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Biomedical subjects

L Watts

Publications and source records attributed to L Watts.

16 recordsLinked to original sources
PubMed2000

The mode-coupling Liouville-Green approximation for a two-dimensional cochlear model.

The Liouville-Green [or Wentzel-Kramers-Brillouin (WKB)] approximation for the two-dimensional cochlear mechanics problem disagrees with the finite-difference solution in the region after the response peak. This disagreement has left doubts about the validity of the Liouville-Green approximation, and has never been satisfactorily explained. In this paper, it is shown that the Liouville-Green approximation fails to satisfy Laplace's equation. A new solution is proposed, called the mode-coupling Liouville-Green approximation, in which energy is coupled into a second wave mode, so as to obey Laplace's equation. The new approximation gives excellent quantitative agreement with the finite-difference solution. Furthermore, it may provide an explanation for a second vibration mode observed in biological cochleas. Also proposed is a high-order formulation of the stapes displacement term, which is necessary to obtain good agreement between the Liouville-Green approximation and finite-difference solutions at low frequencies.

Basilar Membrane↗
PubMed1999

Low recall of local television health care news segment topics, sponsors and program names.

In an effort to examine the effectiveness of hospitals' sponsoring of local broadcast news health care segments, viewer recall of information presented in news reports, the program name of the reports, and the names of the hospital sponsors of those reports were analyzed. Despite the fact that telephone survey respondents said they place a higher value on televised health care information than they do for other mass media, recall was found to be generally poor. A majority of respondents could not name the topic of the televised health news report they had viewed, the program name or the program sponsor.

Adolescent↗
PubMed1996

Microvascular invasion of the seminal vesicles in adenocarcinoma of the prostate.

The objective of this article is to determine the relationship between microvascular invasion and seminal vesicle invasion in prostatic adenocarcinoma. Radical prostatectomies with seminal vesicle involvement were examined histologically and immunohistochemically with antibodies directed against S-100 protein and factor VIII. Microvascular invasion of the seminal vesicles showed a positive correlation with microvascular and capsular invasion of the prostate (P = 0.006 and 0.048, respectively) and lymph node metastases. Tumor progression was found in 8 of 14 (57%) patients with microvascular invasion of the seminal vesicles, compared with 3 of 22 (14%) without microvascular invasion (P = 0.001). Microvascular invasion of the seminal vesicles is predictive of tumor progression and lymph node metastases in prostatic adenocarcinoma.

Adenocarcinoma↗
PubMed1996

Scanning electron microscopy shows inhibited gubernacular development in relation to undescended testes in oestrogen-treated mice.

The morphological relationship between transabdominal testicular descent and the 'swelling reaction' of the gubernaculum was investigated in oestrogen-treated fetal mice by using scanning electron microscopy (scanning EM). In addition, flutamide was also administered to pregnant mice to determine whether androgens cause gubernacular growth and transabdominal testicular descent in offspring. In oestrogen-treated fetal mice, scanning EM showed that both the gubernacular 'swelling reaction' and transabdominal testicular descent were inhibited, in addition to inhibition of Müllerian duct regression. The gubernaculum showed a flat, thin bulb (widest diameter 0.25 +/- 0.04 mm) and an elongated cord (1.28 +/- 0.41 mm) after oestrogen treatment in utero, which was significantly different in appearance from that in normal control mice (width 0.44 mm +/- 0.06 mm, p < 0.001; length 0.27 +/- 0.19 mm, p < 0.0001). However, flutamide-treated mice showed much more normal gubernacular enlargement and transabdominal testicular descent. The width of the gubernacular bulb after flutamide exposure was 0.44 +/- 0.05 mm, which was comparable to that in control animals; the length of the intra-abdominal gubernaculum (0.44 +/- 0.15 mm) was slightly longer than in controls (p < 0.02). These results suggest that both the swelling reaction of the gubernaculum and transabdominal testicular migration are blocked by prenatal exposure to oestrogen. However, oestrogen exposure of the fetus does not block the swelling reaction of the gubernaculum by acting as an antiandrogen.

Androgen Antagonists↗
PubMed1993

Abnormal pedal thermoregulation in interstitial cystitis.

Isolated cold stress tests were used to evaluate the thermoregulatory capacity in the feet of 19 patients with interstitial cystitis (IC) and of 11 healthy volunteer control subjects. Mean pedal skin temperature fell more rapidly in the IC group as compared with controls; significant differences were found at 10-min (P = 0.002) and 20-min (P = 0.0008) cooling. Mean skin temperature remained lower in the IC group throughout the study. Sixteen feet (42%) in the IC group and five (22%) of the control feet failed to return to within 2 degrees C of baseline temperature during the 20-min recovery period. These findings may reflect abnormal vasomotor control in the IC group and, if so, may be indicative of increased spinal sympathetic activity in interstitial cystitis.

Adult↗
PubMed1993

Development of a fatigue scale.

A self-rating scale was developed to measure the severity of fatigue. Two-hundred and seventy-four new registrations on a general practice list completed a 14-item fatigue scale. In addition, 100 consecutive attenders to a general practice completed the fatigue scale and the fatigue item of the revised Clinical Interview Schedule (CIS-R). These were compared by the application of Relative Operating Characteristic (ROC) analysis. Tests of internal consistency and principal components analyses were performed on both sets of data. The scale was found to be both reliable and valid. There was a high degree of internal consistency, and the principal components analysis supported the notion of a two-factor solution (physical and mental fatigue). The validation coefficients for the fatigue scale, using an arbitrary cut off score of 3/4 and the item on the CIS-R were: sensitivity 75.5 and specificity 74.5.

Adult↗
PubMed1993

Comparison of MGH-1 and TuMark antibody detection in transitional cell carcinoma.

Two monoclonal antibodies, TuMark-BTA and MGH-1, were evaluated in patients with benign pathology, history of transitional cell carcinoma with no active disease and active transitional cell carcinoma. Both antibodies were accurate in predicting carcinoma in approximately two-thirds of patients. TuMark showed a 74% sensitivity and 50% specificity, while MGH-1 was more sensitive (86%) and less specific (38%). Positive predictive values for TuMark and MGH-1 were 79% and 78%, respectively.

Adult↗
PubMed1991

Serial Alu sequence transposition interrupting a human B creatine kinase pseudogene.

We have isolated, sequenced, and characterized a single-copy B creatine kinase pseudogene. The chromosomal assignment of this gene is 16p13 and a unique sequence probe from this locus detects EcoRI restriction fragment length polymorphisms of 7.8 and 5.4 kb. In 26 unrelated individuals, the frequencies for the 7.8- and 5.4-kb B creatine kinase pseudogene alleles were calculated to be 17.3 and 82.7%, respectively. The B creatine kinase pseudogene is interrupted by a 904-bp DNA insertion composed of three Alu repeat sequences in tandem flanked by an 18-bp direct repeat, derived from the pseudogene sequence. Nucleotide sequence analysis of the Alu elements suggests that the Alu sequences were incorporated into this locus in three separate integration events. Several complex clustered Alu repeat sequences without defined integration borders have been previously identified at different genomic loci. This is the first evidence that complex tandem Alu elements can integrate in an apparently serial manner in the human genome and supports the contention that Alu repeats integrate nonrandomly into the human genome.

Animals↗
PubMed1991

The University of Texas Medical Branch: a century of service.

The current centennial celebration of The University of Texas Medical Branch (UTMB) at Galveston spotlights not only a history of medicine, but a history of Texas as well. As fellow travelers across the rugged terrain of the past century, UTMB and Texas have shared times of prosperity and times of hardship; both have been gifted with growth and suffered sorrow and loss. Since its first day of class, on October 5, 1981, UTMB has grown from 23 students, one school, and one hospital to 2,360 students, four schools, seven hospitals, and two institutes. Since its first commencement class of three in 1892, UTMB has graduated more than 17,000 health science professionals during the past 100 years, and it is estimated that one in four doctors practicing in the state has trained at UTMB. Today, as UTMB stands on the threshold of its second hundred years, the health science center's first century of service is a history worthy of celebration.

Education, Medical↗
PubMed1990

[Differences in the dietary intake of diabetics with and without early nephropathy].

The dietary regimen of 70 patients with insulin dependent diabetes mellitus is discussed. 24 of these patients are with microalbuminuria (initial nephropathy). The age of manifestation of diabetes and the mean age of these patients are lower and the retinopathy is more frequent than in the patients without microalbuminuria. Only 18% of the diabetic patients studied keep a diet according to contemporary conceptions. In the group with initial nephropathy a higher consumption of fat (130.9 +/- 42.5 g) and proteins (109.6 +/- 28.8 g) is registered than in the other patients. There are no significant differences in the consumption of carbohydrates and fiber products. The possible role of longterm high consumption of fats and proteins by patients with diabetes mellitus in the pathogenesis of diabetic nephropathy is discussed.

Adult↗
PubMedDate not supplied

Attention-deficit hyperactivity disorder and fluctuating asymmetry in another college sample.

Attention deficit/hyperactivity disorder (AD/HD) represents a developmental lag that may be reflected in fluctuating asymmetry (FA), i.e., differences from perfect symmetry in traits that display bilateral symmetry. Burton et al. (2003 Am. J. Hum. Biol. 15:601-619) found a statistical trend for FA to increase (as dermatoglyphic index or as total index) as the behavioral measure for AD/HDness (Rasch logit values derived from the Wender Utah Rating Scale, or WURS) increased in males but not in females. The objective here was to do a similar study in an independently collected sample of college students (n = 222; 61 male, 161 female) not selected for AD/HD, looking at FA vs. symptoms for AD/HD based on Rasch versions of responses to the Diagnostic and Statistical Manual of Mental Disorders (DSM IV) (Barkley and Murphy 1998 Attention-Deficit Hyperactivity Disorder, New York: Guilford Press, p. 95-96) and the more comparable shortened WURS. FAs were lowest for body and ear height, and highest for eye width and nose width, and ranged from 0.01 +/- 0.001 (mean +/- SE) for foot and ankle widths to 0.13 +/- 0.01 in eye and nose widths for both sexes; the sexes did not differ significantly. Males displayed higher AD/HD symptom rates overall. There was a significant correlation between body FA and the WURS measure in females after Bonferroni correction (P = 0.002, r(2) = 0.058). Thus, AD/HD symptoms levels increased with an increase in body FA in female college students not selected for AD/HD.

Adolescent↗