Healthy choices: motivational enhancement therapy for health risk behaviors in HIV-positive youth.

This study piloted a brief individual motivational intervention targeting multiple health risk behaviors in HIV-positive youth aged 16-25. Interviews about sexual behavior and substance use and viral load testing were obtained from 51 HIV-positive youth at baseline and post intervention. Youth were randomized to receive a four-session motivational enhancement intervention (N = 25) or to a wait-list control (N = 26). Of the eligible youth approached, 88% agreed to participate, and 80% percent of participants completed at least three of four sessions. The treatment group showed significantly greater reductions in unprotected sex acts and in viral load compared with controls. Although change scores for substance use were not significantly different between the two groups, paired t tests demonstrated that reductions in alcohol use and marijuana use were significant for the treatment group at the trend level. There were no significant differences in substance use from baseline to posttest for the control group. Findings demonstrate the potential of a brief motivational enhancement intervention to improve health risk behaviors in HIV-positive youth. Larger randomized clinical trials are warranted. Resources required for retention should not be underestimated.     

Multiclefted nuclei. A helpful feature for identification of intermediate trophoblastic cells in uterine curetting specimens.

Intermediate trophoblast is a distinct form of trophoblast, the presence of which in uterine curettings is considered a reliable indicator of intrauterine pregnancy even in the absence of chorionic villi. However, the appearance of intermediate trophoblastic cells have not been described in sufficiently specific terms to permit their reliable identification, and distinction from decidual cells can be difficult. We have noticed for some time that the intermediate trophoblastic cells often show multiple deep clefts in the nuclei, and the present study was performed to address the issue of whether this nuclear feature is reliable for their identification. We reviewed 242 uterine curettings of intrauterine pregnancy, documented by the presence of chorionic villi, and were able to find a distinct population of cells with large, hyperchromatic, multiclefted nuclei scattered in the decidua in 88% of the cases. In most instances, these cells produced a characteristic variegated pattern that was readily recognizable at low magnification. Positive immunostaining for cytokeratin (CAM 5.2) in these isolated cells within the decidua confirmed their trophoblastic nature. In contrast, multiclefted nuclei were absent in the 51 negative control cases, which included decidualized endocervical polyps (40 cases), uterine curettings from patients with tubal pregnancy (10 cases), and endometriosis with decidual change (one case). We conclude that intermediate trophoblastic cells can usually be reliably identified in curettings of intrauterine pregnancy by their characteristic nuclear multiclefting.     

A recombinant bisphosphoglycerate mutase variant with acid phosphatase homology degrades 2,3-diphosphoglycerate.

To date no definite and undisputed treatment has been found for sickle cell anemia, which is characterized by polymerization of a deoxygenated hemoglobin mutant (HbS) giving rise to deformed erythrocytes and vasoocclusive complications. Since the erythrocyte glycerate 2,3-bisphosphate (2,3-DPG) has been shown to facilitate this polymerization, one therapeutic approach would be to decrease the intraerythrocytic level of 2,3-DPG by increasing the phosphatase activity of the bisphosphoglycerate mutase (BPGM; 3-phospho-D-glycerate 1,2-phosphomutase, EC 5.4.2.4). For this purpose, we have investigated the role of Gly-13, which is located in the active site sequence Arg9-His10-Gly11-Glu12-Gly13 in human BPGM. This sequence is similar to the Arg-His-Gly-Xaa-Arg* sequence of the distantly related acid phosphatases, which catalyze as BPGM similar phosphoryl transfers but to a greater extent. We hypothesized that the conserved Arg* residue in acid phosphatase sequences facilitates the phosphoryl transfer. Consequently, in human BPGM, we replaced by site-directed mutagenesis the corresponding amino acid residue Gly13 with an Arg or a Lys. In another experiment, we replaced Gly13 with Ser, the amino acid present at the corresponding position of the homologous yeast phosphoglycerate mutase (D-phosphoglycerate 2,3-phosphomutase, EC 5.4.2.1). Mutation of Gly13 to Ser did not modify the synthase activity, whereas the mutase and the phosphatase were 2-fold increased or decreased, respectively. However, replacing Gly13 with Arg enhanced phosphatase activity 28.6-fold, whereas synthase and mutase activities were 10-fold decreased. The presence of a Lys in position 13 gave rise to a smaller increase in phosphatase activity (6.5-fold) but an identical decrease in synthase and mutase activities. Taken together these results support the hypothesis that a positively charged amino acid residue in position 13, especially Arg, greatly activates the phosphoryl transfer to water. These results also provide elements for locating the conserved Arg* residue in the active site of acid phosphatases and facilitating the phosphoryl transfer. The implications for genetic therapy of sickle cell disease are discussed.     

Systemic effects of inflammation in bronchiectasis

A group of bronchiectatic subjects in the clinically stable state were studied for systemic evidence of inflammation. The following parameters were evaluated: body weight, serum albumin, serum globulin, serum alpha 1-antitrypsin (alpha 1 AT) and peripheral white cell count. For serum albumin and globulin, comparison was made between subjects with bronchiectasis and control subjects with no known pulmonary disease matched for sex and age, and for serum alpha 1 AT and peripheral white cell count, matched for smoking habit as well. The bronchiectatic subjects showed systemic effects of inflammation as indicated by lower body weight and serum albumin (P less than 0.01), higher serum globulin (P less than 0.001), serum alpha 1 AT (P less than 0.05) and total leucocyte count (P less than 0.05). Differential white cell count showed that the elevation was distributed in most cell types. Correlation matrix was done for the above systemic parameters and indices of airway inflammation including sputum volume, purulence, and polymorph count and FEV1. There was an inverse correlation between total peripheral WBC count and FEV1 in percentage of predicted (P less than 0.01), and a positive correlation between sputum purulence and sputum polymorph score (P less than 0.05). This suggests that host peripheral leucocyte response may be a factor in the determination of lung function.     

Electrocardiographic changes during and after isoflurane-induced hypotension for neurovascular surgery

We evaluated the effects of isoflurane anaesthesia and induced hypotension in 33 neurosurgical patients by electrocardiographic monitoring and serial cardiac enzyme measurements. An electrocardiogram (ECG) and serum enzymes were obtained preoperatively, intraoperatively and postoperatively in the recovery room and for three consecutive days. ECG leads II, V1 and V5 were monitored continuously during anaesthesia. Patients who had had a subarachnoid haemorrhage and a high incidence of abnormal preoperative ECG (42 per cent). Ten patients developed ECG changes intraoperatively, but these changes were unrelated to isoflurane-induced hypotension. Fifty-three per cent of patients developed an abnormal postoperative ECG. These abnormalities consisted mostly of nonspecific ST segment or T wave changes. At no time was there an elevation in cardiac enzyme activity. We found that nonspecific ECG changes are relatively common in patients undergoing vascular neurosurgical procedures. There was no enzymatic evidence of myocardial infarction and we can only speculate that these ECG changes are related to intracranial surgical manipulation.     

Direct detection of Epstein-Barr virus in peripheral blood and comparison of Epstein-Barr virus genotypes present in direct specimens and lymphoblastoid cell lines established from nasopharyngeal carcinoma patients and healthy carriers in Hong Kong.

By means of a PCR assay, EBV was demonstrated directly in peripheral blood of previously infected individuals. The virus was detected in approximately 80% of specimens from EBV-seropositive individuals, but not in cord-blood lymphocytes by this method. When virus present in peripheral blood was compared to that observed directly in NPC biopsies or throat washings, it was distinct from that seen in biopsies in 4/15 cases (27%) and from that seen in throat washes in 1/22 cases (5%). The throat-wash virus differed from the biopsy virus in 3/20 cases (15%). The prototype F virus was found in 7/10 LCLs (70%) established from NPC patients' peripheral blood, but was only detected in 2/9 specimens (22%) directly analyzed by the PCR assay. This finding suggests selective isolation of prototype F EBV in spontaneous LCLs established from NPC patients.     

Organization and development of horizontal cells in the goldfish retina, II: Use of monoclonal antibody MH1.

We have produced and characterized a monoclonal antibody, MH1, which selectively labels rod horizontal cells and Müller cells in the goldfish retina. Biochemical and tissue distribution studies indicate that MH1 may recognize four out of five classes of intermediate filament proteins in goldfish: vimentin, desmin, glial fibrillary acidic protein (GFAP), and keratin, but not neurofilament. The intermediate filament which is labeled strongest in the retina is vimentin. In the goldfish retina, the only type of horizontal cells recognized by MH1 appear to be rod horizontal cells. This result suggests that the rod horizontal cell, an interneuron, and Müller (glial) cells share a common antigen: vimentin, which is usually only expressed in mesenchymal origin cells. The development of rod horizontal cells in the goldfish retina was also studied using MH1. The cells were not labeled by MH1 until 4-6 weeks posthatching, a stage in which the animals are already visually active. MH1 also did not label any horizontal cell in the region close to the ora terminalis in the goldfish retina. These results suggest that either the emergence and maturation of rod horizontal cells occur late during goldfish retinal development or the expression of vimentin itself occurs late in the development of rod horizontal cells.     

Purification of the human blood platelet thromboxane A2/prostaglandin H2 receptor protein.

The human platelet thromboxane A2/prostaglandin H2 receptor has been purified 6100-fold to apparent homogeneity by a three-step chromatographic procedure with an overall yield of 6%. A 6-fold purification of the receptor was first achieved by chromatography of 3-[(3-cholamidopropyl)dimethyl-ammonio]-1-propanesulfonate (CHAPS)-solubilized membrane proteins from human platelets on a diethylaminoethyl (DEAE)-Sepharose column. The DEAE eluate fractions containing receptor activity were then applied to a newly developed affinity column using the cyclohexyl derivative of SQ30,741 (SQ31,491) as the immobilized ligand. Elution of the receptor from the affinity column with BM13.177 yielded a further purification of 1700-fold. An additional 4-fold receptor purification from the affinity column eluate was achieved by HPLC using GPC 500 and GPC 100 columns connected in tandem. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and silver staining of the HPLC eluate containing purified receptor revealed a single, distinct band with a molecular weight of 55,000. The receptor binding activity was detected with [3H]SQ29,548 using a newly developed binding assay which involved immobilization of the receptor on polyethyleneimine-treated glass fiber filters. The binding of [3H]SQ29,548 to the purified receptor was time dependent, saturable, reversible and highly specific. Unlabeled SQ29,548, BM13.505, and U46619 (but not thromboxane B2 or 6-keto prostaglandin F1 alpha) competed for [3H]SQ29,548 binding to the purified receptor in a concentration-dependent manner. Scatchard analysis of [3H]SQ29,548 binding to the purified receptor revealed the presence of a single class of high-affinity binding sites, with a Kd of 4 nM and a Bmax of 17 nmol/mg protein.