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Biomedical subjects

B K Willis

Publications and source records attributed to B K Willis.

At least 19 recordsLinked to original sources
PubMed2006

Intraspinal synovial cysts: a retrospective study.

BACKGROUND: We report the clinical presentation, radiographic studies, intraoperative findings, histopathological analysis, and post-treatment outcome in 26 patients diagnosed with spinal synovial cysts (SSCs). AIMS: To describe the clinical presentation, radiographic studies, operative findings, and postoperative follow-up in 26 patients with SSCs. SETTINGS AND DESIGN: The study was retrospective in design, involving chart review. Individual patient data was tabulated and patterns were recognized. MATERIALS AND METHODS: The charts for 26 patients who underwent surgical extirpation of SSC between April 1993 and October 2002 were retrospectively reviewed. Specifically, initial clinical presentation, pertinent radiographs (X-rays, magnetic resonance imaging, computed tomography), intraoperative findings, histopathology, and postoperative follow-up were noted. STATISTICAL ANALYSIS USED: Patient data was tabulated and analyzed for patterns in demographics, symptoms and histopathology. RESULTS: SSCs were more common in females than males (17:9 ratio). Presenting symptoms were back pain with radiculopathy in 13 (50%), radicular pain in the absence of back pain in 10 (38%), and back pain without radicular pain in three (11%). In addition, 17 patients (65%) had sensory deficit, and 9 (35%) had motor deficit. Most SSCs occurred at the lumbar (19/26) or lumbosacral (5/26) regions, with only 2 (2/26) in the thoracic region. One patient had bilateral SSC at the L4-5 level. Intraoperatively, each cyst was located adjacent to a degenerated facet joint. These lesions could grossly be identified intraoperatively and histopathological confirmation was achieved in all the cases. CONCLUSIONS: SSCs are important lesions to consider in the differential diagnosis of lumbar epidural masses and surgical resection leads to significant improvement in the majority of cases.

Humans↗
PubMed2002

The parallel helices of the intermediate filaments of alpha-keratin.

Recent Fourier transform infrared spectroscopy (FTIR) with attenuated total reflection technique (ATR) has been applied to alpha-keratin fibers (horse-hair) extended in water both at 21 and 95 degrees C. Infrared absorption bands in the Amide 1 region indicated that at extensions to 40-50% strain in water at 21 degrees C alpha-helices had completely disappeared and parallel beta-sheets were formed [Appl. Spectrosc. 55 (2001) 552]. However, when the hair fibers were extended to the same strain at 95 degrees C in water the result was the formation of anti-parallel beta-sheets. These results suggest that the relatively more stable anti-parallel beta-state [Polymer 10 (1969) 810] is only attained in extended alpha-keratin fibers at elevated temperatures and must result from major molecular rearrangement. It was concluded that the alpha-helices in the intermediate filaments (IFs) of alpha-keratin fibers must be parallel. This is in contrast to the previously accepted orientation of anti-parallel alpha-helices, based primarily on findings of X-ray diffraction studies of the structure of beta-keratin in highly extended fibers [Polymer 10 (1969) 810; Keratins, IL: Thomas Springfield (1972); Nature 316 (1985) 767].

Animals↗
PubMed2002

Potential involvement of copper and thiol-disulphide interchange in prion proteins' conformational conversion.

The prion protein PrP(C) in transmissible spongiform encephalopathy converts to the pathogenic isoform PrP(Sc) containing less alpha-helical structure and a greater beta-pleated sheet content. The stability of PrP(C) protein is partly dependent on the disulphide bond between two alpha-helices designated B and C. Further stability could arise from ligand complexes of Cu(II) ions formed with carboxylic acid side chains in PrP(C). Electron spin resonance (E.S.R.) spectra and atomic absorption measurements have shown for alpha-keratin that the formation of ligands by Cu(II) is 10(2) more rapid than interaction of Cu(II) with ionised thiols X-S(-) which form X-S-Cu(+). X-S(-) destabilises disulphide bonds by thiol-disulphide interchange. When insufficient Cu(II) is present to form ligands with all available sites in PrP(C) then unblocked X-S(-) groups could potentially destabilise the disulphide bonds by thiol-disulphide interchange followed by reformation of the disulphide bond in the beta form of PrP(Sc) and the release of X-S(-) to interact with other PrP(C).

Animals↗
PubMed2000

Intracranial aneurysms and cocaine abuse: analysis of prognostic indicators.

OBJECTIVE: The outcome of subarachnoid hemorrhage associated with cocaine abuse is reportedly poor. However, no study in the literature has reported the use of a statistical model to analyze the variables that influence outcome. METHODS: A review of admissions during a 6-year period revealed 14 patients with cocaine-related aneurysms. This group was compared with a control group of 135 patients with ruptured aneurysms and no history of cocaine abuse. Age at presentation, time of ictus after intoxication, Hunt and Hess grade of subarachnoid hemorrhage, size of the aneurysm, location of the aneurysm, and the Glasgow Outcome Scale score were assessed and compared. RESULTS: The patients in the study group were significantly younger than the patients in the control group (P < 0.002). In patients in the study group, all aneurysms were located in the anterior circulation. The majority of these aneurysms were smaller than those of the control group (8 +/- 6.08 mm versus 11 +/- 5.4 mm; P = 0.05). The differences in mortality and morbidity between the two groups were not significant. Hunt and Hess grade (P < 0.005) and age (P < 0.007) were significant predictors of outcome for the patients with cocaine-related aneurysms. CONCLUSION: Cocaine use predisposed aneurysmal rupture at a significantly earlier age and in much smaller aneurysms. Contrary to the published literature, this group did reasonably well with aggressive management.

Adult↗
PubMed1999

Infection rate with replacement of bone fragment in compound depressed skull fractures.

BACKGROUND: Traditional management of compound depressed skull fractures entails elevation and removal of all bone fragments with delayed cranioplasty. Bone fragment removal is intended to reduce the potential for infection. However, bone fragment removal often necessitates a second operation to repair the resultant calvarial defect. This study examines the postoperative infection rate when bone fragments are replaced primarily. METHODS: A retrospective study was carried out of all patients admitted with the diagnosis of compound depressed skull fracture to a university hospital from 1991 to 1996. RESULTS: Of 52 patients with the diagnosis of compound depressed skull fracture treated at our university hospital over the past 5 years, 32 underwent elevation and repair within 72 hours. All patients except one received antibiotics during surgery and for at least 1.5 days after surgery. Follow-up averaged just over 22 months. In all 32 consecutive patients treated with debridement and elevation of compound depressed skull fractures with primary replacement of bone fragments within 72 hours of injury, there were no infectious sequelae. CONCLUSIONS: Immediate replacement of bone fragments in compound depressed skull fractures does not increase the risk of infectious complications.

Adolescent↗
PubMed1996

Metastatic disease in the cerebellum. The LSU experience in 1981-1993.

We retrospectively determined the outcome of management of metastatic disease in the cerebellum (MDC) in 45 patients because MDC is considered to be more immediately life-threatening than metastases in other intracranial locations. Treatment consisted of tumor resection and radiotherapy (RR; n = 11) or of radiotherapy alone (RA; n = 34). Significant differences in the median survival (15 months for RR and 3 months for RA, p = 0.005) and in survival rates at 1 year (61 +/- 30% for RR and 9 +/- 10% for RA, p < 0.001) and at 2 years (15 +/- 22% for RR and 0% for RA, p < 0.05) were noted. This combined management program of surgery followed by radiotherapy for MDC produced a worthwhile gain in survival.

Aged↗
PubMed1996

Fatal air bag mediated craniocervical trauma in a child.

This case report describes a 5-year-old child who sustained fatal craniocervical injuries as the result of an inflating automobile air bag. Although air bags have in general been shown to reduce the severity of injury to occupants of vehicles involved in front-end collisions, a growing number of incidents suggests that in some instances the air bag system itself may cause injuries, some of which can be serious or even fatal. Small children and infants in infant seats travelling in the front passenger seat appear to be particularly at risk. The increasing number of reports of air bag mediated injuries highlights the need for changes in both system design and possibly the threshold speed required for air bag deployment.

Air Bags↗
PubMed1995

Inadvertent use of ionic contrast material in myelography: case report and management guidelines.

A 38-year-old man with chronic low back pain underwent myelography and was inadvertently injected with ionic contrast medium. Within minutes, he started complaining of muscle spasms in his lower extremities, followed by respiratory distress and myoclonus. Immediate intravenous treatment with fluids, antihistamines, and supplemental oxygen was started. Within 1 hour after the myelogram, he was intubated and paralyzed with a neuromuscular blocking agent. Shortly thereafter, he began receiving triple anticonvulsant therapy and a lumbar drain was inserted to allow for the evacuation of cerebrospinal fluid. Electroencephalographic monitoring, which initially showed that the patient was in status epilepticus, subsequently showed no more episodes of seizure activity. Massive rhabdomyolysis, renal failure, and metabolic derangement were prevented. He was then extubated and regained full consciousness. He was discharged on the 13th day of hospitalization with mild amnesia and some cognitive dysfunction. A review of the literature reveals descriptions of 9 of 15 patients who survived similar episodes. We conclude that prompt identification of the contrast medium error and prompt intervention are crucial to increase significantly the chances of survival. Elective paralysis, anticonvulsant therapy, and cerebrospinal fluid drainage are the recommended modes of treatment.

Adult↗
PubMed1994

The incidence of vertebral artery injury after midcervical spine fracture or subluxation.

Twenty-six patients with blunt trauma of the cervical spine, producing a subluxation from a "locked" or "perched" facet, facet destruction with evidence of instability, or a fracture involving the foramen transversarium, underwent preoperative vertebral angiography to determine the incidence of vertebral artery injury. The cervical spine injury in all the patients was deemed unstable and in need of surgical stabilization. Spinal cord injury was present in one-half of the patients studied. Vertebral artery injury was identified angiographically in 12 patients (46%). Occlusion of the vertebral artery near its origin or at the level of the spinal injury was identified in nine patients. An intimal flap, arterial dissection, and a pseudoaneurysm were identified in the remaining three patients. The injury involved the left vertebral artery in all but three patients. In none of the patients did the vertebral artery injury clearly result in neurological dysfunction or other sequelae. After cervical spine fracture or dislocation, vertebral artery injury is more prevalent than commonly believed. The possibility of vertebral artery injury should be considered during the establishment of clinical management schemes for blunt trauma of the cervical spine.

Adolescent↗
PubMed1992

Torulopsis glabrata vertebral osteomyelitis.

A case of Torulopsis glabrata osteomyelitis of the thoracic spine producing spinal cord compression and myelopathy is reported. The patient displayed several of the predisposing factors to T. glabrata infection, including diabetes mellitus, a history of abdominal surgery, and intravenous catheterization with hyperalimentation. The patient was successfully managed with surgical decompression, debridement, and curettage of the affected bone, postoperative immobilization, and systemic amphotericin B therapy. Her pain was relieved, spinal cord function recovered, and the vertebrae healed uneventfully. T. glabrata osteomyelitis is a rare and unpredictably progressive infection. This case demonstrates that it requires prompt therapy and close observation.

Aged↗
PubMed1991

Civilian craniocerebral gunshot wounds.

Experience with 120 patients who incurred a gunshot wound to the head with dural penetration is presented. All of the patients were managed by a standard resuscitation protocol and assigned a clinical grade based on their level of consciousness both at the time of presentation and at 2 to 4 months after injury. Fifty patients (42%) underwent surgery. Twenty-eight patients (23%) had a good recovery, 19 (16%) were moderately disabled, 6 (5%) were severely disabled, and 67 (56%) died. All patients who were alert and awake with a normal or near normal neurological examination at the time of admission survived with a good outcome. All but 4 patients who were comatose at the time of admission died. Nine patients, however, who were not comatose at the time of admission died from potentially preventable causes. In 3 of these patients, a more aggressive diagnostic approach (including cerebral angiography) may have altered their ultimate outcome. An expeditious approach to the trauma victim with a comprehensive management scheme after injury may have altered the course in the remainder of these patients.

Adult↗