Obstructive and perforative colonic carcinoma: patterns of failure

Carcinoma of the colon complicated by obstruction or perforation has been recognized as having a poorer prognosis than tumors without obstruction or perforation. To clarify the natural history, failure patterns, and implications for adjuvant treatment after resection with curative intent, a review of the recent Massachusetts General Hospital (MGH) experience was undertaken. From 1970 to 1977, 77 patients with obstructive colonic carcinoma and 34 patients with localized perforation at the tumor site were identified and compared with a control group of 400 patients without obstruction or perforation undergoing curative resection. All patients were observed for a minimum of five years or until the patient's death. The actuarial five-year survival and disease-free survival rates in patients with obstruction was 31% and 44%, respectively, in contrast to 59% and 75% in control patients. For patients with localized perforation, the five-year actuarial survival and disease-free survival rates were 44% and 35%, respectively. Of the 77 patients with obstructing tumors, 32 patients (42%) developed local failure--nine with local failure only and 23 patients with local failure and distant metastases. Thirty-four patients (44%) developed distant metastases. Fifteen (44%) patients of 34 with perforative colonic carcinoma had local failure. Distant metastases occurred in 15 patients (44%). The incidence of local failure and distant metastases in the control group was 14% and 21%, respectively. The rate of local failure and distant metastases increased with stage and was generally higher stage for stage than in the control group.(ABSTRACT TRUNCATED AT 250 WORDS)     

Is there an optimal laser treatment for port wine stains?

Optimization of laser treatment of port wine stains (PWS) is discussed from the standpoint of heat production. Laser wavelength, irradiation time, heat conduction, and external epidermal cooling are the variables considered in conjunction with absorbing and scattering behavior of a PWS-model consisting of epidermis, dermis, and ectatic blood vessel. Ideal treatment is defined as minimal heating of the epidermis and upper dermis, but with irreversible damage to the capillary wall. The analysis shows that irradiation times of 1-10 ms in conjunction with external epidermal cooling may give optimal results. The wavelength of choice is 577 nm, followed by 540, 415, 560, and 500 nm (argon laser). The ruby and Nd-YAG lasers are predicted to damage the epidermis and dermis at all times when the capillary is coagulated. Concurrent cooling to prevent epidermal-dermal damage is also recommended here. The CO2 laser is predicted to be the worst laser and, according to our analysis, should not be used to treat PWS. Both upper dermal and capillary destruction can only result from heat conduction from the damaged epidermis and external cooling cannot be applied here.     

Magnetic fields associated with anoxic depolarization in anesthetized rats

We have performed simultaneous measurements of the DC-magnetoencephalogram (DC-MEG) and DC-electrocorticogram (DC-ECoG) in rats (n = 6) subjected to 90 s of reversible anoxia. The onset of major shifts of electric and magnetic signals occurred at 52 +/- 18 (S.D.) and 68 +/- 14 (S.D.), respectively, and reached a peak at 83 +/- 27 and 102 +/- 19 (S.D.) s, respectively, after termination of mechanical ventilation. DC-ECoG signal deflections were always associated with DC-MEG deflections. The time of onset and peak signals in both DC-MEG and DC-ECoG changes caused by asphyxia were highly correlated (r + 0.83, 0.94; P less than 0.05, 0.001; respectively). Our observations suggest that the non-invasive technique of DC-MEG is reliable and may provide insight into the mechanisms of anoxic cerebral depolarization.     

Mediastinal germ cell tumors in childhood. A clinical and pathological study of 21 cases

Twenty-one patients aged 16 years or less had been treated for a primary mediastinal germ cell tumor at the Children's Hospital, Boston Massachusetts, during the last 54 years. There were 13 boys and eight girls with the average age at diagnosis being 7 years (range 2 weeks to 16 years). Twelve mediastinal germ cell tumors were classified as pure teratoma, five contained embryonal carcinoma admixed with other germ cell components, and four were pure embryonal carcinoma. Of 12 patients with pure teratoma, 10 underwent complete surgical resection and were alive and well 1 to 13 years later; two children left untreated died of complications related to local tumor growth. Complete surgical resection was possible for only two of nine patients with embryonal carcinoma; both received adjuvant therapy and were alive and well 3 and 20 years later. Seven patients received radiation and/or chemotherapy but died of residual or metastatic disease. Successful treatment for children with embryonal carcinoma requires an operation aimed at either debulking or complete resection (if possible) coupled with early and aggressive combination chemotherapy. The role of radiation in primary therapy remains undefined with regard to curative intent.