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Biomedical subjects

K Takebe

Publications and source records attributed to K Takebe.

At least 73 records · Page 4Linked to original sources
PubMed1994

An experimental hemodynamic study of the pelvic collateral circulation.

Iliac arteries were occluded in adult mongrel dogs to investigate pelvic hemodynamics. When the unilateral common iliac artery was occluded, the blood flow making a "stopover" within the pelvis was found to be significantly less than that of anatomical hemodynamics even under a resting condition. The blood flow decreased more significantly under exercise loading than under a resting condition, which demonstrates the presence of the "steal" phenomenon. This only occurs in the collateral circulation in the pelvis formed by two arterial systems which are related in a series. In deciding the appropriacy of reconstruction for the internal iliac artery in patients with aorto-iliac occlusive disease, this "steal" phenomenon should be kept in mind. In most cases, ischemic symptoms in pelvic organs may be due to a simple decrease of the blood flow supplied to the pelvis, or due to the "steal" phenomenon. If the pelvic region is in the state of ischemia owing to the "steal" phenomenon, reconstruction of the blood vessels flowing into the pelvis is not required.

Animals↗
PubMed1994

Octreotide decreases biliary and pancreatic exocrine function, and induces steatorrhea in healthy subjects.

A somatostatin analogue (SMS-201-995, hereinafter "octreotide") was s.c. administered to 5 healthy subjects under consecutive dripping of CCK-PZ (cholecystokinin-pancreozymin) and secretin (0.01 CHR U/kg/minutes), after inserting a Dreiling double tube into Treitz's ligament. Bile acid concentration, and bicarbonate and lipase excretions in duodenal juice were determined every 10 minutes up to 120 minutes and compared with controls. Moreover, octreotide (100 micrograms) was s.c. administered to 5 healthy subjects 30 minutes before meals for 7 days. Fecal fat and bile acid excretions before and after administration were determined. Bile acid concentration, and bicarbonate and lipase excretions in the octreotide group decreased to 1/3-1/4 that of controls. Bile acid concentration became 0 mM for 60 minutes. Fecal fat excretion increased; obvious steatorrhea occurred in 2 cases. Fecal bile acid excretion decreased to about 1/4. These results suggest that decreases in bile acid secretion should be considered, as well as pancreatic lipase and bicarbonate secretions, when fatty stool occurs after octreotide administration.

Adult↗
PubMed1994

Altered postprandial insulin requirement in IDDM patients with gastroparesis.

OBJECTIVE: To evaluate the effect of gastric emptying on postprandial insulin requirement in insulin-dependent diabetes mellitus (IDDM) patients with and without gastroparesis. RESEARCH DESIGN AND METHODS: Postprandial insulin requirement and gastric emptying were simultaneously evaluated in five IDDM patients with gastroparesis and in six control IDDM patients without gastroparesis. Postprandial insulin requirement after test-meal intake was assessed by measuring the insulin infusion rate during a 4-h feedback control with an artificial endocrine pancreas device (Biostator, Life Science Instruments, Miles, Elkhart, IN). Gastric solid and liquid emptyings were evaluated during the Biostator study by measuring the disappearance rate of 99mTc in the stomach and in the time course of plasma acetaminophen concentration, respectively. RESULTS: Total insulin requirement during the first 120 min after the test-meal intake was significantly lower in the gastroparetic patients than in the control patients. The gastroparetic patients showed no apparent postprandial peak for insulin infusion rate during the 4-h study, although the peak rate was observed within 120 min after the test-meal intake in the control patients. The disappearance of 99mTc in the stomach was significantly slower, and plasma acetaminophen concentrations were significantly lower in the gastroparetic patients compared with those in the control patients, respectively. CONCLUSIONS: The results suggest that IDDM patients with gastroparesis, accompanied by impaired solid and liquid emptying, have an altered postprandial insulin requirement.

Adult↗
PubMed1994

Different change in lipoprotein(a) levels from lipid levels of other lipoproteins with improved glycemic control in patients with NIDDM.

OBJECTIVE: To evaluate change both in lipoprotein(a) [Lp(a)] and lipid levels in other lipoproteins in non-insulin-dependent diabetes mellitus (NIDDM) after short-term improvement of glycemic control. RESEARCH DESIGN AND METHODS: We compared Lp(a) levels in 210 NIDDM patients with those in 46 control subjects and evaluated the relationship between glycemic control and Lp(a) levels in diabetic patients. In addition, changes in Lp(a) levels and lipid levels were assessed after the improvement of glycemic control in 54 poorly controlled NIDDM patients. RESULTS: In NIDDM, Lp(a) levels in all patients, 62 patients with HbA1c < 6.0%, and 75 patients with HbA1c between 6.0 and 8.0%, were significantly higher than those in control subjects (19.1 [1.7-106.6], 19.2 [6.0-106.6], and 20.3 [2.7-75.3] vs. 15.4 [2.0-61.7] mg/dl, median [range], P < 0.05). Lp(a) levels in 73 patients with HbA1c of > or = 8.0% (18.7 [1.7-58.8] mg/dl) were not significantly different from those in control subjects. After glycemic control, lipid levels in plasma and in other lipoproteins fell significantly, but Lp(a) did not change (from 18.3 [1.7-58.8] to 18.4 [6.6-95.3] mg/dl). Changes in lipid levels, including Lp(a), did not correlate with those in fasting plasma glucose or HbA1c. CONCLUSIONS: These results suggest that elevated Lp(a) levels do not reflect poor glycemic control and that Lp(a) levels are independent of lipid levels in other lipoproteins after improved glycemic control in NIDDM.

Blood Glucose↗
PubMed1993

Higher levels of plasma cholesterol sulfate in patients with liver cirrhosis and hypercholesterolemia.

An analytical method for the determination of cholesterol sulfate (CS) in plasma using gas-liquid chromatography was developed. We measured plasma CS concentrations in patients with liver cirrhosis and hypercholesterolemia as examples of disorders that involve aberrations in cholesterol metabolism. Patients with liver cirrhosis had plasma CS concentrations that were significantly higher than those of control subjects (444.6 +/- 51.7 vs. 253.0 +/- 24.6 micrograms/dL, mean +/- SE). The levels of other lipids were lower in cirrhotics, although the differences were not significant. There was no correlation between the levels of CS and sulfated bile acids in cirrhotic patients. CS levels in plasma were also higher in subjects with hypercholesterolemia (413.7 +/- 44.5 micrograms/dL); however, the ratio of CS to total cholesterol (TC) clearly differed between cirrhotics and hypercholesterolemic subjects (1.44 +/- 0.11 x 10(-3) vs. 3.31 +/- 0.63 x 10(-3); P < 0.05). Both in subjects with hypercholesterolemia and in healthy controls, the CS/TC ratio was similar and CS accounted for roughly 0.14% of the TC concentration.

Aged↗
PubMed1993

Contradictory clinical implications between paradoxical growth hormone responses to thyrotropin-releasing hormone and those to vasoactive intestinal peptide and luteinizing hormone-releasing hormone in acromegaly.

There is an almost general agreement on the clinical significance of TRH and bromocriptine (Br) tests in acromegaly. That is that positive GH responses to these tests (with an increase or a decrease, respectively) are known to be very frequently associated with the presence of PRL-containing somatotroph adenomas of the pituitary. In this context, however, very little is known about the clinical significance of paradoxical GH responses to vasoactive intestinal peptide (VIP) and LHRH in acromegaly. We therefore examined, as the principal objective of this study, whether a relationship exists among the GH (in some cases also PRL) responses to TRH, VIP, LHRH and Br in acromegaly. Another aim of this study was to examine whether a sexual difference exists in GH and PRL secretion in acromegaly. We examined a total of 24 patients comprising 8 men and 16 women. In agreement with previous reports, TRH-responders tended to have a higher level of basal PRL than TRH-nonresponders. In contrast, VIP-responders and LHRH-responders tended to have a lower PRL level than their respective counterparts. Although Br responsiveness was unexpectedly similar between TRH-responders and nonresponders, it was revealed that pure TRH-responders who were not responsive to VIP or LHRH were more sensitive to Br and more hyperprolactinemic than the remaining TRH-responders. This suggests that the simultaneous GH responsivity to VIP and/or LHRH in TRH-responders may be a factor which lowers their Br responsiveness and basal PRL levels. With respect to a sexual difference in GH and PRL secretion, it was revealed that female acromegalics had higher levels of basal GH and PRL than male patients. In addition, it was found that female acromegalics had supernormal levels of basal PRL, but a subnormal PRL responsiveness to TRH. As the major implication of this study, we hypothesize that the positive GH response to TRH associated with a high sensitivity to Br may, as already suggested, be characteristic of PRL-containing somatotroph adenomas, whereas the GH responsivity to VIP, and possibly also to LHRH, co-existing with no or low sensitivity to Br may be a feature of pure somatotroph adenomas. Although this study is devoid of immunohistochemical evidence to support this hypothesis, we suggest that the present in vivo data may be of some help in understanding the basis of the great variabilities in the GH responses to various dynamic testings in acromegaly.

Acromegaly↗
PubMed1993

Intrahypothalamic perfusion with interleukin-1-beta stimulates the local release of corticotropin-releasing hormone and arginine vasopressin and the plasma adrenocorticotropin in freely moving rats: a comparative perfusion of the paraventricular nucleus and the median eminence.

It is almost generally accepted that an acute-phase ACTH response induced by interleukin (IL)-1 is mediated principally by CRH release from the hypothalamus. However, the precise cellular site of action of IL-1 in activating the CRH neuronal system remains to be determined. Two likely candidates comprise the paraventricular nucleus (PVN) where CRH neuronal cell bodies are located, and the median eminence (ME) where their nerve endings are terminated. Therefore, in this study we performed a comparative perfusion of the ME and the PVN with increasing concentrations of recombinant human IL-1 beta utilizing the push-pull perfusion technique in freely moving rats. We measured the plasma ACTH and ME and PVN levels of CRH, and also of AVP, because AVP, another secretagogue of ACTH, has its cell body in the PVN and axon terminals partly in the ME. In control groups, the ME or the PVN was perfused with artificial cerebrospinal fluid between 12:00 and 15:00 h, and perfusates and blood samples were collected every 20 min. In the other groups, either the ME or the PVN was perfused with three increasing concentrations (0.1, 1.0, and 10 nM) of recombinant human IL-1 beta dissolved in artificial cerebrospinal fluid only between 13:00 and 14:00 h with all the other procedures run in the same way as in the controls. In the control perfusions, the hypothalamic release of CRH and AVP and the plasma ACTH did not change significantly during the entire period of observation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗
PubMed1993

In vivo release of neurotensin from the median eminence of ovariectomized estrogen-primed rats as estimated by push-pull perfusion: correlation with luteinizing hormone and prolactin surges.

In order to assess the physiological role of neurotensin (NT) in regulating the secretions of luteinizing hormone (LH) and prolactin (PRL), we examined whether the in vivo release of NT from the push-pull cannulated median eminence (ME) was altered in association with the LH and PRL surges in free-moving ovariectomized rats primed with estradiol. For comparison, LH-releasing hormone (LHRH) was also measured in the same perfusates from the ME in which NT was determined. NT and LHRH in the ME started to significantly increase roughly concurrently with the initial significant rises in LH and PRL in the plasma, and the highest levels of the neuropeptides clearly preceded the peak levels of LH and PRL. These in vivo data strongly suggest that NT, independently of or in concert with LHRH, may have a facilitatory role in the generation of estradiol-induced LH surge. In addition, these data may not disagree with a similar facilitatory role of NT in the PRL surge. This is the first characterization of the temporal profile of NT secretion in rat ME in terms of its relationship to the estradiol-induced surges of LH and PRL.

Animals↗