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Biomedical subjects

K Konishi

Publications and source records attributed to K Konishi.

At least 109 records · Page 6Linked to original sources
PubMed1998

Management of continuous anastomosis of pancreatic duct and jejunal mucosa after pancreaticoduodenectomy: historical study of 300 patients.

BACKGROUND: Pancreaticojejunostomy is the most problematic anastomosis in the reconstruction after pancreaticoduodenectomy. In the past, much of the morbidity and mortality associated with this operation was related to problems with this anastomosis. Recent data, however, suggest that the use of duct-to-mucosa sutures has led to a marked drop in both morbidity and mortality associated with pancreaticojejunostomy. METHODS: Among the 300 patients who underwent pancreaticoduodenectomy, including pylorus-preserving pancreaticoduodenectomy, 87 patients underwent traditional pancreaticojejunostomy by invagination of the end of the pancreas into the bowel (group B). Recently three-layer anastomosis was created in 213 patients. The outer layer was created between the pancreatic capsule and the serosa of jejunum. The middle layer was created between the pancreatic parenchyma and the seromuscular wall of jejunum. The inner layer was placed between the pancreatic duct and a small opening in the antimesenteric border of the jejunal mucosa. Among the 213 patients, the inner anastomosis was created with interrupted absorbable sutures (group A1) in 93 patients and continuous absorbable sutures (group A2) in 120 patients. RESULTS: The three groups were similar with respect to age, gender, and primary disease. In the anastomosis, the incidence of leakage in group A2 (4.2%) was significantly less than in groups B (17.2%, p < 0.01) and A1 (11.8%, p < 0.05). The operative mortality rates were 3.2% in group A1, 1.7% in group A2, and 5.7% in group B. CONCLUSIONS: We recommend continuous anastomosis of the pancreatic duct and jejunal mucosa as a safe procedure after pancreaticoduodenectomy.

Adolescent↗
PubMed1998

Assessment of hair cell death using the dye extrusion method.

We examined the usefulness of the dye extrusion method for assessing cochlear hair cell death in guinea pigs. Unilateral temporal bones were incubated in sterile Dulbecco modified Eagle's medium for 1-6 h and then perfused with PBS/0.3% trypan blue to determine hair cell viability. Cells with nuclei stained with trypan blue were assumed to have died. The contralateral temporal bones of each animal were incubated with the same medium for 1-6 h and examined by transmission electron microscopy (TEM). This method revealed that hair cell viability under these conditions was maintained for at most 3 h. After incubation for more than 3 h, hair cell injury began and increased. After 6 h incubation, TEM revealed apoptotic death of outer hair cells. The results with this method agreed with the TEM findings. The dye extrusion method is simple, easy and useful for screening hair cell death in the cochlea under pathological conditions.

Animals↗
PubMed1998

Cleavage product from the NO donor NOC-5 and inner ear hair cell damage.

Nitric oxide (NO) is a neurotoxic gas which causes neuronal cell death. NO ototoxicity has also been reported, 1-Hydroxy-2-oxo-3-(3-aminopropyl)-3-isopropyl-1-triazene (NOC-5), NO donor, was used for studying NO. In this in vitro study, we examined whether NOC-5 and the cleavage products arising from it after production of No have ototoxic effects on the cochlea. The temporal bones of 55 guinea pigs were dissected and incubated in Dulbecco Modified Eagle's Medium (DMEM) with low glucose and 10% foetal bovine serum (FBS) perfused with various concentrations (100, 50, 10, 1 mM, 100 microM) of NOC-5 (pH 7.4) or the same concentrations of N-isopropyl 1-3 propanildiamine (R-NH2). Hair cell death was assessed using trypan blue staining. With NOC-5, percentages of outer hair cell death were 99.2, 98.0, 45.2, 40.5, and 20%, respectively, and percentages of inner hair cell death were 69.3, 70.2, 22.5. 11.1 and 0%, respectively. With R-NH2, percentages of outer hair cell death were 90.3, 81.1, 29.8, 21.0 and 19.3%, respectively, and percentages of inner hair cell death were 61.4, 48.1, 10.2, 5.4 and 0%, respectively. Ultramicroscopic examination showed that hair cell death was necrotic. Although NOC-5 is useful for study of NO, its cleavage products are also ototoxic.

Animals↗
PubMed1998

Induction of macrophage exudation in the inner ear by OK432 treatment.

OK432, a heat- and penicillin-treated lyophilized powder of a low virulent Su strain of Streptococcus pyogenes, was injected into the perilymphatic space of guinea pigs in order to determine the kinetics of exudation of inflammatory cells into the cochlea over a 7-day period. OK432 induced exudation of many neutrophils and Asialo GM1-positive cells into the scala tympani. The numbers of these cells peaked on the first day after OK432 treatment, and then gradually decreased. Four days after treatment very few of either of these types of cells were observed in the scala tympani. Asialo GM1-positive cells were confirmed to be activated macrophages. In ears treated with physiological saline or with the additive included in OK432 in control studies, no notable changes in the inner ear were recognized. These findings suggest that the inner ear can undergo induction of macrophage rapidly exudation by OK432 treatment as has previously been observed for other organs.

Animals↗
PubMed1998

Local substances regulating cochlear blood flow.

The regulation of cochlear lateral wall blood flow was investigated in rats using histochemistry, immunohistochemistry and transmission electron microscopy. The contractile protein, tropomyosin (TM) was localized in the pericyte around the vessels of spiral ligament but little was seen around strial capillaries. Prostaglandin I2 (PGI2) is a vasodilatory substance produced by PGI2 synthase (PGI2S), which is present in the endothelium of the vessels of spiral ligament but not much is present around strial capillaries. Endothelial nitric oxide synthase (eNOS) was present in the endothelium of both the vessels of spiral ligament and strial capillaries. These findings indicate that the blood flow of the cochlear lateral wall is regulated mainly in the spiral ligament by locally produced substances and that strial blood flow is not significantly regulated by pericytes responsible for enlargement or constriction of capillaries.

Animals↗
PubMed1998

Surgical treatment of cancer extending from the retromolar fossa to the masticator space.

Cancer extending from the retromolar fossa to the masticator space with neck metastasis (T4N2M0, Stage IV) was surgically removed en bloc by maxillectomy using a mandibular swing technique. This approach allowed a wide surgical view and was useful as handling the external and internal pterygoid muscles and upper neck dissection could be combined. Though there have been several surgical approaches to the masticator space, in the case of tumors which are commonly malignant there, this approach is useful and satisfactory.

Carcinoma, Squamous Cell↗
PubMed1998

Study of tuberculosis in the field of otorhinolaryngology in the past 10 years.

Over the 10 years from 1988 to 1997, a total of 18 cases of tuberculosis of the head and neck (8 of the cervical lymph node, 5 of the larynx, 2 of the salivary glands, and 1 each of the hypopharynx, tongue and middle ear) were diagnosed in our department. Four cases were diagnosed in 1996 and 8 in 1997, indicating a rapid increase over these 2 years. Definitive diagnosis was based on histopathological examination in 14 cases, detection of M. tuberculosis in 1 case and exclusion diagnosis, mainly using the tuberculin skin test, in 3 cases. The length of time from the first examination to obtaining a definitive diagnosis was 14.2 +/- 6.5 days in five subjects in whom tuberculosis was suspected from the beginning or in whom tuberculosis was suggested by the physician in making a differential diagnosis, 25.3 +/- 17.2 days in the group in whom malignant tumour was suspected and 64.3 +/- 57.3 days in other cases. Although no significant difference was found (p = 0.077), the length of time until diagnosis tended to be shorter in the cases that were suspected of having tuberculosis from the beginning. Family history and past history of tuberculosis, contact with a tuberculous patient and abnormal findings at chest X-ray were examined as background factors, and some of these were present in nine out of the 18 cases. In the five cases diagnosed in the early stage, some of the background factors were found in four cases. However, no significant difference in the time until definitive diagnosis was found between the groups with or without background factors in all cases (p = 0.675). These results suggest the importance of considering tuberculosis when performing differential diagnoses.

Adolescent↗
PubMed1998

Apoptotic cell death in Kikuchi's disease: a TEM study.

The pathogenesis of Kikuchi's disease (Kikuchi-Fujimoto disease, histiocytic necrotizing lymphadenitis) remains unclear. However, some previous studies have suggested that a disorder in cellular immunity is responsible for this disease, and apoptotic cell death appears to be the principal finding in the histogenesis of this disease. In the present study, a lymph node from a female patient with Kikuchi's disease was examined by transmission electron microscopy (TEM). TEM revealed specific morphological features of apoptotic cells, such as nuclear chromatin condensation and fragmentation along the nuclear membrane with intact organelles, and the presence of histiocytes phagocytosing karyorrhectic debris (apoptotic bodies) in areas affected by Kikuchi's disease. Although neither the role nor the trigger of apoptosis in Kikuchi's disease has been clearly determined, our findings show that apoptotic cell death clearly plays a role in the pathogenesis of Kikuchi's disease.

Adult↗
PubMed1997

A novel DNA virus (TTV) associated with elevated transaminase levels in posttransfusion hepatitis of unknown etiology.

By means of representational difference analysis, a viral clone (N22) of 500 nucleotides was isolated from serum of a patient (TT) with posttransfusion hepatitis of unknown etiology. The N22 clone showed a poor homology to any reported sequences. Oligonucleotide primers were deduced from the N22 sequence for detecting it by polymerase chain reaction. N22 sequence in serum banded at a sucrose density of 1.26 g/cm3, indicating its association with a viral particle which was designated TT virus (TTV). Since nucleic acids of TTV were sensitive to DNase I, it would be a DNA virus. TTV DNA was detected in sera from three of the five patients with posttransfusion non-A to G hepatitis, including the index case (TT). TTV DNA titers closely correlated with aminotransferase levels in the three patients. These results indicate that TTV would be a novel DNA virus with a possible capacity to induce posttransfusion non-A to G hepatitis.

Aged↗
PubMed1997

A simple and sensitive bioassay for the detection of human interleukin-18/interferon-gamma-inducing factor using human myelomonocytic KG-1 cells.

Interleukin-18 (IL-18)/interferon-gamma-inducing factor (IGIF) is a novel cytokine which plays an important role in Th1 responses. Here we describe a simple, sensitive bioassay for human IL-18 using the human myelomonocytic cell line, KG-1, which produces IFN-gamma in response to human IL-18. IFN-gamma production induced by human IL-18 was completely blocked by an antibody against human IL-18. Human IL-18 could be measured in a concentration range from approximately 100 to 10,000 pg/ml, and intra- and inter-assay coefficient variations were both below 15%. It was possible to measure human IL-18 in human serum, cell lysate or culture supernatant by this bioassay. Thus, the human IL-18 bioassay can be expected to be useful in the investigation of the relationship between human IL-18 and various diseases or in analyzing the mechanisms of human IL-18 secretion from IL-18 producing cells.

Animals↗
PubMed1997

Essential light chain exchange in smooth muscle myosin.

The exchange of 17-kDa essential light chain (LC17) in smooth muscle myosin was carried out by incubating myosin with a 10-fold molar excess of exogenously added LC17 over the corresponding endogenous light chain in the presence of trifluoperazine and 4.5 m ammonium chloride. Porcine aorta myosin contains two kinds of LC17 isoform, LC17nm and LC17gi, while chicken gizzard myosin contains only one kind of LC17 isoform. As LC17gi can be separated from LC17nm and gizzard LC17 by urea-gel electrophoresis, LC17nm in aorta myosin and LC17 in gizzard myosin were exchanged with LC17gi and LC17gi in aorta myosin was exchanged with LC17nm, and the degree of exchange was estimated by urea-gel electrophoresis. Under the optimal conditions (6 and 10 degrees C for aorta and gizzard myosin, respectively), nearly 90% of exchange, which is close to the theoretical value, was achieved for the former combinations, and a slightly lower exchange was obtained for the latter. The LC17-exchanged myosins contained stoichiometric amounts of the heavy and light chains and retained the original nature in the phosphorylation-dependent actin-activated ATPase activity, 6S-10S conformational transition, and filament assembly.

Actin Cytoskeleton↗
PubMed1997

Primary leiomyosarcoma arising in the lesser sac: report of a case.

We describe herein a very rare case of leiomyosarcoma arising in the lesser sac. A 58-year-old man with a psychiatric disorder was admitted to our department for the investigation of epigastralgia and nausea which he had been suffering since the previous month. A laparotomy revealed that the abdominal mass, found on physical examination, was a primary lesser omental tumor, histological examinations of which confirmed a diagnosis of leiomyosarcoma. The tumor cells showed a DNA diploid pattern. Leiomyosarcoma of the lesser sac is extremely unusual and it is important that it be distinguished from an extraluminal tumor of the abdomen.

DNA, Neoplasm↗
PubMed1997

Hepatocellular carcinoma presenting as extrahepatic mass on computed tomography.

The authors describe an extremely rare case of extrahepatic hepatocellular carcinoma. The patient was a 70-year-old man who was examined by a local doctor because of abdominal discomfort. Barium meal examination demonstrated a defect occupying the lesser curvature of the stomach from the middle of the corpus to the fornix. On an abdominal computed tomography (CT) scan, the lesion, 10 cm in diameter, touched the lower surface of the caudate lobe of the liver. Under laparotomy, the tumor was found between the caudate lobe of the liver and posterior wall of the gastric corpus. As the tumor appeared to be connected with the caudate lobe by a pedicle, only the tumor was resected. Histological examination showed the tumor to be hepatocellular carcinoma of Edmondson's grade III-IV, pedunculated type.

Aged↗
PubMed1997

Noxious stimulation enhances release of cytokine-induced neutrophil chemoattractant from hypothalamic neurosecretory cells.

Cytokine-induced neutrophil chemoattractant (CINC), a member of IL-8 family in rat and a counter part of human growth-related oncogene product (GRO), was demonstrated to be synthesized in hypothalamic neurons and released in peripheral blood in response to noxious stimulation. CINC immunoreactive neurons were found mainly in supraoptic nucleus, while positive fibers were found in the median eminence and the posterior lobe of pituitary gland. Colchicine injection into the third ventricle demonstrated additional CINC positive neurons in both parvo- and magno-cellular parts of paraventricular nucleus, and an increase of positive fibers in the external layer of the median eminence. After formalin injection into the foot pad, CINC immunoreactivity substantially increased in the posterior lobe of the pituitary gland and in the external layers of the median eminence. In addition, a parallel increase of CINC level was noticed in the peripheral blood. It is suggested from the present results that, in response to a noxious stimulation, CINC is released from hypothalamic neurosecretory cells via both the anterior and posterior pituitary system. This cytokine mediated noxious response from CNS to peripheral tissue, would be a novel type of cross-talk between nervous and immune system.

Animals↗
PubMed1997

Lock method using sodium hydroxide solution to clear occluded central venous access devices.

Occlusion of central venous access devices (CVADs) is not an uncommon problem duringlong-term parenteral nutrition. A number of techniques have been developed to deal with obstructed CVADs. This study investigated the effectiveness of the sodium hydroxide (NaOH) lock method for gradual CVAD occlusion. When a progressively declining flow was noticed, 0.1 N NaOH solution was injected into the CVAD and locked. Nineteen CVAD occlusions in 11 home parenteral nutrition patients were treated Sixteen of 19 trials cleared the occlusions, whereas 3 of 19 failed. One of the failures was due to a mechanical occlusion and the other two were able to be restored by using ethanol. There were no significant complications. The benefits of this method are: (1) a shorter treatment time and a lower dose than NaOH infusion therapy, (2) it does not require hospital admission and (3) it does not result in bursting of the catheter.

Journal Article↗
PubMed1997

Nitric oxide synthase and contractile protein in the rat cochlear lateral wall: possible role of nitric oxide in regulation of strial blood flow.

The present study demonstrated by histochemical and immunohistochemical methods that NADPH diaphorase reactivity, endothelial nitric oxide synthase (eNOS)-like immunoreactivity, and tropomyosin-like immunoreactivity, were located within the rat cochlear lateral wall. Both NADPH diaphorase reactivity and eNOS-like immunoreactivity were found mainly in the endothelium of the strial capillaries (ESC) and that of the vessels of the spiral ligament (ESL). These reaction products appeared to be somewhat more common in the ESC than in the ESL. On the other hand, tropomyosin-like immunoreactivity was localized in tissues outside the endothelium and its intensity was greater in the ESL than in the ESC. These findings suggest that nitric oxide (NO) produced by eNOS may play a role in regulating the blood flow of the cochlear lateral wall. In addition, NADPH diaphorase reactivity, eNOS-like immunoreactivity, and tropomyosin-like immunoreactivity showed different patterns of distribution between ESC and ESL. This suggests that in these two sites blood circulation is controlled by NO through two different mechanisms that are suitable for regulating strial blood flow.

Animals↗
PubMed1997

Haemodynamic changes during vasodepressor syncope in children and autonomic function.

We investigated postural haemodynamic changes in 24 boys and 30 girls, aged 8-16 years, with orthostatic intolerance. During the orthostatic test, nine boys and seven girls (30%) developed a vasodepressor attack (orthostatic-positive group). The orthostatic-positive group had a more marked increase in heart rate (HR) with slightly lower systolic blood pressure than the orthostatic-negative group during standing, with no significant difference in cardiac output (CO). The shift of blood volume from the intrathoracic region to the lower part of the body determined by electrical impedance and plasma catecholamines on rising were identical in the two groups. At the onset of the vasodepressor attack, CO did not change significantly, indicating that sudden arterial vasodilatation was the cause. In a pharmacological study on autonomic function, higher sensitivity of alpha-adrenoceptor in the resistance vessels was found in the orthostatic-positive group, but there was no significant difference in the basal level of cardiac vagal and sympathetic activity and in cardiac beta-adrenoceptor sensitivity between the two groups. The stepwise regression analysis showed that the magnitude of HR increment during standing was the most useful indicator in predicting the occurrence of a vasodepressor attack. These results suggest that low sympathetic activity in the resistance vessels together with an exaggerated rise in HR during upright posture is strongly associated with vasovagal and vasodepressor attacks in children.

Adolescent↗