CT appearances of hydatid disease at various locations

Hydatid disease has characteristic imaging features on CT, which allow accurate preoperative diagnosis in most cases. However, when it occurs at unusual locations the diagnosis is often difficult, especially as the imaging appearance varies at different sites. In this article we have presented a pictorial review of the CT features of disease due to Echinococcus granulosus at various sites in the human body.     

A developmental study of interphotoreceptor retinoid-binding protein (IRBP) in single and double homozygous rd and rds mutant mouse retinae

Interphotoreceptor retinoid-binding protein (IRBP) was studied using immunochemical and immunocytochemical techniques in retinae of mice with allelic combinations at the rd and rds loci at different stages of development and degeneration. Until postnatal day 7 (P7), IRBP is located intracellularly in developing retinae of the different genotypes. Thereafter, IRBP is present mainly in the interphotoreceptor matrix. As previously noted, cell death is slowest in the heterozygous +/+,rds/+ mutant with loss increasing in order in +/+,rds/rds, rd/rd, rds/rds and rd/rd,+/+ animals. The IRBP content of the total retina also approximates this pattern, with lowest amounts by far in rd/rd, rds/rds and rd/rd,+/+ mutants (after P14). Interestingly though, IRBP loss significantly precedes visual cell loss in the rd/rd,rds/rds retina. In all the mutants, the remaining rod cells in the outer nuclear layer exhibit synthesis of intracellularly located IRBP at late stages of degeneration. In the single homozygous rd/rd,+/+ and the double homozygous rd/rd,rds/rds mutants, IRBP is present intracellularly during the entire degenerative process with somewhat less intracellular IRBP in the rd/rd,rds/rds mutant. Retinae of homozygous +/+,rds/rds and heterozygous +/+,rds/+ animals exhibit a normal distribution pattern of IRBP immunoreactivity until loss of photoreceptor cells becomes pronounced at later stages of the disease. Many of the remaining cells at this time are probably cone elements although they are structurally changed. Double labeling with IRBP and S-antigen demonstrates, in many but not all, the presence of both proteins in the same cell body. Immunocytochemistry clearly demonstrated the presence of IRBP in remaining photoreceptor cells at late stages of the disease. Thus, the biochemically measured loss of IRBP appears to be a complex process neither directly dependent on the loss of photoreceptor outer segments and reduced interphotoreceptor matrix space (e.g. there is a sustained IRBP level in rodless rds mutants) nor simply due to cell death (e.g. in the rd/rd,rds/rds mutant, IRBP loss significantly precedes cell loss). That this IRBP is mainly intracellular, however, may indicate an abnormality in secretion which, combined with other factors, induces a degenerated and less differentiated phenotype.     

Changes in glucose/amino acid/calcium uptake and brush-border membrane-associated enzymes in rat small intestine after the administration of embelin (plant benzoquinone), an antifertility agent

Administration of Embelin, an experimental antifertility agent, to male rats (20 mg/kg body wt/day, daily for 15 and 30 days), caused an elevation in the uptake of D-glucose, L-alanine, L-leucine, and calcium in the small intestinal segments. An increase was also noted in the intestinal brush border membrane (BBM)-associated enzymes, sucrase, lactase, maltase, alkaline phosphatase, and leucine aminopeptidase in both the intestinal homogenates and partially purified BBM preparations, particularly after 30-day administration of the drug. Embelin treatment also caused a significant increase in the microsomal glucose-6-phosphatase and the cytosolic enzyme, lactate dehydrogenase. In the Embelin-treated animals BBM-associated total lipids, phospholipids, cholesterol, triacylglycerol, unesterified fatty acids, ganglioside-sialic acids as well as the cholesterol/phospholipids molar ratio showed a considerable increase. All these changes in the Embelin-treated animals were restored back to the normal or near normal biochemical makeup when the drug therapy was withdrawn and the animals were allowed to recover for another 15 and 30 days, respectively.     

Quantitative (82)Rb PET/CT: development and validation of myocardial perfusion database.

The use of myocardial perfusion (82)Rb PET/CT studies continues to increase but its accuracy using database quantification methods for the diagnosis of coronary artery disease (CAD) has not been established. METHODS: A sex-independent normal database and criteria for abnormality for rest-stress (82)Rb PET/CT myocardial perfusion imaging were developed and validated by evaluation of 281 patients (136 females: mean age +/- SD, 63.3 +/- 13.3 y; 145 males: mean age +/- SD, 63.9 +/- 12.8 y) who underwent a rest-adenosine stress (82)Rb PET/CT study. These patients were divided into 3 groups: (a) healthy group: 30 patients, with <5% likelihood of CAD (low likelihood [LLK]) based on sequential Bayesian analysis; these patients were used to generate the normal distribution; (b) pilot group: 174 patients; these patients were used to determine the optimal criteria for detecting and localizing the perfusion abnormality; and (c) validation group: 76 patients (23 with LLK of CAD and 53 who underwent coronary angiography; these patients were used for prospective validation. RESULTS: Of the 53 patients who underwent coronary angiography, 8 had <50% stenosis and 45 patients had at least one stenosis > or =50% in one major artery. Fifteen patients had single-vessel disease, 17 had double-vessel disease, and 13 had triple-vessel disease. The prospective validation shows a normalcy rate of 78% (18/23) for global CAD. The analyses by individual arteries show a normalcy rate of 96% (22/23) for the left anterior descending coronary artery, 96% for the left circumflex coronary artery (22/23), and 100% for the right coronary artery (23/23). The overall sensitivity for detection of CAD (> or =50% stenosis) was 93% (42/45). The overall specificity for detection of the absence of CAD (< or =50% stenosis) was 75% (6/8). Also, the positive predictive value for global CAD was 95% (42/44), the negative predictive value was 67% (6/9), and the accuracy was 91% (48/53). CONCLUSION: The quantitative (82)Rb PET/CT database created and validated in this study is highly accurate for the detection and localization of CAD. Physicians should consider using the quantitative output of these algorithms as decision support tools to aid with image interpretation.     

Evaluation of beta-tethymustine, a new anticancer compound, in murine tumour models

beta-Tethymustine, 1-[2- {bis(2'-chloroethyl)amino}ethyl]spiro[imidazolidine-4,2'-(1'H),3',4'-dihydronaphthalene]-2,5-dione, has been synthesised and LD50 value determined in Swiss male mice, which was found to be 100.00 mg/kg by single i.p. injection. The following three criteria, namely ascites cell count, ascites fluid measurement and increase in median survival times (MST) of drug-treated (T) over untreated control (C) mice, were studied for evaluation of its antitumour efficacy in vivo in three murine ascites tumours, namely Ehrlich ascites carcinoma (EAC), sarcoma-180 (S-180) and Dalton's lymphoma (DL). At the optimum dose range of 8.0 mg/kg (higher) to 4.0 mg/kg (lower) for 1-7 days treatment following tumour transplantation on day 0, it exhibited a very high percentage of inhibition of both the ascites cell and fluid in these models and displayed excellent ILS(max) value of 80 in EAC, 224 in S-180 and 240 in DL, respectively, showing 'curative' effect (2-3/6 mice having 90 days survival rate). It also demonstrated a high ILS value of 150 with one cure/six mice bearing S-180 for 6 days prior to drug therapy. Screening results were compared with two clinical drugs, cyclophosphamide and 5-fluorouracil, serving as positive controls. Its chemical alkylating activity was compared with nor-HN2 (NSC 10873) and spiromustine (NSC 172112). The results indicate that it possesses greater alkylating activity than nor-HN2 and comparable activity with spiromustine.     

Pseudomonas aeruginosa septicaemia in burns

Out of 1415 patients treated as inpatients at Al-Babtain Center for Burns and Plastic Surgery, Ibn Sina Hospital, Kuwait spanning over a period of 6 years from June 1992 to June 1998, 102 developed clinically and microbiologically proven septicaemia. Only 15 out of them had either single or multiple episodes of septicaemia due to Pseudomonas aeruginosa and were studied during their stay in the hospital. Five of them were males and 10 females, with a mean age of 26 years (range 3-51 years) and mean total body surface area of burns (TBSA) of 66% (range 25-90%). All of them had flame burns and resuscitation was found to be difficult in eight patients either due to delayed hospitalization or accompanied inhalation injury. Seven patients were intubated, four due to inhalation injury and three for septicaemic complications. Among the 15 patients under study, a total of 36 septicaemic episodes were detected of which 21 were due to P. aeruginosa. This organism was found in the first episodes in nine patients, in second episodes in six, in third episodes in three and fourth, fifth and sixth episodes in one patient, each at a variable postburn day. Ten patients had 38 sessions of excision and skin grafting, six of them survived. Nine of the 15 patients under study died due to septicaemia, but only six of them had P. aeruginosa as the last isolate. Except for one, all patients had > 40% TBSA burn, two had difficult resuscitation and four were intubated. The day of death varied between 3 to 52 days postburn (mean 19 days). This study showed that females with flame burns are susceptible to P. aeruginosa septicaemia. Difficult resuscitation and intubation also proved to be important risk factors. Septicaemia could occur quite early in the postburn days and the mortality due to this organism was quite high. Early excision and grafting with other effective management may result in a better outcome.     

Rifampicin as an adjunct to vancomycin therapy in MRSA septicaemia in burns

Rifampicin has been successfully used as an adjunct to vancomycin therapy in several clinical conditions of MRSA infections such as endocarditis, ventriculoperitoneal shunts and septicaemia. However, very little information is available in the literature regarding its use in MRSA septicaemia in burns. The present prospective study was conducted to evaluate the efficacy of rifampicin as an adjunct therapy in burn cases with MRSA septicaemia not responding well to vancomycin. Fourteen out of 36 MRSA septicaemia patients with burns who either did not or only partially responded to therapeutic doses of vancomycin within 5-6 days were treated with rifampicin as an adjunct therapy (600 mg, i.v., o.d) for 5 days during the study period between January 1995 to December 1998. All the patients had burns due to flame and the TBSA varied between 20-90% with a mean of 64%. Eleven patients had deep and three had mixed burns. MRSA septicaemic episodes usually followed 2 3 days of detection of the organism in burn wounds. All the isolates were sensitive to vancomycin with an MIC of < or = 1.0 mg/L and were treated with vancomycin, (500 mg, i.v., 6 hourly). The serum vancomycin levels in all the patients were within the therapeutic range. However, blood cultures still remained positive even after 5-6 days of therapy. Institution of rifampicin, as an adjunct to vancomycin therapy to which the MRSA isolates were susceptible, showed a dramatic clinical response and survival of grafts. Thirteen patients survived and one died who had 70% deep burns and blood cultures revealed a multiresistant Acinetobacter in addition to MRSA. The present study thus confirms the efficacy of clinical use of rifampicin as an adjunct in vancomycin nonresponding cases of MRSA septicaemia in burns.     

Solitary Neurofibromas in and around the ear

Three cases of solitary Neurofibromas in and around the ear are reported.