Detection of Vi-negative Salmonella enterica serovar typhi in the peripheral blood of patients with typhoid fever in the Faisalabad region of Pakistan

The synthesis and transportation proteins of the Vi capsular polysaccharide of Salmonella enterica serovar Typhi (serovar Typhi) are encoded by the viaB operon, which resides on a 134-kb pathogenicity island known as SPI-7. In recent years, Vi-negative strains of serovar Typhi have been reported in regions where typhoid fever is endemic. However, because Vi negativity can arise during in vitro passage, the clinical significance of Vi-negative serovar Typhi is not clear. To investigate the loss of Vi expression at the genetic level, 60 stored strains of serovar Typhi from the Faisalabad region of Pakistan were analyzed by PCR for the presence of SPI-7 and two genes essential for Vi production: tviA and tviB. Nine of the sixty strains analyzed (15%) tested negative for both tviA and tviB; only two of these strains lacked SPI-7. In order to investigate whether this phenomenon occurred in vivo, blood samples from patients with the clinical symptoms of typhoid fever were also investigated. Of 48 blood samples tested, 42 tested positive by fliC PCR for serovar Typhi; 4 of these were negative for tviA and tviB. Three of these samples tested positive for SPI-7. These results demonstrate that viaB-negative, SPI-7-positive serovar Typhi is naturally occurring and can be detected by PCR in the peripheral blood of typhoid patients in this region. The method described here can be used to monitor the incidence of Vi-negative serovar Typhi in regions where the Vi vaccine is used.     

Effectiveness of Preventive Therapy for Persons Exposed at Home to Drug-Resistant Tuberculosis,Karachi, Pakistan

In Karachi, Pakistan, a South Asian megacity with a high prevalence of tuberculosis (TB) and low HIV prevalence, we assessed the effectiveness of fluoroquinolone-based preventive therapy for drug-resistant (DR) TB exposure. During February 2016–March 2017, high-risk household contacts of DR TB patients began a 6-month course of preventive therapy with a fluoroquinolone-based, 2-drug regimen. We assessed effectiveness in this cohort by comparing the rate and risk for TB disease over 2 years to the rates and risks reported in the literature. Of 172 participants, TB occurred in 2 persons over 336 person-years of observation. TB disease incidence rate observed in the cohort was 6.0/1,000 person-years. The incidence rate ratio ranged from 0.29 (95% CI 0.04–1.3) to 0.50 (95% CI 0.06–2.8), with a pooled estimate of 0.35 (95% CI 0.14–0.87). Overall, fluoroquinolone-based preventive therapy for DR TB exposure reduced risk for TB disease by 65%.     

Persistence of effects of nitric oxide synthase inhibitors: Comparisons on blood flow and plasma exudation in guinea pig skin

Plasma protein extravasation has been measured in guinea pig skin using

Full-size image

-albumin and blood flow using

Full-size image

enon (

Full-size image

e) clearance. The nitric oxide (NO) synthase inhibitors N^G-nitro-

Full-size image

-arginine methyl ester (

Full-size image

-NAME), N^G-monomethyl-

Full-size image

-arginine (l

Full-size image

NMMA) and N^G-nitro-

Full-size image

-arginine (

Full-size image

-NOArg) and the α-adrenoceptor agonist, phenylephrine, inhibited bradykinin induced plasma protein extravasation when co-injected with the peptide. The inhibitory effects of

Full-size image

-NAME and

Full-size image

-NOArg lasted for up to 8 and 4 h, respectively, whereas phenylephrine and

Full-size image

-NMMA had no persistent inhibitory effects. When co-injected with

Full-size image

e,

Full-size image

-NAME,

Full-size image

-NMMA,

Full-size image

-NOArg and phenylephrine, but not

Full-size image

-NAME, produced significant reductions in skin blood flow. When injected prior to

Full-size image

e,

Full-size image

-NAME and

Full-size image

-NOArg, but not phenylephrine or

Full-size image

-NMMA, significantly reduced flow. The effect of

Full-size image

-NAME on flow was not significant at 8 h. Thus, although the inhibitory effects of the NO synthase inhibitors on mediator induced plasma protein extravasation show correlations with their effects on blood flow, the persistent effect of

Full-size image

-NAME on exudation appears to extend beyond its effect on flow.     

Future ophthalmology practice pattern: A survey of Saudi Board of Ophthalmology residents

Purpose

The main purpose of the study was to examine and identify factors that influence the future practice pattern of Saudi Board of Ophthalmology residents as well as their academic goals. This study also aimed to compare the plans and career goals of the current Saudi ophthalmology residents with a former cohort of Saudi ophthalmology residents.

Outcome of Judet's quadricepsplasty for knee contractures and the effect of local infiltration of epinephrine on reducing blood loss

Objective: To evaluate the effectiveness of Judet''s quadricepsplasty for treatment of knee contractures and to identify the effect of local infiltration of epinephrine on blood loss associated with this procedure. Methods: A retrospective cohort study was conducted in which all cases of knee contractures managed with Judet''s quadricepsplasty from 1st January 2009 to 31st December 2013 were included and were divided into two groups. The epinephrine group included patients who were infiltrated with diluted epinephrine (1:400,000) along with xylocaine, around the operative field 15 min prior to the incision time, while the control group did not receive any infiltration. Judet''s outcome, blood loss, drop in hemoglobin and required blood transfusion were noted for all patients and compared between both groups. Results: Most common preceding pathology identified for the development of knee contractures was periarticular fracture while ilizarov application was the most common etiology. Both groups were found similar in all preoperative characteristics except preoperative flexion contracture (p=0.02). All functional outcome measures including Judet''s outcome were similar in both groups. In contrast, duration of surgery (p=0.01), blood loss (p=0.02), drop in hemoglobin (p=0.01) and number of transfusions (p=0.03) were significantly reduced in epinephrine group. Conclusion: Judet''s quadricepsplasty is a useful procedure to increase the range of motion of rigid knees and local infiltration of epinephrine is effective in decreasing the amount of subsequent blood loss and transfusion requirements.