+Gz acceleration affects the trace minerals zinc, copper, and chromium in serum and urine of humans

BACKGROUND

Research investigating the relationship between physical training and trace mineral concentrations has primarily focused on athletes. Few investigations, however, have specifically examined the alterations of trace mineral concentrations occurring in humans exposed to +Gz acceleration. Exercise alters mineral content; G-exposure is a form of exercise; therefore, G-exposure may elicit changes in mineral content.

HYPOTHESIS

Exposure to +Gz acceleration may affect the concentrations of the trace minerals zinc, copper, and chromium in human serum and urine.

METHODS

Blood samples were obtained from 7 men and 3 women, before and immediately after +Gz acceleration. Urine samples were obtained before, 30 min after, and 2 h after +Gz acceleration.

RESULTS

The serum zinc concentration was significantly different after +Gz acceleration, decreasing from 90.6 +/- 21.0 micrograms.dl-1 to 80.8 +/- 14.4 micrograms.dl-1. The serum copper concentration was also significantly altered immediately after +Gz acceleration, decreasing from 111.7 +/- 27.5 micrograms.dl-1 to 98.5 +/- 35.2 micrograms.dl-1. The urinary zinc and copper concentrations, and the serum chromium concentration were not significantly affected by +Gz acceleration.

CONCLUSIONS

The circulating levels of these minerals presumably change as they are transported to the tissues requiring greater amounts due to the increased physiological work associated with +Gz acceleration.

[The usefulness of mediastinoscopy for primary lung cancer]

The usefulness of mediastinoscopy for lung cancer was retrospectively evaluated for the aspect of prognosis. The subjects were 421 patients with primary lung cancer except exploratory thoracotomy. In the MD(+) group, there was no difference in prognosis between right and left sided thoracotomies, but in the MD(-) group there was a tendency for poorer prognosis in the left-sided thoracotomy (p < 0.1). In the right-sided thoracotomy, there was no difference of prognosis between the MD(+) group and MD(-) group. On the contrary, in the left-sided thoracotomy there was a statistically better prognosis in the MD(+) group than in the MD(-) group (p < 0.05). In the left-sided thoracotomy group, there was a statistically better prognosis in the MD +) group than in the MD(-) group in the pN 0 or pN 1 group (p < 0.01), but there was no difference of prognosis in the pN 2 group. In lung cancer of the left side, the mediastinal lymph node dissection would be more incomplete because of the presence of the aorta and the mediastinal lymph node metastasis would tend to be missed. Mediastinoscopy gives the right diagnosis of mediastinal lymph node metastasis and an accurate staging of lung cancer. Mediastinoscopy is very useful especially in the left-sided lung cancer.

Molecular cloning of a human neuroD from a neuroblastoma cell line specifically expressed in the fetal brain and adult cerebellum

Several neuron-specific cDNAs were identified using large-scale collection of 3'-directed partial cDNA sequences from a human neuroblastoma cell line. One of such cDNAs encoded a protein homologous to the mouse NeuroD. The mouse NeuroD, a basic helix-loop-helix (bHLH) protein seems to function as a differentiation factor for neurogenesis, as the gene is transiently expressed in postmitoic differentiating neurons. The human counterpart has a bHLH domain completely identical to that of the mouse NeuroD. But its expression was not only in the fetal brain but also in the adult cerebellum. The result of cross-species in situ hybridization also showed the transcripts were detected in the granule cell layer of the adult mouse cerebellum. The results suggest that the human as well as the mouse neuroD may play some important functions not only in the fetal brain but also in the fetal brain but also in the matured neurons of the cerebellum.

Intraoperative implantation of percutaneous left ventricular assist system

The percutaneous left ventricular assist system, using modified Dennis technique, has been used successfully to treat patients experiencing severe cardiogenic shock in a variety of nonsurgical situations. Fluoroscopy is generally essential for implantation. Our experience with the implantation of the percutaneous left ventricular assist system during operations is described here. The percutaneous left ventricular assist system was applied using transesophageal echocardiographic imaging and by leading with the index finger through the right atrium without fluoroscopy.

Expression of the RET proto-oncogene in normal human tissues, pheochromocytomas, and other tumors of neural crest origin

In order to evaluate the roles of the RET proto-oncogene in normal human tissues and tumors derived from the neural crest cells, we examined the expression of RET in a variety of adult human tissues, pheochromocytomas, medullary thyroid carcinomas (MTCs), ganglioneuromas, and a neurinoma. Northern blot analysis demonstrated that RET is normally expressed in the adrenal medulla and cerebellum among adult human tissues. RET transcripts were detected in all of 11 sporadic and one familial pheochromocytomas. The levels of RET mRNA were higher in 8 of 12 pheochromocytomas than in the normal adrenal medulla, indicating that RET is overexpressed in the majority of sporadic pheochromocytomas. There was a considerable difference in the level of RET expression in each pheochromocytoma ranging from 0.2 to 10 times the transcripts found in the normal adrenal medulla. The sizes of the transcripts of 7.0, 6.0, 4.5, and 3.9 kb were the same as those found in the adrenal medulla, suggesting no rearrangements of the RET gene in pheochromocytomas. Southern blot analysis revealed neither amplification nor gross structural changes in the RET gene. RET was also expressed at high levels in four MTCs examined, whereas its transcripts were detected at low abundance in only one of three ganglioneuromas. RET was not expressed in a neurinoma. These results suggest that RET may play some roles in a limited range of adult human tissues, and that its high levels of expression may have relevance to development or growth of pheochromocytomas and MTCs.

Identification of a novel receptor/signal transduction pathway for IL-15/T in mast cells

Interleukin-15/T(IL-15) is a growth factor that utilizes IL-2 receptor (IL-2R) components in addition to its private binding protein IL-15R(alpha) in T-cells. Here, we report that IL-15 induces mast cell proliferation in the absence of IL-2R alpha and beta. Using transfectants of these cells with a cytoplasmic-truncated mutant of gamma(c), we demonstrated that IL-15 signaling in mast cells does not involve gamma(c). Cross-linking of mast cells with [(125)I]IL-15 revealed a 60-65 kDa IL-15 binding protein that is distinct from known components of T-cell IL-15 receptors. Mast cell IL-15 receptors recruit JAK-2 and STAT-5, instead of JAK1/3 and STAT3/5 that are activated in T-cells. Thus IL-15 is a mast cell growth factor that utilizes a novel receptor and distinct signaling pathway.

[Prognostic factors of resected pulmonary metastases of osteogenic sarcoma]

From December 1979 to December 1994, 22 patients with osteogenic sarcoma underwent a total of 34 thoracotomies for resection of pulmonary metastases in our department. We did a retrospective study to identify prognostic factors. The tumor doubling time (TDT) calculated for 21 patients before the first (if multiple) resection was not correlated with days of survival after resection of the primary tumor, nor was it correlated with days of survival after the first (if multiple) resection of the pulmonary metastatic tumors. Of the nine patients who underwent at least two thoracotomies, the TDT calculated from X-ray films taken before the second (or later) thoracotomy was significantly shorter than the TDT calculated before the preceding thoracotomy (p < 0.05). The disease-free interval (DFI) after resection of the primary tumor was correlated with the days of survival after that resection (p < 0.001) and also with survival after resection of the pulmonary metastatic tumors (p < 0.01). This DFI of patients who survived at least 2 years from the date of the resection of the primary tumor was significantly longer than in patients who survived less than 2 years from that date (p < 0.05). The most significant prognostic factor was this DFI. The cumulative survival rate was 42.4% at three years and 33.9% at five years, with an operative mortality of 0%.

Non-decay type fast-setting calcium phosphate cement: setting behaviour in calf serum and its tissue response

Non-decay type fast-setting calcium phosphate cement (nd-FSCPC) was evaluated in terms of its setting behaviour in calf serum and its tissue response to investigate the feasibility of its clinical use in surgical applications. Non-decay type cements were prepared by adding various amounts of sodium alginate to the liquid phase of base cements, fast-setting calcium phosphate cement (FSCPC) and conventional calcium phosphate cement (c-CPC). Cement pastes were immersed in serum at 37 degrees C immediately after mixing, and decay behaviour, setting time and mechanical strength were measured to evaluate the possibility of their use in surgical applications. Also, nd-FSCPC was implanted into rat subcutaneous tissue for the initial evaluation of biocompatibility of this potential bioactive cement. nd-FSCPC set in approximately 6-7 min in serum, even when the cement paste was immersed in the serum immediately after mixing, whereas c-CPC and FSCPC decayed completely upon immersion. nd-FSCPC transforms to hydroxyapatite (HA) within 24 h and shows a diametral tensile strength of approximately 4-5 MPa. As a result of transformation to HA, nd-FSCPC showed excellent tissue response when implanted subcutaneously in rats. We conclude that nd-FSCPC has good potential value for use in orthopaedics, plastic and reconstructive surgery, and oral and maxillofacial surgery, where the cement is exposed to blood.

Ventilatory responses to CO2: constant fraction vs. constant inflow administration

The purpose of this study was to determine whether the transfer function characteristics of the respiratory CO2 control system differs according to whether the CO2 administration method is constant fraction (CF) or constant inflow (CFlow). Ventilatory responses to CO2 changes were measured in seven healthy subjects during random PETCO2 perturbation by the CF and CFlow administration methods in normoxia and hyperoxia. The transfer function from PCO2 to VE was estimated in the frequency domain from 0.002 to 0.02 Hz. The transfer function characteristics showed a low-pass filter character in both of CFlow and CF. The impulse responses to both the methods persisted for > or = 60 sec, while the maximum amplitude (hmax) of the CFlow response was statistically greater than that of the CF response in normoxic condition. The time required until the peak (tmax) of the CFlow impulse response was shorter than that of CF in normoxia. Hyperoxia retarded the tmax and reduced hmax in both CFlow and CF, with the result that significant differences in the normoxic impulse responses were not observed between CFlow and CF in hyperoxia. To characterize the CO2 control system quantitatively, we determined the static transfer gain, oscillatory frequency, damping factor, and pure time delay by applying a second-order delay model to the observed transfer function. The static gain was not significantly different between CFlow and CF responses in both normoxia and hyperoxia. The pure time delay and damping factor were significantly decreased for CFlow only in normoxia. We suggest that inhalation of CO2 by CFlow modifies ventilatory response, probably mediating through the peripheral chemoreceptor activity.

Expression of vascular permeability factor/vascular endothelial growth factor in human hepatocellular carcinoma

Vascular permeability factor (VPF)/vascular endothelial growth factor (VEGF) is unique in its ability to promote vascular permeability and endothelial cell growth, and its role in tumor development has received considerable attention. In this report, we describe the elevation of VPF/VEGF transcript expression in human hepatocellular carcinoma. Surgical samples of 23 patients with hepatocellular carcinoma were studied using reverse transcription-PCR analysis. The oligonucleotide primers were designed to amplify all four known splicing variants that could be expressed in the samples studied. Sixteen cases showed VPF/VEGF transcript expression in the tumor (16/23, 69.6%), whereas only 9 of the 23 patients showed it in the corresponding nontumoral part. There was no difference between the pattern of expression of VPF/VEGF isoforms in tumoral and nontumoral tissues. VPF/VEGF mRNA expression in the liver tumors was associated with fibrous capsule formation and septal formation (P < 0.05 respectively, Fisher's exact P test). In situ hybridization confirmed the presence of VPF/VEGF mRNA expression in tumor cells and less intensely in hepatocytes of nontumoral liver. We also found that VPF/VEGF expression in the tumor cell was increased in the area adjacent to necrotic regions (presumably hypoxic regions). As a regulator of vascular permeability and endothelial cell growth factor, VPF/VEGF may play an important role in the development of hepatocellular carcinoma.

The RET proto-oncogene in sporadic pheochromocytomas

In order to evaluate the role of RET proto-oncogene in the development and growth of pheochromocytomas, we examined mutations in RET and expression of RET in 7 cases of sporadic pheochromocytomas. Tumors were screened for mutations in exons 10 and 11 and codon 918 which are identified in multiple endocrine neoplasia types 2A and 2B. No mutations were found in these regions in all of the sporadic pheochromocytomas examined. On the other hand, RET mRNA was detected in all pheochromocytomas and the levels of RET expression were higher in 5 of 7 pheochromocytomas than in normal adrenal medulla, indicating that RET is overexpressed in a sizable portion of sporadic pheochromocytomas. These results suggest that high levels of expression of RET may have relevance to the development or growth of sporadic pheochromocytomas.

[Coronary artery bypass grafting under bradycardia induced by ultra-short acting beta blocker]

From Dec. 1993 to May, 1994, coronary artery bypass grafting (CABG) was performed in 7 patients under bradycardia induced by an ultra-short acting beta blocker (esmolol). The ages ranged from 51 to 68 years. There was one patient with low ejection fraction (EF = 31%) and two patients with porcelain aorta. A tepid temperature was maintained during cardiopulmonary bypass (CPB). A high flow rate of 2.2-2.6 liter/min/m2 was applied to control perfusion pressure above 50 mmHg during CPB. After CPB was started, a high dose of esomolol was added (10-30 mg/kg intravenous bolus followed by a continuous infusion of 1-4 mg/kg/min). Severe bradycardia was achieved by the initial loading of esmolol. The mean heart rate was significantly (p < 0.01) decreased from 78 +/- 12 bpm to 49 +/- 7 bpm by the loading. Altogether, 25 anastomoses (11 ITA, 6 GEA, 8 SVG) were performed to LAD (10), Cx (7) and RCA (8), with an average of 3.6 +/- 0.9 anastomoses/patient. IABP was required for 2 patients postoperatively. There was no operative death, but one hospital death due to aspiration pneumonia 3 months later. Postoperative max CPK-MB was low (17.4 +/- 9.7 IU/L) in 6 patients. The postoperative angiography was performed in all patients with a patency rate of 88%. It was considered that esmolol facilitated CABG under beating heart and this technique is suitable for patients with severe atheromatous disease of the ascending aorta or patients with a low ejection fraction to avoid aortic cross-clamping.

An assay for lectin activity using microtiter plate with chemically immobilized carbohydrates

A simple microtiter plate assay for lectins or carbohydrate-binding proteins was developed. The method utilizes carbohydrates immobilized in the wells of the microtiter plate containing primary amino groups on their surface. After incubation of the lectins, bound proteins are measured by the protein assay using the colloidal gold solution. When the binding of Ricinus communis agglutinin, concanavalin A, and wheat germ agglutinin was measured using the microtiter plate wells coated with lactose, mannose, or N-acetylglucosamine, binding of the lectins according to their known specificity was observed. Inhibition experiments with various carbohydrates also demonstrated that the specificity of lectins for different carbohydrates could be determined quantitatively. Since there is no need for modification of the lectins, such as biotinylation or conjugation with marker enzymes, the carbohydrate-binding ability of intact proteins can be easily determined by this method. When gel filtration fractions from the extract of the marine invertebrate Cucumaria echinata were subjected to this assay, different carbohydrate-binding activities were observed with different elution profiles, suggesting that this assay could also be widely applicable for the simultaneous detection of lectins from various sources.

[Complicated bronchoplasty for lung cancer--its significance in salvaging a few segments of lung]

We performed bronchial reconstruction by several unusual procedures and succeeded in preserving lung function, which was proven with spirometry and treadmill exercise test. Type 1 (n = 2): Anastomosis between the left main bronchus and upper segmental bronchus with lower lobectomy and lingulectomy. Type 2 (n = 2): Anatomosis between the left main bronchus and basal segmental bronchus with upper lobectomy and superior segmentectomy acompanied by vascular reconstruction. Type 3 (n = 4): Anastomosis between the right main bronchus and lower bronchus with upper and middle lobectomy, accompanied by vascular reconstruction in 2 cases. One patient required completion pneumonectomy but the others had uneventful postoperative courses and maintained better lung function than expected, although the amount of preserved lung tissue was limited. There may be a great difference in the postoperative quality of life if pneumonectomy can be avoided, even though the preserved segments are few. Surgeons should reconsider the choice of pneumonectomy for interlobar tumors invading another lobe, especially in the case of N0 or N1 squamous cell carcinoma.

[HELP syndrome and anesthetic management]

From January 1990 to December 1994, 24 parturients were diagnosed as having HELLP syndrome alone or combined with preeclampsia/eclampsia among 8,224 patients who were delivered at our institution. They consisted of 14 primiparous and 10 multiparous patients. Mean maternal age was 28.9 +/- 3.3 and gestational age was 34.8 +/- 5.6 weeks. Of 24 parturients, 8 had vaginal delivery and the remaining 16 were delivered by caesarean section. Serious maternal morbidity included eclampsia (n = 3), preeclampsia (n = 18), renal failure (n = 5), hydrothorax (n = 4), and DIC (n = 1). There was no maternal death. There were 3 intrauterine fetal deaths and two neonatal deaths. Perinatal deaths were 2 (0.9%, 2/26). Three caesarean sections were performed under general anesthesia, and 13 under spinal anesthesia. In cases with apparent bleeding tendency, spinal and epidural anesthesia should be avoided. In providing general anesthesia, hypertension should be controlled, and the uterus is preferably dilated before the delivery and contracted there-after.

Potentiation of nitric oxide-mediated vasorelaxation by xanthine oxidase inhibitors

Nitric oxide (NO), now almost synonymous with endothelium-derived relaxing factor (EDRF), reacts with superoxide anion radical (O2-) and forms a potentially toxic molecular species, peroxynitrite (ONOO-). Because xanthine oxidase (XO) seems to be a major O2- -producing enzyme in the vascular system, it is important to clarify the mechanism of XO regulation of NO/EDRF. We first characterized the inhibition of XO in vitro by three types of pyrazolopyrimidine derivatives. Kinetic studies indicated that 4-amino-6-hydroxpyrazolo[3,4-d]pyrimidine (AHPP) and allopurinol competitively inhibited the conversion of xanthine to uric acid catalyzed by XO, with apparent Ki values of 0.17 +/- 0.02 and 0.50 +/- 0.03 micro M respectively; alloxanthine inhibited this conversion in a noncompetitive manner with an apparent Ki value of 3.54 +/- 1.12 microM. O2- generation in the xanthine/XO system assayed by lucigenin-dependent chemiluminescence was suppressed most strongly by AHPP in a dose-dependent fashion; allopurinol itself appears to reduce the enzyme by transfer of an electron to O2, thus generating O(2-). AHPP significantly augmented EDRF-mediated relaxation of aortic rings from both rabbits and spontaneously hypertensive rats (SHR) in a dose-dependent manner, whereas allopurinol did not affect the relaxation and only marginal potentiation of the vasorelaxation was observed with alloxanthine. Finally, iv injection of AHPP (50.4 mg/kg; 100 micromol/300 g rat) reduced the blood pressure of SHR rats to 70% of the initial pressure; this pressure is almost the blood pressure of normal rats. Allopurinol (100 micromol/300 g rat; iv) showed transient decrease in blood pressure and moderate reduction of hypertension of SHR (10%) was observed with iv injection of alloxanthine (100 mumol/300 g rat). On the basis of these results, it seems that XO regulates EDRF/NO via production of O2-.

Verruciform xanthoma occurring within oral lichen planus

A verruciform xanthoma occurring within lichen planus on the lateral aspect of the tongue in a 68-year-old Japanese woman is reported. The features suggest that the condition of altered epithelial turnover, as in repeated epithelial desquamation, may cause the verruciform xanthoma.

Internal thoracic artery holder for coronary artery bypass grafting

An arterial graft holder was designed to facilitate coronary artery bypass grafting using arterial conduits. It is possible to open the heel of the arterial conduit and stitch the most difficult angle of the anastomosis under optimal visualization. This internal thoracic artery holder is atraumatic and protects the arterial conduit wall from crush injuries caused by vascular forceps. Anastomosis without the endothelial injury may provide long-term patency of the coronary artery bypass graft.

[Dextran-induced anaphylactoid reactions in two patients with gastrointestinal cancer]

We report dextran-induced anaphylactoid reactions (DIAR) subsequent to rapid infusion of Rheomacrodex (dextran 40) in two patients, a 67 year old man with gastric cancer undergoing distal gastrectomy and a 47 year old man with transverse colon cancer undergoing colectomy. Both showed sudden tachycardia, hypotension and skin flush, which were treated with epinephrine or etilephrine administration. Most cases of severe DIAR are immune complex anaphylaxis mediated by dextran-reactive antibodies (DRA) of the IgG class, which are considered to arise mainly in response to immunization with dextran-cross-reactive bacterial polysaccharides in the gastrointestinal tract. High titers of DRA have previously been reported in gastric ulcer patients with pyloric stenosis, suggesting bacterial polysaccharides permeation through the luminal wall which may easily occur in the presence of local inflammation or ulcer. Although serum DRA titers in our patients have not been examined, inflammation or ulcer around the tumor might have played a role in producing high titers of DRA. In patients suspected of gastrointestinal ulcer or inflammation, including cancer, dextran administration is not preferable or should be avoided, unless hapten-dextran preparation is used for the prophylaxis of severe DIAR.

In vivo gene transfer and expression in rat stomach by submucosal injection of plasmid DNA

Gastrointestinal nonepithelial tissue is a useful target for in vivo gene transfer. The aim of this study was to investigate whether gene transfer into this organ could be achieved by submucosal injection of plasmid DNA. Plasmid DNA carrying either the firefly luciferase or Escherichia coli LacZ reporter gene was injected directly into the gastric submucosa of adult rats. Gene expression was characterized by quantitative luciferase assay and qualitative in situ beta-galactosidase (beta-Gal) staining. Luciferase activity was detected as early as 1 day after injection, increased markedly at 2 days, and then decreased. Some of the rats showed detectable levels of luciferase expression at 14 and 21 days postinjection. Histochemical staining for beta-Gal demonstrated that expression of the recombinant genes was localized in smooth muscle cells of the muscularis mucosae and the muscular layer and mesenchymal cells in the lamina propria. Our results indicate that gene transfer into the gastrointestinal tract can be achieved by simple needle insertion of naked plasmid DNA into the submucosa.