French angles: a simple aid to neurodevelopmental examination

"French angles" are the amplitude of passive movement at a single joint, which can be easily measured using a goniometer, and reflect the lengthening capacity of muscles--a component of passive tone. Fifty infants aged 1-52 weeks had their "French angles" measured by non-expert examiners using a plastic goniometer. All the angles measured, except ankle dorsiflexion, increased in a predictable, linear fashion from birth to one year of age. Thus in normal term infants passive tone gradually relaxes from birth to the age of one year. Three additional infants with known neuromuscular disorders were found to have angles outside the obtained normal range. The babies with cerebral palsy had reduced adductor angles reflecting adductor spasm, and the baby with Werdnig Hoffman syndrome had an increased adductor angle reflecting increased adductor extensibility. The results provide a quantitative measurement of neurological maturation during infancy, and should complement the routine neurodevelopmental assessment. The method proved quick, simple and reliable, and may become useful as a screening test for neuromuscular disorders.     

Fatal outcome in a child with pseudomembranous colitis.

The clinical and histologic changes occurring with antibiotic-associated pseudomembranous colitis are usually reversible with discontinuation of the causative medication. The spectrum of disease patterns ranges from a benign form to a very fulminant and occasionally fatal one. This report describes a child with a severe form of the disease. Despite recognition and sigmoidoscopic confirmation of this syndrome and cessation of antibiotics, his course continued to deteriorate. Sepsis, leukocytosis, refractory diarrhea, and abdominal distension led to exploratory laparotomy. A proctocolectomy was performed for necrosis of the entire colon; however, the patient died of sepsis.     

System identification of human stretch reflex dynamics: Tibialis anterior

Summary System identification methods have shown that the stretch reflex in the human ankle extensor (triceps surae, TS) may be modeled as velocity feedback via a single, short latency pathway containing a uni-directional rate-sensitive nonlinearity. Evidence of differences in the reflex organization in flexors and extensors led us to use the same methods to examine stretch reflexes in the ankle flexor (tibialis anterior, TA). Five normal subjects maintained a tonic contraction of TA while subjected to repeated, stochastic perturbations of ankle position. Position, torque, and smoothed, rectified EMGs from TA and TS were recorded and ensemble averaged over 25 stimulus presentations. Linear impulse response functions relating TA EMG to ankle velocity were then determined. The results confirmed the existence of significant differences between stretch reflexes in TA and TS. In particular: 1. TA impulse response functions were characterized by two distinct peaks of excitation separated by a period of inhibition. The impulse response function amplitude increased with increasing mean torque and decreased with displacement amplitude although the sensitivity of the two peaks to these changes was different. This was interpreted as suggesting that TA stretch reflexes involve two separate pathways both involving muscle spindle information. 2. TA stretch reflexes modulate tonic activity much less than do those in TS. 3. The strong uni-directional rate-sensitive nonlinearity seen in TS was not present in TA. The functional significance of these differences remains to be determined.     

FILELB: A data file structure for the analysis of physiological systems

FILELB is a comprehensive library of subroutines for the storage, retrieval, location, inspection and entry of sequences of experimental and analytical data. The general purpose, highly organised data file structure implemented by FILELB is the core of our interactive computer package for the analysis of physiological systems.     

Cross-reactivity between C-reactive protein and idiotypic determinants on A phosphocholine-binding murine myeloma protein

Binding of human 125I-C-reactive protein (CRP) to sheep erythrocytes sensitized with pneumococcal C polysaccharide (E-PnC) was found to be Ca++ dependent and inhibitable by phosphocholine, CRP, and HOPC 8. Binding of 125I-HOPC 8 to EPnC was Ca++ -independent but could also be inhibited by phosphocholine, CRP, and HOPC 8. Thus, CRP and HOPC 8, despite a differential Ca++ requirement, share a common binding specificity for phosphocholine. A monoclonal anti-idiotypic antibody (MAB), GB4-10, prepared in A/J mice immunized with BALB/c HOPC 8 inhibited the binding of both 125I-CRP and 125I-HOPC 8 to E-PnC. In addition, both proteins bound to GB4-10 immobilized on polysterene tubes. Interestingly, binding of 125I-CRP to GB4-10 required Ca++. Similar results were also obtained with another MAB (AB1-2) prepared similarly to GB4-10, whereas neither protein bound to a control MAB (EB3-7) against an alpha1 leads to 3 dextran-binding myeloma protein, J558. Binding of 125I-HOPC 8 to GB4-10 could be inhibited by HOPC 8, keyhole limpet hemocyanin-phosphocholine but not phosphocholine but not phosphocholine, and in the presence of Ca++ by CRP. These data indicate that CRP bears antigenic determinants cross-reacting with certain idiotypic determinants on HOPC 8. They also suggest that Ca++ acts as an allosteric effector, perhaps stabilizing the phosphocholine-binding site of CRP.