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Biomedical subjects

M H Lewis

Publications and source records attributed to M H Lewis.

At least 37 records · Page 2Linked to original sources

Prevention of venous thromboembolism in Wales: results of a survey among general surgeons.

OBJECTIVE: To examine the current attitudes towards the prevention of venous thromboembolism among a cohort of surgeons. DESIGN: A postal survey, comprising a questionnaire covering various aspects of venous thromboembolism prophylaxis was sent to all (n=84) consultant general surgeons in Wales. RESULTS: Replies were received from 57 surgeons (68%), all of whom routinely used prophylaxis, the most frequent modalities used being heparin (100%) and graded compression stockings (79%). A combination of physical and pharmacological methods was used by over 89% of surgeons, with 60% starting prophylaxis more than two hours before operation. All surgeons continued prophylaxis after surgery, 53% until patients were mobile, 45% until they were discharged, and one surgeon continued prophylaxis for seven days after discharge. The thrombosis risk factors considered most important by surgeons when deciding about prophylaxis were (i) a previous history of venous thromboembolism, (ii) hypercoagulability, and (iii) malignancy. CONCLUSIONS: This study confirms that Welsh surgeons conform to standard methods, but also highlights some uncertainties that are present in current surgical practice. Those who responded all routinely used prophylaxis, the timing of which was variable. The main risk factors identified when considering prophylaxis were previous history of deep vein thrombosis/pulmonary embolism, hypercoagulability, and the presence of malignancy. Suggestions for future practice are made.

Anticoagulants↗

Costs of waiting for gall bladder surgery.

Laparoscopic cholecystectomy is one of the most commonly awaited general surgical procedures in the UK. However, many patients awaiting a cholecystectomy are admitted with recurrent gallstone related symptoms while on the waiting list, resulting in significant morbidity. The aim of this study was to quantify this problem, and also to analyse the cost implications of these admissions for the NHS. A retrospective study was performed of all patients who underwent an elective cholecystectomy by three consultants in a district general hospital between January 1999 and January 2000. The demographic details, indications for surgery, details of the emergency admissions while on the waiting list, and the treatment given during these episodes were recorded. One hundred and fifty six patients were included in the study, of which 122 (78%) were females. The mean (SD) age of the patients was 54 (5) years. The mean waiting time for surgery in these patients was 12 (3) months. Thirty seven patients (23.7%) were admitted as an emergency due to gallstone related symptoms and complications while awaiting surgery. There were 47 episodes of admissions in total, of which 32 were for biliary colic, 13 were for acute cholecystitis, and two were for acute pancreatitis. In addition to routine blood tests, 20 abdominal radiographs, 10 chest radiographs, three endoscopic retrograde cholangiopancreatography tests, five ultrasonograms, and one computed tomogram were carried out in these patients. The mean duration of each episode of admission was three days. The cost of treatment per episode was pound 946 and the total cost of treating the 37 patients was calculated to be pound 44 462. Performing early laparoscopic cholecystectomy for acute cholecystitis may help to reduce costs by preventing recurrent emergency admissions in these patients. Further studies to identify risk factors associated with recurrent symptoms and complications in patients with gallstone disease may help to prioritize them for early surgery.

Cholecystectomy↗

The implications of subspecialisation on the management and outcome of surgery for rectal carcinoma.

BACKGROUND: The management of rectal carcinoma has changed significantly over the last decade. We studied the changing trends in the management of rectal carcinoma over a 7-year period in a district general hospital. METHODS: A retrospective analysis of all patients with histologically proven rectal adenocarcinoma who underwent operative treatment between January 1991 and December 1997 was performed. The type of operative procedure, local recurrence rate and completeness of pathology reporting was documented. RESULTS: There were 200 operative procedures: 102 anterior resections (AR), and 98 abdominoperineal resections (APR). This included 17 palliative resections because of metastatic disease (n = 8) or extensive local invasion (n = 7) or both (n = 2). The APR rate steadily declined from 72% in 1991 to 19% in 1997 (p < 0.005). Subspecialist 'colorectal' surgeons performed only 24% of the operations in 1991 but the figure for 1997 was 85% (p < 0.01). No circumferential resection margin was reported in 1991 but was reported in 85% of the cases in 1997 (p < 0.001). There was a steady increase in stapled anastomoses from 43% in 1991 to 93% in 1997 (p < 0.03). There were 15 local recurrences following 'curative' resection; 7 following APR and 8 following AR (n.s.). CONCLUSION: There was a significant increase in the rate of restorative resection of rectal cancer with a concomitant reduction in permanent stoma formation; this may be attributed to an increase in subspecialisation. Despite this, a low rate of local recurrence was maintained throughout the study period.

Aged↗

Intestinal ischaemia.

Over the past three decades major advances have been made in the diagnosis and management of mesenteric ischaemia. Early identification and treatment of this condition has reduced its mortality and morbidity. This review discusses the causes, preliminary and definitive investigations, and treatment protocols relating to gut ischaemia.

Acute Disease↗

Self-injurious behavior: gene-brain-behavior relationships.

This paper summarizes a conference held at the National Institute of Child Health and Human Development on December 6-7, 1999, on self-injurious behavior [SIB] in developmental disabilities. Twenty-six of the top researchers in the U.S. from this field representing 13 different disciplines discussed environmental mechanisms, epidemiology, behavioral and pharmacological intervention strategies, neurochemical substrates, genetic syndromes in which SIB is a prominent behavioral phenotype, neurobiological and neurodevelopmental factors affecting SIB in humans as well as a variety of animal models of SIB. Findings over the last decade, especially new discoveries since 1995, were emphasized. SIB is a rapidly growing area of scientific interest to both basic and applied researchers. In many respects it is a model for the study of gene-brain-behavior relationships in developmental disabilities.

Animals↗

Spontaneous stereotypy in an animal model of Down syndrome: Ts65Dn mice.

Stereotyped behaviors (e.g., body rocking) occur at high rates in individuals with mental retardation (e.g., Down syndrome). To determine if spontaneous stereotypy occurs in a murine model of Down syndrome, the home cage behavior of Ts65Dn and control mice was monitored during the dark cycle. Motor activity was further assessed in novel automated test chambers, with acoustic startle and rotor rod paradigms providing additional environmental challenges. Spontaneous stereotypy (repetitive jumping and cage top twirling) was observed in the home cage in approximately half of the Ts65Dn mice, compared with approximately 10% of diploid controls. Repetitive jumping was observed exclusively in the Ts65Dn mice. In the open field, although no differences were found between Ts65Dn and control mice, stereotypic Ts65Dn mice exhibited significantly less locomotor activity and rearing relative to control and nonstereotypic Ts65Dn mice. Ts65Dn mice attained significantly lower rotor rod speeds but did not differ from controls in the amplitude of the acoustic startle response. These environmental challenges did not increase stereotypy over home cage rates but induced stereotypy in two additional animals. The Ts65Dn model may aid in identifying genes associated with the development and expression of stereotypy.

Acoustic Stimulation↗

Cover arrangements for consultants on leave: an analysis of job descriptions.

There is much ambiguity about consultant leave allowances and arrangements for cover in the National Health Service. We analysed job descriptions for 47 consultant posts advertised in mid-2000. 35 defined a duty rota but only 3 mentioned specific available leave (all different). In 32 there was no mention of cover for colleagues on leave. When a consultant is absent, colleagues tend to provide cover for emergency cases but not for elective admissions, which are managed largely by junior doctors. This arrangement is particularly hazardous in surgical specialties. If elective surgery is to continue when the consultant is absent, arrangements for leave and cover need to be more clearly defined.

Consultants↗

Stereotypy and motor control: differences in the postural stability dynamics of persons with stereotyped and dyskinetic movement disorders.

We examined whether dynamic measures of postural stability differentiated persons with stereotyped movement disorder from persons with dyskinetic movement disorder. Participants from three groups (stereotypy, dyskinesia, control) were given a goal-oriented postural stability task, and performance was measured using a force platform and computerized posturographic techniques. The results showed that both movement disorder groups differed from the control group in the posture task. Further, the stereotypy and dyskinesia groups demonstrated markedly different postural movement profiles. The postural motion of the stereotypy group was characterized by greater amplitude and variability but lower complexity than the dyskinesia group. These results provide support for a motor control model of stereotypy.

Adult↗

Early social deprivation in nonhuman primates: long-term effects on survival and cell-mediated immunity.

BACKGROUND: Early differential social experience of non-human primates has resulted in long-term alterations in behavior and neurobiology. Although brief maternal separation has been associated with changes in immune status, the long-term effects on survival and immune function of prolonged early social deprivation are unknown. METHODS: Survival rates were examined in rhesus monkeys, half of which had been socially deprived during their first year of life. Repeated measures of immune status were tested in surviving monkeys (18-24 years old). Peripheral blood T, B, and natural killer lymphocytes, macrophages, and monocytes were measured by flow cytometry. Functional cellular immune activity measures included T-cell proliferative responses to mitogens (concanavalin and phytohemagglutinin), T-cell memory response to tetanus toxoid antigen, T-cell-dependent B-cell proliferative responses to mitogen (PWM) and natural killer cell cytotoxic activity. RESULTS: Despite identical environments following isolation, early social deprivation resulted in a significantly decreased survival rate, males being particularly vulnerable to early death. Early social deprivation was associated with a decrease in the ratio of helper to suppressor T cells, and a significant increase in natural killer cell number and in natural killer cell activity in the surviving monkeys. No differences in T- or B-lymphocyte proliferation following mitogen or tetanus toxoid antigen stimulation were observed. CONCLUSIONS: Prolonged early social deprivation of non-human primates profoundly affected mortality and resulted in lifelong effects on cell-mediated immune status.

Age Factors↗

D(3) and D(2) dopamine receptor agonists differentially modulate isolation-induced social-emotional reactivity in mice.

Following isolation housing, mice typically exhibit heightened emotional reactivity to mild social stimulation. Aggression, social avoidance and a variety of defensive behaviors that differ in terms of motor activation (e.g. freezing, escape) can be observed depending on strain. Previous studies suggested that D(2)-like dopamine (DA) receptors play an important, albeit strain specific, role in the mediation of particular forms of defensive behavior. D(3) receptors are subtypes of D(2)-like receptors that are highly expressed in limbic areas of the brain and, therefore, they have been hypothesized to mediate emotional behavior. This study examined the effects of the putative D(3) receptor agonists 7-OH-DPAT and PD128907 on social-emotional behavior in isolated C57BL/6J and A/J mice. These effects were compared with those of the selective D(2) receptor agonist PNU91356A. All three DA agonists increased non-locomotor forms of defensive behavior (e.g. freezing, upright defensive posture). These effects were observed at low doses in C57BL/6J and at higher doses in A/J mice. Only the D(3) receptor agonists were effective in increasing locomotor forms of defensive behavior (i.e. escape, jump) at higher doses. These effects were more pronounced in C57BL/6J mice than A/J mice. The increases in stationary and locomotor defensive behavior were accompanied by marked reduction in social investigation in both the strains. Aggressive behavior was also abolished in the aggressive C57BL/6J strain. These results support previous findings and suggest that DA agonists potentiate defensive behavior and/or social fearfulness. They also suggest that D(3) and D(2) DA receptors differentially modulate the expression of social-emotional reactivity and indicate the importance of strain in examining the effects of DA ligands on emotional behavior.

Aggression↗

Varieties of repetitive behavior in autism: comparisons to mental retardation.

Systematic study of abnormal repetitive behaviors in autism has been lacking despite the diagnostic significance of such behavior. The occurrence of specific topographies of repetitive behaviors as well as their severity was assessed in individuals with mental retardation with and without autism. The occurrence of each behavior category, except dyskinesias, was higher in the autism group and autistic subjects exhibited a significantly greater number of topographies of stereotypy and compulsions. Both groups had significant patterns of repetitive behavior co-occurrence. Autistic subjects had significantly greater severity ratings for compulsions, stereotypy, and self-injury. Repetitive behavior severity also predicted severity of autism. Although abnormal repetition is not specific to autism, an elevated pattern of occurrence and severity appears to characterize the disorder.

Adult↗

Can changes to junior surgical jobs improve training and make a career in surgery more attractive?

Surgical training has been extensively revised in recent years and new challenges are emerging due to a shorter length of training with fewer opportunities for hands-on experience. Junior doctors' hours are likely to be reduced further, some even advocate shift systems. How do junior surgical jobs affect the desire of young doctors to become surgeons? How can further improvements be made to make surgical training more attractive and effective? This study aims to answer these questions by asking the junior doctors concerned.

Attitude of Health Personnel↗

The evolution of a vascular surgeon at a district general hospital: is sub-specialisation inevitable?

We report a 15-year retrospective audit to evaluate the change in arterial surgical commitment on general surgical case mix of a single surgeon with a vascular interest at a district general hospital. There was a 409% increase in the number of arterial procedures performed combined with a fall of 52% in the total number of operations over the study period. We conclude that, with such a rapidly growing arterial caseload, sub-specialisation to vascular surgery is inevitable.

Arteries↗

Development of spontaneous stereotyped behavior in deer mice: effects of early and late exposure to a more complex environment.

Abnormal repetitive behaviors such as stereotypies are associated with neurodevelopmental disorders and are often observed under conditions of environmental restriction, particularly early in development. Few studies, however, have systematically assessed the effects of environmental enrichment and almost no information is available as to whether a sensitive period exists for such enrichment effects. We hypothesized that spontaneous stereotypies exhibited by deer mice housed under standard laboratory conditions were the result of environmental restriction and that a sensitive period exists for the development/prevention of stereotypies. Exposure to a more complex environment early in the post-weaning period resulted in substantially less stereotypy in the complex environment. Importantly, this outcome was maintained even after mice were housed in standard cages for an identical period of time. Later exposure to the more complex environment also resulted in significantly lower levels of stereotypy compared to controls. These effects were observed in the experimental housing condition as well as in a standard test context. The effects of early and late enrichment support the importance of environmental restriction in the genesis of stereotype and provide support for the efficacy of early and late enrichment in the prevention of stereotypies.

Age Factors↗

Smoking--do vascular surgeons practise what they preach?

Smoking is a major health problem in Great Britain and cigarette consumption is rising. Although there are studies concerning the smoking habits of hospital physicians, nurses and oral and maxillofacial surgeons, little is known about the smoking habits of vascular surgeons and the advice given by them to their patients. A questionnaire survey was conducted involving 422 members of the Vascular Surgical Society of Great Britain and Ireland. The response rate was 74%. The median age of responders was 51 years (range, 32-69 years) of whom 98% were men. Of responders, 98% routinely advise patients to stop smoking, 10% advise nicotine gum/patch, 39% provide antismoking information sheets, 11% are involved in an antismoking clinic/group and 74% check to see whether patients continue to smoke. The majority of responders would be prepared to offer revascularisation in patients who continue to smoke. Only 8 surgeons (3%) would not advise revascularisation in this group of patients. Only 10% of respondents were current smokers, 37% were ex-smokers and 53% had never smoked. Vascular surgeons, therefore, seem to practise what they preach.

Adult↗