An optimized, clinically relevant mouse model of cisplatin-induced ototoxicity.

Cisplatin-induced ototoxicity results in significant, permanent hearing loss in pediatric and adult cancer survivors. Elucidating the mechanisms underlying cisplatin-induced hearing loss as well as the development of therapies to reduce and/or reverse cisplatin ototoxicity have been impeded by suboptimal animal models. Clinically, cisplatin is most commonly administered in multi-dose, multi-cycle protocols. However, many animal studies are conducted using single injections of high-dose cisplatin, which is not reflective of clinical cisplatin administration protocols. Significant limitations of both high-dose, single-injection protocols and previous multi-dose protocols in rodent models include high mortality rates and relatively small changes in hearing sensitivity. These limitations restrict assessment of both long-term changes in hearing sensitivity and effects of potential protective therapies. Here, we present a detailed method for an optimized mouse model of cisplatin ototoxicity that utilizes a multi-cycle administration protocol that better approximates the type and degree of hearing loss observed clinically. This protocol results in significant hearing loss with very low mortality. This mouse model of cisplatin ototoxicity provides a platform for examining mechanisms of cisplatin-induced hearing loss as well as developing therapies to protect the hearing of cancer patients receiving cisplatin therapy.

Root contact with maxillomandibular fixation screws in orthognathic surgery: incidence and consequences.

The use of maxillomandibular fixation (MMF) screws in orthognathic surgery has become common in recent years. The risk of injury to adjacent roots with their placement in this population has not been studied extensively. The aim of this study was to review the incidence and consequences of root contact/injury in patients undergoing orthognathic surgery. A retrospective analysis of the treatment and radiographic records of patients who underwent orthognathic surgery between January 2013 and September 2014 at a university in Kentucky, USA was performed. The mean number of screws used was correlated to the mean number of roots affected using Spearman's test, set to a level of significance of 5%. Of 125 patients who underwent orthognathic surgery, 15 (12%) had evidence of root contact. Subsequent radiographs showed resolution of the bone defects. There was no clinical evidence of pulpal necrosis or pain during follow-up. The average number of screws used was 3.14±0.35 per patient, with an average of 0.17±0.52 root contacts per patient. There was no correlation between the number of screws used and the number of roots injured (P=0.279). Based on these results, MMF screws can safely be used to establish interim fixation during orthognathic surgery. Caution should be taken during placement to avoid direct injury to the roots of teeth.

Live imaging the phagocytic activity of inner ear supporting cells in response to hair cell death.

Hearing loss and balance disorders affect millions of people worldwide. Sensory transduction in the inner ear requires both mechanosensory hair cells (HCs) and surrounding glia-like supporting cells (SCs). HCs are susceptible to death from aging, noise overexposure, and treatment with therapeutic drugs that have ototoxic side effects; these ototoxic drugs include the aminoglycoside antibiotics and the antineoplastic drug cisplatin. Although both classes of drugs are known to kill HCs, their effects on SCs are less well understood. Recent data indicate that SCs sense and respond to HC stress, and that their responses can influence HC death, survival, and phagocytosis. These responses to HC stress and death are critical to the health of the inner ear. Here we have used live confocal imaging of the adult mouse utricle, to examine the SC responses to HC death caused by aminoglycosides or cisplatin. Our data indicate that when HCs are killed by aminoglycosides, SCs efficiently remove HC corpses from the sensory epithelium in a process that includes constricting the apical portion of the HC after loss of membrane integrity. SCs then form a phagosome, which can completely engulf the remaining HC body, a phenomenon not previously reported in mammals. In contrast, cisplatin treatment results in accumulation of dead HCs in the sensory epithelium, accompanied by an increase in SC death. The surviving SCs constrict fewer HCs and display impaired phagocytosis. These data are supported by in vivo experiments, in which cochlear SCs show reduced capacity for scar formation in cisplatin-treated mice compared with those treated with aminoglycosides. Together, these data point to a broader defect in the ability of the cisplatin-treated SCs, to preserve tissue health in the mature mammalian inner ear.

Coordination between production and turnover of interphotoreceptor retinoid-binding protein in zebrafish.

PURPOSE: Interphotoreceptor retinoid-binding protein (IRBP), which is secreted by the photoreceptors of most vertebrates, is the major soluble protein component of the interphotoreceptor matrix (IPM). Recent studies suggest that IRBP is short lived in the IPM (half-life, approximately 11 hours). The mechanisms coordinating the production and removal of IRBP are not known. Zebrafish provide a useful system to study the regulation of these two processes, because its IRBP mRNA levels are under circadian regulation. In the present study, the relationship between the quantity of IRBP, the rate of its turnover, and the expression of its mRNA in the zebrafish retina were examined. METHODS: Full-length zebrafish IRBP was expressed in Escherichia coli and an antiserum generated against purified recombinant IRBP. Western and protein dot blot analyses and indirect immunofluorescence were used to define the temporal and spatial patterns of IRBP expression in the adult zebrafish. In vivo and in vitro metabolic labeling experiments were used to examine the regulation of IRBP turnover by both environmental light and the light-dark cycle. RESULTS: Despite the known rhythmicity in IRBP mRNA expression, neither the amount of IRBP nor its localization changes significantly during the light-dark cycle. IRBP is rapidly removed from the zebrafish eye (half life, approximately 7 hours). This rapid turnover is independent of environmental lighting conditions during subjective day and is more rapid during the day than at night. CONCLUSIONS: Because the amount of IRBP remains constant throughout the day, the enhanced daytime IRBP mRNA expression may function to compensate for an increased turnover of the protein during the day. These findings suggest that the processes of IRBP production and removal are coordinately regulated.

Novel expression pattern of interphotoreceptor retinoid-binding protein (IRBP) in the adult and developing zebrafish retina and RPE.

PURPOSE: Interactions between the neural retina and retinal pigment epithelium (RPE) are mediated by the interphotoreceptor matrix (IPM). The transport of retinoids across the IPM is mediated by interphotoreceptor retinoid-binding protein (IRBP). To explore the possibility that IRBP is important during retinal development, we examined its spatiotemporal expression pattern in embryonic zebrafish. METHODS: IRBP mRNA expression was examined using RT-PCR and in situ hybridization. IRBP was localized using antiserum against recombinant zebrafish IRBP. IRBP synthesis and secretion were studied by in vitro metabolic labeling of retinas and RPE-eyecups. RESULTS: IRBP mRNA was first observed in the pineal at 24 hours post-fertilization (hpf) and in the ventral retina at 50 hpf. Immunoreactive IRBP was first observed at 72 hpf. Remarkably, IRBP was expressed not only by photoreceptors but also by the adult and embryonic RPE. In embryos, expression in both retina and RPE began in a ventronasal patch and spread to involve the entire eye. In general, early IRBP expression was dominated by photoreceptors, but then RPE expression spread beyond the limit of photoreceptor expression. Double in situ hybridizations suggests that cones express IRBP mRNA before they express a specific opsin, while rods may express rod opsin prior to IRBP. CONCLUSIONS: The temporal and spatial patterns of IRBP expression by the RPE and retina are consistent with a role in retinal development and suggest coordination of RPE and photoreceptor differentiation.

Posttraumatic growth following breast cancer: a controlled comparison study.

Cancer may be viewed as a psychosocial transition with the potential for positive and negative outcomes. This cross-sectional study (a) compared breast cancer (BC) survivors' (n = 70) self-reports of depression, well-being, and posttraumatic growth with those of age- and education-matched healthy comparison women (n = 70) and (b) identified correlates of posttraumatic growth among BC survivors. Groups did not differ in depression or well-being, but the BC group showed a pattern of greater posttraumatic growth, particularly in relating to others, appreciation of life, and spiritual change. BC participants' posttraumatic growth was unrelated to distress or well-being but was positively associated with perceived life-threat, prior talking about breast cancer, income, and time since diagnosis. Research that has focused solely on detection of distress and its correlates may paint an incomplete and potentially misleading picture of adjustment to cancer.

Physical symptoms, distress, and breast cancer risk perceptions in women with benign breast problems.

Physical symptoms, general and breast cancer-specific distress, and perceived breast cancer risk were assessed in 66 women with benign breast problems (BBP) and 66 age-matched healthy comparison (HC) women. BBP women reported significantly greater worry about breast cancer than HC women. Breast symptom incidence and breast cancer risk perceptions were found to mediate group differences in breast cancer worry. Hierarchical regression analyses indicated that perceptions of control over a potential breast cancer prognosis moderate the impact of breast symptoms on reports of breast cancer worry. Implications for risk counseling with BBP women are discussed.

Social constraints, cognitive processing, and adjustment to breast cancer.

This cross-sectional study of 70 breast cancer survivors examined relationships among social constraints, behavioral and self-report indicators of cognitive processing, depression, and well-being. On the basis of a social-cognitive processing (SCP) model, it was predicted that social constraints would inhibit cognitive processing of the cancer experience, leading to poorer adjustment. Constraints were positively associated with intrusions, avoidance, and linguistic uncertainty in cancer narratives. Greater uncertainty, intrusions, and avoidance, as well as less talking about cancer were associated with greater depression and less well-being. Intrusions partially mediated the positive constraints-depression relationship. Talking about cancer partially mediated the inverse avoidance-well-being relationship. Findings support the SCP model and the importance of using behavioral indicators of cognitive processing to predict positive and negative psychosocial outcomes of cancer.

Physical and sexual abuse among orofacial pain patients: linkages with pain and psychologic distress.

This study examines the incidence of and the potential correlates of sexual and physical abuse among facial pain patients. An anonymous survey composed of standardized self-report measures of abuse, pain, and psychologic status was distributed to 120 adult facial pain patients following their initial evaluations. Forty-five questionnaires were returned by mail. In addition, 206 charts were randomly selected from a population of 520 new patients seen at the Orofacial Pain Center during the same time period that data from the anonymous survey were collected. Results of the anonymous survey indicated that 68.9% of the patients reported a history of abuse. Conversely, a chart review revealed that only 8.5% of the patients indicated a history of abuse on the clinic questionnaire. History of abuse was significantly related to greater pain severity, depression, psychologic distress, and various personality characteristics. Overall, this study indicates that the assessment of the history of abuse may be an important factor in the evaluation and treatment of facial pain.

A bidirectional relationship of oral-systemic responses: observations of systemic host responses in patients after full-mouth extractions.

OBJECTIVE: This investigation tested the hypothesis that systemic inflammatory responses would be attenuated by minimizing the oral microbial burden in patients with moderate to severe periodontitis. STUDY DESIGN: Patients (n = 73) scheduled for full-mouth extractions were categorized as case type I/II (gingivitis/mild periodontitis) or case type III/IV (moderate/severe periodontitis). Serum levels of acute phase proteins (APPs) and immunoglobulin G (IgG) antibody were assessed at baseline and through 1 year after extraction. RESULTS: At baseline, the levels of multiple APPs (e.g., fibrinogen, C-reactive protein) and antibodies to periodontal pathogens were significantly higher with case type III/IV vs I/II. These differences were sustained 12 months after extractions for most APPs. CONCLUSIONS: The results demonstrated that removal of disease by full-mouth extraction of teeth altered the overall burden of challenge to the host. Continued elevation in various APPs in the III/IV group suggested a potential underlying constitutive difference in systemic response characteristics of this population.

Overexpression of cyclin A in oral dysplasia: An international comparison and literature review.

Oral squamous cell carcinoma (OSCC) is one of the most debilitating cancers in the world and while its causes have been heavily researched, the outcome remains grim. Most of these cancers are identified in the late stage and as a result treatment options are limited. Therefore, researchers have focused their efforts on recognizing and identifying dysplastic tissue that has an increased chance of progressing to cancer. Research has begun to look at cell cycle dysfunctions and in particular, aberrant protein functions as a way of identifying the cellular mechanism at fault. The overexpression of a group of regulatory proteins called cyclins has been demonstrated in many types of dysplasia and carcinomas. Although researchers have identified several different types of cyclins as potential culprits, we chose to focus our study primarily on the overexpression of cyclin A. While most research on oral dysplasia and OSCC has been focused on cyclin D, studies have been done on cyclin A. While the etiology of oral dysplasia/SCC appears to be multifactorial, we chose to compare our results with those of similar studies performed across the globe. The social factors, such as the increased use of tobacco that may have contributed to our results, were compared with similar studies performed in Europe and Asia. While our results were remarkably similar and demonstrated a link between the overexpression of cyclin A in oral dysplasia, there exists some differences and thus may require a multicenter, longitudinal study.

Celastrol inhibits aminoglycoside-induced ototoxicity via heat shock protein 32.

Hearing loss is often caused by death of the mechanosensory hair cells of the inner ear. Hair cells are susceptible to death caused by aging, noise trauma, and ototoxic drugs, including the aminoglycoside antibiotics and the antineoplastic agent cisplatin. Ototoxic drugs result in permanent hearing loss for over 500,000 Americans annually. We showed previously that induction of heat shock proteins (HSPs) inhibits both aminoglycoside- and cisplatin-induced hair cell death in whole-organ cultures of utricles from adult mice. In order to begin to translate these findings into a clinical therapy aimed at inhibiting ototoxic drug-induced hearing loss, we have now examined a pharmacological HSP inducer, celastrol. Celastrol induced upregulation of HSPs in utricles, and it provided significant protection against aminoglycoside-induced hair cell death in vitro and in vivo. Moreover, celastrol inhibited hearing loss in mice receiving systemic aminoglycoside treatment. Our data indicate that the major heat shock transcription factor HSF-1 is not required for celastrol-mediated protection. HSP32 (also called heme oxygenase-1, HO-1) is the primary mediator of the protective effect of celastrol. HSP32/HO-1 inhibits pro-apoptotic c-Jun N-terminal kinase (JNK) activation and hair cell death. Taken together, our data indicate that celastrol inhibits aminoglycoside ototoxicity via HSP32/HO-1 induction.

Interphotoreceptor retinoid-binding protein (IRBP) is rapidly cleared from the Xenopus interphotoreceptor matrix.

The interphotoreceptor matrix (IPM) is a highly-organized extracellular matrix critical to retinal development and function. Although the concentrations of its components are carefully regulated, little is known about the mechanisms of this regulation. Interphotoreceptor retinoid-binding protein (IRBP) is the most abundant soluble protein component of the IPM. Although its rate of clearance is thought to be an important factor regulating the concentration of IRBP within the IPM, no study has measured the rate of its extracellular turnover. Here we determine the rate of turnover of matrix IRBP in Xenopus. The rate of IRBP turnover was estimated by measuring the loss of radioactivity from protein labeled by a single injection of a radiolabeled protein precursor. To provide an estimate of the rate of IRBP turnover, we have examined the following issues: (1) Quantitative extraction of IRBP from the IPM for biochemical analysis. (2) Routes of delivery of radiolabeled precursor to achieve a pulse label in vivo. (3) Selection of labeled precursor in order to minimize reutilization of radiolabel. Using Western blot analysis, immunoprecipitation and immuno-electron microscopy, we found that IRBP can be quantitatively extracted from the IPM by a simple saline wash. IRBP was radiolabeled by systemic or intravitreal injection of either [35S]methionine or carboxyl-terminal labeled [1-14C]leucine. The specific activity of matrix IRBP was determined by either phosphorimaging or fluorography of Coomassie blue-stained SDS-polyacrylamide gels. Intravitreal injection of tracer was more effective than systemic delivery in achieving a pulse of radiolabel to the retina. This may be due to intravitreal injection allowing the body to act as a 'sink' for radiolabeled amino acid. When radiolabeled precursor was delivered by intravitreal injection, the calculated half-life of matrix IRBP using [35S]methionine was 25. 6+/-0.82 hr; in contrast, it was 10.7+/-2.9 hr using [1-14C]leucine. The faster apparent IRBP turnover using [1-14C]leucine is interpreted in context of the early decarboxylation of leucine during its degradation. Our results demonstrate rapid turnover of IRBP in the Xenopus IPM in vivo and suggest that the IPM is a dynamic structure undergoing continuous renewal.

Localization of genomic regions specific for the attenuated, mouse-adapted poliovirus type 2 strain W-2.

In order to begin to elucidate the genomic basis of the attenuation of mouse-adapted, poliovirus type 2 strain W-2 (PV2/W-2), we have cloned and sequenced the virus and compared it with the virulent, mouse-adapted PV2/Lansing strain. In addition, we have performed computer-generated comparisons of PV2/W-2 to the non-mouse-adapted, attenuated PV2/Sabin strain to determine whether mutational patterns occur that result in attenuation. The PV2/W-2 genome is 7434 nucleotides in length, which is three bases shorter than PV2/Lansing. The 5' non-coding region of PV2/W-2 is 747 nucleotides in length (compared to 744 in PV2/Lansing) and shares 98.8% identity with PV2/Lansing and 82.3% identity with PV2/Sabin. Overall, the PV2/W-2 polyprotein (2205 amino acids) is two amino acids shorter than that of either PV2/Lansing or PV2/Sabin (2207 amino acids). These contiguous deletions fall within the P3-D region (polymerase). Within these 2205 amino acid residues only 26 differences were observed between PV2/W-2 and PV2/Lansing (98.8% identity), whereas 92 occurred between PV2/W-2 and PV2/Sabin (95.8% identity). The 3' non-coding region of PV2/W-2 is 72 nucleotides in length and shares 100% identity with PV2/Lansing and 98.6% identity with PV2/Sabin. Amino acid changes in the capsid protein region occurred in neutralization sites 1 and 3, areas previously shown to be important for pathogenicity. The cleavage site between non-structural proteins P2-C/P3-A consisted of a glutamine-serine pair, in contrast to other sequenced polioviruses which have a glutamine-glycine dipeptide.

A comparison of questionnaire versus monofilament assessment of neurosensory deficit.

PURPOSE: Because neurosensory deficit is commonly reported by patients after orthognathic surgery, it is important to know how accurately patients can report their own sensory deficit. This analysis compares the results of objective neurosensory tests with the results of a subjective patient questionnaire. MATERIALS AND METHODS: Before and 6 months after bilateral mandibular sagittal ramus split osteotomy, 101 patients with class II facial deformities were asked to rate sensations of numbness or tingling in the area of the mental nerve. Simultaneously, they were objectively tested using monofilament neurosensory tests (light touch and brush stroke direction). RESULTS: More than 70% of patients subjectively reported neurosensory problems, but objective assessment identified neurosensory deficits in less than 60% of the patients. The sensitivity and specificity of the patients' subjective assessments were 75.3% and 52.8%, respectively, for the light touch test, and 77.9% and 59.8%, respectively, for the brush stroke test. CONCLUSIONS: It was concluded that when monofilament neurosensory testing is used as the gold standard, patients appear to overreport neurosensory problems; ie, the positive predictive value of patient reports is only 63.2%, resulting in frequent false positives.

Do participants' reports of symptom prevalence or severity vary by interviewer gender?

BACKGROUND: Although interviews are commonly used to gather research data, the integrity of interview data can be threatened by discrepancies between interviewers and respondents on such characteristics as race, gender, or age. OBJECTIVES: To determine if participants' reports of the prevalence and severity of 30 symptoms varied as a function of interviewer gender. Symptoms that were assessed included general physical symptoms (diarrhea, headaches), psychological symptoms (feel blue and depressed, worry about nervous breakdown), and menopausal symptoms (hot flashes, vaginal dryness). METHOD: Structured telephone interviews were completed by 137 women who were a mean of 56.5 years old (SD = 11.1, range 36-83) and a mean of 38.8 months (SD = 23.6) postdiagnosis of breast cancer. Interviewers included two women and two men. RESULTS: Symptom prevalence and severity did not vary as a function of interviewer gender. CONCLUSIONS: Findings suggest that both male and female interviewers can be used successfully to assess participants' reports of physical, psychological, or menopausal symptoms.

Adherence to recommendations for clinical follow-up after benign breast biopsy.

PURPOSE: Women who undergo a benign breast biopsy are at elevated risk for the subsequent development of breast cancer (BC). Therefore, appropriate clinical follow-up of a benign breast biopsy is important. The present study examines the extent and correlates of nonadherence with follow-up recommendations after a benign breast biopsy. METHODS: Women (n = 114) who had undergone a benign breast biopsy completed an initial telephone interview within 50 days of their biopsy (mean = 21 days). Additional telephone interviews were completed at 4 and 8 months post-biopsy. Measures of BC risk perception, general and BC-specific distress, BC-related attitudes and beliefs, social support, optimism, and informational coping style were completed. Specific recommendations for clinical follow-up and evidence of actual follow-up were obtained from medical records. RESULTS: Of 103 women given a specific recommendation for clinical follow-up, 34% were classified as nonadherent with follow-up recommendations. Logistic regression analyses indicated that nonadherent women were characterized by younger age, recommendations for follow-up by clinical breast examination alone, greater confidence in their ability to perform breast self-examination properly, higher perceived personal risk for BC, and greater BC-specific distress. CONCLUSION: Despite the importance of appropriate clinical follow-up of a benign breast biopsy, about one-third of women did not adhere to recommended follow-up. Risk factors for nonadherence suggest potential avenues for interventions to enhance participation in appropriate clinical follow-up.

Zebrafish interphotoreceptor retinoid-binding protein: differential circadian expression among cone subtypes.

Retinoid trafficking between the photoreceptors and pigmented epithelium is probably mediated by interphotoreceptor retinoid-binding protein (IRBP), a 124-145 kDa glycolipoprotein in mammals and amphibians. In these animals, IRBP is composed of four homologous regions (modules) 300 amino acids in length. We have determined the primary structure of zebrafish IRBP and its expression pattern by northern analysis, reverse transcriptase-polymerase chain reaction and in situ hybridization under a variety of lighting conditions. Zebrafish IRBP is half the size (66.3 kDa) of mammalian IRBP because it is composed of only two modules, similar to goldfish IRBP. The first half of the zebrafish protein is most similar to the first module of mammalian IRBP and the second half to the fourth module of mammalian IRBP. This suggests that during the evolution of the ray-finned fish (Actinopterygii), the middle two modules were lost. Each of the modules contains conserved hydrophobic domains which may form the ligand-binding pocket. The expression of zebrafish IRBP mRNA is sevenfold higher in the middle of the light period (at mid-light) than in the middle of the dark period (at mid-dark). This rhythm persists for 2 days under conditions of constant light or constant darkness, then dampens to an intermediate level by 8 days of constant conditions. At mid-light, IRBP mRNA is expressed by all cone types and to a lesser extent by the rods. At mid-dark, the mRNA is restricted to the ultraviolet-sensitive short single cones. These data suggest that IRBP expression is regulated by circadian and light-driven mechanisms that act differentially on the various photoreceptor subtypes in the zebrafish retina.

Psychometrics for two short forms of the Center for Epidemiologic Studies-Depression Scale.

The Center for Epidemiologic Studies-Depression Scale (CES-D; L. S. Radloff, 1977) assesses the presence and severity of depressive symptoms occurring over the past week. Although it contains only 20 items, its length may preclude its use in a variety of clinical populations. This study evaluated psychometric properties of 2 shorter forms of the CES-D developed by F. J. Kohout, L. F. Berkman, D. A. Evans, and J. Cornoni-Huntley (1993): the Iowa form and the Boston form. Data were pooled from 832 women representing 6 populations. Internal consistency estimates, correlations with the original version of the CES-D, and omitted-included item correlations supported use of the Iowa form over the Boston form when a shortened version of the scale is desired. Regression statistics are provided for use in estimating scores on the original CES-D when either shortened form is used. Factor analytic results from two populations support a single-factor structure for the original CES-D as well as the short forms.