Preparation, characterization, and applications of polyacrylonitrile/ball clay nanocomposite synthesized by gamma radiation

Elimination of hazardous metals is of extreme worry for their toxicity at trace levels and accumulation in the biosystem. Polyacrylonitrile ball clay nanocomposite was prepared by gamma irradiation at 20 kGy. Different analytical tools were applied to prove morphology, functional groups, and chemical structure for prepared composite; SEM, TEM, IR, XRD, and XRF. From TEM and XRD data expose the studied composite has nanoscale and crystalline. The adsorption of Cs⁺, Co²⁺ and Fe³⁺ onto studied material took place after 24 h. Second order was preceded by the kinetic system. The capacity and effect of pH on k_d reflect selectivity sequence; Co²⁺  > Fe³⁺  >  > Cs⁺. Both Freundlich and Langmuir are applicable for investigated material. Finally, PAN/BC nanocomposite is suitable for the column technique.

Ramucirumab With Eribulin Versus Eribulin in Locally Recurrent or Metastatic Breast Cancer Previously Treated With Anthracycline and Taxane Therapy: A Multicenter, Randomized, Phase II Study

BACKGROUND

Use of antiangiogenic agents in treatment of metastatic breast cancer (MBC) remains controversial. We evaluated the efficacy and safety of ramucirumab and eribulin versus eribulin alone as third- to fifth-line therapy in women with advanced breast cancer.

PATIENTS AND METHODS

In this randomized (1:1), open-label, phase II study, US women aged 18 years or older with 2 to 4 previous chemotherapy regimens for locally recurrent or MBC, previous anthracycline and taxane treatment, and Eastern Cooperative Oncology Group performance status of 0 or 1 received ramucirumab with eribulin or eribulin alone in 21-day cycles (eribulin 1.4 mg/m2 intravenously on days 1 and 8; ramucirumab 10 mg/kg intravenously on day 1). Randomization was stratified according to previous antiangiogenic therapy and triple-negative status. The primary end point was progression-free survival (PFS) in the intention to treat population.

RESULTS

One hundred forty-one women were randomized to ramucirumab with eribulin (n = 71) or eribulin alone (n = 70). Median PFS for ramucirumab with eribulin was 4.4 months (95% confidence interval [CI], 3.1-6.7) compared with 4.1 months (95% CI, 3.2-5.6) for eribulin (hazard ratio [HR], 0.83; 95% CI, 0.56-1.23; P = .35). Median overall survival in patients who received ramucirumab with eribulin was 13.5 months (95% CI, 10.4-17.9) compared with 11.5 months (95% CI, 9.0-17.3) in patients who received eribulin alone (HR, 0.91; 95% CI, 0.59-1.41; P = .68); objective response rate was 21% (13 of 62 patients) for the combination and 28% (17 of 60 patients) for eribulin alone. No unexpected toxicity was identified for the combination.

CONCLUSION

Ramucirumab combined with eribulin did not significantly improve PFS in advanced MBC.

Intranasal haloperidol-loaded miniemulsions for brain targeting: Evaluation of locomotor suppression and in-vivo biodistribution

Haloperidol is a commonly prescribed antipsychotic drug currently administered as oral and injectable preparations. This study aimed to prepare haloperidol intranasal miniemulsion helpful for psychiatric emergencies and exhibiting lower systemic exposure and side effects associated with non-target site delivery. Haloperidol miniemulsions were successfully prepared by spontaneous emulsification adopting 2(3) factorial design. The effect of three independent variables at two levels each namely; oil type (Capmul®-Capryol™90), lipophilic emulsifier type (Span 20-Span 80) and HLB value (12-14) on globule size, PDI and percent locomotor activity inhibition in mice was evaluated. The optimized formula (F4, Capmul®, Tween 80/Span 20, HLB 14) showed globule size of 209.5±0.98nm, PDI of 0.402±0.03 and locomotor inhibition of 83.89±9.15% with desirability of 0.907. Biodistribution study following intranasal and intravenous administration of the radiolabeled (99m)Tc mucoadhesive F4 revealed that intranasal administration achieved 1.72-fold higher and 6 times faster peak brain levels compared with intravenous administration. Drug targeting efficiency percent and brain/blood exposure ratios remained above 100% and 1 respectively after intranasal instillation compared to a maximum brain/blood exposure ratio of 0.8 post intravenous route. Results suggested the CNS delivery of major fraction of haloperidol via direct transnasal to brain pathway that can be a promising alternative to oral and parenteral routes in chronic and acute situations. Haloperidol concentration of 275.6ng/g brain 8h post intranasal instillation, higher than therapeutic concentration range of haloperidol (0.8 to 5.15ng/ml), suggests possible sustained delivery of the drug through nasal route.

Modulatory effects of l-carnitine on tamoxifen toxicity and oncolytic activity

The aim of this study was to investigate the protective effect of l-carnitine (l-CAR) in tamoxifen (TAM)-induced toxicity and antitumor activity. Adult female rats were randomly divided into four groups. Group I was served as control, groups II and III were treated with TAM (10 mg/kg, periorally) and l-CAR (300 mg/kg, intraperitoneally), respectively, while group IV was treated with both compounds. The treatment continued daily for 28 days. Administration of TAM resulted in significant increase in serum lipid profiles, liver enzymes, and bilirubin level. TAM produced a significant increase in lipid peroxides (LPO) level and nonsignificant change in nitrogen oxide (NO( x)) level accompanied with significant decrease in superoxide dismutase (SOD) activity of hepatic and uterus tissues and significant decrease in glutathione (GSH) content of uterus tissue. Administration of l-CAR for 1 h prior to TAM treatment decreased serum lipids and liver enzymes significantly and significantly increased SOD activity in liver and uterus tissues compared with TAM-treated group. Furthermore, it restored LPO and GSH levels and increased NO( x) level in uterus tissue. DNA fragmentation and the apoptotic marker, caspase-3, were not detected in the liver of all treated groups. Histopathologically, alterations in the liver and uterus structures after TAM treatment, which was attenuated after l-CAR administration. The antitumor effect and survival of the combined treatment of Ehrlich ascites carcinoma (EAC)-bearing mice was less than each one alone. l-CAR interestingly increased survival rate of EAC-bearing mice more than TAM-treated group. In conclusion, l-CAR has beneficial effects regarding TAM toxicity; however, it interferes with its antitumor effect.

Interim safety results of eribulin (E) combined with ramucirumab (RAM) in patients (pts) with advanced metastatic breast cancer (MBC)

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Background: VEGF-mediated angiogenesis contributes to breast cancer (BC) pathogenesis. RAM (IMC-1121B), a fully human IgG1 monoclonal antibody (MAb), targets VEGFR-2, blocking the interaction of VEGF ligands and VEGFR‑2. DC101 (murine anti-VEGFR-2 MAb) impairs vascular function and increases tumor hypoxia in xenograft BC models and inhibits tumor growth in cytotoxic-resistant models. E is a novel non-taxane microtubule inhibitor indicated in MBC pts who have received ≥2 prior chemotherapy regimens, including an anthracycline and a taxane. It is hypothesized that addition of RAM to E as 3rd-5th line therapy in MBC will result in an improvement of median PFS in this ongoing, multicenter, US study. A planned safety analysis of an initial cohort is reported. Methods: Pts with locally recurrent or MBC (HER2+ or HER2-) and 2-4 prior chemotherapy regimens are randomized 1:1 to receive RAM+E or E (E 1.4 mg/m2 Days 1, 8; RAM 10 mg/kg Day 1; q21 days). Pts are stratified by TNBC and prior antiangiogenic therapy status and must have ECOG PS 0-1 and normal LVEF. Planned accrual: 134 pts. Results: Evaluable pts (n=13, 8 RAM+E) received ≥1 dose of RAM+E or E and completed 2 cycles of therapy (or discontinued prior to completing the initial 2 cycles). Median age is 55 yrs. Assessment of adverse events (all cause) revealed nausea, fatigue, headache, and neutropenia were more frequent for RAM+E; anemia was more frequent for E. G1 sensory neuropathy was reported for 1 pt in each arm. One RAM+E pt experienced G3 febrile neutropenia and odynophagia, recovered within a week, and subsequently received reduced dosage (E = 1.1 mg/m2; RAM = 8 mg/kg). No deaths are reported. The safety assessment committee recommended to continue the trial unmodified. Conclusions: Based on preliminary data, the combination of RAM+E demonstrates an acceptable toxicity profile. Accrual continues, with planned updated safety and dose intensity data to be presented at the meeting. [Table: see text]

Pretransplant variables associated with quality of life in liver transplant recipients

OBJECTIVE

With an increasing number of liver transplant recipients living, understanding quality-of-life issues is essential. Our goal is to identify pretransplant variables associated with post-transplant quality of life in liver transplant recipients.

METHODS

Three hundred and eight liver transplant recipients were administered the Short Form 36 and a basic demographical questionnaire. Variables associated with post-transplant quality of life were studied in a multivariate regression analysis. Interaction terms were used to examine effect modification.

RESULTS

Male gender, longer pretransplant work hours and interaction term between work hours and male gender were independently associated with Physical Functioning. Work hours positively correlated with Role-Physical, while viral hepatitis and ascites were negatively associated with Role-Physical. Ascites and viral hepatitis were independently negatively associated with Bodily Pain. Encephalopathy, hepatocellular carcinoma and viral hepatitis were independently associated with General Health. Ascites was also negatively associated with Social Functioning, Role-Emotional, Bodily Pain, General Health and Vitality. Viral hepatitis was negatively correlated with Vitality and Mental Functioning.

CONCLUSIONS

Pretransplant variables such as ascites, encephalopathy, hepatocellular carcinoma, viral hepatitis, work hours, time unable to work and gender were significantly associated with post-transplant quality of life in liver transplant recipients. Interventions addressing these issues may be initiated to improve the post-transplant quality of life.

Employment and quality of life in liver transplant recipients

The purposes of liver transplantation (LT) include the extension of survival, improvement in quality of life, and the return of the recipient as a contributing member of society. Employment is one measure of the ability to return to society. The aim of this study is to determine the factors affecting employment/subemployment after LT. A total of 308 adult liver transplant recipients who were seen at the University of California, Los Angeles were administered the Medical Outcomes Short Form 36 (SF-36) and a questionnaire regarding work history and insurance coverage. Multivariate analysis were used to identify independent variables associated with posttransplantation employment. Interaction terms were used to examine effect modification. Of 308 transplant recipients, 218 (70.8%) worked prior to transplantation, and 78 (27%) worked posttransplantation. Pretransplant variables that were independently associated with posttransplantation employment included the following: lack of disability income (odds ratio [OR] = 1.86; 95% confidence interval [CI], 1.32-7.18; P = 0.36); health maintenance organization (HMO)/preferred provider organization (PPO) insurance (OR = 3.08; 95% CI, 1.32-7.18; P < 0.01); the number of hours worked (OR = 1.17; 95% CI, 1.08-1.28; P < 0.01); and the lack of diabetes mellitus (OR = 0.23; 95% CI, 0.70-0.73; P < 0.01). An interaction term between disability income and hours worked prior to transplantation (OR = 0.16; 95 % CI, 0.03-0.83; P = 0.03) was independently associated with posttransplantation employment. In a separate regression model of SF-36 responses, posttransplantation physical functioning (OR = 1.17; 95% CI, 1.10-1.26; P < 0.01) and role-physical (OR = 1.1; 95% CI, 1.02-1.16; P < 0.01) were independently associated with employment after transplantation. In conclusion, HMO or PPO insurance, lack of disability income coverage prior to transplant, the absence of diabetes mellitus, the number of hours worked prior to transplantation, and high physical functioning were associated with posttransplantation employment.

Anemia in liver transplant recipients undergoing antiviral treatment for recurrent hepatitis C

Adherence to antiviral therapy is essential to achieve sustained virological responses in patients treated for hepatitis C. An important limitation to use of appropriate doses of ribavirin is development of anemia. The aim of this study is to identify risk factors associated with anemia in liver transplant recipients undergoing treatment for recurrent hepatitis C virus (HCV). Retrospective analysis was performed on 115 adult liver transplantation (LT) recipients who received antiviral treatment. Anemia was defined as hemoglobin of <10 gm/dL or the use of erythropoietin replacement therapy. Variables found to be significant in univariate analysis were further studied in multivariate analysis. The mean (+/- standard deviation [SD]) age of our cohort was 52.1 (+/- 8.8) yr. Anemia developed in 44 patients (38.3%). Mean (+/- SD) onset of anemia was 8.9 (+/- 6.8) weeks after initiation of antiviral therapy. A total of 30 patients (26%) required erythropoietin replacement, at a mean (+/- SD) of 7.9 (+/- 6.0) weeks after start of antiviral treatment. A total of 27 patients (24%) required ribavirin dose reduction, at a mean (+/- SD) time to dose reduction of 8.1 (+/- 6.3) weeks. In univariate analysis, body mass index (BMI) (P < 0.01), mycophenolate mofetil use (P = 0.05), trimethoprim-sulfamethoxazole (P = 0.02), and age (P = 0.02) were statistically significant. In conclusion, in multivariate analysis, BMI (P < 0.01) and age (P = 0.02) were found to be independent predictors of anemia. Anemia is common in liver transplant recipients treated for recurrent HCV. Special vigilance is required for older patients and patients with a low BMI.

The MELD score in advanced liver disease: association with clinical portal hypertension and mortality

BACKGROUND

The Model for End-Stage Liver Disease (MELD) score is a measure of chronic liver disease severity. Patients awaiting transplantation are assessed using this score. However, it has recently been suggested that changes in MELD score may be as important as the absolute MELD score in predicting short-term survival. However, clinical factors that affect the MELD score are unknown. We sought to identify predictors of mortality for potential transplant patients and examine factors that might predict changes in MELD score.

MATERIALS AND METHODS

Between January 1, 2002, and July 30, 2004, we retrospectively examined risk factors of 429 adult patients awaiting liver transplantation at the University of California at Los Angeles (UCLA). Analysis of the data was performed using demographics, manifestations of portal hypertension, time between last MELD recorded and event, and laboratory values. Significant factors in univariate analysis were further studied using Cox proportional hazards regression multivariate analysis.

RESULTS

At mean follow-up of 2.15 years (+/-1.49 years), 71 patients (16.5%) had MELD scores that increased 5-10 points, 22 had changes of 10-15 points, and 14 had changes of 15-20 points. Manifestations of portal hypertension, laboratory values, and etiology of liver disease did not predict changes in MELD score. However, development of hepatic encephalopathy (HR, 3.95; P=.002; 95% CI, 1.70 to 9.42) and MELD score (HR, 1.04; P=.001; 95% CI, 1.004 to 1.08) were associated with variceal bleeding. Also, MELD score (HR, 1.07; P<.001; 95% CI, 1.05 to 1.09), refractory ascites (HR, 2.15; P=.002; 95% CI, 1.31 to 3.53), and alcoholic cirrhosis (HR, 0.40; P=.04; 95% CI, 0.18 to 0.94) were independent predictors of mortality.

CONCLUSIONS

Encephalopathy and MELD score were associated with variceal bleeding. Patients with an elevated MELD score, refractory ascites, and alcoholic cirrhosis had increased mortality while on the liver transplant list. No factors predicting changes in the MELD score were identified.

Same day outpatient transjugular liver biopsies in haemophilia

Patients with haemophilia are at increased risk of hepatitis C infection because of prior transfusion of blood products. Virtually all haemophiliacs who received pooled blood products before the mid-1980s have been infected with hepatitis C. A liver biopsy is important to identify the extent of liver disease, and to help determine the necessity of interferon therapy. With factor replacement, in-hospital liver biopsy is safe. Thirty patients with haemophilia were evaluated for chronic hepatitis C infection. Eleven patients subsequently underwent successful transjugular liver biopsy in the outpatient setting after appropriate factor replacement. Mean +/- SD pre- and posthaemoglobin values were 15.8 +/- 0.79 and 14.4 +/- 0.71 g dL(-1) (P = ns). There was no significant change in heart rate, systolic or diastolic blood pressure during the monitoring period (P = ns) and no major complication was noted in perioperative follow-up. The mean length of the liver biopsy specimens was 1.7 +/- 0.3 cm, mean grade was 2 +/- 0.6 and mean stage was 2.3 +/- 1.2. Our experience demonstrates that outpatient transjugular liver biopsy can be safely performed in patients with haemophilia in the outpatient setting, avoiding the cost and need for hospital admission.

MELD fails to measure quality of life in liver transplant candidates

Previous studies have demonstrated an association between Child Turcotte-Pugh (CTP) class and impaired quality of life. However, the relationship between the model for end-stage liver disease (MELD) score and quality of life (QOL) has not been well studied. In this study, quality of life questionnaires (Medical Outcomes Short Form 36 [SF-36] and the Chronic Liver Disease Questionnaire [CLDQ]) were administered to 150 adult patients awaiting liver transplantation. We also collected demographic data and laboratory results and recorded manifestations of hepatic decompensation. The study found that all domains of the SF-36 and CLDQ were significantly lower in our patient cohort than in normal controls (P < .001). There was a moderate negative correlation between CPT class and physical components of the SF-36 (r = -.30), while there was a weak negative correlation (r = -.10) between CPT class and the mental component. There was a negative moderate correlation between CPT class and overall CLDQ (r = -.39, P < .001) and a weak correlation (r = -.20) between MELD score and overall CLDQ score. Both encephalopathy (correlation coefficient = -.713, P = .004) and ascites (correlation coefficient = -.68, P = .006) were predictive of the QOL using CLDQ (adjusted R(2) = .1494 and f = 0.000). In conclusion, in liver transplant candidates, the severity of liver disease assessed by the MELD score was not predictive of QOL. The presence of ascites and/or encephalopathy was significantly associated with poor quality of life. CTP correlates better to QOL, probably because it contains ascites and encephalopathy.

Seroepidemiology of hepatitis A in patients with chronic liver disease

Hepatitis A virus (HAV) rarely causes fulminant hepatic failure in the general population. Yet it is a cause of significant morbidity and mortality in patients with chronic liver disease (CLD), in whom routine HAV vaccination is recommended. However, studies of HAV seroprevalence and exposure predictors in populations with CLD are scarce. We have studied a cohort of 473 patients with various causes of CLD between July 2000 and June 2002. Patients were stratified on the basis of age, gender, ethnicity and aetiology of liver disease. The HAV seroprevalence in patients with CLD was compared with that in the general population. We used a logistic regression analysis to identify independent predictors of HAV exposure. Of the 473 patients studied, HAV seroprevalence was available for 454 individuals. HCV, HBV, alcohol, and HCV and alcohol were the causes of CLD in 337, 72, 37 and eight patients, respectively. The overall HAV seroprevalence was 55% in the studied cohort. The age-stratified HAV prevalence for ages 21-30, 31-40, 41-50, 51-60, 61-70 and greater than 70 years was 44, 51, 44, 63, 65 and 64%, respectively. Hispanic ethnicity, Asian ethnicity, alcohol use and ages of 51-70 years were found to be independent predictive variables of prior exposure to HAV. HAV infection in patients with CLD causes considerable morbidity and mortality. We demonstrated that age-stratified seroprevalence of HAV in patients with CLD of various aetiologies is significantly higher than that of the general population, and identified several independent predictors of HAV prior exposure.

Hepatitis C positive grafts may be used in orthotopic liver transplantation: a matched analysis

Hepatitis C (HCV)-positive liver grafts have been increasingly used in patients with decompensated liver disease from HCV because of critical shortage of available organs. Fifty-nine recipients of HCV-positive grafts were matched to patients who received HCV-negative grafts. All recipients were transplanted for HCV liver disease. Matching variables were (1) status, (2) pre-transplant creatinine, (3) recipient age, (4) donor age, (5) warm ischemia time, and (6) year of transplantation. Both unmatched and matched analyses were performed on patient survival, graft survival, and time to HCV recurrence. There was no significant statistical difference in patient, graft, or HCV recurrence-free survival between recipients of HCV-positive and HCV-negative grafts with matched and unmatched analyses (p > 0.05). The 3-year estimates of HCV disease-free survival were 12% (+/- 9%) and 19% (+/- 7%) using HCV-positive and -negative grafts, respectively. The use of HCV-positive grafts in recipients with HCV does not appear to affect patient survival, graft survival, or HCV recurrence when compared with the use of HCV-negative grafts. Our results suggest that HCV-positive grafts can be used in a HCV liver transplant recipient.

MELD score predicts 1-year patient survival post-orthotopic liver transplantation

The Model for End-Stage Liver Disease (MELD) is an important predictor in patients awaiting orthotopic liver transplantation (OLT). However, the model's association with posttransplant patient survival is unclear. We studied 1-year patient survival in 404 adult patients who underwent OLT at the University of California Los Angeles. The hazard rates of patient survival according to the MELD strata and United Network for Organ Sharing (UNOS) statuses were assessed by Proportional Hazard Cox regression analysis. The difference in survival for MELD strata and UNOS status were compared using the Cox model. There was a significant difference in 1-year patient (P =.0006) survival using different MELD strata, whereas there was a trend according to UNOS status (P =.051). Increased rate of death was observed in recipients of OLT with higher MELD scores (> 36, hazard ratio 3.9; 95% CI 1.55, 10.27) and more urgent UNOS status (2A; hazard ratio, 1.99; 95% CI 1.07, 3.7). The MELD stratum is better associated with 1-year patient survival in liver transplant recipients than UNOS statuses. Patient survival was worse with higher MELD scores.

Discordance between ALT values and fibrosis in liver transplant recipients treated with ribavirin for recurrent hepatitis C

Hepatitis C virus (HCV) recurrence is a serious problem after orthotopic liver transplantation (OLT). The role of ribavirin as a single agent to treat recurrent HCV is controversial. Our aim was to evaluate the correlation between alanine aminotransferase (ALT) levels and histological findings in OLT recipients treated with ribavirin monotherapy for recurrent HCV. The mean [+/- standard error (SE)] age of 11 patients was 50.1 (SE +/- 8.6) years. The estimated mean dose and duration of ribavirin treatment (+/- SE) was 661.5 (+/- 52.5) mg and 20.4 (+/- 1.7) months, respectively. Five patients required either dose reduction or erythropoietin. We found a significant decrease of mean (+/- SE) ALT value from 246 +/- 44.8 U/L to 109.4 +/- 49.1 U/L (p = 0.002) in patients treated with ribavirin. However, there was also significant worsening of interface activity (p = 0.03) and fibrosis (p = 0.02). No significant association was found between ALT values and (i) stage of hepatic fibrosis, (ii) interface activity, (iii) lobular activity and (iv) HCV RNA values. Our results suggest that HCV disease can progress despite a significant decrease in ALT values. ALT values are inadequate markers of the ribavirin monotherapy and can lead to erroneous conclusions of efficacy.

Dietary fat affects immune response, production of antiviral factors, and immune complex disease in NZB/NZW mice

Autoimmune-prone (NZB x NZW)F1 (B/W) mice fed three nearly isocaloric diets with varied fat content showed a marked difference in their spontaneous development of immune complex disease and their immune response. Those animals received the diets high in either unsaturated or saturated fats had more severe immune complex nephritis and died earlier than mice on the low-fat diet. Endogenous production of the mouse xenotropic virus was unaffected by dietary fats, but the serum lipoproteins associated with antiviral activity were increased to levels as high as 1:600,000 in the B/W mice on the high-fat diets. These lipoproteins may be partially responsible for the decreased mitogenic response of spleen cells from mice fed the two high-fat diets. The mice receiving a diet high in saturated fats produced substantially higher titers of natural thymocytotoxic autoantibody, an IgM class of antibody, than did the mice maintained either on the high-unsaturated-fat or low-fat diet. In contrast, the mice receiving the diet high in unsaturated fats made significantly greater levels of antibodies to double-stranded DNA, an IgG, than did the mice kept on the two other diets. These results suggest that the type of fat in the diet could affect the serum level of different immunoglobulin classes. The data provide further evidence that the amount of dietary lipids alone can influence cellular and humoral immune responses and the spontaneous development of immune complex disease.

Immune response to hepatitis B surface antigen

A total of 69 persons were investigated for assessment of cell-mediated and humoral immunity to hepatitis B surface antigen (HBsAg). Three groups, each consisting of 20 normal persons, 20HBsAg carriers, and 20 convalescent hepatitis B patients, were studied for HBsAg, anti-HBs, and leukocyte migration inhibition with purified HBsAg. Sequential sampling if an additional group of nine acute hepatitis B patients defined the cellular and humoral immune response to HBsAg. The antigen was eliminated rapidly by mounting of cell-mediated immune response detectable for a limited period, followed by antibody response in relatively few patients moore than 3 months after clearance of circulating HBsAg.

Studies on delayed hypersensitivity to hepatitis B antigen in chimpanzees

Twenty-eight chimpanzees were divided into six groups according to their history of previous immunization or exposure to hepatitis B antigen (HBAg) and studied for delayed hypersensitivity (DH) to HBAg. Purified HBAg derived from a normal human carrier was used for in vivo skin testing and in vitro leucocyte migration inhibition tests. Of seventeen chimpanzees immunized with HBAg in Freund's complete adjuvant (FCA), nine exhibited positive DH reactions to HBAg with good correlation between the in vivo and in vitro responses. Of the seventeen chimpanzees, fourteen also exhibited positive DH reactions to purified protein derivative of tuberculin (PPD) with marked erythema and induration; the other three exhibited only erythema with no induration. None of the seventeen animals exhibited any immediate reactivity to either HBAg or PPD. Intradermal injection of HBAg-negative human serum failed to elicit DH reactions in four animals who showed positive skin test with purified HBAg; the DH response was thus probably HBAg-specific. Nineteen chimpanzees, including six unimmunized animals, three chronic carriers of HBAg and two which had been injected with HBAg without FCA, failed to show DH response to HBAg. Thus, DH to HBAg was observed only in animals hyperimmunized with HBAg in FCA.

Experimental induction of anergy to coccidioidin by antigens of Coccidioides immitis

Failure to react to coccidioidin (anergy) often occurs in patients with disseminated coccidioidomycosis. One possible reason may be desensitization by excessive amounts of antigen. This was studied experimentally by injection of soluble and hyphal antigens of Coccidioides immitis into coccidioidin- and tuberculin-sensitive guinea pigs. Guinea pigs sensitized by injection of killed hyphal cells of C. immitis in complete Freund adjuvant were subsequently injected daily either with soluble coccidioidal antigen administered intraperitoneally or with hyphal antigen administered either subcutaneously or intraperitoneally. Gradual loss of cutaneous reactivity to coccidioidin occurred, but the reactivity to tuberculin remained unimpaired. The rapidity of desensitization was roughly proportional to the dose of antigen with desensitization occurring as early as 6 days after beginning injections. This anergic state was temporary, and reactivity returned several days after discontinuing injection of antigen. Injection of coccidioidal antigen led to production of coccidioidal complement-fixing antibody, but there was no consistent relationship between the antibody titer and state of cutaneous reactivity to coccidioidin. Peritoneal exudate or pulmonary alveolar cells from desensitized animals migrated freely in the presence of coccidioidin but were inhibited in the presence of tuberculin. Heat treatment did not impair the capacity of the soluble or hyphal antigen to induce anergy, thus suggesting that the antigen active in complement fixation was perhaps not involved in desensitization. Polysaccharide obtained by ethanol precipitation of dialyzed coccidioidin failed to induce anergy. Dialysis of the soluble coccidioidal antigen caused the loss of the desensitizing activity. Thus, specific desensitization could be induced by administration of large doses of coccidioidal antigen but dialyzable components appear important in this desensitization.

Australia antigen (hepatitis B antigen): a conformational antigen dependent on disulfide bonds

Reduction and alkylation of purified hepatitis-associated Australia antigen (hepatitis B antigen) resulted in a total loss of serologic activity. The reduced and alkylated protein formed a single band with a sedimentation coefficient of 31S on analytical ultracentrifugation, and no subunits were detected by Sephadex gel filtration. Although this preparation induced a delayed hypersensitivity response when injected into guinea pigs, it failed to stimulate humoral antibody formation. The data suggest that hepatitis B antigen is a conformational antigen critically dependent upon the disulfide bonds of the protein moiety.

Medical ecology and epidemiology

No abstract available.

Choriocarcinoma in a postmenopausal nulligravida

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