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Biomedical subjects

T Lichtor

Publications and source records attributed to T Lichtor.

At least 37 records · Page 2Linked to original sources

Demographics of civilian cranial gunshot wounds: devastation related to escalating semiautomatic usage.

The demographics and outcome of patients with gunshot wounds to the head over the past 10 years at Chicago's Cook County Hospital was examined. The study group consisted of 476 consecutive patients admitted to this urban level I trauma center with a diagnosis of penetrating craniocerebral missile injury. All patients followed a protocol that included aggressive surgical management when indicated. The Glasgow Outcome Score was used to assess outcome. There is an alarming rise in firearm violence in general and craniocerebral injury in particular. Some patients with severe neurologic deficits and massive cerebral damage can benefit from aggressive treatment and make a good recovery. A large proportion of this violence is most likely attributable to gang activity. Factors correlating with poor outcome included hypotension, apnea, bihemispheric injuries, or ventricular penetration. Although aggressive surgical and medical management improves the outcome of these patients, much more stringent preventative measures are required to control this violent epidemic.

Adolescent↗

Fibroblasts genetically engineered to secrete cytokines suppress tumor growth and induce antitumor immunity to a murine glioma in vivo.

The genes for interleukin (IL)-2, interferon (IFN)-gamma, or both IL-2 and IFN-gamma were introduced into a mouse fibroblast cell line (LM) expressing defined major histocompatibility complex determinants (H-2k). The cytokine-secreting cells were then co-transplanted with the Gl261 murine glioma cell line (H-2b) into syngeneic C57BL/6 mice that differed at the major histocompatibility complex from the cytokine-secreting cells. The period of survival of mice with glioma treated with IL-2- or IL-2/IFN-gamma-secreting allogeneic cells was significantly prolonged (P < 0.025) relative to the survival of mice receiving equivalent numbers of tumor cells alone or mice with glioma treated with nonsecreting fibroblast (LM) cells. Gliomas in the treated mice had an extensive lymphocytic cell infiltrate. Using a 51Cr release assay, the specific release of isotope from labeled Gl261 cells co-incubated with spleen from mice injected with the glioma cells and IL-2-secreting fibroblasts was higher (P < 0.001) than the release from glioma cells co-incubated with spleen cells from nonimmunized mice. Significantly higher levels of release (P < 0.005) were found in the group immunized with fibroblasts secreting both IL-2 and IFN-gamma. Based upon the effect of monoclonal antibodies for T-cell subsets on the antiglioma response, the immunity was mediated predominantly by natural killer/lymphokine-activated killer cells.

Animals↗

Gunshot wounds to the head in civilian practice.

An aggressive surgical strategy was applied to cranial gunshot wound victims at Cook County Hospital in Chicago from 1983 to 1992. A series of 480 patients with an overall mortality rate of 34% is presented. A total of 150 patients underwent craniotomy with an operative mortality rate of 21%. Criteria for operation were Glasgow Coma Scale scores of 3 through 7 without hypotension or fixed and dilated pupils or Glasgow Coma Scale scores of 8 through 15 with intracranial bone fragments or significant clot. This study supports previous reports that even patients with severe neurological deficits and massive cerebral damage can benefit from aggressive treatment and make satisfactory recoveries.

Adolescent↗

Prolonged survival of mice with glioma injected intracerebrally with double cytokine-secreting cells.

A novel approach toward the treatment of glioma was developed in a murine model. The genes for both interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) were first transfected into a mouse fibroblast cell line that expresses defined major histocompatibility complex (MHC) determinants (H-2k). The double cytokine-secreting cells were then cotransplanted intracerebrally with the Gl261 murine glioma cell line into syngeneic C57BL/6 mice (H-2b) whose cells differed at the MHC from the cellular immunogen. The results indicate that the survival of mice with glioma injected with the cytokine-secreting allogeneic cells was significantly prolonged, relative to the survival of mice receiving equivalent numbers of glioma cells alone. Using a standard 51Cr-release assay, the specific release of isotope from labeled Gl261 cells coincubated with spleen cells from mice injected intracerebrally with the glioma cells and the cytokine-secreting fibroblasts was significantly higher than the release of isotope from glioma cells coincubated with spleen cells from nonimmunized mice. The cellular antiglioma response was mediated by natural killer/lymphokine-activated killer and Lyt-2.2+ (CD8+) cells. The increased survival of mice with glioma and the specific immunocytotoxic responses after immunization with fibroblasts modified to secrete both IL-2 and IFN-gamma indicate the potential of an immunotherapeutic approach to gliomas with cytokine-secreting cells.

Animals↗

Patients with Glasgow Coma Scale scores 3, 4, 5 after gunshot wounds to the brain.

Even this information is only partial. To study fully the effects of treatment would require optimal care at all points from time of injury, including rapid prehospital resuscitation, rapid transport to an optimally equipped and staffed hospital, immediate evaluation and treatment of the initial injury and all complications, rapid and comprehensive rehabilitation, and supportive and flexible home and work settings for the patient on discharge. Patients would need to be stratified for premorbid characteristics, including intelligence, personal traits, and training. Prolonged follow-up, possibly for several years, would be required to determine true outcome. No current study contains sufficient numbers of patients treated optimally and studied for prolonged periods, but this should be done. One way of looking at such patients is to decide that many should be treated to salvage a few. The other way of looking at them is that so many must receive care, at great emotional and economic cost to themselves and others, that such treatment is inappropriate for any of them. Treating all such patients would be a major undertaking. If most of these patients were treated vigorously, a great proportion of them would still die but probably not for a number of days. During this period, their families would be under extreme stress. Once stabilized and receiving ongoing care, some patients would enter a permanent vegetative state and survive for prolonged periods until their prognosis was clear and care was withdrawn, again causing family stress as well as high cost. Some would likely survive although impaired. The charges and real costs of care for all these patients would be tremendous. The question therefore arises as to how to decide what to do about caring for a large group of patients whose maximal care would be costly in emotional and financial terms, particularly at a time when it is recognized that resources for medical care are going to be limited. When discussing such patients as a group with a view toward developing practice guidelines, many considerations must be brought to bear. One consideration is the certainty of the prognosis in both a quantitative and a qualitative sense in an individual case. It is not clear that one can be certain in patients except when there are overwhelmingly unfavorable features. As has been noted, even patients who have been shot through the geographic center of the brain and are posturing can make excellent recoveries. This would push toward aggressive treatment for many patients. Decision making must therefore be considered in terms of bioethics. The major principle-based systems of bioethics are deontologic, arising from accepted principles, and utilitarian, arising from effect on outcome. A virtue-based ethic for physicians arising from "the caring bond and the public trust" is being revived as a balance to analytical ethics. A similar orientation from the point of view of patients is communitarian ethics, that is asking for only what is reasonable and not so much as might harm others. Some of the issues to be considered include the sanctity of life while taking into account the criteria for life--vegetative function versus some level of mental function. One must also review each decision from the viewpoints of all the parties involved--patients, family and friends, physicians, and society--in the context of a heterogeneous society in which individual rights and tolerance enforced by law are primary features. In the patients' terms, there is a desire and right to medical care to maintain a healthy productive life. Even if impaired to some extent, patients may still have an interest in living. Balancing benefits and burdens of life is a complex problem. There is also the right, based on patients' values, to refuse care if there is the wish not to take a chance of having a significantly compromised existence. Such declaration before injury should be honored...

Brain Injuries↗

Intradural thoracic disc herniation.

STUDY DESIGN: Patients with intradural herniation of an intervertebral disc were identified and managed surgically. OBJECTIVES: Illustrative cases of patients with intradural herniated discs at the mid-thoracic level are presented, the literature is reviewed, and the management of these patients is discussed. SUMMARY OF BACKGROUND DATA: Intradural herniation of an intervertebral disc is rare and most common at the lumbar level, but isolated cases have been reported at other levels. Cases reports of this entity have been published, but the surgical details have not been adequately addressed. METHODS: In this report, two patients with calcified intradural herniated discs at the mid-thoracic level are presented. RESULTS: Both patients had progressive paraparesis and had calcified disc material in the mid-thoracic canal. Both were treated successfully with a posterolateral extracavitary costotransversectomy and hemilaminotomy using intraoperative ultrasound and somatosensory-evoked potential monitoring. CONCLUSIONS: This entity should be suspected when a calcified disc within the spinal canal is being treated. The optimal exposure is a posterolateral extracavitary costotransversectomy with a hemilaminotomy. Alternative approaches to a typical thoracic disc would be problematic in managing these patients.

Dura Mater↗

Coexpression of interleukin-1 beta and interleukin-6 in human brain tumors.

Deregulation of the expression of cytokine genes appears to play a role in the development of gliomas. Interleukin-1 beta has been shown to be synthesized in small amounts by astrocytes and can induce the expression of interleukin-6. Interleukin-6 is not expressed by unstimulated astrocytes, but the deregulation of its expression has been implicated in the progression of several tumor types. In this study, tumor specimens from 16 brain tumors and 22 glioma cell lines were studied for the gene expression of both interleukin-1 beta and interleukin-6, and the coexpression of these two cytokines was found in a significant number of these specimens. The expression of these two growth factor genes may play an important role in the growth and development of human gliomas.

Adolescent↗

Expression of insulin-like growth factors and their receptors in human meningiomas.

Meningiomas have previously been shown to highly express the gene for insulin-like growth factor-II (IGF-II), and receptors for IGF-I have been demonstrated by binding studies in membranes prepared for meningiomas. The co-expression of insulin and the insulin-like growth factors with their corresponding receptors in meningiomas has not been explored. Immunofluorescence microscopy was carried out on twelve meningotheliomatous meningiomas using antibodies directed against insulin, IGF-I, IGF-II, insulin receptor and IGF-I receptor. In addition, these results were contrasted with similar studies using antibodies against desmoplakin and basic fibroblast growth factor. Although insulin immunoreactivity was detected in only one tumor, IGF-I and IGF-II immunoreactivity was present in six and eight of the tumors, respectively. In addition, the IGF-I receptor was expressed in four of the tumors while the insulin receptor was expressed in 10 out of 12 meningiomas. The pattern of distribution of IGF-II and the insulin receptor was especially regional. The insulin-like growth factors and their receptors are expressed in meningiomas in a pattern of distribution suggestive of a paracrine mechanism.

Humans↗

Gene expression of apolipoprotein E in human brain tumors.

Samples of normal brain, two meningiomas, one medulloblastoma and seven astrocytomas were analyzed along with two glioma lines to determine the genic expression of apolipoprotein E, which in addition to its major function in lipid metabolism has been postulated to be a marker for astrocytomas. Messenger ribonucleic acid encoding apolipoprotein E was found to be expressed in significant amounts in all of the brain tumor specimens and in the normal brain, but in only one of the two glioma lines. Although the role of apolipoprotein-E in the brain and in brain tumor growth remains undefined, it is clear that this gene is expressed in substantial amounts in a variety of brain tumors and is not specific for astrocytomas.

Adult↗

Differential expression of insulin-like growth factor II in human meningiomas.

Two glioma tumor lines and brain tumor specimens from 10 patients were analyzed to determine genic expression of insulin-like growth factor II. Messenger ribonucleic acid encoding insulin-like growth factor II was found to be expressed in significant amounts in two of two meningiomas but not in any of the gliomas. Immunofluorescence studies on these tumors and normal brain confirmed the presence of insulin-like growth factor II in both meningiomas, but not in any of the gliomas or in normal brain. Within the meningiomas, only a small number of cells highly expressed insulin-like growth factor II immunoreactive material, and this could be evidence for a paracrine mechanism in these tumors. These data suggest that the enhanced expression of insulin-like growth factor II may be a characteristic of meningiomas.

Adult↗

Cytokine gene expression by human gliomas.

Two glioma tumor lines and specimens from five patients with gliomas were analyzed to determine genic expression of four growth factors found in human brain. Messenger RNA encoding for interleukin-1 beta, interleukin-6, and basic fibroblast growth factor was found to be expressed in significant amounts in some of these tumors, while mRNA for interleukin-3 was found in small quantities in only the tumor lines. Multiple species of mRNA for basic fibroblast growth factor were found. Expression of growth factor genes may play a role in the growth of human gliomas.

Adult↗

A 10-year follow-up review of percutaneous microcompression of the trigeminal ganglion.

Percutaneous microcompression of the trigeminal ganglion for the relief of trigeminal neuralgia is a technically simple, nonpainful procedure, carried out under brief general anesthesia. One hundred patients treated by this method have been followed for 1 to 10 years; treatment has been technically successful in 97% of cases. Relief persisted at five years in 80%, and it is estimated that at 10 years the figure will be 70%. There were no deaths, no cerebral damage, no keratitis, and no analgesia dolorosa; 4% of the patients reported dysesthesia.

Adult↗

Suppression of atherogenesis by nifedipine in the cholesterol-fed rhesus monkey.

Diet-induced atherosclerosis in rhesus monkeys was suppressed in the carotid arteries and thoracic aorta by the calcium antagonist nifedipine given orally for a period of 1 year at a dose of 10 mg b.i.d. The extent of atherosclerosis was determined by quantitative micromorphometric studies. No change in serum blood cholesterol or biochemical composition of the major vessels was detected, but the intimal area and thickness of the atherosclerotic plaques in the carotid arteries of the nifedipine group were markedly less than those found with the control group (p less than 0.05). However, no statistically significant differences were seen in the degree of atherosclerotic involvement of the other major arterial vessels. Although the mechanism is not clear, nifedipine may be useful in the treatment of carotid artery disease.

Animals↗

Oxidative metabolism and glycolysis in benign brain tumors.

Glucose utilization in vivo and hexokinase activity and mitochondrial oxygen consumption in vitro were measured in a series of human brain tumors. Several relatively slow-growing tumors appeared to have depressed electron-transport activities coupled with a compensatory elevated glucose utilization. These data suggest that a decrease in oxidative metabolism and a corresponding increase in glycolysis are not necessarily correlated with malignancy in certain human brain tumors.

Brain Neoplasms↗

Arteriovenous malformation in moyamoya syndrome. Report of three cases.

Three patients are reported with the rare combination of moyamoya disease and features of an associated arteriovenous malformation. Two of the patients developed ischemic symptoms, and the third patient presented with an intracerebral hemorrhage. All three patients fit the criteria of a stage III moyamoya syndrome on the basis of the angiographic classification described by Suzuki and Takaku. The patients were referred to this medical center following angiography with the presumptive diagnosis of arteriovenous malformation.

Adult↗

The sympathetic nervous system and atherosclerosis.

Morphometric and chemical changes in the arterial wall were studied after 12 months of diet-induced atherosclerosis in rhesus monkeys treated with either bilateral surgical thoracic sympathectomy or propranolol. There was a marked reduction in the progression of atherosclerosis in the carotid arteries and a moderate reduction in the disease found in the thoracic aorta of monkeys treated initially with a sympathectomy, in comparison to control monkeys fed an atherogenic diet alone. Propranolol at a dose of 40 mg/12 hrs also seemed to reduce the progression of atherosclerosis in the carotid arteries and thoracic aorta, although the differences were less dramatic. There were minimal differences in the extent of atherosclerosis in the abdominal aorta or femoral arteries of animals in either treatment group as compared with the control group. Similarly, the chemical composition of these same major vessels showed no significant differences. Therefore, in the face of severe atherogenic stimuli, chemical or surgical sympathectomy may be useful in controlling atherosclerosis in specific arterial beds.

Animals↗