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Biomedical subjects

N Garrett

Publications and source records attributed to N Garrett.

At least 19 recordsLinked to original sources
PubMed2000

Estimated number of cases of foodborne infectious disease in New Zealand.

AIMS: To estimate the annual number of cases of infectious intestinal disease caused by foodborne pathogens in New Zealand and estimate the impact of these diseases in terms of days lost to illness. METHODS: Incidence of foodborne diseases were derived from data from infectious disease surveillance and hospital sources, and estimates of unreported illnesses using published population based studies. RESULTS: The estimated number of cases of foodborne infectious disease is approximately 119 000 per year, including 19 000 general practitioner visits, 400 hospital admissions, 22 cases of long term illness and two deaths. It is estimated that the number of cases of potentially foodborne infectious disease is approximately 199 000. Total number of cases of all infectious intestinal disease could be as high as 823 000. Days of lost production and leisure time activities lost to foodborne infectious disease are estimated as approximately 497 000. CONCLUSION: Foodborne infectious diseases represent a major public health burden in terms of the number of cases and days lost to illness.

Disease Outbreaks↗
PubMed2000

The Xenopus eomesodermin promoter and its concentration-dependent response to activin.

Eomesodermin is an essential early gene in Xenopus mesoderm formation and shows a morphogen-like response to activin. Here we define the regions of the Eomesodermin promoter required for mesodermal expression and for concentration-dependent response to activin. We find an activin response element (ARE) located between -5.6 and -5.0 kb which contains two critical FAST2 binding sites. The ARE alone is necessary and sufficient for concentration-dependent response to activin. A 5.6 kb promoter recapitulates Eomes expression in normal mesoderm cells. A repressor element extinguishes Eomes expression in the endoderm. We relate our results to mesoderm patterning in early Xenopus development and to a mechanism of morphogen gradient response.

Activins↗
PubMed2000

Household crowding a major risk factor for epidemic meningococcal disease in Auckland children.

BACKGROUND: New Zealand is in its ninth year of a serogroup B meningococcal disease epidemic with annual rates of up to 16.9 cases per 100,000. The highest incidence is in Maori and Pacific Island children in the Auckland region. We conducted a case-control study to identify potentially modifiable risk factors for this disease. METHODS: A case-control study of 202 cases of confirmed and probable meningococcal disease in Auckland children younger than 8 years of age recruited from May, 1997, to March, 1999, was undertaken. Controls (313) were recruited door-to-door by a cluster sampling method based on starting points randomly distributed in the Auckland region. They were frequency matched with the expected distribution of age and ethnicity in the meningococcal disease cases. RESULTS: With the use of a multivariate model and controlling for age, ethnicity, season and socioeconomic factors, risk of disease was strongly associated with overcrowding as measured by the number of adolescent and adult (10 years or older) household members per room [odds ratio (OR), 10.7; 95% confidence interval (CI), 3.9 to 29.5]. This would result in a doubling of risk with the addition of 2 adolescents or adults to a 6-room house. Risk of disease was also associated with analgesic use by the child, which was thought to be a marker of recent illness (OR 2.4, CI 1.5 to 4.0); number of days at substantial social gatherings (10 or more people for > 4 h; OR 1.8, CI 1.2 to 2.6); number of smokers in the household (OR 1.4, CI 1.0 to 1.8); sharing an item of food, drink or a pacifier (OR 1.6, CI 1.0 to 2.7); and preceding symptoms of a respiratory infection (cough, "cold or flu," runny nose, sneezing) in a household member (OR 1.5, CI 1.0 to 2.5). CONCLUSION: Some of these identified risk factors for meningococcal disease are modifiable. Measures to reduce overcrowding could have a marked effect on reducing the incidence of this disease in Auckland children.

Adolescent↗
PubMed1999

Differential expression of VegT and Antipodean protein isoforms in Xenopus.

The VegT/Antipodean (Apod) gene is important for germ layer formation in Xenopus. To investigate the role of this gene at the protein level, as opposed to the RNA level, we have generated affinity purified polyclonal antibodies to Apod, and for comparison, to the other early T-box proteins Xbrachyury and Eomesodermin. An anti-VegT/Apod antibody reveals that there are two protein isoforms in Xenopus, one that we refer to as VegT and a smaller molecular weight isoform that we refer to as Apod. These isoforms have different N-terminal domains resulting from developmentally regulated alternative splicing of a primary transcript arising from a single VegT/Apod gene. VegT is maternally expressed. Its translation is blocked during oogenesis but the protein is present from the egg until gastrulation in the presumptive endoderm. There is no evidence for zygotic expression of this isoform. Conversely, the Apod protein isoform is expressed only after the onset of zygotic transcription in the presumptive mesoderm and is inducible by activin. We conclude that the developmental role of VegT/Apod is mediated by two different proteins, with entirely different patterns of expression and response to growth factors.

Activins↗
PubMed1999

The pathophysiology of pain.

Recent advances in elucidating the physiologic transmission of pain have lead to new targets for analgesic drug development. New agents are being studied in animal trials and familiar drugs are being investigated in novel ways. This paper was written to familiarize nurse anesthetists with one of the new targets, ionotropic glutamate receptors. This article begins with a brief survey of several alternate theories of the origin of pain, then, in more detail, describes the anatomical and physiological basis of pain, focusing on the phenomenon of central sensitization and the role of ionotropic glutamate receptors. An exploration of several recent pharmacological studies targeting N-methyl-D-aspartate receptors concludes the review.

Analgesics↗
PubMed1998

The incidence of hepatocellular carcinoma in New Zealand.

AIM: To measure the incidence rate of hepatocellular carcinoma (HCC) in New Zealand, by ethnicity, sex, region and age. METHODS: Cancer Registry data for 1983-94 were used to calculate rates of primary liver cancer (ICD code 155.0) and HCC (both ICD code 155.0 and ICD-O morphology code 8170) directly standardised to Segi's world population and standardised for region. RESULTS: Rates of HCC per 100,000 person years 6.6 and 1.3 for Maori males and females, 14.7 and 4.6 for Pacific people, and 0.8 and 0.3 for Other (inclusive of Chinese). The rates for Chinese for 1989-94 were 19.9 and 5.8. These rates are likely to be underestimates due to imperfect sensitivity of ICD-O code 8170 registrations for HCC. The rates of HCC for Maori and Pacific people (sexes combined) were 7.3 and 18.0 times that for other for 1983-94; the HCC rate for Chinese was 25.8 times greater than Europeans for 1989-94. Rates of HCC tended to be higher in the north of New Zealand, compared to the south, for Maori and Other/Europeans, but there was no apparent regional gradient for Pacific people and Chinese. CONCLUSIONS: Non-Europeans have higher rates of HCC than Europeans due to variations in hepatitis B carriage. Males have higher rates than females, and Maori and Europeans living in the north of New Zealand have higher rates of HCC than those living in the south. It is estimated that any hepatitis B screening and follow-up programme will detect one incident case of HCC per year per 2000 hepatitis B carriers in the target population, or one incident case per 1000 carriers actually participating in regular follow-up.

Carcinoma, Hepatocellular↗
PubMed1998

Cancer incidence, morbidity and geothermal air pollution in Rotorua, New Zealand.

BACKGROUND: The New Zealand city of Rotorua sits on a geothermal field. However, little is known about the possible health impacts of the geothermal emissions. This was an ecological study that examined cancer incidence and morbidity data for Rotorua. METHODS: Cancer registry and hospital discharge (morbidity) data were obtained for the decade 1981-1990. Standardized incidence ratios (SIR) were calculated comparing Rotorua residents with those living in the rest of New Zealand. Diagnostic categories examined were based on known target organ systems of hydrogen sulphide toxicity. RESULTS: Of the cancer sites, there was an elevated rate for nasal cancers. However, this was based on only four cases. The SIR for cancers of the trachea, bronchus and lung in Maori women was 1.48 (95% CI: 1.03-2.06). This was not explained by higher smoking rates. In the hospital discharge data, a number of diseases showed elevated SIR, notably diseases of the nervous system and the eye. To some extent, these effects were characteristic of effects induced by hydrogen sulphide and also mercury compounds. However, there were few data with which to assess whether significant mercury exposures had occurred, and other explanations were possible. CONCLUSIONS: There are inadequate exposure data for Rotorua to permit conclusions on likely causal associations. However, some of the elevated disease rates were at least consistent with what one might expect to find if sufficient exposures to hydrogen sulphide and/or mercury were occurring.

Air Pollutants↗
PubMed1997

Old paint removal and blood lead levels in children.

AIM: To identify risk factors, particularly paint removal and clean up practices, for elevated blood lead levels in children, 12 to 24 months old, living in Wellington city. METHODS: Children living in residences more than 50 years old, where residential paint removal had taken place in the last two years, were recruited. Care givers were interviewed, a blood sample was taken from the child's arm and a dust wipe sample was collected from the kitchen floor. Blood and dust samples were analysed for lead content. RESULTS: Data were collected for 141 children (75% of those eligible). The mean blood lead level was 0.24 mumol/L (5.06 micrograms/dL). Higher blood levels were associated with lower income of the main family earner, playing outside, eating dirt and parental hobbies involving lead use. Children receiving regular medical treatment were at lower risk of lead absorption. With the exception of paint removal involving blow torches, none of the paint removal, clean up, or disposal practices was more strongly associated than the other methods with elevated blood lead levels in children living in the household. Dust wipes from the kitchen floor had little predictive value for blood lead level. CONCLUSIONS: High temperature methods of paint removal and parental hobbies involving lead are associated with higher lead levels in children. Given the availability of alternative means of paint removal, continuing use of high temperature methods is unnecessary. Further work is needed to assess lead absorption risks associated with hobbies involving lead.

Child, Preschool↗
PubMed1997

Acute gastroenteritis diagnostic practices of New Zealand general practitioners.

AIMS: A sample of New Zealand general practitioners was surveyed to determine the laboratory referral practices of general practitioners for patients with acute gastroenteritis, with particular reference to viral gastroenteritis. METHODS: A mail questionnaire was sent to 209 general practitioners throughout New Zealand. RESULTS: The most important criteria for laboratory referral of a diarrhoeal specimen were prolonged duration of illness, presence of blood in the stool, a recent history of overseas travel, tramping or camping, shellfish consumption, or if the patient worked in the food, child care, or health care industries. Most general practitioners reported that they would refer diarrhoeal specimens from less than 25% of their patients with acute gastroenteritis. Requests for testing for viruses other than rotavirus were rare. CONCLUSION: The viral agents causing acute gastroenteritis were less likely to receive laboratory confirmation than other causes of gastroenteritis. On the basis of current laboratory investigation practices of general practitioners, foodborne viral gastroenteritis outbreaks are unlikely to be identified as such in New Zealand.

Acute Disease↗
PubMed1997

Air pollution and mortality in the Rotorua geothermal area.

The effects on human health of geothermal emissions in the Rotorua area have been little studied. We calculated standardised mortality ratios (SMRs), comparing residents domiciled in the Rotorua territorial local authority area with those living in the rest of New Zealand, using mortality data for the decade 1981-1990. The SMRs were adjusted for age, calendar year, sex, and ethnicity. Diagnostic categories examined were based on known target-organ systems of hydrogen sulphide toxicity. Mortality causes examined were diseases of the nervous system and sense organs, diseases of the circulatory system, diseases of the respiratory system, and birth defects. Of these, notably elevated SMRs were found only for diseases of the respiratory system, particularly in Maori women (SMR = 1.61, 95 per cent confidence interval 1.19 to 2.12). A major concern was the possibility of confounding by ethnicity. This is because ethnicity in census data is based on self-identification, whereas ethnicity on death certificates is often based on funeral directors' impressions. This leads to serious underreporting of Maori mortality statistics. For the purposes of this study, this situation was further complicated by indications that ethnicity recording for Maori may be more accurate in the Rotorua area than in the rest of New Zealand. Our analysis suggested that, in general, SMRs based on ethnicity are likely to be spuriously high. Although this study found no clear indications of excess mortality in the Rotorua area likely to have been associated with geothermal emissions, there were limitations in the data that could have prevented the recognition of causal associations.

Air Pollutants↗
PubMed1997

Campylobacteriosis in New Zealand: results of a case-control study.

STUDY OBJECTIVE: To identify and assess the contributions of major risk factors for campylobacteriosis in New Zealand. DESIGN: Case-control study. Home interviews were conducted over nine months using a standardised questionnaire to assess recent food consumption and other exposures. SETTING: Four centres in New Zealand with high notification rates of campylobacter infections--Auckland, Hamilton, Wellington, and Christchurch. PARTICIPANTS: Case patients were 621 people notified between 1 June 1994 and 28 February 1995 as having campylobacter infection. Control subjects were selected randomly from telephone directories, and were matched 1:1 with case patients in relation to sex, age group, and home telephone prefix. RESULTS: Risk of campylobacteriosis was strongly associated with recent consumption of raw or undercooked chicken (matched odds ratio 4.52, 95% confidence interval 2.88, 7.10). There was also an increased risk with chicken eaten in restaurants (matched odds ratio 3.85; 2.52, 5.88). Recent consumption of baked or roasted chicken seemed to be protective. Campylobacteriosis was also associated with recent overseas travel, rainwater as a source of water at home, consumption of raw dairy products, and contact with puppies and cattle, particularly calves. CONCLUSIONS: Improperly cooked chicken seems to be associated with a large proportion of campylobacteriosis in New Zealand. Thorough cooking of chicken in homes and restaurants could reduce considerably the incidence of this disease.

Campylobacter Infections↗
PubMed1996

Eomesodermin, a key early gene in Xenopus mesoderm differentiation.

Eomesodermin (Eomes) is a novel Xenopus T-domain gene. In normal development, it is expressed in mesodermal cells in a ventral-to-dorsal gradient of increasing concentration. It reaches its peak expression 1-2 hr before any other known panmesodermal gene. It is strongly inducible by normal vegetal cells and by mesoderm-inducing factors. Ectopic expression of Eomes in animal caps induces the transcription of nearly all mesodermal genes in a concentration-dependent way. Overexpression of Eomes dorsalizes ventral mesoderm, inducing gsc and changing cell fate to muscle and notochord. Blocking the function of Eomes causes gastrulation arrest and defective mesoderm-dependent gene activation. We propose that Eomes fulfills an essential function in initiating mesoderm differentiation and in determining mesodermal cell fate.

Activins↗
PubMed1995

Lead in children from older housing areas in the Wellington region.

AIMS: To examine blood lead levels in children, aged 12 to 23 months, living in old housing areas of Wellington and Lower Hutt, and to investigate risk factors for high lead levels. METHOD: Children were selected from Plunket Society rolls. Venous blood samples were collected, and care givers were interviewed with a questionnaire. Soil samples were taken from around the children's homes. Both soil and blood samples were analysed for lead content. RESULTS: Blood samples and completed questionnaires were obtained for 143 children. The geometric mean blood lead level for all the children was 0.25 mumol/L (5.1 micrograms/dL) (95% confidence interval [95% CI]: 0.22-0.28 mumol/L). Three children had blood lead levels that exceeded the level for notification in New Zealand 1.45 mumol/L and a further 13 had blood lead levels exceeding 0.48 mumol/L. Children with elevated lead levels were likely to live in a house greater than 50 years old where paint removal had taken place in the last 2 years (risk ratio [RR] = 14.4, 95% CI: 2-107). Eating dirt, particularly for children who usually played outside within 2 metres of the house, was also a risk factor for elevated blood lead levels. Soil lead levels generally increased with the age of the house and were weakly correlated with blood lead levels (r = 0.32). CONCLUSION: Paint removal in old houses is a major risk factor for elevated blood lead levels. However, the number of study children living in houses less than 50 years old was limited. Because of this and possible participant selection bias, the results of this study require confirmation in a separate population-based study. Information about the specific paint removal procedures that cause high lead levels is also needed.

Cross-Sectional Studies↗
PubMed1995

Expression cloning of Siamois, a Xenopus homeobox gene expressed in dorsal-vegetal cells of blastulae and able to induce a complete secondary axis.

Using an expression cloning strategy that relies on a functional assay, we have cloned a novel Xenopus homeobox-containing gene, Siamois. Embryos injected in a ventral-vegetal blastomere with as little as 5 pg of Siamois mRNA develop a complete secondary axis, but the progeny of the injected cells do not participate in the secondary axis formation. In normal development, Siamois mRNA is first detected shortly after the midblastula transition, which is earlier than mRNAs for goosecoid or Xbrachyury, and is present most abundantly in the dorsal endoderm of early gastrulae. The activation of this gene can be obtained cell autonomously in dispersed embryo cells. These results indicate that Siamois may play an important role in the formation of the Nieuwkoop center.

Amino Acid Sequence↗
PubMed1994

Effect of glucocorticoids on tumor necrosis factor induced suppression of protein synthesis in rat aortic smooth muscle: comparison with extensor digitorum longus.

Protein synthesis was measured in incubated aortic smooth muscle and fast-twitch extensor digitorum longus (EDL) in both sham operated and adrenalectomized (ADX) rats. The studies were performed on four groups: a) untreated controls; b) rats treated with tumor necrosis factor (TNF) @ 50 micrograms/kg. b.w.; c) rats treated with cortisone @ 100 mg/kg/day for 5 days; or d) rats treated with cortisone plus TNF. Both TNF and cortisone suppressed protein synthesis in the aortic smooth muscle and EDL in intact animals. TNF given together with cortisone, induced a significant additional decrease in protein synthesis in both muscle types as compared to cortisone-treated rats. The rate of protein synthesis in aortic smooth muscle from sham operated rats was control > TNF > cortisone > Cortisone+TNF; in the case of EDL, rate was control > cortisone > TNF > Cortisone+TNF. In ADX animals, TNF alone did not affect protein synthesis in both aortic smooth muscle and EDL. Though cortisone alone produced a significant inhibition of protein synthesis, there was no significant further decline in protein synthesis when cortisone was given together with TNF. These findings suggest that the inhibitory effect of TNF on muscle protein synthesis is mediated through glucocorticoids.

Animals↗
PubMed1993

Monoarthritis in the rat knee induces bilateral and time-dependent changes in substance P and calcitonin gene-related peptide immunoreactivity in the spinal cord.

Bilateral changes in the spinal cord and dorsal root ganglion content of the sensory peptides substance P and calcitonin gene-related peptide have been previously reported in animal models of arthritis which affect many joints within the body. The central nervous system has been implicated in the symmetry of joint involvement in human rheumatoid arthritis. We aimed to determine whether unilateral inflammation of the knee joint can also induce bilateral changes in the spinal cord. We have induced a monoarthritis in the knee joint of the rat and used quantitative immunocytochemistry to look at changes of these peptides in the dorsal horn of the spinal cord and the dorsal root ganglia. Furthermore we have examined the responses during the acute (three days) and the chronic (21 days) phases of the model. The data show that in the acute phase of the monoarthritis there is both an ipsilateral and contralateral response which increases the immunoreactive substance P and calcitonin gene-related peptide in the L4 level of the dorsal horn of the spinal cord. In the chronic phase of the monoarthritis, the contralateral side of the dorsal horn returned to control values whilst the ipsilateral side showed reduced amounts of immunoreactive substance P and calcitonin gene-related peptide compared to controls. We propose that the acute response, at three days, to unilateral inflammation is appropriate and has evolved to protect an organism against the original insult ipsilaterally, and the possibility of subsequent insult contralaterally.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Characterisation of Staphylococcus intermedius isolates from canine pyoderma and from healthy carriers by SDS-PAGE of exoproteins, immunoblotting and restriction endonuclease digest analysis.

Ten Staphylococcus intermedius isolates from cases of canine pyoderma and 10 from healthy carriers were examined by SDS-PAGE of exoproteins, immunoblotting and restriction endonuclease digest analysis. Similarities between banding patterns of the isolates were calculated as Dice coefficients for all three methods. For SDS-PAGE and immunoblotting, no significant differentiation was found between the pyoderma and "healthy" groups. Analysis of DNA digested with BglII indicated that S. intermedius is genetically heterogeneous; Dice coefficients for the pyoderma group were distinct from those for the healthy group (p < 0.001), and cluster analysis confirmed that the pyoderma isolates (9) formed a group separate from the majority (6 of 9) of the normal isolates.

Animals↗