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Biomedical subjects

J D Law

Publications and source records attributed to J D Law.

15 recordsLinked to original sources
PubMed1995

Hypothesis about the etiology of unexplained painful myelopathy after minor trauma in the spinal canal.

After electrode insertion for epidural spinal cord stimulation, of 625 electrode operations, unexplained, temporary paralysis resulted in 1.8%, and multidermatomal, painful allodynia in 4.2% (of whom 19% had also had temporary paralysis). Diagnostic testing yielded no anatomical explanation. In patients who were awake during operation, these deficits were noted to begin immediately after pain caused by mechanical deformation of the dura. The author hypothesized the following: myelopathy may result from cord ischemia, caused by vasospasm, triggered by pain within or near the spinal canal. The author proposes to prevent these complications by selective epidural anesthesia.

Electric Stimulation↗
PubMed1992

Clinical and technical results from spinal stimulation for chronic pain of diverse pathophysiologies.

Spinal stimulation has been indicated for pain of peripheral deafferentation, but not for low-back pain. Technical and clinical records of 241 consecutive spinal stimulator recipients were reviewed, including: peripheral deafferentation pain (n = 44); predominant pain of low back, postlaminectomy (n = 96), and predominant pain of leg(s), postlaminectomy (n = 48). The groups were not statistically different with respect to important clinical features. For the postlaminectomy syndromes, only the technical results correlated significantly with outcome. Spinal stimulation actually yielded results as good for the 'failed back surgery syndrome' as for peripheral deafferentation pain, because newer technical methods were proven to stimulate the low back predictably.

Chronic Disease↗
PubMed1983

Nucleotide sequence of the simian sarcoma virus genome: demonstration that its acquired cellular sequences encode the transforming gene product p28sis.

The complete nucleotide sequence of the proviral genome of simian sarcoma virus (SSV), an acute transforming retrovirus of primate origin, has been determined. Like other transforming viruses, SSV contains sequences derived from its helper virus, simian sarcoma-associated virus (SSAV), and a cell-derived (v-sis) insertion sequence. By comparison with the sequence of Moloney murine leukemia virus, it was possible to precisely localize and define sequences contributed by SSAV during the generation of SSV. Comparative sequence analysis of SSV and SSAV showed that SSAV provides regulatory sequences for initiation and termination of transcription of the SSV transforming gene. Moreover, coding sequences for the putative protein product of this gene appear to initiate from the amino terminus of the SSAV env gene. Antibodies to synthetic peptides derived from the carboxy and amino termini of the putative protein predicted by the open reading frame identified within v-sis specifically detect a Mr 28,000 protein, p28sis, in SSV-transformed cells. These and other findings confirm the predicted amino acid sequence of this protein and localize it to the coding region of the SSV transforming gene.

Amino Acid Sequence↗
PubMed1983

Spinal stimulation: statistical superiority of monophasic stimulation of narrowly separated, longitudinal bipoles having rostral cathodes.

A prospective study of a large number of spinal stimulating electrodes permitted a statistical comparison of stimulus parameters, including phase, polarity and orientation of bipolar electrodes. For the treatment of pain, the technical grade of a stimulator is proportional to the range of stimulation, which was found to be significantly greater under the conditions listed in the title.

Electric Stimulation Therapy↗
PubMed1982

Nucleotide sequence analysis of the long terminal repeat of integrated simian sarcoma virus: evolutionary relationship with other mammalian retroviral long terminal repeats.

Nucleotide sequence analysis of the long terminal repeat (LTR) of the integrated simian sarcoma virus showed that the simian sarcoma virus LTR comprised 504 nucleotides with an inverted repeat of seven bases at its 5' and 3' termini. At the site of simian sarcoma virus integration, cellular flanking sequences adjacent to the proviral LTR contained a direct repeat of four bases. A 13-base sequence after the 5' LTR was found to be complementary to prolyl tRNA, suggesting that tRNAPro may serve as the primer for reverse transcription of simian sarcoma virus RNA. The U5 and R regions, derived respectively from the 5' end and terminally redundant sequences of the viral RNA, were found to have similar organization and sequence homology close to that of Moloney murine sarcoma virus or Moloney murine leukemia virus. These results indicate that regions within LTRs with known functionally important sequences have been most well conserved during retrovirus evolution.

Biological Evolution↗
PubMed1980

Retrospective analysis of 22 patients with chronic pain treated by peripheral nerve stimulation.

Twenty-two patients with chronic pain, chiefly from posttraumatic neuropathy, were treated by implanted peripheral nerve stimulators located proximal to the pain. Thirteen of these (62%) have experienced pain control for an average of 25 months. The experience of the surgeon is thought to be a major factor contributing to the successful results. There are theoretical and practical advantages to electrical stimulation and proximal portions of the peripheral nervous system. The surgical technique for implantation is described and the necessity for reoperation in some patients is explained.

Brachial Plexus↗
PubMed1978

Reoperation after lumbar intervertebral disc surgery.

This retrospective study includes 53 patients who underwent reoperation after failure of lumbar disc surgery to relieve pain. All patients had leg pain before reoperation, which was successful in 28% of cases. Most clinical features, such as persistence or mode of recurrence of pain, radicular quality of pain, positive straight-leg raising, and myelographic root sleeve defects, were not helpful in predicting successful and unsuccessful reoperations. However, a significantly larger percentage of women than men had successful reoperations. Patients who had past or pending compensation claims, who had sensory loss involving more than one dermatome, or who failed to have myelographic dural sac indentations resembling those caused by a herniated disc did poorly with reoperation. A very convincing myelographic defect appears to be needed to justify reoperation at a previously unoperated location. Excision of scar alone or dorsal rhizotomy was of no avail in these cases.

Adult↗
PubMed1976

Diagnosis and treatment of abscess of the central ganglia.

The authors present four cases of abscess of the thalamus and basal ganglia and review an additional 10 cases from the literature. These abscesses appear to be metastatic and are usually associated with a cardiac septal defect or a preceding intrathoracic infection. Fever, elevated white blood count, and/or meningismus, in combination with angiography demonstrating an avascular mass, help distinguish abscess from tumor in this location. The authors advocate aspiration rather than excision.

Adult↗