Incidence, timing, and management of biliary tract complications after orthotopic liver transplantation

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Gall bladder tumour, choledochal cyst and an anomalous pancreatico-biliary junction

This report highlights the association of a tumour in an acalculous gall bladder with an anomalous pancreatico-biliary junction (PBJ) and a type IVa choledochal cyst. Cholecystectomy and Rouxen-Y hepatico-jejunostomy (RHJ) was performed after division of the common bile duct (CBD) and excision of the dilated segment. The details of the case are presented and the role of an abnormal PBJ in gall bladder carcinogenesis is discussed.

Comparative antibody response to Salmonella antigens in genetically resistant and susceptible mice

The ELISA was used to titrate the antibody response in mice inoculated with salmonella antigens. The genetically resistant A/J and susceptible C57BL/6J mice were either infected with the virulent or the avirulent Salmonella typhimurium. Alternatively, they were inoculated either once or twice with the heat-killed salmonella vaccine. No appreciable difference could be detected in the relative ability of these two strains of mice to produce antibodies against the lipopolysaccharide antigens of this pathogen under these four conditions.

Risk factors and a risk scoring system for the prediction of malignancy in ovarian cysts

A retrospective study was carried out on 396 patients who presented with ovarian masses. Sixty five (16%) patients were found to have ovarian malignancy while the rest either had benign ovarian tumours (n = 159), endometriotic cysts (n = 130), physiological cysts (n = 20) or inflammatory masses (n = 7). The relative risk for ovarian malignancy among these patients increased significantly (p < 0.001) after the age of 40 years. The presence of ascites, abdominal distension, urinary complaints and loss of appetite and weight were significant individual risk factors for malignancy. Ultrasound image of a complex cyst is also associated with increased risk of malignancy in an ovarian mass. None of the individual risk factors was discriminatory between a benign and malignant cyst. However, these factors can be combined to form a 20-point risk scoring system. The risk of malignancy in an ovarian cyst increased with increasing scores. In this study, the median scores were 3 for benign cyst, 7 for borderline malignancy and 12 for malignant cysts. Using a total score of 7 as a cut off point, one can detect 75% of malignant cysts with a specificity of 84.1%, a positive predictive value of 47.5% and a negative predictive value of 94.6%. It is concluded that the majority of malignant ovarian cysts can be identified preoperatively to allow arrangement and planning of an optimal surgery.

Outcome prediction in early management of severe head injury: an experience in Malaysia

The outcome of 109 patients with severe head injury was studied in relation to clinical and computed tomographic (CT) criteria on admission, after resuscitation. Age, Glasgow Coma Score (GCS) and state of pupils strongly correlated with outcome. The presence of hypothalamic disturbances, hypoxia and hypotension were associated with an adverse outcome. The CT indicators associated with poor outcome were perimesencephalic cistern (PMC) obliteration, subarachnoid haemorrhage, diffuse axonal injury and acute subdural haematoma. The prognostic value of midline shift and mass effect were influenced by concomitant presence of diffuse brain injury. For the subset of patients aged < 20 years, with GCS 6-8 and patent PMC (n = 21), 71.4% correct predictions were made for a good outcome. For the subset of patients aged > 20 years, with GCS 3-5 and partial or complete obliteration of PMC (n = 28), 89.3% correct predictions were made for a poor outcome.

In vitro evaluation of 6-thioguanine and alpha-interferon as a therapeutic combination in HL-60 and natural killer cells

The effect of 6-thioguanine (6-TG) and alpha-interferon (IFN-alpha) was evaluated in vitro to determine their effectiveness in combination on the therapeutically relevant events of: HL-60 cell cytotoxicity, HL-60 cell differentiation, and natural killer (NK)-cell mediated cytotoxicity. 6-TG was toxic to HL-60 cells (ID50 = 0.6 microM; 24-h exposure) while IFN-alpha (up to 1000 IU/ml) had minimal cytotoxic activity. Sequence-dependent activity was observed, inasmuch as the IFN-alpha pretreatment sequence was antagonistic, while the other schedules were additive or, possibly, synergistic. The combination of 0.5 microM 6-TG and 100 IU/ml IFN-alpha produced the same level of HL-60 cell differentiation as each agent alone, suggesting no benefit from the combination on this process. The effect of 6-TG and IFN-alpha on NK cell-mediated cytotoxicity was found to be sequence dependent. NK cell activity was markedly stimulated by IFN-alpha, whereas 6-TG alone seemed to have no direct effect. However, when the NK cells were pretreated with 100 IU/ml IFN-alpha followed by 10 microM 6-TG, the IFN-alpha-enhanced activity of NK cells was ablated. These results suggest that the immunosuppressive activity of 6-TG may be related to the acute inhibition of cytokine activation. Our results suggest that 6-TG and IFN-alpha have considerable interactions, which are sequence dependent. The optimal sequence for potential therapeutic application of these anticancer agents appears to be 6-TG pretreatment followed by IFN-alpha.

Correlation between ribosomal RNA production and RNA-directed fluoropyrimidine cytotoxicity

The relationship between cytotoxicity and fluoropyrimidine effects on the production of mature cytoplasmic 28S and 18S ribosomal RNA was studied in S-180 cells for the fluoropyrimidines: 5-fluorouracil (FUra), 5-fluorouridine (FUrd), 5-fluorodeoxyuridine (FdUrd), and 5'-deoxy-5-fluorouridine (5'-dFUrd). After a 6-hr drug exposure, the total cytotoxicity in the absence of added thymidine (dThd) was determined by soft-agar cloning and resulted in LC90 (lethal concentration to 90% of cells) values of 0.6 microM FdUrd, 0.7 microM FUrd, 5.3 microM FUra and 93 microM 5'-dFUrd. The RNA-directed (dThd-nonreversible) cytotoxicity was assessed by cloning the cells in the presence of 10 microM dThd. This resulted in an altered order of potency and increased LC90 values to 5.5 microM FUrd, 20 microM FUra, 265 microM FdUrd and 870 microM 5'-dFUrd. The production of mature cytoplasmic rRNA was determined by measuring the amount of [3H]cytidine incorporated into the 28S and 18S rANA species following their separation by agarose gel electrophoresis, compared with the level of [3H]cytidine incorporated into the nuclear rRNA. When all four fluoropyrimidines were compared together, the degree of inhibition of cytoplasmic rRNA production was poorly predictive of the total cytotoxicity in the absence of dThd (correlation coefficient, r = 0.77). FdUrd, in particular, had a very minor effect on rRNA production even at very toxic drug concentrations. When toxicity was assessed in the presence of dThd, however, there was a strong and significant correlation between rRNA production and RNA-directed cytotoxicity (r = 0.95, P less than 0.001), for all the fluoropyrimidines tested, including FdUrd. Thus, when the inhibition of thymidylate formation was eliminated as a site of drug action and only RNA-directed cytotoxicity was assessed, the impaired production of cytoplasmic rRNA was strongly associated with cytotoxicity. These results demonstrate that the inhibition of mature cytoplasmic rRNA production may be an important common mechanism of RNA-directed cytotoxicity for all the fluoropyrimidines, and not limited to FUrd or FUra.