The tetracycline efflux protein encoded by the tet(K) gene from Staphylococcus aureus is a metal-tetracycline/H+ antiporter

The tet(K) gene from Staphylococcus aureus was highly expressed in Escherichia coli by an alteration of its initiation codon from TTG to ATG and its ribosome-binding sequence from GAGG to GGAGG [Noguchi, N. et al. (1994) Biol. Pharm. Bull. 17, 352-355]. The inverted membrane vesicles prepared from the tet(K)-expressing cells showed respiration-dependent [3H]tetracycline transport comparable to the vesicles from the tet(B)-expressing cells. The affinity of Tet(K) vesicles to tetracycline was the same as that of Tet(B) vesicles, whereas the former Vmax value was about 60% of the latter one. Contrary to Tet(B) vesicles, Tet(K) vesicles showed no significant minocycline uptake, which was consistent with the low minocycline resistance of the Tet(K)-producing cells. The tetracycline transport mediated by Tet(K) vesicles was coupled with proton transport and the translocation of 60Co2+ ions as well as in Tet(B) vesicles. This observation indicates that the class K tetracycline resistance determinant from Gram-positive bacteria also encodes a metal-tetracycline/H+ antiporter that is functionally similar to that encoded by tet(B), although there is a considerable difference in the primary sequences and the putative topologies of these Tet proteins.

Regional sympathetic denervation detected by iodine 123 metaiodobenzylguanidine in non-Q-wave myocardial infarction and unstable angina

Previous studies have revealed that the sympathetic nervous system is more vulnerable to ischemia than the myocardium itself. Thus our study was undertaken to detect denervated myocardium in non-Q-wave myocardial infarction (MI) and unstable angina with iodine 123 metaiodobenzylguanidine (123I-MIBG), which can delineate myocardial sympathetic innervation. Eight patients with non-Q-wave MI and 12 with unstable angina were studied. Sequential 123I-MIBG and thallium-201 chloride (201TlCl) imaging and single-photon emission computed tomography (SPECT) were performed at rest 24 +/- 12 days after the last ischemic attack. Myocardial perfusion defect was not detected by 201TlCl in 4 of 8 patients with non-Q-wave MI, whereas 123I-MIBG SPECT imaging revealed defects corresponding to myocardial ischemic areas predicted by coronary angiography in all 8 patients. 123I-MIBG imaging revealed defects in 7 of 12 patients with unstable angina corresponding to coronary angiographic findings, whereas no myocardial perfusion defect was detected by 201TlCl imaging in any of them. In conclusion, 123I-MIBG SPECT is a sensitive method for detecting myocardium exposed to transient ischemia that cannot be detected by 201TlCl imaging.

Study on the castability of Co-Cr alloy for cast plates. Part 4. Effects of sectional area, number of sprues and alloy components on castability

Co-Cr alloy is used more frequently than Ni-Cr alloy as a nonprecious alloy for cast plates in Japan. Titanium with good biocompatibility has often been contained in the composition of this Co-Cr alloy. However, since the melting temperature of Co-Cr alloy is very high, about 1300 degrees C, and it oxidizes easily, a vacuum-pressure casting machine capable of melting this alloy in a reduced atmosphere has recently been developed. In this study, using the vacuum-pressure casting machine, the possible effects of sectional area and the number of sprues attached to the cast plate wax pattern, as well as the alloy components, on the castability of three kinds of Co-Cr alloy containing titanium were examined. It was found that all of these parameters had significant effects on Co-Cr alloy castability.

Effects of pravastatin on lipid transfer protein and lecithin cholesterol acyltransferase in heterozygous familial hypercholesterolemia

The effects of HMG CoA reductase inhibitor PRAVASTATIN on plasma lipoprotein levels, lipid transfer protein (LTP) activity and lecithin cholesterol acyltransferase (LCAT) activity were investigated in 20 patients with heterozygous familial hypercholesterolemia. Plasma total cholesterol decreased from 299.2 +/- 45.2 to 245.9 +/- 45.1 (mean +/- SD in mg/dl) (p < 0.0001), low density lipoprotein (LDL) cholesterol from 221.1 +/- 47.6 to 164.9 +/- 48.1 (p < 0.0001) and LDL-triglycerides from 38.0 +/- 10.2 to 30.2 +/- 8.8 (p < 0.0001). High density lipoprotein (HDL) cholesterol increased from 60.1 +/- 13.9 to 63.1 +/- 17.0 (p = 0.0264). The HDL-cholesterol: HDL-triglycerides ratio increased from 3.91 +/- 1.14 to 4.91 +/- 1.65 (p = 0.0029). Lipid transfer protein (LTP) activity (as % of transferred cholesteryl ester (CE)) decreased from 4.68 +/- 2.47 to 3.70 +/- 2.31 (p = 0.0024) and LCAT activity decreased from 113.1 +/- 29.9 (U/L) to 97.0 +/- 22.7. There was a negative correlation between LTP/LCAT ratio and HDL-C levels. These results suggested that the changes in plasma HDL-cholesterol concentrations during treatment with pravastatin may be related to the decreases in LTP and LCAT activity due to this drug.

Immunological detection of F1-ATPase gamma-subunit in rat liver peroxisomes

The gamma-subunit of F1-ATPase was detected in highly purified rat liver peroxisomes by immunoblot analysis using an antiserum against purified mitochondrial F1-ATPase. Other subunits of F1-ATPase such as alpha, beta and delta were not detected in the peroxisomes. The polypeptide corresponding to the gamma-subunit in peroxisomes was also recognized by affinity purified antibody against F1-ATPase gamma-subunit. The amount of gamma-subunit in liver homogenate increased in parallel with proliferation of peroxisomes after administration of clofibrate in rats, whereas the amounts of alpha, beta and delta-subunits were not increased. These results suggest that the gamma-subunit of F1-ATPase is a constituent of peroxisomes in rat liver.

Role of the extracellular Ca2+ on the intracellular Ca2+ changes in fertilized and activated mouse oocytes

Changes in intracellular calcium concentration ([Ca2+]i) in fertilized mouse oocytes were measured using the calcium-sensitive dye, fura-2. After fertilization, an initial long-lasting [Ca2+]i increase was followed by a periodic [Ca2+]i increase. The periodic increase in [Ca2+]i persisted for 1 to 3 h and all fertilized oocytes extruded the second polar body within 4 h. The mean interval of periodic [Ca2+]i increase was 470 +/- 180 s (mean +/- SD). The frequency of the periodic [Ca2+]i increase depended on the extracellular calcium concentration. Verapamil and nifedipine inhibited the periodic [Ca2+]i increase. Sixty-five per cent of tested cells extruded the second polar body within 90 min of exposure to 7% ethanol. In these activated oocytes, the long-lasting [Ca2+]i increase was observed. However, no cells showed a repetitive increase in [Ca2+]i. Both release of calcium from intracellular stores and influx of extracellular calcium contribute to the increase in [Ca2+]i induced by ethanol. We conclude that the extrusion of the second polar body requires an increase in [Ca2+]i above a certain threshold level and the mobilization of calcium of both the intracellular and extracellular space in mouse oocytes.

[Detection of codon 72 polymorphism of p53 gene from blood and loss of heterozygosity in brain tumors using polymerase chain reaction]

p53 gene which is known as a tumor suppressor gene locates in chromosome 17p and has a polymorphism at codon 72 (Arginine CGC-->Proline CCC). In this study, we examined the frequency of polymorphism and of heterozygosity in Japanese, and the loss of p53 gene in brain tumor tissues of the patients with heterozygosity using a novel method. The frequencies of heterozygosity, arginine type, proline type were 43%, 42% and 15%, respectively. Heterozygosity was observed in 15 out of 32 patients with brain tumors and loss of heterozygosity (LOH) in these 15 cases was demonstrated in 40%. Although we are not certain whether LOH of p53 region is inevitable process of oncogenesis of some brain tumors, some false negative results may occur. This quick technique requires small amount of samples and no radioactive isotope, therefore, can be applied to detect mutation and LOH occurred in p53 region in terms of the genesis and progression of human neoplasms.

A case of accessory mitral valve leaflet associated with solitary mitral cleft

Accessory mitral valve leaflet is a rare congenital anomaly. More than half of the cases show other congenital cardiac defects and almost all of the cases show subaortic obstruction. We report a case of an accessory mitral valve tissue without outflow obstruction associated with mitral cleft of the posterior mitral leaflet. To our knowledge, this is the first reported case of the combination of these two congenital anomalies.

Studies on the castability of Co-Cr alloy for cast plates. Part 2: Effect of form of sprue attachment to the wax pattern

Co-Cr alloy is used more frequently than Ni-Cr alloy as a non-precious alloy for cast plates in Japan. However, since the melting point of Co-Cr alloy is very high, about 1300 degrees C, and since it oxidizes easily, a vacuum-pressure casting machine capable of melting this alloy in a reducing atmosphere has recently been developed. Using this vacuum-pressure casting machine, the authors studied the effects on the castability of Co-Cr alloy due to the form of sprue attachment to the wax pattern. The results clarified that in the vacuum-pressure casting method, the form of sprue attachment to the wax pattern has a significant effect (p less than 0.01) on the castability of Co-Cr alloy.

[Surgical correction of tetralogy of Fallot with anomalous origin of left pulmonary artery from the ascending aorta]

A surgically corrected case of tetralogy of Fallot with anomalous origin of left pulmonary artery from the ascending aorta is presented. The patient was under-developed 3-year-old girl. She weighed only 1,000 grams at birth and had a systolic heart murmur and slight cyanosis. Echocardiography demonstrated the features of tetralogy of Fallot shortly after birth. Chest roentgenogram showed right ventricular enlargement, but vascular marking of lung was almost normal. Catheterization and cineangiography demonstrated the findings of tetralogy of Fallot. Final diagnosis of anomalous origin of left pulmonary artery from ascending aorta was confirmed by aortography. Surgical correction was accomplished using cardiopulmonary bypass with surface cooling. The left pulmonary artery was detached from the aorta and anastomosed to the main pulmonary artery. Pulmonary valve stenosis and severe infundibular hypertrophy were corrected, and ventricular septal defect was closed with a patch. Postoperative recovery was uneventful. On follow up after surgery, she appears to be in very good condition.

Reversibility of primary pulmonary hypertension with vasodilator, anticoagulant and nocturnal oxygen therapy

Successful vasodilator therapy of a 19 year old woman with primary pulmonary hypertension is described. Long-term home oxygen therapy during sleep (2 1/min, 8 hours) in combination with vasodilator drugs (prazosin 2 mg and long-acting ISDN 20 mg bid) and an anticoagulant (ticlopidine 100 mg bid) brought significant reduction of pulmonary artery pressure and a rise of cardiac output 3 years later. This combination therapy may be effective in selected patients with primary pulmonary hypertension.

[Surgical management of coarctation of the aorta in early infants]

Thirteen infants under three months old were repaired aortic coarctation between 1980 and 1988. The mean age at operation was 2 +/- 0.8 months, the mean weight was 3.7 +/- 0.6 kg. Patients were simple coarctation in 1, coarctation with VSD in 7, and coarctation with complex heart disease in 5. As the operative method, the prosthetic patch plasty was done in 11 patients, end to end anastomosis in 1 patient and remaining one was primary VSD closure and secondary coarctation repair (patch plasty). Three patients died perioperatively, the overall early mortality rate was 23%. Since the introduction of PGE1 therapy in 1985, operative mortality rate of the operation (patch aortoplasty) was improved dramatically. Two of 10 patients died from LOS after the secondary operation (one was TGA and another was congenital MS with VSD). Eight patients are alive and clinical course after operation had been good. The measurement of arm-leg pressure difference didn't reveal significant residual gradient. Postoperative isthmus index was 90 +/- 13% in follow up measurement. Recoarctation has not been occurred in patients undergoing operations with patch plasty. Postoperative hypoplastic arch index was 93 +/- 19% in 1 to 2 years after operation compared with 70 +/- 16% of the preoperation. Therefore, it is concluded that prosthetic patch aortoplasty and end to end anastomosis of the aorta are both available as reasonable and/or adequate operation for the early infants with coarctation.

[Effects of prophylactically used latamoxef with tobramycin against postoperative infections on therapeutic drug monitoring and renal function in the field of obstetrics and gynecology]

Latamoxef (LMOX) and tobramycin (TOB) were administered to 50 patients via intravenous drip infusion to prevent postoperative infections in the field of obstetrics and gynecology. Blood levels of TOB were determined, and effects of the combined use of TOB and LMOX on renal functions were clinically studied. The results obtained are summarized as follows: 1. Determination of blood levels of TOB after intravenous drip infusion of 90 mg TOB with 1 g LMOX revealed a peak at the end of drip infusion, and thereafter the levels decreased rapidly. The maximum level and the level upon commencement of the next administration were within the safe range. 2. Clinical laboratory test before and after surgery using markers of renal functions (BUN, creatinine, beta 2-MG and NAG) revealed a tendency for slight increases in BUN and NAG, but no significant differences were shown. 3. There were no abnormalities in other clinical laboratory parameters or any appearance of subjective or objective side effects.

A case of spontaneous esophageal rupture treated with conservative therapy

A 51 year-old male was admitted because of abrupt hematemesis and loss of consciousness. Emergency endoscopy depicted a giant esophageal ulcer on the left side extending from the middle intrathoracic region to the lower intrathoracic region. Esophagography, performed on the second day of admission, revealed a huge cavity (10 cm x 7 cm) filled with contrast medium resulting from a rupture in the ulceration. His state of shock improved with conservative therapy and no severe mediastinitis was noted. The drainage from the cavity into the lumen of the esophagus was considered to be acceptable from esophagography and an endoscopic examination. Secondary to his stable condition and continuous drainage, this patient was treated conservatively throughout his clinical course. The patient was given intravenous hyperalimentation (IVH) until the 25th hospital day and was medicated with broad spectrum-antibiotics. On the 21st hospital day the size of the esophageal cavity was markedly decreased (7 cm x 2 cm). Only small irregular mucosa was noted on the esophagogram taken 6 weeks after admission. Six months after the onset, an X-ray examination revealed complete healing of the spontaneous esophageal rupture with no recurrence.

The serum pregnancy-specific beta 1-glycoprotein to beta-human chorionic gonadotrophin ratio as an index of prognosis in patients with choriocarcinoma

The ratio of serum pregnancy-specific beta 1-glycoprotein (SP1) to the beta-subunit of human chorionic gonadotrophin (beta-hCG) before and after chemotherapy was measured in 12 patients with metastatic choriocarcinoma. The ratios before chemotherapy ranged between 0.03 and 0.75, with a mean value of 0.34 (SD 0.21). The ratio increased to over 1.0 (1.05-53.3) after one or two courses of chemotherapy in seven of the 12 patients. These women achieved complete remission. In the other five patients who died of the disease due to drug resistance of the tumour, the ratio after chemotherapy was low (0.04-0.74) and tended to decline. These data suggest that the serum SP1/beta-hCG ratio can be used to predict the prognosis of patients with choriocarcinoma.

[Histopathological characteristics of stromal cells in trophoblastic disease]

The histopathological characteristics of stromal cells in trophoblastic diseases remain unknown, though determination of malignancy depends on the existence of stromal elements in villi. Thus, we tried to clarify the characteristics and role of stromal cells in the development of diseases. The mitosis index (MI) of stromal cells and cytotrophoblasts, and the frequency of vessels observed in the stroma were examined. The results were as follows: 1) Complete moles were characterized by high MI values for stromal cells and cytotrophoblasts. They were similar to the ones from normal villi. 2) In partial moles, the MI values for both cells were remarkably low. 3) Invasive moles showed low stromal MI and high cytotrophoblastic MI values. 4) The frequency of blood vessels observed in the stroma was low in complete and invasive moles, though it was high in partial moles. The present results which showed histopathological differences in stromal elements in partial and complete moles, may correspond to the difference in their pathogenesis. And it is possible to assume that the decrease in stromal MI values in invasive mole play an important role in the abnormal proliferation of trophoblasts.

Incidence of ovarian metastasis in patients with cancer of the uterine cervix

During the period from 1970 to 1985, 706 patients with cervical cancer of stage 0 and Ia were treated by a simple hysterectomy without oophorectomy. In 326 patients with invasive carcinoma in stage Ib to stage III, who were treated by a radical hysterectomy from 1977 to 1985, histological examinations were performed to detect ovarian metastasis. A total of 674 autopsy specimens were obtained from the Annual of the Pathological Autopsy Cases in Japan. (Japanese Pathological Society, 1965 to 1978). Follow-up observations on stage 0 and stage Ia revealed no recurrence in the ovaries. In invasive cases of epidermoid carcinoma (stage Ib to stage III), no ovarian metastases were detected, despite discovery of metastases to the pelvic lymph node in 21.6% of the cases. Conversely, in the cases of cervical adenocarcinoma (pure adenocarcinoma and mixed carcinoma), 6 of 48 cases (12.5%) showed ovarian metastases. Ovarian metastases were found in 22 of 77 (28.6%) autopsy cases of adenocarcinoma, but in only 104 of 597 (17.4%) cases of epidermoid carcinoma. This finding is statistically significant (P less than 0.02). Both corpus invasion and metastasis to the ovaries were found in 20 of 54 cases (37.0%). This rate was significantly higher than the rate of ovarian metastasis in cases without corpus invasion (P less than 0.001).