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Biomedical subjects

K Hamano

Publications and source records attributed to K Hamano.

At least 127 records · Page 7Linked to original sources
PubMed1997

Relationship between respiratory distress and cytokine response after cardiopulmonary bypass.

The influence of cytokines on the inflammatory response in surgery has recently been the subject of investigations. We measured tumor necrotic factor-alpha (TNF-alpha), interleukin 1 beta (IL-1 beta), interleukin 6 (IL-6), interleukin 8 (IL-8), and granulocyte elastase (GEL) in 26 patients undergoing elective cardiac operations using cardiopulmonary bypass (CPB), preoperatively, immediately after CPB, and on post-operative days (PODs) 1, 3, and 6. To evaluate the effect of these cytokines on pulmonary function, the patients were divided according to whether the oxygenation index (OI) on POD 1 was > 250 or < 250, into groups A and B, respectively. TNF-alpha and IL-1 beta were undetectable and there were no significant differences in the preoperative IL-6, IL-8, and GEL levels. However, immediately following CPB, the mean IL-6, IL-8 and GEL levels in both groups were significantly higher than the preoperative levels (P < 0.01). Moreover, all these levels were significantly higher in group B than in group A, at 162 +/- 150 pg/ml vs 64 +/- 53 pg/ml (P < 0.05) for IL-6; 53 +/- pg/ ml vs 22 +/- 20 pg/ml (P < 0.01) for IL-8; and 2477 +/- 1642 mg/ l vs 1397 +/- 774 mg/l (P < 0.01) for GEL. The IL-6 levels returned to the preoperative values in both groups on POD 1; however, the GEL levels remained significantly higher in group B than in group A postoperatively, at 616 +/- 326 mg/l vs 378 +/- 70 mg/l on POD 1, and at 292 +/- 70 mg/l vs 218 +/- 62 mg/ l on POD 3 (P < 0.05). Thus high levels of cytokines such as IL-6, IL-8, and GEL may be detrimental to respiratory function.

Adult↗
PubMed1997

Modified Bentall operation with concomitant total aortic arch replacement for DeBakey type I aortic dissection: report of a case.

The successful implementation of a reoperative Bentall procedure with concomitant total aortic arch replacement after ascending aortic replacement for acute aortic dissection is infrequently reported. We performed a modified Bentall procedure with total replacement of the aortic arch in a patient suffering from worsening aortic regurgitation (AR) and residual dissection. Our strategy involved the button method for coronary reconstruction, selective cerebral perfusion, the use of a composite graft with four branches for aortic arch replacement, and the administration of high-dose aprotinin to decrease bleeding.

Acute Disease↗
PubMed1997

A video-assisted thoracoscopic surgical technique for interruption of patent ductus arteriosus.

We describe herein a technique for patent ductus arteriosus (PDA) closure using a method of video-assisted thoracoscopic surgical (VATS) interruption derived from video-assisted endoscopic surgery. This technique of repair was performed on five patients with a mean age of 3 years and a mean weight of 13.7 kg during 1994 and 1995. Under general anesthesia, two 10-mm trocars and two or three 5-mm trocars were inserted through the left thoracic wall. A video camera and specially designed surgical tools including scissors, dissectors, and a clip applicator were then introduced. The ductus was dissected, and two titanium clips were applied to interrupt the ductus completely. Successful closure of the PDA by this video-assisted technique was achieved in all patients. The only complication which developed in one patient was hoarseness for 2 weeks postoperatively. The hospital stay ranged from 7 to 12 days and there were no serious complications or deaths. There results indicate that video-assisted thoracoscopic surgical interruption is a safe and effective technique for achieving closure of PDA.

Child, Preschool↗
PubMed1997

The induction of operational tolerance is not prevented by simultaneous administration of cyclosporin A1.

In this study, the effect of combining anti-CD4 monoclonal antibody (mAb) and cyclosporin (CyA) therapy at the time of transplantation was examined. A mouse cardiac allograft model was used. Anti-CD4 mAb administered perioperatively induces long-term survival. The addition of a short course of CyA given subcutaneously in a regimen of either a high-dose treatment or a standard dose treatment to the anti-CD4 mAb treatment protocol did not have a detrimental effect on graft survival. Despite having no significant effect on graft survival, the addition of CyA to the treatment protocol did result in a significant decrease in the level of IL-2 present in the hearts 7 days after transplantation. The decrease in IL-2 production was directly related to the presence of CyA in vivo. When CyA treatment was continued throughout the period during which unresponsiveness to the graft is induced by anti-CD4 mAb therapy, 50% of the grafted hearts were rejected once the CyA was discontinued. In conclusion, the combined use of anti-CD4 mAb therapy and CyA did not have a negative effect on graft survival in this model when the two agents were used concurrently at the time of transplantation.

Animals↗
PubMed1997

Volumetric quantification of brain development using MRI.

We devised a three-dimensional method for estimation of cerebral development and myelination which measures cerebral volume using MRI. Accuracy of the system was estimated using cadaver brains. The mean percentage error in the calculated volumes compared with the real volumes was 2.33%, range 0.00-5.33%. We applied the method to the volume of both cerebral hemispheres (CH), basal ganglia, thalamus and internal capsule (BT), and myelinated white matter (WM) in 44 neurologically normal individuals (4 months to 28 years of age), 13 patients with spastic motor disturbances (2-25 years of age), and 9 patients with athetotic motor disturbances (2-23 years of age). In the neurologically normal cases, the volumes of CH, BT and WM increased with age; the volume of MW more slowly than that of CH. In cases with spastic motor disturbances, the volumes of CH, BT and WM were between -1.4 and 3.5 SD, -1.0 and -3.5 SD, and 0.0 and -5.2 SD respectively, of those of neurologically-normal cases. On the other hand, 7 of the 9 cases with athetotic motor disturbances were within 2 SD of the volume of CH in neurologically normal cases. Our method for direct measurement of cerebral volume based on serial MRI should be useful for the accurate assessment of brain development and quantitative analysis of delayed myelination.

Adolescent↗
PubMed1997

Clinicopathologic study of angiogenesis in Japanese patients with breast cancer.

To evaluate the clinicopathologic significance of angiogenesis as a prognostic factor and the objective methods for evaluating angiogenesis, we immunohistochemically stained a representative section of breast tumors with factor VIII-related antigen staining. There were 109 patients with primary breast cancer from 1971 to 1979. The two methods of identifying angiogenesis were the average microvessel count per square millimeter (AMC) and the highest microvessel count per square millimeter (HMC). There was no relation between microvessel count (AMC or HMC) or age, menopausal status, clinical tumor size (T), histologic classification, nuclear grade, node status, histologic grade (HG), mitosis index, or lymphatic invasion (LI). There was a relation between microvessel count and blood vessel invasion (BVI) (HMC:p = 0.0007) and tumor necrosis (TN) (HMC:p = 0.0050). Univariate analysis showed that AMC or HMC was a statistically significant predictor of overall survival in all patients (p = 0.0086 and p = 0.0307, respectively). Multivariate analysis showed that AMC was an independent predictor of node status when we fitted a model with node status, BVI, and either AMC or HMC; but HMC was not independent. However, when we fitted a model including all 11 of the other indicators and AMC or HMC, the node status, HG, and LI were independent predictors, but AMC and HMC were not. Although AMC was a better method than HMC for evaluating angiogenesis, we cannot confirm angiogenesis as a significant independent prognostic factor associated with long-term survival in Japanese breast cancer patients.

Adult↗
PubMed1997

Evaluation of brain oxygenation during selective cerebral perfusion by near-infrared spectroscopy.

BACKGROUND: Although selective cerebral perfusion (SCP) has been used for cerebral protection in aortic arch operations, the appropriate perfusion conditions of SCP are unclear. METHODS: We used near-infrared spectroscopy, which evaluates brain ischemia noninvasively and continuously, to determine whether perfusion with SCP (core temperature, 20 degrees C; flow rate, 10 mL.kg-1.min-1) was acceptable in terms of oxyhemoglobin and deoxyhemoglobin in patients having SCP for aortic arch operations (SCP group, n = 6) versus patients having cardiopulmonary bypass (CPB) for coronary artery bypass grafting (CPB group, n = 6). RESULTS: There were no significant differences in age (65 +/- 10 versus 63 +/- 12 years), CPB time (199 +/- 67 versus 199 +/- 52 minutes), changes in hematocrit (-12.9% +/- 3.7% versus -12.5% +/- 6.0%), lowest blood pressure (43 +/- 7 versus 45 +/- 10 mm Hg), or highest central venous pressure (8 +/- 2 versus 9 +/- 4 mm Hg) between the SCP and CPB groups. In the SCP group, the maximum decrease in oxyhemoglobin level and the maximum increase in deoxyhemoglobin level were -5.0 to -11.4 mumol/L and -0.1 to 3.9 mumol/L, respectively; in the CPB group, the respective changes were -3.2 to -14.2 mumol/L and -0.4 to 3.6 mumol/L. Changes of oxyhemoglobin and deoxyhemoglobin levels in the SCP group were almost within the range of those in the CPB group. There were no brain complications in either group. CONCLUSIONS: As described here, SCP is acceptable and safe for brain protection in aortic arch procedures.

Adult↗
PubMed1997

Abnormal myelination in a patient with ring chromosome 18.

We describe a Japanese boy with ring chromosome 18 in whom abnormal myelination was observed on magnetic resonance imaging. Cytogenetic investigation revealed 46, XY, r(18) (p11.2 q21.33). T2-weighted magnetic resonance imaging scan of the brain demonstrated high signal intensity consistent with abnormal myelination. Microsatellite marker analysis of DNA demonstrated only one copy of the myelin basic protein gene, derived from the mother. The present case indicates that a hemizygous state for the myelin protein gene may be related to the abnormal myelination.

Brain↗
PubMed1997

Metabolic improvement of poorly controlled noninsulin-dependent diabetes mellitus decreases bone turnover.

Patients with poorly controlled noninsulin dependent diabetes mellitus (NIDDM) are shown to have higher bone mass. However, the influence of changes in glycemic control on bone turnover is not known. To clarify whether metabolic improvement of poorly controlled NIDDM affects bone turnover, markers for glucose, mineral, and bone metabolism were assessed before and after glycemic control for 3 weeks in 78 poorly controlled NIDDM patients with initial hemoglobin A1c over 8%. Metabolic improvement caused a reduction in urinary calcium (Ca) and phosphate (Pi) and serum 1,25(OH)2D levels, and an increase in serum Pi without changes in serum Ca or parathyroid hormone levels. Bone resorption markers, urinary deoxypyridinoline (Dpd) and type I collagen carboxy-terminal telopeptide (CTx), as well as a bone formation marker, serum bone type alkaline phosphatase (BALP), were reduced. However, another bone formation marker, serum osteocalcin (OC), was low before treatment and was elevated after treatment. The decrease in Dpd, CTx and BALP, but not the increase in OC, correlated with each other and with the improvement in glycemic indices. In conclusion, metabolic improvement of poorly controlled NIDDM decreases bone turnover within a short period. Thus, glycemic control may protect NIDDM patients from bone loss. It is possible that serum OC is affected by hyperglycemia per se, and may not correctly reflect bone turnover.

Adult↗
PubMed1997

Cyanamide-induced granulocytopenia.

We report a 64-year-old male with granulocytopenia and dermatitis due to cyanamide treatment. We administered cyanamide for alcoholism. After about one month he suffered from scaly erythema over his whole body and granulocytopenia (granulocyte; 140/microliter) with maturation arrest in bone marrow. After cessation of cyanamide and the start of granulocyte colony-stimulating factor administration, the skin eruption ameliorated gradually, and the peripheral blood granulocyte counts increased. Cyanamide showed positive results in the drug lymphocyte stimulation test (198%) and the patch test led to the diagnosis of granulocytopenia and dermatitis induced by cyanamide. After restarting glibenclamide and diazepam administration, his granulocytopenia did not reoccur. To our knowledge, this is the first report of a case with granulocytopenia induced by cyanamide.

Agranulocytosis↗
PubMed1997

Biological activities of novel zaragozic acids, the potent inhibitors of squalene synthase, produced by the fungus, Mollisia sp. SANK 10294.

Four novel zaragozic acids, F-10863A, B, C and D, were isolated from a culture broth of the fungus Mollisia sp. SANK 10294. F-10863 compounds contain a 4,6,7-trihydroxy-2,8-dioxyobicyclo-[3.2.1]octane-3,4,5-tricarboxyl ic acid core like previously reported zaragozic acids, but the structures of the side chains are different. Recently, it was found that F-10863A is identical to zaragozic acid D3, while the other three are novel compounds. F-10863 compounds are potent inhibitors of squalene synthase like previously reported zaragozic acids, and, furthermore, they exhibit serum cholesterol-lowering activity in vivo.

Animals↗
PubMed1997

[Histopathological effect of neoadjuvant chemohormonal therapy for prostatic cancer].

To improve the therapeutic results in prostatic cancer, radical prostatectomy or total cystoprostatectomy were performed with chemohormonal therapy before operation. Radical prostatectomies were conducted in eight patients with localized prostatic cancer and total cystoprostatectomies in ten patients with severe cystic infiltration. The administration schedule of chemohormonal therapy was as follows: prior to operation, 30-60 mg/sqm/day of etoposide was administered for 7 days every 3 weeks, 250-500 mg/day of diethylbestrol diphosphate for 30 days, and 3.6 mg of LH-RH agonist was also administered. Sixteen of the subjects survived, and were socially rehabilitated (14 cases of NED, 1 case of NC and 1 case of PD) and 2 of the subjects died of cancer. Histopathological findings showed 9 cases of poorly differentiated adenocarcinoma, 4 cases of well differentiated adenocarcinoma and 5 cases of moderately differentiated adenocarcinoma. Histopathological effect of neoadjuvant chemohormonal therapy in surgical specimen showed that 2 of the subjects had grade 0a effect, grade 0b in 7 cases, grade 1 in 5 cases and grade 2 in 4 cases.

Adenocarcinoma↗
PubMed1997

[Influence of cardiopulmonary bypass on lymphocyte function].

It is known that lymphocyte function is impaired after cardiopulmonary bypass (CPB). In this study, the lymphocyte stimulation test (LST) with PHA was used before and after CPB in 28 adult patients, and compared with the surgical parameters and serum cytokine (IL-6, IL-8) levels. LST was impaired after CPB in all patients. Although this value usually recovered by the third postoperative day (POD); (normal group, n = 16), some patients showed prolonged duration of the impaired LST (delayed group, n = 12). Therefore, the parameters of surgery, white blood cell (WBC) count, lymphocytes and subsets, and serum cytokine levels were compared between the normal and the delayed groups. There was no significant difference in the number of WBCs or lymphocytes between these two groups. OKT4-positive cells were reduced on the first POD in both groups, and in the normal group, the number of OKT4-positive cells recovered more quickly than in the delayed group. Serum IL-6 and IL-8 levels in the delayed group were elevated after CPB, and were significantly higher in the delayed group than in the normal group. In conclusion, patients who showed prolonged impairment of lymphocyte function may be partly due to prolonged CPB.

Adult↗
PubMed1996

Evidence that the continued presence of the organ graft and not peripheral donor microchimerism is essential for maintenance of tolerance to alloantigen in vivo in anti-CD4 treated recipients.

The source of donor alloantigen required to maintain tolerance in vivo was evaluated in anti-Cd4 monoclonal antibody (mAb) treated mice. Treatment with a depleting anti-Cd4 mAb at the time of transplantation (day -1,0) induces tolerance to C57BL/10 (H2b) vascularized cardiac allografts in C3H.He (H2k) mice. The presence of the vascularized allograft was found to be essential for the induction of tolerance in this experimental model; it is the only source of donor alloantigen during the induction phase of unresponsiveness (0-50 days). In the maintenance phase (>50 days) donor alloantigen is potentially available from two sources, the organ graft itself or donor cells that have migrated out of the graft and are resident in the periphery (donor microchimerism). We show that the vascularized cardiac allograft is essential for the maintenance of tolerance to donor alloantigen in vivo. When the primary heart graft remained in situ, tolerance to donor alloantigens, as assessed by the survival of a second heart graft, was maintained indefinitely (>250 days) (MST of second C57 heart grafts >100 days). However, when the primary heart graft was removed 50 days after transplantation, a time point when tolerance to donor alloantigens was demonstrable in vivo, tolerance was lost 200 days later (MST of second C57 heart grafts 31 days). No evidence of donor microchimerism in the recipient was obtained using allele specific polymerase chain reaction (pcr) analysis for donor class I antigen. Persistence of donor alloantigen in the form of the vascularized organ graft is therefore required for both the induction and maintenance of tolerance to alloantigen in vivo in this experimental model.

Alleles↗
PubMed1996

Prognostic factors for patients with colon or rectal carcinoma treated with resection only. Five-year follow-up report.

BACKGROUND: The prognostic factors and natural history of recurrence in patients with colorectal carcinoma who underwent curative resection and no other therapy were analyzed. METHODS: The object of analysis was the potentially curative resection only subgroup in the randomized clinical trial (RCT) that we performed. Cox's proportional hazards model was used mainly to analyze recurrence rates during the first 5 years after surgery. RESULTS: The analysis was performed on a subgroup of the RCT (279 patients with colon carcinoma and 293 patients with rectal carcinoma). Five-year disease free survival rates were 76.3% and 56.5% for colon and rectal carcinomas, respectively. The prognostic factors for recurrence for colon carcinoma patients were different from those with rectal carcinoma. For colon carcinoma, only Dukes stage was significant, whereas for rectal carcinoma, Dukes stage, age, location of the tumor, and serosal and venous invasion by cancer cells were prognostic factors. Log-transformed disease free survival rates were linear in Dukes Stage B and biphasic in Dukes Stage C for both colon and rectal carcinoma. The two phases in Dukes Stage C intersected at 2.85 and 3.04 years, respectively. The annual hazard value was high for the first 3 years in both colon and rectal carcinoma. CONCLUSIONS: We conclude that follow-up of patients with colorectal carcinoma who undergo potentially curative resection is of particular importance in the first 3 years after surgery. Furthermore, the usefulness of adjuvant chemotherapy can be adequately evaluated from data yielded during this postoperative period.

Chemotherapy, Adjuvant↗
PubMed1996

A quantitative analysis of rat central nervous system myelination using the immunohistochemical method for MBP.

The temporal order of the myelination of the nervous pathways in 0-42-day-old Wistar rats was quantitatively analyzed using immunohistochemistry with anti-myelin basic protein (MBP) antibody. Immunohistochemistry was performed on paraffin-embedded tissue according to the standard ABC technique. For the objective evaluation of myelination, we converted the level stained with the immunohistochemical method into continuous numbers of 0-256 giving the intensity of myelination, using an image analyzing system. We analyzed nine nervous pathways: corpus callosum, optic tract, internal capsule, spinal tract of trigeminal nerve, inferior cerebellar peduncle, cerebellar white matter, pyramidal tract, medial longitudinal fasciculus, and cuneate fasciculus. The onset of the myelination of the spinal tract of the trigeminal nerve, inferior cerebellar peduncle, medial longitudinal fasciculus and cuneate fasciculus was day 7 (postnatal). That of the corpus callosum, optic tract, internal capsule and cerebellar white matter was day 14, and that of the pyramidal tract was day 21. The time required to reach the level of myelination of day 42 was day 21 for the spinal tract of the trigeminal nerve and the inferior cerebellar peduncle, day 28 for the internal capsule, day 35 for the corpus callosum, optic tract, cerebellar white matter and pyramidal tract, and day 42 for the medial longitudinal fasciculus. Our method using immunohistochemistry with anti-MBP antibody provided a highly sensitive and objective criterion for judging precisely the time and the progress of myelination in each nervous pathway and compare one nervous pathway with another.

Age Factors↗
PubMed1996

Changes of thyrotropin-releasing hormone concentration in the brain and levels of prolactin and thyroxin in the serum during spawning migration of the chum salmon Oncorhynchus keta.

Changes in concentration of thyrotropin-releasing hormone (TRH) in various regions of the brain of female and male chum salmon Oncorhynchus keta during their spawning migration toward the home stream were examined to determine the physiological role of TRH. In the same specimens, serum levels of prolactin (PRL) and thyroxin (T4) were also examined and compared with the change of TRH concentration. TRH concentration in the olfactory bulb of males increased significantly just before the upstream migration or entering the river and dropped after entering the home stream. TRH concentration in the olfactory lobe was also slightly higher in Class 2 salmons with nuptial coloration captured in coastal water than in the other groups. TRH concentrations in hypothalamus and pituitary remained relatively low during the spawning migration. The change of TRH concentration in females was similar to that in males, but was smaller and with a wider range. The serum level of PRL was extremely low in both males and females collected in coastal waters (Classes 1 and 2) and increased after the fish entered the river. The serum level of T4 in both males and females tended to be low, as did the TRH concentration in the hypothalamus and pituitary. Immunohistochemistry of the brain using anti-proTRH serum revealed many proTRH cell bodies in the olfactory bulb and olfactory lobe. These results indicate that TRH in the homing salmon is produced mainly in the olfactory bulb and lobe and that its production may be related to changes in olfactory function during migration.

Amino Acid Sequence↗