Receptor subtypes mediating facilitation by serotonin of excitability of spinal motoneurons

Serotonin receptor ligands, with differential affinity for subtypes of serotonin (5-HT) receptors, were administered intravenously or iontophoretically to urethane-anesthetized rats and the effects of these compounds on glutamate-evoked firing of spinal motoneurons were tested. The excitability of spinal motoneurons was markedly enhanced after intravenous administration of the selective 5-HT1A ligand 8-hydroxy-2-(di-n-propylamino) tetralin (DPAT) in rats with acute spinal transections at C1. However, local application of DPAT, directly into the ventral horn by microiontophoresis, inhibited the glutamate-evoked firing of motoneurons in direct contrast to the facilitatory effects of iontophoretically applied 5-HT. The DPAT-induced inhibition may have been nonspecific, since it was not antagonized by methysergide. Other 5-HT agonists, with relatively selective affinity for 5-HT1B, 5-HT1C and 5-HT2 receptors, increased the excitability of spinal motoneurons when applied iontophoretically or intravenously. The excitatory effect of iontophoretically applied 5-HT was antagonized by the nonselective 5-HT antagonist, methysergide and by ketanserin and ritanserin, which have relatively selective affinity for 5-HT1C and 5-HT2 receptors. These results indicate that 5-HT1A receptors do not mediate facilitation of excitability of motoneurons produced by local application of 5-HT directly into the vicinity of the motoneurons. However, the marked increase in firing of motoneurons that was caused by intravenous administration of DPAT in spinal transected rats, suggests that 5-HT1A receptors in the spinal cord may participate in 5-HT-induced enhancement of somatomotor outflow, at sites presynaptic to the motoneurons. The iontophoretic results suggest that 5-HT1B, 5-HT1C and 5-HT2 receptors may all play a role in facilitation of the excitability of spinal motoneurons by locally applied 5-HT. Differentiation between these subtypes of receptor awaits the development of more completely selective agonists and antagonists.     

Immunological blockade of endogenous thyrotropin-releasing hormone impairs recovery from hyperglycemia in mice

Administration of antiserum to thyrotropin-releasing hormone (TRH) into the lateral cerebral ventricle of mice significantly attenuated recovery from hyperglycemia induced by treatment with 2-deoxyglucose but had no effect on the plasma glucose of saline-treated mice. TRH, injected centrally together with the anti-TRH antibody, reversed the effect of the antiserum and blocked the development of hyperglycemia. These findings suggest that activation of TRH neurons in the central nervous system may be a physiological event influencing recovery from hyperglycemia.     

Screening for diabetes: sensitivity and positive predictive value of risk factor total.

OBJECTIVE: Screening for diabetes is recommended for individuals > or =45 years of age, or earlier if they manifest > or = one specific risk factors. This study examined the sensitivity and positive predictive value (PPV) of risk factor total for identifying individuals with diabetes and prediabetes. DESIGN: Subjects were interviewed to assess the presence of risk factors. Fasting plasma glucose levels were obtained. SETTING: The study occurred at a health fair in Greensburg, PA. PATIENTS: Six hundred sixty-one Caucasians between the ages of 19 and 100. RESULTS: Using the criterion of screening individuals with > or = one risk factors detected 100% of both diabetics and prediabetics. This dropped to 91.2% when screening individuals with > or = two factors. The PPV of the risk factor total was poor (80% of individuals with a total of four factors were not diabetic). The ability of the risk factor total to predict individuals with impaired glucose metabolism (prediabetics + diabetics) was considerably better, and increased almost linearly with the risk factor total. Of the subjects with normal glucose values, the mean glucose increased as the risk factor total increased. CONCLUSION: While the sensitivity of using > one risk factor as an algorithm to screen is 100% for identifying diabetics, the PPV of risk factor analysis for identifying diabetics is poor. The same algorithm works well to identify at-risk individuals, presumably allowing early intervention and education.     

肺栓塞疑似病人咳血的原因

当病人出现咳血、胸膜痛等症状，一般都会诊断为肺栓塞。现在有一种趋势就是为了不耽误病人的治疗，在诊断阶段还没有彻底的检查就开始治疗。通常早期使用肝素来减少可疑为肺栓塞病人的死亡率和发病率。然而，如道其它一些并不常见的咳血的原因也非常重要。     

Secondary reconstruction of the short philtrum in the bilateral cleft deformity

Summary This technique for reconstruction of the short philtrum requires an understanding of the viscoelastic properties of the skin and how to use these to increase skin dimensions. This is combined with contouring and splinting with a subcutaneous cartilage graft. Three representative cases are presented to illustrate the method to achieve an aesthetically acceptable lip and its long-term follow-up. No complications have been encountered using this over a 15-year period. The technique can be combined with other secondary reconstructive procedures on the lip and palate. Work completed at: Providence Hospital, 16001 West Nine Mile Road, P.O. Box 2043, Southfield, Michigan 48037, USA     

Blood pressure and retinopathy in type I diabetes

The relationship between blood pressure and diabetic retinopathy was evaluated in 249 young subjects with type I diabetes. Although hypertension is known to be associated with an increased risk for retinopathy, the effects of high-normal blood pressure are unknown. Retinopathy (158 of 249 subjects, 63%) is considerably more common in a young diabetic population than is hypertension (7 of 249 subjects, 2%). Thus, if blood pressure is important in the etiology or progression of diabetic retinopathy, levels below the hypertensive range (less than 141/90 mmHg) must be considered. The combined effect of hypertension and high-normal blood pressure (greater than 90th percentile but less than 141/90 mmHg) was studied. Elevation in diastolic blood pressure, alone, and in combination with elevated systolic blood pressure, correlated significantly (P less than 0.03) with retinopathy. The presence of high-normal blood pressure resulted in a prospectively higher occurrence of retinopathy and of progression of preexisting retinopathy. Glycohemoglobin (HbA1) and duration of diabetes also correlated with retinopathy. Both good glycemic control and maintenance of diastolic blood pressure below the 90th percentile for age may be important in relation to diabetic retinopathy.