Mycobacterium-Specific γ9δ2 T Cells Mediate Both Pathogen-Inhibitory and CD40 Ligand-Dependent Antigen Presentation Effects Important for Tuberculosis Immunity

Numerous pathogens, including Mycobacterium tuberculosis, can activate human γ₉δ₂ T cells to proliferate and express effector mechanisms. γ₉δ₂ T cells can directly inhibit the growth of intracellular mycobacteria and may also act as antigen-presenting cells (APC). Despite evidence for γδ T cells having the capacity to function as APC, the mechanisms involved and importance of these effects on overall tuberculosis (TB) immunity are unknown. We prepared M. tuberculosis-specific γ₉δ₂ T cell lines to study their direct protective effects and APC functions for M. tuberculosis-specific αβ T cells. The direct inhibitory effects on intracellular mycobacteria were measured, and the enhancing effects on proliferative and effector responses of αβ T cells assessed. Furthermore, the importance of cell-to-cell contact and soluble products for γ₉δ₂ T cell effector responses and APC functions were investigated. We demonstrate, in addition to direct inhibitory effects on intracellular mycobacteria, the following: (i) γ₉δ₂ T cells enhance the expansion of M. tuberculosis-specific αβ T cells and increase the ability of αβ T cells to inhibit intracellular mycobacteria; (ii) although soluble mediators are critical for the direct inhibitory effects of γ₉δ₂ T cells, their APC functions do not require soluble mediators; (iii) the APC functions of γ₉δ₂ T cells involve cell-to-cell contact that is dependent on CD40-CD40 ligand (CD40L) interactions; and (iv) fully activated CD4⁺ αβ T cells and γ₉δ₂ T cells provide similar immune enhancing/APC functions for M. tuberculosis-specific T cells. These effector and helper effects of γ₉δ₂ T cells further indicate that these T cells should be considered important new targets for new TB vaccines.     

Clinical Activity and Polymerase Chain Reaction Evidence of Chlamydial Infection after Repeated Mass Antibiotic Treatments for Trachoma

It is unclear how the prevalence of clinically active trachoma correlates with the prevalence of ocular chlamydial infection at the community level. In 24 villages from a cluster-randomized clinical trial of mass azithromycin distributions in Ethiopia, the correlation between the prevalence of clinical activity (on examination) and chlamydial infection (by polymerase chain reaction) was moderately strong before mass antibiotic treatments (Pearson''s correlation coefficient r = 0.75, 95% confidence interval [CI] = 0.52–0.87), but decreased at each time point during four biannual treatments (at 24 months, r = 0.15, 95% CI = −0.14–0.41). One year after the final treatment, the correlation coefficient had increased, but not to the pre-treatment level (r = 0.55, 95% CI = 0.30–0.73). In a region with hyperendemic trachoma, conjunctival examination was a useful indicator of the prevalence of chlamydial infection before treatments, less useful during mass treatments, but regained utility by one year after treatments had stopped.     

Disposition of glucosinolates and sulforaphane in humans after ingestion of steamed and fresh broccoli

The cancer-chemopreventive effects of broccoli may be attributed, in part, to isothiocyanates (ITCs), hydrolysis products of glucosinolates. Glucosinolates are hydrolyzed to their respective ITCs by the enzyme myrosinase, which is inactivated by heat. In this study, the metabolic fate of glucosinolates after ingestion of steamed and fresh broccoli was compared in 12 male subjects in a crossover design. During each 48-hour baseline period, no foods containing glucosinolates or ITCs were allowed. The subjects then consumed 200 g of fresh or steamed broccoli; all other dietary sources of ITCs were excluded. Blood and urine samples were collected during the 24-hour period after broccoli consumption. Total ITC equivalents in broccoli and total ITC equivalents in plasma and urine were assayed by high-performance liquid chromatography as the cyclocondensation product of 1,2-benzenedithiol. The content of ITCs in fresh and steamed broccoli after myrosinase treatment was found to be virtually identical (1.1 vs. 1.0 micromol/g wet wt). The average 24-hour urinary excretion of ITC equivalents amounted to 32.3 +/- 12.7% and 10.2 +/- 5.9% of the amounts ingested for fresh and steamed broccoli, respectively. Approximately 40% of total ITC equivalents in urine, 25.8 +/- 13.9 and 6.9 +/- 2.5 micromol for fresh and steamed broccoli, respectively, occurred as the N-acetyl-L-cysteine conjugate of sulforaphane (SFN-NAC). Total ITC metabolites in plasma peaked between 0 and 8 hours, whereas urinary excretion of total ITC equivalents and SFN-NAC occurred primarily between 2 and 12 hours. Results of this study indicate that the bioavailability of ITCs from fresh broccoli is approximately three times greater than that from cooked broccoli, in which myrosinase is inactivated. Considering the cancer-chemopreventive potential of ITCs, cooking broccoli may markedly reduce its beneficial effects on health.     

Management of traumatic arterio-venous fistulas,experience in Armed Forces General Hospital,Addis Ababa

In Armed Forces General Hospital from March to December 1999, 53 patients were operated for Arterio-venous fistula. All were males, their age ranging from 19 to 46 years, average 27 years. The diagnosis of arterio-venous fistulas was established clinically. The pathological distribution of the lesions were: 23(43.4%) Arterio-Venous aneurysm; 11(20.75%) Arterio-Venous fistula, 19(35.85%) Arterial false aneurysms. The anatomical location was: 15 femoral, 10 Tibial, 6 poplitial, 6 brachial, 4 Axilláry, 1 ulnar, 7 external carotid and 1 occipital. The types of surgical procedures performed were: 29 (54.72%) excision of the arterio-venous fistula and aneurismal sac with arterial restoration by end to end anastomosis and/or saphenous vein graft, 16(30.19%) by excision of arteriovenous fistula and quadriple ligation of small vessels, 8(15.09%) excision of the false aneurismal sac and lateral repair of the artery (lateral arterioraphy). During the post operative period the patients were followed for three months, and we had the following results based on the clinical outcome criteria; 37(69.81%) excellent, 15(28.3%) good and 1(1.89%) fair.     

ABO blood groups,grass pea preparation,and neurolathyrism in Ethiopia

An exploratory study was conducted in the rural Estie district of Ethiopia in 1997 to identify the role of ABO blood group, rhesus factor, and type of grass pea (Lathyrus sativus) diet in the susceptibility to neurolathyrism. Five-hundred study subjects (250 cases and 250 controls) were examined and interviewed, and had their ABO and rhesus blood groups determined. The majority (86%) of the cases were males. Blood group O was the most common in the patients and controls followed by groups A, B, and AB. The vast majority of the study subjects were rhesus-positive. The gravy (Shiro) grass pea preparation was consumed by 91.6% of the study population, boiled (Nifiro) by 86%, and roasted (Kollo) by 56.4%. Almost half (48%) of the cases had consumed grass pea for > 4 months compared to 8% of controls (P < 0.001). There was a significant association between the risk for neurolathyrism and the consumption of boiled (adjusted odds ratio [AOR] = 98.4) and roasted (AOR = 55.62) forms of grass pea. There was no risk of paralysis associated with consumption of the gravy form of grass pea (AOR = 0.40, 95% confidence interval 0.1-2.0). Blood group O remained significantly associated with the disease after adjusting for age, type of grass pea preparation consumed, and duration of consumption (AOR = 2.90).     

Praziquantel efficacy against schistosomiasis mansoni in schoolchildren in north-west Ethiopia

The efficacy of praziquantel against schistosomiasis mansoni has been measured in 10-14 years old schoolchildren in a highly endemic area of north-west Ethiopia. The egg reduction rate was 97% and the cure rate was 94%, as assessed by a single Kato smear. No evidence for praziquantel resistance was detected.     

Pattern and associated factors of the neurolathyrism epidemic in Ethiopia

OBJECTIVES: To describe the neurolathyrism epidemic in Ethiopia and to identify associated household factors. METHODS: We interviewed 589 randomly selected heads of household in Debre Sina district of Ethiopia, the area afflicted by the recent neurolathyrism epidemic. Disease information was obtained for 2987 family members. RESULTS: Neurolathyrism patients were detected in 56 (9.5%) households (prevalence rate 2.38%). The mean number of affected family members per household was 1.27 (SD 0.65, range 1-3). Most (77.5%) patients developed the disability during the epidemic (1995-1999). The median age at onset of paralysis was 11 years with a range of 41 (range 3-44). Younger people were more affected during the epidemic than during the non-epidemic period (P=0.01). The presence of a neurolathyrism patient in the family was associated with illiteracy [adjusted OR (95% CI)=2.23 (1.07-5.10)] of the head of household, with owning a grass pea farm [adjusted OR (95% CI)=2.01 (1.04-3.88)] and with the exclusive cooking of grass pea foods using handmade traditional clay pots [adjusted OR (95% CI=2.06 (1.08-3.90)]. CONCLUSION: Males aged 10-14 years were most affected by neurolathyrism. Increased household risk was associated with illiteracy of the head of the household and exclusive cooking of grass pea foods with handmade traditional clay pots.     

Contribution of hypoglycemia to medical care expenditures and short-term disability in employees with diabetes

OBJECTIVE: Diabetes is the third-most expensive physical health condition among US employees. We sought to evaluate the contribution of hypoglycemia to these costs. METHODS: We studied 2664 employees using insulin for whom medical encounters and short-term disability (STD) records were available. RESULTS: Among these employees, 442 (16.6%) had a diagnosis of hypoglycemia during an average follow-up of 2.5 years. The risk of hospitalization and emergency room visits was increased twofold in this group. Much of this excess was associated with hypoglycemia. The annualized medical cost of hypoglycemia was $3241. Patients with hypoglycemia had 77% more STD days annually. The risk of STD in the week after hypoglycemia was increased fivefold. CONCLUSION: These data suggest that hypoglycemia contributes substantially to medical care utilization and to disability-related work absence among employees using insulin.     

Sexually transmitted disease testing protocols, sexually transmitted disease testing, and discussion of sexual behaviors in HIV clinics in Los Angeles County

OBJECTIVE/GOAL: The objective of this study was to evaluate the use of written protocols for sexually transmitted disease (STD) screening, the frequency and types of STD tests performed, and the occurrence and frequency of obtaining sexual risk assessments among HIV clinics. STUDY: A survey was administered to 36 medical directors, clinic directors, and HIV providers representing 48 HIV healthcare clinics in Los Angeles. RESULTS: The use of a written or electronic protocol for STD testing was reported by 50% of clinics. Clinics with written or electronic STD protocols were significantly more likely to report questioning patients at each visit regarding their sexual practices (prevalence ratio, 2.2; 95% confidence interval, 1.4-3.4). Clinics with written or electronic protocols were not more likely to report more frequent STD testing. CONCLUSIONS: Written or electronic protocols for STD testing may promote sexual risk assessment questioning among HIV healthcare providers and may help to ensure STD testing per Centers for Disease Control and Prevention/IDSA guidelines for HIV-positive persons at sexual risk.