Biomedical subjects

H Takeuchi

Publications and source records attributed to H Takeuchi.

At least 19 recordsLinked to original sources

PubMed1992

Raman spectroscopic study on the conformation of a peptide fragment representing the DNA-binding domain of filamentous virus Pf3 coat protein.

Raman spectra have been measured of a nonapeptide which has an amino acid sequence identical to that of the C-terminal region of the major coat protein subunit of filamentous bacteriophage Pf3. The peptide shows a strong tendency to form a beta-sheet structure in aqueous solution. The beta-sheet formation is significantly promoted by complexation with single-stranded DNA but not with double-stranded DNA. It is suggested that the C-terminal region of the Pf3 coat protein binds to the single-stranded DNA genome in the virion with a beta-sheet conformation, in sharp contrast with the alpha-helical binding in other filamentous bacteriophages.

Amino Acid Sequence↗

PubMed1992

Structural gene and complete amino acid sequence of Vibrio alginolyticus collagenase.

The DNA encoding the collagenase of Vibrio alginolyticus was cloned, and its complete nucleotide sequence was determined. When the cloned gene was ligated to pUC18, the Escherichia coli expression vector, bacteria carrying the gene exhibited both collagenase antigen and collagenase activity. The open reading frame from the ATG initiation codon was 2442 bp in length for the collagenase structural gene. The amino acid sequence, deduced from the nucleotide sequence, revealed that the mature collagenase consists of 739 amino acids with an Mr of 81875. The amino acid sequences of 20 polypeptide fragments were completely identical with the deduced amino acid sequences of the collagenase gene. The amino acid composition predicted from the DNA sequence was similar to the chemically determined composition of purified collagenase reported previously. The analyses of both the DNA and amino acid sequences of the collagenase gene were rigorously performed, but we could not detect any significant sequence similarity to other collagenases.

Amino Acid Sequence↗

PubMed1992

Hollow microspheres for use as a floating controlled drug delivery system in the stomach.

Hollow microspheres (microballoons), loaded with drug in their outer polymer shells, were prepared by a novel emulsion-solvent diffusion method. The ethanol:dichloromethane solution of drug (tranilast or ibuprofen) and an enteric acrylic polymer were poured into an agitated aqueous solution of polyvinyl alcohol that was thermally controlled at 40 degrees C. The gas phase generated in the dispersed polymer droplet by the evaporation of dichloromethane formed an internal cavity in the microsphere of the polymer with the drug. The drugs incorporated in the solidified shell of the polymer were found to be partially or completely amorphous. The flowability and packability of the resultant microballoons were much improved compared with the raw crystals of drug. The microballoons floated continuously over the surface of acidic dissolution media containing surfactant for greater than 12 h in vitro. The drug release behavior of the microballoons was characterized as an enteric property, and drug release rates were drastically reduced depending on the polymer concentration at pH 6.8.

Acrylic Resins↗

PubMed1992

Osteocalcin: is it a useful marker of bone metastasis and response to treatment in advanced prostate cancer?

Serum osteocalcin (OC) is derived largely from new cellular synthesis. It is a marker for bone formation and a noninvasive specific marker of osteoblastic activity. The clinical significance of OC in monitoring prostatic cancer bone metastases was evaluated. Pretreatment serum OC levels were determined with a radioimmunoassay kit in a total of 63 patients with prostate cancer (8 with stage B, 12 with stage C, 12 with stage D1, and 31 with metastatic bone disease). The OC levels in patients with skeletal metastasis were significantly higher than those in patients without bony lesions (P less than 0.01). The pattern of the initial changes in OC levels were analyzed in patients with skeletal metastasis who received endocrine treatment. The pretreatment OC value is of little use in predicting the response to treatment. The patients whose OC level initially increased and remained high tended to have a shorter interval to disease progression. On the other hand, the pattern of initial changes in OC varied according to the regimen of endocrine treatment. Our study suggests that OC seem to reflect the response to treatment and might lead to the improvement in follow-up procedures. However, the clinical significance of OC as a marker of the response of bone metastasis should be carefully discussed with regard to the direct hormonal effect on bone metabolism.

Aged↗

PubMed1992

Electrophysiological follow-up of acute and chronic experimental allergic encephalomyelitis in the Lewis rat.

Cortical somatosensory evoked potentials (c-SEP) and flash visual evoked potentials (f-VEP) were serially recorded in acute monophasic and chronic relapsing experimental allergic encephalomyelitis (EAE) in the Lewis rat. In acute EAE, a significantly delayed latency and broadened peak of the c-SEP were observed corresponding to the clinical onset, and then returned to normal with the disappearance of clinical signs. In chronic EAE, the c-SEP showed the same changes as in acute EAE, also reflecting the first attack, remission and relapsing phase. However, chronic EAE, when paralysis had recovered in the relapsing phase, showed c-SEP abnormalities suggestive of subclinical active lesions. In contrast, the f-VEP showed no obvious abnormalities in acute or chronic EAE. These findings suggest that the c-SEP is an objective and sensitive index for detecting clinical and pathological changes in acute and chronic EAE in the Lewis rat.

Animals↗

PubMed1992

Characteristics and management of patients with fetal neuroblastoma.

At 35 weeks 6 days of gestational age, ultrasound evaluation of the fetal abdomen showed a mixed cystic mass in the superior pole of the left kidney. The mass was suspected to be an adrenal hemorrhage or neuroblastoma. The diagnosis was fetal neuroblastoma. Differential diagnosis enabled the fetal neuroblastoma to be distinguished from adrenal hemorrhage. The parameters of diagnosis of fetal neuroblastoma include no specific ultrasonographic pattern, lack of palpability, and no tumor markers. However, certain features do characterize fetal neuroblastoma, such as little metastases, complete resection at operation, and excellent prognosis. In cases of suspected neuroblastoma, a laparotomy performed as soon as possible is generally regarded as the best course of treatment. Nonetheless, biological analyses of the tumor may prove in the future to be necessary for determining whether or not laparotomy is the best treatment.

Adrenal Gland Diseases↗

PubMed1992

Immunogenic properties of structurally modified human tissue plasminogen activators in chimpanzees and mice.

Immunogenic properties of second generation human tissue plasminogen activator (tPA) derivatives were examined in chimpanzee and mouse systems. Five species of modified tPAs (mtPAs) (designated 2660, 2663, 2810, 8000, and 9200), recombinant native tPA or bovine serum albumin (BSA) as a positive control were subcutaneously injected nine times at suitable intervals into chimpanzees, genetically the closest species to man. These animals were tested for antigen(Ag)-specific antibodies to the corresponding proteins by means of enzyme-linked immunosorbent assay and Western blot analysis. Neither 9200, one of the five mtPAs tested, nor tPA was immunogenic, although BSA and the other four mtPAs were immunogenic under these conditions. Thus, an antigenic determinant was not exposed by the modification on 9200 and this modified tPA is expected not to be immunogenic in humans. In the mouse studies, mice were immunized with mtPAs. Serum samples from these animals were tested for antibodies to the mtPAs which did not concomitantly recognize native tPA by immune adsorption of the antibodies to tPA. The amount of such antibodies after the elimination of native tPA-reactive antibodies was little or none when the serum samples from 9200 and from the other mtPAs, except 8000, were tested. Taking into consideration the results of the chimpanzee studies, it can be concluded that Ag-specific antibodies are dominantly produced to unchanged epitopes present in modified proteins in the mouse system, in which the native protein is immunogenic.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

Sensitivities of Achatina giant neurones to putative amino acid neurotransmitters.

1. GABA receptors in Achatina identifiable giant neurones were classified into the muscimol I, muscimol II and baclofen types. Muscimol I and II type GABA receptors were sensitive to GABA and muscimol but insensitive to baclofen, whereas baclofen type receptors were sensitive to GABA and baclofen but insensitive to muscimol. Muscimol I and baclofen types were associated with the inhibition caused by GABA, while muscimol II type with the GABA excitation. 2. GABA, muscimol and TACA produced a transient outward current (Iout) with an increase in membrane conductance (g) of an Achatina neurone, TAN, having the muscimol I type GABA receptors. Their relative potency values (RPV) at GABA ED50 (approximately 10(-4) M) were: GABA:muscimol:TACA = 1:0.6:0.3. The GABA effects were potentiated by pentobarbitone, antagonized competitively by pitrazepin and non-competitively by picrotoxin and diazepam, and unaffected by bicuculline. The ionic mechanism of effects of GABA and its two analogues was the increase in membrane Cl- conductance (gCl). 3. GABA and (+/-)-baclofen produced a slow Iout with a g increase of another Achatina neurone, RPeNLN, having the baclofen type GABA receptors. The two compounds were almost equipotent (ED50: approximately 3 x 10(-4) M). The ionic mechanism of their effects was the increase in gk. The two compounds hardly affected the voltage-gated and slowly inactivating calcium current. Iout produced by GABA and (+/-)-baclofen were reduced by TEA, but unaffected by 4-AP, bicuculline, pitrazepin and picrotoxin. 4. Beta-hydroxy-L-glutamic acid (L-BHGA) showed the marked effects on the Achatina giant neurones; the two neurones were excited by the compound, whereas the three inhibited. D-BHGA, L-Glu, D-Glu and NMDA were less effective than L-BHGA or almost ineffective. Erythro-L-BHGA was more or less effective than threo-L-BHGA according to the neurones tested. 5. alpha-Kainic acid and domoic acid excited the two neurones, which were excited by L-BHGA. L-Quisqualic acid showed the similar effects to L-BHGA, which were mostly much stronger than L-BHGA. Erythro-L-tricholomic acid and DL-ibotenic acid showed the effects similar to L-BHGA selectively on some neurones. 6. It was pointed out that the pharmacological features of GABA on the Achatina neurones are simpler than those of L-BHGA, due to the simpler structure of the former compound having less binding sites than the latter.

Animals↗

PubMed1992

Papillary adenocarcinoma in a seminal vesicle cyst associated with ipsilateral renal agenesis: a case report.

Cysts and tumors of the seminal vesicle are uncommon, and their coexistence is extremely rare. We report a case of multiple papillary tumors inside a seminal vesicle cyst associated with ipsilateral renal agenesis in a 17-year-old man. Surgical excision of the cyst and tumors was performed without any morbidity and histology revealed well differentiated papillary adenocarcinoma.

Adenocarcinoma, Papillary↗

PubMed1992

Laparoscopic varicocelectomy: a simple technique for clip ligation of the spermatic vessels.

Less invasive laparoscopic surgery is replacing the conventional open operation for the treatment of several conditions. We performed laparoscopic clamping of the internal spermatic vessels in 12 subfertile patients to treat varicocele of the testis. Seven operations were performed with the patient under general anesthesia, whereas a local anesthetic was used in the 5 most recent patients. The internal spermatic vessels were successfully clipped in all 12 patients. Postoperative physical examination with a Doppler stethoscope showed that the venous reflux had disappeared in all patients. Semen quality was improved in 7 patients with a followup of 3 to 10 months. Neither hydrocele nor testicular atrophy was observed postoperatively. Laparoscopic varicocelectomy was effective and minimally invasive, especially when performed with the patient under local anesthesia.

Adult↗

PubMed1992

Evaluation of the usefulness of a novel injectable cephalosporin, E1040, and ceftazidime for management of complicated urinary tract infections caused by Pseudomonas aeruginosa and Proteus mirabilis by using the rat urolithiasis model.

A novel injectable cephalosporin, E1040, significantly eradicated Pseudomonas aeruginosa from the urine, in contrast to ceftazidime, in rats with complicated P. aeruginosa urinary tract infections associated with urinary stones, suggesting that E1040 is a prospective therapeutic agent in the management of refractory Pseudomonas urinary tract infections.

Animals↗

PubMed1992

Control of prolonged drug release and compression properties of ibuprofen microspheres with acrylic polymer, eudragit RS, by changing their intraparticle porosity [corrected].

Prolonged-release spherical micro-matrices of ibuprofen with Eudragit RS were prepared using a novel emulsion-solvent diffusion method. Those particles were termed "microspheres" due to their characteristic sponge-like texture and unique dissolution and compression properties unlike conventional microcapsules or microspheres. The internal porosity of microspheres could be easily controlled by changing the concentration of the drug and the polymer in the emulsion droplet (ethanol). With lower concentration of ibuprofen in the ethanol, the resultant microspheres had a higher porosity, about 50%. The drug release rate from the microspheres was interpreted by the Higuchi model of spherical matrices, which depended only on their internal porosity of the microspheres when size distribution and drug content were the same. The tortuosities in the microspheres were found to be almost constant (3-4) irrespective of porosity, suggesting the same internal texture. Microsphere compressibility was much improved over the physical mixture of the drug and polymer owing to the plastic deformation of their sponge-like structure. The more porous microspheres produced stronger tablets [corrected].

Acrylic Resins↗

PubMed1992

A case of biliary cystadenocarcinoma arising in the liver with a congenital retention of indocyanine green.

A case of biliary cystadenocarcinoma that occurred in a 45-year-old woman is reported. Ultrasonography and computed tomography clearly revealed papillary projections in the cyst of the liver. Percutaneous transhepatic cystography showed connection between the cyst and the common bile duct. The tumor was surgically resected and proved to be a mucinous papillary adenocarcinoma arising from a biliary cystadenoma. The patient is doing well 4 years after surgery. Interestingly, this is the first reported case of a biliary cystadenocarcinoma in the liver with markedly diminished excretion of indocyanine green.

Adenocarcinoma, Mucinous↗

PubMed1992

A case of primary retroperitoneal mucinous cystadenocarcinoma.

A rare case of primary retroperitoneal mucinous cystadenocarcinoma in a 44-year-old woman is reported. The cystic tumor was delineated by CT and echography. The tumor was removed intact in the presence of bilateral normal ovaries and demonstrated an infiltrating malignant process. This neoplasm may have arisen from a supernumerary ovary. The patient died of recurrence 4 months after surgery. A comparison of the known cases indicates that aggressive treatment by hysterectomy with bilateral salpingo-oophorectomy in addition to cyst extirpation may improve prognosis.

Adult↗

PubMed1992

Time course of the impairment of cerebral autoregulation during chronic cerebral vasospasm after subarachnoid hemorrhage in primates.

The time course of the impairment of cerebral autoregulation during chronic cerebral vasospasm after subarachnoid hemorrhage was studied in 18 monkeys. Changes in cerebral blood flow (CBF) at the regional level and central conduction times during either graded hypo- or hypertension were evaluated in these animals at three stages (3, 7, and 14 days) following the introduction of an autologous blood clot around the right middle cerebral artery (MCA). Angiograms revealed a reduction in vessel caliber (compared to the baseline level in the involved MCA) of 30% at 3 days, 50% at 7 days, and 10% at 14 days. At all stages, CBF remained constant at mean arterial blood pressures (MABP) of 60 to 160 mm Hg in the noninvolved hemisphere. In contrast, at the 3- and 7-day stages, there was an impairment of autoregulation in the involved hemisphere at MABP of 40 to 180 mm Hg. The right hemispheric CBF was significantly (p less than 0.05) lower than that in the left throughout the period of investigation at MABP below 120 mm Hg, but rose to exceed the left CBF at MABP above 180 mm Hg at the 7-day stage and 160 mm Hg at the 14-day stage. The right-sided central conduction time showed significant (p less than 0.05) prolongation at MABP below 60 mm Hg at the 3-day stage and 40 mm Hg at the 7-day stage. It is suggested that these results may help to develop guidelines for hemodynamic therapy for vasospasm in its various stages.

Analysis of Variance↗

PubMed1992

[Endocrine environment of benign prostatic hyperplasia--relationships of sex steroid hormone levels with age and the size of the prostate].

To determine the influence of endocrine factors on benign prostatic hyperplasia (BHP), the levels of three sex steroid hormones i.e., total testosterone (Total-T), free testosterone (Free-T) and estradiol (E2), were measured in serum of healthy 154 men. Their ages ranged from 18 to 91 years old. In 59 men, prostatic size was estimated by digital examination and was subdivided into three groups: smaller than or equal to walnut size, small hen's egg size and equal to or larger than hen's egg size. Firstly, relationships of sex hormone levels with age were studied. There was a slight decrease in Total-T over 60 years old, a significant decrease in Free-T, and no change in E2 with age. Thus, E2/Total-T and E2/Free-T ratio increased significantly after middle-age. Secondly, relationships of hormone levels with prostatic size were studied. In the larger prostate group, a significantly lower level of Total-T and significantly higher level of E2 were detected. But there was no difference in Free-T. Thus, the prostatic size was correlated positively with E2 level, E2/Total-T and E2/Free-T ratio. These suggest that the endocrine environment tended to be estrogens-dominant with age, in particular, after middle-age, and that patients with large prostates have more estrogens-dominant environments. We conclude that estrogens are key hormones for the induction and the development of BPH.

Adolescent↗

PubMed1992

[Value of prostate-specific antigen measurements with newly developed enzyme immunoassay (MARKIT-M PA)].

Serum prostate-specific antigen (PSA) levels in patients with prostate cancer and benign prostate hypertrophy (BPH) were investigated with a newly developed enzyme immunoassay (MARKIT-M PA, Dainippon Pharmaceutical Co. Ltd., Osaka, Japan). Sensitivity of the assay system is 0.5 ng/ml and the detection range is 0.5-100 ng/ml. There was a high linear correlation (r = 0.987) between the assay and MARKIT-F PA, and values obtained with the assay were almost equal to those yielded by MARKIT-F PA assay. Using the BPH group as a negative control, the upper cut-off value in BPH patients was determined to be 3.6 ng/ml. Of the 48 patients with untreated prostate cancer, 77% was detectable by means of MARKIT-M PA assay. Using the BPH group as a negative control, specificity and efficiency were 93% and 86%, respectively. In another group of 27 BPH patients whose blood samples were taken immediately after digital prostatic examination, PSA was elevated in 15%. During follow-up of prostate cancer patients, PSA was elevated in 82% at the time of clinically detectable progression. In 15 patients whose disease was clinically well controlled, all levels of PSA were observed to be negative. These findings suggests that detection of serum PSA with this assay is of great use both in the diagnosis and monitoring of prostate cancer patients.

Biomarkers, Tumor↗

PubMed1992

[Clinical analysis of urolithiasis in Poh Ai Hospital of I-Lan, Taiwan, R.O.C.--a comparative study with urolithiasis in Japan].

Between August 1987 and December 1990, 546 patients were admitted to the department of Urology at the Poh Ai Hospital of I-Lan, Taiwan, R.O.C. for the treatment of urinary stones. These urinary stone cases accounted for 50 to 60% of all urology patients admitted. The incidence of urolithiasis in I-Lan was estimated at 147/100,000 population in 1990. There were 402 male patients and 144 female patients, The male to female ratio was 2.8: 1. There were 450 upper urinary tract stones (kidney, ureter) in 314 males and 136 females, and 79 lower urinary tract stones (bladder, urethra) in 72 males and 7 females. The ratio of upper to lower urinary tract stones was 6:1. Endourological treatments such as percutaneous nephrolithotripsy and transurethral ureterolithotripsy have increased rapidly in recent years. A summary of the present analysis for composition of 365 stones follows. The most frequent type was calcium-containing stone (92.3%), followed by infection stone (4.7%), then uric acid (UA) stone (3.0%). There were no UA stones found in the female patients. According to urinalysis criteria of more than 10 WBC/HPF (x 400), pyuria was found in 67 cases of 334 metabolic stones (20.1%), and 11 cases of 17 infection stones (67.7%). There were neither pediatric case of stone formation nor cystine stones.

Adolescent↗