Biomedical subjects

Peter Barry

Publications and source records attributed to Peter Barry.

9 recordsLinked to original sources

PubMed2006

ESCRS study of prophylaxis of postoperative endophthalmitis after cataract surgery: Case for a European multicenter study.

PURPOSE: To present the development and design of the European Society of Cataract & Refractive Surgeons multicenter study of the prevention of postsurgical infective endophthalmitis after phacoemulsification and to describe the process for its successful implementation and conduct. SETTING: Twenty-four ophthalmology units and eye clinics in Austria, Belgium, Germany, Italy, Poland, Portugal, Spain, Turkey, and the United Kingdom, with an administrative office in Ireland, coordinating center in England, and data management and statistical unit in Scotland. METHODS: This partially masked randomized placebo-controlled multinational clinical study was designed to evaluate prospectively the prophylactic effect of intracameral cefuroxime and/or perioperative topical levofloxacin on postoperative endophthalmitis after cataract surgery. Random allocation was based on a 2 x 2 factorial design that included participating centers as a class variable. Real-time electronic data collection monitored study progress and provided weekly outcome tables, monthly recruitment summaries, and quarterly analytical reports for the study's Data Monitoring Committee, which evaluated the safety and efficacy by Internet-based conferences. RESULTS: A 2-year lead time was required to meet harmonized standards of clinical research in the European Union, obtain ministerial authorization in 3 countries, gain institutional approvals at 24 hospitals, and procure indemnity insurance for surgical centers. Informed consent instruments, designed to comply with national health policies, were translated into 8 languages. The use of information technology to collect study data enabled the organizers to evaluate individual eligibility at enrollment, adherence with study medications during and after surgery, and postoperative status during follow-up. CONCLUSION: This international cooperative study provided the opportunity to estimate the current incidence of endophthalmitis after cataract surgery in Europe and determine whether 1 or both of 2 antimicrobial regimens reduces the risk for postsurgical intraocular infection.

Administration, Topical↗

PubMed2006

ESCRS study of prophylaxis of postoperative endophthalmitis after cataract surgery: Preliminary report of principal results from a European multicenter study.

PURPOSE: To report results in the European Society of Cataract & Refractive Surgeons (ESCRS) multicenter study of the prophylaxis of endophthalmitis after cataract surgery. SETTING: Twenty-four ophthalmology units and eye clinics in Austria, Belgium, Germany, Italy, Poland, Portugal, Spain, Turkey, and the United Kingdom, with an administrative office in Ireland, coordinating center in England, and data management and statistical unit in Scotland. METHODS: This partially masked randomized placebo-controlled multinational clinical study to evaluate prospectively the prophylactic effect of intracameral cefuroxime injection and/or perioperative levofloxacin eyedrops on the incidence of endophthalmitis after phacoemulsification cataract surgery began in September 2003 and was terminated early in January 2006. The study used random allocation of patients in a 2 x 2 factorial design. RESULTS: By the end of 2005, complete follow-up records had been received for 13 698 study patients. Such a clear beneficial effect from the use of intracameral cefuroxime had been observed that it was agreed it would be unethical to continue the study and to wait for the completion of all follow-up procedures before reporting this important result. If total reported cases of endophthalmitis are considered, the incidence rate observed in those treatment groups not receiving cefuroxime prophylaxis (23 cases in 6862 patients) was almost 5 times as high (odds ratio [OR], 4.59; 95% confidence interval [CI], 1.74-12.08; P = .002) as that in the groups receiving this treatment (5 cases in 6836 patients). If only cases proved to be due to infection are considered, the rate was more than 5 times as high (OR, 5.32; 95% CI, 1.55-18.26; P = .008) in the treatment groups not receiving cefuroxime. Although the use of perioperative levofloxacin eyedrops as prophylaxis was also associated with a reduction in the observed incidence rate of postoperative endophthalmitis, this effect was smaller and was not statistically significant, whether total reported cases or only cases proven to be due to infection are used in calculating the rates. As not all follow-up procedures are complete, it is possible that further cases of endophthalmitis may be reported; however, it is not expected that this will alter the main conclusion. Nevertheless, it is anticipated that successful completion of follow-up procedures in all patients will increase the total number in the study to approximately 16,000. CONCLUSION: Intracameral cefuroxime administered at the time of surgery significantly reduced the risk for developing endophthalmitis after cataract surgery.

Administration, Topical↗

PubMed2005

Incidence of presumed postoperative endophthalmitis in Dublin for a 5-year period (1997--2001).

PURPOSE: To evaluate the incidence of presumed endophthalmitis following cataract surgery over a 5-year period in a busy ophthalmic hospital. SETTING: Ophthalmology unit in the Royal Victoria Eye and Ear Hospital, Dublin, Ireland. METHODS: A retrospective series of 8736 consecutive cases of cataract extraction with intraocular lens implantation carried out during a period of 5 years from 1997 to 2001 were studied. All cases requiring readmission due to suspected postoperative infection were investigated as part of the study. RESULTS: A total of 8763 patients had a cataract procedure. Forty three of them were readmitted with suspected endophthalmitis, giving a total suspected endophthalmitis rate of 0.5%. Of the 43 readmitted cases, 29 cases (67%) had hypopyon and 14 cases (32%) had fibrinous uveitis. Of those with hypopyon, 83% received intravitreal antibiotics. Of those with fibrinous uveitis, none received intravitreal antibiotics. There was a difference in the numbers achieving visual acuity of 6/12 or better between the 2 groups (33% and 14% of patients, respectively). In cases that had a vitreous biopsy, 10 (42%) were culture positive and of these, the most common organism found was Staphylococcus aureus (50%). Fourteen of the 43 cases (32.5%) that presented with fibrinous uveitis were treated with topical, subconjunctival, and systemic antibiotics with steroids. Visual acuity of 6/12 or better was achieved in 6 patients (14%). CONCLUSIONS: The incidence of suspected endophthalmitis following cataract surgery in a 5-year period in a busy Irish ophthalmic unit was 0.49%. Culture-positive endophthalmitis was 0.1%, but only 56% of cases with presumed endophthalmitis had a vitreous biopsy performed. The visual outcome was better in patients who were treated with intravitreal antibiotics at the first sign of symptoms. These findings support the hypothesis that infection is the most likely cause of postoperative endophthalmitis and that it may present as hypopyon or fibrinous uveitis. Prompt investigation and treatment of such patients with a standard endophthalmitis protocol should be instituted to save vision.

Aged↗

PubMed2004

Novel cassette-based shuttle vector system for gram-positive bacteria.

Our understanding of staphylococcal pathogenesis depends on reliable genetic tools for gene expression analysis and tracing of bacteria. Here, we have developed and evaluated a series of novel versatile Escherichia coli-staphylococcal shuttle vectors based on PCR-generated interchangeable cassettes. Advantages of our module system include the use of (i) staphylococcal low-copy-number, high-copy-number, thermosensitive and theta replicons and selectable markers (choice of erythromycin, tetracycline, chloramphenicol, kanamycin, or spectinomycin); (ii) an E. coli replicon and selectable marker (ampicillin); and (iii) a staphylococcal phage fragment that allows high-frequency transduction and an SaPI fragment that allows site-specific integration into the Staphylococcus aureus chromosome. The staphylococcal cadmium-inducible P(cad)-cadC and constitutive P(blaZ) promoters were designed and analyzed in transcriptional fusions to the staphylococcal beta-lactamase blaZ, the Vibrio fischeri luxAB, and the Aequorea victoria green fluorescent protein reporter genes. The modular design of the vector system provides great flexibility and variety. Questions about gene dosage, complementation, and cis-trans effects can now be conveniently addressed, so that this system constitutes an effective tool for studying gene regulation of staphylococci in various ecosystems.

Artificial Gene Fusion↗

PubMed2003

Prevalence of antibodies to selected viruses in a long-term closed breeding colony of rhesus macaques (Macaca mulatta) in Brazil.

The rhesus macaque breeding colony of the Oswaldo Cruz Foundation (FIOCRUZ) was established in 1932 from a founding stock of 100 animals. This population has remained closed to new animal introductions for almost 70 years. A serologic survey was performed to determine the prevalence of antibodies to selected viruses as a first approach to identifying viral pathogens endemic in this population. Banked serum samples were tested for antibodies to simian immunodeficiency virus (SIV), simian T-lymphotropic virus (STLV), simian type D retrovirus (SRV), cercopithecine herpesvirus type-1 (B virus), rhesus cytomegalovirus (RhCMV), measles virus (MV), and hepatitis A virus (HAV). All samples were negative for antibodies against the simian retroviruses. The overall prevalence of antibodies was 95% for RhCMV, 45% for B virus, 35% for HAV, and 1% for MV. Prevalence was found to vary by age group.

Animals↗

PubMed2003

Direct relationship between suppression of virus-specific immunity and emergence of cytomegalovirus disease in simian AIDS.

Although opportunistic infections like cytomegalovirus (CMV) are common sequelae of end-stage AIDS, the immune events leading to CMV reactivation in human immunodeficiency virus (HIV)-infected individuals are not well defined. The role of cellular and humoral CMV-specific immune responses in immune control of latent CMV infection was evaluated prospectively in a cohort of 11 simian immunodeficiency virus (SIV)-infected CMV-seropositive rhesus macaques, 6 of whom had histologic evidence of CMV disease at death. Macaques with CMV disease differed from macaques without CMV disease in having significantly higher levels of plasma SIV RNA and CMV DNA and significantly lower titers of anti-CMV binding antibodies (Abs) at the time of death. A significant decline in anti-CMV Abs and CMV-specific CD4(+) and CD8(+) T lymphocytes over time was observed in the macaques with CMV disease, but not in the macaques without CMV disease. Reduction in CMV-specific CD8(+) T lymphocytes and anti-CMV neutralizing Abs was significantly correlated with a decline in CMV-specific CD4(+) T lymphocytes. Although declines in CMV-specific T lymphocytes alone were sufficient for reactivation of low-level CMV viremia, high-level viremia (>1,000 copies of CMV DNA per ml of plasma) was observed when anti-CMV neutralizing and binding Abs had also declined. Thus, the occurrence of CMV reactivation-associated disease in AIDS is associated with suppression of both cellular and humoral CMV-specific immune responses. The underlying mechanism may be a dysfunction of memory B and CD8(+) T lymphocytes associated with SIV-induced impairment of CMV-specific CD4(+) T-cell help.

Animals↗

PubMed2002

Cardiovascular and respiratory adjustments at altitude sustain cerebral oxygen delivery -- Severinghaus revisited.

Analysis of a paper by Severinghaus et al. (see text) has already shown that sea level oxygen delivery (D(a)O(2)) is sustained 8 h after ascent to 3810 m, despite low arterial oxygen content (C(a)O(2)), largely as a result of increased cerebral blood flow (CBF). The present study extends the analysis to show that D(a)O(2) is also sustained after 3 and 5 days at altitude, despite a progressively falling CBF. It is shown that this later compensation is a result of the improvement in C(a)O(2), which accompanies acclimatisation. Since less than 3% rise in haemoglobin occurred, the rise in C(a)O(2) was predominantly respiratory. It has been shown elsewhere that as acclimatisation occurs, the fall in arterial PCO(2) (P(a)CO(2)) results in increased arterial PO(2) (P(a)O(2)) until they are related according to P(a)CO(2)=0.25 P(a)O(2)+/-15 mmHg. The results from Severinghaus et al. at 3 and 5 days fall close to this line. We also report arterialised capillary blood gases from 18 normal subjects, acclimatised at 5300 m. The values fall in a group centred on the same line. In summary, soon after arrival at altitude (8 h), cerebral oxygen delivery is largely sustained by an increase in CBF. The present study shows that, although CBF declines during the 3-5 day period, D(a)O(2) is sustained as a result of the improvement in C(a)O(2), which is mainly due to respiratory acclimatisation.

Acclimatization↗

PubMed2002

Aerosols in bronchiolitis.

Bronchiolitis is a common illness of the lower respiratory tract affecting infants that has considerable short and long-term morbidity and occasional mortality. It is the commonest cause of hospitalization for respiratory infection in early childhood, and the seasonal nature of the illness places considerable strain on health care resources during the bronchiolitis season. The youngest infants and those with preexisting cardiorespiratory disease are particularly at risk of severe illness. The treatment of infants with bronchiolitis is largely supportive. There are no therapies that have been proven to reduce the length of the hospitalization or intensive care stay. This paper will review the clinical course of bronchiolitis and discuss the aerosolized therapies that have been proposed for its treatment.

Administration, Inhalation↗

PubMed2002

The output of flunisolide from different nebulisers.

The objective of this study was to determine the output, in-vitro, solution of a concentrated solution of flunisolide from two different nebulisers under simulated breathing conditions. The BimboNeb and Nebula nebulisers were used to nebulise 2.6 mL of flunisolide solution (600 microg). Particle size was determined by inertial impaction and the total output of drug from the nebulisers under simulated breathing conditions was measured using a sinus flow pump. Two different breathing patterns were used, simulating nebuliser use by a child and an adult. The mass median aerodynamic diameter of flunisolide particles from the BimboNeb and Nebula were both 3.9 microm. With the simulated paediatric breathing pattern, both nebulisers delivered similar amounts of flunisolide (56.4 microg (s.d. 1.4 microg) and 56.1 microg (5 microg) over 5 min from the BimboNeb and Nebula, respectively). With the adult breathing pattern, flunisolide delivery from the BimboNeb was increased to 88.9 microg (3.3 microg), but delivery from the Nebula was only slightly increased to 64.6 microg (1.4 microg). With both nebulisers, little drug was released after 5 min of nebulisation. Both nebulisers delivered 9-15% of the nominal dose of flunisolide to the breathing simulator, a similar percentage to previous studies with budesonide and more than previous studies with beclometasone. Drug delivery from the BimboNeb, but not the Nebula, was affected by the simulated breathing pattern. This study suggests that drug delivery from nebulisers is dependent upon the interaction between the nebuliser, the drug and the patient.

Administration, Inhalation↗