Pathological complications of non-survivors of newborn extracorporeal membrane oxygenation

The pathology was reviewed of the early deaths identified from the first 50 neonates treated with extracorporeal membrane oxygenation (ECMO) during its introduction to the UK. Fifteen neonates died during or shortly after ECMO between August 1989 and June 1992. Data on 12 are presented (three did not have a postmortem examination). The clinical diagnoses at referral for ECMO were as follows: persistent pulmonary hypertension of the newborn (six infants), primary congenital pneumonia (one infant), community acquired pneumonia (two infants), birth asphyxia (one infant), respiratory distress syndrome (one infant), and meconium aspiration syndrome (one infant). In our group, at necropsy, five had significant haemorrhage (three intracranial, one pulmonary, one pericardial and intraventricular). Three of five infants with evidence of haemorrhage also had signs of sepsis. Six infants had evidence at necropsy of systemic sepsis, five showed evidence of severe anoxic brain injury, and four infants had cerebellar haemorrhages. Three infants had evidence of myocardial ischaemia. It is difficult to discriminate between the relative influence of the primary diagnosis, the mode of treatment, and the severity of presentation in the genesis of this pathology. It is likely that the extent and severity of some of the findings represent a pathological progression that would have been interrupted by the death of the patient, had ECMO not been instituted.     

Adenosine A2A receptor agonists increase Fos-like immunoreactivity in mesolimbic areas

Expression of the early-gene c-fos is an useful method for studying potential sites of action of drugs active in the CNS. Stimulation of adenosine A_2A receptors by CGS 21680 (5 mg/kg) induced an increase in Fos-like immunoreactivity in the rat nucleus accumbens shell, while in the rostral pole and core CGS 21680 induced Fos-like immunoreactivity only after a high dose. CGS 21680 (5 mg/kg) stimulated c-fos expression also in the lateral septal nucleus and dorso-medial striatum, but not in the dorso-lateral striatum. A similar pattern of Fos-like immunoreactivity was obtained after administration of the A_2A agonist HENECA (5 mg/kg) which displays higher selectivity for A_2A receptors than CGS 21680. Administration of the selective A_2A antagonist SCH 58261 counteracted CGS 21680-induced Fos-like immunoreactivity. Lesions of the dopaminergic mesostriatal projection by 6-hydroxydopamine and stimulation of dopamine D₂/D₃ receptors by quinpirole, prevented CGS 21680-induced Fos-like immunoreactivity in the nucleus accumbens shell. The present results show that stimulation of A_2A receptors induces a profile of c-fos expression similar to that of atypical neuroleptics. A_2A receptor stimulation has been reported to have dopamine antagonistic actions, it is therefore suggested that A_2A agonists might have antipsychotic activity without producing extrapyramidal side effects.     

Parathyroid adenomas evaluated by Tl-201/Tc-99m pertechnetate subtraction scintigraphy and high-resolution ultrasonography

Thallium-201/technetium-99m pertechnetate subtraction scintigraphy of the parathyroid glands was performed in a prospective study of 33 patients who had undergone bilateral neck exploration for elevated serum calcium and serum parathyroid hormone levels. In 31 cases, the Tl-201/Tc-99m subtraction technique yielded an overall sensitivity of 81%, specificity of 99%, and accuracy of 94% for identifying solitary parathyroid adenomas. Tl-201/Tc-99m subtraction scintigraphy correctly identified 73% of parathyroid adenomas weighing less than 499 mg, 79% of those weighing 500-1,499 mg, and 100% of adenomas weighing more than 1,500 mg. In a subgroup of 24 patients with solitary parathyroid adenomas who underwent both scintigraphy and high-resolution sonography, the sensitivity, specificity, and accuracy of both procedures were similar.     

Outcome, incidence, and timing of infectious complications in small bowel and multivisceral organ transplantation patients

BACKGROUND: Infectious complications still represent a major cause of morbidity and mortality in patients with organ transplantation. In particular, small bowel or multivisceral transplantation is complicated to a greater extent than other grafts as a consequence of infectious complications including sepsis. METHODS: This prospective study assessed outcome, incidence, and timing of infections in sequential patients undergoing small bowel or multivisceral transplantation (SB/MVTx) performed at a university transplant center between January 2001 and October 2003. Nineteen patients underwent transplantation during this period, 13 of whom (68%) undergoing isolated SB and 6 (32%) MV grafts with or without liver. RESULTS: The median follow up was 524 days (interquartile range=252-730) with an overall 24.4 person/year of observation. Postoperative mortality rate was 0.1 death/person/year; all patients, except one who died intraoperatively, were alive 6 months postsurgery. There were 100 documented infections including: 59 bacterial (2.4 events/person/year), 35 viral (1.4 events/person/year) and 6 fungal (0.2 events/person/year). Patients developed at least one episode of bacterial infection in 94% of the cases, viral infection in 67%, and fungal infection in 28%. CONCLUSIONS: This cohort describes the very common and complex nature of infectious complications in this challenging group of transplantation patients. Larger cohorts are needed to specifically address infection risk factors and longer term outcomes.     

Role of therapeutic drug monitoring in a patient with human immunodeficiency virus infection and end-stage liver disease undergoing orthotopic liver transplantation

Pharmacological interactions between protease inhibitors and tacrolimus require careful monitoring to prevent toxicity in the posttransplantation period. A 42-year-old man with human immunodeficiency virus (HIV) infection and end-stage liver disease due to hepatitis C virus (HCV) received an orthotopic liver transplant. At the time of surgery the patient was on triple antiretroviral therapy (tenofovir, lamivudine, and lopinavir/ritonavir) with a stable CD4(+) count (>500 cells/mm(3)) and HIV-1 RNA (<50 copies/mL). Immunosuppression was maintained with tacrolimus (0.5 mg at a single dose once per week). One month after surgery HCV recurrence was documented. Pharmacokinetic evaluation of lopinavir/ritonavir showed a rapid increase in the area under the curve. Drug concentrations returned to normal levels, with reduction in liver enzymes. At the same time, tacrolimus dosages were reduced to a maintenance dose of 0.5 mg every 2 weeks. The patient, at 17 months postoperatively, is alive in good health with normal liver function and HCV RNA load levels. This is the first case in which a profound change in the pharmacokinetics of a protease inhibitor caused by a drug-drug interaction was observed during transient liver damage. Because this clinical event is particularly common in HIV-infected patients, our findings suggest that therapeutic drug monitoring should be performed to determine the impact of potential drug interactions in the early posttransplantation period, at the time of resumption of therapy or introduction of new anti-retroviral therapy and during HCV recurrence in order to optimize both tacrolimus and protease inhibitor treatment.     

Outcome in Right Living Related Liver Transplantation with Branch-Patch Arterial Reconstruction

cRight lobe living liver transplantation is being performed worldwide with increased frequency. Difficult arterial reconstructions are often encountered because of small diameter or discrepancy between arterial stumps. The risk of arterial thrombosis is reported as high as 26%: microsurgical techniques have reduced this rate below 2%, increasing warm ischemia time. We have developed a new branch patch technique in living related liver transplantation using the donor cystic artery to create an enlarged patch anastomosis that enables increase in the vessel’s diameter and therefore greater inflow to the liver. We have followed 8 patients treated with this technique. After more than 1 year (mean follow-up: 636 days) we did not observe any arterial thrombosis by Doppler ultrasound performed every 3 months. The mean resistance index was 0.68 (0.57–0.83–). Three patients died with functional graft without signs of thrombosis. We believe that the cystic artery branch patch technique is feasible in all cases. It is fast (mean time: 6.2 min), it allows a shorter warm ischemia time, and there is no increased risk of thrombosis.     

Role of HSD11B2 polymorphisms in essential hypertension and the diuretic response to thiazides

BACKGROUND: The renal 11beta-hydroxysteroid dehydrogenase type 2 (11beta HSD2) enzyme inactivates 11-hydroxy steroids in the kidney, thereby protecting the nonselective mineralocorticoid (MR) receptor from occupation by glucocorticoids. Loss-of-function mutations in the gene encoding 11beta HSD2 (HSD11B2) result in overstimulation of the MR and cause salt-sensitive hypertension. METHODS: We have investigated the role of HSD11B2 in hypertension in 377 genetically homogeneous essential hypertensives from North Sardinia. RESULTS: Thirty of these patients displayed increased urinary cortisol metabolite ratios (greater than or equal to 2) (tetrahydrocortisol [THF]+allotetrahydrocortisol [aTHF]/tetrahydrocortisone [THE]) reflecting a mild reduction in 11beta HSD2 activity. No mutations in HSD11B2 were detected in these patients. All 377 patients were genotyped for a CA repeat microsatellite in intron 1 of HSD11B2 and a G534A polymorphism in exon 3 of HSD11B2. CA repeat length was associated with the (THF+aTHF)/THE ratio, which in turn was significantly related to PRA levels. No associations were found between the G354A polymorphism and the other parameters. There were no differences in blood pressure (BP) levels between HSD11B2 genotypes, but in a subgroup of 91 patients that underwent diuretic therapy, CA repeat length was strongly associated with the BP response to hydrochlorothiazide. CONCLUSION: This study highlights the role of this HSD11B2 polymorphism in sodium handling and is consistent with a role in the BP response to thiazide diuretics.