A critical evaluation of the application of capillary electrophoresis to the detection and determination of 1,4-benzodiazepine tranquilizers in formulations and body materials

Studies of the capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MEKC) behaviour of 1,4-benzodiazepines have seen application in subject areas such as the development of pharmaceuticals, therapeutic drug monitoring and forensic toxicology. In the development of pharmaceuticals, pKa determinations by CZE can be used in preclinical studies whereas analytical data on the detection and determination of 1,4-benzodiazepines is of value primarily in raw material/formulation assay and in the analysis of body fluids in clinical studies. The capillary electrophoresis (CE) techniques, which generally have inferior limits of detection (LOD) to rival techniques such as gas chromatography (GC) and high-performance liquid chromatography (HPLC), are particularly applicable in forensic toxicology where reasonably high concentrations of these drugs can be encountered. It is anticipated that, with the interfacing of CZE and capillary electrochromatography (CEC) with mass spectrometry (MS) techniques, the excellent selectivity of CZE and particularly CEC will be effectively combined with the sensitivity of MS and the identification capabilities of tandem mass spectrometry (MS/MS) and MS hyphenated (MSn) techniques.     

Interaction of the Hsp70 molecular chaperone, DnaK, with its cochaperone DnaJ

Chaperones of the Hsp70 family bind to unfolded or partially folded polypeptides to facilitate many cellular processes. ATP hydrolysis and substrate binding, the two key molecular activities of this chaperone, are modulated by the cochaperone DnaJ. By using both genetic and biochemical approaches, we provide evidence that DnaJ binds to at least two sites on the Escherichia coli Hsp70 family member DnaK: under the ATPase domain in a cleft between its two subdomains and at or near the pocket of substrate binding. The lower cleft of the ATPase domain is defined as a binding pocket for the J-domain because (i) a DnaK mutation located in this cleft (R167H) is an allele-specific suppressor of the binding defect of the DnaJ mutation, D35N and (ii) alanine substitution of two residues close to R167 in the crystal structure, N170A and T173A, significantly decrease DnaJ binding. A second binding determinant is likely to be in the substrate-binding domain because some DnaK mutations in the vicinity of the substrate-binding pocket are defective in either the affinity (G400D, G539D) or rate (D526N) of both peptide and DnaJ binding to DnaK. Binding of DnaJ may propagate conformational changes to the nearby ATPase catalytic center and substrate-binding sites as well as facilitate communication between these two domains to alter the molecular properties of Hsp70.     

Specificity of the Speed''s test: arthroscopic technique for evaluating the biceps tendon at the level of the bicipital groove

A historical cohort study was conducted in Misasa town, Tottori prefecture, Japan, where radon spas have been operating for a long time. Misasa town was divided into an elevated radon level area and a control area, with mean indoor radon levels of about 60 and 20 Bq/m3, respectively. In total, 3,083 subjects in the elevated radon level area and 1,248 in the control area, all aged 40 or older on January 1, 1976, were followed up until December 31, 1993, for a mean period of 14 years. The mortality rates from all causes exhibited no difference between the elevated radon level area and the control area for both sexes. No difference was observed in the incidence of all-site cancers (age, period-adjusted rate ratios by Poisson regression, RR = 1.06, 95% confidence interval (CI) 0.79-1.42 for males, RR = 0.90, 95% CI 0.65-1.24 for females), while stomach cancer incidence seemed to decrease for both sexes (RR = 0.70, 95% CI 0.44-1.11 for male, RR = 0.58, 95% CI 0.34-1.00 for female) and lung cancer incidence for males only seemed to increase (RR = 1.65, 95% CI 0.83-3.30 for male, RR = 1.07, 95% CI 0.28-4.14 for female) in the elevated radon level area. Caution is needed in the interpretation of these findings, however, since the individual exposure level was not measured and major confounding factors, such as smoking and diet, could not be controlled in this study.     

Gender differences in FFM accumulation and architectural characteristics of muscle

OBJECTIVE: To characterize the existence and role of transforming growth factor-beta (TGF-beta) in otitis media with effusion (OME). STUDY DESIGN: Retrospective. METHODS: The levels of two major TGF-beta isoforms, TGF-beta1 and TGF-beta2, in the middle ear effusions (MEEs) of 44 children were evaluated using enzyme-linked immunospecific assays (ELISAs). Forty-eight MEEs were separated into three clinically relevant groups (i.e., serous, mucoid, and purulent), and TGF-beta levels were correlated with clinical parameters of disease for these MEEs. RESULTS: Both TGF-beta1 and TGF-beta2 were present in the samples. Mean levels of TGF-beta1 (920.36 +/- 437.75 pg/mg total protein) were generally 100-fold greater than those of TGF-beta2 (9.65 +/- 11.19 pg/mg total protein). TGF-beta1 levels were elevated in association with a history of previous tympanostomy tube placements (TTPs) (P = .029) and mucoid effusions (P = .042). TGF-beta2 levels were elevated in association with a history of previous TTPs (P = .100) and chronic (i.e., serous or mucoid) effusions (P = .003). CONCLUSIONS: TGF-beta1 is present in the MEEs of children with OME. Furthermore, TGF-beta1 and TGF-beta2 levels were elevated differentially in the presence of chronic disease indicators in OME, suggesting that these isoforms may have differing roles in the inflammatory processes that characterize OME.     

Identification of clustered microcalcifications on digitized mammograms using morphology and topography-based computer-aided detection schemes. A preliminary experiment

RATIONALE AND OBJECTIVES: A mathematical morphology-based computer-aided detection (CAD) scheme for the identification of clustered microcalcifications was developed and tested. The potential for improving either sensitivity or specificity by combining the results with those previously reported was investigated. METHODS: The CAD scheme presented here is based on mathematical morphology and a series of simple rule-based criteria for the identification of clustered microcalcifications. A database of 105 digitized mammograms was used for training and rule setting of the scheme. A test set of 191 digitized mammograms was used to evaluate its performance. The same test set had been used to evaluate a multilayer, topography-based scheme. The results obtained by the two schemes were then combined using logical OR and AND operations. RESULTS: The morphology-based and topography-based CAD schemes performed at sensitivities of 82.9% and 89.5%, with false-positive detection rates of 1.3 and 0.4 per image, respectively. A logical OR operation resulted in 95.4% sensitivity. An AND operation achieved 76.2% sensitivity, with no false identifications on 93% of images. CONCLUSIONS: By combining the results of the morphology-based and the topography-based schemes, either sensitivity or specificity can be improved.     

Clinicopathological characteristics of prostatic adenocarcinoma in men with atypical prostate needle biopsies

PURPOSE: Atypical or nondefinitive diagnoses comprise 1.5 to 10% of all prostate needle biopsies and many men with atypical biopsy have carcinoma on rebiopsy. We characterize the clinical and pathological features of these men and the tumors, and compare them to those of other men who had more than 1 biopsy. MATERIALS AND METHODS: All prostate needle biopsies done at our institution between 1989 and 1996 on men with a followup biopsy were reviewed and the clinicopathological features were correlated. RESULTS: A total of 343 men had more than 1 biopsy during this period. Of the biopsies 64 were atypical and followup (repeat biopsy) was available for 59. Men with an atypical diagnosis were more likely to have carcinoma (34%) and to be diagnosed subsequently earlier (270 days) than those with an initial negative diagnosis (22%, 603 days). No significant differences were noted in patient age, results of digital rectal examination, initial or followup serum prostate specific antigen, subsequently identified tumor size or Gleason score on needle biopsy or at resection. Although on review as many as 38% of the original atypical foci could be reclassified, this reclassification did not significantly change the results of rebiopsy. CONCLUSIONS: Men with an atypical diagnosis on prostate biopsy are significantly more likely to have carcinoma on rebiopsy than men with an initial negative diagnosis, and the second biopsy should be performed at a significantly shorter interval. The tumors that are subsequently identified in these men are similar to those identified in men without an atypical biopsy.     

Determinants of rifabutin-associated uveitis in patients treated with rifabutin, clarithromycin, and ethambutol for Mycobacterium avium complex bacteremia: a multivariate analysis. Canadian HIV Trials Network Protocol 010 Study Group

Two patients with the Kennedy's disease (KD) mutation have been identified in the Newcastle Brain Tissue Bank. One of these patients had presenile dementia as a prominent clinical feature, previously undescribed in KD. The pathologic substrate underlying the cognitive changes in this patient included neuronal depletion and gliosis in the hippocampus and subcortical gliosis in the prefrontal region. Immunostaining for macrophage markers showed evidence for subtle corticospinal tract pathology in both cases. In contrast to the molecular pathologic features found in ALS, surviving motor neurons in the two KD cases showed no evidence of ubiquitinated inclusions or alterations in neurofilament phosphorylation.     

Persistent pulmonary hypertension of the neonate and asymmetric growth restriction

OBJECTIVE: To evaluate the possible associations between persistent pulmonary hypertension of the neonate, need for extra-corporeal membranous oxygenation, small for gestational age (SGA), and low ponderal index for gestational age in infants with persistent pulmonary hypertension of the neonate and in matched controls. METHODS: Eighty-six infants with persistent pulmonary hypertension of the neonate delivered from 1991 to 1994 at our hospital were matched with 430 contemporaneous control singleton neonates. Birth weight and ponderal indices (100 x weight/length3) less than the tenth percentile for gestational age and gender were defined as SGA and low ponderal index, respectively. We assessed associations between these markers, the presence of persistent pulmonary hypertension of the neonate, and the need for extracorporeal membranous oxygenation. RESULTS: Low ponderal index was associated with persistent pulmonary hypertension of the neonate (odds ratio [OR] 5.4), whereas SGA was not. Low ponderal index (OR 4.0) was an independent correlate of persistent pulmonary hypertension of the neonate after adjustment with logistic regression for 5-minute Apgar scores less than 7, umbilical arterial pH less than 7.10, and presence of meconium. Low ponderal index was associated with need for extracorporeal membranous oxygenation in neonates with persistent pulmonary hypertension (P < .001). CONCLUSION: Fetal developmental events may significantly affect neonatal pulmonary status. Diminished neonatal nutritional status, as measured by low ponderal index for gestational age, is associated with increased risk of persistent pulmonary hypertension of the neonate and severity of the disease process.     

Impact of protein deprivation on protein and DNA synthesis in the developing rat pancreas

The metabolic effects of protein malnutrition on growth and development of the exocrine pancreas are largely unknown. The aim of the present study was to evaluate the effects of protein malnutrition on pancreatic protein and DNA synthesis during postnatal development. Rat dams and their offspring were fed a protein-deficient diet (6% casein) or a control diet (25% casein) during gestation, lactation and after weaning. Pancreatic protein and DNA synthesis were measured in vitro at postnatal ages 1, 3, 10, 23, 36 and 60 days, by assessing [3H]leucine and [3H]thymidine incorporation in freshly isolated acini. Different patterns of protein synthesis were seen in the two groups. At birth, pancreatic protein synthesis was low in both control and malnourished animals. At day 3, protein synthesis in the control acini increased 10-fold while synthesis in acini of the malnourished animal group was only 50% of age-matched control values. No differences in protein synthesis were detected between the control and malnourished groups between 10 and 36 days of age. At 60 days (adulthood), acinar protein synthesis declined in the control-fed rats, but a significant increase was observed in the malnourished animals (p < 0. 0005). At birth, DNA synthesis was high in the acini from both control and malnourished animals. The low-protein diet induced a slight reduction in DNA synthesis at day 3, without altering the general pattern during later stages of development. In conclusion, protein deprivation has variable effects on pancreatic protein and DNA synthesis at different stages of postnatal development. Furthermore, the mechanisms of control within acini appear to be intrinsically regulated.