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Biomedical subjects

B Hewitt

Publications and source records attributed to B Hewitt.

At least 19 recordsLinked to original sources
PubMed2002

Socioeconomic differences in food purchasing behaviour and suggested implications for diet-related health promotion.

BACKGROUND: The relationship between socioeconomic position (SEP) and diet has been examined mainly on the basis of food and nutrient intake. As a complement to this work, we focused on the socioeconomic patterning of food purchasing, as many educational dietary messages emphasize behaviours such as food choice when shopping. Also, the type of food people buy influences the quality of their nutrient intake. METHODS: A probability sample of households in Brisbane City, Australia (n = 1003, 66.4% response rate). Data were collected using face-to-face interviews. SEP was measured using education, occupation and household income. Food purchasing was examined on the basis of grocery items (including meat and chicken) and fruit and vegetables. RESULTS: Significant associations were found between each socioeconomic indicator and food purchasing. Persons from socioeconomically disadvantaged backgrounds were less likely to purchase grocery foods that were comparatively high in fibre and low in fat, salt and sugar. The least educated, those employed in blue-collar (manual) occupations and residents of low income households purchased fewer types of fruit and vegetables, and less regularly, than their higher status counterparts. CONCLUSIONS: Health promotion efforts aimed at narrowing socioeconomic differences in food purchasing need to be designed and implemented with an understanding of, and a sensitivity to, the barriers to nutritional improvement that difficult life circumstances can impose.

Australia↗
PubMed2001

A straightforward method of assessing the accuracy of implantation of knee prostheses.

Accurate component placement in knee replacement surgery is important. The precision with which the implants are placed directly affects patient outcome as implant position and alignment influence stability, durability and patellar tracking. The ability to measure the accuracy of implantation of knee replacement components is valuable in assessing not only ones own technique but also in evaluating new instruments or implants and in teaching. The standard AP and lateral radiographs employed by most surgeons give inadequate information to assess alignment of each component accurately. We present a straightforward way of assessing femoral and tibial component alignment by using a series of three radiographs. This technique is reproducible and can be performed using standard equipment in any radiology department. This technique was applied to 160 total knee replacements performed using newly developed instrumentation. It was shown to be simple and the measurements were reproducible, with very little inter observer bias. We believe this technique has a role in audit, teaching, training and assessing new techniques and instruments.

Aged↗
PubMed2001

Flexion vs. extension: a comparison of post-operative total knee arthroplasty mobilisation regimes.

We report a prospective trial comparing the effectiveness of a post-operative flexion regime versus a standard extension regime on the early outcome of total knee arthroplasty. A total of 160 knees were allocated to two separate post-operative mobilisation regimes: a static flexion regime or an active extension regime. Patients were implanted with either an IBII or 913 total knee replacement systems. All operations were performed by the same surgeon. Patients were assessed pre-operatively and at 6 weeks, and were well matched with respect to age, sex, diagnosis and pre-op movement. Patients subjected to the flexion regime had a better maximum flexion and range of movement at 6 weeks and were also discharged earlier. These results were statistically significant (P < 0.05). Histograms of results at 6 weeks show that the flexion group had a more predictable outcome with smaller standard deviations (S.D.) than the extension group. Differences were also observed in the percentage of 'sub-optimal' results. No difference was observed in post-operative wound problems. We believe a static flexion regime is as good as reported results with CPM, better than an extension regime and does not result in an increase in wound problems.

Aged↗
PubMed2001

Managing clinical data in an electronic environment.

Clinical data has moved to the forefront as a valuable resource to enhance patient care and measure organizational performance. These data, most of which is now captured electronically, must be assessed for value and appropriateness. This article examines a data quality management model and its use in the initiation of computerized patient record (CPR) projects.

Decision Support Systems, Clinical↗
PubMed1995

Human flexor pollicis longus: role of peripheral inputs in weight-matching.

We investigated the role of local cutaneous signals and of co-contraction of antagonists in repeated judgements of heaviness of weights lifted by flexor pollicis longus. A reference weight lifted by right thumb flexion was matched to a weight lifted by left thumb flexion. Anaesthesia of the right thumb, or of the superficial radial, dorsal ulnar or mixed radial nerves failed to impair accuracy of weight judgements. However, perceived heaviness significantly increased by 85% and 20% following anaesthesia of the thumb and dorsal radial surface of the hand, respectively, confirming a role for cutaneous inputs from these areas in motor control of the thumb.

Humans↗
PubMed1995

Amnion rupture in the second trimester.

Two cases of amnion rupture are presented in 'low-risk' pregnancies. One case ended in fetal death in utero at 21 weeks. The other resulted in the preterm delivery of an otherwise normal male with mild amniotic band syndrome.

Amnion↗
PubMed1993

Nuchal translucency in the first trimester.

All fetuses reported as having nuchal (nape of the neck) thickening or translucency detected by a first trimester ultrasound at 2 centres were reviewed to determine the incidence of aneuploidy. Twenty nine pregnancies were registered, amongst which 12 (41%) had an abnormal karyotype, the most common aneuploidy being trisomy 21 (5 fetuses). The likelihood of aneuploidy increased with increasing thickness of the translucency. Where the karyotype was found to be normal, there was complete resolution of this ultrasound appearance by the second trimester in 15 of the 16 ongoing pregnancies: 9 have delivered normal neonates and 6 pregnancies are continuing. The other fetus developed evidence of a skeletal dysplasia by the second trimester.

Adult↗
PubMed1986

Allergy in the Mediterranean area. II: Cross-allergenicity among Urticaceae pollens (Parietaria and Urtica).

Pollens of related species usually share common antigens and are cross-reacting but this is not always the case. The cross-allergenicity of two species of Urticaceae pollens (Parietaria and Urtica, nettle) was sought by means of RAST-inhibition and isoelectric focusing. A preliminary experiment in forty-two patients investigated by means of skin tests and RAST showed that most patients were either allergic to Parietaria or nettle and that both reactivities were uncommonly associated. The results of RAST-inhibition confirmed the total absence of cross-reactivity between these two related species. IEF patterns indicated that most proteins are in the acidic range of pH and did not reveal large discrepancies. Parietaria and Urtica pollens, although belonging to the same family and having close microscopic patterns, have very different allergenic activities. This study demonstrates that cross-allergenicity cannot be predicted.

Adolescent↗
PubMed1985

[Atopy screening: prick multitest, total IgE or RAST? On the value of allergologic testing of the staff of an industrial bakery].

The predictive value of diagnostic tests for the recognition and differentiation of allergic diseases of the immediate type has been evaluated on the basis of the results of a non-selective allergologic-pneumologic examination of the staff of an industrial bakery. Out of the 314 subjects tested, 22 (7%) had a respiratory allergy against flour (flour rhinitis and/or flour asthma), and 21 (6.7%) a preexistent atopic disease without actual symptoms of flour allergy. Thus the predominance of atopy in the group examined was 13.7%. A prick-multitest was carried out in all 314 subjects on each forearm and allowed simultaneous and easy application of twice eight test substances ("atopy-screening" and "bakery-line"). 50% of the bakers with flour allergy also showed positive skin tests with non-occupational inhalative allergens (housedust, housedust mite, pollen) while only 9.2% of the subjects without respiratory allergy to flour did so. 17.1% of the heavily exposed, asymptomatic bakers showed a positive immediate reaction to the highly sensitive intracutaneous test with wheat flour. Here the problem of latent sensitization arises. With histamine the prick-multitest resulted - compared to the intracutaneous test - in 1.6% "false negative" and 3.2% only questionably positive results. Furthermore, 6.1% of the subjects showed a strong, and 3.2% a very strong, nonspecific reaction to the control solution glycerin. Despite these restrictions the prick-multitest proved far superior to measurement of total serum IgE for screening of atopy. Technical improvements have been made in the meantime by the manufacturer. Specific IgE was detected in RAST screening in 59 of the 306 subjects who underwent blood tests. The geometric mean of total IgE values was only 75 U/ml, and for the RAST-negative subjects 23.3 U/ml, while their 95% confidence level was 225 U/ml. This logarithmic-normal distribution of the measured values, together with the excessive normal-atopic overlap, makes it impossible to lay the test cutoff point in a way which results in an acceptable relation between sensitivity and specificity. For the population examined the sensitivity of the total IgE measurement was already below 50% at a cutoff point of 80 U/ml, while the positive predictive value did not yet reach 50% at 160 U/ml. This diagnostic test is at present certainly used too often and without sufficient awareness of its very limited predictive value. As a screening method the RAST is too expensive. Furthermore, the problem of a latent sensitization also exists for the RAST.

Adolescent↗
PubMed1985

Occupational allergy to sunflower pollen.

Although the sunflower belongs to the Compositeae family, allergy to sunflower pollen is not common. The occurrence of occupational allergy to this pollen species made it possible to characterize cross-reactive patterns of Compositeae pollens in a human experimental model. A 24-yr-old man developed rhinitis and conjunctivitis over 5 yr of exposure to sunflower pollens, and asthma developed during the fifth year. All respiratory and occular symptoms disappeared after he was removed from exposure, but he had a food allergic reaction while he was eating honey containing 30% sunflower pollens. The diagnosis of occupational allergy was based on history, skin prick tests and RAST to the pollen. Bronchial provocation tests performed after removal from exposure confirmed the sensitivity to sunflower pollens but there was no nonspecific hyperreactivity. It was found by RAST inhibition that sunflower pollen does not cross-react with other Compositeae pollens tested or with sunflower seed. The honey that elicited food intolerance was demonstrated to inhibit significantly sunflower pollen RAST.

Adult↗
PubMed1985

Immunotherapy with a standardized Dermatophagoides pteronyssinus extract. I. In vivo and in vitro parameters after a short course of treatment.

Dermatophagoides pteronyssinus (Dp) is the major allergen in allergic asthma in France. Standardized and lyophilized Dp extracts are available, and their effectiveness after a short course of rush immunotherapy was examined in a placebo-controlled, double-blind study. Twenty patients received the Dp standardized extract, and 10 other patients received a placebo extract. Before and 7 weeks after rush immunotherapy, in vivo and in vitro parameters were examined. Bronchial provocation tests performed in a standardized manner demonstrated that a provocative dose causing a 20% fall in FEV1, a 25% fall in maximum mild expiratory flow rate, a 25% fall in maximum flow when 50% of the forced vital capacity has been expired, and a 35% fall in specific airway conductance were significantly (p less than 0.005 to p less than 0.01, Wilcoxon W test) improved in the treated group and remained unchanged in the placebo group. Skin test titration demonstrated that patients placed in the treated group had a significant (p less than 0.001, Wilcoxon W test) decrease of both end point titer and size of the largest wheal. No significant difference was observed in the placebo group. Serum Dp-IgE did not vary significantly in either group. Serum Dp antigen P1-IgG was significantly (p less than 0.001, Wilcoxon W test) increased in the treated group and slightly increased in the placebo-treated group. This study demonstrated that a Dp standardized extract administered by a rush protocol elicits a rapid and significant immune response and leads to a significant protection of the patients.

Adult↗
PubMed1985

Comparison of the stability of a mite and a pollen extract stored in normal conditions of use.

Pollen extracts are stable in solutions containing 50% glycerol. The stability of Dermatophagoides pteronyssinus (Dp) extracts have not been determined. Two lyophilised extracts (Dp and cocksfoot pollen) were reconstituted in 50% glycerol and stored for up to 6 months at +4 degrees C. Every day the extracts were placed at room temperature for 1 hr to mimic the natural use of allergen extracts by allergists. Every 2 months the extracts initially prepared were compared to freshly reconstituted extracts by means of prick skin tests in fifteen allergic patients. It was observed that cocksfoot pollen extract is stable but there appears a slight but significant (P less than 0.05) decay in activity when the extract stored for up to 6 months was compared with a freshly prepared extract. On the other hand there is a significant (P less than 0.01) decay in activity of the Dp extract after 2 months of storage. Dermatophagoides pteronyssinus and cocksfoot pollen extracts behave differently when stored. These findings have particular importance in the diagnosis and treatment of allergic disorders.

Allergens↗
PubMed1985

Comparison between rush immunotherapy with a standardized allergen and an alum adjuved pyridine extracted material in grass pollen allergy.

Rush immunotherapy with a standardized and lyophilized cocksfoot pollen extract was performed in twenty-three allergic subjects and compared with classical immunotherapy done with an alum adjuved, pyridine extracted cocksfoot pollen extract (fifteen subjects) and a control group of ten patients. The three groups were perfectly matched. Clinical benefits were analysed by means of symptom scores. It was shown that rush immunotherapy gave significantly better results when asthma or rhinitis was considered than either classical immunotherapy (P less than 0.02) or in the control group (P less than 0.01 and 0.02). Skin tests were significantly reduced after rush immunotherapy and did not change in the two other groups. After the pollen season the skin test reactivity was increased in the rush immunotherapy group. Cocksfoot pollen specific IgE did not vary significantly in the three groups. Cocksfoot pollen specific IgG was significantly (P less than 0.05) increased in the rush immunotherapy group before the pollen season and did not vary significantly in the other groups.

Adolescent↗