Haramiyids and Triassic mammalian evolution

Isolated teeth referred to the family Haramiyidae are among the earliest known fossil evidence of mammals. First discovered in European Late Triassic deposits a century and a half ago, haramiyids have been interpreted as related to multituberculates, a diverse and widespread lineage that occupied a rodent-like niche from the Late Jurassic to the Early Tertiary. Nonetheless, haramiyid relationships have remained enigmatic because the orientation and position of the teeth in the upper or lower jaw could not be determined with certainty; even their mammalian status has been questioned. The discovery of haramiyid dentaries, a maxilla and other skeletal remains in the Upper Triassic of East Greenland reveals haramiyids as highly specialized mammals with a novel pattern of puncture-crushing occlusion that differs dramatically from the grinding or shearing mechanisms of other Early Mesozoic mammals.     

The results of radiotherapy for ependymomas: the Mayo Clinic experience

It is known that exogenous 11-cis-retinol inhibits the recovery of photosensitivity of bleached rod outer segments (ROS) and 11-cis-retinol exists in the interphotorecepter matrix. We examined the conversion of 11-cis-retinol with bovine ROS. ROS was incubated with 11-cis-retinol under dim red light. Retinoids were extracted from the reaction mixture with hexane and analyzed by HPLC coupled with a fluorescence spectrophotometer. Isomerization of 11-cis-retinol to all-trans-retinol was observed in the presence of ROS. This isomerization was not suppressed by heat treatment and did not have stereospecificity. In addition, we incubated purified rhodopsin and phospholipids extracted from ROS with 11-cis-retinol. Rhodopsin was found to isomerize 11-cis-retinol to all-trans-retinol as well as ROS, but phospholipids did not. In contrast, the phospholipids inhibited the isomerization of 11-cis-retinol to all-trans-retinol by the purified rhodopsin. Commercially available phospholipids, especially phosphatidylserine, also inhibited the isomerization. Our results suggest that rhodopsin has activity for the isomerization of 11-cis-retinol to all-trans-retinol and may play an important role in the detoxification of 11-cis-retinol in the ROS.     

Magnetic resonance imaging of muscle in amyotrophic lateral sclerosis

In the present study we were interested to determine whether the maximum unilateral nasal airflow associated with the nasal cycle (Fmax physiol) was equivalent to the maximum unilateral nasal airflow that could be achieved by the application of a topical nasal decongestant (Fmax pharmacol). Eight healthy subjects (three male and five female, aged between 19-28 years) were recruited for this study. Unilateral nasal airflow was measured using posterior rhinomanometry at the inspiratory reference pressure of 75 Pa by alternately occluding each nostril with surgical tape. The study was run over 2 consecutive days. On day one, measurements of unilateral nasal airflow were performed every hour for 8 h in each subject and Fmax physiol was found to be 265 cm3/sec (147) (median and interquartile range). On day 2 the median unilateral nasal airflow before application of the nasal decongestant was 171 cm3/sec (140) and this increased to 251 cm3/sec (127) (p = 0.046) at 15 min and to 278 cm3/sec (134) (p = 0.005) at 45 min after application of the decongestant (Fmax pharmacol). A paired comparison of Fmax physiol and Fmax pharmacol showed that these nasal airflow measurements were not significantly different (p > 0.999). The results show that there was no difference between the maximum physiological decongestion produced during the course of the nasal cycle and that produced pharmacologically by a topical nasal decongestant. This indicates that the point of maximal sympathetic vasoconstrictor tone occurring during the nasal cycle causes a constriction of the nasal venous sinuses that is equal to the constrictor response that can be achieved by applying a topical sympathomimetic medication.     

Cutaneous manifestations of systemic diseases

Many aspects of dermatologic diagnosis are either of importance or interest to the nondermatologist, and there are many excellent textbooks available for guidance. This article focuses on four categories of conditions that are the source of frequent queries from the primary care setting: (1) common skin diseases that frequently mimic systemic illness, (2) common skin diseases that have important systemic associations, (3) common systemic diseases that have prominent cutaneous findings, and (4) the seldom seen but frequently raised concerns regarding cutaneous signs of internal malignancy.     

Projected cost-effectiveness of primary angioplasty for acute myocardial infarction

OBJECTIVES: This study sought to evaluate the cost-effectiveness of primary angioplasty for acute myocardial infarction under varying assumptions about effectiveness, existing facilities and staffing and volume of services. BACKGROUND: Primary angioplasty for acute myocardial infarction has reduced mortality in some studies, but its actual effectiveness may vary, and most U.S. hospitals do not have cardiac catheterization laboratories. Projections of cost-effectiveness in various settings are needed for decisions about adoption. METHODS: We created a decision analytic model to compare three policies: primary angioplasty, intravenous thrombolysis and no intervention. Probabilities of health outcomes were taken from randomized trials (base case efficacy assumptions) and community-based studies (effectiveness assumptions). The base case analysis assumed that a hospital with an existing laboratory with night/weekend staffing coverage admitted 200 patients with a myocardial infarction annually. In alternative scenarios, a new laboratory was built, and its capacity for elective procedures was either 1) needed or 2) redundant with existing laboratories. RESULTS: Under base case efficacy assumptions, primary angioplasty resulted in cost savings compared with thrombolysis and had a cost of $12,000/quality-adjusted life-year (QALY) saved compared with no intervention. In sensitivity analyses, when there was an existing cardiac catheterization laboratory at a hospital with > or = 200 patients with a myocardial infarction annually, primary angioplasty had a cost of < $30,000/QALY saved under a wide range of assumptions. However, the cost/QALY saved increased sharply under effectiveness assumptions when the hospital had < 150 patients with a myocardial infarction annually or when a redundant laboratory was built. CONCLUSIONS: At hospitals with an existing cardiac catheterization laboratory, primary angioplasty for acute myocardial infarction would be cost-effective relative to other medical interventions under a wide range of assumptions. The procedure's relative cost-ineffectiveness at low volumes or redundant laboratories supports regionalization of cardiac services in urban areas. However, approaches to overcoming competitive barriers and close monitoring of outcomes and costs will be needed.     

Anchor structure of staphylococcal surface proteins. II. Cooh-terminal structure of muramidase and amidase-solubilized surface protein

Surface proteins of the Gram-positive organism Staphylococcus aureus are anchored to the bacterial cell wall by a transpeptidation mechanism during which the polypeptide is cleaved between the threonine (T) and the glycine (G) of the LPXTG motif. The carboxyl of threonine is subsequently amide linked to the amino of the pentaglycyl cross-bridge within the staphylococcal peptidoglycan. Previous work examined the anchor structure of surface proteins solubilized from the peptidoglycan by treatment with lysostaphin or phi11 hydrolase and identified COOH-terminally linked triglycyl or L-Ala-D-iGln-L-Lys(Gly5)-D-Ala and MurNAc-[L-Ala-D-iGln-L-Lys(Gly5)-D-Ala](beta1-4)-GlcNAc, respectively. Here, we report the anchor structure of surface proteins solubilized with N-acetylmuramidase and N-acetylmuramyl-L-alanine amidase. N-Acetylmuramidase-released surface protein was linked to MurNAc-[L-Ala-D-iGln-L-Lys(Gly5)-D-Ala](beta1-4)-GlcNAc, whereas N-acetylmuramyl-L-alanine amidase treatment of the cell wall solubilized surface proteins linked to L-Ala-D-iGln-L-Lys(Gly5)-D-Ala. Most, but not all, anchor structures were cross-linked to other cell wall subunits, in which the D-alanyl at position four was amide linked to the pentaglycyl of a neighboring wall peptide.     

Studies on the mechanism of antimalarial action of a novel arylene bis(methylketone)

CT-guided neurolytic splanchnic nerve block is a technique for relieving abdominal cancer pain; the goal is the alcoholic neurolytic interruption of the sensitive structures in retroperitoneal space. CT yields accurate anatomical detailing and the course for needle placement and alcohol spread. January, 1993, to July, 1996, twenty-one bilateral splanchnic nerve blocks were performed through the posterior access. Forty-eight hours after alcoholization, 14 patients (66%) had complete pain regression; 52% of the patients needed no analgesics for 6 to 54 days and only 9 patients (42%) needed another low opioid therapy. Complications included hypotension and diarrhea in all cases. One had a cardiac arrest and died 8 days after the procedure. There were no other complications. The whole procedure usually lasted 60 min (range: 45 to 90 min). Splanchnic nerve neurolysis is a useful treatment in the patients with severe chronic abdominal pain. It is used as a second line treatment when large lesions change celiac anatomy and complicate the percutaneous block of the celiac plexus.