Development of Perovskite (MACl)0.33FA0.99MA0.01Pb(I0.99Br0.01)3 Solar Cells via n-Octylammonium Iodide Surface Passivation.

The influence of n-octylammonium iodide (OAI, passive layer) on the types of phases formed in a (MACl)0.33FA0.99MA0.01Pb(I0.99Br0.01)3 perovskite film was studied using X-ray diffraction. Using UV spectrophotometric techniques, it was determined how varied OAI additive layer ratios affected the linear and nonlinear optical characteristics of glass substrates/FTO/compact TiO2/mesoporous TiO2/(MACl)0.33FA0.99MA0.01Pb(I0.99Br0.01)3 films. All films' direct optical bandgap energies were determined to be 1.54 eV. The effects of OAI addition on the films' photoluminescence intensity and emitted colors were also investigated. For the fabricated perovskite solar cells (PSCs) without an OAI passivation layer, the corresponding power conversion efficiency (PCE), open-circuit voltage (VOC), short-circuit current density (JSC), and fill factor (FF) values were 18.8%, 1.02 V, 24.6 mAcm-2, and 75%, respectively. When the concentration of OAI reached 2 mg, the maximum obtained values of PCE, VOC, JSC, and FF were 20.2%, 1.06 V, 24.2 mAcm-2, and 79%, respectively. The decreased trap density and increased recombination resistance were responsible for the improvement in solar cell performance.

Evaluation of two doses of triclabendazole in treatment of patients with combined schistosomiasis and fascioliasis.

To determine the safety and efficacy of 2 consecutive doses of triclabendazole (TCBZ) in the treatment of Schistosoma mansoni infection in human cases infected with both S. mansoni and Fasciola sp., we conducted a field survey involving 6314 individuals from 15 villages. The overall prevalence of schistosomiasis alone was 15.8%, of fascioliasis alone 2.2%, and of combined infection 0.7%. Treatment with 2 doses of TCBZ was given to the 49 cases with combined infection. Eight weeks after treatment, the cure rate was 96% for fascioliasis and was 32.7% for schistosomiasis. All schistosomiasis cases cured had a low intensity infection. Liver function tests done before treatment and 8 weeks after substantiate the safety of 2 doses of TCBZ given to those with combined infection. Administration of TCBZ should precede praziquantel in treatment of combined infection, however TCBZ cannot be recommended for infection with S. mansoni alone.

Ineffectiveness of myrrh-derivative Mirazid against schistosomiasis and fascioliasis in humans.

The present study assessed the schistosomicidal and fasciolicidal actions of the myrrh-derivative Mirazid in an area of low schistosomiasis transmission. A total of 27 patients infected with Schistosoma mansoni and 16 with Fasciola spp. received the maximum recommended dose of Mirazid. Pretreatment egg counts in 4 Kato-Katz slides were compared with similar counts in stool samples collected 1 and 2 months after treatment. Standard procedures and quality control measures were followed. The results revealed that Mirazid used as schistosomicidal or fasciolicidal agent in the maximum recommended dose has a low cure rate and produced a negligible reduction in egg counts. Prescribing such an ineffective drug in Egypt might endanger the achievements of the schistosomiasis control strategy.

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.

Specific IgG avidity in acute and chronic human fascioliasis.

The detection of IgG avidity in sera is potentially useful in the diagnosis of acute and chronic infection. We studied IgG avidity in 31 patients with fascioliasis, with the aim of evaluating the clinical application of this test to confirm the diagnosis of incubating cases and to distinguish between acute and chronic cases. Of the 31 cases, 13 were incubating and had a mean avidity index of 57.28 +/- 5.79%. The 18 chronic cases had an avidity index of 68.80 +/- 8.92%. The difference was highly significant. We conclude that IgG avidity is a reliable means of identifying the stage of fascioliasis and suggest a cut-off point of 59.90% to distinguish between acute and chronic infection.

IL-1, IL-4 production and IgE levels in acute and chronic fasciolosis before and after triclabendazole treatment.

IL-1 generation by mononuclear phagocytes, IL-4 production by Th2 lymphocytes and IgE levels in serum were measured in eight patients with acute fasciolosis and seven patients in the chronic stage of the disease before and after triclabendazole treatment. Results were compared with those of a control group of ten individuals. The monocytes and lymphocytes from patients with acute and chronic fasciolosis produced significantly lower levels of IL-1 and IL-4 respectively, particularly in the chronic phase of the disease, as compared to the control. A significant increase in IgE level in both acute and chronic fasciolosis was observed. The level was significantly higher in acute as compared to chronic cases. After treatment with triclabendazole IL-1, IL-4 and IgE levels moved towards the control indicating obvious improvement in the immunological responses of the patients.

Human fasciolosis: a study on the relation of infection intensity and treatment to hepatobiliary affection.

Seventeen patients with established fasciolosis and ten normal controls were enrolled in the study. The Fasciola patients were divided according to infection intensity into two groups (four patients with high intensity and thirteen patients with low intensity) as assessed by egg counts coupled with ultrasonography for detection of worms in the biliary system. Aspartate and alanine aminotransferases (AST and ALT) levels were similar to those of the controls, within the accepted normal limits, before and after treatment denoting absence of hepatocellular injury. Total serum bile acids, individual bile acids: cholic acid (CA) and chenodeoxycholic acid (CDCA), gamma glutamyl transpeptidase (GGT) and serum alkaline phosphatase (SAP) were significantly higher among all patients as compared to the controls denoting a degree of cholestatic lesion in those patients. Patients with high infection intensity revealed higher parameters than those with low intensity. The difference was not significant. One month after treatment, there was a significant improvement in the cholestasis indicating parameters in all Fasciola cases compared to the pretreatment ones. This indicates the effective role of the drug on the hepatobiliary function. However, the levels were still different from the controls. In Fasciola infection, total and individual serum bile acids in conjunction with GGT and SAP evaluate the hepatobiliary status and detect any minor abnormalities especially in anicteric subjects. Studied after treatment, they can be useful indices for assessment of the improvement.

Circulating antibodies and antigens correlate with egg counts in human fascioliasis.

We explored the relationships between specific IgG antibody levels and circulating E/S antigen to intensity of Fasciola infection in the human host. Twenty patients with patent infection and six healthy individuals were enrolled in the study. Intensity of infection was determined by repeated egg counts in stools, while IgG antibodies against adult Fasciola gigantica somatic FI, FII and against E/S antigens were measured as ELISA O.D. readings. The level of circulating E/S antigens was determined by IELISA. Positivity as well as levels of antibodies and antigen correlated with infection intensity. These findings may disclose in the future a relation between morbidity in the acute phase and worm load.

IL-10, IFN-gamma and TNF-alpha in acute and chronic human fascioliasis.

The three cytokines, IL-10 (Th2 product), IFN-gamma (Th1 product) and TNF-alpha work in concert. The present work was undertaken to study the level of these cytokines during the acute and chronic stages of human fascioliasis in an attempt to assess the involvement of Th1 and Th2 cells in regulation of the immune response in this disease. Sera of twenty six Fasciola patients were obtained and divided into two groups: twelve with acute and fourteen with chronic fascioliasis, sera of a control group were studied simultaneously. During the acute stage, a significant increase was observed in IL-10, IFN-gamma as well as TNF-alpha and specific antibody level. In the chronic phase, a significant increase of IL-10 level was observed. IFN-gamma showed a lower level as compared to the acute stage but TNF-alpha was still high. Accordingly, in fascioliasis in the early phase of infection B cells, macrophages, Th1 and Th2 cells were all activated. They cooperate in overcoming the parasite and work to the benefit of the host. With time and after maturation of the evading worms, Th2 action predominates. IL-10 (Th2 cytokine) which is antagonistic to IFN-gamma (Th1 product) and consequently to TNF-alpha limits the immunopathology that may be caused by the latter.

Short-term preoperative radiotherapy results in down-staging of rectal cancer: a study of 1316 patients.

BACKGROUND AND PURPOSE: This study was undertaken to investigate down-staging effects after short-term, high-fractionated preoperative radiotherapy. MATERIAL AND METHODS: The relationships between preoperative radiotherapy 25-25.5 Gy given over 5-7 days and clinical variables (sex, age, tumour level, metastatic disease, and tumour size) and the risk of lymph node metastases were examined in 1316 patients with rectal adenocarcinoma by uni-, and multivariate analyses. RESULTS: Irradiated specimens contained smaller tumours (P < 0.00001) and nodal metastases were less common (P < 0.001). In a logistic regression model, tumour size in cm was positively related to the risk for nodal spread (odds ratio, OR = 1.14, 95% confidence limits, CL, of OR 1.08-1.22). In the same model, radiotherapy decreased the risk for nodal involvement (OR 0.73, 95% CL 0.58-0.92. This risk was particularly reduced when the time interval between start of radiotherapy and surgery equalled 10 days or more. CONCLUSIONS: These results demonstrate a down-staging effect by a short course of preoperative radiotherapy which should be considered in the interpretation of radiotherapy trials and in the recruitment of patients for further postoperative adjuvant treatment.

Prevention of human fascioliasis: a study on the role of acids detergents and potassium permenganate in clearing salads from metacercariae.

Prevention of human fascioliasis could depend on clearing of the leafy salads from the metacercariae. The present work evaluated the role of some chemicals in detaching and killing this infective stage. It was observed that washing in running water for 10 minutes detached only 50% of the metacercariae. Citric acid in the concentration of (10 ml/L) commercial vinegar (120 ml/L), liquid soap (12 ml/L) and KMnO4 (24 mg/L) detached all metacercariae after 10 minutes exposure. The use of vinegar and KMnO4 is recommended: the first is lethal to other parasites in the vegetables, the second destroyed the metacercariae. Vegetable leaves were not softened and remained fresh.

Metacercarial precipitin test for diagnosis of human fascioliasis.

A metacercarial precipitin test was devised for diagnosis of human fascioliasis. The sera tested were those of cases of fascioliasis (acute and chronic), of schistosomiasis and of normal healthy individuals. Metacercariae were prepared in the laboratory from naturally infected snails. Serum dilutions of 1:5 (20%) and 1:10 (10%) were incubated with metacercariae for periods of 6, 24 and 48 hours. No precipitation was observed when the sera of healthy persons were used. With sera of fascioliasis cases a precipitate was formed which increased in amount with time. It was more rapid in its formation and greater in its quantity with sera of acute fascioliasis. When incubation was prolonged a free precipitate was seen in the medium. With sera of schistosoma cases, a precipitate was observed in a few cases only; it was negligible in amount and localized to the plug area. Metacercarial precipitin is considered a simple, sensitive and specific test for diagnosis of human fascioliasis. It is recommended to use the serum in a dilution of 1:5 (20%), to give preliminary results after 6 hours incubation and to confirm 24 hours later.