SOX9 directly regulates the type-II collagen gene.

Mutations in human SOX9 are associated with campomelic dysplasia (CD), characterised by skeletal malformation and XY sex reversal. During chondrogenesis in the mouse, Sox9 is co-expressed with Col2a1, the gene encoding type-II collagen, the major cartilage matrix protein. Col2a1 is therefore a candidate regulatory target of SOX9. Regulatory sequences required for chondrocyte-specific expression of the type-II collagen gene have been localized to conserved sequences in the first intron in rats, mice and humans. We show here that SOX9 protein binds specifically to sequences in the first intron of human COL2A1. Mutation of these sequences abolishes SOX9 binding and chondrocyte-specific expression of a COL2A1-driven reporter gene (COL2A1-lacZ) in transgenic mice. Furthermore, ectopic expression of Sox9 trans-activates both a COL2A1-driven reporter gene and the endogenous Col2a1 gene in transgenic mice. These results demonstrate that COL2A1 expression is directly regulated by SOX9 protein in vivo and implicate abnormal regulation of COL2A1 during, chondrogenesis as a cause of the skeletal abnormalities associated with campomelic dysplasia.

Online monitoring of volatile organic compounds emitted from human bronchial epithelial cells as markers for oxidative stress.

Particulate air pollution is associated with adverse respiratory effects and is a major factor for premature deaths.In-vitroassays are commonly used for investigating the direct cytotoxicity and inflammatory impacts due to particulate matter (PM) exposure. However, biological tests are often labor-intensive, destructive and limited to endpoints measured offline at single time points, making it impossible to observe the progression of cell response upon exposure. Here we explored the potential of a high-resolution proton transfer reaction mass spectrometer (PTR-MS) to detect the volatile organic compounds (VOCs) emitted by human bronchial epithelial cells (BEAS-2B) upon exposure to PM. Cells were exposed to single components (1,4-naphthoquinone and Cu(II)) known to induce oxidative stress. We also tested filter extracts of aerosols generated in a smog chamber, including fresh and aged wood burning emissions, as well asα-pinene secondary organic aerosol (SOA). We found that 1,4-naphthoquinone was rapidly internalized by the cells. Exposing cells to each of these samples induced the emission of VOCs, which we tentatively assigned to acetonitrile, benzaldehyde and dimethylbenzaldehyde, respectively. Emission rates upon exposure to fresh and aged OA fromα-pinene oxidation and from biomass burning significantly exceeded those observed after exposure to similar doses of Cu(II), a proxy for transition metals with high oxidative potential. Emission rates of biomarkers from cell exposure toα-pinene SOA exhibited a statistically significant, but weak dose dependence. The emission rates of benzaldehyde scaled with cell death, estimated by measuring the apical release of cytosolic lactate dehydrogenase. Particle mass doses delivered to the BEAS-2B cells match those deposited in the human tracheobronchial tract after several hours of inhalation at elevated ambient air pollution. The results presented here show that our method has the potential to determine biomarkers of PM induced pulmonary damage in toxicological and epidemiological research on air pollution.

On the fate of oxygenated organic molecules in atmospheric aerosol particles.

Highly oxygenated organic molecules (HOMs) are formed from the oxidation of biogenic and anthropogenic gases and affect Earth's climate and air quality by their key role in particle formation and growth. While the formation of these molecules in the gas phase has been extensively studied, the complexity of organic aerosol (OA) and lack of suitable measurement techniques have hindered the investigation of their fate post-condensation, although further reactions have been proposed. We report here novel real-time measurements of these species in the particle phase, achieved using our recently developed extractive electrospray ionization time-of-flight mass spectrometer (EESI-TOF). Our results reveal that condensed-phase reactions rapidly alter OA composition and the contribution of HOMs to the particle mass. In consequence, the atmospheric fate of HOMs cannot be described solely in terms of volatility, but particle-phase reactions must be considered to describe HOM effects on the overall particle life cycle and global carbon budget.

Effects of intermittent transdermal nitroglycerin on occurrence of ischemia after patch removal: results of the second transdermal intermittent dosing evaluation study (TIDES-II).

OBJECTIVES: We sought to evaluate the effects of intermittent transdermal nitroglycerin (TD-NTG) on the occurrence of ischemia during patch-off hours in patients with stable angina pectoris receiving a beta-adrenergic blocking agent or calcium antagonist, or both. BACKGROUND: The current recommendations for the use of intermittent TD-NTG may be associated with the occurrence of rebound ischemia. METHODS: This was a multicenter, randomized, double-blind, placebo-controlled, crossover trial with three study periods. Tolerability to TD-NTG was assessed in Period I. Seventy-two patients were assigned to receive either double-blind transdermal placebo or maximally tolerated TD-NTG for 2 weeks (Period II) and were then crossed over to the alternative treatment for another 2 weeks (Period III). The patients were instructed to apply medication daily at 8 AM, to remove it at 10 PM and to note symptoms and sublingual nitroglycerin (SL-NTG) use in a diary. The occurrence of ischemia was assessed from patient-perceived angina, symptom-limited exercise treadmill test (ETT) and 48-h ambulatory electrocardiographic (AECG) monitoring. RESULTS: Transdermal NTG (0.2 to 0.4 mg/h) significantly reduced the magnitude of ST segment depression at angina onset during ETT compared with placebo. Total angina frequency was not significantly different between TD-NTG (mean [+/-SD] 3.2 +/- 4.2) and placebo (3.3 +/- 5.2). During patch-off hours, angina frequency increased with TD-NTG (1.1 +/- 2.1) compared with placebo (0.7 +/- 1.6) (p = 0.03). Similar trends for an increase in ischemia after TD-NTG were also observed from AECG analyses. Specifically, ischemia frequency tended to be lower during patch-off hours for placebo than with TD-NTG (0.05 +/- 0.09 vs. 0.08 +/- 0.20 episodes/h, respectively, p = 0.08), even though frequency of ischemia tended to be higher during patch-on hours for placebo than with TD-NTG (0.12 +/- 0.19 vs. 0.07 +/- 0.15 episodes/h, respectively, p = 0.11). During placebo, ischemia frequency decreased 58% (patch-on to patch-off, p = 0.01) compared with a 14% increase with TD-NTG. These changes attenuate the usual circadian variation in ischemia. CONCLUSIONS: An increase in ischemia frequency during patch-off hours after use of intermittent TD-NTG was perceived by patients, and this subjective finding was supported by a corresponding trend for AECG ischemia to increase during these same hours.

Transmission of HIV from infected health-care workers to patients.

The five patients of the Florida dentist remain the only cases in which HIV transmission from an infected health-care worker to patients during invasive procedures had been reported by 1991. In this instance, neither the precise mode of HIV transmission to these patients nor the reasons for transmission to multiple patients are known. However, even in the HBV outbreaks that have been investigated, the causes of increased transmissibility by the health-care worker are not always clear, and may include variations in the procedures performed, surgical or dental techniques used, infection control precautions taken, titer of the infecting agent, and the susceptibility of the patients to infection. The investigation of the Florida dentist's practice is ongoing. Additional studies of the patients of other infected health-care workers are being conducted in an attempt to answer some of the remaining questions about the risk and circumstances which allow the transmission of HIV from infected health-care workers to patients.

Human immunodeficiency virus transmission in health care settings: risk and risk reduction.

Surveillance data and case reports document that health care workers (HCWs) risk occupationally acquired human immunodeficiency virus (HIV) infection. Transmission of HIV to patients of an infected HCW during invasive procedures has also been reported. The risk to a susceptible HCW depends on the prevalence of HIV infection among patients, the nature and frequency of occupational blood exposures, and the risk of transmission per exposure. Blood exposure rates vary by occupation, by procedure, and by compliance with preventive measures. Future efforts to protect both HCWs and patients must include improved surveillance, risk assessment, study of postexposure prophylaxis, and an emphasis on exposure prevention, including development of safer medical devices, work practices, and personal protective equipment that are acceptable to HCWs and do not adversely affect patient care.

Occupational risk of human immunodeficiency virus infection in healthcare workers: an overview.

Healthcare workers (HCWs) are at risk for occupational acquisition of human immunodeficiency virus (HIV) infection, primarily due to percutaneous exposure to infected blood. As of June 1996, 51 documented cases and 108 possible cases of occupationally acquired HIV infection in HCWs in the United States had been reported to the Centers for Disease Control and Prevention. The frequency of blood exposure among HCWs varies according to occupation, procedures performed, and use of preventive measures. Based on limited data, it has been estimated that approximately 500,000 percutaneous blood exposures may occur annually among hospital-based HCWs in the United States. Of these, approximately 5,000 may involve exposures to blood that is known to be HIV infected. The average risk of HIV transmission after percutaneous exposure to HIV-infected blood is approximately 0.3%; however, the risk is believed to be higher for exposures involving an increased volume of blood and/or high viral load.

Prevalence and incidence of human immunodeficiency virus among patients undergoing long-term hemodialysis. The Cooperative Dialysis Study Group.

PURPOSE: The purpose of this voluntary multicenter study was to estimate the prevalence and incidence of human immunodeficiency virus (HIV) infection and the risk of nosocomial transmission of HIV in hemodialysis patients in the United States. PATIENTS AND METHODS: In June 1986, we began collecting epidemiologic data, risk factor information, and serum for HIV antibody testing from long-term hemodialysis patients on entry into the study and 1 year later. RESULTS: Initial data and specimens were collected from 1,324 patients in 28 dialysis centers in 12 states. On entry, 26 were positive or equivocal by enzyme immunoassay; 13 of these were positive by Western blot assay (overall seroprevalence 0.98%). Seroprevalence was higher for patients tested in eight centers located in areas from which a high cumulative incidence of acquired immunodeficiency syndrome has been reported (500 or more cases per 1 million persons) than for patients in other areas (10 of 387 [2.6%] versus three of 937 [0.3%]; p = 0.00048). According to their dialysis records, all 13 of the Western blot-positive patients had received transfusions. Seropositive patients were not more likely to have received a transfusion than seronegative patients (13 of 13 versus 1,038 of 1,311; p = 0.08). The confidential risk factor questionnaire was completed by 1,206 (91%) patients including nine of 13 (69%) of the seropositive patients. A question on sharing needles for injection of drugs was answered by 1,158 patients; seropositive patients were more likely to report they had shared needles than seronegative patients (five of nine versus 17 of 1,149; p = 0.0000002). After 1 year of follow-up, data were collected from 667 patients, including 254 negative patients who underwent dialysis at centers with seropositive patients. None of the previously seronegative patients seroconverted, yielding an incidence rate of 0% (upper limit of 95% confidence interval = 0.45%). No case of possible nosocomial transmission was identified. CONCLUSION: These results suggest that use of long-standing infection control precautions is effective minimizing the risk of transmission of HIV in hemodialysis settings.

Risk of human immunodeficiency virus infection among emergency department workers.

PURPOSE: To estimate (1) the prevalence of human immunodeficiency virus (HIV) infection in emergency department (ED) patients, (2) the frequency of blood contact (BC) in ED workers (EDWs), (3) the efficacy of gloves in preventing BC, and (4) the risk of HIV infection in EDWs due to BC. PATIENTS AND METHODS: We conducted an 8-month study in three pairs of inner-city and suburban hospital EDs in high AIDS incidence areas in the United States. At each hospital, blood specimens from approximately 3,400 ED patients were tested for HIV antibody. Observers monitored BC and glove use by EDWs. RESULTS: HIV seroprevalence was 4.1 to 8.9 per 100 patient visits in the 3 inner-city EDs, 6.1 in 1 suburban ED, and 0.2 and 0.7 in the other 2 suburban EDs. The HIV infection status of 69% of the infected patients was unknown to ED staff. Seroprevalence rates were highest among patients aged 15 to 44 years, males, blacks and Hispanics, and patients with pneumonia. BC was observed in 379 (3.9%) of 9,793 procedures; 362 (95%) of the BCs were on skin, 11 (3%) were on mucous membranes, and 6 (2%) were percutaneous. Overall procedure-adjusted skin BC rates were 11.2 BCs per 100 procedures for ungloved workers and 1.3 for gloved EDWs (relative risk = 8.8; 95% confidence interval = 7.3 to 10.3). In the high HIV seroprevalence EDs studied, 1 in every 40 full-time ED physicians or nurses can expect an HIV-positive percutaneous BC annually; in the low HIV seroprevalence EDs studied, 1 in every 575. The annual occupational risk of HIV infection for an individual ED physician or nurse from performing procedures observed in this study is estimated as 0.008% to 0.026% (1 in 13,100 to 1 in 3,800) in a high HIV seroprevalence area and 0.0005% to 0.002% (1 in 187,000 to 1 in 55,000) in a low HIV seroprevalence area. CONCLUSIONS: In both inner-city and suburban EDs, patient HIV seroprevalence varies with patient demographics and clinical presentation; the infection status of most HIV-positive patients is unknown to ED staff. The risk to an EDW of occupationally acquiring HIV infection varies by ED location and the nature and frequency of BC; this risk can be reduced by adherence to universal precautions.

Skin and mucous membrane contacts with blood during surgical procedures: risk and prevention.

OBJECTIVE: To study the epidemiology and preventability of blood contact with skin and mucous membranes during surgical procedures. DESIGN: Observers present at 1,382 surgical procedures recorded information about the procedure, the personnel present, and the contacts that occurred. SETTING: Four US teaching hospitals during 1990. PARTICIPANTS: Operating room personnel in five surgical specialties. MAIN OUTCOME MEASURES: Numbers and circumstances of contact between the patient's blood (or other infective fluids) and surgical personnel's mucous membranes (mucous membrane contacts) or skin (skin contacts, excluding percutaneous injuries). RESULTS: A total of 1,069 skin (including 620 hand, 258 body, and 172 face) and 32 mucous membrane (all affecting eyes) contacts were observed. Surgeons sustained most contacts (19% had > or = 1 skin contact and 0.5% had > or = 1 mucous membrane-eye contact). Hand contacts were 72% lower among surgeons who double gloved, and face contacts were prevented reliably by face shields. Mucous membrane-eye contacts were significantly less frequent in surgeons wearing eyeglasses and were absent in surgeons wearing goggles or face shields. Among surgeons, risk factors for skin contact depended on the area of contact: hand contacts were associated most closely with procedure duration (adjusted odds ratio [OR], 9.4; > or = 4 versus < 1 hour); body contacts (arms, legs, and torso) with estimated blood losses (adjusted OR, 8.4; > or = 1,000 versus < 100 mL); and face contacts, with orthopedic service (adjusted OR, 7.5 compared with general surgery). CONCLUSION: Skin and mucous membrane contacts are preventable by appropriate barrier precautions, yet occur commonly during surgery. Surgeons who perform procedures similar to those included in this study should strongly consider double gloving, changing gloves routinely during surgery, or both.

Risk of occupational infection with blood-borne pathogens in operating and delivery room settings.

Surveillance data and case reports substantiate that health care workers are at risk for occupationally acquired infection with blood-borne pathogens. The risk of transmission of blood-borne pathogens to a health care worker depends on the prevalence of blood-borne pathogen infection among patients, the likelihood of transmission of infection per blood contact, and the nature and frequency of occupational blood contacts. In surgical and obstetrical settings, blood contact varies with occupation, specialty, procedures performed, and precautions used. Many contacts appear to be preventable by changes in technique or instrument design and by use of protective barriers. Studies are needed to assess the impact of such interventions.

Bloodborne pathogen transmission in health care workers. Risks and prevention strategies.

Occupational transmission of hepatitis B virus (HBV), hepatitis C virus, and HIV has been documented. The risk for occupationally transmitted infection varies for these three viruses. Despite effective pre- and postexposure prophylaxis for HBV and recent recommendations for postexposure chemoprophylaxis after an HIV exposure, the best approach to prevent occupational bloodborne infection is the prevention of blood exposures. Epidemiologic data of percutaneous injuries and other blood contacts have provided the basis for prevention strategies. These strategies include the development of improved engineering controls, work practices, and personal protective equipment.

HIV transmission in the health-care setting. Risks to health-care workers and patients.

Transmission of HIV from patients to health care workers (HCWs) has been documented. Data from surveillance projects and epidemiologic studies provide the basis for evaluation of the risk of HIV transmission in health care settings. Strategies to further reduce this risk should focus on prevention of blood contacts between HCWs and patients through the use of universal precautions and implementation of new or modified medical devices, techniques, and personal protective equipment.

Markers for progression of coronary disease.

Endothelial cells play numerous physiologic roles including regulation of vascular tone, regulation of hemostasis and fibrinolysis, regulation of inflammatory processes, and maintenance of a permeability barrier to provide for exchange and active transport of substances into the artery wall. Pathophysiologic stimuli can result in localized alterations in endothelial activity. These changes include increased permeability to plasma lipoproteins, imbalances in local thrombogenic substances causing a prothrombotic state, and release of vasoactive compounds resulting in vasoconstriction. Loss of endothelium-dependent vasodilatation is thought to be an early physiologic event in the development of arteriosclerosis, occurring before morphologic changes in the endothelium can be detected. Much of the effects of healthy endothelium appear to be produced by nitric oxide. Decreased bioavailability of nitric oxide results in endothelial dysfunction, which is the first step in the atherosclerotic process. Risk factor modification and pharmacologic interventions that can reverse endothelial dysfunction have the potential to decrease cardiovascular events in patients at risk.

Analysis of number needed to treat and cost of platelet glycoprotein IIb/IIIa inhibitors in percutaneous coronary interventions and acute coronary syndromes.

This retrospective review and analysis of pivotal clinical trials compared acquisition costs and outcomes of platelet glycoprotein IIb/IIIa inhibitors. Absolute reduction in the number of deaths and nonfatal myocardial infarctions at 30 days, number of patients that need to be treated to prevent one event, and drug costs expended to prevent one event were assessed. In patients undergoing percutaneous coronary intervention (PCI), abciximab is the better value, especially in high-risk patients. In those with unstable angina and non-Q wave myocardial infarction, costs of eptifibatide and tirofiban were not significantly different, but the cost of tirofiban was more variable. These agents have the potential to be cost-effective if administered to populations at high risk for adverse outcomes of acute coronary syndromes or PCI. Prospective methods to identify these high-risk patients are being developed.

Myocardial infarction in women: a critical appraisal of gender differences in outcomes.

In every year since 1984, cardiovascular disease has claimed the lives of more women than men. Data from randomized trials indicate that gender contributes to increased mortality after myocardial infarction independent of other risk factors, but additional confounding variables cannot be discounted. Data from registry databases indicate that women are less likely to receive medically proven therapies for myocardial infarction. Women experience more vague symptoms, which may account for underuse of effective therapies. In addition, they may benefit less from thrombolytic therapy than men. Increased use of thrombolytic therapy has resulted in a continued decrease in cardiovascular deaths for men, but not for women. It is unclear if this disparity is a result of inequitable access to therapy or decreased efficacy of these agents in women.

Rash in patients receiving ticlopidine after intracoronary stent placement.

As many as half of the approximately 400,000 patients who undergo nonsurgical coronary artery procedures every year receive an intracoronary stent. To prevent thrombus formation within the stent, antiplatelet treatment with ticlopidine and aspirin is administered. Ticlopidine is known to cause cutaneous adverse reactions in up to 5.1% of patients, with a 3.4% discontinuation rate. However, published studies of patients receiving the drug to prevent subacute thrombosis after intracoronary stent placement report a frequency of rash ranging from 0.8-1.6%. We hypothesized that the frequency of rash in this patient population is underreported, and conducted a retrospective chart review, collecting data on frequency and severity of rash, treatment required, patient demographics, and concomitant drugs that may predispose patients to rash. The frequency of rash was approximately 7% in this group of patients.

A comparative pharmacokinetic study of intravenous and intramuscular midazolam in patients with epilepsy.

The pharmacokinetics of midazolam, a water soluble 1,4-benzodiazepine, has been studied in 12 patients (11 male, 1 female; age range 19-57 years) with epilepsy. All patients were taking hepatic enzyme inducing antiepileptic drugs (AEDs) on a regular basis. Midazolam (5 mg) was administered intravenously and 1 week later midazolam was administered intramuscularly, the dose used being dependent on the sedative response to the intravenous dose (10 mg, n = 2; 7 mg, n = 8; 5 mg, n = 2). Serial blood samples were collected at timed intervals for 5-7 h. After intravenous administration initial distribution was rapid with a mean half-life (t 1/2 alpha) of 0.06 +/- 0.03 h followed by a terminal half-life (t 1/2 beta or gamma) of 1.5 +/- 0.3 h. Volume of distribution was 0.62 +/- 0.27 l/kg. After intramuscular administration midazolam was rapidly absorbed with peak serum concentrations achieved at 25 +/- 23 min. Two patients showed delayed absorption. Mean terminal half-life was 2.8 +/- 1.7 h. The absolute bioavailability of intramuscular midazolam was calculated in 11 patients as 87 +/- 18%. Sedation was rapid (less than 1-2 min) but transient (7-75 min) after intravenous and slower (2-30 min) and for a longer period (20-120 min) after intramuscular administration. Since intravenous administration of AEDs including diazepam is not always feasible in status epilepticus there are obvious advantages in having an effective intramuscular formulation. Our data suggest that midazolam may be such a drug.

Combined cataract extraction and trabeculotomy; further experiences.

A procedure combining external trabeculotomy with intracapsular cataract extraction was performed in 40 eyes of 28 patients. 77.5% were controlled without medication and there was no final reduction in visual acuity due to complication from the combined operations. The procedure is advocated for patients with glucoma who must undergo cataract extraction.

Patient nutrition education follow-up in the hospital setting.

Ideally, hospital patients should have the opportunity as outpatients for continued nutritional counseling by a dietitian or nutritionist. However, when this is not feasible, alternate methods can be developed to provide some follow-up and improve nutritional care. The outpatient nutrition education questionnaire is one such tool that can be implemented and utilized to give the patient an opportunity to ask for further help, while alerting the dietitian to patients needing further assistance.