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Michael B Pritz

Publications and source records attributed to Michael B Pritz.

9 recordsLinked to original sources
PubMed2005

Comparisons and homology in adult and developing vertebrate central nervous systems.

Comparisons of characters in both adult and developing vertebrate central nervous systems require an understanding of the concept of homology. This article begins with a definition of homology in adult animals and then discusses criteria and methodology used to make appropriate comparisons of characters at a variety of hierarchical levels. Crucial to such an analysis is the methodology employed by neurocladistics to ensure meaningful comparisons. Then, a similar approach is used to address these identical problems in embryos. Concerns unique to comparisons of developing central nervous systems are enumerated. In addition, a number of special features of central nervous system formation and organization in both adults and embryos are discussed within the framework of homology and neurocladistics. Lastly, the concept of field homology as applied to vertebrate central nervous system characters is addressed.

Animals↗
PubMed2003

Surgical Treatment of Chiari I Malformation: Simplified Technique and Clinical Results.

A simplified technique for decompressing the posterior fossa and foramen magnum in symptomatic patients with a Chiari I malformation is described. The approach uses a curvilinear dural incision and an autologous pericranial graft. This procedure was used in 14 symptomatic patients, 8 of whom had a cervical or cervicothoracic syrinx. Neurologic signs and symptoms improved or were unchanged in all patients. The size of the syrinx decreased in all patients. No patient developed a new neurologic deficit, cerebrospinal fluid leak, pseudomeningocele, or infection. Postoperatively, one patient developed new, dysesthetic, unilateral arm pain that did not require medication. This technique has several advantages. The procedure is simple and requires a single skin incision. Autologous graft can be used. The occipital sinus can be avoided. Finally, the contralateral region remains pristine if a repeat procedure becomes necessary.

Journal Article↗
PubMed2003

Cell proliferation during early hindbrain development in Alligator.

Cell proliferation, as determined by immunoreactivity to proliferating cell nuclear antigen (PCNA) was investigated during early hindbrain development in Alligator. At the earliest stage examined, stage 3, when five rhombomeres are present, PCNA immunoreactivity is more robust laterally towards the pial margin and interrhombomeric boundaries are clearly seen. Subsequently, PCNA immunoreactivity fills each respective rhombomere and increases in intensity but respects the boundaries between segments until stage 7. At this time, borders between rhombomeres become less distinct. At stage 8, when the full compliment of rhombomeres is present, two longitudinal columns of PCNA immunoreactivity are seen rostrally which coalesce into a single column caudally. Interrhombomeric borders are indistinct. Later, at stage 9/10, two longitudinal columns span the entire length of the hindbrain and interrhombomeric boundaries remain less clear. The more lateral column fades whereas the medial stripe persists through stage 12. Thereafter, immunoreactivity fades. These observations confirm the findings in other species that rhombomeres are centers of cell proliferation. This feature is most likely common to hindbrain development in all gnathostomes. It is hypothesized that these two longitudinal columns of cell proliferation might be important for future patterning of the hindbrain.

Alligators and Crocodiles↗
PubMed2002

Midbrain projecting dorsal column nucleus neurons in a reptile.

The origin of midbrain projecting cells in the dorsal column nucleus (DCN) was investigated in reptiles, Caiman crocodilus, using a retrograde tracer. Labeled neurons were confined to a caudal-central portion of the DCN. Midbrain projecting DCN neurons had round, oval, or triangular soma and were small. While neurons that project to the spinal cord in Caiman are also located in the caudal half of the DCN, midbrain projecting cells are located more dorsally and are smaller than those whose axons terminate in the spinal cord. Taken together, these observations suggest that the DCN in Caiman is subdivided, at least in part, according to target location. In view of similar findings in certain birds and mammals, subdivisions of the DCN into sectors is likely a phylogenetically ancient feature of amniote sensory systems transmitting somatosensory information from the body surface.

Afferent Pathways↗
PubMed2002

Lateral orbital rim osteotomy in the treatment of certain skull base lesions.

Quantitative data from a recent human cadaveric study suggested that removal of the lateral orbital rim alone may be sufficient to reach many targets for which the orbitozygomatic craniotomy has been used. Consequently, a lateral orbital rim osteotomy was substituted for an orbitozygomatic craniotomy in seven patients with a variety of pathologies located in the anterior, middle, and interpeduncular fossae. In each case, lateral orbitotomy provided a satisfactory surgical corridor for diagnosis and treatment. Compared with the orbitozygomatic craniotomy, the lateral orbital rim osteotomy offers several advantages: technical simplicity, shorter operating time, and a low risk of postoperative malocclusion. If, however, prolonged access to a wide expanse of the anterior portion of the middle fossa and inferotemporal area is needed, an orbitozygomatic approach is a better choice.

Journal Article↗
PubMed2002

Aneurysm observation versus intervention: a literature review.

Aneurysmal subarachnoid hemorrhage (SAH) is a devastating illness that affects persons at the peaks of their lives. The 1990s witnessed rapid growth in noninvasive vascular imaging technologies, which allowed safe diagnosis of unruptured saccular intracranial aneurysms. Presently, it is unclear who will benefit from screening. Mass screening is neither feasible nor cost-effective. The current literature suggests that persons in a family with two or more relatives with a history of SAH are most likely to benefit from screening. Individuals with a history of SAH, with aneurysms greater than 10 mm in diameter or with symptomatic aneurysms are clearly at increased risk for SAH. These aneurysms should be treated, though the method of treatment remains open to question. Treatment of older patients or those with smaller aneurysms has been modeled by decision analysis, but has yet to be verified in a prospective clinical trial. Future directions for aneurysm management are explored.

Cost-Benefit Analysis↗