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H Hoshi

Publications and source records attributed to H Hoshi.

At least 199 records · Page 11Linked to original sources
PubMed1994

[Rescue effect of 15-deoxyspergualin for acute rejection on heart transplantation--using a rat model].

15-Deoxyspergualin (DSG) attracts a lot of attention as an immunosuppressive drug which has less side effects these days. In the present study, we researched the rescue effect of DSG for acute rejection on heart transplantation (HTX) by using rat models. We performed 40 heterotopic heart transplantation models. We injected them DSG (group A: 5 mg/kg/day, group B: 10 mg/kg/day) intravenously through 3 days, starting from the 3rd day the 4th day, and the 5th day after HTX. Our previous study showed the pathology on the 3rd day after HTX corresponded to mild rejection, the 4th day to moderate rejection, and the 5th day to severe rejection. One day after the injection was completed, the recipients were sacrificed. The rescue effect was histopathologically assessed by H-E stain, and the action mechanism of DSG was considered by immunohistochemical stain using monoclonal antibodies, which were against CD4 positive cells, CD8 positive cells, and macrophages. In result, the rescue effect of DSG was significant in all groups, in comparison with controls, which had no immunosuppression. And the rescue effect of group B was superior to group A. We also found using a immunohistochemical technique, that DSG inhibited the accumulation of CD4 and CD8 positive cells. We concluded the rescue effect of DSG for acute rejection on HTX was significant, especially in 10 mg/kg/day even in the severe rejection. And the suppression of helper and cytotoxic T cells accumulation might be one of the action mechanisms of DSG.

Acute Disease↗
PubMed1993

Direct trophic effects of fibroblast growth factors on rat pancreatic acinar cells in vitro.

We examined the effects of fibroblast growth factors (FGFs) on rat pancreatic acinar cells in primary culture. Both basic and acidic FGF stimulated [3H]thymidine incorporation in a dose-dependent fashion. Maximum effects of 6-7 fold over control were seen with 1 nM bFGF or 100 nM aFGF. These data indicate that FGFs are potent stimulants of rat pancreatic acinar cell DNA synthesis. Therefore, FGFs may play an important role in long term regulation of the exocrine pancreas in vivo. We also examined the interaction of bFGF with the pancreatic secretogogues CCK and carbachol. Effects of CCK, which is itself an acinar cell trophic factor, were additive with those of bFGF. In contrast, carbachol, which has no growth stimulatory effect, did not affect bFGF mediated stimulation of DNA synthesis. These data suggest that the mechanisms involved in acinar cell growth regulation are independent from those involved in secretion.

Animals↗
PubMed1993

Production and characterization of monoclonal antibodies specific for bovine oviductal glycoproteins.

Four monoclonal antibodies (MAbs) were produced in rat cells against materials obtained from the bovine oviduct. The MAbs (1H10, 2A4, 2C5, and 1B12) reacted strongly with the oviductal epithelium of cows in the follicular phase. An immunohistochemical study demonstrated that each of the MAbs bound strongly to the supranuclear cytoplasm of epithelial cells of the oviduct, but not of the stromal cells. Antigens that reacted with the MAbs were characterized by immunoblotting analysis of proteins after fractionation by SDS-PAGE under reducing conditions of oviductal flushings obtained from cows at estrus. All MAbs strongly stained a band of protein with a molecular weight (MW) of 85-97 kD. MAb 1H10 also reacted with the minor band of a 55-kD protein. Similar antigens were not detected in uterine flushings, follicular fluid, and serum. No specific immunohistochemical reactivity with the MAbs was observed with other tissues from the reproductive tract and with nonreproductive tissues. The immunohistochemical reactions were completely eliminated by pretreatment of tissues with trypsin, but not with periodic acid, results that suggest that the antigenic determinants that react with the MAbs were proteinaceous rather than carbohydrate. We have thus established clones that produce 4 MAbs that are specific for oviduct-specific glycoproteins of the cow.

Animals↗
PubMed1993

Time sequential single photon emission computed tomography studies in brain tumour using thallium-201.

Time sequential single photon emission computed tomography (SPECT) studies using thallium-201 were performed in 25 patients with brain tumours to evaluate the kinetics of thallium in the tumour and the biological malignancy grade preoperatively. After acquisition and reconstruction of SPECT data from 1 min post injection to 48 h (1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and 15-20 min, followed by 4-6, 24 and 48 h), the thallium uptake ratio in the tumour versus the homologous contralateral area of the brain was calculated and compared with findings of X-ray CT, magnetic resonance imaging, cerebral angiography and histological investigations. Early uptake of thallium in tumours was related to tumour vascularity and the disruption of the blood-brain barrier. High and rapid uptake and slow reduction of thallium indicated a hypervascular malignant tumour; however, high and rapid uptake but rapid reduction of thallium indicated a hypervascular benign tumour, such as meningioma. Hypovascular and benign tumours tended to show low uptake and slow reduction of thallium. Long-lasting retention or uptake of thallium indicates tumour malignancy.

Brain↗
PubMed1993

Effect of early pregnancy on maternal regional cerebral blood flow.

OBJECTIVE: The purpose of this study was to assess the effect of early pregnancy on maternal regional cerebral blood flow. STUDY DESIGN: We studied 10 pregnant women at 7 to 19 weeks' gestation by the xenon 133 washout technique by means of single-photon emission computed tomography the day before the abortion was induced and then again at a mean of 42.8 days after the abortion. RESULTS: Blood flow in the cerebral hemispheres decreased after the abortion, with a decline of 8.1% (p < 0.001). Each regional decrease was as follows: 7.6% (p < 0.01) in the frontal lobe, 9.1% (p < 0.01) in the temporal lobe, 12.9% (p < 0.001) in the parietal lobe, 9.8% (p < 0.01) in the basal ganglia, and 16.7% (p < 0.001) in the cerebellum. There was no significant difference in blood flow in the occipital lobe before versus after the abortion. CONCLUSION: Maternal regional cerebral blood flow was increased in early pregnancy compared with the nonpregnant state, except in the occipital lobe.

Adult↗
PubMed1993

6-[18F]fluoro-L-dopa metabolism in living human brain: a comparison of six analytical methods.

In 11 normal volunteers and six patients with Parkinson's disease, we compared six different analyses of dopaminergic function with L-3,4-dihydroxy-6-[18F]fluorophenylalanine (FDOPA) and positron emission tomography (PET). The caudate nucleus, putamen, and several reference regions were identified in PET images, using magnetic resonance imaging (MRI). The six analyses included two direct determinations of DOPA decarboxylase activity (k3D, k3*), the slope-intercept plot based on plasma concentration (K), two slope-intercept plots based on tissue content (k3r, k3s), and the striato-occipital ratio [R(T)]. For all analyses, the difference between two groups of subjects (normal volunteers and patients with Parkinson's disease) was larger in the putamen than in the caudate. For the caudate nucleus, the DOPA decarboxylase activity (k3D, k3*), tissue slope-intercept plots (kr3, ks3); and striato-occipital ratio [R(T)] analyses significantly discriminated between the normal volunteers and the patients with Parkinson's disease (p < 0.005) [with least significance for k3* (p < 0.05)], while the plasma slope-intercept plot (K) failed to do so. For the putamen, the values for k3D, k3*, K, k3r, k3s, and R(T) of normal volunteers were significantly higher than those of patients (p < 0.005) [with least significance for K (p < 0.025)]. Linear correlations were significant between k3D and k3s; k3D and k3r; k3D and R(T); and k3D and k3*, in this order of significance. We found no correlation between k3D and K values in the caudate nucleus.

Adult↗
PubMed1993

Cholangioscopic extraction of intrahepatic stones associated with biliary strictures using a rendezvous technique.

Two patients with a severe biliary stricture of one intrahepatic duct and associated intrahepatic stones were successfully treated after dilatation of their stricture by a new endobiliary rendezvous technique with the aid of percutaneous transhepatic cholangioscopy (PTCS). The strictured bile duct was approached from a contralateral percutaneous tract via PTCS and from the diseased duct by introducing a guidewire. This guidewire was then extracted through the other side using a PTCS-guided biopsy forceps to form a communication between both sides which could be used as a pathway for subsequent dilatation. Our technique allows the extraction of intrahepatic stones even in the presence of biliary strictures.

Adult↗
PubMed1993

Levator palpebrae superioris muscle: MR evaluation of enlargement as a cause of upper eyelid retraction in Graves disease.

Sympathetic stimulation of the Müller muscle may be responsible for most of the medically reversible cases of eyelid retraction in patients with Graves disease. The authors studied 21 patients with class I Graves ophthalmopathy (GO), 32 patients with Graves disease without ophthalmopathy (GD), and 12 control subjects. T1-weighted spin-echo magnetic resonance (MR) imaging was performed with a 0.5-T superconducting system. The thickness of the levator palpebrae superioris muscle was determined from sagittal MR images. The thickness of the levator muscles in patients with GD did not differ from the thickness in control subjects, but the levator muscles in patients with GO were significantly thickened (P < .01). The thickness of the levator muscles in patients with GO was significantly greater than in those of patients with GD (P < .01). In 64 orbits of patients with GD, 3% of levator muscles were thickened. In 33 of 40 (83%) orbits of patients with GO presenting with upper eyelid retraction, the levator muscles were thickened. Sagittal MR imaging demonstrated thickening of the levator muscles in patients with persistent upper eyelid retraction. The authors conclude that a thickened levator muscle probably causes upper eyelid retraction in patients with GO.

Adult↗
PubMed1993

Both low- and high-affinity CCK receptor states mediate trophic effects on rat pancreatic acinar cells.

Cholecystokinin (CCK) stimulates the growth of pancreatic acinar cells. However, the molecular mechanisms involved in this trophic action are unknown. CCK binds to both high- and low-affinity receptor states, and these two states appear to activate separate sets of intracellular messengers and have opposite effects on amylase release. JMV-180 is a CCK analogue that interacts in the rat with the high-affinity state as an agonist and the low-affinity state as an antagonist. In the current study, CCK octapeptide (CCK-8) and JMV-180 were tested for their ability to stimulate the growth of rat pancreatic acinar cells in primary culture. CCK-8 stimulated [3H]thymidine incorporation into DNA in a dose-dependent manner. Effects were observed with 0.3 nM, and maximal increases were seen at 3 nM CCK-8 (442 +/- 53% of control, n = 5, P < 0.01). JMV-180 also stimulated DNA synthesis. Effects were noted with 10 nM, and a maximal increase of 267 +/- 82% (n = 4, P < 0.01) of control was stimulated by 100 nM JMV-180. These data with JMV-180 indicate that the high-affinity receptor state for CCK is capable of stimulating DNA synthesis. However, within the same experiment the effects of CCK were always significantly greater than those of JMV-180. To test whether CCK has an additional effect through interactions with the low-affinity state, the effects of a combination of JMV-180 with a maximal dose of CCK-8 were examined. JMV-180 inhibited the maximal effect of CCK-8 in a dose-dependent manner with a maximal inhibition occurring with 1 microM JMV-180. The effects of the combination of 3 nM CCK-8 and 1 microM JMV-180 were no greater than those of JMV-180 alone. Taken together these data indicate that CCK-mediated increases in DNA synthesis in rat pancreatic acinar cells in vitro occur by interactions with both high- and low-affinity receptor states.

Animals↗
PubMed1993

Pronounced ST-segment depression during paroxysmal supraventricular tachycardia.

To determine the clinical significance of ST-segment depression observed in paroxysmal supraventricular tachycardia (PSVT), we evaluated the 12-lead electrocardiogram (ECG) during spontaneous PSVT in 54 patients (27 men and 27 women: mean age +/- SD; 47 +/- 18 years), who came to our clinic for the treatment of PSVT. Coronary angiography was performed in 16 patients (16 to 74 years; mean = 50 +/- 18) and treadmill exercise testing was performed in 21 patients. A cardiac electrophysiological study was carried out in 24 patients. During PSVT, ST-segment score was calculated as the sum of the ST-segment depression in 12 leads. The correlations between the ST-segment score, PSVT rate and age of the patient were analyzed as follows: The most significant positive correlation was observed between the ST-segment score and the PSVT rate (r = 0.615, p < 0.000001). The next most significant correlation was found between the PSVT rate and the age of the patient (r = -0.500, p = 0.00011). A negative correlation was also observed between the ST-segment score and the age of the patient (r = -0.429, p = 0.0012). In 13 of 16 patients, coronary angiography did not reveal any significant (> or = 75% in area) stenosis. Exercise testing induced significant ST-segment depression in 3 patients, of whom two had significant coronary artery lesions. PSVT was due to atrioventricular reentry via an overt (n = 3) or concealed accessory pathway (n = 15), atrioventricular nodal reentry (n = 5) and sinus node reentry (n = 1). In conclusion, patients with a faster PSVT rate revealed more pronounced ST-segment depression than did those with a slower PSVT rate, possibly reflecting the modified repolarization process instead of coronary artery involvement.

Adult↗
PubMed1993

Synthesis and antifungal activity of pradimicin derivatives. Modifications on the aglycone part.

Synthesis and antifungal activity of pradimicin analogs modified on the aglycone part is described. Upon modification studies at various sites of the aglycone part using pradimicin A (PRM A), C-11 position was found to be the sole site to be modified without loosing antifungal activity. Further modification studies at C-11 position were carried out with 11-OH derivative of pradimicin T1 (PRM T1) because of its easy availability. Among the compounds prepared, 11-demethoxy derivative of PRM A (12) and 11-O-ethyl (13) and 11-O-fluoroethyl (14) derivatives of PRM T1 showed promising antifungal activity comparable to that of PRM A.

Antibiotics, Antineoplastic↗
PubMed1993

Thallium-201 SPECT for predicting histological types of meningiomas.

Early and delayed 201Tl SPECT studies were performed on 13 patients with intracranial meningiomas, which were classified in three groups according to their histological types: meningothelial (n = 7); transitional and fibroblastic (n = 3); and malignant types (n = 3). The early uptake indices (UI, ratios of average counts/pixel in the lesion to those of the contralateral area on early images) were relatively high in all types: meningothelial meningiomas, 5.75 +/- 2.16 (mean +/- s.d.); transitional and fibroblastic meningiomas, 4.69 +/- 0.54; and malignant meningiomas, 7.10 +/- 3.72. There were no statistical differences in relation to histological type. The delayed uptake indices were 2.65 +/- 0.89, 3.37 +/- 1.02, and 5.16 +/- 1.62, respectively. Statistically, the delayed UI of meningothelial meningiomas were lower than those of malignant types (p < 0.05). The retention indices (RI, ratios of delayed to early UI) were 0.48 +/- 0.08, 0.79 +/- 0.16, and 0.84 +/- 0.16, respectively. The RI of the meningothelial type were also statistically lower than those of the other two groups (p < 0.05). There were no statistically significant differences between transitional plus fibroblastic types and malignant meningiomas. We conclude that 201Tl exhibits early high accumulations in all types of meningiomas, but its retention rates probably differ according to histological types, and a high retention index is predictive of the malignant potential in a meningioma.

Adult↗
PubMed1993

[A case of intracranial malignant melanoma with increased uptake of IMP in SPECT].

A patient with intracranial malignant melanoma was assessed by 123I-IMP SPECT. Early image, performed 30 minutes after intravenous injection of 111 MBq 123I-IMP, demonstrated an accumulation similar to normal gray matter-defect. Delayed image, performed 4-hour after injection, demonstrated increased accumulation of 123I-IMP. 123I-IMP SPECT, especially delayed scan, was valuable for qualitative diagnosis of intracranial malignant melanoma.

Adult↗
PubMed1993

Further histological observations on popliteal lymph nodes after interruption of the afferent lymphatic vessels.

Lymphatic vessels afferent to the popliteal nodes in young adult rats and guinea pigs were interrupted at the lowest edge of the popliteal fossa, and regressive changes in the nodes occurring 4 to 16 or 18 weeks after surgery were re-examined histologically. In the rat, some popliteal nodes were drained by lymphatic channel(s) from the tail. After surgery, the popliteal nodes without lymphatic channel(s) from the tail underwent regression of all their constituent deep cortical units and also the peripheral cortex comprising lymph follicles, until at 18 weeks, the lymphoid organization of the node reached a minimal level. On the other hand, in popliteal nodes having a lymphatic channel from the tail, some deep cortical units and the overlying peripheral cortex underwent hypotrophy, leaving the remaining units and their overlying peripheral cortex little affected. In the guinea pig, the treated nodes underwent progressive atrophy and ultimately became rudimentary, or even vanished, after 16 weeks. Treated rudimentary nodes were composed largely of stromal cells only, and these were replaced to a various extent by fat. The present results are discussed in relation to complete and incomplete inhibition of the afferent lymph flowing into the surgically treated nodes.

Animals↗
PubMed1993

[Pathological assessments of allografts after heart transplantation using a dog model--allograft vasculopathy].

The pathological findings of allografts after heart transplantation were assessed in long-term period using a dog model. Eight orthotopic heart transplantations were performed with cross-circulation method using a dog. Two dogs survived over 1 year after heart transplantation. One dog died due to cardiac rejection, and the another dog died due to infection at 14 months and 16 months after the transplantation, respectively. The coronary artery morphologic features were assessed in the allografts. The pathological findings showed fibrous intimal thickening with infiltration of lymphocytes and macrophages. And it was diffusely distributed to each area of transplanted heart. The stenosis of coronary lumen was significantly seen in middle size of coronary arteries which was from 100 microns to 50 microns. The characteristics of these findings in comparison with arteriosclerosis change were 1) rapid progression, 2) diffuse fibrous intimal thickening, 3) preserved internal elastic lamia. These findings might be important for treating this complication.

Animals↗
PubMed1993

[Regional cerebral blood flow in the patients with closed-head injury using 123I-IMP SPECT and computed tomography].

123I-IMP SPECT and CT were evaluated in 20 patients with closed-head injury. The detected focal lesions by both examinations were 36. Twenty lesions (55.6%) were seen on both CT and SPECT, and SPECT revealed larger abnormality than CT. Sixteen (44.4%) of 36 lesions were seen only on SPECT. Regional cerebral blood flow (r-CBF) of thirty-one focal lesions were quantified by reference sampling method and compared to r-CBF of the patients without neurological problem. r-CBF of 18 localized lesions accordant with low density area (LDA) on CT were significantly lower than those of 13 lesions seen only on SPECT. And r-CBF of both lesions were significantly lower than that of control patients. Regional cerebral blood flow on the areas with visually normal RI uptake were also significantly lower than that of control group. Regardless of CT findings, some disturbance of r-CBF was considered in patients with head trauma. Therefore the quantification of r-CBF with 123I-IMP SPECT was a useful method for evaluating functional change in those patients.

Adult↗
PubMed1993

[Regional cerebral blood flow in diabetic patients].

N-isopropyl-p-123I-iodoamphetamine (IMP) was used to quantify the regional cerebral blood flow (r-CBF) in 11 diabetic patients (average age; 67.9 years) and 12 non-diabetic subjects (average age; 67.4 years), none of whom had CVD (Cerebrovascular disease) on CT studies. A reference sampling method by continuous arterial blood sampling was used to quantify r-CBF. There were no significant differences in physiological or laboratory data between diabetic and non-diabetic groups except for fasting plasma glucose and HbA1C levels. The average of r-CBF in each region of cerebrum and cerebellum was significantly lower in diabetic group than that in the control group (p < 0.01). These observations show that r-CBF of diabetic patients is reduced, even in the absence of findings of CVD on a CT study.

Aged↗