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Biomedical subjects

K Suga

Publications and source records attributed to K Suga.

At least 145 records · Page 8Linked to original sources
PubMed1995

Modeling of penicillin G hydrolysis to 6-APA in an immobilized enzyme-ion exchange system.

A composite system of an immobilized enzyme reactor combined with an ion exchange column was employed for hydrolysis of penicillin G to 6-APA with continuous removal of PAA. In this study, a mathematical model of penicillin G hydrolysis to 6-APA in the composite system was developed based on the compartment model, the profile of concentration in the ion exchange column, and the enzyme kinetics in the immobilized enzyme reactor. After checking the simulation values and experimental data, the effects of the resin volume, the flow rate, and the switching time on the time required to reach the desired conversion rate was also examined by computer simulation.

Bacillus megaterium↗
PubMed1995

Utilization of dietary protein in the vitamin B12-deficient rats.

Utilization of dietary protein in vitamin B12 (B12)-deficient rats was evaluated by determinating the content of plasma protein, urinary excretion of nitrogen compounds, and nitrogen-balance after the rats were fed on a B12-deficient soy bean protein diet by pair-feeding for 100 days. The severe B12-deficiency was confirmed in rats by a remarkable increase in urinary methylmalonic acid excretion and a remarkable decrease in the hepatic B12 level. Growth of B12-deficient rats was significantly retarded as compared both with ad libitum-feeding control rats and pair-feeding control rats. The growth retardation due to B12-deficiency was alleviated by the administration of 1 microgram/day of CN-B12 for 30 days. Plasma total protein and albumin levels in rats fed on a B12-deficient diet decreased, compared with those in pair-feeding control, and increase in urea-nitrogen was observed. The excretion of urinary nitrogen compounds, such as urea-nitrogen, allantoin, and creatinine, was significantly depressed by B12-deficiency compared with those in pair-feeding control. The administration of CN-B12 to B12-deficient rats for 30 days resulted in the recovery of the changes in plasma proteins and urinary excretion of nitrogen compounds. The above results suggested that the extreme B12-deficiency depressed the utilization of dietary protein in rats. Moreover, the decrease in urinary urea-nitrogen excretion was supposed to be due to the adaptation by the depression of the dietary protein utilization.

Animal Nutritional Physiological Phenomena↗
PubMed1994

[Regional pulmonary Xenon-133 washout study using dynamic SPECT images obtained by a triple-headed SPECT system].

We investigated preliminary the clinical utility of dynamic SPECT in studying pulmonary Xenon-133 gas washout, using the continuous repetitive rotating acquisition method with a triple-headed SPECT system. The subjects included one healthy volunteer and 16 various lung diseases. After obtaining the equilibrium images, the sequential washout images were acquired every 60 sec for 6 min. As the ventilation index, the real half-time of regional activity was evaluated. With or without abnormalities on chest CT, these images allowed us to show effectively the three-dimensional distribution of ventilation abnormalities, such as peripheral or segmental air trapping.

Humans↗
PubMed1994

Clinical importance of extraordinary integration patterns of human T-cell lymphotropic virus type I proviral DNA in adult T-cell leukemia/lymphoma.

The proviral DNA of human T-cell lymphotrophic virus type I (HTLV-I) is known to be integrated monoclonally in the malignant cells of adult T-cell leukemia/lymphoma (ATL), which is a peripheral T-cell malignancy caused by this virus. We studied the relationship between the integration patterns of HTLV-I and clinical characteristics in 89 patients with ATL. The proviral DNA of HTLV-I was examined by the standard Southern blot analysis using the endonucleases EcoRI and Pst I. One clear band of greater than 9 kb was detected in most of the patients (83 case) when cellular DNA was digested with EcoRI. On the other hand, extraordinary integration patterns of HTLV-I proviral DNA were detected in 6 patients; 3 of them showed two bands, while the other 3 showed one band smaller than 9 kb. When cellular DNA was digested with PstI, the band patterns of these patients were quite different from those of typical patients. The patients with the extraordinary integration patterns had clinical characteristics dissimilar to those of the other 83 patients with the ordinary integration pattern. The patients with two bands by EcoRI digestion always had severe hypoxemia with extremely high levels of serum lactate dehydrogenase at first presentation and showed peculiar organ infiltrations, such as retina and muscle, which were less frequent in the other ordinary 83 patients. They all died within 8 months after the onset. In contrast, the patients with one smaller band by EcoRI digestion always had small and mature T lymphocytes with bilobulated nuclei without lymphadenopathy and showed a favorable clinical course, which was uncommon in the ordinary cases. They were alive 20 to 38 months after diagnosis. Rearranged bands of the T-cell receptor gene were detected in all patients with unusual integration. These findings indicate that the integration patterns of HTLV-I proviral DNA have a clinical implication and may be one of the explanations for heterogeneity in the behavior of this disease.

DNA, Viral↗
PubMed1994

Enhancement effects of BSA and linoleic acid on hybridoma cell growth and antibody production.

The effects of linoleic acid and bovine serum albumin on hybridoma cell growth and antibody production were investigated. In dish cultivation, linoleic acid on its own promoted cell growth when used at concentrations below 50 mg L-1, but strongly inhibited growth at a concentration of 100 mg L-1 on more. However, linoleic acid bound to bovine serum albumin did not inhibit cell growth, even at a concentration as high as 100 mg L-1. Also, linoleic acid did not affect the specific antibody production rate, with or without bovine serum albumin. In order to elucidate the enhancement of antibody production by bovine serum albumin, fractions were prepared by ultrafiltration (98% molecular weight cut-offs, 50,000 and 17,000) and the effects of the fractionation on antibody production were studied in batch cultivation. The high-molecular-weight fraction (> or = 50,000) promoted antibody production whereas the low-molecular-weight fraction (< or = 17,000) inhibited it. In continuous cultivation, the high-molecular-weight fraction was also found to enhance antibody production.

Animals↗
PubMed1994

I-123 IMP scintigraphy in two patients with primary pulmonary malignant lymphoma.

123I-IMP lung scintigraphy was performed in two patients with primary malignant lymphoma, whose radiographic features were difficult to differentiate from inflammatory or atelectatic lesions. 123I-IMP scans revealed a defect in the lesions on the delayed (24 hr) image, suggesting a tumorous lesion. 123I-IMP scan may contribute to differential diagnosis of this rare tumorous entity from benign disorders having a different appearance.

Aged↗
PubMed1994

Experimental evaluation of the usefulness of 201Tl-chloride scintigraphy for monitoring radiotherapeutic effects.

The level of Na(+)-K+ adenosine triphosphatase (ATPase) has been demonstrated to be correlated with tumour growth potential, and accelerated active transport of K+ carried out by Na(+)-K+ ATPase is said to be a trigger of 201Tl affinity for malignant tumour cells. Therefore, 201Tl scintigraphy appears to be a good indicator for evaluation of changes of tumour proliferative potential after treatment. In the present study, the usefulness of 201Tl scintigraphy for monitoring radiotherapeutic effects was evaluated in VX-2 tumours irradiated with variable doses (10-40 Gy of radiation). Changes in 201Tl uptake were compared with tumour growth, and 201Tl uptake on day 7 after irradiation was compared with tumour bromodeoxyuridine (BrdU) uptake, which reflects DNA synthesis. All the treated tumours showed dose-dependent diminished 201Tl uptake, accompanied by either dose-dependent tumour growth delay or tumour regression/resolution. The diminished 201Tl uptake had already appeared on day 7 after irradiation, accompanied by diminished BrdU uptake, although, at this time, the tumour volumes were increased, or were not significantly decreased compared to pre-irradiation. Moreover, the 20 Gy tumours demonstrated two different tumour growth patterns, each accompanied by a different degree of reduction of 201Tl uptake. These findings suggest that the degree of reduction of tumour 201Tl uptake following irradiation can reflect the degree of suppressed proliferative activity in the treated tumours, and that assessment of altered 201Tl uptake at a relatively early time following irradiation allows prediction of subsequent tumour growth, regardless of the tumour volume.

Animals↗
PubMed1994

Prophylaxis of symptoms of hyperhistaminemia after the treatment of acute promyelocytic leukemia with all-trans retinoic acid.

A 61-year-old man with acute promyelocytic leukemia (APL) is described in whom some leukemic promyelocytes contained granules similar to those of basophils, and hyperhistaminemia developed after treatment with all-trans retinoic acid. The symptoms of hyperhistaminemia, mediated via H2 receptors, were prevented by the administration of an H2-blocker, famotidine, but wheezing due to bronchospasms, mediated via H1 receptors, developed and was improved by administration of chlorpheniramine. In APL, it is generally thought that the maturation of neutrophilic leukocytes is arrested at the level of abnormal promyelocytes. However, heterogeneity of leukemic promyelocytes has been described and in a few patients some leukemic promyelocytes have been known to show basophilic features. Marked basophilia and severe symptoms due to hyperhistaminemia have recently been reported after the treatment of APL with all-trans retinoic acid. Our case presented similar basophilic features, but indicated that the symptoms of hyperhistaminemia after administration of retinoic acid can be prevented with antihistaminic drugs and suggested that both H1- and H2-blockers should be administered to such APL patients with basophilia.

Basophils↗
PubMed1994

Essential thrombocythemia terminating in acute leukemia with minimal myeloid differentiation--a brief review of recent literature.

Essential thrombocythemia (ET), one of the chronic myeloproliferative disorders, is a clonal disorder of multipotent stem cells. Although most patients with ET have a prolonged benign course, a minority of patients may develop a blastic crisis similar to chronic myelogenous leukemia (CML). A case of ET terminating in blastic crisis 8 years after the initial diagnosis is presented. The blast cells were cytochemically and immunophenotypically consistent with the acute myelogenous leukemia with minimal myeloid differentiation subtype of the FAB classification. From the review of the literature on blastic transformation of ET, acute leukemia with an M4 or M7 phenotype occurred more frequently. In addition, three valuable factors to predict the leukemic transformation of ET appear to be karyotypic abnormalities, such as involvement of chromosome 21, previous therapies with a mutagenic potential, and the capability of bone marrow cells to form in vitro spontaneous colonies as in CML.

Acute Disease↗
PubMed1994

A human T-cell lymphotropic virus type I carrier with temporal arteritis terminating in acute myelogenous leukemia.

A human T-cell lymphotropic virus type I (HTLV-I) carrier with temporal arteritis (TA) in whom acute myelogenous leukemia (AML) developed 1 year after successful treatment of the autoimmune disease is described. This case suggested that the induction of immunodeficiency by infection with HTLV-I may be related to the development of the autoimmune disease and malignancy.

Aged↗
PubMed1994

Exogenous zinc ion is required for inhibitory activity of botulinum neurotoxin C1 against norepinephrine release and its endopeptidase activity toward substance P.

Botulinum neurotoxin C1 inhibited Ca(2+)-evoked norepinephrine secretion from digitonin-permeabilized PC12 cells. The inhibition by the neurotoxin was dependent on the presence of Zn2+ added exogenously. This zinc-dependent inhibition was neutralized by monoclonal antibodies that recognize the sites close to the putative zinc-binding motif in the light chain. The neurotoxin was found to have an endopeptidase activity toward small peptide, substance P. The presence of exogenous Zn2+ was also indispensable to the full expression of this endopeptidase activity. Thus both the inhibition of neurotransmitter release by the C1 neurotoxin and its endopeptidase activity are dependent on exogenous Zn2+, which suggests a strong link between the two activities.

Adrenal Gland Neoplasms↗
PubMed1994

Technetium-99m-HMPAO as a marker of chemical and irradiation lung injury: experimental and clinical investigations.

UNLABELLED: We evaluated the ability of 99mTc-hexamethylpropyleneamine oxime (99mTc-HMPAO) to serve as a sensitive marker of lung injury. METHODS: Two experimental rabbit models of minimal lung injury were designed using injections of a low dose (0.05 ml/kg) of oleic acid or 50 Gy of irradiation. In addition, we clinically investigated whether patients who received chemotherapy (n = 14) or radiotherapy (n = 13) for lung cancer showed high uptake of 99mTc-HMPAO in the lungs. RESULTS: Despite the minimal endothelial lesions visualized by electron microscopy (edematous changes and blebbing), in both animal models, the lungs showed high uptake of 99mTc-HMPAO, which occurred rapidly within 1 min after injection. Clinically, the mean lung-to-liver ratio of 99mTc-HMPAO activity in the patients who received chemotherapy (0.649 +/- 0.185, p < 0.01) was significantly higher than that of the controls (n = 16; 0.387 +/- 0.108), and all 12 patients who received more than 30 Gy of irradiation showed abnormal uptake in the irradiated lungs, despite the lack of abnormal opacities on chest CT. CONCLUSION: These findings suggest that 99mTc-HMPAO has the potential to be a sensitive marker of chemical and irradiation lung injury.

Adult↗
PubMed1994

[Experimental and clinical evaluation of 99mTc-HMPAO as a sensitive marker for chemical lung injury].

To investigate whether 99mTc-hexamethylpropyleneamine oxime (99mTc-HMPAO) can be a sensitive marker of lung injury, an animal model of lung injury was designed in the rabbits using the injection of a low dose (0.05 ml/kg) of oleic acid. In the injured rabbit lungs, electron microscope revealed morphologic changes localized in the microvascular endothelium (edematous change), although their chest radiographies and light microscope did not show any significant changes compared to the controls. In these situations, 99mTc-HMPAO showed a diffusely, high pulmonary uptake, which occurred rapidly within the first 1 min after the injection. Clinically, the lungs in the patients who had been administered with cytotoxic anti-cancer drugs showed a significantly higher 99mTc-HMPAO uptake compared to the controls. These findings indicate that 99mTc-HMPAO may have potential as a sensitive marker of chemical lung injury.

Adult↗
PubMed1994

[Difference of thallium-201 kinetics between VX-2 tumors and inflammatory lesions in rabbits].

To evaluate the difference of thallium-201 chloride (201Tl) kinetics between malignant tumors and inflammatory lesions, 201Tl scintigraphy was performed in the 30 rabbits with variable sized VX-2 tumors; and in the 27 rabbits with variable sized inflammatory lesions induced by turpentine oil and the solution of auto-feces. The degree of 201Tl uptake was expressed as the count ratios of the lesions over the contralateral normal muscle tissue, and the early uptake ratio (1 min after the injection) and the delayed uptake ratio (30 min) were acquired. The retention index derived from these ratios was used to assess the degree of 201Tl washout from the lesions. When dividing both the tumors and inflammatory lesions into the large lesions (more than 40 mm in diameter) and smaller ones, different 201Tl kinetics according to the size of the lesions were demonstrated. In the small lesions, the VX-2 tumors showed higher early and delayed uptake ratios and a faster washout than the inflammatory lesions. In contrast, in the large lesions, both the early and delayed uptake ratios were not significantly different; however, the retention index in the tumors was higher compared to the inflammatory lesions. Thus, our animal study indicates that 201Tl kinetics are different according to the size of the tumor and inflammatory lesions, and that in the small lesions the higher tumor uptake compared to the inflammatory lesions may be available to differentiate. However, in the large sized lesions, assessment of the 201Tl washout from the lesions is necessary for differentiation.

Animals↗
PubMed1993

Spontaneous regression in adult T-cell leukemia/lymphoma.

BACKGROUND: Spontaneous regression of adult T-cell leukemia/lymphoma (ATL) is considered to be extremely unusual. Of the 82 patients with ATL who the authors saw between 1981 and 1991, spontaneous regression occurred in 3 (3.7%), 2 of whom were previously untreated and one who had been previously treated. Surgical excisional biopsy triggered the spontaneous regression in these patients. METHODS: In two of these patients with spontaneous regression, gene analysis studies of human T-cell leukemia virus type I (HTLV-I) proviral DNA, and T-cell receptor (TCR) were carried out by Southern blot analysis in lymph node cells or peripheral lymphocytes before regression and after recurrence. RESULTS: One patient exhibited monoclonal integration of HTLV-I proviral DNA and the rearranged band of the TCR-beta gene at the same positions both before regression and after recurrence. The other patient showed them at the different positions before regression and after recurrence. CONCLUSIONS: The authors' studies indicated heterogeneity in ATL patients with spontaneous regression. Temporary spontaneous regression could occur in typical ATL and might be associated with a longer survival time than that for prototypic ATL.

Blotting, Southern↗
PubMed1993

[MR imaging during arteriography (MR arteriography) in the detection of hepatocellular carcinoma].

MR imaging during arteriography was performed to evaluate the clinical utility to patients with hepatocellular carcinoma. After a conventional hepatic arteriography, the patients were transferred to the MR unit and MR arteriography was obtained with the gradient echo technique synchronously starting manual injection of Gd-DTPA diluted with normal saline into the hepatic artery using 5-F Cobra angiographic catheter. The tumors showed high signal intensity relative to surrounding normal parenchyma and a clear liver-to-lesion contrast was obtained. Especially in one case, a conventional hepatic arteriography did not show the recurrent mass, however it was demonstrated as a high signal intensity area on MR arteriography. Therefore, this new technique seemed to be useful for the detection of hepatocellular carcinoma.

Carcinoma, Hepatocellular↗
PubMed1993

Improved or fatal acute disseminated intravascular coagulation in systemic lupus erythematosus.

To analyze the outcome of systemic lupus erythematosus (SLE) associated with acute disseminated intravascular coagulation (DIC) and also to clarify the clinical factor(s) contributing to the outcome, we retrospectively investigated 120 SLE patients treated between 1981 and 1991. Eight of these patients (6.7%) developed acute DIC; four recovered and the other four died within 2 weeks of onset. Infection preceded acute DIC in all these patients. Acute DIC associated with atypical pneumonia was always fatal, while the patients with pharyngitis or urinary tract infection survived when they were treated adequately. Comparison of the dead and surviving groups revealed that the activity of SLE before the onset of DIC, the severity of DIC, and the treatment given for DIC and the coexistent infection were not significantly related to a fatal outcome. However, severe infection such as atypical pneumonia in patients with secondary immunodeficiency was likely to be fatal irrespective of the presence of DIC.

Acute Disease↗