Biomedical subjects

Y Taki

Publications and source records attributed to Y Taki.

At least 37 records · Page 2Linked to original sources

PubMed1994

Kinetic analysis of the drug permeation process across the intestinal epithelium.

The rat intestinal lumen and the blood vessel were simultaneously perfused to study drug permeation across the intestinal epithelium. On the basis of drug disappearance from the intestinal lumen and its appearance into the vascular outflow, the mean time required for permeation across the intestinal membrane (MPT) and the permeation clearance (CLp) were calculated. MPT values of water, antipyrine, propranolol, imipramine and mannitol, varied from 0.45 min to 9.91 min depending on their physicochemical property. From both MPT and CLp, five drugs were classified as being (i) highly and rapidly absorbed (water, antipyrine), (ii) highly but slowly absorbed (propranolol, imipramine) and (iii) low and slowly absorbed (mannitol). Permeation profiles of these drugs were analyzed based on the diffusion model which defined the parameter for each permeation process, i.e. partitioning to and diffusion through the epithelium and clearance into the blood flow. Propranolol and imipramine partitioned into the membrane at a higher level than the other drugs. However, the clearance of both drugs from the epithelium was extremely slow, suggesting that this process is the rate-limiting step in their permeation. On the other hand, the rate-limiting step in the permeation of water and antipyrine was found to be the diffusion process in the epithelial layer.

Animals↗

PubMed1994

Epidural anesthesia modifies the cardiovascular response to marked hypercapnia in dogs.

BACKGROUND: There is little information on the cardiovascular response to marked hypercapnia during epidural anesthesia (EA). Our objective was to assess the potential modifying effects of various levels of EA on this response. METHODS: We randomly assigned 48 mongrel dogs anesthetized with halothane (0.5%) to one of four groups: control (n = 12), receiving general anesthesia alone; lumbar (n = 12), also receiving lumbar EA; thoracic (n = 12), also receiving thoracic EA; and thoracolumbar (n = 12), also receiving thoracolumbar EA. During marked hypercapnia (mean arterial CO2 tension > 90 mmHg for 15 min), we measured hemodynamic parameters and plasma catecholamine concentrations in each group. RESULTS: In the control condition, marked hypercapnia increased cardiac output, reduced systemic vascular resistance, modestly increased mean arterial blood pressure. Lumbar EA abolished the increase in cardiac output, and thoracic and thoracolumbar EA caused CO2 to depress the cardiac output and the mean arterial blood pressure during marked hypercapnia. The physiologic increase in circulating catecholamines during marked hypercapnia was abolished only in the thoracolumbar EA group. CONCLUSIONS: We conclude that sympathetic blockade by EA modifies the cardiovascular response to marked hypercapnia in dogs. Although modest hypoventilation is often effective in treating hypotension during general anesthesia, the current results suggest that hypoventilation may be detrimental during the combination of EA and general anesthesia.

Anesthesia, Epidural↗

PubMed1994

[Radiological approach to the pleura and pleural cavity with CT and MRI].

We discuss the efficacy and limitations of CT and MRI in the assessment of the pleura and pleural cavity. With CT and MRI findings from 610 patients, we address six topics: 1) Normal anatomy of the pleural cavity, 2) Pleural effusion, 3) Pleural tumors, 4) Pyothorax, 5) Lung cancer, and 6) The pleura as a mirror of systemic diseases. CT showed specific findings of acute bleeding. MRI was sensitive enough for the diagnosis of subacute bleeding and chylothorax. In the evaluation of pleural tumors, CT and MRI revealed specific evidence of pedunculated localized fibrous tumors and lipomas. In long-standing pyothorax, it is important to detect any associated secondary malignancies. CT and MRI show as a mass penetrating the bony thorax. B-cell non-Hodgkin malignant lymphoma is the most commonly associated malignancy. The sensitivities for diagnosis of pleural extension of bronchogenic carcinoma are 80% with CT and 86% with MRI. The specificities are 89% with CT and 75% with MRI. To study the pleura as a mirror of systemic diseases, we used high resolution CT to examine 104 patients without evidence of the diseases mentioned above. Eighteen of those 104 patients were found to have pleural thickening, and all 18 were smokers. Of the 24 non-smokers, none had pleural thickening. The difference in the occurrence of pleural thickening between smokers and non-smokers was significant (p < 0.01).

Humans↗

PubMed1994

[Respiratory arrest following diazepam administration during spinal anesthesia in a patient with myotonic dystrophy].

A 43 year old female with previously undiagnosed myotonic dystrophy received abdominal hysterectomy under spinal anesthesia. Respiratory arrest occurred when diazepam 5 mg was slowly administered intravenously during operation. Mask ventilation was continued during operation with nitrous oxide and pentazocine 30 mg i.v. After the operation ventilatory failure continued. Arterial blood gas analysis revealed pH; 7.21, Pao2; 57 mmHg, Paco2; 82 mmHg in spite of oxygen therapy by a face mask. For 5 days after the operation, oxygen therapy was necessary. The patient was diagnosed as myotonic dystrophy by further examination after the operation. In a patient with myotonic dystrophy, we should be very careful in administering a drug which may cause respiratory depression to prevent respiratory complication.

Adult↗

PubMed1993

Fluoride and iron concentrations in the enameloid of lower teleostean fish.

Our quantitative elemental analyses with the electron microprobe indicated that the fluoride and iron concentrations in the enameloid of bony fish are related to the phylogeny of fish. The enameloid of some bony fish with high F also contained high Fe. In order to clarify the phylogenetic significance of such a peculiar dual deposition of F and Fe into developing enameloid, quantitative electron microprobe analyses of these elements were made on the teeth of taxonomically lower teleosts. There were significantly different trends of F and Fe concentrations in the enameloid among various forms of lower teleosts. In the Osteoglossiformes, the enameloid of the osteoglossid species contained very low levels of F and Fe, whereas in the single representative of the Mormyroidei, the F was very low but Fe was very high. In the Elopomorpha, the enameloid of the elopiform species contained a medium level of F and high Fe, and that of the anguilliform high levels of F and Fe. In the Salmoiformes, the salmonid species had medium F and high Fe, and in a species of the Esocidae, high F and high Fe levels were found. The stomiiform fish exhibited levels of medium and high F and high Fe. The results of the present study and our previous investigations made on archaic non-teleostean and various teleostean fish indicate that the mechanisms of F and Fe concentrations into developing enameloid are independent of each other, and that the mechanisms of Fe concentration appeared earlier and disappeared later than, or concurrently with, that of the F concentration, in the course of fish evolution.

Amelogenesis↗

PubMed1993

Systematic synthesis of sulfur-containing p-nitrophenyl alpha-maltopentaoside derivatives for a differential assay of human alpha-amylases.

For use in a differential assay of human alpha-amylases, a variety of 6(5)-S-substituted p-nitrophenyl alpha-maltopentaoside derivatives (6-54) were systematically synthesized via the key intermediate, p-nitrophenyl O-(2,3-di-O-acetyl-6-S-acetyl-4-O-benzoyl-6-thio-alpha-D-glucopyranosyl) - (-->4)-tris[O-(2,3,6-tri-O-acetyl-alpha-D-glucopyranosyl)-(1-->4)]-2,3,6 -tri-O-acetyl-alpha-D-glucopyranoside (4), which was easily prepared from p-nitrophenyl alpha-maltopentaoside (G5P) in four steps. The sulfoxide and sulfone derivatives were prepared by oxidizing the corresponding sulfides with m-chloroperbenzoic acid.

Carbohydrate Sequence↗

PubMed1993

[A study of localized inflammatory pulmonary lesions by ultra-thin bronchofiberscope].

We used a new type of endoscope developed by the authors in 10 patients with localized inflammatory pulmonary lesions in the peripheral areas which were far from the 3 branch and needed to be distinguished from lung cancer. Endoscopic findings revealed reddening, obstruction, stenosis, hypersecretion and dilation in the peripheral airway. The endoscopic findings in this disease were different from those peripheral lung cancer. The combination of thin-section CT, endoscopy and lung biopsy was the best method for determining the morphological changes in localized pulmonary lesions.

Adult↗

PubMed1992

Mitochondrial changes in phospholipid molecular species during the increased oxidative phosphorylation after hepatectomy.

The changes in liver mitochondrial and microsomal phospholipid molecular species were analyzed during the period of remarkably increased oxidative phosphorylation following partial hepatectomy in rabbits. At 24 hours after hepatectomy, phosphorylative activity increased significantly from 69.7 +/- 5.5 to 118.5 +/- 5.7 nmol of ATP synthesized/min/mg protein, compared to the sham operated group. The ratio of phosphatidylethanolamine to phosphatidylcholine (PE/PC) in mitochondria increased significantly in the hepatectomy group compared with the sham operated group. Remarkable changes in molecular species were observed in mitochondrial phosphatidylethanolamine. 1-Stearoyl-2-arachidonoyl species decreased in the hepatectomy group. On the other hand, microsomal phospholipids hardly changed compared with mitochondrial ones. The change in content of 1-stearoyl-2-arachidonyl phosphatidylethanolamine in mitochondria tended to return to normal levels concomitant with the normalization of phosphorylative activity. The changes in content of mitochondrial phospholipids, especially phosphatidylethanolamine, might also be related to enhancement of phosphorylative activity.

Animals↗

PubMed1992

A prolongation of hepatic vascular exclusion by in situ hypothermic perfusion in dogs.

In situ hypothermic hepatic perfusion was performed in dogs to explore whether the time limit of hepatic vascular exclusion could be prolonged. During hepatic vascular exclusion, hepatic hypothermic perfusion was performed via portal vein using various perfusates under active bypass from the portal vein and infrahepatic inferior vena cava area to the superior vena cava system. Dogs receiving hepatic hypothermic perfusion for 1 hour died when given Ringer's solution but survived more than 7 days when given Euro-Collins' and University of Wisconsin solutions. Although dogs tolerated 2 hours of hepatic hypothermic perfusion when give University of Wisconsin solution, all dogs died by 2 hours of hepatic hypothermic perfusion when given Euro-Collins' solution. The hepatic energy charge and arterial ketone body ratio of dogs that died were significantly lower than for those that survived. This suggests that the regimen of hepatic hypothermic perfusion with University of Wisconsin solution is able to maintain the energy metabolism of the liver under hepatic vascular exclusion for prolonged periods, hence, its possible clinical application.

Adenosine↗

PubMed1992

Bone metastases of hepatocellular carcinoma after liver resection.

Between January 1985 and July 1990, 323 cases of hepatocellular carcinoma underwent liver resection in our department. Bone metastases were found in 12 of these cases (3.7%). Bone metastases were mainly found in vertebral bone (58.3%) and pelvic bone (41.7%). The time interval to the development of bone metastasis after liver resection was closely related to the presence of intrahepatic metastasis and the stage at operation. In all cases, the initial clinical symptom was pain and/or motor disturbance. Radiotherapy was performed in 10 cases and transcatheter arterial embolization or surgery was performed in 4 cases. The pain or neurological symptoms improved with these therapies in all cases. Cumulative survival was 1 year in 74%, 2 years in 34%, and 3 years in 17%, respectively.

Adult↗

PubMed1992

Analysis of length and surface area of each segment of the large intestine according to age, sex and physique.

Length, diameter and surface area of each of 6 segments of the large intestine were determined and calculated in 920 Japanese patients who underwent barium enema. Of the length and surface area measurements obtained, those of the transverse colon were the largest, followed by those of the sigmoid colon. The diameter of the ascending colon was the largest, while those of the descending colon and sigmoid colon were the smallest. There were various sex differences in size of the large intestine. Length and surface area of the entire large intestine in males were shorter and smaller respectively than those in females. Lengths of the cecum, ascending colon, transverse colon and rectum in males were shorter than those in females. Diameters of the descending colon, sigmoid colon and rectum in males were larger than those in females. Total surface areas of the ascending colon and transverse colon in males were smaller than those in females, while total surface areas of the descending colon, sigmoid colon and rectum in males were larger than those in females. Length of the entire large intestine tended to be increased with age. Length and surface area of the entire large intestine tended to be increased with an increase in physical dimensions in females.

Adolescent↗

PubMed1992

Iron in the enameloid of perciform fish.

It is known that a high concentration of iron is deposited in the enameloid of some teleostean fish. Previously, Suga et al. (1989) pointed out that the iron concentration in the enameloid is related to the phylogeny of fish rather than to the feeding habits, according to the results of quantitative iron analyses on the teeth of marine teleost fish of the Tetraodontiformes. In the present study, in order for the previous idea to be verified, quantitative iron analysis was made with an electron microprobe on the enameloid of fish belonging to the Perciformes, which is the largest group of teleostean fish in the world and consists of both marine and freshwater species. The enameloid of all the fish examined (57 species) contained high iron concentrations ranging from 0.2% to 10.2% at the surface or middle layer, whereas that of an advanced suborder, Tetraodontoidei, of the Tetraodontiformes was very low in iron, at a level which could not be discriminated from the background value of the emission intensity. The distribution pattern of iron in the enameloid was classified into at least two types, namely, type A, in which a high iron concentration was observed mainly in the surface layer, and type B, in which iron was deposited throughout the entire layer, although there were differences in concentration. There were some differences in the concentration and distribution of iron in the enameloid for the families; for example, those of the Scaridae had a type A distribution, with about 0.2% iron only at the surface layer, whereas those of the Cichlidae, Centrarchidae, and Acanthuridae, which showed a type B distribution, contained iron ranging from 2.9% to 10.5% at the surface or middle layer of enameloid. Such differences seemed to be associated with the difference in timing of the commencement of the iron deposition into the developing enameloid, which is probably related to the phylogeny of fish. There was no evidence to support the idea that the iron concentration in the enameloid is associated with the feeding habits of fish, as proposed by previous investigators.

Africa↗

PubMed1991

Hepatic vascular exclusion as a model for complete and stable hepatic ischemia in dogs.

In order to confirm a complete ischemia model, 1-hour warm hepatic ischemia by hepatic vascular exclusion (HVE) was studied in dogs, in comparison with that by inflow occlusion (IOC) only. The splanchnic venous bed and/or infrahepatic inferior vena cava were decompressed by a centripetal pump-driven venovenous bypass. Indocyanine green retention test revealed no hepatic blood flow in the HVE model during ischemia, while hepatic blood perfusion was still present in the IOC model. All 5 of the IOC dogs survived more than 7 days after revascularization, while 4 of the 5 HVE dogs died within 9 h. After the induction of hepatic ischemia, lactate increased in both HVE and IOC dogs. After revascularization, transaminases and guanase were elevated, the arterial ketone body ratio (acetoacetate/3-hydroxybutyrate) decreased and the serum lactate accumulated more in HVE dogs than in IOC dogs. The hepatic redox state of IOC dogs was significantly decreased by additional clamping of the inferior vena cava. It is concluded that the HVE model with a pump-driven active bypass provides complete and stable hepatic ischemia, resulting in greater deterioration of hepatic cellular functions; hence it is more suitable as a model of complete hepatic ischemia than the IOC one.

Animals↗

PubMed1991

Restriction fragment length polymorphism of the L-myc gene and susceptibility to metastasis in genitourinary cancers.

We examined Southern blot analysis of genomic DNAs from 70 patients with sporadic renal cell carcinoma, using the human L-myc oncogene fragment as a hybridization probe. Our purpose was to study the relationship between the restriction fragment length polymorphism (RFLP) of the L-myc and the frequencies of metastasis. The patients were classified into 3 genotypes according to the polymorphic patterns defined by two alleles (L-L:17, L-S:31, S-S:22). The relative ratios of the 3 genotypes in the renal cancer patients were similar to those seen in healthy Japanese. However, of 20 patients who exhibited distant metastases at diagnosis, only 2 belonged to the L-L type. The incidence of distant metastasis in L-L type patients was significantly lower than that in L-S and S-S patients (p = 0.068, by Fisher's exact probability test). These results basically correspond to the previous findings in the lung cancer patients [Kawashima et al.: Proc. natn. Acad. Sci. USA 85: 2353-2356, 1988]. On the other hand, L-myc RFLP analysis in 50 prostatic cancer patients revealed that the incidence of metastasis at diagnosis did not correlate with L-myc genotypes. L-myc RFLP seems to be less promising in prostatic cancer than in lung or kidney cancer.

Blotting, Southern↗

PubMed1991

[A resected case of renal cell carcinoma with metastasis to pancreas].

We report a case of renal cell carcinoma with metastasis to the pancreas, treated by radical nephrectomy and total pancreatectomy. A 56-year-old man visited our hospital because of macrohematuria and right low backache. An intravenous pyelography, ultrasonography and a CT scan of the abdomen revealed right renal tumor at the upper portion, about 11 cm in diameter, but no abnormal findings of the pancreas. Aortic and celiac angiograms demonstrated multifocal lesions, 1 or 2 cm in size, compatible with a metastatic tumor in the region of the pancreas. The patient underwent right radical nephrectomy and open biopsy of the pancreas. The right renal tumor was histologically revealed to be renal cell carcinoma without nodal or venous extension. Histological examination of the pancreas biopsy specimen confirmed it to be a renal cell carcinoma metastatic to the pancreas. Therefore, he underwent total pancreatectomy 1 month after the previous surgery. Three months after the second surgery, a CT scan of the brain revealed metastasis to the pituitary gland. He is still under therapy.

Carcinoma, Renal Cell↗

PubMed1991

[Effects of upper thoracic epidural anesthesia on hemodynamics and oxygen supply-demand relationship in hypovolemic dogs].

The purpose of the present study is to assess the influence of upper thoracic epidural anesthesia (TEA) on hemodynamics, the systemic oxygen supply-demand relationship, and several indications of stress in the presence of preexisting hypovolemia. Sixteen adult mongrel dogs were anesthetized with halothane and nitrous oxide, and blood was withdrawn at the rate of 3 ml.kg-1.min-1 for 10 min. The dogs were randomly assigned to two groups; one receiving TEA (TEA group, n = 8), and the other without (controls, n = 8). Mean arterial blood pressure, heart rate, arterial concentrations of epinephrine and norepinephrine remained significantly lower (P less than 0.05) in the TEA group than in the controls during the 100-min observation period following the start of TEA. Cardiac index, oxygen supply-demand ratio (O2 delivery/O2 consumption) and arterial lactate concentration showed no significant intergroup differences at any point during observation. By contrast, there was a significant difference in arterial pH between the TEA group (7.22 +/- 0.05, mean +/- SD) and the controls (7.15 +/- 0.08) after 100 min of TEA. These results indicate that in hypovolemic dogs anesthetized with halothane and nitrous oxide, TEA affects the acid-base balance favorably without significantly influencing the systemic oxygen supply-demand relationship.

Anesthesia, Epidural↗

PubMed1991

[A case of pelvic lipomatosis].

This is a report of the fifth case of pelvic lipomatosis in Japan. A 52-year-old man presented himself in our hospital with a complaint of left lower abdominal pain on August 28, 1988. At that time, physical examination was unremarkable with the exception of mild obesity. The excretory urogram and retrograde pyelogram revealed left hydroureteronephrosis with tapering of the left lower ureter. Urethrocystogram showed an elongated posterior urethra with anterior displacement and elevation of the bladder. Computed tomography revealed excess of diffuse fatty tissue in the pelvic space with bladder deformity and rectal compression. Pelvic arteriogram demonstrated no neovascularity. A diagnosis of pelvic lipomatosis was established. He lost 6 kg by diet therapy. Left lower abdominal pain disappeared, but excretory urogram after eight months showed no changes.

Humans↗

PubMed1991

[A case of emphysematous cystitis with familial amyloidosis].

This is a report of the thirteenth known case in Japan of emphysematous cystitis. A 70-year-old man visited our hospital because of pollakisuria and macrohematuria on November 21, 1989. The patient had been known to have familiar amyloid polyneuropathy for the previous 3 years. Urinalysis showed marked hematopyuria. The residual urine was 216 cc, and urine cultures yielded 10,000,000 colonies of Escherichia coli per ml. Laboratory studies revealed systemic inflammatory findings, but no diabetic change. A plain X-ray film of the abdomen and an excretory urogram (DIP) showed small linear and round gas collections in the bladder shadow. A CT scan revealed multiple gas locules within the bladder wall. A diagnosis of emphysematous cystitis was established. The patient was given antibiotics, and there was striking clinical improvement. Histological examination of the endoscopically obtained biopsy specimen of the bladder revealed amyloidosis. We believe that this patient had a cystitis emphysematosa precipitated neurogenic bladder due to amyloid polyneuropathy and amyloidosis of the bladder.

Aged↗