Biomedical subjects

H Shimazu

Publications and source records attributed to H Shimazu.

At least 37 records · Page 2Linked to original sources

PubMed1996

The community health center and family practice residency training.

Community health centers (CHCs), sponsored by US Public Health Service (USPHS) Section 330, represent successful models of the application of community-oriented primary care principles. Recently, increased interest has been shown in conducting medical education programs in CHCs. The USPHS has tried to facilitate this interest, particularly through its support of establishing linkages between CHCs and family practice residency programs. In this paper, we describe an integrated CHC-family practice residency continuity training clinic program. We discuss the challenges inherent to conducting family practice residency training in the CHC, including the educational content of clinical experiences, the impact of provider productivity expectations, the academic and operational governance of the program, and the financial considerations pertinent to the integrated function of the program. We conclude that while the clinical experiences available in the CHC differ somewhat from mainstream family practice, successful adaptations can be made, and a CHC offers a rich educational environment. We also conclude that the challenges inherent to integrated CHC-family practice residency programs can be successfully addressed. Of great concern, however, are financial considerations relevant to the operation of such integrated programs. These considerations underscore the urgent need for a reassessment of the funding of ambulatory clinical medical education.

Ambulatory Care↗

PubMed1995

Plasma catecholamine and cortisol concentrations during acceleration stress.

Serial changes in catecholamine (CA) and cortisol (Col) concentrations of human subjects exposed to acceleration stress with the vector in the head-foot direction (+ 5Gz for 1 min) were determined using a newly designed continuous blood sampling system. The results demonstrated that the time course changes in noradrenaline (NA), adrenaline (A) and Col concentrations were quite different from each other during and after the Gz exposure. The NA remained relatively unchanged during the exposure, and showed a marked increase at the end of the exposure, peaking at about 110 s after the end of the exposure. The A showed a gradual increase from the start of the exposure and continued to rise during and after the exposure. Its maximal peak was also found at about 110 s after the exposure. The A showed a sevenfold increase, while NA showed only about a threefold increase as high as pre-exposure levels. The more rapid and greater magnitude of increase in A concentration during exposure may have reflected the larger emotional stress and strenuous physical activities involved in the Gz exposure. Heart rate showed a rapid increase upon exposure and remained significantly increased during the exposure; it then showed a transient fall immediately after the exposure, despite the increase in CA. An interesting observation was a decrease in Col during the Gz exposure. A plausible explanation would appear to be the result of an enhanced rate of Col removal from the plasma. From these observations, the importance of serial determination of hormonal excretion during Gz stress for the precise analysis of hormonal response to Gz stress was confirmed.

Acceleration↗

PubMed1995

Site of interaction between saccade signals and vestibular signals induced by head rotation in the alert cat: functional properties and afferent organization of burster-driving neurons.

1. Extracellular spikes of burster-driving neurons (BDNs) were recorded within and immediately below the prepositus hypoglossi nucleus in the alert cat. BDNs were characterized by short-latency activation after stimulation of the contralateral vestibular nerve (latency: 1.4-2.7 ms) and the ipsilateral superior colliculus (latency: 1.7-3.5 ms). Convergence of vestibular and collicular inputs was found in all of 85 BDNs tested. Firing of BDNs increased during contralateral horizontal head rotation and decreased during ipsilateral rotation. A burst of spikes was induced in association with contralateral saccades and quick phases of nystagmus. 2. BDNs showed irregular tonic discharges during fixation. There was no significant correlation between the firing rate during fixation and horizontal or vertical eye position in most BDNs. During horizontal sinusoidal head rotation, the change in firing rate was approximately proportional to and in phase with contralateral head velocity. The phase lag of the response relative to head angular velocity was 13.8 +/- 20.1 degrees (mean +/- SD) at 0.5 Hz and 7.2 +/- 13.5 degrees at 0.2 Hz on the average. The gain was 0.88 +/- 0.25 (spikes/s)/(degrees/s) at 0.5 Hz and 1.19 +/- 0.49 (spikes/s)/(degrees/s) at 0.2 Hz. 3. Quantitative analysis of burst activity associated with saccades or quick phases indicated that the ON direction of BDNs was contralateral horizontal. The number of spikes in the burst was linearly related to the amplitude of the contralateral component of rapid eye movements. The slope of regression line was, on the average, 1.14 +/- 0.48 spikes/deg. There was no significant difference between the mean slopes for saccades and quick phases. The number of spikes depended on the difference between initial and final horizontal eye positions and not on the absolute eye position in the orbit. The mean burst firing rate was proportional to the mean velocity of the contralateral component of rapid eye movements. The slope of the regression line was 0.82 +/- 0.34 (spikes/s)/(degrees/s). Significant correlation was also found between intraburst instantaneous firing rate and instantaneous component eye velocity. 4. Objects presented in the contralateral visual field elicited a brief burst of spikes in BDNs independent of any eye movement. Contralateral saccades to the target were preceded by an early response to the visual stimulus and subsequent response associated with eye movement. 5. Excitation of BDNs produced by stimulation of the ipsilateral superior colliculus was facilitated by contralateral horizontal head rotation. Therefore saccadic signals from the superior colliculus to BDNs may be augmented by vestibular signals during head rotation.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1995

Synthetic studies on condensed-azole derivatives. III. Synthesis and anti-asthmatic activities of C-substituted alkyl side chain derivatives of omega-sulfamoylalkylthioimidazo[1,2-b]pyridazines and related compounds.

A series of novel alkylthioimidazo[1,2-b]pyridazines was synthesized and evaluated for ability to inhibit platelet activating factor (PAF)-induced bronchoconstriction in guinea pigs. Among them, 3-(imidazo[1,2-b]pyridazin-6-yl)thio-2,2-dimethylpropanesulfona mide (15) showed the most potent inhibitory effect. The structure-activity relationships in this series of compounds, in particular, the effects of conversion of the imidazopyridazine ring into other heterocyclic rings, introduction of a substituent group at the 2 or 3 position of the imidazopyridazine ring and introduction of a substituent group into the alkyl side chain, are also discussed.

Animals↗

PubMed1995

[Comparison of CAF plus MPA with CAF plus TAM for advanced or recurrent breast cancer--Kyushu CAFT Study Group of Advanced or Recurrent Breast Cancer].

A multi-center randomized comparison study of CAF + TAM therapy (Arm A) and CAF + MPA therapy (Arm B) in advanced or recurrent breast cancer was conducted at 37 institutions in Kyushu. Out of 119 registered cases, 114 were eligible and 76 were evaluable. The response rate was 42% (15/36) in Arm A and 58% (23/40) in Arm B. In the comparison of side effects, nausea/vomiting and anorexia were significantly less and moon face and body weight gain were significantly more in Arm B. Leucocytopenia was significantly inhibited in Arm B compared with Arm A, which indicated the myeloprotective effect of MPA. These results indicated that CAF + MPA therapy (Arm B) may be more advantageous than CAF + TAM therapy (Arm A) in advanced or recurrent breast cancer.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1994

Hepatocyte growth factor prevents acute renal failure and accelerates renal regeneration in mice.

Although acute renal failure is encountered with administration of nephrotoxic drugs, ischemia, or unilateral nephrectomy, there has been no effective drug which can be used in case of acute renal failure. Hepatocyte growth factor (HGF) is a potent hepatotropic factor for liver regeneration and is known to have mitogenic, motogenic, and morphogenic activities for various epithelial cells, including renal tubular cells. Intravenous injection of recombinant human HGF into mice remarkably suppressed increases in blood urea nitrogen and serum creatinine caused by administration of cisplatin, a widely used antitumor drug, or HgCl2, thereby indicating that HGF strongly prevented the onset of acute renal dysfunction. Moreover, exogenous HGF stimulated DNA synthesis of renal tubular cells after renal injuries caused by HgCl2 administration and unilateral nephrectomy and induced reconstruction of the normal renal tissue structure in vivo. Taken together with our previous finding that expression of HGF was rapidly induced after renal injuries, these results allow us to conclude that HGF may be the long-sought renotropic factor for renal regeneration and may prove to be effective treatment for patients with renal dysfunction, especially that caused by cisplatin.

Acute Kidney Injury↗

PubMed1994

Occult lymph node metastasis in gastric cancer with submucosal invasion.

To evaluate more precisely the incidence of lymph node metastasis in patients with submucosally invaded (sm) gastric cancer, three additional sections were made from the remaining half of 1,794 lymph nodes taken from 57 patients, for a detailed reexamination. Lymph node metastasis was demonstrated in 19 nodes from 11 patients by the initial routine examination; however, the detailed reexamination showed cancer involvement in a further nine lymph nodes from eight patients. Of these eight patients, metastasis had not been detected in any lymph nodes by routine examination in six. Macroscopically, the lesion was of the depressed or mixed type in six of the eight patients. From the intranodal location and growth pattern of the cancer foci, lymph nodes with occult metastasis were divided into the marginal sinus type, the medullary sinus type, and the mixed type, with the marginal type being found most frequently. The overall incidence of lymph node metastasis in patients with sm gastric cancer was as high as 29.8% (17/57) in this series. Moreover, a follow-up study revealed that two patients with occult metastasis died of cancer recurrence postoperatively. Accordingly, systematic regional lymph node dissection should be carried out at the time of surgery for sm gastric cancer.

Adenocarcinoma↗

PubMed1994

Electrical admittance cuff for noninvasive and simultaneous measurement of haematocrit, arterial pressure and elasticity using volume-oscillometric method.

An improved technique based on the electrical admittance cuff was designed for the non-invasive measurement of haematocrit (Hct), together with blood pressure (BP) and arterial elasticity represented as volume elastic modulus (Ev), in human fingers. This device is made of a rigid annular chamber installed with a surrounding thin-walled tube (cuff), which is filled with electrolyte solution. A tetrapolar method is used to detect the admittance signals, both in the solution and in a finger segment placed through the cuff. With this device, it is theoretically shown that the resistivity of blood flowing into the segment is equal to that of the solution multiplied by the ratio of the admittance variation in the solution to that in the segment. Thus, the blood resistivity and therefore Hct can be non-invasively determined from the electrolyte resistivity and these two admittance variations. On the other hand, BP and Ev are also simultaneously measured from the admittance signals following the gradual change of the chamber pressure based on the volume-oscillometric method. Experiments were successfully made in 14 subjects, showing that the indirect Hct values agreed well with the direct values obtained from sampled blood and that this simple technique was significant for the non-invasive ad simultaneous measurement of these physiological variables.

Adult↗

PubMed1994

Inhibition of the increase of intrahepatic Ca2+ by diltiazem in rats with liver ischemia.

The effects of a continuous infusion of a calcium entry blocker, 1, 5-benzothiazepine derivative (diltiazem), on ischemic liver cell damage were studied using quantitative 45Ca-autoradiographic and liquid scintillation techniques. The drug was administered to male Wistar rats as a continuous infusion for 3 h, beginning 30 min before ischemia. Autoradiographic studies showed that 45Ca accumulated in the liver lobuli after 1 h of liver ischemia and 3 h of reperfusion, but the level of 45Ca accumulation was significantly lower in drug-treated rats than in untreated animals. In addition, liquid scintillation studies showed significant differences in the intrahepatic 45Ca contents. These results suggest that diltiazem may inhibit the rise of intracellular Ca2+ due to the flow of extracellular Ca2+ into the cytosol, and may protect the ischemic liver from damage.

Animals↗

PubMed1994

Long-term results of subtotal esophagectomy with three-field lymphadenectomy for carcinoma of the thoracic esophagus.

OBJECTIVE: This study evaluated the impact of aggressive surgery on survival in patients with carcinoma of the thoracic esophagus. SUMMARY BACKGROUND DATA: Prognostic value of lymph-node status for patients with esophageal carcinoma was emphasized, although it is currently under debate whether extensive lymph node dissection improves survival. METHODS: Two hundred ninety-five patients with thoracic esophageal carcinoma were admitted to Kagoshima University Hospital from December 1982 to December 1990. Esophagectomy was performed on 244 (82.7%) of these patients; 106 of whom underwent three-field lymphadenectomy (bilateral cervical, mediastinal, and abdominal regions) were analyzed regarding lymph-node status, tumor recurrence, and the effect of prognostic factors on survival using Cox's proportional hazards model. RESULTS: Hospital mortality and morbidity were 10.4% (11/106) and 65.1%, respectively. Seventy-eight patients (73.6%) had nodal involvement, including 49 patients with abdominal lymph-node metastases and 46 patients with recurrent nerve-node metastases. Five-year survival rates were 54.5% for 16 patients with a solitary nodal metastasis, 30.3% for stage III, 17.4% for stage IV, and 7.2% for 28 patients with six or more metastatic nodes. The most frequent sites of recurrence were the upper mediastinal region and the lung--its incidence increased significantly as the number of positive nodes increased. The most unfavorable prognostic factors included regional or recurrent nerve-node metastasis and patient age of more than 71 years. CONCLUSIONS: Three-field lymphadenectomy, including especially the removal of bilateral recurrent nerve nodes in the cervical region, is essential for improving the survival of patients with carcinoma of the upper two thirds of the thoracic esophagus.

Adult↗

PubMed1994

[An adult of intrathoracic lipoma arising from the chest wall].

A 34-year-old male with intrathoracic lipoma arising from the chest wall is described. Although asymptomatic, the patient was pointed out an abnormal shadow on the chest X-ray film taken at the mass survey. No findings of CT suggested lipoma. The tumor, measuring 2.5 x 2.0 x 1.5 cm in diameter, was surgically removed, and the diagnosis of lipoma was confirmed postoperatively by histopathologic examination.

Adult↗

PubMed1994

[Significance of preservation of tracheal proper sheath at the time of cervical and upper mediastinal lymph node dissection for thoracic esophageal cancer].

Extended lymph node dissection in the neck and upper mediastinum often brings about postoperative pulmonary complications. Since September 1987, we have performed this type of lymph node dissection in 18 patients paying special attention to the preservation of tracheal proper sheath along with left bronchial artery and autonomic nerve branches. We compared their postoperative respiratory and circulatory outcomes with those of 17 patients in whom lymph node dissection was carried out without consideration for these aspects. Tracheal mucosal damage, respiratory functional parameters such as PaO2, AaDO2 and Qs/Qp and actual incidence of pneumonia significantly improved in recent cases undergoing meticulous dissection in the neck and upper mediastinum. However, neither circulatory dynamics nor incidences of recurrent nerve palsy and arrhythmia showed a significant improvement. The postoperative period required for reappearance of cough reflex was shorter in this group of patients, but the difference was not significant. The results indicated that pulmonary disorders occurring frequently after extended lymph node dissection for thoracic esophageal cancer was able to be well controlled by meticulous dissection procedure as mentioned above.

Adult↗

PubMed1993

Correlation of expression of ABH blood group carbohydrate antigens with metastatic potential in human lung carcinomas.

METHODS. The expression of ABH blood group carbohydrate antigens was examined histochemically in tumors and adjacent nontumorous tissues of 89 cases of human lung carcinoma in which nontumorous tissues expressed blood group carbohydrate antigens compatible with the erythrocyte blood group types. RESULTS AND CONCLUSIONS. Loss of ABH blood group antigens in lung carcinomas correlated with their metastatic potential, especially with the recurrence of hematogenous metastasis. Consequently, patients with tumors that retained compatible ABH blood group antigens showed a better prognosis than patients with tumors of altered antigenic profiles. The loss of blood group B antigen more significantly affected both the hematogenous metastasis and prognosis than that of A and H antigens.

ABO Blood-Group System↗

PubMed1993

A new family of heparin-binding growth/differentiation factors: increased midkine expression in Wilms' tumor and other human carcinomas.

Midkine (MK) and heparin-binding growth-associated molecule/pleiotrophin form a new family of heparin-binding growth/differentiation factors. We studied MK gene expression in human tumors. In normal human reference tissues, MK was highly expressed in the mucosal tissue of the small intestine, moderately in the thyroid, weakly in the tissues of the lung, colon, stomach, kidney, and spleen, and not at all in the liver. All of 6 surgically removed specimens of Wilms' tumor highly expressed MK. Also, a moderate to intense level of MK expression was noted in the majority of surgically removed hepatocellular carcinomas. The MK mRNA level was analyzed in a number of cultured and nude mice-transplanted lines of human tumors. In stomach, colon, pancreatic, lung, and esophageal carcinomas, a moderate to high level of MK expression was found in the majority of them. These results suggest an important role of MK in the development and/or biological behavior of tumors and raised a possibility to use MK as a diagnostic marker. Heparin-binding growth associated molecule/pleiotrophin mRNA was low or scarcely detectable in samples analyzed thus far except for significant levels of the expression that were observed in PA-1 teratocarcinoma cells and in some surgical specimens of Wilms' tumor.

Base Sequence↗

PubMed1993

Inflammatory pseudotumor of the spleen: report of a case.

A case of an inflammatory pseudotumor arising in the spleen of a 60-year-old Japanese male is described herein. This benign lesion is extremely rare, with only 12 cases, including our own, having been reported in the world literature. We preoperatively diagnosed the splenic tumor as a metastasis, due to the coexistance of advanced stage carcinoma in the sigmoid colon. However, after splenectomy, histopathological examination of the mass revealed an inflammatory process. Inflammatory pseudotumors often pose diagnostic difficulties because the clinical and radiologic findings are suggestive of malignancy. The clinical and pathological features of cases previously reported are reviewed following the presentation of this case.

Adenocarcinoma↗

PubMed1993

Hepatocellular carcinoma coexistent with adenomatous hyperplasia: report of a case.

We would like to draw attention to hepatic tumor-like lesions which frequently complicate the differential diagnosis of hepatocellular carcinoma (HCC), while considering their pathology and diagnosis by radiographic imaging. In particular, adenomatous hyperplasia is recognized as a precancerous lesion of HCC, and the relationship between adenomatous hyperplasia and the multicentric development of HCC is recognized. We observed a patient who demonstrated hyperplastic changes in both the liver cells and a well-differentiated HCC lesion adjacent to the adenomatous hyperplasia, suggesting a multicentric development of the HCC. The histopathological features of adenomatous hyperplasia are also described.

Carcinoma, Hepatocellular↗

PubMed1993

Modified pancreaticogastrostomy following pancreaticoduodenectomy.

A modified pancreaticogastrostomy without gastrotomy was performed in 46 patients undergoing pancreaticoduodenectomy for malignant or benign disease. Postoperative complications related to the modified pancreaticogastrostomy occurred in one patient (2%). Operative mortality was 4% and was unrelated to the pancreaticogastrostomy itself. During the first postoperative year, four patients died of causes unrelated to the original disease process, and nine patients died of recurrent carcinoma. The remaining 31 patients were alive and well at a mean follow-up of 20 months. Results of postoperative gastroscopy were normal in all patients studied. A modified pancreaticogastrostomy without gastrotomy is a safe and effective procedure for pancreatic reconstruction in pancreaticoduodenectomy.

Adult↗

PubMed1993

Ischemic liver cell damage and calcium accumulation in rats.

Regions of calcium accumulation were studied by 45Ca-autoradiography and microdensitometry during liver ischemia and reperfusion in rats. In autoradiographic studies 45Ca accumulated in all zones of the liver lobuli after 1-2 h of liver ischemia and 1, 3 and 6 h of reperfusion, but did not accumulate in non-ischemic liver lobes. Significant 45Ca accumulation occurred only with reperfusion after 1 or 2 h of liver ischemia. In the presence of reperfusion, 45Ca accumulation correlated with the length of ischemia. In histopathologic studies, liver necrosis was absent in lobuli after 1-h reperfusion. Some liver necrosis was observed in the group reperfused for 3 h and widespread liver necrosis appeared after 6-h reperfusion. Regions of 45Ca accumulation coincided with sites of microscopic liver cell damage and necrosis. These results suggested that calcium accumulation might be responsible for the liver cell damage induced by ischemia with reperfusion, that the intensity of calcium accumulation in 45Ca-autoradiograms indicates the degree of ischemia damage, and that the primary event leading to hepatocellular necrosis might be calcium accumulation and subsequent liver cell death.

Animals↗