Automated MRI Volumetric Analysis in Patients with Rasmussen Syndrome.

BACKGROUND AND PURPOSE: Rasmussen syndrome, also known as Rasmussen encephalitis, is typically associated with volume loss of the affected hemisphere of the brain. Our aim was to apply automated quantitative volumetric MR imaging analyses to patients diagnosed with Rasmussen encephalitis, to determine the predictive value of lobar volumetric measures and to assess regional atrophy differences as well as monitor disease progression by using these measures. MATERIALS AND METHODS: Nineteen patients (42 scans) with diagnosed Rasmussen encephalitis were studied. We used 2 control groups: one with 42 age- and sex-matched healthy subjects and the other with 42 epileptic patients without Rasmussen encephalitis with the same disease duration as patients with Rasmussen encephalitis. Volumetric analysis was performed on T1-weighted images by using BrainSuite. Ratios of volumes from the affected hemisphere divided by those from the unaffected hemisphere were used as input to a logistic regression classifier, which was trained to discriminate patients from controls. Using the classifier, we compared the predictive accuracy of all the volumetric measures. These ratios were used to further assess regional atrophy differences and correlate with epilepsy duration. RESULTS: Interhemispheric and frontal lobe ratios had the best prediction accuracy for separating patients with Rasmussen encephalitis from healthy controls and patient controls without Rasmussen encephalitis. The insula showed significantly more atrophy compared with all the other cortical regions. Patients with longitudinal scans showed progressive volume loss in the affected hemisphere. Atrophy of the frontal lobe and insula correlated significantly with epilepsy duration. CONCLUSIONS: Automated quantitative volumetric analysis provides accurate separation of patients with Rasmussen encephalitis from healthy controls and epileptic patients without Rasmussen encephalitis, and thus may assist the diagnosis of Rasmussen encephalitis. Volumetric analysis could also be included as part of follow-up for patients with Rasmussen encephalitis to assess disease progression.

Dispersions of alkyl-capped silicon nanocrystals in aqueous media: photoluminescence and ageing.

Alkyl-capped silicon nanocrystals can be dispersed in aqueous media by shaking or stirring their solutions in organic solvents (DMSO, ether, THF) with excess water. THF is the most straightforward choice with which to prepare stable aqueous dispersions, because the nanocrystals are very soluble in THF and it is also miscible with water. As little as 0.01% v/v tetrahydrofuran is sufficient. DMSO and ether were the preferred choices for subsequent staining of live cells because THF shows some acute toxicity even when very dilute. The luminescence intensity of the aqueous dispersions is linear in particle concentration and independent of pH over the range 5-9. The sols retain their photoluminescence and are stable against flocculation for at least 6 months.

Influence of diabetes on manifestations and treatment outcome of pulmonary TB patients.

OBJECTIVE: To understand the influence of diabetes on the clinical and bacteriological aspects and treatment outcome of pulmonary tuberculosis (PTB) patients. SETTING AND DESIGN: Records of 692 consecutive smear-positive PTB patients admitted to a referral hospital in Riyadh, Saudi Arabia, were reviewed retrospectively. The characteristics of 187 patients with diabetes mellitus (PTB-DM group) were compared to 505 patients without DM (PTB group). RESULTS: In the PTB-DM group, 65.2% of the patients had numerous acid-fast bacilli (AFB) on sputum smear examination compared to 54.1% in the control group (P = 0.008). Among new cases, PTB-DM patients had a lower prevalence of resistance to any anti-tuberculosis drug (6.4% vs. 16.0%, P = 0.007) and achieved higher sputum conversion rates at the end of 3 months of treatment (98.9% vs. 94.7%, P = 0.013). Favourable outcomes (cured/treatment completed), failure, death and default were comparable in both groups (P = 0.7005). CONCLUSIONS: PTB-DM patients have a higher pre-treatment bacillary load, a lower prevalence of anti-tuberculosis drug resistance and achieve slightly higher sputum conversion by the end of 3 months of treatment compared to non-diabetic patients. The association of diabetes does not alter the final treatment outcome among PTB patients.

Factors predicting persistent sputum smear positivity among pulmonary tuberculosis patients 2 months after treatment.

SETTING: Studies have shown that adverse outcomes are more likely in patients showing persistent sputum positivity at the end of 2 months of anti-tuberculosis treatment. OBJECTIVE: To identify simple clinical, microbiological or radiological factors associated with persistent sputum positivity under national programme conditions. DESIGN: Sputum smear-positive pulmonary tuberculosis patients admitted in 2 consecutive years to a referral hospital, and who received standard short-course chemotherapy under direct observation, were reviewed retrospectively. Factors associated with persistent sputum smear positivity were analysed. RESULTS: A total of 514 patients were available for review. Logistic regression analysis showed that age groups 41-60 years and more than 60 years, numerous bacilli on initial sputum smear examination, and presence of multiple cavitary diseases were significant factors associated with persistent sputum positivity at the end of 2 months of treatment (P < 0.0001). CONCLUSIONS: Identification of high risk factors associated with persistent sputum positivity, such as specific age groups, numerous bacilli on initial sputum smear examination, and presence of multiple cavitary diseases, may be helpful in stratifying the patients according to the risk of adverse outcome, thus allowing greater efficiency in resource utilisation.

Influence of anti-tuberculosis drug resistance on the treatment outcome of pulmonary tuberculosis patients receiving DOTS in Riyadh, Saudi Arabia.

OBJECTIVE: To determine the influence of anti-tuberculosis drug resistance existing prior to treatment on the outcome of pulmonary tuberculosis patients receiving standard short-course chemotherapy (SCC) under direct observation under national programme guidelines. DESIGN: Treatment outcomes of sputum smear- and culture-positive pulmonary tuberculosis patients admitted consecutively from 1998 through 1999 in a referral hospital in Riyadh, Saudi Arabia, were reviewed retrospectively. RESULTS: A total of 515 patients were reviewed; 139 patients were deported or transferred out. Treatment outcomes and follow-up for about 2 years were analysed for the remaining 376 patients. Among 315 patients with sensitive isolates, 301 achieved favourable outcome, none relapsed or failed, 10 defaulted, one died and three were lost to follow-up at 6 months. Mono-resistance to isoniazid, streptomycin or ethambutol did not influence the treatment outcome. All the 18 patients with mono-resistance to rifampicin were cured, but two relapsed later. Among 39 patients with any rifampicin resistance, 37 patients had favourable outcome and two failed treatment; three later relapsed. Among eight patients with MDR-TB, six had favourable outcome and two failed treatment; one later relapsed. Sputum smear conversion rates at the end of 3 months of treatment in patients with any rifampicin resistance or with multidrug resistance were inferior to those of patients with sensitive strains (89.8% vs. 96.3%, P = 0.016 and 80% vs. 96.3%, P = 0.008, respectively). CONCLUSIONS: Anti-tuberculosis drug resistance existing prior to treatment, especially rifampicin and multidrug resistance, has an adverse effect on treatment outcome, even with directly observed standard SCC under national programme guidelines.

Pulmonary tuberculosis in Saudi Arabia: A retrospective study of 1566 patients.

A review was conducted of 1566 cases of pulmonary tuberculosis admitted to Sahary Chest Hospital in Riyadh between July 1983 and August 1987. The medical records, chest rafiographs, and sputum results were studied. The 21 to 30 year age group represented 40.7% of all patients, which indicates the need for improving measures for the control of tuberculosis in young adults, whose protection may have waned despite BCG vaccination in infancy. Non-Saudi males patients constituted more than half of the admission which raises the question of the efficacy of the current pulmonary tuberculosis screening policy for individuals entering the Kingdom. The four-drug regimen of rifampicin, isoniazid, pyrazinamide, and ethambutol, when properly supervised, was very effective in achieving early sputum conversion. Based on results of this study, decentralizing tuberculosis services and attaching them to other local and general hospitals appears to be recommended.

Hypercalcemia in active pulmonary tuberculosis.

In a retrospective review of 241 patients with active pulmonary tuberculosis, hypercalcemia was found in 62 (26%). It was detected on presentation in 48 patients and developed in 14 patients 4 to 6 weeks aftr the start of antituberculous therapy. The mean (+/- SD) serum calcium level in those cases was 2.78 (+/- 0.137) mmol/L. The majority of cases (67.6%) had a mild rise in the calcium level that remained below 2.8 mmol/L but 35% had a level that ranged between 2.8 and 3.0 mmol/L. Only 2.4% had serum level higher than 3.0 mmol/L, which could explain the predominant absence of hypercalcemia-related symptoms. Hypercalcemia was more common in patients older than 50 years (P<0.05), but this did not correlate with the extent of the tuberculosis shown on radiological evaluation. Spontaneous return to normocalcemia occurred in all 42 patients who underwent serial assessments of their serum calcium concentration, 6 to 8 weeks after the start of chemotherapy. Saudi Arabia is known to have a high prevalence of vitamin D deficiency, but none of our patients were immobilized or had received vitamin D supplements or multivitamins. This supports the view that vitamin D intake does not play a major role in inducing hypercalcemia in cases of active pulmonary tuberculosis, as has been suspected.

Pulmonary tuberculosis in diabetic patients.

In a retrospective study of 1566 cases of pulmonary tuberculosis, 136 were found to have diabetes mellitus for a prevalence of 8.7%. There were 100 males and 36 females, and the average age patient age was 52 years. Saudis accounted for 94 (69%) of the cases. The prevalence of diabetes was 13% for Saudi patients as compared with 5% for non-Saudis (P < 0.005). Sputum conversion took an average of 46 days. There was a 19% prevalence of lower lung field lesions. Ninety-three (68.4%) patients were on insulin therapy, 25 (18.9%) were on oral hypoglycemics, and 18 (13.2%) were managed on diet alone. Of 104 patients who were sputum positive, 100 showed conversion after treatment with first-line antitubercular drugs. There was no statistically significant difference in the sputum conversion between diabetic and nondiabetic patients.

Unilateral post-tuberculous lung destruction: the left bronchus syndrome.

In a prospective study of 13 patients requiring pneumonectomy for unilateral post-tuberculous lung destruction the left side was found to be affected in 12. Review of a further 172 cases showed the left lung to have been destroyed in 109 (63%). It is suggested that this predominance of the left side is due to the anatomical characteristics of the left main bronchus and that disordered haemodynamics also appear to play a part.