On the regularization of solution of an inverse ultraparabolic equation associated with perturbed final data

In this paper, we study the inverse problem for a class of abstract ultraparabolic equations which is well-known to be ill-posed. We employ some elementary results of semi-group theory to present the formula of solution, then show the instability cause. Since the solution exhibits unstable dependence on the given data functions, we propose a new regularization method to stabilize the solution. then obtain the error estimate. A numerical example shows that the method is efficient and feasible. This work slightly extends to the earlier results in Zouyed et al. \cite{key-9} (2014).Comment: 19 pages, 4 figures, 1 tabl

The transfer and decay of maternal antibody against Shigella sonnei in a longitudinal cohort of Vietnamese infants.

BACKGROUND: Shigella sonnei is an emergent and major diarrheal pathogen for which there is currently no vaccine. We aimed to quantify duration of maternal antibody against S. sonnei and investigate transplacental IgG transfer in a birth cohort in southern Vietnam. METHODS AND RESULTS: Over 500-paired maternal/infant plasma samples were evaluated for presence of anti-S. sonnei-O IgG and IgM. Longitudinal plasma samples allowed for the estimation of the median half-life of maternal anti-S. sonnei-O IgG, which was 43 days (95% confidence interval: 41-45 days). Additionally, half of infants lacked a detectable titer by 19 weeks of age. Lower cord titers were associated with greater increases in S. sonnei IgG over the first year of life, and the incidence of S. sonnei seroconversion was estimated to be 4/100 infant years. Maternal IgG titer, the ratio of antibody transfer, the season of birth and gestational age were significantly associated with cord titer. CONCLUSIONS: Maternal anti-S. sonnei-O IgG is efficiently transferred across the placenta and anti-S. sonnei-O maternal IgG declines rapidly after birth and is undetectable after 5 months in the majority of children. Preterm neonates and children born to mothers with low IgG titers have lower cord titers and therefore may be at greater risk of seroconversion in infancy

Efficacy of Oral Isotretinoin in Combination with Desloratadine in the Treatment of Common Vulgaris Acne in Vietnamese Patients

AIM: To evaluate the efficacy of oral isotretinoin used alone and in combination with desloratadine in the treatment of moderate acne vulgaris. METHODS: A comparative clinical trial was undertaken to evaluate the efficacy of oral isotretinoin alone and in combination with desloratadine in the treatment of 62 moderate acne vulgaris patients. Patients were randomised into two groups with 31 patients in each group. Each studied group's patient took 20 mg isotretinoin and 5 mg desloratadine per day. In the control group, patients took only 20 mg isotretinoin per day. The treatment time was 16 weeks. The evaluation and follow-up were done at week 2, 4, 8, 12 and 16 of the treatment. RESULTS: The studied group had a better curative rate than the control group (45.2% versus 22.6%). The average number of inflammatory lesions in the studied group was significantly lower than the control group (0.19 versus 0.94). The mean GAGS score of the studied group was significantly lower than the control group (3.71 versus 6.52). Acne outbreaks rate of the studied group was lower than the control group (in week 2: 22.6% versus 45.2% and in week 4: 16.1% versus 38.7%, respectively). The rate of itchy was lower in the studied group. CONCLUSION: In the treatment of moderate acne vulgaris, oral isotretinoin in combination with desloratadine is more effective and has fewer side effects than using isotretinoin alone

Efficacy of Oral Isotretinoin in Combination with Desloratadine in the Treatment of Common Vulgaris Acne in Vietnamese Patients

AIM: To evaluate the efficacy of oral isotretinoin used alone and in combination with desloratadine in the treatment of moderate acne vulgaris. METHODS: A comparative clinical trial was undertaken to evaluate the efficacy of oral isotretinoin alone and in combination with desloratadine in the treatment of 62 moderate acne vulgaris patients. Patients were randomised into two groups with 31 patients in each group. Each studied group's patient took 20 mg isotretinoin and 5 mg desloratadine per day. In the control group, patients took only 20 mg isotretinoin per day. The treatment time was 16 weeks. The evaluation and follow-up were done at week 2, 4, 8, 12 and 16 of the treatment. RESULTS: The studied group had a better curative rate than the control group (45.2% versus 22.6%). The average number of inflammatory lesions in the studied group was significantly lower than the control group (0.19 versus 0.94). The mean GAGS score of the studied group was significantly lower than the control group (3.71 versus 6.52). Acne outbreaks rate of the studied group was lower than the control group (in week 2: 22.6% versus 45.2% and in week 4: 16.1% versus 38.7%, respectively). The rate of itchy was lower in the studied group. CONCLUSION: In the treatment of moderate acne vulgaris, oral isotretinoin in combination with desloratadine is more effective and has fewer side effects than using isotretinoin alone

The Effectiveness of Oral Mini-Pulse Methylprednisolonein - the Treatment of Alopecia Areata in Vietnam

BACKGROUND: Systemic corticosteroid is used to treat alopecia areata, but it is associated with side effects. Mini-pulse therapy is thought to be effective but able to reduce side effects. AIM: The study aimed to evaluate the effectiveness of oral mini-pulse methylprednisolone in the treatment of alopecia areata. METHODS: Patients received methylprednisolone 16 mg orally for 2 consecutive days every week. RESULTS: After 3 months, among patients, 40% recovered well, and 55.6% recovered fairly. After 6 months, 82.2% recovered well, 17.8% recovered fairly. No adverse events were detected, and the recurrence rate was low (2.2%). CONCLUSION: Oral mini-pulse methylprednisolone therapy is an effective and safe therapeutic option for alopecia areata without side effects, and the time of the treatment is short

The Role of Maternally Acquired Antibody in Providing Protective Immunity Against Nontyphoidal Salmonella in Urban Vietnamese Infants: A Birth Cohort Study.

BACKGROUND: Nontyphoidal Salmonella (NTS) organisms are a major cause of gastroenteritis and bacteremia, but little is known about maternally acquired immunity and natural exposure in infant populations residing in areas where NTS disease is highly endemic. METHODS: We recruited 503 pregnant mothers and their infants (following delivery) from urban areas in Vietnam and followed infants until they were 1 year old. Exposure to the dominant NTS serovars, Salmonella enterica serovars Typhimurium and Enteritidis, were assessed using lipopolysaccharide (LPS) O antigen-specific antibodies. Antibody dynamics, the role of maternally acquired antibodies, and NTS seroincidence rates were modeled using multivariate linear risk factor models and generalized additive mixed-effect models. RESULTS: Transplacental transfer of NTS LPS-specific maternal antibodies to infants was highly efficient. Waning of transplacentally acquired NTS LPS-specific antibodies at 4 months of age left infants susceptible to Salmonella organisms, after which they began to seroconvert. High seroincidences of S. Typhimurium and S. Enteritidis LPS were observed, and infants born with higher anti-LPS titers had greater plasma bactericidal activity and longer protection from seroconversion. CONCLUSIONS: Although Vietnamese infants have extensive exposure to NTS, maternally acquired antibodies appear to play a protective role against NTS infections during early infancy. These findings suggest that prenatal immunization may be an appropriate strategy to protect vulnerable infants from NTS disease

The Efficacy of a Two-Fold Increase of H1-Antihistamine in the Treatment of Chronic Urticaria - the Vietnamese Experience

BACKGROUND: Chronic urticaria, a mast cell-driven condition, is common, debilitating and hard to treat. H1-antihistamines are the first line treatment of chronic urticaria, but often patients do not get satisfactory relief with the recommended dose. European guidelines recommend increased antihistamine doses up to four-fold. AIM: We conducted this study to evaluate the efficacy of increased H1-antihistamine doses up to two-fold in Vietnamese chronic urticaria patients. METHODS: One hundred and two patients with chronic urticaria were recruited for treatment with levocetirizine (n = 52) or fexofenadine (n = 50). Treatment started at the conventional daily dose of 5 mg levocetirizine or 180 mg fexofenadine for 2 weeks and then increased to 10 mg levocetirizine or 360 mg fexofenadine for 2 weeks if patients did not have an improvement in symptoms. At week 0, week 2 and week 4 wheal, pruritus, size of the wheal, total symptom scores, and associated side-effects were assessed. RESULTS: With the conventional dose, the total symptom scores after week 2 decreased significantly in both groups compared to baseline figures, i.e. 7.4 vs 2.3 for levocetirizine group and 8.0 vs 2.6 for fexofenadine group (p < 0.05). However, there were still 26 patients in each group who did not have improvements. Of these 26 patients, after having a two-fold increase of the conventional dose, 11.5% and 38.5% became symptom-free at week 4 in levocetirizine group and fexofenadine group, respectively. At week 4 in both groups, the total symptom scores had significantly decreased when compared with those at week 2 (2.8 ± 1.5 versus 4.7 ± 1.6 in levocetirizine group; 2.1 ± 1.9 versus 5.1 ± 1.4 in fexofenadine group). In both groups, there was no difference in the rate of negative side effects between the conventional dose and the double dose. CONCLUSION: This study showed that increasing the dosages of levocetirizine and fexofenadine by two-fold improved chronic urticaria symptoms without increasing the rate of negative side effects