Activity-dependent survival and enhanced turnover of calcium in cultured rat cerebellar granule neurons

Neurons survive when their activity is maintained. An influential hypothesis on the cellular mechanism underlying this phenomenon is that there is an appropriate range of intracellular Ca²⁺ concentration ([Ca²⁺]i) for survival. The rat cerebellar granule neuron in culture serves as the most often used model system for the analysis of activity-dependent survival, since it does not survive unless an excitant (KCl or glutamate) is added to the culture medium. Against the above-mentioned hypothesis, we found in our previous examination no difference between steady-state [Ca²⁺]i in granule neurons cultured under high KCl (i.e., survival) and low KCl (i.e., death) conditions. In this report, we present the quantitative background of unchanged [Ca²⁺]i between the two culture conditions. Influx of Ca²⁺ due predominantly to L-type voltage-dependent calcium channels was higher in high KCl cultures than in low KCl cultures. At the same time, efflux of Ca²⁺ due to the activity of Ca²⁺/Na⁺ antiport was also higher in high KCl cultures. Additionally, we found that the endocytotic activity was greater in high KCl cultures than in low KCl cultures, as monitored by the rate of uptake of horseradish peroxidase added to medium. Since the uptake was blocked by an internal Ca²⁺ chelator, the increased endocytotic activity in high KCl cultures might be a consequence of the enhanced Ca²⁺ turnover.     

A case of emergency surgery for acute mitral regurgitation due to complete papillary muscle rupture as complication of acute inferior myocardial infarction

We experienced a case with acute mitral regurgitation caused by complete posterior papillary muscle rupture as complication of acute inferior myocardial infarction, who underwent successfully emergency operation of mital valve replacement and coronary revascularization in acute stage. A 64-year-old woman developed sudden cardiogenic shock shortly after the onset of acute inferior myocardial infarction. The diagnosis of acute inferior myocardial infarction was based on the electrocardiographic findings. Under IABP support, preoperative coronary angiography visualized total occlusion of segment 3 of the right coronary artery, and preoperative left ventriculography showed akinesis of inferior wall and severe mitral regurgitation. At 6 hours after onset of papillary muscle rupture, emergency operation was performed. At operation, posterior papillary muscle was found to be totally ruptured. Coronary artery revascularization and mitral valve replacement were performed. Postoperative course was uneventful, with 4 days of IABP and 5 days of ventilatory support. She was discharged on the twentieth postoperative day in NYHA class I. Reports of successful emergency operation for total papillary muscle rupture following acute myocardial infarction are rare. Early diagnosis and surgical treatment are mandatory to save this group of patients.     

Clinical efficacy of sulbactam/ampicillin in the field of pediatrics

Sulbactam (SBT) is a new derivative of the basic penicillin nucleus. It effectively and irreversibly inhibits several important bacterial beta-lactamases and displays synergistic effects against the resistant organisms when co-administered with ampicillin (ABPC). SBT/ABPC, which is a fixed combination of SBT and ABPC in a 1:2 ratio, was studied for clinical efficacy in the field of pediatrics. Patients treated were infants and children ranging from 12 days to 13 years and 2 months old suffering from acute tonsillitis in 2 cases, acute bronchitis in 2 cases, septicemia in 2 cases, acute enteritis, acute pyelonephritis and osteomyelitis in 1 case each, a total of 9 cases. SBT/ABPC was administered 100-300 mg/kg in daily doses and durations of treatment ranged from 4 to 17 days. Clinical results were "excellent" in 6 and "good" in 2: the efficacy rate was 88.9% or 8 cases out of 9. Neither clinical side effects nor abnormal laboratory findings obviously attributable to SBT/ABPC were observed in any cases.     

The change of antithrombin III activity of pregnant women and women on oral contraceptives (author's transl)

Antithrombin 3 (AT 3) activity was examined in pregnant women, women using oral contraceptives (mestranol .1 mg plus norethisterone 2 mg daily or mestranol .05 mg plus norethisterone 1 mg daily), and women on the gestagens alone. AT 3 activity in serum was found to decrease significantly in the third trimester of pregnancy and postpartum period (2 or 3 days); it returned to the level of nonpregnant females 6 or 7 days postpartum. AT 3 in plasma as well as serum was found to decrease significantly after the first month administration of the oral contraceptives. It returned to normal level after the cessation of administration. The successive course of administration again caused the decrease of AT 3 activity. The degree of the decrease became less and less. Finally the decrease was not in effect after 3-5 courses of administration. Norethisterone alone did not cause any change of AT 3 level. (Author's Modified)     

Synergism between interleukin-11 and bone morphogenetic protein-2 in the healing of segmental bone defects in a rabbit model.

Recombinant human interleukin-11 (rHuIL-11) and recombinant human bone morphogenetic protein-2 (rHuBMP-2) have been shown to act synergistically in the induction of osteoblast differentiation. To determine whether these two proteins can be used clinically in fracture healing and reconstructive surgery, we investigated whether rHuIL-11 and rHuBMP-2 act synergistically to heal segmental bone defects in a rabbit model. A 1.5-cm segmental defect was created in the right ulnar diaphysis of 20 Japanese white rabbits. Polylactic-co-glycolic acid (PLGA)-coated gelatin sponges (PGS) permeated with rHuBMP-2 (n = 8), rHuIL-11 plus rHuBMP-2 (n = 8), or rHuIL-11 (n = 4) were implanted into the bone defects. Radiographs were scored by two independent observers for bone formation and union rates after 2, 3, 4, and 8 weeks. Bone formation was higher in rabbits implanted with rHuBMP-2 plus rHuIL-11 than in those implanted with rHuBMP-2 alone, reaching statistical significance after 4 weeks. At early time points, the union rate in rabbits implanted with rHuBMP-2 plus rHuIL-11 was higher than in rabbits implanted with rHuBMP-2. At 2, 4, and 8 weeks, new bone volume was significantly higher in rabbits administered rHuIL-11 plus rHuBMP-2 than in those given rHuBMP-2 alone. In contrast, mechanical testing after 8 weeks showed that bone strength in the two groups of rabbits was equivalent. These findings show that rHuIL-11 and rHuBMP-2 act synergistically to accelerate bone formation without affecting bone strength. Treatment with a combination of rHuIL-11 and rHuBMP-2 may thus be of great benefit in fracture healing and for patients undergoing reconstructive surgery.     

Rapid serodiagnosis of active pulmonary Mycobacterium tuberculosis by analysis of results from multiple antigen-specific tests

We have prospectively analyzed three antigens for serodiagnosis of tuberculosis (TB). These antigens were tuberculous glycolipid antigen, lypoarabinomannan polysaccharide antigen, and antigen 60 (A60), which was derived from purified protein derivatives. Of the 131 patients with active pulmonary TB, 57 were both smear and culture negative and 14 had chronic active pulmonary TB that remained smear positive for >12 months of chemotherapy. One hundred twenty healthy adults were controls. The percentages of patients positive in all three tests were 58.8% for smear-positive active pulmonary TB and 71.4% for chronic active pulmonary TB. When the results of the three serodiagnostic tests were evaluated in combination, the sensitivity increased to 91.5% in patients with active pulmonary TB and to 86.0% in smear- and culture-negative patients. The false-positive rate of the three-test combination was 12.5% in the healthy control groups. In conclusion, it was not possible to detect all of the antibodies against antigenic substances in the cell walls of the tuberculous bacilli in the sera of all TB patients by using available serodiagnostic tests. However, the combined use of tests with three separate antigens maximizes the effectiveness of serodiagnosis.     

Repair of infarcted myocardium mediated by transplanted bone marrow-derived CD34+ stem cells in a nonhuman primate model

Rodent and human clinical studies have shown that transplantation of bone marrow stem cells to the ischemic myocardium results in improved cardiac function. In this study, cynomolgus monkey acute myocardial infarction was generated by ligating the left anterior descending artery, and autologous CD34(+) cells were transplanted to the peri-ischemic zone. To track the in vivo fate of transplanted cells, CD34(+) cells were genetically marked with green fluorescent protein (GFP) using a lentivirus vector before transplantation (marking efficiency, 41% on average). The group receiving cells (n = 4) demonstrated improved regional blood flow and cardiac function compared with the saline-treated group (n =4) at 2 weeks after transplant. However, very few transplanted cell-derived, GFP-positive cells were found incorporated into the vascular structure, and GFP-positive cardiomyocytes were not detected in the repaired tissue. On the other hand, cultured CD34(+) cells were found to secrete vascular endothelial growth factor (VEGF), and the in vivo regional VEGF levels showed a significant increase after the transplantation. These results suggest that the improvement is not the result of generation of transplanted cell-derived endothelial cells or cardiomyocytes; and raise the possibility that angiogenic cytokines secreted from transplanted cells potentiate angiogenic activity of endogenous cells.     

Serum leptin correlates with serum uric acid but not serum testosterone in non-obese male adolescents

To identify the serum factors that affect circulating leptin levels, we measured the serum concentrations of leptin, testosterone (T), estradiol (E), serum alanine aminotransferase, total cholesterol and uric acid (UA) in healthy male adolescents (age, 18.3 +/- 0.1 years, n=96). We also measured body mass index (BMI), percent body fat and thickness of skin fold to assess the effect of body constitution on serum leptin level. Since serum concentration of leptin significantly correlated with BMI (r=0.820, p<0.001), we analyzed the relation-ship between leptin/BMI ratio (L/BMI) and serum parameters. Analysis of data of subjects with normal serum T level showed a significant inverse correlation between L/BMI and serum T levels (n=96, r=-0.294, p<0.005), but no such correlation was present among non-obese subjects (n=70) with BMI of +/-20% of normal (22 kg/m2). There was no correlation between L/BMI and serum E level. Serum UA level significantly correlated with L/BMI in both the test group (n=96, r=0.520, p<0.001) and non-obese subjects (r=0.369, p<0.005). Stepwise multiple regression analysis showed that UA independently and significantly influenced serum leptin levels in both the test and control groups. Our results demonstrate that T weakly influences serum leptin concentration, and that UA concentrations strongly influences serum leptin in healthy male adolescents independent of their obesity level.     

Prospective clinical evaluation of the serologic tuberculous glycolipid test in combination with the nucleic acid amplification test

We have conducted a prospective controlled multicenter study to evaluate differences in the levels of clinical utility of the tuberculous glycolipid (TBGL) serodiagnostic test and the nucleic acid amplification test in patients with smear-negative active pulmonary tuberculosis (TB). The TBGL test and the PCR test were individually not so useful for the rapid diagnosis of smear-negative active pulmonary TB. However, clinical utility was considerably improved by using the TBGL test and the PCR test in combination, especially in patients with smear-negative and culture-negative active pulmonary TB and in patients with minimally advanced lesions.