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1.
Int J Drug Policy ; 72: 84-90, 2019 10.
Article in English | MEDLINE | ID: mdl-31351752

ABSTRACT

BACKGROUND: In Australia, Hepatitis C Virus (HCV) treatment is declining, despite broad access to direct-acting antiviral medication. People who inject drugs are proportionally over-represented in emergency department presentations. Emergency department assessment of people who have injected drugs for HCV presents an opportunity to engage this marginalised population with treatment. We describe the outcomes of risk-based screening and point-of-care anti-HCV testing for emergency department patients, and linkage to outpatient antiviral treatment. METHODS: During the three-month study period, consecutive adult patients who presented to the emergency department during the study times were screened for risk factors and offered the OraQuick oral HCV antibody test. Those with reactive results were offered venepuncture in the emergency department for confirmatory testing and direct-acting antiviral treatment in clinic. The main outcome measures were the number and proportion of viremic participants that were linked to the hepatitis clinic, commenced treatment and achieved a sustained viral response. Secondary outcome measures were the proportion (%) of presentations screened that were oral antibody reactive, and the prevalence and type of HCV risk factors. RESULTS: During the study period, 2408 of the 3931 (61%) presentations to the emergency department were eligible for screening. Of these 2408 patients, 1122 (47%) participated, 307 (13%) declined participation and 977 (41%) could not be approached during their time in the emergency department. Among the 1122 participants, 378 (34%) reported at least one risk factor. Subsequently, 368 (97%) of the 378 participants underwent OraQuick anti-HCV test, and 50 (14%) had a reactive result. A risk factor of ever having injected drugs was present in 44 (88%) of participants who were sero-positive. Of the 45 that had blood tested, 30 (67%) were HCV ribonucleic acid (RNA) positive. Three participants died. Of the 27 remaining participants, 10 (37%) commenced treatment and 7 of these 10 (70%) obtained a cure. There was a high rate of homelessness (24%) among anti-HCV positive participants. CONCLUSION: Among emergency department participants with a risk factor for HCV, positive serology was common using a rapid point-of-care test. A history of injecting drug use was identified as the risk factor with highest yield for positive HCV serology, and is suitable as a single screening question. However, linkage to care post ED presentation was low in this marginalised population. There is a need for new pathways to improve the care cascade for marginalised individuals living with HCV infection.


Subject(s)
Emergency Service, Hospital , Hepatitis C/diagnosis , Point-of-Care Systems , Substance Abuse, Intravenous/complications , Adult , Antiviral Agents/administration & dosage , Australia , Female , Follow-Up Studies , Hepacivirus/isolation & purification , Hepatitis C/drug therapy , Hepatitis C/epidemiology , Ill-Housed Persons/statistics & numerical data , Humans , Male , Mass Screening/methods , Mass Screening/statistics & numerical data , Middle Aged , Prospective Studies , RNA, Viral/analysis , Risk Factors , Substance Abuse, Intravenous/epidemiology
2.
Arch Dis Child Fetal Neonatal Ed ; 97(2): F88-92, 2012 Mar.
Article in English | MEDLINE | ID: mdl-21813569

ABSTRACT

OBJECTIVES: To determine the effects on weight gain and temperature control of transferring preterm infants from incubators to open cots at a weight of 1600 g versus a weight of 1800 g. DESIGN: Randomised controlled trial. SETTING: One tertiary and two regional neonatal units in public hospitals in Queensland, Australia. PARTICIPANTS: 182 preterm infants born with a birth weight less than 1600 g, who were at least 48 h old; had not required ventilation or continuous positive airways pressure within the last 48 h; were medically stable with no oxygen requirement, or significant apnoea or bradycardia; did not require phototherapy; and were enterally fed with an intake (breast milk/formula) of at least 60 ml/kg/day. INTERVENTIONS: Transfer into an open cot at 1600 or 1800 g. MAIN OUTCOME MEASURES: The primary outcomes were temperature stability and average daily weight gain over the first 14 days following transfer to an open cot. RESULTS: 90 infants in the 1600 g group and 92 infants in the 1800 g group were included in the analysis. Over the first 72 h, more infants in the 1800 g group had temperatures <36.4°C than the 1600 g group (p=0.03). From post-transfer to discharge, the 1600 g group had more temperatures >37.1°C (p=0.02). Average daily weight gain in the 1600 g group was 17.07 (SD±4.5) g/kg/day and in the 1800 g group, 13.97 (SD±4.7) g/kg/day (p=<0.001). CONCLUSIONS: Medically stable, preterm infants can be transferred to open cots at a birth weight of 1600 g without any significant adverse effects on temperature stability or weight gain. TRIAL REGISTRATION: ACTRN12606000518561 (http://www.anzctr.org.au).


Subject(s)
Body Weight/physiology , Incubators, Infant , Infant Equipment , Infant, Premature/physiology , Patient Transfer , Birth Weight/physiology , Body Temperature Regulation/physiology , Female , Gestational Age , Humans , Infant Care/methods , Infant, Newborn , Infant, Small for Gestational Age , Male , Weight Gain/physiology
3.
Cochrane Database Syst Rev ; (1): CD004214, 2008 Jan 23.
Article in English | MEDLINE | ID: mdl-18254041

ABSTRACT

BACKGROUND: The use of incubators in helping to maintain a thermoneutral environment for preterm infants has become routine practice in neonatal nurseries. As one of the key criteria for discharging preterm infants from nurseries is their ability to maintain temperature; the infant will need to make the transition from incubator to open cot at some time before discharge. The timing of this transition is important because, when an infant is challenged by cold, the infant attempts to increase its heat production to maintain body temperature. The increase in energy expenditure may affect weight gain. The practice of transferring infants from incubators to open cots usually occurs once a weight of around 1700 - 1800 g has been reached; however, this practice varies widely among neonatal units. This target weight appears to be largely based on tradition or the personal experience of clinicians, with little consideration of the infant's weight or gestational age at birth. OBJECTIVES: The main objective was to assess the effects on weight gain and temperature control of a policy of transferring preterm infants from incubator to open cot at lower versus higher body weight. SEARCH STRATEGY: Searches were undertaken of MEDLINE from April 2007 back to 1950, CINAHL from April 2007 back to 1982 and the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 2, 2007). The title and abstract of each retrieved study were examined to assess eligibility. If there was uncertainty, the full paper was examined. SELECTION CRITERIA: Trials in which preterm infants were allocated to a policy of transfer from incubators to open cots at a lower body weight versus at a higher body weight. DATA COLLECTION AND ANALYSIS: Quality assessments and data extraction for included trials were conducted independently by the reviewers. Data for individual trial results were analysed using relative risk (RR) and mean difference (MD). Results are presented with 95% confidence intervals (CI). Due to insufficient data, meta-analysis could not be undertaken. MAIN RESULTS: Five studies were identified as potentially eligible for inclusion in this review. Three studies were excluded as neither random nor quasi-random allocation to the exposure was employed. Two small quasi-randomised studies, involving 74 preterm infants are included in this review. These studies compared the transfer of infants to open cots at 1600 - 1700 g vs. 1800- 1900 g, and 1700 g vs. 1800 g. Data for only two prespecified outcomes could be included in this review. No statistically significant difference was shown for either return to incubator [one trial (N = 60) RR 2.00; 95% CI 0.40 to 10.11] or daily weight gain measured in g/kg/day [one trial (N = 14) MD 1.00 g/kg/day; 95% CI -2.89, 4.89]. Due to insufficient data, meta-analysis was not performed and effects on clinically important outcomes could not be adequately assessed. AUTHORS' CONCLUSIONS: There is currently little evidence from randomised trials to inform practice on the preferred weight for transferring preterm infants from incubators to open cots. There is a need for larger randomised controlled trials to address this deficiency.


Subject(s)
Body Weight , Incubators, Infant , Infant Equipment , Infant, Premature/physiology , Transportation of Patients , Body Temperature Regulation , Humans , Infant, Newborn , Weight Gain
4.
Cochrane Database Syst Rev ; (2): CD005092, 2007 Apr 18.
Article in English | MEDLINE | ID: mdl-17443570

ABSTRACT

BACKGROUND: Breast milk provides optimal nutrition for newborn infants, and the ideal way for infants to receive breast milk is through suckling at the breast. Unfortunately, this may not always be possible, as there are numerous reasons why a newborn infant may not be able to breastfeed and, as a result, require supplemental feeding. Currently, there are a variety of ways in which newborn infants can receive supplemental feeds. Traditionally, bottles and nasogastric tubes have been used; however, more recently, cup feeding has become a popular practice in many nurseries in an attempt to improve breastfeeding rates. There is no consistency to guide the choice of supplementation. OBJECTIVES: To determine the effects of cup feeding versus other forms of supplemental enteral feeding on weight gain and achievement of successful breastfeeding in newborn infants who are unable to fully breastfeed. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 2, 2006), CINAHL (1982 - April 2006) and MEDLINE (1966 - April 2006). SELECTION CRITERIA: Randomised or quasi-randomised controlled trials comparing cup feeding to other forms of enteral feeding for the supplementation of newborn infants. DATA COLLECTION AND ANALYSIS: Quality assessments and data extraction for included trials were conducted independently by the review authors. Outcomes reported from these studies were: weight gain, proportion not breastfeeding at hospital discharge, proportion not feeding at three months of age, proportion not feeding at six months of age, proportion not fully feeding at hospital discharge, proportion not fully breastfeeding at three months of age, proportion not fully breastfeeding at six months of age, average time per feed (minutes), length of stay and physiological events of instability such as bradycardia, apnea, and low oxygen saturation. For continuous variables such as weight gain, mean differences and 95% confidence intervals were reported. For categorical outcomes such as mortality, the relative risks (RR) and 95% confidence intervals were reported. MAIN RESULTS: Four studies were eligible for inclusion. The experimental intervention was cup feeding and the control intervention was bottle feeding in all four studies included in this review. There was no statistically significant difference in the incidence of not breastfeeding at hospital discharge in three included studies (typical RR 0.82, 95% CI 0.62, 1.09) and not breastfeeding at three months in two included studies (typical RR 0.88, 95% CI 0.76, 1.03) or six months for the one study that reported this outcome (RR 0.91, 95% CI 0.78, 1.05). There was a statistically significant difference in not fully breastfeeding at hospital discharge (from three included studies) in favour of cup feeding (typical RR 0.75, 95% CI 0.61, 0.92). However, this was not statistically significant at three months (one study, RR 1.18, 95% CI 0.88, 1.58) or six months (one study, RR 1.31, 95% CI 0.89, 1.92). There was no statistically significant difference in weight gain from one study that reported this outcome (MD -0.60, 95% CI -3.21, 2.01). In the one study that assessed it, there was a significantly increased length of hospital stay in the cup fed infants [mean difference between groups was 10.1 days (95% CI 3.9, 16.3)]. Time to full breastfeeding was not assessed in any study. AUTHORS' CONCLUSIONS: Cup feeding cannot be recommended over bottle feeding as a supplement to breastfeeding because it confers no significant benefit in maintaining breastfeeding beyond hospital discharge and carries the unacceptable consequence of a longer stay in hospital.


Subject(s)
Cooking and Eating Utensils , Enteral Nutrition/methods , Bottle Feeding , Breast Feeding , Enteral Nutrition/instrumentation , Humans , Infant, Newborn , Infant, Premature , Length of Stay
5.
Cochrane Database Syst Rev ; (2): CD004214, 2004.
Article in English | MEDLINE | ID: mdl-15106242

ABSTRACT

BACKGROUND: The use of incubators in helping to maintain a thermoneutral environment for preterm infants has become routine practice in neonatal nurseries. As one of the key criteria for discharging preterm infants from nurseries is their ability to maintain temperature, the infant will need to make the transition from incubator to open cot at some time before discharge. The timing of this transition is important because when an infant is challenged by cold, the infant attempts to increase its heat production to maintain body temperature. The increase in energy expenditure may affect weight gain. The practice of transferring infants from incubators to open cots usually occurs once a weight of around 1700-1800 g has been reached; however, this practice varies widely between neonatal units. This preferred weight mark appears to be largely based on tradition or the personal experience of clinicians, with little consideration of the infant's weight or gestational age at birth. OBJECTIVES: The main objective was to assess the effects on weight gain and temperature control of a policy of transferring preterm infants from incubator to open cot at lower versus higher body weight. SEARCH STRATEGY: Searches were undertaken of MEDLINE from June 2003 back to 1966, CINAHL from June 2003 back to 1987 and the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2003). The title and abstract of each retrieved study were examined to assess eligibility. If there was uncertainty, the full paper was examined. SELECTION CRITERIA: Trials in which preterm infants were randomly allocated to a policy of transfer from incubators to open cots at a lower body weight versus at a higher body weight. DATA COLLECTION AND ANALYSIS: Quality assessments and data extraction for included trials were conducted independently by the reviewers. Data for individual trial results were analysed using relative risk (RR) and mean difference (MD). Results are presented with 95% confidence intervals (CI). Due to insufficient data, meta-analysis could not be undertaken. MAIN RESULTS: Four studies were identified as potentially eligible for inclusion in this review. Two studies were excluded as random allocation to the exposure was not employed. One study is pending, awaiting additional information from the authors. Therefore, one study involving 60 preterm infants, employing a matched-pairs design, which compared the transfer of infants to open cots at 1700 g versus 1800 g, is included in this review. Only two outcomes could be included from this study; return to incubator and daily weight gain. No statistically significant difference was shown for either return to incubator (RR 2.00, 95% CI 0.40 to 10.11) or daily weight gain [MD 4.00 g/day (95% CI -5.23, 13.23)]. Due to small numbers, effects on clinically important outcomes could not be adequately assessed. REVIEWERS' CONCLUSIONS: There is currently little evidence from randomised trials to inform practice on the preferred weight for transferring preterm infants from incubators to open cots. There is a need for larger randomised controlled trials to address this deficiency.


Subject(s)
Body Weight , Incubators, Infant , Infant Equipment , Infant, Premature/physiology , Transportation of Patients , Body Temperature Regulation , Humans , Infant, Newborn , Weight Gain
6.
Heart ; 90(2): 169-74, 2004 Feb.
Article in English | MEDLINE | ID: mdl-14729789

ABSTRACT

OBJECTIVE: To assess the need for pacing in adults with chronic Mobitz type I second degree atrioventricular block (Mobitz I). DESIGN: Prospective study. SETTING: District general hospital. PATIENTS: 147 subjects aged > or = 20 years (age cohorts 20-44, 45-64, 65-79, and > or = 80) with chronic Mobitz I without second degree Mobitz II or third degree (higher degree) block on entry, seen from 1968 to 1993 and followed up to 30 June 1997. Sixty four had organic heart disease. The presence of symptomatic bradycardia was defined as highly likely in 47 patients (class 1); probable in 14 (class 2); and absent in 86 (class 3). INTERVENTIONS: Pacemakers were implanted in 90 patients for the following indications: symptoms in 74 and prophylaxis in 16. MAIN OUTCOME MEASURES: The main outcome measure was death, with conduction deterioration to higher degree block or symptomatic bradycardia the alternative measure. RESULTS: Five year survival to death was reduced in unpaced patients relative to that expected for the normal population (overall mean (SD) 53.5 (6.7)% v 68.6%, p < 0.001; class 3, 54.4 (7.3)% v 70.1%, p < 0.001). Paced patients fared better than unpaced (overall (mean (SD) five year survival 76.3 (4.5)% v 53.5 (6.7)%, p = 0.0014; class 3, 87.2 (5.4)% v 54.4 (7.3)%, p = 0.020; and organic heart disease, 68.2 (7.6)% v 44.0 (9.9)%, p < or = 0.0014). There were no deaths in the < 45 cohort. Survival to first outcome (main or alternative) was further reduced to 31.7 (5.0)% in 102 patients unpaced initially and 34.2 (5.7)% in class 3. Only the 20-44 cohort and patients with sinus arrhythmia had > 50% survival. CONCLUSION: Mobitz I block is not usually benign in patients > or = 45 years of age. Pacemaker implantation should be considered, even in the absence of symptomatic bradycardia or organic heart disease.


Subject(s)
Cardiac Pacing, Artificial , Heart Block/therapy , Adult , Aged , Aged, 80 and over , Cardiac Pacing, Artificial/methods , Cardiac Pacing, Artificial/mortality , Cohort Studies , Female , Heart Block/classification , Humans , Male , Middle Aged , Prospective Studies , Survival Analysis , Treatment Outcome
7.
Diagn Cytopathol ; 24(5): 361-3, 2001 May.
Article in English | MEDLINE | ID: mdl-11335970

ABSTRACT

A 25-yr-old male presented with a cerebellar mass, underwent a suboccipital craniotomy, and was diagnosed with medulloblastoma. Six months later he developed a large mass in the right iliac crest. Fine-needle aspiration biopsy (FNAB) confirmed the diagnosis of metastatic medulloblastoma. The diagnosis of metastatic medulloblastoma is usually suspected clinically or radiographically, and is uncommonly confirmed by cytologic evaluation. Here we report on a rare case of FNAB used to diagnose metastatic medulloblastoma.


Subject(s)
Bone Neoplasms/pathology , Bone Neoplasms/secondary , Cerebellar Neoplasms/pathology , Medulloblastoma/pathology , Medulloblastoma/secondary , Pelvic Neoplasms/pathology , Pelvic Neoplasms/secondary , Adult , Biopsy, Needle , Humans , Male
8.
J Pediatr Surg ; 36(2): 338-40, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11172429

ABSTRACT

BACKGROUND/PURPOSE: Lipopolysaccharide (LPS) and cytokines produced during neonatal sepsis trigger free radical production, which eventually results in inhibition of liver metabolism. Studies in adults have indicated a hypermetabolic response to sepsis; however, evidence for a hypermetabolic response in neonates is equivocal. This study was carried out to determine whether LPS and cytokines can cause liver hypermetabolism in neonates. METHODS: The initial bacterial insult and cytokine cascade were mimicked by the addition of lipopolysaccharide (Escherichia coli 055:B5), tumour necrosis factor (TNF-alpha), and interleukin-6 (IL6) during the isolation of hepatocytes by collagenase digestion from 11- to 13-day-old Wistar rats. Hepatocyte oxygen consumption was measured polarographically with cells respiring on palmitate (0.5 mmol/L). Myxothiazol, a specific inhibitor of mitochondrial respiration, was used to distinguish extra- and intramitochondrial oxygen consumption. Morphologic changes were assessed by electron microscopy. RESULTS: The addition of LPS, TNF-alpha and IL6 during hepatocyte isolation resulted in a 10% decrease in cell yield (P <.05) compared with untreated controls; however, cell viability was unchanged (n = 31). Both total and extramitochondrial oxygen consumption were significantly greater in treated cells compared with untreated controls (P <.05, Student's t test). Electron microscopy indicated that LPS, TNF-alpha, and IL6 did not cause ultrastructural changes to hepatocytes. CONCLUSIONS: The increase in oxygen consumption was predominantly extramitochondrial and likely to be caused by increased oxygen requirement for cytosolic detoxification and repair purposes. This study shows that liver hypermetabolism metabolism can occur in response to LPS and cytokines. However, during in vivo neonatal sepsis, additional free radical damage may blunt this hypermetabolic response.


Subject(s)
Cytokines/metabolism , Lipopolysaccharides/metabolism , Liver/metabolism , Sepsis/metabolism , Animals , Animals, Newborn , Hepatocytes/metabolism , Interleukin-6/metabolism , Oxidative Stress/physiology , Oxygen/metabolism , Rats , Rats, Wistar , Tumor Necrosis Factor-alpha/physiology
9.
Eur J Biochem ; 259(3): 684-91, 1999 Feb.
Article in English | MEDLINE | ID: mdl-10092853

ABSTRACT

The primary aim of this paper was to calculate and report flux control coefficients for mitochondrial outer-membrane carnitine palmitoyltransferase (CPT I) over hepatic ketogenesis because its role in controlling this pathway during the neonatal period is of academic importance and immediate clinical relevance. Using hepatocytes isolated from suckling rats as our model system, we measured CPT I activity and carbon flux from palmitate to ketone bodies and to CO2 in the absence and presence of a range of concentrations of etomoxir. (This is converted in situ to etomoxir-CoA which is a specific inhibitor of the enzyme.) From these data we calculated the individual flux control coefficients for CPT I over ketogenesis, CO2 production and total carbon flux (0.51 +/- 0.03; -1.30 +/- 0.26; 0.55 +/- 0.07, respectively) and compared them with equivalent coefficients calculated by similar analyses [Drynan, L., Quant, P.A. & Zammit, V.A. (1996) Biochem. J. 317, 791-795] in hepatocytes isolated from adult rats (0.85 +/- 0.20; 0.23 +/- 0.06; 1.06 +/- 0.29). CPT I exerts significantly less control over ketogenesis in hepatocytes isolated from suckling rats than those from adult rats. In the suckling systems the flux control coefficients for CPT I over ketogenesis specifically and over total carbon flux (< 0.6) are not consistent with the enzyme being rate-limiting. Broadly similar results were obtained and conclusions drawn by reanalysis of previous data {from experiments in mitochondria isolated from suckling or adult rats [Krauss, S., Lascelles, C.V., Zammit, V.A. & Quant, P.A. (1996) Biochem. J. 319, 427-433]} using a different approach of control analysis, although it is not strictly valid to compare flux control coefficients from different systems. Our overall conclusion is that flux control coefficients for CPT I over oxidative fluxes from palmitate (or palmitoyl-CoA) differ markedly according to (a) the metabolic state, (b) the stage of development, (c) the specific pathway studied and (d) the model system.


Subject(s)
Carnitine O-Palmitoyltransferase/metabolism , Ketone Bodies/metabolism , Liver/metabolism , Membrane Proteins/metabolism , Mitochondria, Liver/enzymology , Animals , Animals, Suckling , Carbon Dioxide/metabolism , Carnitine/metabolism , Cells, Cultured , Energy Metabolism , Enzyme Inhibitors/pharmacology , Epoxy Compounds/pharmacology , Malonyl Coenzyme A/metabolism , Palmitic Acid/metabolism , Palmitoyl Coenzyme A/metabolism , Palmitoylcarnitine/metabolism , Rats , Rats, Wistar
12.
J Neurochem ; 71(6): 2304-12, 1998 Dec.
Article in English | MEDLINE | ID: mdl-9832128

ABSTRACT

Defective herpes simplex virus (HSV) vectors containing glutamic acid decarboxylase (GAD) cDNAs, either GAD65 or GAD67, were used to examine GAD function and GABA synthesis in rat cortical astrocytes, CNS cells that do not endogenously synthesize GABA. GAD vector infection resulted in isoform-specific expression of GAD as determined by western blotting and immunohistochemistry. Astrocytes infected with a beta-galactosidase vector or uninfected expressed no GAD and contained no detectable GABA. GABA was detected in glial fibrillary acid protein-expressing cells after GAD65 vector infection. Significant amounts of GABA, as determined by HPLC, were synthesized in cultures infected with either GAD vector. The levels of GABA in GAD67 vector-infected cells were almost twofold higher than in GAD65 vector-infected cells. Vector infection did not alter levels of other intracellular amino acids. GABA was tonically released from astrocytes infected with the GAD67 vector, but no increase in release could be detected after treatment of the cells with K+, veratridine, glutamate, or bradykinin. The ability to transduce astrocytes so that they express GAD and thereby increase GABA levels provides a potential strategy for the treatment of neurologic disorders associated with hyperexcitable or diminished inhibitory activity.


Subject(s)
Astrocytes/metabolism , Defective Viruses/metabolism , Genetic Vectors/metabolism , Glutamate Decarboxylase/metabolism , Herpes Simplex/metabolism , gamma-Aminobutyric Acid/biosynthesis , Animals , Astrocytes/virology , Cells, Cultured , Chlorocebus aethiops , DNA, Complementary/genetics , DNA, Viral/genetics , Defective Viruses/genetics , Genetic Vectors/genetics , Glutamate Decarboxylase/genetics , Isomerism , Rats , Rats, Sprague-Dawley , Transgenes/genetics , Vero Cells , gamma-Aminobutyric Acid/metabolism
13.
Brain Res Mol Brain Res ; 61(1-2): 121-35, 1998 Oct 30.
Article in English | MEDLINE | ID: mdl-9795182

ABSTRACT

The inhibitory amino acid neurotransmitter gamma-aminobutyric acid (GABA) is synthesized from glutamate in a single step by the enzyme glutamatic acid decarboxylase (GAD). We sought to determine whether viral vectors containing GAD cDNA could be used to enhance synthesis and stimulation-evoked release of GABA in cultures of CNS neurons. For this purpose, we generated double-cassette defective herpes simplex virus (HSV) vectors that expressed one of the two GAD isoforms (GAD65 or GAD67), and Escherichia coli LacZ. Infection of cerebellar granule cell (CGC) cultures with vectors containing GAD cDNA resulted in a significant increase in isoform-specific expression of GAD, synthesis of GABA, and stimulation-evoked GABA release. GAD65 and GAD67 vector-infected neurons exhibited a comparable profile of GABA levels, synthesis and release, as well as GAD protein distribution. In CGCs cultured for 6 days in vitro (DIV), GABA synthesized after vector-derived GAD expression was released by treatment with glutamate or veratridine, but only in a Ca2+-independent fashion. In more mature (10 DIV) cultures, both Ca2+-dependent, K+ depolarization-induced, as well as Ca2+-independent, veratridine-induced, GABA release was significantly enhanced by GAD vector infection. Treatment of CGCs with kainic acid, which destroys most of the GABAergic neurons (<1% remaining), did not prevent vector-derived expression of GAD nor synthesis of GABA. This suggests that defective HSV vector-derived GAD expression can be used to increase GABA synthesis and release in CNS tissue, even in the relative absence of GABAergic neurons. The use of such GAD vectors in the CNS has potential therapeutic value in neurologic disorders such as epilepsy, chronic pain, Parkinson's and Huntington's disease.


Subject(s)
Cerebellum/cytology , Glutamate Decarboxylase/biosynthesis , Glutamate Decarboxylase/genetics , Simplexvirus/genetics , gamma-Aminobutyric Acid/biosynthesis , gamma-Aminobutyric Acid/metabolism , Animals , Cells, Cultured , Cerebellum/drug effects , Chlorocebus aethiops , Gene Expression/genetics , Genetic Vectors/biosynthesis , Glutamate Decarboxylase/analysis , Kainic Acid/pharmacology , Rats , Rats, Sprague-Dawley , Time Factors , Transfection/methods , Vero Cells , gamma-Aminobutyric Acid/analysis
17.
Brain Res Mol Brain Res ; 37(1-2): 317-23, 1996 Apr.
Article in English | MEDLINE | ID: mdl-8738167

ABSTRACT

Defective herpes simplex virus (HSV) vectors are an efficient means to deliver genes to cells of the central nervous system (CNS). Such vectors containing two independent transcription units would be extremely valuable for many studies, including the comparative analysis of promoter function and expression of multiple gene products in the CNS. We have constructed a 'double-cassette' vector expressing two easily detectable marker enzymes, beta-galactosidase (beta-gal) and human placental alkaline phosphatase (AP). Cells infected in vitro, including neurons and glia, and in vivo expressed both gene products.


Subject(s)
Central Nervous System/metabolism , Genetic Vectors/metabolism , Proteins/metabolism , Simplexvirus/metabolism , Animals , Blotting, Southern , Humans , Rabbits
18.
Scanning ; 16(5): 300-4, 1994.
Article in English | MEDLINE | ID: mdl-7994491

ABSTRACT

Corneal wound healing following excimer laser keratectomy is the major cause of regression of treatment results. The amount of anterior stromal haze that develops may be influenced by topical medications. Over a period of 6 months, we followed 15 New Zealand white rabbit eyes that underwent excimer laser keratectomy with the VISX 193-nm ArF laser at a fluence of 150 mJ/cm2 for a depth of 130 microns. Eyes were randomized to treatment with prednisolone acetate, diclofenac sodium (Voltaren), a combination of both, and a control group. Drops were administered four times a day for 1 week, two times a day for 3 weeks, and the drops were then tapered. All eyes were reepithelialized by 5 to 7 days. The tandem scanning confocal microscope (TSCM) was used to evaluate the corneal wound in vivo weekly for a month and monthly for 6 months. During the early postoperative period, the TSCM revealed significant anterior stromal keratocyte activation with cell elongation and the spindle-shaped appearance of fibroblasts in all groups. Collagenous stromal scarring was evident initially, then slowly decreased in all treatment groups. This study shows that TSCM is clinically useful for successive in vivo examinations of corneal wounds after excimer laser keratectomy and for comparing the effects of various topical medications.


Subject(s)
Cornea/pathology , Wound Healing , Animals , Cornea/surgery , Cornea/ultrastructure , Diclofenac/therapeutic use , Follow-Up Studies , Laser Therapy/adverse effects , Microscopy, Confocal , Postoperative Complications/drug therapy , Postoperative Complications/pathology , Prednisolone/analogs & derivatives , Prednisolone/therapeutic use , Rabbits
20.
Invest Ophthalmol Vis Sci ; 33(12): 3283-91, 1992 Nov.
Article in English | MEDLINE | ID: mdl-1428703

ABSTRACT

The relationship between changes in wound gape and corneal curvature after radial keratotomy (RK) was evaluated in five primates. Four-incision RK was performed using a diamond knife set to 100% of central corneal thickness with a 3-mm optical zone. In vivo measurements of wound gape were obtained using tandem scanning confocal microscopy at 3, 7, 14, and 45 days after surgery. The changes in corneal contour were measured at the same time points using a corneal modeling system with a specially designed primate cone. Wounds progressively increased in width to a maximum of 38 +/- 1 microns (n = 5) at day 7. After day 7, wounds showed increasing fibrosis which correlated with decreasing wound gape to 20 +/- 1 microns at day 45. A similar temporal change was detected in central corneal curvature (K), with maximum flattening occurring at day 7 (delta K = -3.17 +/- 0.90 diopters, n = 5), and progressive regression of effect to -1.32 +/- 0.61 diopters (n = 5) at day 45. Although there was interanimal variation, the mean temporal changes in corneal curvature significantly paralleled the changes in wound gape (r = -0.96, n = 4, P < 0.05). Based upon these findings, a simple geometric model was proposed which provides a hypothetic foundation for the relationship between corneal curvature and wound gape after RK. Calculations of wound gape made from this analytic model (using the measured topographic data) showed significant correlation with the actual wound gape measurements (r = 0.96, n = 4, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Cornea/pathology , Keratotomy, Radial , Wound Healing , Animals , Macaca fascicularis , Male , Models, Anatomic , Postoperative Period
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