Chlamydia trachomatis Scavenges Host Fatty Acids for Phospholipid Synthesis via an Acyl-Acyl Carrier Protein Synthetase.

The obligate intracellular parasite Chlamydia trachomatis has a reduced genome but relies on de novo fatty acid and phospholipid biosynthesis to produce its membrane phospholipids. Lipidomic analyses showed that 8% of the phospholipid molecular species synthesized by C. trachomatis contained oleic acid, an abundant host fatty acid that cannot be made by the bacterium. Mass tracing experiments showed that isotopically labeled palmitic, myristic, and lauric acids added to the medium were incorporated into C. trachomatis-derived phospholipid molecular species. HeLa cells did not elongate lauric acid, but infected HeLa cell cultures elongated laurate to myristate and palmitate. The elongated fatty acids were incorporated exclusively into C. trachomatis-produced phospholipid molecular species. C. trachomatis has adjacent genes encoding the separate domains of the bifunctional acyl-acyl carrier protein (ACP) synthetase/2-acylglycerolphosphoethanolamine acyltransferase gene (aas) of Escherichia coli. The CT775 gene encodes an acyltransferase (LpaT) that selectively transfers fatty acids from acyl-ACP to the 1-position of 2-acyl-glycerophospholipids. The CT776 gene encodes an acyl-ACP synthetase (AasC) with a substrate preference for palmitic compared with oleic acid in vitro. Exogenous fatty acids were elongated and incorporated into phospholipids by Escherichia coli-expressing AasC, illustrating its function as an acyl-ACP synthetase in vivo. These data point to an AasC-dependent pathway in C. trachomatis that selectively scavenges host saturated fatty acids to be used for the de novo synthesis of its membrane constituents.

Distal Transradial Access in the Anatomic Snuffbox for Diagnostic Cerebral Angiography.

The aim of this study was to describe the feasibility, technique, and safety of distal transradial access in the anatomic snuffbox for diagnostic cerebral angiography. A retrospective review of diagnostic cerebral angiograms obtained during a 6-month period with distal transradial access was performed. Thirty-four successful procedures were performed via distal transradial access. There were 4 failed attempts. This single-center experience using distal transradial access suggests that this technique is safe and effective.

Imported seabass as a source of mercury exposure: a Wisconsin case study.

The Wisconsin Division of Health investigated mercury exposure in a 40-year-old man, his 42-year-old wife, and their 2.5-year-old son. At the time of our investigation, these individuals had blood mercury levels ranging from 37 to 58 micrograms/L (normal < 5 micrograms/L) and hair samples from the adults contained 10-12 micrograms mercury/g dry weight. A personal interview and home inspection failed to identify any occupational or household sources of mercury exposure. The family's diet included three to four fish meals per week. The fish was purchased from a local market and included Lake Superior whitefish, Lake Superior trout, farm-raised trout and salmon, and imported seabass. Analysis of these fish found that only one species, the imported seabass, contained significant mercury levels. Two samples of the seabass obtained from the vendor on different days contained mercury concentrations of 0.5 and 0.7 mg/kg. Based on consumption estimates, the average daily mercury intakes for these individuals ranged from 0.5 to 0.8 micrograms/kg body weight. Six months after the family stopped consuming the seabass, blood mercury levels in this man and woman were 5 and 3 micrograms/L, respectively. Analysis of sequential blood samples confirmed that mercury elimination followed first-order kinetics with a half-life of approximately 60 days.

Defensive projection and paranoid delusions.

The present study considered the implication of a new explanation of defensive projection for the thematic qualities of schizophrenic delusions. Projection was proposed to be a form of self-deception practiced by people who make excessive use of social comparison in self-evaluation. Defensive projection occurs when an unacceptable quality is minimized by distorting this quality in other people used as standards of comparison. Reactive paranoid schizophrenics were expected to show projection as a distortion of social comparison and process paranoid schizophrenics were not. This was tested in terms of a number of thematic qualities that should appear in actual delusions of reactive paranoids but not in those of process paranoids (i.e. more specific social references, attribution of untrustworthiness by men, attribution of hostility by women, concern with female identity in women). The results confirmed these predictions and supported the social-comparison interpretation of projection as a defense in reactive schizophrenics that contributes to the development of delusions.

Systemic lupus erythematosus complicated by panniculitis, optic atrophy, and hemiplegia: report of a case.

A case is presented of a patient with systemic lupus erythematosus who had three of its rarest complications--panniculitis, optic atrophy, and hemiplegia, the latter two occurring despite adequate corticosteroid therapy. There appears to be a missing link in this patient's immune mechanism, which faulted her complete response to corticosteroid therapy and led to the three complications.

Hepatitis B in Wisconsin male prisoners: considerations for serologic screening and vaccination.

To develop a protocol for prevention of hepatitis B virus (HBV) transmission in Wisconsin prisons, we interviewed 619 male prisoners at incarceration to obtain information on hepatitis B risk factors. We defined previous infections by the presence of hepatitis B surface antigen (HBsAg), antibody to hepatitis B surface antigen (anti-HBs), or antibody to hepatitis B core antigen (anti-HBc). Logistic regression was used to develop a model of relative risk (RR) of HBV infection. Use of illicit intravenous (IV) drugs was the most important risk factor because of a high prevalence of IV drug use and an RR which ranged from 2.93-7.47. Other important risk factors were: prior hepatitis or jaundice (RR = 6.28), race (RR = 2.54 for Blacks, RR = 3.28 for Latinos), transfusion (RR = 3.00), and age. Previous imprisonment was not an independent risk factor for HBV, hence selective serologic screening and vaccination of prisoners are justified rather than mass screening and vaccination. Based upon prevalence of hepatitis B markers in subgroups, it is necessary to screen prisoners with prior hepatitis or jaundice, prior transfusion, and users of IV drugs. The identification of HBsAg carriers by such screening could prevent infection of "household" contacts. Users of IV drugs who are susceptible to HBV infection should be vaccinated. The remaining prisoners constitute a low-risk group for HBV infection and do not require serologic screening or vaccination.

Differences in frequency of finger tremor in otherwise asymptomatic mercury workers.

Tremor was measured from the index finger during low force, position holding in 18 control subjects and 18 battery workers with low level exposure to mercury. All workers were asymptomatic on clinical neurological examination. No differences were found in average tremor amplitudes between the groups, but statistically significant abnormalities in tremor frequency distribution existed. Tremor power spectra in the group of mercury workers were shifted toward the higher frequencies and compressed into narrow frequency peaks. These results suggest that measurements of finger tremor that evaluate the frequency distribution can produce a higher diagnostic yield than traditional visual clinical judgement. The findings also confirm other reports that currently permitted exposures to mercury are associated with subtle but distinctive differences in tremor accompanying voluntary movement.