[Successful valvuloplasty for isolated tricuspid regurgitation due to traumatic ruptured papillary muscle]

A 44-year-old man suffered from an traffic accident on May 27, 1994. He was transferred to a hospital because of emergent operation for a laceration of liver, right-sided hemothorax and pneumothorax. After surgical treatment for these lesions, he was doing well. However, systolic murmur appeared from August, 1994. By echocardiography and cardiac catheterization, he was diagnosed of isolated tricuspid regurgitation due to traumatic ruptured papillary muscle. Because right heart failure was progressive, an operation was recommended. At operation, annular dilatation of tricuspid valve and ruptured papillary muscle of anterior leaflet were found. And the ruptured end of right ventricular aspect was recognized. Therefore, we performed tricuspid valvuloplasty and annuloplasty. Postoperative course was uneventful. And residual regurgitation was not detected by right ventriculography. Especially, in patients with tricuspid regurgitation due to ruptured papillary muscle, symptoms usually begin soon after trauma. Therefore, an operation should be recommended promptly in the presence of right heart failure not relieved by medical treatment. And an earlier operation could increase the feasibility of tricuspid valvuloplaty, and the possibility of maintaining sinus rhythm.

Reciprocal regulation by cyclic nucleotides of the differentiation of rat osteoblast-like cells and mineralization of nodules

The effects of cAMP and cGMP on the differentiation of osteoblast-like cells derived from rat calvariae and on the formation of bone in vitro were studied. Continuous culture of osteoblast-like cells in the presence of 8-bromo-cyclic AMP (8-Br-cAMP) resulted in the dose-related inhibition both of the synthesis of cellular alkaline phosphatase (ALPase), which is known as a marker of osteoblastic differentiation, and of the formation of mineralized nodules, which is a model of the formation of bone in vitro. By contrast, 8-bromo-cyclic GMP (8-Br-cGMP) promoted the synthesis of ALPase and the formation of mineralized nodules. Northern blot analysis revealed that these cyclic nucleotides modulated the steady-state levels of mRNAs for ALPase and osteocalcin, a bone-matrix protein that is specifically produced by osteoblast. The present results indicate that cAMP and cGMP act reciprocally to regulate osteoblastic differentiation and the subsequent formation of mineralized nodules.

Reconstitution of the metal-tetracycline/H+ antiporter of Escherichia coli in proteoliposomes including F0F1-ATPase

The tetracycline resistance gene (tetA) was cloned downstream of the lac promoter. When expression of the tetA gene in E. coli cells carrying the lac Iq gene was induced with isopropyl beta-D-thiogalactopyranoside, the tetracycline resistance protein (TetA) was overproduced, amounting to about 30% of the integral cytoplasmic membrane protein. Essentially pure TetA protein could be obtained by solubilization with 1.25% n-octyl-beta-D-glucopyranoside and one-step purification by DEAE Sepharose CL-6B column chromatography. The TetA protein was incorporated into proteoliposomes with F0F1-ATPase. The proteoliposomes exhibited [3H]tetracycline transport dependent on ATP hydrolysis. The specific activity was about 2 nmol/mg protein/min. The proteoliposomes also showed H+ efflux coupled with tetracycline influx. Tetracycline/H+ antiport by proteoliposomes reconstituted with the Ser-65-->Cys mutant TetA protein was inhibited by N-ethylmaleimide. These results proved for the first time that the tetracycline/H+ antiport is only mediated by the TetA protein.

[A case of coronary artery bypass grafting using arterial grafts in a patient with Buerger's disease]

A 50-year-old male with Buerger's disease underwent coronary artery bypass grafting (CABG) using left and right internal thoracic arteries (LITA and RITA). In our case, his saphenous veins could not be used because of migrating thrombophlebitis, and we could not use right gastroepiproic artery because he had undergone gastrectomy for gastroduodenal ulcer. He underwent CABG with LITA-left anterior descending artery and free RITA-right coronary artery. Postoperative coronary angiogram showed good patency of both grafts, and his postoperative course has been uneventful for 42 months. To our knowledge, there is no report of CABG in a patient with Buerger's disease, but we think the use of arterial grafts is useful in such cases.

Left ventricular end-systolic volume index in patients with ischemic cardiomyopathy predicts postoperative ventricular function

BACKGROUND

We investigated the usefulness of the preoperative left ventricular end-systolic volume index (LVESVI) as a predictor of postoperative ventricular function.

METHODS

We retrospectively reviewed the records of 310 patients who underwent coronary artery bypass grafting and identified 20 patients with ischemic cardiomyopathy with a preoperative ejection fraction less than 0.30. We determined the preoperative and postoperative ejection fraction, LVESVI, and left ventricular enddiastolic volume index using biplane left cineventriculography. Patients were divided into groups depending on whether their preoperative LVESVI was less than 100 mL/m2 (group A, n = 10) or greater than 100 mL/m2 (group B, n = 10).

RESULTS

The mean ejection fraction increased significantly after coronary artery bypass grafting in group A from 0.25 +/- 0.05 to 0.40 +/- 0.09 (p < 0.01), but did not change significantly in group B (0.26 +/- 0.05 versus 0.23 +/- 0.06). The mean LVESVI decreased significantly in group A from 83.2 +/- 13.7 to 61.7 +/- 20.4 mL/m2 after operation (p < 0.05), but did not change significantly in group B (124.7 +/- 21.0 versus 121.5 +/- 37.6 mL/m2). In group B, 4 patients had signs of congestive heart failure during the follow-up period and had to be rehospitalized.

CONCLUSIONS

The mean ejection fraction improved significantly after coronary artery bypass grafting in patients with a preoperative LVESVI less than 100 mL/m2, despite the presence of a global left ventricular ejection fraction less than 0.30. Our results suggest that the preoperative LVESVI predicts the postoperative status and left ventricular function in patients with ischemic cardiomyopathy.

Second-site suppressor mutations for the Asp-66-->Cys mutant of the transposon Tn10-encoded metal-tetracycline/H+ antiporter of Escherichia coli

Asp66 is the only essential acidic residue in the putative hydrophilic loop2-3 region of the transposon Tn10-encoded metal-tetracycline/H+ antiporter [TetA(B)] [Yamaguchi, A., Nakatani, M., & Sawai, T. (1992a) Biochemistry 31, 8344-8348]. Escherichia coli cells producing a D66C mutant of TetA(B) showed no tetracycline resistance. A spontaneous second-site revertant was isolated from the cells carrying the D66C mutant gene, which showed moderate resistance to tetracycline [minimum inhibitory concentration (MIC), 50 micrograms/mL]. The entire sequencing of the revertant genes revealed two secondary mutations, i.e., the codon 40 of GCT (Ala)-->GAT (Asp) and T-->G at 17 bases upstream from the initiation codon of the tetA gene. There was a T-->G mutation at position -17, which was a mutation in the tet promoter/operator region, which caused a decrease in TetA(B) production. The full expression of the A40D/D66C double and the A40D single mutants, which were constructed by site-directed mutagenesis, was deleterious for cell growth. The -17T-->G mutation mitigated the deleterious effect of these mutants through reduction of expression. The -17T-->G single mutation introduced into the wild-type tet gene did not affect the level of resistance, although the expression was significantly reduced. Intact cells carrying the A40D/D66C and -17T-->G/A40D/D66C mutant plasmids showed a reduced level of tetracycline accumulation due to active efflux, whereas no significant tetracycline uptake was observed in inverted membrane vesicles prepared from these mutant-producing cells. The A40D mutation is located at opposite side of the membrane to the D66C mutation in the putative secondary structure of TetA(B). The second-site mutation might mediate its effects through a structural perturbation propagated along the polypeptide backbone.

[Clinical significance of selective cerebral perfusion with cold blood on the brain protection]

In 42 patients with thoracic aortic disease, a selective cerebral perfusion with 16 degrees C cold blood was applied for the brain protection during the repair of the thoracic aorta. The surgical repair consisted of the replacement of the ascending aorta (9 cases), the ascending aorta and aortic arch (12 cases), the aortic arch (18 cases), and the aortic arch and descending aorta (3 cases). Twenty-two patients of them (52%) required emergency surgery and four patients died due to postoperative complications including visceral organ ischemia (2 cases) and multiple organ failure (2 cases). The mortality rate of this group was 18.2% (4/22 cases). In elective surgical classes, one patient died due to intraoperative coronary embolism. The mortality rate of this group was 5.0% (1/20 cases). No postoperative obvious brain defect was observed except one old patient (85-year-old female) with ruptured aortic arch who already had the brain infarction preoperatively. She died due to multiple organ failure with unconsciousness. Other patients including the patients with long cerebral perfusion (> 180 min) recovered well and returned to normal daily life. The selective cerebral perfusion with cold blood was easy to prepare and demonstrated the superb efficacy of brain protection in the patient.

[Successful surgical treatment of mitral regurgitation associated with anti-phospholipid syndrome and systemic lupus erythematosus]

A 39-year-old woman with the diagnosis of mitral regurgitation was admitted to our hospital for surgical treatment. Cerebral thromboembolism and spontaneous abortion had been repeated in her past history. She was suffered from chronic renal failure associated with systemic lupus erythematosus (SLE) and anti-phospholipid syndrome (APS). An operative procedure was recommended because of the progressive heart failure due to mitral regurgitation. For renal failure, continuous ambulatory peritoneal dialysis (CAPD) was introduced at one month before operation. As the operative procedure, valve replacement using Carpentier-Edwards bioprosthesis (27 mm) was done rather than valve reconstruction, because chordal rupture of posterior leaflet and severe hypertrophy of both leaflets were recognized. During operation, uncontrollable bleeding was not observed. However, platelet transfusion was needed. We use warfarin and antiplatelet agents jointly as postoperative anticoagulant therapy. Thromboembolic episodes have not been observed 4 years postoperatively. Relationship between SLE with APS and cardiac valvular lesions has been focused. The present case was considered to be the interesting case which various devices were necessary to operative management including chronic renal failure, cardiopulmonary bypass, selection of prosthetic heart valve, and postoperative anticoagulant therapy for preventing thrombus formation.

[Re-replacement of Starr-Edwards mitral valve (model 6320) for prosthetic valve endocarditis 22 years after replacement]

The patient was a 43-year-old woman who had undergone mitral valve replacement with Starr-Edwards ball valve (model 6320) 22 years ago. Perivalvular mitral leakage due to prosthetic valve endocarditis and tricuspid regurgitation were found. She underwent re-replacement of the mitral valve. The operative findings revealed almost intact valvular function of the ball valve. As far as we know, 22 years is the longest follow-up for the Starr-Edwards ball valve which has maintained normal function.

Evaluation of the antithrombogenicity of a new microdomain structured copolymer

A new antithrombogenic material was studied, fluorine-acryl-styrene-urethane-silicone (FASUS) copolymer, the theoretical basis of which attributed to its hydrophilic and hydrophobic microdomain structure. In this series of experiments, the blood compatibility of this copolymer was evaluated in vitro and ex vivo. For the in vitro evaluation, a whole blood clotting test and the microsphere column test were performed. For the ex vivo evaluation, two series of shunt tests in rabbits were performed, one was the arterioartery (A-A) shunt model, and the other was the arteriovenous (A-V) shunt model. The antithrombogenicity was assessed by measuring the shunt obstructive time in the A-A shunt experiment. The A-V shunt experiment was assessed by measuring the circulating platelet counts, platelet aggregability, activated partial thromboplastin time (APTT), and prothrombin time (PT). In the whole blood clotting test, FASUS revealed the significantly longer blood clotting time than that of the control glass tubings (19.7 +/- 1.0 versus 6.5 +/- 0.7 min, p < 0.001). In the microsphere column test, the coated group had a 30% reduction of the platelet number in the eluted blood in contrast with a marked decrease of 70% in the control group (p < 0.05). In the ex vivo A-A shunt experiment, the occlusion time for the FASUS-coated group was significantly longer than that of the control (109.7 +/- 17.3 versus 3.0 +/- 0.4 min, p < 0.05). The A-V shunt experiment showed that the FASUS copolymer suppressed the decrease in platelet counts and tended to improve prolonged APTT compared with that of the control. Clinically, in 25 patients, we placed coated FASUS copolymer into the cannulas for use in percutaneous cardiopulmonary support (PCPS) procedures. There was no evidence of thrombus on the blood contacting surface and no thromboembolism in major organs clinically or upon postmortem examination. In summary, this new copolymer may be effective in preventing thrombus formation in vitro, ex vivo, and in clinical situations.

[The role of CD44 adhesion molecules]

CD44 is a transmembrane glycoprotein involved in the interaction between cells and extracellular matrix. CD44 is ubiquitously expressed on cells, and has been thought to be a cell adhesion molecule with proposed functions in extracellular matrix binding, cell migration and lymphocyte homing. In 1991, Stamenkovic et al. showed the existence of two forms of CD44: a hematopoietic (standard) and an epithelial form which was highly expressed by carcinomas. The alternative splicing of 10 variant exons encoding the membrane proximal portion of the external domain of CD44, in particular, results in many variant isoforms. These may play a critical role in malignant behavior and in determining organ specificity in metastasis.

Proinflammatory cytokine levels in patients undergoing cardiopulmonary bypass. Does lung reperfusion influence the release of cytokines?

Proinflammatory cytokines have been implicated in mediating tissue injury after cardiopulmonary bypass. Causative factors of inflammatory response after cardiopulmonary bypass include contact of the blood with the extracorporeal circuit and heart-lung reperfusion injury when discontinuing bypass. To evaluate proinflammatory cytokine release during cardiopulmonary bypass, plasma levels of interleukin-6, 8, and monocyte chemoattractant factor were measured in the radial artery (for systemic blood) and left atrium before and after cardiopulmonary bypass. A total of 13 patients were studied, with no deaths or complications. In both radial artery and left atrium, interleukin-6, 8, and monocyte chemoattractant factor rose significantly after cardiopulmonary bypass (p < 0.05 versus before cardiopulmonary bypass). These changes may have been caused by removal of the aortic cross clamp and recommencement of artificial ventilation, which result in reperfusion of the pulmonary capillary beds. There were no differences in cytokine levels after cardiopulmonary bypass in the radial artery and left atrium. This result suggested that lung reperfusion injury after cardiopulmonary bypass may not be the major causative factor of the release of proinflammatory cytokines.

A possible role of vitamin D receptors in regulating vitamin D activation in the kidney

The vitamin D endocrine system is regulated reciprocally by renal 25-hydroxyvitamin D3 1 alpha- and 24-hydroxylases. Previously, we reported that renal proximal convoluted tubules, the major site of 1 alpha, 25-dihydroxyvitamin D3 production, have vitamin D receptors. In the presence of vitamin D receptors, renal proximal convoluted tubules cannot maintain the state of enhanced production of 1 alpha, 25-dihydroxyvitamin D3. To clarify this discrepancy, we proposed a working hypothesis for the reciprocal control of renal 25-hydroxyvitamin D3 1 alpha- and 24-hydroxylase activities. In rat models of enhanced renal production of 1 alpha, 25-dihydroxyvitamin D3, expression of vitamin D receptors and 25-hydroxyvitamin D3 24-hydroxylase mRNAs was strikingly suppressed in renal proximal convoluted tubules but not in the cortical collecting ducts. In vitamin D-deficient rats with up-regulated renal 25-hydroxyvitamin D3 1 alpha-hydroxylase activity, expression of vitamin D receptor mRNA in renal proximal convoluted tubules was also down-regulated, indicating that the down-regulation of vitamin D receptor mRNA is not the result of the enhanced production of 1 alpha, 25-dihydroxyvitamin D3. In Japanese quail models with up-regulated renal 25-hydroxyvitamin D3 1 alpha-hydroxylase activity by sex steroids, expression of vitamin D receptor mRNA was also down-regulated in the kidney but not in the duodenum. These results suggest that the down-regulation of vitamin D receptors plays a critical role in production of 1 alpha, 25-dihydroxyvitamin D3 in renal proximal convoluted tubules.

Microgravity generated by space flight has little effect on the growth and development of chick embryonic bone

Seven days' space flight of fertilized chicken eggs pre- incubated for 7 and 10 days on earth caused no differences in the morphology of osteoblasts, osteoclasts, and osteocytes of humerus and tibia from those of control embryos. Bone-resorbing and -forming activities of the femur were not different between control and flight groups. As a consequence, calcium and phosphorus contents of the femora between control and flight groups were not changed. Alkaline phosphatase activity of 3 different regions (resting cartilage, growth cartilage, and cortical bone) of tibia showed no significant difference between control and flight groups. No significant difference of gene expressions of hepatocyte growth factor and receptors of fibroblast growth factor was observed in perichondrium, trabecula, and skeletal muscles and tendons of hind limbs between control and flight groups. Unlike the results of previous space flight experiments in which young growing mammals were used, these morphological and biochemical results indicate that microgravity has little effect on bone metabolism of the chick embryo.

[Intermediate to late results of aortic or mitral valvuloplasty by rasping procedure]

We have proposed Rasping procedure as one of the methods of aortic valvuloplasty (A-Rasping) and defined as debridement of the thickened surface of the rheumato-degenerative aortic valve using an electric rasper since 1986. Furthermore, we have extended this technique to mitral valvuloplasty (M-Rasping). The purpose of this study is to evaluate intermediate to late results of valvuloplasty by Rasping procedure. From 1986 to 1994, this method was carried out on 14 patients with mild-to-moderate aortic valve disease in severe mitral valve disease or coronary artery disease, and on 6 patients with mitral stenosis. In A-Rasping group, aortic regurgitation was found in 10 patients and aortic stenosis was found in 4 patients. The degree of regurgitation, the transvalvular pressure gradient, and the pre- and postoperative cardiac function in both group were investigated chronologically by echocardiography. In this series of patients, no hospital mortally including operative death was observed. Furthermore, reoperation for repaired aortic or mital valve was not required. In A-Rasping group, 2 late deaths (14.2%) occurred at 1 year and 4 years after operation. Cause of 2 late deaths was prosthetic valve endocarditis in mitral position. In A-Rasping group, at 1 year after operation, regurgitation was reduced to degree I or less in all patients. However, at the 3rd postoperative year, regurgitation increased to degree II in 2 patients. As compared with the preoperative values, the transvalvular pressure gradient significantly decreased in 4 patients (29.5 +/- 7.6 mmHg vs 12.5 +/- 5.0 mmHg, p = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Regulation of differentiation pathway of skeletal mesenchymal cells in cell lines by transforming growth factor-beta superfamily

The skeletal mesenchymal cells including osteoblasts, chondrocytes, muscle cells and adipocytes are believed to be derived from the common mesenchymal progenitors. Using various cell lines, multipotential mesenchymal progenitors capable of differentiating into these cell lineages have been demonstrated to be present in the skeletal tissues. The developmental potential of the progenitors becomes more restricted according to their maturation stages in the specialized cell lineages. Among the various growth factors, bone morphogenetic protein (BMP), which belongs to the transforming growth factor-beta (TGF-beta) superfamily, plays an important role in the regulation of the differentiation pathway of these mesenchymal cells. BMP-2 induces the undifferentiated mesenchymal progenitors to differentiate into osteoblasts, chondrocytes and adipocytes. BMP-2 also stimulates the committed osteo-chondroprogenitors to differentiate into more mature cell types, but inhibits myogenic cells to differentiate into myotubes. BMP-2 converts the differentiation pathway of C2C12 myoblasts into the osteogenic lineage associating with decreases in the expression levels of the muscle specific regulatory factors such as myogenin and MyoD. TGF-beta inhibits myotube formation in myogenic cell lines, but does not stimulate osteoblast differentiation. The TGF-beta superfamily plays important roles in the differentiation process of the skeletal mesenchymal cells.

[Successful resection and repair of the superior vena cava and right atrium in a patient with invasive thymoma]

A 45-year-old female, who suffered from Superior Vena Cava (SVC) syndrome, was diagnosed as invasive thymoma by means of trans-sternal aspiration cytology (TSAC). After preoperative radiotherapy and two courses of neoadjuvant chemotherapy, she underwent radical tumor resection combined with partial resection of both SVC and the right atrium followed by pericardial patch repair under the cardiopulmonary bypass. Complete resection is the most important procedure for the therapy of invasive thymoma, even if the tumor is in advanced stage invading to large vessels such as SVC. As far as our knowledges are concerned, complete resection of invasive thymoma combined with partial resection of the right atrium is very rare. Our case shows that partial resection of the right atrium is not risky operative procedure, if the invaded lesion of the right atrial wall is localized at the antero-lateral side to which the sinus node and the conducting system is not close. And we chose pericardial patch repair for the large defect of SVC. This patch repair was good method in this case because the blood flow through the Azygos vein was well maintained. We would also like to emphasize that TSAC is useful diagnostic procedure for the mediastinal mass lesion to which transcutaneous aspiration using the ultrasound or CT scan as a guide is impossible.

[A case of duodenal duplication and a review of reported cases]

We report a case of duodenal duplication and review of literatures on 43 cases reported in Japan including ours. A 34-year-old female who was admitted with chief complaints of epigastric pain and hematoemesis. An endoscopic examination and a hypotonic duodenography revealed a protruding tumor with bleeding ulcer. Wedge resection of the duodenum, including the lesion, was performed. A diagnosis of duodenal duplication was made by histopathological examination.

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.

[The glutamic acid decarboxylase (GAD) antibodies and their clinical significance]

Since it was reported that the 64kD antigen that had been found to be the target of autoantibodies in the sera from IDDM patients was the same as GAD, GAD antibodies have been one of the focuses of many investigations. In this study, we developed a sensitive radioimmunoassay (RIA) system for GAD antibodies in human sera using native GAD purified from the pig brain. To confirm the relevance of pig GAD as the target antigen, we compared the sequences and antigenic activities among pig, rat and recombinant human GAD65. Based on the data from our and other laboratories, the homology of amino acid sequences between pig and human GAD65 was 96.4%. The coefficient of correlation between the results of human and pig GAD RIA was 0.948. The GAD antibody study group confirmed the clinical usefulness of GAD antibodies not only for the diagnosis of IDDM but also slowly progressive IDDM.

Effect of sevoflurane on the vascular reactivity of rabbit mesenteric artery

Sevoflurane is well known to cause depression of cardiovascular function, but detailed information on its actions on the contractility and reactivity of blood vessels is lacking. We have assessed therefore the direct effect of this anaesthetic on the functional reactivity of isolated rabbit mesenteric artery ring preparations. We found that contractions of endothelium intact rings induced by noradrenaline and phenylephrine were significantly attenuated by 4% sevoflurane; the observation that the maximal tension generation decreased without a significant reduction in pD2 is consistent with the view that receptor dysfunction was not involved. The effect of sevoflurane was not affected by NG-monomethyl-L-arginine. Sevoflurane 4% also produced attenuation of noradrenaline-induced contractions of endothelium denuded ring preparations. The contractions of endothelium denuded ring preparations produced by noradrenaline in Ca(2+)-free media in the presence of K+ were not affected by 4% sevoflurane, but sevoflurane depressed external Ca(2+)-dependent contractions. When vasodilators (acetylcholine and nitroglycerin) were added to the bathing media in the presence of 2% sevoflurane, the endothelium-dependent relaxation produced by acetylcholine, but not the endothelium-independent relaxation produced by nitroglycerin, was attenuated; superoxide dismutase inhibited the effect of sevoflurane on endothelium-dependent relaxation. These results are consistent with the view that sevoflurane inhibits alpha adrenoceptor-mediated contractions of isolated rabbit mesenteric artery ring preparations; this effect may be caused by reduced Ca2+ influx, as estimated from the effect on external Ca(2+)-dependent contractions, but is unlikely to be caused by reduced Ca2+ release from the sarcoplasmic reticulum of vascular smooth muscle, as estimated from noradrenaline-induced contractions in Ca(2+)-free bathing media.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationships among the expression of epidermal growth factor receptor, proliferating cell nuclear antigen labeling index, and lymph node metastasis in gastric cancer

The expression of epidermal growth factor receptor (EGFR), epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha) and the labeling index of proliferating cell nuclear antigen (PCNA LI) were examined immunohistochemically in 288 gastric cancer patients, and the relationships between these results and the lymph node metastasis were studied. To investigate the relation between the expression of EGFR and PCNA LI, we divided the patients into the following three groups according to the immunohistochemical findings: group A, EGFR (+); group B, EGFR (-), and EGF(+) or TGF alpha(+); group C, EGFR(-), EGF(-) and TGF alpha(-). In the cancers invading submucosal or proper muscle layer, high-PCNA tumors (PCNA LI > or = 70) in both groups A and B had more frequent lymph node metastasis than in the intermediate-(40-69) and low- (< or = 39) PCNA tumors. In the cancers invading subserosal layer or further, the frequency of metastasis in group A was over 78% and was not related to the PCNA range. In group B, metastasis was more frequent in high- and intermediate-PCNA tumors (about 80%) than in low-PCNA tumors (44%). These results suggest that growth regulation by EGFR is related to lymph node metastasis in gastric cancer, and the higher the PCNA LI of cancer cells becomes, the more frequent the occurrence of lymph node metastasis.

Exercise at high temperature causes maternal hyperthermia and fetal anomalies in rats

Hyperthermia is thought to be a teratogen in many animal species and also in humans. It has been reported that hyperthermia caused by sauna, hot tub, or fever during the early stages of pregnancy is related to an increased risk for neural tube defects. During exercise, especially in hot conditions, body temperature can also rise to fairly high levels. Thus, we can surmise that hyperthermia induced by exercise can also cause fetal malformation. To investigate this hypothesis, pregnant rats at 9 days of gestation were divided into four groups. In the first group, the animals were made to swim for 30 minutes in water at a temperature of 40.5 degrees C. In the second group, they were restrained and immersed in water for the same time at the same temperature. In the third group, the rats were forced to swim in water at 36.0 degrees C. The fourth group were controls. The core temperature of the rats was measured during these procedures. On the 18th gestational day, fetuses were extracted by cesarean section. The elevation of maternal core temperature was significantly greater in the first group than in the other groups. In the first group, 69% of fetuses had various external anomalies. No anomalies were found in the other groups. Our results show that exercise in hot conditions caused the elevation of core temperature and resulted in fetal anomalies in rats.