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K Kosaka

Publications and source records attributed to K Kosaka.

At least 181 records · Page 10Linked to original sources
PubMed1994

Calcium-binding protein parvalbumin-immunoreactive neurons in the rat olfactory bulb. 1. Distribution and structural features in adult rat.

The laminar distribution and morphological features of parvalbumin-immunoreactive [PV(+)] neurons, one of the subpopulations of GABAergic neurons, were studied in the rat olfactory bulb at a light microscopic level. In the main olfactory bulb of adult rats, PV(+) neurons were mainly located in the external plexiform layer (EPL), and a few were scattered in the glomerular layer (GL), mitral cell layer (ML), and granule cell layer (GRL); whereas PV(+) neurons were rarely seen in the accessory olfactory bulb. The inner and outer sublayers of the EPL (ISL and OSL) appeared to be somewhat different in the distribution of PV(+) somata and features of PV(+) processes. PV(+) somata were located throughout the OSL, and PV(+) processes intermingled with one another, making a dense meshwork in the OSL; whereas, in the ISL, PV(+) somata were mainly located near the inner border of the EPL, and PV(+) processes made a sparser meshwork than that in the OSL. PV(+) neurons in the EPL were apparently heterogeneous in their structural features and appeared to be classifiable into several groups. Among them there appeared five distinctive types of PV(+) neurons. The most prominent group of PV(+) neurons in the OSL were superficial short-axon cells, located in the superficial portion of this sublayer and giving rise to relatively thick processes, in horizontal or oblique directions, which usually bore spines and varicosities. Another prominent group of PV(+) neurons extended several short, branched dendrites with spines and varicosities, which appeared to intermingle with one another, making a relatively small, spherical or ovoid dendritic field around the cell bodies; most of them resembled Van Gehuchten cells reported in previous Golgi studies. A third distinctive and most numerous group of PV(+) neurons were of the multipolar type; their somata and processes were located throughout the EPL. Their relatively smooth processes with frequent varicosities and a few spines were extended horizontally or diagonally throughout the EPL. A fourth group, which could be a subtype of the multipolar type, were located in or just above th ML and extended several thin, smooth dendrites in the EPL, some of which appeared to reach the border between the GL and EPL. Occasionally, axon-like processes arose from their cell bodies and extended into the ML. This fourth type of PV(+) neuron was named inner short-axon cells. A fifth group of neuron was located in the ML; processes of these neurons were extended horizontally, so they were named inner horizontal cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1994

Calcium-binding protein parvalbumin-immunoreactive neurons in the rat olfactory bulb. 2. Postnatal development.

The laminar development of the external plexiform layer (EPL) in the rat main olfactory bulb and the postnatal development of parvalbumin-immunoreactive [PV(+)] neurons mainly located in this layer were studied in animals at postnatal week 1-4 at a light microscopic level. The EPL in the adult olfactory bulb consists of two sublayers, the inner sublayer (ISL) and the outer sublayer (OSL). The ISL was already developed well even at postnatal day 7 (P7), whereas the OSL was first recognized at P10 as a thin zone consisting of more or less loosely packed large-sized and small-to-medium-sized somata subjacent to the glomerular layer (GL). The OSL increased in thickness and came to occupy nearly one-third to -half of the EPL at P14. PV(+) neurons first appeared at P10 mainly in the inner border of EPL. Only a few PV(+) neurons were scattered in the EPL at P10, but they increased remarkably in number during P14-21. Some of these PV(+) neurons at P10 had an intensely immunoreactive soma, extending relatively long processes with varicosities and/or spines. At P14, PV(+) neurons were located not only in the ISL but also at the border between the ISL and OSL, but in the OSL proper they were rarely observed. These PV(+) neurons showed branched and complicated processes with numerous varicosities and spines, displaying more mature features than those in previous stages. Even at P14 many of these PV(+) neurons appeared to exhibit some characteristic structural features of those in the adult stage.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Quantitative analysis of GABA-like-immunoreactive and parvalbumin-containing neurons in the CA1 region of the rat hippocampus using a stereological method, the disector.

The numerical density of neurons in the CA1 region of the rat dorsal hippocampus has been estimated by a stereological method, the disector, using pairs of video images of toluidine blue-stained, plastic-embedded, 0.5-microns-thick sections, 3 microns distant from each other. The chemical properties of those disector-counted cells were further analyzed by postembedding immunocytochemical methods on adjacent, semithin sections using antibodies against gamma-aminobutyric acid (GABA) and a specific calcium-binding protein, parvalbumin (PV). The density of neurons in the CA1 region was 35.2 x 10(3)/mm3; numerical densities in the stratum oriens (SO), stratum pyramidale (SP), and strata radiatum-lacunosum-moleculare (SRLM) were 11.3 x 10(3)/mm3, 272.4 x 10(3)/mm3, and 1.9 x 10(3)/mm3, respectively. The numerical densities of GABA-like immunoreactive (GABA-LIR) and PV-immunoreactive (PV-IR) neurons were 2.1 x 10(3)/mm3 and 1.1 x 10(3)/mm3, respectively, which were 5.8% and 3.2% of all neurons, respectively. In the CA1 region only about 60% of PV-positive neurons were GABA-LIR. However, taking the previous observation into consideration that almost all hippocampal PV-positive neurons were immunoreactive for the GABA-synthesizing enzyme glutamic acid decarboxylase (GAD), neurons that were immunoreactive to either GABA or PV or both (GABA+ and/or PV+ neurons) were regarded as a better representative of GABAergic neurons in this region; thus, the numerical density of these GABA+ and/or PV+ neurons was 2.5 x 10(3)/mm3 and they were 7.0% of all neurons in the CA1 region. Lamellar analysis showed that the numerical densities of GABA+ and/or PV+, GABA-LIR, and PV-IR neurons were highest in the SP, where they were 8.2 x 10(3)/mm3, 6.2 x 10(3)/mm3, and 5.4 x 10(3)/mm3, respectively. The results of the present study indicate that the proportions of GABAergic neurons and a subpopulation of them, PV-containing GABAergic neurons, to other presumable non-GABAergic neurons are far smaller in the CA1 region of the hippocampus than in several neocortical regions previously reported.

Animals↗
PubMed1994

Lack of association of the transporter associated with antigen processing with Japanese insulin-dependent diabetes mellitus.

The transporter associated with antigen processing (TAP) encoded in the major histocompatibility complex (MHC) class II region is a molecule required for endogenous antigen processing. We have typed TAP polymorphism in 95 Japanese patients with insulin-dependent diabetes mellitus (DDM) and 75 normal controls. Amino acid substitutions at positions 333 and 637 of TAP1 and at positions 379, 665, and 687 of TAP2 were typed by the polymerase chain reaction (PCR)-sequence-specific oligonucleotide method. In addition, DNA typing of human leukocyte antigen (HLA)-DQA1 and -DQB1 loci was performed by the PCR-restriction fragment length polymorphism method. There was no significant difference between IDDM patients and normal controls in the frequencies of TAP1 and TAP2 alleles. On the contrary, the HLA-DQ locus showed a strong association with IDDM in the same series of subjects. The frequencies of HLA-DQA1*0301 and -DQB1*0401 were increased significantly and those of HLA-DQA1*0103, -DQB1*0501, -DQB1*0601 and -DQB1*0602 were decreased significantly in Japanese IDDM patients compared with normal controls. Positive linkage disequilibrium was observed between HLA-DQB1*0303 and TAP2C and between HLA-DQB1*0401 and TAP2B. Negative linkage disequilibrium was observed between HLA-DQA1*0103 and TAP2A. Even when subjects with HLA-DQA1*0103, -DQA1*0301, -DQB1*0302, -DQB1*0303, and -DQB1*0401 were considered separately, no significant differences was found in the distribution of TAP1 and TAP2 alleles between IDDM patients and normal controls. We conclude that it is not TAP but HLA-DQ that exhibits a primary association with Japanese IDDM.

Adolescent↗
PubMed1994

History of medicine and changes in concept of diabetes mellitus in Japan.

In Japan, diabetes mellitus was called 'Shoukachi', thirst disease, before the 18th century. Western medicine was first introduced by the Portuguese in the 16th century. During the period of National Isolation from the 16th to the middle of the 19th century, Nagasaki served as the sole window of Japan, through which Dutch medicine came into Japan. After the Meiji Reform in the 19th century, German medicine was actively introduced. There remains a record of a lecture by Prof. Aoyama on diabetes mellitus delivered in 1906, in which the restriction of carbohydrate intake and a meat-rich diet was recommended. Prof. Sakaguchi, the successor of Prof. Aoyama and a pioneer of diabetes research in Japan, studied blood sugar profiles in healthy and diabetic subjects and invented a rice-meal test to examine glucose tolerance. In 1928, he wrote 'diabetes occurs by the deficiency of insulin, genetic factors are important, and the bodily need for insulin is increased with obesity'. He and his colleagues found that too low an intake of carbohydrate may impair glucose tolerance. After the 2nd World War, Japanese doctors eagerly learned foreign medicine, especially from the United States. Since the 1940s, a new concept has arisen in which diabetes was defined by blood glucose values after glucose loading. But, in 1970, a Committee of the Japan Diabetes Society (JDS) expressed an opinion that diabetes should not be solely defined by the results of the glucose tolerance test but should be considered as a disease or diseases with characteristic metabolic and clinical features, based on deficient insulin action.(ABSTRACT TRUNCATED AT 250 WORDS)

Diabetes Mellitus↗
PubMed1994

Diagnostic criteria for diabetes mellitus in Japan--from a report of the Japan Diabetes Society (JDS) Committee on the Diagnosis of Diabetes Mellitus, 1982.

After the proposal of diagnostic criteria for diabetes mellitus by the National Diabetes Data Group (1979) and by WHO (1980), a committee was set up by the Japan Diabetes Society (JDS) to reconsider the old criteria by the JDS which had been proposed in 1970. Items covered by the report of the committee in 1982 included the concept of diabetes mellitus, describing it's features, and stating that it's diagnosis is a procedure of recognizing the disease 'diabetes' characterized by these features. Cutoff blood glucose values for fasting samples, after a 75 g oral glucose tolerance test, were proposed to define normal and diabetic types. The cutoff values for the diabetic type are identical to those of the WHO defining diabetes, whereas the values for the normal type (fasting < 110 mg/dl and 1-h < 160 and 2-h < 120 mg/dl for venous plasma) are much lower than those for the lower limit of IGT by the WHO. Subjects whose glucose tolerance is neither diabetic nor normal are classified as borderline type, which includes not only IGT but cases with milder glucose intolerance. The cutoff points for the normal type were selected based on the long-term follow-up data for mild glucose intolerance in Japan. The Committee further stated that the clinical diagnosis of diabetes should be made not only on the basis of the glucose tolerance data, but also after clinical consideration of the possibility of any other diseases which might impair glucose tolerance.

Blood Glucose↗
PubMed1994

Family history of diabetic patients in Japan.

The frequency of a positive family history of diabetes in diabetic patients has increased in recent studies. In this study, it was 16-33% for type 1 diabetes and 43-49% for type 2 diabetes. It was significantly higher than in non-diabetic subjects, and in type 2 than in type 1 diabetic patients. The prevalence of diabetes in parents and siblings of type 2 diabetic patients was higher than in those of type 1 patients, and it was particularly high in parents of young onset type 2 patients. Among type 2 diabetic patients, positive family history was somewhat lower in those with marked obesity in the past. Comparison of groups with varying degrees of glucose intolerance revealed that a family history of diabetes increased in parallel with the impairment of glucose tolerance. The results suggest that genetic factors in the pathogenesis of diabetes are more important in type 2 than in type 1 diabetes, and in the younger onset and less obese subjects than in older onset and more obese patients for type 2 diabetes.

Adult↗
PubMed1994

Insulin secretory response in Japanese type 2 (non-insulin-dependent) diabetic patients.

Insulin (immunoreactive insulin, IRI) response during a 100 g oral glucose tolerance test was studied in a large number of patients with definite diabetes, equivocal diabetes, and other pathological states causing glucose intolerance. Definite diabetes was diagnosed in patients with overt fasting hyperglycemia. Once the diagnosis of definite diabetes was made, IRI response remained low after improvement of glucose tolerance. Glucose intolerance caused by other pathological extra-pancreatic conditions was usually accompanied by increased IRI response. IRI response in equivocal diabetes was variable, but almost always decreased in those who developed definite diabetes later. In subjects with a strong family history of type 2 diabetes, the prevalence of a low IRI response was high. In non-diabetic subjects, weight gain caused a marked increase in IRI response and a small increase in blood glucose, while in those who developed diabetes, IRI increased little despite the marked increase in blood glucose. These data suggest that low IRI response is an important feature of type 2 diabetes, perhaps with a hereditary basis in part. It precedes the occurrence of overt hyperglycemia and persists after improvement of glucose tolerance.

Blood Glucose↗
PubMed1994

Historical changes in diabetes therapy in Japan.

The origins of many aspects of ancient Japanese culture lie in knowledge brought from China, and medicine was no exception. Subsequently, however, in the middle of the 16th century, Portuguese missionaries introduced Western medicine to Japan along with Christianity. They were followed by the Dutch in the 17th century, who introduced Western culture while carrying on commerce at their Dejima outpost in Nagasaki. This was called the Dutch school in Japan, and although there was thus contact with Western culture and the Japanese eagerly studied Western medicine, it was not until after the establishment of the Meiji Reform government in the middle of the 19th century that there was aggressive incorporation and acceptance of modern Western medicine in Japan. The University of Tokyo was the first university in Japan. Preserved in the library of the Third Department of Internal Medicine are old records of hospitalized cases in Japan, and those documents form the basis of this review of the history of the treatment of diabetes mellitus in Japan.

Diabetes Mellitus↗
PubMed1994

History and activities of Japan Diabetes Society.

After 1953, Dr. Y. Kobayashi organized a study group of chemotherapy of diabetes mellitus, and then a more broader 'Diabetes Study Group' sponsored by the Ministry of Education. During these group activities, the members felt the need to establish a forum to discuss various aspects of diabetology. In December 1957, an inaugural meeting of the Japan Diabetes Society (JDS) was held. The objectives of the Society were to promote the investigation and to spread the knowledge on diabetes and to thereby prevent the hazard arising from diabetes. Since that time, JDS has been admitted as a member of the International Diabetes Federation in 1958, and was approved as an incorporated association by the Ministry of Education in 1985. It has now seven regional branches. Members increased greatly and reached 7795 in March 1993. In every year, JDS has a 3-day nationwide general scientific meeting, and local meetings are held by each of its branches. The official journal 'Tonyobyo (Journal of the Japan Diabetes Society)' is being issued monthly. JDS edited educational books for diabetic patients, such as 'Guidebook for the Treatment of Diabetes', 'The Exchange List of Foods for the Treatment of Diabetes Mellitus' and 'The Guidebook of Summer Camp for Diabetic Children'. In 1967, JDS began to hold a 2-day post-graduate course named 'Progress in Diabetology' for physicians, nurses, dieticians and other health professionals. JDS has a close connection with the Japan Association of Diabetes Care and Education, co-sponsoring the 'diabetes week' every year.(ABSTRACT TRUNCATED AT 250 WORDS)

Diabetes Mellitus↗
PubMed1994

Diffuse neurofibrillary tangles with calcification: a new presenile dementia.

The term "diffuse neurofibrillary tangles with calcification" (DNTC) is proposed for a new form of presenile dementia. It is characterised by slowly progressive cortical dementia in the presenium, localised temporal or temporofrontal lobar atrophy, numerous neurofibrillary tangles widespread in the cerebral cortex, and pronounced calcareous deposits; 16 cases of DNTC, have been reported.

Aged↗
PubMed1994

Marked elevation of carcinoembryonic antigen and carbohydrate antigen 19-9 in the peripheral blood as an initial manifestation of meningeal carcinomatosis.

Marked elevation of tumor markers in the peripheral blood was initially a sole manifestation of meningeal carcinomatosis in a man with gastric carcinoma. In addition to extensive meningeal carcinomatosis, no metastatic lesions were found at autopsy other than microscopic infiltration into a tiny paraaortic lymph node. Elevation of these markers in the peripheral blood is best explained by meningeal carcinomatosis. When elevation of these markers is otherwise unexplainable, meningeal carcinomatosis should be considered as a diagnostic possibility even in the absence of neurological symptoms.

CA-19-9 Antigen↗
PubMed1994

Increased risk factors for coronary artery disease in Japanese subjects with hyperinsulinemia or glucose intolerance.

OBJECTIVE: To understand the interrelationship of coronary artery disease (CAD) risk factors including hyperlipidemia, hypertension, and glucose intolerance to prevent and better manage this disease. RESEARCH DESIGN AND METHODS: We performed a 100-g oral glucose tolerance test in 2,113 subjects, and we evaluated their plasma lipid levels, blood pressure (BP), and plasma glucose and plasma insulin responses. RESULTS: Multiple regression analysis demonstrated a significant relationship of either BP, plasma triglyceride (TG), or high-density lipoprotein (HDL) cholesterol levels to plasma insulin and glucose response after the glucose load. Plasma cholesterol levels were related only to the plasma glucose response. In subjects matched for age, sex, and body mass index (BMI) with hyperinsulinemia or normoinsulinemia, the hyperinsulinemic subjects had a significantly higher mean BP and plasma TG level than the normoinsulinemic subjects (128.8/82.3 vs. 122.9/79.3 mmHg and 172.1 vs. 119.4 mg/dl), and the HDL-cholesterol level was significantly lower (43.9 vs. 47.8 mg/dl). Furthermore, subjects matched for age, sex, and BMI with glucose intolerance had a higher mean BP (128.4/81.8 vs. 123.5/78.7 mmHg) and higher plasma TG level (154.2 vs. 123.0 mg/dl) than those without glucose intolerance. CONCLUSIONS: Based on these findings, subjects with hyperinsulinemia or glucose intolerance should be carefully managed to prevent CAD, because they have more numerous and more severe risk factors than subjects with normal plasma insulin levels or subjects without glucose intolerance.

Blood Glucose↗
PubMed1994

Methenamine-silver staining: a simple and sensitive staining method for senile plaques and neurofibrillary tangles.

An improved methenamine-silver impregnation method is presented which exhibits sensitivity for amyloid substances comparable to that of anti-beta protein immunostaining. In optimally treated sections, this technique stained both beta-amyloid deposits and neurofibrillary tangles, which are known to have a beta-pleated structure. This simple procedure allows a large number of sections to be stained for routine examination.

Alzheimer Disease↗
PubMed1994

Exocrine pancreatic ductograms in insulin-dependent diabetes mellitus.

OBJECTIVES: To examine the prevalence of abnormal pancreatic ductograms in patients with insulin-dependent diabetes mellitus (IDDM) and to determine the clinical characteristics of those patients. METHODS: Pancreatic exocrine morphology was studied by endoscopic retrograde pancreatography (ERP) in 43 patients with IDDM, 12 patients with islet cell antibody (ICA)-positive non-insulin-dependent diabetes mellitus (NIDDM), and 22 patients with ICA-negative NIDDM. RESULTS: ERP revealed a significantly higher prevalence of abnormal pancreatic ducts (dilation and stenosis, tortuosity, obstruction, and intraductal calculi) in the patients with IDDM (17/43, 40%) than in the patients with ICA-negative NIDDM (2/22, 9%, p = 0.018). IDDM patients who slowly progressed to insulin dependency more than 13 months after the onset of diabetes had a higher frequency of abnormal pancreatic ducts (13/22, 59%) than those who needed insulin therapy within 12 months after the onset (4/21, 19%, p = 0.016). There was no difference in duration of diabetes between the two groups. ICA-positive NIDDM patients also had a higher frequency of abnormal pancreatic ducts (7/12, 58%) than ICA-negative NIDDM patients (2/22, 9%, p = 0.0074). CONCLUSIONS: These results indicate that a high proportion of IDDM patients who have prolonged histories of non-insulin dependency with ICA suffer pancreatic exocrine impairment. A similarity between IDDM with a slowly progressive clinical course and fibrocalculous pancreatic diabetes seen in tropical countries also was suggested.

Autoantibodies↗
PubMed1994

Quantitative EEG in patients with presenile and senile dementia of the Alzheimer type.

EEG data obtained from 27 patients with presenile Alzheimer's disease (AD) and 28 patients with senile dementia of the Alzheimer type (SDAT) were compared with data from 30 age- and sex-matched controls. Both patient groups exhibited more pronounced delta and theta activity and less prominent alpha and beta activity than the controls. AD, however, was accompanied by more severe slowing than SDAT. The slowing was distributed in the left temporal and frontal regions in AD, and bilaterally in the frontal regions in SDAT. As the severity of the dementia increased, delta activity alone increased in AD, whereas, there were significantly greater increases in both delta and theta activity and decreases in alpha and beta activity in SDAT. These EEG differences appear to be related to the degree of brain damage and the speed of progression of the disease process.

Aged↗
PubMed1993

Axons and axon terminals of cerebellar Purkinje cells and basket cells have higher levels of parvalbumin immunoreactivity than somata and dendrites: quantitative analysis by immunogold labeling.

The immunointensities of calcium-binding proteins parvalbumin (PV) and calbindin D28K were quantified in different parts of Purkinje cells and interneurons (basket cells and stellate cells) of the rat cerebellum. An electron microscopic, postembedding immunogold procedure on Lowicryl K4M-embedded thin sections was applied. Neuronal profiles were identified by double-labeling immunocytochemistry using the combination of the two primary antibodies, mouse monoclonal anti-rat calbindin D28K and rabbit polyclonal anti-rat PV. The secondary antibodies were conjugated with colloidal gold of different sizes (10 and 15 nm diameter). In the cerebellar cortex, double-labeled profiles were identified as Purkinje cells and profiles labeled only with anti-PV were identified as inteneurons. The densities of gold particles were used for statistical comparison of the relative levels of PV and calbindin D28K in somata, dendrites, dendritic spines, axons and axon terminals of Purkinje cells, and interneurons. The axons and axon terminals of Purkinje cells and basket cells had significantly higher levels of PV immunoreactivity than Purkinje cell somata, primary, secondary, and tertiary dendrites, and dendritic spines, as well as interneuron somata. On the other hand, the present study could not determine conclusively whether calbindin D28K was distributed homogeneously throughout soma, dendrites, and axons of Purkinje cells or was also concentrated in Purkinje cell axons. To estimate absolute PV concentrations, we made a series of artificial standard samples which were aldehyde-fixed 10% bovine serum albumin containing given concentrations of PV (0, 12.5, 25, 50, 100, 200, and 400 microM, 1 and 2 mM), and calibration curves were deduced from quantitative immunogold analyses of these standard samples.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗