Acute ammonium dichromate poisoning in a 2 year-old child

Hexavalent chromium compounds are most commonly used in printing, dyeing, plastics and rayon manufacturing. Poisoning in children by ammonium dichromate, an odorless and bright orange-red crystal, are rarely reported. Acute poisoning will result in death due to multi-organ failure. The target organs that are affected by this poison are the respiratory system, kidneys, liver, eyes and skin. On ingestion, initially there is a relative lack of severe symptoms and signs. Hence, the delay in seeking medical attention could lead to the increased rate of mortality. In this case study, we report the ingestion of ammonium dichromate by a child. Despite appropriate management, such as hepatic supportive measures and plasma transfusion, the toxicity progressed to multi-organ failure and death.     

An evaluation of the role of noninvasive positive pressure ventilation in the management of acute respiratory failure in a developing country

OBJECTIVE: Noninvasive positive pressure ventilation (NIPPV) has been shown to decrease the need for invasive mechanical ventilation (MV) in patients presenting with acute respiratory failure (ARF). We conducted a prospective study to assess if NIPPV use, in a developing country, was associated with clinical and physiological improvements. DESIGN: Prospective observational study. MATERIALS AND METHODS: Forty patients admitted to a medical intensive care unit during a 2-year period who fulfilled criteria for inclusion formed the study cohort to receive NIPPV. FINDINGS: Baseline (mean +/- SD) pH, PaCO 2 and PaO 2 were 7.25 +/- 0.08, 76.6 +/- 20.9 and 79.18 +/- 40.56 mmHg respectively. The primary indication for NIPPV was hypercapnic respiratory failure (n = 36, 90%). The success rate with NIPPV was 85%, with 34 of 40 patients weaned successfully. Significant improvements were observed at 1 hour following institution of NIPPV in pH (7.31 +/- 0.09, P 2 (65 +/- 17.9, P 2 54.7 +/- 20) and maintained (within 12 h) postweaning from the ventilator (pH 7.39 +/- 0.08, PaCO 2 51.9 +/- 12.4). No significant change in the PaO 2 was observed during NIPPV; PaO 2 after 1 h, prior to weaning and after weaning was 90.53 +/- 42.85, 84.80 +/- 33.76, 78.71 +/- 43.81 respectively. CONCLUSION: This study has demonstrated benefits of NIPPV in avoiding the need for invasive MV in patients presenting with ARF of diverse etiology, with results comparable to developed nations. Increased use of NIPPV in ARF is likely to impact favorably in nations with limited resources.     

Phylogenic and ontogenic expression of hepatocellular bile acid transport.

The phylogenic and ontogenic expression of mRNA for the Na+/bile acid cotransporter was determined by Northern analysis utilizing a full-length cDNA probe recently cloned from rat liver. mRNA was detected in several mammalian species, including rat, mouse, and man, but could not be found in livers from nonmammalian species, including chicken, turtle, frog, and small skate. When expression of the bile acid transporter in developing rat liver was studied, mRNA was detected between 18 and 21 days of gestation, at the time when Na(+)-dependent bile acid transport is first detected. Two hepatoma cell lines (HTC and HepG2), the latter of which is known to have lost the Na+/bile acid cotransport system, also did not express mRNA for this transporter. Finally, when mRNA from the lower vertebrate (the small skate) was injected into Xenopus oocytes, only a sodium-independent, chloride-dependent transport system for bile acids was expressed, confirming the integrity of the mRNA and consistent with prior functional studies of bile acid transport in this species. These findings establish that the Na+/bile acid cotransport mRNA is first transcribed in mammalian species, a process that is recapitulated late during mammalian fetal development in rat liver, and that this mRNA is lost in dedifferentiated hepatocytes. In contrast, the mRNA for a multispecific Na+/independent organic anion transport system is transcribed earlier in vertebrate evolution.     

Production of monoclonal antibodies to a tumor--associated antigen by spontaneous cell fusion

Spontaneous cell fusion induced by the bacterium Haemophilus paragallinarum has been recently reported as an alternative technique to generate hybridomas producing monoclonal antibody (mAb). In order to investigate the advantages of this technique to produce anti-tumor monoclonal antibodies we performed comparative experiments between H. paragallinarum induced spontaneous cell fusion and polyethylene glycol (PEG) mediated fusion. Hybridomas producing monoclonal antibodies to an experimental murine lymphoma antigen, the Dalton's lymphoma associated antigen (DLAA) were generated and their sensitivity and specificity were ascertained. The spontaneous fusion yielded more number of stable and specific hybridomas than PEG mediated fusion. The results suggest the advantage of H. paragalinarum induced cell fusion for the simplified production of specific antitumor monoclonal antibodies.