OIL BEHAVIOUR AND THE RESPONSE TO A SUNKEN OIL SPILL OF SLURRY IN QUINTERO BAY, CHILE

Slurry oils are one of the few groups of oils that have a density greater than full salinity seawater. Slurry spills at sea are rare, but when they do occur, the response can be difficult, with low final recovery rates. Oil spill response planning and recovery techniques have been refined over many years and the research and development of most methods has been underpinned by the principle that oil floats on water. This recent case study provides an example of the behavior of a slurry spill and the subsequent response operations. A leak of an API gravity 4° slurry occurred from a submarine pipeline in Quintero Bay, Chile, on 14th May 2016. The oil sank to the adjacent sea bed and covered an area of approximately 10,000 m2 in water depths of 18–22 m. The initial response involved over 20 dry-suit divers with surface air to recover the oil with vacuum hoses. These were then supplemented by four diver-operated vacuum dredges. Fortunately weak bottom currents did not redistribute the oil; nevertheless “sea bed booms” were deployed around the perimeter to prevent migration. These “booms” were initially a screen mesh that was later supplemented by sturdier metal frame screens deployed around the zone of the sunken oil in a zigzag configuration. Baseline benthic sediment samples were collected from the adjacent unaffected area and subsequently from the treatment area after completion of operations. A benthic SCUBA SCAT survey using a track-line positioning system was conducted to systematically document the distribution of the oil and post-treatment systematic ROV survey ensured that the end-point oiling conditions had been achieved.

The development of novel organically modified sol-gel media for use with ATR/FTIR sensing

The ability to prepare and develop novel pre-concentration media by the sol-gel process, and their integration with mid-infrared transparent waveguides has been demonstrated. This research approach resulted in a mid-infrared sensing methodology in which the properties (porosity, functionality, polarity, etc.) of the recognition layer could be tailored by variation of the sol-gel precursors and processing conditions. Cross-linker type and concentration notably influenced p-xylene absorption and diffusion rate. Unreacted silanol groups appeared to be the dominant factor in the hydrophobicity of sol-gel layers. Variation of sol-gel precursors and thermal treatment altered both film cross-link density and polarity, as demonstrated by variation in the rate of analyte diffusion and equilibrium analyte concentration. The use of a novel 1 : 1 PTMOS : DPDMS material as pre-concentration medium in this analytical sensing approach was validated through the determination of p-nitrochlorobenzene in an aqueous environment. The response demonstrated linearity between 0-30 mg L(-1) with a correlation coefficient of 0.989 and a limit of detection of 0.7 mg L(-1). Sensing times for p-nitrochlorobenzene were also reduced from several hours to 24 minutes, without loss of measurement accuracy or sensitivity, by a 10 degrees C increase in the sensing temperature and the use of a predictive Fickian model previously developed by this research group.

Clarifications on breakpoints in HSAX and BTAX by comparative mapping of F9, HPRT, and XIST in cattle

The coagulation factor IX gene (F9), the hypoxanthine phosphoribosyl transferase 1 gene (HPRT1), and the X-inactive specific transcript gene (XIST) were physically assigned in cattle to analyze chromosomal breakpoints on BTAX recently identified by radiation hybrid (RH) mapping experiments. Whereas the FISH assignment of XIST indicates a similar location on the q-arm of the human and cattle X chromosomes, the locus of HPRT1 supported the assumption of a chromosome rearrangement between the distal half of the q-arm of HSAX and the p-arm of BTAX identified by RH mapping. F9 previously located on the q-arm of BTAX was assigned to the p-arm of BTAX using RH mapping and FISH. The suggested new position of F9 close to HPRT1 supports the homology between HSAXq and BTAXp. The F9 locus corresponds with the gene order found in the homologous human chromosome segment. XIST was assigned on BTAXq23, HPRT1 and F9 were mapped to BTAXp22, and the verification of the location of F9 in a 5000 rad cattle-hamster whole genome radiation hybrid panel linked the gene to markers URB10 and HPRT1.

Effect of a la carte and snack bar foods at school on children's lunchtime intake of fruits and vegetables

OBJECTIVES

To compare lunch fruit, juice, and vegetable (FJV) intake of fourth-grade students who receive only National School Lunch Program meals and fifth-grade students who also have access to a school snack bar and to compare FJV intake by meal source among fifth-grade students.

DESIGN

Cross-sectional study: students completed FJV preference questionnaires and 5 days of lunch food records in classrooms.

SUBJECTS/SETTING

312 fourth- and 282 fifth-grade students in south Texas.

MAIN OUTCOME MEASURES

Mean FJV consumption.

STATISTICAL ANALYSES PERFORMED

Descriptive statistics, correlation analyses, analysis of variance, analysis of covariance.

RESULTS

Fourth-grade students (n = 312) consumed significantly more fruits, juices, and vegetables (0.80 serving) than fifth-grade students (n = 282) (0.60 serving). Students whose parents reported a high school education or less consumed more regular and total vegetables than students whose parents reported some college or higher education. There were no interaction effects among gender, grade, ethnic, or family education groups. Fifth-grade students who ate only snack bar meals consumed significantly less total fruits, juices, and vegetables (0.40 serving) than fifth-grade students who ate school lunch meals (0.82 serving). Controlling for FJV preferences did not change the main effect for grade level in the FJV consumption models.

APPLICATIONS/CONCLUSIONS

FJV consumption during school lunch is low. School foodservice staff should identify FJV items that middle school students prefer and increase availability of those items in middle school cafeterias and snack bars.

Socioenvironmental influences on children's fruit, juice and vegetable consumption as reported by parents: reliability and validity of measures

OBJECTIVE

To pilot test theory-based questionnaires to measure socioenvironmental influences on children's fruit, juice and vegetable (FJV) consumption as reported by parents.

DESIGN

Cross-sectional.

SETTING

Parents of fourth to sixth grade students completed socioenvironmental questionnaires. The students completed food records (FRs) for 2 days in the classroom.

SUBJECTS

Interviews were completed by 109 parents (17% African-American, 32% Hispanic-American and 51 Euro-American).

RESULTS

Student mean daily FJV intake was 2.1 servings. Principal components analyses revealed subscales measuring positive and negative parenting practices; self-efficacy for modelling and planning/encouraging FJV consumption, and making FJV available; encouraging, consequences and discouraging food socialization practices; negative home, cost and canned/frozen food barriers; meal planning; child shopping; mother food preparation; and child lunch and dinner FJV preparation practices. Internal consistencies were adequate to high. Negative parent practices and negative home FJV barriers were significantly negatively correlated with child FJV consumption variables. Planning/encouraging self-efficacy was positively associated with fruit consumption, and child dinner FJV preparation was significantly negatively correlated with child juice consumption.

CONCLUSIONS

These questionnaires may provide important insights about the relationship between parent-reported socioenvironmental influences and children's FJV consumption. Future work should test these questionnaires with larger groups of parents and youths, with more reliable estimates of usual FJV intake, e.g. 7-day food records, to obtain a detailed understanding of how parents influence what children eat. Tests of models of relationships among these variables are warranted, but should control for possible confounding variables, e.g. socioeconomic status, gender of the child, etc.

The effect of patient position on intrarenal anatomy

BACKGROUND AND OBJECTIVE

Although flexible ureteroscopes are designed with mechanisms for active and passive tip deflection, one of the major problems is the not infrequent inability to enter the lower pole calices. Accordingly, we measured the change in the lower pole infundibulopelvic (LIP) angle when the patient's position was varied (i.e., prone, supine, head down) during intravenous urography (IVU).

PATIENTS AND METHODS

The LIP angle was measured in 20 right and 26 left adult kidneys during an IVU with the patient in six different positions: supine level, supine 20 degrees head down, supine 45 degrees head up, prone level, prone 20 degrees head down, and prone 45 degrees head up. None of the patients had a history of renal surgery.

RESULTS

In all cases, the broadest angle of entry to the lower pole infundibulum was obtained with the patient in a prone position and 20 degrees head down.

CONCLUSIONS

The LIP angle broadens when the patient lies in a prone 20 degrees head down position. This maneuver could improve the surgeon's ability to access the lower pole calices when performing flexible ureteronephroscopy.

Prevention of skeletal muscle catabolism in sepsis does not impair visceral protein metabolism

We investigated whether the preservation of gastrocnemius proteins by interleukin-1 receptor antagonist (IL-1ra) during sepsis altered protein metabolism in visceral tissues. Sepsis was induced by creation of an abdominal abscess followed by infusion of saline of IL-1ra. Five days later, the tissue protein content and rate of protein synthesis were measured. IL-1ra did not significantly alter hepatic protein metabolism in septic or control animals. In kidney, the protein content and rate of protein synthesis were both decreased by sepsis and significantly ameliorated by the infusion of IL-1ra. Sepsis decreased the rate of protein synthesis in the small intestine. IL-1ra increased intestinal protein synthesis in both control and septic animals; however, the effects were localized to the seromuscular layer. The preservation of muscle protein by IL-1ra in sepsis did not adversely affect protein synthesis in any of the visceral tissues examined. IL-1 appears to mediate the sepsis-induced changes in protein synthesis in kidney and small intestine but not in liver or spleen. Protein synthesis in each visceral organ responds differently to the septic insult and modulation of IL-1 bioactivity.

Interleukin-1 receptor antagonist prevents sepsis-induced inhibition of protein synthesis

To understand the role of interleukin-1 (IL-1) as a mediator of the sepsis-induced skeletal muscle catabolism, we investigated the effects of a specific IL-1 receptor antagonist (IL-1ra) on skeletal muscle protein metabolism in a rodent model of chronic abdominal sepsis. A constant infusion of IL-1ra (2 mg.kg-1.h-1) or saline was begun immediately after the induction of sepsis and continued for 5 days. The effect of IL-1ra on protein metabolism was examined in individual muscles (gastrocnemius, soleus, heart) containing different fiber types. Infusion of IL-1ra in control animals did not alter protein metabolism in any of the muscles examined. Muscle weight, protein content, and the rate of protein synthesis in gastrocnemius were reduced by sepsis, whereas none of these parameters were affected in soleus or heart. Infusion of IL-1ra prevented the sepsis-induced loss of muscle protein and inhibition of protein synthesis in gastrocnemius but was without effect in soleus or heart. IL-1ra infusion restored translational efficiency in the gastrocnemius of septic rats and was without effect on the RNA content. These results provide evidence for a role of IL-1 as a mediator of the sepsis-induced abnormalities in skeletal muscle protein metabolism.

Stallion karyotype variability and lack of association with abortion: A case reprot

Karyotype analysis was done on a stallion that impregnated 23 mares during the 1991 breeding season, of which 14 aborted between 2 and 4 mo fo gestation. Lymphocytes examined contained a 64,XY complement of normal appearing sex chromosomes and autosomes, except for slight dimorphism of the centric heterochromatin of chromosome No. 1. A skin biopsy was procured form the stallion for karyotype analysis, and the stallion was bred to 11 mares. Three mares were detected pregnant 16, 35, 45 d after breeding. The fetuses were recovered transcervically using curved intestinal forceps 47 (n=2) and 49 (n=1) d after breeding. Fetal tissue was rinsed and packed in culture media, transported overnight in a chilled container, cultured by standard tissue culture techniques, and prepared for karyotype analysis. No abnormalities were found in standard karyotypes from those cultures. One fetal karyotype revealed slight dimorphism of the heterochromatin of chromosome No. 1. Chromosome spreads obtained from the stallion's skin biopsy revealed a normal karyotype with no difference in the amount of heterochromatin present in No. 1 chromosomes. During the 1992 breeding season, the stallion impregnated 23 of 25 mares bred. Only 1 mare aborted, at 8 mo of gestation. Apparently, the amount of heterochromatin of No. 1 horse chromosomes can vary, and caution should be used in diagnosing this as a cause of pregnancy failure.

DEVELOPMENT OF A STRANDED OIL IN COARSE SEDIMENT (SOCS) MODEL

Oil spills in Canadian waters have a high probability of impacting coarse sediment beaches, yet our ability to predict oil fate and estimate natural self-cleaning rates is less than adequate. Data is lacking to understand fully many oillsediment interactions. Historically, shoreline interactions have been considered using fairly simple concepts.

We examined the processes that may occur on a coarse sediment beach, selected those which are important, and developed a fate and persistence model for stranded oil. The processes were divided into stages relative to the spill event, and the factors which affect each stage were evaluated. Three areas of special interest were the capacity of a beach to hold oil, the residual capacity of a beach for oil, and the long-term fate of the oil. After developing model algorithms, the outputs were compared to a data base of information collected during the Exxon Valdez oil spill.

The stranded oil in coarse sediment model will provide information at two levels: a general level for planning and sensitivity mapping and a more detailed level intended for the prediction of oil fate on specific known beaches. The strengths and weaknesses of the model have been assessed in terms of data deficiencies. The type and nature of the data which are most useful to, and which need to be collected for, spill planning and spill monitoring were identified.

Activity profiles of developmental toxicity: design considerations and pilot implementation

The available literature was searched for quantitative test results from both in vitro and in vivo assays for developmental toxicity for five model compounds: cyclophosphamide, methotrexate, hydroxyurea, caffeine, and ethylenethiourea. These compounds were chosen on the basis of their extensive utilization in a variety of assay systems for developmental toxicity as evidenced by their representation in the ETIC database (each generally has 100-500 citations encompassing multiple test systems). Nine cellular-based assays, six assays using whole embryos in culture, as well as Segment II and abbreviated exposure tests for mammalian test species are included in the database. For each assay, the critical endpoints were identified, each of which was then provided a three-letter code, and the criteria for extraction of quantitative information were established. The extracted information was placed into a computerized reference file and subsequently plotted such that the qualitative (positive/negative) and quantitative (e.g., IC50, highest ineffective dose (HID), lowest effective dose (LED] results across all test systems could be displayed. The information contained in these profiles can be used to compare qualitative and quantitative results across multiple assay systems, to identify data gaps in the literature, to evaluate the concordance of the assays, to calculate relative potencies, and to examine structure-activity relationships.

Kinetic analysis of 3-quinuclidinyl 4-[125I]iodobenzilate transport and specific binding to muscarinic acetylcholine receptor in rat brain in vivo: implications for human studies

Radioiodinated R- and S-Quinuclidinyl derivatives of RS-benzilate (R- and S-125IQNB) have been synthesized for quantitative evaluation of muscarinic acetylcholine receptor binding in vivo. Two sets of experiments were performed in rats. The first involved determining the metabolite-corrected blood concentration and tissue distribution of tracer R-IQNB (active enantiomer) and S-IQNB (inactive enantiomer) in brain 1 min to 26 h after intravenous injection. The second involved the measurement of brain tissue washout over a 2-min period after loading the brain by an intracarotid artery injection of the ligands. Various pharmacokinetic models were tested, which included transport across the blood-brain barrier (BBB), nonspecific binding, low-affinity binding, and high-affinity binding. Our analysis demonstrated that the assumptions of rapid equilibrium across the BBB and rapid nonspecific binding are incorrect and result in erroneous estimates of the forward rate constant for binding at the high-affinity receptor sites (k3). The estimated values for influx across the BBB (K1), the steady-state accumulation rate in cerebrum (K), and the dissociation rate constant at the high-affinity site (k4) of R-IQNB were independent of the specific compartmental model used to analyze these data (K1 approximately 0.23 ml/min/g, K approximately 0.13 ml/min/g, and k4 approximately 0.0019 min-1 for caudate). In contrast, the estimated values of k3 and the efflux rate constant (k2) varied over a 10-fold range between different compartmental models (k3 approximately 2.3-22 min-1 and k2 approximately 1.6-16 min-1 in caudate), but their ratios were constant (k3/k2 approximately 1.4). Our analysis demonstrates that the estimates of k3 (and derived values such as the binding potential) are model dependent, that the rate of R-IQNB accumulation in cerebrum depends on transport across the BBB as well as the rate of binding, and that uptake in cerebrum is essentially irreversible during the first 360 min after intravenous administration. Graphical analysis was consistent with compartmental analysis of the data and indicated that steady-state uptake of R-IQNB in cerebrum is established within 1-5 min after intravenous injection. We propose a new approach to the analysis of R-IQNB time-activity data that yields reliable quantitative estimates of k3, k4, and the nonspecific binding equilibrium constant (Keq) by either compartmental or graphical analysis. The approach is based on determining the free unbound fraction of radiolabeled ligand in blood and an estimate of K1.(ABSTRACT TRUNCATED AT 400 WORDS)

Preparation and biological evaluation of 18F-labeled benzamide analogs as potential dopamine D2 receptor ligands

Three 18F-labeled benzamide derivatives were prepared and evaluated as potential ligands to study the dopamine D2 receptor phenomenon. The compounds are analogs of iodobenzamide, eticlopride and raclopride and are labeled with an N-2-[18F]fluoroethyl functionality on the pyrrolidine ring. The compounds were tested in vitro for binding affinity and found to exhibit somewhat lower affinity than the non-fluorinated analog. In vivo distribution studies revealed that all compounds were more highly bound to plasma proteins than was raclopride. In addition, compartmentation of radioactivity demonstrated nonspecific binding to be the predominate retention in the brain as reflected by the low caudate to cerebellum ratios for these compounds. These three 18F-labeled benzamide derivatives are inferior to raclopride and iodobenzamide for studies of the D2 receptor system using positron emission tomography.

Performance inventory for profound and severe loss (PIPSL)

This study was undertaken to develop a quantifiable and reliable self-rating inventory specifically for persons with profound and severe hearing losses. Fifty such subjects with such losses who wore hearing aids rated themselves on a scale of 0-6 (never to always) on 125 items that sampled their performance in a variety of communicative situations. Items were assigned to tentative categories that were then refined so as to achieve high internal consistency, reflected by high alpha coefficients, with a minimal number of items. Six final categories, or scales, containing a total of 58 items, emerged with alpha coefficients .86 or higher. The scales were labeled Understanding Speech With Visual Cues, Intensity, Response to Auditory Failure, Environmental Sounds, Understanding Speech With No Visual Cues, and Personal. Another 16 items that failed to fit into any scale, and did not form a scale of their own, were also included in the final inventory because they related to individual rehabilitative concerns and activities in ways not represented among the items of the six scales.

Local blood flow and vascular permeability of autonomic ganglion-transplants in the brain

The purpose of this study was to determine whether the blood vessels of transplanted neural tissue retain their functional characteristics. Quantitative autoradiography was used to measure local blood flow (F) with iodoantipyrine and the blood-to-tissue transfer constant (K) with alpha-aminoisobutyric acid in superior cervical ganglion (SCG) allografted to the surface of ventricle IV and into the cerebellum of the same rat. The F of the intraparenchymal grafts was slightly lower than that of the intraventricular grafts; F decreased between 1 and 4 weeks in SCG grafts at both sites. The permeability-surface area (PS) product of the microvessels and extraction fraction of AIB were calculated from these results and indicated restricted transvascular passage of the amino acid in both the in situ and grafted SCG. Surface area (S) and average length (L) of the microvessels were determined morphometrically and their permeability (P) was calculated from these data. Although K and PS decreased in the grafts compared to in situ SCG, a comparable decrease in S indicated that P was similar for the microvessels of both in situ and 1-week-old SCG transplants: 3.5-4.3 x 10(-6) cm/s. Between 1 and 4 weeks after transplantation, the P of the microvessels decreased to approximately 1.6-2.3 x 10(-6) cm/s without any change in S. Thus, the blood vessels of SCG grafts within or upon the brain initially retain the functional attributes of in situ SCG microvessels, but the average permeability of the graft microvessels decreases to approximately one half of the initial value by 4 weeks after transplantation.

The UCSF tracking procedure for evaluation and training of speech reception by hearing-impaired adults

A tracking procedure that emphasizes practical coping strategies for hearing-impaired patients, along with practice in responding to other cues in the perception of connected speech, is described in detail in the course of its use with one subject. The subject's tracking scores before and after training illustrate the potential value of the procedure both as an evaluative measure and as a training tool. The organization of the materials and the design of the training protocol allow for a wide range of practice activities in tracking, including the use of nonverbatim as well as verbatim responses.

Evaluation of lidocaine as an adjunct to fentanyl anesthesia for coronary artery bypass graft surgery

A double-blind, randomized, prospective trial was conducted to evaluate intravenous lidocaine, 3 mg/kg, followed by an infusion of 0.05 mg X kg-1 X min-1, as an adjunct to fentanyl in 20 patients undergoing coronary artery bypass graft surgery. Lidocaine prevented hemodynamic abnormalities during tracheal intubation and after skin incision, but was ineffective in preventing hypertension following sternotomy. Intravenous lidocaine, 3 mg/kg, produced a decrease in mean arterial pressure after fentanyl, 30 micrograms/kg, that was unacceptable in some patients. Total fentanyl requirements for the duration of surgery were similar in the control group and in patients given lidocaine. We conclude that lidocaine, when administered as an adjunct to fentanyl in the dosage used in this study, can cause cardiovascular depression, and is of minimal benefit in preventing hemodynamic abnormalities after sternotomy during coronary artery bypass graft surgery.

Analysis and revision of the minimal auditory capabilities (MAC) battery

The Minimal Auditory Capabilities (MAC) Battery was administered individually to 75 hearing aid users with profound sensorineural hearing loss. The purposes of the study were (1) to determine the reliability of the individual tests, their range of difficulty, and their intercorrelations; (2) to undertake a standardization procedure based on data from this population; and (3) to assess the need for revisions. Difficulty ranged gradually from a mean score of 86% correct for the Spondee Same/Different test to a mean of 16% for the NU 6 monosyllabic word test. Alpha estimates of reliability were 0.89 or higher for all but the Everyday Sounds test (0.85), the Question/Statement test (0.83), and the Spondee Same/Different test (0.81). Along with the reliability and range of difficulty results, interest correlations provided no indication that any of the tests should be discarded. In the standardization of the MAC, the mean score correct on each test was set at 100 and the standard deviation at 10. Prepared tables for immediate conversion of a raw score to a standardized score for any test are included in an Appendix. Among revisions, also listed in the Appendix, the CID Everyday Sentences test was reduced to 20 items from 40, the SPIN High-Context Sentences were assigned key words, and the assessment of distinctive feature identification was discontinued.

Regional measurements of [14C]misonidazole distribution and blood flow in subcutaneous RT-9 experimental tumors

Regional [14C]misonidazole-derived radioactivity (MISO*) was measured by quantitative autoradiography in s.c. RT-9 experimental tumors 0.5, 2, and 4 h after an i.v. bolus (25 mg) and constant infusion (10 mg/h) in rats. Misonidazole (MISO) concentration in plasma, tumor, and other tissues was also measured by high-pressure liquid chromatography. The distribution of MISO* in the tumors always resulted in a characteristic pattern with high peripheral and low central values. The high-activity regions in the tumor rim achieved tissue: plasma MISO* activity ratios of 0.97 and 2.2 by 0.5 and 4 h, respectively; for central tumor regions, this ratio was 0.20 and 0.32 for the same periods, respectively. The limited distribution of MISO* to central tumor regions could be correlated to low values of blood flow (measured with [131I]iodoantipyrine) and to diffusion from peripheral tumor regions. Low blood flow in the central regions of these tumors will significantly limit the distribution of MISO and other drugs to viable-appearing cells in these areas and could account in part for the failures of chemotherapy in certain solid tumors. Pharmacokinetic modeling indicates that 1 to 9 h may be necessary for MISO concentrations in some tumor regions to reach 50% of that in plasma.

Concurrent measurements of blood flow and transcapillary transport in avian sarcoma virus-induced experimental brain tumors: implications for chemotherapy

A blood-to-tissue transfer constant, K, and tissue blood flow, F, were measured concurrently in seven rats with a total of 19 separate brain tumors induced by intracerebral inoculation of avian sarcoma virus. Regional and local measurements of K and F were obtained using double-label quantitative autoradiography with alpha-[14C]aminoisobutyric acid and [131I]iodoantipyrine, computerized microdensitometry and image analysis. Apparent tissue extraction fractions and capillary permeability-surface area products were calculated for different tumor regions, brain adjacent to tumor and tumor-free brain. The following observations were made: five histological categories of the tumors were found; significant local and regional variations of both K and F were typical in each group, resulting in marked regional variability of permeability-surface area products but more uniform values of apparent extraction fraction; the values of F, K, permeability-surface area products and apparent extraction fraction correlated poorly with morphological features of the tumors (necrosis, cellularity, cytology, location and size); the extraction fraction of alpha-aminoisobutyric acid was usually highest in tumor centers and then decreased in a gradient from tumor periphery through adjacent brain; and regardless of classification or histological features, capillary permeability and surface area, and not tissue perfusion or blood flow, seem to determine the blood-to-tissue transport processes (delivery of bloodborne materials) in most regions of these experimental brain tumors. An operational pharmacokinetic model of drug concentration in tumor tissue is developed and the results of our analysis indicate that increases in capillary permeability such as measured in these studies would not be sufficient to deliver adequate amounts of water-soluble drugs with short plasma half-lives to tumor tissue.

Regional thymidine transport and incorporation in experimental brain and subcutaneous tumors

The regional distribution and local incorporation of [14C]thymidine into a nonextractable tissue fraction, probably DNA, was measured in normal and neoplastic tissues. We studied brain tumors induced by avian sarcoma virus and ethylnitrosourea, and transplanted RG-2 intracerebral and subcutaneous gliomas. An incorporation quotient, Q, was calculated for different tumor regions and brain from the methanol nonextractable radioactivity in the tissue and the plasma concentration-time integral of thymidine. The incorporation quotient represents the rate of clearance of thymidine from blood and its incorporation into macromolecules (probably DNA). The values of Q were compared with a labeling index measured in the same tissue regions with conventional autoradiography. The following observations were made: (1) the mean plasma half-life of thymidine was 6.5 min; (2) the regional incorporation quotient in tumors varied from values comparable to normal brain to more than 100 times higher; (3) RG-2 tumors had significantly higher Qs than the other tumor models; (4) Q in subcutaneous tumors varied most widely (greater than 500-fold range); (5) the labeling index reflected the values of Q in some tumor regions but not in others; differences between the two were most frequently related to tumor cell density and the intensity of individual tumor cell labeling. A comparison of these data with previous studies of capillary permeability and blood flow in these tumor models indicates that the incorporation of [14C]thymidine into a nonextractable tissue fraction can be limited by transcapillary transport in brain tumors and by blood flow in systemic tumors, and that thymidine disposition in these tumors is not always indicative of the rate of DNA synthesis.

The revised form of the Hearing Performance Inventory

The revised Hearing Performance Inventory contains 90 items selected in part on a statistical basis and in part on clinical relevance from a previous experimental form. An analysis of the responses of 354 hearing-impaired subjects was used to evaluate the performance of each of the 90 items remaining in the Revised Form. Because the only items eliminated were either found or deemed to be too easy, too difficult or redundant, the Revised Form maintains the strength of the previous form while reducing significantly the time required for its administration.

Interim assessment of candidates for cochlear implants

The Minimal Auditory Capabilities battery was administered to patients with profound postlingual sensorineural hearing loss to obtain interim audiometric indices on the relative benefits of cochlear implants and hearing aids. One group used a cochlear implant comprising a multielectrode array and a single-channel stimulator, another group wore hearing aids, with only borderline satisfaction, and the third group wore hearing aids to good advantage. Scores for the latter group were consistently higher than the borderline group on two prosodic tests, but the borderline group scored better on closed-set spondee and vowel recognition tests. Scores were essentially the same for the two groups on the remaining tests. Tentative criteria induces were applied to members of the borderline group in terms of the hearing improvement that might be anticipated from an implant.

Progressive hearing loss in children: hearing aids and other factors

A sample of 20 children monitored for progressive hearing loss combined with 25 progressive loss cases were obtained. The effects of hearing aid use on progressive loss were examined in the context of etiology and other factors, particularly the time relations between hearing aid application and the period of progression. Results indicate a limited role played by hearing aids in progressive hearing loss. Hearing aid use was not implicate in 30 (69%) of the progressive loss subjects, questionably implicated in nine (20%), and probably implicated in five (11%). In the identification and monitoring of progressive hearing loss, it is unwise to conclude that hearing aid use is the cause of the deterioration without considering all other plausible factors.

Speech perception with hearing aids and cochlear implants

A battery of tests using speech materials was developed to evaluate the auditory perception skills of five subjects with profound postlingual hearing loss. Two of the subjects wore hearing aids, and three subjects used cochlear implants. Responses of the two subjects with hearing aids were consistently superior to those of the subjects with implants, and one of the three subjects with implants consistently performed better than the other two. The subjects with implants displayed wide variations in response, indicating the necessity of evaluating each implant prosthesis as it was used by a given subject. In addition to tests of auditory speech perception, a measure of lipreading ability with amplification provided useful information.

The hearing performance inventory and hearing aid use in profound hearing loss

Subjects with profound postlingual hearing loss completed the Hearing Performance Inventory (HPI) during the course of their hearing aid evaluations. Comparisons of responses to the HPI were made for (a) subjects who wore hearing aids versus subjects who did not, and (b) hearing aid users with losses greater than 100 dB versus users with losses between 80-100 dB. The former set of comparisons indicated consistently superior performance for the aided group, and the latter set indicated consistently superior performance for the 80-100 dB group. The HPI may be a valuable tool in hearing aid considerations.

Hearing aid evaluation for persons with postlingual hearing levels of 90 to 100 dB

Of 20 subjects with profound (90 to 100 dB) hearing loss who underwent a careful hearing aid evaluation, 16 were able to benefit from hearing aid use. With the recommended aids, all subjects could detect speech at levels within the normal conversational range; 75% had some understanding of spondee words; and 56% successfully accomplished tasks in phoneme identification. Two subjects succeeded on a standard speech discrimination test. Ear-level instruments, five binaural, were recommended for 13 of the 16 subjects. Microphones were front-facing in the majority of instances; none were directional. Seven aids used amplitude compression. Subjects were encouraged to relate their subjective impressions, and home trial was an important part of the evaluation. In the majority of instances, lipreading scores were markedly better with hearing aid use than without.

Hearing performance inventory

The Hearing Performance Inventory (HPI) was developed to assess hearing performance in problem areas experienced in everyday listening. It consists of six sections: (1) Understanding Speech, (2) Intensity, (3) Response to Auditory Failure, (4) Social, (5) Personal, and (6) Occupational. A self-report response style is used. Sentences were written to describe a number of listening situations covering a variety of talker characteristics and communication processes. The development, current status, and clinical implications of the HPI are presented.

Two years of a program in hearing-aid-related services

A program of hearing-aid-related services is described in which a dispenser of hearing aids visits an audiology facility on a regular basis as a supplier. Surveys to assess the program were conducted during a two-year period. Of the 128 patients who participated in the study, 89% continued wearing their hearing aids during the first year and 86% during the second year. The adjustment period of about 30 days with an accompanying orientation program was crucial. Ear mold considerations and use of the hearing aid during noisy situations constituted two major problem areas. Five aids were returned to the factory during the adjustment period, six during the first year, and 15 during the second year. Group work in hearing aid evaluation and orientation was a positive factor.

Hearing aid evaluations for persons with total postlingual hearing loss

To answer the question whether persons with total postlingual hearing loss can benefit from hearing aid use, hearing aid evaluations were carried out for 18 subjects. Nonstandardized listening tasks were necessitated because none of the subjects could discriminate speech. Subjective considerations played an integral role in the evaluation procedure. The results of the evaluations were as follows: (1) six subjects became new hearing aid users; (2) two retained the aids they were already wearing; (3) one improved when the hearing aid was changed to the opposite ear; (4) one obtained a satisfactory replacement for an inadequate instrument; and (5) eight were unable to use an aid to advantage. Thus, it is important that all persons with total postlingual hearing loss be afforded the opportunity of a careful hearing aid evaluation.

Consonant errors and remediation in sensorineural hearing loss

An analysis of consonant errors for hearing-impaired subjects in a multiple-choice format revealed that about 14 consonants caused most of the difficulty in consonant recognition. For a given consonant, error probability was typically lower in the initial position of the stimulus word than in the final position. When errors were made, the substitutions were limited typically to two or three other consonants, with a greater variety occurring for consonants in the final position. Substitutions tended to be the same over a wide range of pure-tone configurations. Place errors were predominant, but manner errors also occurred. In only a few instances did specific relationships occur between particular stimulus consonants and pure-tone configurations. With knowledge of the error consonants and typical substitutions, auditory recognition of consonants can be improved by programmed instruction methods. Shaping can be accomplished by a manipulation of the response foils (choices). Since it has been shown that visual recognition of consonants can also be improved, advantage can be taken of both the visual and auditory modalities in remedial procedures. Frequency of usage in the language should be considered in the ordering of consonants for retraining purposes. Work in consonant recognition should be beneficial to the hearing-impaired patient as part of a total rehabilitation program.

Therapy of heavy drinking during pregnancy

A survey of patients registering at the Boston City Hospital Prenatal Clinic had demonstrated that 9 percent were heavy drinkers. To reduce the health hazards to mothers and children, treatment of heavy alcohol use was integrated with prenatal care. A pediatric neurologist independently examined 322 offspring, including 42 whose mothers were heavy drinkers. Frequency of congenital anomalies, growth retardation, or functional abnormalities among these 42 was twice that of infants born to abstinent or moderate drinking mothers P less than .001). Within that group of 42, there were 15 whose mothers were able to abstain or reduce alcohol intake during the third trimester. These 15 demonstrated fewer abnormalities than those 27 whose mothers had continued heavy drinking (P less than .001). Since pregnant women can be motivated to reduce heavy drinking, treatment programs can benefit both mothers and infants.

Development of the California Consonant Test

A 100-item, multiple-choice test for consonant identification labeled the California Consonant Test (CCT) has been developed expressly for use with hearing-impaired patients. A computer-assisted analysis was obtained for the test responses of 550 patients with sensorineural hearing loss. The test seems highly sensitive to configurations of high-tone loss, but the correlation with degree of loss, especially in the instance of flat configurations, is somewhat low (-0.40). Test-retest correlation is 0.96. A correlation of 0.35 with a W-22 list indicates that the two tests are measuring different aspects of speech reception. In addition to its usefulness in identifying consonant confusions for rehabilitation purposes, the CCT may prove helpful in ranking hearing aids. For the latter purpose, two 50-item subforms, designed for equivalence, have been under observation for possible use when time is a critical factor. Repetitions of the 100-item list offer greater stability, however.