Association of methemoglobinemia and intravenous nitroglycerin administration

Significant elevation of arterial methemoglobin levels has been reported with the administration of intravenous (i.v.) nitroglycerin (NTG). To determine the incidence and clinical significance of this side effect of i.v. NTG, serial arterial methemoglobin levels were determined in 50 consecutive patients receiving i.v. NTG for 48 hours or longer. The mean i.v. NTG infusion rate was 290 +/- 13 micrograms/min (4.1 +/- 0.2 micrograms/kg/min) and the mean duration of infusion was 7.1 +/- 0.5 days. The mean methemoglobin level for the 141 samples was 1.57 +/- 0.08%, which differs from the control mean value in our laboratory of 0.44 +/- 0.01%. Although no patient had clinical symptoms from methemoglobin, 20 patients had elevated (greater than 1%) levels on at least 1 measurement. Seventy-eight of the 141 samples analyzed were in the normal range; 63 determinations were between 2 and 5%. Patients with normal methemoglobin levels differed from those with abnormal levels in the dose of i.v. NTG (mean infusion rate 244 +/- 16 vs 351 +/- 17 micrograms/min; total cumulative dose 1,612 +/- 153 vs 3,398 +/- 308 mg). Age, weight, renal and hepatic function, and arterial oxygen saturation were not different between the groups. In conclusion, clinically significant methemoglobinemia is uncommon with i.v. NTG infusion; however, when large doses of NTG are administered, this complication is more likely.     

Tumor necrosis factor infusions have a procoagulant effect on the hemostatic mechanism of humans

Several investigators have reported that tumor necrosis factor (TNF) can alter the hemostatic properties of vascular endothelial cells in vitro. We have examined the in vivo effects on the hemostatic mechanism of recombinant human TNF administered as a continuous intravenous infusion to 23 cancer patients with active disease. A battery of sensitive and specific immunochemical techniques were used to monitor changes in blood coagulability. Serial determinations of F1 + 2, the protein C activation peptide (PCP), and fibrinopeptide A (FPA) were obtained prior to the initiation of the TNF infusions and at three and 24 hours after the start of therapy in 12 individuals who received greater than 3 x 10(5) U/m2/24h. The mean levels of F1 + 2, PCP, and FPA were significantly elevated at both time points as compared to the baseline values. The metabolic behavior of 125I-F1 + 2 in an animal model was not affected by infusions of the cytokine. We therefore conclude that the observed elevations in the concentration of this marker in humans receiving TNF result from hemostatic system hyperactivity. In 11 subjects infused with 1 x 10(5) to 2.4 x 10(5) U/m2/24 h of the cytokine, the mean levels of F1 + 2, PCP, and FPA were not significantly greater at 24 hours as compared with the baseline values, indicating that there is a threshold dose at which the cytokine can exert a biochemical effect on the coagulation system. Our studies demonstrate that TNF is able to provide a substantial net procoagulant stimulus to the hemostatic mechanism, and suggest that this cytokine may be a mediator of certain hypercoagulable states in humans.     

Personality profiles of hospitalized pathological gamblers: the California Personality Inventory

Studies of the personality of the pathological gambler have consisted primarily of case reports and findings on the MMPI. This article presents data on a sample of 70 pathological gamblers, 70 alcoholics in treatment, and 70 medical/surgical controls on the California Personality Inventory (CPI). Gamblers and alcoholics differed significantly from hospitalized controls on a number of scales, particularly on measures of socialization, ego control, and flexibility. Differences between the gamblers and alcoholics were few, with a trend for the alcoholics to be similar to the gamblers and intermediate between the other two groups. Implications for the treatment of the pathological gambler are discussed.     

Congenital nasolacrimal mucoceles: CT evaluation

A congenital nasolacrimal mucocele, a lacrimal sac mucocele with intranasal extension, is an uncommon mass arising in the medial canthal region of the orbit. The authors describe four infants who presented with medial canthal masses and nasal airway obstruction. All underwent computed tomographic (CT) evaluation, which revealed the triad of cystic dilatation of the lacrimal sac, dilatation of the nasolacrimal duct, and an intranasal cystic mass. Appropriate therapy was determined following identification of the intranasal cystic component. Relevant discussions of the embryology, clinical presentation, and the characteristic CT findings of infants with congenital nasolacrimal mucoceles are included.     

刺激剂类药物及代谢物的分离鉴定

报道了41种刺激剂的气相色谱和质谱数据以及人尿中原药和它们的游离型和结合型代谢物的分离和鉴定方法。用分辨率高的毛细管气相色谱分离,以灵敏度高专属性好的氮磷检测器检测志愿者24 h尿样中游离型母体药及代谢物。选择部分时间收集尿样进行直接气质联用分析以及采用三氟醋酰化、三甲基硅烷化和两者并用的衍生化方法鉴定母体药及游离型代谢物。尿样酸水解后,再进行以上选择性衍生化,可测定它们的结合型代谢物。     

Adult respiratory distress syndrome in children

Clinical, radiological, and pathologic data for nine children with adult respiratory distress syndrome (ARDS) were reviewed. The children ranged in age from 7 months to 15 years (mean age, 7.4 yrs). Underlying diseases and precipitating events included sepsis, pneumonia, near drowning, aspiration pneumonia, central nervous system trauma, and malignancy. All patients had the rapid onset of diffuse bilateral lung opacification, required assisted ventilation for periods of 5-86 days (mean, 25.2 days), and received high levels of inspired oxygen for 2-41 days (mean, 12.7 days). Eight patients manifested air leak complications; these problems persisted until the patients died or were weaned from the respirator. Five of the nine patients died. Autopsy in three patients demonstrated alveolar duct fibrosis characteristic of the late proliferative phase of ARDS and consistent with oxygen toxicity. Two survivors demonstrated mild restrictive changes on follow-up pulmonary function tests and showed persistent linear densities on chest radiographs.     

Tomographic digital subtraction angiography: initial clinical studies using tomosynthesis. Work in progress

We have developed a method for acquiring multiple tomographic subtraction images using a rapid, repetitive, circular tomographic motion. The method combines the principles of digital subtraction angiography (DSA) and electronic tomosynthesis. Fifteen patients were examined with the technique using single intravenous bolus injections of contrast material. The image sequence obtained during each injection was first processed with a nontomographic mask subtraction, and the result was then compared with the tomographic DSA scans synthesized from the same sequence. The effective section thickness was approximately 0.5 cm, with each section being 0.5-1.0 cm apart. Twelve of the intravenous DSA scans provided the necessary diagnostic or clinically useful information. Two of the three nondiagnostic scans were caused by avoidable technical reasons. In eight cases, the tomographic DSA scans were superior in quality to the nontomographic scans, exhibited significantly less artifact from patient motion and overlying bowel gas, and were effective in separating overlapping vessels. Tomosynthesis permits multiple electronic imaging of the area of interest without reinjection of contrast material and appears to be more informative than nontomographic intravenous DSA imaging.