Differentiation between extrahepatic and intrahepatic cholestasis by discriminant analysis

Discriminant analysis was used to differentiate between extrahepatic biliary atresia and intrahepatic cholestasis. Among the ten laboratory variables tested, three (gamma-glutamyl transpeptidase, alkaline phosphatase and total serum bilirubin) were useful in the differential diagnosis. gamma-Glutamyl transpeptidase contributed most to the discrimination (85%). From a population study of 28 babies with extrahepatic biliary atresia and 24 infants with intrahepatic cholestasis, the procedure achieved a diagnostic accuracy and specificity of 92.9% and an efficiency of 92.3%. The jackknife procedure has also confirmed that the mathematical model was robust for discriminant analysis and therefore it may be valid for screening infants with cholestasis for early surgical intervention. Discriminant analysis is a useful adjunct for differentiation between intrahepatic cholestasis and extrahepatic biliary atresia.     

Transcutaneous bilirubinometer: Its use in Chinese term infants and the effect of haematocrit and phototherapy on the TcB index

The application of the transcutaneous bilirubinometer in screening for neonatal jaundice was evaluated in 259 full-term Chinese infants: 202 who had not received any treatment and 57 who were receiving phototherapy. The transcutaneous bilirubin index correlated well with the serum bilirubin level (SB) of the untreated infants and the coefficient of correlation was slightly higher for TcB readings obtained over the mid-sternal area ( r =0.91; P <0.001) than those over the forehead ( r =0.85; P <0.001). Transcutaneous bilirubinometry was unreliable in predicting the SB level in infants receiving phototherapy even if the SB readings were obtained over shaded skin. The haematocrit of the infants, though having a statistically significant effect on the TcB index, contributed only minimally to the regression line and correlation coefficient between the TcB index and SB level.     

Amplified rhinovirus colds in atopic subjects

Abstract. Evidence suggests that atopic individuals may be predisposed to more severe rhinoviral colds coupled to a worsening of existing airway disease than those with asthma. The role of atopy and IgE levels, as well as their relationship to clinical disease expression have not been defined. We hypothesized that an allergic diathesis modulates rhinoviral colds and have initiated studies of normal, atopic and asthmatic subjects employing experimental rhinoviral infection, with measurements of symptom scores, viral shedding and cultures, albumin in nasal washes and serological responses. Twenty-two subjects (11 normal, 5 atopic, 6 atopic and asthmatic) participated and were inoculated with human rhinovirus serotype 16 (HRV 16). Measurements of neutralizing antibody and viral culture were performed at screening, pre-inoculation, during the cold and at 8–10 weeks convalescence. Daily symptoms were noted, nasal washes done, IgE measured and atopy was diagnosed by skin tests. Seventeen volunteers developed clinical colds as assessed by symptom scores, virus shedding was demonstrated (with positive culture) in all subjects and a fourfold or higher seroconversion occurred in 11/22. Neutralizing HRV antibody developed unexpectedly in 10 subjects between screening and inoculation and the presence or absence of this pre-inoculation antibody determined subsequent severity of colds in normal but not in atopic subjects. Atopic antibody positive individuals developed severe clinical colds that were independent of preinoculation antibody in contrast to normal subjects who developed mild colds in the presence of a neutralizing antibody (.P= 0.01). Both atopic and normal antibody negative subjects developed severe colds. This differential response was matched by nasal wash albumin levels which were significantly increased (P= 0–01) during the cold in atopic (but not in normal) volunteers with pre-inoculation antibody. Levels of IgE were not correlated with severity of clinical disease or viral shedding. Our studies of HRV disease in atopic subjects suggest heightened susceptibility to the detrimental effects of colds; additional studies are needed to clarify the relevant mechanisms.     

CHANGES IN CLINICAL TRIALS MANDATED BY THE ADVENT OF META-ANALYSIS

Service on the Data Monitoring Committee of the CPEP (Calcium for Pre-eclampsia Prevention) has led us to four conclusions about clinical trials which we should like to present to this gathering of biostatisticians for their reactions: (i) meta-analyses of the pertinent published trials of the same therapy should always be undertaken before the start of a new trial, and the results examined to help determine the design of a new trial or determine if a trial should be undertaken at all; (ii) assuming that a decision is made to go ahead, the results of the past trials should be used in sizing the new one; (iii) in the course of the new one, regardless of the size estimates, stopping early should be considered if the trends conform to the results of the meta-analysis; and (iv) heterogeneity of patients entering clinical trials is desirable and should be specifically studied, and it should never be concluded that an average outcome is applicable to all future patients.     

Team-based approach reduces learning curve in robot-assisted laparoscopic radical prostatectomy

AIM: We assessed the team approach in reducing the learning curve during our 2-year experience transiting from open to robot-assisted laparoscopic radical prostatectomy (rLRP). METHODS: A team of three urologists progressed through assistant phase to console phase to obtain competency in robotic prostatectomy. One hundred patients underwent rLRP by this team using the da Vinci robotic surgical system from 1 February 2003 to 15 May 2005. RESULTS: The immediate perioperative outcome was divided into three corresponding time frames and the results demonstrated gradual improvement in outcome parameters. The mean set-up time and dissection time were 24+/-14 min and 182+/-52 min, respectively. The mean perioperative blood loss was 272+/-240 mL, and 7% of patients (n=7) required blood transfusion. The mean duration of bladder catheterization was 8.4+/-4.1 days, and mean hospital stay was 2.9+/-1.6 days. There was no perioperative mortality or conversion to open radical prostatectomy. Major complications (4%) included urethrovesical leak requiring re-operation, postoperative cerebrovascular accident, and transient ureteric obstruction. Minor complications (7%) included minor urethrovesical leak, bladder neck stenosis, and urinary tract infection. Mean follow up was 6.6+/-5.0 months. Pathological assessment showed pT2 disease in 55% and pT3 in 45% of specimens. CONCLUSIONS: A team-based approach to robot-assisted LRP helped to reduce the learning curve of the procedure for individual surgeons and continued to show significantly lower perioperative blood loss, transfusion requirements and postoperative pain compared to open radical retropubic prostatectomy.     

Immunodeficiency in methylmalonic acidaemia

Three Chinese infants with methylmalonic acidaemia were described. They presented in the neonatal period with recurrent episodes of poor feeding, lethargy, apnoea and severe acidosis. The diagnosis was established by increased methylmalonic acid concentration in the plasma and/or urine. Pancytopenia was a prominent feature in all three patients. Only patient three had assessment of lymphocyte subsets and it showed diminished population of B-lymphocytes and a reversed CD4/CD8 ratio. All three patients were unresponsive to vitamin B12. They experienced severe infections including Gram-negative septicaemia, candidiasis and Pneumocystis carinii pneumonia which caused their deaths. Patients with this disease should be regarded as having severe immunodeficiency, and in addition to optimal metabolic control, they should be treated aggressively for any suspected infective episodes.     

Actuarial Survival of Transvenous Pacing Leads in a Pediatric Population

This study was undertaken to examine the actuarial survival of endocardial pacing leads in a pediatric population. We prospectively followed 148 children and young adults age 4 months to 38 years. Of these, 58 had normal cardiac anatomy and 90 had surgically corrected congenitai heart disease. A total of 213 leads were inserted in these patients. Actuarial analysis showed that at 5 years 76.0% of the pacemaker leads were still in use. The reasons for abandonment included death (10), exit block (8), lead fracture (8), adapter malfunction (7), and other including infection, lead migration, and pacemaker malfunction (12). Excluding deaths, an actuarial survival curve was constructed. Stepwise discriminant analysis and independent measures of association showed a significant difference in lead abandonment when the leads placed in the atrium were compared to those placed in the ventricle (30 vs 5: P < 0.0005). Lead insulating material, cardiac anatomy, and/or indication for pacemaker placement had no statistically significant impoct on lead survival.     

High Resolution CT Scanning of the Bronchial Tree CT Bronchography: Anatomy

Detail CT study of the bronchial tree is now possible with high resolution CT scanning. The anatomy of the bronchial tree and the major associated vessel are described. Familarization with these structures would be helpful to interpret pathological studies.