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Biomedical subjects

R L Carter

Publications and source records attributed to R L Carter.

At least 145 records · Page 8Linked to original sources
PubMed1980

Prostaglandin-like material extracted from squamous carcinomas of the head and neck.

Tumour-associated prostaglandin-like material, assessed by bioassay, has been examined in 37 patients with primary and metastatic squamous carcinomas of the head and neck, previously treated by radiotherapy and chemotherapy followed by radical surgery. High amounts of prostaglandin-like material were extracted from tumours excised within 3 months of radiotherapy and chemotherapy. These amounts correlated with necrosis, inflammation and fibrosis, but not with tumour site, size or degree of differentiation. Most of the prostaglandins formed by these treated tumours thus seem to be associated with host stromal and inflammatory cells, rather than the neoplastic cells. The possible roles of prostaglandins in facilitating the spread of squamous carcinomas are discussed.

Adult↗
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

Natural antibodies to EBV-VCA antigens in common marmosets (Callithrix jacchus) and response after EBV inoculation.

Healthy common marmosets from two separate colonies, one in England and one in France, were found to have antibodies cross-reacting with Epstein-Barr virus structural antigens (EBV-VCA). All seropositive animals were at least 2 years old. Experimental EBV infection of marmosets of different ages led to seroconversion of inoculated weanlings. Adult animals either developed antibody for the first time or showed an increase in their existing titers. Both control and infected animals developed a progressive interstitial nephritis. The lymphocytic infiltration was more extensive, diffuse and immature in appearance in inoculated animals, but no definite evidence of lymphoproliferative disease or lymphoma was found.

Animals↗
PubMed1980

Squamous carcinomas of the head and neck: some patterns of spread.

Patterns of tumour spread are examined in 160 patients with squamous carcinomas of the head and neck with reference to perineural infiltration, direct invasion of bone and ossified cartilage, and lymph node metastases in the previously irradiated neck. Perineural spread is comparatively common in large (T3, T4) tumours; it may be apparent early in the disease; it is often detectable clinically; and it is an adverse prognostic feature which may modify clinical management. Direct bone invasion is described with particular reference to tumours of the oral cavity. Most bone destruction is mediated by osteoclasts which appear to be stimulated by materials such as prostaglandins released in the vicinity of the tumour. The numbers of involved lymph nodes in surgical dissections from the irradiated neck are usually few and restricted to the submandibular and jugular groups; nodes in the posterior triangle are infrequently involved by metastatic carcinoma. Transcapsular spread and keratin granulomas are common. The scope of modified neck dissections in this group of patients is discussed.

Adult↗
PubMed1979

Changes in tight junctions of rat intestinal crypt cells associated with changes in their mitotic activity.

The freeze-fracture appearance of tight junctions between rat duodenal crypt cells was studied in normal, mitotically suppressed, and mitotically enhanced animals. In normal animals crypt cell tight junctions present a pleomorphic appearance. The population includes junctions resembling postmitotic junctions of the intestinal villus, junctions composed largely or completely of particle chains, and regions at the cell apex in which junctions are absent for 3-4 micron distances laterally. Mitotic suppression by inhibition of DNA synthesis with cytosine arabinoside results in the disappearance of pleomorphism and crypt tight junctions progressively come to resemble those of the intestinal villus. With recovery from the drug and further synchronization with Colcemid, the crypt cells undergo a mitotic burst, and all varieties of unusual junctional configurations are observed with increased frequency.

Animals↗
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↗
PubMed1979

Local invasion by laryngeal carcinoma--the importance of focal (metaplastic) ossification within laryngeal cartilage.

Patterns of cartilage invasion by squamous carcinoma were examined in 34 consecutive laryngectomy specimens with particular reference to selective involvement of ossified cartilage. Direct infiltration of the laryngeal framework was demonstrated in 17 cases--16 (out of 17) transglottic carcinomas and in a simgle example of a combined glottic and infraglottic tumour. The susceptibility of ossified laryngeal cartilage to tumour invasion was confirmed, and morphological studies ahve clarified the underlying mechanisms. Invasion is a largely indirect process dominated by local bone destruction by osteoclasts, operating in front of the advancing tumour. One established, carcinoma cells infiltrate and erode bone alone, and the osteoclasts disappear. Reasons for the particular susceptibility of ossified laryngeal cartilage to tumour invasion are discussed and attention is drawn to the role of the tumour-associated osteoclast activating factors such as postaglandins. Therapeutic implications of cartilage invasion are noted.

Adult↗
PubMed1979

Balkan (endemic) nephropathy.

The clinical and pathological features of Balkan (endemic) nephropathy are discussed and correlations of incidence with excess late summer and autumn rainfall outlined. Cultures of a strain of Penicillium verrucosum var. cyclopium isolated from maize collected in an endemic area were fed to rats and lesions were produced in the straight third segment of the proximal kidney tubules. Extensive degeneration and nuclear changes were seen and on prolonged feeding further nuclear enlargement (to greater than 6n) and the formation of multinucleate cells occurred. The relevance of these findings to the clinical disease in man, especially the occurrence of urinary tract tumours, and the evidence supporting mycotoxin involvement, are discussed.

Animals↗
PubMed1978

An ultrastructural investigation of nephrotoxicity in rats induced by feeding cultures of Penicillium verrucosum var. cyclopium.

A renal tubular lesion was induced in male rats by giving them a culture homogenate or culture filtrate of Penicillium verrucosum var. cyclopium by gastric gavage for 20 days. The fungus was obtained from stored maize in an area of endemic nephropathy in Bulgaria. Changes in the proximal convoluted tubules were studied by light and electron microscopy. The lesion was confined to the pars recta in the outer stripe of the outer zone of the medulla. It consisted of degeneration and necrosis of epithelial cells, prominent karyomegaly, arrested mitotic divisions and production of binucleate and tetranucleate tubular cells. Two patterns of degeneration occurred with comparable frequency: a vesicular form with pyknotic nucleus and electron lucent degeneration. Nuclei of the epithelial cells in affected tubules contained segregated nucleoli. The necrotic cells were replaced by actively regenerating cells derived from adjacent viable epithelium. The similarity between the tubular lesions induced in rats and the changes found in patients with Balkan endemic nephropathy is discussed.

Animals↗
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↗