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Biomedical subjects

A Reisner

Publications and source records attributed to A Reisner.

17 recordsLinked to original sources
PubMed2001

Outcome analysis for correction of single suture craniosynostosis using resorbable fixation.

A retrospective review was performed on 63 patients at Childrens Healthcare of Atlanta at Scottish Rite who underwent correction of single-suture craniosynostosis using a resorbable fixation system. Included in the series were 24 patients with metopic synostosis, 15 with sagittal synostosis, and 24 with unicoronal synostosis. The average age at operation was 22.7 months (range: 2.8 months-18 years), and mean follow-up time was 30.7 months (range: 7.1-10 years). Reoperation equal to or exceeding the magnitude of the original procedure occurred in 4.76% of the patients. This was comparable to the reoperation rate observed at our institution using traditional fixation systems. Minor complications related to the use of resorbable plates were also identified, and the final outcome for single-suture synostosis was favorable. Results suggest that resorbable plates and screws are as effective as titanium-based systems in the treatment of single-suture synostosis.

Absorbable Implants↗
PubMed2000

Traumatic intracranial aneurysms.

Traumatic intracranial aneurysms are rare, occurring in fewer than 1% of patients with cerebral aneurysms. They can occur following blunt or penetrating head trauma and are more common in the pediatric population. Traumatic aneurysms can be categorized histologically as true, false, or mixed, with false aneurysms being the most common. These aneurysms can present in a variety of ways, but are typically associated with an acute episode of delayed intracranial hemorrhage with an average time from initial trauma to aneurysm hemorrhage of approximately 21 days. The mortality rate for patients harboring these aneurysms may be as high as 50%. Prompt diagnosis based on arteriography and aggressive surgical management are associated with better outcome than conservative treatment. The authors describe a classification scheme for traumatic aneurysms based on their anatomical location and conclude that 1) posttraumatic aneurysm must be considered in patients with acute neurological deterioration following closed head injury; 2) they can occur following mild closed head injury; 3) they occur more commonly in children than in adults; and 4) surgical clipping and/or endovascular occlusion is the definitive treatment.

Age Factors↗
PubMed1999

Neonatal brain tumors: a review.

This article presents two cases of infants with brain tumors and reviews the literature pertinent to congenital and neonatal brain tumors. Information regarding epidemiology, presentation, prognosis, and clinical management are also addressed with specific regard to differences between neonatal and childhood brain tumors. An appeal is made to consider (1) coordination of the care of these children through pediatric multidisciplinary neuro-oncology programs; (2) enrollment, whenever possible, in clinical trials; and (3) submission of available tumor tissue to pediatric tumor banks to assure its availability to interested researchers.

Brain Neoplasms↗
PubMed1999

Endovascular occlusion of a carotid pseudoaneurysm complicating deep neck space infection in a child. Case report.

Pseudoaneurysm formation of the cervical internal carotid artery (ICA) is a rare, potentially lethal complication of deep neck space infection. This entity typically occurs following otolaryngological or upper respiratory tract infection. The pseudoaneurysm is heralded by a pulsatile neck mass, Homer's syndrome, lower cranial neuropathies, and/or hemorrhage that may be massive. The recommended treatment includes prompt arterial ligation. The authors present a case of pseudoaneurysm of the cervical ICA complicating a deep neck space infection. A parapharyngeal Staphylococcus aureus abscess developed in a previously healthy 6-year-old girl after she experienced pharyngitis. The abscess was drained via an intraoral approach. On postoperative Day 3, the patient developed a pulsatile neck mass, lethargy, ipsilateral Horner's syndrome, and hemoptysis, which resulted in hemorrhagic shock. Treatment included emergency endovascular occlusion of the cervical ICA and postembolization antibiotic treatment for 6 weeks. The patient has made an uneventful recovery as of her 18-month follow-up evaluation. Conclusions drawn.from this experience and a review of the literature include the following: 1) mycotic pseudoaneurysms of the carotid arteries have a typical clinical presentation that should enable timely recognition; 2) these lesions occur more commonly in children than in adults; 3) angiography with a view to performing endovascular occlusion should be undertaken promptly; and 4) endovascular occlusion of the pseudoaneurysm is a viable treatment option.

Abscess↗
PubMed1995

Isolation and culture of bovine intracranial arterial endothelial cells.

We report a simple explant technique to isolate and propagate endothelial cells from bovine cerebral arteries. The endothelial nature of the cells was confirmed by the presence of Factor VIII/von Willebrand antigen, the ability to phagocytize low-density lipoprotein, and the ability to be induced to express E-selectin. The lack of expression of the CD11c antigen and the absence of smooth muscle alpha-actin immunofluorescence suggested that the cultures were not contaminated with macrophages or smooth muscle cells, respectively. This technique yields pure cerebral arterial endothelial cell cultures, which will be of value for in vitro investigation of cerebrovascular physiology and disease processes.

Animals↗
PubMed1994

The efficacy and distribution of suramin in the treatment of the 9L gliosarcoma.

Suramin inhibits the stimulation of brain tumor deoxyribonucleic acid synthesis in vitro at concentrations of 200 to 400 mg/ml. This report evaluates suramin in the rodent 9L tumor model. Survival was analyzed by treating 10 tumor-bearing animals with suramin (7 mg/kg/d intraperitoneally) for 7 days, beginning 1 week after implantation, and compared with 20 untreated animals. Tissue distribution was analyzed with reverse-phase high-pressure liquid chromatography in homogenized organs of normal animals. Tumor concentration was measured over time in animals treated with a range of suramin doses, beginning 2 weeks after implantation. Suramin imparted no benefit as tumor-bearing control animals and treated animals survived 24.7 +/- 3.4 days and 24.5 +/- 1.5 days, respectively. In the animals receiving 7 mg/kg/d, renal concentrations of suramin were highest--339.8 +/- 30.9 mg/g as late as 25 days after treatment. Concentration in the brain peaked at only 3.3 +/- 1.3 mg/g after 10 days. Concentration in the tumor peaked at 74.4 +/- 16.5 mg/g the day of the last injection, significantly less than estimated by in vitro studies of efficacy. After injections of 35 mg/kg/d, tumor levels reached 230.9 +/- 139.2 mg/g with no evidence of inhibition of tumor progression. The response to a 7 mg/kg direct brain inoculation of suramin was assessed and compared with saline as a control. Animals treated with suramin died after 1 to 3 hours. Intracerebral hematoma volume at the injection site was 13.9 +/- 10.7 mm3 and 1.9 +/- 3.32 mm3 in the suramin-treated and control animals, respectively (P = 0.02), confirming the reported anticoagulant activity of suramin. Suramin is without efficacy in the 9L model because of poor systemic delivery. Alternative direct inoculation results in lethal local hemorrhage. Further consideration is necessary before the broad clinical application of this drug.

Animals↗
PubMed1994

Student opinion formation on animal agriculture issues.

Agriculture and animal science student bodies are shifting toward a more urban composition at the same time that criticism of animal industries by nonagricultural groups is increasing. Animal science classes include students with diverse educational goals, agricultural knowledge and experience, and values. Students without agricultural backgrounds or who have not formed opinions on agricultural questions may lack the integrated knowledge that motivates them to seek, organize, and retain the technical subject matter presented in their animal science courses. A survey of undergraduates in animal science and other agriculture majors indicates that significant numbers are unable or unwilling to offer opinions on questions related to critical social issues facing animal agriculture. Opinion holding among animal science majors and non-majors was relatively similar. However, students from urban backgrounds were less likely than rural students to offer opinions, and many of those who offered opinions held views different from those of students from rural backgrounds. Students reporting recent exposure to the issue in their academic course work were somewhat more likely to hold opinions. The findings are consistent with a social-psychological learning model that suggests instructors should require students to express and defend positions on agricultural issues in course activities.

Adult↗
PubMed1993

Basic fibroblastic growth factor as a potential meningeal angiogenic factor.

Vascular supply plays a significant role in the management of skull base tumors. The diagnosis is aided by contrast-enhanced imaging and angiographic techniques, and embolization procedures are used to devascularize certain lesions. The degree of surgical technical difficulty is strongly influenced by the degree of tumor vascularity. Although the importance of this blood supply is clearly understood, the mechanism involved in developing a system of tumor-perfusing vessels is yet to be defined. The development of a vascular network, or angiogenesis, is an important event in allowing tumor proliferation to progress beyond small clusters of cells. Basic fibroblastic growth factor (bFGF) is an especially attractive candidate as an angiogenic growth factor because of its ability to stimulate processes that are characteristic of angiogenesis in vitro. Tumors that involve the meninges may have the ability to liberate normally stored bFGF, which may, in turn, induce new vessel formation for continued tumor proliferation. An immunohistochemical analysis of rodent and bovine meninges to study this phenomenon is described. The dura, arachnoid, and their associated vessels are shown clearly to contain this growth factor. Ultimately, an adjuvant therapy based on the inhibition of angiogenesis may provide a reasonable alternative to aggressive surgical approaches in skull base tumors that are incompletely resectable.

Journal Article↗
PubMed1993

Cocaine-induced aneurysmal rupture: an emergent negative factor in the natural history of intracranial aneurysms?

Recent statistics from the National Institute on Drug Abuse indicate that cocaine abuse continues to be a significant public health problem. Between 1988 and 1990 at Grady Memorial Hospital in metropolitan Atlanta, Georgia, we identified 12 patients in whom subarachnoid hemorrhage was temporally related to cocaine abuse. All 12 patients had underlying cerebral aneurysms that had ruptured. Currently, the incidence of ruptured intracranial aneurysms in patients with cocaine-induced subarachnoid hemorrhage is 84.9% (mean age, 31.1 years; overall mortality, 60.5%). Hypertension is the likely precursive factor in cocaine-induced aneurysmal rupture. Cocaine abuse appears to be a significant negative factor in the natural history of cerebral aneurysms, especially in young adults. We review the epidemiology of cocaine-induced subarachnoid hemorrhage and its effects on the cerebral circulation, and suggest guidelines for patient management.

Adult↗
PubMed1993

Natural history of intracranial aneurysms and vascular malformations.

A fundamental aspect of the practice of a medical or surgical specialty is clinical decision making. This process presumes a careful comparison of the risks of various treatment options and the risks of the natural history of the patient's disorder. A multitude of factors enter into an accurate assessment of the risks involved in any surgical or medical therapy. In the specialty of vascular neurosurgery, these risks are often of great consequence. Potential complications underscore the importance of the other side of the clinical decision-making equation, namely, the natural history of the patient's affliction. Our knowledge of the natural history of intracranial vascular anomalies is incomplete. Much, however, is known of the outlook for patients harboring intracranial vascular malformations and aneurysms. It is of paramount importance that this knowledge be reviewed periodically so that the most accurate information is used when one consults an individual patient on the most appropriate course of therapy.

Adolescent↗
PubMed1990

Diffuse idiopathic skeletal hyperostosis causing acute thoracic myelopathy: a case report and discussion.

A case of diffuse idiopathic skeletal hyperostosis presenting as acute thoracic myelopathy is reported. Diffuse idiopathic skeletal hyperostosis has long been regarded as a radiological entity with an innocuous clinical course. The manifestations of this disease are reviewed. There is mounting evidence that it is neither a clinically infrequent nor, as this case report illustrates, an exclusively benign condition.

Female↗
PubMed1987

Effect of dietary supplementation with vitamin A on arterial healing in rats.

The effect of dietary supplementation with vitamin A on the healing of rat aortas was studied. Rats were divided into two groups: rats fed a standard chow and rats fed the chow supplemented with 150 IU vitamin A palmitate/g diet. Seven rats from each group were fed with the above diets for 7 days, killed with ether, and the abdominal aorta excised and assayed for hydroxyproline content and collagenase activity. Ten rats from each group were fed for 7 days on the above diets and then underwent a longitudinal aortotomy which was sutured with prolene sutures under pentobarbital anesthesia. The rats were maintained on their respective diets for 7 days and then killed with ether, their abdominal aorta was excised and both the segment with the arteriotomy and the adjacent distal normal segment were analyzed for hydroxyproline content and collagenase activity. Seven rats from each group were fed with the above diets and then underwent transverse division of the abdominal aorta and reanastomosis using nylon sutures under pentobarbital anesthesia. Rats were maintained on their respective diets throughout the postoperative period. Seven days later, all rats were killed with ether and the bursting strength of the aortic anastomoses was measured. The results showed that vitamin A supplementation in non-operated animals had no significant effect on aortic hydroxyproline content or collagenase activity. In rats undergoing longitudinal aortotomy and suture, there was a significant increase in hydroxyproline content both at the healing arteriotomy and at the adjacent non-wounded aorta in the vitamin A-supplemented group. There was also a significant increase in bursting strength of the healing aortic anastomosis in the vitamin A-supplemented rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Survival, organization, and function of microcarrier-attached hepatocytes transplanted in rats.

Hepatocytes harvested by collagenase perfusion of rat liver were attached to collagen-coated microcarriers and injected intraperitoneally into congeneic or allogeneic bilirubin-UDP-glucuronosyltransferase (EC 2.4.1.17)-deficient (Gunn) rats or allogeneic analbuminemic (NAR) rats. Five days later, the microcarriers were observed to have formed conglomerates chiefly on the anterior surface of the pancreas. Scanning electron microscopy showed hepatocytes attached to the granular collagen-coated surface of the microcarriers and newly formed connective tissue. Light microscopy revealed that the microcarriers formed a lattice with the collagen tissue; hepatocytes were seen within this lattice or on the surface of the microcarriers. Hepatocyte plasma membranes were nucleoside-diphosphatase (NDPase)-positive. Newly formed blood islands, blood vessels containing erythrocytes and leukocytes and NDPase-positive endothelium were observed in close proximity to the hepatocytes and fibroblasts. Transmission electron microscopic examination showed hepatocytes with microvilli and nucleoid-containing peroxisomes with catalase activity. Hepatocytes were present for up to 2 months in congeneic recipients, the longest period of observation after transplantation. After normal microcarrier-attached hepatocytes were transplanted into allogeneic Gunn rats, bilirubin glucuronides were present in bile for 6 days. When congeneic Gunn rat recipients were used, bilirubin glucuronides were present in bile throughout the study (28 days); this was accompanied by reduction of serum bilirubin concentrations to nearly normal levels. After injection of normal hepatocytes into allogeneic NAR rats, plasma albumin concentration progressively increased for 6 days and then declined. In NAR recipients which were immunosuppressed with cyclosporin A, peak plasma albumin levels were reached in 14 days and persisted nearly at that level throughout the study (28 days).

Animals↗
PubMedDate not supplied

Transplantation of microcarrier-attached hepatocytes into 90% partially hepatectomized rats.

We previously reported a method of intraperitoneal transplantation of liver cells attached to collagen-coated microcarriers, which resulted in prolonged survival and function of the transplanted cells. In the present study, we evaluated the efficacy of liver cell transplantation in providing metabolic support during acute liver insufficiency induced by 90% partial hepatectomy in rats. Ninety per cent of the liver mass (all lobes except the caudate lobe) was resected, and the rats were provided with 5% dextrose orally ad libitum upon regaining consciousness. This regimen results in severe hypoglycemia and death within 48 hr. When microcarrier-attached liver cells were transplanted into syngeneic and allogeneic recipients 3 days prior to 90% partial hepatectomy, significantly higher blood glucose levels were observed (p less than 0.01), compared to the levels in control rats which received injections of microcarriers, liver cells or medium alone. There was a marked improvement in long-term survival (40% survived longer than 28 days; p less than 0.001) in rats transplanted with microcarriers-attached cells. None of the rats given injections of microcarriers, liver cells or medium alone survived beyond 5 days. When liver cells alone or attached to microcarriers were injected intraperitoneally immediately after 90% partial hepatectomy, all rats became hypoglycemic and died within 48 hr, suggesting that vascularization of the transplant is required for function of the transplanted hepatocytes. The results indicate that intraperitoneal transplantation of microcarrier-attached hepatocytes prior to 90% partial hepatectomy in rats provides acute metabolic support resulting in improved survival.

Acute Disease↗
PubMedDate not supplied

Spinal injuries in children: role of MR.

PURPOSE: To define the clinical and prognostic role of MR in a pediatric population with spinal cord injury. METHODS: Fifteen children underwent MR 12 hours to 2 months postinjury using decoupled surface coils and ventilator support as needed. MR was correlated retrospectively with clinical, CT, and radiographic findings. RESULTS: On MR, of seven children with spinal cord neurologic deficits, four had hemorrhagic contusions, one had nonhemorrhagic contusion, one had extensive infarction, and one revealed a normal cord. All had persistent deficits on hospital discharge. Eight without cord neurologic deficit revealed no cord lesions on MR; this group included two with epidural hematoma, four with ligamentous disruption, and two with bone compression. CONCLUSIONS: Children may have extensive cord contusion and/or infarction with minor, remote, or no fracture dislocation. Because both hemorrhagic and nonhemorrhagic cord lesions found on MR were associated with significant, persistent cord deficits, the authors conclude that MR provides a practical tool for diagnosis/prognosis in children with acute/subacute spinal injury.

Adolescent↗