Large-scale annotated dataset for cochlear hair cell detection and classification

Our sense of hearing is mediated by cochlear hair cells, of which there are two types organized in one row of inner hair cells and three rows of outer hair cells. Each cochlea contains 5-15 thousand terminally differentiated hair cells, and their survival is essential for hearing as they do not regenerate after insult. It is often desirable in hearing research to quantify the number of hair cells within cochlear samples, in both pathological conditions, and in response to treatment. Machine learning can be used to automate the quantification process but requires a vast and diverse dataset for effective training. In this study, we present a large collection of annotated cochlear hair-cell datasets, labeled with commonly used hair-cell markers and imaged using various fluorescence microscopy techniques. The collection includes samples from mouse, rat, guinea pig, pig, primate, and human cochlear tissue, from normal conditions and following in-vivo and in-vitro ototoxic drug application. The dataset includes over 107,000 hair cells which have been identified and annotated as either inner or outer hair cells. This dataset is the result of a collaborative effort from multiple laboratories and has been carefully curated to represent a variety of imaging techniques. With suggested usage parameters and a well-described annotation procedure, this collection can facilitate the development of generalizable cochlear hair-cell detection models or serve as a starting point for fine-tuning models for other analysis tasks. By providing this dataset, we aim to give other hearing research groups the opportunity to develop their own tools with which to analyze cochlear imaging data more fully, accurately, and with greater ease.

Hear and Now: Ongoing Clinical Trials to Prevent Drug-Induced Hearing Loss

Each year over half a million people experience permanent hearing loss caused by treatment with therapeutic drugs with ototoxic side effects. There is a major unmet clinical need for therapies that protect against this hearing loss without reducing the therapeutic efficacy of these lifesaving drugs. At least 17 clinical trials evaluating 10 therapeutics are currently underway for therapies aimed at preventing aminoglycoside- and/or cisplatin-induced ototoxicity. This review describes the preclinical and clinical development of each of these approaches, provides updates on the status of ongoing trials, and highlights the importance of appropriate outcome measures in trial design and the value of reporting criteria in the dissemination of results.

Macrophage Depletion Protects Against Cisplatin-Induced Ototoxicity and Nephrotoxicity

Cisplatin is a widely used and highly effective anti-cancer drug with significant side effects including ototoxicity and nephrotoxicity. Macrophages, the major resident immune cells in the cochlea and kidney, are important drivers of both inflammatory and tissue repair responses. To investigate the roles of macrophages in cisplatin-induced ototoxicity and nephrotoxicity, we used PLX3397, an FDA-approved inhibitor of the colony-stimulating factor 1 receptor (CSF1R), to eliminate tissue-resident macrophages during the course of cisplatin administration. Mice treated with cisplatin alone (cisplatin/vehicle) had significant hearing loss (ototoxicity) as well as kidney injury (nephrotoxicity). Macrophage ablation using PLX3397 resulted in significantly reduced hearing loss measured by auditory brainstem responses (ABR) and distortion-product otoacoustic emissions (DPOAE). Sensory hair cells in the cochlea were protected against cisplatin-induced death in mice treated with PLX3397. Macrophage ablation also protected against cisplatin-induced nephrotoxicity, as evidenced by markedly reduced tubular injury and fibrosis as well as reduced plasma blood urea nitrogen (BUN) and neutrophil gelatinase-associated lipocalin (NGAL) levels. Mechanistically, our data suggest that the protective effect of macrophage ablation against cisplatin-induced ototoxicity and nephrotoxicity is mediated by reduced platinum accumulation in both the inner ear and the kidney. Together our data indicate that ablation of tissue-resident macrophages represents a novel strategy for mitigating cisplatin-induced ototoxicity and nephrotoxicity.

Brief summary

Macrophage ablation using PLX3397 was protective against cisplatin-induced ototoxicity and nephrotoxicity by limiting platinum accumulation in the inner ear and kidney.

Large-scale annotated dataset for cochlear hair cell detection and classification

Our sense of hearing is mediated by cochlear hair cells, localized within the sensory epithelium called the organ of Corti. There are two types of hair cells in the cochlea, which are organized in one row of inner hair cells and three rows of outer hair cells. Each cochlea contains a few thousands of hair cells, and their survival is essential for our perception of sound because they are terminally differentiated and do not regenerate after insult. It is often desirable in hearing research to quantify the number of hair cells within cochlear samples, in both pathological conditions, and in response to treatment. However, the sheer number of cells along the cochlea makes manual quantification impractical. Machine learning can be used to overcome this challenge by automating the quantification process but requires a vast and diverse dataset for effective training. In this study, we present a large collection of annotated cochlear hair-cell datasets, labeled with commonly used hair-cell markers and imaged using various fluorescence microscopy techniques. The collection includes samples from mouse, human, pig and guinea pig cochlear tissue, from normal conditions and following in-vivo and in-vitro ototoxic drug application. The dataset includes over 90'000 hair cells, all of which have been manually identified and annotated as one of two cell types: inner hair cells and outer hair cells. This dataset is the result of a collaborative effort from multiple laboratories and has been carefully curated to represent a variety of imaging techniques. With suggested usage parameters and a well-described annotation procedure, this collection can facilitate the development of generalizable cochlear hair cell detection models or serve as a starting point for fine-tuning models for other analysis tasks. By providing this dataset, we aim to supply other groups within the hearing research community with the opportunity to develop their own tools with which to analyze cochlear imaging data more fully, accurately, and with greater ease.

Stability of Early Auditory Evoked Potential Components Over Extended Test-Retest Intervals in Young Adults

OBJECTIVES

Synaptic damage from noise exposures can occur even in the absence of changes in hearing sensitivity in animal models. There is an unmet clinical need for measurements sensitive to such damage to the human auditory system that can augment the pure-tone audiogram. Early components (i.e., <10 msec) of the auditory evoked potential (AEP) may be useful noninvasive indicators of synaptic integrity. Wave I is a measure of synchronous neural activity at the level of the synapse between cochlear inner hair cells and the auditory nerve and may be of particular clinical utility. This amplitude measure has historically been classified as too variable in humans to be used for clinical waveform interpretation, though several recent reliability studies have challenged this view. The focus of the present study is to examine across-session stability of early AEP amplitude measures.

DESIGN

In this study, amplitudes of early components (wave I, wave V, summating potential [SP]) of the AEP were measured in a cohort of 38 young adults aged 19 to 33 years (21 female). Stability of these amplitude measures was examined in a subset of 12 young adults (8 female), at time intervals ranging from 15 hr to 328 days between tests. Eligibility criteria included normal pure-tone hearing sensitivity, normal tympanometry, and intact acoustic reflexes. Participants were tested at up to four time points. Each evaluation included pure-tone thresholds, tympanometry, speech-in-noise testing, distortion-product otoacoustic emissions (DPOAE), and early AEPs. AEPs were collected in response to click and tone burst stimuli, with both ear canal and mastoid electrode montages.

RESULTS

No clinical changes in pure-tone hearing were found between baseline and follow-up visits. Intraclass correlation coefficients (ICCs) indicated good to excellent reliability for wave I and wave V peak-to-trough amplitudes within individuals across time, with greatest reliability (0.92, 95% confidence interval [0.81 to 0.96]) and largest amplitudes for wave I when measured from the ear canal in response to a click stimulus. Other measures such as amplitude ratios of waves V/I and the SP and action potential (AP) showed lower ICC values when measured from the ear canal, with SP/AP ratio demonstrating the lowest reliability.

CONCLUSIONS

The results of this study suggest that, when recorded under certain conditions, wave I amplitude can be a stable measure in humans. These findings are consistent with previous work and may inform the development of clinical protocols that utilize wave I amplitude to infer inner ear integrity.

The Lifebox Surgical Headlight Project: engineering, testing, and field assessment in a resource-constrained setting

BACKGROUND

Poor surgical lighting represents a major patient safety issue in low-income countries. This study evaluated device performance and undertook field assessment of high-quality headlights in Ethiopia to identify critical attributes that might improve safety and encourage local use.

METHODS

Following an open call for submissions (December 2018 to January 2019), medical and technical (non-medical) headlights were identified for controlled specification testing on 14 prespecified parameters related to light quality/intensity, mounting and battery performance, including standardized illuminance measurements over time. The five highest-performing devices (differential illumination, colour rendering, spot size, mounting and battery duration) were distributed to eight Ethiopian surgeons working in resource-constrained facilities. Surgeons evaluated the devices in operating rooms, and in a comparative session rated each headlight in terms of performance and willingness to purchase.

RESULTS

Of 25 submissions, eight headlights (6 surgical and 2 technical) met the criteria for full specification testing. Scores ranged from 8 to 12 (of 14), with differential performance in lighting, mounting and battery domains. Only two headlights met the illuminance parameters of more than 35 000 lux during initial testing, and no headlight satisfied all minimum specifications. Of the five headlights evaluated in Ethiopia, daily operation logbooks noted variability in surgeons' opinions of lighting quality (6-92 per cent) and spot size (0-92 per cent). Qualitative interviews also yielded important feedback, including preference for easy transport. Surgeons sought high quality with price sensitivity (using out-of-pocket funds) and identified the least expensive but high-functioning device as their first choice.

CONCLUSION

No device satisfied all the predetermined specifications, and large price discrepancies were critical factors leading surgeons' choices. The favoured device is undergoing modification by the manufacturer based on design feedback so an affordable, high-quality surgical headlight crafted specifically for the needs of resource-constrained settings can be used to improve surgical safety.

Lovastatin protects against cisplatin-induced hearing loss in mice

Cisplatin is used to treat a variety of solid tumors in both children and adults. However, cisplatin has serious side-effects, some of which may permanently affect patients' quality of life following treatment, such as ototoxicity. There is currently no FDA-approved therapy for the prevention or treatment of cisplatin-induced hearing loss. Herein we examine the potential for statins to prevent cisplatin-induced ototoxicity. Statins, a class of drugs commonly used to prevent or manage hypercholesterolemia, have been of clinical utility for decades with dependable outcomes and reliable safety profiles in humans. Statins are known to be protective in animal models of noise-induced and age-related hearing loss. Moreover, studies have demonstrated an additive benefit of statins in cancer treatment. In the current study, lovastatin reduces cisplatin-induced hearing loss in adult mice. Lovastatin-mediated protection was significantly greater among female than male mice, and the dose of lovastatin required for protection was different between the sexes. Taken together our data indicate that lovastatin reduces cisplatin-induced hearing loss in mice and suggest that concurrent statin and cisplatin therapy may represent a feasible clinical strategy for reducing cisplatin-induced ototoxicity that should be explored for future clinical use.

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.

Abstract PD7-07: Synergistic targeting of CDK4/6 and BCL-2 pathways in estrogen receptor positive breast cancer

Background: Despite incremental advances in chemotherapy and endocrine therapy, survival outcomes for patients with ER-positive (ER+) metastatic breast cancer (MBC) remain poor. The majority of relapsing tumors exhibit deregulation of the cyclin-dependent kinase 4 and 6 (CDK4/6)/cyclin D1 (CCND1)/Rb signaling pathway. CDK4/6 inhibitors (such as palbociclib) in combination with endocrine therapy have been shown to significantly improve progression free survival in patients who are in 1st or 2nd line relapse, although overall survival benefit has yet to be demonstrated. This may reflect their largely cytostatic mechanism of action, with minimal induction of tumor cell death. Thus, combinatorial strategies that also induce apoptosis could be beneficial. Notably, the pro-survival protein BCL-2 is overexpressed in the majority of ER+ tumors and the potent and specific BCL-2 inhibitor venetoclax (ABT-199) has been found to synergize with endocrine therapy in patient derived xenograft (PDX) models. Promising activity has also been observed in an early phase clinical trial. We therefore investigated dual targeting of the CDK4/6 and BCL-2 pathways in pre-clinical models of ER+ and BCL-2+ breast cancer.

Results: We first examined endocrine sensitive or resistant cell-lines and found that pro-survival BCL-2 proteins were upregulated in resistant cells. BCL-2 family protein levels were also found to be elevated in palbociclib resistant cells, suggesting that BCL-2 could represent a therapeutic target. We next determined whether venetoclax improved response to dual therapy comprising the selective estrogen receptor degrader fulvestrant and palbociclib. In clonogenic assays of endocrine sensitive breast cancer cell lines, triple therapy containing venetoclax significantly reduced the number and size of colonies, when compared to double therapy. The addition of venetoclax to fulvestrant/palbociclib also augmented cell death in tumor organoid models derived from either ER+ BCL-2+ primary tumors or PDX models. Moreover, triple therapy improved tumor response and overall survival in mice bearing ER+ BCL-2+ PDX tumors. Mechanistically, this was accompanied by increased apoptosis and reduced cellular proliferation (as determined by cleaved caspase-3 and Ki67 levels, respectively). As CDK4/6 inhibitors have recently been shown to promote anti-tumor immunity, we evaluated immune modulation using the ER+ 67NR cell line in a syngeneic (BALB/c) mouse mammary tumor model. Similar to the PDX models, triple therapy comprising fulvestrant, palbociclib and venetoclax was more effective than double therapy comprising either fulvestrant/palbociclib or fulvestrant/venetoclax. Flow cytometric analysis of tumors revealed that this was accompanied by a reduced intratumoral FOXP3+:cytotoxic CD8 T-cell ratio.

Conclusions: The addition of the BCL-2 inhibitor venetoclax to conventional therapy comprising endocrine therapy and a CDK4/6 inhibitor augments tumor response and elicits a favorable intratumoral immune profile. Collectively, these findings support investigation of combination therapy in the clinic for patients with ER+ BCL-2+ MBC.

Citation Format: Whittle JR, Vaillant F, Policheni AN, Liu K, Pal B, Giner G, Fernandez K, Gray DH, Caldon CE, Smyth GK, Visvader JE, Lindeman GJ. Synergistic targeting of CDK4/6 and BCL-2 pathways in estrogen receptor positive breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD7-07.

Abstract P1-10-20: A multi-center trial of intra-operative electronic brachytherapy during breast conservation surgery for early stage breast cancer: Early results of unplanned boost participants

Objective

To assess the safety and efficacy of single-fraction, intra-operative radiation therapy (IORT) delivered as a boost using the Xoft® Axxent® Electronic Brachytherapy System® (eBx®) immediately following surgical resection for treatment of early stage breast cancer.

Methods

This phase 4, open-label, single-arm, prospective, non-randomized trial is still enrolling participants and is currently being conducted at 26 hospitals in the USA (25) and Portugal (1). 878 participants with biopsy-proven ductal carcinoma in situ (DCIS) or invasive ductal carcinoma who met the inclusion criteria underwent lumpectomy followed by single-fraction IORT to the lumpectomy cavity. Briefly, a small, presterilized lead shield piece was placed on the chest wall to reduce the dose to the ribs, and then a balloon applicator, suitable to the surgical bed, was placed in the lumpectomy cavity and inflated with saline (30-75 cc); skin was temporarily closed over the balloon and ultrasound was used to confirm a balloon surface-to-skin distance ≥ 1.0 cm. The Xoft System was used to deliver the 20 Gy dose at the balloon applicator surface. The balloon was deflated, lead shield and balloon removed and the surgical site sutured. Upon the presence of additional risk factors, 37 participants subsequently received whole breast radiation therapy (WBRT); thus, these participants received an unplanned IORT boost and were removed from the primary analysis but will continue to be followed for the duration of the 10-year study. Cosmesis (Harvard Scale) was assessed in this subset of participants. The primary outcome for the main trial is recurrence of ipsilateral breast tumor at 5 years. Trial Registry: ClinicalTrials.gov; Identifier: NCT01644669.

Early Findings

37 boost participants received WBRT (up to 50 Gy) after IORT (36 received the prescribed 20 Gy dose; one received 14 Gy). Mean follow-up time was 430 days (range 13-1119). Mean age at IORT was 62 years (range 45-78). Boost participants had either DCIS (N=5) or invasive ductal carcinoma (N=32). The DCIS nuclear grade was high (N=3), intermediate (N=1), or low (N=1). Invasive cancers were Grade 1 (N=15), 2 (N=10), 3 (N=6), or unknown (N=1). 29 participants had T1, 3 had T2, and 5 had Tis lesions. Mean tumor size was 13.04 ± 10.26 mm. For the two participants who have reached 3-year follow-up, cosmesis was excellent (N=1) and fair (N=1). For the six participants who have reached 2-year follow-up, cosmesis was excellent (N=4), good (N=1), and fair (N=1). There was one serious adverse event with a Grade 3 for skin necrosis. The most frequent side effects were seroma (10%), edema (9%), pain (9%), erythema (6%), and induration (5%). There have been no deaths, recurrences, or new primary tumors among the boost participants to date.

Conclusions

Early results from this multi-center trial suggest that IORT as a tumor-bed boost using the Xoft Axxent eBx System at the time of breast conservation surgery is safe and has low morbidity. To date, the majority of participants receiving an unplanned IORT boost have had excellent to good cosmetic results and the majority of adverse events have been low-grade.

Funding

Funded by Xoft, Inc., a subsidiary of iCAD, Inc.

Citation Format: Syed AMN, Chang H, Schwartzberg B, Bremner A, Boylan S, Lopez-Penalver C, Vito C, Davis M, Dooley W, Chakravarthy AB, Coomer C, Proulx G, Golder S, Ivanov O, Fernandez K, Farha MJ, Gonzalez V, Wengler C, Bhatnagar A, Neuner GA, Kopkash K, Rahman S, Costa P. A multi-center trial of intra-operative electronic brachytherapy during breast conservation surgery for early stage breast cancer: Early results of unplanned boost participants [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-10-20.

Abstract P3-12-11: One-year follow-up results of a multi-center trial of intra-operative radiation therapy using electronic brachytherapy at the time of breast conservation surgery for early stage breast cancer

Objectives: To describe observations of one-year follow-up of subjects treated on a multi-center, non-randomized study with a single fraction of intra-operative radiation therapy (IORT) using the Xoft® Axxent® Electronic Brachytherapy System® (eBx®) immediately following surgical resection of early stage breast cancer.

Methods: Two-hundred forty three (243) subjects were treated at seventeen (17) US hospitals. Upon meeting the inclusion/exclusion criteria, patients underwent partial mastectomy, placement of a balloon applicator suitable to the surgical bed in the lumpectomy cavity and inflated with saline (30 – 75 cc). The skin was temporarily closed over the balloon and ultrasound examination performed to confirm that the balloon surface-to-skin distance was &gt; 1.0 cm. A single fraction of intra-operative radiation therapy was delivered to the lumpectomy cavity using the Xoft System. The prescribed dose was 20 Gy at the balloon applicator surface, and the mean treatment time was 10.2 minutes. After treatment, the balloon was deflated and removed, and skin sutured.

Results: Two-hundred forty two (242) subjects received the prescribed dose of 20 Gy; one subject received 21 Gy. Eighteen (18) subjects were removed from the primary analysis post-IORT due to positive surgical margins (N=2), positive sentinel lymph nodes (N=13), or balloon surface-to-skin distance &lt; 1 cm (N=3). However, these eighteen subjects will continue to be followed for the duration of this 10-year study. The mean follow-up for the two-hundred twenty five evaluable subjects is 494 days (range 300-465 days). The mean patient age was 65 years (41-89). Forty-nine subjects (21.8%) had ductal carcinoma in situ, one-hundred seventy one (76%) had invasive ductal carcinoma, and five (2.2%) had unknown histology. The DCIS nuclear grade was evenly distributed between high (N=18) and low/intermediate (N=23); 5 were unknown. Invasive cancer was Grade 1-2 in 142/171 cases. Two-hundred twelve subjects (94.2%) had T1 lesions, eight (3.6%) had T2 lesions, and five (2.2%) were unknown. The mean tumor size was 10.6 mm ± 6.4 mm. At the time of the last subject visit, 49/318 reported adverse events were Grade 2 or higher, and only 1/100 had serious side effects, i.e. infection. One patient died of aortic aneurism and two developed secondary malignancies, i.e. ovarian cancer and chronic lymphocytic leukemia. The most frequent side effects were seroma (12.5%), erythema (9.1%), and induration (7.5%). Cosmesis was excellent to good in 95% of cases.

Conclusions: IORT using the Xoft System as part of the conservative treatment of breast cancer is safe, with low morbidity. Early results from this multi-center trial demonstrate this short, convenient course of radiation therapy for select patients with early stage breast cancer has excellent-to-good cosmetic results and a low rate of low-grade adverse events.

Citation Format: Syed AMN, Chang H, Schwartzberg BS, Bremner AK, Lopez-Penalver C, Coomer C, Boylan S, Chakravarthy A, Vito CA, Bhatnagar A, Proulx GM, Dooley WC, Davis M, Golder SL, Ivanov O, Fernandez K, Rahman S. One-year follow-up results of a multi-center trial of intra-operative radiation therapy using electronic brachytherapy at the time of breast conservation surgery for early stage breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-12-11.

[Evaluation of a state social program including a nutritional component implemented in the city of Cordoba for the elderly. 1999]

Actually the nutrition programmes had become into a fundamental resource for people living in low social conditions, to cover their feeding requires. The elderly retired persons with high socio-economic vulnerability are the direct beneficiaries of a social programme that includes a nutritional intervention executed by the PAMI.

OBJECTIVE

Evaluate the ProBienestar programme at Córdoba Capital city during 1999.

MATERIAL AND METHOD

Descriptive and transversal study.

TARGET GROUP

Older aged persons from 60 years old or more (n = 330) and assistance units (n = 26) TECHNIQUES: Survey observation

VARIABLES

Focal criterions, accessibility, food assistance nutritional quality, socio-economic status, nutrition specialists participation, beneficiaries satisfaction assessed into the following dimensions "satisfaction with the including requirements", "food assistance regularity", "adjustment to the beneficiaries food consumption standard", "food quality".

RESULTS

The beneficiaries are between 60 and 74 years aged; most of them are widows and separated women that live with their sons or/and daughters or/and grandchildren. The most are owners of the house they live in. There is a different opinion between beneficiaries and assistance units' responsible at the moment of establish the including criterions. The food assistance is regular and geographic and administrative accessible. There is some difficult by the way of the older aged beneficiaries to recall the food aid boxes. The nutritional quality of the complement for one-person box was assessed as good, while for the two-persons boxes the quality downs. It is adequate to the food consumption standard of the older aged beneficiaries.

CONCLUSION

The satisfaction degree of the beneficiaries is high. (73%).

Comparison of two commercially available near-infrared spectroscopy instruments for cerebral oximetry. Technical note

Two near-infrared spectroscopy (NIRS) devices were compared with regard to their responses to changes in cerebral hemoglobin oxygenation induced by hypoxia and hypercapnia in five healthy volunteers. Sensors belonging to each NIRS device were placed on opposite sides of the volunteer's forehead. The INVOS-3100A device, approved by the United States Food and Drug Administration, records the percentage of oxyhemoglobin (HbO2) saturation and the investigational NIRO500 device records absolute changes in HbO2, deoxyhemoglobin, and total hemoglobin in micromolar concentrations referenced to an arbitrary baseline. The volunteers breathed separate mixtures of 7% CO2 in O2 and 10% O2 for 5 minutes in random order. Arterial blood pressure, end-tidal CO2 (ETCO2), arterial O2 saturation, and electrocardiographic data were continuously monitored. Hypercapnia increased (p < 0.01) ETCO2 from 42+/-2 to 56+/-3 mm Hg (mean +/- standard deviation), resulting in a 7.3+/-0.2% increase (p < 0.005) in cerebral HbO2 saturation detected by the INVOS3100A device and an 11.6+/-3 microM increase (p < 0.0008) in HbO2 detected by the NIRO500. Hypoxia decreased (p < 0.01) arterial HbO2 saturation from 98+/-1 to 87+/-3%, causing a 5.1+/-1.2% decrease (p < 0.01) in the percentage of HbO2 saturation detected by the INVOS3100A device and a 9.7+/-6.3 microM decrease in HbO2 detected by the NIRO500. The responses of the NIRO500 and the INVOS3100A instruments to changes in cerebral oxygenation resulting from hypercapnia and hypoxia were generally similar; however, responses tended to be greater when recorded by the NIRO500 device, perhaps because, unlike the INVOS3100A device, the NIRO500 does not correct for skin and bone contamination.

The effect of temperature on the growth of strains of Kloeckera apiculata and Saccharomyces cerevisiae in apple juice fermentation

The influence of temperature (10 degrees C and 25 degrees C) on the survival and growth of Saccharomyces cerevisiae and Kloeckera apiculata was examined in mixed and pure cultures during fermentation in apple juice. The growth reached by S. cerevisiae did not seem to be affected by temperature and the presence of K. apiculata. However, the growth and survival of K. apiculata, both in single and mixed cultures, were substantially enhanced at 10 degrees C. The highest amount of ethyl acetate was produced by K. apiculata in pure culture at 10 degrees C. Nevertheless, this concentration was lowest when both yeasts were fermented together at 10 degrees C and 25 degrees C.

Characterization and DNA Plasmid Analysis of Ropy Pediococcus spp. Strains Isolated from Basque Country Ciders

Ten strains of Pediococcus spp. causing ropiness were isolated from Basque Country spoiled ciders and characterized with regards to growth at different pHs, temperatures, and ethanol and SO₂ concentrations. They grew well at pHs above 3.7 and failed to grow at temperatures over 37°C. In addition, they were tolerant to 10% ethanol and to 15, 25, and 50 mg/l total SO₂ (pH 3.8). A selected ropy strain was used to carry out plasmid DNA analysis; the agarose gel pattern showed the presence of 6 bands of plasmid DNA. Plasmid-curing experiments with ethidium bromide and novobiocin suggested that the ropy phenotype was encoded by plasmid DNA. In addition, this nonropy strain lost its resistance to oleandomycin after curing trials.

Electrical injuries in a pediatric emergency department

STUDY OBJECTIVE

To examine the spectrum of electrical injuries and develop guidelines for management.

DESIGN

Retrospective review of charts compiled during a 6-year period (1988 through 1993).

SETTING

Pediatric emergency department.

PARTICIPANTS

Seventy-eight patients seen for electrical injuries.

RESULTS

Fifty-four percent of patients were boys, and the mean age of the patients was 5.3 years. Eighty-two percent sustained burns. We divided patients into those who were involved in major electrical current events (n = 8) (water contact and high voltage) and minor electrical current events (n = 70) (injury sustained while placing an object in an outlet or touching/plugging in a cord or during oral contact with a cord). Of the minor events, all burns (n = 61) involved less than 1% of body surface area. Eighteen patients sustained second-degree burns, and 19 sustained third-degree burns. Of the eight major-event patients, one had abnormal ECG/rhythm strip findings, two had abnormal urinalysis results, and six had abnormal levels of creatine phosphokinase. All eight were admitted. Of the 70 minor-event patients, 2 of 53 had abnormal ECG/rhythm strip findings, 1 of 48 had abnormal urinalysis results, and 2 of 40 had abnormal creatine phosphokinase levels. Thirty-six of the 70 minor-event patients were admitted. Patients involved in major events were more likely to undergo studies (P = .002), to have an abnormal result (P = .000008), and to be hospitalized (P = .008). In minor-event patients, hospitalization was limited to observation and the fitting of oral appliances.

CONCLUSION

Children involved in electrical events are usually exposed to low-voltage household current resulting in minor injury. Asymptomatic children with minor electrical injuries do not require laboratory evaluation or hospitalization.

Nerve growth factor and neurotrophin-3 enhance neurite outgrowth and up-regulate the levels of messenger RNA for growth-associated protein GAP-43 and T alpha 1 alpha-tubulin in cultured adult rat sensory neurones

The effect of nerve growth factor (NGF) and neurotrophin-3 (NT-3) on neurite outgrowth was related to the level of mRNA for the growth-associated protein GAP-43 and the neurone specific alpha-tubulin, T alpha 1, in dissociated cultures of adult rat sensory neurones. Treatment with NGF or NT-3 for 3 days enhanced neurite outgrowth in a dose-dependent manner and by 7-fold and 5-fold, respectively, over control at the highest concentrations used. NGF and NT-3 elevated the level of mRNA encoding GAP-43 by 2.3-fold and T alpha 1 alpha-tubulin by 3.2-3.5-fold. The estimated ED50 values were 0.1-0.3 ng/ml for NGF and 2 ng/ml for NT-3 for both neurite outgrowth and mRNA up-regulation.

Heterofermentative Lactobacilli Causing Ropiness in Basque Country Ciders

Ropy strains of heterolactic Lactobacillus spp. were isolated from bottled spoiled ciders produced in the Basque Country. The isolates were able to produce slime experimentally on glucose containing medium and apple must. The production of ropy slime occurred during exponential growth and the increase in viscosity was correlated with production of polysaccharide. They were characterized with regards to growth at different pH, sulfur dioxide (SO₂), ethanol and temperatures and showed similar behavior. All ropy strains grew in the presence of high ethanol concentrations (15%) and at low temperatures (10 and 15°C). In addition, these were tolerant to 10, 25 and 50 mg/l of total SO₂ (pH 3.8), but with longer lag times as the concentration of SO₂, increased. However, the ropy lactobacilli studied were affected by the pH of the medium and in general pH below 3.7 limited their growth seriously.

Respiratory failure due to interstitial lung metastases of ovarian carcinoma reversed by chemotherapy

A woman with metastatic ovarian carcinoma developed postoperative respiratory failure due to interstitial lung metastases demonstrated by bronchoalveolar lavage. After chemotherapy, she was able to be removed from mechanical ventilation and has shown progressive resolution of her interstitial lung disease. Metastatic ovarian carcinoma can be a treatable etiology of life-threatening interstitial lung disease.

Teaching oncology nurses about epidural catheters

Medication administered through epidural catheters for control of acute and chronic pain is becoming a common practice in some hospitals. The care of epidural catheters usually is not included in basic nursing education curriculum. In settings where RNs will administer medication by this route or monitor patients receiving epidural medication, adequate preparation of the RN staff is vital to ensure that the catheter remains intact, that therapy is administered without complications, and that the patient has optimal pain relief. Instruction should include information on the catheter's purpose, administration techniques, pharmacology of the drug, side effects, and monitoring techniques. For program planning, a multidisciplinary group set criteria on which the policy and procedure for administration of epidural analgesia were based. The educational program focused on administering morphine sulfate through an epidural catheter and on safe discontinuation of the catheter.

Effects of short-term prenatal alcohol exposure on maze, activity, and olfactory orientation performance in rats

Long-Evans rats were gavaged twice each day with 4 g/kg/day, of ethanol on days 10-14 of gestation. Ethanol and control offspring were reared by untreated surrogate dams to minimize possible postnatal maternal treatment influences. Ethanol-exposed offspring exhibited delayed olfactory orientation (discrimination) to home cage scent and delayed lower incisor eruption compared to pair-fed or ad lib fed controls. After weaning, the ethanol offspring exhibited increased open-field section entries, particularly of centrally located sections, and facilitated swimming performance in a water maze. Ethanol exposure significantly decreased weight gain and increased postnatal, but not prenatal, mortality in the progeny. The female ethanol offspring also showed delayed vaginal patency development. This was due to large delays in vaginal development in a small number of individuals in this group; no such lag was seen in any members of either control group. The data confirm that short-term prenatal alcohol exposure can produce many of the behavioral effects previously reported when alcohol is administered throughout most or all of pregnancy.

Pervasive hyperactivity and long-term learning impairments in rats with induced micrencephaly from prenatal exposure to methylazoxymethanol

Pregnant Long-Evans rats were given a single i.p. injection of 30 mg/kg of methylazoxymethanol (MAM) acetate or saline on day 14 of gestation (vaginal plug = day 0). All litters were reduced to 8 at birth and were reared by their biological dams. Between 49-192 days of age all offspring were examined on open-field, figure-8 (at two different ages), and hole-board tests of activity, as well as passive avoidance and Biel water maze tests of learning (also at two different ages). The MAM offspring showed no increase in mortality, but weighed less than controls, a difference that remained relatively constant throughout the experiment. At 204-215 days of age the MAM offspring were confirmed to be micrencephalic, a known effect of this drug at this dose and exposure period. On all tests of activity the MAM offspring were markedly hyperactive. The female progeny also exhibited a pronounced impairment of normal activity habituation patterns. The MAM males, however, showed a marked impairment of passive avoidance performance, while the females did not. At 2 months of age the MAM offspring also showed a pronounced deficit in learning a water maze. This maze deficit had not abated when tested again at 6 months of age. The MAM induced brain and behavioral abnormalities provide a potentially useful animal model of congenital micrencephaly and associated mental retardation.

Effects of prenatal ethanol exposure on heart rate, activity, and response suppression

Pregnant rats were intubated during days 10-14 of gestation with equal volumes of isocaloric ethanol-sucrose solutions. Groups 8g, 4g, and 0g received one-half these amounts of ethanol per kg body weight twice each treatment day. Although these maternal treatments did not significantly affect offspring birth weights, activity levels during classical conditioning were elevated in animals prenatally exposed to the 8g dose of ethanol. Further, the initial rate of extinction was slowed during CS presentations in a lick-suppression situation in this ethanol-exposed group. These findings are relevant to considerations of prenatal ethanol's effects on activity, reactivity, and the course of response extinction.

Effects of prenatal alcohol on homing behavior, maternal responding and open-field activity in rats

A radial-maze was used to study homing in offspring and maternal retrieval behaviors after prenatal exposure to alcohol. Pair-fed and untreated (ad lib control diet) groups were included and all offspring were either fostered or cross-fostered at birth. Offspring given ethanol prenatally exhibited a deficit in homing development and were retrieved significantly longer by ad lib control dams over the ten days of testing. The observed retrieval response may represent a compensation for the delayed development of the ethanol-exposed offspring. Consistent with our previous work, ethanol treatment had long-lasting effects on maternal body weight, offspring growth, and juvenile and adult activity as measured in the open-field. The findings suggest that these effects can be attributed to ethanol per se and not undernutrition or postnatal maternal influences. Further work aimed at identifying the stimulus properties underlying the complex maternal-infant interaction is needed in order to explain the observed differences in maternal retrieval response.

Malformations and growth of rat fetuses exposed to brief periods of alcohol in utero

The effects of acute alcohol exposure at specific stages of gestation on fetal growth and morphology were investigated in rats. Alcohol was administered by gavage on either days 7-9, 10-12, or 13-15 of gestation (sperm positive, day 0). Increased resorptions and reduced body weights in fetuses were related to prenatal alcohol treatment and were not related to the period of alcohol administration. The teratological examinations did not reveal structural anomalies related to alcohol treatment. These findings are of interest in that they were observed in fetuses treated in an acute model of the fetal alcohol syndrome (FAS) which has shown reductions in protein synthesis.

Effects of chronic alcohol exposure on offspring activity in rats

The purpose of the present study was to investigate the postnatal effects of long-term chronic exposure to ethanol in a treatment that has been shown to alter fetal viability and protein synthesis. Two groups of dams were included. One group (n = 7) received alcohol (6% w/v) in a liquid diet (Bio-Serve) prior to mating as well as throughout pregnancy. Another group consumed the same volume of the diet (isocalorically-matched, maltose-dextrines substituted for the alcohol) for the same time period. The ethanol treatment significantly reduced offspring body weights and increased offspring mortality. At adulthood, the treated offspring ambulated more than the non-treated offspring in an open field and made a higher number of entrances into a shocked area between trials on the first day of testing in an active-avoidance Y-maze task. These behavioral results are consistent with findings of increased open field activity and impaired ability to inhibit responding reported by other investigators in rats after prenatal alcohol administration.

Behavioral effects of prenatal ethanol exposure and differential early experience in rats

Offspring of rats that were intubated with ethanol during Days 10--14 of gestation and offspring in two control groups were compared on measures of growth, viability, and performance in behavioral tasks. Influences of postnatal environment were assessed by using fostering-cross fostering procedures and by providing different postweaning housing conditions. Results were that offspring from dams treated with ethanol displayed prenatal and postnatal growth deficiency as well as increased postnatal mortality. In the open field, offspring in the Ethanol group were more active than those in the other two groups. Ethanol offspring were also more active in the Y maze and made more avoidance responses and correct discriminations. Early experience as manipulated by the fostering-cross fostering procedures and post-weaning rearing conditions had no impact on the effects of prenatal ethanol on offspring growth, viability, or behavior.