Identification of the replication region of the Lactobacillus acidophilus plasmid pLA106

Several naturally occurring antibiotic resistance plasmids were isolated from Pasteurella multocida type D strains. One plasmid, pPM1, was used to study transfer of DNA among P. multocida strains, and could be transferred into Escherichia coli and some P. multocida isolates. However, pPM1 could only be transferred into the toxigenic P. multocida LFB3 at very low frequency. Plasmid recovered from the electrotransformants could be transferred to LFB3 at high frequency. These plasmid DNAs were resistant to PstI, and sensitive to DpnI digestion. Sensitivity to DpnI was common to all the P. multocida DNAs, but resistance to PstI was confined to LFB3. Plasmid pPM1 treated with PstI methylase was able to transform LFB3 at an increased frequency compared to unmethylated DNA, suggesting that LFB3 has a restriction system which cleaves at or near PstI sites.     

Microscopical study of frictional properties of molybdenum disulphide

The frictional properties of molybdenum disulphide were examined on a microscopic scale. A friction trace was recorded for diamond sliding on MoS₂ and scanning electron micrographs were taken from the track formed. Stick-slip occurred and produced characteristic features different from those observed for diamond sliding on stainless steel. Cleaved fragments of MoS₂ piled up and curved concavely to the direction of sliding. A change in the superficial density of sulphur corresponding to stick-slip was found by Auger scanning electron microscopy indicating its important role in reducing friction. Many edge scratching was examined, using emery paper sliding on MoS₂; the finer the abrasive particles, the better the orientation of crytallites having {0001} parallel to the surface.     

Angiotensin-converting enzyme inhibition delays pulmonary vascular neointimal formation

Primary pulmonary hypertension (PPH) is a disease characterized pathologically by pulmonary artery medial hypertrophy, adventitial thickening, and neointimal proliferation. Increasing recognition of the importance of remodeling to the pathogenesis of PPH suggests new therapeutic possibilities, but it will be necessary to (1) identify essential mediators of remodeling, and (2) demonstrate that inhibiting those mediators suppresses remodeling before new antiremodeling therapies can be considered feasible. The effect of angiotensin-converting enzyme (ACE) inhibition on pulmonary vascular remodeling was studied in a newly developed rat model in which neointimal lesions develop between 3 and 5 wk after monocrotaline injury is coupled with increased pulmonary artery blood flow after contralateral pneumonectomy. Neointimal formation was significantly suppressed at 5 wk by ACE inhibition whether it was started 10 d before or 3 wk after remodeling was initiated, although medial hypertrophy and adventitial thickening still developed. By 11 wk, the extent of neointimal formation in rats treated with ACE inhibition was similar to rats without ACE inhibition at 5 wk. Pulmonary artery pressures and right ventricular weights correlated with the extent of neointimal formation. Northern blot analysis and in situ hybridization demonstrated marked suppression of lung tropoelastin and type I procollagen gene expression in the presence of ACE inhibition. An angiotensin II type I receptor antagonist partially, but not completely, replicated the effects of ACE inhibition. These data suggest that the tissue angiotensin system may be a target for therapeutic efforts to suppress the vascular remodeling that is characteristic of primary pulmonary hypertension.     

Evaluation of antitumor effect of chemotherapy for pancreatic cancer

The status of chemotherapy for pancreatic cancer (PC) has been difficult to assess because of the problem of evaluating tumor response, which id dependent on the accurate measurement of tumor size using imaging modalities such as computed tomography. Recently, new assessment methods for chemotherapy in PC, which include clinical benefit response and tumor marker response, have been proposed. The clinical response is evaluated using two parameters; pain and performance status. In our trial of combined chemotherapy with 5-FU and cisplatin in PC patients, 4 (19 %) of 21 PC patients showed remarkable clinical benefit response. With respect to the tumor marker (CA 19-9 and CEA) response, responders, which were defined as patients whose levels were reduced by more than 50% of the pretreatment level, survived significantly longer than non-responders. These new methods may be useful for evaluating chemotherapeutic response and may provide a strong rationale for continuing chemotherapy in patients with stable disease or with non-measurable disease by imaging modalities.     

High-dose dexamethasone therapy for a 14-month-old boy with refractory idiopathic thrombocytopenic purpura

A 14-month-old boy with refractory idiopathic thrombocytopenic purpura (ITP), who was successfully treated with pulsed high-dose oral dexamethasone therapy is reported. The platelet count increased after six scheduled courses of treatment (10 mg/day x 4 days, six courses). Twenty-four months later, the platelet count remained over 10.0 x 10(4)/microL. No obvious side effects were observed during or after the therapy. This treatment could be taken into consideration not only for adults but also for young children with refractory ITP. It is effective, safe, easy to administer, patient comfort is taken into consideration, and hospitalization duration and costs are minimized.     

The efficacy of pulmonary thromboendarterectomy on long-term gas exchange

It has not been delineated in detail how pulmonary thromboendarterectomy (PTE) affects gas exchange through long-term follow-up. In Japan, this surgery has been undertaken in a limited number of institutions, and the results of PTE have not been well publicized. A total of 25 patients were operated on during the period from 1985 to 1996 at our institution, and the overall mortality rate was 16%. Our criteria for PTE were based on the following: 1) thrombi surgically accessible as judged by angiographic study; 2) mean pulmonary arterial pressure > or = 30 mmHg. The efficacies of PTE were analysed on haemodynamics as well as gas exchange at one month postsurgery and during follow-up (6-24 months). Significant haemodynamic improvement was obtained as early as 1 month after surgery. Improvement of gas exchange lagged, but was then observed during follow-up, and the improvement level of pulmonary haemodynamics was sustained. The early postoperative restrictive impairment and ventilation-perfusion abnormality on lung perfusion scan resolved during the follow-up period. It was concluded that the early postoperative efficacy of pulmonary throm-boendarterectomy was mainly achieved due to the reduction of pulmonary hypertension, whereas improvement in gas exchange was obtained over the longer term.     

Reevaluation and potential therapeutic effects of estrogen therapy to prostate cancer patients

Survival time of 65 patients with stage D2 prostate cancer who were treated by estrogen with or without antiplatelet drugs was examined. Survival time of 37 patients with antiplatelet drugs was significantly longer than that of 28 histological control ones. The frequency of death of cardiovascular disease in the former group decreased to 5.3%. Next, progression free time of the 37 patients was compared to the time of 37 patients treated by antiandrogen therapy. The former one was better than the latter. However, survival time after relapse of the estrogen group was shorter than the control. These results suggest that estrogen therapy improved by a combination of antiplatelet drugs has to be reevaluated and contains specific therapeutic effects differing from antiandrogen therapy.     

Analysis of localization of mutated tissue-nonspecific alkaline phosphatase proteins associated with neonatal hypophosphatasia using green fluorescent protein chimeras

Hypophosphatasia is associated with a defect of the tissue-nonspecific alkaline phosphatase (TNSALP) gene. The onset and clinical severity are usually correlated in hypophosphatasia; patients with perinatal hypophosphatasia die approximately at the time of birth. In contrast, we describe a male neonatal patient with hypophosphatasia who had no respiratory problems and survived. He was compound heterozygous for the conversion of Phe to Leu at codon 310 (F310L) and the deletion of a nucleotide T at 1735 (delT1735), causing the frame shift with the result of the addition of 80 amino acids at the C-terminal of the protein. Because the C-terminal portion of TNSALP is known to be important for TNSALP to bind to the plasma membrane, the localization of wild-type and mutated TNSALP proteins was analyzed using green fluorescent protein chimeras. The expression vectors containing the complementary DNA of fusion proteins consisting of signal peptide, green fluorescent protein, and wild-type or mutated TNSALP, caused by delT1735 or F310L mutation, were introduced transiently or stably in Saos-2 cells. The delT1735 mutant failed to localize at the cell surface membrane, whereas the wild-type and the F310L mutants were located in the plasma membrane and cytoplasm. The assay for enzymatic activity of TNSALP revealed that the delT1735 mutant lost the activity and that the F310L mutant exhibited an enzymatic activity level that was 72% of the normal level. The F310L mutation was also detected in another neonatal patient with relatively mild (nonlethal) hypophosphatasia (reported in J Clin Endocrinol Metab, 81:4458-4461, 1996), suggesting that residual ALP activity of the F310L mutant contributes to the less severe phenotype. The patient is unique, with respect to a discrepancy between onset and clinical severity in hypophosphatasia.     

Synchronous multifocal development of invasive transitional cell carcinoma of the urinary tract in a patient with renal failure receiving long-term hemodialysis: a case report

We report a case of transitional cell carcinoma in a patient with chronic renal failure receiving hemodialysis for 22 years. A 55-year-old man was admitted to our hospital. Under diagnosis of invasive bladder cancer and left renal pelvic tumor, removal of the whole urinary tract, e.g., bilateral nephroureterectomy and total cystourethrectomy was performed. Transitional cell carcinoma was found in bilateral renal pelvis, left ureter, bladder and prostate in the resected specimen. Thirteen months after the operation, multiple lung metastases and pathologic bone fracture of the 4th lumber vertebra were found. Chemotherapy (3 courses of modified CISCA, consisting of cisplatin, adriamycin and cyclophosphamide) was performed, but the died of systemic metastases of cancer and bleeding due to perforation of multiple gastric ulcers.