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Biomedical subjects

A McAuley

Publications and source records attributed to A McAuley.

6 recordsLinked to original sources
PubMed2007

Effect of manufacturing process parameters on virus inactivation by dry heat treatment at 80 degrees C in factor VIII.

BACKGROUND AND OBJECTIVES: Dry heat treatment at 80 degrees C for 72 h is used as a virus inactivation step for some coagulation factor concentrates such as Bio Products Laboratory's (BPL) factor VIII 8Y. In the current study, the effect of this process has been tested on a range of viruses. In addition the effect of various manufacturing process parameters on virus inactivation has been investigated. MATERIALS AND METHODS: Samples of product intermediate were obtained from manufacturing, spiked with virus and subjected to freeze drying and dry heat treatment. Virus inactivation was determined by infectivity assay. RESULTS: Freeze drying followed by dry heat treatment was effective for inactivating a wide range of enveloped and nonenveloped viruses. Sucrose or protein concentration had no effect on virus inactivation. Product presentation or the interruption of heat treatment also had no effect. The inactivation of some of the viruses was greater at higher residual water content but under such conditions the stability of the product was reduced. CONCLUSION: This virus inactivation step was effective for a wide range of viruses and over the range of process conditions encountered in manufacturing. This demonstrates the robustness of this process step.

Decontamination↗
PubMed2001

Synthesis of 14-oxa-1,4,8,11-tetraazabicyclo[9.5.3]nonadecane(L1) and a spectroscopic and structural study of [Ni(L1)(ClO4)](ClO4) and of the macrobicyclic precursor diamide complex, [Ni(HL2)](ClO4); chloride substitution kinetics of the corresponding [Ni(III)(L1)]3+ species.

The pentadentate ligand 14-oxa-1,4,8,11-tetraazabicyclo[9.5.3]nonadecane (L1) has been synthesized by the high dilution cyclization of 1-oxa-4,8-diazacyclododecane ([10]aneN(2)O) (1) with 1,3-bis(alpha-chloroacetamido)propane (2) and subsequent reduction of the diamide intermediate. The structure [Ni(L1)(ClO(4))](ClO(4)) (P2(1)/c (no. 14), a = 8.608(3), b = 16.618(3), c = 14.924(4) A, beta = 91.53(3) degrees converged at R = 0.050 (R(w) = 0.046) for 307 parameters using 2702 reflections with I > 2sigma(I). For the nickel(II) complex of the (monodeprotonated) precursor diamide ligand 14-oxa-1,4,8,11-tetraazabicyclo[9.5.3]nonadecane-3,9-dione (H(2)L2), [Ni(HL2)](ClO(4)) (Pbca (no. 61), a = 15.1590(3), b = 13.235(2), c = 18.0195(6) A), the structure converged at R = 0.045 (R(w) = 0.038) for 265 parameters using 1703 reflections with I > 3sigma(I). In the reduced system, the cyclam-based ligand adopts a trans-III configuration. The [Ni(L1)(ClO(4))](2+) ion is pseudooctahedral with the Ni-O(ether) 2.094(3) A distance shorter than the Ni-O(perchlorate) 2.252(4) A. The nickel(II) and nickel(III) complexes are six-coordinate in solution. Oxidation of [Ni(L1)(OH(2))](2+) with K(2)S(2)O(8) in aqueous media yielded an axial d(7) Ni(III) species (g( perpendicular) = 2.159 and g( perpendicular) = 2.024 at 77 K). The [Ni(L1)(solv)](2+) ion in CH(3)CN showed two redox waves, Ni(II/I) (an irreversible cathodic peak, E(p,c) = -1.53 V) and Ni(III/II) (E(1/2) = 0.85 V (reversible)) vs Ag/Ag(+). The complex [Ni(HL2)](ClO(4)) displays square-planar geometry with monodeprotonation of the ligand. The ether oxygen is not coordinated. Ni-O(3) = 2.651(6) A and Ni-O(3a) = 2.451(12) A, respectively. The Ni(III/II) oxidation at E(1/2) = 0.24 V (quasi-reversible) vs Ag/Ag(+) is considerably lower than the saturated system. The kinetics of Cl(-) substitution at [Ni(L1)(solv)](3+) are pH dependent. Detachment of the ether oxygen atom is proposed, with insertion of a protonated water molecule which deprotonates at a pK(a) more acidic than in the corresponding cyclam complex. Mechanistic implications are discussed.

Journal Article↗
PubMed1998

Platelet activation, epinephrine, and blood pressure in obstructive sleep apnea syndrome.

OBJECTIVE: There is an increased risk of patients with obstructive sleep apnea syndrome (OSAS) to have stroke or cardiac infarcts. Besides hypertension, epinephrine-induced platelet activation could be a further reason for the increased cardiovascular morbidity and mortality in OSAS. METHODS: During a 4-month period (August 1994 to December 1994) we recruited prospectively 76 patients referred for polysomnograms because of a suspected sleep disorder such as OSAS. RESULTS: Fifty patients had no respiratory events during sleep (non-OSAS), 19 patients had more than five but less than 50 obstructive apneas or hypopneas per hour of total sleep time (mild-to-moderate OSAS group), and seven patients had an apnea hypopnea index of more than 50 per hour of total sleep time (severe OSAS group). Blood pressure, plasma epinephrine levels, and P-selectin expression (as a marker for platelet activation) were measured in every patient at 9 PM and 6 AM (before and after the polysomnogram). There was a significant correlation of the apnea hypopnea index with 9 PM and 6 AM systolic and diastolic blood pressure, with 9 PM platelet activation, and with 6 AM epinephrine levels mainly due to high values in the severe OSAS group. CONCLUSIONS: Our results suggest that platelet activation, epinephrine, and high blood pressure play a role in the high prevalence of cerebrovascular and cardiovascular events in patients with OSAS.

Adult↗
PubMed1995

Mental disorder among a homeless population in Belfast: an exploratory survey.

This study aimed to identify the prevalence of mental disorder in hostels for the homeless in Belfast, Northern Ireland. In addition, it attempted to assess the facilities and support offered from both the hostels and the Health Service to homeless people who have a mental disorder. Lastly it sought to determine whether or not psychiatric hospital bed closure had any influence on the prevalence of homelessness among these persons in Belfast. An exploratory approach was adopted, using semi-structured interviews as the method of data collection. The sample consisted of 12 hostels for the homeless with a total occupancy of 250 residents. Officers in charge were surveyed. The results obtained indicated that approximately 25% of the homeless in Belfast hostels have a diagnosed mental disorder and that hospital closure has had a direct effect on the size of this percentage. In addition, it was found that the hostels generally are not able to offer the levels of therapy and support given in hospital or in designated hostels for people with mental health problems. Responses also suggest that support from Health Service personnel is less than satisfactory. While the findings in this study do not look at the entire homeless population in Northern Ireland, interesting and useful information emerged that has implications for policy and further areas of study elsewhere.

Health Facility Closure↗