Multifocal mesenchymal hamartoma of the chest wall in infancy.

The authors report on an infant who had multifocal mesenchymal hamartoma of the right posterior chest wall. The tumors were found incidentally, on a chest radiograph, during routine evaluation for upper respiratory tract infection. Resection of both lesions with chest wall reconstruction was performed, with a good result. Only 46 cases of this unusual tumor have been reported previously, and only two of them were multifocal.

Problem-based learning in American medical education: an overview.

The recent trend toward problem-based learning (PBL) in American medical education amounts to one of the most significant changes since the Flexner report motivated global university affiliation. In PBL, fundamental knowledge is mastered by the solving of problems, so basic information is learned in the same context in which it will be used. Also, the PBL curriculum employs student initiative as a driving force and supports a system of student-faculty interaction in which the student assumes primary responsibility for the process. The first PBL medical curriculum in North America was established at McMaster University in Toronto in 1969. The University of New Mexico was the first to adopt a medical PBL curriculum in the United States, and Mercer University School of Medicine in Georgia was the first U.S. medical school to employ PBL as its only curricular offering. Many interpretations of the basic PBL plan are in use in North American medical schools. Common features include small-group discussions of biomedical problems, a faculty role as facilitator, and the student's relative independence from scheduled lectures. The advantages of PBL are perceived as far outweighing its disadvantages, and the authors conclude that eventually it will see wider use at all levels of education.

Problem-based learning: an assessment of its feasibility and cost.

As our knowledge of human biology becomes more complex and the medical school applicant pool declines, there is ample reason to consider an alternative to the conventional medical curriculum. Many authorities feel that a format incorporating problem-based learning (PBL) would be more appropriate and effective. The problem-based medical curriculum is one in which facts and principles are learned in the context of a clinical problem. Problem-based medical education began as a revision of the McMaster University medical curriculum in 1969 and was instituted in the United States as a problem-based experimental track at the University of New Mexico School of Medicine in 1979. The first completely integrated, totally problem-based, McMaster-type, medical curriculum in the United States began operation in 1982 with the establishment of Mercer University School of Medicine. Many years of experience at these three institutions have shown that the problem-based curriculum works well. Several medical schools throughout the world are either practicing PBL or investigating the feasibility of adopting it. A comparison of the costs (in faculty time) of problem-based and conventional pathology programs suggests that the PBL curriculum is quite feasible for schools with a class size of 60 or less and may be so for many schools and programs with classes of less than 100.

Preservation of pathology specimens by silicone plastination. An innovative adjunct to pathology education.

The authors have used the process of plastination to preserve gross anatomic specimens for teaching purposes. A specimen is fixed in 10% buffered formalin and dehydrated in increasing grades of ethanol. Thereafter it is saturated with methylene chloride and then impregnated in vacuo at -20 degrees C with silicone rubber. Final steps involve drainage and exposure to a curing agent. The total time required is approximately 16 weeks. The finished plastinated specimen is dry to the touch, odorless, and nontoxic, yet it maintains its original shape and, in many cases, is reasonably close in color and consistency. It resists deterioration and can be stored at room temperature indefinitely. The authors have found plastinated specimens to be superior to those preserved in formalin for teaching anatomic pathology to undergraduate medical students.

Changes in thyroid function in pregnancy and with oral contraceptive use.

We measured T4, T3, T3 uptake, and TSH in nonpregnant patients, pregnant patients in the early and late first, and third trimesters, and patients using oral contraceptives. Mean T4 levels increased and T3 uptake decreased during pregnancy. Concentrations of T3 decreased in early pregnancy, then increased during the rest of pregnancy. Thyroid-stimulating hormone (TSH) values were elevated in the second trimester. Decreased T3 concentration in the early first trimester suggests increased use of T3 by the fetus, placenta, and/or mother not compensated for by increased T4 pool size. Values found in oral contraceptive users were similar to those found in early pregnancy and may reflect changes in response to levels of estrogen found in oral contraceptives. Values provided illustrate changes in thyroid function parameters and are useful in providing a target range of laboratory values for therapeutic manipulation when comparing thyroid function values in nonpregnant patients, pregnant patients, and those using oral contraceptives.