Pathogen reduction and blood transfusion safety in Africa: strengths, limitations and challenges of implementation in low-resource settings.

Transfusion-transmitted infection risk remains an enduring challenge to blood safety in Africa. A high background incidence and prevalence of the major transfusion-transmitted infections (TTIs), dependence on high-risk donors to meet demand, suboptimal testing and quality assurance collectively contribute to the increased risk. With few exceptions, donor testing is confined to serological evaluation of human immunodeficiency virus (HIV), hepatitis B and C (HBV and HCV) and syphilis. Barriers to implementation of broader molecular methods include cost, limited infrastructure and lack of technical expertise. Pathogen reduction (PR), a term used to describe a variety of methods (e.g. solvent detergent treatment or photochemical activation) that may be applied to blood following collection, offers the means to diminish the infectious potential of multiple pathogens simultaneously. This is effective against different classes of pathogen, including the major TTIs where laboratory screening is already implemented (e.g. HIV, HBV and HCV) as well pathogens that are widely endemic yet remain unaddressed (e.g. malaria, bacterial contamination). We sought to review the available and emerging PR techniques and their potential application to resource-constrained parts of Africa, focusing on the advantages and disadvantages of such technologies. PR has been slow to be adopted even in high-income countries, primarily given the high costs of use. Logistical considerations, particularly in low-resourced parts of Africa, also raise concerns about practicality. Nonetheless, PR offers a rational, innovative strategy to contend with TTIs; technologies in development may well present a viable complement or even alternative to targeted screening in the future.

Cold tolerance and disinfestation of Bactrocera invadens (Diptera: Tephritidae) in 'Hass' avocado.

Bactrocera invadens (Diptera: Tephritidae) has spread rapidly across Africa and currently poses a phytosanitary threat to the fruit industry of South Africa. In reaction a cold mitigating treatment to provide phytosanitary security to importing countries was developed in Nairobi, Kenya. Using laboratory reared fruit flies, the rate of development in 'Hass' avocado (Persea americana Miller) was determined at 28 degrees C. Fruit ripeness or softness was found to be a factor improving larval fruit fly survival. Using this information the egg and larval developmental stages were subjected to 2 degrees C cold treatment and it was found that the third instars were the most cold tolerant life stage and that it was expected that between 16 and 17 d treatment would provide phytosanitary security. There were no survivors in the treatment of an estimated 153,001 individuals in four replicates at an average fruit pulp temperature of 2 degrees C satisfying the Probit 9 level of efficiency at a confidence of >95%. These data provide evidence that a continuous cold treatment of 1.5 degrees C or lower for 18 d would provide phytosanitary security in that any consignment entering an importing country poses no risk of accidental importation of B. invadens.

Cold Disinfestation of "Hass" Avocado (Persia americana) of Three Species of Fruit Fly (Diptera: Tephritidae)-Ceratitis capitata, Ceratitis rosa, and Ceratitis cosyra.

The avocado industry is important in South Africa, but access to certain markets is impeded by the presence of phytosanitary pests. One of the ways of securing entry to these markets is to demonstrate that a mitigating treatment will result in there being a negligible chance of accidental importation. In cold treatment comparative studies at 0 °C and 2 °C of immature stages of Ceratitis capitata (Wiedemann), Ceratitis rosa Karsch, and Ceratitis cosyra (Walker) in "Hass" avocado, the third instar of C. cosyra was shown to be the most cold tolerant. This larval life stage was used in a large-scale trial to test treatment efficacy at 2 °C, a temperature known to be the better for fruit quality. There were no survivors from the 49,795 individual fruit fly larvae subjected to the cold treatment at 2 °C for 20 d. It is argued that, although this level of assessment falls short of the Probit 9 level normally required for fruit fly, they are rarely found in avocado fruit and that the level of disinfestation obtained is more than sufficient to achieve quarantine security.

Raised troponin T and echocardiographic abnormalities after prolonged strenuous exercise--the Australian Ironman Triathlon.

BACKGROUND: There is concern about whether cardiac damage occurs as a result of prolonged strenuous exercise. OBJECTIVE: To investigate whether competing in a triathlon is associated with cardiac damage based on a sustained increase in cardiac troponin T (cTnT), and whether such an increase correlates with echocardiographic changes METHODS: cTnT and echocardiographic measurements were made in 38 participants in the 2001 Australian ironman triathlon. cTnT was measured the day before, immediately after, and the day following the race. Echocardiography was done the day before, immediately after, and two to six weeks later for measurement of ejection fraction, stroke volume, cardiac output, wall motion analysis, and global left ventricular function (LVF). RESULTS: No subject had detectable cTnT in the pre-race sample. Following the race, 32 subjects (86.5%) had detectable levels of cTnT (>0.01 ng/ml), with six (16.2%) having >0.10 ng/ml. The day after the race, nine subjects (23.7%) still had detectable cTnT, with two recording a level >0.10 ng/ml. Previously described echocardiographic changes of "cardiac fatigue" were observed in the whole cohort. There was a modest but significant correlation between change in ejection fraction and peak cTnT level (p = 0.02, r = 0.39). Athletes with a post-race cTnT >0.10 ng/ml had a greater decrease in global LVF (p = 0.02) and a trend toward a greater fall in ejection fraction and stroke volume than athletes with cTnT levels <0.10 ng/ml. Cardiac output fell in the group with cTnT >0.10 ng/ml (p>0.05). CONCLUSIONS: Participation in ironman triathlon often resulted in persistently raised cTnT levels, and the troponin rise was associated with echocardiographic evidence of abnormal left ventricular function. The clinical significance and long term sequelae of such damage remains to be determined.

False Codling Moth, Thaumatotibia leucotreta (Lepidoptera: Tortricidae), Cold Disinfestation Treatment Using Grapes as the Test Medium.

Some countries consider false codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), a phytosanitary pest and may require the application of a mitigation treatment before accepting T. leucotreta-susceptible produce. This research reports on cold treatments that provide the phytosanitary security that this pest would not be accidentally imported alive. More than 35,000 individuals were treated for 20 d at 0.8 °C and >30,000 individuals subjected to - 0.6 °C for 18 d, with no survivors. The adoption of these treatments in international fruit trade protocols is recommended.

Rubella antibodies and adverse events late after renal transplantation.

Rubella antibody titers were determined pretransplant and then serially posttransplantation in 52 consecutive patients whose renal allografts survived at least three months. Group A patients (18) had antibody titers greater than or equal to 1:128 in the posttransplant period. Group B (24) had intermediate antibody titers that never rose higher than 1:64. Group C (10) consistently had antibody titers less than 1:8. Group A did not differ from groups B and C with respect to age, race, sex, type of transplant, underlying renal disease, or maximum complement fixation antibody titers posttransplant to cytomegalovirus or herpes simplex virus, type 1. Group A did differ from groups B and C in its frequency of hepatitis, chronic liver disease, episodes of late rejection (greater than or equal to 21 days after transplant), transplant nephrectomy required for rejection, infections whose defense involves intact cell-mediated immunity, and the number of late rejection episodes per patient. Mechanisms underlying these associations are not known but apparently are not related to HLA phenotype.

Disease due to cytomegalovirus and its long-term consequences in renal transplant recipients. Correlation of allograft survival with disease due to cytomegalovirus and rubella antibody level.

We prospectively studied 52 consecutive renal allograft recipients who retained their grafts at least three months. The transplant recipients were observed for five years or longer. Disease due to cytomegalovirus (CMV) occurred in nine (17.3%). Manifestations of disease due to CMV that were significantly more common than in chronologically matched controls in comparable periods after transplantation included fever, leukopenia, hepatic function abnormalities, pneumonia, and renal dysfunction. Life-table analyses suggested a trend of decreased allograft survival with disease due to CMV, but the difference between controls was not statistically significant. A significant inverse correlation were noted between the level of hemagglutination inhibition antibody to rubella virus reached after transplantation and allograft survival. This correlation remained statistically significant even when patients with disease due to CMV were excluded from the analysis.

Validity of the Maternal and Child Health Services Block Grant as an indicator of state infant mortality reduction initiatives.

Since state Maternal and Child Health Services Block Grant applications represent the most comprehensive source of information about community and state needs assessment, policy development, and program assurance for the population of mothers and children, these documents have the potential to play a central role in state accountability to Congress and the Maternal and Child Health Bureau. To measure the validity of block grant applications as a reporting mechanism, we assessed the sensitivity of the applications from seven states to strategies for reducing infant mortality. We used the independent coding of infant mortality strategies from the Healthy Futures/Healthy Generations Program intensive evaluation as the standard. Overall, the sensitivity of the block grant applications was only 45%. Since the open-ended design of the block grant applications does not appear to reflect the extent of state activity in infant mortality reduction, a uniform application should be adopted that will facilitate clear and systematic reporting of state activities.

SPECT thallium-201 combined with Toxoplasma serology for the presumptive diagnosis of focal central nervous system mass lesions in patients with AIDS.

OBJECTIVE: To determine the utility of brain thallium-201 single photon emission computerized tomography (Tl-201 SPECT) combined with Toxoplasma serology for the diagnosis of focal CNS lesions in patients with AIDS. METHODS: Sixty-one consecutive HIV-infected patients with focal CNS lesion(s) on head computed tomography (CT) or MRI scan who underwent brain Tl-201 SPECT and serum Toxoplasma serology were evaluated, retrospectively. Thallium-201 uptake ratios were calculated by comparing lesion activity to contralateral scalp activity. Diagnoses were made by a combination of histology, serology, PCR, and empirical response to therapy. Toxoplasma serologies (IgG IFA) were compared in the patients with central nervous system (CNS) toxoplasmosis and those without CNS toxoplasmosis. RESULTS: Fifty-six patients were evaluable and a definitive diagnosis was made in 38 patients: toxoplasmosis (17), lymphoma (14), PML (three), Aspergillus (one), tuberculoma (one), Cryptococcus (one), varicella-zoster virus (one). Patients with lymphoma had significantly higher lesion/contralateral scalp ratios compared to patients without lymphoma: 1.03 vs. 0.67, P < 0.05. Using a cut-off of 0.90 for the lesion/scalp uptake ratios (based on analysis of ROC curves) the sensitivity and specificity for the diagnosis of lymphoma were 86% and 83%, respectively. Serum Toxoplasma IgG titres were significantly higher in patients diagnosed with toxoplasmosis compared to those with a diagnosis other than toxoplasmosis, 1:5444 vs. 1:15, P < 0.05. Only one patient with confirmed toxoplasmosis had a Toxoplasma serology < 1:256, while no patients without toxoplasmosis (including all lymphoma patients) had serologies > 1:256. CONCLUSIONS: In a series of HIV-infected patients, Tl-201 SPECT was able to accurately differentiate primary brain lymphoma from other causes of focal CNS lesions in most patients; however, both false positive and false negative results occurred. By combining Tl-201 SPECT with serum Toxoplasma IgG, diagnostic accuracy was improved.

Determination of low concentrations of iodine-131 in fast-reactor coolant systems.

A method has been devised for the determination of iodine-131 in the presence of mixed fission products in reactor coolants, by oxidation to elemental iodine followed by sublimation on to copper gauzes. The method reduces to a minimum contamination of the copper gauzes by ruthenium-103 and ruthenium-106 and eliminates contamination due to technetium-99 and caesium-137. It is possible to determine 10(2)cpm ml from iodine-131 in a total count of 2 x 10(6)cpm ml of fission products, with an accuracy of +/- 3%. The only activity collected on the copper gauzes was iodine-131 (62% collection efficiency) and ruthenium-103 (0.005% of total activity) which gave comparable count rates. The activity of these two isotopes was separated by single-channel gamma analysis.

Determination of caesium-137 in fast-reactor coolant systems.

A method for the separation of caesium by ion-exchange involving ammonium 12-molybdophosphate has been investigated, and found to be 100% efficient for aqueous solutions with high sodium and potassium concentrations.

Experimental evidence of coupling between sheared-flow development and an increase in the level of turbulence in the TJ-II stellarator.

The link between the development of sheared flows and the structure of turbulence has been investigated in the plasma boundary region of the TJ-II stellarator. The development of the naturally occurring velocity shear layer requires a minimum plasma density. Near this critical density, the level of edge turbulent transport and the turbulent kinetic energy significantly increases in the plasma edge. The resulting shearing rate in the phase velocity of fluctuations is comparable to the one required to trigger a transition to improved confinement regimes with reduction of edge turbulence, suggesting that spontaneous sheared flows and fluctuations keep themselves near marginal stability. These findings provide the experimental evidence of coupling between sheared flows development and increasing in the level of edge turbulence. The experimental results are consistent with the expectations of second-order transition models of turbulence-driven sheared flows.

Comparative Efficacy of Preplant Fumigation and Postplant Chemical Treatment of Replant Citrus Trees in an Orchard Infested with Tylenchulus semipenetrans.

Preplant soil fumigation with methyl bromide at 49 and 98 g/m2 was compared with various postplant nematicide and fungicide programs in a replant citrus orchard infested with the citrus nematode Tylenchulus semipenetrans and the fungal pathogens Phytophthora nicotianae, Fusarium solani, and F. oxysporum. Postplant treatments comprised multiple applications of fenamiphos at 4.0 g a.i./m2 soil, aldicarb at 4.5 g a.i./m2 soil, metalaxyl at 4 g a.i./m2 soil, fose-tyl-Al stem painting at 400 g a.i./liter, and combinations of fenamiphos + fosetyl-Al and aldi-carb + fosetyl-Al at the same rates as for single treatments. P. nicotianae could not be detected in the entire experimental site after replanting, but populations of F. solani and F. oxysporum showed only a temporary decline following site preparation. T. semipenetrans did not re-establish in any of the treatments within the first 2 years. Numbers of juveniles remained low in most treatments during the third year, but thereafter both juveniles and females increased significantly in all except the fumigated plots. Female populations on roots of citrus trees planted in fumigated soil remained suppressed for 8 years and the trees developed more vigorously and produced higher yields and larger fruit than those in non-fumigated soil. Compared with the control, net income for the period 4 to 8 years after planting increased by 101 and 46% in plots fumigated with 49 and 98 g/m2, respectively. With the exception of aldicarb, all other treatments showed net losses.

Single absorbable polydioxanone pin fixation for distal chevron bunion osteotomies.

The distal chevron osteotomy is a well-established technique for correction of symptomatic mild to moderate metatarsus primus varus with hallux valgus deformity. Fixation of the osteotomy ranges from none to bone pegs, Kirschner wires, screws, or absorbable pins. We evaluated one surgeon's (J.K.D.) results of distal chevron osteotomy fixation with a single, nonpredrilled, 1.3-mm poly-p-dioxanone pin and analyzed any differences in patients with unilateral or bilateral symptomatic metatarsus primus varus with hallux valgus deformities. All osteotomies healed without evidence of infection, osteolysis, nonunion, or necrosis. Equal correction was achieved in unilateral and bilateral procedures. The technique is quick and easy, and adequate fixation is achieved.

A comparison of methods for determining setting rate of amalgam.

Four methods were compared for determining the setting rate of amalgams. The resultant order of preference as a standard method was compressive strength at 30 minutes after preparation of the specimen, the time to the last transverse cut on a cylindrical specimen with a "guillotine" blade and the time to nonfracture of a ball of a amalgam with a final set Gillmore needle. A mercury absorption method was unacceptable. Alloys labelled fast and standard setting could be separated and limits between fast and standard alloys have been examined for each method.