Bone metabolism in children with human immunodeficiency virus infection receiving highly active anti-retroviral therapy including a protease inhibitor.

We measured serum osteocalcin levels in prepubertal children with human immunodeficiency virus (HIV) infection receiving highly active antiretroviral therapy including a protease inhibitor and uninfected control children. Osteocalcin values were significantly elevated in the HIV-infected patients. Though osteocalcin serves as an index of bone formation, it likely functions as a negative regulator of bone formation. Further study is necessary to determine whether protease inhibitors normalize bone physiology or decrease bone formation and reduce bone mineral density in children receiving these therapies.

Acute childhood ataxia: 10-year experience.

Forty cases of acute childhood ataxia were retrospectively assessed for main etiologies and for factors that can be used in planning the most effective and cost-efficient management. The most common discharge diagnoses were acute cerebellar ataxia, ingestion, and Guillain-Barré syndrome, encompassing 80% of all cases. The remaining 20% included various isolated causes. Acute cerebellar ataxia was primarily seen in children less than 6 years of age who had preceding viral syndromes or varicella. Ingestions were also most frequent in children less than 6 years of age, but a second peak occurred in adolescents. History was suggestive of drug ingestion in 61.5% of cases, and in addition to ataxia, lethargy was an associated symptom. The drug screen was the most informative laboratory test, with 17 of 35 being positive. Lumbar punctures were positive in seven of 25, with pleocytosis in six and elevated protein in two. Of 26 computed tomographic scans and magnetic resonance imaging scans performed, only two were positive, one for cerebellar infarct and one for cerebral edema. Acute ataxia in childhood has multiple etiologies, but it is usually due to a benign, self-limited process. A thorough history, physical examination, and drug screen should be performed before other costly and invasive tests and before admission to the hospital. This approach may eliminate the need for hospitalization of some patients with postinfectious acute cerebellar ataxia and ingestion. Neuroimaging studies should be used judiciously in the evaluation of acute ataxia, considering their low yield.

Detection of cell specific cluster determinant expression by reverse transcriptase polymerase chain reaction.

We describe a new, rapid, sensitive, and reproducible method for examining gene expression of several cell specific surface cluster determinants, CD2, CD3-gamma, CD4, CD8-beta, CD14, CD19, CD20, CD23, and CD25-alpha, and terminal deoxynucleotidyl transferase which heretofore have been commonly detected by flow cytometry. The method presented uses the reverse transcriptase polymerase chain reaction (RT-PCR) to analyze CD gene expression in stable human cell lines, peripheral blood lymphocytes, bone marrow, and lymph node cells. Polymerase chain reaction products were quantitated by incorporation of radiolabeled nucleotide during PCR and the amount of nucleotide incorporated into DNA was measured by ion exchange filter chromatography. The usefulness of this methodology is demonstrated in an analysis of peripheral blood samples from a patient who presented with B cell deficiency. Results of analyses of peripheral blood samples from this patient by flow cytometry and RT-PCR are similar except that the increased sensitivity of RT-PCR permitted the detection of CD19, CD20, and CD23 in the blood samples of this patient who otherwise appeared to be lacking in all markers of B cell development.

Polymerase chain reaction from bench to bedside. Applications for infectious disease.

The past decade has seen the rapid advancement of molecular biology and its application in the field of infectious diseases. The polymerase chain reaction (PCR) is a technique which allows for the in vitro amplification of DNA. The ability of this method to recognize and amplify small quantities of foreign genome from unpurified samples will revolutionize the diagnoses of microbial diseases which have previously been cumbersome or impossible. It has already been widely applied in this area, and clinical labs will soon be offering this test for selected pathogens. There are ongoing studies evaluating its use in CNS infections and for the identification of viruses in the immunocompromised host. The PCR is not without problems, particularly false positive results from contamination. Because it is so sensitive, the significance of a positive result in patients with latent or chronic infections is yet to be determined. As our knowledge and familiarity with PCR expands, it will become a powerful tool for the clinician to use to identify various infectious diseases.

Mycobacterial infections in the transplant patient.

Mycobacterial infections in the transplant recipient differ considerably from those occurring in the normal host. The incidences of active disease, atypical disease, and extrapulmonary disease, especially dissemination, are all increased. These differences are reflected clinically in an increased mortality (30%) and a high rate (37%) of infection associated with rejection. The clinician must rely on sparse data to draw conclusions regarding prophylaxis and therapy. In general, cyclosporine-related drug interactions must be constantly monitored. Pyrazinamide should replace rifampin whenever cyclosporine is in use. Prompt recognition of the diverse presentations of mycobacterial disease and definitive diagnosis and treatment will improve outcome.