The immunosuppressive effects of the halogenated aromatic hydrocarbons (HAHs), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 2,3,4,7,8-pentachlorodibenzofuran (PeCDF), 2,3,7,8-tetrachlorodibenzofuran (TCDF), 1,2,3,7,9-PeCDF and 1,3,6,8-TCDF were investigated utilizing the Mishell-Dutton model for in vitro immunization. The selected polychlorinated dibenzofuran congeners and 2,3,7,8-TCDD caused a concentration-dependent suppression of the splenic plaque-forming cell response to sheep red blood cells using cell cultures derived from C57BL/6 (Ah responsive) mice. Previous studies showed that there was up to a 14,900-fold difference in the in vivo immunotoxicity of these compounds, however in the in vitro studies, their immunosuppressive potencies were comparable. In addition, these congeners also exhibited similar potencies using spleen cell cultures from DBA/2 (Ah-nonresponsive) mice. Previous research demonstrated that alpha-naphthoflavone was relatively inactive in the in vitro splenic assay system and that co-treatment of cells from C57BL/6 mice with alpha-naphthoflavone (10 microM) plus 2,3,7,8-TCDD (20 mM) resulted in a significant inhibition of the immunotoxicity of 2,3,7,8-TCDD. In these studies, comparable interactive effects were also observed in cells treated with alpha-naphthoflavone plus 1,3,6,8-TCDF, a weak in vivo Ah receptor agonist. Collectively, the results from this study suggest that there may be mechanism(s) of action for HAH-induced suppression of the in vitro murine humoral response to sheep red blood cells which are independent of the Ah receptor protein.

Animals↗

PubMedDate not supplied

Endoscopic variceal ligation: an alternative to sclerotherapy.

Endoscopic variceal ligation (EVL) consists of mechanical ligation and thrombosis of varices using elastic "O" rings. This study assessed the efficacy and safety of EVL as definitive therapy for bleeding esophageal varices. During a 16-month period, 68 consecutive patients with bleeding varices had EVL. Fourteen patients died from 3 to 125 (median = 12.5) days after initial EVL. Fifteen (88%) of those actively bleeding at index treatment had bleeding controlled during index hospitalization. Survivors of index hospitalization had a 37% incidence of recurrent bleeding. Thirty-five patients had varices eradicated or reduced to small size with a median of five EVL treatments. No significant treatment-related nonbleeding complications resulted from 265 EVL sessions. EVL appears to control active variceal bleeding and eradicates varices with repeat treatments. EVL results in few nonbleeding complications, and may be employed as a safe alternative to sclerotherapy.

Adolescent↗

PubMedDate not supplied

Toxic shock syndrome: case report of a postpartum female and a literature review.

Toxic shock syndrome is one of the best understood of the systemic inflammatory response syndromes. The mechanisms of disease have been extensively studied; however, no therapies have been developed that can effectively reverse the syndrome once the inflammatory response has begun. Although toxic shock syndrome classically has been associated with tampon use, multiple other etiologies exist including postpartum toxic shock, which usually affects patients in the immediate weeks following delivery. We present a case of toxic shock in a woman 10 weeks postpartum and review the literature regarding both menstrual-related and nonmenstrual-related toxic shock.

Adult↗

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Hypothermic blood substitution enables resuscitation after hemorrhagic shock and 2 hours of cardiac arrest.

Uncontrollable hemorrhage accounts for a large proportion of total mortality in both civilian (31%) and military (47%) trauma victims. Hypothermia is a relatively safe method that could provide total body protection during hypovolemic shock and facilitate surgical intervention as a potentially life-saving procedure. This study tested the hypothesis that profound hypothermia and complete blood replacement in an established canine model, would facilitate resuscitative therapy from exsanguinating hypovolemic shock. Adult dogs were prepared for extracorporeal bypass using closed-chest peripheral cannulation under general anesthesia. Controlled hypotensive, hemorrhagic shock (mean arterial blood pressure < 50 mmHg) was induced for 30 min at normal temperature followed by temporary resuscitation using crystalloid infusion for approximately 10 min. Using our established procedure, the dogs were then cooled externally to 27 degrees C before initiating blood substitution with Hypothermosol (Cryomedical Sciences, Inc. Rockville, MD) via the extracorporeal pump. The heart was arrested during further cooling to below 10 degrees C and Hypothermosol was recirculated for 2 hr, with (3 dogs) or without (5 dogs) 1 hr of circulatory arrest. During rewarming the animals were autotransfused, weaned from the pump, and allowed to recover. All dogs (n = 8) survived, all but one with complete neurologic recovery: blood chemistry samples examined immediately after the procedure showed significant differences (p < 0.05) in only a few parameters, including creatine kinase (CK-BB and CK-MB), compared with the previous group of control dogs. The consistent survival of dogs showing apparently normal neurologic, physiologic, and biochemical recovery supports the concept that profound hypothermia using a protective hypothermic blood substitute could provide time for therapeutic resuscitation of currently intractable trauma cases.

Animals↗

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Effect of malnutrition at the time of diagnosis on the survival of children treated for cancer in El Salvador and Northern Brazil.

PURPOSE: To investigate the relationship between survival and malnutrition at the time of diagnosis among children treated for cancer in two developing countries. PATIENTS AND METHODS: We studied 443 children treated for cancer between 1995 and 1998 at two centers in San Salvador, El Salvador, and Recife, Brazil. Median age at diagnosis was 4.9 years; 283 children had leukemia and 160 had solid tumors. Z-scores were calculated for weight for age (WAZ), height for age (HAZ), and weight for height (WHZ) at diagnosis. Z scores <-2 indicated malnutrition. Patients were also stratified by low-risk disease (solid tumors: stage I, stage II, or localized; acute lymphocytic leukemia: white blood cell count <25,000/microL, no central nervous system involvement, no mediastinal mass and age >1 and <10 yrs) and high-risk disease (all other patients, including those with acute or chronic myelocytic leukemia). RESULTS: Z-scores indicated malnutrition in 23.5% (WAZ), 22.8% (HAZ), and 15.7% (WHZ) of patients. Z-score was not significantly related to overall survival rates, to survival rates analyzed by type of malignancy or risk status, or to survival rates at the end of the first month of treatment. CONCLUSIONS: We found no relationship between nutritional status and survival in these patients. This implies that future protocols for use in developing countries can be designed to provide optimal treatment intensity despite the high incidence of malnutrition.

Brazil↗

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The role of type-1 and type-2 T-helper immune responses in HIV-1 vaccine protection.

The dichotomy of type-1 and type-2 T-helper (Th) immune responses is thought to be an obstacle to develop Human immunodeficiency virus-type- (HIV-1) vaccines capable of inducing effective cellular as well as humoral immune responses. Macaca mulatta were immunized using two different HIV-1sf2 envelope vaccine strategies, based on either immune-stimulating complexes (ISCOM) or chimeric Fowlpox (FP) vaccines. One month following the third immunization all animals were heterologously challenged with simian/human immunodeficiency virus (SHIVsf13). Vaccinated monkeys, which were protected had the highest levels of both type-1 and type-2 HIV-1 specific T-helper cell (Th) responses in addition to the highest homologous and heterogenous virus neutralizing antibodies. To determine how long Th responses persisted and if they correlated with protection, animals were rechallenged after waiting for four months without re-boosting. Macaques which maintained the highest gp120-specific type-1 (IFN-gamma) responses were protected, while there was evidence of viral clearance in two others. These findings demonstrate the importance of both or mixed type-1 and type-2 Th responses in HIV-1 vaccine induced immunity while suggesting a possible role of persistent type-1 responses in maintaining protective immunity over time.

AIDS Vaccines↗

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Efforts to broaden HIV-1-specific immunity by boosting with heterologous peptides or envelope protein and the influence of prior exposure to virus.

In two previous studies, we have demonstrated the successful protection of human immunodeficiency virus type 1 (HIV-1)-vaccinated rhesus macaques from challenge with SHIV(SF13) with envelop immunogens derived from the closely related HIV-1(SF2) strain. Here we report on two follow-up studies in which we aimed to broaden immunity in order to elicit protection from a more diverse heterologous challenge with SHIV(SF33). In the first study, animals were boosted once with HIV-1(SF33) V2 and V3 peptides that were cross-linked to influenza immune-stimulating complexes (ISCOMs). In the second study, monkeys were boosted twice at 12-week intervals, using a heterologous recombinant gp120 derived from HIV-1(SF33) that was either incorporated into ISCOMs or mixed with the MF59 adjuvant. In both studies, the animals were challenged with 50 monkey infectious doses of SHIV(SF33) 4 weeks after the final boost. All controls became readily infected with the heterologous challenge virus SHIV(SF33). Neither boosting with heterologous SF33 peptides or gp120 afforded protection from infection to SF2-vaccinated animals that had previously resisted SHIV(SF13) challenge. These results demonstrate the importance of developing vaccine strategies that are capable of generating broad immune responses early in the immunization protocol. Furthermore, these findings may illustrate the potential pitfalls of early antigenic sin.

AIDS Vaccines↗

PubMedDate not supplied

Plasma norepinephrine in the evaluation of baroreceptor function in humans.

The value of plasma norepinephrine measurement in assessing baroreceptor-mediated changes in sympathetic vasomotor activity was studied in seven healthy normotensive volunteers. Blood pressure was decreased by graded steady-state infusions of sodium nitroprusside (25-100 micrograms/min) and increased by infusions of phenylephrine (25-100 micrograms/min) at rates producing a 10% to 20% change in diastolic blood pressure. Sodium nitroprusside produced significant decreases in diastolic blood pressure (p less than 0.01) and calculated mean arterial blood pressure (p less than 0.005), and increases in heart rate (p less than 0.001) and plasma norepinephrine (p less than 0.001). Phenylephrine administration produced increases in systolic (p less than 0.005), diastolic (p less than 0.005), and mean blood pressure (p less than 0.001). Heart rate (p less than 0.001) and plasma norepinephrine (p less than 0.05) fell. The absolute changes in diastolic and mean pressure and heart rate were not significantly different for the two drugs, but were of opposite sign; however, the increase in plasma norepinephrine during hypotension was greater than the decrease during hypertension (p = 0.02). We conclude that plasma norepinephrine changes appropriately in response to altered blood pressure and that the response is greater to a given fall than to a rise in blood pressure, consistent with known changes in sympathetic vasomotor outflow.

Adult↗

PubMedDate not supplied

A measure of preference for speaking rather than writing and its relationship to expressive language skills in adolescents.

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Adolescent↗

PubMedDate not supplied

Subclavian arterial injury associated with blunt trauma.

Blunt subclavian artery trauma is an uncommon but challenging surgical problem. The purpose of this study was to retrospectively review the management of blunt subclavian artery injuries treated by the Trauma and Vascular Surgery Services at the East Tennessee State University-affiliated hospitals between 1992 and 1998. Six patients with seven blunt subclavian artery injuries were identified. Physical signs indicating blunt subclavian artery injury were pain or contusion around the shoulder joint; fractures of the clavicle, scapula, or ribs; periclavicular hematomas; and ipsilateral pulse or neurologic deficits. Seven subclavian artery injuries were treated-two arterial transections, two pseudoaneurysms, and three intimal dissections. Associated injuries included four clavicle fractures, one humerus fracture, one combined rib and scapular fractures, and two pneumothoraxes. Vascular surgical treatment included three primary arterial repairs, two saphenous vein interposition grafts, and one polytetrafluoroethylene (PTFE) graft. One patient was treated nonoperatively with anticoagulation. No deaths occurred. Morbidity occurred in two patients with chronic upper extremity neuropathy producing prolonged disability from pain and weakness; one patient had reflex sympathetic dystrophy, and the other had a brachial plexus injury. In conclusion, blunt subclavian artery trauma can be successfully managed with early use of arteriography and prompt surgical correction by a variety of vascular techniques. Vascular morbidity is usually low, but long-term disability because of chronic neuropathy may result from associated brachial plexus nerve injury despite a successful arterial repair.

Accidents, Traffic↗

PubMedDate not supplied

The technical challenge of cruciate ligament reconstruction.

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Anterior Cruciate Ligament↗

PubMedDate not supplied

Analytical performance characteristics of the T4 method in the Abbott AxSYM immunoassay analyzer.

OBJECTIVE: To evaluate the tetraiodothyronine (T4) method in the Abbott AxSYM immunoassay analyzer. DESIGN: The single-value criteria proposed by Westgard et al. were employed. Assays of control materials established random error (RE) analytical sensitivity, and linearity. Constant error (CE) was established by studying the effects of interferents on T4 quantification. The AxSYM random access immunoassay analyzer was compared with TDx batch analyzer to determine systematic error (SE). Critical concentrations of T4 are 3.0 micrograms/dL and 13.0 micrograms/dL, as these concentrations represent medical decision points. Allowable error at these critical concentrations are 1.0 and 2.6, respectively. SETTING: Peninsula Regional Medical Center Clinical Laboratories. RESULTS: Based on Health Care Financing Administration [HCFA] allowable error goals, RE, SE, and CE were acceptable for concentrations of T4 ranging from 3.0 micrograms/dL to 13 micrograms/dL. PE was virtually absent. Total error (TE) = RE + SE was acceptable at 13 micrograms/dL but exceeded allowable error at the lower critical value of 3.0 micrograms/dL. Abbott AxSYM was sensitive to T4 at a concentration of 0.34 microgram/dL. Linearity was excellent and consistent with the manufacturer's claim over a range 1.0 microgram/dL to 24 micrograms/dL. Of the interferents studied only hemoglobin caused a > 15% change in the measurement of T4. CONCLUSION: The AxSYM immunoasssay analyzer performed to manufacturer's specifications and met HCFA allowable error limits for quantifying T4.

Bias↗