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Biomedical subjects

R D Gordon

Publications and source records attributed to R D Gordon.

At least 199 records · Page 11Linked to original sources
PubMed1987

Complications of venous reconstruction in human orthotopic liver transplantation.

In 313 consecutive recipients of 393 orthotopic liver grafts, there were 51 (16.3%) and nine (2.9%) patients who had pre-existing portal vein and inferior vena cava abnormalities, respectively. These abnormalities required adjustments in the transplant operation and were a source of morbidity and mortality. The incidence of thrombosis of the reconstructed portal vein was 1.8%. Only three (0.8%) vena caval thromboses were seen after 393 liver replacements. Venous stenoses or disruptions were rare. Six women with the Budd-Chiari syndrome had liver replacement. Although this disorder is a veno-occlusive disease, five of the recipients achieved prolonged survival, only one had recurrence of disease, and three are alive after 2-6 years.

Adolescent↗
PubMed1987

Liver replacement after massive hepatic trauma.

Two patients sustained massive hepatic injuries from blunt trauma in motor vehicle accidents. At the time of operation, nonreconstructable injuries to the porta hepatis were found in addition to destruction of the right lobe. Life-threatening hemorrhage was controlled, but both patients were left with nonfunctional or inadequate hepatic remnants. Liver transplantation was performed. Both patients recovered after liver replacement. One died 7 weeks later of cytomegalovirus infection. The other recipient is well 16 months later. Liver transplantation is a reasonable option in patients with lethal hepatic injuries or unreconstructable injuries to the porta hepatis.

Accidents, Traffic↗
PubMed1987

Biliary tract complications in human orthotopic liver transplantation.

The results of 393 consecutive orthotopic liver transplants in 313 patients were reviewed to determine the incidence of primary biliary tract complications. There were 52 biliary tract complications in 393 grafts (13.2%), and 5 directly related deaths. Choledochojejunostomy over an internal stent to a Roux-en-Y limb of proximal jejunum (RYCJ-S) was the most frequently used technique (175 cases) and the most successful with only 9 technical failures (5.2%). Choledochocholedochostomy over a T tube (CC-T) was used in 159 cases and was successful in all but 20 cases (12.6%). Other methods of reconstruction were associated with high failure rates or technical complexity that do not justify their use. Biliary leak and obstruction were the most common complications. Leakage after CC-T at the T tube exit site was usually directly repaired, but anastomotic leakage required conversion to RYCJ-S. Obstruction may be relieved by percutaneous balloon dilatation but definitive treatment also usually required conversion to RYCJ-S. The most common complication after RYCJ-S is functional obstruction by a retained stent, which has a low morbidity but may necessitate surgical removal. Anastomotic leaks, which occurred in 2 cases, were successfully managed by revision of the choledochojejunostomy.

Adult↗
PubMed1987

Effect of graded low-dose noradrenaline infusions on noradrenaline clearance in normals and essential hypertensives.

1. In normal subjects and essential hypertensives, plasma noradrenaline (NA) levels, and NA clearance (3H-NA constant infusion), were measured during graded infusion of NA. 2. Plasma levels of NA were similar in both groups, with parallel increases to levels approximately three times basal, but still in the upper normal range. 3. Clearance did not increase in either group with increasing plasma NA levels. There was no correlation between plasma NA achieved and NA clearance, which was similar in hypertensives and normotensives. 5. Insofar as plasma clearance reflects tissue clearance, these studies provide no support for the contention that altered NA metabolism might predispose to elevated NA levels in essential hypertension.

Adult↗
PubMed1987

Aldosterone-producing adenomas responsive to angiotensin pose problems in diagnosis.

1. A subgroup of patients with aldosterone-producing adenoma (APA) have been identified who lack many of the biochemical features regarded as characteristic of APA and used to distinguish APA from bilateral adrenal hyperplasia. 2. In these patients, aldosterone is responsive to infused angiotensin II (angiotensin-responsive APA), which explains their uncharacteristic responses to upright posture, saline infusion and fludrocortisone acetate administration. 3. The angiotensin-responsiveness of these patients may derive from the contralateral adrenal gland, since renin levels are less completely suppressed in angiotensin-responsive APA than in angiotensin-unresponsive APA. 4. However, while the excretion of 18-oxo-cortisol was consistently increased in angiotensin-unresponsive APA, it was normal in angiotensin-responsive APA, consistent with biochemical and biosynthetic distinctiveness residing in the tumours. 5. Angiotensin-responsive APA should always be considered as an alternative diagnosis to bilateral hyperplasia causing primary aldosteronism.

Adenoma↗
PubMed1987

Aldosterone regulation during saline infusion: usefulness of aldosterone/cortisol ratio in the diagnosis of aldosterone-producing adenoma.

1. Saline infusion was performed in normal subjects, in essential hypertensives and in patients with aldosterone-producing adenoma (APA), with serial measurements of plasma aldosterone, cortisol and atrial natriuretic peptide (ANP). The effect of recumbency alone was also observed in the normal subjects. 2. Plasma aldosterone after saline infusion was less than 7 ng per 100 ml in the essential hypertensives and normal subjects, but greater than 9 ng per 100 ml in the patients with APA. 3. The aldosterone/cortisol ratio in normal subjects and in essential hypertensives was unchanged or fell during saline infusion, but rose in five of eight patients with APA. 4. Thus, an increase in aldosterone/cortisol ratio after saline infusion appears to be diagnostic of APA, but its absence does not exclude it.

Adenoma↗
PubMed1987

Effects of angiotensin and noradrenaline on atrial natriuretic peptide levels in man.

1. A significant positive correlation was found between changes in circulating noradrenaline (NA) levels and changes in atrial natriuretic peptide (ANP) levels during NA infusion and clonidine administration. 2. A significant positive correlation was also found between changes in arterial blood pressure and changes in ANP level during infusion of angiotensin II and of NA. 3. Two patients with very high circulating NA levels due to phaeochromocytoma, but receiving alpha- and beta-blockade, did not have clearly elevated ANP. A third not receiving medications and aged 73 years had elevated levels. 4. Atrial natriuretic peptide response to NA and angiotensin II may be mediated by changes in blood pressure levels or increased noradrenergic and angiotensinergic receptor activity in the atria or both. Atrial natriuretic peptide may have a role in blood pressure regulation in both normotensive and hypertensive man.

Adolescent↗
PubMed1987

Use of OKT3 with cyclosporin and steroids for reversal of acute kidney and liver allograft rejection.

OKT3 monoclonal antibody therapy was added to preexisting baseline immunosuppressive treatment with ciclosporin and steroids to treat rejection in 52 recipients of cadaveric livers and 10 recipients of cadaveric kidneys. Rejection was controlled in 75% of patients treated, often after high-dose steroid therapy had failed. Rejection recurred during the 17-month follow-up period, after completion of OKT3, in only 25% of the patients who had responded. The safety and effectiveness of this monoclonal therapy, added to ciclosporin and steroids, has been established in this study.

Adolescent↗
PubMed1987

Monoclonal antibody therapy with ciclosporin and steroids in nonmatched cadaveric renal transplants.

Thirty-six ciclosporin-prednisone-treated recipients of nonmatched cadaver renal allografts were given a course of Orthoclone OKT3 monoclonal antibody for steroid-resistant cell-mediated rejection. Although side effects were common, only 2 patients had to be withdrawn from therapy and there were no deaths related to therapy. Twenty-three (63.9%) allografts were rescued with OKT3 therapy and 21 (58.3%) of the grafts have continued to function well. We conclude that OKT3 is an effective agent for the treatment of steroid-resistant cell-mediated rejection and that rebound rejection can be prevented in most patients if adequate therapy with ciclosporin-prednisone is maintained.

Adolescent↗
PubMed1987

Voltage-sensitive sodium channels: an evolving molecular view.

Sodium channel proteins have now been isolated from a number of nerve and muscle preparations. All are characterized by the presence of a very large glycoprotein subunit of approximately 260 kilodaltons which may contain the structural features required for voltage-dependent channel gating and cation selectivity. These purified proteins have been reconstituted into vesicle systems and planar bilayers and demonstrate the ensemble and single-channel behavior characteristic of the native sodium channel. Although the sodium channel from eel appears to consist of only the 260-kilodalton protein, the channels from rat brain and rat or rabbit skeletal muscle contain one or more smaller subunits of 37-39 kilodaltons. In skeletal muscle, a 38-kilodalton subunit is present in both conventionally purified channel and channel isolated with immunoaffinity techniques. The stoichiometry of the large (alpha) and the small (beta) subunits appears to be 1:1 in skeletal muscle but 1:2 in rat brain. The role of the small subunits in the normal functioning of the sodium channel remains to be defined.

Animals↗
PubMed1987

Angiotensin-responsive aldosterone-producing adenoma masquerades as idiopathic hyperaldosteronism (IHA: adrenal hyperplasia) or low-renin essential hypertension.

We have identified a subgroup of patients with aldosterone-producing adenoma (APA) who are responsive to angiotensin. Thus, a fall in plasma aldosterone (PA) during saline infusion may cause confusion with low-renin essential hypertension. Responsiveness of PA to angiotensin infusion and to upright posture may cause confusion with bilateral hyperplasia. Renin levels were not as completely suppressed in this angiotensin-responsive subgroup, leading to speculation that non-tumorous adrenal glomerulosa might also be less suppressed and might respond to angiotensin. This is unlikely, since angiotensin infusion soon after removal of the adenoma produced aldosterone levels of less than 10% of those achieved preoperatively. A biosynthetic peculiarity of the tumours is more likely, since urinary 18-oxo-cortisol levels were normal in this subgroup (as in bilateral hyperplasia) and raised in the more typical angiotensin-unresponsive subgroup (as in glucocorticoid-suppressible hyperaldosteronism). Since angiotensin-responsive tumours respond just as well to surgery as angiotensin-unresponsive tumours, it is important not to misdiagnose this subgroup as bilateral hyperplasia or low-renin essential hypertension.

Adenoma↗
PubMed1987

Atrial natriuretic peptide levels during angiotensin infusion and indomethacin administration are consistent with angiotensin-mediated regulation in man.

Low-dose angiotensin II (ANG II) infusion raised plasma atrial natriuretic peptide (ANP) levels only when endogenous renin-angiotensin levels were low, as in aldosterone-producing adenoma. When plasma renin activity (PRA) levels rose tenfold following removal of the tumour, low-dose ANG II infusion no longer stimulated ANP, but fivefold higher doses did. Indomethacin lowered both PRA and ANP in Bartter's syndrome and in normal subjects. The effect of indomethacin on ANP is probably not direct, since it did not lower ANP in aldosterone-producing adenoma. Neither did it lower PRA in aldosterone-producing adenoma, and in most studies ANP and PRA moved in parallel, consistent with positive regulation of ANP by ANG II. When ANG II infusion stimulated ANP, it also raised blood pressure, which could therefore be mediating the effects of ANG II on ANP. However, both PRA and ANP are high in Bartter's syndrome, while blood pressure is normal or low, and indomethacin lowers PRA and ANP in Bartter's syndrome and in normal subjects without lowering the blood pressure. The relative importance of regulatory factors such as central blood volume/atrial pressure and ANG II level probably varies in different situations. In aldosterone-producing adenoma, a high central blood volume appears to over-ride the effect of a low ANG II level. In Bartter's syndrome a high ANG II level appears to over-ride the effect of low central blood volume.

Adenoma↗
PubMed1987

Analysis of donor criteria for the prediction of outcome in clinical liver transplantation.

The results of 219 orthotopic human liver transplants performed during 1985 at the University of Pittsburgh were reviewed to determine whether donor parameters could be used to predict the quality of early graft function. Multivariate discriminant analysis demonstrated that traditional parameters of donor assessment are unreliable predictors of poor graft function. Furthermore, 56% of the donors considered poor by conservative selection criteria produced livers with good early posttransplant function. Survival of recipients of primary allografts from donors rated poor was no different than survival of recipients of allografts from donors rated good.

Adolescent↗
PubMed1987

OKT3 in the reversal of acute hepatic allograft rejection.

OKT3 was an effective immunosuppressant agent in patients with acute cell-mediated allograft rejection that had not responded to initial steroid therapy. OKT3 was also valuable for treating patients with early hepatic graft dysfunction caused by other factors than rejection. In such recipients, the doses of CyA can be greatly reduced, allowing recovery of frequently damaged kidneys while maintaining effective immunosuppression.

Adolescent↗