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Biomedical subjects

T J Phillips

Publications and source records attributed to T J Phillips.

At least 55 records · Page 3Linked to original sources

Effect of daily versus intermittent sunscreen application on solar simulated UV radiation-induced skin response in humans.

BACKGROUND: Acute and chronic skin damage occurs as a consequence of solar UV radiation exposure. To diminish such skin damage, the dermatologic community advocates the daily use of sunscreens as part of a sun avoidance strategy. OBJECTIVE: We determined the effectiveness of a sunscreen product with a sunscreen protection factor (SPF) of 15 applied daily in preventing UV-induced histologic damage in human skin compared with the protection afforded by sunscreens with equal or higher SPF applied intermittently. METHODS: Twenty-four subjects were exposed to 2 minimal erythema doses of solar-simulated UV on 4 consecutive days. Three sunscreen products were applied to the buttock of each subject. One SPF 15 product was applied daily before exposure to UV and, to simulate intermittent product use, an SPF 15 or SPF 29 product was applied on 3 of 4 days, with one missed application on days 2, 3, or 4. Skin biopsy specimens were taken and processed for routine and immunohistochemical staining. Changes in number of sunburn cells and Langerhans cells as well as degree of inflammatory infiltrate and lysozyme immunostaining were determined. RESULTS: There was a statistically significant increase in the number of sunburn cells, degree of inflammation, and intensity of lysozyme staining, and there was a decrease in the number of Langerhans cells at sites where sunscreen application was missed as compared with unirradiated control and daily SPF 15 sunscreen-treated sites. CONCLUSION: Our data suggest that daily use of a sunscreen reduces the skin damage produced by UV exposure compared with intermittent use of equal or higher SPF products. The daily application of sunscreens in appropriate quantities reduces the harmful effects of solar UV radiation on skin. Compliance is essential for maximal benefit of sunscreens.

Adult↗

Prognostic indicators in venous ulcers.

BACKGROUND: Venous ulcers can be difficult to heal, and prognostic factors for healing have not been fully elucidated. OBJECTIVE: The objective of this study was to analyze the results of a large multicenter venous ulcer trial to retrospectively establish prognostic factors for venous ulcer healing. METHODS: This study examined data from a previously published prospective randomized placebo-controlled trial of an oral medication versus placebo treatment for venous ulcers. Local leg ulcer care involved the use of a moisture-retentive dressing and sustained graduated compression with a paste bandage and a self-adherent wrap. The oral medication or placebo was administered on a daily basis with the same dressings and bandage system in both groups for 12 weeks. A total of 165 patients completed the full 12-week treatment period; 83 received ifetroban, 82 received placebo. RESULTS: There was no statistically significant difference in outcome between the two groups. The study showed that consistent local ulcer treatment with a clearly defined system of care was associated with an unexpectedly high percentage (55%) of long-standing large venous ulcers (mean duration, 27 months; mean area, 15.9 cm(2)) being healed in both groups. Baseline ulcer area and duration of leg ulcer were found to be important in predicting outcome. Ulcers of short duration were found to be most likely to heal. Percent healing and ulcer area at week 3 were good predictors of 100% healing. Ulcers that had at least 40% healing by week 3 predicted more than 70% of the outcomes correctly. CONCLUSION: From this large study it was determined that baseline ulcer area and ulcer duration are significant predictors of 100% healing and time to heal. Percent healing and ulcer area at week 3 are good predictors of complete ulcer healing. Ulcers that are large, long-standing, and slow to heal after 3 weeks of optimal therapy are unlikely to heal rapidly, and might benefit from alternative therapies.

Double-Blind Method↗

Living with chronic venous leg ulcers: a descriptive study of knowledge and functional health status.

A descriptive design was used to identify the functional health status and knowledge level of individuals living at home with chronic venous leg ulcers (N = 21). Limitations in physical function and vitality were moderate to severe, impacting on study participants' productive activities and activities of daily living. Severe to moderate pain was experienced by 19% of the participants. In addition, knowledge deficits were apparent regarding the cause and treatment of leg ulcers. Findings of this study suggest the importance of assessing these factors in addition to the wound when caring for individuals in the community with chronic venous leg ulcers.

Activities of Daily Living↗

Surgical treatment of 45 horses affected by squamous cell carcinoma of the penis and prepuce.

The medical records of 45 horses treated for suspected squamous cell carcinoma of the penis and/or prepuce were reviewed. The age of 40 horses was known, and these had a mean age of 17.4 years. The duration of neoplasia was known for only 3 of the 45 horses. The results of histological evaluation of lesions, available for 35 horses, confirmed that the diseased tissue was squamous cell carcinoma. The location of gross neoplastic lesions was recorded for 43 horses; the glans penis was involved in 24 horses, the body of the penis or the inner lamina of the preputial fold in 27 horses, and the external fold of the prepuce in 10 horses. Surgical treatments of these horses included phallectomy (penile amputation) in 35 horses, segmental posthectomy in 4 horses, phallectomy plus segmental posthectomy in 2 horses, and en bloc resection of the penis, prepuce and superficial inguinal lymph nodes with penile retroversion in 4 cases. Short-term complications in the immediate postoperative period included preputial oedema and haemorrhage at the end of urination. One horse developed acute urinary retention because of severe urethral oedema. Long-term (>1 year) follow-up information was obtained for 31 horses. Neoplasia of the penis and/or prepuce recurred in 6 of these 31 horses (19%), and in 5 of these the recurrence necessitated euthanasia of the horse.

Animals↗

Sensitivity to ethanol-induced motor incoordination in 5-HT(1B) receptor null mutant mice is task-dependent: implications for behavioral assessment of genetically altered mice.

Neuromuscular impairment by ethanol likely involves complex effects on balance, gait, muscle strength, and other features of motor coordination. The present experiments showed that relative sensitivity to ethanol-induced motor impairment in serotonin 1B (5-HT(1B)) null mutant and control mice was task dependent. We found that ethanol-treated null mutant mice made fewer missteps on a balance beam than did ethanol-treated wild-type mice, and confirmed a previous finding of their lesser ethanol sensitivity in the grid test. The genotypes did not differ in ethanol sensitivity as measured by the screen test, static dowel, fixed-speed rotarod, accelerating rotarod, grip strength, or loss of righting reflex tests. These experiments suggest that within a behavioral domain, alternative tests of function are not equivalent, so multiple assessment tools should be used to avoid misinterpretation of gene function.

Animals↗

Successful methods of treating leg ulcers. The tried and true, plus the novel and new.

The cause of a leg ulcer should be determined before a course of treatment is undertaken, and this often can be accomplished through history taking, physical examination, and use of simple noninvasive testing. Most leg ulcers are caused by venous disease, arterial insufficiency, neuropathy, or a combination of these factors. Complete management should address the patient's general health as well as specific findings, and treatment of any underlying cause is paramount. In venous ulcers, compression is the cornerstone of treatment, and a variety of effective stockings and other compression devices are available. Arterial ulcers usually require reestablishment of an adequate vascular supply, often through surgery. Neuropathic ulcers need thorough debridement to allow good granulation and epithelialization. Five types of occlusive dressings are available that achieve debridement less painfully but also more slowly than the surgical approach. Several adjunctive methods are now available that facilitate successful therapy in these ulcers, which have often been considered nonhealing wounds.

Bandages↗

The effect of passage number on fibroblast cellular senescence in patients with chronic venous insufficiency with and without ulcer.

BACKGROUND: Fibroblasts (fb) cultured from venous ulcer patients and patients with venous reflux disease without ulcer demonstrate characteristics of cellular senescence, such as increased fibronectin level and senescence-associated beta-galactosidase (SA beta-gal) positive cells. Cellular senescence is an in vitro event characterized by the progressive loss of proliferative capacity with increased passage number, and has been associated with impaired healing in vivo. This report examines progressive stages of cellular senescence in fb from the distal area (du-fb) and proximal fb (pu-fb) of patients with venous ulcer, as well as in distal fb (dr-fb) and proximal fb (pr-fb) from patients with venous reflux without ulcer, by comparing the population doubling time (T) and percent SA beta-gal expression. RESULTS: The mean value of T over 6 passages for fb in the ulcer group was 132.5 +/- 29.0 hours for pu-fb and 492.9 +/- 146.2 hours for du-fb (P = 0.0009). For fb in the reflux group the mean value of T over 5 passages was 79.3 +/- 12.8 hours for pr-fb and 94.2 +/- 16.8 hours for dr-fb (P = 0.8). Comparing ulcer and reflux fb, no difference in T was observed between pu-fb and pr-fb (P = 0.6), but a difference was noted between du-fb and dr-fb (P = 0.0004). The mean percent SA beta-gal activity for fb in the ulcer group was 11.2% +/- 3.1% for pu-fb and 63.8% +/- 8.9% for du-fb (P = 0.0001). Individual passages demonstrated significant difference (P <0.05) in SA beta-gal activity between pu-fb and du-fb at early and late passages. No difference was noted in SA beta-gal activity for fb in the reflux group or between pu-fb and pr-fb, but comparison between du-fb and dr-fb was significant (63.8% +/- 8.9% versus 7.8% +/- 2.9%; P = 0.0001). CONCLUSIONS: The in vitro passage of du-fb and pu-fb in chronic venous ulcer patients has an effect on T and cellular senescence as measured by SA beta-gal activity. Our data further suggest that du-fb are at a more progressive stage of cellular senescence when compared with pu-fb, and more importantly with fb cultured from patients with venous reflux without ulcer. These findings are consistent with impaired wound healing of venous stasis ulcer. The accumulation of senescent fb and a more advanced stage of cellular senescence of du-fb may explain why repeated episodes of venous ulceration are resistant to conservative treatment and require more aggressive measures of therapy.

Adult↗

Ontogeny of ethanol-induced locomotor activity and hypothermia differences in selectively bred FAST and SLOW mice.

The replicate lines of selectively bred FAST and SLOW mice differ in locomotor response to 2 g/kg ethanol (EtOH). FAST mice show enhanced locomotion; SLOW mice exhibit no change or locomotor depression. Little is known about the responses of FAST and SLOW mice to EtOH during development. We assessed the locomotor responses of FAST and SLOW mice at postnatal days (P) 10, 15, 30, and 60. A genetically correlated response, EtOH-induced hypothermia, was also investigated. Although all animals demonstrated their respective selection phenotypes in adulthood, developing FAST mice exhibited ethanol stimulation by P15 (replicate 1) or P30 (replicate 2). At these ages, responses of FAST mice differed from those of SLOW. The stimulant response in FAST mice was adult-like at P30. EtOH-induced hypothermia was seen in SLOW mice by P15. These data suggest that sensitivity to the locomotor stimulant effects of EtOH changes during postnatal development, and may mirror developmental profiles for certain neurotransmitter systems.

Aging↗

Identifying genes for alcohol and drug sensitivity: recent progress and future directions.

New methods for identifying chromosomal regions containing genes that affect murine responses to alcohol and drugs have been used to identify many provisional quantitative trait loci (QTLs) since 1991. By 1998, 24 QTLs had been definitively mapped (P<5x10(-5)) to specific murine chromosomes, which indicates the presence of a relevant gene or genes at each location. The syntenic (homologous) region of the human genome for these genes is often known. For many mapped QTLs, candidate genes with relevant neurobiological function lie within the mapped region. Data that implicate candidate genes for specific responses include studies of knockout animals. Current strategies for gene identification include the use of congenic strains containing QTL regions introduced from another strain. There is increasing emphasis on gene-gene and gene-environment interactions in such studies.

Alcohol Drinking↗

Patients with chronic leg ulcers show diminished levels of vitamins A and E, carotenes, and zinc.

BACKGROUND: Nutrition plays an important role in the wound healing process, particularly in the elderly. OBJECTIVE: Comparison of nutritional serum indices between patients with chronic leg ulcers and an age-matched control population. METHODS: Seventeen patients with chronic leg ulcers (age range 47-90) were studied. A panel of vitamins (A, B1, B2, B6, B12, E), trace elements (zinc, copper, iron), folate, and carotene levels were screened on fasting blood samples. Study data were compared with data obtained from the nutritional status survey (NSS) in the greater Boston area. RESULTS: Significantly lower levels of vitamin A (P < 0.0001), zinc (P < 0. 0001 men, P = 0.027 women) and carotenes (P = 0.0023 men, P = 0.0067 women) were found in chronic ulcer patients. Significantly lower levels of vitamin E (P < 0.009) were observed in the men with a tendency to lower levels in women. CONCLUSION: Elderly Bostonian patients with chronic leg ulcers have low levels of vitamins A and E, carotenes, and zinc. Nutritional deficiency or increased consumption of nutritional elements in these patients may influence wound healing rates.

Aged↗

The long-term effect of an innovative family physician curricular pathway on the specialty and location of graduates of the University of Washington.

PURPOSE: To report the specialty and rural/urban distribution a mean of 19 years after graduation for a cohort of students from a family physician curricular pathway. METHOD: Specialty and location information for medical students who had entered the University of Washington between 1968 and 1973 was obtained from the 1994 Physician Masterfile of the American Medical Association. RESULTS: Of the 239 family physician pathway graduates, 173 (72%) had intended family practice at graduation, and 136 (57%) were family physicians two decades later. The proportions of all graduates in family practice and of graduates serving rural Washington as family physicians had increased over that of a cohort of students who had entered the University of Washington prior to the introduction of the pathway curriculum. These proportions surpassed the goals set at the time the new curriculum was introduced. CONCLUSION: With early identification and support of students interested in family practice, an increased number entered the specialty and were still family physicians in mid-career.

Career Choice↗

Endoscopy of the navicular bursa: a new technique for the treatment of contaminated and septic bursae.

A technique for evaluation of the navicular bursa using a 4 mm 25 degrees inclined view arthroscope is described. This allows examination of the palmar/plantar surface of the navicular bone, the insertions of the navicular suspensory, T and impar ligaments, the bursal synovium and the dorsal surface of the deep digital flexor tendon. The technique was used in 16 horses with punctures of the navicular bursa. Procedures facilitated by the technique were bursal lavage, removal of pannus, synovial resection and debridement of lesions on the palmar/plantar surface of the bone and in the deep digital flexor tendon. Following treatment, 10 animals were sound and returned to their pre-injury use and 6 animals had persistent lameness; 2 of these were salvaged after neurectomy, 1 was retired for use as a broodmare and 2 were destroyed. In contrast to the 'streetnail' procedure, the reported technique is less invasive and post operative care is simpler. The success rate is also better. Endoscopically guided treatment therefore appears to offer an advantage in the treatment of contaminated or septic navicular bursae.

Animals↗

Locomotor activity in D2 dopamine receptor-deficient mice is determined by gene dosage, genetic background, and developmental adaptations.

Locomotor activity is a polygenic trait that varies widely among inbred strains of mice (). To characterize the role of D2 dopamine receptors in locomotion, we generated F2 hybrid (129/Sv x C57BL/6) D2 dopamine receptor (D2R)-deficient mice by gene targeting and investigated the contribution of genetic background to open-field activity and rotarod performance. Horizontal activity of D2R-/- mice was approximately half that of drug-naive, strain-matched controls but was significantly greater than haloperidol-treated controls, which were markedly hypokinetic. Wild-type 129/SvEv and C57BL/6 mice with functional D2 receptors had greater interstrain differences in spontaneous activity than those among the F2 hybrid mutants. Incipient congenic strains of D2R-deficient mice demonstrated an orderly gene dosage reduction in locomotion superimposed on both extremes of parental background locomotor activity. In contrast, F2 hybrid D2R-/- mice had impaired motor coordination on the rotarod that was corrected in the congenic C57BL/6 background. Wild-type 129/SvEv mice had the poorest rotarod ability of all groups tested, suggesting that linked substrain 129 alleles, not the absence of D2 receptors per se, were largely responsible for the reduced function of the F2 hybrid D2R-/- and D2R+/- mice. Neurochemical and pharmacological studies revealed unexpectedly normal tissue striatal monoamine levels and no evidence for supersensitive D1, D3, or D4 dopamine receptors in the D2R-/- mice. However, after acute monoamine depletion, akinetic D2R+/- mice had a significantly greater synergistic restoration of locomotion in response to SKF38393 and quinpirole compared with any group of D2R+/+ controls. We conclude that D2R-deficient mice are not a model of Parkinson's disease. Our studies highlight the interaction of multiple genetic factors in the analysis of complex behaviors in gene knock-out mice.

Adaptation, Physiological↗