Search PubMed⌕ Search

Biomedical subjects

F Collins

Publications and source records attributed to F Collins.

At least 109 records · Page 6Linked to original sources
PubMed1981

The effect of electrode placement on frontalis EMG measurement in headache patients.

Comparisons were made between frontalis EMG surface recordings concurrently taken from horizontal, right vertical, and left vertical electrode placement configurations. Six migraine and seven tension headache patients were used as subjects. Results showed that, in general, a positive correlation existed between recordings from the three placements for both migraine and tension subjects as a group. However, marked individual differences were noted. It was concluded that electrode placement can be quite important in measuring changes in frontalis muscle tension for headache patients.

Action Potentials↗
PubMed1980

Elongating nerve fibers are guided by a pathway of material released from embryonic nonneuronal cells.

Dissociated parasympathetic neurons rapidly initiate neurite outgrowth when exposed to culture medium previously conditioned by the growth of embryonic heart cells. The inducer of neurite outgrowth in the conditioned medium is a substratum-conditioning factor; that is, it does not act in a soluble form, but acts only when bound to the nerve cell culture substratum. When a sharp border is created between a region of the substratum coated with this factor and a region coated with unconditioned medium, neurites fail to cross this border; rather, they change their direction of outgrowth so as to remain on the conditioned substratum. Thus, long after the initiation of outgrowthhas been induced, elongating neurites continue to respond to the substratum-conditioning factor in a manner that allows their outgrowth to be channeled along a pathway of this neurotropic substratum-associated material.

Animals↗
PubMed1980

Structure of and alterations to defective murine sarcoma virus particles lacking envelope proteins and core polyprotein cleavage.

HTG2 hamster cells produce a defective murine sarcoma virus lacking gp70 and, consequently, viral surface projections (knobs), but the lack of knobs appears to have no effect on intramembrane particle distribution. In addition, it has been noted that the core of the virus remains in the "immature" form as a result of the failure of the polyprotein precursor (p65) to undergo cleavage. However, incubation of HTG2 virus with avian myoblastosis virus was found to yield specific cleavage products of p65.

Animals↗
PubMed1979

Mixed malignant tumour of the lung.

A mixed malignant tumour of the lung intermediate in type between pulmonary blastoma and carcinosarcoma is described. The epithelial component consisted of squamous carcinoma, undifferentiated carcinoma, and clefts lined by bland epithelial cells. The supporting stroma was composed of pleomorphic sarcoma, fibrosarcoma, chondrosarcoma, osteosarcoma, and indeterminate mesenchymal tissue. The tumour was removed surgically, but the patient died postoperatively with rapidly developing multiple bony and soft tissue metastases. Subcutaneous metastases showed the appearnce of poorly differentiated pleomorphic sarcoma. Published reports of mixed malignant lung tumours are reviewed.

Adenocarcinoma↗
PubMed1978

Induction of neurite outgrowth by a conditioned-medium factor bound to the culture substratum.

Heart-cell conditioned medium (HCM) induces rapid neurite outgrowth from isolated neurons in culture. The following evidence indicates that this action of HCM is due to a trypsin-sensitive factor which attaches to the polyornithinecoated culture substratum: (i) Pretreatment of the culture substratum with HCM allows rapid neurite outgrowth to occur even in unconditioned media. The active factor remains bound to the substratum during the period of neurite outgrowth. (ii) The substratum-bound activity is destroyed by trypsin treatment, but is insensitive to collagenase, RNase, and DNase. (iii) The factor that binds to the substratum is essential for neurite outgrowth, because HCM is no longer active when the material that binds to the polyornithine substratum has been removed by passage of the HCM over a series of culture dishes. However, this "depleted" HCM is still able to support the growth of nonneuronal cells. (iv) Most significantly, when neurons are cultured in whole HCM, the extent of neurite outgrowth is proportional to the amount of substratum-bound activity and not to the amount in solution, indicating that the substratum-bound form of the factor is more active. Previous observations [Collins, F. (1978) Dev. Biol. 65, 50-57] suggest that HCM promotes neurite outgrowth by increasing the adhesion between nerve cell surface extensions and the polyornithine-coated culture substratum. It is possible, therefore, that the factor in HCM that binds to the substratum possesses sites to which nerve cell surface components adhere.

Axons↗
PubMed1977

The effect of hyperimmunization with Neisseria gonorrhoeae on the presence of gonococcal antibody in serum, tissues, and secretions of the rabbit.

Antibody responses in sera, tissues, and secretions of the urogenital tract and lower respiratory tract of rabbits hyperimmunized with Neisseria gonorrhoeae were examined. Antibody was detected by passive hemagglutination, whole-cell agglutination, bentonite flocculation, and in some cases immunodiffusion-in-gel. Immunization of rabbits either intravenously or intramuscularly resulted in the presence of gonococcal antibodies in the sera, spleens, and tissue of the urogenital tract (vagina, cervix, uterus, and fallopian tubes). Gonococcal antibody was also found in secretions bathing the mucosa of the urogenital tract and lower respiratory tract. Antibodies were not detected in sera, tissues, and secretions of non-immunized rabbits. The spleen was shown to synthesize gonococcal antibody in vitro in response to hyperimmunization. Tissues of the urogenital tract did not appear to synthesize gonococcal antibody thus suggesting and antibodies present in secretions of the urogenital tract were derived mainly from serum.

Agglutination Tests↗
PubMed1977

Inhibition of attachment of Neisseria gonorrhoeae to tissue cells by goat milk antigonococcal immunoglobulin G.

An immunoglobulin G (IgG)-containing fraction was isolated from milk, obtained from a goat before and after instillation of the mammary gland with Neisseria gonorrhoeae colony type 1 (T1). The presence of IgG and the absence of immunoglobulins-A and -M in this fraction was confirmed by immunodiffusion in gel and immunoelectrophoresis. Postinstillation IgG inhibited the attachment of the homologous strain of N. gonorrhoeae (T1) to tissue cells. The percentage of Rhesus monkey kidney cells with gonococci attached was 38.9% +/- 6.4. Inhibition was significant (P less than 0.01) when compared to the inhibitory effect of preinstillation IgG (73.5% +/- 3.1) or buffer control )76.8% +/- 2.8). Absorption of postinstillation IgG with rabbit anti-goat IgG or whole cell gonococci removed the inhibitory effect. Postinstillation IgG gave little or no inhibition of attachment (maximun 13%) of seven heterologous (T1) strains of N. gonorrhoeae to tissue cells. These results may provide a reason for recurrent gonococcal infection in humans despite the presence of circulating antibody (IgG) to N. gonorrhoeae. Such an antibody, if present in secretions bathing the mucosa, may fail to prevent infection and colonization of the urogenital tract by a different immunotype of N. Gonorrhoeae.

Animals↗
PubMed1975

Physiologic correlates of affect during psychotherapy.

Eight physiologic parameters were correlated with global ratings of affect intensity in four psychotherapeutic interviews with one patient. Highly significant covariation of affect with five of the eight physiologic parameters was obtained. It was concluded that affect intensity may be a useful psychologic parameter in studying psychophysiologic relationships in psychotherapy.

Adult↗
PubMed1975

Intellectual and attitudinal characteristics of medical students selecting family practice.

Family practice residents were compared with residents in internal medicine, surgery, obstetrics-gynecology, and pediatrics in terms of cognitive and non-cognitive characteristics. Family practice residents were in most instances significantly different from the other four groups. On non-cognitive measures they scored higher on affiliation need and lower on aggression and materialism. Their scores on several cognitive measures were among the highest of the five groups. These results were contrary to others from earlier studies. However, if the trend reported here is confirmed on other samples, it is the more intellectually gifted and idealistic physician who is currently being attracted to the practice of family medicine.

Attitude of Health Personnel↗