Prediction of chemical carcinogenicity in rodents from in vitro genetic toxicity assays

Four widely used in vitro assays for genetic toxicity were evaluated for their ability to predict the carcinogenicity of selected chemicals in rodents. These assays were mutagenesis in Salmonella and mouse lymphoma cells and chromosome aberrations and sister chromatid exchanges in Chinese hamster ovary cells. Seventy-three chemicals recently tested in 2-year carcinogenicity studies conducted by the National Cancer Institute and the National Toxicology Program were used in this evaluation. Test results from the four in vitro assays did not show significant differences in individual concordance with the rodent carcinogenicity results; the concordance of each assay was approximately 60 percent. Within the limits of this study there was no evidence of complementarity among the four assays, and no battery of tests constructed from these assays improved substantially on the overall performance of the Salmonella assay. The in vitro assays which represented a range of three cell types and four end points did show substantial agreement among themselves, indicating that chemicals positive in one in vitro assay tended to be positive in the other in vitro assays.

Complicated grief and bereavement-related depression as distinct disorders: preliminary empirical validation in elderly bereaved spouses

OBJECTIVE

This study sought to determine whether a set of symptoms interpreted as complicated grief could be identified and distinguished from bereavement-related depression and whether the presence of complicated grief would predict enduring functional impairments.

METHOD

Data were derived from a study group of 82 recently widowed elderly individuals recruited for an investigation of physiological changes in bereaved persons. Baseline data were collected 3-6 months after the deaths of the subjects' spouses, and follow-up data were collected from 56 of the subjects 18 months after the baseline assessments. Candidate items for assessing complicated grief came from a variety of scales used to evaluate emotional functioning (e.g., the Hamilton Depression Rating Scale, the Brief Symptom Inventory). The outcome variables measured were global functioning, medical illness burden, sleep, mood, self-esteem, and anxiety.

RESULTS

A principal-components analysis conducted on intake data (N = 82) revealed a complicated grief factor and a bereavement-depression factor. Seven symptoms constituted complicated grief: searching, yearning, preoccupation with thoughts of the deceased, crying, disbelief regarding the death, feeling stunned by the death, and lack of acceptance of the death. Baseline complicated grief scores were significantly associated with impairments in global functioning, mood, sleep, and self-esteem in the 56 subjects available for follow-up.

CONCLUSIONS

The symptoms of complicated grief may be distinct from depressive symptoms and appear to be associated with enduring functional impairments. The symptoms of complicated grief, therefore, appear to define a unique disorder deserving of specialized treatment.

Parental involvement in diabetes management tasks: relationships to blood glucose monitoring adherence and metabolic control in young adolescents with insulin-dependent diabetes mellitus

OBJECTIVES

The goal of this study was to identify parental behaviors that relate to adherence and metabolic control in a population of young adolescents with insulin-dependent diabetes mellitus (IDDM), and to understand the interrelationships among the variables of parental involvement, adherence to blood glucose monitoring, and glycemic control.

STUDY DESIGN

A cross-sectional design was used to investigate parental involvement in diabetes regimen tasks in 89 youth, aged 10 to 15 years, with IDDM. Levels of parental involvement in blood glucose monitoring (BGM) and insulin administration were evaluated through interviews. Assessment of adherence was made by physicians or nurses, independent of patient or parent reports of adherence. Glycemic control was assessed with glycosylated hemoglobin (HbA1c) (reference range, 4% to 6%).

RESULTS

There were significant differences in the mean HbA1c values between the older (13 to 15 years of age) (HbA1c = 8.9% +/- 1.03%) and younger (10 to 12 years) patients (HbA1c = 8.4% +/- 1.06%) (p < 0.02). Parental involvement in BGM was significantly related to adherence to BGM (number of blood sugar concentrations checked daily) in both groups of adolescent patients. The younger patients monitored their blood glucose levels more frequently than did the older patients, 39% of the younger patients checked sugar concentrations four or more times daily compared with only 10% of the older group (p < 0.007). In a multivariate model controlling for age, gender, Tanner staging, and duration of diabetes, the frequency of BGM was a significant predictor of glycemic control (R2 = 0.19, p < 0.02). Increased frequency of BGM was associated with lower HbA1c levels. When the frequency of BGM was zero or once a day, the mean HbA1c level was 9.9% +/- 0.44 (SE); when the frequency of BGM was two or three times a day, the mean HbA1c level was 8.7% +/- 0.17; and when the frequency of BGM was four or more times daily, the mean HbA1c level was 8.3% +/- 0.22.

CONCLUSIONS

Parental involvement in BGM supports more frequent BGM in 10- to 15-year-old patients with IDDM. This increased adherence to BGM is associated with better metabolic control (i.e., lower HbA1c levels). These findings suggest that encouraging parental involvement in BGM with 10- to 15-year-old patients with IDDM may help to prevent the well-documented deterioration in glycemic control and adherence to treatment that often occurs in later adolescence.

Spontaneous autoimmune diabetes in monoclonal T cell nonobese diabetic mice

It has been established that insulin-dependent diabetes mellitus (IDDM) in nonobese diabetic (NOD) mice results from a CD4+ and CD8+ T cell-dependent autoimmune process directed against the pancreatic beta cells. The precise roles that beta cell-reactive CD8+ and CD4+ T cells play in the disease process, however, remain ill defined. Here we have investigated whether naive beta cell-specific CD8+ and CD4+ T cells can spontaneously accumulate in pancreatic islets, differentiate into effector cells, and destroy beta cells in the absence of other T cell specificities. This was done by introducing Kd- or I-Ag7-restricted beta cell-specific T cell receptor (TCR) transgenes that are highly diabetogenic in NOD mice (8.3- and 4.1-TCR, respectively), into recombination-activating gene (RAG)-2-deficient NOD mice, which cannot rearrange endogenous TCR genes and thus bear monoclonal TCR repertoires. We show that while RAG-2(-/-) 4.1-NOD mice, which only bear beta cell-specific CD4+ T cells, develop diabetes as early and as frequently as RAG-2+ 4.1-NOD mice, RAG-2(-/-) 8.3-NOD mice, which only bear beta cell-specific CD8+ T cells, develop diabetes less frequently and significantly later than RAG-2(+) 8.3-NOD mice. The monoclonal CD8+ T cells of RAG-2(-/-) 8.3-NOD mice mature properly, proliferate vigorously in response to antigenic stimulation in vitro, and can differentiate into beta cell-cytotoxic T cells in vivo, but do not efficiently accumulate in islets in the absence of a CD4+ T cell-derived signal, which can be provided by splenic CD4+ T cells from nontransgenic NOD mice. These results demonstrate that naive beta cell- specific CD8+ and CD4+ T cells can trigger diabetes in the absence of other T or B cell specificities, but suggest that efficient recruitment of naive diabetogenic beta cell-reactive CD8+ T cells to islets requires the assistance of beta cell-reactive CD4+ T cells.

The effect of extent of resection on time to tumor progression and survival in patients with glioblastoma multiforme of the cerebral hemisphere

BACKGROUND

We retrospectively analyzed preoperative and postoperative radiographic tumor volumes in 92 patients who underwent hemispheric glioblastoma multiforme operations (107) to determine the factors that affect time to tumor progression (TTP) and overall survival.

METHODS

Quantification of tumor volumes was based on a previously described method involving computerized image analysis of contrast enhancing tumor on computerized tomography or magnetic resonance imaging scans.

RESULTS

Among the variables analyzed, preoperative Karnofsky Performance Status (KPS) (p < 0.05), chemotherapy (p < 0.05), percent of resection (POR) (p < 0.001), and volume of residual disease (VRD) (p < 0.001) had a significant effect on TTP. Factors that affected survival were age (p < 0.05), preoperative KPS (p = 0.05), postoperative KPS (p < 0.005), POR (p < 0.0005), and VRD (p < 0.0001). Greater resections did not compromise the quality of life, and patients without any residual disease had a better postoperative KPS than those patients who received less than total resections.

CONCLUSIONS

The extent of tumor removal and the amount of residual tumor volume, documented on postoperative imaging studies, are highly significant factors affecting the median time to tumor progression and median survival for patients with glioblastoma multiforme of the cerebral hemisphere.

Detection of 16 gamma-ray pulsars through blind frequency searches using the Fermi LAT

Pulsars are rapidly rotating, highly magnetized neutron stars emitting radiation across the electromagnetic spectrum. Although there are more than 1800 known radio pulsars, until recently only seven were observed to pulse in gamma rays, and these were all discovered at other wavelengths. The Fermi Large Area Telescope (LAT) makes it possible to pinpoint neutron stars through their gamma-ray pulsations. We report the detection of 16 gamma-ray pulsars in blind frequency searches using the LAT. Most of these pulsars are coincident with previously unidentified gamma-ray sources, and many are associated with supernova remnants. Direct detection of gamma-ray pulsars enables studies of emission mechanisms, population statistics, and the energetics of pulsar wind nebulae and supernova remnants.

Detection of Rochalimaea henselae DNA in specimens from cat scratch disease patients by PCR

A PCR assay was developed by using degenerate primers that allow amplification of a 414-bp fragment of DNA from the rickettsia-like organisms Rochalimaea henselae and R. quintana. Internal oligonucleotides were used as hybridization probes, permitting rapid differentiation of these two Rochalimaea species. DNAs from 12 different isolates of R. henselae were amplified with the PCR primers, and the resulting 414-bp PCR product hybridized only with the R. henselae-specific probe. DNAs from four different isolates of R. quintana were amplified and produced a PCR product of the same size that hybridized only with the R. quintana-specific probe. DNAs from isolates of R. elizabethae, R. vinsonii, Bartonella bacilliformis, and Afipia felis failed to amplify the 414-bp fragment in the PCR assay. This two-step assay was applied to DNAs extracted from 16 fresh (unfixed) lymph node biopsy specimens and nine aspirates from patients with clinical cat scratch disease (CSD) to assay for the presence of R. henselae or R. quintana DNA in these samples. Twenty-one (84%) of 25 lymph node samples from CSD patients were positive for R. henselae, while none were positive for R. quintana. The characteristic 414-bp fragment was not amplified from eight lymph node tissue samples from non-CSD cases. These results provide evidence that R. henselae, and not R. quintana, plays the central role in the etiology of CSD.

Psychiatric morbidity in adult inpatients with childhood histories of sexual and physical abuse

OBJECTIVE

To extend the knowledge on long-term effects of childhood abuse in psychiatric patients to a large sample, the authors explored childhood sexual and physical abuse in adult inpatients over 1,040 consecutive admissions.

METHOD

The 947 patients were admitted to a tertiary-care military medical center. Each patient was interviewed, and abuse history, DSM-III-R diagnosis, and other characteristics were recorded.

RESULTS

The prevalence of reported childhood abuse was 18% overall: 9% for sexual abuse (with or without physical abuse), 10% for physical abuse (with or without sexual abuse), and 3% for combined abuse. More female than male patients reported abuse. Alcohol use disorders were more common in victims of physical or combined abuse than in sexually abused or nonabused patients. Axis II diagnoses, particularly borderline personality disorder, were more frequent in abuse victims than in nonabused patients. Histories of drug and alcohol abuse were more common in patients reporting physical or combined abuse than in nonabused patients. Suicidality was also more frequent in abused than nonabused inpatients and was noted in 79% of the patients with histories of combined abuse. Combined abuse in women and physical abuse in men were associated with a family history of psychiatric illness, most commonly alcoholism in male relatives.

CONCLUSIONS

These findings emphasize the need for greater attention to family dynamics, aggressive diagnosis and treatment of alcoholism within the family, and, especially, determination of patients' abuse histories, even if repeated questioning is necessary.

Psychosocial therapies in diabetes: report of the Psychosocial Therapies Working Group

OBJECTIVE

To review key advances in the behavioral science literature related to psychosocial issues and therapies for persons with diabetes, to discuss barriers to research progress, and to make recommendations for future research.

RESEARCH DESIGN AND METHODS

Key findings from the literature on psychosocial research in diabetes are reviewed separately for children and adults. Specific issues covered include psychosocial adjustment and psychiatric disorders, neurocognitive functioning, quality of life, and psychosocial therapies. Barriers that must be addressed to allow research in this area to progress are discussed. Recommendations are then made concerning high-priority areas for advancing research in the field.

CONCLUSIONS

A substantial amount of behavioral science research has demonstrated that psychosocial factors play an integral role in the management of diabetes in both children and adults. Research has also shown the efficacy of a number of psychosocial therapies that can improve regimen adherence, glycemic control, psychosocial functioning, and quality of life. More research in this area is needed to develop psychosocial intervention programs for specific patient populations and to demonstrate the cost-effectiveness of these approaches.

Kinetic characterization and cross-resistance patterns of HIV-1 protease mutants selected under drug pressure

Eleven different recombinant, drug-resistant HIV-1 protease (HIV PR) mutants--R8Q, V32I, M46I, V82A, V82F, V82I, I84V, V32I/I84V, M46I/V82F, M46I/I84V, and V32I/K45I/F53L/A71V/I84V/L89M--were generated on the basis of results of in vitro selection experiments using the inhibitors A-77003, A-84538, and KNI-272. Kinetic parameters of mutant and wild-type (WT) enzymes were measured along with inhibition constants (Ki) toward the inhibitors A-77003, A-84538, KNI-272, L-735,524, and Ro31-8959. The catalytic efficiency, kcat/Km, for the mutants decreased relative to WT by a factor of 1.2-14.8 and was mainly due to the elevation of Km. The effects of specific mutations on Ki values were unique with respect to both inhibitor and mutant enzyme. A new property, termed vitality, defined as the ratio (Kikcat/Km)mutant/(Kikcat/Km)WT was introduced to compare the selective advantage of different mutants in the presence of a given inhibitor. High vitality values were generally observed with mutations that emerged during in vitro selection studies. The kinetic model along with the panel of mutants described here should be useful for evaluating and predicting patterns of resistance for HIV PR inhibitors and may aid in the selection of inhibitor combinations to combat drug resistance.

Responsiveness of the Problem Areas In Diabetes (PAID) questionnaire

AIM

Responsiveness (sensitivity to change over time) is a key psychometric quality for an outcome measure. We examined the responsiveness of the Problem Areas In Diabetes (PAID) questionnaire, a measure of diabetes-specific emotional distress.

METHODS

PAID data were obtained from seven diabetes intervention studies following a literature search that included both published papers and conference abstracts. To estimate responsiveness we used two indices: (i) a statistical test (the dependent t-test), and (ii) a commonly used effect size index (Cohen's d).

RESULTS

Mean patient PAID scores improved from baseline to follow-up for all seven studies. Specifically, t-statistics ranged from t= 8.5 (P < 0.001) to t= 2.1 (P < 0.06). Effect size results ranged from 0.32 (i.e. small) for a disease management intervention to 0.65 (i.e. moderate) for an intensive medical/educational intervention.

CONCLUSIONS

Despite the pilot nature of the studies, the pattern of findings provided strong support for the responsiveness of the PAID. Information on responsiveness helps clinical researchers select measures, accurately estimate sample size to ensure adequate statistical power, and prioritize outcomes to be assessed.

Randomized trial of cisplatin versus cisplatin plus mitolactol versus cisplatin plus ifosfamide in advanced squamous carcinoma of the cervix: a Gynecologic Oncology Group study

PURPOSE

Cisplatin, mitolactol (dibromodulcitol), and ifosfamide have been the most active single agents in squamous carcinoma of the cervix identified so far by the Gynecologic Oncology Group (GOG). Combinations of cisplatin plus ifosfamide and cisplatin plus mitolactol are prospectively compared with cisplatin alone.

PATIENTS AND METHODS

Patients were randomized to receive cisplatin 50 mg/m2 or the same dose of cisplatin plus mitolactol (C + M) 180 mg/m2 orally on days 2 to 6, or cisplatin plus ifosfamide (CIFX) 5 g/m2 given as a 24-hour infusion plus mesna 6 g/m2 during and for 12 hours after the ifosfamide infusion, every 3 weeks for up to six courses. Of 454 patients entered, 438 were eligible and analyzed for response and survival.

RESULTS

CIFX had a higher response rate (31.1% v 17.8%, p = .004) and longer progression-free survival (PFS) time (P = .003) compared with cisplatin alone. The median times to progression or death were 4.6 and 3.2 months, respectively. C + M showed no significant improvement in these parameters compared with cisplatin alone. Survival was associated with initial performance score (PS; 0 was more favorable; P < .001) and with age (younger was unfavorable, P = .025). There was no significant difference in overall survival between cisplatin and either of the combinations. Leukopenia, renal toxicity, peripheral neurotoxicity, and CNS toxicity were more frequent with CIFX (P < .05).

CONCLUSION

CIFX improved the response rate and PFS duration in advanced cervix cancer compared with cisplatin alone, but at the cost of greater toxicity and with no improvement in survival.

Stressful life events and social rhythm disruption in the onset of manic and depressive bipolar episodes: a preliminary investigation

BACKGROUND

The association between stressful life events and onset of bipolar episodes is unclear. The association between bipolar episode onset and types of life events that disrupt social routines, and potentially sleep, has not yet been investigated.

METHODS

Thirty-nine bipolar patients with primarily manic (n = 20) or depressed (n = 19) index episodes were interviewed with the Bedford College Life Event and Difficulty Schedule to determine the presence of severe events during 8-week pre-onset and control periods. All life events were also rated for degree of social rhythm disruption (SRD).

RESULTS

More bipolar subjects experienced at least 1 SRD event and severe event in the pre-onset vs control periods. When subjects were divided into those with manic or depressive onsets, the only significant pre-onset vs control difference was for manic patients with SRD events. Additionally, the proportion of subjects with a pre-onset SRD event was greater for manic than for depressed patients.

CONCLUSIONS

We found evidence that life events characterized by SRDs routines are associated with the onset of manic, but not depressive, episodes. Severe events seem to be related to onset of bipolar episodes, although it remains unclear whether severe events relate differentially to depressive and manic onsets.

The influence of the composition of the nursing staff on primary bloodstream infection rates in a surgical intensive care unit

OBJECTIVES

To determine the risk factors for acquisition of nosocomial primary bloodstream infections (BSIs), including the effect of nursing-staff levels, in surgical intensive care unit (SICU) patients.

DESIGN

A nested case-control study.

SETTING

A 20-bed SICU in a 1,000-bed inner-city public hospital.

PATIENTS

28 patients with BSI (case-patients) were compared to 99 randomly selected patients (controls) hospitalized > or =3 days in the same unit.

RESULTS

Case- and control-patients were similar in age, severity of illness, and type of central venous catheter (CVC) used. Case-patients were significantly more likely than controls to be hospitalized during a 5-month period that had lower regular-nurse-to-patient and higher pool-nurse-to-patient ratios than during an 8-month reference period; to be in the SICU for a longer period of time; to be mechanically ventilated longer; to receive more antimicrobials and total parenteral nutrition; to have more CVC days; or to die. Case-patients had significantly lower regular-nurse-to-patient and higher pool-nurse-to-patient ratios for the 3 days before BSI than controls. In multivariate analyses, admission during a period of higher pool-nurse-to-patient ratio (odds ratio [OR]=3.8), total parenteral nutrition (OR=1.3), and CVC days (OR=1.1) remained independent BSI risk factors.

CONCLUSIONS

Our data suggest that, in addition to other factors, nurse staffing composition (ie, pool-nurse-to-patient ratio) may be related to primary BSI risk. Patterns in intensive care unit nurse staffing should be monitored to assess their impact on nosocomial infection rates. This may be particularly important in an era of cost containment and healthcare reform.

Surgical management of cervical cancer complicating pregnancy: a case-control study

A retrospective, case-control analysis of 30 women with cervical cancer associated with pregnancy, surgically managed at the University of Iowa between 1960 and 1994, was performed. Controls were matched with cases based on age, histology, stage, treatment, and year of treatment. Patients were divided into two groups: Group I, radical hysterectomy (26 patients) and group II, simple hysterectomy (4 patients). Eleven patients underwent surgical treatment in the third trimester with a mean planned delay in therapy of 16 weeks. None of the patients with a planned delay in therapy developed recurrent disease. No neonatal morbidity was encountered in these patients. Among group I patients, there was longer anesthesia time (P < 0.03), but there were no differences in the mean operative time. There was more blood loss at the time of surgery among pregnant patients (1493 cc vs 1065 cc for group I, P = 0.005; 812 cc vs 362 cc for group II, P = 0.03); however, there was no difference in the frequency of blood transfusion. The percentage of patients receiving a transfusion decreased significantly after 1991 (33% versus 90%, P = 0.01 for pregnant patients and 33% versus 85%, P = 0.03 for nonpregnant patients). There were no differences in the time required for postoperative bladder drainage, mean hospital stay, febrile morbidity, incidence of wound infection, wound separation, pelvic abscess, thromboembolic disease, or urinary tract infection. One case patient and 3 control patients died of disease, but this difference was not statistically significant. Based upon our data, in selected cases of early-stage cervical cancer, surgical management of cervical cancer is safe during pregnancy. For early Stage I squamous cancers, planned delay in therapy is safe.

Prevalent CD8(+) T cell response against one peptide/MHC complex in autoimmune diabetes

Spontaneous autoimmune diabetes in nonobese diabetic (NOD) mice is the result of a CD4(+) and CD8(+) T cell-dependent autoimmune process directed against the pancreatic beta cells. CD8(+) T cells play a critical role in the initiation and progression of diabetes, but the specificity and diversity of their antigenic repertoire remain unknown. Here, we define the structure of a peptide mimotope that elicits the proliferation, cytokine secretion, differentiation, and cytotoxicity of a diabetogenic H-2K(d)-restricted CD8(+) T cell specificity (NY8.3) that uses a T cell receptor alpha (TCRalpha) rearrangement frequently expressed by CD8(+) T cells propagated from the earliest insulitic lesions of NOD mice (Valpha17-Jalpha42 elements, often joined by the N-region sequence M-R-D/E). Stimulation of splenic CD8(+) T cells from single-chain 8. 3-TCRbeta-transgenic NOD mice with this mimotope leads to preferential expansion of T cells bearing an endogenously derived TCRalpha chain identical to the one used by their islet-associated CD8(+) T cells, which is also identical to the 8.3-TCRalpha sequence. Cytotoxicity assays using islet-derived CD8(+) T cell clones from nontransgenic NOD mice as effectors and peptide-pulsed H-2K(d)-transfected RMA-S cells as targets indicate that nearly half of the CD8(+) T cells recruited to islets in NOD mice specifically recognize the same peptide/H-2K(d) complex. This work demonstrates that beta cell-reactive CD8(+) T cells mount a prevalent response against a single peptide/MHC complex and provides one peptide ligand for CD8(+) T cells in autoimmune diabetes.