Biomedical subjects

H Miki

Publications and source records attributed to H Miki.

359 records · Page 20Linked to original sources

PubMedDate not supplied

Giant symptomatic myelolipoma of the adrenal gland.

A case of giant symptomatic myelolipoma is described in which clinical differentiation was difficult. It was considered to be an extremely rare case of giant myelolipoma arising in the adrenal gland. Histologically the present case contained more lipomatous elements than others reported to data. This is a case of giant adrenal myelolipoma with a few foci of myeloid elements and it is suggested that this case has a true neoplastic nature rather than a hyperplastic or metaplastic one.

Adrenal Gland Neoplasms↗

PubMedDate not supplied

Cataractogenesis in neonatal Sprague-Dawley rats by N-methyl-N-nitrosourea.

Cataract was induced by a single intraperitoneal injection of 100 mg/kg N-methyl-N-nitrosourea (MNU) to 0-, 5-, 10-, 15-, or 20-day-old male and female Sprague-Dawley rats. In day 0, 5, 10, and 15 MNU-treated rats, mature cataracts were constantly seen 7, 14, 14, and 30 days after dosing, respectively. In the day 20 MNU-treated rats, only subcapsular cataract was seen 30 days after dosing. Therefore, the rats exposed to MNU at an earlier age caused cataract more rapidly and severely. In the day 0 MNU-treated rats, 7-methyldeoxyguanosine DNA adduct was detected in the lens epithelial nuclei 12 hours after MNU dosing, followed by apoptosis, which was confirmed by morphology, by TUNEL signals, and by DNA ladder and peaked 3 days after MNU dosing. In the apoptosis cascade, upregulation of Bax, downregulation of Bcl-2, and increased CPP32 protease (caspase-3) activity were seen 12 hours after MNU dosing. Therefore, the pathogenesis of MNU-induced cataract was associated with DNA adduct formation in the lens epithelial cell nuclei leading to apoptosis by upregulation of Bax protein, downmodulation of Bcl-2 protein, and activation of caspase-3.

Animals↗

PubMedDate not supplied

Intramembranous and endochondral bone changes induced by a new bisphosphonate (YM175) in the beagle dog.

Oral treatment with a new bisphosphonate, YM175, for 13 wk resulted in increased bone tissue mass by both intramembranous and endochondral ossification processes in adult beagle dogs. Intramedullary bone formation due to intramembranous process was observed in dogs treated with a highly toxic dose of YM175. The newly formed woven bone trabeculae, showing immature to relatively mature figures, were present between the preexisting cancellous bone. The immature bone consisted of spindle-shaped mesenchymal cells with osteoid tissues. Many active osteoblasts surrounded the immature woven bone, while only few osteoclasts were seen on the surfaces of the new bone. Endochondral bone change was observed at the costochondral junction in all YM175-treated groups. Accumulation of unresorbed mineralized cartilage with its covering of bone at this site resulted in an increase in length of the area of primary spongiosa. Although the endochondral bone change induced by YM175 was due to a bisphosphonate-induced inhibitory effect on bone resorption, the intramedullary bone formation is unique to YM175.

Animals↗

PubMedDate not supplied

Treatment with bifemelane for optic nerve damage following high intraocular pressure in rat eyes.

This study found that pretreatment with 4-(o-benzylphenoxy)-N- methylbuty-lamine hydrochloride (bifemelane hydrochloride, Celeport) reduced ischemia-reperfusion injury in rat eyes. Bifemelane (25 mg/kg) was injected intraperitoneally 30 minutes before an ischemic insult, then acute ischemia of the retina and optic disc was induced by increasing intraocular pressure to 110 mmHg for 45 minutes. After one week, the axonal count of the optic nerve was investigated using electron microscopy. The control group consisted of vehicle-treated eyes which received normal saline. The axon count was 93.4 +/- 7.9 for the bifemelane treated group, and 79.2 +/- 6.4 for the controls. The axon count in the treated group was significantly higher. These results suggest that bifemelane, which prevents cerebral nerve cell damage from ischemia, can reduce ischemic retinal nerve cell injury.

Animals↗

PubMedDate not supplied

Electrophysiological comparison between catechol- and urea-induced myoclonus models in the rat.

Catechol- and urea-induced myoclonus models in the rat were electrophysiologically compared to clarify pathophysiological differences. Catechol-induced myoclonus had various similarities with cortical reflex myoclonus in that there were electroencephalogram (EEG) discharges prior to myoclonic discharges, a spread of myoclonic discharges from the rostral to the caudal site, and a high amplitude somatosensory evoked potential (SEP). In urea-induced myoclonus, there were no EEG discharges related to myoclonic discharges and no enlarged SEP components as in reticular reflex myoclonus. Catechol-induced myoclonus had two evoked EMG responses of the biceps femoris at mean onsets of 8.0(C1) and 13.4 (C2) ms, and urea-induced myoclonus had a response (U1) at the mean onset of 10.2 ms. A study of the effects of various lesions in the central nervous system on these evoked EMG responses suggests that C1 is a monosynaptic spinal reflex. C2 which disappeared when the bilateral sensorimotor cortex for the hind limb had been resected and the lesion cooled is generated by the deep cerebral structures, such as the thalamus or basal ganglia, and U1 originates in the brain stem reticular formation. These results imply definitive differences of the pathophysiological mechanisms between catechol- and urea-induced myoclonus.

Animals↗

PubMedDate not supplied

Smooth tubular aggregates associated with plasmalemmal invagination in alveolar soft part sarcoma.

The ultrastructure of four alveolar soft part sarcomas was examined to search for ultrastructural signs of myogenic or neural origin. A new ultrastructural structure, an unusual tubular structure, was found in two of four cases. The structure appeared as a large, smooth, tubular aggregate in the cytoplasm of some tumor cells but did not show a honeycomb arrangement of tubules. The aggregate was composed of long, serpentine, branching, smooth, irregularly arranged tubules without ribosomes that ran in various directions. The aggregates intermingled with small amounts of cytoplasmic organelles. Because the aggregated tubules were at times continuous with cell membranes, it was shown that they were the complex extensions or invaginations of cell membranes. Neither myelin-axon complexes nor myofilaments, including Z band material, were seen in any case. There was a possibility that the smooth tubular aggregate was a T-tubule-like structure, suggesting that the tumors were derived from skeletal muscle cells.

Cell Membrane↗

PubMedDate not supplied

Involvement of p38 MAP kinase in apoptotic and proliferative alteration in human colorectal cancers.

Mitogen-activated protein kinases (MAPKs) have been thought to be involved in tumor development, and recently implicated in the regulation of apoptosis. We assessed the activation of p38 MAPK and extracellular signal-regulated kinases (ERKs) in human colorectal adenocarcinoma by immunoblotting with antibodies raised against each activated form. We also assessed the alteration of proliferative and apoptotic states, and analyzed the association of p38 MAPK with these alterations. The incidence of p38 MAPK activation in the cancer nucleus was significant (p = 0.0215), while ERKs activation was not significant. Proliferating cell nuclear antigen (PCNA)-labeling index and apoptotic index were increased in all cancer tissues. These findings suggested that p38 MAPK was constitutionally activated and was associated with increased proliferative and apoptotic states in colorectal cancers. Serum-deprivation-induced apoptosis in colonic adenocarcinoma cell line was significantly inhibited by SB203580, a specific p38 MAPK inhibitor, suggesting that apoptosis was mediated by the p38 MAPK pathway.

Adenocarcinoma↗

PubMedDate not supplied

The utility of diffusion-weighted imaging with navigator-echo technique for the diagnosis of spinal epidermoid cysts.

We report a case of a spinal epidermoid cyst in which diffusion-weighted imaging with a navigator-echo technique was useful for the differential diagnosis from other cystic tumors. Motion artifacts are inherent on diffusion-weighted images of the spinal region; however, the navigator-echo technique compensated for this problem and provided high-quality images. Diffusion-weighted imaging with navigator echoes is considered to be a potentially useful tool in the differential diagnosis of spinal cystic tumors.

Adult↗

PubMedDate not supplied

Hepatic resection induces a shift in the Th 1/2 balance toward Th 2 and produces hypermetabolic and hyperhemodynamic states.

BACKGROUND/AIMS: Recent studies have shown that the type 1/2 T-helper (Th 1/2) cell balance is shifted toward a Th 2-type immune response not only by malignancy but also by surgical stress. The present study evaluated surgical stress as a result of liver surgery in comparison with that of other major abdominal surgeries. Immune, metabolic and circulatory responses to surgery were measured for determination of surgical stress. METHODOLOGY: Eighty-five patients who underwent abdominal surgeries were divided into three groups: hepatic resection (n=17), gastric resection (n=38), colorectal resection (n= 30). Blood sampling was performed before surgery, and on postoperative days (POD) 2 and 14. The Th 1/2 helper T cell balance was determined by flow cytometric analysis of interferon-gamma and interleukin-4 expression. Energy expenditure was measured by indirect calorimetry, and hemodynamics was studied using pulse dye densitometry until POD 14. RESULTS: Following surgery Th 1/2 ratios decreased significantly. Additionally, the Th 1/2 balance in patients with hepatic resection on POD 2 was significantly lower than that of patients with other major surgeries. However, on POD 14 there were no significant differences among the three groups. Resting energy expenditure and cardiac index on postoperative days 1 and 3 in patients with hepatic resection increased significantly above levels in the other surgical groups. Conversely, blood volume in the hepatic resection patients was significantly lower than that of other patients until POD 3. Ten patients who developed postoperative complications had significantly lower Th 1/2 ratios and more hypermetabolism. CONCLUSIONS: This study reveals that hepatic resection induces a more marked shift toward a Th 2 helper T cell response and significantly more hypermetabolism than other major surgeries. A distinct pattern of Th 1/2 ratio changes during the early phase of the postoperative course in hepatic resection may be related to changes in metabolism and circulation. Therefore, determination of Th 1/2 balance may be of help in evaluating different surgical procedures, and management of energy intake and circulatory management may be cautiously determined based on the shift in Th 1/2 balance.

Aged↗

PubMedDate not supplied

Postoperative metabolic and circulatory responses in patients that express SIRS after major digestive surgery.

BACKGROUND/AIMS: Systemic inflammatory response syndrome (SIRS) includes a number of pathologic states because of its loose definition. This study assessed differences in metabolic and circulatory host responses in various patients with SIRS perioperatively. METHODOLOGY: Fifty-four patients who underwent abdominal surgeries [gastric resection (n=20), colorectal resection (n=24), hepatic resection (n=8)] were divided into two groups: Group A; SIRS (+) on 1 postoperative day (POD), (n=29), B; SIRS (-) on 1 POD, (n=25). The other eight non-operated patients with SIRS caused by infection were enrolled in Group C, as common SIRS. Indirect calorimetry, body impedance measurement to assess water compartments and pulse dye-densitometry for hemodynamic examination were performed in subjects until 14 POD. RESULTS: The ratio of energy expenditure to basal energy expenditure (%REE) was significantly increased postoperatively, and there were significant differences on %REE from 3 POD to 14 POD between groups A and B. However, %REE in group C was 162+/-23%, which was significantly increased compared with that at 1 POD of groups A (130 +/- 17%) and B (125+/-18%). Cardiac output in group A showed a significant increase until 3 POD compared with that in group B but was significantly lower than that in group C. CONCLUSIONS: Subjects with common SIRS caused by infection were significantly more hypermetabolic than subjects with postoperative SIRS. Adequate energy intake and circulatory management should be cautiously determined according to the severity of SIRS.

Aged↗

PubMedDate not supplied

Postoperative host responses in elderly patients after gastrointestinal surgery.

BACKGROUND/AIMS: The age-associated dysregulation of hemodynamic, metabolic and immune responses contributes to the high incidence of complications after major abdominal surgery. METHODOLOGY: Ninety-five patients who underwent gastric resection (n=51) and colorectal resection (n=44) were divided according to age into Groups A (n=45, less than 70 years old), B (n=30, 70-79 years) and C (n=20, over 80 years). Flow cytometric analysis of CD4+ lymphocytes for interferon (IFN)-gamma and interleukin (IL)-4 production determined the Th1/2 balance. Energy expenditure was measured by indirect calorimetry, and hemodynamics were studied using pulse dye densitometry. RESULTS: Surgical procedures, operating time, blood loss and morbidity did not significantly differ among the three groups. The cardiac index (CI) in group A and B increased significantly over preoperative levels until POD 3, but there were no significant perioperative changes in the CI levels of group C. Resting energy expenditure levels changed similarly to those of CI. The postoperative Th1/2 ratio decreased from young to elderly to very elderly patients, although no differences were significant before surgery. The postoperative percentage of CD4+IFN-gamma +T cells (Th1) in group C decreased significantly despite of no significant changes in that of group A and B. In contrast, the ratio of CD4+IL-4+T cells (Th2) in the all groups significantly increased after surgery. CONCLUSIONS: Host responses in elderly patients after major abdominal surgery were more hyperdynamic and hypermetabolic than those of young patients. Postoperative dysregulation of the Th1/2 balance was also associated with aging. However, host responses appear to significantly differ between elderly and very elderly patients.

Aged↗

PubMedDate not supplied

The long loop reflex in spinocerebellar degeneration and motor neuron disease--its changes with TRH therapy.

This study aimed to define the characteristics of the long loop reflex (LLR) in patients with spinocerebellar degeneration (SCD) and motor neuron disease (MND), and observe changes in LLR caused by thyrotropin releasing hormone (TRH), a facilitator of cerebellar and motor neurons. The markers used for LLR were: V1-2 peak Latency (the latency between the V1 and V2 peaks); V2 peak-P24 Latency (the latency between the V2 peak and P24 of a somatosensory evoked potential); V2 Amplitude, and V2 Square (the area of the V2 wave). V1-2 peak Latency was significantly longer, and V2 Amplitude was significantly lower than the control in SCD. We attributed these alterations of the LLR to cerebellar ataxia, since all SCD cases had cerebellar ataxia, and extrapyramidal symptoms were only present in one SCD case; the MND cases with motor neuron disturbance showed no significant difference from the control. TRH injection resulted in an increase in V2 Square and a decrease in V2 peak-P24 Latency in SCD and other neurological disease patients. We regarded these changes as activation of the LLR by TRH. With TRH therapy, activation of the LLR coincided with improvement of cerebellar ataxia in SCD. Symptomatic improvement, however, was not observed and the LLR changes were not stable in MND. These results suggest that TRH-induced activation of LLR is caused by the activation of cerebellar function, and indirectly concerns with upper motor neurons because V2 Square increased in MND without pyramidal tract signs.

Aged↗

PubMedDate not supplied

Total organic carbon as an index for specification of water for injection.

Determination of organic compounds present as contaminants in purified water is of great importance. Total organic carbon (TOC) may be a useful parameter for evaluating the purity of water. This paper describes and compares the analytical results for solutions of 12 model compounds obtained by 3 methods: total organic carbon (TOC) analysis, determination of potassium permanganate consumption, and UV spectroscopy. TOC analysis gave values corresponding to the expected amounts of organic carbon for all the model compounds, whereas the other 2 methods gave highly variable results.

Carbon↗

PubMedDate not supplied

Exfoliative cytology of a primary adenocarcinoma of the renal pelvis. A case report.

The cytologic features of a primary adenocarcinoma of the renal pelvis in a 64-year-old woman are reported. Cytologic examination of voided urine revealed an ordinary papillary pattern, characterized by clumping of cells with nuclear overlapping, eccentric position of nuclei and cytoplasmic vacuolization due to mucus production. Leukocytes and micro-organisms were also present. Multiple lesions of papillary adenocarcinoma were subsequently found in the right renal pelvis and ureter. The histogenesis of the primary adenocarcinoma seemed to be closely related to columnar-cell metaplasia of lining of the renal pelvis of this patient, who had previously been treated for tuberculosis of the urinary bladder.

Adenocarcinoma↗

PubMedDate not supplied

Cytology and immunohistochemistry of anaplastic meningiomas in squash preparations. A report of two cases.

Cytodiagnosis is a useful adjunct to frozen section diagnosis of brain tumors during surgery and has been applied in many pathology laboratories. Although anaplastic (malignant) meningiomas are not extremely rare tumors, their cytologic features have not been well described. Cytologic details of anaplastic meningioma, papillary meningioma with a fibroblastic component and anaplastic angiomatous meningioma are presented. Papillary meningioma showed atypical cell clusters having a close relation to mature endothelial cells and that corresponded to papillary proliferation. Other cell clusters of this tumor showed an ordinary fibroblastic pattern with coarse cytoplasmic filaments and necrotic changes in the cytoplasm. Anaplastic angiomatous meningioma exhibited loose cell clusters. Some of them had coarse cytoplasmic filaments, and others were similar to epithelial cells in origin. Specific features commonly found in anaplastic meningioma were hyperchromatic and pleomorphic nuclei and cytoplasmic filaments more obscure than those of the benign counterpart. Immunocytochemically the tumor cells in the papillary area of papillary meningioma had a positive reaction to antiserum of vimentin, cytokeratin and S-100 protein. The tumor cells of anaplastic plastic angiomatous meningioma showed intracytoplasmic positivity to antivimentin and anti-epithelial membrane antigen serum.

Adult↗

PubMedDate not supplied

N-methyl-N-nitrosourea-induced photoreceptor apoptosis in the mouse retina.

Retinal degeneration induced by a single intraperitoneal injection of N-methyl-N-nitrosourea (MNU) in male and female albino (GRS/A and DDD/1) and colored (C57BL) mice at 7 weeks of age was examined morphologically 1, 3, 7, 14 and 21 days after the treatment. A dose of 60 mg/kg body weight evoked progressive retinal degeneration in all mice. All albino and colored mice had a comparable progression of photoreceptor cell degeneration by an apoptotic mechanism, as confirmed by morphological and TUNEL methods. Apoptosis had already taken place 1 day after the treatment and was completed by Day 7. This process resulted in a thin remnant of retina with complete loss of photoreceptor cells-21 days after the treatment. During the course of apoptosis, the pigment epithelial cells were maintained in a continuous layer in all strains of mice. In colored mice, several layers of the swollen pigment-enriched cells were seen between the inner nuclear layer and the pigment epithelial layer 14 and 21 days after the treatment. In summary, the destruction of photoreceptor cells by the apoptotic process was the mechanism by which retinal degeneration was induced by MNU.

Animals↗

PubMedDate not supplied

Intensive preoperative chemotherapy for osteosarcoma in the lower extremity.

BACKGROUND: The aims of this study were to investigate the effect, if any, of preoperative chemotherapy and to investigate the adaptation and the limits for achieving a more functional limb in our limb-salvaging procedure. MATERIALS AND METHODS: Since 1983 to 1997 we have treated 53 cases of osteosarcoma in an upper or lower limb at our Institute. According to surgical staging by Enneking, there were 37 cases at stage II B, and 16 cases at stage III. Neoadjuvant chemotherapy was performed according to one or other of our four protocols. RESULTS: The 5-year-survival rate was 68% for those cases at stage II B, and was 13% for those at stage III. In particular, we adopted the protocol involving hyperthermic isolated regional perfusion (HIRP) for those cases in which the lesion affected the knee joint. CONCLUSION: The various protocols of chemotherapy including HIRP were effective to permit reduction in the surgical margin and were also effective to achieve an increase in the limb-salvaging rate and especially effective for increasing the salvaged limb-functionality.

Adolescent↗