The cloning and functional characterization of the nifH gene of Rhodospirillum rubrum.

Dinitrogenase reductase (the nifH product) from Rhodospirillum rubrum is regulated by a post-translational modification system encoded by draTG. As demonstrated in this report, the cloning, sequencing, and functional characterization of the nifH gene provides a basis for further analysis as well as revealing interesting features of gene organization. The coding regions of nifH and draT are separated by only 400 bp, though the genes are divergently transcribed and differentially regulated.

Cervical spondylotic myelopathy. A diagnostic challenge in aging patients.

Cervical spondylotic myelopathy remains a diagnostic and therapeutic challenge to physicians in a number of specialties. The diagnostic evaluation consists of a comprehensive neurologic and orthopedic examination supplemented by appropriate neurophysiologic and neuroradiologic studies. Currently, magnetic resonance imaging and myelography with computed tomography are the imaging methods of choice.

Closed head injuries in athletes.

Nervous system sports-related injuries constitute a major source of serious morbidity and mortality in athletes. In particular, acute closed head injuries account for some 6000 potentially preventable deaths and literally millions of episodes of less severe head injuries each year. The long-term significance of chronic head injuries resulting from repetitive blows to the brain is only now being fully appreciated.

Intracranial pressure monitoring and treatment: a contemporary view.

ICP monitoring and recording provide another important parameter in the intensive care management of many critically ill patients and have been shown to augment the clinical neurologic examination, particularly in comatose patients suffering from severe head trauma, toxic and metabolic encephalopathies, massive cerebral infarctions, and many other central nervous system insults. Once considered an experimental tool restricted exclusively to sophisticated specialty neurosurgical and neuroanesthesia intensive care units, this straightforward and rapidly evolving technology is readily available and relatively easy to apply as a bedside intensive care procedure for selected patients. Many indications of particular interest to emergency physicians are indicated.

Cow milk feeding in infancy: further observations on blood loss from the gastrointestinal tract.

Because feeding of cow milk causes normal infants to lose increased amounts of occult blood from the gastrointestinal tract, we conducted a prospective trial to measure intestinal blood loss quantitatively and to monitor iron nutritional status. Fifty-two infants entered the trial at 168 days of age and were assigned at random to receive either cow milk or a milk-based formula. Initially, 31 infants had been breast-fed and 21 had been fed formulas.

Reversible ADP-ribosylation of dinitrogenase reductase in a nifD- mutant of Rhodospirillum rubrum.

Dinitrogenase reductase from a Rhodospirillum rubrum strain lacking dinitrogenase was reversibly ADP-ribosylated in vivo in response to dark-light transitions. Addition of ammonia also led to ADP-ribosylation in this strain. These results demonstrate that reduced dinitrogenase is a satisfactory substrate for the reversible ADP-ribosylation system of R.

Paraparesis during myelography associated with a ruptured thoracic intervertebral disc.

Serious or permanent neurological complications following routine lumbar myelography are uncommon in clinical practice. We describe the sudden and dramatic onset of a symmetrical dense paraparesis in a patient after an uneventful lumbar puncture performed during myelography. A herniated thoracic intervertebral disc was subsequently diagnosed and successfully treated.

Regulation of carbon monoxide dehydrogenase and hydrogenase in Rhodospirillum rubrum: effects of CO and oxygen on synthesis and activity.

Exposure of the photosynthetic bacterium Rhodospirillum rubrum to carbon monoxide led to increased carbon monoxide dehydrogenase and hydrogenase activities due to de novo protein synthesis of both enzymes. Two-dimensional gels of [35S]methionine-pulse-labeled cells showed that induction of CO dehydrogenase synthesis was rapidly initiated (less than 5 min upon exposure to CO) and was inhibited by oxygen. Both CO dehydrogenase and the CO-induced hydrogenase were inactivated by oxygen in vivo and in vitro.

Preventing nervous system sports injuries.

Physical fitness and sports remain integral components of overall good health and a cornerstone of preventive medicine. When performed safely, under adequate supervision, and with appropriate protective gear, most of these activities are enjoyable, healthful and psychologically gratifying. When not performed safely by trained athletes, these same activities can be treacherous, injurious and permanently disabling.

Preventing and anticipating neurologic injuries in sports.

Transient and permanent neurologic injuries from sports accidents may involve the cervical, thoracic or lumbar spine, the brain, or peripheral nerves or plexi. Preventing these often devastating injuries is of paramount importance. Serious secondary complications, such as worsening neurologic status, respiratory compromise and hemodynamic instability, may be prevented by careful and meticulous pre-injury triage drills.

Head trauma in the elderly.

Head trauma in the elderly is a major source of morbidity and mortality in this population. Prevention of the primary injury is ideal and requires that the primary care physician understands the neurosensory changes of aging. Failing prevention, rapid diagnosis and efficient management of the traumatized patient are of greatest concern.

Nervous system sports-related injuries.

With the evolution of sports medicine as a subspecialty comes a redirection of attention to the medical and athletic communities to the prompt recognition and timely treatment of many potentially serious conditions. Nervous system complications of sports injuries have gone largely unaddressed in the literature. It is the goal of this communication to review the wide range of nervous system injuries due to sports activities, discuss the mechanisms of such injuries, and focus attention on their prevention and management.