Identification and total synthesis of novel fatty acids from the Siphonarid limpet Siphonaria denticulata

The novel fatty acids 17-methyl-6(Z)-octadecenoic acid and 17-methyl-7(Z)-octadecenoic acid were identified for the first time in nature in the mollusk Siphonaria denticulata from Queensland, Australia. The principal fatty acids in the limpet were hexadecanoic acid, octadecanoic acid, and (Z)-9-octadecenoic acid, while the most interesting series of monounsaturated fatty acids was a family of five nonadecenoic acids with double bonds at either Delta(7), Delta(9), Delta(11), Delta(12), or Delta(13). The novel compounds were characterized using a combination of GC-MS and chemical transformations, such as dimethyl disulfide derivatization. The first total syntheses for the two novel methyl-branched nonadecenoic acids are also described, and these were accomplished in four to five steps and in high yields.

Sarcoplasmic reticulum function and muscle contractile character following fatiguing exercise in humans

1. This study examined the alterations in calcium release, calcium uptake and calcium ATPase activity of skeletal muscle sarcoplasmic reticulum in response to a bout of intense dynamic knee extensor exercise, and the relationship between these changes and alterations in muscle contractile characteristics in the human quadriceps. 2. In biopsy samples taken from the vastus lateralis, sarcoplasmic reticulum calcium release and calcium uptake were significantly depressed (P < 0.01 and 0.05, respectively) immediately following the exercise with no alteration in the sarcoplasmic reticulum Ca2+-ATPase activity. 3. A 33 % reduction in the maximum voluntary isometric torque was found following the exercise, with reduced torques from electrically evoked isometric contractions at low frequencies of stimulation (10 and 20 Hz) but not at higher frequencies (50 and 100 Hz). 4. The depressed calcium release was correlated (P < 0.05) with a decreased ratio of torques generated at 20:50 Hz, indicating an involvement in low frequency fatigue; however, no correlations between the muscle relaxation times or rates of change of torque and calcium uptake were observed.

Analysis of the expressed genome of the lone star tick, Amblyomma americanum (Acari: Ixodidae) using an expressed sequence tag approach

An expressed sequence tag (EST) approach was used to study the genome of two developmental stages of the lone star tick, Amblyomma americanum. cDNA libraries were constructed from the larval and adult stages of A. americanum. In total, 1942 ESTs were sequenced (1462 adult ESTs and 480 larval ESTs) and analyzed using bioinformatic programs. Contig assembly using the CAPII program revealed 11% and 15% redundancy of sequences in the larval and adult ESTs, respectively. Of the 1942 ESTs, 1738 sequences were considered quality sequences and of these, 771 or approximately 44.4% of the sequences were putatively identified based on amino acid identity using the protein Basic Local Alignment Search Tool (BLAST) algorithm. Putatively identified sequences were classified according to their predicted gene function. In total, 967 sequences, or 55.6% of the quality sequences, had limited or no protein similarity to previously identified gene products. Sequences lacking protein homology were analyzed using an automated sequence annotation system for predicted protein characteristics such as open reading frames, signal peptides, protein motifs, and transmembrane regions. In this paper we describe the sequencing of the largest number of ESTs obtained from an arachnid species to date and the subsequent detailed analysis of these sequences.

Information technology and supply chain management: a study of the food industry

This paper's topic is the use of information technology (IT) for the development of supply chain management (SCM). In today's business environment, both in academics and industry, the term SCM has become a popular paradigm. In particular, the use of IT to facilitate the development of supply chain partners is gaining interest within industry. This paper develops the topic of SCM and further develops the relationship between the use of IT, in the form of electronic data interchange, and the development of supply chain integration. The goal of using SCM along with IT is to develop a supply chain that is capable of responding more quickly and efficiently in the meeting of consumer's requirements.

Technical note: evaluating mandibular ramus flexure as a morphological indicator of sex

Described as a highly reliable method of sex identification, mandibular ramus flexure is a morphological trait expressed on the posterior border of the ramus at the occlusal plane (Loth and Henneberg [1996] Am. J. Phys. Anthropol. 99:473-485). In a blind test, 158 mandibles were examined for the presence of flexure as defined by Loth and Henneberg, resulting in 79.1% accuracy, which is well below the reported 91-99% accuracy. Twenty-five of these mandibles were assigned the ambiguous score of 0, an outcome of a +1 score for one side, and a -1 score for the other. Seventeen mandibles were examined twice to measure intraobserver error. Only 64.7% of the scores were duplicated in the second session, suggesting difficulty in consistent identification of flexure. Low overall accuracy, an invalid scoring system, and high intraobserver error indicate that mandibular ramus flexure is an unreliable technique for estimation of sex.

Histopathological effects of Bacillus thuringiensis on the alimentary canal of the sheep louse, Bovicola ovis

Sequential observations were made of the ultrastructural effects of Bacillus thuringiensis (Bt) subsp. kurstaki strain WB3S16 on midgut epithelial cells of the sheep biting louse, Bovicola ovis, after the lice were fed, ad libitum, a powdered preparation of Bt spores, delta-endotoxin crystals, and lysed cellular components. Light microscope observations revealed cytopathological changes to the midgut epithelial cells 4 h postfeeding. Transmission electron micrographs showed that the microvilli of the midgut epithelial cells became disrupted 4-8 h postfeeding, after which the cells became vacuolated and swollen, and the cell organelles lost definition and disappeared. Paralysis and death of B. ovis occurred between 8 and 12 h postfeeding, coincident with midgut cells lysis and release of cellular contents into the midgut lumen. The histopathological effects reported here are similar to those reported in lepidopteran and coleopteran larvae affected by the delta-endotoxin crystal proteins. The constituent fractions of the Bt preparation were tested for toxicity to B. ovis using a feeding bioassay. Native delta-endotoxin crystals were not toxic to B. ovis and remained intact in the midgut of the insect. There was no evidence that the native Bt crystal was involved in the cytopathology and death of the lice. However, in vitro solubilized delta-endotoxin crystal proteins were significantly toxic to B. ovis. In addition, a louse active toxin was associated with the Bt membranes and culture supernatant.

Confirmation of the diagnosis of schizophrenia after death using DSM-IV: a Victorian experience

OBJECTIVE

This study examines the reliability of antemortem diagnoses of schizophrenia using DSM-IV criteria.

METHOD

The case histories of 83 subjects with a provisional diagnosis of schizophrenia at autopsy were retrospectively reviewed using a semi-structured chart review and application of DSM-IV criteria. Agreement between antemortem and postmortem diagnoses of schizophrenia was examined, as well as the concordance between DSM-IV diagnoses and previously obtained diagnoses using DSM-III-R and ICD-10 criteria for schizophrenia.

RESULTS

According to DSM-IV, 30.1% of cases did not have schizophrenia, compared to 36.1% using DSM-III-R criteria and 51.8% of cases using ICD-10 criteria. Concordance between DSM-IV and DSM-III-R diagnoses of schizophrenia was excellent (kappa = 0.81), but only fair between DSM-IV and ICD-10 (kappa = 0.57). Of the cases that did not meet the formal criteria for schizophrenia, the majority were reassigned diagnoses of schizoaffective disorder and affective disorder.

CONCLUSIONS

The use of human brain tissue in postmortem studies of schizophrenia must be linked to standardised diagnostic assessment procedures. Diagnoses can be upgraded with the development of new criteria, providing sufficient clinical data is available in case histories.

"Best hospitals": a description of the methodology for the Index of Hospital Quality

Starting in 1991, U.S. News & World Report has published an annual cover story. "America's Best Hospitals," for which the National Opinion Research Center (NORC) has provided the underlying data. Since 1993, the rankings have been based on a combination of data, including physicians' nominations, the American Hospital Association's Annual Survey of Hospitals database, and mortality data from the Health Care Financing Administration. This article reports on the theoretical framework and methodological design of the "Index of Hospital Quality" used in the U.S. News & World Report rankings.

Polarization states and output powers of a CO(2) laser with an electro-optic phase retarder

We study the power output and polarization state of a CO(2) laser that contains both passive polarization-sensitive elements (Brewster plates) and an active phase-retarding electro-optic modulator (CdTe crystal). The theoretical threshold condition (i.e., the retardation required to extinguish the laser) is obtained from a cavity round-trip Jones matrix. We show that adding extra Brewster plates may be counterproductive in that the required retardation voltage increases. We calculated the output power, which depends on the saturated gain properties of the active media, by iterative modeling, with the elliptically polarized light propagated repeatedly around the cavity. We compare the theory with results from a folded rf-excited waveguide CO(2) laser (Laser Ecosse Model CM3500). Theory and experiment are in fair agreement for low powers. As expected, at high powers there are extra difficulties in modeling the cavity behavior, probably because of distortions induced in and by the crystal.

Two-dimensional MRI at 1.5 and 0.5 T versus CT myelography in the diagnosis of cervical radiculopathy

A prospective comparison was made of standard two-dimensional MRI sequences, at both high and midfield strength, with CT myelography in 23 patients with cervical spondylosis. MRI is adequate for assessment of cord compression, where high field strength is superior to midfield strength. MRI using 4-mm sections is inadequate for presurgical assessment of root compression. It remains to be proven whether thin-section white-CSF volume sequences or gadolinium-enhanced volume studies can replace CT myelography.

Effects of curved mirrors in waveguide resonators

Waveguide gas lasers (CO(2) ones especially) continue to be widely used. We have previously studied simple resonator designs with plane mirrors close to each end of the waveguide. Here we examine theoretical predictions concerning hybrid waveguide/free-space resonators with square-bore guides and curved mirrors. We show how resonator mode losses vary as functions of guide length and width, guide-to-mirror distance, mirror radius of curvature, and mirror tilt. We have tested a 7-W cw rf-excited CO(2) laser with unusually good near-TEM(00) transverse-mode quality; it is one of many promising resonator geometries not covered by earlier published research. The common case 3 reflector, sometimes viewed as guaranteeing near-TEM(00) mode performance, is shown to be alarmingly sensitive to small misalignments for certain guide geometries.

The enzymatic removal of a surfactant coating from quartz and kaolin by P388D1 cells

The macrophage-like cell line, P388D1, was exposed to dipalmitoyl lecithin (DPL)-coated respirable quartz and kaolin, and the disappearance of the DPL was monitored for up to 9 days. The coating was removed rapidly at first (about 50% in the first 3 days) and then more slowly over the remaining 6 days, until about 30% remained on day 9. The rate of DPL digestion was independent of the type of dust and the amount of coated dust within the cell, indicating the existence of an extracellular phospholipase activity. This extracellular phospholipase activity was partially characterized. It was sensitive to temperatures above 56 degrees C, the presence of EDTA, the action of the proteases trypsin and proteinase K, and pH, being active at pH 7 but not at pH 5. This is consistent with reports in the literature of the existence of an extralysosomal phospholipase which is active at pH 7 and dependent on the presence of divalent metal ions. There was a dust-dependent difference in the extracellular rate of DPL digestion from quartz and kaolin. The coating was removed more slowly from the kaolin than it was from quartz. The removal of the DPL coating seen in the presence of cells was presumably due to both an intracellular and an extracellular phospholipase.

Ultrasound determination of the normal location of the conus medullaris in neonates

PURPOSE

To establish the normal range of the position of the conus medullaris in neonates and determine whether it differs from that in adults.

METHODS

One hundred five healthy neonates born over an 18-day period in a single obstetric unit had ultrasound examinations of their lower spines to relate the conus medullaris to the nearest intervertebral disk or midvertebral level.

RESULTS

The mean position of the conus was midway between the L1-2 disk and mid-L-2 body, ranging from T-12/L-1 to L-3, with the modal position being L1-2 (47.6%). A small but significant rise in position from 33 to 42 weeks postconceptual age was identified. Comparison with data previously reported from adults showed a small but highly significant difference in conus position of approximately 0.25 vertebral levels.

DISCUSSION

Our data confirm studies suggesting that ascent of the cord after birth is minor.

High-risk sexual behavior at a midwestern university: a confirmatory survey

According to a 1991 study of sexual behavior based on a random sample of heterosexual undergraduates at a Midwestern university, 80% of the males and 73% of the females had experienced vaginal or anal intercourse. The average age at first vaginal intercourse was 17.2 years for both sexes. Seventeen percent of the sexually experienced males and 18% of the sexually experienced females had engaged in heterosexual anal intercourse; among these respondents, the average age at first anal intercourse was 20.3 for males and 19.1 for females. Although less than four years, on average, had elapsed since the respondents had first had vaginal intercourse, males reported an average of 8.0 lifetime vaginal-sex partners and females reported an average of 6.1. Overall, the findings from this random sample of students are similar to those from a 1988 convenience sample of the same college population.

Higher moments of scattered light fields by heterodyne analysis

In heterodyne detection (such as in coherent lidar) the optical local oscillator defines a single mode of the incoming-signal light field; this single-mode selectivity has been previously predicted to preserve the full fluctuation character of scattered light. This is in contrast with direct-detection schemes, as in photon-correlation spectroscopy, where aperture averaging usually reduces the range of fluctuations. Examples of Gaussian and non-Gaussian statistics in laser light scattered from a moving ground-glass screen have been studied. This simple laboratory experiment has several advantages over equivalent direct-detection schemes and has been shown to yield experimentally the theoretically predicted factorial intensity moments (up to the seventh order) that result from zero-mean, circulo-complex Gaussian statistics.

The components of hospital quality: a nursing perspective

The first stage of a larger investigation intended to define objective and standardized measures of the quality of care provided by hospitals included the conduct of focus groups with registered nurses, eliciting their opinions as to the merit of a number of potential indicators of hospital quality. The registered nurses in the focus groups settled on the ratio of registered nurses to beds, the percentage of board-certified physicians, the presence of discharge planning services, service mix, the number of technological services, and Council on Teaching Hospitals membership as the best indicators of high-quality care delivery.

Does myodil introduced for ventriculography lead to symptomatic lumbar arachnoiditis?

Although there is a substantial body of evidence implicating Myodil or Pantopaque as a cause of lumbar arachnoiditis, assessment of the clinically based evidence is complicated by the additional potentially causative factors present in a high proportion of cases. These include pre-existing spinal pathology, traumatic lumbar puncture and surgery. The aim of this retrospective study was to attempt to ascertain whether Myodil introduced via ventricular catheter was associated with subsequent development of symptomatic lumbar arachnoiditis. In 222 patients in whom clinical records were reviewed there was no excess of back pain following ventriculography compared to the general population. Myodil ventriculography does not appear to be a major cause of symptomatic lumbar arachnoiditis. Several unavoidable problems with the methodology of this study are discussed.

Contrasting respirable quartz and kaolin retention of lecithin surfactant and expression of membranolytic activity following phospholipase A2 digestion

Respirable-sized quartz, a well-established fibrogenic mineral dust, is compared with kaolin in erythrocyte hemolysis assays after treatment with saline dispersion of dipalmitoyl phosphatidylcholine, a primary phospholipid component of pulmonary surfactant. Both dusts are rendered inactive after treatment, but the membranolytic activity is partly to fully restored after treatment with phospholipase A2, an enzyme normally associated with cellular plasma membranes and lysosomes. Phospholipid-coated dusts were incubated for periods of 2-72 h at a series of applied enzyme concentrations, and the adsorbed lipid species and hemolytic activity were quantitated at each time for both dusts. Surfactant was lost more readily from quartz than from kaolin, with consequent more rapid restoration of mineral surface hemolytic activity for quartz. Interactions of surfactant and mineral surface functional groups responsible for the mineral-specific rate differences, and implications for determining the mineral surface bioavailability of silica and silicate dusts, are discussed.