IMCI indicators of childhood TBM at primary health care level in the Western Cape Province of South Africa

BACKGROUND

The diagnosis of tuberculous meningitis (TBM) in children is often delayed, with disastrous consequences. The Integrated Management of Childhood Illness (IMCI) strategy aims to ensure the accurate assessment of ill children using simple yet reliable clinical signs.

METHODS

We conducted a retrospective observational study of 30 consecutive children aged 3 months to 5 years diagnosed with TBM at Tygerberg Hospital, Cape Town, South Africa. Clinical records were reviewed to assess diagnostic delay and identify IMCI indicators that were present at the time of initial presentation.

RESULTS

Six patients (20%) presented with stage I, 6 (20%) with stage II and 18 (60%) with stage III TBM. Recent contact with an adult TB source case was recorded in 21 (70%) cases. The median number of health care visits before hospital admission was 4.0 (range 1-6). At the first health care visit, 21 (70%) had potential TB features and recent contact with an adult household TB source case.

CONCLUSION

Adequate implementation of IMCI clinical indicators is essential to ensure earlier diagnosis and prompt treatment initiation in children with TBM, as the majority of cases present with advanced disease. Recent contact with an adult TB source case is an important consideration.

Formation of chiral morphologies through selective binding of amino acids to calcite surface steps

Many living organisms contain biominerals and composites with finely tuned properties, reflecting a remarkable level of control over the nucleation, growth and shape of the constituent crystals. Peptides and proteins play an important role in achieving this control. But the general view that organic molecules affect mineralization through stereochemical recognition, where geometrical and chemical constraints dictate their binding to a mineral, seems difficult to reconcile with a mechanistic understanding, where crystallization is controlled by thermodynamic and kinetic factors. Indeed, traditional crystal growth models emphasize the inhibiting effect of so-called 'modifiers' on surface-step growth, rather than stereochemical matching to newly expressed crystal facets. Here we report in situ atomic force microscope observations and molecular modelling studies of calcite growth in the presence of chiral amino acids that reconcile these two seemingly divergent views. We find that enantiomer-specific binding of the amino acids to those surface-step edges that offer the best geometric and chemical fit changes the step-edge free energies, which in turn results in macroscopic crystal shape modifications. Our results emphasize that the mechanism underlying crystal modification through organic molecules is best understood by considering both stereochemical recognition and the effects of binding on the interfacial energies of the growing crystal.

Unusual facet cyst containing struvite and hydroxyapatite

This case report describes a patient with severe back pain and radiculopathy. She was found to have a facet cyst within the lumbar spine that appeared to contain calcium on MRI and CT. Upon aspiration the cyst was found to contain calcium ammonium phosphate (struvite) and calcium phosphate (hydroxyapatite). Ammonia production in the presence of urease-producing bacteria is responsible for the production of struvite in the human body. We postulate that there was a prior infection of the facet with urease-producing bacteria, thus accounting for the production of the struvite within the facet cyst.

Littoral cell angioma of the spleen

Littoral cell angioma (LCA) is a rare benign vascular tumor of the spleen. LCA most commonly presents with constitutional symptoms (low grade fever and fatigue) and signs of hypersplenism (anemia and thrombocytopenia). Radiographically and at gross pathology an enlarged spleen containing multiple nodules is most commonly seen. Currently the radiological findings are nonspecific and correlation with clinical findings is necessary to narrow the differential while tissue is required for a definitive diagnosis.

Nondisjunction of chromosome 21: comparisons of cytogenetic and molecular studies of the meiotic stage and parent of origin

In the present report, we summarize studies aimed at examining the reliability of chromosome heteromorphisms in analyses of chromosome 21 nondisjunction. We used two cytogenetic approaches--fluorescent in situ hybridization (FISH) to repetitive sequences on 21p and traditional Q-banding--to distinguish chromosome 21 homologues and then compared the results of these studies with those obtained by DNA markers. Using a conservative scoring system for Q-banding and FISH heteromorphisms, we were able to specify the parental origin of trisomy in 10% of cases; in contrast, DNA marker studies were informative for parental origin in almost all cases. The results of the molecular and cytogenetic studies of parental origin concurred in all cases in which assignments were made independently using both techniques. However, in 4 of 13 cases in which the molecular studies contributed to the interpretation of the cytogenetic findings, the two results did not agree with respect to the meiotic stage of nondisjunction. A relatively high frequency of crossing-over on either the short arm or proximal long arm of chromosome 21 could explain these results and may be a mechanism leading to nondisjunction.

Trisomy 21: association between reduced recombination and nondisjunction

To assess the association between recombination and nondisjunction of chromosome 21, we analyzed cytogenetic and DNA markers in 104 trisomy 21 individuals and their parents. Our DNA marker studies of parental origin were informative in 100 cases, with the overwhelming majority (94) being maternal in origin. This value is significantly higher than the 75%-80% maternal nondisjunction rate typically observed in cytogenetic studies of trisomy 21 and illustrates the increased accuracy of the molecular approach. Using the maternally derived cases and probing at 19 polymorphic sites on chromosome 21, we created a genetic map that spans most of the long arm of chromosome 21. The map was significantly shorter than the normal female linkage map, indicating that absence of pairing and/or recombination contributes to nondisjunction in a substantial proportion of cases of trisomy 21.

Molecular studies of non-disjunction in trisomy 16

The origin of the additional chromosome in 26 trisomy 16 spontaneous abortions was studied using DNA probes for chromosome 16, including a probe for centromeric alpha sequences. We were able to determine the parent and meiotic stage of origin of trisomy in 22 cases, with all being attributable to maternal meiosis I non-disjunction. Furthermore, in each of the remaining four cases the results were compatible with this origin. Thus, it is likely that the high incidence of trisomy 16 results from an abnormal process acting at maternal meiosis I which more frequently involves chromosome 16 than other similar sized chromosomes. In studies of recombination, we found little evidence for an association between reduced or absent recombination and chromosome 16 non-disjunction; however, we were unable to rule out an effect of hyperrecombination.

Evaluating the competence of clinical nurses from beginning to advanced practitioner

Frequently, clinically competent nurses leave direct patient care for non-clinical positions or other careers to achieve greater professional advancement and recognition. The drain of clinical nursing expertise away from the patient prompted the development and evaluation of a clinical promotion program to appraise and recognize clinical nursing competence. At the beginning of the evaluation period, 205 nurses were appraised for clinical competence and categorized as: Level 1--a beginning practitioner or a nurse returning to service; Level 2--a skilled clinical practitioner; and Level 3--an advanced clinical practitioner. Nurses volunteered information related to demographic characteristics, education, clinical experience, and attitudes to their work and work environment. Reassessments were completed after one year. Evaluation of the program employed a longitudinal comparative design. The major finding shows significant shift in clinical nurses' competence over time with a greater percentage of nurses at higher levels of ability. Further evaluation of the program is in process.

Recruiting and retaining competent clinical nurses. The Clinical Promotion Project Victoria General Hospital, Halifax, Nova Scotia

A career advancement program for nurses has been developed and implemented at the Victoria General Hospital, Halifax, as part of a manpower planning strategy for recruitment and retention of clinical nurses. A competency based performance appraisal system was developed and implemented as part of the program. This system identifies four levels of clinical expertise. Progression through each level indicates that a nurse has achieved a certain level of skill, knowledge and abilities. Demonstrated competence in one level is a prerequisite to promotion to the next level of practice. Implementation of this system provides clinical career opportunities for nurses in direct patient care. This article will provide the nurse administrator with an insight into the development and implementation of a clinical career advancement program. Future articles will described the research evaluation of the Clinical Performance Appraisal System and clinical nurses' reactions to the new system.