Characterization of human humoral responses to the major outer membrane protein and OMP2 of Chlamydophila pneumoniae

Chlamydophila pneumoniae infection is associated with a range of diseases including pneumonia, asthma and heart disease. Although an obligate intracellular pathogen, high levels of antigen-specific antibody are induced and serology is frequently used to diagnose these infections. Proteins targeted by the humoral response include the major outer membrane protein (MOMP) and outer membrane protein 2 (OMP2). Using human anti-chlamydial sera we have defined the B cell epitopes recognized on MOMP and OMP2. Peptides from MOMP, unlike OMP2, were not strongly recognized. Two of these epitopes when linked to an inert carrier reacted strongly with high-titer anti-C. pneumoniae sera.

Visualization of spatially and temporally regulated N-WASP activity during cytoskeletal reorganization in living cells

Members of the WASP/WAVE family of proteins are key regulators of cytoskeletal reorganization across a diverse range of cellular processes. Despite a wealth of biochemical data about WASP/WAVE regulation in vitro, our understanding of the in vivo regulation of these proteins is hampered by the inability to monitor subcellular regulation of their activities in living cells. Here we establish a fluorescence resonance energy transfer-based approach to visualize spatial and temporal regulation of neuronal Wiskott-Aldrich syndrome protein (N-WASP) activity in living cells. Using time-lapse microscopy, we characterize the activation of N-WASP in response to growth-factor stimulation, and we reveal that N-WASP is activated inside extending filopodia. Furthermore, we suggest a role of N-WASP in regulating membrane ruffling downstream of phosphatidylinositol 4,5-bisphosphate and Cdc42.

Role of Cl− currents in rat aortic smooth muscle activation by prostaglandin F2α

The aim of this study was to determine the role of Cl(-) channel activation in prostaglandin F(2 alpha)-stimulated aortic contraction and in membrane depolarization during stimulation with prostaglandin F(2 alpha) in an aortic smooth muscle cell line (A7r5). The Cl(-) channel antagonists 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB), indanyloxyacetic acid-94 (IAA-94) and 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) were found to decrease (P<0.05) the maximum tension generated by rat thoracic aortic segments during stimulation with prostaglandin F(2 alpha) and to shift the concentration-response relationship to the right. In the presence of Nifedipine and Cesium, rat aorta-derived A7r5 smooth muscle cells demonstrated outwardly rectifying voltage-dependent currents that were inhibited by NPPB, IAA-94 and DIDS. Both inward and outward currents were enhanced (P<0.05) following addition of prostaglandin F(2 alpha) (4 micromol/l, final concentration) to the bath solution and this increase was completely inhibited by NPPB. In the absence of Cesium, the addition of prostaglandin F(2 alpha) (4 micromol/l) to the extracellular bath solution either depolarized or hyperpolarized the cell membrane depending on the equilibrium potential for Cl(-) ions. Our results indicate that altered Cl(-) conductance is an important mechanism mediating membrane depolarization and contraction of aortic smooth muscle cells during stimulation with prostaglandin F(2 alpha). Given the significant role that prostaglandin F(2 alpha) and its biologically active isomers, the F(2) isoprostanes, play in the control of vascular tone during hypoxic and oxidative stress in the systemic circulation, alterations in Cl(-) channel function and expression may represent an important mechanism in the pathogenesis of abnormal blood flow regulation in disease states.

Mucosal and systemic immune responses to plasmid protein pgp3 in patients with genital and ocular Chlamydia trachomatis infection

The circulating and cervical B cell responses to Chlamydia trachomatis plasmid protein pgp3 were characterized in children and adults with ocular or genital chlamydial infection using the enzyme-linked immunospot assay (ELISPOT) and ELISA. No pgp3-specific ASCs were detected in healthy controls, but predominantly IgA ASCs were detected in UK adults with uncomplicated cervicitis or urethritis (P = 0.03, 0.019). In patients with extragenital complications or pelvic inflammatory disease a mixed response with more IgG and IgM ASCs was evident, suggesting a breach of mucosal immune compartmentalization with more extensive infection. In women with chlamydial cervicitis, ASCs secreting predominantly IgA, but also IgG, to pgp3 were present in cervix at presentation, with a frequency 30-50 times higher than blood. Cervical ASC numbers, especially IgG, fell markedly six weeks after antibiotic treatment. We detected principally IgA pgp3-specific antibody secreting cells (ASCs) in children resident in a Gambian endemic area, with a trend towards suppression of IgA responses during intense trachomatous inflammation (P = 0.06), as previously reported for other chlamydial antigens, and in keeping with the findings in genital disease. These data provide a rationale for further studies of immune responses to pgp3 in humans and animal models of chlamydia-induced disease, and its potential use in diagnostic assays and protective immunization strategies.

Increased myofibrillar protein phosphatase-1 activity impairs rat aortic smooth muscle activation after hypoxia

We hypothesized that increased myofibrillar type 1 protein phosphatase (PP1) catalytic activity contributes to impaired aortic smooth muscle contraction after hypoxia. Our results show that inhibition of PP1 activity with microcystin-LR (50 nmol/l) or okadaic acid (100 nmol/l) increased phenylephrine- and KCl-induced contraction to a greater extent in aortic rings from rats exposed to hypoxia (10% O(2)) for 48 h than in rings from normoxic animals. PP1 inhibition also restored the level of phosphorylation of the 20-kDa myosin light chain (LC(20)) during maximal phenylephrine-induced contraction to that observed in the normoxic control group. Myofibrillar PP1 activity was greater in aortas from rats exposed to hypoxia than in normoxic rats (P < 0.05). Levels of the protein myosin phosphatase-targeting subunit 1 (MYPT1) that mediates myofibrillar localization of PP1 activity were increased in aortas from hypoxic rats (193 +/- 28% of the normoxic control value, P < 0.05) and in human aortic smooth muscle cells after hypoxic (1% O(2)) incubation (182 +/- 18% of the normoxic control value, P < 0.05). Aortic levels of myosin light chain kinase were similar in normoxic and hypoxic groups. In conclusion, after hypoxia, increased MYPT1 protein and myofibrillar PP1 activity impair aortic vasoreactivity through enhanced dephosphorylation of LC(20).

Modulation of rat pial arteriolar responses to flow by glucose

BACKGROUND

Pial arteriolar responses to flow contribute to regulation of cerebral perfusion and vary according to the transmural pressure to which the vessel is exposed. This study determined the effect of increased glucose concentration on the flow responses of pial arterioles at low and high levels of transmural pressure.

METHODS

Pial arterioles from Sprague-Dawley rats were mounted in a perfusion myograph. In some arterioles, the endothelium was removed by perfusion with air. Diameters were recorded at transmural pressures of 60 and 120 mmHg during superfusion with physiologic saline containing 5 mm D-glucose, 20 mm D-glucose, or 5 mm D-glucose and 15 mm L-glucose. Diameters during superfusion with saline containing 44 mm D-glucose were measured at an intraluminal pressure of 60 mmHg. Flow-diameter relationships (5-30 microl/min) were recorded during perfusion with the same solutions.

RESULTS

Increasing D-glucose concentration caused constriction (P < 0.05) in endothelium-denuded but not in endothelium-intact arterioles. Addition of L-glucose caused constriction in endothelium-intact and -denuded vessels (P < 0.05 for both). At a D-glucose concentration of 5 mm and at low intraluminal pressure, flow elicits endothelium-dependent dilation such that shear stress remains constant. At a D-glucose concentration of 20 or 44 mm, after addition of L-glucose (15 mm), and at high intraluminal pressures, flow elicits constriction and shear stress is unregulated.

CONCLUSIONS

High glucose concentrations elicit increased basal arteriolar smooth muscle tone that is counteracted by release of endothelium-derived relaxing factors. Endothelium-dependent relaxation to flow (shear stress) is inhibited at high glucose concentrations.

Mechanisms of aortic smooth muscle hyporeactivity after prolonged hypoxia in rats

The aim of this study was to determine whether the effects of hypoxia on aortic contractility reflect a decrease in smooth muscle activation [phosphorylation of the 20-kDa myosin regulatory light chain (LC(20))], the capacity for myofibrillar ATP hydrolysis (mATPase activity), or both. Our results indicate that, in endothelium-denuded aortic rings from rats exposed to hypoxia for 48 h (inspired O(2) concentration = 10%), contractions to phenylephrine and potassium chloride (KCl) are impaired compared with rings from normoxic rats. The proportion of phosphorylated to total LC(20) during aortic contraction induced by 10(-5) M phenylephrine was reduced after hypoxia (51.4 +/- 5.4% in normoxic control rats vs. 32.5 +/- 4.7% in hypoxic rats, P < 0.01). Aortic mATPase activity was also decreased (maximum ATPase rate = 29.6 +/- 3.4 and 20.7 +/- 3.7 nmol. min(-1). mg protein(-1) in control and hypoxic rats, respectively, P < 0.05). Neither proliferation nor dedifferentiation of aortic smooth muscle was evident in this model; immunostaining for smooth muscle expression of the proliferating cell nuclear antigen was negative and smooth muscle-specific isoforms of myosin heavy chains, h-caldesmon, and calponin were increased, not decreased, after hypoxic exposure. Decreased aortic reactivity after hypoxia is associated with both impairment of smooth muscle activation and diminished capacity of the actomyosin complex, once activated, to hydrolyze ATP. These changes cannot be attributed to smooth muscle dedifferentiation or to reduced contractile protein expression.

Capillary electrophoresis analysis of nitrite and nitrate in sub-microliter quantities of airway surface liquid

We developed a simple capillary electrophoresis (CE) method to measure nitrite and nitrate concentrations in submicroliter samples of rat airway surface liquid (ASL), a thin (10-30 microm) layer of liquid covering the epithelial cells lining the airways of the lung. The composition of ASL has been poorly defined, in large part because of the small sample volume (approximately 1-3 microl per cm2 of epithelium) and difficulty of harvesting ASL. We have used capillary tubes for ASL sample collection, with microanalysis by CE using a 50 mM phosphate buffer (pH 3), with 0.5 mM spermine as a dynamic flow modifier, and direct UV detection at 214 nm. The limit of detections (LODs), under conditions used, for ASL analysis were 10 microM for nitrate and 30 microM for nitrite (SIN= 3). Nitrate and nitrite were also measured in rat plasma. The concentration of nitrate was 102+/-12 microM in rat ASL and 70+/-1.0 microM in rat plasma, whereas nitrite was 83+/-28 microM in rat ASL and below the LOD in rat plasma. After instilling lipopolysaccharide intratracheally to induce increased NO production, the nitrate concentration in ASL increased to 387+/-16 microM, and to 377+/-88 microM in plasma. The concentration of nitrite increased to 103+/-7.0 microM for ASL and 138+/-17 microM for plasma.

Inhibition of prostanoid-mediated contraction to endothelin-1 after hypoxia in rat aorta

The role of the thromboxane A(2)/prostaglandin H(2) receptor in endothelin-1 contraction was investigated in aortic rings from rats exposed to normoxia (21% O(2)) or hypoxia (10% O(2)) for 12 h. Indomethacin (10 microM) and SQ 29,548 (0.1 microM, thromboxane A(2)/prostaglandin H(2) receptor antagonist) reduced maximum tension and increased EC(50) in endothelium-intact and -denuded rings from normoxic animals. Neither inhibitor had any effect on rings from hypoxic rats. Thromboxane A(2) and/or prostaglandin H(2) contribute to the response to endothelin-1 in aortas from normoxic rats but not from rats exposed to hypoxia. Loss of prostanoid-enhancement of endothelin-1 contraction contributes to impair vascular reactivity after hypoxia.

The association between deaths from myocardial infarction and household size in England and Wales

BACKGROUND

Chronic infection with organisms such as Chlamydia pneumoniae is thought to cause coronary heart disease. We investigated whether myocardial infarction deaths are associated with large household size and overcrowding, as these are factors that may facilitate the transmission of infection.

DESIGN

Ecological study of England and Wales.

METHODS

Population data were obtained from the 1991 National Census and mortality data were obtained from the Office of National Statistics. For various categories of household size and overcrowding, we calculated mortality rates standardized for age, sex and deprivation.

RESULTS

Standardized mortality rates for acute respiratory infections were associated with household size and overcrowding, while rates for myocardial infarction and gastric carcinoma, both putatively associated with chronic infection, were associated with household size. For combined deaths from causes other than myocardial infarction, there were small associations with household size and overcrowding. In the case of myocardial infarction, the association was generally strongest in the age group 45-54.9 years. For this age group, the standardized mortality rate ratio for the category of largest size household was 2.7 in the year 1991.

CONCLUSIONS

There is an association between household size and mortality from myocardial infarction. Chronic infection is a possible cause.

Flow modulation of pressure-sensitive tone in rat pial arterioles: role of the endothelium

BACKGROUND

Cerebral arteriolar tone is modulated in response to changes in transmural pressure and luminal flow. The effect of flow on the relation between pressure and diameter has not been fully evaluated in these vessels. This study was conducted to investigate this interaction and to determine the role of the endothelium in mediating it.

METHODS

Rat pial arterioles from the territory of the posterior cerebral artery were mounted in a perfusion myograph. In some arterioles, the endothelium was removed by air perfusion. Diameters were recorded at pressures from 20 to 200 mmHg in the presence and absence of flow (10 microl/min). The response to flow (0-30 microl/min) was recorded at 60 and 120 mmHg.

RESULTS

In the absence of flow, endothelium-intact arterioles demonstrated tone at distending pressures between 40 and 140 mmHg. In the presence of flow, tone did not develop until pressure exceeded 100 mmHg, and the vessels remained active at pressures up to 200 mmHg. Endothelium-denuded arterioles developed tone at the same pressure when perfused as when unperfused, but perfused vessels were able to maintain active tone at higher pressures. At 60 mmHg, flow caused dilation if the endothelium was intact and constriction if it had been removed. At 120 mmHg, flow caused constriction. Endothelium-dependent flow-relaxation was inhibited by N(G)-nitro-L-arginine methyl ester (10(-5) M) and abolished by indomethacin (10(-5) M).

CONCLUSION

Flow inhibits the development of pial arteriolar tone at low intraluminal pressures through endothelium-dependent mechanisms. Conversely, perfusion extends the upper limit of the myogenically regulated pressure range through endothelium-independent activation of arteriolar smooth muscle contraction.

Ballistic characterization of the Remington Premier Copper Solid sabot shotgun slug

We evaluated the impact and penetration characteristics of the Remington Copper Solid sabot shotgun slug with standardized ballistic tests and used this information to predict tissue wounding patterns. This unique ammunition, first distributed in 1993, is composed of a solid copper, hollow-point slug with longitudinal slots cut into the nose. The slug is fitted into a hard plastic sabot with 8 finger-like projections and loaded into a shotgun shell with two plastic wads separating it from the underlying gunpowder charge. The ammunition was fired through a 12-gage shotgun using a rifled barrel, a smooth-bore barrel with rifled choke, and a smooth-bore barrel with a smooth modified choke into targets consisting of poster board and 10% ballistic gelatin at a variety of distances. The copper slug and plastic sabot created single 8-fingered asterisk-shaped defects in the poster board when fired at distances of less than 7 to 9 ft (approximately 2 to 3 m). All three barrel types performed similarly. At greater distances, the sabot impacted the targets separately from the slugs and created variably shaped defects that reflected base-first, nose-first, and side-first impacts. Increasing muzzle-to-target distances generally increased the impact distances between the slug and sabot. There was no predictable relationship between the sabot and slug impact points for any of the three barrel types. With each barrel tested, the wads created separate defects from the slug at distances greater than 5 ft (1.5 m). The distances between the slug and the wad impact points increased with increasing muzzle-to-target distances up to 40 ft (12 m), after which the wads generally no longer struck the targets. The slug created atypical defects at distances between 7 and 150 ft (approximately 2 to 45 m), probably due to yawing or tumbling. When the slug impacted the gelatin block in a nose-first orientation, the slotted nose portion tended to fragment and radially deposit pieces in the gelatin that were visible on radiographs. When the slug struck the gelatin target in a side-first orientation, it passed through the gelatin intact. The slug, sabot, and wads of this unique projectile separate and create independent impact points in a stereotypical manner independent of barrel type. This pattern of separation allows estimates to be made of ranges of fire. Wounds created in human tissues by this ammunition would likely have similar asterisk-shaped configurations, and nose fragments may be deposited in tissues and seen radiographically. Rectangular wounds created by the tumbling or yawing slug might be mistaken for intermediate target wounds.

Incomplete shored exit wounds: a report of three cases

Typical and atypical exit wounds are well described in the forensic literature. Included in the descriptions of atypical exit wounds are perforating, "shored" exit wounds, in which the perforation of the skin is associated with an abrasion, whether or not the bullet fully exits the body. The authors describe an atypical, incomplete, shored exit wound in which the skin was abraded by supporting material at the site the bullet was recovered, but there was no associated perforation of the skin. Recognition of this injury pattern can be important in reconstruction of the crime scene in relation to the victim at the time of the shooting.

Chlamydia pneumoniae infection and mortality from ischaemic heart disease: large prospective study

OBJECTIVE

To determine whether there is an independent association between infection with Chlamydia pneumoniae and ischaemic heart disease.

DESIGN

Prospective study using a nested case-control design.

SETTING

Medical centre in London run by BUPA, a private medical organisation.

PARTICIPANTS

21 520 professional men aged 35-64 who attended for a medical examination in London between 1975 and 1982.

MAIN OUTCOME MEASURE

Death from ischaemic heart disease.

RESULTS

The distributions of concentrations of IgG and IgA antibodies to C pneumoniae were similar in the 647 men who subsequently died of ischaemic heart disease and in 1294 age matched controls who did not. There was no material association with heart disease irrespective of the cut-off point chosen to define seropositivity. At a cut-off point that defines 15% of controls as positive, for example, the odds ratios were 1.26 (95% confidence interval 0.95 to 1.68) for IgG and 1.09 (0.82 to 1.43) for IgA.

CONCLUSIONS

No material association was found between infection with C pneumoniae and ischaemic heart disease. The size and prospective design of the study and the socioeconomic homogeneity of the cohort minimise both random and systematic error.

Downregulation of endothelial nitric oxide synthase in rat aorta after prolonged hypoxia in vivo

The goal of this study was to determine whether hypoxia alters expression of endothelial nitric oxide synthase (eNOS) in the systemic circulation. Rats breathed either air or 10% oxygen for 12 hours, 48 hours, or 7 days. Thoracic aortas were excised and either mounted in organ bath myographs or frozen in liquid nitrogen for later extraction of protein and RNA. eNOS protein (Western blotting) was decreased (20% of normoxic control) after 12 hours, 48 hours, and 7 days of hypoxia. eNOS mRNA (ribonuclease protection assay) was similarly reduced. Acetylcholine (10(-4) mol/L) reversed phenylephrine (10(-5) mol/L) preconstriction by 53.3+/-5.6% in aortic rings from normoxic rats and 26.1+/-4.8% in rings from rats exposed to hypoxia for 48 hours (P<0.05), with comparable impairment of relaxation by the calcium ionophore A23187 (10(-5) mol/L). Responses to diethylamine nitric oxide and 8-bromo-cGMP were unaffected. Aortic cGMP levels after incubation with acetylcholine (10(-6) mol/L) averaged 14.0+/-1.8 fmol/mg in rings from normoxic rats compared with 8.7+/-1.0 fmol/mg in rings from hypoxic rats (P<0. 05). Similarly, nitrate concentration (by capillary electrophoresis) in the media in which the rings were incubated was reduced in the hypoxic group (5.6+/-0.23 micromol/L for hypoxic rats and 7.8+/-0.7 micromol/L for normoxic rats). Impaired endothelial NO release may handicap the vascular responses that defend vital organ function during hypoxia.

Pulmonary insulin administration using the AERx system: physiological and physicochemical factors influencing insulin effectiveness in healthy fasting subjects

BACKGROUND

Orally inhaled insulin may provide a convenient and effective therapy for prandial glucose control in patients with diabetes. This study evaluated the influence of formulation pH and concentration and different respiratory maneuvers on pharmacokinetic and pharmacodynamic properties of inhaled insulin.

METHODS

Three, open-label crossover studies in a total of 23 healthy subjects were conducted in which the safety, pharmacokinetics, and pharmacodynamics of insulin inhalation were compared to subcutaneous (SC) injection into the abdomen of commercially available regular insulin. A novel, aerosol generating system (AERx Diabetes Management System, Aradigm Corporation, Hayward, CA) was used to deliver aqueous insulin bolus aerosols to the lower respiratory tract from formulations at pH 3.5 or 7.4 and concentrations of U250 (250 U/mL) or U500 (500 U/mL).

RESULTS

Time to maximum insulin concentration in serum (Tmax) after SC dosing occurred approximately 50-60 minutes with the time to minimum plasma glucose concentration (i.e., maximum hypoglycemic effect), (TGmin), occurring later, at around 100-120 minutes. In contrast, pulmonary delivery led to a significantly earlier Tmax (7-20 minutes) and TGmin (60-70 minutes), parameters that were shown to be largely unaffected by changing the pH or concentration of the insulin. However, investigation of changes in inhaled volume (achieved by different programming of the AERx system) for administration of the same sized aerosol bolus revealed significant effects. Significantly slower absorption and time to peak hypoglycemic activity occurred when aerosol delivery of insulin occurred during a shallow (approximately 40% vital capacity) as opposed to a deep (approximately 80% vital capacity) inspiration. In addition, it was shown that serum concentration of insulin increased immediately after a series of forced expiraratory maneuvers 30 minutes after inhaled delivery.

CONCLUSIONS

Pulmonary delivery of aqueous bolus aerosols of insulin in healthy subjects resulted in rapid absorption with an associated hypoglycemic effect quicker than is achieved after subcutaneous dosing of regular insulin. Inhaled insulin pharmacokinetics and pharmacodynamics were independent of formulation variables (pH, concentration) but affected by certain respiratory maneuvers.

'Speaking in tongues'. Paradoxical fixation on a non-native language following anaesthesia

An intriguing case of transient language disturbance following anaesthesia is described which may throw some light on the way languages are stored in the brain. A review of the existing literature and its relevance to this unique case is discussed.

Hypothermia: a natural cause of death

Deaths due to hypothermia are usually accidental and are the result of exposure to extreme environmental temperatures. Often these individuals are intoxicated, elderly, or exposed to severe cold temperatures. We report the case of a blind, nonambulatory, elderly man who was found alive in his home in an unresponsive state. Core body temperature at hospital was 24 degrees C (75 degrees F). At autopsy, punctate hemorrhages were present in the stomach mucosa. A 4- x 7-cm pituitary adenoma extended from a dilated sella turcica, obliterated the optic chiasm, and compressed the base of the brain in the region of the hypothalamus. Compression in this region of the brain would disrupt the temperature regulatory function of the hypothalamus and create an individual who would be susceptible to minor fluctuations in ambient temperature. The manner of death was designated as natural. This is an unusual presentation of a pituitary adenoma in the current era of advanced imaging techniques in which microadenomas are often detected and treated.

Circulating Chlamydia pneumoniae DNA as a predictor of coronary artery disease

OBJECTIVE

To determine whether current vascular Chlamydia pneumoniae (CPn) infection as diagnosed by circulating CPn DNA is more common in subjects with coronary artery disease (CAD).

BACKGROUND

Serological, pathological and animal studies have associated CPn with CAD and preliminary trials suggest antibiotics may prevent adverse coronary events. C. pneumoniae is thought to disseminate systemically within macrophages. We therefore detected CPn DNA in blood to determine whether its presence was a predictor of CAD.

METHODS

One thousand, two hundred and five subjects attending for diagnostic and interventional coronary arteriography were recruited. The mononuclear cell layer and platelets were separated from collected blood and the polymerase chain reaction (PCR) was used to detect CPn DNA.

RESULTS

Circulating CPn DNA was found in 8.8% of 669 men with CAD compared with 2.9% of 135 men with normal coronary arteries (odds ratio [OR] 3.2, 95% confidence interval [CI] 1.1-8.9). In men with CAD, those with CPn DNA had higher mean platelet counts than those without CPn DNA. Monocyte counts and indirect fibrinogen levels were also raised but not significantly so. By contrast, no association of circulating CPn DNA and CAD was seen in women.

CONCLUSIONS

Circulating CPn DNA is a predictor of CAD in men. Unlike serology, it is a specific indicator of current infection and is a means of identifying subjects who may potentially benefit from antichlamydial therapy.

Chlamydial urethral infection in male students in Chiang Mai: a screening test of urine deposits by enzyme immunoassay (EIA)

Adolescent males are considered to be an important genital chlamydial reservoir. However, there has been little information on urethral chlamydial infection in Thai adolescent males. About one fourth of males who are genital chlamydial reservoirs are asymptomatic. An appropriate means of defining the extent of chlamydial infection in adolescent males would be a non-invasive screening survey, instead of the conventional method of a deep swab cell culture, which is painful. The objectives of this study were to estimate the prevalence and to determine what factors should indicate the use of a screening test for urethral chlamydial infection in adolescent males residing in Chiang Mai. Chlamydial urethritis was detected by examining urine deposits for chlamydial antigen by enzyme immunoassay (EIA).

Relation between direct detection of Chlamydia pneumoniae DNA in human coronary arteries at postmortem examination and histological severity (Stary grading) of associated atherosclerotic plaque

BACKGROUND

Numerous studies have suggested a link between Chlamydia pneumoniae infection, atherosclerosis, and coronary artery disease. However, it is still unclear whether C pneumoniae plays a causal role in the pathogenesis of these conditions. Accordingly, we have performed a systematic dissection of the 3 coronary arteries on 33 postmortem subjects and studied the relationship in individual artery segments between the presence of C pneumoniae DNA and the severity of associated atherosclerosis.

METHODS AND RESULTS

The prevalence of C pneumoniae DNA in arterial segments was determined by polymerase chain reaction (PCR) after controlling for the presence of PCR inhibitors. Atherosclerosis in each arterial segment was graded histologically with the Stary classification. C pneumoniae was detected by PCR in 78.8% of subjects, but there was no association between the presence of this DNA and cause of death or grade of atherosclerosis. When paired mild and severe atherosclerotic lesions within subjects were compared, mild lesions were as likely to be positive for C pneumoniae as severe lesions.

CONCLUSIONS

This study demonstrates that C pneumoniae can frequently be detected in atheromatous plaques in coronary arteries. However, its distribution did not correlate with severity or extent of disease.

Multifactorial analysis of firearm wounds to the head with attention to anatomic location

Firearm wounds to the head are often fatal and are routinely encountered in the practice of forensic pathology in the United States. Often, the anatomic site of the entrance wound is used to support or refute the manner of death indicated by the scene investigation and/or circumstances of the case. The present retrospective study of 120 fatalities resulting from 140 firearm wounds to the head correlates the anatomic region of the entrance wound and range of fire with the manner of death. Other demographic data analyzed include age, race, and gender of the decedents, as well as evidence of drug and/or ethanol use. It is hoped that this study will provide concrete data to support the largely anecdotal associations between the specific site of entry of firearm injuries to the head and the manner of death.

The Brigham integrated computing system (BICS): advanced clinical systems in an academic hospital environment

The Brigham integrated computing system (BICS) provides nearly all clinical, administrative, and financial computing services to Brigham and Women's Hospital, an academic tertiary-care hospital in Boston. The BICS clinical information system includes a very wide range of data and applications, including results review, longitudinal medical records, provider order entry, critical pathway management, operating-room dynamic scheduling, critical-event detection and altering, dynamic coverage lists, automated inpatient summaries, and an online reference library. BICS design emphasizes direct physician interaction and extensive clinical decision support. Impact studies have demonstrated significant value of the system in preventing adverse events and in saving costs, particularly for medications.

Dilation of rat diaphragmatic arterioles by flow and hypoxia: roles of nitric oxide and prostaglandins

The in vitro responses to ACh, flow, and hypoxia were studied in arterioles isolated from the diaphragms of rats. The endothelium was removed in some vessels by low-pressure air perfusion. In endothelium-intact arterioles, pressurized to 70 mmHg in the absence of luminal flow, ACh (10(-5) M) elicited dilation (from 103 +/- 10 to 156 +/- 13 microm). The response to ACh was eliminated by endothelial ablation and by the nitric oxide synthase antagonists NG-nitro-L-arginine (L-NNA; 10(-5) M) and NG-nitro-L-arginine methyl ester (L-NAME, 10(-5) M) but not by indomethacin (10(-5) M). Increases in luminal flow (5-35 microl/min in 5 microl/min steps) at constant distending pressure (70 mmHg) elicited dilation (from 98 +/- 8 to 159 +/- 12 microm) in endothelium-intact arterioles. The response to flow was partially inhibited by L-NNA, L-NAME, and indomethacin and eliminated by endothelial ablation and by concurrent treatment with L-NAME and indomethacin. The response to hypoxia was determined by reducing the periarteriolar PO2 from 100 to 25-30 Torr by changing the composition of the gas used to bubble the superfusing solution. Hypoxia elicited dilation (from 110 +/- 9 to 165 +/- 12 microm) in endothelium-intact arterioles but not in arterioles from which the endothelium had been removed. Hypoxic vasodilation was eliminated by treatment with indomethacin and was not affected by L-NAME or L-NNA. In rat diaphragmatic arterioles, the response to ACh is dependent on endothelial nitric oxide release, whereas the response to hypoxia is mediated by endothelium-derived prostaglandins. Flow-dilation requires that both nitric oxide and cyclooxygenase pathways be intact.