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Biomedical subjects

Y Katoh

Publications and source records attributed to Y Katoh.

At least 145 records · Page 8Linked to original sources
PubMed1991

Organization of cortical and subcortical projections to the feline insular visual area, IVA.

Extracellular recordings with carbon fiber-filled microelectrodes were used to identify the visually responsive area within the insular cortex (referred to hereafter as the insular visual area, IVA) of anaesthetized cats. Broadly speaking, IVA comprises the cortex surrounding the anterior ectosylvian sulcus (AEs) along its ventral bank and the major portion of the anterior sylvian gyrus. Visually sensitive cells were recorded along the whole length of the AEs. In the same animals, the afferent connections of IVA were studied through the use of the retrograde tracers wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP) and fluorescent Diamidino yellow (DY), in combination with standard electrophysiological stimulation and recording techniques. The results indicate that: (1) the IVA receives a wide variety of telencephalic inputs, not only from visual, sensorimotor, auditory, limbic and association cortical areas, and from the claustrum, amygdala and basal nucleus of Meynert, as well, but also from the diencephalic projections arising mainly from the lateralis medialis-suprage niculate nuclear complex (LM-Sg) and the ventral medial nucleus (VM). (2) The gyral part of IVA (gIVA) receives afferents mainly from the lateral part of the lateral suprasylvian visual area (LS) throughout almost its entire length, as well as from area 20, the posterior suprasylvian sulcal area (PS), the frontal eye fields, areas 6 and 36, and almost the whole length of the cortical area lying along the anterior ectosylvian sulcus (AEs). (3) By contrast with (2), the sulcal part of IVA (sIVA) which corresponds to the anterior part of the anterior ectosylvian visual area (AEV) of Norita et al. ('86), receives cortical projections mainly from the lateral and medial parts of the anterior half of LS, area 20, PS, the frontal eye fields, area 36, and most parts of the cortical area extending along the AEs. (4) Subcortically, IVA receives thalamic afferents mainly from VM and LM-Sg. The connections between IVA and LM-Sg are organized topographically, with the more anterior part of IVA being related to the more ventral portion of LM-Sg, and with sIVA being related chiefly to the mid-portions of LM-Sg. These results thus suggest that IVA may function as an integrative centre among structures belonging to the extrageniculostriate system, the sensorimotor system, as well as to the limbic system. Furthermore, our electrophysiological and anatomical findings, together with previous reports concerning AEV, suggest that the posterior part of AEV (AEV proper) is distinctive from gIVA, and that the sIVA apparently serves as a transitional region between AEV and gIVA.

Afferent Pathways↗
PubMed1991

[Extracorporeal shock wave lithotripsy for ureteral stones and cystine stones].

We report our experience with extracorporeal shock wave lithotripsy (ESWL) in the treatment of ureteral and cystine stones, which are known to be difficult to treat by this method. First, in order to determine the effectiveness of the ureteral catheter in the destruction of ureteral stones, we compared the clinical results of 121 patients treated without the catheter and 141 patients inserted with the catheter. There was no significant difference in the success rate between the two groups regardless of stone size, which indicates that the use of the ureteral catheter had no effect on the outcome of treatment. We then studied the clinical results of impacted ureteral stones which are especially difficult to destroy. Excretory urography was performed to non-invasively diagnose these stones, and those without visualization in the ureter below the stone were diagnosed as impacted stones and treated by ESWL without the ureteral catheter. Among the stones with a diameter of 1 to 2 cm, the success rate was significantly lower in impacted stones compared to non-impacted stone. These findings suggest that ESWL treatment without the ureteral catheter may be effective for ureteral stones with a diameter of less than 1 cm and non-impacted stones with a diameter of 1 to 2 cm, while combination therapy with other methods such as TUL may be better for other stones. We also performed ESWL on 6 patients with renal stones and 2 patients with ureteral stones which were cystine stones. Renal stones required an average 4.1 treatment with an average of 1,875 shocks per treatment, and ureteral stones required 1.5 treatment with an average of 1,833 shocks.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[The effectiveness of prophylactic dietary treatment in renal stones].

By following individual dietary guidelines which were established from analysis of the dietary intake and habits of male renal stone patients, the stone recurrence rate in 75 male calcium stone patients who had only received individual dietary instruction decreased markedly, as compared with that in 114 male calcium stone patients who had not received such instructions. Among 75 patients, recurrence was noted in 6 normocalciuric recurrent stone patients and 1 normocalciuric single stone patient during the period of outpatient visits. Investigation of the daily consumption of various nutrients and urinary excretion revealed no differences among the 6 normocalciuric recurrent stone patients, hypercalciuric recurrent stone patients, hypercalciuric single stone patients and normocalciuric single stone patients. Our findings suggest that the high recurrence rate in the normocalciuric recurrent stone patients is associated with stone lithogenic factors, such as heredity and anatomy, that could not be controlled by the daily treatment in this group.

Adolescent↗
PubMed1991

[Indications for surgical treatment of secondary hyperparathyroidism].

From 1978 to 1990 subtotal parathyroidectomy was carried out on 41 patients for secondary hyperparathyroidism. The indications for parathyroidectomy and suitable operative time, especially in the point of view of renal osteodystrophy are discussed. Serum ALP and PTH level and the presence of generalized fibrous osteitis were good indicators for parathyroidectomy. Furthermore, 99mTc-Pyrophosphate bone scintigraphy and Dual Photon Absorptiometry were proved to be valuable for patient selection for parathyroidectomy. Parathyroidectomy for patients in whom 99mTc-pyrophosphate bone uptake is diminished or patients in whom bone mineral contents are dramatically decreased must be carefully performed.

Absorptiometry, Photon↗
PubMed1991

[One-and-a-half syndrome due to a brain tumor--a case report and review of the literature].

A 69-year-old woman was admitted to our hospital on March 13, 1990, with a 1-month history of progressive gait disturbance. She had been operated on for colon cancer in May 1987. Examination in March 1989 revealed that she had metastatic liver tumor. On neurological examination, slight right abducens palsy, gaze-evoked horizontal nystagmus to the left, upbeat nystagmus and mild left hemiparesis were noted. Two weeks after admission, right lateral gaze palsy developed. Right MLF syndrome became apparent in the 3rd week. She was diagnosed as having one-and-a-half syndrome. Left hemi-hypesthesia and left limb ataxia were noted at that time. CT scan revealed ring-enhancing mass lesions in and around the right pontine tegmentum. Two weeks after development of the one-and-a-half syndrome, she became comatose with her eyes' conjugate deviation to the left and died on April 24, 1990. The metastatic lesions in both paramedian pontine reticular formation and medial longitudinal fasciculus were considered to be causative of her one-and-a-half syndrome. Clinical characteristics of 13 reported cases with one-and-a-half syndrome caused by brain tumor were reviewed. Half of them were caused by metastatic brain tumor.

Aged↗
PubMed1991

Growth inhibition of tumour cells by a liposome-encapsulated, mycolic acid-containing glycolipid, trehalose 2,3,6'-trimycolate.

In vivo growth of syngeneic tumour cells in the peritoneal cavity was strongly inhibited by intraperitoneal injection of a liposome-encapsulated, mycolic acid-containing glycolipid, trehalose 2,3,6'-trimycolate (TTM), derived from a non-pathogenic, acid-fast bacterium. Gordona aurantiaca. Peritoneal macrophages from mice after this treatment lysed tumour cells in vitro at a low effector/target ratio, and their culture supernatant inhibited tumour cell growth. The supernatant inhibited growth of not only tumour necrosis factor (TNF)-sensitive tumour cells, but also TNF-insensitive tumour cells. This inhibitory activity was enhanced by addition of lipopolysaccharide (LPS) to the culture medium of the macrophages. The macrophages released more superoxide (O2-), TNF and interleukin-1 (IL-1) on LPS triggering, and the releases of these compounds were further increased by addition of recombinant interferon-gamma (IFN-gamma) to the medium. Moreover, splenic T cells of TTM liposome-primed mice were found to produce eight times more IFN-gamma upon stimulation with LPS. These results indicated that priming with TTM liposomes resulted in strong activation of macrophages, which lysed tumour cells directly and also inhibited tumour cell growth by released factors.

Animals↗
PubMed1990

Stretching cardiac myocytes stimulates protooncogene expression.

Recently cellular protooncogenes have been found to be induced as an early response to pressure overload in cardiac hypertrophy. To examine whether mechanical stimuli directly induce specific gene expression in the heart, we cultured rat neonatal cardiocytes in elastic silicone dishes and stretched these adherent cells. Myocyte stretching stimulated expression of the protooncogene, c-fos, in a stretch length-dependent manner, followed by an increase in amino acid incorporation into proteins. c-fos mRNA levels were enhanced within 15 min by cardiocyte stretching, peaked at 30 min, and declined to undetectable levels by 240 min. In the presence of cycloheximide, a greater increase in c-fos mRNA was seen by stretching. The transfected chloramphenicol acetyltransferase gene linked to upstream sequences of the fos gene including its promoter was also activated by stretching cardiac myocytes. These results suggest that mechanical loading directly regulates gene transcription without the participation of humoral factors in cardiocytes.

Animals↗
PubMed1990

Expansive laminoplasty for lumbar spinal stenosis.

Expansive laminoplasty, a procedure used for cervical myelopathy, was carried out in 4 patients with degenerative lumbar spinal stenosis. The method was used in relatively young patients with severe low back and sciatic pain who had intraspinal ossification at multiple segments, with or without developmental spinal stenosis. The advantages of osteoplastic enlargement of the lumbar spinal canal with reinforcement of spinal stability are confirmed by our follow up of 2 to 5 1/2 years. The results were very satisfactory in each case. The indications and operative technique are described.

Adult↗
PubMed1990

An autopsy case of a cystic variant of thymic carcinoma mimicking a thymic cyst.

An autopsy case of thymic carcinoma is reported. The surgically excised cystic tumour from a 38-year-old Japanese male mimicked a thymic cyst pathologically. After a clinical course of 6 years, postmortem examination disclosed extensive metastases, including cystic lesions lined by benign-looking squamous epithelium. This evidence suggested that the present tumour was not of the specific variants of thymic carcinoma and not a thymic cyst with malignant transformation.

Adult↗
PubMed1990

Relationship of plasma and urine composition to recurrence of calcium urinary stones in patients on drug therapy.

Factors relating alterations in plasma and urine composition to recurrence of urinary stones during drug therapy were investigated by using a multiple regression analysis technique. These factors were influenced not only by the efficacy of the drugs but also by other factors (plasma or urinary constituents and overall health of the patients, etc.). In order to study the effect of drug therapy or other treatment on the alteration of plasma and urine constituents, multiple regression analysis is more appropriate than Student's paired t-test which has been used by some workers. These two analytical methods yield different results even if used on the same data.

Adult↗
PubMed1990

Allopurinol and thiazide effects on new urinary stone formed after discontinued therapy in patients with urinary stones.

We treated 87 patients with calcium-containing urinary stones with either allopurinol alone (44 patients) or in combination with thiazide (43 patients) and studied new stone formation before, during, and after the discontinuation of the drug therapy. The number of stones formed were 1.18, 0.24, and 0.13 before, during, and after discontinuation of the drug therapy, respectively, in the patients treated with allopurinol alone and 1.32, 0.20, and 0.09 in those treated in combination with thiazide. No differences were observed in these values and the duration of each observation period between the two groups. Decreases in the incidence of stone formation even after interruption of drug therapy suggested that recurrence-preventive effects observed following administration of these drugs include the effects of medical guidance. However, allopurinol therapy was effective in preventing recurrence in patients with hyperuricosuria.

Allopurinol↗
PubMed1990

Calcium oxalate crystal formation in patients with hyperparathyroidism and hyperthyroidism and related metabolic disturbances.

The crystallization of calcium oxalate in the urine of patients with hyperparathyroidism and hyperthyroidism was studied using a mixed suspension mixed product removal (MSMPR) system. In addition, calcium metabolism in hyperthyroidism and its relationship to urolithiasis was investigated. The urines from all the three groups (normal subjects, hyperparathyroid and hyperthyroid patients) showed reduced nucleation rates and increased growth rates in comparison with the control synthetic urine. The nucleation rate was not significantly different between the three human urine groups, while the growth rate was significantly higher in the hyperparathyroid group compared to the normal and hyperthyroid groups. Crystal volume (suspension density) in the hyperparathyroid group was approximately twice that in the other two groups. Serum and ionized calcium levels in hyperparathyroid patients were higher than in normal subjects, while hyperthyroid patients had levels only slightly higher than those in normal subjects. The hyperparathyroid and hyperthyroid groups differed significantly from the normal group in urinary calcium excretion. These two groups also showed significantly higher levels of serum alkaline phosphatase and urinary hydroxyproline than did the normal group. Although hyperthyroid patients have a calcium metabolism similar to hyperparathyroid patients, the incidence of urolithiasis is no different between hyperthyroid and normal subjects. The results of both crystallization and calcium metabolism in hyperparathyroid patients were not significantly different between those with and without urolithiasis. The result of crystallization was also not significantly different between hyperparathyroid patients with and without hypercalciuria. This study suggests that hypercalciuria alone does not produce urinary stones and that urine from hyperparathyroid patients may contain promotors of calcium oxalate crystallization and calcium stone formation.

Calcium Oxalate↗
PubMed1990

Clinical effects of prophylactic dietary treatment on renal stones.

From the investigation of the dietary intake and habits of male Japanese renal stone patients we established several general guidelines. Fluid intake should be increased, especially after dinner. Unbalanced diets should be corrected and avoided (the diet should include different types of food, with vegetables being eaten at every meal and an excessive intake of meat should also be avoided). Three meals a day should be eaten and an excessive intake at dinner should be avoided. The interval from dinner until retiring should be extended. By following these individual dietary guidelines the stone recurrence rate in 199 male calcium stone patients who had received individual dietary instruction decreased remarkably compared to that in male calcium stone patients who had not received individual dietary instruction, not only during the period of outpatient visits but also after outpatient visits were discontinued. From these results we conclude that individual dietary management should be the primary measure for the prophylaxis of renal stone disease in Japan.

Adult↗
PubMed1990

Dietary intake and habits of Japanese renal stone patients.

The daily consumption of various nutrients as well as the daily habits of 241 male stone patients were investigated. Hypercalciuric (300 mg. or more per day) calcium stone patients ingested much more total protein, fats, oils and calcium than normocalciuric calcium stone patients, and uric acid stone patients ingested much more total and animal protein, and carbohydrates than calcium stone patients. However, the amount of ingested calcium by the patients (470 mg.) was similar to that of age-matched healthy male subjects (476 mg.) and did not reach the level of the daily nutritive requirements (600 mg.). The patients ingested large amounts of nutrients, especially animal protein, during the evening meal. From these results it was believed that synthetic dietary management, including not only ingesting various amounts of nutrients but also changing dietary habits, is necessary for the prophylaxis of renal stones.

Adult↗
PubMed1990

Complications of lateral C1-2 puncture myelography.

This study reviewed the technical complication of 112 cases of lateral C1-2 puncture myelography for cervical spinal cord disorders. Spinal cord puncture and contrast injection, puncture between the occiput and C1, and blood vessel puncture were the main complications. These principally depended on the positioning of the patient's neck (hyperextension) and misdirection of the x-ray beam. For preventing major arterial puncture, the authors also reviewed 164 vertebral angiograms and determined the pathway of the vertebral arteries and the incidence of anomaly.

Female↗