Chilean experience in liver transplantation for acute liver failure in children

BACKGROUND

Acute liver failure (ALF) in children is a life-threatening condition, associated with high mortality, and in almost one third of the cases, with no other therapeutic option than orthotopic liver transplant (OLT). The aim of this study was to present our experience with OLT for ALF in pediatric patients in Chile. Patients fulfilling the criteria for ALF who were transplanted in our centers were prospectively included in an excel Microsoft database. We analyzed demographics, etiology, surgical techniques, complications, and long-term results.

PATIENTS AND METHODS

Between 1994 and 2009, we transplanted 52 pediatric patients with ALF. The most frequent known etiology was acute hepatitis A in 9 cases (18%), but in 26 cases (50%) it was impossible to determine the etiology. Thirty- one patients were males (63%). The overall mean age was 7.5 years and the mean weight, 28.1 kg. Thirty-five (67%) received a cadaveric graft. Among them in 18 cases (34%) the liver had to be reduced but 17 (33%) received whole livers. There were 17 (33%) recipients of living-related livers. Twenty-two patients needed reoperation, including 13 due to surgical complications (59%) and 9 (41%) as planned interventions. Ten patients were retransplanted.

RESULTS

Actuarial survival of patients at 1 year was 80% and at 5 and 10 years, 72%. Graft survival at 1 year was 79%, at 5 years 69%, and at 10 years 50%.

CONCLUSION

We have reported a series of pediatric liver transplant patients due to ALF whose results were comparable to other reported series. Living donor transplantation for ALF should be considered and offers a low morbidity rate without mortality.

Phase I study of bi-weekly pemetrexed (P) plus cisplatin (C) in patients with advanced cancer

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Background: Cisplatin and pemetrexed have demonstrated clinical activity in several malignant tumors including mesothelioma and non small cell lung cancer. There is preclinical evidence of synergism between both agents as well as clinical non-overlapping toxicities, thus providing the rationale for their evaluation in combination. Our aim was to develop a well-tolerated combination of bi-weekly CP able to deliver higher dose intensity than the every 3-week standard. Methods: Escalating doses of P from a starting dose level of 300 mg/m2, with a fixed-dose of C 50 mg/m2, both biweekly on 28-day cycles, were administered to patients with refractory advanced solid malignancies and calculated creatinine clearance = 45 mL/min. Results: Twenty one patients (5 female/16 male); median age 61 (39–76); ECOG 0 (16), 1 (5); lung cancer (9); soft-tissue sarcoma (3); unknown primary, bladder, breast, rectum, esophagus, melanoma, mesothelioma, prostate, and tonsil (1, each) have received a total of 48 courses (median 2, range 0–5), at P dose levels of 300 mg/m2 [8 pts, Dose level 1 (DL1)], 400 mg/m2 (7 pts, DL2), and 500 mg/m2 (6 pts, DL3), with full doses of C. Four patients were non-evaluable (2 at DL1, 1 at DL2 and 1 at DL3) because of early PD (2) and non-drug related serious adverse event (2 pt). Dose Limiting Toxicities (DLT) were G4 neutropenia (1 pt) at 300 mg/m2; and prolonged G 1/2 thrombocytopenia (1 pt) at 500 mg/m2. There were also 2 pts with non-DLT G4 neutropenia at DL3. The rest of toxicities were mild to moderate being the most frequent asthenia, nausea, anorexia, stomatatis, and sensory neuropathy. DL3 was considered the Maximum Tolerated Dose (MTD) and the previous level with P at 400 mg/m2 was declared the recommended phase II dose. Three additional patients were treated at DL2 for dose confirmation. A PR has been observed in 2 pts with NSCLC, 1 pt with breast, and 1 with esophagus cancer. Conclusions: Biweekly administration of pemetrexed (400 mg/m2) plus cisplatin (50 mg/m2) is clinically well tolerated and can be used safely. The regimen delivers higher dose intensity of P and equal of C as the standard. This regimen is currently being studied in a phase 2 trial in patients with locally advanced, non resectable or metastatic urothelial cancer.

No significant financial relationships to disclose.

Activated charcoal laryngitis in an intubated patient

Activated charcoal is useful in the management of poisonings, but it is not harmless. We report the case of a patient who developed obstructive laryngitis secondary to aspiration of activated charcoal with a protected airway.

CASE

A 2-year-old girl presented acute mental alteration secondary to presumed poisoning. Mechanical ventilation was initiated, and a single dose of activated charcoal was administered. She had an episode of vomiting during the respiratory weaning. Black-tinted tracheal secretions were suctioned through the tube immediately. Pulmonary auscultation and radiologic examination were normal. When she was extubed, she developed obstructive laryngitis. Fiberbronchoscopy was performed and showed edema and a significant amount of charcoal particles on the epiglottis, arytenoids, and arytenoepiglottic folds. Charcoal particles were removed by bronchoscopy successfully. Later evolution was normal, and no symptoms were present when she was discharged at home.

COMMENTS

Obstructive laryngitis is a new major complication of activated charcoals use in upper airway. It is remarkable that this complication occurred in a protected airway. Charcoal is not an innocuous agent. This case shows that nasogastric administration of activated charcoals presents a significant degree of risk.

Chronic otitis externa/media with total ear canal ablation and bulla curettage in a North American bison (Bison bison)

An adult female North American bison (Bison bison) with a chronic otitis externa/media of the right ear was examined because of a 4-mo history of intermittent anorexia, apparent painful behavior, and auricular discharge from the right ear. Computerized tomography (CT) demonstrated osteolysis of the tympanic, petrous, and squamous aspects of the temporal bone with soft tissue replacement and sclerosis of the right bulla. A total ear canal ablation with bulla curettage was performed, and cefazolin-impregnated polymethacrylate beads were left within the right bulla and the remnant temporal bone. Six months after the surgery, the bison had no clinical signs of otitis media.

Cold-induced increment in rat adrenal gland type II deiodinase is corticosterone dependent

In this study we analyzed whether corticosterone synthesis is involved in the regulation of adrenal gland type II deiodinase (AG-D2) activity during acute cold exposure. Two well-known inhibitors of steroidogenesis, aminoglutethimide (AGT) and metyrapone (MTP), were administered to male Wistar rats maintained either at room temperature or acutely exposed to cold (1 h at 4 degrees C). AG-D2 activity was measured by the radioiodide release method, and corticosterone circulating levels were measured by competitive protein binding assay. Results show that resting corticosterone levels and AG-D2 activity were lower in both AGT- and MTP-treated rats. Furthermore, the phasic increase normally exhibited by AG-D2 activity in response to acute cold stress was blunted in AGT- and MTP-treated animals. Therefore, we conclude that corticosterone synthesis is necessary in preserving the physiologic response of AG-D2 activity to cold exposure.

Kinetic characterization of outer-ring deiodinase activity (ORD) in the liver, gill and retina of the killifish Fundulus heteroclitus

Conversion of T4 to T3 is the first step in TH action and deiodinases are the major determinants of TH tissue availability and disposal. We here report the kinetic characterization of the outer-ring deiodinating (ORD) enzymes in the liver, gill and retina of sea water-adapted killifish, by using both rT3 and T4 as substrates. In liver, by using rT3, we detected a high Km (84 nM) and a low Km (1.3 nM) component with kinetic characteristics similar to mammalian deiodinases DI and DII. In contrast, T4-ORD only generated a low Km (0.5 nM) component. As judged by its Vmax (920 fmol 125I/mg per h) this DII enzyme is very abundant, approximately five and 20 times higher than that found in trout liver and hypothyroid rat, respectively. Kinetic analysis in killifish gill showed only one enzymatic component, with a high rT3 Km (430 nM) and a relatively low Vmax (4.3 pmol 125I/mg per h). Our results in killifish retina show the expression of a T4-low Km (0.6 nM) deiodinase with high cofactor requirements akin to the mammalian DII. The Vmax value for this enzyme is 182 fmol 125I/mg per h, five times lower than the one found in killifish liver, but comparable to that in hypothyroid rat pituitary. The biochemical similarities between fish and mammalian deiodinases could reflect their high conservation during vertebrate evolution and thus their importance in the regulation of thyroid hormone action.

[Neck hydatidosis. Thyroid and submaxillary gland involvement in 2 cases]

Neck located hydatid cysts are of rare occurrence. We report two patients with such condition. A 66 years old male with a slowly progressive painless 4 cm nodule located in the right thyroid. It did not concentrate 131I and a fine needle aspiration cytology was informed as an acute thyroiditis. A 5 years old boy presented with a 5 cm painless right submaxillary cyst. Ultrasound examination showed that it was unilocular, and fine needle aspiration biopsy disclosed unspecific findings. In both cases surgical findings and the pathological study showed hydatid cysts. Both patients had normal chest x ray and abdominal ultrasound examinations. They had an uneventful postoperative evolution. Echinococcosis must be considered in the differential diagnosis of cervical cysts in endemic area.

Mammary type I deiodinase is dependent on the suckling stimulus: differential role of norepinephrine and prolactin

Mammary deiodinase type I (M-D1) is present only during lactation and exhibits a clear direct correlation with lactation intensity (size of litters). The present work shows that M-D1 is suckling dependent and that intervals between suckling periods no longer than 12 h are essential to maintain this activity. Moreover, we find that with only 15 min of resuckling in 12-h nonsuckled mothers, the 50% decrease in both M-D1 messenger RNA and enzymatic activity could be restored to control values. This restorative effect by suckling may involve pre- and posttranscriptional mechanisms in which norepinephrine and PRL play important roles. Norepinephrine elicits a potent stimulatory effect on M-D1 messenger RNA and enzyme activities, whereas PRL only increases M-D 1 activity and may modulate the enzyme response to norepinephrine. Oxytocin and GH had no effect. These data suggest that the adrenergic nervous system and PRL could directly participate in mammary energetic expenditure, regulating the local T3 supply.

Frequency of spontaneous congenital defects in rhesus and cynomolgus macaques

This paper summarizes the spontaneous incidence of congenital defects in the rhesus and cynomolgus macaque colonies (Macaca mulatta and M. fascicularis) at the California Regional Primate Research Center. The computerized database used in this analysis included fetuses, term infants, juveniles, and adults that underwent a necropsy procedure over a 14-year period (1983-1996). The calculated malformation rates were 0.9% (40/4,390) and 0.3% (3/965) for the rhesus and cynomolgus monkey, respectively. Most of the observed malformations in both species affected the musculoskeletal and the cardiovascular systems, while a smaller number of defects were observed in the gastrointestinal, urogenital, endocrine, and central nervous systems. Inbreeding did not contribute to the spontaneous malformation incidence and there was no predilection for sex (male vs. female) or housing (indoors vs. outdoors) among the malformed cases. This spontaneous malformation database in our macaque colony aids in the interpretation of defects that occur in an experimental study as well as in the ongoing assessment of a healthy nonhuman primate breeding colony.

Kinetic characterisation of skin inner-ring deiodinative pathway and its correlation with circulating levels of reverse tri-iodothyronine in developing rainbow trout

The present study has demonstrated the presence of circulating reverse tri-iodothyronine (rT3) levels and its main generating pathway in rainbow trout. A specific rT3, RIA using thyronine-stripped sera in the standard curve was standardised, allowing precise and accurate quantification of radioimmunoassayable rT3. We also demonstrated that trout skin is an important source of rT3 production. T3 or thyroxine trout skin inner-ring deiodination (IRD) activity was assessed by using rT3 RIA and/or paper chromatography. The kinetic characterisation of this deiodinative pathway disclosed a typical deiodinase type III (DIII) enzyme, except for its conspicuous thermodependency which attained its maximal catalytic efficiency at 15 degrees C. This finding suggested the expression of enzymatic variants, which is a common functional array in teleosts. Both circulating rT3 and DIII activity were present in juvenile and adult individuals and were inversely correlated with age, weight and length. In conclusion, this study demonstrated that (1) skin IRD activity and its product rT3 are present throughout the development of rainbow trout, and (2) trout skin DIII activity attains its higher catalytic efficiency in the physiological range of temperature for this species, thus suggesting the expression of enzymatic variants.

Mitogenic effects of thyroxine and TRH on thyrotrophs and somatotrophs of the anterior pituitary gland in thyroidectomized rats

The question of whether thyroxine (T4) and TRH have a mitogenic effect on pituitary thyrotrophs and somatotrophs in thyroidectomized rats was investigated. Mitoses were counted in hematoxylin-eosin-stained or periodic acid-Schiff-hematoxylin-stained pituitary slides or immunostained for TSH or GH using male rats thyroidectomized for 5 months. Ten days before they were killed groups of rats were injected with different doses of T4 (0.5, 3 or 10 micrograms i.m. every second day for 10 days), TRH alone (100 ng s.c. three times a day for 10 days), or T4 plus TRH (same doses as above). Mitoses (stopped with colchicine) were counted in 1 mm2 areas at a magnification of x1000. In thyroidectomized rats, mitoses were not significantly increased and treatment with TRH or 0.5 microgram T4 alone in thyroidectomized rats did not affect mitotic counts. In thyroidectomized rats treated with higher doses of T4, mitoses were increased in a dose-dependent fashion. Simultaneous administration of TRH and T4 had a significant synergistic effect on pituitary mitoses in a T4 dose-dependent manner. The treatments also had differential effects on the relative percentages of cellular types in mitosis. Thus, 60% somatotrophs and 12.5% thyrotrophs were found in the euthyroid group. In thyroidectomized and thyroidectomized plus TRH groups, no somatotrophs in mitosis were seen, while thyrotrophs were 28.5% and 33.3% respectively. In thyroidectomized rats treated with low doses of T4, somatotrophs and thyrotrophs in mitosis increased to 38.4% and 80% respectively and, with simultaneous administration of a low dose of T4 plus TRH, although less effective than T4 alone, mitosis increased in somatotrophs and thyrotrophs to 11.1% and 54.5% respectively. A high dose of T4 alone did not increase the mitotic figures in somatotrophs (38.8%), while it diminished the percentage of thyrotrophs to 25%. The administration of high doses of T4 plus TRH had an opposite effect on the mitotic figures of somatotrophs and thyrotrophs and thus the percentage of somatotrophs increased to 50% while thyrotrophs decreased to 5.5%. Ten days of treatment with T4 were insufficient to reverse the histology to euthyroidism. It can be concluded that in long-standing hypothyroidism: (1) thyroid hormone replacement elicits a dose-dependent and differential proliferative response on pituitary thyrotrophs and somatotrophs, (2) TRH is devoid of mitogenic effects when administered alone and (3) the proliferative response of somatotrophs to T4 is enhanced by its co-administration with TRH, suggesting a permissive and/or synergistic effect of the thyroid hormone and TRH.

Cloning and expression of a 5'-iodothyronine deiodinase from the liver of Fundulus heteroclitus

Recent molecular cloning studies in mammals and amphibians have demonstrated that the types I, II, and III deiodinases constitute a family of selenoproteins of critical importance in metabolizing T4 to active (i.e. T3) and inactive (i.e. rT3) metabolites. In several tissues of teleost fish, various deiodinase processes have been described, but the structural and functional characteristics of these enzymes and their relationship to the deiodinases present in higher vertebrates remains uncertain. Using a complementary DNA library derived from the liver of the teleost Fundulus heteroclitus, we have identified a complementary DNA that codes for a deiodinase with functional characteristics virtually identical to those of the mammalian and amphibian type II deiodinase. Sequence analysis demonstrates a high degree of homology at both the nucleotide and predicted amino acid levels between the Fundulus clone and these previously characterized type II enzymes, including the presence of an in-frame TGA codon that codes for selenocysteine. These findings demonstrate that the deiodinase family of selenoproteins has been highly conserved during vertebrate evolution and underscores their importance in the regulation of thyroid hormone action.

Needs assessment for an urban native HIV and AIDS prevention program

At the request of Native community-based organizations in Montreal, a needs assessment for an HIV and AIDS education and prevention program for urban Natives was initiated. A five-session focus group concerning HIV and AIDS was attended by nine Native persons over a 2-month period. Data was collected using the guidelines of the HIV/AIDS Rapid Anthropological Assessment Procedures (AIDS RAP) developed by the Social and Behavioural Research Unit of the World Health Organization's Global Programme on AIDS. We followed these up with in-depth semistructured interviews with five different members of the Montreal Native community. The data were reviewed by a steering committee to ensure validity. Findings highlight the potential explosive route of transmission of HIV along networks of sexual interaction between persons in urban areas and then to rural partners. Maintaining control over the AIDS program planning within the community permits issues such as traditional values and healing practices to be discussed and taken into account.

Autonomic mediation of glucagon secretion during insulin-induced hypoglycemia in rhesus monkeys

Autonomic activation mediates the majority of the increase of glucagon secretion during insulin-induced hypoglycemia in several species including dogs, mice, and rats. However, the role of the autonomic nervous system to increase glucagon during hypoglycemia in humans remains controversial, and investigations in nonhuman primates have not been previously conducted. The autonomic contribution to glucagon secretion during hypoglycemia in a nonhuman primate was examined by two independent pharmacological approaches. Glucagon responses to clamped insulin-induced hypoglycemia were compared in conscious rhesus monkeys in the presence or absence of ganglionic blockade with trimethaphan, or during combined muscarinic and adrenergic receptor blockade with atropine, propranolol, and tolazoline. Insulin-induced hypoglycemia (plasma glucose = 1.9 +/- 0.1 mmol/l) activated parasympathetic nerves to the pancreas as assessed by increased plasma pancreatic polypeptide (PP) levels (delta = 135.0 +/- 36.8 pmol/l, P < 0.01), produced sympathoadrenal activation as assessed by elevations of plasma epinephrine (EPI) (delta = 22.3 +/- 2.95 nmol/l, P < 0.0005) and norepinephrine (NE) (delta = 3.72 +/- 0.77 mmol/l, P < 0.0025) and increased plasma immunoreactive glucagon (IRG) (delta = 920 +/- 294 ng/l, P < 0.025). Nicotinic ganglionic blockade with trimethaphan prevented parasympathetic (deltaPP = 16.5 +/- 16.3 pmol/l, P < 0.01 vs. control) and sympathoadrenal (deltaEPI = 1.52 +/- 0.98 nmol/l; deltaNE = -0.62 +/- 0.24 mmol/l, both P < 0.0025 vs. control) activation during hypoglycemia and inhibited the IRG response by 70% (delta = 278 +/- 67 ng/l, P < 0.025 vs. control). Combined muscarinic and adrenergic receptor blockade reduced parasympathetic activation (deltaPP = 48.3 +/- 16.3 pmol/l, P < 0.01 vs. control) and inhibited the IRG response by a similar degree to ganglionic blockade (deltaIRG = 284 +/- 60 ng/l, P < 0.025 vs. control). These results demonstrate by two independent pharmacological approaches that autonomic activation makes a substantial contribution to increased glucagon secretion during hypoglycemia of approximately 2.0 mmol/l in a species of nonhuman primate.