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Biomedical subjects

L A Rogers

Publications and source records attributed to L A Rogers.

At least 37 records · Page 2Linked to original sources
PubMed1988

Experience with limited versus extensive disc removal in patients undergoing microsurgical operations for ruptured lumbar discs.

Of 68 patients undergoing microsurgical operations for ruptured lumbar discs, 33 were treated by removing only the herniated fragments. In the remaining 35, an attempt was made to remove the entire disc. No recurrences followed the more extensive discectomies during follow-up periods varying from 11 to 30 months. Seven recurrences followed operations in which only the offending fragment was removed (recurrence rate of 21%), four within 6 months. Among 68 patients treated by conventional neurosurgical techniques, there was only one recurrence during follow-up periods of at least 4 years. None of the operations was clearly superior in relieving leg pain, but microsurgically treated patients spent less time in the hospital and returned to work more quickly.

Cerebrospinal Fluid↗
PubMed1988

Postendarterectomy heparin-induced thrombocytopenia. Case report.

Two episodes of massive bleeding from a sutured arteriotomy were observed within 30 hours after carotid endarterectomy. The patient had received anticoagulation therapy with heparin for 72 hours prior to surgery. A platelet count of 93,000/cu mm was demonstrated following the second hemorrhage. The potential problem of drug-induced thrombocytopenia following vascular surgery is discussed.

Aged↗
PubMed1986

Three-year prospective study of HTLV-III/LAV infection in homosexual men.

170 symptom-free homosexual men were recruited in London in 1982-83 and 133 were evaluable in 1983-85. Of the 33 who were seropositive to HTLV-III/LAV at entry, 4 (12%) progressed to AIDS, 16 (48%) progressed to persistent generalised lymphadenopathy (PGL), and 13 (40%) remained symptom-free. A further 15 men seroconverted during the study (7% per annum), of whom 8 progressed to PGL. Serial estimations of T lymphocyte subsets showed progressive reduction in T4 numbers in the seropositive groups, but these indices also varied widely in the seronegative group. Counts of T4 and T8 cells or T4/T8 ratio at entry were not of prognostic value. Seronegative subjects were as likely as seropositives to have abnormal immunological tests. Serial measurement of T lymphocyte subsets seems to be of little prognostic or clinical value in the monitoring of populations infected with the HTLV-III/LAV virus. The strongest association with prognosis was an episode of sexually transmitted disease in the six months before entry to the study. This supports the hypothesis that intercurrent infection may be an important co-factor in the acquisition of HTLV-III/LAV infection, and in subsequent disease progression.

Acquired Immunodeficiency Syndrome↗
PubMed1982

Carotid angioplasty in the management of external carotid artery stenosis associated with an occluded internal carotid artery.

The author describes the surgical treatment of 14 patients in whom angiography demonstrated total occlusion of the internal carotid artery (ICA) associated with stenosis at the origin of the ipsilateral external carotid artery (ECA). Each patient underwent ECA endarterectomy followed by an angioplasty to enlarge the ECA outflow tract by incorporating the ICA stump into the proximal ECA. Nine patients subsequently underwent superficial temporal-middle cerebral artery anastomosis. There was no mortality or permanent neurological morbidity. This method of treating ECA stenosis is recommended because it is simple and effective and because it simultaneously eliminates the ICA stump as a potential source of cerebral emboli.

Aged↗
PubMed1976

The time of origin and the pattern of survival of neurons in the isthmo-optic nucleus of the chick.

The time of origin of the cells in the isthmo-optic nucleus (ION--the nucleus of origin of centrifugal fibers to the avian retina) has been determined in the chick by a variant of the cumulative labeling method, using 3H-thymidine autoradiography. All the neurons of the ION are generated (i.e., pass through their last phase of DNA synthesis) over a 50-hour period between the latter part of the fifth and the seventh days of incubation (stages 28--31 of the Hamburger and Hamilton ['51] series) but the cells come to be assembled within the nucleus along a distinct temporo-spatial gradient. The earliest-formed cells occupy the ventrolateral part of the nucleus while the last neurons to be generated come to lie along its dorsomedial margin. When the nucleus is numerically complete, around the eleventh day of incubation, it contains about 22,000 neurons, but between the thirteenth and seventeenth days (stages 39 through 43) this number is produced by nearly 60% to about 9,500 cells. Following the radical extirpation of the one optic cup or the circumscribed removal of the neural retina early on the third day of incubation, the cell loss in the contralateral ION is greatly accentuated, so that by the eighteenth day of incubation no cells remain in the nucleus. Serial counts of the numbers of cells in the nucleus on the side of the eye (or retinal) removals show that it, too, undergoes additional cell degeneration, so that by the end of the phase of naturally occurring neuronal loss, only about half the normal number of cells persist in these experimental animals.

Age Factors↗
PubMed1975

Studies on the development of the chick optic tectum. IV. An autoradiographic study of the development of retino-tectal connections.

The normal pattern of innervation of the optic tectum has been studied autoradiographically in a series of chick embryos which were injected intraocularly with [3-H]proline at intervals between the 6th and 21st days of incubation. From the distribution of the radioactively labeled proteins transported in the rapid phase of axonal flow, it is evident that retinal fibers first enter the tectum late on the 6th day of incubation and then spread across its surface from its rostrolateral aspect to its caudo-dorso-medial pole during the ensuing 6 days. At the 9th day, when the fibers have grown across the surface of the rostral half of the tectum, there is no indication that the terminal portions of the axons have left the stratum opticum to enter the outer layers of the stratum grieseum et fibrosum superficiale. The first suggestion of such an invasion of the stratum grieseum et fibrosum superficiale is found at day 10, when labeled fibers can be seen in this stratum, over a restricted, oval, area near the center of the tectum. Over the course of the next 2 days the region of the stratum grieseum et fibrosum superficiale occupied by retinal fibers expands, more-or-less concentrically, until by day 14 some labeled fibers are seen in the outer part of the stratum, throughout the tectum. Concurrent with the ingrowth of optic nerve fibers the final cytoarchitectonic differentiation of the outer layers of the tectum occurs so that by day 18 the autoradiographs show a pattern of labeling of layers a-f of the stratum griseum et fibrosum superficiale similar to that seen in mature, post-hatched chicks. Since the region of the tectum which is first innervated by retinal fibers corresponds to the projection field of the region around the upper end of the choroid fissure where the first ganglion cells are generated, it would appear that the axons of the first-formed ganglion cells grow over the rostral surface of the tectum before establishing the first retino-tectal synapses near the central portion of the tectum. Subsequently, as the ganglion cell population grows concentrically from around the area centralis, there is a parallel expansion of the region in which retino-tectal synapses are being formed in the tectum.

Animals↗