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Biomedical subjects

A R Kerr

Publications and source records attributed to A R Kerr.

At least 19 recordsLinked to original sources
PubMed2006

Clinical evaluation of chemiluminescent lighting: an adjunct for oral mucosal examinations.

OBJECTIVE: The purpose of this study was to describe the utility of oral chemiluminescent lighting (FDA-cleared ViziLite) as an adjunct to standard visual examination (SVE) to enhance visualization of mucosal lesions, particularly those "clinically suspicious" for oral pre-cancer or cancer. Subjects were considered at risk for oral cancer or pre-cancer if they have no a priori knowledge of the presence or absence of an oral lesion at the time of examination. METHODOLOGY: Five-hundred and one consecutive consenting subjects, over 40 years of age and with a positive tobacco history, received a standard visual examination with conventional incandescent lighting, followed by chemiluminescent lighting. All lesions were recorded, and for lesions detected by both screening modalities, comparisons were made of the subjective parameters of lesion brightness, sharpness, surface texture, and relative size. RESULTS: A total of 410 epithelial lesions were detected in 270 subjects by standard visual examination, of which 127 were clinically "suspicious" for oral cancer and pre-cancer. Ninety-eight lesions were also visualized by chemiluminescent lighting as "aceto-white" (CL+), in addition to six lesions not previously seen by standard visual examination. Seventy-seven of the CL+ lesions (78.5%) were clinically suspicious; all "suspicious" lesions with an ulcerative component and ulcerated lesions consistent with trauma were CL+. Leukoplakias were significantly more likely to be CL+ than erythroplakias (p < 0.01). Overall, those lesions illuminated by chemiluminescent lighting appeared brighter, sharper, and smaller compared to incandescent illumination. CONCLUSION: The results of this study suggest that oral chemiluminescent lighting, when used as a screening adjunct following the standard visual oral examination, provides additional visual information. Leukoplakias may be more readily visualized by chemiluminescence. Studies are underway to explore the clinical significance and predictive value of oral chemiluminescent lighting.

Adult↗
PubMed2004

The Ami-AliA/AliB permease of Streptococcus pneumoniae is involved in nasopharyngeal colonization but not in invasive disease.

The Ami-AliA/AliB oligopeptide permease is an ATP-binding cassette transporter which is found in Streptococcus pneumoniae and which is involved in nutrient uptake. We investigated the role of the three paralogous oligopeptide-binding lipoproteins AmiA, AliA, and AliB by using murine models of pneumococcal colonization and invasive disease. A series of mutants lacking aliA, aliB, and amiA either alone or in combination as double or triple mutations were used. Inoculation of the nasopharynx with a mixture of the obl (oligopeptide-binding lipoprotein-negative) triple-mutant and wild-type (D39) bacteria resulted in significantly smaller numbers of obl bacteria colonizing the nasopharynx. The use of a mixture of individual mutants and wild-type pneumococci revealed that AmiA, AliA, and AliB were all required for successful colonization of the nasopharynx. The obl mutant was more attenuated than the aliB mutant but not the aliA or amiA mutant. Therefore, there is some redundancy in the Ami-AliA/AliB complex in terms of nasopharyngeal colonization, with AliA and AmiA being able to compensate for the removal of AliB. Animals with invasive disease caused by these mutants had survival times, bacterial loads, and inflammatory cytokine production levels similar to those of animals infected with wild-type pneumococci. Our results show that although the Ami-AliA/AliB complex is not required for virulence during pneumococcal pneumonia, it does play a role in colonization of the nasopharynx.

Animals↗
PubMed2003

ZmpB, a novel virulence factor of Streptococcus pneumoniae that induces tumor necrosis factor alpha production in the respiratory tract.

Inflammation is a prominent feature of Streptococcus pneumoniae infection in both humans and animal models. Indeed, an intense host immune response to infection is thought to contribute significantly to the pathology of pneumococcal pneumonia and meningitis. Previously, induction of the inflammatory response following infection with S. pneumoniae has been attributed to certain cell wall constituents and the toxin pneumolysin. Here we present data implicating a putative zinc metalloprotease, ZmpB, as having a role in inflammation. Null mutations were created in the zmpB gene of the virulent serotype 2 strain D39 and analyzed in a murine model of infection. Isogenic mutants were attenuated in pneumonia and septicemia models of infection, as determined by levels of bacteremia and murine survival. Mutants were not attenuated in colonization of murine airways or lung tissue. Examination of cytokine profiles within the lung tissue revealed significantly lower levels of the proinflammatory cytokine tumor necrosis factor alpha following challenge with the Delta zmpB mutant (Delta 739). These data identify ZmpB as a novel virulence factor capable of inducing inflammation in the lower respiratory tract. The possibility that ZmpB was involved in inhibition of complement activity was examined, but the data indicated that ZmpB does not have a significant effect on this important host defense. The regulation of ZmpB by a two-component system (TCS09) located immediately upstream of the zmpB gene was examined. TCS09 was not required for the expression of zmpB during exponential growth in vitro.

Animals↗
PubMed2001

Outcome following heart transplantation in Maori and Polynesian patients: a comparison with European New Zealanders.

AIM: To compare demographic, clinical and outcome data of Maori and Polynesian with New Zealand European heart transplant patients. METHODS: A retrospective analysis was made of data from the 104 patients who underwent heart transplantation at Green Lane Hospital over a period of twelve years, of whom 79 were European, 23 Maori/Polynesian, and two Asian. Clinical characteristics, blood group, HLA matching and outcomes of recipients were compared. RESULTS: There was no significant difference in age and gender between the two groups. Maori and Polynesian patients were heavier, had a greater body mass index and were more likely to have rheumatic heart disease than their European counterparts. Maori/Polynesian patients were predominantly blood group A, whilst European patients were mainly group O. The waiting time for a donor heart was similar in both groups. There was no significant difference in number of rejection episodes and survival. CONCLUSIONS: Green Lane Hospital has the largest international experience of heart transplantation in Maori and Polynesian patients. Although there are some differences in clinical profile, outcome in terms of rejection episodes and survival is similar in the two groups.

Adolescent↗
PubMed2001

Rare venous connection causes severe cyanosis after the Fontan operation.

We describe a rare case of cyanosis following the Fontan operation secondary to right-to-left shunting through a pulmonary vein connected to both the left atrium and the hepatic veins. This is a hazardous anomaly in a Fontan candidate and should be considered in those with unexpected postoperative desaturation.

Angiography↗
PubMed2001

Stage one Norwood procedure results: the green lane experience.

AIMS: This study examined the presentation outcome, morbidity and mortality of infants who have undergone the stage one Norwood procedure for single ventricle reconstruction. METHODS: A retrospective review was done on the first 20 patients to undergo this procedure at Green Lane Hospital, Auckland, New Zealand. Seven patients were diagnosed antenatally. Fetal cardiology records in the same time period were reviewed. RESULTS: Twelve of the 20 patients (60%) have survived, and all of these patients have undergone their bi-directional Glenn procedure with no mortality. Eight patients died, with five of the deaths occurring in the perioperative period. Initial surgical mortality was 75%, decreasing to 25% since 1998. Antenatal diagnosis has not improved surgical outcome to date. CONCLUSION: With advances in surgical technique and pre- and postoperative care, neonates born with single ventricle anatomy have an acceptable surgical option. Babies who survive the Norwood operation have a good chance of surviving the later stages of the cardiac reconstruction process, and they have a reasonable outlook in the intermediate term.

Journal Article↗
PubMed2000

Transposition of the great arteries: operative outcome in the current era.

AIMS: To assess the operative outcome, cardiac and neurodevelopmental sequelae in infants with transposition of the great arteries (TGA) undergoing the arterial switch operation (ASO). METHOD: Cross-sectional review of the 48 consecutive patients operated on in the calendar years 1995 and 1996 was undertaken to obtain recent cardiac, growth and neurodevelopmental parameters, and the mortality results were compared to the entire cohort of infants who underwent the ASO for definitive repair of TGA and double outlet right ventricle at Greenlane hospital between 1984 and 1998. RESULTS: Between January 1995 and December 1996, 48 patients underwent the ASO. 96% were alive, and 88% alive and free from reoperation or significant neurological sequelae at a mean followup interval of sixteen months. Six (13%) had important residual cardiac lesions, of which supra valvular pulmonary stenosis was the most common. Growth parameters at follow-up were normal, as was the neurodevelopmental progress of all but two survivors (96%). CONCLUSION: In the current era, the ASO is a relatively safe procedure with excellent cardiac and neurodevelopmental outcome in the majority of infants.

Cardiac Surgical Procedures↗
PubMed1999

Blunt chest trauma and the heart.

The Green Lane Hospital experience of patients presenting with cardiac damage as a result of chest trauma has been reviewed following the recent referral of a patient with tricuspid regurgitation due to trauma. A retrospective search of surgical records was made over the preceding 28 years which yielded a further nine patients. Our group has experienced a number of unusual causes of non-fatal cardiac trauma that have followed accidents. In nine out of ten cases closed chest injury resulted in damage to the heart. In some, diagnosis had been delayed for years. Echocardiography is a very useful diagnostic tool. Surgery was undertaken in all cases.

Adolescent↗
PubMed1999

Long-term survival and valve-related complications in young women with cardiac valve replacements.

BACKGROUND: The type of cardiac valve replacement associated with the lowest health risks for young women who may undergo pregnancies is unknown. We investigated which valve type was associated with greatest patient and valve survival and the effect of pregnancy on valve loss. METHODS AND RESULTS: In this retrospective study, all women 12 to 35 years old who underwent valve replacements between 1972 and 1992 at Greenlane Hospital were identified, and follow-up was available in 93%. The 232 women were followed up for 1499 patient-years. Ten-year survival of women with mechanical (n=178), bioprosthetic (n=73), and homograft (n=72) valves was 70% (95% CI, 59% to 83%), 84% (95% CI, 72% to 99%), and 96% (95% CI, 91% to 100%), P=0.002. After adjustment for confounding variables, the relative risk (RR) of death with mechanical compared with bioprosthetic valves was 2.17 (95% CI, 0.78 to 5.88). Thromboembolic events occurred in 45% of women with mechanical valves within 5 years, compared with 13% with bioprosthetic valves, P=0.0001. Valve loss at 10 years was higher in bioprosthetic valves [82% (95% CI, 62% to 92%)] than in mechanical [29% (95% CI, 17% to 39%)] or homograft [28% (95% CI, 12% to 41%)] valves, P=0.0001. Pregnancy was not associated with increased bioprosthetic (RR, 0.96; 95% CI, 0.68 to 1. 35), homograft (RR, 0.65; 95% CI, 0.37 to 1.13), or mechanical (RR, 0.54; 95% CI, 0.27 to 1.08) valve loss. CONCLUSIONS: Although 10-year valve survival was greater with mechanical than bioprosthetic valves, mechanical valves may be associated with reduced patient survival in young women. Thromboembolic complications, often with long-term sequelae, were common with mechanical valves. Pregnancy did not increase structural deterioration or reduce survival of bioprosthetic valves.

Adult↗
PubMed1999

Subclinical aortic perforation with the infant double-button patent ductus arteriosus occluder.

Modification of the double-button (Sideris) patent ductus arteriosus (PDA) occluder has resulted in a single-strut aortic component rather than the conventional cross-strut design. We report the use of this infant PDA occluder for transcatheter closure in three patients with PDA measuring 2 mm, 3.7 mm, and 4 mm. Subclinical aortic perforation with a small aortic aneurysm developed in two patients 1 year after occluder implantation. The third patient had developed a small aortic aneurysm without perforation at 3-month follow-up. All three patients had a residual shunt and underwent successful PDA surgical closure with aortic aneurysmal repair. Single-strut umbrella designs are not recommended for PDA transcatheter closure.

Aorta, Thoracic↗
PubMed1999

The failing Fontan with atrial flutter: a successful surgical option.

Two successful cases of eliminated atrial flutter and improved clinical status for Fontan patients are presented. An operation combining introduction of an extracardiac conduit for the Fontan connection, to direct all systemic venous blood away from the atrium, and atrial pathway division and cryoablation, is a useful surgical option for failing Fontan patients.

Adolescent↗
PubMed1997

Coronary revascularisation in young adults.

OBJECTIVE: To evaluate the long-term outcome of coronary artery bypass surgery (CABG) in patients < 40 years old and to determine factors predictive of adverse outcomes. METHODS: Retrospective review of data on 220 patients who underwent isolated CABG at Green Lane Hospital, New Zealand from 1970 to 1992. RESULTS: The actuarial survival after surgery was 91, 74 and 50% at 5, 10 and 15 years, respectively. Recurrence of ischaemic symptoms occurred at a median time of 72 months, and only 20% of patients remained asymptomatic 10 years after CABG. Univariate analysis of potentially adverse surgical factors showed that patients who had prolonged bypass time (> or = 100 min, P < 0.007) had increased late mortality. There were two distinct operative eras with respect to the use of IMA conduits (4% pre 1985, 87% post 1984) The relationship between IMA conduits use and survival was significant on time independent analysis (P < 0.02), but was not using the log-rank test. Preoperative clinical characteristics associated with increased late mortality were impaired left ventricular function (end-systolic volume (ESV) > or = 80 ml, P = 0.008; ejection fraction < 40%, P = 0.0005), and lack of aspirin use either pre- or post-operatively (P < 0.0001). Multivariate analysis indicated that reduced ejection fraction (P = 0.04) and prolonged bypass time (P = 0.05) was associated with an increased risk of late death. Aspirin therapy (P = 0.001) was associated with decreased late mortality. Cumulative events rate of reintervention and mortality was reduced in female patients (P = 0.0009). At review, 45% of patients had total cholesterol > 6.5 mmol/l. CONCLUSION: To avoid the early recurrence of symptoms, the need for reintervention and late mortality, young patients should receive IMA conduits, cardioplegia as myocardial protection, aspirin and therapy to modify/ameliorate their risk factors including dyslipidaemia, diabetes and left ventricular dysfunction.

Actuarial Analysis↗
PubMed1996

Risk factors in heart transplantation. A statistical study of New Zealand cases.

The first heart transplantation in New Zealand was performed on December 2, 1987. This study covers all forty-five transplantations that were performed in New Zealand at Green Lane Hospital from that time through January 1994. Eleven patients from that group have died. The 30 day and 1, 2 and 4 year survival rates were found to be 91.1, 86.7, 80.0 and 75.6%, respectively. The mean waiting period of the patients for heart transplantation was 61.9 days. Only pulmonary vascular resistance was a statistically significant risk factor for early death after cardiac transplantation. Ischemic time was not a significant risk factor in this study.

Adult↗
PubMed1995

Late outcome after coronary artery bypass graft surgery in patients < 40 years old.

BACKGROUND: Randomized trials confirm the long-term efficacy of coronary artery bypass graft surgery (CABG), although there are no randomized data in patients < 40 years old. Because these patients have been reported to have an early recurrence of symptoms, the long-term postoperative outcome was examined. METHODS AND RESULTS: The long-term outcome of patients (n = 221) < 40 years old undergoing CABG at Green Lane Hospital, New Zealand, from 1970 to 1992 was determined. The 30-day mortality rate was 1.8% for initial and 9.5% for redo CABG. The median times to angina or myocardial infarction (recurrent ischemic event), further intervention, and death were 6.0, 9.6, and 14.2 years, respectively. Factors associated with increased late mortality on univariate analysis included end-systolic volume (ESV) > or = 80 mL (P = .004; 10-year mortality 19% versus 39% ESV > or = 80 mL), no internal mammary conduit (P = .01), no lipid-modifying therapy (P = .005), and no postoperative aspirin use (P = .0002); the latter was also associated with increased recurrent ischemic events (P = .04) or increased reintervention (P = .02). On stepwise logistic regression analysis, factors associated with increased late mortality were increasing ESV (P = .004), no internal mammary artery conduit (P = .009), diabetes (P = .04), and no postoperative aspirin (P = .02); the latter was also associated with increased recurrent ischemic events (P = .02). Hypercholesterolemia (> or = 6.5 mmol/L) was present in 65% of patients at presentation and 45% at follow-up. CONCLUSIONS: To attempt to prevent recurrent ischemia or late death, patients < 40 years old who require CABG should receive internal mammary conduits, aspirin, lipid-modifying therapy, therapy to inhibit ventricular dilatation, and strict diabetes management.

Actuarial Analysis↗
PubMed1995

Good long-term outcome following surgical repair of post-infarction ventricular septal defect.

BACKGROUND: A post-infarction ventricular septal defect (VSD) is a serious complication of a myocardial infarction with 90% of patients dying by two months, in published series. Urgent surgical repair improves the prognosis. AIMS: To assess the Green Lane Hospital experience over a ten year period, especially with regard to hospital mortality and long-term follow up. METHODS: A retrospective case note review of all 35 consecutive patients undergoing post-infarct VSD repair from 1981 to 1990. Long-term follow up was obtained in all but one patient (97%). RESULTS: Twenty-one male and 14 female patients presented with a mean age of 67 years (range 51-75). All were in NYHA class 3 or 4, 14 (40%) were in cardiogenic shock. Following urgent surgical repair, 30 day mortality was 31% (11 patients). A further three patients died at two, 33 and 39 months; one patient was lost to follow up. At a mean follow up of 61 months (range 16-111), 15 patients were in NYHA class 1 or 2, five in NYHA class 3 or 4. For the whole group (n = 35) the actuarial survival was 66% at one year, 62% at three years and 58% at nine years. CONCLUSION: Post-infarct VSD surgery is of major prognostic benefit with patients obtaining a good long-term outcome.

Aged↗