Cushing's syndrome caused by an adrenal adenoma

A 10-year-old boy presented with features of Cushing's syndrome. Investigations, including ultrasound scan and computed tomography scans, demonstrated a right adrenal tumor. The tumor was excised and histologically found to be an encapsulated adrenal adenoma. Surgical excision is the treatment of choice for adrenal tumors. However, because it is often difficult to differentiate benign from malignant lesions on histopathologic grounds, these patients need a regular long-term follow-up.

Inflammatory mediators in adults undergoing cardiopulmonary bypass: comparison of centrifugal and roller pumps

BACKGROUND

The nonocclusive centrifugal pump is used for cardiopulmonary bypass (CPB) and mechanical cardiac assistance. This study examined its impact on proinflammatory cytokine release.

METHODS

Forty-one patients undergoing elective coronary artery bypass grafting were randomized prospectively to either a standard roller pump group (n = 21) or a centrifugal vortex pump group (n = 20) for CPB. The two groups were well matched in age, sex, severity of disease, and duration of CPB and aortic cross-clamping. Plasma levels of the cytokines tumor necrosis factor-alpha, interleukin-1beta, interleukin-6, and interleukin-8, as well as terminal complement, neutrophil counts, and leukocyte elastase, were analyzed before, during, and after CPB.

RESULTS

In both groups, traces of tumor necrosis factor-alpha were observed infrequently and interleukin-1beta was not detected. Plasma levels of interleukin-6 and interleukin-8 increased during and after CPB, reaching a peak at 2 hours after protamine administration in both groups before returning toward baseline at 24 hours. The release of interleukin-6 was significantly greater in the centrifugal group (p < 0.05), whereas the interleukin-8 concentration did not differ between the groups throughout the study period. Levels of terminal complement increased in both groups perioperatively, reaching a peak 30 minutes after protamine administration, whereas neutrophil counts and elastase peaked 2 hours after protamine administration. Plasma terminal complement, neutrophil counts, and elastase release were significantly higher in the centrifugal group (p < 0.05). Peak terminal complement correlated (r = 0.64, p < 0.01) with peak elastase in the centrifugal group only.

CONCLUSIONS

This study confirms the proinflammatory nature of CPB in adults and demonstrates that use of the centrifugal pump induces a greater systemic inflammatory response than use of the standard roller pump.

Release of proinflammatory cytokines during pediatric cardiopulmonary bypass: heparin-bonded versus nonbonded oxygenators

BACKGROUND

Heparin bonding of the cardiopulmonary bypass (CPB) circuit may be associated with a reduced inflammatory response and improved clinical outcome. The relative contribution of a heparin-bonded oxygenator (ie, >80% of circuit surface area) to these effects was assessed in a group of pediatric patients.

METHODS

Twenty-one pediatric patients undergoing CPB operations were assigned randomly to receive either a heparin-bonded oxygenator (group H, n = 11) or a nonbonded oxygenator (group C, n = 10) in otherwise nonbonded circuits. The two groups were similar in pathology, age, weight, CPB time, and cross-clamp time. Plasma levels of the cytokines tumor necrosis factor-alpha, interleukin-6, and interleukin-8, as well as terminal complement complex, neutrophils, and elastase, were analyzed before, during, and after CPB.

RESULTS

Significant levels of tumor necrosis factor-alpha were not detected in either group. Plasma levels of all other markers increased during and after CPB compared with baseline. Plasma levels of interleukin-6 peaked in both groups 2 hours after the administration of protamine but remained significantly higher in group C 24 hours after operation. Plasma concentrations of interleukin-8 peaked at similar levels in both groups 30 minutes after protamine administration and returned to baseline thereafter. Levels of terminal complement complex and elastase peaked in both groups 30 minutes after protamine administration. Plasma levels of terminal complement complex were significantly higher at the end of CPB and after protamine administration in group C. Elastase levels were significantly higher 2 and 24 hours after CPB in group C. The ventilation time of patients in group H was significantly lower than that of patients in group C: 10 (range, 3 to 24) versus 22 (range, 7 to 24) hours, respectively (p < 0.01).

CONCLUSIONS

The present study confirms the proinflammatory nature of pediatric operations and demonstrates a lessened systemic inflammatory response with the use of heparin-bonded oxygenators. This is achieved without bonding of the entire circuit, which could have significant cost-benefit implications by negating the need for custom-built heparin-bonded circuitry.

Two-stage repair of adult coarctation of the aorta with congenital valvular lesions

BACKGROUND

Coarctation of the aorta associated with intracardiac pathologic conditions presenting in adult life poses some technical and management challenges. When deciding on the best surgical strategy, the surgeon must pay careful attention to the changes that will occur in the circulation.

METHODS

In our small series of 3 patients, the intracardiac pathologic lesions were corrected first, and the coarctation was repaired as a second-stage procedure 2 to 3 months later.

RESULTS

All patients had an uneventful recovery from both operations. The potential problems of renal impairment caused by inadequate perfusion during bypass and perioperative systemic hypertensive complications resulting from coarctation of the aorta were not observed. At the time of coarctation repair as a second-stage procedure, anticoagulation was easily controlled. All 3 patients had short intensive care unit and hospital stays.

CONCLUSIONS

Staged surgical repair of this complex pathologic combination in adult patients is a safe option and is easy to manage perioperatively.

Blood vessels in liver metastases from both sarcoma and carcinoma lack perivascular innervation and smooth muscle cells

Hepatic arterial infusion (HAI) chemotherapy as treatment for human colorectal liver metastases is promising, but not entirely satisfactory. Improved drug delivery during HAI may be achieved by manipulating the different control mechanisms of normal versus tumour blood vessels. The peptidergic/aminergic innervation of vessels in normal liver and in two animal models of liver metastasis (Lister Hooded rat with syngeneic MC28 sarcoma; athymic (nude) rat with human HT29 carcinoma) was investigated to assess the suitability of these models for future pharmacological studies. Normal liver and metastases were studied immunohistochemically for the presence of protein gene product 9.5 (PGP), neuropeptide Y (NPY), tyrosine hydroxylase (TH), calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP) and substance P (SP). Perivascular innervation was also examined by transmission electron microscopy. In Lister rat normal livers, perivascular immunoreactive nerve fibres containing PGP, NPY, TH, CGRP and SP were observed around the interlobular blood vessels near the hilum and in the portal tracts. The highest density was seen for PGP, followed in decreasing order, by NPY, TH, CGRP and SP. VIP-immunoreactive nerves were absent. No immunoreactive nerves were observed in the hepatic lobule. In athymic rat livers, the pattern of innervation was similar, except that SP immunoreactivity was more sparse. No perivascular immunoreactive nerves were observed in either MC28 or HT29 tumours. Electron microscopy confirmed the absence of perivascular nerves. Smooth muscle cells were not observed in tumour blood vessel walls. These results are comparable with previous observations on human liver metastases and suggest that the animal models may be suitable for pharmacological studies on vascular manipulation of HAI chemotherapy.

Cell activation and thrombin generation in heparin bonded cardiopulmonary bypass circuits using a novel in vitro model

OBJECTIVE

It is generally agreed that when the blood contact surfaces of a cardiopulmonary bypass circuit are treated with a layer of heparin molecules the activation of the humoral pathways is attenuated. However, there is still debate as to whether heparin-bonded circuits reduce thrombin generation. This study aims to examine the effects of immobilized heparin on cell activation and thrombin generation in a novel, well controlled model of cardiopulmonary bypass.

METHODS

The model used consisted of a heparin-bonded and a non-bonded cardiopulmonary bypass circuit perfused in tandem with the same unit of fresh heparinized (3.3 U/ml) human blood for a period of 6 h. Samples were taken for analysis from the bag just prior to perfusion and at 30, 60, 120 and 360 min of perfusion. Whole blood was used to analyse platelet and white blood cell count, haematocrit and activated coagulation time. Plasma samples were prepared for batch analysis of the cell activation markers p-selectin, elastase and interleukin-8, and the thrombin generation markers thrombin-antithrombin and prothrombin fragment F1 + 2. A sample of tubing was taken from each circuit at the end of the perfusion and prepared for visualization by scanning electron microscopy.

RESULTS

Platelet counts were significantly reduced in the non-bonded circuits compared with the heparin-bonded circuits at 30 (22 versus 200 x 10(9)/L P < 0.01), 60 (26 versus 193 x 10(9)/L P < 0.01) and 120 min (28 versus 193 x 10(9)/L P < 0.01) as were white blood cell counts at 30(1.5 versus 2.7 x 10(9)/L P < 0.01), 60 (0.9 versus 2.4 x 10(9)/L P < 0.01), 120 (0.9 versus 1.8 x 10(9)/L P < 0.01) and 360 min (0.4 versus 0.9 x 10(9)/L P < 0.05). The concentration of p-selectin was found to be significantly higher in the non-bonded circuits than in the heparin-bonded circuits at 30 (37 versus 29 ng/ml P < 0.01), 60 (37 versus 28 ng/ml P < 0.01). 120 (42 versus 27 ng/ml P < 0.01) and at 360 min (72 versus 46 ng/ml P < 0.01). Elastase was elevated in the non-bonded circuits at 30 (570 versus 145 micrograms/l P < 0.01), 60 (646 versus 278 micrograms/l P < 0.01) and 120 min (613 versus 403 micrograms/l P < 0.05) and interleukin-8 at 120 (705 versus 520 pg/ml P < 0.05) and 360 min (11326 versus 9910 pg/ml P < 0.05). A similar picture was found for the thrombin generation markers. Thrombin-antithrombin complexes were raised in the non-bonded circuits compared with heparin-bonded circuits at 60 (24 versus 13 micrograms/l P < 0.05) and 120 min (46 versus 17 micrograms/l P < 0.05) as was prothrombin fragment F1 + 2 at 30 (1.1 versus 0.7 nmol/l P < 0.01), 60 (1.3 versus 0.7 nmol/l P < 0.01), 120 (1.8 versus 0.9 nmol/l P < 0.01) and 360 min (15.0 versus 13.6 nmol/l P < 0.05). Scanning electron microscopy revealed a greater amount of adherent material on the non-bonded surface relative to the heparin-bonded surface.

CONCLUSIONS

In a cardiopulmonary bypass circuit perfused with human blood the activation of platelets and white blood cells has been seen to be significantly reduced in the presence of a heparin-bonded surface. Thrombin generation due to contact activation of the intrinsic coagulation pathway is also reduced.

Increase in immunoreactivity for endothelin-1 in blood vessels of rat liver metastases: experimental sarcoma and carcinoma

Using electron immunocytochemistry, blood vessels in the normal rat liver and in 2 different animal models of liver metastases: (1) Hooded Lister rat with MC28 tumour, a sarcoma, and (2) nude rat with HT29 tumour, a carcinoma, were investigated for the presence of endothelin-1. In the normal livers, small subpopulations of vascular endothelial cells displayed discrete immunoreactivity for endothelin-1. In the livers with malignant tumours, there was a substantial increase in endothelin-1-immunoreactive endothelial cells in vessels located at the tumour periphery. In the controls, antibody to endothelin-1 also labelled sporadically some fibroblast/fibroblast-like cells associated with the blood vessels. In contrast, intense immunoreactivity for endothelin-1 was frequently associated with the tumour cells and/or fibroblast cells in both types of tumour examined.

Low heparinization with heparin-bonded bypass circuits: is it a safe strategy?

BACKGROUND

The use of heparin-bonded cardiopulmonary bypass circuits with reduced doses of heparin sodium has been shown to give hemostatic benefits to the patient. However, fears persist that the use of less heparin may put the patient at risk for thrombotic events. This work tested the hypothesis that heparin-bonded circuits per se are effective in preserving cells and reducing thrombin generation when a reduced dose of heparin is used in vitro.

METHODS

Simulated extracorporeal circulation was carried out using the same unit of fresh heparinized (1.1 U/mL) human blood to simultaneously perfuse a heparin-bonded circuit and a nonbonded circuit. Samples were taken at 30, 60, 120, and 360 minutes and analyzed for markers of cell activation and thrombin generation.

RESULTS

The concentrations of platelet and white blood cell activation markers were found to be significantly lower in the heparin-bonded circuits compared with the nonbonded circuits. In addition, markers of thrombin generation were significantly lower in bonded circuits. Scanning electron microscopy revealed fewer adherent cells and less debris on the bonded surface compared with the nonbonded surface.

CONCLUSIONS

Cell activation and thrombin generation were significantly reduced as a result of the presence of immobilized heparin in a system of cardiopulmonary bypass with reduced plasma heparin. However, evidence of contact activation in the bonded circuits was found after 120 minutes, indicating that anticoagulation in the system was not adequate. This becomes more important clinically where the extrinsic pathway of coagulation is also involved.

"Low-dose" aprotinin modifies hemostasis but not proinflammatory cytokine release

BACKGROUND

Cytokines are implicated in the pathogenesis of the "whole-body inflammatory response" that may complicate the period after cardiopulmonary bypass (CPB). Low-Dose aprotinin in the pump during CPB has been shown to improve postoperative hemostasis and platelet preservation. We tested the hypothesis that low-dose aprotinin influences the inflammatory reaction (in terms of cytokine release) after CPB.

METHODS

In a prospective, randomized study, 36 patients undergoing elective coronary artery bypass grafting were investigated. Nineteen patients received low-dose aprotinin (2 x 10(6) KIU (280 mg] in the pump), and a control group of 19 did not. Complement activation, cytokine production, leukocyte elastase release. D-dimer level, full blood count, postoperative blood loss, and transfusion requirements were analyzed before, during, and after after CPB.

RESULTS

Interleukin-1 beta was not detected in either group, whereas traces of tumor necrosis factor-alpha were infrequently observed. Plasma elastase, interleukin-6, interleukin-8, and neutrophil count increased (p < 0.001) during and after CPB compared with the baseline levels, reaching a peak at 2 hours after protamine administration in both groups before returning toward baseline at 24 hours. Proinflammatory cytokine markers did not differ significantly (p > 0.1) between the groups throughout the study period. The C5b-9 level increased (p < 0.001) in both groups perioperatively, reaching its peak 15 minutes after protamine. Twenty-four-hour postoperative blood loss was significantly (p < 0.001) reduced in the aprotinin group in association with markedly reduced D-dimer levels (p < 0.001). Patients in the aprotinin group also received significantly less banked blood postoperatively than the control group (p < 0.01).

CONCLUSIONS

Low-dose aprotinin fails to modify proinflammatory cytokine release, yet confers hemostatic improvement through reduced fibrinolysis in patients undergoing routine coronary artery bypass grafting.

Characterization of high-affinity protein D binding sites on the surface of rat epididymal spermatozoa

125I-labeled protein D was shown to bind to whole rat epididymal sperm in a time-dependent, saturable, and reversible manner. Scatchard analysis indicates that there are 3.4 x 10(5) binding sites/sperm cell with a binding efficiency (Kd) of 2.3 x 10(-10) M. Binding of protein D to sperm reaches equilibrium by 95 min. and is reversible by 30 min. Specific binding of protein D to sperm pre-treated with a dilute trypsin solution is reduced significantly when compared with controls. Our findings establish that protein D-specific binding proteins displaying characteristics of a true receptor are present on the surface of rat epididymal sperm.

The absence of autonomic perivascular nerves in human colorectal liver metastases

The peptidergic/aminergic innervation of normal liver and tumour blood vessels was investigated in order to determine vascular control with a view to improving the efficacy of hepatic arterial cytotoxic infusion in the treatment of colorectal liver metastases. Selected areas of liver metastases and macroscopically normal liver from resection specimens (n = 13) were studied using light microscope immunohistochemistry for the presence of protein gene product 9.5 (PGP), vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), calcitonin gene-related peptide (CGRP), substance P (SP) and tyrosine hydroxylase (TH). The ultrastructure of blood vessels supplying liver metastases and their perivascular innervation were also examined by transmission electron microscopy. In the normal liver, perivascular immunoreactive nerve fibres containing PGP, NPY and TH were observed around the interlobular blood vessels and along the sinusoids and the central vein of the hepatic lobule. The greatest density of immunoreactive nerve fibres was seen for PGP, followed (in decreasing order) by NPY and TH. VIP, SP and CGRP immunoreactivity was observed only in nerve bundles associated with the large interlobular blood vessels. In contrast, no perivascular immunoreactive nerves were observed in colorectal liver metastases. Electron microscopy confirmed the absence of perivascular nerves in liver metastases. In addition, it showed that the walls of these blood vessels were composed of a layer of endothelial cells surrounded by an incomplete or, very rarely in the periphery of the tumour, a complete, layer of synthetic phenotype of smooth muscle-like cells. These results imply that the blood vessels supplying liver metastases are bereft of normal neuronal regulation; whether there is a role for endothelial cell control of blood flow in these vessels is not yet known.

Primary ocular relapse in acute lymphoblastic leukemia

Relapse of acute lymphoblastic leukaemia (ALL) occurred in the anterior segment of four children. All cases had been treated according to the Medical Research Council's UK Acute Lymphoblastic Leukaemia trial protocol (UKALL) including 2 years of continuation chemotherapy. In three cases the diagnosis was confirmed by anterior chamber aspirate while in one case the diagnosis was presumed on clinical grounds alone. All four cases experienced isolated leukaemic relapse in the anterior segment within 2 months of stopping therapy. The months immediately following cessation of continuation chemotherapy as part of the UKALL regime appear to represent a 'high-risk' period for primary anterior segment relapse of ALL. Children with ALL presenting with uveitis should be regarded as having leukaemic relapse and anterior chamber taps with or without an iris biopsy should be considered to confirm this diagnosis. Early diagnosis and treatment of ocular leukaemic relapse is likely to give these children the best chance of ultimate cure.

Calbindin immunoreactivity of horizontal cells in the developing rabbit retina

Horizontal cells are retinal interneurons that establish inhibitory feedback loops within the outer plexiform layer of the primary visual pathway. Most mammalian retinas contain two types of horizontal cells. A-type horizontal cells have neuritic branches that contact cone photoreceptors exclusively, while the B-type horizontal cells have dendritic branches that contact cones, in addition to axons that form synapses with rod photoreceptors. Immunoreactivity for calbindin, a calcium binding protein involved in calcium transport, was used as a marker for horizontal cells during post-natal development of the rabbit retina. On post-natal days 1, 3 and 5, calbindin immunoreactivity is limited to a single population of A-type horizontal cells. They appear as a monolayer of cells with broad tapering processes, establishing the proximal border of the nascent outer plexiform layer and forming a target for ingrowing cone photoreceptor terminals. The size and density of the cell bodies and the length of neuritic processes are essentially unchanged during this period, which corresponds to the time of peak expression of GABAergic markers in horizontal cells. Coincident with a decrease in GABAergic markers and the completion of cone-to-horizontal cell synaptogenesis by day 7, changes within the horizontal cell mosaic are detected morphometrically. A delayed phase of overall cell growth results in a 70% increase in average somal diameter (representing a 3.7-fold increase in spherical volume), a six-fold increase in mean neurite length and a decrease in cell density to one-third of that found in the newborn. We conclude that the process of terminal differentiation of horizontal cells is not complete until some time after the second post-natal week. Furthermore, the expression of GABAergic markers is associated primarily with early maturational events, whereas expression of calbindin is sustained throughout post-natal development, suggesting a prominent role for calcium dependent mechanisms at all development stages.

Myocardial infarction in a young adult due to Kawasaki disease. A case report and review of the late cardiological sequelae of Kawasaki disease

Although Kawasaki disease is generally self-limiting, 15-25% of children with Kawasaki disease may develop significant cardiovascular sequelae, presentation may occur acutely or late (death has been reported up to 14 years after the acute illness). The most common late complication is the persistence of coronary artery aneurysms, these may produce myocardial ischaemia and even myocardial infarction, valvular dysfunction has also been reported. However the occurrence of late abnormalities of myocardial function is controversial. We describe a 24-year-old man who presented with myocardial infarction as a result of coronary artery aneurysms caused by Kawasaki disease, he gave no recent or childhood history of prodromal illness compatible with Kawasaki disease. The diagnosis was confirmed at post mortem.

Evaluation of nutritional status and its effects on morbidity and mortality of surgical patients

Sixtynine patients (31 males and 38 females) above the age of 12 years undergoing surgery under general anaesthesia were selected for this study. Thirty percent males and 29% females were depleted, 55% and 37% males and females, respectively, were normal and 13% and 34% males and females, respectively, were obese as indicated by Body-mass index (BMI). Measurement of midarm-muscle-circumference (MAMC) indicated mild to moderate protein deficiency in 32% of the patients while triceps skinfold thickness (T.S.T) indicates mild to severe calorie deficiency in 68% males and 50% females. Dietary intake both pre and post operatively was unsatisfactory. Pre-operatively 26% of the females had Hb level below normal (less than 11 G%). Only 3-5% of the patients had protein and albumin level below normal (less than 3.5 G%). Post-operatively all the anthropometric measurements as well as serum protein and albumin levels decreased and BUN increased significantly indicating body catabolism. Post operative hospital stay was significantly more in undernourished patients.