Octreotide dependency and headache: a case report

We report on headache induced by a somatostatin octapeptide analog (octreotide) used for the treatment of acromegaly, This "rebound" headache has severe tension-type characteristics and occurs every 6–8 h. It resolves dramatically within minutes with octreotide administration. This is the first report of headache developing under treatment with octreotide.     

Recovery of a rare clone from a population of unstable retroviral vector-expressing mammalian cells using a new RNA extraction and slot-blot protocol

Although a useful and important method of gene transfer, retroviral vectors can be genetically unstable. In the course of experiments using DOEJS, a retroviral vector able to confer expression of a H-ras oncogene and a neomycin resistance gene (neo) on mammalian cells (Compere et al., 1989), it was found that the vast majority of infected rat embryo fibroblasts, recovered on the basis of neo activity (i.e., G418 resistance), did not express ras mRNA. It was subsequently observed that most cells in the ψ2 cell line used to propagate DOEJS failed to produce virus capable of expressing both ras and neo in primary rat embryo fibroblasts. A simplified RNA extraction and slot-blot technique was developed to screen mRNA from several hundred fibroblast clones and, in doing so, infected fibroblast clones producing both neo and ras mRNA were identified at low frequency. The DOEJS/ψ2 packaging line was subsequently subcloned and individual clones screened for their ability to confer appropriate gene expression on target cells. Subclone DOEJS/ψ2-B6 was eventually isolated after screening 24 DOEJS subclones and 240 infected rat embryo fibroblast colonies. DOEJS/ψ2-B6 was shown to induce reliably phenotypic transformation, G418 resistance, and ras and neo mRNA expression in primary rat embryo fibroblasts. The RNA extraction and screening procedure was thus useful for recovering an infrequent subclone producing a retrovirus with the original properties.     

Etiology and pathogenesis of Attention-deficit Hyperactivity Disorder (ADHD): significance of prematurity and perinatal hypoxic-haemodynamic encephalopathy

Attention-deficit Hyperactivity Disorder (ADHD), defined as a disorder of awareness with impul-sivity, has lately been characterized as a dysfunction of the striatum (neostriatum = globus pallidus + putamen). This structure is in a unique position for contextual analysis and samples information from almost the entire cortex through its spiny neurons. The etiology is heterogeneous, with genetic as well as lesional factors. Among the latter, pre- and perinatal events are prominent. Advances in the understanding of the role of fetal circulatory insufficiency with loss of autoregulation and systemic hypotension have drawn attention to the vulnerability of watershed regions, including the striatum. Not only circulatory facts are important for this selectivity, however. The anatomical characteristics, with convergent glutaminergic afferent synaptic transmission from almost the entire cortex contribute to the vulnerability in ischemia-induced liberation of glutamate: The striatum becomes the victim of its virtue. Repeated hypoxic-ischemic events are particularly common in prematurity, a fact which seems to explain the high incidence of ADHD in this patient group. The magnitude of the problem is increasing with the increased survival rate among premature infants.     

In-111-labeled white blood cell uptake in noninfected closed fracture in humans: prospective study

Since indium-111 white blood cell (In-111 WBC) scintigraphy is often used to evaluate for osteomyelitis in bone fractures, it is important to know if noninfected fractures have In-111 WBC uptake. Twenty-seven noninfected closed fracture sites in 19 patients were prospectively evaluated with technetium-99m methylene diphosphonate bone scintigraphy and In-111 WBC scintigraphy. In-111 WBC uptake was present in 41% of the 27 sites. In the 11 positive sites, the In-111 WBC uptake was 1+ (definite but minimal) in 55%, 2+ (moderate) in 36%, and 3+ (marked) in 9%. The visual intensity of the radioactive uptake on In-111 WBC scintigrams relative to that on bone scintigrams was less in 82%, equal in 9%, and greater in 9%. The visual size of the area of uptake on In-111 WBC scintigrams and bone scintigrams was smaller in 36%, equal in 55%, and greater in 9%. Factors that may help distinction of In-111 WBC uptake due to fracture alone from infection associated with fracture are discussed.     

PREVALENCE OF MITRAL VALVE PROLAPSE IN HONG KONG CHINESE A CLINICAL AND AUTOPSY STUDY

The prevalence of mitral valve pro.lapse in Chinese was determined by screening 156 heal- thy subjects and by patholobic examination of 86 adult autopsies. Mitral valve prolapse was found in 7.7% in the clinical study and 5.8% in the autopsy study. A slight female preponderance was noted.     

Posterior spinal cord block: a dosimetric study

To determine the optimal width of a midline posterior spinal block (MPSB) (to avoid delivering too great a dose to the cord and too small a dose to adjacent tissue), the authors determined with magnetic resonance (MR) imaging normal ranges of cord depth and width and correlated them with film dosimetric data. In 59 randomly selected patients there was a wide range for both depth and width. The average depths of the anterior and posterior surfaces of the cord were 6.7 cm +/- 1.4 and 5.4 cm +/- 1.3, respectively. The average cord width was 1.6 cm +/- 0.4. Optimal cord block width as a function of cord width was determined for a 6-MV photon beam. The optimal cord block width at the surface (half-value layer [HVL] thickness = 6) varied from 1.5 to 3.0 cm for cord widths of 0.8-2.4 cm, which correspond to two standard deviations from the average. There was no significant dependence on depth of the cord. For optimal treatment outcome, the MPSB width may have to be determined for each patient individually.