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Biomedical subjects

B Nordlinger

Publications and source records attributed to B Nordlinger.

At least 163 records · Page 9Linked to original sources
PubMed1979

Tyramine kinetics and metabolism in cirrhosis.

Hypertyraminemia is common in hepatic cirrhosis and correlates in severity with encephalopathy. The mechanism of cirrhotic hypertyraminemia has not been established. The alternative possibilities are increased production from tyrosine and impaired degradation by monoamine oxidase. This investigation determined the pharmacokinetics of tyramine after an intravenous bolus injections of [3H]-tyramine (180--200 muCi 12 Ci/mmol sp act) in 13 cirrhotics and 9 controls. In normals, [3H]tyramine levels initially declined rapidly (alpha-phase) followed by a slower decline (beta-phase) with an average t 1/2 of 20.8 min. Average normal metabolic clearance rate and production rate were 13.2 liters/min and 15.4 microgram/min, respectively. In cirrhotic patients, the plasma disappearance curve for [3H]tyramine was qualitatively similar to that of the control subjects with no apparent different in beta-t 1/2 (17.2 min). The hypertyraminemia of cirrhosis resulted primarily from overproduction of tyramine, as the production rate (32.0 microgram/min) in these patients was significantly greater (P less than 0.05) than in controls, whereas the metabolic clearance rate remained normal (average 12.2 liters/min). A difference in ratio of tyramine metabolic products was noted as well. Cirrhotics had a high ratio of plasma 4-hydroxyphenylethanol:4-hydroxyphenylacetic acid (60:40 vs. 30:70) as compared with normals. Although the tyramine clearance rates are similar in normals and cirrhotics, different mechanisms may be responsible for catabolism.

Adult↗
PubMed1979

Accurate measurement of liver, kidney, and spleen volume and mass by computerized axial tomography.

Computerized axial tomography permits accurate cross-sectional radiographic visualization of visceral organs. Thus, "radiographic area" of an organ slice can be calculated and converted to actual area from a standard grid printed on the roentgenogram. Because the width between slices is known, the volume of an organ slice can be calculated as area times width. Mass of the organ slice is then the product of slice volume and organ density, and entire mass of the organ is the sum of the masses of all the organ slices. The validity of this method was examined in four water-filled balloons, in 12 excised human cadaver organs (six kidneys, three livers, and three spleens), and in two human cadavers while the organs (four kidneys, one liver, and two spleens) remained in situ. Radiographic volume and mass agreed with actual volume and mass within +/- 3% to 5%, thus confirming the accuracy of this method.

Humans↗
PubMed1979

[Experimental hepatic ischemia].

Total clamping of the hepatic pedicle was performed for a period of two hours in the normothermic pig. During this time an external pulsed spleno-jugular shunt ensured effective-portal decompression. Under such conditions, the biological and histological consequences of this ischaemia were minimal and perfectly compatible with survival. This would suggest that the clinical syndrome of "shock liver" above all reflects splanchnic impairment.

Abdomen↗
PubMed1978

Tolerance of the human liver to prolonged normothermic ischemia. A biological study of 20 patients submitted to extensive hepatectomy.

To evaluate the biological tolerance of the human liver to prolonged warm ischemia, two groups of extensive hepatic resection for tumor were compared. Group 1 (11 patients) performed with short hepatic inflow occlusion (7 [mean] +/- 2 [SEM] minutes), and group 2 (nine patients) operated with use of complete hepatic vascular exclusion and prolonged warm liver ischemia (38 [mean] +/- 5 [SEM] minutes). Comparison of biological values, such as transaminase, bilirubin, total protein, albumin, and fibrinogen levels, the platelet count, prothrombin complex, and proaccelerin level, did not show statistically significant differences between the two groups. Therefore, the hepatic warm ischemia period may be, if needed, safely extended beyond the classical 15 minutes. It lasted 65 minutes in one case without adverse effect. These clinical observations parallel recent experimental work and should destroy the myth of the high sensitivity of the liver to warm ischemia.

Adolescent↗
PubMed1978

Normothermic hepatic vascular exclusion for extensive hepatectomy.

In humans, there is still considerable controversy concerning the tolerance of the liver to warm ischemia. To avoid anoxic hepatocellular damage, chilled intraportal and intra-arterial infusion has been advised as an adjunct to hepatic vascular isolation. Fourteen patients with hepatic tumors underwent extensive hepatic resection, complete hepatic vascular exclusion being used but without the use of refrigeration. This procedure may considerably reduce blood loss during resection of large and hypervascular hepatic tumors and increase the safety of hazardous lobectomies. Careful hemodynamic monitoring including pulmonary artery pressure is necessary. Hepatic tolerance to prolonged warm ischemia up to 65 minutes is surprisingly good, in the absence of preoperative, extensive hepatic dysfunction. The use of this procedure is advised for resection of large hepatic tumors when the technical risks appear to be high. It is suggested that the classical delay of 15 to 20 minutes of normothermic hepatic ischemia may be safely extended to about one hour when necessary.

Adult↗
PubMedDate not supplied

Noninvasive measurement of nutrient portal blood shunting: an experimental study with [14C]ursodeoxycholic acid.

All of the methods proposed for measuring portal blood flow are either invasive, estimate total rather than nutrient flow, and none has proved reliable in cirrhotic patients. A method has been derived from pharmacokinetic principles used for the calculation of bioavailability of drugs according to the route of administration (i.v. or p.o.) and tested experimentally in 20 pigs. A tracer dose of [14C]ursodeoxycholic acid, a biliary acid with a high-liver first-pass effect, is administered in the duodenum, and serial peripheral blood samples are taken. Later, the same dose of the same drug is administered i.v. The shunt fraction of portal blood F is obtained by the ratio of the areas under the plasma level vs. time curves ("AUC") after p.o. and i.v. administrations: (see formula in text). The pigs were divided into three experimental groups. (i) Group I: undisturbed portal flow; (ii) Group II: total diversion of portal blood with an end-to-side portacaval shunt, and (iii) Group III: partial diversion of portal blood through a side-to-side portacaval shunt. Portal flow was measured during surgery with an electromagnetic flowmeter above and below the shunt and the degree of shunting calculated. Results show that the shunt fraction measured with ursodeoxycholic acid is well-correlated with hemodynamic data. No overlap between Groups I and III is observed. It is concluded that the shunt fraction of nutrient portal blood can be measured with this noninvasive method. Minute amounts of ursodeoxycholic acid were used in order to be completely metabolized by the liver, even in spite of hepatocellular dysfunction. Therefore, this method should be valid in cirrhotic patients and be useful to decide the type of portasystemic shunt to propose for the decompression of gastroesophageal varices.

Animals↗
PubMedDate not supplied

Health care delivery system in France: effects on surgical education.

Surgical education in France has changed in recent years. It had to conform to the transformation of surgery into a more scientific discipline, to European Community regulations, and to increasing costs of health care. It is now organized on a national scale and is based on anonymous selection. The main objective is to train general surgeons who only afterward become specialized in various surgical specialties. The aim is to make them able to adapt to the changes that will transform surgery in the near future. In France the obligatory social insurance system, called Social Security, reimburses most medical expenses for 99% of the population. Patients can be reimbursed in a similar way whether they seek treatment in a private or a public institution. However, the system has to face major and presently unsolved problems due to the rapidly increasing cost of health care.

Delivery of Health Care↗
PubMedDate not supplied

Excision of the rectum with colonic J pouch-anal anastomosis for adenocarcinoma of the low and mid rectum.

The results of rectal excision with colonic pouch-anal anastomosis are reviewed from a series of 162 patients covering 7 years. All patients have been operated upon in the same institution and consecutively. The follow-up is now sufficient to allow an accurate evaluation of the outcome of the patients. The main goal of this study was to provide a detailed report of the functional results. Continence was satisfactory in 96% of the patients, with either a perfect continence or minor troubles that would not have been detectable other than by a rigorous questioning. The mean number of bowel movements was 2 per 24 hours. Fragmentation of the defecation and urgency were absent. Twenty-five per cent of the patients had to elicit the evacuation of the reservoir with a suppository or an enema. Improvement of function yielded by a reservoir over straight colo-anal and low colo-rectal anastomoses are significant and, as suggested by manometric studies, are directly related to the restoration of a reservoir function.

Adult↗
PubMedDate not supplied

Evaluation of clinical efficacy of new medical treatments in advanced colorectal cancer. Results of a workshop organized by the EORTC GITCCG. European Organization for Research and Treatment of Cancer. Gastrointestinal Tract Cancer Cooperative Group.

During the last few years several factors have contributed to an increasing change in the medical treatment of advanced colorectal cancer. Among them are the more general acceptance of the impact of chemotherapy on quality of life and survival in first as well as in second-line treatment, the introduction of new drugs and the definition of novel endpoints which can roughly be defined as "patient benefit". For this reason the European Organization for Research and Treatment of Cancer (EORTC) Gastrointestinal Tract Cancer Cooperative Group (GITCCG) felt it was appropriate to organize a workshop with experts from different countries and national groups to discuss in depth several aspects concerning the treatment of patients with advanced colorectal cancer.

Clinical Trials as Topic↗
PubMedDate not supplied

Prolonged survival after resection of pancreatoblastoma and synchronous liver metastases in an adult.

Pancreatoblastoma is an uncommon pediatric neoplasm with distinct acinar and squamoid cell differentiation. Pancreatoblastoma is exceedingly rare in adults with only ten reported cases. Pancreatoblastoma in adults has a poor prognosis and no survival without recurrence exceeding 30 months has been reported. We report the first adult case of pancreatoblastoma revealed by gastric bleeding due to segmental hypertension. On computed tomography scan, the tumor appeared lobulated and extended from the splenic hilum to the portal vein. Two hypervascular centimetric hepatic metastases were observed in segments III and VII. The patient was operated and a distal pancreatectomy with splenectomy associated with two hepatic wedge resections was performed. The diagnosis of pancreatoblastoma was made on immunohistochemical examination. The patient received 6 cycles of adjuvant therapy. After three years of follow-up, the patient was well with no sign of recurrence on computed tomography scan. This case suggests that in the presence of pancreatic tumor of unknown origin, aggressive management including complete surgical resection and adjuvant chemotherapy should be attempted even in the presence of synchronous liver metastases.

Chemotherapy, Adjuvant↗
PubMedDate not supplied

[Resection of liver metastasis of colo-rectal cancer].

Surgical resection currently represents the only available approach to improve the survival rate of patients with liver metastases from carcinoma of colon and rectum. The mean 5-year survival rate in patients treated with liver resection is 25% (with a range from 16 to 45%). Despite the lack of safe criteria for selection of patients with liver metastases, the following factors can give indications to surgical resection: evidence of single or multiple, but unilobar, metastases; lack of hepatic hilum metastases; easy approach; satisfactory liver function after resection; staging and grading of primary tumor, timing between resection of primary tumor and diagnosis of liver metastases; safe margin of liver resection (10 mm) from metastatic lesions. To improve the surgical treatment of liver metastases from colo-rectal cancer, larger series of patients and aggressive surgical approach are needed, with mortality rates acceptable for long-term better results.

Colorectal Neoplasms↗
PubMedDate not supplied

Surgical resection of liver metastases from colo-rectal cancers.

Surgical resection is currently the only potentially curative treatment in some selected patients with colo-rectal liver metastases (LM). Unfortunately only a minority of patients are candidates for resection. Only solitary or unilobar LM that can be removed by partial liver resection, are considered to be resectable. The second condition for the resection of LM is that the primary cancer must be resected. The third condition for resection is that the patient must be able to undergo a major liver resection if it is necessary. Small metastases which do not exceed 5 cm, and appear on the surface of the liver can be removed by a simple wedge resection. If the tumor is larger than 5 cm, or if multiple unilobar nodules are discovered, a major liver resection becomes necessary. Hospital mortality does not exceed 5% in most published series. Five year survivals are very rare when histologically proven colo-rectal LM are left in place. After surgical resection of LM, five year survival rates are close to 25% and range from 18% to 52%. Surgical resection is of benefit to approximately one fourth of the patients, who survive five years or more, but three fourths of the patients have early recurrences. None of the studied criteria can predict which patients will benefit from surgical resection of LM. In order to try to reduce the rate of early recurrences adjuvant chemotherapy has been proposed. No positive data have yet been obtained.

Colonic Neoplasms↗
PubMedDate not supplied

Hepatic vascular exclusion (HVE) for major liver resections.

One hundred fifty-three patients underwent hepatic resection. Hepatic venous exclusion (HVE) was utilized in 23%. Aortic clamping was used in 20% of cases with hepatic venous exclusion. The mean duration of liver ischemia was 33 minutes. HVE increases the resectability of massive posterior or hypervascular liver tumors and prevents the risk of massive bleeding or air embolism. The only counterindication is the presence of severe preexisting cardiac dysfunction.

Hemodynamics↗