Osteochondritis dissecans: analysis of mechanical stability with radiography, scintigraphy, and MR imaging

Twenty-one joints with stable (n = 9) or loose (n = 12) osteochondritis dissecans (OCD) lesions were examined in 15 subjects with plain radiography, three-phase bone scintigraphy, and magnetic resonance (MR) imaging. The lesion size and the thickness of the sclerotic margin as measured on plain radiographs were good parameters for predicting loosening. However, bone scintigraphy was more sensitive and specific in determining the mechanical stability of OCD lesions. MR imaging permitted direct visualization of loosening and fragment displacement; the latter permits differentiation of in situ loosening from a grossly unstable lesion. The noninvasive nature of bone scintigraphy and MR imaging makes them potentially preferable diagnostic modalities to arthrography for evaluating the mechanical status of OCD lesions.     

Spectrum of medulloblastomas demonstrated by computed tomography

Twenty-two patients with medulloblastomas were evaluated by computed tomography. Pretreatment evaluation in 13 patients has shown the various presentations of the tumor. Eighteen of the patients have had post-therapy computed tomographic studies. Computed tomography is sensitive in detecting residual and locally recurrent tumor as well as tumor seeding by cereborspinal fluid pathways. Computed tomography has proved to be valuable in patient management and in evaluating the effectiveness of various forms of treatment. The present group of medulloblastomas is compared to other pediatric posterior fossa tumors and differential diagnoses are discussed.     

Comparison of intracellular bactericidal activities of human neutrophils and eosinophils

Eosinophils from a patient with hypereosinophilia were observed to phagocytize radiolabeled E. coli or S. aureus as effectively as neutrophils from a normal control. This was observed at a number of bacteria/cell ratios and a various time intervals following initial challenge and was confirmed by direct microscopic examination. In spite of comparables rates of phagocytosis, the eosinophils were consistently less capable of killing the bacteria. This correlates with an inability of eosinophil peroxidase to catalyze the peroxidase-H2O2-CI--mediated decarboxylation of amino acids; in contrast, both eosinophil and neutrophil peroxidases showed similar capabilities to iodinate protein in vitro. These data are compatible with the importance of the chloride- mediated mechanism in the bactericidal activity of intact phagocytes.     

Hemodynamic effects of rapid and slow infusions of manganese chloride and gadolinium-DTPA in dogs

The acute hemodynamic effects of two paramagnetic contrast materials, manganese chloride and gadolinium-DTPA, were examined in dogs using ultrasonic dimension gauge crystals. Slow infusions (more than 15 minutes) of MnCl2 (0.1 mm/kg) or Gd-DTPA (0.1 mm/kg) via an infusion pump had no significant hemodynamic effects. When given in just over 1 minute, Gd-DTPA produced elevated left ventricular (LV) end diastolic pressure and minor dilation of the ventricle and slowed diastolic filling. MnCl2, given rapidly, reduced systemic vascular resistance, resulting in hypotension. It also reduced LV volume and had less marked diastolic effects (probably secondary to the amount of hypotension created). With both agents, these side effects waned after 5-10 minutes. It is concluded that both Gd-DTPA and MnCl2 can be given safely in 0.1-mm/kg doses when administered as a slow, continuous infusion. The acute hemodynamic effects of Gd-DTPA are consistent although minor. While the acute effects of Gd-DTPA are small, neither agent is sufficiently innocuous to be given as a rapid injection in clinically unstable patients. Slow, intravenous infusion of Gd-DTPA or MnCl2 is likely to be tolerated well by even severely ill individuals.     

Potential amelioration of morbidity in patients with chromosomal anomalies: relevance to Bardet‐Biedl syndrome

Genuis SJ, Lobo RA. Potential amelioration of morbidity in patients with chromosomal anomalies: relevance to Bardet‐Biedl syndrome. Given the genetic basis of their disease, children with major chromosomal abnormalities including Bardet–Biedl syndrome (BBS) are generally considered to have a guarded prognosis with persistence or progression of disease manifestations. Although various therapeutic interventions are commonly used to control signs and symptoms of illness, parents of BBS children are usually cautioned against hoping for sustained improvement. A case of a 21‐month‐old girl, diagnosed with BBS, manifesting signs of worsening visual impairment, obesity, irascible and disordered behaviour, as well as developmental delay, is presented. After initial evaluation suggested specific biochemical deficiencies, nutritional status correction was undertaken and the patient's signs and symptoms subsequently resolved over the course of several months. To the authors' knowledge, this is the first case report of sustained resolution of all disease manifestations in the face of previously deteriorating health in a young child with this major chromosomal abnormality. It appears that biochemical imbalances and insufficiencies resulting from abnormal metabolism and excretion are potentially amenable to extraordinary dietary supplementation, with partial or complete resolution of clinical abnormalities. It is recommended that all children with chromosomal abnormalities have biochemical and nutritional status evaluation with correction of disordered biochemistry as is possible.