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Biomedical subjects

M Michejda

Publications and source records attributed to M Michejda.

17 recordsLinked to original sources
PubMed1989

Fetal tissue from spontaneous abortions: a new alternative for transplantation research?

While transplantation of fetal tissues may alleviate a great deal of suffering, current policy bars federal funding of research using tissue from elective abortions. Using fetal tissue from spontaneous abortions would obviate the moral concerns. If existing studies of small samples are extrapolated to the US population, then each year about 750,000 fetuses are aborted spontaneously by week 28 (500,000 in the first trimester and 250,000 in the second trimester). The consensus among researchers is that spontaneously aborted fetuses are few in number, and inappropriate for transplantation because they are born dead or have defects. This intuition may not be supported by the evidence, and there is a compelling need to focus research on these issues.

Aborted Fetus↗
PubMed1988

Allogeneic fetal bone cranioplasty in Macaca mulatta.

Teratogen-induced herniation of the occipital lobes (encephalocele) associated with cranium bifidum in monkey fetuses (Macaca mulatta) were repaired by amputation and cranioplasty in utero or postnatally. Fetal allogeneic cranial bone which had been fresh frozen was used in conjunction with a bone paste to provide a protective covering of the neural tissue following repair of the encephalocele. The bone graft in those animals treated in utero or 1-2 weeks post-partum developed a strong union with the calvarium, provided good protection for the underlying dura and neural tissue, had a smooth surface, and provided good cosmetic-reconstructive results. In contrast, when the cranioplasty procedure was performed on infant monkeys at 2-3 months of age the bone graft was rejected.

Age Factors↗
PubMed1987

New animal model for the study of neural tube defects.

The induction of spina bifida in rhesus monkeys by treating the pregnant females with the anticonvulsant drug, valproic acid (VPA), during the early stage of gestation which coincides with the critical period of neural tube fusion is discussed. It was found that both the dosage and timing of VPA administration were crucial in the development of lesions which are similar to human spina bifida aperta. The teratogenic protocols and the gross and hystologic characterization of the induced lesions are presented and the epidemiological findings are discussed.

Animals↗
PubMed1986

Intrauterine treatment of hydrocephalus.

The current status of the intrauterine treatment of fetal hydrocephalus is presented. The new data from the International Fetal Surgery Registry at the University of Manitoba in Winnipeg are discussed. Technical problems of antenatal shunting, clinical trials and experimental treatment are assessed. The outcome of the antenatal diagnosis and treatment of fetal hydrocephalus is evaluated.

Cerebrospinal Fluid Shunts↗
PubMed1979

Estimation of gestational and skeletal age in Macaca mulatta.

Results of qualitative and quantitative studies of prenatal skeletal development in Macaca mulatta are presented. Longitudinal radiographic observations were carried out on 20 monkeys of known gestational age, beginning on 120 days of gestation until the neonatal stage of skeletal development. These studies were based on multiple uterotomies on each pregnant female. The technique described provides accurate data on prenatal bone ossification, and permits an accurate estimation of fetal age in pregnant rhesus monkeys with unknown conception dates.

Age Determination by Skeleton↗
PubMed1975

Ontogenic growth changes of the skull base in four genera of nonhuman primates.

Cross-sectional studies of the degree of the cranial base flexion were carried out in infant, juvenile and adult skulls in four genera of nonhuman primates (P. paniscus, H. lar, P. urinus, and M. mullatta). The cephalometric observations of the cranial base included linear and angular measurements of each specimen. The data obtained in this study showed that the anterior portion of the cranial base exhibits a significant shortening trend as the mammalian evolutionary scale ascends. Moreover, the growth pattern of the anterior portion of the skull base follows that of the facial bony structures. The ontogenic growth changes of the posterior portion of the skull base follows the growth pattern of the endocranial cavity. The significant trend of elongation in this area directly contributes to the posterior migration of the foramen magnum. The magnitude of these growth changes decreases as the evolutionary scale ascends. The angular measurements of the cranial flexion showed a less obtuse cranial base angle in young specimens and the ones higher on the mammalian scale. The skull kyphosis was less pronounced in these specimens and the anatomical features of the cranial base were more humanlike, including the balance of the head expressed by the position of the foramen magnum.

Age Factors↗