Application opportunities of geographic information systems analysis to support achievement of the UNAIDS 90-90-90 targets in South Africa.

In an effort to achieve control of the HIV epidemic, 90-90-90 targets have been proposed whereby 90% of the HIV-infected population should know their status, 90% of those diagnosed should be receiving antiretroviral therapy, and 90% of those on treatment should be virologically suppressed. In this article we present approaches for using relatively simple geographic information systems (GIS) analyses of routinely available data to support HIV programme management towards achieving the 90-90-90 targets, with a focus on South Africa (SA) and other high-prevalence settings in low- and middle-income countries. We present programme-level GIS applications to map aggregated health data and individual-level applications to track distinct patients. We illustrate these applications using data from City of Johannesburg Region D, demonstrating that GIS has great potential to guide HIV programme operations and assist in achieving the 90-90-90 targets in SA.

Isoniazid preventive therapy in HIV-infected children on antiretroviral therapy: a pilot study.

SETTING: Tuberculosis (TB) is a common cause of mortality and morbidity in children infected with the human immunodeficiency virus (HIV). Data on isoniazid preventive therapy (IPT) efficacy in HIV-infected children receiving antiretroviral therapy (ART) are inconclusive. OBJECTIVE: To assess the efficacy, tolerability and safety of isoniazid (INH) in HIV-infected children on ART. DESIGN: A pilot randomised controlled study of INH was undertaken in HIV-infected children on ART. The primary outcome measure was TB disease or death. RESULTS: A total of 167 children were randomised to receive INH (n = 85) or placebo (n = 82), and followed for a median of 34 months (interquartile range [IQR] 24-52). The median age was 35 months (IQR 15-65). There was one death in a child on INH and none in the placebo group. Eleven (6.6%) cases of TB occurred, 4 (5%) in the INH and 7 (9%) in the placebo group. Among the TB cases, 5 were culture confirmed-2 in the INH group and 3 in the placebo group, all susceptible to INH. Severe adverse events occurred rarely (n = 6; 2%). CONCLUSION: IPT is safe and well tolerated in HIV-infected children on concomitant ART. This study supports the need for a larger study to assess efficacy in HIV-infected children living in TB-endemic areas.

A glass ionomer for reconstructive surgery. Ionogran--an ionomeric micro implant. A biological evaluation.

A porous glass-ionomer (Ionogran) was evaluated and compared to hydroxyapatite Interpore 200. In an in-vivo screening test procedure, microfilter diffusion chambers embedded on the tibial surfaces of adult baboons were used to evaluate cell survival, cell regeneration and cell differentiation. In a bulk testing procedure a standardized bone core was removed from the tibia through the knee joint and the material exposed to the defense mechanisms of the system. Both materials were found to be biocompatible, non-toxic and did not inhibit cell proliferation in the enclosed environment of diffusion chambers. Histological response and cell arrangement within the chambers containing Ionogran were similar to that of the controls with cancellous bone only. Highly specialized haemopoietic tissues were in direct contact with the Ionogran. In the presence of hydroxyapatite new bone was actively formed. Haemopoietic elements were never found in contact with the hydroxyapatite. In the bulk testing procedure, the general histological appearance was that of a reactive tissue response to a low grade persistent stimulation coupled to surface degradation products. The Ionogran was found to be stable, osteo-conductive and promoted osteoid formation when in contact with bone. From a clinical point of view the material could serve as a permanent scaffold, maintaining form, and will be of value in bone reconstructive procedures.

Preparation and biokinetic evaluation of various halogenated iminodiacetic acid-type compounds labeled with technetium-99m for hepatobiliary scintigraphy in the baboon (Papio ursinus) model.

In an evaluation of various 99mTc-labeled halogenated (F, Cl, Br, I) iminodiacetic acid (IDA) derivatives for hepatobiliary scintigraphy, it was found that, in the baboon model, none of these compounds performed as well as did disida. F-IDA was least effective, with the lowest biliary excretion and highest renal participation, but multihalogen substitution as in penta-F-IDA increased the biliary specificity and reduced urinary excretion to the extent that penta-F-IDA scored second to disida and even above I-IDA, with its high molecular weight. Surprising also was the relatively good performance of Cl-IDA compared to Br-IDA and I-IDA.

Ionos bone cement (glass-ionomer): an experimental and clinical evaluation in joint replacement.

Ionos bone cement (glass-ionomer) was evaluated in total joint replacement procedures, initially in a baboon model, and finally in a highly selected group of patients in whom polymethyl methacrylate cement was contra-indicated. It was found that the cement has no inhibitory effect on bone tissue development. It is effectively incorporated into the bone, both structurally and functionally without the interposition of fibrous tissue. Under the functional stress situation in baboon hip and knee arthroplasties, the bone and marrow in direct contact with the cement responded favourably. A direct bone bond was demonstrated. The clinical results achieved were satisfactory, notwithstanding the complexity of the clinical problems included in the series. The continued clinical evaluation on a controlled basis has been shown to be well-justified.

Charnley low-friction arthroplasty of the hip. Long-term results in South Africa.

Long-term results of 98 Charnley low-friction arthroplasties were followed for a period of a mean of 12 years; 98 of 470 operations qualified for this strict long-term study, 78 (79.6%) with excellent results. If excessive medialization of the cup is avoided, socket complications appear to be minimal (4%). The majority of femoral component failures resulted from femoral stem breakage. Only four hips (4.08%) developed loosening of the femoral stem.

Localization of parathyroid adenomas by digital subtraction angiography. A report of 4 cases.

Intravenous digital subtraction angiography provides an accurate but not specific method for localization of small vascular tumours. It is carried out on outpatients as an intravenous procedure and takes only 40 minutes. It appears to be eminently suited to the demonstration of parathyroid adenomas and shows that a hyperplastic parathyroid gland can produce a significant enough vascular blush to create a visible image.

The radiation improvement of polyethylene prostheses. A preliminary study.

The radiation crosslinking of high-density polyethylene prostheses was investigated over a wide range of doses in the presence and absence of gaseous crosslinking agents. It was found that in the bulk polymer the crosslinking pattern is completely different from the homogeneous crosslinking that occurs in polymer films. The presence of crosslinking agents causes highly crosslinked polymer to be formed on the surface while the bulk of the polymer is largely unaffected--which is explained in terms of diffusion phenomena. This surface crosslinking has a profound effect on the mechanical properties of the prostheses and restricts cold flow and deformation of the polymer without sacrificing the excellent abrasion-resistance properties of the polyethylene when subjected to high pressures. Based on this research a number of high-density polyethylene knee prostheses have been radiation-crosslinked and the results in vitro appear to be very promising.