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Biomedical subjects

N C Davis

Publications and source records attributed to N C Davis.

At least 37 records · Page 2Linked to original sources
PubMed1978

Carcinoma of the large bowel in patients aged 70 years and older.

In a prospective series of 443 cases of large-bowel cancer there were 192 cases occurring in patients aged 70 years and over. The resectability rate in this group was 84.9% and was almost identical with that of the whole series (84.6%). There was an overall operative mortality rate of 7.3% in the older age group, compared with 6.4% in the whole series. However, when octogenarians were considered, the resectability rate fell to 74.6% and the overall operative mortality rate increased to 19%. In the treatment of large-bowel cancer it would seem that special consideration should be given to octogenarians.

Adult↗
PubMed1978

Secondary malignant melanoma in lymph nodes: incidence, time of occurrence, and mortality.

During a follow-up period of six to 12 years, 15.4% of patients in the Queensland Melanoma Project (Q.M.P.) developed histologically proven secondary deposits in lymph nodes. The incidence rate in males (21%) was twice that in females (11%), but the mortality rate was similar (M., 67%; F., 61%). Thirty-two patients (2%) had positive nodes with no known primary lesion. Metastases developed in males with lesions on the foot (50%), on the thigh (29%), and on the back (22%); and in females with lesions on the lower leg (9%) and thigh (20%). About one-half of the nodes were removed at the time of treatment of the primary growth or within two months. Three-quarters were removed in the first year. However, it was found that tumour could remain dormant for more than eight years. Dormant tumours behaved in a similar aggressive fashion on regrowth as non-dormant secondaries. Nodal metastases were present in 5% of patients at the time of their first presentation with primary melanoma. Elective node dissections were done in 6% of males and 11% of females.

Adolescent↗
PubMed1977

An evaluation of leukocyte adherence inhibition in the immunodiagnosis of colorectal cancer.

The leukocyte adherence inhibition technique was used to assess cell-mediated immunoreactivity and serum-blocking factors related to adenocarcinoma of the colon or rectum. In the group of 48 patients with confirmed tumors of this type, 36 of 38 had reactive leukocytes and 46 of 47 had serum-blocking factors. Patients whose tumors had been removed surgically, with no sign of recurrence, retained their leukocyte activity for up to 3.5 years in 6 of 6 cases, but only a small proportion (7 of 30) retained blocking factors. In 67 controls (who were patients with nonmalignant gastrointestinal disorders, patients with gastrointestinal tumors other than colorectal adenocarcinoma, patients with other cancers, or healthy volunteers), negative reactions were obtained, with diverticular disease the only prominent exception. The leukocyte adherence inhibition test appeared to be highly sensitive and specific. Application to the immunodiagnosis of colorectal cancer thus seems to be warranted.

Adenocarcinoma↗
PubMed1976

Oncornavirus-like particles in malignant melanoma and control biopsies.

Tests for the presence of oncornavirus-like particles in human biopsies were made by the Spiegelman simultaneous assay for 70S RNA and RNA-dependent DNA polymerase and by detection of 600-900S particles, incorporating 3H-uridine, produced by cultured biopsy cells. Thirty-one malignant melanoma biopsies from 29 patients were studied. Using the simultaneous assay, evidence of virus-like particles was found in 15/26 (58%) of melanoma biopsies, 0/3 naevi pools, 1/4 samples of skin adjacent to melanoma, 0/3 samples of normal adult skin and 0/3 prepuces. The velocity sedimentation technique was shown to be a useful screening test for oncornaviruses in studies of two virus-producing mouse cell lines (TKL-5 and WEHI-22), and was positive with 7/9 melanoma biopsies. Overall, these results are compatible with the earlier findings of similar virus-like particles in malignant melanoma cell lines, but the exact nature of the particles remains to be defined.

Cell Line↗
PubMed1976

Do polyunsaturated fats predispose to malignant melonoma?

The consumption of polyunsaturated fats of patients with malignant melanoma and of a control group of patients with benign naevi has been compared in order to determine whether polyunsaturated fats predispose to the development of malignant melanoma. Patients with malignant melanoma had not consumed excessive quantities of polyunsaturated fats. Thus, there was no evidence to indicate that ingestion of polyunsaturated fats is associated with an increase in incidence of melanoma.

Adipose Tissue↗
PubMed1975

Leukocyte adherence inhibition and specific immunoreactivity in malignant melanoma.

The leukocyte adherence inhibition (LAI) test has been used to assess specific anti-tumour immunoreactivity in 80 patients with malignant melanoma, 21 of whom had apparently been successfully treated by surgery, and 44 control subjects. Reaction with melanoma extracts in vitro enabled the activity of blood leukocytes to be detected by inhibition of their adherence to glass, while serum was tested for factors which modified this inhibition. Of the patients with tumours (ranging from primary melanoma in situ to advanced disseminated disease), 22/24 had active leukocytes and 50/58 has serum blocking factor; two of the sera, from patients with regressing tumours were unblocking. After surgery with no clinical recurrence, leukocytes continued to be active except when tested several years after operation. Blocking factor rapidly disappeared in 16/20 patients tested, and in several patients examined serially the serum became unblocking. In three cases, persistence of serum blocking was followed by clinical diagnosis of metastases. Leukocyte activity was nerver detected in control subjects (0/10), many of whom had other kinds of tumours or skin lesions. Blocking activity in serum was found in only 3/38 controls with no history of melanoma (1 had a fibrosing cellular blue naevus and 2 had liver disease). Thus the LAI test correlated well with clinical and pathological findings, and shows great promise for the reliable, rapid and specific immunodiagnosis of malignant melanoma.

Adult↗
PubMed1975

Multiple primary cutaneous melanomas.

Of 1,444 patients with primary cutaneous melanomas, 57 (3.9%) developed more than one. Most had two primary lesions but one had six. Every effort was made to insure that all melanomas were primary tumors. Most patients developed new primary melanonas within five years of the original operation, but an appreciable number developed them many years later. In the largest group, second and subsequent primary tumors developed in different areas of the body at later times. The subsequent tumors were not diagnosed at an earlier biological stage than the original tumors. Patients with primary cutaneous melanoma should be made aware of increased risk of developing another primary melanoma and physicians should do careful examinations for new primary melanomas as well as for recurrences of the original melanoma.

Adolescent↗
PubMed1973

Hypocomplementemia of membranoproliferative nephritis. Dependence of the nephritic factor reaction on properdin factor B.

Membranoproliferative nephritis in children is frequently associated with a hypocomplementemia produced at least in part by C3 breakdown mediated by a circulating anticomplementary factor known as C3 nephritic factor (C3NeF). C3 breakdown by this factor in vitro requires the presence of a pseudoglobulin cofactor and magnesium. The present study provides evidence that properdin factor B (C3 proactivator) is activated in the nephritic factor reaction and is the direct mediator of C3 breakdown by C3NeF. Depletion of factor B from mixtures of normal human serum (NHS) and plasma from a patient with membranoproliferative nephritis (MPP), either by heating or by immune equivalence absorption, blocks C3 breakdown by C3NeF. Addition of purified factor B to these mixtures restores the anticomplementary effect. When purified factor B is added to mixtures of MPP and purified C3, breakdown also occurs. Associated with the C3 breakdown is a change in the electrophoretic mobility of factor B from the beta to the gamma position, a shift which has been associated with cleavage activation of the molecule. Further, serum factor B levels are often low in patients with membranoproliferative nephritis and bear a rough inverse correlation with C3NeF levels. It thus appears that factor B is the previously described heat-labile C3NeF cofactor. Whether the C3NeF reaction proceeds via a pathway comparable to that activated by the cobra venom factor or via that activated by zymosan or inulin cannot be determined from the present data.

Absorption↗