Late cretaceous precessional cycles in double time: a warm-Earth milankovitch response.

Late Cretaceous climatic cycles are reflected in lithological and magnetic variations in carbonate sediments from South Atlantic Deep-Sea Drilling Project site 516F at a paleolatitude of roughly 30 degrees S. Magnetic susceptibility cycles 20 to 60 centimeters in length appear to be controlled by the precession of the equinoxes. Cyclicity is particularly robust within a 24-meter interval in the lower Campanian, where overtone spectral peaks are observed as well as secondary susceptibility maxima within individual precession cycles. One model for this behavior is that sedimentation in the narrow Cretaceous South Atlantic was controlled by equatorial climate dynamics, with the precessional insolation signal rectified by the large land masses surrounding the ocean basin.

A clinical approach to hepatitis B.

Hepatitis B virus (HBV) infections continue to be a major public health problem. Although the use of sensitive screening tests for hepatitis B surface antigen has reduced the incidence of posttransfusional hepatitis B, sexual transmission and other forms of nonparenteral and parenteral transmission of HBV still occur frequently. Until an effective HBV vaccine is commercially available, physicians will have to rely on accurate serologic diagnosis, education of patients and hospital employees, and the appropriate use of immunoglobulin preparations to alter the spread of this viral infection.

Cold agglutinin disease in a patient with Legionnaires' disease.

We present a case of Legionnaires' disease complicated by cold agglutinin disease. Therapy with erythromycin gluceptate was associated with resolution of both the pneumonia and the hemolysis. Complement-fixing antibody levels to Mycoplasma pneumoniae, influenza A, and adenoviruses were measured repeatedly throughout the clinical illness and were persistently nondiagnostic. The cold agglutinin present in the patient's serum was characterized as an IgM that demonstrated anti-I specificity. Thus, Legionella pneumophila should be considered a potential causative agent in patients with pneumonia and cold agglutinin disease.

Leprosy in six isolated residents of northern Louisiana. Time-clustered cases in an essentially nonendemic area.

Northern Louisiana has been essentially free of indigenous leprosy, and now it is not. Six new cases of leprosy have been diagnosed: three in 1986, the other three in 1985, 1983, and 1982, respectively. The patients had been lifelong residents of six scattered rural parishes. Leprosy had never been reported from five of them. No patient had had contact with human leprosy. The patients were white; four were women; the mean +/- SD age at onset was 60.3 +/- 16.4 years (age range, 31 to 80 years); and the mean +/- SD interval to diagnosis was 1.2 +/- 1.4 years. One patient had Hodgkin's disease at the age of 25 years and leprosy at the age of 31 years; another patient had cervical carcinoma. All rural northern Louisiana residents coexist with armadillos (Dasypus novemcinctus), some of which are infected with Mycobacterium leprae, the significance of which is unknown. Hypothetically, exposure to an unknown human case, reactivation of "asymptomatic" leprosy through immunosenescence or immunosuppression, or infection from an environmental source might have occurred. Because the patients lacked contact, travel, residence, and exposure risk factors, the origin of leprosy in the new indigenous cases is noteworthy and is not understood.

Systemic infections treated with amdinocillin in combination with other beta-lactam antibiotics.

Amdinocillin is a semisynthetic derivative of 6-beta-amidinopenicillanic acid, which has bactericidal activity against a broad spectrum of gram-negative bacteria. We report the results of a multicenter study evaluating the safety and efficacy of amdinocillin in combination with other beta-lactam antibiotics in the treatment of 120 serious gram-negative bacterial infections. Amdinocillin was safe and well tolerated and, in combination with other beta-lactam antibiotics, was effective in the treatment of a broad range of gram-negative bacterial infections. Therapy with amdinocillin and other beta-lactam antibiotics was often associated with a demonstrable synergistic effect. Thus, amdinocillin holds promise as an effective antibiotic with synergistic potential when used in combination with penicillins and cephalosporins.

Variable intrathoracic upper airway obstruction due to non-small cell lung cancer. Palliation using physiologic and mechanical stenting.

A 48-year-old woman with non-small cell lung cancer involving the mediastinum and producing extrinsic tracheal compression is presented. The patient failed to respond to all conventional therapy and presented with stridor and respiratory distress due to progressive airway obstruction. Continuous positive airway pressure (CPAP) by mask was used to physiologically stent the airway until a mechanical Silastic stent could be placed by tracheostomy.

Late dissemination of pulmonary blastomycosis during ketoconazole therapy.

We report a patient with pulmonary blastomycosis who suffered relapse with dissemination of her disease after five months of apparent response to therapy with ketoconazole, 400 mg daily. Common causes of drug failure, including noncompliance and failure of absorption, were excluded, and there was no evidence of altered host immunity. Previous reports of relapse during and after ketoconazole therapy are reviewed; no previous case was found with recurrence near the end of a six-month period of apparently effective therapy. Close followup during the entire course of ketoconazole therapy for blastomycosis and following its completion is recommended.

Microbial contamination of arterial infusions used for hemodynamic monitoring: a randomized trial of contamination with sampling through conventional stopcocks versus a novel closed system.

Arterial catheters are now commonly used to monitor blood pressure and obtain blood samples for arterial blood gas and other laboratory determinations. Stopcocks inserted into the pressure monitoring circuit have been the primary means of obtaining blood from arterial catheters. However, these stopcock systems have been associated with nosocomial contamination and bacteremias. Because of the problems of bacterial contamination and blood wasting with the stopcock sampling systems, we compared the frequency and extent of contamination of external sampling ports and the monitoring tubing fluid in stopcocks with that of a novel closed needle-sampling system (Lab-Site, Migada Ltd, Rehovot, Israel), incorporated into pressure monitoring tubing (Abbott Laboratories Inc., North Chicago, Illinois). We found that use of the novel sampling system resulted in significantly fewer episodes of internal bacterial contamination of the arterial monitoring line (7%) than did the use of a stopcock system (61%). External contamination of the sampling port was also lower in the novel system (8%) than in the stopcock system (37%). This suggests that the closed system may reduce the risk of nosocomial infections in patients requiring arterial pressure monitoring.

Simplified neutrophil hexose monophosphate shunt assay on whole blood.

Neutrophil function was determined in resting and phagocytic cells by an assay of hexose monophosphate shunt activity performed on small volumes of whole blood. This new micromethod clearly differentiated between zymosan-stimulated and unstimulated hexose monophosphate shunt activity. Furthermore, the whole blood microassay was able to measure the large quantities of 14CO2 that previously have been measured by hexose monophosphate shunt assays performed on erythrocyte-free leukocyte preparations. Thus, because of its simplicity and accuracy, the microassay described in this report can be used for routine evaluation of those metabolic activities of neutrophils associated with phagocytosis and bactericidal activity.

Event-related potentials elicited by spoken relative clauses.

Sentence-length event-related potential (ERP) waveforms were obtained from 23 scalp sites as 24 subjects listened to normally spoken sentences of various syntactic structures. The critical materials consisted of 36 sentences each containing one of two types of relative clauses that differ in processing difficulty, namely Subject Object (SO) and Subject Subject (SS) relative clauses. Sentence-length ERPs showed several differences in the slow scalp potentials elicited by SO and SS sentences that were similar in their temporal dynamics to those elicited by the same stimuli in a word-by-word reading experiment, although the effects in the two modalities have non-identical distributions. Just as for written sentences, there was a large, fronto-central negativity beginning at the linguistically defined "gap" in the SO sentences; this effect was largest for listeners with above-median comprehension rates and is hypothesized to index changes in on-line processing demands during comprehension.

BAY k 8644, a calcium channel agonist, reverses hypotension in endotoxin-shocked rats.

The hypotension and depressed myocardial function frequently observed in endotoxin-induced shock are difficult to overcome pharmacologically. In this paper we demonstrate that the calcium channel agonist BAY k 8644 potently elevates blood pressure in endotoxin-shocked rats. A one time dose as low as 10 micrograms/kg of BAY k 8644 significantly elevated mean arterial pressure (MAP) in endotoxin-treated hypotensive rats while having minimal effects in normal rats. The maximum BAY k-induced percentage increase in MAP was greater in endotoxin-treated rats when compared with saline-treated control (153% vs. 120% increase respectively). BAY k 8644 also caused a dose-dependent decrease in heart rate of 37% in endotoxin-treated rats and 39% in control rats (NS vs. control). No differences in the regulatory properties of [3H]nitrendipine binding sites were discerned comparing control and endotoxin-treated rats. Thus, the enhanced activity of BAY k 8644 in hypotensive rats was not due to augmented affinity for the cardiac dihydropyridine binding site. These results demonstrate that the use of calcium channel agonists might represent a unique pharmacologic approach in pathologic states characterized by hypotension and diminished cardiac function.

Neural plasticity in the dynamics of human visual word recognition.

Repeated exposure to words leads to plastic changes in the nervous system throughout the lifespan, with the consequence that common words are processed more rapidly and accurately than rare words. Most behavior time measures correlate highly with the logarithm of a stimulus word's experiential frequency. Here, we demonstrate similar but earlier changes in the latency of a brain-generated evoked potential recorded over the left anterior scalp as individuals silently read sentences. We conclude that experience can speed the processing of some words by at least 50 ms within the first 335 ms of visual processing.

Cardiopulmonary arrest after retrobulbar anesthesia in a patient with an orbital roof defect.

PURPOSE: Cardiopulmonary arrest developed after injection of bupivacaine hydrochloride, lidocaine, and hyaluronidase in a 78-year-old woman who had previously undergone ipsilateral transcranial orbital surgery with removal of the bone of the orbital roof. METHODS: The patient required immediate cardiopulmonary resuscitation and intubation. Mechanical ventilation was necessary for 18 hours before spontaneous respirations resumed. RESULTS: The patient improved and was discharged on the fifth postanesthetic day. CONCLUSIONS: There were several possible mechanisms by which the local anesthetic could have entered the central nervous system. In patients with orbital roof defects, we recommend that retrobulbar anesthetic agents be used with caution.

Urine drug screening for cocaine after lacrimal surgery.

We investigated whether the results of routine urine drug screening for cocaine would be positive after dacryocystorhinostomy. Postoperative urine specimens were analyzed for the presence of benzoylecgonine, the major metabolite of cocaine, by gas chromatography-mass spectrometry. The results of urine tests of all 12 patients were positive for cocaine 24 hours postoperatively. Nine (75%) were positive 48 hours postoperatively, and three (33%) had detectable levels 72 hours after surgery. Patients given cocaine at the time of lacrimal surgery should be warned that they may test positive for cocaine for at least three days postoperatively.

Supercritical fluid extraction and chromatography for fat-soluble vitamin analysis.

Extraction and chromatographic separation of fat-soluble vitamins is a challenging task, due to the sensitivity of these compounds towards light, oxygen, heat and pH. In light of this, supercritical fluid extraction (SFE) and supercritical fluid chromatography (SFC) are attractive techniques as they function at considerably milder conditions than conventional solvent-based analytical techniques. Moreover, supercritical techniques consume much less amounts of organic solvents than conventional ones. This review gives a brief description of suitable supercritical media as well as basic theory on SFE and SFC processes. Furthermore, guidelines are provided for optimizing the important extraction and separation parameters to facilitate a successful method development. Finally, applications employing SFE and/or SFC for fat-soluble vitamin enrichment and final determination are reviewed.

Fat content for nutritional labeling by supercritical fluid extraction and an on-line lipase catalyzed reaction.

A method using sequential supercritical fluid extraction (SFE) and enzymatic transesterification has been developed for the rapid determination of total nutritional fat content in meat samples. SFE conditions of 12.16 MPa and 50 degrees C were utilized to extract lipid species from the sample matrix. The enzymatic transesterification of the lipids by methanol was catalyzed by an immobilized lipase isolated from Candida antarctica. Conversion of the triglycerides to fatty acid methyl esters was monitored by supercritical fluid chromatography, while the fatty acid content of the extract was determined by capillary gas chromatography (GC). Total fat, saturated fat and monounsaturated fat contents were calculated from the GC data and compared to values from traditional extraction and lipid determination methods. Both off-line SFE and automated SFE followed by on-line GC analysis using two different instruments were utilized in this study. The enzymatic-based SFE method gave comparable results to the organic solvent extraction-based method followed by conventional BF3-catalyzed esterification.

Metabolism of diethylstilbestrol in the C3H mouse: chromatographic systems for the quantitative analysis of DES metabolic products.

Initial excretion studies with orally administered [monoethyl-1-3H] DES demonstrated the feces to be the principal mode of elimination of DES in the C3H mouse. Metabolic studies with tritiated DES and/or [UL-14C] DES were performed with orally dosed C3H high (MTV+) and low (MTV-) titer MMTV female mice. Extraction and partitioning of the fecal radioactivity demonstrated 77 to 86% (n = 4) to be benzene soluble and the remainder H2O soluble. The principal product in the organic phase following Sephadex LH-20 and HPLC purification was DES. The aqueous phase was resolved by LH-20 into two conjugate fractions that were partially hydrolyzed by beta-glucuronidase. The principal aglycone was chromatographically identical with authentic DES. The urinary conjugates were resolved into six fractions. The four major fractions were 80% hydrolyzable with beta-glucuronidase. Two of these fractions had trans-DES as the principal aglycone, whereas the other two had a major peak similar to but not chromatographically coincident with cis-DES. In certain experiments mice were sequentially dosed with tritium (24 hr) followed by a 14C dose (24 hr). Two mice (MTV+) were also previously fed 1000 ppb DES prior to these experiments. The tritated and 14C products were combined and analyzed simultaneously. This experiment did not reveal significant differences in the metabolism due to the modes of radioactive labeling, MMTV titer, or the prior feeding of DES. The developed methodology was judged to purify quantitatively 90% or more of the DES radioactive products.

Results of a prospective statewide reporting system for infective endocarditis.

To better understand the microbiology, anatomy, and demography of infectious endocarditis, we devised a prospective statewide reporting system to study these infections. Because our study design required accurate diagnosis, reliable case reporting, and a high probability of physician-to-case exposure, we enlisted the help of cardiologists, cardiovascular surgeons, and infectious disease specialists throughout Louisiana. All Louisiana members of the American College of Cardiology and the Infectious Diseases Society of America were invited to participate. Participants were supplied with a brief endocarditis report form and asked to complete the form as they saw patients with infective endocarditis. Seventy-five patients with infective endocarditis were reported for a case rate of 1.7 per 100,000 persons per year. This report analyzes the results from this one-year study.

Herpes zoster myelitis occurring during treatment for systemic lupus erythematosus.

A 15-year-old girl with systemic lupus erythematosus suddenly developed fever, meningismus, and herpes zoster. Within 48 hours, transverse myelitis developed at the level of the nerve root involvement of the herpes zoster. Since both systemic lupus erythematosus and varicella-zoster have been reported to cause myelitis, therapy was initiated for both. The rapid and simultaneous resolution of both the herpes zoster and the neurologic deficits strongly supports the causal association of both with varicella-zoster. This is the second reported case of herpes zoster-associated transverse myelitis in a patient with systemic lupus erythematosus.

Survival from sino-orbital mucormycosis due to Rhizopus rhizopodiformis.

We report the first case of sino-orbital mucormycosis caused by Rhizopus rhizopodiformis. Therapy consisted of conservative surgical drainage and intravenous amphotericin B. The patient, an insulin-dependent diabetic, survived her infection with minimal residual deformity. This case and a literature review suggest that infection due to R. rhizopodiformis in diabetics might be more amenable to treatment than mucormycosis caused by other species of fungi. Speciation of such fungi would permit the determination of species specific mortality rates, and may be of therapeutic and prognostic value.