Absorber design for a compound parabolic concentrator collector without transmission loss

A new design method for a compound parabolic concentrator heat collector is described. The conventional design of the ideal compound parabolic concentrator collector has a touching point between a light absorber and the reflectors. This structure is not preferable from the standpoint of conductive heat leakage and thermal stress on reflector materials. On the other hand, if the absorber and the reflectors are separated from each other, the gap between them usually causes optical errors such as light transmission loss or an increase in the reflection number. We discuss the fact that ideal heat collection is possible, in spite of the gap, by introducing the idea of an effective heat concentration ratio.

[Electron microscopic and immunohistochemical studies of acute stages of severe brain injury in rats]

Few morphological studies on fluid-percussion experimental models using mechanically produced severe brain injury have been reported. This study was initiated to evaluate light and electron microscopic and immunohistochemical findings in severe brain injury models using rats. The experimental rats and the methods used were as described for a fluid-percussion model. Fluid-percussion models of traumatic brain injury produce injury rapidly by injecting fluid volumes into the epidural space of the temporal lobe. We used 5 rats which sustained various degrees of injury by high (7.0 atm), medium (5.6 atm) and low (3.5 atm) magnitudes of impact and sham control. The rats were sacrificed and perfused transcardially with buffer solution followed by 2.5% glutaraldehyde at intervals of 24 hours, 3 days, and 7 days, and there were normal and sham control groups. In this immunohistochemical study, monoclonal antibody to 70 kilodalton neurofilament subunit has been used in a standard Avidin-Biotin Complex Kit (DAKO). Microscopic findings of the animals revealed subarachnoid hemorrhage, lateral IIIrd ventricular hemorrhage, and rarefaction and petechial hemorrhage of the local contusional lesion. In the medium level injury, there was a marked petechial hemorrhage in the corpus callosum and subependymal area. In the high level injury, there was marked edema in the white matter of the ipsi and contralateral cerebral hemisphere, and multiple petechial hemorrhage in the brain stem and cerebellum. Microscopic findings in the corpus callosum, subependyma and brain stem in the vicinity of petechial hemorrhage revealed a large number of axonal swellings, but in these specimens only a few typical axonal retraction balls were seen using Bodian and immunohistochemical stains.(ABSTRACT TRUNCATED AT 250 WORDS)

Fluctuations of the sympathetic nerve discharges in animals without natural heartbeat

To assess the effect of artificial circulation on the circulatory regulatory system, rhythmical fluctuations in the cardiovascular system and autonomic nerve discharges were analyzed in animal experiments using adult mongrel dogs. Two pneumatically actuated ventricular assist devices were implanted as total biventricular bypass (BVB) under general anesthesia; then, the natural heart was electrically fibrillated to constitute the BVB part of the complete prosthetic circulation model. All hemodynamic data and sympathetic nerve discharges were recorded and calculated in the computer system by the use of spectral analyzing methods. In the power spectrum of the arterial blood pressure waveform during prosthetic circulation, the Mayer wave peak was significantly decreased though the respiratory wave peak was not significantly changed. However, the Mayer wave peak in sympathetic nerve discharges was significantly increased though the respiratory wave peak was not significantly changed. These results suggest that rhythmical fluctuations are a necessary response of the circulatory regulatory system including the autonomic nervous system. However, sympathetic nerve discharges respond to the artificial heart without rhythmical fluctuations.

[A case of metachronous bilateral malignant lymphoma of the testis]

We report a case of metachronous bilateral malignant lymphoma of the testis. A 67-year-old man was admitted to our hospital with complaints of left scrotal swelling with swelling of the left inguinal lymph node. Left high orchiectomy and dissection of the left inguinal lymph node were done under the diagnosis of the testicular tumor. Histopathological diagnosis was non-Hodgkin's lymphoma of diffuse, medium-sized cells of the B cell type. Several examinations revealed no apparent additional involvement. Chemotherapy was initiated with cyclophosphamide, adriamycin, vincristine and prednisolone (VEPA). One year and 10 months later, contralateral right scrotal swelling with swelling of the right inguinal lymph node occurred. Histopathological findings were similar to those of the resected left testis. We discussed malignant lymphoma of the testis, especially bilateral cases.

Secretion of intrinsic factor from cultured rat gastric chief cells

Intrinsic factor (IF) is a vitamin B12 binding protein that is secreted from the gastric mucosa. We tested secretagogues which stimulate IF secretion in rat gastric perfusion and found that carbachol and cholecystokinin octapeptide (CCK-8) stimulated secretion, but histamine and tetragastrin did not. To confirm these results, we examined IF secretion from isolated rat chief cells. For this purpose, we established an enzyme immunoassay (EIA) using an avidin-biotin peroxidase complex to measure small amounts of IF. To prepare an anti-rat IF, IF was isolated from the stomach, and was injected into a rabbit for immunization. Rat gastric chief cells were isolated from the gastric mucosa with Dispase and a Percoll gradient centrifugation, and were cultured. We examined the effects of chemicals by adding them to culture dishes of chief cells in a CO2 incubator. Released IF in culture medium was determined by EIA. Carbachol, CCK-8 and secretin stimulated IF secretion from cultured chief cells, while histamine and tetragastrin did not; Forskolin and A23187 also stimulated the secretion. We concluded that carbachol and CCK-8 stimulated IF secretion via an increase of intracellular Ca2+ concentration and that secretin did so via a cAMP accumulation.

Use of vascularized corticoperiosteal flap from the femur for reconstruction of the orbit

The reconstruction of small and thin defects in the orbital area using vascularized cortex is described herein. This vascularized cortex is taken from the medial supracondyle area of the femur because a small, thin, and flexible bone can be harvested. We have treated 5 patients with orbital bony defects that would have been difficult to reconstruct using conventional free bone grafts. All flaps took perfectly, the results were satisfactory, and no functional loss occurred in the donor site. The advantages of this bone flap include rich vascularity, a long vascular pedicle of about 7 cm, easy flap elevation, and the ability to include a saphenous flap. The thinness and flexibility of the bone flap make it a suitable vascularized bone donor site for treating small, flat craniofacial bony defects such as in the orbital area.

[Preclinical studies for development of anti-cancer drugs: current and historical status and problems]

In this review, we present the current and historical status of preclinical studies for development of new anti-cancer drugs. In our company, especially focusing on the stage of drug screening, pharmacology, toxicology and pharmacokinetic studies. We have discovered numerous new compounds with anti-cancer potential mainly with microbial origins, from which some drugs have been developed to clinical trials. We hope that clinical trials of drugs with a new mode of action will be designed and conducted with a more rational basis, and followed by analysis of the pharmacokinetics and pharmacodynamics so as to predict the toxicity and efficacy of the drugs in humans.

A rare case of Young's syndrome in Japan

A 56-year-old man was admitted for the evaluation of recurrent pulmonary infections. Since the patient presented with the combination of diffuse cystic bronchiectasis, chronic sinusitis and obstructive azoospermia, the diagnosis of Young's syndrome was made. Because the sweat chloride value, pancreatic function and ciliary ultrastructure were normal, this case could be clearly differentiated from cystic fibrosis and primary ciliary dyskinesia. There have been only a few reported cases of Young's syndrome in Japan.

Urinary protein fractions in healthy subjects using cellulose acetate membrane electrophoresis followed by staining with acid violet 17

We fractionated normal urinary proteins obtained from 40 healthy subjects using cellulose acetate membrane electrophoresis and stained them with Acid Violet 17. The electrophoretic patterns were classified into four groups. Each of groups I, II, III, IV had an albumin peak and 1, 2, 3, and 4 additional globulin peaks, respectively. Within-day variation study showed that the pattern was fundamentally specific to the individual, although some intermediate cases were observed. We were unable to determine which type was standard for normal subjects. However, the concentration of Tamm-Horsfall protein was speculated to be an important factor in determining the patterns. Group III showed significantly higher values than group I in urine albumin, total protein, and beta-N-acetyl-D-glucosaminidase and this group was believed to include subjects in the subclinical stage of a glomerular disease. All specimens belonging to group IV showed an obvious fraction of alpha 1 globulin which is often found in urine specimens of patients with renal diseases of tubular origin or other pathological conditions.

Role of interleukin-8 (IL-8) and an inhibitory effect of erythromycin on IL-8 release in the airways of patients with chronic airway diseases

To evaluate of the role of interleukin-8 (IL-8), a chemotactic cytokine, in the continuous neutrophil accumulation in the airways of patients with chronic airway disease (CAD) and persistent Pseudomonas aeruginosa infection, we investigated the cell population, IL-8 levels, IL-1 beta levels, tumor necrosis factor (TNF) activities, and neutrophil elastase (NE) activities of bronchoalveolar lavage (BAL) fluids in 17 CAD patients (with P. aeruginosa infections [CAD+PA], n = 9; without any bacterial infections [CAD-PA], n = 8) and 8 normal volunteers. We found significant elevations of neutrophil numbers, IL-8/albumin ratios, and NE/albumin ratios in BAL fluids from CAD patients, in the following rank order: CAD+PA > CAD-PA > normal volunteers. IL-1 beta/albumin ratios were elevated only in CAD+PA, while no TNF bioactivity was detected in BAL fluids. The neutrophil numbers correlated significantly with the IL-8/albumin ratios and NE/albumin ratios in the BAL fluids of CAD patients. When anti-human IL-8 immunoglobulin G was used for neutralizing neutrophil chemotactic factor (NCF) activities in BAL fluids, the mean reduction rate of NCF activities in CAD+PA patients was significantly higher than that in CAD-PA patients. We also evaluated the effects of low-dose, long-term erythromycin therapy in BAL fluids from three CAD+PA and two CAD-PA patients. Treatment with erythromycin caused significant reductions of neutrophil numbers, IL-8/albumin ratios, and NE/albumin ratios in BAL fluids from these patients. To elucidate the mechanism of erythromycin therapy, we also examined whether erythromycin suppressed IL-8 production by human alveolar macrophages and neutrophils in vitro. We demonstrated a moderate inhibitory effect of erythromycin on IL-8 production in Pseudomonas-stimulated neutrophils but not in alveolar macrophages. Our data support the view that persistent P. aeruginosa infection enhances IL-8 production and IL-8-derived NCF activity, causing neutrophil accumulation in the airways and the progressive lung injuries observed in patients with CAD. The clinical efficacy of erythromycin therapy for CAD patients might be partly mediated through a reduced IL-8 production, diminishing neutrophil accumulation and NE release in the airways.

[Coronary artery bypass surgery-redo operation particularly in patients with a functioning ITA graft or with a patent atheromatous vein graft]

An experience with redo-CABG in 20 patients is described. The incidence of reoperation in patients undergoing primary CABG in our hospital was 1.4%, relatively low even in Japanese population. The low incidence of redo-CABG in our hospital depends on the relatively short period of follow-up of 14 years, the prevalence of interventional cardiology and the early routine use of ITA grafts. The main cause of reoperation was the failure of a SVG to the LAD in 70 to 80% of the cases. The most important and difficult decision-making in redo-CABG is the selection of surgical approaches and cardioprotective methods in patients with a patent functioning ITA graft, and the management of an atherosclerotic patent SVG. Surgical strategies in these situations are discussed.

cDNA cloning and expression of bovine endothelin converting enzyme

We have cloned cDNA encoding bovine endothelin converting enzyme (ECE). The predicted amino acid sequence of bovine ECE consisted of 758 amino acid residues. Northern blot analysis revealed that ECE mRNA was abundantly expressed in lung. Co-expression of the cloned cDNA of bovine ECE with human preproET-1 cDNA in CHO-K1 cells resulted in the production of mature ET-1 and this production was inhibited by phosphoramidon.

Differential distribution of neurocalcin isoforms in rat spinal cord, dorsal root ganglia and muscle spindle

The cellular distribution of neurocalcin isoforms in rat spinal cord, dorsal root ganglia and muscle spindle was examined using immunohistochemical techniques and two antibodies against different isoforms. In the study using the antibody against the purified neurocalcin from bovine brain, nerve fiber terminals and the cytoplasm of small-sized neurons in the posterior horn, some medium-sized neurons and numerous axons were strongly stained. In dorsal root ganglia, the cytoplasm of various-sized neurons, including about 40% of the total neurons, was also stained. Sensory nerve endings in muscle spindle were immunopositive. When the antibody against the expressed neurocalcin delta was applied, nuclei of the neurons were mainly stained in the spinal cord and dorsal root ganglion. The cytosol of glial cells but not axons in white matter showed neurocalcin delta-like immunoreactivity against the antibody. These findings suggest that each of the differently located isoforms may play a distinct role in Ca2+ signaling in sensory systems.

Genetic transfer of endothelin converting enzyme activity to CHO-K1 cells: detection of positive cells by reverse hemolytic plaque assay

We have established a novel method of molecular cloning of endothelin converting enzyme, a key enzyme in the production of a potent vasoconstrictor endothelin-1, by modification of the reverse hemolytic plaque assay. Also, we demonstrated that a cell line, CHO-K1, showed no detectable activity of endothelin converting enzyme. This cell line was transfected with a cDNA library of bovine endothelial cells. The modified reverse hemolytic plaque assay was shown to detect even a single CHO-K1 cell that was changed to produce mature ET-1 by transfection. Thus, this novel method is suggested to be useful for the molecular cloning of other secreted antigens and their processing enzyme.

Klinefelter's syndrome and rheumatoid arthritis. Report of a case and review of the literature

Our case report describes a patient with Klinefelter's syndrome (KFS) associated with rheumatoid arthritis (RA). He had active RA in 1985 but his arthritis almost subsided in 1993 without intensive treatments for RA as well as KFS. Recently, the lower levels of testosterone in male RA patients, especially at the active phase has been reported. However, it is still questionable whether hypogonadism is a predisposing factor or just a consequence of disease. Since our case had a mild clinical course, and since the incidence of RA associated with KFS is very rare in comparison with other rheumatic diseases, may suggest that the low levels of testosterone are not a predisposing factor to the activity of RA.

Basic fibroblast growth factor stimulates the competence phase of subcultured endothelial cells and the progression phase of primary cultured smooth muscle cells from rat aorta

The proliferative effects of basic fibroblast growth factor (bFGF) on the cell cycle were compared in subcultured endothelial cells (EC) and primary cultured smooth muscle cells (SMC) from rat aorta by monitoring the starting time (an index of the competence phase) and rate (an index of the progression phase) of [3H]thymidine incorporation. Persistent treatment with bFGF (1, 10 and 30 ng/ml) reduced the starting time of EC proliferation in the presence of 1% fetal bovine serum (FBS) in a concentration-dependent manner. The starting time of [3H]thymidine incorporation into EC was reduced by a maximum of 4 h by pretreatment with bFGF for 12 h but not for 3 h. DNA synthesis in EC was inhibited by pretreatment with bFGF for 24 h. The rate of [3H]thymidine incorporation into SMC was accelerated both by persistent treatment with bFGF and pretreatment for 3 h in the presence of 3% FBS. In serum-free medium, bFGF (30 ng/ml) stimulated [3H]thymidine incorporation into SMC but not into EC after incubation for 36 h. Together, bFGF (10 ng/ml) and insulin (10 micrograms/ml) synergistically stimulated [3H]thymidine incorporation into EC, but insulin alone did not. These findings indicate that bFGF is a competence factor in EC and a progression factor in SMC from rat aorta.

IGF-I and IGF-binding protein gene expressions in spontaneous dwarf rat

Effects of growth hormone (GH) and fasting on hepatic expressions of insulin-like growth factor I (IGF-I) and IGF-I-binding protein (IGFBP)-1, -2, -3, and -4 were examined in spontaneous dwarf rats (SDR), which completely and specifically lack GH among pituitary hormones. The hepatic expressions of mRNA encoding IGF-I and IGFBP-3 were reduced and IGFBP-1 mRNA was elevated in the SDR. Both chronic and acute administration of GH restored these changes, indicating the association of GH but not other pituitary hormones with hepatic expressions of these genes. In addition, the present examination revealed that mRNA level of IGFBP-2 was elevated in SDR, which could not be attenuated by exogenous GH, and that GH may not be directly relevant to the regulation of hepatic IGFBP-4 expression. Fasting for 2 days reduced IGF-I mRNA level and increased IGFBP-2 mRNA level in the SDR, as well as in the normal rat, suggesting the presence of factors other than reduced serum GH responsible for fasting-induced alteration in the expression of these mRNAs. On the other hand, fasting resulted in little change or even a reduction of IGFBP-1 mRNA level in the SDR.

Effects of endothelium removal by saponin and of oxyhemoglobin on canine cerebrovascular responses

The stainless steel cannula method was applied to isolated and perfused canine basilar arteries to examine the role of endothelium in the responses to intraluminal vasoactive substances. After intraluminal treatment with saponin to remove the endothelium, the monophasic constrictions to potassium chloride and prostaglandin F2 alpha were potentiated, while those to phenylephrine (alpha 1-adrenoceptor agonist) and 5-hydroxytryptamine were not changed. Xylazine (alpha 2-adrenoceptor agonist) and acetylcholine induced a constriction preceded by a small dilation in controls. The response to xylazine was not modified, while the constriction to acetylcholine was augmented after endothelium removal. Bradykinin, substance P and vasopressin caused a dilation in lower doses, and a dilation followed by a secondary constriction in higher doses in controls. The dilations to these peptides were reduced and the constrictions were enhanced after endothelial removal. Adenosine triphosphate produced a biphasic response, i.e., a dilation followed by a constriction, which was occasionally preceded by a small constriction in higher doses, and only the dilation in lower doses was attenuated. The monophasic dilation to adenosine was potentiated, while the papaverine-induced dilation was not influenced by endothelial removal. After extraluminal treatment with oxyhemoglobin, the dilations to calcium ionophore A23187 and thimerosal were attenuated, while the constriction to acetylcholine was enhanced. The dilations to substance P and vasopressin were depressed, and the constrictions were potentiated. The monophasic dilation to sodium nitroprusside was augmented, while that to papaverine was not changed. These results suggest that the endothelium may play important roles not only in producing endothelium-derived relaxing factors but also in modulating the calcium influx into the smooth muscle cells. The mechanisms of altered responsiveness might be implicated in cerebral vasospasm following subarachnoid hemorrhage.

Chaotic hemodynamic during oscillated blood flow

A vibrating flow pump (VFP), which can generate oscillated blood flow (10-50 Hz/min), has been developed by our team for the artificial heart system. However, the flow pattern of this pump was different from that of the natural heart; therefore, it is important to analyze the effect of this oscillated blood flow on the circulatory regulatory system. To analyze the hemodynamics of high frequency oscillated blood flow as an entity, (not decomposed), nonlinear mathematical techniques were utilized. VFPs were implanted between the left atrium in animal experiments using adult goats. After the implantation procedure, the ascending aorta was clamped to constitute the complete left heart circulation with VFP. Using a nonlinear mathematical technique, an arterial blood pressure waveform was embedded into four-dimensional phase space and projected into three-dimensional phase space. The Lyapunov numerical method was used as an adjunct to graphic analysis of the state space. Phase portrait of the attractor showed a high dimension complex structure, suggesting deterministic chaos during natural circulation. However, phase portrait of the hemodynamics during oscillated blood flow showed a single circle with banding and a forbidden zone, similar to a limit-cycle attractor, suggesting a lower dimensional dynamic system. Positive Lyapunov exponent during oscillated blood flow suggests the existence of lower dimensional chaotic dynamics. These results suggest that the circulatory regulatory system during oscillated blood flow may be a lower dimensional homeochaotic state; thus, hemodynamic parameters must be carefully regulated when unexpected external stimuli are present.

Study on pulmonary delivery of salmon calcitonin in rats: effects of protease inhibitors and absorption enhancers

Effects of protease inhibitors and absorption enhancers on the absorption of salmon calcitonin (sCT) were evaluated after intratracheal coadministration to rats using the plasma Ca level as an index. Remarkable absorption enhancement could be attained with unsaturated fatty acids such as oleic acid and polyoxyethylene oleyl ether (absorption enhancers) and with chymostatin, bacitracin, potato carboxypeptidase inhibitor and phosphoramidon (protease inhibitors). sCT degrading enzymes had four times higher activity per total protein in membrane fraction of lung homogenates than the activity in cytosol fraction. These enzymes are thought to be serine proteases and metalloenzymes from the in vitro action profile of protease inhibitors. A good correlation between the in vitro activity of protease inhibitors and the in vivo enhancing effect on sCT activity suggested that membrane enzymes are responsible for the inactivation of sCT. Metabolic degradation and low permeability of sCT may be possible barriers to the absorption of sCT.

[To avoid complications during laparoscopic cholecystectomy]

Laparoscopic cholecystectomy is now becoming a safe procedure for the benign cholecystic diseases. But the differences, for example in the method of access to peritoneal cavity, visual field, and tools, between laparoscopic surgery and open surgery results in different complications. The purpose of this paper is to discuss how to avoid complications during laparoscopic cholecystectomy. A hundred consecutive patients were expected to receive an elective laparoscopic cholecystectomy from April 1991 to November 1992 in our clinic. Two patients were converted to open cholecystectomy. The reasons for conversion were uncontrollable bleeding from cystic artery and common-bile duct injury. Two other patients were obliged to undergo laparotomy due to post-operative bile leakage. Arterial bleeding from abdominal wall caused by inserting trocar was experienced in one case. Improvement of the equipment and surgical technique have got rid of these complications. We think it is still necessary to do intra-operative examinations such as cholangiography or ultrasonography. The previous two cases with complication of biliary injury underwent laparoscopic cholecystectomy without intraoperative examinations. We could have avoided these complications if intraoperative examinations were used. To prevent the complication of bleeding from abdominal wall, we have been carrying out a unique method. After the introduction of these procedures, we have never experienced any of these complications.

Predisposing factors in fixation failure of femoral prostheses following primary Charnley low friction arthroplasty. A 10- to 20-year followup study

To identify factors affecting radiologically detected loosening of the Charnley femoral prosthesis, 326 femoral prostheses with 10- to 20-year followup were studied. After observation of postoperative radiological changes, the criteria for fixation failure detected radiologically, of femoral prostheses were defined as progression or accompanying occurrences of subsidence, demarcation, separation of the prosthesis from cement, cement fracture, or endosteal cavitation. Sixteen femoral prostheses (4.9%) developed radiologically detected fixation failure. Male gender, low canal flare index, low femoral score, large medullary canal width, low implant (cement and stem)/canal ratio, low stem/canal ratio, and varus orientation of the stem affected fixation failure. Inadequate cementing techniques such as low implant/canal and stem/canal ratios and varus stem orientation might be within the surgeon's control and should be avoided. An unfavorable canal geometry (stovepipe canal) and osteopenia of the femur, indicated by a low femoral score, are risk factors that might be out of the surgeon's control, and require future research.

Risk factors affecting radiological failure of the socket in primary Charnley low friction arthroplasty. A 10- to 20-year followup study

To identify the factors affecting Hodgkinson Type 3 or 4 radiological demarcation (presence of complete demarcation or migration, respectively) of the Charnley socket, 328 sockets with 10- to 20-year followup were studied. Fifty-five sockets (16.8%) developed Type 3 or 4 demarcation. In the osteoarthrosis group (237 sockets), removal of eburnated bone at the acetabular roof, the presence of large acetabular angles before and after surgery, and high placement of the socket were related to development of Type 3 or 4 demarcation. In the rheumatoid group (32 sockets), young patient age predisposed the socket to Type 3 or 4 demarcation. Rapid polyethylene wear, correlated with young age, male gender, and thin cement mantle in Zones I and II, was another important factor related to Type 3 or 4 demarcation in both groups and in the entire series. These risk factors should be taken into account when assessing the indications for arthroplasty, when performing arthroplasty, and when educating the patient.

Reduction of visual P300 during transient global amnesia

Transient global amnesia (TGA) is a syndrome of selective loss of recent memory without other neurological deficits. Auditory and visual P300s were recorded during and after TGA to investigate the contribution of the short-term memory system to P300 generation. The auditory P300 during TGA was comparable to that recorded 1 week and 9 months after TGA. In contrast to the auditory modality, the visual target P300 was reduced in amplitude during TGA and at 1 week after the attack. The P300 to novel visual stimuli was also reduced during TGA. Both target and novelty visual P300 recovered by 9 months after TGA. The results support the notion that the neuronal networks responsible for P300 generation are modality dependent and that brain structures perfused by the posterior circulation are involved in visual P300 generation.