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Biomedical subjects

S Lynch

Publications and source records attributed to S Lynch.

126 records · Page 7Linked to original sources
PubMedDate not supplied

Evidence that host size determines liver size: studies in dogs receiving orthotopic liver transplants.

Orthotopic liver transplantation was performed in two groups of dogs; Group I animals consisted of large dogs that served as recipients of livers obtained from smaller dogs while Group II animals consisted of dogs that received liver from donor dogs of nearly the same size. The small-for-size livers transplanted into the Group I dogs rapidly increased in size over the course of 2 weeks until they achieved a size equal to that originally present in the larger recipient dogs. In contrast, the livers transplanted into dogs of the same size as the donors underwent some degree of atrophy. In both groups of animals, plasma levels of insulin and glucagon and hepatic (graft) activities of thymidine kinase and ornithine decarboxylase were followed serially. The only difference between the two groups of animals for these measures was that the ornithine decarboxylase activity rose to a greater degree in the liver that underwent graft enlargement. These data suggest that recipient size determines, at least in part, liver graft size once it is transplanted. These data also suggest that of the parameters followed, only ornithine decarboxylase activity parallels the finding of growth of the transplanted liver.

Animals↗
PubMedDate not supplied

Pancreatic hormones and amino acid levels following liver transplantation.

Glucose intolerance, hyperinsulinemia, peripheral insulin resistance and hyperglucagonemia are common in patients with advanced liver disease. These abnormalities in the plasma levels of the pancreatic hormones, insulin and glucagon have been thought to be responsible, at least in part, for the abnormal plasma ratio of branched-chain amino acids to aromatic amino acids. To evaluate this issue, plasma levels of glucose, insulin, glucagon, C-peptide and the branched-chain and aromatic amino acids were measured before and serially after orthotopic liver transplantation in 9 humans and 5 dogs. The abnormal plasma amino acid levels rapidly improved and achieved normal levels following orthotopic liver transplantation. Insulin levels also became normal following orthotopic liver transplantation, despite enhanced insulin secretion documented by an even further increased level of C-peptide. In contrast, the baseline abnormal plasma glucagon levels which are commonly seen in cirrhotics became even more abnormal following orthotopic liver transplantation. Despite this progressive increase in the abnormally elevated plasma glucagon levels, plasma amino acid levels, both branched-chain and aromatic, became normal. These data demonstrate that before and after orthotopic liver transplantation, there is: (i) no relationship between the changes in the plasma levels of glucagon and changes observed in the plasma level of amino acids; and (ii) plasma insulin and amino acid levels change in the same direction. In addition, these changes in plasma insulin and amino acid levels following orthotopic liver transplantation occur despite enhanced secretion of insulin evidenced by the progressive increase in plasma levels of C-peptide.

Adolescent↗
PubMedDate not supplied

Pre-operative nutritional support in children with end-stage liver disease accepted for liver transplantation: an approach to management.

Pre-operative nutritional support was studied in 28 children with end-stage liver disease awaiting orthotopic liver transplantation. Nasogastric supplemental administration of a standard semi-elemental enteral nutritional formula was compared with a similar formula enriched with branched chain amino acids, and with a group receiving oral nutrition only. The duration of treatment in all groups was similar (mean 90 days). Energy intakes in the supplemented groups were 120-150% of recommended daily intakes (RDI), whereas ad libitum intakes in the oral group ranged 58-100% RDI. A significant improvement in mean Z-score for body weight (denoting catch-up) was noted only in those children who received nasogastric supplements enriched with branched-chain amino acids. The standard enterally-fed group maintained their body weight and Z-scores did not change significantly. In contrast, body weight Z-scores in those fed orally declined significantly. Nutritional supportive therapy of malnourished children with end-stage liver disease can minimize or improve nutritional status in children awaiting liver transplantation. The use of nutritional formulae rich in branched-chain amino acids may have nutritional advantages in children with chronic liver disease which require further study and evaluation.

Amino Acids, Branched-Chain↗
PubMedDate not supplied

Cytomegalovirus infection after liver transplantation in children.

Post-liver transplant cytomegalovirus (CMV) infection (seroconversion or virus isolation) and CMV disease (infection plus clinical signs and symptoms) were studied in relation to pretransplant recipient and donor serology, age, nutritional status and the effect of paediatric versus adult (reduced size) grafts. Of 70 children receiving 79 transplants, 26 (37%) had evidence of CMV infection, and eight (11.5%) had evidence of CMV disease, four of whom died. The primary infection rate (where the recipients were CMV negative) was 71% with mortality of 7% with most receiving a CMV-positive graft. The active secondary infection rate (reactivation or reinfection, where the recipients were CMV positive) was 60% with mortality of 12.5%. No significant differences in infection or disease rates were found comparing malnourished versus well-nourished patients, or between those who received whole or reduced-size grafts. The high prevalence of CMV infections supports the view that clinical signs alone are inadequate to direct investigations for CMV. Both primary and active secondary CMV infection can result in serious morbidity and mortality in children receiving liver transplants. These data do not support the strategy of providing immunoprophylaxis to seronegative recipients only, at least in paediatric liver transplantation.

Adolescent↗
PubMedDate not supplied

Fetal echocardiography at West Virginia University: a seven-year experience.

The last decade has seen tremendous growth and utilization of fetal echocardiography. In order to assess the indications and yield of fetal echocardiography at West Virginia University, all fetal echocardiograms performed during a seven-year period were reviewed. There were 931 fetal echocardiograms performed on 803 women during this time period and there was a large increase in referral rate as has been seen in other regions. The highest yield of abnormalities was seen in fetuses referred secondary to the finding of an abnormal fetal cardiac exam on routine screening ultrasound (55.6%), or fetal anomalies of other organs (8.2%). These two indications alone were responsible for 77.8% of identified cases of congenital heart disease by fetal echocardiography during this time period. The resultant findings highlight the need for thorough obstetrical screening ultrasound, including the four chamber view of the heart.

Echocardiography↗
PubMedDate not supplied

Phenotypic and genetic alterations in pre-cancerous cells in the colon.

Cell dysplasia in polyps and in ulcerative colitis are thought to be the pre-cancerous lesion leading to invasive colon cancer. Many polyps and dysplastic lesions in ulcerative colitis have phenotypic changes (blood group antigen, cytokeratins, CEA, TAG-72.3 antigen expression) and genetic changes (c-K-ras mutation, enhanced c-myc expression and pp60c-src activity) which are characteristic of invasive cancers. Thus, these early pre-cancerous lesions may be a late stage in the genetic evolution of colon cancer.

Colonic Neoplasms↗