Brain regions showing increased activation by threat-related words in panic disorder

Threat-related stimuli consistently activate the posterior cingulate cortex in normal subjects and have exaggerated effects on memory in patients with panic disorder. We hypothesized that panic patients would show increased response to threat-related stimuli in the posterior cingulate cortex. While undergoing fMRI, six panic patients and eight healthy volunteers made valence judgements of threat-related and neutral words. Both groups showed threat-related activation in the left posterior cingulate and left middle frontal cortices, but the activation was significantly greater in panic patients. Panic patients also had more right>left asymmetry of activation in the mid-parahippocampal region. The increased responsivity observed in the posterior cingulate and dorsolateral prefrontal cortices is consistent with the hypothesis that panic disorder patients engage in more extensive memory processing of threat-related stimuli.     

Impact of skin cancer prevention on outdoor aquatics staff: the Pool Cool program in Hawaii and Massachusetts

BACKGROUND: Aquatic staff, including lifeguards, are exposed to intense sunlight for many hours each day and are likely to be at a relatively high risk for developing skin cancer. However, no interventions have been specifically directed to staff at outdoor swimming pool sites. METHODS: We conducted a randomized controlled trial among aquatic staff at 28 outdoor pool sites in Hawaii and Massachusetts. Intervention pools received sun protection education and control pools received education on child injury prevention. Staff in both arms received orientation sessions and led instruction during swim lessons. Analysis of covariance was used to compare and test for changes in outcome variables (sun protection habits and sunburning rates of aquatic staff) and pool protection policies. Surveys were completed at the beginning and end of the summer. RESULTS: Surveys were completed by 220 aquatics staff at baseline; 194 surveys were completed at posttest. Compared with staff at control pools, sun protection policies (P < 0.04) and sunburning rates (P < 0.05) improved at sun protection pools from baseline to posttest. However, the difference in the mean score of all sun protection habits between the two study groups was nonsignificant. CONCLUSION: The Pool Cool sun protection intervention had significant effects on lifeguards' sunburn rates and pool sun safety policies but did not improve reported sun protection behaviors. More intensive strategies may be needed to influence aquatics workers who have already begun to adopt skin cancer prevention practices.     

The lactic acid response to alkalosis in panic disorder : an integrative review

Panic patients consistently show exaggerated lactic acid response to alkalosis, whether produced by hyperventilation or by sodium lactate infusion. Understanding why this occurs may provide important clues to the pathogenesis of panic disorder. Although brain hypoxia from excessive hypocapnia-induced cerebral vasoconstriction is often cited as the mechanism of elevated brain lactic acid in panic disorder, studies of brain metabolism show that hypocapnia rarely leads to brain hypoxia. Increased lactic acid production is a normal response to intracellular alkalosis and to intracellular cyclic AMP. Thus, other possible mechanisms of the exaggerated lactic acid response in panic disorder include a disturbance of mechanisms regulating intracellular pH and factors increasing intracellular cyclic AMP. Both mechanisms are consistent with the suffocation false alarm theory of panic disorder. This review suggests a theoretical framework for future magnetic resonance spectroscopy studies that can test some of the predictions of these competing models.     

Cytokine-induced p38 activation feedback regulates the prolonged activation of AKT cell survival pathway initiated by reactive oxygen species in response to UV irradiation in human keratinocytes

A previous study has shown that UV activates the PI3K/AKT cell survival pathway while inducing cell death in human skin in vivo and cultured human keratinocytes in vitro, and yet the upstream pathway leading to the activation of AKT has not been thoroughly investigated. In this study we found that UV-induced phosphorylation of p38 and AKT in a time-dependent manner. The phosphorylation of p38 started at 5 min post UV irradiation, peaked at about 30 min, and remained elevated up to 2 h. The phosphorylation of AKT started at 15 min post UV treatment, peaked at about 1 h, and remained elevated up to 2 h. We also found that H2O2 induced phosphorylation of p38 and AKT in a time- dependent manner. Pretreatment with NAC abolished UV-induced AKT phosphorylation, suggesting the involvement of reactive oxygen species in AKT activation. Interestingly, SB203085, a known p38 inhibitor, had partially inhibited UV-induced AKT phosphorylation. Further studies showed that cytokines such as TNF-alpha and IL-1beta induced AKT phosphorylation in a time-dependent manner. Pretreatment with SB203085 inhibited IL-1beta-induced p38 and AKT phosphorylation. Collectively, our data suggest that UV activation of PI 3-kinase/AKT pathway is initiated by ROS and prolonged by feedback activation of p38 induced by released cytokines in response to UV irradiation in cultured human keratinocytes.     

RENAL FUNCTION IN CHRONICALLY CATHETERIZED CONSCIOUS DIABETIC RATS USING CONSTANT AND SERVO-CONTROLLED INFUSION

1. Infusion experiments were performed on chronically catheterized conscious rats to assess kidney function before and after the induction of diabetes mellitus with streptozotocin. 2. Two infusion regimens were used, a conventional constant-infusion protocol and a novel computer-driven, servo-controlled fluid replacement technique. The latter enables body fluid status to be maintained throughout a study occasion by servo-controlled replacement of spontaneous urinary fluid losses. 3. The chronically catheterized conscious rat infused using a servo-controlled system appears to be the optimum model for a study of diabetic renal function. The conscious preparation circumvents problems associated with anaesthesia and acute surgery. The servo-controlled infusion protocol maintains the altered fluid status of the diabetic condition. Both hyperfiltration and polyuria, characteristics of human diabetes often absent in anaesthetized and/or constantly infused diabetic rats, were seen in all conscious servo-controlled diabetic animals. 4. The new regimen enables a more accurate assessment of renal function in experimental diabetes than with previous protocols. It should prove useful in future studies, particularly those assessing the role of anti-diabetic drugs on the kidney.     

Unexplained diarrhoea and failure to thrive in 2 siblings with unusual facies and abnormal scalp hair shafts: a new syndrome

A family is described in which 2 siblings born to healthy parents presented with abnormal facies, persistent diarrhoea, and early death. Exhaustive pathological and biochemical investigations failed to find a cause. The scalp hair of both babies had an abnormal amino-acid composition, and presented an appearance that was unique on scanning electron microscopical examination; this fact and the clinical picture probably represents a new syndrome.     

Pineal germinoma: MR imaging

Magnetic resonance (MR) imaging characteristics of pineal germinomas are described in seven patients imaged with MR and computed tomography (CT). In patients with symptoms of an enlarging process in the quadrigeminal plate cistern, MR imaging was as sensitive as CT scanning in detecting the mass. MR imaging did not detect a normal-sized, calcified neoplastic gland. Germinoma, germinoma with embryonal cell carcinoma elements, and pineoblastoma demonstrated different MR signal characteristics. Although direct coronal and sagittal MR images were useful in defining the relationship of the tumor to the posterior third ventricle, Sylvian aqueduct, and vein of Galen, the ease, rapidity, and sensitivity of CT scanning suggest that CT should remain the modality of choice for initial evaluation and screening of the pineal region, especially in the younger pediatric population, in whom detection of calcification may provide the only clue of an abnormality.