Minimal ventilation to prevent bronchopulmonary dysplasia in extremely-low-birth-weight infants

OBJECTIVE: To determine whether minimal ventilation decreases death or bronchopulmonary dysplasia (BPD).Study design: Infants with birth weight 501 g to 1000 g and mechanically ventilated before 12 hours were randomly assigned to minimal ventilation (partial pressure of carbon dioxide [PCO(2)] target >52 mm Hg) or routine ventilation (PCO(2) target <48 mm Hg) and a tapered dexamethasone course or saline placebo for 10 days, using a 2 x 2 factorial design. The primary outcome was death or BPD at 36 weeks' postmenstrual age. RESULTS: After enrollment of 220 patients, the trial was halted because of unanticipated nonrespiratory adverse events related to dexamethasone therapy. The relative risk for death or BPD at 36 weeks in the minimal versus routine ventilation groups was 0.93 (95% CI, 0.77-1.12; P =.43). Ventilator support at 36 weeks was 1% in the minimal versus 16% in the routine group (P <.01). Major morbidities and long-term outcome were comparable in both treatment groups. CONCLUSIONS: With the sample size studied, minimal ventilation did not reduce the incidence of death or BPD. The reduced ventilator support at 36 weeks in the minimal ventilation group warrants further study of this intervention.     

The skeletal site-differential changes in bone mineral density following bone marrow transplantation: 3-year prospective study

Loss of bone mass is usually detected after bone marrow transplantation (BMT) during the early post-transplant period. However, little is known about the long-term effects of BMT on bone metabolism. We have prospectively investigated 11 patients undergoing BMT. Bone mineral density (BMD) was measured before BMT, and 1, 2, and 3 yr after BMT. Serum markers of bone turnover were serially measured before BMT and 1, 2, 3, 4, and 12 weeks, 6 months, and 1 yr after BMT. The mean change in the lumbar spine (L2-4) BMD, calculated as the percent change from the baseline to the level at 1, 2, and 3 yr was -4.7% (NS), -1.1% (NS), and +6.4% (p<0.05), respectively. The mean change in the total proximal femur BMD from the baseline to the level at 1, 2, and 3 yr was -8.5% (p<0.01), -8.7% (p<0.05) and -5.6% (p<0.05), respectively. In summary, there was little decline in lumbar BMD at 1 yr following BMT and gradual recovery until 3 yr. In contrast, femoral BMD decreased much more than the lumbar area at 1 yr and did not recover until 3 yr. The mechanism of skeletal site-selective differences in the changes of BMD needs to be elucidated.     

Sonographic findings of tuberculous thyroiditis in a patient with Behçet's syndrome

We report a case of tuberculous thyroiditis in a woman with Behçet's syndrome. The initial physical examination in May 1998 revealed multiple soft, nontender, mobile lymph nodes, each measuring less than 1 cm, in the left lower internal jugular chain. Sonography performed in February 2000 showed multiple small (< 1 cm), oval lymph nodes, each with an intact fatty hilum, in the left lower internal jugular chain; the thyroid gland appeared normal. Follow‐up sonography 6 months later showed multifocal, heterogeneous, hypoechoic lesions with ill‐defined margins in both lobes of the thyroid and several small, oval lymph nodes, each with an intact fatty hilum, in the left lower internal jugular chain. Fine‐needle aspiration was performed on the largest thyroid lesion, and cytologic analysis of the aspirate revealed a small number of epithelioid histiocytes in a necrotic background, which was suggestive of tuberculosis. Follow‐up sonography after 3 months of antituberculosis chemotherapy showed that the thyroid lesions had resolved. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 30:184–188, 2002; DOI 10.1002/jcu.10041     

Exogenous wild-type p16INK4A gene induces delayed cell proliferation and promotes chemosensitivity through decreased pRB and increased E2F-1 expressions

Human gastric cancer SNU 484 cells express mutant p16, which migrates slower than the wild-type p16. We constructed an expression vector containing human p16 cDNA to evaluate the cytotoxic effects of exogenous p16 expression on SNU 484 cell proliferation and to explore the potential use of p16 in cancer gene therapy. The stable transfectant expressing wild-type p16, showed a 2-fold slower growth rate than mock and non-infected cells through down-regulation of CDK4-dependent kinase activity. When cells were transiently transfected with mock or p16 encoded vector, the mock cells showed larger survival colonies than those of wild-type p16. Furthermore, p16-expressing stable transfectant was readily progressed into cell death by combination with treatment of chemotherapeutic drug in a dose-dependent manner. According to western blot analysis, both decreased expression of pRB and increased expression of E2F-1 may contribute to the susceptibility of cell death. Our data indicate that exogenous wild-type p16 induces delayed cell proliferation and promotes chemo-sensitivity in the gastric cancer cell line, implying the promise of p16 in cancer gene therapy.     

Effects of lithium fluoride and maleic acid on the bioactivity of calcium aluminate cement: Formation of hydroxyapatite in simulated body fluid

To improve the bioactivity of calcium aluminate cement (CAC), which has the potential of restoring defective bone and the joints between artificial prostheses and natural bone, lithium fluoride and maleic acid were added to CAC. Then the bioactivity of the CAC, together with the lithium fluoride and maleic acid, was estimated by examining the hydroxyapatite (HAp) formation on its surface in simulated body fluid (SBF). When 0.5 g of lithium fluoride and 8.75 g of maleic acid were added to 100 g of CAC, LiAl(2)(OH)(7).2H(2)O was formed on the surface of CAC after 1 day of soaking, and HAp was formed after 2 days. The depth of the LiAl(2)(OH)(7). 2H(2)O and HAp-mixed layers after 60 days of immersion was approximately 20 microm. However, after CAC, which contains only 8.75 g of maleic acid per 100 g of CaO.Al(2)O(3), had been soaking for just 30 days, 3CaO.Al(2)O(3).6H(2)O and HAp were detected. These results indicate that lithium fluoride accelerates HAp formation on the surface of CAC in SBF while maleic acid has little influence on HAp formation. The promotion of HAp formation on the surface of CAC in SBF can be explained in terms of the help of an intermediate layer, LiAl(2)(OH)(7).2H(2)O, which contains hydroxyl groups that act as the nuclei of HAp formation and a tremendous dissolution of calcium ions from CAC into the SBF solution within a short induction time.     

Evaluation of carbazole degradation by Pseudomonas rhodesiae strain KK1 isolated from soil contaminated with coal tar

In this study, strain KK1 isolated from coal tar-contaminated soil was found to be able to mineralize carbazole as a sole source of carbon by radiorespirometric analysis. KK1 cells pregrown on phenanthrene were able to mineralize carbazole much more rapidly than cells pregrown on naphthalene, suggesting a possible close linkage between the pathways for carbazole and phenanthrene catabolism. Also, Rieske-type iron sulfur center sequence of dioxygenase from KK1 was analyzed to evaluate carbazole catabolism by KK1. A gene cloned out from KK1 using a universal dioxygenase primer set was found a dioxygenase for initial catabolism of carbazole based on deduced amino acid sequences. Northern hybridization using the putative carbazole dixoygenase gene fragment as a probe provided the information that catabolism of carbazole might be greatly activated in phenanthrene-grown cells. Analysis of PLFAs extracted from KK1 cells exposed to carbazole revealed that lipids 10:0 3OH, 17:0 cyclo, and 18:0 were representatives produced or significantly increased in response to carbazole. Strain KK1 was identified as Pseudomonas species with 94% confidence when BIOLOG system was applied, as Pseudomonas sp. with over 90% confidence by total cellular compositions of fatty acid, and as Pseudomonas rhodesiae with 99% confidence by 16S rRNA sequence. Accordingly, strain KK1 was identified as Pseudomonas rhodesiae based on combination of the data, and designated Pseudomonas rhodesiae KK1. The phylogenetic tree based on 16S rRNA suggested that strain KK1 was far away in the phylogenetic distance from the strains that can degrade carbazole.     

Comparison of sevoflurane-nitrous oxide and target-controlled propofol with fentanyl anesthesia for hysteroscopy

A randomized prospective study was performed on the anesthetic induction, maintenance, and recovery characteristics of sevoflurane-nitrous oxide, compared to that of target- controlled propofol and fentanyl anesthesia, for forty day-case hysteroscopic surgery. The patients in the sevoflurane group (n = 20) received sevoflurane-nitrous oxide for both induction (8%) and maintenance (1 - 2%) of anesthesia, while the patients in the propofol group (n = 20) received target-controlled propofol (4 micro g/ml, 3-6 micro g/ml as occasion demanded) with fentanyl (1 micro g/kg). In both groups, the airway was maintained by a facemask with the patient breathing spontaneously during the surgery. The mean times to unconsciousness and readiness for surgery were similar in both groups, with those for the sevoflurane group, compared to the propofol group being 80.4 +/- 18.9 vs. 83.6 +/- 38.8 sec, and 220.1 +/- 76.9 vs. 231.0 +/- 95.4 sec, respectively. Propofol was associated with significantly higher incidences of involuntary movement (30% vs. 5%) and apnea (35% vs. 0%) during the induction period than with sevoflurane. Hemodynamic variables were similar with the exception of significantly lower blood pressures during the first 5 minutes of induction with propofol. Emergence times to eye opening, hand squeezing and orientation for sevoflurane compared to propofol were: 316.6 +/- 79.3 vs. 507.4 +/- 218.8 sec, 390.0 +/- 69.3 vs. 653.1 +/- 201.6 sec and 380.6 +/- 80.8 vs. 666.3 +/- 208.7 sec, respectively, all of these being significantly faster for sevoflurane than propofol. The postanesthetic Aldrete's recovery scores of the patients immediately after surgery were higher in the sevoflurane group. Propofol was associated with more drowsiness, with sevoflurane being associated with more nausea, in the recovery period; however, neither delayed the time to discharge (103.7 +/- 28.1 vs. 99.0 +/- 36.2 min). In conclusion, sevoflurane-nitrous oxide appears to be superior for day-case hysteroscopic surgery, than target-controlled propofol with fentanyl, with regards to the speed of recovery from anesthesia and the return to hemodynamic stability.     

A direct sandwich ELISA to detect antibodies against the C-terminal region of merozoite surface protein 1 could be a useful diagnostic method to identify Plasmodium vivax exposed persons

We expressed a C-terminal 108-aa region of the Plasmodium vivax merozoite surface protein 1 (PvMSP1c) excluding the C-end transmembrane region in Escherichia coli in order to evaluate the antibody level to MSP in Korean malaria patients. We optimized a direct sandwich enzyme-linked immunosorbent assay (ELISA) method to simultaneously determine the total antibody levels, including IgG and IgM, to PvMSP1c. If the cut-off for seropositivity was determined as the mean+3SD of the antibody levels of the negative control group, the antibody levels were positive in 99.5% of the patient group (sensitivity 199/200). The antibody levels were negative in 99.4% of the negative control group (specificity 504/507). The positive reactions in the negative control group came from non-specific reactions, as confirmed by a competition assay. This direct sandwich ELISA for PvMSP1c antibody could prove to be a useful tool for the diagnosis of malaria patients and for blood screening in blood banks.     

Ultrasonographic evidence of phenotypic instability during hepatocarcinogenesis in N-nitrosomorpholine-treated rats

Carcinogen-induced hepatoma in immunocompetent animal models has shown a progress similar to the clinical course of human hepatoma. Ultrasonography (US) was used for consecutive evaluation of the phenotypic changes in Sprague-Dawley rats exposed for 8 weeks to N-nitrosomorpholine (NNM, 200 mg/L). Three distinctive US findings were ascites, coarseness (defined as small and heterogeneously widespread increased echogenecity), and nodularity (defined as a >0.6-cm-sized echogenic region and clearly showing a tumor-like mass). Abdominal ascites was observed in 5 of 26 rats at week 8 NNM posttreatment and the number of rats showing ascites gradually increased. Coarseness (22 of 26 rats) and nodularity (1 of 18) appeared at weeks 8 and 17 NNM posttreatment, respectively. The gross and histological findings indicated that coarseness and nodularity shown in US reflected fibrosis and hepatocellular carcinoma or cholangiofibroma, respectively. The computer-aided quantification of coarseness and nodularity showed that the regression-linked phenotypic instability was present in coarseness but not in nodularity. We conclude that the heterogeneity of preneoplasia in NNM-treated rats might be induced by phenotypic instability rather than random initiating events of preneoplastic lesion.     

The emerging role of telomerase in cardiac muscle cell growth and survival

Most mammalian cells-excepting germ cells, tumor cells, and stem cells, that is-possess a finite replicative life span, manifested by the eventual cessation of cell proliferation. Clinically, this is germane not just to the overt derangements of cell growth in cancer, but also to organs such as the heart, in which the capacity for cell replacement and repair is insufficient to maintain organ function following cell death. Among the intrinsic mechanisms that control a conserved program of replicative senescence is the enzyme telomerase, which synthesizes the telomeric repeat for end-capping of each chromosome. The implications of telomerase for cardiac growth have recently begun to be defined. Other functions of telomerase, in maintaining genome integrity, also hold importance for cardiac muscle, as a novel means to suppress apoptosis and, thus, salvage myocardium following ischemic injury.