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Biomedical subjects

C R Taylor

Publications and source records attributed to C R Taylor.

At least 37 records · Page 2Linked to original sources
PubMed2000

Pendulaser carbon dioxide resurfacing laser versus electrodesiccation with curettage in the treatment of isolated, recalcitrant psoriatic plaques.

BACKGROUND: Treatment of recalcitrant psoriatic plaques located on certain areas of the body remains problematic despite the many therapeutic options available. OBJECTIVE: This study was conducted to determine the efficacy of Pendulaser carbon dioxide (CO(2)) resurfacing laser to that of electrodesiccation with curettage in the treatment of recalcitrant psoriatic plaques. METHODS: A single psoriatic plaque was divided into thirds, one part treated with CO(2) resurfacing laser, another with electrodesiccation and curettage, and the third left untreated. The psoriatic epidermis and papillary dermis were removed by the two treatment modalities. RESULTS: CO(2) resurfacing laser and electrodesiccation with curettage produced similar therapeutic effects in terms of improvement of psoriasis and were significantly better than the control 4 months later, but not at 6 months. CONCLUSION: For limited recalcitrant psoriatic plaques, CO(2) resurfacing laser and electrodesiccation with curettage may provide an alternative short-term treatment; however, caution must be exercised and the moderately high risk of scarring carefully weighed against the potential benefits.

Curettage↗
PubMed1999

Telomerase activity: comparison between fine-needle aspiration and biopsy specimens for the detection of tumor cells.

BACKGROUND: The purpose of the current study was to determine telomerase activity as a sensitive biomarker for the detection of malignant cells in fine-needle aspiration (FNA) specimens. METHODS: FNA specimens with parallel samples of fresh tumor tissue were obtained from surgical specimens after surgical excision. Using a polymerase chain reaction-based telomeric repeat amplification protocol (TRAP) assay, telomerase activity was determined systematically in FNA specimens (n = 21) and corresponding available tissue biopsy specimens (n = 16) containing malignant cells. In addition to a case of myelolipoma, normal counterparts for 3 of 16 cancer cases, including both biopsy and FNA specimens, also were available for the determination of telomerase activity. RESULTS: Telomerase activity was observed in 14 of 16 of the FNA specimens (88%) and 15 of 16 of the corresponding biopsy specimens (94%). Telomerase activity was detected in both the biopsy specimen and the corresponding FNA specimen, with one exception (a case of mucinous adenocarcinoma of the cecum). In contrast, specimens from three normal tissue biopsies and FNA specimens of normal tissue adjacent to the malignant lesions, as well as the myelolipoma, exhibited no telomerase activity. It is interesting to note that both tissue biopsy specimens and FNA specimens from a patient with high grade sarcoma were negative for telomerase activity. The examination of hematoxylin and eosin-stained adjacent tissue biopsy sections or FNA smears revealed similar low populations of lymphocytes, including those cases that were negative for telomerase activity. There was agreement in the detection of telomerase activity between tissue biopsies and their corresponding FNA specimens in 15 of the 16 patients, indicating a 94% concordance rate (95% confidence interval, 70%, 98%). CONCLUSIONS: The results of the current study clearly suggest that the telomerase activity in FNA specimens was comparable to that of their corresponding biopsy specimens, and that this activity was associated with the presence of malignant cells. The TRAP assay has potential for use in the detection of malignant cells in FNA specimens, particularly cases in which the cytology is not characteristically malignant and/or is present in insufficient numbers. Cancer (Cancer Cytopathol)

Adolescent↗
PubMed1999

Turbo-PUVA: dihydroxyacetone-enhanced photochemotherapy for psoriasis: a pilot study.

BACKGROUND: Dihydroxyacetone (DHA), a colorless sugar in "sunless" tanning lotions, binds to stratum corneum to form a UV-A-protective brown pigment. Bound DHA polymer is shed faster from hyperproliferative skin sites such as psoriatic plaques. We tested the hypothesis that selective shedding of DHA pigment during psoralen-UV-A (PUVA) treatment of psoriasis may allow higher UV-A doses, thus accelerating clearing while protecting uninvolved skin. Concurrent use of lactic acid was investigated as an aid in removing scale and residual DHA from psoriatic plaques. OBSERVATIONS: Thirty psoriatic patients with more than 20% body surface area involvement were recruited. The 6 PUVA study groups were (1) standard American style, (2) American style plus lactic acid, (3) DHA-PUVA or "topical ultraviolet-resisting barrier to optiimize PUVA" (Turbo-PUVA), (4) Turbo-PUVA with lactic acid, (5) European style, and (6) European style plus DHA. Combinations of lactic acid and European-style treatment were not studied. Each subject received up to 30 oral PUVA treatments twice weekly 3 days apart. The DHA-PUVA groups used 15% DHA lotion twice weekly. Lactic acid groups used 7% lotion daily except on treatment days. Psoriasis area and severity index scores were recorded weekly. Turbo-PUVA allowed higher UV-A exposures with minimal burns, showed faster clearing, and required fewer treatments for 90% clearing (P<.001). CONCLUSIONS: Protection of uninvolved skin by DHA during PUVA treatment allows higher UV-A exposures to be tolerated, demonstrates faster clearing, and requires fewer treatments to clear psoriasis. By reducing the total body dose received, Turbo-PUVA may also reduce long-term risks.

Adult↗
PubMed1999

Analysis of telomerase activity in ovarian cystadenomas, low-malignant-potential tumors, and invasive carcinomas.

OBJECTIVE: Inappropriate telomerase expression has been reported to be associated with the development and/or progression of malignancies. Therefore, the purpose of the study was to determine and evaluate the levels of telomerase activity in normal ovary, cystadenomas, low-malignant-potential tumors, and carcinomas of the ovary. METHODS: In the present study, telomerase activity was examined in frozen tissue specimens of normal ovary (n = 6), ovarian cystadenomas (n = 13), ovarian low-malignant-potential (LMP) tumors (n = 12), and ovarian invasive carcinomas (n = 81). Clinicopathological information including age at diagnosis, histological grade, FIGO stage, presence of distant metastasis at diagnosis, and residual disease was available for all patients with ovarian carcinomas (n = 81). Telomerase activity was assessed by the telomeric repeat amplification protocol (TRAP). Arbitrary values were assigned to processivity of telomerase activities based on the molecular weights of the telomeric repeat DNA ladders, and were graded as "negative," "moderate" (< or =99 bp), or "high" (>100 bp) activities. The specificity of telomerase activity was determined by the pretreatment of telomerase-positive control or tumor samples with RNase that led to the abolition of the activity. In addition, to determine the possibility of false negativity due to the presence of telomerase inhibitors, TRAP assay was performed on each of the telomerase-negative specimens by mixing them individually with the telomerase-positive control. RESULTS: Telomerase activity in the progression of ovarian carcinogenesis was evaluated. In comparison with normal ovary/cystadenoma (32%), a much higher frequency of the moderate activity was observed in LMP tumors (67%) or invasive carcinomas (57%), suggesting a close association between the latter two categories. The results reflect a subpopulation of telomerase-positive LMP tumor cells with the potential to develop invasive carcinomas. None of the specimens of the benign or LMP tumors exhibited high activity. In contrast, 18% of ovarian invasive carcinomas showed high telomerase activity (P = 0.013, Fisher exact test) and further 57%, moderate activity (75% in all). A statistically significant difference was observed in the expression of telomerase activity between normal ovary/benign cystadenomas and ovarian invasive carcinomas (P = 0.001, chi(2) test). CONCLUSIONS: The study showed a high prevalence of telomerase activity in LMP tumors or invasive carcinomas, the high levels of telomerase activity being associated exclusively with the invasive ovarian carcinomas. Therefore, the levels of processivity of telomerase activity and evidence of its statistically significant association with ovarian carcinoma suggest its role in the progression of ovarian carcinogenesis.

Adult↗
PubMed1999

Photosensitivity in the Smith-Lemli-Opitz syndrome: the US experience of a new congenital photosensitivity syndrome.

Photosensitivity has been briefly mentioned in several publications on the Smith-Lemli-Opitz (SLO) syndrome, an autosomal recessive mental retardation syndrome. We conducted a questionnaire-based survey to determine the incidence and main features of photosensitivity in SLO. We confirmed a high incidence, and initial evidence suggests that SLO may be the first example of an inherited photosensitivity disorder in which sensitivity to UVA is common.

Adolescent↗
PubMed1999

Characterization of photosensitivity in the Smith-Lemli-Opitz syndrome: a new congenital photosensitivity syndrome.

Photosensitivity has recently been reported as a feature of the Smith-Lemli-Opitz syndrome (SLO). The aim of this study was to establish the photobiological features of this disorder and to examine the hypothesis that the photosensitivity is caused by the high levels of 7-dehydrocholesterol found in SLO. All known cases of SLO in the U.K. were reviewed and clinical details of photosensitivity were recorded in detail. The action spectrum of the photosensitive eruption was defined by monochromator light testing. Thirteen of the 23 subjects (57%) had severe photosensitivity, and in 10 there was no photosensitivity. No correlation was identified between levels of 7-dehydrocholesterol and severity of photosensitivity, suggesting that the photosensitivity in SLO is not caused by a direct phototoxic effect mediated by 7-dehydrocholesterol. A novel pattern of photosensitivity was observed, with onset of a sunburn-like erythema on sun-exposed skin within minutes of sun exposure, which persisted in most cases for up to 24-48 h before fading. Monochromator light testing in three subjects showed an ultraviolet (UV) A-mediated photosensitivity eruption with greatest photosensitivity at 350 nm. Photosensitivity is a common and prominent feature of SLO and appears to be UVA-mediated. Elucidation of its biochemical basis may provide insight into normal cutaneous protective mechanisms against UVA-induced photodamage, and also sun sensitivity in general.

Adolescent↗
PubMed1999

Immunohistochemical identification of androgen receptors in human lacrimal glands.

PURPOSE: Androgens are thought to play a role in the regulation of the human lacrimal gland. Androgen receptor mRNA has been isolated from human lacrimal tissue; however, it is not known which cell(s) in human lacrimal tissue may contain androgen receptors. This study is an immunohistochemical investigation of the location and distribution of androgen receptors in human lacrimal tissue. METHODS: Formalin-fixed, paraffin-embedded human lacrimal gland tissues were subjected to established antigen retrieval techniques. This was followed by routine immunohistochemical staining, employing one of two anti-human androgen receptor monoclonal antibodies, each specific for a different antigenic epitope within the receptor molecule. RESULTS: The two anti-human androgen receptor monoclonal antibodies demonstrated similar staining patterns in adjacent tissue sections from the same human lacrimal gland specimens. Specific staining for androgen receptors was observed in the nucleus and cytoplasm of lacrimal acinar cells, as well as in lacrimal duct cells. Both the intensity of staining and the number of cells demonstrating staining varied among specimens. We also observed staining for androgen receptors in interstitial and inflammatory cells distributed between lacrimal acinar units in some specimens. CONCLUSIONS: Androgen receptors are located in human lacrimal gland acinar cell nuclei as observed in other animals. However, the detection of androgen receptors in lacrimal interacinar interstitial and inflammatory cells suggests that androgens may play a role in modulating the activities of cells other than lacrimal cells within the human lacrimal gland.

Adolescent↗
PubMed1999

Temperatures reached inside stand-up ultraviolet treatment boxes.

Heat generated within ultraviolet treatment units can exacerbate eczema. To document the actual temperature changes within the treatment units, we measured the air temperatures in standard stand-up psoralen plus ultraviolet A (PUVA), narrowband ultraviolet B (UVB), broadband UVB, and combination UVA/UVB cabinets using a thermocouple thermometer. For the latter unit, we also measured the air temperatures with and without ventilation systems, and actual skin temperatures on individuals undergoing light treatment. The air temperatures rose significantly in all the treatment units, more so with PUVA and narrowband UVB boxes, and were highest with the ventilation systems shut off. Skin temperatures also rose significantly, but less dramatically. Ventilation is essential in maintaining comfortable temperatures within ultraviolet treatment units.

Humans↗
PubMed1999

Hand and foot PUVA soaks: an audit of the Massachusetts General Hospital's experience from 1994 to 1998.

Palmoplantar psoriasis and eczema can be chronic recalcitrant dermatoses. Oral psoralen plus ultraviolet A (PUVA) has proven effective for these, but has a number of unwanted side effects. Previous studies have shown that regional PUVA therapy using the 8-methoxypsoralen (8-MOP) soak method followed by immediate UVA irradiation is also beneficial and well tolerated. The purpose of this audit was to determine the efficacy of hand and foot PUVA soaks by reviewing the experience of the Massachusetts General Hospital's Phototherapy Unit with this treatment modality. Phototherapy records of all patients who underwent hand and foot PUVA soaks from 1994 to 1998 were reviewed. Details regarding the treatment procedure, patient compliance, patient response and incidence of side effects were noted and summarized. Of the 56 patients who underwent at least 20 treatments, 29% had excellent response, 42% had minimal to moderate response, and 29% had poor response. The average number of treatments to induce clearing was 41. The average maximum treatment dose at clearing was 5.85 J/cm2, while the average cumulative dose to achieve clearing was 267.17 J/cm2. 8-MOP PUVA soak therapy is quite useful for chronic hand and foot dermatoses. Patient compliance must be emphasized to obtain favorable results.

Adolescent↗
PubMed1999

Calcium-induced modification of protein conformation demonstrated by immunohistochemistry: What is the signal?

A recent study by Morgan et al. on the mechanism of the heating antigen retrieval (AR) has raised an interesting issue concerning calcium-induced modification of protein conformation demonstrated by immunohistochemistry (IHC). The current study is based on calcium-induced modification of thrombospondin (TSP) and Ki-67, as demonstrated by IHC using seven monoclonal antibodies (MAbs) to TSP and an MAb MIB1. Experiments were carried out on frozen tissue sections of bladder carcinoma and lymph node. Frozen sections were incubated with solutions of 50 mM CaCl2 and/or 10 mM EDTA at 4C overnight before formalin or acetone fixation for TSP and Ki-67, respectively. Sections were then fixed in 10% neutral buffered formalin or acetone before immunostaining. Seven MAbs to TSP, named Ab1 to 7 representing clone numbers of A4.1, D4.6, C6.7, A6.1, B5.2, A2.5, and HB8432, respectively, and MIB1 were utilized as primary antibodies. ABC was used as the detection system and AEC as the chromogen for immunohistochemical staining. An extracellular immunostaining pattern represented a positive result for TSP, and nuclear staining for MIB1. Frozen sections preincubated in 50 mM CaCl2 overnight at 4C showed significant loss of staining and/or altered staining pattern for six of the seven antibodies to TSP and MIB1 compared to positive controls not exposed to CaCl2. Lack of immunostaining of TSP and MIB1 attributable to exposure to CaCl2 could be partially recovered by incubating the frozen sections in EDTA. Calcium-induced modification of protein structure was demonstrated more than 10 years ago on the basis of immunochemical techniques. In this study, similar calcium-induced modification of protein was detectable by IHC in frozen tissue sections, suggesting that calcium-induced modification of protein structure may occur independently of fixation-induced modification. The fact that calcium binding may affect IHC staining is not surprising in view of the fact that antibody/antigen interactions are protein structure-dependent. However, in this experiment the change occurred before and independent of formalin fixation and does not necessarily imply a role for calcium in AR. There may be a valuable role for the use of chemical modification in visualization of protein structure changes in tissue sections by IHC. (J Histochem Cytochem 47:463-469, 1999)

Calcium↗
PubMed1998

Effect of p21WAF1/CIP1 expression on tumor progression in bladder cancer.

BACKGROUND: Altered expression of p53 protein is an important predictor of progression in bladder cancer. The action of p53 on cell cycle regulation is mediated, in part, through expression of the cyclin-dependent kinase inhibitor p21WAF/CIP1 (p21). Loss of p21 expression may, therefore, contribute to tumor progression. We sought to determine the relationship between p21 expression in bladder cancer and disease progression. METHODS: Tumor specimens were obtained from 242 patients who underwent cystectomy for bladder cancer. Median follow-up was 8.5 years (range, 0.1-11.8 years). Nuclear p21 status was determined by immunohistochemistry and was then analyzed in relationship to the probability of tumor recurrence, overall survival, and tumor p53 status. Reported P values are two-sided. RESULTS: Nuclear p21 expression was detected in the tumors of 156 (64%) of the 242 patients. Patients with p21-positive tumors had a decreased probability of tumor recurrence (P<.00001) and an increased probability of overall survival (P<.00001) in comparison with patients with p21-negative tumors. In a multivariable analysis, p21 expression was an independent predictor of tumor recurrence (P = .0017) and of survival (P = .006) when assessed with tumor grade, tumor stage, lymph node status, and p53 status. p21 expression was associated with p53 status (P<.001); 56% of tumors with p53 alterations showed loss of p21 expression, whereas 79% of tumors expressing wild-type p53 were p21 positive. Patients with p53-altered/p21-negative tumors demonstrated a higher rate of recurrence and worse survival compared with those with p53-altered/p21-positive tumors (P<.0001). Patients with 53-altered/p21-positive tumors demonstrated a similar rate of recurrence and survival as those with p53-wild type tumors. CONCLUSION: Loss of p21 expression is a statistically significant and independent predictor of bladder cancer progression. Maintenance of p21 expression appears to abrogate the deleterious effects of p53 alterations on bladder cancer progression.

Aged↗
PubMed1998

Elevated and absent pRb expression is associated with bladder cancer progression and has cooperative effects with p53.

Rb protein (pRb) expression was evaluated in 185 cases of transitional cell carcinoma of the bladder from patients that underwent radical cystectomy. Tumors were stratified into three categories based on the percentage of nuclei expressing pRb: (a) 0, 0% of tumor cells showing nuclear reactivity; (b) 1+, 1-50% of tumor cells showing nuclear reactivity; and (c) 2+, >50% of tumor cells showing nuclear reactivity. Cases with undetectable (pRb 0) and high (pRb 2+) pRb reactivity had identical rates of recurrence. These cases had significantly higher recurrence (P = 0.0001) and lower survival rates (P = 0.0002) compared to cases with moderate (pRb 1+) pRb reactivity, indicating that high levels of pRb expression may reflect a dysfunctional (altered) Rb pathway. The tumors were also examined for alterations in p53 expression; patients with tumors altered in both p53 and pRb had significantly increased rates of recurrence (P < 0.0001) and survival (P < 0.0001) compared to patients with no alterations in either p53 or pRb; patients with alterations in only one of these proteins had intermediate rates of recurrence and survival. These results suggest that: (a) bladder cancers with high pRb expression do not show the tumor suppressor effects of the protein; and (b) alteration in both p53 and pRb may act in cooperative or synergistic ways to promote tumor progression.

Carcinoma, Transitional Cell↗