Simultaneous non-parametric confidence intervals for survival probabilities from censored data

In medical studies with censored data Kaplan and Meier's product limit estimator has frequent use as the estimate of the survival function. Simultaneous confidence intervals for the survival function at various time points constitute a useful addition to the analysis. This study compares several such methods. We consider in a simulation investigation two whole curve confidence bands and four methods based on the Bonferroni inequality. The results show that three Bonferroni-type methods are essentially equivalent, all being better than the other methods when the number of time points is small (3 or 5).     

Characteristics of thyroidectomy in Taiwan.

BACKGROUND AND PURPOSE: Thyroidectomy is a common treatment for thyroid disorders in Taiwan, and constitutes a significant percentage of medical expenses. This study investigated the characteristics of thyroidectomy in Taiwan. METHODS: A total of 21 senior general surgeons from 16 medical centers and 5 regional hospitals participated. One surgeon from each hospital reviewed the hospital's medical records of thyroid operations performed in the year 2001. Medical records for 3846 thyroidectomies were retrospectively analyzed, including surgical indications and modalities, complications, pathology reports, and the use of antibiotics. RESULTS: Most of the patients were women (85%). Indications for surgery included proven malignancy (9%), suspicious malignancy (30%), evident compression symptoms (20%), hyperthyroidism (20%), and cosmetic reasons (12%). The majority of patients (78%) underwent a surgical procedure with lobectomy or bilateral thyroidectomy; 13% had unilateral partial thyroidectomy. Prophylactic antibiotics were administered in 46% of procedures, and continued postoperatively in 12%. Postoperative complications occurred in 12% of patients. Hypocalcemia was the most common complication (8%), and its incidence was significantly correlated with the frequency of total thyroidectomy (p < 0.01). Complete pathology reports for the thyroidectomized specimens were available in only 65% of the cases. The frequency of cosmetic reasons for surgery, unilateral subtotal resection, routine antibiotic administration, and incomplete pathology reports were significantly higher in regional hospitals than in medical centers. CONCLUSIONS: Reduction in the high rates of cosmetic reasons for surgery, unilateral partial thyroidectomy, incomplete pathology reports, and use of antibiotic prophylaxis are needed to improve the quality of thyroidectomy in Taiwan.     

Recurrent acalculous cholecystitis and sclerosing cholangitis in a patient with X-linked hyper-immunoglobulin M syndrome.

X-linked hyper-immunoglobulin M (IgM) syndrome (XHIGM) is a rare genetic primary immunodeficiency disease caused by mutations of the CD40 ligand (CD40L) gene with normal or elevated levels of IgM and markedly decreased serum IgG, IgA, and IgE. Liver disease may occur as a clinical manifestation in XHIGM. This complication appears to increase with age. We report an 18-year-old male patient who had recurrent episodes of acalculous cholecystitis (AC) and sclerosing cholangitis (SC). The diagnosis of XHIGM was confirmed by the finding of CD40L expression < 1% of normal and a tyrosine 169 asparaginase (t526a) mutation in exon 5 (the tumor necrosis factor domain) of the CD40L gene. The patient had direct hyperbilirubinemia (direct bilirubin 5.5 mg/dL, total bilirubin 8.7 mg/dL), cholestasis (alkaline phosphatase 1133 U/L, gamma-glutamyl transferase 1019 U/L) and elevated transaminases (aspartate aminotransferase 70 U/L, alanine aminotransferase 101 U/L). Findings on abdominal ultrasound and abdominal computed tomography were compatible with AC. After the fourth episode of cholecystitis, cholecystectomy and liver biopsy were performed. Operative cholangiography revealed poor opacification of the hepatic duct and proximal common bile duct; the upstream intrahepatic bile ducts were not visualized. The biopsy specimen showed marked fibrosis of the portal areas. Enterococcus species was cultured from the bile. Children or adolescents with recurrent AC and SC should be evaluated for an underlying immunodeficiency syndrome such as XHIGM.     

SNAP-II predicts mortality among infants with congenital diaphragmatic hernia.

OBJECTIVE: Outcomes analysis in congenital diaphragmatic hernia (CDH) requires a validated risk-adjustment tool. The purpose of this study was to use the Canadian Neonatal Network (CNN) database to validate the Score for Neonatal Acute Physiology, Version II (SNAP-II) for prediction of mortality among CDH infants admitted to a neonatal intensive care unit (NICU), and to compare this to the predictive equation recently developed by the Congenital Diaphragmatic Hernia Study Group (CDHSG). STUDY DESIGN: Infants with CDH in the CNN database were identified. Bivariate and multivariable logistic regression models were used to identify risk factors predictive of mortality. Model predictive performance and calibration were assessed using the area under the receiver operator characteristic curve and the technique of Hosmer-Lemeshow, respectively, and compared with the CDHSG predictive equation. RESULTS: There were 88 patients with CDH among 19,507 admissions to CNN hospitals. The mortality rate among CDH patients surviving to NICU admission was 17%, and 12.5% received extracorporeal membrane oxygenation therapy. Gestational age and admission SNAP-II score predicted mortality. Model predictive performance and calibration were optimized with these variables combined. The CDHSG equation was equally predictive of mortality, but was only marginally calibrated. CONCLUSIONS: SNAP-II is highly predictive of mortality among patients with CDH, and can be used to risk-adjust these patients.     

Clinical status and emotional adjustment of children of depressed mothers

The authors compared children (ages 7-13 years) of unipolar depressed mothers with children of nondepressed psychiatric patients, of nondepressed medical patients, and of nondepressed mothers in the community. The children's adjustment was rated by clinicians on the Child Adjustment Schedule and by the mothers on the Child Behavior Checklist. The highest proportion of clinically significant problems was found in the children of the depressed mothers. However, the overlap between the problems of these children and those of the children of the nondepressed psychiatric patients calls into question the formulation that children's adjustment difficulties are specific to parental depression.     

Late atrioventricular block after heart transplantation.

Bradyarrhythmia requiring permanent pacing after heart transplantation remains a common problem. Sinus node dysfunction is the most common indication, and late onset of atrioventricular (AV) block has rarely been reported. We report the case of a patient who developed advanced AV block at 41 months after transplantation. Right bundle branch block with progressive increase of QRS complex duration was noted in serial electrocardiograms. At the time of late AV block development, the patient did not have acute rejection and coronary angiogram was normal. The mechanism of late onset of AV block is unclear, but it may be caused by progressive conduction.     

Modified Nile red staining method for improved visualization of neutral lipid depositions in stratum corneum.

The neutral lipids existing in the intercellular spaces of the stratum corneum (SC) provide a permeability barrier to prevent water loss. Nile red is the most sensitive lipid stain for tissue sections. However, due to the extremely flattened morphology of corneocytes and the resolution limits of the light microscope, Nile red staining is seldom used as a fluorescent probe for the lipid-rich SC. In this study, we modified the traditional method for visualization of intracellular lipid by adding 4% potassium hydroxide after Nile red staining. This modified method not only allowed visualization of lipids existing in the intercellular membrane regions and the lateral junctions of the adjoining corneocytes, but also clearly demonstrated small lipid droplets within pathological corneocytes. These features were not observed with the traditional staining method. Thus, this modified Nile red staining method greatly improved the resolution of the SC lipids under light microscopy and should be useful for studying lipid depositions in both normal and pathological SC.