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Biomedical subjects

T Komatsu

Publications and source records attributed to T Komatsu.

At least 253 records · Page 14Linked to original sources
PubMed1991

Evaluation of a new reflectance pulse oximeter for clinical applications.

The design of a noninvasive reflectance pulse oximeter that uses the same principle of transmittance pulse oximeter and analyses the oxygen saturation of arterial blood was described. Four sets of red and infra-red LEDs were used as light sources. The respective reflectance photoelectric outputs were used to make an internal calibration curve of the instrument relative to the arterial oxygen saturation values measured with a Co-Oximeter (OSM-3) in five healthy nonsmoking subjects during steady-state hypoxaemia. The accuracy of the present instrument was studied in six patients with respiratory failure. From 22 samples, a good correlation coefficient (0.98) with a standard deviation of 1.42 was obtained in the range between 73 and 100 per cent between the arterial oxygen saturation measured with the present instrument and that with the Co-Oximeter. The result strongly suggests the usefulness of this oximeter in monitoring patients with hypoxaemia.

Adult↗
PubMed1991

Neurotoxic effects of 2,5-hexanedione on growing peripheral nerve axons of rat fetuses.

Peripheral nerves of rat fetuses were used to investigate the potential neurotoxicity of 2,5-hexanedione (2,5-HD) on developing axons. Pregnant female Sprague-Dawley rats were injected subcutaneously with 680 mg/kg of 2,5-HD once a day from day 12 of gestation (GD12) through GD16. On GD20 live fetuses were removed from the uterus, and the sciatic nerves were examined morphologically. Upon electron-microscopy affected nerves showed axons which were aggregated and fused together; the number of large axons was increased, but there were no axons aggregated with neurofilaments.

Animals↗
PubMed1991

Lobular involvement in human breast carcinoma.

One hundred twenty-nine cases of breast carcinoma were examined in order to clarify the occurrence of lobular involvement with regard to stromal invasion. Lobular involvement was clearly recognized in 56 cases (43%) having discernible portions of intraductal carcinoma components. The process of lobular involvement was first recognizable as an extension of a few carcinoma cells from intralobular ducts into the acinar lumina. Progressive accumulation of the carcinoma cells resulted in marked swelling and distortion of the involved lobules. During the process, perilobular myoepithelial cells (actin-positive cells) were stretched and disappeared. Subsequently, breaks in the basement membranes were also observed, resulting in stromal invasion of carcinoma cells. The lobular involvement was classified into common and round varieties, possibly reflecting different growth activities of the carcinoma cells. The stromal invasion was initiated by peripheral budding or focal necrosis of the involved lobules. The latter pattern was often observed in comedo carcinoma. It was thus revealed that in breast carcinomas the terminal ductal-lobular units are quite often involved and can become sites of extraductal invasion.

Actins↗
PubMed1991

Increased resistance to multiple drugs by introduction of the Enterobacter cloacae romA gene into OmpF porin-deficient mutants of Escherichia coli K-12.

Introduction of the romA gene cloned from Enterobacter cloacae into Escherichia coli K-12 resulted in almost complete inhibition of OmpF expression and a concomitant increase in resistance to quinolones, beta-lactams, chloramphenicol, and tetracyclines. In addition, the romA gene reduced the susceptibility to these multiple drugs even in the OmpF porin-deficient mutants of E. coli K-12. Results indicate the presence of romA-sensitive penetration pathway(s) for these multiple drugs other than the OmpF porin in E. coli.

Anti-Bacterial Agents↗
PubMed1991

Biosynthesis of Klebsiella K2 capsular polysaccharide in Escherichia coli HB101 requires the functions of rmpA and the chromosomal cps gene cluster of the virulent strain Klebsiella pneumoniae Chedid (O1:K2).

The genes determining the biosynthesis of type 2 (K2) capsular polysaccharide [3----beta Glc1,4----beta Man(1,3----beta GlcUA) 1,4----alpha Glc1----] of Klebsiella pneumoniae Chedid (O1:K2), which is highly virulent for mice, were cloned and introduced into Escherichia coli HB101 and into four noncapsulated mutants derived from K. pneumoniae reference strains of K1, K7, K9, and K28. The recombinant plasmid pCPS7B06 carried 23 kb of a chromosomal DNA fragment of strain Chedid and encoded a part of the Klebsiella cps gene cluster. However, pCPS7B06 encoded enough genetic information for the production of Klebsiella K2 capsular polysaccharide on the cell surfaces of four noncapsulated mutants of K. pneumoniae. On the other hand, both pCPS7B06 and pROJ3 carrying the rmpA gene locus derived from a resident large plasmid of Chedid were required for the biosynthesis of Klebsiella K2 capsular polysaccharide on the cell surface of E. coli HB101. The insertion inactivation analysis using Tn5 revealed that the cps gene cluster occupied more than 15 kb of the chromosome of Chedid. We conclude that rmpA, which has been known to enhance the biosynthesis of colanic acid in E. coli, is also involved in the biosynthesis of Klebsiella capsular polysaccharide in E. coli HB101.

Animals↗
PubMed1991

Expression of the cloned Escherichia coli O9 rfb gene in various mutant strains of Salmonella typhimurium.

To investigate the effect of chromosomal mutation on the synthesis of rfe-dependent Escherichia coli O9 lipopolysaccharide (LPS), the cloned E. coli O9 rfb gene was introduced into Salmonella typhimurium strains defective in various genes involved in the synthesis of LPS. When E. coli O9 rfb was introduced into S. typhimurium strains possessing defects in rfb or rfc, they synthesized E. coli O9 LPS on their cell surfaces. The rfe-defective mutant of S. typhimurium synthesized only very small amounts of E. coli O9 LPS after the introduction of E. coli O9 rfb. These results confirmed the widely accepted idea that the biosynthesis of E. coli O9-specific polysaccharide does not require rfc but requires rfe. By using an rfbT mutant of the E. coli O9 rfb gene, the mechanism of transfer of the synthesized E. coli O9-specific polysaccharide from antigen carrier lipid to the R-core of S. typhimurium was investigated. The rfbT mutant of the E. coli O9 rfb gene failed to direct the synthesis of E. coli O9 LPS in the rfc mutant strain of S. typhimurium, in which rfaL and rfbT functions are intact, but directed the synthesis of the precursor. Because the intact E. coli O9 rfb gene directed the synthesis of E. coli O9 LPS in the same strain, it was suggested that the rfaL product of S. typhimurium and rfbT product of E. coli O9 cooperate to synthesize E. coli O9 LPS in S. typhimurium.

Agglutination↗
PubMed1991

Distribution of substance P-immunoreactive and calcitonin gene-related peptide-immunoreactive nerves in normal human lungs.

The distribution of substance P (SP)-immunoreactive (IR) and calcitonin gene-related peptide (CGRP)-IR nerves in normal human lungs was immunohistochemically investigated. SP-IR and CGRP-IR nerves were found in lamina propria and adjacent to blood vessels, and also in some of the ganglia and nerve bundles in the submucosal area. Comparison of serial consecutive sections revealed that SP-IR and CGRP-IR nerves represented similar distribution patterns. CGRP-IR nerves were scarce in bronchial smooth muscles, whereas SP-IR nerves were always present therein. Neither SP-IR nor CGRP-IR nerves were found, however, among submucosal glands or in alveolar septa. These localization patterns were closely related to the functions of SP and CGRP in normal lungs.

Axons↗
PubMed1991

[Serious complication of retrograde perfusion during repair of dissecting aneurysm: compression of the true lumen].

Between 1982 and 1990, 61 patients underwent the repair of dissecting aneurysm. Retrograde perfusion from the unilateral femoral artery were performed for 56 patients and the selective false lumen perfusion occurred in 3 patients. As for those 3 patients, compression of the true lumen and insufficient cerebral perfusion were suspected. Selective cerebral perfusion and antegrade systemic perfusion from the ascending aortic graft were performed. Although 2 patients took uneventful postoperative courses, 1 patient died of massive brain damage. It is very important to accomplish the means to maintain adequate cerebral circulation as soon as possible toward this fetal complication.

Adult↗
PubMed1991

[A case of small cell carcinoma of the lung responding well to oral etoposide therapy].

A case of recurrent small cell carcinoma of the lung, accompanied by intraperitoneal metastasis, was orally treated with etoposide (50 mg/day) for 3 consecutive weeks. Subjective symptoms such as abdominal pain began to improve one week after the start of treatment. After three weeks of treatment, these symptoms disappeared completely, and CT findings also improved. The serum NSE level, which was as high as 89.5 ng/ml before treatment, fell to 8.7 ng/ml after 3 weeks of treatment. The patient is now being followed at the outpatient clinic of our hospital. As adverse reactions to the drug, alopecia and leukopenia were observed. The leukopenia appeared in the third week of treatment, but the white blood cell count returned to normal soon after the drug was discontinued.

Administration, Oral↗
PubMed1991

[The effect of extradurally administered analgesics on somatosensory evoked eyelid microvibration in rabbits].

We examined the effect of various analgesics administered lumboextradurally or intravenously on acceleration of the eyelid microvibration (EMV) due to reflex contraction which was evoked by electrical stimulation of the sciatic and ulnar nerve in rabbits. No significant difference in the inhibition of EMV was observed initially between the sciatic nerve and the ulnar nerve stimulated group after 2 mg of morphine, administered either extradurally or intravenously. However, greater inhibition of EMV by the extradural morphine than by intravenous administration of this drug was observed after 10 min in sciatic nerve stimulated and after 20 min in the ulnar nerve stimulated group. With the extradural administration of 0.05 mg fentanyl, EMV was inhibited more significantly in the sciatic stimulated group than in the ulnar nerve stimulated group. Intravenous administration of this drug failed to reveal any change in either sciatic nerve stimulated or ulnar nerve stimulated group. When butorphanol 0.5 mg or buprenorphine 0.05 mg was administered, no significant difference in the inhibition of EMV was observed between the drugs, regardless of the routes of administration or sites of stimulation. Extradural administration of ketamine 0.5 mg showed none of the inhibition of EMV in both the sciatic nerve stimulated, and the ulnar nerve stimulated groups. These results indicate that various analgesics administered into the extradural space produced characteristic actions depending on the pharmacokinetic properties of each drug, locally and/or generally. In conclusion, monitoring of EMV can be a useful procedure for evaluation of the effect of analgesics.

Analgesia, Epidural↗
PubMed1991

[Experimental study on avoidance of surgical heart block in septation for single ventricle].

A new method was developed to prevent surgical injury of the atrioventricular conduction system in septation for single ventricle. The new method includes the use of small Teflon pledgets to cover the conduction system at the crossing sites of suture line, and so that stitches can be placed on the pledgets to skip the conduction system. This paper describes the results of an experimental study to delineate the effects of covering pledgets on the morphology and function of the underlying conduction tissues. Deep hypothermia was employed for this experiment in 15 mongrel dogs. The small Teflon pledgets were sutured to bridge the endocardial surface of the atrioventricular node through the right atriotomy. They were subjected to sacrifice at 1 week to 12 months postoperatively. Electrophysiological study including electrocardiography. His bundle electrography and responsiveness of the atrioventricular conduction to rapid stimulation was done before the sacrifice. The resected heart was embedded in Ceroidin-Paraffin and serially sectioned for pathological study. No noticeable injuries were noted in the underlying conduction system. The electrophysiological study showed normal sinus rhythm at the time of sacrifice. No significant changes were noted in PQ intervals comparing to preoperative state. There were no significant differences in AH intervals, HV intervals and responsiveness to rapid atrial stimulation between experimental and normal control groups. In conclusion, the Teflon felt pledgets were demonstrated to have no detrimental effects on the atrioventricular conduction system in the chronic stage.

Animals↗
PubMed1990

Transcatheter arterial injection of autologous lymphokine-activated killer (LAK) cells into patients with liver cancers.

We studied the effect of transcatheter arterial injection of lymphokine-activated killer (LAK) cells in conjunction with interleukin-2 on 13 patients with liver cancers, 9 primary hepatocellular carcinomas (HCC), and 4 metastatic liver cancers. Based on the fact that the LAK-cell phenomenon was observed to exist equally in these patients as in healthy controls, an injection of autologous LAK cells into these patients was performed. Of 13 patients receiving LAK cells plus interleukin-2, one had a partial response and three had minor responses. The response duration of this "partial-response" patient was around 6 months after the LAK-cell injection. Simultaneously, a reduction of serum AFP level was found in six of eight HCC patients. One patient having a minor response after receiving this therapy had severe side effects, such as dyspnea and hypotension. The others had only a transient fever which was easy to control by medication. Thus the present study indicates that a measurable tumor regression and a reduction of serum AFP level are observed in some liver cancers after undergoing this therapy.

Adult↗
PubMed1990

Relationship between general or specific immunoreactivity and prognosis in postoperative patients with hepatocellular carcinoma.

The levels of a variety of immunological parameters were examined in 203 preoperative patients with hepatocellular carcinoma (HCC) at various stages (I-IV). The changes in the peripheral blood lymphocyte (PBL) count, the serum level of immunosuppressive acidic protein and the degree of the skin reaction to purified protein derivative were associated significantly with the stage of HCC progression. However, the percentages of lymphocyte subsets, mitogenic responsiveness of PBL and serum immunoglobulin concentration remained at the levels of stage I. Further study demonstrated that in patients undergoing hepatic artery ligation, there were statistically significant correlations between the PBL count, immunosuppressive acidic protein concentration and intensity of the skin reaction to purified protein derivative, assayed 1 month after surgery, and the prognosis. HCC-specific immunity was examined in 34 patients treated by hepatic resection or hepatic artery ligation using in vitro responses of PBL to HCC extracts (ATS test). This test was performed using culture medium containing added arginine. None of the PBL from the patients showed a positive response to allogeneic HCC extracts, but the PBL from 12 patients (9 hepatic resections, 3 hepatic artery ligations) were stimulated significantly (SI greater than or equal to 2.5) with autologous HCC extracts. In 7 of 9 hepatic resection patients who were positive in the ATS test, tumor recurrence was identified. Statistical analysis indicated that the ATS test result was significantly correlated with tumor recurrence in hepatic resection patients. Autologous-PBL-stimulating activities were isolated in a fraction at pH 8.3 and in fractions at pH 6.7-7.0 by chromatofocusing of the crude extract. Although identification of the HCC-specific antigen remains to be done, use of the above fractions may simplify the ATS test procedure and improve its sensitivity.

Carcinoma, Hepatocellular↗
PubMed1990

Antitumor activity of MST-16, a novel derivative of bis(2,6-dioxopiperazine), in murine tumor models.

We studied the antitumor activity of newly synthesized bis(1-acyloxymethyl) derivatives of 4,4'-(1,2-ethanediyl)bis(2,6-piperazinedione) using i.p.-i.p. models of P388 leukemia and B16 myeloma. As a result, we found 4,4'-(1,2-ethanediyl)bis(1-isobutoxycarbonyloxymethyl-2,6-piperazi nedione) (MST-16) to possess considerable therapeutic activity. MST-16 showed not only marked life-prolonging effects in both P388 leukemia- and B16 melanoma-bearing mice but also a greater therapeutic ratio than did its parent compounds, ICRF-154 and ICRF-159. Further studies revealed that MST-16 has considerable therapeutic activity against a number of other tumors such as ascitic forms of L1210 leukemia, colon 26 adenocarcinoma, and MH-134 hepatoma and solid forms of B16 melanoma, Lewis lung carcinoma, colon 38 adenocarcinoma, and M5076 fibrosarcoma. These results suggest that MST-16 is very promising as an antitumor agent.

Animals↗