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Biomedical subjects

M Horikawa

Publications and source records attributed to M Horikawa.

At least 55 records · Page 3Linked to original sources
PubMed1993

Lung cancer mortality among a cohort of male chromate pigment workers in Japan.

In 1975, five manufacturers of chromate pigment in Japan were examined in a study of the carcinogenicity of chromates. These companies were producing lead chromate, zinc chromate, molybdate orange and/or strontium chromate. The current study covers a cohort of 666 workers involved in the manufacture of chromate pigment for at least 1 year between 1950 and 1975. The workers were followed up for 15-40 years, until 1989. Many previous reports have found an excess lung cancer risk among workers involved in the manufacture of chromate pigments and chromate chemicals. In the current study, subjects were classified on the basis of years worked, years of observation, characteristics of company, type of work engaged in for the longest period of time, and involvement in the manufacture of zinc chromate. Mortality was compared with that of all Japanese males by means of the person-year method. The route of exposure was primarily inhalation through the respiratory system. None of the results showed statistically significant differences that would suggest an excess risk for malignant neoplasms, particularly lung cancer, among workers engaged in the manufacture of chromate pigment in Japan.

Cause of Death↗
PubMed1993

Bio-microscopical observation of dystrophic calcification induced by calcium hydroxide.

Calcium hydroxide paste was introduced into a rabbit ear chamber, and the effect of calcium hydroxide on the vascular tissue was observed under a bio-microscope continuously up to 14 weeks. Many precipitates were observed at the border of living tissue, after the dissolution of microvessels around the paste. They increased both in size and number to combine like a river bank in the first 48 h. After 1 week, microcirculation recovered, and newly-formed capillaries approached the precipitate-bank, the edge of which became smoother as weeks went by. The bank was stable and compatible to microvessels during the observation period. By SEM observation, the width of the bank was from 200 to 400 microns, and the tissue-side of the bank appeared like amorphous lamellae, while the inner-side showed particle-like appearance. EDX examination revealed high peaks of Ca and P similar to calcium phosphate at the tissue-side of the bank, but only Ca peak at the inner-side. The precipitates seemed to have the potential to induce dystrophic calcification by absorbing Ca and P from the tissue.

Animals↗
PubMed1992

Initial hepatic metabolic function in canine liver and pancreas cluster transplantation.

In this study, initial hepatic metabolic function was evaluated by determining the arterial ketone body ratio (AKBR) and plasma amino acid concentrations in an experimental orthotopic combined hepatopancreatic transplantation (OHPT), and comparing the same values in orthotopic liver transplantation (OLT). In OHPT, AKBR decreased in the anhepatic phase and recovered to the preoperative value just 1 h after reperfusion. On the other hand, in OLT, the recovery of AKBR took 3 h after reperfusion with a significant difference compared to OHPT (P less than 0.05). Plasma amino acid levels, especially alanine and total free plasma amino acids increased in the anhepatic phase and recovered within 1 h of reperfusion in OHPT. However, they did not recover until 3 h after reperfusion in OLT. This rapid recovery of hepatic metabolic function in OHPT should be attributed to the order of reperfusion in which the reconstruction of arterial blood flow precedes that of portal blood flow. This model is useful for assessing the best way by which the grafted liver can for assessing the best way by which the grafted liver can control the timing, order, rate, and volume of blood that should be released.

Amino Acids↗
PubMed1992

The Rett syndrome and CSF lactic acid patterns.

We investigated both blood and cerebrospinal fluid (CSF) lactate and pyruvate levels in seven girls with the Rett syndrome (RS) and evaluated the relationship between CSF lactate and pyruvate levels and the clinical manifestations, particularly seizures, anticonvulsant medication, and breathing dysfunction including breath holding, apnea and hyperventilation. Elevated lactate and pyruvate levels in CSF with normal serum lactate were found in two RS patients. Elevated CSF lactate correlated significantly with the clinical occurrence of hyperventilation (P0 = 0.048, Fisher exact probability). We measured native and dichloroacetate (DCA)-activated pyruvate dehydrogenase (PDH) complex activities in two patients (#1 and 2) using cultured lymphoblastoid cell lines which were transformed by EB virus and the results were normal. We also analyzed CSF citric acid intermediates from 7 RS patients including citric acid, cis-aconitate, alpha-ketoglutarate, succinate, fumarate, malate and oxaloacetate. These concentrations were not significantly different from those control patients (N = 21). An elevated lactate level may be a clue to clarify the etiology of RS.

Acid-Base Equilibrium↗
PubMed1991

[Usefulness of Doppler method for evaluating intracranial hemodynamics in infantile hydrocephalus].

The changes of pulsatility index (PI) were followed for anterior cerebral artery (ACA) and basilar artery (BA) in 8 hydrocephalic infants. PI increased with the progression of hydrocephalus in both ACA and BA, from an average of 0.69 to 0.80 and from 0.73 to 0.81, respectively. The index made a sharp dip in 6 hours 0.65 for ACA and 0.70 for BA after placing a V-P shunt. It eventually stabilized within mean +/- SE. (ACA:0.69 +/- 0.0042, BA:0.71 +/- 0.0036). The index enabled us to observe objectively cerebral vascular resistance of the illness in numerical values. It may become a useful tool for setting criteria for placing a shunt (about 0.80) as well as for judging the shunt effectiveness. Throughout the entire observation, changes in PI of both ACA and BA were well correlated. Anterior fontanel pressure was also correlated with PI in the period, except PI of BA before the shunt operation. However, the pre-shunt correlation of PI to lateral ventricle enlargement was lost after the shunt operation. And the ventricle size reduced only slightly when PI rapidly decreased in 6 hours after the V-P shunt. These facts indicated that the changes in PI was affected directly by the intracranial pressure rather than the enlarged ventricle. The findings of this study indicated the necessity of evaluating of the intracranial hemodynamics with other diagnostic approaches in managing infantile hydrocephalus.

Cerebrospinal Fluid Shunts↗
PubMed1990

Partial trisomy 22 with Dandy-Walker malformation.

Partial trisomy 22 usually occurs through a 3:1 meiotic segregation of the parental 11q;22q translocation carrier, which is the most common balanced translocation in man. Common neurologic findings are delayed psychomotor development and muscular hypotonia. There have been a few neuroradiologic and neuropathologic studies, which include ventricular dilatation, arrhinencephaly, and aplasia or hypoplasia of the cerebellar vermis, corpus callosum and pons. We here add one patient with partial trisomy 22 who had, in addition to the usual features, Dandy-Walker malformation, which, to our knowledge, is a previously undescribed feature.

Chromosomes, Human, Pair 11↗
PubMed1989

A rapid cross-sectioning and freeze-clamping device for the beating canine heart.

A new sampling method of cross-sectioning the canine heart in situ was developed. A mechanical device, driven by spring power, enabled cross-sectioning of a short-axis plane of the beating canine heart (4 mm thick) with high speed rotating blades, at a pre-determined phase of the cardiac cycle, and instantaneous freeze-clamping (2.4 mm thick) with pre-cooled aluminum blocks, all within 120 ms. By this method, the anatomical structures of the sample were well preserved. Transmural metabolism and flow distribution were instantaneously fixed and high resolution of the two-dimensional redox state was obtained by application of NADH fluorescence photography. Micro-samplings from the desired portion of the cross-sectional slice were possible at -190 degrees C. NADH fluorescence of the samples did not increase from the surface to 1.2 mm in depth, confirming that there was no ischemic artifact. With the present technique, a heart sample in which transmural metabolism, and the redox state, are fixed and visualized is attainable, thus providing a new tool for the study of myocardial ischemia.

Adenine Nucleotides↗
PubMed1989

Incidences of antibodies to Yersinia enterocolitica: high incidence of serotype O5 in autoimmune thyroid diseases in Japan.

Antibodies to Yersinia enterocolitica serotype O3, O5, O6 and O9 were measured by the micro-agglutination method in 445 healthy subjects and patients with Grave's disease (n = 70), Hashimoto's disease (n = 45) and thyroid tumor (n = 29). In contrast to previous reports, the incidence of antibodies to serotype O3 in each group of patients with thyroid diseases was not significantly different from that in healthy subjects. However, the incidence of antibodies to serotype O5 was significantly higher in patients with Graves' disease (81.4%, P less than 0.001) and Hashimoto's disease (91.1%, P less than 0.001) than in healthy subjects (258.9%). Significantly increased incidence of antibodies to serotypes O6 and O9 was observed only in patients with Hashimoto's disease (40.0% and 51.1% vs healthy subjects 24.7% and 29.9%, respectively). Patients with thyroid tumor showed no increase in any serotype of Yersinia enterocolitica. No correlations was found between the titers of anti-Yersinia antibodies and anti-thyroglobulin or anti-microsomal antibodies. These data indicate an association between thyroid autoimmunity and antibodies to Yersinia enterocolitica. These results are different from those in reports from other countries, suggesting that serotype specificity may be influenced by racial or genetic factors.

Antibodies, Bacterial↗
PubMed1989

[Thoracic and lumbo-sacral spinal lipoma in an infant].

We reported a case of thoracic and lumbosacral spinal lipoma in an 8 month-old boy. He was born in asphyxia. Six months after birth, spastic paraparesis developed gradually at both lower extremities and secondary funnel chest due to shallow thoracic movement and scoliosis in the thoracic region was observed. MRI was then performed where tumor mass demonstrated by the high signals in both T1 and T2 in ages was confirmed in the thoracic and lumbo-sacral regions. Surgery was performed only for the thoracic lesion which was considered primary. The tumor in the Th3-4 level had developed subdurally, while the tumor in the Th5-10 extradurally. Only partial removal could be done for the subdural tumor because its boundary with the spinal cord was not clearly identified. Postoperative histological study revealed it as lipoma. During the following 6 months only slight recovery from paraparesis was observed. Surgical intervention against the mass in the lumbosacral region was not performed for the conus medullaris was found located in its normal position and no concomitant symptoms could be observed. In summary, it is considered that spinal lipoma is rare (1% of total spinal tumor) and commonly associated with other types of congenital anomalies (in 31% of spinal lipoma). Particularly in infants, spinal lipoma in the thoracic region as experienced in our case is extremely rare and any medical treatment started after clinical symptoms once developed seems ineffective.

Humans↗
PubMed1989

[Acute cerebellar ataxia and facial palsy after DPT immunization].

Since the initial report of Beyers & Moll (1948), numerous cases of seizures and encephalopathy after pertussis immunization or DPT immunization have been reported. However, acute cerebellar ataxia and/or facial palsy after DPT immunization is unusual, although there have been several reports from Japan. We report a 1-year-11-month-old girl with acute cerebellar ataxia and facial palsy after DPT immunization. On admission, she was alert. She was active and had a 6-day history of an ataxic gait and asymmetric facial movement which had begun 5 hours after DPT immunization. Neurological examination revealed an ataxic gait, horizontal nystagmus and right facial palsy. A CT scan showed low density on the right side of the pons with marked contrast enhancement. A MRI scan indicated the involvement of not only the right side of the pons, but also of the bilateral cerebellar peduncles. The child did well subsequently and was neurologically normal 20 days after the initial symptoms. To our knowledge, the present case is probably the first reported one of acute cerebellar ataxia after DPT immunization with CT and/or MRI correlation.

Acute Disease↗
PubMed1989

[A ten-year-old autistic girl with neuroleptic malignant syndrome caused by neuroleptic agents].

We reported a ten-year-old autistic girl who had developed neuroleptic malignant syndrome (NMS) caused by administration of neuroleptic agents, haloperidol and chlorpromazine, because of her behavioral disorders. She had fever (38.4 degrees C) and elevated CK (796 IU). Her extrapyramidal symptoms and autonomic disturbance improved gradually after discontinuation of these drugs. However, altered consciousness did not change for three months despite treatment with L-DOPA, bromocriptine, dantrolene Na, biperiden, diltiazeM HCL and diazepam. Administration of amantadine HCL dramatically cleared not only the persistent symptom but also extrapyramidal symptoms and autonomic disturbance. She recovered from NMS one month later. The study of this case indicated that these neuroleptic drugs could cause NMS also in children. Therefore, the use of them in children with behavioral problems should be carefully evaluated clinically. It was concluded that NMS in this case occurred due to a defective dopamine release from presynaptic vesicles because L-DOPA was not effective and amantadine HCL was effective against these symptoms.

Autistic Disorder↗