Valine-Specific tRNA-like Structure in Turnip Yellow Mosaic Virus RNA

The 3' terminal nucleotide of turnip yellow mosaic virus (TYMV) RNA (23-25 S) may be esterified with valine in the presence of ATP and an enzyme preparation from Escherichia coli. The nucleotide composition near the valine-binding site is different for TYMV RNA and tRNA(Val) from cabbage, as shown by comparison of the valine adducts of nucleotides labeled with radioactive valine in T(1) RNase digests. Consequently, host tRNA(Val) is not involved in the observed charging of TYMV RNA with valine. The TYMV RNA appears to have a tRNA-like structure, at or near its 3' end, that is recognized by three different enzymes which specifically catalyze reactions involving tRNA.     

Isolation of drug delivery from drug effect: problems of optimizing drug delivery parameters

A recurring question in the treatment of malignant brain tumors has been whether treatment failure is due to inadequate delivery or ineffective drugs. To isolate these issues, we tested a paradigm in which the "therapeutic" agent was a toxin about which there could be no question of efficacy, provided it was delivered in adequate amounts; we used 10% formalin. We infused 10% formalin into 5- to 8-mm subcutaneous RG-2 and D54-MG gliomas at increasing rates until we achieved 100% tumor cell kill. In RG-2 gliomas, infusions of 10 microl/h x 7 days, and 2, 4, 6, and 8 microl/min x 2 h failed to kill tumors, although growth was delayed, while infusion rates of 12 microl/min x 60 min and 48 microl/min x 15 min produced 100% tumor kill. In D54-MG tumors, infusions of 4, 8, and 24 microl/min produced 100% tumor kill. 14C-Formalin autoradiographs showed a heterogeneous distribution after infusions of 2 microl/min x 2 h, whereas infusions of 48 microl/min x 15 min showed a homogeneous distribution within the tumor, but more than 95% of tissue radioactivity was found in tissue surrounding tumor. Drug delivery remains a major issue in brain tumor treatment: Distribution inhomogeneity, rapid efflux, and consequent treatment failures are likely due to high interstitial fluid pressure. Because the infusion rates being used in the treatment of human brain tumors are low and the tumors are larger, treatment failures can be expected on the basis of inadequate drug delivery alone, regardless of the effectiveness of the drug.     

Congenital colorectal tubular duplication in an infant: A tale of radiological diagnostic challenges

Enteric duplications (EDs) are rare congenital anomalies that result from defect during embryonic development of the gut. Although EDs can literally occur at any part of the gastrointestinal tract, ileocecal duplication is the commonest type followed by colorectal type. Morphologically, EDs are mostly cystic in nature; tubular duplications are uncommon. We report radiological diagnostic challenges encountered in dealing with a 10 month-old infant who presented with chronic constipation, progressive abdominal distension, and voiding difficulty for several weeks followed by colicky abdominal pain for three days. After a series of radiological procedures, a diagnosis of tubular colorectal duplication was made. The duplicated segment was loaded with impacted feces which exerted pressure effect on the rectum and urinary bladder. The case was treated surgically through laparoscopic procedure that included fenestration and stapling of the duplicated bowel followed by irrigation. Postoperatively, the child was followed up half-yearly for three years and was found to remain symptom-free. This case exemplifies the challenges a radiologist may experience while dealing with a case presenting with features of as acute-on-chronic intestinal obstruction and voiding difficulty.Keyword: Hindgut duplication cyst, Colonic duplication cyst, Gastrointestinal tract (GIT) duplication cyst     

The economic impact of alcohol consumption: a systematic review

Background  

Many opiate users entering British prisons require prescribed medication to help them achieve abstinence. This commonly takes the form of a detoxification regime. Previously, a range of detoxification agents have been prescribed without a clear evidence base to recommend a drug of choice. There are few trials and very few in the prison setting. This study compares dihydrocodeine with buprenorphine.     

Economic evaluation of treatment administration strategies of ganciclovir for cytomegalovirus retinitis in HIV/AIDS patients in Thailand: a simulation study

BACKGROUND: There are many effective interventions, via various routes (intravenous [IV], oral [OR], intravitreal injection [IVT] and intraocular implantation [IMP]), for treating cytomegalovirus retinitis (CMVR) that have become available. There are large variations in treating CMVR in clinical practice in Thailand. OBJECTIVE: To evaluate the incremental cost-effectiveness ratio (ICER) of providing (i) IVT, (ii) IV/OR and (iii) IMP ganciclovir to patients with HIV/AIDS and CMVR versus providing no treatment. DESIGN: A simulation study for which the input parameters were derived from a systematic review of the literature, a hospital-based survey and patient interviews. SETTING: The analysis assumed a Thai healthcare system perspective. However, the model was run using both societal and healthcare provider perspectives. RESULTS: Our results suggest that IVT ganciclovir was cost effective and the best option for treating patients with CMVR irrespective of whether patients received antiretroviral treatment (ART). In patients receiving ART, moving from IVT to IV/OR ganciclovir was also likely to be a cost-effective option. Offering IMP ganciclovir was not likely to be cost effective. Providing treatments for patients with bilateral CMVR was more cost effective than providing treatments for those with unilateral CMVR, and offering treatments for patients receiving ART was better value for money than treating patients without ART. CONCLUSIONS: Our models suggest that IV/OR ganciclovir should be recommended for the treatment of unilateral and bilateral CMVR for patients receiving ART in the Thai healthcare system. IVT ganciclovir may also have a role in the treatment of CMVR patients not receiving ART.     

Priority-Setting Institutions in Health: Recommendations from a Center for Global Development Working Group

The rationing problem is common to all health systems—the challenge of managing finite resources to address unlimited demand for services. In most low- and middle-income countries, rationing occurs as an ad hoc, haphazard series of nontransparent choices that reflect the competing interests of governments, donors, and other stakeholders. Yet in a growing number of countries, more explicit processes, with strengths and limitations, are under development that merit better support. Against this background, the purpose of the Center for Global Development Working Group, which is to examine how priorities are set currently, and to propose institutional arrangements that promote country ownership and improve health outcomes by more systematically managing this complex process of politics and economics, is discussed. Current global and national priority-setting practices in low- and middle-income countries, the potential for strengthened national institutions, and increased global support are reviewed. Recommendations for action are provided.     

Rare late-presentation congenital diaphragmatic hernia mimicking a tension pneumothorax

Congenital Diaphragmatic Hernia (CDH) is due to a defect in the diaphragm and is usually detected soon after birth. However, in rare cases, asymptomatic CDHs can be missed and present later in life. Late-presentation CDH can be misdiagnosed as tension pneumothorax leading to iatrogenic complications. We report a case of a 10-year-old boy who presented with non-specific symptoms of vomiting and occasional breathlessness, but was subsequently diagnosed as late-presentation CDH. This case highlights the role of imaging in the diagnosis and management of late-presenting CDH. The role of CT imaging as an invaluable tool to further evaluate equivocal radiographic findings in CDH is discussed.