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At least 379 records · Page 21Linked to original sources
PubMed1993

Asexually proliferous tetrathyridia of Mesocestoides sp. in the hepatic portal system of the prairie rattlesnake (Crotalus viridis viridis).

A female prairie rattlesnake (Crotalus viridis viridis) was gastric intubated with 250 tetrathyridia of Mesocestoides sp. The snake was killed 12 wk postinfection; a portion of the liver was examined histologically for evidence of tetrathyridia. Five tetrathyridia were seen in two hepatic portal triad vessels. We propose that a blood-borne metastasis of tetrathyridia in reptiles and rodents may occur.

Animals↗
PubMed2005

Late complication in patients undergoing pancreatic resection with intraoperative radiation therapy: gastrointestinal bleeding with occlusion of the portal system.

BACKGROUND: There are few reports of late complications in patients who have undergone pancreatic resection with intraoperative radiation therapy (IORT), because carcinoma of the pancreas (PCa) and the bile duct (BCa) have a poor prognosis. The purpose of the present paper was to review gastrointestinal (GI) bleeding occurring with occlusion of the portal system (PVs) as a complication of IORT in patients surviving long term without recurrence. PATIENTS: From 1990 to 1999, 45 patients underwent surgical resection of the pancreas with IORT. Eleven of these patients survived >3 years without recurrence, and occlusion of PVs was recognized in five patients at follow-up examination. Three of these five patients received repeated blood transfusions for GI bleeding. RESULTS: One patient had BCa and two had PCa, and pancreatoduodenectomy was carried out. The delivered radiation doses of IORT were 30 Gy (two patients) and 35 Gy (one patient). The postoperative periods to initial GI bleeding were 36, 26 and 9 months, respectively. In all cases, angiography revealed occlusion of PVs and the collateral circulation. The bleeding points were esophageal varix (case 1), remnant stomach varix (case 2) and a jejunal ulcer (case 3), and blood transfusions were carried out totaling 44, 60 and 16 units, respectively. The GI bleeding disappeared spontaneously in case 1, developed sporadically in case 2 and was stopped by metallic stent insertion in PVs in case 3. CONCLUSION: During long-term follow up after pancreatectomy with IORT, it is necessary to monitor patients for GI bleeding. A clinical trial on optimum doses, long-term safety and benefit of IORT is necessary.

Bile Duct Neoplasms↗
PubMed1998

Possibility of partial absorption of nicardipine by routes other than the hepato-portal system after oral administration in rats.

The systemic availability of nicardipine after different routes of administration has been examined in rats, with particular attention to differentiating oral absorption from intestinal and hepatic metabolism. The quantities of nicardipine and its metabolite were determined by capillary column gas chromatography. A linear relationship was shown between the hepatic first-pass effect and dose after hepato-portal administration of nicardipine; the hepatic first-pass effect was calculated to be approximately 80%. However, the availability after oral and rectal administration was found to be more than twice that observed after hepato-portal administration. Partial avoidance of the hepatic first-pass effect after oral and rectal administration are estimated to be 37.3% and 35.2%, respectively, assuming that all absorbed molecules pass through the liver. These findings suggest that the absorption of nicardipine after oral administration also occurs by routes other than the hepato-portal system.

Administration, Oral↗
PubMed1989

Blood vascular beds of rat adrenal and accessory adrenal glands, with special reference to the corticomedullary portal system: a further scanning electron microscopic study of corrosion casts and tissue specimens.

Blood vascular casts of the rat adrenal glands were observed with a scanning electron microscope. The cortical capillary plexus drains, through the corticomedullary venous radicles, into the subcortical veins continuous with the medullary collecting veins. The medullary capillary plexus drains into the corticomedullary venous radicles, subcortical veins and medullary collecting veins. No portal vessel was noted between the cortical and medullary capillaries. These findings indicate that the cortical blood rich in glucocorticoids preferentially and continuously flows into the corticomedullary venous radicles, subcortical veins and medullary collecting veins all three of which are fenestrated in type, and also suggest that the vascular route from the cortical capillaries to the medullary collecting veins functions as a substitute for the portal system, controlling the biosynthesis of catecholamines in the adrenal medulla. The vascular bed of the accessory adrenal gland (extra-adrenal cortical or chromaffin body) is sometimes annexed to that of the adrenal gland. On rare occasions, the vascular beds of the extra-adrenal cortical and chromaffin bodies fuse with each other. Additional scanning of tissue samples confirmed the direct drainage of cortical capillaries into the medullary veins and also the endothelial fenestrations of these capillaries and veins.

Adrenal Glands↗
PubMed1995

[Hemodynamic changes in portal system after transjugular intrahepatic portosystemic shunts (TIPS)].

In this study portal venous flow (PVF), splenic venous flow (SPVF), hepatic artery volume (HAV), and portal pressure were measured before and after TIPS in 11 patients with portal hypertension. The results were compared with those of normal controls. In the normal controls PVF averaged 947.2 +/- 133.4ml/min, SPVF 239.6 +/- 116.3ml/min, and HAV 241.6 +/- 78.8ml/min. In the TIPS group before and after TIPS, PVF was 883.2 +/- 233.4ml/min vs. 958.7 +/- 185.2ml/min; SPVF was 448.9 +/- 111.6ml/min vs. 333.1 +/- 101.5ml/min; HVP was 225.3 +/- 122.7ml/min vs. 249.3 +/- 103.8ml/min. Portal pressure dropped from 3.94kPa +/- 0.46 to 2.52 +/- 0.60kPa after TIPS. We conclude that in patients after TIPS portal pressure drops blood flow in the truck of the portal vein increases, flow of hepatic tissue decreases, and blood flow in splenic vein decreases. Blood flow in hepatic aftery was not significantly changed.

Adult↗
PubMed1983

An unusual portal-systemic shunt, most likely through a patent ductus venosus. A case report.

A 46-yr-old man with cirrhosis presented with mental confusion, headache, and nausea. Colloid liver scintigraphy showed a defect in the hilar area, and portograms after superior mesenteric arteriography demonstrated varicose veins in the same area. Computed tomography revealed a sausage-shaped low-density channel connecting the hepatic hilum and the inferior vena cava, and bolus injection contrast enhancement demonstrated transit of contrast medium from the portal vein directly into the inferior vena cava through this channel. Real-time ultrasound demonstrated a large conduit contiguous from the portal vein to the inferior vena cava through and behind the liver. The catheter introduced into the inferior vena cava opacified a large opening of this shunt below the right and left hepatic vein openings. Measurements of blood pressure, ammonia, and PaO2 clearly indicated that portal vein blood was being shunted through this channel. These findings are highly suggestive of a portosystemic shunt through a patent ductus venosus.

Hepatic Encephalopathy↗
PubMed1990

[The regulatory and activating role of the portal system in physiological mechanisms of adaptation of metallurgical workers to high temperature of the air].

A screening of metallurgic plant workers under the conditions of a heat stress revealed the importance of the regulating and activating role of the portal vascular system in hemodynamics, as well as the starting mechanisms of the regulation. It was established that the portal vascular system participated in hydropoiesis in case with profuse perspiration and the latter's topography on the skin. In heat treatment shops with low humidity, drinking of cooled aerated water contributes to the optimal ratio between thermoregulation and the blood circulation systems.

Adaptation, Physiological↗
PubMed1997

Simultaneous evaluation of intestinal absorption and hepatic extraction of 5-fluorouracil using portal-systemic concentration difference by short-period double dosing in a single conscious rat.

The intestinal local absorption and the hepatic local disposition of 5-fluorouracil (5-FU) in a single conscious rat was investigated by the simultaneous sampling of portal and systemic bloods (PS method). The portal blood flow rate, measured using a compact electromagnetic flow-meter, was estimated to be 15.3 +/- 2.2 ml/min per body weight (250g). The portal vein and the femoral artery of the rat were cannulated to simultaneously obtain blood samples from two sites. 5-FU (30 mg/kg) was administered first intraarterially, and subsequently orally 90 min after intraarterial administration to a single conscious rat (short-period double dosing; DD). Concentrations of 5-FU in the portal and arterial bloods were determined by HPLC. The local absorption ratio (Fa) and the absolute bioavailability (F) were 71.2 +/- 15.4 and 25.1 +/- 13.2%, respectively. Consequently, the hepatic extraction ratio (F[H] = F/Fa) was estimated to be 34.9 +/- 14.4%. The mean local absorption time (t[a]) and the mean absorption time (MAT) were 37.5 +/- 15.5 and 31.4 +/- 13.7 min, respectively and they were statistically the same. In conclusion, a PS method by short-period double dosing (PS-DD method) has been developed to evaluate the first-pass effect, separating the intestinal absorption and hepatic elimination of a drug in a single conscious rat. It was demonstrated by applying PS-DD method that the low bioavailability of 5-FU can be explained by the large hepatic first-pass extraction, and that the large inter-individual variation in bioavailability of 5-FU is caused mainly by a large variation in the hepatic first-pass effect. The large variation in t(a) (or MAT) was predicted to be due to a variation in the gastric emptying time.

Animals↗
PubMed2002

[Portal-systemic shunt with cerebellar ataxia as the initial neurological manifestation which was dramatically improved by an intravenous administration of branched amino acid].

A 58-year-old woman began to show ataxia at age 45 and dysarthria at age 56. Neurological examination revealed slurred speech, truncal ataxia, and pyramydal sign. Neither history of alcoholism nor hereditary factors were found. The level of serum ammonia was increased. Brain MRI study showed a high signal intensity in the cerebral peduncle and globus pallidus and mild cerebellar atrophy on T1-weighted image. A portal-systemic shunt due to a shunt vessel was found between the left splenic and kidney veins although she did not show any other symptoms or signs due to liver cirrhosis. Her symptoms dramatically improved by an intravenous administration of branched amino acid. The present case suggests an importance in finding a treatable cerebellar ataxia.

Amino Acids, Branched-Chain↗