parathyroid adenoma. Using a sensitive two-site immunoradiometric assay, iPTH levels were measured pre, peri-, and postoperatively. Blood samples were taken at very early and at late stages, including 3, 6, 9, and 15 minutes and 48, 72, and 96 h after adenomectomy. A biexponential formula was calculated to fit the decreasing values of iPTH in all patients. The PTH half-life in the early phase was 1.4 +/- 1.1 minutes (95% confidence limits). The PTH half-life in the second phase was 64.45 +/- 32.19 minutes (95% confidence limits). A third phase is represented by a slow, linear increase in plasma iPTH values as a result of the recovery of healthy suppressed parathyroid glands. The extrapolation to baseline of the later phase shows that the recovery of normal parathyroid function begins as soon as 240 minutes after adenomectomy and is independent of the decrease in PTH of adenomatous origin. All individual results were consistent with this model. Five patients had iPTH values below 5 pg/ml, one had 15 pg/ml, and the last had 27 pg/ml 5 h after parathyroid adenomectomy. The recovery of the hormonal activity of the remaining glands occurred rapidly. By the postoperative hour 24 the mean serum iPTH concentration was 12.28 +/- 8.07 pg/ml. The intraoperative serum iPTH concentration offers a model to assess both recovery of hormonal secretion from functionally suppressed parathyroid glands and disappearance of parathyroid hormone.

Adenoma↗
PubMed2003

Impact of diltiazem administration and cyclosporine levels on the incidence of acute rejection in heart transplant patients.

To identify the clinical factors associated with acute rejection (AR) in the first year after heart transplantation (HT), we analysed 112 patients. All patients received OKT3 and standard triple-drug therapy. We analysed the following variables to determine their relationship with AR: age and gender, panel-reactive antibodies, HLA-DR mismatch, use of Sandimmune vs Neoral, diltiazem administration, and cyclosporine levels in week 2 and months 1, 2, and 3 after HT. Fifty-two patients had no AR and 49 had at least one episode. The variables independently associated with absence of AR were diltiazem administration (odds ratio 0.306, confidence limit 0.102-0.921) and cyclosporine level in the first month after HT (odds ratio 0.996, confidence limit 0.992-0.999). Furthermore, a cyclosporine level greater than 362 ng/ml in the first month predicted the absence of AR. In conclusion, a cyclosporine level greater than 362 ng/ml and diltiazem administration in the first month after HT reduce AR during the first year. Both cyclosporine level and diltiazem show a large and independent protective effect.

Acute Disease↗
PubMed1992

The risk of upper gastrointestinal cancer in familial adenomatous polyposis.

Adenomas with potential for malignancy occur frequently in the upper gastrointestinal tract of patients with familial adenomatous polyposis. However, an assessment of relative risk of upper gastrointestinal cancer in patients with adenomatous polyposis has never been performed. Therefore, the incidence rate of upper gastrointestinal cancer in patients with familial adenomatous polyposis in The Johns Hopkins Registry was compared with the rate of the general population through person-year analysis with adjustment for demographics. There was an increased relative risk of duodenal adenocarcinoma (relative risk, 330.82; 95% confidence limits, 132.66 and 681.49; P less than 0.001) and ampullary adenocarcinoma (relative risk, 123.72; 95% confidence limits, 33.65 and 316.72; P less than 0.001). No significant increased risk was found for gastric or nonduodenal small intestinal cancer. These results indicate that periodic surveillance of the upper gastrointestinal tract for duodenal and periampullary cancer is needed in patients with familial adenomatous polyposis. Prophylactic duodenectomy is a consideration when large adenoma(s) with high-grade dysplasia are identified but awaits risk benefit analysis.

Adenomatous Polyposis Coli↗
PubMed1994

Normal values of urinary albumin and total protein excretion during pregnancy.

OBJECTIVE: Our purpose was to determine the normal 24-hour excretion values of urinary albumin and total protein in healthy pregnant women. STUDY DESIGN: We evaluated 270 healthy pregnant women < or = 35 years old without a history of diabetes, hypertension, pyelonephritis, preeclampsia, or renal or connective tissue disease. Adequacy of 24-hour collection was determined by creatinine excretion. RESULTS: The mean protein excretion in 24 hours was 116.9 mg, upper 95% confidence limit 259.4 mg. The mean albumin excretion in 24 hours was 11.8 mg, upper 95% confidence limit 28.7 mg. Both protein and albumin excretion increased after 20 weeks of gestation. No patient had evidence of microalbuminuria, defined as urinary albumin excretion > 30 mg/L. CONCLUSION: These data support 260 mg per 24 hours of urinary protein and 29 mg per 24 hours of albumin as the upper limit of normal in pregnancy. Albumin accounts for a small fraction of total urinary protein excretion.

Adult↗
PubMed1987

Vasectomy and the risk of prostatic cancer and benign prostatic hypertrophy.

The incidence of prostatic disease (prostatic cancer and benign prostatic hypertrophy) was studied in a cohort of 5,332 vasectomized Kaiser Permanente Health Plan members, each matched with 3 nonvasectomized comparison subjects. Relative risks of 1.0 for prostatic cancer (68 cases, 95 per cent confidence limits 0.6 and 1.7) and 1.2 for benign prostatic hypertrophy (90 cases, 95 per cent confidence limits 0.7 and 1.8) were associated with vasectomy. In this study group the risk of prostatic disease was not altered by a history of vasectomy.

Adult↗
PubMed1986

A simple method for definition of incomplete suppression of aldosterone and its association with hypertension and hypokalaemia in man.

By defining a model for control of potassium homoeostasis, patients with unexplained hypokalaemia may then be described as fitting or not fitting the model. Fitting the model implies an abnormality of known control mechanisms (e.g. aldosterone); by contrast, not fitting the model suggests other unknown factors responsible for the hypokalaemia and, possibly, hypertension. In the presence of normal acid-base status, potassium excretion (UK+V) is regulated by plasma potassium (PK+), delivery of sodium to the distal tubule and aldosterone secretion. A linear relationship (correlation coefficient of 0.72) was defined by: UK + V/PK+ = 5.1 X log(UAldoV) X log(UNa+ V) + 1.4 based on a 24 h urine collection and plasma sample, in 16 normal subjects, 50 hypertensive normokalaemic subjects and 11 patients with hyperaldosteronism. The relationship was robust and held true for variations in dietary sodium and potassium intake (5-300 and 20-100 mmol/day respectively) and variations in aldosterone excretion produced by enalapril. Patients with abnormal renal potassium wasting due to known extraneous factors (n = 11) all fell outside the 95% confidence limits. Twelve patients with hypertension and hypokalaemia and renal potassium wasting all fitted within the confidence limits, being no different from 22 controls selected on the basis of age and urinary potassium excretion (30-50 mmol/day). This suggests that in these 12 patients the hypokalaemia (but not necessarily the hypertension) was not due to 'unknown' steroids but rather lack of regulation of the controlling variable, aldosterone.

Aged↗
PubMed2002

Incidence and risk factors of upper extremity deep vein lesions after permanent transvenous pacemaker implant: a 6-month follow-up prospective study.

The incidence of venous lesions after permanent pacemaker insertion is around 45%. However, this incidence has been based on retrospective studies in a small series; moreover, factors predicting the development of these venous injuries have not been clearly defined. The aim of this study was to identify the risk factors for higher incidence of upper extremity deep vein thrombosis after transvenous permanent pacemaker insertion. The study included 229 patients and the criteria were age above 12 years and first permanent transvenous pacemaker implant. Exclusion criteria were pulmonary embolism, lower or upper extremity deep venous thrombosis, previous use of central venous catheters, coagulation disturbances, and malignancy. Age, race, sex, underlying cardiac disease, functional class to heart failure, LVEF, venous access, number, material and caliber of the leads, and previous use of a transvenous temporary pacemaker were considered. Six months after the pacemaker was implanted, 202 patients were submitted to digital subtraction venography ipsilateral to pacemaker implant. The venographies were normal in 73 (36%) patients and abnormal in 129 (64%) patients. Patients with previous use of transvenous temporary leads (P = 0,0001, OR = 4,260, confidence limits = 2,133-8,465) and LVEF < or = 40% (P = 0,0378, OR = 3,437, confidence limits = 1,064-12,326), had higher incidence of venous lesions. Previous use of a temporary pacemaker and LVEF < or = 0.40 were considered independent risk factors to a higher incidence of venous stenosis or thrombosis 6 months after permanent pacemaker insertion.

Angiography, Digital Subtraction↗
PubMedDate not supplied

Equine trypsin: purification and development of a radio-immunoassay.

Shock is accompanied by generalised splanchnic hypoperfusion, and splanchnic organs like the pancreas can be damaged, as shown in animal experimental models and in humans, by the presence of high plasma concentrations of trypsin and other pancreatic enzymes. In order to design a radioimmunoassay technique (RIA) for the measurement of equine trypsin-like immunoreactivity (TLI) in biological fluids, trypsin was purified (with purity > or = 96%) from the equine pancreas by extraction in an acid medium, ammonium sulfate precipitations, gel filtration chromatography and, after activation of trypsinogen into trypsin, affinity chromatography. Gel polyacrylamide electrophoresis showed a monomeric enzyme with a molecular weight of 27 kDa. The purified equine trypsin served for the immunisation of rabbits in order to obtain a specific antiserum, and the labelled antigen was prepared by iodination of equine trypsin with 125I. The RIA was based on the binding of the antigen to the antibody followed by the separation of the antigen-antibody complex by immunoprecipitation in the presence of sheep anti-rabbit gammaglobulins and the assay of the radioactivity in the precipitate. The RIA showed good sensitivity, specificity, precision, accuracy and reproducibility. The reference mean value of TLI in the plasma of healthy horses (n = 20) was 30.01+/-6.84 ng/mL (upper confidence limit 50.52 ng/mL; p < 0.01). Three horses with non strangulating intestinal obstruction without shock showed TLI values within normal limits whereas 5 of 7 horses with strangulation obstruction showed TLI levels above the upper confidence limit. Further studies using the RIA and the enzymatic assay should be performed in order to confirm the role of the pancreas in equine intestinal obstruction.

Animals↗
PubMed2002

Intrahepatic heterogeneity of hepatic venous pressure gradient in human cirrhosis.

BACKGROUND: The hepatic venous pressure gradient (HVPG) is used to evaluate portal hypertension. METHODS: We measured HVPG in two separate liver veins in 169 liver vein catheterizations in 102 cirrhosis patients and in 27 patients with no liver disease (controls). RESULTS: In the controls, the two measurements differed by 0.0 +/- 1.8 mmHg (mean +/- s, n = 27), upper 95% confidence limit 3.6 mmHg (mean + 2 s). HVPG ranged from -0.1 to 8.3 mmHg, upper 95% confidence limit 6.7 mmHg. In cirrhosis, the two measurements agreed within +/- 3.6 mmHg in 39%. In 61%, the measurements differed by 4-34 mmHg. In 35%, fluoroscopy demonstrated hepatic vein-to-hepatic-vein shunting in veins with low HVPG values. In some patients with HVPG measurements above 30 mmHg, Doppler ultrasound examination showed arterialization of the hepatic vasculature. DISCUSSION: Our results demonstrate a hitherto unrecognized notable heterogeneity of the intrahepatic vasculature and HVPG measurements in cirrhosis. The presumption of interposition of non-flowing blood between the catheter tip and the portal system for the measurement of HVPG may thus be violated in about one-third of the cirrhosis cases because of abnormal outlet into hepatic venous shunts and in a minor fraction because of abnormal arterial inlet. In 26%, one measurement was below 12 mmHg, the other measurement above. If the HVPG had been measured in only one liver vein, 13% of the cases would have been classified in a lower risk group than appropriate according to the 12 mmHg concept of risk of bleeding from oesophageal varices.

Adult↗
PubMed1994

Megakaryocyte DNA content is increased in patients with coronary artery atherosclerosis.

OBJECTIVE: Increased megakaryocyte size and megakaryocyte ploidy have been observed in man following myocardial infarction and sudden cardiac death. The aim of this study was to compare megakaryocyte ploidy in patients with and without coronary artery atherosclerosis. METHODS: Sternal megakaryocytes were obtained immediately prior to cardiac surgery in 26 patients with significant coronary artery atherosclerosis requiring surgical bypass grafting and in 14 age matched control patients requiring cardiac valve replacement or repair with minimal or no coronary atherosclerosis on arteriography. Megakaryocytes were identified using a monoclonal antibody to the CD41 (GPIIb/IIIa) surface antigen and ploidy was studied using flow cytometry. RESULTS: Megakaryocyte modal ploidy was significantly higher in the coronary atherosclerosis patients (modal ploidy 8N, n = 0 subjects; 16N, n = 16; 32N, n = 10) as compared with the control group (modal ploidy 8N, n = 5 subjects; 16N, n = 7; 32N, n = 2), p = 0.008. Ploidy correlated with the degree of coronary atherosclerosis defined as the number of atherosclerotic vessels observed on angiography (r = 0.51, p < 0.001, 95% confidence limits 0.25 to 0.70) and the serum total cholesterol concentration (r = 0.50, p = 0.006, 95% confidence limits 0.18 to 0.72). Bleeding time was not different [315(semiquartile range 45) s v 315(75) s] between the two groups in spite of the fact that 20 of 26 coronary atherosclerosis patients were taking aspirin versus one of 14 valve patients. CONCLUSIONS: Megakaryocyte ploidy is increased in human coronary atherosclerosis and correlates with serum lipids. Hypercholesterolaemia may induce increases in megakaryocyte ploidy, and hence the production of hyperfunctional platelets, which will contribute to atherogenesis.

Cholesterol↗
PubMed1984

Cancer mortality of the Korean population in Japan 1968-1977.

Cancer mortality of the Korean population in Japan for the period 1968-1977 was examined using a standardized mortality ratio (SMR) based on Japanese mortality for 1975. The most frequent site of cancer for Korean males and females in Japan was the stomach but the rate has declined recently for both sexes. Based on deaths from all malignant neoplasms in the period 1973-77, the SMR for all sites among Korean males in Japan was 161 (95% confidence limits - 147 and 176), whereas the ratio for Korean females in Japan was 94 (95% confidence limits - 81 and 109). Compared with Japanese, Koreans in Japan had a significantly higher SMR for cancer of the liver and trachea-bronchus-lung in both sexes.

Epidemiologic Methods↗
PubMed1998

Total knee arthroplasty in patients 55 years old or younger. 10- to 17-year results.

Seventy-four consecutive total knee arthroplasties in 54 patients who were 55 years of age or younger (average age 43 years) were reviewed. All patients had a minimum followup of 10 years with an average followup of 13 years (range, 10-17 years). No patients died or were lost to followup. The preoperative diagnosis was rheumatoid arthritis in 47, gonarthrosis in 12, posttraumatic arthritis in six, osteonecrosis in three, hemophilia in two, and one patient each with pigmented villonodular synovitis, tuberculosis, systemic lupus erythematosus, and achondroplasia. The knee score improved from an average of 36 points (range, 10-80 points) preoperatively to 84 points (range, 37-100 points) at latest followup. The functional score improved from 45 points (range, 0-100 points) to 60 points (range, 0-100 points) at latest followup. Two patients had their implants revised: one at 3 years because of ligamentous laxity and one at 13 years because of aseptic loosening of the tibial component. There were no deep infections. There were no radiographically loose implants at latest followup. The implant survival to revision at 10 years was estimated at 99% (confidence limit, 96%-100%). The implant survival to revision at 15 years was estimated at 95% confidence limit, 88%-100%). Cemented total knee arthroplasty in the young patient is a reliable procedure and has excellent results at 13-year followup with an estimated survivorship of 99% at 10 years.

Adult↗
PubMed1992

Genetic control of the renal clearance of urate: a study of twins.

Although a genetic predisposition to gout has been recognised for centuries, its mechanism has never been defined. This study was designed to determine whether this factor might be the renal clearance of urate, which is an important determinant of the concentration of urate in serum. In this study the renal clearance of urate was examined in 37 pairs of normouricaemic twins to determine whether this resemblance was genetically mediated. Monozygotic twins had more similar values of urate clearance and fractional excretion of urate than dizygotic twins. The heritability of the renal clearance of urate was estimated as about 60% (95% confidence limits 40 to 100%), whereas the heritability of the fractional excretion of urate was 87% (confidence limits 45 to 100%). This study supports the hypothesis that genetic factors exert an important control on the renal clearance of urate, which determines some of the familiarity of hyperuricaemia and gout.

Adolescent↗