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Biomedical subjects

H Katoh

Publications and source records attributed to H Katoh.

At least 271 records · Page 15Linked to original sources
PubMed1995

[Comparative clinical study of azithromycin with tosufloxacin tosilate in the treatment of acute odontogenic infection].

To objectively assess azithromycin (AZM) for its clinical efficacy, safety and usefulness in the treatment of acute odontogenic infections (periodontitis, pericoronitis and osteitis of the jaw), a double-blind, randomized, multi-center trial was conducted in which tosufloxacin tosilate (TFLX) was used as the control drug. AZM was administered to 90 patients at a once-daily 500 mg dose for 3 days, while TFLX was given to 90 patients at a 150 mg t.i.d. dose for 7 days. 1. The clinical efficacy rates calculated according to evaluation at an endpoint set on the 3rd day of treatment by a committee of experts were 85.9% (73/85) in the AZM group and 78.9% (71/90) in the TFLX group. No statistically significant difference between the treatment groups was detected, and clinical equivalence was verified (p = 0.002). 2. The clinical efficacy rates according to evaluations made by investigators at the end-of-tail point was 87.1% (74/85) in the AZM group and 73.3% (66/90) in the TFLX group. The efficacy rate in the AZM group was higher than that in the TFLX group, and the difference was statistically significant (p = 0.006). 3. The bacteriological elimination rate in the AZM group was 97.5% (39/40) and that in the TFLX group was 85.7% (30/35), but the difference was deemed statistically not significant. 4. Adverse reactions were observed in 11 of 88 cases (12.5%) in the AZM group and 5 of 90 cases (5.6%) in the TFLX group. Six of 85 cases (7.1%) in the AZM group and 5 of 85 cases (5.9%) in the TFLX group showed laboratory abnormalities. However, neither adverse reactions nor laboratory abnormalities showed any differences in statistical significance between the treatment groups. 5. The safety rates, expressed as percentages of cases with no adverse events and no laboratory abnormalities, was 84.1% (74/88) in the AZM group and 90.0% (81/90) in the TFLX group. The difference between the two groups was found to be statistically insignificant. 6. The usefulness rates, the ratio of cases rated as either "Very useful" or "Useful", was 83.9% (73/87) in the AZM group, and it was statistically higher (p = 0.025) than 72.2% (65/90) obtained for TFLX group. Judging from the above results, it has been concluded that AZM is as useful as TFLX in the treatment of acute dental infections.

Adolescent↗
PubMed1995

[Thoracoscopic surgery, current indication and technique].

Thoracoscopy has become an important tool in the diagnosis and management of intrathoracic disease. The development of endoscopic suturing techniques and stapling devices for abdominal surgery dramatically expanded the potential of thoracoscopic surgery. Between 1993 and 1994, 43 patients underwent thoracoscopic surgery. Lung resection were performed on 23 patients for pulmonary nodules and on 9 patients for diagnosis of interstitial lung disease. Extirpation were performed on 2 patients for mediastinal tumor. A procedure done thoracoscopically is far less invasive and the postoperative pain and its consequences are drastically reduced. As endoscopic instrumentation develops, newer operations will become technically feasible. We think that indications for thoracoscopic surgery will expand in developing these techniques in the future, if thoracoscopic surgery is safer and more efficient.

Adult↗
PubMed1995

[The catecholamine concentrations of collected autologous blood during adrenalectomy for pheochromocytoma].

We studied the catecholamine concentrations in collected autologous blood of a patient undergoing adrenalectomy for pheochromocytoma. In the preoperative laboratory data, plasma concentrations (normal ranges) of epinephrine, norepinephrine and dopamine were 60180 pg.ml-1 (< 100), 11090 pg.ml-1 (100-450) and 104 pg.ml-1 (< 20), respectively. The catecholamine levels of collected blood were epinephrine 2490000 pg.ml-1, norepinephrine 352300 pg.ml-1 and dopamine 6100 pg.ml-1 before wash. Wash of collected blood with 1000 ml saline diluted the catecholamines to epinephrine 212000 pg.ml-1, norepinephrine 18700 pg.ml-1 and dopamine 4900 pg.ml-1. Platelet activation by contact with tissue collagen or thrombin results in the release of catecholamine concentrated in the dense body. The mechanical stimulation by suction, roller pump and centrifugation during blood collection may accelerate the catecholamine release from platelets. Thus, saline wash hardly reduces catecholamine concentrations of collected blood from a patient with pheochromocytoma. In this particular case, plasma catecholamines seem to exceed the potential capacity of platelets in amount. The dilution effect for epinephrine and norepinephrine probably reflects the washout of greater amount of plasma catecholamines. However, saline wash was unable to reduce catecholamines contained in the collected blood to a safe level, and hypertension following autotransfusion was predictable. We conclude that hemodynamic change should be monitored carefully during intraoperative autotransfusion in a case of pheochromocytoma.

Adrenal Gland Neoplasms↗
PubMed1995

Single photon emission computed tomography to determine effective hepatic blood flow and intrahepatic shunting.

The noninvasive determination of effective hepatic blood flow, intrahepatic shunted blood flow, intrahepatic shunt index, and total hepatic blood flow was investigated by using the sequential single photon emission computed tomography. This method was performed for a period of 10 minutes following an intravenous injection of 99mTc-(Sn)-N-pyridoxyl-5-methyltryptophan and a venous blood sampling. This study comprised 8 healthy volunteers, 16 patients with chronic hepatitis, and 33 patients with liver cirrhosis. The intrahepatic shunt index measured with this method coincided with the intrahepatic shunt index determined by catheterization, indicating the high reliability of this procedure. The effective hepatic blood flow in patients with liver cirrhosis was significantly lower than that in the healthy controls and the chronic hepatitis group. The intrahepatic shunted blood flow was significantly higher in patients with liver cirrhosis compared with the flow in healthy controls. The intrahepatic shunt index was also significantly higher in patients with liver cirrhosis compared with the index of healthy controls and those with chronic hepatitis. No substantial differences were noted in the total hepatic blood flow among the three groups. The effective hepatic blood flow, the intrahepatic shunted blood flow, and the intrahepatic shunt index, correlated with the serum albumin concentration, the serum cholinesterase level, and the plasma indocyanine green attenuation rate. From these results, it was concluded that the present procedure constitutes a reliable and effective method for the noninvasive determination of hepatic blood flows. Consequently, it will be of high clinical value for assessing the functional and the pathological alterations of the liver.

Adult↗
PubMed1995

Long-term results after conservative aortic valve repair for aortic regurgitation with ventricular septal defect.

Aortic valve repair was performed in 61 patients having aortic regurgitation (AR) associated with ventricular septal defect (VSD). Preoperative regurgitation was classified according to the Sellers' classification and grade I was in 3 patients, grade II in 19, grade III in 34, and grade IV in 5 patients. Forty-six patients underwent only plication of aortic valve, and in 15 patients the commissuroplasty was added to reinforce the free edge of the cusp. Furthermore, aortoplasty (aortic annuloplasty) was performed in 11. Actuarial survival rate and freedom from reoperation rate were 91.6% and 87.2%, respectively at 10 years after the initial repair. The rate of freedom from deterioration for 22 patients showing grade I or II of AR before the initial operation was 86.4% at 1 year, 76.7% at 5 and 10 years, while the rate for 36 patients with grade III or more severe AR was 91.7% at 1 year, 77.4% at 5 years and 63.9% at 10 years. The rate at 10 years after operation between the two groups was different significantly (p < 0.05). Twenty among 22 patients having grade I or II of AR before operation were in NYHA class I, while 23 of 30 survivors with grade III or IV of AR were in class I, 6 in class II, and 1 in class III. Eight patients received reoperation and four of them underwent repeated conservative aortic valve repair, and one received aortic valve replacement at reoperation. Five of 7 survivors with reoperation improved in NYHA class I and 2 in class II. These results suggested that careful follow-up was required especially for the first 10 years after the initial operation in patients showing preoperative severe AR and receiving aortic repair.

Adolescent↗
PubMed1994

Simultaneous measurement of [Na+]i and Ca2+ transients in an isolated myocyte: effects of strophanthidin.

We have developed a new method to measure [Na+]i and Ca2+ transients of a beating cardiac myocyte using a Na(+)-sensitive fluorescent probe, sodium-binding benzofuran isophthalate (SBFI) and a Ca(2+)-sensitive fluorescent probe, fluo-3. There was no interaction between two probes, and the artifact due to contraction could be eliminated in the measurement of [Na+]i. [Na+]i in guinea pig ventricular myocytes stimulated at 1 Hz was 8.0 +/- 0.7mM. Strophanthidin (10 microM), initially, increased the amplitude and the basal level of Ca2+ transients in association with an increase in [Na+]i. When arrhythmias were induced, the amplitude of Ca2+ transients decreased while [Na+]i and the basal level of Ca2 transients continued to increase. These results suggested that the diastolic [Ca2+]i was closely related to [Na+]i. However, the systolic [Ca2+]i, which could be influenced by other factors, was dissociated from [Na+]i in the condition of Ca2+ overload.

Aniline Compounds↗
PubMed1994

The role of Na+/H+ exchange and the Na+/K+ pump in the regulation of [Na+]i during metabolic inhibition in guinea pig myocytes.

To investigate the mechanisms of Na+ loading during metabolic inhibition (MI), [Na+]i and pHi were measured in quiescent guinea pig myocytes using fluorescent probes, sodium-binding benzofuran isophthalate and 2,7,bis(carboxyethyl)-5,6-carboxyfluorescein. When myocytes were exposed to MI (3.3 mM amobarbital and 5 microM carbonyl cyanide m-chlorophenylhydrazone, without glucose) for 20 min, [Na+]i increased from 8.3 +/- 0.7 mM to 17.7 +/- 1.3 mM (p < 0.01) and pHi decreased from 7.22 +/- 0.03 to 7.00 +/- 0.04 (p < 0.05). The inhibition of Na(+)-H+ exchange by hexamethylene amiloride (HMA) significantly attenuated the increase in [Na+]i during MI (9.3 +/- 0.9 mM; p < 0.01 vs MI without HMA). When a K(+)-free solution was perfused to inhibit the Na+/K+ pump in the presence of HMA, there was an immediate increase in [Na+]i during MI. Perfusion of a K(+)-free solution after 10 min of MI caused no change in the rate of the increase in [Na+]i. We concluded that 1) Na+/H+ exchange was an important mechanism for Na+ elevation during MI, and 2) the Na+/K+ pump was functional during the early phase of MI, but was inhibited 10 min after MI in this model.

Amiloride↗
PubMed1994

The ter primordial germ cell deficiency mutation maps near Grl-1 on mouse chromosome 18.

A single recessive gene, ter (teratoma), causes germ cell deficiency and a high incidence of congenital testicular teratomas in the 129/Sv-ter strain of the mouse. Linkage analyses between the ter gene and 36 marker genes of 19 chromosomes were performed with matings between the C57BL/6J-ter congenic strain and four inbred strains. Results showed that the ter gene was linked to D18Mit9, D18Mit14, and D18Mit17 on Chromosome (Chr) 18. Gene order estimated on the basis of recombination distance (in centimorgans) was [centromere-D18Mit14-5.1 (cM)-ter-0 (cM)-D18Mit17-23.8 (cM)-D18Mit9]. D18Mit17 is the microsatellite DNA of the Grl-1 (glucocorticoid receptor-1) locus. We conclude that the ter gene is closely linked to Grl-1 on Chr 18 and is a new mutation involving the developmental modification of primordial germ cells in mice.

Animals↗
PubMed1994

Reactive oxygen intermediates in autoimmune islet cell destruction of the NOD mouse induced by peritoneal exudate cells (rich in macrophages) but not T cells.

The non-obese diabetic (NOD) mouse spontaneously develops autoimmune Type 1 (insulin-dependent) diabetes mellitus. NOD mice exhibit massive infiltrates of T cells and macrophages into pancreatic islets (insulitis) prior to diabetes. The contribution of oxygen free radicals to the development of insulitis in NOD mice was examined by administration of its scavengers, such as superoxide dismutase and catalase. Bovine superoxide dismutase and catalase were each coupled to polyethylene glycol. The treatment with superoxide dismutase-polyethylene glycol reduced the number of islets with insulitis and increased the undamaged islet tissue, as compared with the control group. The treatment with catalase-polyethylene glycol showed a similar tendency which did not reach significance. Using a flow cytometric assay of the oxidation of 2', 7'-dichlorofluorescein, the content of reactive oxygen intermediates in islet cells in the culture system was measured and the effect of peritoneal exudate cells and T cells on their production examined. Peritoneal exudate cells, but not T cells, from NOD mice increased the content of reactive oxygen intermediates in islet cells of either the NOD mouse or the ILI mouse (MHC-identical to NOD); the addition of superoxide dismutase to the culture medium suppressed this increase in NOD or ILI islet cells. The present data support the concept that production of oxygen free radicals mediated by macrophages can damage islet beta cells, directly resulting in autoimmune Type 1 diabetes in NOD mice.

Animals↗
PubMed1994

The attitude of Japanese physicians regarding genetic service for autosomal dominant polycystic kidney disease (ADPKD).

A questionnaire carried out among Japanese physicians revealed that a strong demand for genetic counseling among patients and families with autosomal dominant polycystic kidney disease (ADPKD). In contrast, the awareness of physicians regarding genetic counseling for the disease seemed to be low. For example, 66.0% of the respondents to the questionnaire revealed a negative attitude to providing genetic counseling for patients, and 30.7% of the respondents did not know that most types of polycystic kidney disease are inherited disorders. With the advance of scientific research, the demand for genetic counseling among patients is bound to increase. Therefore, the providers of genetic counseling including the physicians are now pressed to improve their services.

Adult↗
PubMed1994

Importance of pre-operative recognition of the nonrecurrent laryngeal nerve.

The nonrecurrent laryngeal nerve is vulnerable during thyroid surgery. Pre-operative recognition of this nerve allows surgeons to avoid injuring the nerve. This anomaly depends upon the aortic arch anomaly and, therefore, in some cases, surgeons are able to predict the presence of this nerve pre-operatively by chest X-ray or barium swallow. Two patients with nonrecurrent laryngeal nerve are reported, one of whom, a 48-year-old man, had an abnormal shadow of the aortic arch, which led to confirmation of a right aberrant subclavian artery. Barium swallow plays a decisive role in the diagnosis of nonrecurrent laryngeal nerve, and this test is mandatory in patients who complain of difficulty in swallowing.

Abnormalities, Multiple↗
PubMed1994

The distally based superficial sural artery flap.

The distally based superficial sural artery flap, first described as a distally based neuroskin flap by Masquelet et al., is a skin island flap supplied by the vascular axis of the sural nerve. The aim of this paper is to refine the surgical technique in order to establish the reliability of this flap. We treated 20 patients with 21 distally based superficial sural artery flaps, including 2 fascial flaps. All flaps survived. Most flaps showed slight venous congestion. In the largest flap (10 cm wide by 13 cm long), edema lasted 2 months. In the flap whose pedicle was raised without the deep fascia, there was necrosis at the distal tip of the flap. The advantages are the following: The blood supply is reliable, elevation is easy and quick, and major arteries are not sacrificed. This new flap may be useful in selected circumstances.

Accidents, Traffic↗
PubMed1994

Long-term use of FK 506 in living related liver transplantation.

FK 506 (Tacrolimus) was used with steroids to treat 61 pediatric patients who received living related partial liver transplantation. Fifty-two recipients survived and 9 died between 6 months and 3 years after transplantation. In the surviving patients, oral doses of Tacrolimus were tapered from 0.298 +/- 0.277 mg/kg daily at 1 month after transplantation to 0.078 +/- 0.054 at 24 months after transplantation. The 12 h trough levels of Tacrolimus were 12.6 +/- 7.1 ng/ml and 4.1 +/- 2.4 at 1 and 24 months after transplantation, respectively. The percentage of recipients free from steroids was 77%, 97%, and 94% at 6, 12, and 24 months after transplantation, respectively. Liver allograft rejection was encountered in seven recipients, five of whom were treated by steroid pulse therapy and a dose increase of Tacrolimus; the remaining two required OKT3. However, there was no episode of rejection that required retransplantation. Infectious complications encountered in 34 patients included 12 bacterial, 3 fungal, and 19 viral infections. Two recipients died one of fungal pneumonia and one of Epstein-Barr virus-associated lymphoproliferative disorder. Regarding adverse reactions of Tacrolimus, hypertension was observed in 28 patients, diabetes mellitus in 3, pancreatitis in 3, convulsion in 1, tremor in 12, itching in 5, and pigmentation in the oral mucosa in 2. Slightly increased values of creatinine were observed in most of the patients; however, an abnormal increase of serum of serum creatinine (> 1.0 mg/dl) was confined to the complicated cases. Improvement of somatic growth was observed in 21 patients (62%) and 13 (75%) at 12 and 24 months after transplantation, respectively. The long-term use of Tacrolimus is highly effective in terms of its immunosuppressive potential and reduced adverse reaction. Steady growth development can be expected in pediatric recipients free from steroids.

Adolescent↗
PubMed1994

Segmental tetrasomy of chromosome 12 in the mouse.

An inbred strain of mice has been identified that is homozygous for a chromosomal segment attached to the centromeric region of Chromosome (Chr) 5. The altered chromosome arose spontaneously, and it does not appear to interfere with fertility or to have a phenotypic effect. Karyotypic analysis based on G-banding and quinacrine/Hoechst-banding studies revealed a morphological similarity between the additional segment of Chr 5 and the centromeric region of Chr 12. The mutant strain possessed silver-stainable nucleolar organizer regions, not only in the centromeric regions of Chrs 12, 15, and 18 but also on the additional segment of Chr 5. We investigated the relationship between the additional segment and the restriction fragment length polymorphisms (RFLPs) for the variable region of ribosomal DNA and found a correlation between a HincII RFLP and either the abnormal Chr 5 or Chr 12. These results indicate that the origin of the additional segment was Chr 12 and that the segmental tetrasomy of the present strain is therefore due to a nondetrimental translocation between pericentromeric regions.

Aneuploidy↗
PubMed1994

[Study of left ventricular function in cerebral thrombosis with pulsed Doppler echocardiography].

To evaluate the cardiac dysfunction of the cerebral infarction (cerebral thrombosis) patients in the chronic period, non-invasive studies were performed on 45 cerebral infarction patients (CI group: 25 males and 16 females, mean age 64.1 y). Forty hospitalized patient without cerebral infarction served as controls (non-CI group: 23 males and 19 females, mean age 64.8 y). The CI and non-CI group were divided into two sub-groups: patients with a past history of hypertension (HT) and without (NT). In each sub-group, the cardiac functions were compared between CI and non-CI by M-mode and Doppler echocardiography. In echocardiography, research based on the premise that the function of the left ventricle can be divided into preload (EDVi), afterload (SVR), contractility (EF, mVcf, SBP/ESV) and distensibility (E/A). On results show that there were no significant differences in preload, afterload and contractility of the left ventricle between CI and non-CI group in each HT and NT sub group. However, a significant difference was demonstrated in the diastolic function the left ventricle between the two groups in the HT (p = 0.007) and NT (p = 0.04) sub-groups. In conclusion, left ventricle diastolic function was deteriorated in cerebral infarction patients although systolic function not deteriorated. Because diastolic dysfunction may be caused by existing latent heart failure and/or silent myocardial ischemia, echocardiographic study is useful for early detection of left ventricle impairments in cerebral infarction patients.

Aged↗
PubMed1994

Ca2+ waves and intracellular Ca2+ concentration in guinea pig and rat myocytes.

We measured [Ca2+]i of guinea pig and rat myocytes with Ca2+ waves, using fura-2 fluorescence image processing. In guinea pig myocytes, Ca2+ waves were absent during the control perfusion period, but could be induced by the addition of strophanthidin (100 microM) or sodium cyanide (NaCN: 2 mM) to the perfusate. The [Ca2+]i increased from the control values of 69 +/- 5 nM and 46 +/- 2 nM, to 263 +/- 9 (p < 0.05 vs. control) nM and 225 +/- 20 (p < 0.05) nM, respectively, when cells exhibited Ca2+ waves. Although 13% (16 of 121) of the rat myocytes displayed Ca2+ waves during the control perfusion, the [Ca2+]i with Ca2+ waves (56 +/- 9 nM) did not differ from [Ca2+]i in the absence of Ca2+ waves (54 +/- 3 nM). Ca2+ waves were induced by the perfusion with a high Ca2+ solution (24.5 microM) or NaCN (2 microM), and [Ca2+]i increased from the control values of 67 +/- 11 nM and 74 +/- 5 nM, to 231 +/- 41 (p < 0.05 vs. control) nM and 266 +/- 64 nM, respectively, when cells exhibited Ca2+ waves. The Ca2+ waves were abolished by the removal of extracellular Ca2+, or by the perfusion with ryanodine (10 microM) or caffeine (20 mM). In conclusion, it was shown that Ca2+ waves were due to oscillatory Ca2+ release and that the absolute value of [Ca2+]i is important for the appearance of Ca2+ waves in guinea pig and rat myocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

The importance of prevention of sinusoidal endothelial cell injury during cold preservation of liver graft.

We investigated adenosine triphosphate (ATP) synthesis, lipid peroxidation, and activities of radical scavenging enzymes in mitochondria, as well as the ultrastructural morphological changes during cold preservation of swine liver grafts (n = 6) with either Euro Collins (EC) or University of Wisconsin (UW) solutions. The liver, harvested by a standard procedure, was preserved in one of the solutions at 4 degrees C. The values of the total adenine nucleotide and mitochondrial respiratory control ratio (RCR), an index of ATP synthesis, decreased gradually for up to 24 hr during preservation with either of the two solutions and there was no statistical difference between them. Chemiluminescence of mitochondria, an index of lipid peroxidation, in the graft preserved with EC solution or UW solution decreased, and after 24 hr there was no significant difference between the two solutions. Activities of radical scavenging enzymes were well maintained in any of the two solutions. Transmission electron microscopy (TEM) findings showed that the sinusoidal endothelial cells were preserved much better with UW solution than with EC solution even after 12 hr preservation. We concluded that UW solution, more effective for the protection against injuries of the sinusoidal endothelial cells during cold preservation, leads to better results in clinical transplantation, but this solution has no protective effects on energy production, nor radical scavenging enzyme activities of mitochondria. In the maintenance of liver graft viability, protection of the sinusoidal microcirculatory disturbance is more important than that of the mitochondrial function.

Adenosine↗