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Biomedical subjects

H Sugimoto

Publications and source records attributed to H Sugimoto.

At least 343 records · Page 19Linked to original sources

Regional blood flow in sciatic nerve, biceps femoris muscle, and truncal skin in response to hemorrhagic hypotension.

Regional blood flow was measured simultaneously in rat sciatic nerves (NBF), truncal skin (SBF), and biceps femoris muscles (MBF) after graded hemorrhages. A modified 14C-butanol "indicator-fractionation" technique was used. In controls NBF was 11.4 +/- 1.38 ml X min-1 X 100 gm-1 and did not differ significantly between limbs. After hypotension, NBF was: 101 mm Hg, 7.7 +/- 1.3; 83 mm Hg, 5.3 +/- 0.6; 62 mm Hg, 4.1 +/- 0.6; 38 mm Hg, 3.1 +/- 0.3. The relationship between NBF and MAP was linear: (r = 0.56; p less than 0.001). SBF also declined linearly in hypotension (r = 0.54; p less than 0.01), but MBF did not change significantly. No significant change in nerve vascular resistance occurred with hypotension but muscle vascular resistance declined progressively. The data indicate a striking absence of autoregulation of NBF, but MBF, as expected, displayed close autoregulation. The vascular mechanisms which regulate resting NBF following hemorrhage differ from those in both muscle and skin: during hypotension, the calculated neurovascular resistance was unchanged, while the resistance in muscle fell and that in the skin increased.

Animals↗

Regional sciatic nerve blood flow response to limb movement.

The regional blood flow in the sciatic nerves (NBF), biceps femoris muscles (MBF), and hind limb skin (SBF) was measured simultaneously in anesthetized, normal rats, in other rats immediately after 15 min of electrical stimulation of one sciatic trunk (10 shocks/s), and in a group of similarly stimulated but previously curarized rats. These experiments were done to quantitate NBF during direct nerve stimulation in both the presence and absence of associated vigorous limb twitching, as these relationships have not previously been examined. Tissue blood flows were measured by an "indicator-fractionation" technic, using the distribution of [14C]butanol. NBF in normal controls was 11.1 +/- 1.4 ml X min-1 X 100 g-1; MBF was 6.8 +/- 0.6 ml X min-1 X 100 g-1. In the stimulated limb of noncurarized rats, NBF rose to 19.8 +/- 3.5 ml X min-1 X 100 g-1. MBF was elevated approximately tenfold. SBF also rose. In stimulated limbs of curarized rats, NBF was also approximately double the resting normal value, 23.2 +/- 4.8 ml X min-1 X 100 g-1, but MBF was then only slightly increased. We conclude that sciatic NBF increases appreciably when this nerve is stimulated, irrespective, for the most part, of whether limb motor activity is increased. The vascular mechanisms which regulate NBF differ from and are largely independent of those regulating MBF.

Animals↗

Pupillary light reflex in patients with hemispheric cerebrovascular disease.

Pupillary dynamics were investigated in 41 patients with hemispheric CVD by means of computerized open-loop videopupillography. The patients were alert and showed either abnormal high- or low-density areas on CT scan. Fourteen cases were examined in the acute stage (within 7 days from onset), 28 cases in the subacute stage (between 8 and 28 days) and 11 cases in the chronic stage (over 29 days). In the acute stage, the parasympathetic nervous functions (maximum velocity and acceleration of pupillary constriction) were hyporeactive and showed no significant differences between the ipsilateral and contralateral side of the lesion. In the subacute stage, these functions were significantly more hyperreactive on the ipsilateral side than on the contralateral side, that is, the parasympathetic functions of the healthy hemisphere became significantly improved in comparison with those in the acute stage. In the chronic stage, no significant differences were observed between the two sides. In contrast, the sympathetic nervous function (maximum velocity of dilatation) showed no differences with respect to either laterality or the time course after onset. The above data suggest that bilateral parasympathetic hypofunctions exist in the acute stage of hemispheric CVD, with an ipsilateral improvement of these functions with the passage of time, and that such autonomic dysfunctions may play some role in the pathophysiology of CVD.

Aged↗

Therapeutic modulation of growth-promoting activity in platelets from diabetics.

Proliferation of vascular smooth muscle is thought to be involved in the major diabetic complication atherosclerosis. We have previously reported an increase of growth-promoting activity (GA) in platelets from insulin-dependent diabetics. In this study, GA was measured in the platelet extract (PE) from eight diabetic patients who had been treated by conventional insulin therapy. Vascular smooth muscle cells from rat aorta were cultured and used as an assay system for GA. Incorporation of [3H]thymidine into DNA of cultured cells was stimulated by diabetic PE significantly more (P less than .05) than by normal PE. Diabetic PE incubated with cells for 4 days increased cell numbers significantly more (P less than .05) than normal PE. These abnormalities were corrected by long-term intensive insulin treatments (continuous subcutaneous insulin infusion and Pen infuser). The decrease of platelet extract GA appeared to correlate with the amount of insulin administered before meals as short-acting boluses, whereas the level of basal or long-acting insulin appeared to correlate with an increase of PE GA. Thus, the growth-promoting potential of platelets can be normalized by intensive insulin therapy. The relationship of insulin levels to this activity needs further evaluation.

Adult↗

[Development of an animal model of autonomic over-activity in tetanus].

Although present day progressive respiratory management has decreased the tetanus mortality rate, tetanus-related autonomic overactivity remains a lethal condition. The cause, pathophysiology, and treatment of this condition are controversial and no animal model has ever been reported. So we tried to make a rabbit model of this condition. At first we injected 30 micrograms of purified tetanus toxin intravenously. Blood pressure oscillation occurred, but the degree of oscillation was smaller than that was seen in the clinical cases. The degree of oscillation had not changed by addition of 30 micrograms purified toxin 12 hours after first injection. Secondly, 7 days before the experiment we injected 0.5 micrograms of purified tetanus toxin intravenously. On the experiment day, we injected 30 micrograms of purified toxin again. By this method there occurred blood pressure oscillation as same as that was seen in the clinical cases. But no rabbits progressed to circulatory collapse by purified toxin. Then to the last group of rabbits, we injected crude tetanus toxin for purified toxin. The degree of blood pressure oscillation was same as that of cases in which purified toxin was injected, and all rabbits progressed to circulatory collapse.

Animals↗

Identification of inflammatory cells infiltrating renal allografts.

Eight nephrectomies and 13 biopsies of renal allografts (living 15, cadaveric 6) were investigated on the origin of inflammatory cells in the graft tissues by the use of an immunohistologic method (ABC method). Various monoclonal antibodies and heterosera were used to identify different leukocyte subsets. In all specimens the most predominant inflammatory cells were T cells. Other cells decreased in the following order; B cells, neutrophils and monocytes, and natural killer cells. In T cell subsets Leu 2a-positive cells (suppressor/cytotoxic T cells) predominated over Leu 3a-positive cells (helper/inducer T cells) in 4 nephrectomies (living 1, cadaveric 3) and 12 biopsies (living 11, cadaveric 1). Among these 16 cases, 7 were undergoing acute rejection in various degrees, and 9 were without clinical rejection. In the former 7 cases only one was suffering from another disease. In contrast, Leu 3a-positive cells predominated over Leu 2a-positive cells in 1 biopsy (living) and 4 nephrectomies (living 2, cadaveric 2). Four of these 5 cases concurrently had other diseases in addition to acute rejection. Two cases underwent acute tubular necrosis (cadaveric graft nephrectomies) and 2 underwent chronic rejection and crescentic glomerulonephritis (living graft nephrectomies). The one remaining case was without clinical rejection.

Antibodies, Monoclonal↗

Percutaneous brachial artery catheterization.

We describe modifications and suggestions for safer percutaneous catheterization of the brachial artery based in part on the anatomy of the axillary-brachial artery and surrounding nerves of the brachial plexus. The brachial artery approach should be nearly as safe as the femoral artery approach for percutaneous catheterization and should not be avoided if the femoral arteries cannot be used.

Brachial Artery↗

Regional sciatic nerve and muscle blood flow in conscious and anesthetized rats.

The regulation of peripheral nerve blood flow is incompletely understood. Regional blood flow in the rat sciatic nerve (NBF) and hamstring muscle (MBF) was measured in both conscious and anesthetized normal rats and in rats that had undergone surgical exposure of one sciatic nerve just prior to measurement. The distribution of [14C]butanol following its bolus intravenous injection was used to determine the flows in a modification of the "indicator fractionation" technique. NBF in normal rats was similar in limb pairs and was unaffected by pentobarbital sodium anesthesia. The pooled value was 12.5 +/- 1.1 ml X min-1 X 100 g-1. NBF was unaffected by sham operation in the conscious rats but was doubled in operated limbs of anesthetized rats (P less than 0.001). MBF in conscious normal rats was five times that measured during anesthesia. As in NBF, sham operation significantly increased MBF only in anesthetized rats (P less than 0.01). [14C]butanol distribution is a sensitive indicator of NBF and MBF. Mere surgical exposure of the nerve significantly increases NBF and MBF in anesthetized, but not in conscious rats.

Anesthesia↗

Prolonged hemodynamic maintenance by the combined administration of vasopressin and epinephrine in brain death: a clinical study.

The present study attempted long term hemodynamic maintenance in 16 adult brain-dead patients, 14 with head injury and 2 with cerebrovascular accidents. In addition to respiratory and fluid management, 10 were treated with continuous infusion of epinephrine to maintain systolic blood pressure above 90 mm Hg. The remaining 6 patients each received a continuous infusion of synthetic arginine vasopressin (ADH) at a rate of 1 or 2 units/hour (285 +/- 45 microunits/kg/minute) simultaneously with epinephrine. The 10 patients treated with epinephrine alone all succumbed to cardiac arrest within 48 hours of brain death, with a mean survival time of 24.1 +/- 17.2 hours. In the patients who received simultaneous ADH infusion, a minimal dose of epinephrine of no more than 0.5 mg/hr in most instances sufficed to maintain blood pressure. Their mean survival time after brain death was remarkably prolonged to 23.1 +/- 19.1 days. In brain death, ADH plays a critical role in hemodynamic maintenance, and ADH administration permits long term hemodynamic stabilization of brain-death patients, offering increasing opportunities for organ transplantation.

Adolescent↗

[Present diagnostic status of scirrhous type gastric cancer--with special reference to the endoscopic diagnosis].

First, we presented an actual diagnostic situation in nowadays for gastric cancer of Borrmann 4, which is virtually the same as scirrhous gastric cancer. Among 12 patients treated by the author, all of whom were discovered late, only 3 underwent surgery. In fact, with inoperable cases in Borrmann 4, even those endoscopically found to show insufficient stretching of the gastric wall, thickening and tortuosity of folds, uneven gastric mucosa, redness and white coating, there may be negative in gastric biopsy. However, the significance of an endoscopic examination for diagnosis of scirrhous cancer is in obtaining proof of the carcinoma (especially when still operable) by gastric biopsy. Thus, one must strive not to overlook slight redness, white coating which means small erosions, but to go over gastric biopsy again and again. Next, with carcinoma presenting a leather bottle (linitis plastica type) of the stomach itself, the II c portion of the stomach consisted of fundic glands (undifferentiated carcinoma) shall become the primary focus supporting Nakamura's theory. One case of diffuse invasive cancer, mistakenly diagnosed as a II c case, and two cases of regional type, one similar to II c and the other a Borrmann 2 carcinoma of advanced carcinoma showing strongly fibrous scirrhous tendency toward infiltration, were jointly monitored.

Adenocarcinoma, Scirrhous↗