Biomedical subjects

C O'Brien

Publications and source records attributed to C O'Brien.

At least 19 recordsLinked to original sources

PubMed2006

Relative performance of soft contact lenses having lathe-cut posterior surfaces with and without additional polishing.

After a preliminary investigation of the effects of tool feed rate and spindle speed on the surface roughness of unhydrated, lathe-cut polymacon surfaces, a laboratory and clinical comparison was made between lenses with identical parameters except that the lathe-cut posterior surface was left unpolished in the "test" lenses and was polished in the "control" lenses. The lenses had moulded anterior surfaces. Laboratory comparisons included surface roughness, lens power and its uniformity across the surface. Double-blind clinical trials over 4-hour (27 subjects) and 1-month (10 subjects) periods, involved one eye of each subject wearing a "test" lens and the other, a "control" lens. No clinically significant differences were found between the results for the test and control lenses. It is concluded that today's lathing technology makes a final polishing stage unnecessary.

Biomedical Technology↗

PubMed2006

Issues in designing and interpreting clinical trials of treatments for chronic hepatitis C.

Many of the major advances in treating patients for chronic hepatitis C have been made based on the results of randomized, double-blind, controlled clinical trials. However, given the large number of hepatitis C medications in development, physicians need to understand the unique elements and types of clinical trials in order to make accurate comparisons of differing drug efficacy claims. Clinicians also need to be aware of the various factors that can influence the outcomes and interpretations of these trials, irrespective of the intervention under study. For example, similar trials conducted in the United States and Europe may have different outcomes simply because the study populations differ. Thus, both trial design and patient population are important considerations in the design and analysis of clinical trials for patients with chronic hepatitis C.

Antiviral Agents↗

PubMed2006

Trends in blind registration in the adult population of the Republic of Ireland 1996-2003.

BACKGROUND/AIM: The Republic of Ireland has a centralised database of all registered, blind people in the country. The last study of the national blind register was undertaken in 1996. The current study sought, firstly, to investigate and identify any recent changes in the register composition. Secondly, there is concern that many eligible people are not appropriately registered. To examine this further, registration levels among patients attending an Irish outpatient ophthalmology clinic were determined. METHODS: Criteria for blind registration in Ireland are (1) a best corrected visual acuity of 6/60 or less in the better eye, or (2) a visual field subtending an angle of 20 degrees or less. The National Council for the Blind in Ireland (NCBI) is the sole custodian of a national registration database recording all eligible, registered people. This computerised database was analysed to provide information on the demographics and blind registration condition of those on the register in 2003. This information was compared with the results of the 1996 study. To assess the accuracy of the current register, the registration status of eligible patients attending the outpatient clinic of a busy, tertiary referral ophthalmology department, over a 9 week period, was studied. RESULTS: 6862 adults were registered as blind on the NCBI register in Ireland in 2003, representing an increase of 37% since 1996. The leading causes of registration were age related macular degeneration (ARMD) (25%), glaucoma (12%), and retinitis pigmentosa (7%). Comparing the 1996 and 2003 data, dramatic increases in the numbers registered caused by ARMD (from 812 to 1729 people, a 113% increase) and diabetic retinopathy (DR) (from 147 people to 323 people, a 120% increase) were found. The numbers registered as a result of glaucoma were relatively stable (795 in 1996 and 811 in 2003). A substantial drop, of 53%, was noted in the number of people registered as a result of cataracts, from 561 people to 261. Of the 672 new cases registered in 2003, ARMD accounted for 44%, glaucoma 13%, and DR 7%. Over the 9 week study period 75 patients, out of a total 2320 patients who attended the outpatient department, fulfilled the blind registration criteria. It was found that 21% (16 of 75) of the eligible clinic outpatients had not been appropriately registered. CONCLUSION: An overall increase in adult blind registration of 37% in the Republic of Ireland was found between 1996 and 2003. There were large increases in registered blindness as a result of ARMD (113%) and DR (120%). A notable decrease in registration as a result of cataracts was discovered. Vigilance by clinicians is necessary to ensure that eligible patients are registered.

Adolescent↗

PubMed2006

The rising cost of glaucoma drugs in Ireland 1996-2003.

BACKGROUND: Glaucoma affects approximately 2% of the population in developed countries and is estimated to affect 67 million people worldwide. The authors investigated the effect of the introduction of new medications on the volume and cost of drugs for glaucoma in two countries, Northern Ireland (NI, population approximately 1.7 million) and the Republic of Ireland (ROI, population approximately 3.9 million) in the 8 years from 1996 to 2003. They also looked at the surgical rates for glaucoma within the same time period for the two countries. METHODS: A retrospective analysis was performed of drug costs, prescribing data, and operation rates for glaucoma in Ireland from January 1996 to December 2003. Information regarding costs and volume were obtained for each type of glaucoma drug and these were then grouped into the glaucoma treatment subsections as found in the British National Formulary. The drug information was obtained from the Central Services Agency in NI and IMS Health in the ROI and included both public and private prescriptions. The information on surgical rates for glaucoma was obtained from the Department of Health and Social Services in NI and the Hospital In-patient Enquiry (HIPE) data national files in the ROI. RESULTS: There was a 30% increase in prescription items for glaucoma in NI and a 59% increase in the ROI from 1996 to 2003. The costs increased more rapidly than the number of items: 227% in the ROI and 78% in NI from January 1996 to December 2003. In the ROI, there was an average 19% year on year increase in costs. In NI, new drugs accounted for 40% of the quantity of prescription items for glaucoma and 63% of the market cost in 2003. In the ROI new drugs accounted for 57% of the quantity and 77% of the market cost for glaucoma in 2003; prostaglandin analogue drugs alone accounted for 53% of the cost. The number of trabeculectomies performed decreased by more than 60% in both countries. CONCLUSION: Volume and cost of glaucoma drugs increased dramatically in both NI and the ROI from 1996 to 2003, probably the result of a combination of changing demographics and a changing approach towards the management of patients with glaucoma and ocular hypertension. In 2003 in the ROI, prostaglandin analogues were the most commonly prescribed class of drug for patients with glaucoma and/or ocular hypertension causing a profound rise in drug expenditure.

Adrenergic beta-Antagonists↗

PubMed2005

The importance of clinical parameters when differentiating cholestatic hepatitis C virus from allograft rejection.

BACKGROUND: The exact cause and appropriate treatment for cholestasis following liver transplantation in recipients with hepatitis C virus recurrence (RHCV) are difficult to determine. Our objective was to determine the diagnostic accuracy of clinical and histological parameters in liver transplant recipients with RHCV and concurrent cholestasis. METHODS: A retrospective analysis from June 1996 to May 2003 was performed on adult liver transplant (OLT) recipients with hepatitis C virus. Patients with cholestasis (bilirubin >5 mg/dL, 6 months after OLT) were selected. Demographics, etiology, immune suppression, clinical and histologic outcomes, and virologic features were evaluated. Patients were divided into two groups based on clinical and histological criteria: (1) patients with parameters suggestive of cholestatic HCV; and (2) patients with parameters consistent with acute cellular rejection. RESULTS: Thirty-seven patients met study criteria (20 males). The average age was 54 years (range = 14-72), and time from transplant to jaundice was 769 days (range = 48-2981). The groups were comparable regarding HCV viral load, age, gender, time from transplant, and United Network of Organ Sharing status at time of transplant. Retransplantation was performed in two patients in group 1, neither of whom survived, and in three patients in group 2, all of whom survived. Clinical parameters correlated well with diagnosis of cholestasis (r = 0.85, P < .001) whereas histological evaluation did not (r = 0.11, P = .53). Mortality in group 1 was 78% (7 of 9) vs. 50% (13 of 26) in group 2. Median duration of survival following liver transplantation in group 1 was 132 days versus 435 days in group 2. CONCLUSION: Clinical diagnosis parameters for RHCV with cholestasis appear more accurate than histology parameters and should be the primary consideration in directing therapy. Despite timely diagnosis, cholestatic RHCV LTx recipients have a poor prognosis.

Adult↗

PubMed2005

Enhanced endothelium derived hyperpolarising factor activity in resistance arteries from normal pressure glaucoma patients: implications for vascular function in the eye.

BACKGROUND/AIMS: Endothelial cell dysfunction in the ocular circulation may contribute to normal pressure glaucoma (NPG). This study aimed to investigate the contributions made by endothelium derived relaxing factors to relaxation of (1) subcutaneous resistance arteries from patients with NPG, and (2) porcine ciliary arteries. METHODS: Human gluteal resistance arteries were isolated from seven patients with NPG and matched controls. Human and porcine arteries produced endothelium dependent relaxation when exposed to acetylcholine (ACh) (10(-9)-3 x 10(-5)M) or bradykinin (10(-10)-3 x 10(-6)M). Pharmacological agents were used to inhibit the nitric oxide pathway (l-arginine analogues, soluble guanylate cyclase inhibitor), endothelium derived hyperpolarising factor (EDHF) activity (potassium channel antagonists), and prostaglandin synthesis (cyclo-oxygenase inhibitors). RESULTS: In all arteries, endothelium dependent relaxation was attenuated by nitric oxide (NO) inhibition or potassium channel blockade, but not by cyclo-oxygenase inhibition. Inhibition of ACh mediated relaxation by potassium channel antagonists was greater (p<0.05) in patients with NPG (Emax, 55.4% (SD 8.16%) relaxation, n = 4) than controls (Emax, 81.8% (6.0%), n = 5). In contrast, combined inhibition of NO synthase (NOS) and cyclo-oxygenase produced similar inhibition of ACh mediated relaxation in both groups. CONCLUSIONS: The enhanced contribution of EDHF to ACh mediated relaxation in systemic resistance arteries from NPG patients may contribute to the maintained endothelium mediated relaxation in these vessels. EDHF also contributes significantly to bradykinin mediated relaxation in porcine ocular ciliary arteries. Therefore, similar changes in the balance of relaxing factors in the ocular circulation could influence the response of the eye to vascular endothelial dysfunction in NPG.

Acetylcholine↗

PubMed2005

Elevated aqueous humour tissue inhibitor of matrix metalloproteinase-1 and connective tissue growth factor in pseudoexfoliation syndrome.

BACKGROUND/AIMS: Pseudoexfoliation syndrome (PXF) was recently found to be associated with increased expression of transforming growth factor beta(1) (TGFbeta(1)) in the aqueous humour. As concern has been raised regarding anti-TGFbeta therapy, which can potentially disrupt the maintenance of anterior chamber associated immune deviation, the authors explored the levels of tissue inhibitor of matrix metalloproteinase-1 (TIMP-1), matrix metalloproteinase-9 (MMP-9), and connective tissue growth factor (CTGF) in aqueous humour to determine if these may represent alternative therapeutic targets. METHODS: Aqueous humour samples were collected from patients who underwent routine cataract surgery. All patients were categorised into three main groups-PXF, uveitis, and control. The PXF group was further subcategorised into three grades based on the density of the exfoliative material observed on biomicroscopy, as well as the presence or absence of glaucoma. TIMP-1, MMP-9, and CTGF levels were measured using specific enzyme immunoassays (ELISA). RESULTS: Eyes with PXF had significantly higher aqueous humour TIMP-1 concentration (n = 56, mean (SE), 9.76 (1.10) ng/ml) compared with controls (n = 112, 5.73 (0.43) ng/ml, p<0.01). Similarly, the CTGF level in PXF eyes (n = 36, 4.38 (0.65) ng/ml) was higher than controls (n = 29, 2.35 (0.46) ng/ml, p<0.05). Further, the CTGF concentration in the PXF glaucoma group is significantly higher compared with PXF eyes without glaucoma (6.03 (1.09) ng/ml v 2.73 (0.45) ng/ml, p<0.01). The MMP-9 levels were low and below detection limit in all PXF and control samples with no statistical difference between groups. CONCLUSION: A raised TIMP-1 level and a low MMP-9 level in aqueous humour of PXF eyes may imply a downregulation in proteolytic activity. The increased CTGF concentration supports the proposed fibrotic pathology of PXF. Regulation of MMP/TIMP expression and anti-CTGF therapy may offer potential therapeutic avenues for controlling PXF associated ocular morbidity.

Aged↗

PubMed2005

Gremlin gene expression in bovine retinal pericytes exposed to elevated glucose.

AIM: To assess the influence of high extracellular glucose on the expression of the bone morphogenetic protein (BMP) antagonist, gremlin, in cultured bovine retinal pericytes (BRPC). METHODS: BRPC were cultured under conditions of 5 mM and 30 mM d-glucose for 7 days and total RNA was isolated. Gremlin mRNA levels were correlated, by RT-PCR, with other genes implicated in the pathogenesis of diabetic retinopathy and the signalling pathways in high glucose induced gremlin expression were probed using physiological inhibitors. Gremlin expression was also examined in the retina of streptozotocin induced diabetic mice. RESULTS: High glucose stimulated a striking increase in BRPC gremlin mRNA levels in parallel with increases in mRNA for the growth factors vascular endothelial growth factor (VEGF), transforming growth factor beta (TGFbeta), and connective tissue growth factor (CTGF) and changes in other genes including fibronectin and plasminogen activator inhibitor-1 (PAI-1). High glucose triggered gremlin expression was modulated by anti-TGFbeta antibody, by the uncoupler of oxidative phosphorylation, CCCP, and by inhibition of MAP-kinase (MAPK) activation. Striking gremlin expression was observed in the outer retina of diabetic mice and also at the level of the vascular wall. CONCLUSIONS: Gremlin gene expression is induced in BRPC in response to elevated glucose and in the retina of the streptozotocin induced diabetic mouse. Its expression is modulated by hyperglycaemic induction of the MAPK, reactive oxygen species, and TGFbeta pathways, all of which are reported to have a role in diabetic fibrotic disease. This implicates a role for gremlin in the pathogenesis of diabetic retinopathy.

Animals↗

PubMed2004

Median and ulnar nerve conduction in pregnancy.

OBJECTIVE: A prospective, observational study assessed median and ulnar nerve conduction during pregnancy, to identify the optimum test for differentiating physiological effects of pregnancy from pathological carpal tunnel syndrome (CTS). METHODS: Pregnant women (n=18) and age- and parity-matched non-pregnant controls (n=13) were recruited. Symptomatic and neurophysiological evaluations were performed. Median and ulnar nerve latencies and intrapalmar latency (difference between median and ulnar nerve latencies) were computed. RESULTS: Median nerve distal latency is more prolonged in pregnant women compared with non-pregnant controls. Median nerve latency is more prolonged in pregnant women with symptoms of CTS than in asymptomatic women. The difference between median and ulnar nerve conduction (normal <0.2 ms) discriminates well between symptomatic and asymptomatic pregnant women. CONCLUSIONS: Intrapalmar latency is proposed as a useful diagnostic test for classification of carpal tunnel syndrome during pregnancy.

Carpal Tunnel Syndrome↗

PubMed2004

Liver transplant for the septuagenarians: importance of patient selection.

With the increasing success of liver transplantation (OLT), more patients above 70 years of age are being considered for OLT. There is not enough data about the predictors for survival in this patient population. We retrospectively analyzed the medical records of 33 patients at least 70 years of age who received 34 OLT from July 1995 to July 2002. There were 16 women and 17 men of mean age 73.7 years. Etiologies of end-stage liver disease (ESLD) were: HCV (17/33, 52%), cryptogenic cirrhosis (8/33, 24%), PBC (3/33, 9%), Laennec's cirrhosis (2/33, 6%), and others (3/33, 9%). According to the UNOS classification, 15/34 (44%) were status 3, 16/34 (47%) status 2, and 3/34 (9%) status 1. Among 13/33 patients who died (39%), 1-year and 3-year survival rates were 78.79% and 71.43%, respectively. Based on UNOS criteria, 4/15 (26%) were status 3; 6/16 (37%), status 2; and 3/3 (100%), status 1 (P value = .04 for status 1 patients). There was no statistical differences between the scores using the Model for End-Stage Liver Disease (MELD) among those who died (MELD (19) versus MELD (17.35) respectively (P = .50). There was a statistically significant difference in cold ischemia time (CIT) and warm ischemia time (WIT) between those who died (P = .024 and.010, respectively). These results suggest that in this group of patients UNOS status classification, CIT and WIT correlate with survival. The sample size was too small to derive a conclusion about the association with the MELD score.

Adult↗

PubMed2004

Measurement of movement is an objective method to assist in assessment of opiate withdrawal in newborns.

OBJECTIVE: To develop an objective and reliable method to assess drug withdrawal in newborns by quantitatively estimating the amount of movement rather than scoring individual withdrawal signs. DESIGN: In this cross sectional study, a commercial portable motion detector with computer memory, similar to a wrist watch (the actigraph) was used to measure movement. The measurements were compared with a clinical decision based on the neonatal abstinence syndrome (NAS) score. Movement was analysed, using non-parametric tests, in three groups: a control group of 10 infants, 13 opiate exposed newborns not treated for NAS, and 30 newborns treated for NAS (17 before treatment, eight within 24 hours of treatment, five when stabilised). RESULTS: There were significant differences in the median activity score, expressed as counts per minute (cpm), in the pretreatment group (124 cpm) compared with the control (42 cpm, p < 0.0001), non-treated (74 cpm, p = 0.001), and stabilised treatment (75 cpm, p = 0.007) groups. The accuracy of the actigraph in the identification of newborns requiring treatment from those who did not was high compared with the clinical scores; sensitivity 94%; specificity 85%; positive and negative predictive values 88% and 92% respectively. CONCLUSIONS: The measure of movement is comparable to the clinical score in the identification of newborns who require treatment and in determining the severity of withdrawal. The clear advantage of this method is its objectivity, reliability, and efficiency as a simple, non-invasive, bedside measure. Further evaluation in a randomised, controlled trial would establish comparative benefits, potential harms, safety, and acceptability.

Cross-Sectional Studies↗

PubMed2003

Role of cyclooxygenase and haemoxygenase products in nitric oxide-independent vasodilatation in the porcine ciliary artery.

PURPOSE: Vascular endothelial cell dysfunction has been noted in patients with normal pressure glaucoma. Although nitric oxide (NO) accounts for a large proportion of vasorelaxation in the posterior ciliary artery, considerable relaxation remains unexplained. We investigated the roles of haemoxygenase (HO) and cyclooxygenase (COX), which produce the vasodilators carbon monoxide (CO) and prostacyclin, respectively, in NO-independent endothelium-dependent vasodilatation in porcine posterior ciliary arteries. METHODS: Isolated vascular rings were mounted in a Mulvaney-Halpern small vessel myograph for the measurement of isometric tension development. Vasodilator responses to bradykinin (BK) were elicited in each ring on three separate occasions following preconstriction with prostaglandin F(2alpha): first in the absence of inhibitors, second in the presence of the NO synthase inhibitor N-nitro-L-arginine methyl ester (L-NAME, 10(-3) M), and third in the presence of L-NAME and either a COX (indomethacin, 10(-6) M) or an HO inhibitor (tin protoporphyrin-IX 10(-5) M). Results were expressed as a percentage of the maximal relaxation in the presence of L-NAME alone. RESULTS: Incubation with indomethacin (n=6), in the presence of L-NAME, significantly reduced (P<0.01) maximum BK-induced relaxation (-103.5+/-8.8%) compared to paired rings in the presence of L-NAME alone (-130.8+/-8.8%). HO inhibition did not reduce NO-independent, BK-induced relaxation when compared to paired control vessels. CONCLUSIONS: These data suggest that in the presence of L-NAME, a COX product accounts for a significant proportion of NO-independent vasodilatation. In contrast, endogenous CO production does not have a functionally significant role in the porcine ciliary artery. Eye (2003) 17, 628-636. doi:10.1038/sj.eye.6700437

Animals↗

PubMed2003

Resolution of bronchial inflammation is related to bacterial eradication following treatment of exacerbations of chronic bronchitis.

BACKGROUND: Recent studies of the role of bacteria in chronic bronchitis have shown that bacterial colonisation is associated with enhanced inflammation and that purulent acute exacerbations of chronic bronchitis (AECB) are associated with bacteria and characterised by increased inflammation. Changes in bronchial inflammation in response to the success or failure of bacterial eradication following AECB were therefore studied. METHODS: Bacterial quantitative culture and sputum markers of inflammation (myeloperoxidase (MPO), neutrophil elastase, leukotriene B4 (LTB4), sol:serum albumin ratio, and secretory leukoprotease inhibitor) were measured in patients presenting with culture positive purulent AECB and repeated 10 days and 2 months later. 41 patients provided sputum sufficient for both bacteriology and assessment of inflammation at baseline and day 10, and 46 provided sufficient sample for bacteriology, 40 of which could also be analysed for inflammation at 2 months (when clinically stable). RESULTS: At day 10, 17 of the 41 patient samples had a positive bacterial culture. In the stable state, 18 of the 46 samples had a positive culture, but with a significantly lower bacterial load than at presentation. Although there was no difference between the groups at presentation, the concentration of MPO was lower (p<0.05) in those in whom bacteria were eradicated by day 10 than in those with persisting bacteria. The LTB4 concentration was similarly lower (p<0.001) in those in whom bacteria were eradicated than in those with persistent bacteria. In the stable clinical state the concentrations of both MPO and LTB4 were lower in those in whom bacteria were eradicated than in patients with persisting bacteria. CONCLUSION: Resolution of bronchial inflammation following AECB is related to bacterial eradication. Those in whom bacteria continue to be cultured in their sputum have partial resolution of inflammation which may reflect continued stimulation by the reduced bacterial load.

Adult↗

PubMed2002

Bioelectrical impedance to estimate changes in hydration status.

Bioelectrical impedance analysis (BIA) has been suggested as a simple, rapid method to assess changes in hydration status. BIA measures the electrical impedance to a low amperage current that is affected by both water and electrolyte content of the body. While BIA can reliably estimate total body water and body density in euhydrated individuals under standardized clinical conditions, changes in fluid and electrolyte content can independently alter bioimpedance measurements. Because hydration changes typically involve concomitant changes in fluid and electrolyte content, the interpretation of a change in bioimpedance will often be confounded. This paper examines the assumptions underlying estimations of total body water from BIA and addresses the factors known to influence bioimpedance independently from actual change in total body water. The results indicate that current BIA methodology may not provide valid estimates of total body water when hydration state is altered.

Body Water↗

PubMed2002

Tracheostomy, lingular tonsillectomy and sleep-related breathing disorders.

Laser resection of lingual tonsils and formal closure of a tracheostomy improved the airway in a 14-yr-old patient with Down's syndrome. Non-invasive airway support to treat obstructive sleep apnoea was postponed with this treatment. During the anaesthetic a laryngeal mask airway was used to support the airway after lingual tonsillectomy, to assess the suitability of defunctioning the tracheostomy. Laryngeal mask airways assist management of lingual tonsils. Lingual tonsillar hypertrophy can lead to obstructive sleep disorders.

Adolescent↗

PubMed2002

2002: Hiatal hernia in a puppy.

A sliding hiatal hernia (where the terminal oesophagus, oesophagogastric junction and part of the stomach move cranially through a diaphragmatic defect) was diagnosed in a 4-month-old, Shar-Pei puppy presented for evaluation of regurgitation. The diagnosis was confirmed using radiography. Herniorraphy consisted of repositioning the stomach within the abdomen, plicating the diaphragmatic hiatus and performing a tube gastropexy to the left abdominal wall. Veterinary practitioners should have a high index of suspicion of hiatal hernia in young puppies, particularly Shar-Peis and British Bull Dogs, that present with persistent vomiting or regurgitation.

Animals↗

PubMed2002

Physiological responses to cold exposure in men: a disabled submarine study.

A disabled submarine (DISSUB) lacking power and/or environmental control will become cold, and the ambient air may become hypercapnic and hypoxic. This study examined if the combination of hypoxia, hypercapnia, and cold exposure would adversely affect thermoregulatory responses to acute cold exposure in survivors awaiting rescue. Seven male submariners (33 +/- 6 yrs) completed a series of cold-air tests (CAT) that consisted of 20-min at T(air) = 22 degrees C, followed by a linear decline (1 degrees C x min(-1)) in T(air) to 12 degrees C, which was then held constant for an additional 150-min. CAT were performed under normoxic, normocapnic conditions (D0), acute hypoxia (D1, 16.75% O2), after 4 days of chronic hypoxia, hypercapnia and cold (D5, 16.75% O2, 2.5% CO2, 4 degrees C), and hypoxia-only again (D8, 16.75% O2). The deltaTsk during CAT was larger (P < 0.05) on D0 (-5.2 degrees C), vs. D1 (-4.8 degrees C), D5 (-4.5 degrees C), and D8 (-4.4 degrees C). The change (relative to 0-min) in metabolic heat production (deltaM) at 20-min of CAT was lower (P < 0.05) on D1, D5, and D8, vs. D0, with no differences between D1, D5 and D8. DeltaM was not different among trials at any time point after 20-min. The mean body temperature threshold for the onset of shivering was lower on D1 (35.08 degrees C), D5 (34.85 degrees C), and D8 (34.69 degrees C), compared to D0 (36.01 degrees C). Changes in heat storage did not differ among trials and rectal temperature was not different in D0 vs. D1, D5, and D8. Thus, mild hypoxia (16.75% F1O2) impairs vasoconstrictor and initial shivering responses, but the addition of elevated F1CO2 and cold had no further effect. These thermoregulatory effector changes do not increase the risk for hypothermia in DISSUB survivors who are adequately clothed.

Adult↗

PubMed2001

Effectiveness of propranolol for cocaine dependence treatment may depend on cocaine withdrawal symptom severity.

Propranolol may reduce symptoms of autonomic arousal associated with early cocaine abstinence and improve treatment outcome. This trial was an 8-week, double-blind, placebo-controlled trial of propranolol in 108 cocaine dependent subjects. The primary outcome measure was quantitative urinary benzoylecgonine levels. Secondary outcome measures included treatment retention, addiction severity index results, cocaine craving, mood and anxiety symptoms, cocaine withdrawal symptoms, and adverse events. Propranolol treated subjects had lower cocaine withdrawal symptom severity but otherwise did not differ from placebo treated subjects in any outcome measure. However, in a secondary, exploratory analysis, subjects with more severe cocaine withdrawal symptoms responded better to propranolol in comparison to placebo. In these subjects, propranolol treatment was associated with better treatment retention and lower urinary benzoylecgonine levels as compared with the placebo treatment. Propranolol may be useful only for the treatment of cocaine dependent patients with severe cocaine withdrawal symptoms.

Adolescent↗