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Biomedical subjects

J H Sampson

Publications and source records attributed to J H Sampson.

At least 37 records · Page 2Linked to original sources

Subcutaneous vaccination with irradiated, cytokine-producing tumor cells stimulates CD8+ cell-mediated immunity against tumors located in the "immunologically privileged" central nervous system.

Vaccination with cytokine-producing tumor cells generates potent immune responses against tumors outside the central nervous system (CNS). The CNS, however, is a barrier to allograft and xenograft rejection, and established tumors within the CNS have failed to respond to other forms of systemic immunotherapy. To determine what barriers the "immunologically privileged" CNS would pose to cytokine-assisted tumor vaccines and what cytokines would be most efficacious against tumors within the CNS, we irradiated B16 murine melanoma cells producing murine interleukin 2 (IL-2), IL-3, IL-4, IL-6, gamma-interferon, or granulocyte-macrophage colony stimulating factor (GM-CSF) and used these cells as subcutaneous vaccines against tumors within the brain. Under conditions where untransfected B16 cells had no effect, cells producing IL-3, IL-6, or GM-CSF increased the survival of mice challenged with viable B16 cells in the brain. Vaccination with B16 cells producing IL-4 or gamma-interferon had no effect, and vaccination with B16 cells producing IL-2 decreased survival time. GM-CSF-producing vaccines were also able to increase survival in mice with pre-established tumors. The response elicited by GM-CSF-producing vaccines was found to be specific to tumor type and to be abrogated by depletion of CD8+ cells. Unlike the immunity generated against subcutaneous tumors by GM-CSF, however, the effector responses generated against tumors in the CNS were not dependent on CD4+ cells. These data suggest that cytokine-producing tumor cells are very potent stimulators of immunity against tumors within the CNS, but effector responses in the CNS may be different from those obtained against subcutaneous tumors.

Animals↗

The impact of human immunodeficiency virus infection on drug-resistant tuberculosis.

Infection with human immunodeficiency virus (HIV) has been associated with increased rates of single- and multidrug-resistant (MDR) tuberculosis in the New York City area. In order to examine the relationship of HIV infection to drug-resistant tuberculosis in other selected regions of the United States, we established a registry of cases of culture-proven tuberculosis. Data were collected from sites participating in an NIH-funded, community-based HIV clinical trials group. All cases of tuberculosis, regardless of HIV status, which occurred between January 1992 and June 1994 were recorded. Overall, 1,373 cases of tuberculosis were evaluated, including 425 from the New York City area, and 948 from seven other metropolitan areas. The overall prevalence of resistance to one or more drugs was 20.4%, and 5.6% of isolates were resistant to both isoniazid and rifampin (MDR). In the New York City area, HIV-infected patients were significantly more likely than persons not known to be HIV-infected, to have resistance to at least one drug (37% versus 19%) and MDR (19% versus 6%). In other geographic areas, overall drug resistance was 16%, and only 2.2% of isolates were MDR. In multiple logistic regression analyses, HIV infection was shown to be a risk factor for drug-resistant tuberculosis, independent of geographic location, history of prior therapy, age, and race. We concluded that HIV infection is associated with increased rates of resistance to antituberculosis drugs in both the New York City area and other geographic areas. MDR tuberculosis is occurring predominantly in the New York City area and is highly correlated with HIV infection.

Adolescent↗

Recurrence of a cerebral arteriovenous malformation after surgical excision. Case report.

Complete excision of a cerebral arteriovenous malformation (AVM) should eliminate the future risk of an associated intracranial hemorrhage. Because total removal of an AVM may be difficult to assess at the time of surgery, postoperative angiography has become the accepted standard for documenting that the removal has been accomplished. However, even angiography confirmed excision of an AVM does not completely ensure against rebleeding. Regrowth of an AVM with subsequent hemorrhage can occur. This has been documented in children and is attributed to forces acting on the immature vasculature of these younger patients. The authors report the case of an older patient whose AVM recurred when he was 28 years of age, despite an angiography proven complete excision, and emphasize that, even in adults, angiography documentation of total removal does not always eliminate the risk of reformation of an AVM.

Adult↗

Metastatic melanoma to the spine. Demographics, risk factors, and prognosis in 114 patients.

STUDY DESIGN: One-hundred-fourteen patients with metastatic melanoma of the spine were retrospectively reviewed. OBJECTIVE: The goal was to define the demographics, risk factors, and prognosis for this population. SUMMARY OF BACKGROUND DATA: The incidence of melanoma is increasing faster than any other cancer. Therefore, orthopedic and neurologic surgeons will be increasingly confronted by patients with spinal metastases from melanoma. However, the demographics, risk factors, and prognosis remain unclear. METHODS: From 7010 consecutive patients with melanoma, 114 were identified with clinically or radiographically evident spinal metastases. A comparison was made between these patients and the remainder of the population with melanoma seen at our institution using contingency table analysis with statistical significance determined by a chi-squared test. Survival data were represented by Kaplan-Meier curves, and log-rank testing was used for statistical comparisons. RESULTS: Risk factors associated with the development of these metastases included primary lesions that were ulcerated, deeper than 0.76 mm, or of Clark level II, or located on the trunk or mucosal surfaces. The median survival time for all patients was 86 days, but this was reduced in patients with more than one metastatic site in addition to the spine. CONCLUSION: The prognosis for most patients with spinal metastases from melanoma is dismal. However, patients with metastatic disease limited to the spine and one other organ may survive for a relatively prolonged time and may be candidates for surgical intervention directed toward symptomatic relief.

Adult↗

Glomus jugulare tumor metastatic to the sacrum after high-dose radiation therapy: case report.

A 47-year-old woman with left ear pain and hearing loss was diagnosed with a glomus jugulare tumor for which she received radiation therapy as the primary treatment. Over a period of 20 years, she developed temporal bone necrosis, brain stem calcifications, local tumor recurrence, and eventually metastases to her lungs and sacrum. This case underscores the often indolent nature of glomus jugulare tumors, the late sequelae of radiation therapy for benign intracranial tumors, and the potential of these tumors to metastasize. This patient's history suggests that aggressive surgical resection should be considered early for such tumors, particularly because radiation treatment does not ablate the tumor. This is only the second reported case of a glomus jugulare tumor metastatic to the sacrum.

Aged↗

Dorsal root entry zone lesions for intractable pain after trauma to the conus medullaris and cauda equina.

This review was undertaken to determine the efficacy of using dorsal root entry zone (DREZ) lesions to treat intractable pain caused by trauma to the conus medullaris and cauda equina. Traumatic lesions of this area are unique in that both the spinal cord and the peripheral nerve roots are injured. Although DREZ lesions have been shown to relieve pain of spinal cord origin in many patients, they have been shown not to relieve pain of peripheral nerve origin. Therefore, 39 patients with trauma to the conus medullaris and cauda equina who underwent DREZ lesioning for intractable pain were reviewed retrospectively. The results of this review demonstrate the efficacy of DREZ lesions in these patients. At a mean follow-up period of 3.0 years, 54% of patients were pain-free without medications, and 20% required only nonnarcotic analgesic drugs for pain that no longer interfered with their daily activities. Better outcomes were noted in patients with an incomplete neurological deficit, with pain having an "electrical" character, and with injuries due to blunt trauma. Operative complications included weakness (four patients), bladder or sexual dysfunction (three), cerebrospinal fluid leak (two), and wound infection (two), but overall, 79.5% of patients (31 of 39) were without serious complications. Complications were limited to patients with prior tissue damage at the surgical exploration site and were most prevalent in patients who underwent bilateral DREZ lesions. In conclusion, this preliminary report suggests that DREZ lesions may be useful in combating intractable pain from traumatic injuries to the conus medullaris and cauda equina, with some risk to neurological function that may be acceptable in this group of patients.

Adult↗

On being poor with HIV.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗

Oral atovaquone compared with intravenous pentamidine for Pneumocystis carinii pneumonia in patients with AIDS. Atovaquone Study Group.

OBJECTIVE: To test the hypothesis that the therapeutic success rate of oral atovaquone is not worse than that of intravenous pentamidine in the primary treatment of mild and moderate Pneumocystis carinii pneumonia in patients with the acquired immunodeficiency syndrome and to detect differences in the toxicity rates of the two treatments. DESIGN: Patients were randomly assigned to receive 21 days of open-label therapy with either atovaquone, 750 mg orally with meals three times daily, or intravenous pentamidine, 3 to 4 mg per kg body weight once daily. SETTING: Multicenter study including university and community treatment facilities. PATIENTS: Patients with human immunodeficiency virus infection and clinical presentations consistent with mild or moderate P. carinii pneumonia were eligible. For efficacy and safety analyses, patients with histologically confirmed P. carinii pneumonia were emphasized. MEASUREMENTS: Patients were monitored by clinical and laboratory evaluations for therapeutic efficacy and adverse events during the acute treatment phase and for 8 weeks after therapy was discontinued. RESULTS: As initial therapy for a histologically confirmed episode of P. carinii pneumonia, 56 patients received atovaquone and 53 received pentamidine. More patients were successfully treated with atovaquone (57%) than with pentamidine (40%), a difference of 17% (95% CI, -3% to 38%; P = 0.085), but more patients failed to respond to atovaquone (29%) than to pentamidine (17%), a difference of 12% (CI, -6% to 29%; P = 0.18). Discontinuation of original therapy because of treatment-limiting adverse events was more frequent in the pentamidine group (36%) than in the atovaquone group (4%) (difference, -32%; CI, -48% to -17%; P < 0.001). Nine patients in each treatment group died during the study. CONCLUSIONS: Oral atovaquone and intravenous pentamidine have similar rates for successful treatment of mild and moderate P. carinii pneumonia, but atovaquone has significantly fewer treatment-limiting adverse events.

AIDS-Related Opportunistic Infections↗

The gravitational shunt: an alternative approach to cerebrospinal fluid shunting.

Current cerebrospinal fluid shunts use complex differential pressure values to regulate drainage. Such systems are prone to overdrainage and obstruction, and thus have an unpredictable effect on intracranial pressure (ICP). The gravitational shunt (GS) introduces an alternative approach. It uses a single, simple valve to balance the pressures generated within a vertical shunt system. The ICP is then regulated by the position of the valve along the cranioabdominal shunt axis and not by the mechanical properties of the valve. Bench testing demonstrated that when using the GS (1) a linear correlation (r = 0.91, p < 0.001) exists between the ICP and the position of the valve along the vertical shunt axis, (2) positive and negative ICPs are maintained, and (3) the ICP can be predicted by an equation derived from theoretical principles. The GS uses a single, simple valve as a pressure regulator and an antisiphon device. It allows the maintenance of a normal negative ICP in the upright position without risk of over-drainage. The other benefits of this system are discussed.

Cerebrospinal Fluid Shunts↗

Solitary eosinophilic granuloma invading the clivus of an adult: case report.

A 41-year-old white man with facial pain and diplopia was found to have an invasive lesion of the clivus. The final pathological diagnosis was eosinophilic granuloma. The patient's symptoms resolved completely after transsphenoidal resection of the lesion. The pathological and radiological diagnosis and the treatment of solitary eosinophilic granulomas are discussed.

Adult↗

Initial management of pediatric head trauma.

Head injuries are the most common cause of disability and death in children. Identification of children who require specialized management following a head injury will reduce the associated morbidity and mortality. Thus, it is important to differentiate the child who can be safely observed and who will recover spontaneously from the child who will develop a progressive neurologic deficit from a treatable cause. A thorough history, a tailored neurologic examination and limited radiographic studies will assist the family physician in making this determination.

Adolescent↗

Physician house call services for medically needy, inner-city residents.

To increase access to services, a non-profit, voluntary health agency was developed to provide on-site services to residents of hotels and night shelters in the Skid Road area of Portland, Oregon. From a hotel-based clinic site, volunteer physicians, nurses, and medical students make house calls. During the first 18 months, 1,184 evaluations were made, and 21 hotels and two shelters visited. Volunteers were well accepted by residents and served as members of case management teams. The additional benefits of such a program vis-a-vis extension of local government's mission and student education are discussed.

Adult↗

Pregnancy rates in patients treated for antisperm antibodies with prednisone.

Circulating antisperm antibodies are associated with decreased fertility in both men and women. Several recent reports suggest that corticosteroids suppress antibody levels and thus enhance fertility in such patients. Prednisone was given to 24 patients; 26 patients with antibodies were not so treated and served as controls. The treated group comprised five women and 19 men; the control group comprised one woman and 25 men who had equivalent levels of circulating antibodies. The drug, when given to men, did not cause changes in sperm count, motility, or normal forms, but it did cause significant reductions in levels of circulating immobilizing (P less than or equal to 0.039) and agglutinating (P less than or equal to 0.001) antisperm antibodies in both sexes. Fourteen pregnancies occurred during the 4-month posttreatment study period. Significantly more pregnancies occurred in the treated group than in the control group (11 treated patients [45%] and three controls [12%]; P less than or equal to 0.025). Of the five treated women, four conceived.

Antibodies↗

Gender after artificial induction of ovulation and artificial insemination.

Several studies on artificial insemination by donor (AID) semen have suggested that the gender of infants can be influenced by treatment of the women with clomiphene citrate (CC) and by the type of semen used (fresh versus cryopreserved). We conducted a 3-year prospective clinical trial to test these hypotheses. Two groups of pregnant women were evaluated. Group I (n = 130) comprised women whose ovulation was induced by CC; group II (n = 190) comprised those who conceived during spontaneous ovulatory cycles. In a total of 320 pregnancies, 55 spontaneous abortions occurred, 23.1% in group I and 13.2% in group II (P less than or equal to 0.05). Two tubal ectopic pregnancies occurred in group I. Of the 100 and 165 pregnancies carried to term in the treated and control groups, respectively, 11% and 1.8% involved twins (P less than or equal to 0.005). When only single births were considered, group I had 46.1% males in 89 term pregnancies, and group II had 60.5% males in 162 term pregnancies. Significantly more female offspring occurred in the group treated with CC (P less than or equal to 0.05). Because it is possible that a portion of the effects observed in this study were a function of cryopreservation of the AID semen, we compared data on frozen sperm with data on fresh sperm in terms of abortion, gender, and incidence of multiple births; there were no significant differences. Fertil Steril 40:481, 1983.

Clomiphene↗

Competitive trail and endurance riding in the UK.

A description is given of trail and endurance riding in the UK as controlled by the Endurance Horse and Pony Society. Veterinary involvement and responsibility are described and measures for their satisfactory execution discussed. Opportunities and need for research into the problems arising are mentioned.

Animals↗