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Biomedical subjects

W J Kelly

Publications and source records attributed to W J Kelly.

At least 19 recordsLinked to original sources
PubMed2004

Characterization of closely related lactococcal starter strains which show differing patterns of bacteriophage sensitivity.

AIMS: To characterize a group of closely related Lactococcus lactis subsp. lactis casein starter strains used commercially, which differ in their sensitivity to bacteriophages isolated from the same industrial environment. METHODS AND RESULTS: Nine strains of L. lactis, six of which had been used as starter cultures for lactic casein manufacture, were shown to be closely related by pulsed-field gel electrophoresis and total DNA profiles. Nineteen phages which propagated on one or more of these starter strains were isolated from industrial casein whey samples. The phages were all small isometric-headed and could be divided into five groups on the basis of host range on the nine strains. Most of the phages did not give a PCR product with primers designed to detect the two most common lactococcal small isometric phage species (936 and P335). The hosts could be divided into six groups depending on their phage sensitivity. Plasmids encoding genes for the cell envelope associated PI-type proteinase, lactose metabolism and specificity subunits of a type I restriction/modification system were identified. CONCLUSIONS: This work demonstrates how isolates of the same starter strain may come to be regarded as separate cultures because of their different origins, and how these closely related strains may differ in some of their industrially relevant characteristics. SIGNIFICANCE AND IMPACT OF THE STUDY: This situation may be very common among lactococci used as dairy starter cultures, and implies that the dairy industry worldwide depends on a small number of different strains.

Bacterial Typing Techniques↗
PubMed2002

Rapid analysis of a plasmid by hydrophobic-interaction chromatography with a non-porous resin.

A HPLC technique has been developed, based on hydrophobic-interaction Chromatography with a non-porous packing (TSKgel Butyl-NPR, Tosoh Biosep LLC), that allows separation of the open circular (nicked) and supercoiled forms of five DNA plasmids, ranging in size from 4 to 30 kilo base pairs (kb). The identity of the bands was determined through light scattering and gel electrophoresis. Several buffers, gradients, flow-rates and temperatures were evaluated in determining the optimum operating conditions for the separation. For all plasmids a reversed ammonium sulfate in phosphate buffer (pH 7.1) gradient was established. The chromatographic resolution between the supercoiled and nicked peaks was found to be a function of flow-rate and temperature. The resolution and the elution order did not vary with plasmid size, with the open-circular form always being eluted before the supercoiled form. Hydrophobic-interaction chromatography is a useful alternative to ion exchange or size exclusion for the chromatography of large plasmids, up to 30 kb.

Chromatography, High Pressure Liquid↗
PubMed2001

Early extubation after cardiac surgery: emotional status in the early postoperative period.

OBJECTIVE: To compare the emotional state during the first 3 days after coronary artery surgery of patients who had undergone early versus conventional extubation. DESIGN: A prospective, randomized, controlled trial. SETTING: University hospital, single center. PARTICIPANTS: Eligible patients (n = 100) presenting for elective coronary artery surgery, randomized to an early extubation group or a conventional extubation group. INTERVENTIONS: Emotional status was measured by the Hospital Anxiety and Depression Scale (HAD), the Self Assessment Manikin (SAM), and the Multiple Affect Adjective Check List-Revised (MAACL-R). Tests were administered preoperatively and on the 1st and 3rd days postoperatively. MEASUREMENTS AND MAIN RESULTS: Of patients in the conventional extubation group, 30% showed moderate-to-severe depressive symptoms (HAD score >10) on day 3 postoperatively compared with 8% of patients in the early extubation group (p = 0.02). There was a clinically insignificant increase in MAACL-R depression score on the 1st postoperative day within both groups but no other differences within or between groups in SAM or MAACL-R scores. CONCLUSION: Early extubation results in fewer patients displaying depressive symptoms on the 3rd postoperative day but appears to have little effect on other measurements of emotional status. Anesthetic management during coronary artery bypass graft surgery may play an important role in the overall well-being of the patient by decreasing the incidence of postoperative depression.

Affect↗
PubMed2000

Novel sucrose transposons from plant strains of Lactococcus lactis.

Lactococcus lactis strains isolated from vegetable products transferred the ability to ferment sucrose in conjugation experiments with the recipient strain L. lactis MG1614. Nisin production and sucrose fermentation were transferred together from two strains, but transfer also occurred from several other strains which did not produce nisin. Pulsed-field gel electrophoresis analysis showed that all transconjugants had acquired large chromosomal insertions at two main sites. Nisin sucrose transconjugants had gained inserts of 70 kb, while those that fermented sucrose without nisin production contained inserts of between 50 and 110 kb. Transconjugants from one donor had acquired a separate insertion of 55 kb which correlated with enhanced bacteriophage resistance, but contained neither nisin nor sucrose fermentation genes.

Bacteriophages↗
PubMed1998

Characterization of lactococci isolated from minimally processed fresh fruit and vegetables.

Lactic acid bacteria isolated from minimally processed fresh fruit and vegetable products were identified as Lactococcus lactis subsp. lactis on the basis of phenotypic tests, presence of lactococcal IS elements, and partial sequence analysis of the 16S rRNA gene. Isolated bacteria were differentiated using pulsed-field gel electrophoresis of SmaI digests of genomic DNA. Sprouted seeds were the best source of strains, and lactococci appear to be the dominant microflora on these products during the period they are intended to be eaten. Although these plant strains showed many similarities to strains of L. lactis used as dairy starter cultures, their carbohydrate fermentation patterns were unusual and probably reflect their environmental origin. Most strains fermented sucrose and xylose, and some also fermented raffinose and melibiose. Most of the bacteriocin-producing strains produced nisin, and nisin genes could also be detected in strains that showed no bacteriocin activity, or that produced a different bacteriocin with a narrow spectrum of activity. One strain produced nisin but was unable to ferment sucrose, properties that have been generally regarded as linked. These strains may have uses as biopreservatives for minimally processed plant products.

Blotting, Southern↗
PubMed1998

Early extubation following coronary artery bypass surgery: a prospective randomized controlled trial. The Fast Track Cardiac Care Team.

STUDY OBJECTIVES: To determine the safety of early extubation (EE) after coronary artery surgery. DESIGN: Prospective randomized controlled trial. SETTING: The cardiac surgery operating room and ICU of a university-affiliated teaching hospital. PATIENTS: One hundred eligible patients presenting for elective coronary artery surgery. INTERVENTIONS: Patients randomized to the EE group were administered a reduced dose of fentanyl (15 microg/kg) and an anesthetic compatible with EE, while patients randomized to the conventional extubation (CE) group were given fentanyl (50 microg/kg). MEASUREMENTS AND RESULTS: The time to extubation in the EE group (median, 240 min; range, 30 to 930 min) was significantly less than the CE group (median, 420 min; range, 125 to 1,140 min) (p<0.01). Twenty patients were withdrawn from the study according to protocol guidelines. There were no cases of reintubation or complications attributable to EE. CONCLUSIONS: By using an appropriate anesthetic technique and postoperative management, EE can be achieved following coronary artery bypass surgery without major complications.

Anesthesia↗
PubMed1997

Early developmental destruction of terminals in the striatal target induces apoptosis in dopamine neurons of the substantia nigra.

Many developing neural systems with peripheral projections depend on their target for trophic support during a critical period of natural cell death. Much less is known about central systems. That dopaminergic neurons of the substantia nigra may depend on their target, the striatum, during development is suggested by the presence of a natural apoptotic cell death event in these neurons that can be augmented by an early developmental axon-sparing striatal injury. To further assess the target dependence of these neurons, we have used the selective neurotoxin 6-hydroxydopamine to lesion their terminals within the striatum during development, while sparing intrinsic striatal target neurons. This lesion results in an induction of apoptotic cell death in phenotypically defined dopaminergic neurons that appears on the third postlesion day and persists until the tenth. This inducibility of cell death is dependent on developmental age: it is most marked before postnatal day (PND) 14. As late as PND42, inducibility is still detectable but much less so. In addition, at day 42 the morphology of cell death changes and becomes nonapoptotic in some cells. We conclude that terminal injury during a critical period of postnatal development, like axon-sparing target injury, induces augmented apoptotic death in mesencephalic dopaminergic neurons. These results suggest that these neurons have a period of target dependence. Regulation of this dependence is likely to influence the mature adult number of dopaminergic neurons.

Animals↗
PubMed1996

Apoptotic neuron death in rat substantia nigra induced by striatal excitotoxic injury is developmentally dependent.

We have previously observed that an axon-sparing lesion of the striatum during development is associated with an induction of apoptotic cell death in the substantia nigra (SN). We have postulated that the induced death is due to a loss of striatum-derived trophic support. In other paradigms of neural development, it is often found that a need for trophic support is primarily observed only during a critical development period. We have therefore examined the time course for early striatal lesion to induce cell death in substantia nigra. We find that induction of apoptotic cell death is largely restricted to the first 2 postnatal weeks. After that time, induction of death in SN pars compacta abates. In SN pars reticulata, apoptotic death also abates, but by postnatal day 28, a non-apoptotic morphology of death appears. Thus, induced apoptotic death in SN is restricted to a critical developmental period.

Animals↗
PubMed1996

Isolation and characterization of bacteriocin-producing lactic acid bacteria from ready-to-eat food products.

Lactic acid bacteria isolated from a range of foods sold in ready-to-eat form were screened for bacteriocin production. Twenty-two bacteriocin-producing cultures were isolated from 14 of the 41 foods sampled. Bacteriocin-producing isolates from meat, fish and dairy products were Lactobacillus and Leuconostoc species typically found associated with these products. Most of these isolates gave only a narrow inhibitory spectrum although two showed activity against Listeria monocytogenes. Fruit and vegetable products gave a broader range of organisms but most of the bacteriocin-producing cultures were found to be strains of Lactococcus. Several lactococci produced a nisin-like activity, and showed a broad inhibitory spectrum against the indicator strains tested. The ease with which bacteriocin-producing strains could be isolated implies that they are already being safely consumed in food, and highlights the potential for using bacteriocin-producing cultures for biopreservation, especially in association with minimally processed products.

Bacteriocins↗
PubMed1996

Initial qualitative evaluation of computed radiography in an intensive care unit.

The first computed radiography (CR) unit in Australia was installed at St Vincent's Hospital, Melbourne, in February 1994. An initial qualitative evaluation of the attitude of the intensive care unit (ICU) physicians to the CR unit was conducted in June 1994 by use of a survey. The results of the survey of ICU physicians indicated that images were available faster than under the previous system and that the use of the CR system was preferred to evaluate chest tubes and line placements. While it is recognized that a further detailed radiological evaluation of the CR system is required to establish the diagnostic performance of CR compared with conventional film, some comments on the implementation of the system and ICU physician attitudes to the CR system are put forward for consideration by other hospitals examining the possible use of CR systems.

Attitude of Health Personnel↗
PubMed1995

Differentiation of dextran-producing Leuconostoc strains from fermented rice cake (puto) using pulsed-field gel electrophoresis.

Lactic acid bacteria were isolated from puto, a fermented rice cake consumed as a breakfast and snack food in the Philippines. The microflora was dominated by dextran-producing leuconostocs, and these were differentiated into four groups using pulsed-field gel electrophoresis of restriction enzyme digested chromosomal DNA, in conjunction with taxonomic tests. The four groups corresponded to the species Leuconostoc mesenteroides subsp. mesenteroides, Leuconostoc pseudomesenteroides, Leuconostoc citreum and Leuconostoc fallax. Several strains showed an unusual clumping phenotype, and two of these were capable of inhibiting other strains of lactic acid bacteria.

Bacteriocins↗
PubMed1995

Clinical information systems and quality of care in the intensive care unit.

The introduction of new medical technology needs to be associated with the assessment of the value of this technology in patient care. Traditional outcome measures of quality in health care (such as survival, cost, and "quality of life") may be of little value in assessing quality of patient care at the bedside. A model of quality in bedside patient care is presented and used in the assessment of the impact of introducing a bedside information system on patient care quality.

Australia↗
PubMed1994

Fluctuating and/or progressive sensorineural hearing loss in children.

Sensorineural hearing loss (SNHL) which is sudden in onset, fluctuating, and/or progressive complicates medical management, hearing aid selection, and individualized educational planning for a hearing-impaired child. In spite of multidisciplinary evaluation and intervention, a gradual decrease in auditory acuity may continue unabated in a significant number of cases. Intercurrent middle ear disease and inconsistent audiologic technique can account for threshold variation in some cases. The study population consisted of 229 children (132 boys; 97 girls) aged 1 to 19.9 years at first audiogram which revealed at least a mild degree of sensorineural hearing loss in one or both ears (35 unilateral), and who demonstrated threshold variation of 10 dB or more in at least one ear at one or more of the standard audiometric test frequencies (250, 500, 1000, 2000, 4000, and 8000 Hz) and were without concurrent middle ear disease (mean length of follow-up, 4.9 years; mean number of audiograms, 10.3). Of 365 ears demonstrating threshold variation of 10 dB or more, 22 (6%) had purely progressive losses without intercurrent upward fluctuation, 208 (57%) had fluctuating thresholds with gradually progressive losses, and 135 (37%) had intermittent threshold fluctuation without permanent deterioration. The probability of contralateral threshold fluctuation if one ear fluctuated was 0.91, while the probability of contralateral progressive SNHL if one ear progressed was 0.67. Demographic data, presumptive etiology, degree of initial SNHL, audiometric configuration, and symmetry of threshold variation were considered as potential predictors of the likelihood of threshold fluctuation and/or progression.

Adolescent↗
PubMed1993

Middle ear disease in young children with sensorineural hearing loss.

Early identification of children with sensorineural hearing loss (SNHL), coupled with the provision of appropriate conventional amplification constitute important elements of a (re)habilitative strategy. Often overlooked, however, is the problem posed by recurrent and chronic middle ear disease in the child with coexisting SNHL. This study focuses on 437 (237 boys and 200 girls) consecutive patients with bilateral SNHL, in the moderate range or poorer, who were diagnosed prior to age 5 years at Boys Town National Research Hospital. The mean threshold shift with effusion was 25.0 dB at 250 Hz, 28.5 dB at 500 Hz, 29.5 dB at 1000 Hz, 24.5 dB at 2000 Hz, and 27.5 dB at 4000 Hz. During a median follow-up period of 3.21 years, 154 (35.2%) of these children required surgical placement of tympanostomy tubes because of the severity of middle ear disease and its impact on auditory acuity. Accurate determination of the degree and audiologic configuration of a SNHL may be seriously hindered by a coexisting middle ear effusion. If initial findings indicate the presence of a middle ear effusion, measures of auditory function must be repeated after the effusion has been resolved by medical and/or surgical intervention.

Acoustic Impedance Tests↗
PubMed1993

Comparison of Leuconostoc oenos Strains by Pulsed-Field Gel Electrophoresis.

Pulsed-field gel electrophoresis of chromosomal DNA digested with NotI or SfiI was used to differentiate individual strains of Leuconostoc oenos. L. oenos isolates with 13 different restriction digest patterns were detected in New Zealand wines undergoing malolactic fermentation. The average genome size was estimated to be 1,800 kb.

Journal Article↗
PubMed1992

Recurrence of neisserial meningococcemia due to deficiency of terminal complement component.

Recurrent infections with Neisseria meningitidis are attributed to deficiencies of terminal complement components. The serotype most commonly responsible for recurrent N meningitidis infections is serotype Y. We have reported a case of recurrent meningitis due to N meningitidis in a patient who was found to be deficient in the sixth component of complement. Complement deficiencies should be considered in any patient with recurrent infections caused by N meningitidis.

Adult↗
PubMed1992

Noise-induced hearing loss in children.

Occupational noise exposure remains the most commonly identified cause of noise-induced hearing loss (NIHL), but potentially hazardous noise can be encountered during leisure-time activities. NIHL in the pediatric population has received scant attention. This study focuses on 114 children and adolescents (ages 19 and under: 90.3% males) who were diagnosed as having probable NIHL on the basis of history and audiometric configuration. In 42 children the loss was unilateral, while the remaining 72 had sensorineural losses of varying configurations in the contralateral ear. The mean age of referral for evaluation was 12.7 years (range 1.2 to 19.8, SD 4.21), although 26% of these losses were diagnosed in children aged 10 years and younger. Such irreversible, but potentially preventable losses, should be given high priority on the public health agenda. Comprehensive, age-appropriate educational programs must be developed for elementary and secondary students and their parents to acquaint them with potentially hazardous noise sources in their environment.

Adolescent↗