Antigenicity of low molecular weight surfactant species.

The authors tested the antigenicity of human lung surfactant isolated from amniotic fluid. Mice and rabbits were immunized. Rabbit polyclonal antisera to these surfactant preparations were absorbed with normal human plasma proteins. Polyclonal antisera reacted with both high molecular weight (35 kd) surfactant apoprotein and to lower molecular weight species, both 18 kd and 9 kd. Mice were used to generate monoclonal antibodies to surfactant. Enzyme-linked immunosorbant assay was used to identify five monoclonal antibodies that reacted with surfactant. By Western blot analysis, all of these recognized a low molecular weight surfactant species (9 kd) that could be either SP-B or SP-C. One reacted with a 37 kd protein in the surfactant preparation, consistent with SP-A. One monoclonal antibody also recognized a higher molecular weight species (44 kd) of unknown origin. The ability of antisera and monoclonal antibodies to inhibit the functional activity of surfactant was assayed using a pulsating bubble surfactometer. Rabbit polyclonal antisera inhibited initial surface adsorption to equilibrium surface tension and increased the minimum surface tension after 1 and 5 minutes of initiation of pulsations. This inhibitory activity of the antisera was noted in divalent F(ab')2 fragments. Monovalent F(ab) fragments and control normal rabbit sera did not inhibit surfactant function in this assay. Of the anti-surfactant monoclonal antibodies that reacted with surfactant by ELISA and Western blot, three inhibited its capacity to lower surface tension on the pulsating bubble apparatus. The other two monoclonal antibodies showed no functional inhibitory activity. It is concluded that both the 35 kd SP-A and the 9 kd proteins of human surfactant are highly immunogenic and partially crossreactive. Resulting antibodies could alter the ability of surfactant to perform its physiologic function, ie, to lower surface tension.     

Autoimmunity to a 28-30 kD cell membrane DNA binding protein: occurrence in selected sera from patients with SLE and mixed connective tissue disease (MCTD).

Previous experiments have established the presence of a 30-kD DNA binding protein on the surface of human leukocytes. Herein we report that selected sera from patients with systemic lupus erythematosus (SLE) and MCTD are reactive with a 28-30 kD protein on immunoblots of peripheral blood mononuclear cells (PBMC) cell membrane preparations; the reactivity is abolished by prior incubation of the blot with DNA. Antibodies eluted from the 28-30 kD strip inhibited the binding of 3H. DNA to human PBMC. An immunomatrix of 28-30 kD reactive immunoglobulins was able to extract a 29-kD DNA binding protein from a PBMC cell membrane preparation. Flow cytometry experiments confirmed the cell surface IgG reactivity of sera with T lymphocytes. Additional experiments indicated that cell surface IgG binding was not due to antibodies binding to cell surface DNA, DNA anti-DNA immune complexes reacting with a DNA binding protein, anti-histone antibodies or anti-Sm antibodies. It is hypothesized that this autoimmune response could be one component of an idiotypic network involving anti-DNA antibodies.     

In vitro biocompatibility of polyetheretherketone and polysulfone composites

Short carbon fiber reinforced composites could potentially replace some of the metal alloys used in orthopedic implants. In particular, polysulfone and, more recently, polyetheretherketone have been considered as the matrix material for carbon fiber reinforced composite implant materials. ASTM standards F813 and F619 for direct contact cell culture evaluation and extraction were employed to determine the in vitro biocompatibility of a carbon fiber composite of polyetheretherketone, PEEK, in comparison to a carbon fiber reinforced polysulfone composite. The cell cultures were assessed qualitatively by microscopy and quantitatively using an enzyme assay to determine cytotoxicity. Overall, the cellular response to the PEEK and polysulfone composites were negligible indicating that further in vivo studies with these materials are appropriate.     

Prophylactic treatment of very premature infants with human surfactant

We undertook a randomized, controlled trial to determine whether human surfactant administered endotracheally at birth to very premature infants (gestational age, 24 to 29 weeks) would prevent the respiratory distress syndrome or reduce its severity. Thirty-one treated infants (birth weight, 938 +/- 286 g) were compared in a blinded fashion with 29 control infants (birth weight, 964 +/- 174 g). The lecithin/sphingomyelin ratio was less than 2 in all infants, and phosphatidylglycerol was not present in amniotic fluid or tracheal fluids at birth, indicating a deficiency of surfactant in the lungs. The principal dependent variables were neonatal death, the incidence of bronchopulmonary dysplasia, and the infant's requirement for respiratory support (and its complications). The surfactant-treated group had significantly fewer deaths than the control group (16 percent vs. 52 percent, P less than 0.001), fewer cases of bronchopulmonary dysplasia (16 percent vs. 31 percent), and significantly fewer cases of pulmonary interstitial emphysema (P less than 0.001) and pneumothorax (P less than 0.02). Prophylactic treatment with human surfactant also substantially reduced the period of neonatal intensive care. We conclude that treatment with human surfactant offers promise for improving the survival of very premature infants with a surfactant deficiency and for reducing the pulmonary sequelae of the respiratory distress syndrome.     

Significance of hypoalbuminemia in pediatric oncology patients--malnutrition or infection?

Nutritional status was evaluated on 210 occasions in 90 pediatric oncology inpatients during a 7-month period; 39 had solid tumors and 51 leukemia. Ages ranged from 3 months to 20 yr. Nutritional parameters were defined as normal, "at risk," or "probably malnourished." Fifty-seven and 29% of assessments revealed at least one parameter "at risk" or "probably malnourished," respectively. Prognosis was negatively related to the number of abnormal nutritional parameters. Serum albumin was most frequently abnormal. However, on most occasions, hypoalbuminemia was associated with weight/height, arm muscle area, and triceps skinfold measurements in the normal range. In order to further identify determinants of serum albumin, we analyzed dietary, chemotherapy, and temperature data in 10 prospectively studied leukemia patients, half of whom received parenteral nutrition. In these patients there was little relationship of serum albumin to chemotherapy or dietary intake. In all of these patients, especially those receiving total parenteral nutrition, low serum albumin was highly associated with fever (p less than 0.0005). We concluded that febrile illness is an important determinant of abnormal serum albumin concentrations. In pediatric cancer patients, abnormal serum albumin may more often reflect the acute metabolic response to fever and infection than depletion of body mass.     

Clinical utility of PTSD,resilience, sleep,and blast as risk factors to predict poor neurobehavioral functioning following traumatic brain injury: A longitudinal study in U.S. military service members

Quality of Life Research - This study examined the clinical utility of post-traumatic stress disorder (PTSD), low resilience, poor sleep, and lifetime blast exposure as risk factors for predicting...     

Enhancing Behavior Change Skills in Health Extension Workers in Ethiopia: Evaluation of an Intervention to Improve Maternal and Infant Nutrition

Maternal and infant nutrition are problematic in areas of Ethiopia. Health extension workers (HEWs) work in Ethiopia’s primary health care system, increasing potential health service coverage, particularly for women and children, providing an opportunity for health improvement. Their roles include improving maternal and infant nutrition, disease prevention, and health education. Supporting HEWs’ practice with ‘non-clinical’ skills in behavior change and health communication can improve effectiveness. This intervention study adapted and delivered a UK-developed training intervention for Health Extension Workers (HEWs) working with the United Nations World Food Programme in Ethiopia. The intervention included communication and behavioral training adapted with local contextual information. Mixed methods evaluation focused on participants’ reaction to training, knowledge, behavior change, and skills use. Overall, 98 HEWs were trained. The intervention was positively received by HEWs. Pre-post evaluations of communication and behavior change skills found a positive impact on HEW skills, knowledge, and motivation to use skills (all p < 0.001) to change women’s nutritional behavior, also demonstrated in role-play scenarios. The study offered substantial learning about intervention delivery. Appropriate cultural adaptation and careful consideration of assessment of psychological constructs are crucial for future delivery.     

The epidemiology of acute hepatitis A in north Queensland, 1996-1997.

Details on all cases of hepatitis A notified in North Queensland in 1996 and 1997 were prospectively collected. There were two substantial outbreaks and a total of 225 cases during this period. The total incidence rate (per 100,000) was 11.0 in 1996 and 27.0 in 1997. Aborigines and Torres Strait Islanders constituted 29% of cases and had incidence rates of 75.2 and 62.7 per 100,000 for 1996 and 1997 respectively. Thirty-nine cases (17.3%) were admitted to hospital for a total of 202 bed-days and a 4 year old died with fulminating hepatitis. A probable source of infection was identified for 69% of cases. The common risk categories for infection were: living in or visiting a rural Aboriginal or Torres Strait Islander community, injecting drug use, contact with a known case of hepatitis A, and travel to countries with endemic hepatitis A.     

Review article: the pharmacokinetics of rabeprazole in health and disease

Rabeprazole, a newly developed proton pump inhibitor, has been shown to be effective for the treatment of gastric and duodenal ulcers and for gastro-oesophageal reflux disease. It is a rapid and potent inhibitor of gastric H⁺,K⁺-ATPase, the gastric acid (proton) pump. The maximum plasma concentration ( C _max) and the area under the plasma concentration time curve ( AUC ) are linearly related to dose, while the time to maximum plasma concentration ( t _max) and elimination half-life ( t _½) are dose-independent. Rabeprazole is extensively metabolized in the liver via the cytochrome P450 enzyme system, and its metabolites are excreted primarily in the urine. Rabeprazole does not accumulate with repeated dosing. Its bioavailability is not influenced by the coingestion of either food or antacids. The pharmacokinetic profile of rabeprazole is substantially altered in the elderly and patients with stable compensated chronic cirrhosis; however, these alterations are not associated with clinically significant abnormalities in laboratory parameters or serious adverse events. The influence of severe decompensated liver disease on the pharmacokinetics of rabeprazole has not been assessed. The pharmacokinetic profile of rabeprazole is not significantly altered by renal dysfunction requiring maintenance haemodialysis. These findings suggest that dosage adjustment is not required in these special patient populations. Caution should be exercised, however, in patients with severe liver disease.