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T J Clarke

Publications and source records attributed to T J Clarke.

At least 19 recordsLinked to original sources
PubMed2003

Laser Doppler imaging determines need for excision and grafting in advance of clinical judgment: a prospective blinded trial.

INTRODUCTION: Clinicians' judgment as to which burns require excision and grafting remains one aspect of burn care without objective measurements. This study presents a prospective, blinded trial to assess decision to operate by laser Doppler imaging (numerical criteria) versus the clinical judgment of an experienced burn surgeon. METHODS: A number of 23 patients were enrolled in this prospective trial and 41 representative wounds of indeterminate depth were selected for observation. Daily determination of need to operate (burn depth) was made by a single burn surgeon. Laser Doppler imager (LDI) scans of the same wounds were simultaneously obtained, and not revealed to the clinician. Data analysis compared quickness of decision to operate by LDI to the clinician's judgment. Concurrence of decisions by either method was compared. RESULTS: A total of 23 patients and 41 wounds were analyzed. LDI and the surgeon agreed in determination of wound depth 56% of the time (23/41, P=0.031). Biopsy confirmation was obtained for 21 wounds. The surgeon's determination of burn depth was accurate in 71.4% of wounds biopsied (15/21). When the LDI scan median flux indicated need for excision, it was 100% accurate (7/7). When both the surgeon and the LDI were correct in assessing wound depth, LDI would have saved median number of 2 days (minimum=0, maximum=4). CONCLUSION: LDI allowed for earlier, objective determination of need to operate. Concurrence with clinical judgment in this blinded study was excellent. LDI should be seen as an effective aid to clinical judgment when contemplating excision of burns with indeterminate depth.

Adolescent↗
PubMed2001

Respiratory muscle injury: evidence to date and potential mechanisms.

Respiratory muscle dysfunction associated with ventilatory loading may be partially attributed to respiratory muscle injury. Exertion-induced muscle injury can be defined as structural alterations of the muscle, however, a better understanding of the biochemical, morphologic, and functional correlates of injured respiratory muscles will facilitate discrimination of how injury, fatigue, and weakness contribute to respiratory muscle dysfunction. In addition to the increased loads associated with lung disease, many factors such as poor arterial blood gases, immobilization, sepsis, decreased nutrition, and corticosteroids may increase susceptibility to exertion-induced respiratory muscle injury. Respiratory muscle injury in humans is not well-described, however, more extensive evidence has been shown in animal models of increased ventilatory loading. Potential mechanisms of respiratory muscle injury are mechanical stress, metabolic stress, and inflammation. In order to optimize therapeutic interventions, a better understanding of these mechanisms and the patients that are most susceptible to respiratory muscle injury needs to be determined.

Animals↗
PubMed1996

The evaluation of diagnostic and prognostic criteria and the terminology of thin cutaneous malignant melanoma by the CRC Melanoma Pathology Panel.

Sections from 95 skin lesions excised at pigmented lesion clinics in England and Scotland were studied by eight histopathologists in order to evaluate consistency in the use of histopathological terms for features of diagnostic and prognostic importance for cutaneous malignant melanoma. The level of agreement (kappa) amongst the panel improved after discussion and re-definement of criteria for several features. These included, architectural and nuclear atypia, pagetoid infiltration and radial and vertical growth phases. A high level of agreement was achieved for an overall benign or malignant diagnosis (kappa = 0.77) but use of more specific terms such as benign naevi with atypia and melanoma < or = 0.76 mm thickness, was associated with only an intermediate level of agreement. Of the original diagnosis of melanoma, 17% were re-classified by the panel as benign with atypia and 2% reported to be benign were judged to be melanoma. This reflected the high proportion of borderline lesions in the study. The use of standardized diagnostic criteria with precise definitions has been shown to improve consistency in diagnosis and it is recommended for general application. From this should emanate more reliable incidence figures for thin melanoma, and improved understanding of the nature of these early lesions, to the benefit of patient and clinician alike. The poor concordance in distinguishing severe dysplasia in the junctional component of melanocyte proliferations from melanoma in situ and superficial dermal invasion improved only modestly despite intensive efforts. Since melanoma in situ and severe dysplasia cannot be distinguished by objective measurements and since their clinical management is the same, the panel suggests that attempts to separate them in diagnostic reports should be discontinued and they could both be referred to as melanocytic intraepidermal neoplasia (MIN). If it becomes accepted that dermal invasion without a vertical growth component can also be managed identically to MIN, then this invasive radial phase may be appropriately referred to as microinvasion and linked to MIN for the purposes of clinical management.

Biopsy↗
PubMed1991

Polymorphous low-grade adenocarcinoma of the salivary glands: a clinicopathological comparison with adenoid cystic carcinoma.

Six cases of polymorphous low-grade adenocarcinoma (terminal duct adenocarcinoma) of the minor salivary glands are presented. In all but one there was a history of a painless intra-oral mass of fairly long duration. The histopathological appearances were characterized by cytological uniformity in a variety of morphological patterns, including tubular, solid, fascicular and cribriform areas. At a cellular level, the tumours possessed regular, often vesicular nuclei and generally eosinophilic cytoplasm. Five of the patients are still alive, although one had recurrent disease 16 years after her original operation; none died of their tumour. These findings are compared with those of six salivary adenoid cystic carcinomas, a neoplasm with many similar histological features, but with a much worse prognosis. The microscopic differences were mainly cytological and, to a lesser extent, morphological. The immunohistochemical reactions of the two tumours were not sufficiently dissimilar to be of practical value. Polymorphous low-grade adenocarcinoma has only rarely been reported in Britain, but we believe it deserves wider recognition as a distinct clinicopathological entity and, in particular, separation from adenoid cystic carcinoma.

Adenocarcinoma↗
PubMed1991

Salivary duct adenocarcinoma.

Six cases of salivary duct adenocarcinoma are presented. All had a history of a rapidly enlarging mass in the parotid gland with involvement of the facial nerve. The histopathological appearance was distinctive, each case showing an invasive tumour resembling ductal carcinoma of the breast, often with areas of comedo necrosis. Five patients died within 26 months, and the one long-term survivor (68 months) has widespread metastatic disease. These findings are similar to cases which have previously been described, but the tumour has not been widely reported, particularly in Britain. We feel that salivary duct adenocarcinoma is a distinct clinicopathological entity and, as its histological appearance is usually unmistakable, we believe it deserves wider recognition.

Adenocarcinoma↗
PubMed1991

Epithelial-myoepithelial carcinoma of salivary glands.

Four cases of epithelial-myoepithelial carcinoma of the salivary glands arose as painless masses in patients over 60 years old, three in the parotid and one in the submandibular gland. Histologically, all the tumours were composed of small ducts with a double cell lining surrounded by a basement membrane. The inner cells were epithelial and the outer cells myoepithelial, the latter usually possessing clear cytoplasm. There was a variable degree of intervening hyalinised stroma. All the tumours were partly encapsulated, but also displayed local invasiveness. One of the tumours also showed areas of dedifferentiation when it later recurred and metastasised. The other three were apparently cured by initial excision, with adjuvant radiotherapy in one instance. In the past this tumour has been described as clear cell adenoma, and it was only recently that its true malignant nature, albeit low grade, was recognised. Reports of epithelial-myoepithelial carcinoma are still relatively few, with only one case described from Britain. It is recommended that this histologically distinct neoplasm deserves wider recognition.

Aged↗
PubMed1991

Primary squamous cell carcinoma of the caecum.

A case of primary squamous cell carcinoma of the caecum arising in a tubulo-villous adenoma is described. This rare lesion develops following genomic derangement of the multipotential colonic stem cells. The literature is reviewed and factors contributing towards squamous cell differentiation discussed.

Adenoma↗
PubMed1990

Histogenesis of ovarian malignant mixed mesodermal tumours.

The histogenesis of ovarian malignant mixed mesodermal tumours, which includes the concept of metaplastic carcinoma, is controversial. Four such tumours were examined for evidence of metaplastic transition from carcinoma to sarcoma using morphology and reticulin stains. Consecutive sections were stained immunohistochemically using cytokeratin and vimentin to determine whether cells at the interface between carcinoma and sarcoma expressed both cytokeratin and vimentin. There was no evidence of morphological, architectural, or immunohistochemical transitions from carcinoma to sarcoma in the four tumours studied. This suggests that ovarian malignant mixed mesodermal tumours are not metaplastic carcinomas but are composed of histogenetically different elements.

Adenocarcinoma↗