Cerebral blood flow in the diabetic patient

Asthma affects about 1 in 10 children. The condition is characterized by acute respiratory distress brought on by environmental factors. The condition is treated with medications aimed to reduce reaction to stimulants by the airway. Dental management involves attention to the status of the patient and awareness of stimulants of the reactive airway. Clinical recommendations are provided.     

The influence of age on the canine immune system

Immune function was assessed in a group of 47 Labrador Retrievers, ranging in age from 0.8 to 11.5 years, in order to establish baseline data on canine immunosenescence. Natural killer cell activity, lymphocyte subset distributions, antibody production, and mitogen-induced lymphoproliferative responses, all of which have been demonstrated to undergo age-related changes in humans and mice, were chosen as indicators of immune function. Dogs were categorized by age as young (mean 2.4 years), middle-aged (mean 5.8 years), and old (mean 9.1 years). Natural killer cell activity was not affected significantly by age. Lymphocyte subset analysis revealed a significant age-related increase in the percentage of cells staining with a pan T-cell reagent, accompanied by a corresponding increase in the percentage of CD8 cells from youth to middle age. An age-related decrease in the percentage of B-cells was observed concomitant with the increases in T-cell percentages. A gender-related difference in pan T-cell distribution was also observed, with females having a higher percentage than males. Lymphoproliferative responses of both young and middle-aged dogs to the mitogens concanavalin A, phytohemagglutinin, pokeweed mitogen, and staphylococcal enterotoxin B were significantly higher than those of old dogs. In general, the mitogen responses of male dogs were affected more dramatically by age than those of females. A significant age-related decline in in vivo antibody responses to the protein antigen, keyhole limpet hemocyanin, was not observed, although the mean titers of the young dogs were higher than those of the old.     

Selective blockade of substance P or neurokinin A receptors reduces the expression of c-fos in trigeminal subnucleus caudalis after corneal stimulation in the rat

Stimulation of the cornea activates neurons in two distinct regions of the spinal trigeminal nucleus: at the transition between trigeminal subnucleus interpolaris and subnucleus caudalis and at the transition between trigeminal subnucleus caudalis and the upper cervical spinal cord as estimated by expression of the immediate early gene, c-fos. To determine if receptors for substance P or neurokinin A, neurokinin 1 and neurokinin 2 receptors, respectively, contribute to the production of Fos-positive neurons in these brainstem regions, receptor-selective antagonists were given intracerebroventricularly 15 min prior to stimulation of the cornea in anesthetized rats. The number of Fos-positive neurons produced in superficial laminae at the trigeminal subnucleus caudalis/cervical cord transition by application of the selective small fiber excitant, mustard oil, to the corneal surface was reduced by the neurokinin 1 receptor antagonist, CP99,994 (5-100 nmol, i.c.v.) and the neurokinin 2 receptor antagonist, MEN10,376 (0.01-1.0 nmol, i.c.v.). Combined pretreatment with CP99,994 and the competitive N-methyl-D-aspartate receptor antagonist, CPP, caused a greater reduction in c-fos expression at the subnucleus caudalis/cervical cord transition than after either drug alone suggesting interaction between receptors for glutamate and substance P. Tachykinin receptor antagonists did not reduce the number of Fos-positive neurons produced at the subnucleus interpolaris/subnucleus caudalis transition. The elevation in plasma concentration of adrenocorticotropin, but not the increases in arterial pressure or heart rate, evoked by corneal stimulation was prevented by pretreatment with CP99,994 or MEN10,376 at doses lower than those needed to reduce c-fos expression. The results indicate that receptors for substance P and neurokinin A contribute to the transmission of sensory input from corneal nociceptors to brainstem neurons in trigeminal subnucleus caudalis and to increased activity of the hypothalamo-pituitary axis that accompanies acute stimulation of the cornea.     

The chemokine SLC is expressed in T cell areas of lymph nodes and mucosal lymphoid tissues and attracts activated T cells via CCR7

Secondary lymphoid-tissue chemokine, SLC, also known as exodus-2 and 6Ckine, is a novel CC chemokine with selectivity for T lymphocytes and preferential expression in lymphoid tissues. We have studied its production, receptor usage and biological activities. High levels of SLC mRNA were detected in lymph nodes, the gastrointestinal tract and several gland tissues, but no expression was found by Northern blot analysis in freshly isolated or stimulated blood monocytes and lymphocytes, or neutrophils and eosinophils. In situ hybridization revealed constitutive expression of SLC in the T cell areas and the marginal zone of follicles in lymph nodes and the mucosa-associated lymphoid tissue, but not in B cell areas or sinuses. Comparison with immunocytochemical staining showed similarity between the in situ expression of SLC and the distribution of interdigitating dendritic cells but not with sinus-lining dendritic cells, macrophages or T lymphocytes. SLC induced chemotaxis of T lymphocytes and its activity increased considerably when the cells were conditioned with IL-2 or phytohemagglutinin (PHA). Under optimal conditions SLC had unusually high efficacy and induced the migration of up to 50 % of input T lymphocytes. SLC also induced Ca2+ mobilization in these cells. Similar responses were obtained with EBI1 ligand chemokine (ELC), and sequential stimulation with both chemokines led to cross-desensitization, suggesting that SLC acts via the ELC receptor, CCR7. This was confirmed using murine pre-B cells stably transfected with CCR7 which bound SLC with high affinity and showed chemotaxis and Ca2+ mobilization in response to both SLC and ELC. In T lymphocytes PHA and IL-2, which enhanced chemotactic responsiveness, also markedly enhanced CCR7 expression. In contrast to all known chemokine receptors, up-regulation of CCR7 by IL-2 was transient. A maximum was reached in 2-3 days and expression returned to initial levels within 8-10 days. The present study shows that SLC is constitutively produced within the T cell areas of secondary lymphoid organs and attracts T lymphocytes via CCR7.     

Warfarin resistance in a patient with short bowel syndrome

Drug therapy in short bowel syndrome can be complicated by inadequate or incomplete absorption of drugs in the small intestine. Many case reports claim that warfarin absorption is not affected by the syndrome. We treated a patient with oral warfarin for recurring deep vein thrombosis; up to 20 mg/day was administered with no increase in the international normalized ratio. Drug-drug interactions that may prevent absorption, increase metabolism, or antagonize the effects of warfarin were ruled out. Intravenous lipid administration, which is anecdotally reported to precipitate warfarin resistance, may have contributed to the condition, but dosing was less frequent than in published reports. The most probable explanation of warfarin resistance is the reduced surface area for drug absorption secondary to surgical removal of the patient's duodenum and gastrojejunostomy.     

Cat scratch disease: the rare role of Afipia felis

Since its isolation in 1988, Afipia felis has been associated with cat scratch disease (CSD) in only one report and its role in CSD has been questioned. We have cultured A. felis from a lymph node of a patient with CSD. 16S rRNA gene sequencing, DNA relatedness studies, fatty acid analysis, and PCR of the A. felis ferredoxin gene showed that the isolate is identical to the previously reported A. felis isolate. To determine the role of A. felis in CSD, PCR of the 16S rRNA gene followed by hybridizations with specific probes were performed with lymph node specimens from CSD patients. All 32 specimens tested positive for Bartonella henselae and negative for A. felis. We conclude that A. felis is a rare cause of CSD. Diagnostic tests not conducive to the identification of A. felis might cause the diagnosis of CSD due to A. felis to be missed.     

Case report: Fracture of an ossified Achilles tendon - MR appearances

Hyperparathyroidism is a potentially life-threatening disease, caused primarily by parathyroid adenoma. Surgical excision of the tumor, with consequent return of calcium levels to the normal range, is considered the treatment of choice. Within the last few years, several reports have described the destruction of parathyroid tissue using ultrasonically guided injection of 96% ethanol into pathologic parathyroid glands, resulting in successful regulation of both primary and secondary hyperparathyroidism. The procedure was reported as an alternative to operative treatment for patients as high surgical risk, such as the elderly and the critically ill. We report the occurrence of transient Horner's syndrome and vocal fold paralysis after successful injections of ethanol into a parathyroid adenoma, and discuss the implications and restrictions of the procedure in view of the medical literature.     

Conditioned taste aversion is a confound in behavioral studies that report a reduction in the reinforcing effects of drugs

Pharmacologic agents with a potential to attenuate the reinforcing properties of drugs of abuse may have an important role in the treatment of drug addiction. The reduction of drug self-administration and sweet solution intake are two common animal models employed to screen for promising therapeutic agents. When these agents are effective in suppressing the behavior maintained by drugs of abuse, the cause is usually attributed to a neuronal mechanism such as the modification of neurotransmitters that subserve reinforcement. These experiments present data for an alternate interpretation which suggest that some of these agents produce a conditioned taste aversion (CTA) that acts as a confounding variable in the screening of potential therapeutic agents. Both carbamazepine and isradipine were shown to establish a CTA at doses reported to attenuate the reinforcing properties of drugs of abuse. It is concluded that CTA represents a potential experimental confound in studies of pharmacologic agents that appear to attenuate the reinforcing properties of drugs. These results suggest that screening for a CTA is necessary in any paradigm that measures the suppression of consummatory behavior in response to pharmacologic intervention.     

Hyperthyroidism and radio-iodine therapy in a district general hospital

This study was undertaken to determine whether pediatric patients with migraine without aura who have failed standard outpatient regimens including intravenous dihydroergotamine mesylate (DHE) in conjunction with oral metoclopramide would respond to an inpatient treatment protocol of intravenous DHE and oral metoclopramide. Thirty patients were evaluated in this study which was an open label, retrospective review of treatment. Independent of the duration of the refractory migraine, 80% of the patients responded to the protocol with only minimal side effect. The dose of DHE mesylate ranged from 0.1 to 0.5 mg. The dose of DHE is lower than is typically utilized in standard adult protocols. The patients received an average of five doses of DHE.