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Biomedical subjects

K Yamaguchi

Publications and source records attributed to K Yamaguchi.

At least 631 records · Page 35Linked to original sources
PubMed1998

[Pulmonary emphysematous changes associated with Pneumocystis carinii pneumonia in an AIDS patient].

A 60-year-old man was admitted to our hospital complaining of non-productive cough. He had worked in Africa and received a blood transfusion after a traffic accident in 1985. On admission, the patient had remarkable hypoxemia and a decreased CD4+ lymphocyte count. A serological test for human immuno-deficiency virus (HIV)-1 was positive. His chest radiographs showed diffuse reticular and linear opacities, and broncoalveolar lavage findings established a diagnosis of Pneumocystis carinii pneumonia (PCP). A high-resolution CT of the chest revealed peripheral infiltrates and low attenuation areas (LAA) consistent with severe emphysematous alterations. We administered high-dose methylprednisolone and trimethoprim-sulphamethoxazole (TMP-SMX). Because of marked eosinophilia, TMP-SMX was discontinued, and the patient was given inhaled pentamidine isothiocyanate. Although there was a striking clinical improvement, the emphysema-like lesion on chest CT remained unaltered. LAA on CT had been modest in 1994, but had markedly enlarged during the three years thereafter, leading us to speculate that most of the LAA lesions recognized on admission might have developed in association with PCP. Pulmonary function tests showed an obstructive ventilatory defect and impaired diffusing capacity. Although PCP classically presents with diffuse ground-glass or fine granular opacities, thin-walled cavities or other atypical findings have recently been reported, especially in AIDS patients. There have been several reports about emphysema-like lesions associated with PCP. It was suggested that these lesions might be due to lung parenchyma destruction induced by HIV itself or increased elastase release from HIV-infected macrophages. This is the first report of PCP with pulmonary emphysematous lesions in Japan.

AIDS-Related Opportunistic Infections↗
PubMed1998

Pancreatic carcinoma in remnant pancreas after pancreatectomy for mucinous cystadenoma.

There are very few benign or malignant diseases which arise in the remnant pancreas after pancreatectomy. Pancreatic carcinoma in the remnant pancreas after pylorus preserving pancreatoduodenectomy (PpPD) for mucinous cystadenoma in a 66-year-old Japanese man is reported in this paper. The patient underwent PpPD for a mucinous cystadenoma in the pancreatic head 39 months prior to the present operation. The surgical margins of the PpPD specimen were free from atypical cells. Follow-up ultrasonography revealed a hypoechoic lesion in the body of the remnant pancreas. Magnetic resonance cholangiopancreatography (MRCP) revealed a stenosis of the main pancreatic duct, with upstream dilatation in the remnant pancreas. Segmental resection of the remnant pancreas, splenectomy, pancreaticojejunostomy and intraoperative radiotherapy were performed under the diagnosis of pancreatic carcinoma of the remnant pancreas. Final histopathological diagnosis was adenocarcinoma of the pancreas. There were no malignant cystic components. The present pancreatic carcinoma was regarded as independent of the previous mucinous cystadenoma. Postoperative radiation therapy and chemotherapy were added. He is doing well 20 months after the second operation although diabetes mellitus has slightly deteriorated. In this communication, we would like to recommend that clinicians should constantly be on guard against the development of pancreatic carcinoma even in the remnant pancreas after pancreatectomy for mucinous cystadenoma.

Adenocarcinoma↗
PubMed1998

[Mechanism of the development of organ failure].

Multiple organ failure (MOF) is a critical condition developing in patients with overwhelming bodily injury resulting from major surgical insult, severe trauma, extensive burns, acute pancreatitis, and sepsis. It has recently become evident that the host response to such injury is the main pathogenetic factor contributing to the development of MOF. The proinflammatory cytokines tumor necrosis factor (TNF) and interleukin (IL)-1 are known to play a pivotal role in the pathogenetic mechanisms of MOF. In response to bodily injury, macrophages produce and release TNF and IL-1, which subsequently induce the production of other cytokines (IL-6, IL-8, etc.) and other endogenous chemical mediators. The resultant systemic inflammation may develop into MOF mainly through neutrophil-endothelial cell interaction when the primary injury is overwhelming or a second inflammatory insult such as sepsis triggers an exacerbated inflammation. It has recently been confirmed that the transcription factor NF-kappaB is involved in the up-regulation of a variety of proinflammatory genes and that cell-mediated immunity is down-regulated in the event of major bodily injury through a shift in the balance between T helper 1 (Th1) and Th2 cytokine response patterns. The molecular immunological mechanisms by which these factors participate in the development of MOF should be characterized.

Humans↗
PubMed1998

[Legionella pneumonia--epidemiology, clinical characteristics and development of diagnosis].

We have characterized clinical and diagnostic features in 18 cases of Legionella pneumonia. Age average of patients was 62.0 years old (male: female = 14:4) and underlying diseases were observed in 12 patients. Legionella pneumonia were diagnosed in 3, 5, 7 and 9 cases by culture, serum antibody measurement, urinary antigen detection and PCR, respectively. Sixteen cases were caused by L. pneumophila, while the other 2 cases were due to L. bozemanii and L. pneumophila or L. dumoffii. Chest X-rays of those patients showed multiple pneumonia shadows in 14 cases, alveolar shadows in 10 cases, pleural effusion in 5 cases. Blood-gas analysis on admission indicated hypoxemia in all cases with abnormal A-a DO2. Laboratory findings showed abnormal data in WBC, CRP, LDH, CPK and liver function tests (ex. GOT, GPT) in most cases. Serum antibody testing showed positive by 5 weeks after onset of pneumonia, but 10 cases of Legionella pneumonia diagnosed by other techniques were judged to be negative. In urinary antigen detection test, 6 and 2 cases showed positive 1 and 4 weeks after onset of pneumonia, respectively. Macrolide antibiotics were administered in all cases during the episode, but delay of macrolide administration was observed in 3 of 4 cases of dead outcome. Serum antibody measurement, urinary antigen detection and PCR, in addition to culture of bacteria, may be required for exact diagnosis of Legionella infection.

4-Quinolones↗
PubMed1998

Edema along the optic tract: a useful MR finding for the diagnosis of craniopharyngiomas.

BACKGROUND AND PURPOSE: The pattern of edema caused by craniopharyngiomas and other common suprasellar masses could be useful for determining the differential diagnosis of lesions in this region. The purpose of this study was to ascertain whether the pattern of edema spread on MR images can be used in the diagnosis of craniopharyngiomas. METHODS: The preoperative MR images in eight consecutive patients with craniopharyngiomas, 15 patients with large pituitary adenomas compressing the optic chiasm, and six patients with tuberculum sellae meningiomas were evaluated. All the patients were treated surgically at our hospital and a pathologic diagnosis was obtained. We analyzed the spread of edema surrounding the tumor on the coronal dual-echo fast spin-echo images and compared this finding with tumor location and size as seen on contrast-enhanced T1-weighted images. RESULTS: Not only peritumoral edema but also edema spreading along the optic tracts was observed in five patients with craniopharyngiomas, one of whom also had edema within one optic nerve. The location of edema in the visual pathway was not always associated with the degree of visual disturbance. None of the patients with large pituitary adenomas or with tuberculum sellae meningiomas had such edema along the visual pathway. CONCLUSION: Edema caused by craniopharyngiomas tends to spread along the optic tracts. It is a useful MR finding for distinguishing craniopharyngiomas from other common parasellar tumors.

Adult↗
PubMed1998

Preoperative exocrine pancreatic function predicts risk of leakage of pancreaticojejunostomy.

BACKGROUND: The objective of this study was to clarify the relationship between preoperative exocrine pancreatic function and pancreatic anastomotic leakage after pancreatectomy. METHODS: Fifty-five patients who underwent proximal pancreatectomy with pancreaticojejunostomy were reviewed with regard to preoperative exocrine pancreatic function, size of the main pancreatic duct, postoperative pancreatic juice output, and pancreaticojejunostomy leakage. RESULTS: There were 32 patients with a normal value at the preoperative N-benzoyl-L-tyrosyl-p-aminobenzoic acid (BT-PABA) excretion test (> 70%) and 23 with a low BT-PABA value (< or = 70%). The greatest diameter of the main pancreatic duct in the group with normal BT-PABA results was significantly smaller than that in the group with low BT-PABA results (4.6 +/- 2.7 mm vs 7.1 +/- 4.2 mm; P < .05). The output of pancreatic juice during a 10-day period (from postoperative days 5 through 14) in the group with normal BT-PABA results was significantly higher than that in the group with low BT-PABA results (1738 +/- 898 mL vs 1072 +/- 1174 mL; P < .05). Pancreatic leakage occurred in 8 (25%) of the 32 patients in the group with normal BT-PABA results and in none of the 23 patients in the group with low BT-PABA results (P < .01). CONCLUSIONS: Patients with normal exocrine pancreatic function produce a larger amount of pancreatic juice than those with low exocrine pancreatic function and have a potential risk of anastomotic leakage after pancreatectomy.

4-Aminobenzoic Acid↗
PubMed1998

[A case of vertebrobasilar dissection which was associated with progressing stroke and was successfully treated by intravascular surgery in the acute stage].

A case of vertebrobasilar dissection which deteriorated in the acute stage and was successfully treated by intravascular surgery is described. A 26-year-old male presented with sudden onset of occipitalgia, weakness of the right upper and lower extremities, and speech disturbance. He was transferred to our hospital 3 hours after the onset. On admission, neurological examination showed right hemiparesis including the face and dysarthria. CT of the head showed no definite abnormality and left vertebral angiograms (VAG) revealed only slight wall irregularity of the basilar artery. T2-weighted MR imaging demonstrated an area of high intensity in the left side of the pons. He was treated conservatively under a diagnosis of pontine infarction. On the 8th hospital day, he developed left hemiparesis. T2-weighted MR imaging revealed a new high intensity lesion in the opposite side of the pons. 3D-SPGR images showed double lumen of the left vertebral artery. Angiography showed that the wall irregularity of the basilar artery had become more obvious. These findings strongly suggested a dissection extending from the left vertebral artery to the basilar artery. Progression of the dissection was presumed to have caused the worsening in clinical symptoms, and further progression of the dissection would involve perforators of the basilar artery top and would be fatal. To prevent further progression of the dissection, the left vertebral artery was occluded at the proximal site of the orifice of the dissection with platinum coils after a test occlusion on the same day. Postoperatively, further deterioration of the clinical symptoms ceased. Left VAG on the 33rd postoperative day demonstrated improvement in the wall irregularity of the basilar artery. His clinical symptoms improved markedly and he was ambulatory at discharge and returned to his previous occupation. We emphasize that a progressive vertebrobasilar dissection that causes clinical deterioration in the acute stage can be prevented from progressing further by occlusion at the proximal site of the orifice of the dissection.

Adult↗
PubMed1998

[A case of orbital mesenchymal chondrosarcoma].

A 22-year-old male presented with proptosis of his right eye of one month's duration. No abnormalities were present regarding visual acuity, ocular motility, or fundus findings. Systemic examinations gave negative results. An orbital tumor, 25 mm in size, was detected by computed tomography and magnetic resonance imaging in the affected side. The tumor was located nasal-posterior to the eyeball and appeared to be in apposition with the orbital floor. The tumor was removed through a maxillary sinus approach. Histopathological studies led to the diagnosis of extraskeletal mesenchymal chondrosarcoma. To the best of our knowledge, this is only the fifth case reported in Japan of mesenchymal chondrosarcoma. Originating in the orbit.

Adult↗
PubMed1998

[Discrepancy between 99mTc-HMPAO and 99mTc-ECD in Alzheimer's disease: does the retention mechanism depend on the disease?].

The discrepancy between 99mTc-hexamethyl-propyleneamine oxime (HMPAO) and 99mTc-ethyl cysteinate dimer (ECD) in Alzheimer's disease (AD) was investigated and compared with in cerebral ischemic disease (CID). The subjects were fourteen AD and thirty-one CID patients with clinically reasonable rCBF reduced lesion on 133Xe SPECT. The subjects did not include the cases of acute and subacute CID. These SPECT were performed within two weeks by ring-type dynamic SPECT (HEADTOME, Shimadzu, Japan). In the CID group, both of HMPAO and ECD SPECT could hardly detect the mildly reduced rCBF lesion on 133Xe SPECT but normal on X-CT. In the case of AD group, the rCBF-reduced lesion on 133Xe SPECT could be detected well by ECD SPECT, but the HMPAO hardly detected the reduced lesion. This discrepancy between HMPAO and ECD may be due to the difference of the retention mechanism. In the case of AD, the injury of esterase activity that participates with the ECD retention may be more notable than that of glutathione activity for the HMPAO retention. These results suggest suggest that the reduction of ECD or HMPAO density depends directly on the insufficiency of retention mechanism rather the than rCBF reduction. And the insufficiency of this retention mechanism depends on also type of the disease i.e. AD or CID.

Alzheimer Disease↗
PubMed1998

[Improved the accuracy of 99mTc-MAG3 plasma clearance method: the problem of the calculated plasma volume and its modification].

The 99mTc-MAG3 plasma clearance method (MPC method), reported by Oriuchi et al., is a simple and useful count-based gamma camera method for calculating the 99mTc-MAG3 plasma clearance (CLMAG). However, a discrepancy of CLMAG calculated by MPC method (MPC-CLMAG) from the tubular extraction rate (TER) calculated by Russell's single-sample clearance determination (Russell-TER) was noted. The calculated plasma volume is assumed to be the cause. Since the plasma volume is reported to have a linear correlation with body surface area, Dissmann's formula was applied to calculate the plasma volume. Then Dissmann's formula was replaced by Ogawa's formula in the MPC method, and the procedure was then called the modified MPC method. The CLMAG were obtained using MPC method, modified MPC method and the TER was obtained Russell's method in 95 patients with urological disorders. Then the MPC-CLMAG and modified MPC-CLMAG were compared with Russell-TER. Comparison of the MPC-CLMAG with the Russell-TER demonstrated a coefficient of correlation of 0.82, but dissociation of the slope of regression lines was found between males and females. The modified MPC-CLMAG improved the coefficient of correlation to 0.92, and diminished the dissociation of the slope of regression lines between males and females. We verified that the dissociation was due to the plasma volume calculated by Ogawa's formula. Ogawa's formula included hematocrit, body weight, body height and different coefficients for gender. The plasma volume calculated by Ogawa's formula were lower in males and higher in females than that calculated by Dissmann's formula. And marked discrepancy in the plasma volume in patients with a body surface area below 0.5 m2 was observed. So the MPC method might become more accurate by substituting Dissmann's formula for Ogawa's formula resolting in a method that is applicable to both males and females, children and adults in clinical use.

Adolescent↗
PubMed1998

[Leiomyosarcoma of the prostate: report of two cases].

We herein present two cases prostatic leiomyosarcoma. The first case was in a 45-year-old man who presented at our department with the chief complaints of pain on voiding and pollakisuria on November 13, 1996. Ultrasonography and computed tomographic (CT) scan revealed a prostatic tumor. A histological examination of biopsy specimens revealed leiomyosarcoma of the prostate. Total prostatectomy and partial cystectomy were performed. No adjuvant therapy was performed. He is still alive without disease 12 months after operation. The second case was in a 63-year-old man who was admitted to our hospital for treatment of a lung tumor and colon polyp on February 28, 1997. CT scans showed a large prostatic tumor and multiple tumors in the lung, liver and bilateral kidneys. He was referred to our department for evaluation of the prostatic tumor. A transrectal needle biopsy of the prostate for histological diagnosis revealed leiomyosarcoma. No treatment was performed and he died 3 months later. In addition, 57 cases of prostatic leiomyosarcoma collected from the Japanese literature are also reviewed.

Cystectomy↗
PubMed1997

Substitution of the urease active site carbamate by dithiocarbamate and vanadate.

Urease possesses a dinuclear nickel active site with the metals bridged by a carbamylated lysine residue. In vitro activation of apoprotein (Apo) is achieved by incubation with Ni(II) and bicarbonate as a source of CO2. Analogues of CO2 and bicarbonate were examined for their effects on the Apo activation process. While SO2 had little effect, CS2 was shown to inhibit Apo activation via its ability to substitute for CO2 to yield an inactive dithiocarbamate-containing protein. Sulfur-to-Ni charge-transfer transitions arising from this species yielded an electronic absorption band at 324 nm with a shoulder at 382 nm. Borate, sulfate, phosphate, and molybdate had essentially no effect on Apo activation and did not substitute for bicarbonate, while treatment of Apo with Ni(II) plus vanadate led to the production of active urease containing two Ni and one V per active site. Vanadate-dependent activation of Apo resembled the normal activation process in terms of concentration of anion required, optimal pH, and incubation time needed. Furthermore, the UV-visible spectrum, maximal specific activity [386 +/- 26 U.(mg of protein)-1], Km (1.83 +/- 0.20 mM urea), and pH dependence for the vanadate-containing urease were essentially identical to properties observed for bicarbonate-activated enzyme. Vanadate-activated Apo is proposed to possess a vanadylated lysine that bridges the two Ni ions comprising its metallocenter.

Binding Sites↗
PubMed1997

Proliferation of adult T cell leukemia/lymphoma cells is associated with the constitutive activation of JAK/STAT proteins.

Human T cell leukemia/lymphotropic virus type I (HTLV-I) induces adult T cell leukemia/lymphoma (ATLL). The mechanism of HTLV-I oncogenesis in T cells remains partly elusive. In vitro, HTLV-I induces ligand-independent transformation of human CD4+ T cells, an event that correlates with acquisition of constitutive phosphorylation of Janus kinases (JAK) and signal transducers and activators of transcription (STAT) proteins. However, it is unclear whether the in vitro model of HTLV-I transformation has relevance to viral leukemogenesis in vivo. Here we tested the status of JAK/STAT phosphorylation and DNA-binding activity of STAT proteins in cell extracts of uncultured leukemic cells from 12 patients with ATLL by either DNA-binding assays, using DNA oligonucleotides specific for STAT-1 and STAT-3, STAT-5 and STAT-6 or, more directly, by immunoprecipitation and immunoblotting with anti-phosphotyrosine antibody for JAK and STAT proteins. Leukemic cells from 8 of 12 patients studied displayed constitutive DNA-binding activity of one or more STAT proteins, and the constitutive activation of the JAK/STAT pathway was found to persist over time in the 2 patients followed longitudinally. Furthermore, an association between JAK3 and STAT-1, STAT-3, and STAT-5 activation and cell-cycle progression was demonstrated by both propidium iodide staining and bromodeoxyuridine incorporation in cells of four patients tested. These results imply that JAK/STAT activation is associated with replication of leukemic cells and that therapeutic approaches aimed at JAK/STAT inhibition may be considered to halt neoplastic growth.

Adult↗
PubMed1997

Enhancement of synaptic transmission by HPC-1 antibody in the cultured hippocampal neuron.

To clarify the function of HPC-1/syntaxin 1A in the mammalian central synapse, the effects of intracellularly applied antibody on the synaptic transmission were examined at the autapse of the cultured rat hippocampal neuron. Intracellularly applied antibody against HPC-1/syntaxin 1A (IgG, 0.3 mg ml(-1)) during whole-cell recording enhanced the autaptic excitatory postsynaptic current (EPSC). Pre-immune IgG (0.3 mg ml(-1)) showed no effect. The amplitude-distribution of an asynchronous EPSC was not affected by administration of this antibody, indicating that the increase in the amplitude of the evoked EPSC was attributable to an increase in transmitter release from the presynaptic terminal HPC-1/syntaxin 1A could be involved in suppressing as well as facilitating process of the exocytosis at the mammalian central synapse.

Animals↗