Rat fetal ventral mesencephalon grown as solid tissue cultures: influence of culture time and BDNF treatment on dopamine neuron survival and function

The method of analysis described permits the determination of 2,4-dinitrobenzoic acid down to the lower microg l(-1) range in the urine of persons exposed to dinitrotoluene. 2,4-Dinitrobenzoic acid is the main metabolite of 2,4-dinitrotoluene and technical dinitrotoluene. After acidic hydrolysis, which served to release the conjugated part of the 2,4-dinitrobenzoic acid, the analyte was selectively separated from the urine matrix via various extraction steps and then derivatised to the methyl ester. Quantitative analysis was carried out using capillary gas chromatography and mass selective detection. 3,5-Dinitrobenzoic acid was used as an internal standard. The detection limit was 1 microg l(-1) urine. The relative standard deviations of within-series imprecision were between 5 and 6%. The relative recoveries were between 91 and 110% depending on the concentration. The analytical method developed as part of this study was used to investigate a collective consisting of 82 urine samples from persons working in the area of explosives disposal. The concentrations of 2,4-dinitrobenzoic acid determined ranged from the detection limit to 95 microg l(-1) urine. The method allowed the quantification of low-level internal exposure to dinitrotoluene.     

Diagnostic and therapeutic challenges

A laparoscopic cholecystectomy on a 63-year-old woman was uneventful. Twenty-one months after the operation she complained of dull right flank pain, loss of appetite, weight loss, and cough. CT of the abdomen showed an 8.5 cm mass adjacent to the posterior aspect of the upper pole of the right kidney. CT also demonstrated a small calcification (5 mm diameter) posterior to the upper pole of the right kidney. The patient underwent exploratory laparotomy 2 months after the presentation with flank pain. Examination of the mass showed a thick abscess wall and 250 mL of pus. The patient's symptoms improved after the abscess was drained.     

Compression ultrasonography for diagnostic management of patients with clinically suspected deep vein thrombosis: prospective cohort study

OBJECTIVE: To evaluate the safety of withholding anticoagulant treatment from patients with clinically suspected deep vein thrombosis but normal findings on compression ultrasonography. DESIGN: Compression ultrasonography was done with a simplified diagnostic procedure limited to the common femoral vein in the groin and the popliteal vein extending down to the trifurcation of the calf veins. Patients with normal ultrasonography findings at presentation were retested 1 week later. MAIN OUTCOME MEASURE: The incidence of venous thromboembolic complications during follow up for 6 months in patients in whom anticoagulant treatment was withheld on the basis of normal results on two ultrasonography tests 1 week apart. SETTING: University research centres in four hospitals. RESULTS: A total of 1702 patients were included in the study. Abnormal results on compression ultrasonography at presentation or at 1 week were found in 400 and 12 patients, respectively, for a prevalence of deep vein thrombosis of 24%. None of the patients were lost to follow up. Venous thromboembolic complications during the week of serial testing occurred in a single patient and in eight patients during 6 months' follow up, resulting in a cumulative rate of venous thromboembolic complications of 0.7% (95% confidence interval 0.3% to 1.2%). The mean number of extra hospital visits and additional tests required per initially referred patient was 0.8. CONCLUSION: It is safe to withhold anticoagulant treatment from patients with clinically suspected deep vein thrombosis who have a normal result on compression ultrasonography at the time of presentation and at 1 week.     

Catalytic mechanism of the phospholipase D superfamily proceeds via a covalent phosphohistidine intermediate

The phospholipase D (PLD) superfamily includes enzymes of phospholipid metabolism, nucleases, as well as ORFs of unknown function in viruses and pathogenic bacteria. These enzymes are characterized by the invariant sequence motif, H(X)K(X)4D. The endonuclease member Nuc of the PLD family was over-expressed in bacteria and purified to homogeneity. Mutation of the conserved histidine to an asparagine in the endonuclease reduced the kcat for hydrolysis by a factor of 10(5), suggesting that the histidine residue plays a key role in catalysis. In addition to catalyzing hydrolysis, a number of phosphohydrolases will catalyze a phosphate (oxygen)-water exchange reaction. We have taken advantage of this observation and demonstrate that a 32P-labeled protein could be trapped when the enzyme was incubated with 32P-labeled inorganic phosphate. The phosphoenzyme intermediate was stable in 1 M NaOH and labile in 1 M HCl and 1 M hydroxylamine, suggesting that the enzyme forms a phosphohistidine intermediate. The pH-stability profile of the phosphoenzyme intermediate was consistent with phosphohistidine and the only radioactive amino acid found after alkaline hydrolysis was phosphohistidine. These results suggest that the enzymes in the PLD superfamily use the conserved histidine for nucleophilic attack on the substrate phosphorus atom and most likely proceed via a common two-step catalytic mechanism.     

Valsartan and hydrochlorothiazide in patients with essential hypertension. A multiple dose, double-blind, placebo controlled trial comparing combination therapy with monotherapy

OBJECTIVE: This study compares the antihypertensive efficacy and tolerability of valsartan, a novel angiotensin II antagonist, given with hydrochlorothiazide (HCTZ) vs placebo or vs valsartan or HCTZ alone. DESIGN: 871 adult out-patients with essential hypertension participated in this double-blind study. Patients were randomised in equal number to receive either combination therapy of valsartan (80 mg or 160 mg) and HCTZ (12.5 mg or 25 mg), or valsartan (80 mg or 160 mg) or HCTZ (12.5 mg or 25 mg) alone, or placebo. Patients were treated once daily for 8 weeks and assessed at 2, 4 and 8 weeks after randomisation. MAIN OUTCOME MEASURES: The primary efficacy variable was change from baseline in mean sitting diastolic blood pressure (MSDBP) at end-point. The secondary variable was change in mean sitting systolic blood pressure (MSSBP) from baseline to end-point. RESULTS: All active treatments produced a statistically significant difference in MSDBP (P < 0.001) from baseline to end-point compared with placebo. Similar results were obtained for MSSBP. All combination regimens produced a statistically significantly greater reduction in MSDPB and MSSBP than the corresponding monotherapies. Dizziness and headache were the most common treatment-related adverse experiences reported. Hypokalaemia, associated with the use of thiazide diuretics, was more commonly reported in the higher dose HCTZ 25 mg groups. CONCLUSIONS: Valsartan 80 mg and 160 mg act additively with HCTZ 12.5 mg or 25 mg to lower MSDBP and MSSBP in patients with essential hypertension. The addition of HCTZ to valsartan 80 mg or 160 mg was well tolerated.     

The substrate-binding site in the lactose permease of Escherichia coli

Site-directed N-ethylmaleimide labeling was studied with Glu-126 and/or Arg-144 mutants in lactose permease containing a single, native Cys residue at position 148 in the substrate-binding site. Replacement of either Glu-126 or Arg-144 with Ala markedly decreases Cys-148 reactivity, whereas interchanging the residues, double-Ala replacement, or replacement of Arg-144 with Lys or His does not alter reactivity, indicating that Glu-126 and Arg-144 are charge-paired. Importantly, although alkylation of Cys-148 is blocked by ligand in wild-type permease, no protection whatsoever is observed with any of the Glu-126 or Arg-144 mutants. Site-directed fluorescence with 2-(4-maleimidoanilino)-naphthalene-6-sulfonic acid (MIANS) in mutant Val-331 --> Cys was also studied. In marked contrast to Val-331 --> Cys permease, ligand does not alter MIANS reactivity in mutant Glu-126 --> Ala/Val-331 --> Cys, Arg-144 --> Ala/Val-331 --> Cys, or Arg-144 --> Lys/Val-331 --> Cys and does not cause either quenching or a shift in the emission maximum of the MIANS-labeled mutants. However, mutation Glu-126 --> Ala or Arg-144 --> Ala and, to a lesser extent, Arg-144 --> Lys cause a red-shift in the emission spectrum and render the fluorophore more accessible to I-. The results demonstrate that Glu-126 and Arg-144 are irreplaceable for substrate binding and suggest a model for the substrate-binding site in the permease. In addition, the findings are consistent with the notion that alterations in the substrate translocation pathway at the interface between helices IV and V are transmitted conformationally to the H+ translocation pathway at the interface between helices IX and X.     

Intestinal transport of gentamicin with a novel, glycosteroid drug transport agent

PURPOSE: The objective was to investigate the ability of a glycosteroid (TC002) to increase the oral bioavailability of gentamicin. METHODS: Admixtures of gentamicin and TC002 were administered to the rat ileum by injection and to dogs by ileal or jejunal externalized ports, or PO. Bioavailability of gentamicin was determined by HPLC. 3H-TC002 was injected via externalized cannulas into rat ileum or jejunum, or PO and its distribution and elimination was determined. The metabolism of TC002 in rats was evaluated by solid phase extraction and HPLC analysis of plasma, urine and feces following oral or intestinal administration. RESULTS: The bioavailability of gentamicin was substantially increased in the presence of TC002 in both rats and dogs. The level of absorption was dependent on the concentration of TC002 and site of administration. Greatest absorption occurred following ileal orjejunal administration. TC002 was significantly more efficacious than sodium taurocholate, but similar in cytotoxicity. TC002 remained primarily in the GI tract following oral or intestinal administration and cleared rapidly from the body. It was only partly metabolized in the GI tract, but was rapidly and completely converted to its metabolite in plasma and urine. CONCLUSIONS: TC002 shows promise as a new drug transport agent for promoting intestinal absorption of polar molecules such as gentamicin.     

Tetranucleotide STR system D8S1132: sequencing data and population genetic comparisons

A case of microcytic anemia, leukopenia (with lymphocytic reduction prevalence) and light thrombocytopenia is reported. The case occurred to a 63-year old diabetic woman suffering from Basedow's disease. The thyropathy was diagnosed first and the patient did not undergo to any previous treatment with antithyroid agents. The bone marrow aspiration only showed slight dyserythropoietic notes, with slight reduction of myeloid-erythroid ratio. The blood cell indexes rapidly normalized as soon as euthyroidism was achieved by radioiodine therapy (I131, 4mCi), and this led to think there was a relationship between thyropathy and blood modifications. The patient was subsequently treated with levothyroxine because of the occurrence of a iatrogenic hypothyroidism. Two years later, during a follow-up, all the hematologic parameters were normal, as well as the serum concentration of thyroid hormones and TSH (during opotherapy). We report the hematologic alterations most frequently observed in hyperthyroidism and underline the peculiarity of this case as it shows the simultaneous alterations of different cellular lines in the same patient.     

Day surgery for cervical microdiscectomy: is it safe and effective?

The objective of this pilot study was to evaluate the safety and efficacy of cervical discectomy with fusion performed on an outpatient basis. The experimental group (50 consecutive patients) was studied prospectively and the outcomes were compared with 53 consecutive, retrospectively analyzed, admitted controls who underwent the same procedure. Outcomes for both groups were assessed by patient-response questionnaires and clinical examination. At follow-up times of 1.3 (outpatient) and 1.6 (inpatient) years, outcomes (outpatient/inpatient) expressed as percent successful were as follows: Relief of arm pain (80/70%); relief of neck pain (78/68%); relief of arm muscle weakness and atrophy (94/96%); return to normal activities (64/70%); return to work (65/68%); and satisfaction with the results of surgery (86/83%). No statistically significant differences between outpatients and inpatients were found for any of the outcome parameters studied. There was no mortality and the operative complication rate was 2% for each study group. The results indicate that conversion of cervical discectomy with fusion from an admitted to an ambulatory practice did not compromise the safety or efficacy of the surgical procedure. Potential economic savings to overall health costs of the United States that might result from such conversion could exceed $100 million annually.