Moment-to-moment dynamics of ADHD behaviour in South African children

Background  

The behaviour of children with Attention-Deficit/Hyperactivity Disorder is characterized by low predictability of responding. Low behavioural predictability is one way of operationalizing intra-individual ADHD-related variability. ADHD-related variability may be caused by inefficient behavioural selection mechanisms linked to reinforcement and extinction, as suggested by the recently published dynamic developmental theory (DDT) of ADHD. DDT argues that ADHD is a basic neurobehavioural disorder, caused by dysfunctioning dopamine systems. For establishing ADHD as a neurobehavioural disorder, findings from studies conducted in Western countries should be replicated in other cultural populations. The present study replicated the study conducted in Norway, with children from the Limpopo province in the Republic of South Africa.     

Intraoperative management of penile erection with intracorporeal phenylephrine during endoscopic surgery

Intraoperative penile tumescence during endoscopic surgery is a troublesome complication that often is refractory to recommended methods of management. We report a new approach of pharmacological management with intracorporeal penile injections of phenylephrine (total dose of 0.1 mg.), which was successful in 3 successive patients. This approach is prompt, safe and reproducible, and it provides sustained resolution of erection without systemic side effects. It is concluded that local intracorporeal penile administration of this sympathomimetic agent appears to be a potent new tool in the armamentarium of the endoscopic surgeon dealing with this frustrating clinical situation, which merits further clinical trial.     

A comprehensive eye/vision program

As an essential element of the comprehensive rehabilitation efforts at Northport VA Medical Center, and as a service whose demand is projected to increase substantially with the expanding proportion of aging veterans, eye/vision care has become increasingly important. As a result, the administration of the Medical Center decided to heed the suggestions of Congress and the Director of Optometry in VA Central Office and reorganize the delivery of eye/vision services so the ever-increasing demand could be met more rationally, efficiently and effectively. In this paper, the Northport VA Medical Center's Comprehensive Eye/Vision Program, including the residency program in rehabilitative optometry, will be described and the benefits of the reorganization will be discussed.     

Effects of unilateral cortex lesions on gene expression of rat cortical cholecystokinin neurons.

In rat neocortex, the gene encoding preprocholecystokinin is expressed in interneurons which also synthetize gamma-aminobutyric acid. An injury to the meninges and the underlying cortex increased the concentration of mRNA coding for preprocholecystokinin in all ipsilateral cortical areas. Simultaneous treatment of the rats with the anti-inflammatory agent diclofenac did not affect the injury-induced change in gene expression indicating that inflammatory processes were not involved. The injury also enhanced the expression of the immediate early gene c-fos in the ipsilateral cortex in a time-dependent manner. There was an increase in c-fos mRNA 1 h after the operation, which was no longer observed 3 h later. Twenty-four hours after the operation, cells containing c-fos mRNA were found in cortical layers II, III, V and VI. The neurons which showed an increased expression of preprocholecystokinin were also in these layers. The N-methyl-D-aspartate (NMDA) receptor antagonist MK-801 prevented the injury-induced increases in both preprocholecystokinin and c-fos gene expression, indicating that stimulation of this glutamate receptor subtype may initiate the changes in expression of both genes. It is hypothetized that the immediate early gene c-fos is activated first and this then leads to the increase in preprocholecystokinin mRNA.     

4,5-Dianilinophthalimide: a protein-tyrosine kinase inhibitor with selectivity for the epidermal growth factor receptor signal transduction pathway and potent in vivo antitumor activity.

Deregulated signal transduction via the epidermal growth factor receptor (EGF-R) family of protein-tyrosine kinase growth factor receptors is associated with proliferative diseases. We describe a class of compounds (4,5-dianilinophthalimides) that inhibit the EGF-R protein-tyrosine kinase in vitro with high selectivity. In cells, 4,5-dianilinophthalmide selectively inhibited both ligand-induced EGF-R and p185c-erbB2 autophosphorylation and c-fos mRNA induction. Antitumor activity could be demonstrated in vivo against xenografts of the A431 and SK-OV-3 tumors, which overexpress the EGF-R and p185c-erbB2, respectively. In contrast, a platelet-derived growth factor-driven tumor was not inhibited by 4,5-dianilinophthalimide, which is compatible with its cellular selectivity and hypothesized mechanism of action. No overt cumulative toxicity was observed during treatment even though high efficacy was observed, indicating a good therapeutic window. 4,5-Dianilinophthalimides may offer therapeutic agents for the treatment of hyperproliferative diseases that overexpress EGF-R family protein-tyrosine kinases or their ligands.     

Hugh Morriston Davies and lobectomy for cancer, 1912

The report of a lobectomy for bronchogenic carcinoma in 1912, by Hugh Morriston Davies of London, and without precedent, describes a surgical technique strikingly similar to that of today. Unfortunately, Davies' patient died because postoperative management of the pleural space was not yet well understood. The tumor had been identified by radiographic examination and the diagnosis confirmed by cytological examination of the sputum. The operative technique included individual ligation of hilar vessels and suture closure of the bronchus, neither of which was to be reported again for more than 20 years. More effective management of the pleural space was described, without special emphasis, by Harold Brunn of San Francisco 17 years later.