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Biomedical subjects

D W Webb

Publications and source records attributed to D W Webb.

At least 37 records · Page 2Linked to original sources
PubMed1994

A population study of renal disease in patients with tuberous sclerosis.

OBJECTIVE: To establish the prevalence of renal disease, asymptomatic renal lesions and possible renal symptoms in a geographically defined population of individuals with tuberous sclerosis. PATIENTS AND METHODS: The study involved 131 patients (64 men, 67 women) with tuberous sclerosis who were resident in nine of the districts within the Wessex Region and three Bristol Health Districts and who had been identified by a prevalence study [1]. The patients' mean age was 22 years (range 6 months-74 years). Established renal disease was identified by history. Where possible individuals were seen and were examined. Specific enquiry was made for flank pain and macroscopic haematuria. Renal ultrasound, blood pressure measurement and urine analysis was offered to all individuals with tuberous sclerosis who were resident in the Bath Health District. RESULTS: Eight patients (6%) had a history of either renal polycystic kidney disease (two patients) or haemorrhage from renal angiomyolipomas (five female patients, one male patient). A further 21% of female and 3% of male patients had a history of severe flank pain or haematuria. Renal ultrasound screening revealed abnormalities in 10 of 21 individuals; angiomyolipomas > 1 cm were found in seven and were twice as common in female patients. CONCLUSIONS: Regular clinical review of individuals with tuberous sclerosis should include enquiry for renal symptoms and abdominal examination. Lesions > 4 cm are most likely to be symptomatic but longitudinal studies are needed before renal ultrasound screening of adolescents or adults can be recommended.

Adolescent↗
PubMed1994

Effects on production of milking three times daily on first lactation Holsteins and Jerseys in Florida.

First lactation DHI records of 4293 Holstein and 2143 Jersey cows from 14 herds for 1984 through 1992 in Florida were studied to estimate effects on milk, fat, and protein yields of milking three times daily. Analyses were by derivative-free REML using the animal model. Advantages of milking three times daily for 305 d compared with milking twice daily were 1226 (17.3%), 29 (12.3%), and 19 kg (8.8%) for the milk, fat, and protein yields for Holsteins, respectively, and 284 (6.3%), 13 (6.2%), and 7 kg (4.3%) for Jerseys. Additional research is needed to evaluate effects on other economically important traits such as composition, health, and reproduction. Economic studies are required to determine the efficacy of milking three times daily, especially for Jerseys with their relatively low response.

Animals↗
PubMed1993

Cardiac rhabdomyomas and their association with tuberous sclerosis.

A search for children presenting with signs or symptoms of cardiac rhabdomyomas was made through members of the paediatric section of the British Cardiac Society in order to establish their birth incidence, presenting features, clinical course, and the frequency of a concurrent diagnosis of tuberous sclerosis. Fifteen children were identified and 12 had tuberous sclerosis (80%). Heart failure was the presentation in six, five of whom died; six presented because of a murmur and three because of arrhythmias. The prevalence of echocardiographic evidence of cardiac rhabdomyomas in a population of patients with tuberous sclerosis was established. Twenty individuals had echocardiography and eight had echodensities consistent with cardiac rhabdomyomas. It is concluded that the minimum birth incidence for children presenting because of the effects of cardiac rhabdomyomas is 1/326,000 and a minimum of 80% have tuberous sclerosis. In a population of patients with tuberous sclerosis a minimum of 60% under 18 years have cardiac rhabdomyomas.

Echocardiography↗
PubMed1992

Echocardiography and genetic counselling in tuberous sclerosis.

OBJECTIVE: To assess echocardiography as an investigation for the detection of occult gene carriers in tuberous sclerosis. PATIENTS: Sixty parents of children with tuberous sclerosis who had been extensively investigated for signs of the disease and 60 age and sex matched controls. PROCEDURE: Blind study by two experienced echocardiographers and blind interpretation of video recordings by an adult cardiologist. SETTING: Cardiology department of a district general hospital. RESULTS: Two parents and three controls had bright echodense areas interpreted as possible rhabdomyomas. CONCLUSIONS: In our hands echocardiography of adults is not an investigation with a high specificity for gene detection in tuberous sclerosis.

Adult↗
PubMed1991

Cranial magnetic resonance imaging in patients with tuberous sclerosis and normal intellect.

The pattern of cerebral hamartomas among a population of patients with tuberous sclerosis and normal intellect was determined. All patients with tuberous sclerosis over 5 years old with normal intellect who were resident in the Bath health district were offered cranial scanning by magnetic resonance imaging. Cerebral axial and coronal images were obtained in 10 mm contiguous sections with a Picker 0.5 tesla magnetic resonance imaging unit. The number, size, and distribution of lesions found was recorded. Eleven of 13 eligible patients underwent scanning. Two patients had normal scans. Seven patients had between one and five subependymal nodules. Nine patients had between two and nine cerebral tubers best seen on T2 weighted images. Our findings suggest that the wrong conclusions may be drawn if the number of lesions alone is used to predict neurological outcome in tuberous sclerosis.

Adolescent↗
PubMed1991

On the incidence of fits and mental retardation in tuberous sclerosis.

OBJECTIVES: To establish the frequency of fits and mental retardation in an unbiased group of tuberous sclerosis patients. METHODS: Known tuberous sclerosis families with more than one affected person were ascertained for a genetic linkage study. A number of members were born after genetic counselling had been given after identification of the proband. These subjects were then carefully examined clinically and in many cases with cranial computerised tomography, renal ultrasound, and skeletal survey but not echocardiography. They provide an unbiased group of tuberous sclerosis patients and allow affected patients with normal intellect to be diagnosed. PATIENTS: Thirty-seven tuberous sclerosis families were ascertained and 26 patients born after the family proband were identified. RESULTS: Sixteen of these 26 patients suffered fits (62%) and 10 patients were mentally retarded (38%). CONCLUSIONS: A lower incidence of fits and mental retardation has been found in an unbiased sample of tuberous sclerosis patients. The lifetime risk for fits might be higher had we been able to follow the patients for longer. However, we believe these are more appropriate figures to use in genetic counselling for this disease.

Adolescent↗
PubMed1991

Non-penetrance in tuberous sclerosis.

Non-penetrance has not been reported in tuberous sclerosis when modern non-invasive investigations have been performed. We report a four generation family in which there was a subject with minimal expression and another with non-penetrance between a great grandfather and his great grandson. This situation highlights the need for full investigation of children of tuberous sclerosis patients before counselling a low recurrence risk for the disease.

Adult↗
PubMed1991

A new method for monitoring mosquito oviposition in artificial and natural containers.

A new method is described for the direct measurement of Aedes albopictus, Ae. atropalpus, Ae. triseriatus and Orthopodomyia signifera oviposition in artificial and natural containers. Seed germination papers were mounted on the insides of can-traps, tree holes and discarded tires to obtain a direct measure of mosquito oviposition. This durable paper substrate was removed weekly while minimizing the disruption of the oviposition habitat. After the germination papers were dried, the aforementioned mosquito eggs were hatched successfully and reared in the laboratory through the adult stage.

Aedes↗
PubMed1990

Penetration rate of two pesticide carriers at a large used-tire storage facility in Chicago, Illinois.

During August 1987, a large and concentrated infestation of Aedes albopictus was discovered on the property of a tire recapper and gasket manufacturer in Chicago, IL, in a densely populated urban environment. The infestation called for special abatement procedures because of the large number of tires and the varied ways they were stacked. An effective method for delivering pesticides into the cavity of each tire is described. Corncob granules, when applied to stacked tires, effectively penetrated this larval habitat at rates of 85% in column-stacked piles, 93% in random-stacked piles and an average of 95% in shingle-stacked piles. By comparison, gypsum pellet carriers sustained penetration rates of 37% in shingle-stacked piles and 87% in random-stacked piles.

Aedes↗
PubMed1989

Oviposition behavior of Aedes triseriatus (Diptera: Culicidae): prevalence, intensity, and aggregation of eggs in oviposition traps.

The oviposition behavior of the treehole mosquito Aedes triseriatus (Say) was studied by counting the eggs laid in 300 oviposition traps weekly for one season (May-October) in Illinois. Eggs were aggregated spatially among traps each week, and temporally among weekly samples and for individual traps over weekly counts. Aggregation could be associated with a nonrandom dispersion pattern of oviposition events and with the oviposition of 20-60 eggs per event. Thus, females were laying clumps of eggs in an overdispersed manner. The greatest number of eggs was found in late July when prevalence (proportion of traps with eggs) and intensity (number of eggs per positive trap) peaked simultaneously. Intensity also peaked in May and prevalence peaked in mid-June and early September. When traps from which eggs were removed each week were compared with traps in which eggs were allowed to accumulate, prevalence was naturally higher in the latter group. However, the intensity of eggs was similar in both groups, indicating that more eggs were laid in traps from which eggs were removed. Thus, the presence of eggs on oviposition surfaces was associated with a decrease in further oviposition.

Aedes↗
PubMed1989

Administration in ambulatory care.

Deficiencies in management of U.S. Department of Veterans Affairs (USDVA) ambulatory care programs have been documented in the literature and were reaffirmed by conference participants. These represent significant barriers to developing an effective and efficient system of outpatient health care delivery for veterans and to expanding educational opportunities for trainees. Based on impact and feasibility rankings from the symposium, review of the literature, and the personal experiences of USDVA ambulatory care managers, several recommendations emerged: (1) implement a system of matrix management; (2) invest in a leader; (3) develop "user-friendly" management information systems; (4) utilize existing resources efficiently; (5) embrace quality assurance; and (6) improve support from clerical and diagnostic services, nursing, and pharmacy personnel. Although intervention from leadership at the level of the USDVA Central Office will be necessary, many of these recommendations can be adopted by managers at the local facilities. The biggest challenge is to change the attitudes of clinical and support staff whose responsibilities have traditionally been inpatient-oriented.

Ambulatory Care↗
PubMed1989

Biochemical testing in patients with alcoholic liver disease.

We evaluated physicians' laboratory utilization patterns for hospitalized patients with alcoholic liver disease and examined the relationship between the frequency of test ordering and certain variables in clinical outcome. During the study, 185 patients with alcoholic liver disease were hospitalized 378 times at the VA Medical Center, Long Beach, California. Physicians ordered liver panels (including serum albumin, alkaline phosphatase, total bilirubin, lactic dehydrogenase, glutamic pyruvate transaminase, and glutamic oxaloacetic transaminase) an average of 7.4 times per hospitalization. Increased biochemical testing did not decrease length of stay or improve clinical outcomes such as development of complications or survival of hospitalization. Since the treatment of alcoholic liver disease is largely supportive and not dependent upon frequent biochemical testing, we recommend that these tests be ordered only when patients are admitted to or discharged from the hospital, and when there has been a clinical change.

Diagnostic Tests, Routine↗
PubMed1985

Invasive candidal balanitis due to a condom catheter in a neutropenic patient.

A 58-year-old man with acute leukemia had balanitis and penile ulceration due to Candida tropicalis after a condom catheter was used because of urinary incontinence. This case illustrates that condom catheters can be associated with serious complications in neutropenic patients and should be used only when absolutely necessary.

Agranulocytosis↗