Use of monoclonal antibodies to identify cerebrospinal fluid lymphoblasts in children with acute lymphoblastic leukemia

The identification of small numbers of leukemic cells in the cerebrospinal fluid (CSF) presents a diagnostic problem in the treatment of children with acute lymphoblastic leukemia (ALL). We adapted a latex sphere rosetting technique to allow us to identify simultaneously cell surface markers and cell morphology in 199 CSF samples from 34 patients and 14 control subjects. In patients without leukemic meningitis, the majority of CSF lymphocytes (69%) were found to be mature T cells positive for OKT11. A much smaller number of cells (8%) were found to be B cells positive for la. In these children, only 3% of CSF lymphoid cells expressed the common acute lymphoblastic leukemia antigen (CALLA). Similar results were found in the control subjects. By contrast, 28 CSF samples from nine children with varying numbers of CSF lymphoblasts had much greater proportions of CALLA- and la-positive CSF cells (24% to 96%). Leukemic meningitis was present in one of these patients and later developed in four others. However, three patients with small numbers of lymphoblasts present but with low proportions of CALLA-positive CSF cells (less than 5%) subsequently had normal CSF examinations. We found the use of this rosetting technique valuable in providing information complementary to that obtained from cell morphology alone about the possible malignant nature of small numbers of lymphoblast-like CSF cells seen on cytocentrifuge preparations in children with ALL.     

A human liposarcoma cell line producing hyaluronic acid

A human liposarcoma cell line COLO 222, derived from a primary tumor in a 62-year-old male, elaborates hyaluronic acid. COLO 222 is characterized on the basis of histochemical, ultramorphological, and cytogenetic properties, along with isozyme phenotype and cell products. A chromosome mode of 53 predominates and unique Giemsa-banded marker chromosomes are identified. An autochthonous lymphoid cell line, COLO 143v, was established after the addition of exogenous Epstein-Barr virus. Cytogenetic analysis of Colo 143v is consistent with a normal male karyotype. COLO 143v possesses B-cell characteristics. This autochthonous system had been used for immunological studies and cytotoxicity assays.     

Nephrogenic diabetes insipidus and tubulointerstitial nephritis during continuous therapy with rifampin

While receiving continuous daily rifampin therapy, a 57-year-old man developed acute renal failure and nephrogenic diabetes insipidus due to acute tubulointerstitial nephritis which was reversible by discontinuing the rifampin. Tubulointerstitial nephritis rarely develops during continuous rifampin therapy, and associated nephrogenic diabetes insipidus has not previously been reported. The majority of cases of tubulointerstitial nephritis due to rifampin have occurred following reintroduction of rifampin after an interruption in therapy. The clinical differences between patients developing tubulointerstitial nephritis during interrupted and continuous therapy are discussed.     

Prospective evaluation of the sonographic murphy sign in suspected acute cholecystitis

The sonographic Murphy sign, the presence of maximal tenderness elicited over a sonographically localized gallbladder, has been considered useful in the evaluation of patients with suspected acute cholecystitis. We prospectively evaluated this sign in 427 consecutive patients referred for evaluation of acute cholecystitis. The overall accuracy of the sonographic Murphy sign in the 219 patients with sufficient confirmation to be included in the statistical analysis was 87.2%. Sensitivity was 63% and specificity was 93.6%. The predictive value of a positive sign was 72.5%, while the predictive value of a negative sign was 90.5%. The sonographic Murphy sign is a useful, albeit imperfect, adjunct in the assessment of patients with suspected acute cholecystitis.     

Genes and learning in Drosophila

To survive, every animal needs appropriate behavior patterns. Evolution has provided simple creatures with the necessary behavioral repertoire in the form o f fixed action patterns — programmed reactions to external stimuli, coded by the genes and ‘hard-wired’ into the nervous system. More complex organisms require more versatility to cope with unusual situations and to occupy new niches. They need to learn. For this they also rely on genes to specify components of the neural machinery that makes learning and memory possible. By studying the learning behavior of normal and mutant flies it may be possible to isolate and identify some of these mechanisms.     

Optical imaging and electrophysiology of rat barrel cortex. I. Responses to small single-vibrissa deflections

A study was undertaken to investigate the response of the rodent somatosensory barrel cortex to single-whisker, near-threshold vibrissal stimuli. Cortical responses to controlled whisker deflections were recorded by (i) conventional multi-unit extracellular recording within the cytochrome oxidase rich barrels centers and the interbarrel septa, and (ii) intrinsic signal optical imaging, a technique that provides a spatial view of cortical activation thought to be related to the deoxygenation of hemoglobin in activated areas. Barrel cortex neurons responded weakly to whisker deflections of 0.04 degrees. Their response to a series of small stimuli of increasing amplitude was well-fitted by a logarithmic function. Responses to larger stimuli declined monotonically with distance from the center of the barrel column, and were characterized by greater onset and offset firing rates, by greater post-excitatory reduction of firing to below spontaneous levels, and by shorter response latency. In comparison to measurements taken previously from primary vibrissal afferent fibers, we conclude that cortical cells can respond to activity in a very small fraction of first-order sensory neurons.      

Strength in Parkinson's disease: Relationshp to rate of force generation and clinical status

Maximum elbow flexor and extensor muscle strength was measured in 9 patients with Parkinson's disease on and off antiparkinsonian medication. In addition, the rate of force generation, the rate of actively returning force to resting levels, and passive release of force “relaxation” were measured in submaximal contractions. The measures of strength and contraction time were correlated with changes in clinical status as measured by the Unified Parkinson's Disease Rating Scale. When patients were off medication, their reduction in strength was significantly greater in extension than flexion. The reduction in flexion strength did not reach statistical significance. The extensor weakness was primarily due to decreased tonic activation of the extensor muscles and not to muscle coactivation. Muscle relaxation time was much more prolonged than was force generation time or active force return time. The increase in relaxation time and the decrease in extensor strength both correlated with changes in clinical status. Finally, changes in extensor torque correlated with the time to actively return force, suggesting that reduced strength is related to a reduced ability to generate rapid contractions in some patients with Parkinson's disease. These results suggest that there is an asymmetric distribution of muscle weakness in Parkinson's disease and that selected measures of muscle strength and muscle relaxation correlate with changes in clinical status.     

The performance on learning tasks of patients in the early stages of Parkinson's disease

It is known that in animals learning is disrupted by caudate lesions; but there has been no agreement about whether pathology in the basal ganglia causes a similar impairment in man. Nineteen patients in the early stages of Parkinson's disease were tested on two associative learning tasks and on the Wisconsin Card Sorting Task; and their performance was compared with that of patients with frontal or temporal lobe lesions. On the two associative learning tasks there was no overall difference between the Parkinsonian group and the controls. However, a minority of the Parkinsonian patients performed very poorly on these tasks; and it was noted that these tended to be the older patients.     

Identification of Chlamydia pneumoniae by DNA amplification of the 16S rRNA gene.

Chlamydia pneumoniae is an important cause of respiratory disease in humans, but diagnosis of C. pneumoniae is hindered by difficulties in the in vitro growth of the organism. In order to improve detection and identification, we recently developed a polymerase chain reaction (PCR) assay which uses oligonucleotide primers specific for C. pneumoniae. The nucleic acid sequence was determined for the 16S rRNA of C. pneumoniae, and regions in which C. pneumoniae differed from both Chlamydia psittaci and Chlamydia trachomatis were identified. Oligonucleotide primers corresponding to these unique regions were then synthesized and used in a PCR for the detection of C. pneumoniae. The C. pneumoniae-specific primers permitted the identification of six isolates of C. pneumoniae, but no reaction was observed with the 15 serovars of C. trachomatis or two strains of C. psittaci. PCR should prove to be valuable in confirming the identification of C. pneumoniae and in the diagnosis of C. pneumoniae infections.