Role of nitric oxide in the pancreatic blood flow response to caerulein

To clarify the role of nitric oxide (NO) in the pancreas, blood flow in the rat pancreas (pancreatic blood flow: PBF) was investigated by the hydrogen clearance technique using a specific NO synthase inhibitor, N omega-nitro-L-arginine (L-NNA). Continuous infusion of caerulein at doses of 5 and 20 micrograms/kg/h caused a significant increase in PBF in the early phase of caerulein infusion. The caerulein-induced increase in PBF was not affected significantly by atropine sulfate (100 micrograms/kg), nor by phenoxybenzamine (5 mg/kg) plus propranolol (50 micrograms/kg). Administration of L-NNA (0.5, 5, or 30 mg/kg) did not affect the basal PBF, but at 5 mg/kg it inhibited completely the caerulein-induced increase in PBF. The inhibitory action of L-NNA was reversed by a large dose of L-arginine (100 mg/kg bolus, i.v., followed by a continuous infusion at 400 mg/kg/h), but not by its enantiomer D-arginine. These results strongly suggest that NO has a mediator role in the early phase vascular response of the pancreas to superphysiologic doses of caerulein.

[Localized muscular load to different work patterns and heat loads during handgrip]

The physiological responses and the magnitude of perceived fatigue (MPF) were estimated from eight healthy men during isometric continuous and intermittent handgrip at 10% maximum voluntary contraction (MVC). The physiological responses involved electromyogram (EMG), heart rate (HR), mean blood pressure (MBP) and forearm blood flow during contraction (FBFC) and relaxation (FBFR). The sequence of tests included three different work patterns: 1) continuous handgrip for 30 min, 2) intermittent handgrip (10 sec contraction +5 sec relaxation) for 45 min, 3) intermittent handgrip (10 sec contraction +10 sec relaxation) for 60 min. These experiments were performed on two different heat loads (25 degrees C and 40 degrees C, H.R. 50%). The results were as follows: 1) The localized muscle fatigue in the forearm was observed during the work periods. 2) The mean frequency of EMG was higher at 40 degrees C than 25 degrees C. 3) FBFR was significantly lower than FBFC at 40 degrees C. 4) MPF and MBP were little influenced by the heat load. 5) MPF correlated well with both HR and MBP.

[Effects of handgrip work and heat load on heart rate variability]

The purpose of the present study was to evaluate cardiac sympathetic (SNS) and parasympathic (PNS) nervous system activities during isometric continuous and intermittent handgrip with power spectrum analysis of heart rate variability (HRV). Eight healthy men performed work at 10% maximum voluntary contraction. The sequence of tests included three different work patterns: 1) the continuous handgrip for 30 min, 2) the intermittent handgrip (10 sec contraction +5 sec relaxation) for 45 min, 3) the intermittent handgrip (10 sec contraction +10 sec relaxation) for 60 min. These experiments were performed at two different heat loads (25 degrees C and 40 degrees C, R.H. 50%). To evaluate HRV, low frequency component (0.03-0.15Hz: LFP) and high frequency component (0.15-0.5Hz: HFP) power were calculated. The SNS and PNS activities were evaluated by LFP/HFP and HFP/(HFP + LFP), respectively. Summary of the results was shown below. 1) The change of the SNS and PNS activities were not significant among the different work patterns, due to the lower work load in the present experiment. 2) The increase of HR at 25 degrees C was mediated primarily by the decrease of the PNS activities during the work periods. 3) The effects of heat loads on the SNS and PNS activities were significant. Briefly, at the same work pattern, the SNS activities at 40 degrees were higher than those at 25 degrees C, but the PNS activities at 40 degrees C were lower than those at 25 degrees C.

[Responses of electroencephalogram to different odors]

The responses of electroencephalogram (EEG) to different odors and their densities were studied on four men and two women at rest while sitting. The odors examined were citrus, floral and lavender, and their densities were 100 ppb and 200 ppb. The odors were released for ten minutes from a duct to fill the room completely. The subjective estimation indicated that citrus had a tendency to be the most comfortable odor in this study, but it was not significant. To evaluate changes of EEG, the power spectra of frequency-fluctuation of alpha wave (Fz) and the rate of alpha, beta, and beta/alpha wave (Oz, Fz) were calculated. The rate of alpha wave (Oz) in the period of giving out the citrus at 100 ppb was significantly (p < 0.05) higher than that of the lavender. The rate of beta wave (Oz) in the period of giving out the floral at 200 ppb was significantly (p < 0.05) higher than that of the lavender. The regression coefficient of the power spectra of frequency-fluctuation of alpha wave in the period of giving out the lavender at 100 ppb was significantly higher than those in the other periods of the experiment. The regression coefficient of the power spectra of frequency-fluctuation of alpha wave for lavender given out at 200 ppb was significantly (p < 0.01) higher than those for the other odors given out. It seems that the regression coefficient of the power spectra of frequency-fluctuation of alpha wave can be used for the evaluation of psychophysiological responses.

Prevalence and pathogenesis of silent myocardial ischemia following myocardial infarction

The objective of this study was to examine the prevalence and pathogenesis of silent myocardial ischemia during exercise following myocardial infarction. Exercise-induced myocardial ischemia was assessed by 201Tl-SPECT (single photon emission computed tomography) 4.5 weeks after acute myocardial infarction in 229 patients. Exercise-induced myocardial ischemia occurred in 109 patients (48%), and 72 (32%) had silent ischemia. Although the prevalence of multivessel coronary artery disease was similar between patients with silent and symptomatic ischemia, the size of reversible myocardial ischemia was larger in patients with symptomatic ischemia than in those with silent ischemia (21.3 +/- 3.0% vs 13.2 +/- 1.9% of LV, p < 0.05). The incidence of reversible ischemia remote from the infarct area was higher in patients with symptomatic ischemia than in those with silent ischemia (30% vs 17%, p < 0.10). The cause of silent ischemia after myocardial infarction may be closely related to the smaller size of reversible myocardial ischemia. Ischemia remote from, or adjacent to, the infarct area could be a factor in determining the presence or absence of pain.

Effects of continuous intravenous infusion of isosorbide dinitrate on development of tolerance to vasodilating action in human epicardial coronary arteries

This study was performed to determine the effects of long-term intravenous infusion on the coronary vasodilating actions of continuous intravenous and bolus intracoronary administration of isosorbide dinitrate (ISDN). With quantitative coronary angiography, the coronary diameter and the vasodilating response to intracoronary ISDN (1 mg) at angiographically normal segments were studied before and after intravenous administration of ISDN, 10 to 60 micrograms/min for 1 hour, 2 days, or 5 days. The vasodilating effects of intravenous ISDN were 72% +/- 13%, 65% +/- 21%, and 6% +/- 11% of the response to intracoronary ISDN in the baseline study in each group. Irrespective of the duration of intravenous infusion, subsequent intracoronary ISDN dilated coronary arteries to extent similar to that observed in each baseline study. In conclusion, significant coronary vasodilating effects of intravenous ISDN were observed after a 2-day infusion, whereas tolerance to the vasodilating effects apparently developed within 5 days of infusion. The vasodilating response to bolus intracoronary ISDN was preserved even when the vasodilating effects of intravenous ISDN were no longer present.

Stages in the development of the rat lung: morphometric, light and electron microscopic studies

Ontogenic changes of the pulmonary epithelium of the rat, ranging from fetal day 15 to 1 hour after birth (21st day), were observed using light and electron microscopy as well as morphometric analysis on the area occupied by terminal segments of epithelial tubes or by alveolar sacs (ATETAS) in the terminal region of the lung. The development of the lung was classified into four stages. In the pseudoglandular period (fetal days 15 and 16), epithelial tubes lined by columnar epithelium were not yet associated with blood capillaries. The percentages occupied by ATETASs in the terminal region of the lung were 15.3% and 15.7%, respectively, on fetal days 15 and 16. In the precanalicular period (fetal days 17 and 18), blood capillaries began to appose to epithelial tubes lined by cuboidal epithelium. Small osmiophilic lamellar bodies (OLBs) emerged in cuboidal epithelial cells (type II cells) on day 18. The percentages occupied by ATETAS were 24.9% and 25.5%, respectively, on days 17 and 18. In canalicular period (fetal days 19 and 20), sac-like end segments showed progressive thinning of the epithelial linings, and the amount of interstital tissues markedly decreased. The epithelial cells differentiated into squamous, or type I cells, and type II cells containing OLBs. Extrusion of OLBs was recognized on day 20. Most of the capillaries were located close to the epithelial linings. The thickness of the blood-air barrier on day 20 was 10 times that of the adult. The percentages occupied by ATETAS were 35.8% and 38.5%, respectively, on days 19 and 20. In the terminal sac period (in neonate), the wall of terminal sacs showed a thin epithelial lining. Blood capillaries protruded close to the air-way surfaces. The thickness of the blood-air barrier was 3.5 times as thick as that of adult. The percentage occupied by ATETAS was 53.1% of the total terminal region of the lung. When the area occupied by ATETAS at a given day was compared to the area of the adult, the percentage on day 20 was approximately 60% of the adult value, whereas the percentage in neonates was 85%. This suggested that a remarkable transformation took place in ATETAS between day 20 and neonate. In addition to the four periods mentioned above, we also discussed the embryonic and alveolar periods in the development of the rat lung.

Identification of the bphA and bphB genes of Pseudomonas sp. strains KKS102 involved in degradation of biphenyl and polychlorinated biphenyls

The nucleotide sequence of the upstream region of the bphC gene from Pseudomonas sp. strain KKS102 was determined. Four genes were found in this region. Deduced amino acid sequences of the first, second, third and fourth genes showed significant homology with a large subunit of iron-sulfur protein, a small subunit of iron-sulfur protein, ferredoxin and dihydrodiol dehydrogenase, respectively, from other bacteria which degrade biphenyl/polychlorinated biphenyls, toluene and benzene. E. coli, in which the four genes, bphC and the gene for ferredoxin reductase from benzene degrading bacterium were expressed, was able to produce meta-cleavage compounds from chlorinated biphenyls. These results show that these gene products are functional in both biphenyl and polychlorinated biphenyls degradation.

Nucleotide sequence and functional analysis of the meta-cleavage pathway involved in biphenyl and polychlorinated biphenyl degradation in Pseudomonas sp. strain KKS102

Pseudomonas sp. strain KKS102 is able to degrade biphenyl and polychlorinated biphenyls via the meta-cleavage pathway. We sequenced the upstream region of the bphA1A2A3BCD (open reading frame 1 [ORF1]) A4 and found four ORFs in this region. As the deduced amino acid sequences of the first, second, and third ORFs are homologous to the meta-cleavage enzymes from Pseudomonas sp. strain CF600 (V. Shingler, J. Powlowski, and U. Marklund, J. Bacteriol. 174:711-724, 1992), these ORFs have been named bphE, bphG, and bphF, respectively. The fourth ORF (ORF4) showed homology with ORF3 from Pseudomonas pseudoalcaligenes KF707 (K. Taira, J. Hirose, S. Hayashida, and K. Furukawa, J. Biol. Chem. 267:4844-4853, 1992), whose function is unknown. The functions of meta-cleavage enzymes (BphE, BphG, and BphF) were analyzed by using crude extracts of Escherichia coli which expressed the encoding genes. The results showed that bphE, bphG, and bphF encode 2-hydroxypenta-2,4-dienoate hydratase, acetaldehyde dehydrogenase (acylating), and 4-hydroxy-2-oxovalerate aldolase, respectively. The biphenyl and polychlorinated biphenyl degradation pathway of KKS102 is encoded by 12 genes in the order bphEGF (ORF4)A1A2A3BCD (ORF1)A4. The functions of ORF1 and ORF4 are unknown. The features of this bph gene cluster are discussed.

In vivo release of glutamate in nucleus tractus solitarii of the rat during hypoxia

1. An attempt has been made to test the hypothesis that, in the caudal part of nucleus tractus solitarii (NTS) where carotid sinus nerve (CSN) afferents project, L-glutamate (Glut) modulates the hypoxic ventilatory response. 2. Unanaesthetized, peripherally chemodenervated (carotid body denervated; CBD) and sham-operated, freely moving rats were used. During peripheral chemoreceptor stimulation by hypoxia (10% O2 for 30 min) or doxapram (Dox) infusion (2 mg kg-1 (30 min)-1), ventilation was recorded and successively, under the same conditions, the extracellular Glut concentration ([Glut]o) in the caudal NTS was measured by in vivo microdialysis. [Glut]o was also measured during hyperoxic hypercapnia (10% CO2-30% O2 for 30 min). 3. Furthermore, the effects on ventilation of exogenous Glut, the NMDA (N-methyl-D-aspartate) receptor antagonist MK-801 or the ionotropic receptor antagonist kynurenate microinjected into the caudal NTS were investigated in sham-operated rats. 4. In sham-operated rats, both ventilation and [Glut]o in NTS were increased during peripheral chemoreceptor stimulation. On the other hand, no increases in either ventilation or Glut release were observed in CBD rats. In spite of ventilatory augmentation during hypercapnia, no response of [Glut]o to hypercapnia was observed in either group. 5. Local Glut application into NTS increased ventilation. Pretreatment with MK-801 or kynurenate reduced the hypoxic ventilatory response. This reduction in ventilation was mainly due to the decrease in tidal volume. 6. These results suggest that hypoxia induced the release of Glut in NTS and that this effect was mediated by arterial chemosensory input.

Effects of unilateral phrenic nerve denervation on diaphragm contractility in rat

We examined the early effects of phrenic nerve denervation on the diaphragm muscle 1, 3, 7 and 14 days after unilateral denervation in rats. In the denervated hemidiaphragms, force frequency curves at 3, 7 and 14 days decreased significantly by 51%, 50% and 38% respectively of the peak tension of the force frequency curves of the diaphragms of rats with sham operation. Twitch tensions increased significantly at 14 days, and contraction times and half relaxation times slowed significantly at 3, 7 and 14 days. The tensions of denervated diaphragms at 5 min during the fatigue runs was significantly increased at 14 days. As determined by histological staining, the mean cross sectional area of fast-twitch fibers (type II) decreased significantly from 2,742 (sham) to 1,599 microns (14 days), but that of the slow-twitch fibers (type I) did not change significantly during the same period. These findings suggest that, during the first two weeks of denervation, fast twitch fibers (type II) atrophy more rapidly than slow twitch fatigue resistant fibers (type I), as confirmed by the contractile properties and histological findings.

Reappraisal of preoperative carcinoembryonic antigen levels as a prognostic factor in resectable colorectal cancer

Preoperative carcinoembryonic antigen levels in sera were measured in 124 cases of primary colorectal cancer, and their usefulness as a prognostic factor were evaluated. There were no significant differences in the CEA levels with regard to age, sex, size of the primary tumor, histological differentiation, peritoneal dissemination or DNA ploidy, but CEA levels were significantly higher in patients with liver metastasis. By using Cox proportional hazard model, the most significant discriminant in prognosis was liver metastasis, followed by preoperative CEA level, depth of invasion and DNA ploidy pattern. Preoperative CEA measurements were applied as a parameter of biological behavior of colorectal cancer in the follow-up course.

[Potentiation of cisplatin sensitivity of cisplatin-resistant human ovarian cancer cell lines by L-buthionine-S,R-sulfoximine]

We established two human ovarian cancer cell lines (KK and MH) from the ascites of patients who did not respond to cisplatin (CDDP)-based combination chemotherapy. These cell lines showed higher resistance to CDDP in vitro than HRA cells which were established previously in our laboratory, and also have cross resistance with its analogues. The amount of intracellular glutathione (GSH) in these cells correlated with the degree of resistance to CDDP and was high, but the intracellular platinum (Pt) uptake was unchanged. Preincubation with L-buthionine-S,R-sulfoximine (BSO) reduced cellular GSH in these cells to 9-25%, while the Pt uptake remained unchanged. When the CDDP-resistant KK and MH cells were incubated in the presence of 10 microM BSO, they were sensitized to CDDP and its analogues showing a decrease to 79-38% in the IC50 values. On the basis of these results, we conclude that GSH may be involved in the mechanisms of resistance to CDDP and its analogues in the KK and MH cells.

Anthropometrical data of middle-aged Japanese women for industrial design applications

Despite the growing importance of human interface design, and despite the growing number of working women, no considerations have been given to women's working spaces and tools. Their designs are based on men's anthropometrical data, and this does not assure safety and amenity of women's working environments. Moreover, few data on women's body measurements are available. The Research Institute of Human Engineering for Quality Life is carrying out an ergonomic anthropometrical study on a large number of Japanese people to create a database for industrial use. The fee for the use of these data is, however, making it very difficult to profit from their acquisition. Therefore, we conducted an anthropometrical study for industrial design use on middle-aged female subjects, who are in the most difficult age group to access. This report should be useful in designing working spaces and tools for women as laborers as well as users.

Preproenkephalin gene expression in the rat cerebral cortex during chronic tracheal stenosis

To evaluate whether the endogenous opioid system is activated in the higher brain centre while a chronic resistance to airflow, we examined changes of mRNAs for preproenkephalin (PPE)-A, which is a precursor of enkephalin, and for 70 kD heat shock protein (HSP70) in the cerebral cortex of rat brain during chronic tracheal stenosis. Northern blot revealed that PPE-A mRNA was induced at 3 days of airway stenosis. In situ hybridization revealed that PPE-A mRNA was gradually induced in frontal cortex. The significant induction of PPE-A mRNA was observed at 3 and 7 days. However, no significant induction of HSP70 gene was observed. These results suggest that the endogenous opioid system may be at work as an important compensatory mechanism to reduce the respiratory sensation during chronic respiratory stress.

The MCS1/SSD1/SRK1/SSL1 gene is involved in stable maintenance of the chromosome in yeast

A temperature-sensitive (ts) mutant of Saccharomyces cerevisiae was isolated in which mini-chromosomes were unstable at high temperature. The MCS1 gene (Mini-Chromosome Stability 1) was cloned by the ability of complementing the temperature sensitivity, and was found to be identical to SSD1/SRK1/SSL1. When MCS1/SSD1 was disrupted in a certain wild-type (wt) strain, mini-chromosomes were unstable, even at 30 degrees C, indicating that the gene is involved in chromosome stability. The Mcs1/Ssd1 protein was detected as a 170-kDa protein by immuno-blotting analysis and this 170-kDa protein could not be detected in the ts mutant and certain wt strains. Our results are consistent with the genetic data that there are two polymorphic forms of the gene, SSD1-v and ssd1-d [Sutton et al., Mol. Cell. Biol. 11 (1991) 2133-2148]. Furthermore, genetic backgrounds other than MCS1/SSD1 caused strain-specific phenotype. The protein, precipitated by specific antibodies, was phosphorylated.

Chemosensitivity and perception of dyspnea in patients with a history of near-fatal asthma

BACKGROUND

Many deaths from attacks of asthma may be preventable. However, the difficulty in preventing fatal attacks is that not all the pathophysiologic risk factors have been identified.

METHODS

To examine whether dyspnea and chemosensitivity to hypoxia and hypercapnia are factors in fatal asthma attacks, we studied 11 patients with asthma who had had near-fatal attacks, 11 patients with asthma who had not had near-fatal attacks, and 16 normal subjects. Their respiratory responses to hypoxia and hypercapnia, determined by the standard rebreathing technique while the patients were in remission, were assessed in terms of the slopes of ventilation and airway occlusion pressure as a function of the percentage of arterial oxygen saturation and end-tidal carbon dioxide tension, respectively. The perception of dyspnea was scored on the Borg scale during breathing through inspiratory resistances ranging from 0 to 30.9 cm of water per liter per second.

RESULTS

The mean (+/- SD) hypoxic ventilatory response (0.14 +/- 0.12 liter per minute per percent of arterial oxygen saturation) and airway occlusion pressure (0.05 +/- 0.05 cm of water per percent of arterial oxygen saturation) were significantly lower in the patients with near-fatal asthma than in the normal subjects (0.60 +/- 0.35, P < 0.001, and 0.16 +/- 0.08, P < 0.001, respectively) and the patients with asthma who had not had near-fatal attacks (0.46 +/- 0.29, P = 0.003, and 0.15 +/- 0.09, P = 0.004). The Borg score was also significantly lower in the patients with near-fatal asthma than in the normal subjects, and their lower hypoxic response was coupled with a blunted perception of dyspnea.

CONCLUSIONS

Reduced chemosensitivity to hypoxia and blunted perception of dyspnea may predispose patients to fatal asthma attacks.

Induction of metallothionein in astrocytes by cytokines and heavy metals

Immunohistochemical staining of human and rat brains for metallothionein (MT) using a monoclonal anti-MT antibody (MT45) revealed that protoplasmic astrocytes, which are densely localized in the gray matter, contain high levels of MT. Human U373MG astrocytoma cells were stimulated with interleukin (IL)-1 or heavy metals to produce MT. When expression of MT in U373MG cells was analyzed by Northern blotting or indirect immunofluorescence using the MT45 antibody, it was found that IL-1 (> or = 10 U/ml), CdCl2 (50 microM) and high concentrations of ZnCl2 (500 microM) induced marked biosynthesis of MT.IL-6 (up to 3,000 U/ml) and lower concentrations of ZnCl2 (10-50 microM), however, showed little inducing activity. Hippocampal astrocytes in primary culture produced a relatively high basal level of MT. The MT level increased in response to addition of IL-1 (> or = 10 U/ml), ZnCl2 (50 microM) and CdCl2 (5 microM). However, the increase induced by IL-6 (1,000 U/ml) was not very marked. The in vivo induction of MT in the brain by cytokines is not fully understood. However, our data and other indirect evidence suggest that IL-1 may be a potent stimulator of MT induction in astrocytes. Furthermore, the astrocytoma cell line, U373MG, is a suitable in vitro system to analyze the expression of MT in astrocytes.

[Clinical significance of flow cytometric DNA analysis in metastatic lymph node of colorectal cancer]

Significance of flow cytometric DNA analysis in metastatic lymph nodes for assessing malignant potential of colorectal cancer was investigated using paraffin-embedded materials of primary lesions and metastatic lymph nodes from 65 patients who had been treated between 1975 and 1990. The DNA ploidy patterns of metastatic nodes were identical in 61.5% with those of primary lesions. Diploid cancers were significantly more frequent in metastatic nodes than in primary lesions. There were significantly more aneuploid cancers in proximal nodes than in distant nodes. There was no relation between ploidy patterns in primary lesions and survival. However, a significant relation was found between ploidy patterns in metastatic nodes and survival. Diploid cancer in metastatic nodes had a significantly better survival than aneuploid cancer, in all patients as well as those with curative resection. In patients with stage III and in those with the same depth of invasion, the survival rate of diploid cancer in metastatic nodes was significantly higher. There was no correlation between ploidy patterns in metastatic nodes and clinicopathological variables in primary lesions, such as histological type, depth of invasion, nodal involvement, peritoneal or hepatic involvement and stage. These results suggest that nuclear DNA content in metastatic lymph nodes may be a prognostic indicator in colorectal cancer with nodal involvement.

Clinical experience of Hokkaido University-PACS and FCR-angiography

Three years' experience with Hokkaido University-PACS (HU-PACS) is reported. In particular, this paper describes the suitability of FCR-angiography for HU-PACS, which has been in clinical use since March 1991. Image quality of FCR-arteriograms was evaluated in the head-and-face region and the abdominal region independently. The image quality in both regions was excellent. Quality of transferred images to image workstation for HU-PACS with 10:1 data compression was also evaluated, and no appreciable image degradation or loss of information was found in the transferred images. There was no significant difference in the examination time required for one patient in abdominal angiography between conventional angiography and FCR-angiography. In summary, FCR-angiography is suitable for HU-PACS as its image acquisition modality.

Effects of submental stimulation for several consecutive nights in patients with obstructive sleep apnoea

BACKGROUND

It has previously been reported that short term submental stimulation can reduce the frequency of apnoea and improve sleep architecture in patients with obstructive sleep apnoea. The effects of submental stimulation during consecutive nights on apnoea or on daytime sleepiness have not, however, been studied.

METHODS

Patients with obstructive sleep apnoea were studied by polysomnography on a control night, for five consecutive nights of submental stimulation, and on three following nights (n = 8). A multiple sleep latency test (MSLT) (n = 8) and measurement of the upper airway resistance (n = 5) were performed during the day after the polysomnographic study, on the control night, and on the fifth stimulation night. In an additional five patients with obstructive sleep apnoea, matched for age, sex, and weight, the effects of two nights of stimulation were examined for comparison. Submental stimulation began when an apnoea lasted for five seconds and stopped with the resumption of breathing as detected by oronasal flow.

RESULTS

The apnoea index, the number of times per hour that SaO2 dropped below 85% (SaO2 < 85%/hour), and the total apnoea duration expressed as a percentage of total sleep time during stimulation nights decreased to approximately 50% of the corresponding values on the control night. This improvement persisted for at least two nights after the five consecutive stimulation nights, but not after the two consecutive stimulation nights. Sleep architecture and MSLT following the stimulation nights improved but upper airway resistance did not change.

CONCLUSIONS

Submental stimulation for five consecutive nights in patients with obstructive sleep apnoea improved the breathing disturbance, sleep quality, and daytime sleepiness. The effect lasted for the following two nights, but did not completely abolish the sleep disordered breathing.

Polymerase chain reaction-single strand conformation polymorphism analysis of the p53 gene in paraffin-embedded surgical material from human renal cell carcinomas

p53 tumour suppressor gene mutations were studied in 118 renal cell carcinomas using paraffin-embedded surgical material. Optimal results were obtained with analysis of exon lengths between 150 and 200 base pairs for polymerase chain reaction. Single strand conformation polymorphism and sequencing analysis revealed only two point mutations (2/118, 2%): one involving codon 135; TGC-->TTC (cysteine-->phenylalanine) and the other codon 175; CGC-->CAC (arginine-->histidine). Both of these cases were classified as granular cell subtype on microscopic observation. The data suggest that the p53 tumour suppressor gene is not related to tumour initiation, promotion, or progression of renal cell carcinomas. However, there is the possibility that granular cell type carcinomas may have a different genetic background from clear cell type renal neoplasms.

Oxygen consumption of respiratory muscles in patients with COPD

We measured the oxygen consumption (VO2) of respiratory muscles in 8 COPD patients and 12 age-matched healthy subjects using a closed circuit device which allows a continuous increase in external dead space and is equipped with a 9-L Collins spirometer. Furthermore, we measured simultaneously mouth occlusion pressure at 0.1 s of inspiration (P0.1), minute ventilation (VE), and other ventilatory parameters during the measurement of total VO2 (VO2 tot). We found that the logarithm of VO2tot (logVO2tot) had a good correlation with VE in both groups. The mean slope of the regression line of logVO2tot and VE (delta logVO2tot/delta VE) of COPD patients was significantly higher than that of normal subjects (p < 0.001). However, the mean Y-intercept (metabolic VO2[VO2met]) of the regression lines did not differ between the two groups. The P0.1 in COPD patients was higher than that in normal subjects at the corresponding dead space loading. However, the VE did not differ between the two groups except for at rest and the first 1 min after dead space loading. These results suggest that the VO2 of respiratory muscles in patients with COPD is higher at given ventilation compared with that in age-matched normal subjects and that this increased VO2 partly may be due to an augmented ventilatory drive.

[Treatment and prognostic factors of stage I and II non-Hodgkin's lymphoma]

In order to assess prognostic factors and therapeutic methods, 104 patients (aged 6 to 89; mean age 57.4; male 68, female 36; stage: I 45, II 59) with clinical stages I and II non-Hodgkin's lymphoma treated at our department between 1977 and 1991 were reviewed. Factors, such as sex, age, clinical stage, primary site, presence of general symptoms, pathology, tumor size, LDH and therapeutic methods (radiotherapy alone; initial radiotherapy plus chemotherapy; initial chemotherapy plus radiotherapy) were calculated by univariated analysis to determine important factors influencing the survival. The survival of patients with symptoms and large tumors (more than 70 mm) was shorter than that of those without symptoms and with small tumors (5 years survival: symptom B 17.9%, A 68.2%, p < 0.001; tumor more than 70 mm 44.0%, less than 70 mm 67.1%, p < 0.05). Regarding therapeutic methods, radiotherapy alone achieved a 5-year survival rate of 37.1%; initial radiotherapy plus chemotherapy had 64.6% and initial chemotherapy plus radiotherapy 78.5%, but a significant difference was noticed only between radiotherapy alone and initial chemotherapy plus radiotherapy (p < 0.001). These results suggest that important factors influencing the survival are presence of general symptoms, tumor size and therapeutic methods.