Automated noninvasive epithelial cell counting in phase contrast microscopy images with automated parameter selection.

Cell counting is commonly used to determine proliferation rates in cell cultures and for adherent cells it is often a 'destructive' process requiring disruption of the cell monolayer resulting in the inability to follow cell growth longitudinally. This process is time consuming and utilises significant resource. In this study a relatively inexpensive, rapid and widely applicable phase contrast microscopy-based technique has been developed that emulates the contrast changes taking place when bright field microscope images of epithelial cell cultures are defocused. Processing of the resulting images produces an image that can be segmented using a global threshold; the number of cells is then deduced from the number of segmented regions and these cell counts can be used to generate growth curves. The parameters of this method were tuned using the discrete mereotopological relations between ground truth and processed images. Cell count accuracy was improved using linear discriminant analysis to identify spurious noise regions for removal. The proposed cell counting technique was validated by comparing the results with a manual count of cells in images, and subsequently applied to generate growth curves for oral keratinocyte cultures supplemented with a range of concentrations of foetal calf serum. The approach developed has broad applicability and utility for researchers with standard laboratory imaging equipment.

Effect of early introduction of microencapsulated diet to larval Atlantic halibut, Hippoglossus hippoglossus L. assessed by microarray analysis.

An experimental microdiet prepared using an internal gelation method was used to partially replace the traditional live feed (Artemia) for larval Atlantic halibut, Hippoglossus hippoglossus L. Three trials were conducted with microdiet introduced at 20, 32, and 43 days post first feeding and larvae were sampled at approximately 2, 13, 23, and 33 days after microdiet introduction in each trial. The success of feeding was assessed by morphometrics and histological analysis of gut contents. Microdiet particles were readily consumed after a period of adaptation and provided an adequate source of nutrients with no significant increase in mortality in the microdiet-fed group compared to the control group. However, growth was limited and there was an increased incidence of malpigmentation of the eye and skin. Subtle changes in underlying digestive and developmental physiology were revealed by microarray analysis of RNA from control and experimental fish given microdiet from day 20 post first feeding. Fifty-eight genes were differentially expressed over the four sampling times in the course of the trial and the 28 genes with annotated functions fell into five major categories: metabolism and biosynthesis, cell division and proliferation, protein trafficking, cell structure, and stress. Interestingly, several of these genes were involved in pigmentation and eye development, in agreement with the phenotypic abnormalities seen in the larvae.

Hypertension registers in general practice: levels of control and nondrug management.

Sixty-five general practitioners throughout Northland agreed to establish and maintain hypertension registers for a three year trial period beginning in 1982. Opportunistic blood pressure screening was undertaken of all patients aged 20-69 attending practices for whatever reason. Patients with an average of six readings on at least three separate occasions which exceeded WHO criteria for hypertension (diastolic blood pressure greater than 95 mmHg and/or systolic blood pressure greater than 160 mmHg) were entered onto the registers as were patients already receiving antihypertensive drugs. In all 3703 patients were registered. The percentage exceeding WHO criteria fell from 49.4% to 38.8% for those followed up for twelve months and from 48.6% to 34.5% for those followed up for twenty-four months. The percentage with diastolic blood pressure less than 90 mmHg increased significantly for each follow up group and with length of follow up. Overall 8.2% at entry were managed without drugs, for those followed up for thirty months this fell to 6.2% with individual practice percentage varying from nil to over twenty. There appears scope to manage between 10-20% of hypertensives without drugs.

The Northland rheumatic fever register.

A rheumatic fever register retrospective to 1969 was established in Northland during 1980-81 from hospital discharge diagnoses and general practitioner sources. Since 1981 the register has been regularly maintained and updated. From January 1969 to June 1981 303 patients were identified in whom acute rheumatic fever had been diagnosed, but only 218 met the modified Jones criteria. Four others had first presented with rheumatic heart disease without a past record of rheumatic fever. For those aged under 20 the cases on the register represent an annual incidence per 100 000 of 23.6 for non-Maoris and 115.9 for Maoris. There were 106 recurrent attacks recorded during this period amongst 307 patients, with a significantly higher rate from Maoris (p = 0.001). There was a great variation in the period for which prophylaxis was prescribed.

The health status of fourth form students in Northland.

A random sample of fourth form students throughout Northland was studied. Uncorrected visual defects were found in 4.5% and significant hearing loss in 9.1%. Appreciable numbers were overweight; 6.2% of boys and 22.5% of girls exceeded the desirable bulk index range. Levels of total cholesterol appear decreased compared to earlier New Zealand studies and were significantly lower than the Wairoa College survey levels. There was a strong correlation between total cholesterol and low density lipoprotein cholesterol. High density lipoprotein cholesterol was significantly higher in non-Maori than in Maori girls. Overall systolic blood pressure for boys at 114.3 mmHg (15.2 kPa) was significantly higher than for girls at 109.5 mm Hg (14.56 kPa). One-third of boys exceeded the adult uric acid reference range; a significantly higher proportion than for girls. Fifteen point one percent of boys and 23.5% of girls reported smoking seven or more cigarettes per week; 19.1% of boys and 9% of girls reported taking regular amounts of alcohol at least every weekend.

Self-reported use of alcohol, cigarettes, tranquillisers and sedatives in patients admitted to a general hospital.

The relation between alcohol and hospital admissions and the patterns of use of cigarettes, tranquillisers and sedatives was studied in a sample of 339 consecutive admissions to Northland Base Hospital. Also examined was the usefulness of serum gamma glutamyl transferase (GGT) and blood ethanol as screening tests for high alcohol use in general hospital patients. A short multiple choice questionnaire was used, completed answers being obtained from 91.7 percent of the sample; GGT estimations were done on 64 percent and blood ethanol on 38 percent of the sample. Alcohol was considered to be a factor in the admission of at least 6.4 percent of the total sample. Blood ethanol estimations were not found useful as a screening test but GGT had a specificity of at least 27 percent for diagnosing high alcohol use in the general hospital situation. The regular use of tranquillisers and sedatives in elderly non-Maori patients was high but appears rare in Maoris of all ages.

Sexually transmitted disease seen in general practice in Northland: a survey.

A three month survey was made of all new cases of gonorrhoea, non-specific urethritis (NSU) and syphilis seen by general practitioners in Northland during the summer of 1979/80. Sixty-eight new cases of gonorrhoea, 39 of NSU and 2 of syphilis were reported. For gonorrhoea 88 percent of the cases where age was supplied were under 30 and for NSU 70 percent. There was a high male to female ratio for gonorrhoea and NSU of 4.2 to 1 and it is concluded that there is a need for improved contact tracing and for increased health promotion directed at the under 30 group. A method of estimating seasonal variation and annual incidence in Northland is described.