Tetraether archaeal lipids promote long-term survival in extreme conditions

The sole unifying feature of the incredibly diverse Archaea is their isoprenoid-based ether-linked lipid membranes. Unique lipid membrane composition, including an abundance of membrane-spanning tetraether lipids, impart resistance to extreme conditions. Many questions remain, however, regarding the synthesis and modification of tetraether lipids and how dynamic changes to archaeal lipid membrane composition support hyperthermophily. Tetraether membranes, termed glycerol dibiphytanyl glycerol tetraethers (GDGTs), are generated by tetraether synthase (Tes) by joining the tails of two bilayer lipids known as archaeol. GDGTs are often further specialized through the addition of cyclopentane rings by GDGT ring synthase (Grs). A positive correlation between relative GDGT abundance and entry into stationary phase growth has been observed, but the physiological impact of inhibiting GDGT synthesis has not previously been reported. Here, we demonstrate that the model hyperthermophile Thermococcus kodakarensis remains viable when Tes (TK2145) or Grs (TK0167) are deleted, permitting phenotypic and lipid analyses at different temperatures. The absence of cyclopentane rings in GDGTs does not impact growth in T. kodakarensis, but an overabundance of rings due to ectopic Grs expression is highly fitness negative at supra-optimal temperatures. In contrast, deletion of Tes resulted in the loss of all GDGTs, cyclization of archaeol, and loss of viability upon transition to the stationary phase in this model archaea. These results demonstrate the critical roles of highly specialized, dynamic, isoprenoid-based lipid membranes for archaeal survival at high temperatures.

Abstract P1-15-01: Final analysis of SWOG S0230/Prevention of early menopause study (POEMS)

BACKGROUND: The SWOG S0230/POEMS study demonstrated a 70% reduction in ovarian failure (OF) with goserelin coadministration during chemotherapy (CT) for ER-negative early breast cancer (BC; Moore H et al, NEJM 2015). Goserelin use was also associated with more pregnancies as well as favorable disease free survival (DFS) and overall survival (OS). Here we report the final analysis after 5 years of follow-up.

METHODS: Premenopausal women age <50 with stage I-IIIA ER/PR-negative BC to be treated with cyclophosphamide-containing CT were randomized to receive standard CT with or without monthly goserelin 3.6 mg SQ starting at least 1 week prior to the first CT dose. The primary endpoint was OF at 2-years, defined as amenorrhea for the prior 6 months and post-menopausal FSH. Secondary endpoints included pregnancies, disease free survival (DFS) and overall survival (OS). An unplanned analysis of rate of menses recovery at 2 years (presence of menses within 6 months of the 2 year time-point or pregnancy within the first 2 years) was also conducted. OF and pregnancy endpoints were analyzed using multivariable logistic regression adjusting for stratification factors (age and CT regimen); DFS and OS were examined using multivariable Cox regression, adjusting for stratification factors and stage. Two-sided p-values are reported unless otherwise specified in accordance with protocol design.

RESULTS: Among 257 randomized participants, 218 were eligible and evaluable. One hundred thirty-six eligible and evaluable patients had OF data and 186 had menstrual data. Median age was 37.7 years. Among the 136 patients with OF data, the odds ratio (OR) for OF at 2 years was 0.30 (95% CI 0.1-0.98; one-sided p=0.023) comparing CT with goserelin to standard CT alone. Among 186 patients with menstrual data, 80% recovered menses by 2 years in the goserelin arm compared with 70% in the standard arm (OR=1.74, 95% CI: 0.83-3.66, p=0.15). Pregnancies, DFS and OS are reported for all 218 eligible and evaluable patients. With a median follow-up of 5.1 years, 22% of patients in the goserelin group had at least one pregnancy compared with 12% in the standard group (OR 2.38, 95% CI 1.08-5.26, p=0.03). Cumulative incidence of pregnancy at 5 years is 23% in the goserelin arm compared with 12% in the standard group. Five-year Kaplan-Meier DFS estimates are 88% in the goserelin arm compared with 79% in the standard arm (HR=0.50, p=0.05). Five-year OS is 92% with goserelin versus 83% in the standard arm (HR=0.47, p=0.06). Including all 257 randomized patients, HR for DFS and OS are 0.67 and 0.48 (p=0.18 and p=0.05).

CONCLUSION: Ovarian suppression with goserelin during chemotherapy for hormone receptor-negative breast cancer reduces OF risk and, after 5 years of follow-up, continues to be associated with more pregnancies and improved survival compared with chemotherapy without goserelin.

SUPPORT: NIH/NCI grant awards CA189974, CA180888, CA180819, CA074362; AstraZeneca

Citation Format: Moore HCF, Unger JM, Phillips K-A, Boyle F, Hitre E, Moseley A, Porter D, Francis PA, Goldstein LJ, Gomez HL, Vallejos CS, Partridge AH, Dakhil SR, Garcia AA, Gralow J, Lombard JM, Forbes JF, Martino S, Barlow WE, Fabian CJ, Minasian L, Meyskens FL, Gelber RD, Hortobagyi GN, Albain KS. Final analysis of SWOG S0230/Prevention of early menopause study (POEMS) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-15-01.

A multicenter, open-label, expanded phase 2 study to evaluate the safety and efficacy of etirinotecan pegol, a polymer conjugate of irinotecan, in women with recurrent platinum-resistant or refractory ovarian cancer

OBJECTIVE

Etirinotecan pegol (EP) is a novel polyethylene glycol conjugated form of irinotecan with documented activity in platinum-resistant ovarian cancer (PROC). We report the results of the expanded portion of a phase II study of EP in patients with PROC who received prior pegylated liposomal doxorubicin (PLD) or who were unable to receive it.

METHODS

This multicenter, open-label, phase II study evaluated EP q21d for PROC. The primary endpoint was objective response rate (ORR) by Response Evaluation Criteria in Solid Tumors version 1.0. Secondary endpoints included progression-free survival (PFS), overall survival (OS), and safety. Patient populations evaluated included a modified intent-to-treat (mITT) group consisting of all patients who received at least one dose and with measurable disease and a primary efficacy (pEFF) group (subset of the mITT population who received prior PLD).

RESULTS

One hundred thirty-nine patients were enrolled. Of the 132 patients in the mITT group, 20 achieved an ORR (15.2%; 95% CI 9.5-22.4); median PFS and OS were 4.4 months and 10.2 months, respectively. In the pEFF group (n=104), 15 patients (14.4%; 95% CI 8.3-22.7) achieved an ORR; median PFS and OS were 4.4 months and 10.9 months, respectively. The most common grade 3/4 toxicities were diarrhea (20%), abdominal pain (17%), vomiting (14%), dehydration (13%), and nausea (13%). Severe diarrhea was reduced to 15% with strict adherence to screening and management guidelines.

CONCLUSIONS

This study confirms the activity and safety of single-agent EP in patients with PROC, including patients who received prior PLD. Further evaluation earlier in the disease course and in combination is warranted.

Bacillus anthracis lethal toxin alters regulation of visceral sympathetic nerve discharge

Bacillus anthracis infection is a pathophysiological condition that is complicated by progressive decreases in mean arterial pressure (MAP). Lethal toxin (LeTx) is central to the pathogenesis of B. anthracis infection, and the sympathetic nervous system plays a critical role in physiological regulation of acute stressors. However, the effect of LeTx on sympathetic nerve discharge (SND), a critical link between central sympathetic neural circuits and MAP regulation, remains unknown. We determined visceral (renal, splenic, and adrenal) SND responses to continuous infusion of LeTx [lethal factor (100 μg/kg) + protective antigen (200 μg/kg) infused at 0.5 ml/h for ≤6 h] and vehicle (infused at 0.5 ml/h) in anesthetized, baroreceptor-intact and baroreceptor (sinoaortic)-denervated (SAD) Sprague-Dawley rats. LeTx infusions produced an initial state of cardiovascular and sympathetic nervous system activation in intact and SAD rats. Subsequent to peak LeTx-induced increases in arterial blood pressure, intact rats demonstrated a marked hypotension that was accompanied by significant reductions in SND (renal and splenic) and heart rate (HR) from peak levels. After peak LeTx-induced pressor and sympathoexcitatory responses in SAD rats, MAP, SND (renal, splenic, and adrenal), and HR were progressively and significantly reduced, supporting the hypothesis that LeTx alters the central regulation of sympathetic nerve outflow. These findings demonstrate that the regulation of visceral SND is altered in a complex manner during continuous anthrax LeTx infusions and suggest that sympathetic nervous system dysregulation may contribute to the marked hypotension accompanying B. anthracis infection.

Effects of combined aging and heart failure on visceral sympathetic nerve and cardiovascular responses to progressive hyperthermia in F344 rats

Sympathetic nerve discharge (SND) responses to hyperthermia are attenuated in aged rats without heart failure (HF) and in young HF (Y(HF)) rats, demonstrating that individually aging and HF alter SND regulation. However, the combined effects of aging and HF on SND regulation to heat stress are unknown, despite the high prevalence of HF in aged individuals. We hypothesized that SND responses to heating would be additive when aging and HF are combined, demonstrated by marked reductions in SND and mean arterial pressure (MAP) responses to heating in aged HF (A(HF)) compared with aged sham HF (A(SHAM)) rats, and in A(HF) compared with Y(HF) rats. Renal and splenic SND responses to hyperthermia (colonic temperature increased to 41.5°C) were determined in anesthetized Y(HF), young sham (Y(SHAM)), A(HF), and A(SHAM) Fischer rats. HF was induced by myocardial infarction and documented using echocardiographic, invasive, and postmortem measures. The severity of HF was similar in Y(HF) and A(HF) rats. SND responses to heating were attenuated in Y(HF) compared with Y(SHAM) rats, demonstrating an effect of HF on SND regulation in young rats. In contrast, A(HF) and A(SHAM) rats demonstrated similar SND responses to heating, suggesting a prominent influence of age on SND regulation in A(HF) rats. Splenic SND and MAP responses to heating were similar in Y(HF), A(HF), and A(SHAM) rats, indicating that the imposition of HF in young rats changes the regulatory status of these variables to one consistent with aged rats. These data suggest that the effect of HF on SND regulation to hyperthermia is age dependent.

Use of the etonogestrel-releasing implant is associated with hypoactivation of the coagulation cascade

BACKGROUND

The role of progestogens in haemostasis is controversial. Our objective is to evaluate the haemostatic effects of an etonogestrel-releasing implant.

METHODS

This open-label, self-controlled, longitudinal study involved 20 healthy women receiving subcutaneous etonogestrel-releasing implants. At baseline, 1, 3 and 6 months, we measured the following: activated partial thromboplastin time; prothrombin time; thrombin time; fibrinogen; coagulation factors II, V, VII, VIII, IX, X and XI; von Willebrand factor; activated protein C (APC); antithrombin; free protein S; plasminogen activator inhibitor type 1 (PAI-1); alpha2-antiplasmin; thrombin-antithrombin (TAT) complex; prothrombin fragment 1 + 2 (F1 + 2); D-dimers; APC resistance. Statistical analyses included the Friedman test and ANOVA.

RESULTS

Levels of APC (P < 0.01), factor II (P = 0.02), factor VII (P = 0.006), factor X (P = 0.01) and F1 + 2 (P < 0.001) were reduced, whereas those of PAI-1 (P = 0.01) and factor XI (P = 0.006) were transitory increased. All of these values, however, remained within normal ranges. Surprisingly, TAT concentrations fell below the normal range (P < 0.001).

CONCLUSIONS

Our findings suggest that the etonogestrel-releasing implant does not induce a prothrombotic pattern during the first six months of use, and that its use is associated with a reduction in thrombin generation.

Dynamics of rotating paramagnetic particles simulated by lattice Boltzmann and particle dynamics methods

Novel biochemical sensors consisting of rotating chains of microscale paramagnetic particles have been proposed that would enable convenient, sensitive analyte detection. Predicting the dynamics of these particles is required to optimise their design. The results of lattice Boltzmann (LB) and particle dynamics (PD) simulations are reported, where the LB approach provides a verified solution of the complete Navier-Stokes equations, including the hydrodynamic interactions among the particles. On the other hand, the simpler PD approach neglects hydrodynamic interactions, and does not compute the fluid motion. It is shown that macroscopic properties, like the number of aggregated particles, depend only on the drag force and not on the total hydrodynamic force, making PD simulations yield reasonably accurate predictions. Relatively good agreement between the LB and PD simulations, and qualitative agreement with experimental data, are found for the number of aggregated particles as a function of the Mason number. The drag force on a rotating cylinder is significantly different from that on particle chains calculated from both simulations, demonstrating the different dynamics between the two cases. For microscopic quantities like the detailed force distributions on each particle, the complete Navier-Stokes solution, here represented by the LB simulation, is required.

Efficacy and safety of erlotinib HCl, an epidermal growth factor receptor (HER1/EGFR) tyrosine kinase inhibitor, in patients with advanced ovarian carcinoma: results from a phase II multicenter study

The aim of this single-arm, phase II study was to estimate the tumor response rate and safety profile of erlotinib HCl (erlotinib, Tarceva, OSI-774) monotherapy in patients with refractory, recurrent, HER1/EGFR-positive epithelial ovarian tumors, who had failed prior taxane and/or platinum-based chemotherapy. Thirty-four patients received 150 mg erlotinib orally once daily for up to 48 weeks or until disease progression or dose-limiting toxicity. Two patients had partial responses, lasting 8+ and 17 weeks, giving an objective response rate of 6% (95% confidence interval [CI], 0.7-19.7%). Fifteen patients (44%) had stable disease, and 17 patients (50%) had progressive disease. Median overall survival was 8 months (95% CI, 5.7-12.7 months), with a 1-year survival rate of 35.3% (95% CI, 19.8-53.5%). Patients with rash survived significantly longer than those without (P= 0.009), correlating with rash grade. Erlotinib was generally well tolerated. The most frequent erlotinib-related adverse events were rash (68%) and diarrhea (38%). Erlotinib had marginal activity but was generally well tolerated. The safety profile appears more favorable than typically experienced with standard chemotherapeutic agents, which is encouraging in these heavily pretreated patients. Combination of erlotinib with chemotherapy or other targeted agents should be considered.

Evaluation of recurrent gastric malignancy with [F-18]-FDG positron emission tomography

AIM

We retrospectively assessed the use of [(18)F] fluorodeoxyglucose positron emission tomography (FDG PET) in the evaluation of recurrent disease in patients with history of gastric malignancy.

MATERIALS AND METHODS

Eighteen patients were referred for FDG PET for evaluation of recurrent gastric cancer. Prior treatments included total (n = 4) or partial gastrectomy (n = 14) followed by chemotherapy alone (n = 7) or combined chemoradiation therapy (n = 2). The interval between the most recent treatment and PET ranged from 3 months to 2 years. Correlative diagnostic data were available in 16 patients and were all obtained within 3 months of the PET study. Validation was by clinical or imaging follow-up (2-45 months) in 16 patients and histology in two patients.

RESULTS

PET was concordant with computed tomography (CT) in 12 patients (5 TP, 6 TN, 1 FN). In one patient with negative imaging studies, an incidental finding of left obstructive uropathy was determined to be due to metastatic ureteral stricture. Discordant imaging findings were present in four patients (22% of total). PET-detected diffuse metastatic lesions in three of these patients with rising serum tumour markers while other imaging studies were negative. Additional chemotherapy was initiated in these three patients (17% of total) based on PET localization of disease. PET and a gastric anastomosis biopsy were negative in another patient with positive CT. The remaining two patients without correlative imaging studies died shortly after positive PET studies with presumed recurrent cancer.

CONCLUSION

FDG PET may be useful in the evaluation of recurrent gastric cancer, and can localize the disease when CT is non-diagnostic. Imaging evaluation with PET may also impact on the clinical management of patients with recurrent gastric cancer.

Flow-based microimmunoassay

A small-volume heterogeneous immunoassay system is demonstrated in microchannels exploiting magnetic manipulations of small paramagnetic particles (1-2-microm diameter). The small-diameter particles help to create a high surface-area-to-volume ratio that generates the sensitivity for the small detection volumes. Flow characteristics of the magnetically formed packed bed within the channel allow the assay to be carried out quickly (minutes) while passing appropriate volumes of both samples and reagents (microliters to hundreds of nanoliters) through the system. The assay is demonstrated with a direct interaction of fluorescein isothiocyanate (FITC) with an immobilized anti-FITC conjugate in which a small-volume sample (< 1 microL) reaches 90% of maximum signal in 3 min. Heterogeneous sandwich assays are demonstrated with parathyroid hormone (PTH) and interleukin-5 (IL-5). Both the PTH assay and IL-5 assays were carried out on microliter volumes and demonstrated physiologically relevant sensitivity (approximately microg/L).

Phase I and pharmacologic study of i.v. hydroxyurea infusion given with i.p. 5-fluoro-2'-deoxyuridine and leucovorin

Preclinical data suggests that the action of fluoropyrimidines may be enhanced by the addition of hydroxyurea. We developed a phase I trial to determine the maximum tolerated dose and pharmacokinetics of i.v. hydroxyurea (HU) in combination with i.p. 5-fluoro-2'-deoxyuridine (FUdR) and leucovorin (LV). Eligible patients had metastatic carcinoma confined mostly to the peritoneal cavity, and adequate hepatic, renal and bone marrow function. Patients were treated with a fixed dose of FUdR (3 g) and LV (640 mg) administered on days 1--3. HU was administered as a 72-h infusion starting simultaneously with i.p. therapy on day 1. The following dose levels were studied: 2.0, 2.5, 3.0 and 3.6 g/m(2)/day. Pharmacokinetics were studied in blood and peritoneal fluid. Twenty-eight patients were accrued. Steady-state plasma and peritoneal fluid HU levels increased with increasing dose, and steady state was achieved within 12 h of continuous dosing. The steady-state HU plasma:peritoneal fluid concentration ratio ranged from 1.06 x 10(3) to 1.25 x 10(3) and the plasma HU clearance ranged from 4.63 to 5.81 l/h/m(2). Peritoneal fluid AUC = 137,639 +/- 43,914 microg/ml x min, t(1/2) = 100.9 +/- 56.4 min and Cl = 25.29 +/- 10.88 ml/min. Neutropenia represented the dose-limiting toxicity. We conclude that i.p. FUdR and LV in combination with i.v. HU is well tolerated. The addition of systemic HU increased the incidence of myelosuppression.

Phase II trial of outpatient schedule of paclitaxel in patients with previously untreated metastatic, measurable adenocarcinoma of the stomach

BACKGROUND

Chemotherapy represents the standard treatment for patients with metastatic stomach cancer. Conflicting results have been published regarding the activity of paclitaxel in this setting. Therefore, we developed a phase II study to evaluate an outpatient 3 h infusion of paclitaxel.

METHODS

Patients with chemonaive metastatic stomach cancer received paclitaxel 210 mg/m(2) every 3 weeks. Patients with esophageal cancer were not eligible.

RESULTS

Twenty-one patients were enrolled. The median age was 55.5 years (range 37-81 years). Two partial responses were observed among the 18 patients evaluable for response and toxicity (response rate 11%, 95% CI: 2-33%). The median time to progression was 10.5 weeks and median survival 23 weeks. There was only one episode of grade IV neutropenia and no episodes of grade 3-4 non-hematological toxicity were observed.

CONCLUSION

Paclitaxel exhibited minimal activity in this patient population.

The Starr County Diabetes Education Study: development of the Spanish-language diabetes knowledge questionnaire

OBJECTIVE

This study reports the psychometric properties of the 24-item version of the Diabetes Knowledge Questionnaire (DKQ).

RESEARCH DESIGN AND METHODS

The original 60-item DKQ was administered to 502 adult Mexican-Americans with type 2 diabetes who are part of the Starr County Diabetes Education Study. The sample was composed of 252 participants and 250 support partners. The subjects were randomly assigned to the educational and social support intervention (n = 250) or to the wait-listed control group (n = 252). A shortened 24-item version of the DKQ was derived from the original instrument after data collection was completed. Reliability was assessed by means of Cronbach's coefficient alpha. To determine validity, differentiation between the experimental and control groups was conducted at baseline and after the educational portion of the intervention.

RESULTS

The 24-item version of the DKQ (DKQ-24) attained a reliability coefficient of 0.78, indicating internal consistency, and showed sensitivity to the intervention, suggesting construct validation.

CONCLUSIONS

The DKQ-24 is a reliable and valid measure of diabetes-related knowledge that is relatively easy to administer to either English or Spanish speakers.

Phase II study of liposomal doxorubicin in advanced gynecologic cancers

OBJECTIVE

Pegylated liposomal doxorubicin (Doxil) may have enhanced therapeutic efficacy and reduced toxicity compared with the parent compound. This phase II study further evaluates the activity of Doxil in patients with ovarian cancer and explores activity in other gynecologic cancers.

METHODS

Sixty-three patients were treated with Doxil 50 mg/m(2) infused over 1 h; 44 were evaluable. Forty-eight had epithelial ovarian cancer and all received prior treatment with cisplatin and paclitaxel: 27 received two to six prior regimens, 44 were platinum resistant, 21 patients had measurable disease, and 27 had evaluable disease only.

RESULTS

The overall survival of these patients was 10 months (range, 0.25-33); progression-free survival was 3 months (range, 0.25-18). The response rate among those with measurable disease was 19%, with a median duration of 4.5 months (range, 3-12). The response rate of 22 patients with elevated CA-125 was 59%; median duration was 3.5 months (range, 1-12). Also, 27% achieved prolonged stabilization of disease for a median of 7 months (range, 5-18). Overall, treatment was well tolerated in this heavily pretreated population. Grade 3 and 4 toxic effects were: 5 grade 3 stomatitis, 3 grade 3 skin, 1 each grade 4 neutropenia and thrombocytopenia, 5 admits for infection, and no neutropenic fever; nausea and vomiting were uncommon in 204 cycles to ovarian cancer patients.

CONCLUSION

This study demonstrates the activity of Doxil in heavily pretreated patients with ovarian cancer and poor prognostic features and confirms the prolonged responses and favorable toxicity profile. Encouraging findings were also observed in the patients with nonovarian gynecologic cancers.

Tapping mode Atomic Force Microscopy of scleroglucan networks

Tapping mode Atomic Force Microscopy (TmAFM) has been used to study the fungal polysaccharide scleroglucan deposited from aqueous solution and dimethyl sulfoxide (DMSO) onto a mica surface. The solutions from which the microscope samples were produced were prepared by first dissolving the solid scleroglucan in 0.1M NaOH, then neutralizing the solution with HCl, followed by dilution to the required concentration in either water or DMSO. It was found that from the aqueous solution described above, scleroglucan forms networks. Based on a comparison of the denatured-renatured and aqueous solution samples, network formation is due to the imperfect registration between the chains forming the triple helices. The relatively large stiffness of the scleroglucan triple helix is also assumed to contribute to the formation of the extended networks. The triple helix diameter was measured to be 0.92 +/- 0.27 nm, which is in the same range as that obtained by other researchers using similar techniques. Denatured scleroglucan, deposited from DMSO onto mica, forms a web-like layer on top of which there are sphere-like structures. These morphologies are believed to be due to triple helix denaturation yielding highly flexible single chains in DMSO, which results in coiling and web-like dense packing of scleroglucan upon deposition onto mica. Most interestingly after additional of water to the samples deposited from DMSO, some of the chains can be renatured into short, stiff rod-like structures which are similar to the structures observed by others researchers. The imaging data for aqueous solution deposition can be analyzed by plotting maximum end-to-end distance versus the perimeter of the networks deposited onto mica. This yields a Flory-like exponent of 0.67, which is almost similar in value to that obtained by other researchers for linear structures of scleroglucan but less than that expected for a polymer chain following a self-avoiding walk (upsilon = 0.75) model on a two-dimensional surface. The fractal dimension that can be used to characterize the networks was determined graphically to be 1.22 +/- 0.06.

A phase II study of gemcitabine and cisplatin in patients with advanced, persistent, or recurrent squamous cell carcinoma of the cervix

OBJECTIVE

The aim of this study was to determine the response rate and toxicity of cis-platinum and gemcitabine in advanced, recurrent, or persistent squamous cell carcinoma of the cervix.

METHODS

From July 1997 to January 1999, we conducted a Phase II trial in patients with advanced, persistent, or recurrent carcinoma of the cervix. The schedule employed 1250 mg/m(2) of gemcitabine on days 1 and 8 and 50 mg/m(2) of cis-platinum on day 1 in a 21-day cycle. Eligibility criteria were a GOG performance status of 0-2, adequate bone marrow reserve, serum creatinine less than 1.8 mg%, and a lesion which could be measured in two dimensions. None of the patients had received prior chemotherapy other than radiation sensitizers. Standard GOG toxicity and response criteria were used.

RESULTS

Nineteen patients were enrolled into the trial. Two patients were inevaluable because of inadequate trial of drug. Seventeen patients were evaluable for response and toxicity. The median age of the patients was 47 years (range 24-72). The median number of cycles delivered was 5 (range 2-8). The incidence of grade 4 neutropenia and anemia was 2.4 and 1.2%, respectively. Two patients developed a single episode of grade 3 gastrointestinal toxicity. The overall response rate was 41% (7/17). There was 1 complete response of 14 months duration and 6 partial responses. Among those patients not previously irradiated, the response rate was 57% (4/7). Among the radiated patients, the response rate was 30% (3/10) with all responses occurring in the radiation field.

CONCLUSION

This combination of cis-platinum and gemcitabine is a well-tolerated regimen which exhibits high activity in advanced, recurrent, or persistent squamous cell cervical cancer.

Salvage therapy for ovarian cancer

The majority of patients with ovarian cancer will relapse after initial chemotherapy and will be candidates for salvage treatment. Currently, five agents show clear activity in patients with platinum- and paclitaxel-resistant disease: topotecan, oral etoposide, liposomal doxorubicin, gemcitabine, and, possibly, docetaxel. In addition, other agents have activity in platinum-resistant patients: vinorelbine, tamoxifen, ifosfamide, altretamine, 5-fluorouracil with leucovorin, and, possibly, irinotecan. Furthermore, selected patients may benefit from other therapeutic approaches such as surgery or radiation therapy.

Beta-lactam degradation catalysed by Cd2+ ion in methanol

Kinetic schemes are established for degradation catalysed by Cd2+ ions in methanolic medium for penicillin G, penicillin V and cephalothin, a cephalosporin. Methanolysis of penicillin V and cephalothin occurs with the formation of a single substrate-metal ion intermediate complex, SM, while degradation of penicillin G occurs with the initial formation of two complexes with different stoichiometry, SM and S2M. In each case. degradation is of first order with respect to SM with rate constant values equal to 0.079 min(-1), 0.120 min(-1) and 0.166 min(-1) at 20, 25 and 30 degrees C, respectively, for penicillin G; 0.061 min(-1) at 20 degrees C for penicillin V; and 2.0 x 10(-3) min(-1) at 20 degrees C for cephalothin. Activation energy for the decomposition process of the SM intermediate for penicillin G was calculated to be about 5.5 x 10(4) J/mol. Equilibrium constant values between SM compound and S2M at 20 degrees C (77.1 l/mol), 25 degrees C (45.3 l/mol) and at 30 degrees C (25.7 l/mol) were also calculated as well as the normal enthalpy of this equilibrium. With respect to the reaction products there is evidence that Cd2+ becomes part of their structure, forming complexes between Cd2+ and the product resulting from antibiotic methanolysis (L). Some characteristics of these complexes are discussed.

Phase I study of AG 331, a novel thymidylate synthase inhibitor, in patients with refractory solid tumors

PURPOSE

This was a phase I study of AG 331 to determine systemic tolerance and pharmacokinetics following single and multiple escalating intravenous doses.

METHODS

The study was an open-label phase I trial that was divided into two components. In phase IA (single dose), six dose levels from 12.5 to 225 mg/m2 were administered to 18 patients (3 at each dose level) and serial blood samples were collected for 72 h. Upon achieving satisfactory pharmacologic parameters, the multiple dosing component (phase IB) was initiated. Six dose levels from 50 to 800 mg/m2 per day were administered for 5 consecutive days to 18 patients. Pre- and postdose blood samples were obtained on days 1-4 and serial blood samples were collected over 24 h following dose 5. Nonhematologic and hepatic toxicities were assessed, serum AG 331 concentrations were measured and pharmacokinetic parameters determined.

RESULTS

Other than fatigue, no severe toxicities were encountered in phase IA. Liver toxicity was manifested by elevations in transaminase first noted at multiple doses of 200 mg/m2 per day for 5 days. Fever and malaise but no myelosuppression were noted. The mean terminal t1/2 following single doses was significantly shorter than the t1/2 following multiple dosing (6.8 vs 9.9 h) and clearance was significantly faster following single doses than following multiple dosing (81.7 vs 30.4 l/h), but no significant difference in Vd was noted.

CONCLUSIONS

The dose-related toxicity profile precludes further clinical development at this time. The pharmacokinetics of AG 331 following single and multiple doses showed significant differences.

Interferon beta modulates experimental autoimmune encephalomyelitis by altering the pattern of cytokine secretion

The mechanism of action underlying the beneficial effect of IFNbeta in Multiple Sclerosis is poorly understood. Experimental Autoimmune Encephalomyelitis (EAE) is the experimental model for Multiple Sclerosis; therefore, we investigated the effects of recombinant mouse IFNbeta on the severity of EAE induced in SJL mice and on cytokine production by Th1 and Th2 lymphocytes. The results indicated that rmIFN beta reduced the disease activity with an I.P. dosage of 10,000 U/day every other day, and successfully treated EAE mice revealed reduced amounts of IFN gamma; no changes in the levels of IL4 were observed, although thera was a significant increase in IL10 and TGFbeta production. Beneficial effects on EAE are associated with inhibition of inflammatory cytokines and stimulation of anti-inflammatory cytokines.

A phase II study of Doxil (liposomal doxorubicin): lack of activity in poor prognosis soft tissue sarcomas

BACKGROUND

Liposomal doxorubicin (Caelyx, Doxil) delivers doxorubicin to a tumor, but has a vastly altered pharmacology and attenuated acute and chronic toxicities. Therefore, its efficacy in soft tissue sarcomas is worth exploring.

PATIENTS AND METHODS

Sixteen patients with recurrent or metastatic soft tissue sarcomas who had not failed prior doxorubicin were accrued into this phase II study. Patients were treated with Doxil at a dose of 50 mg/m2 every four weeks.

RESULTS

No responses were seen but three patients were removed from study after only one cycle of treatment. Moreover, leiomyosarcoma was the most common histology and most patients had low grade, and bulky, disseminated tumors. Treatment was well tolerated with no episodes of grade 4 toxicity and only five episodes of grade 3 toxicities: two episodes of neutropenia and one each of stomatitis, dermatologic toxicity and nausea and vomiting.

CONCLUSIONS

Doxil's lack of activity in this study of patients with adult soft tissue sarcoma may be related to the poor prognostic features of our population. We confirm its favorable toxicity profile and suggest that additional studies be done in patients with other characteristics.

Phase I and pharmacologic study of estramustine phosphate and short infusions of paclitaxel in women with solid tumors

PURPOSE

We sought to determine the tolerance of estramustine phosphate (EMP) combined with a 3-hour paclitaxel infusion in women with solid paclitaxel-pretreated solid tumors. Paclitaxel pharmacology was to be studied at the recommended phase II dose.

PATIENTS AND METHODS

Paclitaxel was administered to cohorts of at least three assessable patients at doses of 150, 180, 210, and 225 mg/m2, while EMP was given at 900 and 1,200 mg/m2/d in divided doses orally for 2 days preceding and on the day of paclitaxel. The pharmacologic study was performed at 225 mg/m2 paclitaxel given in the absence and 3 weeks later in the presence of EMP 900 mg/m2/d.

RESULTS

Thirty-eight patients received a total of 178 courses. Grade 3 nausea, vomiting, and diarrhea were common at EMP 1,200 mg/m2 and paclitaxel 225 mg/ m2; this was considered the maximum-tolerated dose. Since these toxicities appeared related to EMP, the pharmacologic study used a dose of 900 mg/m2 of this agent with 225 mg/m2 paclitaxel. Antitumor activity was documented against breast and ovarian cancers at all levels. Paclitaxel pharmacokinetics without and with EMP did not differ.

CONCLUSION

EMP 900 mg/m2 for 3 days and 225 mg/m2 paclitaxel by 3-hour infusion are well tolerated; antitumor activity was seen in women with paclitaxel-pretreated solid tumors. This apparent enhancement of antitumor effects is unlikely to be mediated by P-glycoprotein.

Symptom-related self-care of Mexican Americans with type 2 diabetes: preliminary findings of the Starr County Diabetes Education Study

Starr County, Texas, a Texas-Mexico border community, was the site of a study involving culturally-appropriate education and group support for Mexican Americans with type 2 diabetes. Data were collected from 63 subjects on frequency of diabetes-related symptoms during the previous month and on self-care symptom treatments. On average, subjects were 57-year-old females, diagnosed with diabetes for 10 years, and exhibiting HbA1c levels of 12.5%. Almost 50% experienced excessive urination, excessive thirst, shakiness/nervousness, and numbness and/or tingling in their extremities. More than 50% of those who experienced symptoms did not view them as serious. Only one subject checked blood sugar levels when symptoms occurred. Significantly higher mean glycosylated hemoglobin levels were found for individuals who experienced dizziness and/or chest pain compared with those who did not. A variety of self-care treatments were employed, including over-the-counter medications and home remedies.

Tolerance of paclitaxel 3-hour infusion with and without granulocyte colony-stimulating factor on a biweekly schedule

The object of this study was to define the toxicity and maximum tolerated dose of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) administered on a biweekly schedule, without and with granulocyte colony-stimulating factor support. Eligible patients had a diagnosis of recurrent or metastatic carcinoma and had received no more than one prior chemotherapy regimen. Patients were treated with paclitaxel administered as a 3-hour infusion. Entry dose level was 150/mg/m2. Subsequent dose levels were 175, 200, and 225 mg/m2. Granulocyte colony-stimulating factor was added at the two highest dose levels beginning on day 4, until absolute neutrophil count was above 10 x 10(9)/L. Forty-six patients were entered. Up to 175 mg/m2 could be safely administered every 2 weeks. Previously treated patients experienced severe dose-limiting neutropenia at 200 mg/m2, and at 225 mg/m2 all patients experienced treatment delays due to grade 3/4 neutropenia. Dose intensity was maintained in all patients due to the addition of granulocyte colony-stimulating factor. Escalation to 250 mg/m2 does not appear desirable, due to neurotoxicity.

Microvascular permeability with sulfonylureas in normal and diabetic hamsters

The hamster cheek pouch is an experimental model in which quantitative studies of macromolecular permeability can be made by direct observation of extravasated fluorescein isothiocyanate (FITC)-dextran (leaks). The advantage of this model is that simultaneous light and fluorescent-light microscopy observations can be performed with instantaneous correlations between the site of FITC-dextran extravasation and the vessel morphology. The aims of our study were to compare, using the cheek pouch preparation, the effects of two sulfonylureas, gliclazide and glibenclamide, on the macromolecular permeability increase induced by histamine using control (normoglycemic) hamsters. In these studies, FITC-labeled dextran 150,000 daltons was administered intravenously and quantified by UV-light microscopy, and the drugs used were applied topically at therapeutic concentrations. Gliclazide and glibenclamide dose-dependently decreased the macromolecular permeability increase induced by histamine. This effect of gliclazide could be blocked by nifedipine (Ca2+ channel blocker) and not by diazoxide (K+ channel opener), whereas for glibenclamide it could be blocked by diazoxide and not by nifedipine. To better characterize the antioxidant capacity of gliclazide and glibenclamide, their effect on the macromolecular permeability increase induced by ischemia/reperfusion was also compared with the effect of vitamin C in diabetic hamsters (glycemia > 240 mg/dL). Total ischemia of the preparation was obtained with a cuff placed around the neck of the everted pouch. Diabetes was induced by three intraperitoneal injections of streptozotocin 50 mg/kg/d in 3 days. In diabetic hamsters during ischemia/reperfusion, gliclazide was more effective in inhibiting the macromolecular permeability increase than glibenclamide (136.0 +/- 5.8 leaks/cm2 for placebo; 68.0 +/- 2.9 for 1.2 x 10(-6) mol/L gliclazide; 55.3 +/- 3.5 for 1.2 x 10(-5) mol/L gliclazide; 89.2 +/- 5.7 for 8 x 10(-8) mol/L glibenclamide; 107.0 +/- 3.8 for 8 x 10(-7) mol/L glibenclamide; 56.7 +/- 3.4 for 10(-6) mol/L vitamin C; and 20.5 +/- 0.6 for 10(-5) mol/L vitamin C). Our results suggest that (1) the inhibition of the permeability increase induced by histamine elicited by gliclazide may be mediated by Ca2+ channels, while that of glibenclamide may be mediated by K+ channels, and (2) gliclazide appears to have an antioxidant capacity in ischemia/reperfusion injury similar to that of 10(-6) mol/L vitamin C. Improvement in the microcirculation was independent of the hypoglycemic properties of the drug.

Xanthogranulomatous cystitis as a cause of elevated carcinoembryonic antigen mimicking recurrent colorectal cancer. Report of a case

We report a case of xanthogranulomatous cystitis that developed in a patient with a history of colon cancer. While undergoing adjuvant chemotherapy with fluorouracil and levamisole, rising carcinoembryonic antigen (CEA) levels and the appearance of a pelvic mass, suspicious for recurrent cancer, were identified. Exploratory laparotomy demonstrated the presence of a benign condition of the bladder, xanthogranulomatous cystitis, which was resected by partial cystectomy. CEA levels have normalized. This is the first reported case of xanthogranulomatous cystitis producing an elevated CEA level.

Ifosfamide-induced Fanconi syndrome

OBJECTIVE

To report a case of possible ifosfamide-induced Fanconi syndrome in and adult with cancer.

CASE SUMMARY

A 20-year old man was treated for an osteosarcoma with a chemotherapy regimen that included ifosfamide, methotrexate, and doxorubicin. Three months after completing therapy he developed polyuria, polydypsia, and bilateral ankle pain. Laboratory findings showed decreased serum concentrations of phosphorus, uric acid, calcium potassium, and bicarbonate; elevated blood urea nitrogen and creatinine; and increased urinary excretion of phosphorus, potassium, calcium, citrate, and protein. The patient was diagnosed with Fanconi syndrome and osteomalacia. Treatment with oral supplements of potassium, sodium, citric acid, calcium, and calcitriol corrected the electrolyte abnormalities.

DISCUSSION

The adverse effect most frequently associated with ifosfamide is hemorrhagic cystitis. The incidence of hemorrhagic cystitis is decreased with the concomitant administration of the uroprotective agent mesna. The development of Fanconi syndrome after ifosfamide therapy has been described previously, although it occurs more frequently in children than adults. the mechanism by which ifosfamide causes renal tubular damage is not well understood, but it appears to involve metabolites of the drug.

CONCLUSIONS

The development of renal tubular defects and renal failure should be considered in patients receiving ifosfamide. Although this complication appears more frequently in children, adults also can be affected. Renal function should be monitored closely to detect the appearance of this adverse effect. Renal tubular dysfunction can, as this case illustrates, develop months after completing chemotherapy.

Pancreatic cancer and primary care providers

Pancreatic cancer is a relatively uncommon neoplasm for which long-term survival is unusual. Early diagnosis can lead to prolonged survival, because successful treatment is possible with surgical resection of stage 1 tumors. However, clinical findings are nonspecific and diagnosis usually occurs at advanced stages. Radiologic and laboratory techniques can help to identify patients earlier in the course of the disease. To detect tumors in early stages, efficient and cost-effective application of clinical, laboratory, and radio-logic methods should be used. But the primary care provide must understand the general characteristics of pancreatic cancer.

Bilateral psoas abscesses following acupuncture

Images

BCG cell imaging using scanning probe microscopy

Scanning tunneling microscopy (STM) and atomic force microscopy (AFM) were used to obtain images of the surface of whole, intact BCG (bacille Calmette Guerin, a mycobacterium) cells in air and under solution by immobilizing the cells onto glass slides (AFM only) or highly oriented pyrolytic graphite. The technique used for AFM imaging involved depositing a submonolayer of cells under a centrifugal force followed by fixation/dehydration using polar organic solvents. AFM images agree well with images from light and electron microscopy and showed large numbers of BCG cells in their distinctive cord arrangement. The AFM also proved useful for identifying extracellular microgranules which cannot be seen with light microscopy. For STM imaging, the hydrophobicity of BCG enabled strong adhesion from aqueous solution onto graphite. STM images of BCG could only be obtained while scanning in aqueous solution, and the cells showed a large variation in contrast when different samples were imaged. The STM provided greater detail of surface features than the AFM and was able to produce images of periodic layers corroborating observations made by transmission electron microscopy.

Strategies for the recovery of chemicals from fermentation: a review of the use of polymeric adsorbents

Many different compounds can be produced by using microorganisms or enzymes. An important element in the design of a viable biotechnological process is the selection of an economical and efficient separations train. Production of chemicals via biotechnology generally requires isolation and purification from dilute, aqueous solution. A general framework for separation process design relies on exploiting a unique molecular physicochemical property (or properties) for separating the molecule of interest from water and the other species in solution. Important properties that can be utilized for the recovery of low molecular weight polar compounds are molecular charge, hydrophobicity, Lewis acidity or basicity, volatility, and limited solubility. In turn, it can be useful to characterize molecular properties by using separation processes, such as, for example, hydrophobicity by measuring octanol/water partition coefficients. This paper reviews the use of adsorption onto hydrophobic, nonpolar macroreticular polymers and Lewis acid-base complexation by using functionalized polymers for the recovery of amino acids, carboxylic acids, alcohols, and ketones from dilute aqueous solution. The focus will be on utilizing physical and chemical properties to predict uptake capacity. This information will be relevant to separation process development and will help to characterize molecular properties in aqueous solution.

Epithelioid hemangioendothelioma of the liver with myocardial metastases

Epithelioid hemangioendothelioma is an unusual type of endothelial-derived vascular tumor located mainly in the soft tissues of the limbs. The present report describes a 48-year-old woman with an epithelioid hemangioendothelioma located in the liver with very unusual metastases to the myocardium. While the disease itself was controlled by adriamycin the patient died as a consequence of portal hypertension due to the abundant fibrotic component distinctive of this type of tumor. An epithelioid appearance can sometimes lead to a mistaken diagnosis of metastatic carcinoma, as happened initially in our case. The endothelial origin of the tumor must be confirmed by electron microscope identification of Weibel-Palade bodies or by immunohistochemical staining of factor VIII-related antigen. To the authors knowledge, this is the first case of myocardial metastases from an epithelioid hemangioendothelioma of the liver to be reported in English in the medical literature.

Lymphokine production by blood or spleen mononuclear cells from patients with schistosomiasis mansoni

Peripheral blood mononuclear cells (PBMN) from individuals with active or former intestinal schistosomiasis mansoni or splenocytes from patients with the hepatosplenic form of the disease were evaluated for their ability to generate chemotactic factors for neutrophils in response to schistosomal antigenic preparations derived from adult worms (SWAP), eggs (SEA), or phytohemagglutinin (PHA). When supernatants from cultures of stimulated PBMN from normal donors were assayed, only those obtained from cells which had been cultured in presence of PHA displayed chemotactic activity for neutrophils. In contrast, supernatants from cultures of SWAP or SEA stimulated PBMN from patients with intestinal or hepatosplenic schistosomiasis were shown to contain chemotactic activity for neutrophils from normal individuals. PBMN from persons who previously had been infected with Schistosoma mansoni but had received chemotherapy years before presented a pattern of response to SWAP or SEA similar to those from patients with active infections. The response of splenocytes from patients with hepatosplenic schistosomiasis was considerably different from PBMN from individuals with active or with treated schistosomiasis. Splenocytes from most of those patients with hepatosplenic disease failed to produce chemotactic factors for neutrophils in response to stimulation with at least 1 of the schistosome antigens tested. These results indicate that the lymphocytes from schistosomiasis mansoni patients are able to recognize and are stimulated by adult worm and egg antigens to produce chemotactic substances for neutrophils, and that this ability persists for many years after chemotherapy with schistosomicidal drugs. At the hepatosplenic stage, immunoregulatory mechanisms, which may prevent the production of chemotactic factors by splenocytes and/or their activity upon neutrophils in vitro, seem to occur.

Immune responses during human schistosomiasis mansoni. XIII. Immunological status of spleen cells from hospital patients with hepatosplenic disease

Splenocytes from 25 patients with severe hepatosplenic schistosomiasis mansoni were obtained after therapeutic splenectomy. Spleen cells were phenotyped and analysed for responsiveness to mitogens or heterogeneous schistosome-derived antigenic preparations (eggs, SEA; adult worms, SWAP; cercariae, CERC) in blastogenesis assays and lymphokine production systems, and were compared with peripheral blood mononuclear cells (PBMN). Splenic lymphocytes were 55% T lymphocytes (sheep erythrocyte rosette-positive) and 37% surface immunoglobulin-positive B lymphocytes. The mean T4+:T8+ ratio of these splenocytes was 1.0. Phytohaemagglutinin stimulated spleen cell production of the lymphokine mitogenic factor, but exposure to SEA or SWAP did not. Spleen cell and PBMN blastogenic responses to SEA and SWAP were sometimes, but not always in accord. Removal of plastic adherent cells allowed the non-adherent spleen cells of 30-40% of the patients to respond substantially more vigorously to SEA, SWAP and CERC. Spleen cells from a subgroup of 20-30% of the patients failed to respond to the schistosomal antigens regardless of removal of adherent cells. Spleen cell responses to gram-negative lipopolysaccharide peaked on day 5 or 6 of culture, and were augmented by adherent cell removal. Pokeweek mitogen-stimulated responses were optimal on day 5 of culture. Spleen cells from most severe, hepatosplenic schistosomiasis mansoni patients do not respond well to schistosomal antigens or B-cell mitogens. The splenic responses of many of these patients were elevated by the removal of adherent spleen cells.

Immune responses during human schistosomiasis. XII. Differential responsiveness in patients with hepatosplenic disease

Thirty-four hospitalized patients and 12 ambulatory patients, all with hepatosplenic schistosomiasis mansoni were evaluated in regard to their peripheral blood mononuclear (PBMN) cell responses to schistosomal antigenic preparations and compared with groups of 40 patients with the hepatointestinal form and 39 patients with the more common, chronic intestinal form of schistosomiasis mansoni. PBMN cell blastogenic responses were measured upon exposure to schistosomal egg antigens (SEA), adult worm antigens (SWAP) and a cercarial antigenic preparation (CERC). All groups had some individuals who did not respond to some or all of these preparations. In the hospitalized hepatosplenic group greater than 50% did not respond to SEA. Analysis of the responses in each group revealed that all responders could be subdivided into moderate and high responders. High responders to SEA had experimental minus control values of greater than 8,000 counts per minute (CPM). For SWAP and CERC, this arbitrary cut-off value was greater than 25,000 CPM and greater than 11,000 CPM, respectively. The percent of high SEA responders in the groups differed considerably. This was 23% in the chronic intestinal group, 40% in the chronic hepatointestinal group, 67% for ambulatory hepatosplenic patients and 20% for hospitalized hepatosplenic patients. Previous studies had demonstrated that 94% of patients with early (2-3 month) acute schistosomiasis mansoni were high responders to SEA and none were nonresponders. Furthermore, at the other end of the spectrum, 100% of former schistosomiasis mansoni patients (treated and cured 7-35 years previously) were high responders to SEA. None were nonresponders to any of the antigen preparations. It is proposed that during acute infection all patients express vigorous responses to SEA. Upon continued infection most patients (75%) modulate this florid response. However, continued high responders comprise 40% of the chronic hepatointestinal cases and almost 70% of the ambulatory hepatosplenic patients. These latter 2 groups may likely represent early forms of the severe clinical disease found in the hospitalized hepatosplenic patient population. Fifty percent of the hospitalized group appear anergic and no longer respond to SEA, while only 20% are high responders. Long after chemotherapy it appears that the anti-SEA regulatory mechanisms of former chronic patients have subsided, leaving strong anti-SEA responsiveness.

Prophylactic use of lidocaine to prevent advanced ventricular arrhythmias during pulmonary artery catheterization. Prospective double-blind study

To determine whether prophylactic lidocaine could decrease the incidence of advanced ventricular arrhythmias, 62 patients undergoing 67 pulmonary artery catheterizations were given lidocaine or placebo before and during catheterization. Advanced ventricular arrhythmias occurred in 42 of the 67 catheterizations (63 percent). In 18 of 31 patients receiving lidocaine (58 percent) arrhythmias developed, whereas 24 of 36 patients who received placebo (67 percent) had evidence of arrhythmias. These differences were not significant. However, patients with catheterization times of less than 20 minutes who were treated with lidocaine had less ectopy (25 percent) than patients treated with placebo (68 percent) (p less than 0.05). Two patients has sustained ventricular tachycardia and both were receiving placebo. No complications of lidocaine prophylaxis were noted. Prophylactic lidocaine appears to decrease the incidence of mechanically induced arrhythmias in critically ill patients undergoing catheterization that is not prolonged.

Thyrotrophin-binding-inhibition assay: comparison of crude and purified membrane preparations

Two different thyroid membrane preparations (TMP), crude and pure, made from a homogenate of normal human thyroid tissue, were used to test purified serum IgG from 36 patients with Graves' disease, and 10 normal control subjects, in the thyrotrophin-binding-inhibition (TBI) assay. All reagents for the assay were identical, and aliquots of each IgG were tested in both TMP simultaneously, under exactly comparable conditions. Blood was drawn while the patients were hyperthyroid (19), euthyroid (13), or hypothyroid (4); 15 of the patients were untreated and 21 were being treated. The frequency of positive TBI was similar in both TMPs and highest among the 131I-treated patients. Comparison of TBI results in both TMP for each IgG sample revealed wide differences, and 47.1% of the Graves' IgGs were TBI positive in one membrane preparation, while negative in the other. There was no correlation of TBI values between the two TMP, or with clinical status, or the presence of standard thyroid antibodies. The findings indicate that the IgGs of Graves' disease, as now tested in the TBI assay, bind heterogeneous to different fractions of the thyroid membranes.