Evaluation of atypical human immunodeficiency virus immunoblot reactivity in blood donors

Blood donors reactive by enzyme-linked immunosorbent assay for antibody to the human immunodeficiency virus (HIV) who showed atypical patterns of viral core protein reactivity on Western blot were monitored for several months. Characterization of their antibodies was performed by 1) use of recombinant HIV proteins; 2) determination of cross-reactivity to HTLV-I, HTLV-II, and HTLV-IV: 3) assessment of immune status; and 4) identification of potentially interfering autoantibodies. Nineteen of 20 donors maintained the same HIV antibody reactivity throughout the follow-up period; the other donor became fully antibody-positive. Eighteen of 20 donors' sera showed clear reactivity with HIV recombinant core proteins. Ten of 19 donor samples demonstrated cross-reactivity to HTLV-IV; 3 of these 10 also cross-reacted with HTLV-I. The immune status of all donors was normal, although the medical histories and HLA antibody screens suggested possible autoimmune reactivity in 9 of 18 donors. During follow-up interviews, three donors reported possible risk factors for HIV infection that had not been acknowledged at the time of blood donation. We conclude that exclusion of donors with these atypical serologic test results is warranted while further studies to determine significance are being conducted.     

Biochemical consequences of protein depletion in the rabbit heart

We showed previously that cardiac function was depressed in rabbits subjected to 6 weeks of protein depletion and was restored after 4 weeks of protein refeeding. To identify nutritional or metabolic factors that underlie cardiac dysfunction, we assessed the nutritional status and myocardial content of energy-providing substrates in three groups of rabbits: group I served as control; group II was fed a protein-free diet; and group III was fed a protein-free diet and then repleted. Animal weights were 2.73 +/- 0.22 kg in group I, 1.92 +/- 0.28 kg in group II, and 2.78 +/- 0.12 kg in group III. Serum albumin concentrations decreased from 3.70 +/- 0.12 g/dl in group I to 2.81 +/- 0.10 g/dl in group II, and returned to normal (3.71 +/- 0.11 g/dl) in group III. The heart weights; myocardial contents of water, nitrogen (N), total fat, and glycogen; skeletal muscle N concentrations; and liver N contents were measured. Protein depletion produced a reduction in total cardiac mass due to decreased nitrogen and glycogen contents, but there was an increased fat content. Comparison with other organs suggests that cardiac muscle plays a role in energy homeostasis, undergoing glycogenolysis and proteolysis similar to those of liver and skeletal muscle. Protein repletion restored normal mass of the heart, but not of the liver. We conclude that adequate nutrition may be important in maintaining cardiac function.     

Is a T-tube Necessary after Common Bile Duct Exploration?

BACKGROUND: T-tube drainage used to be standard practice after surgical choledocholithotomy, but there is now a tendency in some centers to close the common bile duct (CBD) primarily. This study was designed to review the complications associated with T-tube drainage after CBD exploration and to determine whether primary closure of the bile duct reduces postoperative morbidity. METHODS: A retrospective audit was performed on patients undergoing CBD exploration between July 1997 and March 2007, who were identified from the theatre database of one teaching hospital. Intraoperative findings and postoperative complications were recorded from the clinical notes. RESULTS: During the study period, 158 patients (97 women; median age 65 (range, 25-90) years) underwent CBD exploration. A T-tube was inserted in 91 patients (group I) and the CBD was closed primarily in 67 (group II). One or more biliary complications occurred in 26 patients (16.5%): 20 (22.0%) in group I and 6 (8.9%) in group II (p = 0.03). In group I, 15 had a biliary leak (3 needed reoperation), 2 had accidental slippage of the tube, 2 an entrapped T-tube, and 1 a retained stone. In group II, six patients had biliary leakage, two of whom were re-explored. Six patients in group I also had peritubal infection, necessitating the use of antibiotics. There were three deaths: two in group I (1 T-tube-related) and 1 in group II (p = 1, not significant). CONCLUSION: There is a lower biliary complication rate associated with primary closure of the CBD than after T-tube drainage.     

Management of pancreatic pseudocysts

BACKGROUND: This review analyses the outcome for patients with acute and chronic pancreatic pseudocysts managed in two major referral centres. PATIENTS AND METHODS: From 1987 to 1997, 33 patients were treated with either acute (n = 19) or chronic (n = 14) pseudocysts. Procedures performed included cystgastrostomy (64%), cystduodenostomy (6%), cystjejunostomy (3%), distal pancreatectomy with resection of pseudocyst (12%), laparotomy with external drainage (9%), endoscopic transpapillary stenting (3%) and endoscopic pancreatic duct sphincterotomy with percutaneous drainage of the pseudocyst (3%). RESULTS: All patients had resolution of their pseudocyst and no patient developed recurrence. There were no deaths in this series. There was a 9% incidence of major complications and a 21% incidence of minor complications. Outcome was excellent in 63% and good in 27% of patients. Two patients (6%) had persistent chronic pain and one patient (3%) had evidence of exocrine pancreatic insufficiency with malabsorption. CONCLUSIONS: Surgical internal drainage of pancreatic pseudocysts can be performed safely with low morbidity and mortality provided patients are carefully selected and their medical management is optimized. Although minimally invasive techniques now offer a variety of treatment options, open surgical drainage is still indicated for a significant number of cases.     

The perceptual response to exercise of progressively increasing intensity in children aged 7–8 years: Validation of a pictorial curvilinear ratings of perceived exertion scale

This study assessed the validity of the Eston-Parfitt (E-P) curvilinear Ratings of Perceived Exertion (RPE) Scale and a novel marble quantity task to provide estimates of perceived exertion during cycle ergometry. Fifteen children aged 7–8 years performed a discontinuous incremental graded-exercise test, and reported exertional ratings at the end of each minute. Significant increases in physiological and perceptual data were observed with increasing work rate. The relationship between work rate and marbles was curvilinear (mean R ²=.94), supporting the theoretical justification for the E-P Scale. Strong linear ( R ²=.93) and curvilinear ( R ²=.94) relationships between RPE from the E-P Scale and work rate confirmed the robustness of the E-P Scale. Valid exertional ratings may be obtained using the E-P Scale with young children. The novel marble quantity task offers an alternative method of deriving perceived exertion responses in children.     

Children's physical activity and psychological health: the relevance of intensity

Aim: To examine the relevance of physical activity intensity when assessing the relationship between activity and psychological health in 9–10-year-old children.
Methods: Activity was assessed by accelerometry in 57 boys (n = 23) and girls (n = 34). Total activity and time spent in very light (≤1.9 METs) through to vigorous activity (≥6 METs) were recorded. Psychological health inventories to assess anxiety, depression and aspects of self-worth were completed.
Results: Time accumulated in very light activity had positive correlations with anxiety and depression (r > 0.30, p < 0.05) and negative correlations with aspects of physical self-worth (r > −0.29, p < 0.05). Time accumulated in vigorous activity had negative correlations with anxiety and behavioural conduct (r > −0.30, p < 0.05) and positive correlation with aspects of physical self-worth (r > 0.28, p < 0.05). Children spending over 4 h in very light intensity activity had more negative psychological profiles than children spending under 4 h at this intensity.
Conclusion: Aspects of psychological health were negatively correlated with very light intensity activity and positively correlated with vigorous intensity activity. Further research should investigate whether reducing time spent in very light intensity activity and increasing time spent in vigorous intensity activity improves psychological health in children.     

High frequency oscillation in newborn infants with respiratory failure

Objective: To report ventilation strategies, survival and complications in 39 outborn infants treated with high frequency oscillatory ventilation (HFOV).
Methodology Data were collected prospectively between 1 May 1992 and 31 December 1993 on all infants treated with HFOV who had severe respiratory failure despite optimal conventional ventilation.
Results Twenty-eight out of 39 (72%) survived. Of the 15 infants with birthweights <1500g, eight survived. Best survival rates were for infants with pulmonary interstitial emphysema with air leak (4/5) and for infants of birthweight >1500g with hyaline membrane disease (8/8), and meconium aspiration syndrome (7/7). Three infants deteriorated while on HFOV and required extracorporeal membrane oxygenation. Complications were: (i) development of pulmonary interstitial emphysema (1); (ii) recurrence of pneumothorax (3); (iii) hypotension (2); and (iv) bronchopulmonary dysplasia (9). One of the eight infants weighing <1500g who received HFOV in the first week of life developed periventricular haemorrhage.
Conclusion The initial results of HFOV for severe respiratory failure were encouraging although a learning curve was encountered with its introduction.