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Biomedical subjects

G Howells

Publications and source records attributed to G Howells.

At least 19 recordsLinked to original sources
PubMed2003

Oral tobacco cessation with UK resident Bangladeshi women: a community pilot investigation.

Our objective was to establish the short-term outcomes for successful tobacco cessation of a programme offering UK resident Bangladeshi women chewing paan with tobacco nicotine replacement therapy (NRT) in addition to brief advice and encouragement alone. We used a short-term longitudinal, quasi-experimental study design, in the setting of two local authority housing estates in Tower Hamlets, London. Bangladeshi women volunteers were recruited following presentations to community groups. The volunteers were assigned, after matching for age, number of paan with tobacco chewed daily and medical screening, to receive one of two tobacco cessation interventions (NRT with brief encouragement and advice, and brief advice and encouragement alone). The main outcome measures were changes in tobacco use and nicotine dependence, assessed by questionnaire and intake measures, adverse effects, and withdrawal symptoms. In total, 130 volunteers were recruited. Their mean age was 42.5 years (SD = 11.3). Mean number of paan quid with tobacco chewed daily was 10.7 (SD = 9.3) and the average age of starting to add tobacco to paan was 24 years (SD = 12). Ninety-one percent completed the 4-week trial. We found that 19.5% had stopped tobacco use, of whom 22% had received NRT, and 17% brief advice and encouragement alone. The successful members of the NRT group made a significantly greater reduction in their salivary cotinine scores at final review compared to baseline. Oral pain was reported as a barrier to successful oral tobacco cessation by 62% of the volunteers at final review. We conclude that methods identified as helping tobacco smokers successfully stop smoking can be used with Bangladeshi women chewing paan with tobacco. More research is needed to investigate these short-term outcomes and to explore the particular barriers to successful cessation for this group such as oral pain.

Adult↗
PubMed2001

Improving ARTMAP learning through variable vigilance.

This paper presents a mechanism to vary the vigilance parameter in the RePART fuzzy neural network. This mechanism helps to smooth out the problem of category proliferation which affects ARTMAP-based networks. Empirical experiments show that the use of variable vigilance improves the performance of the RePART model while, at the same time, requiring a less complex structure.

Algorithms↗
PubMed1997

Nonoperative management of adult blunt splenic trauma: a 15-year experience.

From January 1989 to December 1993, 40 consecutive adult patients with ruptured spleen from blunt trauma were examined. Fourteen patients (35%) were taken to the operating room initially because of hemodynamic instability and generalized peritoneal signs. Twenty-six patients (65%) were hemodynamically stabilized at admission and treated by nonoperative management, which included strict bed rest, intensive care unit monitoring, frequent physical examinations, and serial hematocrits. Four patients failed nonsurgical management and required a splenectomy, three because of clinical deterioration within 1 to 3 days of admission; the fourth patient had recurrent bleeding 7 days after injury. The patients in the operative group had a greater severity of injury with a mean injury severity score of 26.6, four deaths, and mean transfusion requirements of 3.7 to 4.0 units of blood, compared to a mean injury severity score of 14.6, one late death from cardiac causes, and average blood requirement of 0.4 to 0.7 units. Splenic injury grading averaged 3.2 in the surgical group (grade 1, one patient; grade 2, four patients; grade 3, eight patients; grade 4, no patients; and grade 5, one patient) and differed significantly from that of the nonoperative group (mean = 2.4; grade 1, 12 patients; grade 2, seven patients; grade 3, six patients; grade 4, two patients; and grade 5, no patients). Recent ultrasound analysis of select grades I to IV has shown excellent resolution or repair of these injuries. This report extends our series from 1978 to 1993 and includes 144 adult patients sustaining blunt splenic ruptures. Seventy-nine (55%) of these patients were treated nonsurgically. Seven patients (of 80) failed nonoperative management and required interval laparotomy, representing a 91 per cent success rate. Follow-up on more than 90 per cent of the patients has shown no sequelae from their splenic injuries. We conclude that adult patients with splenic injuries from blunt trauma who are hemodynamically stable and are without abdominal findings requiring celiotomy can be safely managed by a nonoperative approach.

Adolescent↗
PubMed1991

Interleukin 4 induces interleukin 6 production by endothelial cells: synergy with interferon-gamma.

Interleukin (IL)4 induces IL6 production by human umbilical vein endothelial cells (HUVEC) in a dose-dependent manner, as shown by bioassay and immunoprecipitation. Interferon (IFN)-gamma, which antagonizes IL4 effects on leukocytes, synergized with IL4 in the induction of IL6 production by HUVEC. Contamination with endotoxin was excluded by heat-inactivated IL4, preincubating with anti-IL4 polyclonal antibody and the use of polymyxin B. The presence of IL4 receptors on HUVEC was shown by affinity cross-linking with 125I-IL4, revealing a 110-kDa binding protein. However, compared with the amount seen on T cells the 60-70-kDa cross-linked doublet was present at much lower levels. Additional lower molecular weight cross-linked proteins were isolated only with HUVEC, but the origin of these is unclear. IL6 is a pluripotent cytokine produced by many cells which promotes the differentiation and growth of lymphocytes and the production of acute phase protein by hepatocytes, and is important in the regulation of immunity at the systemic and local levels. Since IL4 and IFN-gamma are produced by T cells, which are frequently associated with vascular endothelium during chronic inflammation, IL4 is likely to be an important cytokine in the regulation of IL6 and perhaps other cytokine production by endothelium in vivo.

Drug Synergism↗
PubMed1989

Down's syndrome and the general practitioner.

People with Down's syndrome form a heterogeneous group sharing a single constant feature--an extra chromosome. This paper reviews the many clinical problems associated with Down's syndrome and emphasizes the prevention of secondary handicapping conditions. Current policies on antenatal screening for Down's syndrome are discussed. The review draws attention to the need for general practitioners to see themselves as part of a network of community services providing support to people with Down's syndrome and their families.

Adult↗
PubMed1986

Are the medical needs of mentally handicapped adults being met?

This paper reports on the apparent inadequate level of primary medical care provided to many of the 151 mentally handicapped people who attend an adult training centre. A large number of common medical problems were identified that were not known to the general practitioners and/or were not being managed, including problems known to be associated with Down's syndrome. Many trainees were further handicapped by unmanaged defects of hearing and vision. Contact rates with the general practitioner showed that the mentally handicapped adults did not place a greater burden on the doctor than the rest of the population. Comparing these rates with those for other vulnerable groups such as those aged over 75 years and under four years showed that only 28% of the trainees had an adequate consultation rate with the general practitioner.A lack of awareness among general practitioners of the special needs of this group is thought to be in part responsible but the major factor is the inherent problem of communication which exists almost universally in people who suffer from mental handicap. Ways of improving the situation are discussed with an emphasis on the need for a change in our attitudes towards mentally handicapped people. Reference is made to the desirability of increasing the cooperation between primary care and community mental handicap teams and the increasing importance of voluntary organizations.

Adult↗
PubMed1983

Pattern of uptake of americium-241 by the rat skeleton and its subsequent redistribution and retention: implications for human dosimetry and toxicology.

The distribution and retention of intravenously injected 241Am in the skeleton of the female rat has been investigated using autoradiographic and radiochemical techniques. The studies were designed to assess the dosimetric and toxicologic implications of an 241Am intake by man. They showed that in the rat approximately one third of the intravenously injected 241Am was deposited in the skeleton where it appeared to be retained with a long biological half-time. The studies also showed: 1 241Am is initially deposited onto all types of bone surface including endosteal surfaces, periosteal surfaces and those of the vascular canals within cortical bone, but seems to be preferentially deposited onto those that are resorbing, 2 Bone accretion results in the burial of surface deposits of 241Am, 3 Bone resorption causes the removal of 241Am from surfaces, 4 Resorbed 241Am is retained by phagocytic cells (probably macrophages) in the bone marrow, 5 The transfer of 241Am from the phagocytic cells in the marrow to adjacent bone surfaces seems to occur, (local recycling). 6 The possibility that some of the 241Am removed from the bone surfaces enters the blood and is redeposited in bone, (systemic recycling) cannot be dismissed. These results show that 241Am deposition and redistribution in bone shares many characteristics with other 'bone surface-seeking radionuclides' typified by 239Pu. Consequently, it is suggested that a similar model to that used to calculate annual limits of intake for 239Pu in man would be suitable for the calculation of corresponding values for the 241Am isotopes.

Americium↗
PubMed1983

Autoradiographic studies of the distribution of radium-226 in rat bone: their implications for human radiation dosimetry and toxicity.

A solution containing 226Ra chloride was injected into young female rats via the saphenous vein. Subsequently, the distribution and retention of the 226Ra in the skeleton was studied. The results show that: 226Ra is initially deposited in the rat femur as a volume deposit and is fairly evenly distributed throughout the bone matrix. Much of the 226Ra initially deposited in the skeleton is lost within a few days of its administration. During the first week 226Ra gradually accumulates at sites of bone deposition including accreting surfaces. Subsequent bone growth results in the burial of contaminated bone surfaces and Following bone resorption some of the 226Ra released from individual bones is recycled systemically so that all skeletal components tend towards a uniform 226Ra concentration per unit of bone mineral. Of the two models conventionally used for radiation dosimetry purposes, the results reported here for rats suggest that though neither is ideal, the volume distribution model is preferable to the surface model at all times after the uptake of radium by the skeleton.

Animals↗