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Biomedical subjects

P Clifford

Publications and source records attributed to P Clifford.

At least 37 records · Page 2Linked to original sources
PubMed1983

Patterns and mechanisms of bone invasion by squamous carcinomas of the head and neck.

Patterns and mechanisms of local bone invasion by squamous carcinomas of the head and neck have been investigated. Detailed surgical pathology has shown that these tumors invade contiguous skeletal or metaplastic bone principally through an indirect process; the normal bone resorbing cells of the host (osteoclasts) are activated and erode bone in front of the advancing tumor edge. Tumor cells take over the destructive process when the osteoclast response has waned. These morphologic patterns have been reproduced in an in vitro model where calcium-45-labelled mouse calvaria, cocultured with a tumor for 3 days, are resorbed by osteoclasts. Freshly excised tumors, established tumor cell lines, and tumor xenografts release osteolysins in vitro which act as osteoclastic stimulants. They include both prostaglandins E2 and F2 alpha, and nonprostaglandin factors, and are derived from tumor cells and from the associated host stroma. Virtually all the tumors examined released osteolysins and resorbed bone in vitro independent of their site, size, degree of differentiation, and the presence or absence of clinical bone invasion.

Bone Neoplasms↗
PubMed1982

Small-area variations in the use of common surgical procedures: an international comparison of New England, England, and Norway.

We examined the incidence of seven common surgical procedures in seven hospital service areas in southern Norway, in 21 districts in the West Midlands of the United Kingdom, and in the 18 most heavily populated hospital service areas in Vermont, Maine, and Rhode Island. Although surgical rates were higher in the New England states than in the United Kingdom or Norway, there was no greater degree of variability in the rates of surgery among the service areas within the three New England states. Hernia repair was more variable in England (P less than 0.05) and hysterectomy in Norway (P less than 0.05) than in the other countries. There was consistency among countries in the rank order of variability for most procedures: tonsillectomy, hemorrhoidectomy, hysterectomy, and prostatectomy varied more from area to area than did appendectomy, hernia repair, or cholecystectomy. The degree of variation generally appeared to be more characteristic of the procedure than of the country in which it was performed. Thus, differences among countries in the methods of organizing and financing care appear to have little relation to the intrinsic variability in the incidence of common surgical procedures among hospital service areas in these countries. Despite the differences in average rates of use, the degrees of controversy and uncertainty concerning the indications for these procedures seem to be similar among clinicians in all three countries.

Appendectomy↗
PubMed1981

The diagnosis and surgical management of olfactory neuroblastoma: the role of craniofacial resection.

The diagnosis and clinical management of olfactory neuroblastoma are discussed. Computerized tomography is a valuable means of assessing the pre-operative extent of disease and the efficacy of subsequent major surgery. The tissue diagnosis is facilitated by electron microscopy, demonstrating the presence of dense core vesicles and cytoplasmic filaments. Radiotherapy followed by craniofacial resection is the treatment of choice for olfactory neuroblastomas that are locally extensive at presentation.

Adolescent↗
PubMed1981

Nutritional status and general immune competence in patients with head and neck cancer.

Anergy to 2,4-dinitrochlorobenzene (DNCB) has been reported as a highly significant adverse prognostic immunological factor in several studies of patients with squamous cell carcinomas involving the head and neck. Patients with these tumours often present with concurrent nutritional deficiencies. This paper reports the findings of a prospective study into both the nutritional status and general immune competence of 53 such patients.Analysis of the results has demonstrated a statistically highly significant positive correlation between nutritional status and both the delayed hypersensitivity response to DNCB, and the pretreatment total lymphocyte count levels. It is suggested that nutritional deficit may be a primary adverse prognostic factor in this disease group, with immunoincompetence a secondary phenomenon, and supporting evidence is presented. The consequent probable importance of nutritional status with regard to clinical trials, and the necessity for controlled studies to determine the possible beneficial effect of nutritional support on `cure' rates, are discussed.

Aged↗
PubMed1980

Direct bone invasion in squamous carcinomas of the head and neck: pathological and clinical implications.

Direct bone invasion by tumour--an uncommon event at most sites--has been demonstrated in 18 out of 150 consecutive major surgical specimens from patients with squamous carcinomas of the head and neck. Intra-oral carcinomas invading the jaw(s) comprise the single commonest group. The tumour gains access to bone by direct spread or along perineural spaces: infiltration of periosteal lymphatics was rare. The morphological phases of bone invasion are described, the main feature being bone destruction by osteoclasts in front of the advancing tumour; tumour cells do not directly impinge on the bone surface until the late stages of invasion. Osteoblastic activity is less marked. Evidence that osteoclasts are directly stimulated by local tumour is discussed. The clinical implications relate to the possible uses of scintigraphy and the need to ensure adequate bone resections in operable lesions: the tumours sometimes infiltrate laterally beneath apparently intact bone cortex (cf. submucosal spread), and the normal tissue planes at the bone-soft tissue interface are usually distorted by previous radiotherapy.

Adult↗
PubMed1980

The irradiated radical neck dissection in squamous carcinoma: a clinico-pathological study.

A preliminary clinico-pathological survey is presented of radical neck dissections from 50 patients with advanced (T3, T4) squamous carcinomas of the head and neck, previously treated by irradiation and combination chemotherapy. The total yield of lymph nodes (1411) from these dissections was high--mean of 28 nodes/dissection, range 8-60; the proportion of nodes containing metastatic carcinoma was low--100 (7%)--with only 1 or 2 nodal masses/dissection in most instances. The involved nodes tended to be concentrated in 1 or 2 anatomical groups, principally in the upper anterior neck, with apparent sparing of nodes in the posterior triangle. There was a high incidence (88%) of transcapsular spread. Keratin granulomas, with or without intact metastatic carcinoma, were commonly found; on occasions they formed large masses simulating nodal metastases. The morphological patterns in uninvolved lymph nodes were shown to be of no prognostic significance. Initial data on postoperative follow-up indicated a crude survival of 52% (24 patients) at 30 months. Most deaths (80%) occurred within 12 months of major surgery; the majority (72%) died with residual malignant disease; and uncontrolled primary tumour, particularly in the oral cavity and oropharynx, was found more frequently than metastatic disease in the neck or elsewhere. Clinical implications are discussed with reference to the use of modified radical neck dissection in the surgical salvage of this poor-risk group of previously irradiated patients.

Adult↗
PubMed1980

Transcranial--facial approach for tumours of superior paranasal sinuses and orbit.

A monobloc resection of the fronto-ethmoid sphenoid area may be performed through a combined cranial and facial approach. Osmotic cerebral dehydration increases the exposure of the anterior cranial fossa. The results of treatment in 26 patients (24 with malignant disease of the ethmoid area who had disease recurrence after previous radiotherapy with or without surgery) and the complications encountered are described. The clinical details of 9 of these patients have been included in an earlier report (Clifford 1977).

Craniotomy↗
PubMed1979

Advanced head and neck cancer treated by combined radiotherapy and VBM cytotoxic regimen--four-year results.

The 4-year results of treatment of advanced squamous cell cancer of the head and neck regions by radiotherapy combined with a cytotoxic regimen VBM (Vincristine, Bleomycin, Methotrexate) given synchronously are compared with those obtained with radiotherapy alone in similar patients. There was a statistically significant improvement in the results of the combined treatment at four years in terms of crude survival rate (56.1% v. 24.5%) and disease free survival rate (56.5% v. 21.8%). Both groups are examined for general prognostic features which might account for the difference. In the absence of such features it must be concluded that the addition of VBM to radiotherapy had produced a marked therapeutic improvement.

Bleomycin↗
PubMed1979

Perineural spread in squamous cell carcinomas of the head and neck: a clinicopathological study.

Perineural spread of tumour has been demonstrated in 24% of an unselected series of 70 patients with squamous carcinomas of the head and neck treated by surgery. Slightly more than half the patients had primary tumours arising within the buccal cavity. Clinical features suggesting perineural infiltration were found in about two thirds of the cases; the symptoms and signs were usually sensory and occurred early in the disease. The mandibular division of the trigeminal nerve was most commonly affected. Perineural spread was more likely to occur with large carcinomas, moderate or poorly differentiated, showing local invasion and lymph node metastases. The associated pathological changes are described and a high incidence of damage to nerve fibres is recorded. The practical implications of perineural spread of tumour are discussed with reference to indications for more radical surgery or for more conservative measures supplemented with other modes of treatment.

Adult↗
PubMed1978

Pharyngeal rhabdomyoma: an unusual presentation.

A case of pharyngeal rhabdomyoma is reported with the unusual presenting symptom of haemoptysis. After complete excision of the lesion, the(71-year-old) patient remained tumour-free until his death from heart disease 19 months later. Seven other published cases of pharyngeal rhabdomyoma are reviewed together with 27 other reported extracardiac adult rhabdomyomas which, with a single exception, occurred in the head and neck region.

Aged↗
PubMed1978

Replication of age and physical activity effects on reaction and movement time.

The latency and consistency of simple reaction time, choice reaction time, and movement time of older men who chronically run or participate in racket sports were compared to those of nonactive men of similar age and also to young men of similar characteristics (young runners, young racketsportsmen, and young nonactive men). The findings of Spirduso's (1975) study, of which this investigation was both a replication and an expansion, that older active men physically reacted to stimuli and moved their forearm over a 20 cm distance as quickly as young sedentary men was reported. The older active men were far superior to older sedentary men in all measures. In addition, the older active group was similar to the groups in terms of group homogeneity and within-subject variability, unlike the older nonactive group, who revealed the commonly reported group heterogeneity and within-subject inconsistency.

Adult↗