Biomedical subjects
M Clark
Publications and source records attributed to M Clark.
Multiple hamartoma and neoplasia syndrome (Cowden's syndrome).
A case report involving a patient with Cowden's syndrome is presented. The patient's family is shown to be affected in a pattern consistent with an autosomal dominant form of transmission of this inherited disorder. The disorder can be diagnosed in its early stages by gingival and cutaneous manifestations; it is emphasized that the dentist is therefore perhaps the best-qualified health care professional to recognize the disease in its early stages and to alert the patient to be monitored for later predictable neoplasia which can perhaps be treated before metastasis develops.
Experimental comparison of extradural and i.m. morphine.
Morphine sulphate 3 or 4 mg was administered to the extradural space in five volunteers. Morphine 10 or 15 mg i.m. was given as control. Extradural administration resulted in an increase of pain threshold in the legs but not in the forehead. There was no significant depression of carbon dioxide response or deterioration of co-ordination or short-term memory. I.m. morphine caused an increase in forehead pain threshold, depression of the carbon dioxide response and some deterioration of cerebral function. Extradural morphine caused urinary retention in four and inability to ejaculate in three of the subjects. The principal site of action of extradural morphine appears to be regional, at spinal cord level, but it appears that autonomic function as well as pain perception can be affected.
The poetry of aging: views of old age in contemporary American poetry.
Explore the source record for details and available documents.
Effects of paced respiration on affective responses during dental stress.
Explore the source record for details and available documents.
Median palatal cyst--report of a case of unusual size.
Explore the source record for details and available documents.
Bone marrow transplantation: an option for children with acute leukemia.
Explore the source record for details and available documents.
Labor-saving devices.
Explore the source record for details and available documents.
Disciplining doctors.
Explore the source record for details and available documents.
Doctoring yourself.
Explore the source record for details and available documents.
Detection of deep venous thrombosis by impedance plethysmography.
Ninety-eight limbs in sixty-seven patients supected of having lower extremity deep venous thrombosis were evaluated by physical examination, venous impedance plethysmography (IPG), and venography. Diagnosis based on physical signs commonly associated with deep venous thrombosis was false-positive in 43 to 66 per cent and false-negative in 26 to 73 per cent when compared with evidence obtained by venography. The overall accuracy of IPG was 94 per cent, with false-positive results occurring in 10 per cent and false-negative results in 4 per cent. IPG is sufficiently accurate to be considered a reliable screening test for lower extremity deep venous thrombosis.
Macrophages in experimental and human brain tumors. Part 1: Studies of the macrophage content of experimental rat brain tumors of varying immunogenicity.
Although the presence of lymphoreticular cells within tumors has been recognized for over 100 years, it is only within the last decade that the concept has arisen that standard histological examination techniques may lead to an underestimation of the true extent of tumor infiltration by lymphoreticular cells, and particularly by macrophages. The macrophage content of certain systemic tumors has been correlated with their immunogenicity and growth characteristics. Since the central nervous system is to some extent an "immunologically privileged site" and contains within it specialized reticuloendothelial cells called microglia, the authors determined the macrophage content of three rodent brain-tumor cell lines, and attempted to correlate this macrophage content with their immunogenicity and growth characteristics. Their findings indicate a direct correlation between the immunogenicity and macrophage content of these three neural tumor cell lines.
Macrophages in experimental and human brain tumors. Part 2: studies of the macrophage content of human brain tumors.
The authors have analyzed 47 tumors of the central nervous system (11 glioblastomas, nine meningiomas, three medulloblastomas, 12 assorted primary neural tumors, and 12 brain metastases) for their content of macrophages. Cell suspensions were prepared by enzymatic digestion and macrophages were quantitated by IgGEAC rosette formation. Adsorption of sensitized indicator cells (EA) to sections of tumor was used as a measure to determine the distribution of IgGFc receptor-positive cells within the tumors and to serve as a control for selective release of IgGFc receptor-positive cells by enzyme digestion. The 11 glioblastomas had a mean macrophage content of 45% (range: 8% to 78%), the nine meningiomas had a mean of 44% (range: 5% to 81%), the three medulloblastomas a mean of 6% (range 2% to 15%), and the metastatic tumors a mean of 24% (range: 4% to 70%). Adsorption of EA demonstrated that IgGFc receptor-positive cells were distributed throughout the tumor mass, although different types of patterns were observed. There was an excellent correlation between the percent of IgGEAC positive cells in suspensions and the extent of EA adsorption to the tumor sections. Compared to systemic neoplasms, most nervous system tumors have a high macrophage content. It is possible that the high macrophage content of brain tumors is related to their immunogenicity, and may be a partial explanation for tha rarity of brain-tumor metastases.
Necrotizing sialometaplasia: a result of ischemia? Report of two cases and review of the literature.
Explore the source record for details and available documents.