A model of well-being for children with neurodevelopmental disorders: Parental perceptions of functioning, services, and support

BACKGROUND

Both child function and supports and services have been found to impact the well-being of parents of children with neurodevelopmental disorders (NDD). The relationship between function and services and the well-being of children with NDD is less well-understood and is important to clarify in order to effect program and service change.

METHODS

The current project assessed whether child function as well as the adequacy of formal supports and services provided to children and their families were predictive of child well-being. Well-being was assessed using a measure of quality of life developed for use with children with NDD. Data from 234 parents were analysed using structural equation modelling.

RESULTS

Each predictor was found to load significantly on the overall outcome variable of well-being. Parent concerns about child function were significantly related to child well-being; parents who reported more concerns about their children's functioning reported lower levels of child well-being. Unmet needs for formal supports and services were also significantly related to child well-being; parents who reported that more of their children's and family's service needs were unmet reported lower child well-being. An indirect relationship was also found between child function and child well-being. When parents reported that their formal support needs were adequately met, their children's functional difficulties had a lower impact on parent perceptions of their children's overall well-being.

CONCLUSIONS

Taken together, the results of the current study enrich our understanding of well-being for children with NDD. Discussion focuses on the service implications for children with NDD and their families.

The Effects of Isolation Rearing on Behavioural Inhibition in the Rat

The possibility that isolation-rearing in the rat affects the development of inhibitory mechanisms was studied in a series of experiments. It was found that socially-isolated rats were (1) slower to learn both a lever-panel alternation, and a two-lever alternation schedule of reinforcement, (2) more persistent than controls in pressing a lever for food when a supply of identical “free food” was introduced into the operant chamber, but (3) similar to control rats in their response to preloading with food, a procedure which inhibited lever pressing to the same extent in the two groups. Finally, it was shown in a separate experiment that the effects of increased food deprivation on lever pressing in the presence of free food were qualitatively different from the effects of social isolation, and therefore the social/isolate difference cannot be interpreted as motivational. The possible contributions of neophobia to the difference are discussed. It is concluded that isolates may well suffer from a disinhibitory defect, but that there are probably other effects of isolation in addition.

The impact of autism services on mothers' psychological wellbeing

BACKGROUND

Families with a child diagnosed with autism spectrum disorder (ASD) often utilize a variety of professional services. The provision of these services has many potential benefits for families; however, these services also place demands on parents, particularly mothers, to access, navigate and participate. Little is known about how involvement with these services and service systems influences the psychological wellbeing of mothers of children diagnosed with ASD. We examined the relationship between professional services and psychological wellbeing for mothers of children diagnosed with ASD.

METHODS

Mothers (n = 119) of children (mean child age 10.1 years; range 2-24 years) diagnosed with ASD anonymously completed a comprehensive survey. The survey included data related to maternal psychological wellbeing, professional services received and perceptions of these services, and child, mother and household characteristics.

RESULTS

Regression analyses revealed that maternal psychological wellbeing was positively associated with the perceived continuity of services, and negatively associated with the number of professionals involved. Child and maternal age, and household income were also statistically significant predictors of maternal psychological wellbeing.

CONCLUSIONS

The study findings draw attention to the potentially negative impact of systems-level challenges, especially fragmentation of services, on maternal psychological wellbeing, despite positive front-line services. In particular, our data suggest that psychological wellbeing among mothers of children with ASD may vary more as a function of service system variables than practitioner-level or child-level variables.

Altered breathing mechanics and ventilatory response during exercise in children born extremely preterm

Background

Extreme preterm birth confers risk of long-term impairments in lung function and exercise capacity. There are limited data on the factors contributing to exercise limitation following extreme preterm birth. This study examined respiratory mechanics and ventilatory response during exercise in a large cohort of children born extremely preterm (EP).

Methods

This cohort study included children 8–12 years of age who were born EP (≤28 weeks gestation) between 1997 and 2004 and treated in a large regionalised neonatal intensive care unit in western Canada. EP children were divided into no/mild bronchopulmonary dysplasia (BPD) (ie, supplementary oxygen or ventilation ceased before 36 weeks gestational age; n=53) and moderate/severe BPD (ie, continued supplementary oxygen or ventilation at 36 weeks gestational age; n=50). Age-matched control children (n=65) were born at full term. All children attempted lung function and cardiopulmonary exercise testing measurements.

Results

Compared with control children, EP children had lower airway flows and diffusion capacity but preserved total lung capacity. Children with moderate/severe BPD had evidence of gas trapping relative to other groups. The mean difference in exercise capacity (as measured by oxygen uptake (VO₂)% predicted) in children with moderate/severe BPD was −18±5% and −14±5.0% below children with no/mild BPD and control children, respectively. Children with moderate/severe BPD demonstrated a potentiated ventilatory response and greater prevalence of expiratory flow limitation during exercise compared with other groups. Resting lung function did not correlate with exercise capacity.

Conclusions

Expiratory flow limitation and an exaggerated ventilatory response contribute to respiratory limitation to exercise in children born EP with moderate/severe BPD.

An Exploration of Care Mapping Among Families of Children with Medical Complexity (CMC)

BACKGROUND: A care map is a visual diagram that illustrates all of the resources needed to support a child with medical complexity, providing a contextualized view of the child in a broader health network. It is believed that health care providers (HCPs) can utilize care maps to enable child and family centered care by helping families prioritize and coordinate their health needs. While the popularity of care maps has been growing, there is a paucity of research on their clinical usefulness.

OBJECTIVES: The objective of this study is to explore how care maps are constructed by parents, what they mean for parents and HCPs, and how they can be applied in a clinical setting.

DESIGN/METHODS: This is a qualitative study informed by a grounded theory approach. Theoretical sampling of parents and HCPs of CMC was utilized. Fifteen care map training sessions and forty-five semi-structured interviews with parents and HCPs of CMC were conducted. The data was coded and analyzed iteratively for predominant themes and emerging theory.

RESULTS: Both HCPs and parents strongly identified the care map [Figure 1] as a valuable tool in the care of CMC. Data analysis revealed key themes that demonstrated how and why care maps are useful. Care maps allow HCPs to recognize family experiences, identify parental goals of care and promote improved care coordination and communication. Parents described creating care maps as an empowering and therapeutic process that helped them to organize and communicate their complex interplay of supports. Both parents and HCPs acknowledged challenges associated with care mapping including the ability of parents to create a care map as well as the HCPs ability to independently interpret the care map’s meaning.

CONCLUSION: Care maps are a useful communication and coordination tool to demonstrate a contextualized view of a family’s narrative of their experience caring for a CMC. Findings may inform a model of how to utilize care maps in clinical practice.

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About my Child: measuring 'Complexity' in neurodisability. Evidence of reliability and validity

BACKGROUND

About my Child, 26-item version (AMC-26) was developed as a measure of child health 'complexity' and has been proposed as a tool for understanding the functional needs of children and the priorities of families.

METHODS

The current study investigated the reliability and validity of AMC-26 with a sample of caregivers of children with neurodevelopmental disorders (NDD; n = 258) who completed AMC-26 as part of a larger study on parenting children with NDD. A subsample of children from the larger study (n = 49) were assessed using standardized measures of cognitive and adaptive functioning.

RESULTS

Factor analysis revealed that a four-component model explained 51.12% of the variance. Cronbach's alpha was calculated for each of the four factors and for the scale as a whole, and ranged from 0.75 to 0.85, suggesting a high level of internal consistency. Construct validity was tested through comparisons with the results of standardized measures of child functioning. Predicted relationships for factors one, two and three were statistically significant and in the expected directions. Predictions for factor four were partially supported. AMC-26 was also expected to serve as an indicator of caregiver distress. Drawing on a sample of caregivers from the larger study (n = 251) the model was found to be significant and explained 23% of the variance in caregiver depressive symptoms (R(2)  = .053, F (1, 249) = 14.06, P < .001).

CONCLUSIONS

Based on these observations, the authors contend that AMC-26 may be used by clinicians and researchers as a tool to capture child function and child health complexity. Such a measure may help elucidate the relationships between child complexity and family well-being. This is an important avenue for further investigation.

Trajectory of parental hope when a child has difficult-to-treat cancer: a prospective qualitative study

OBJECTIVE

This prospective and longitudinal study was designed to further our understanding of parental hope when a child is being treated for a malignancy resistant to treatment over three time points during the first year after diagnosis using a qualitative approach to inquiry.

METHODS

We prospectively recruited parents of pediatric cancer patients with a poor prognosis who were treated in the Hematology/Oncology Program at a large children's hospital for this longitudinal grounded theory study. Parents were interviewed at three time points: within 3 months of the initial diagnosis, at 6 months, and at 9 months. Data collection and analysis took place concurrently using line-by-line coding. Constant comparison was used to examine relationships within and across codes and categories.

RESULTS

Two overarching categories defining hope as a positive inner source were found across time, but their frequency varied depending on how well the child was doing and disease progression: future-oriented hope and present-oriented hope. Under future-oriented hope, we identified the following: hope for a cure and treatment success, hope for the child's future, hope for a miracle, and hope for more quality time with child. Under present-oriented hope, we identified hope for day-to-day/moment-to-moment, hope for no pain and suffering, and hope for no complications.

CONCLUSIONS

For parents of children with a diagnosis of cancer with a poor prognosis, hope is an internal resource that can be present and future focused. These views fluctuated over time in response to changes in the child's well-being and disease progression.

Public health approach to detection of non-O157 Shiga toxin-producing Escherichia coli: summary of two outbreaks and laboratory procedures

Routine laboratory testing may not detect non-O157 Shiga toxin-producing Escherichia coli (STEC) reliably. Active clinical, epidemiological, environmental health, and laboratory collaboration probably influence successful detection and study of non-O157 STEC infection. We summarized two outbreak investigations in which such coordinated efforts identified non-O157 STEC disease and led to effective control measures. Outbreak 1 involved illness associated with consuming unpasteurized apple cider from a local orchard. Public health personnel were notified by a local hospital; stool specimens from ill persons contained O111 STEC. Outbreak 2 involved bloody diarrhoea at a correctional facility. Public health personnel were notified by the facility infection control officer; O45 STEC was the implicated agent. These reports highlight the ability of non-O157 STEC to cause outbreaks and demonstrate that a coordinated effort by clinicians, infection-control practitioners, clinical diagnostic laboratorians, and public health personnel can lead to effective identification, investigation, and prevention of non-O157 STEC disease.

A new test to measure attentional bias and cognitive disinhibition in drinkers, based on the Hayling task

AIMS

To generate and pilot unfinished sentences, based on the Hayling Task of disinhibition, which could be completed with alcohol or non-alcohol words. To determine whether drinking habits influenced responses on the new sentences, which may advance understanding of the cognitive processes underlying alcohol-related behaviours.

METHODS

Three phases: I-Generation of appropriate sentences (via email correspondence); II-Sentence completion to establish proportion of alcohol-related and non-alcohol-related responses; III-A Hayling-style task using the sentences (laboratory-based). During the Hayling task, sentences were completed with the first word that came to mind (initiation task), and with a word that did not make semantic sense (inhibition task). In Phase III, the alcohol use disorder identification test (AUDIT) was also completed to determine whether drinking habits were related to responses.

RESULTS

Fifteen sentences were generated and tested. Compared with low hazardous drinkers, higher hazardous drinkers gave more alcohol-related responses; persisted in giving alcohol responses in the inhibition task; and were slower to make non-alcohol-related responses. A positive correlation was found between AUDIT score and number of alcohol-related responses.

CONCLUSIONS

A new alcohol-related sentence-completion tool, based upon the Hayling disinhibition task, was developed and piloted. Responses on the task were associated with measures of alcohol use disorders. The task can be used in research investigating the processes underlying the acute and chronic effects of alcohol, such as attentional bias and disinhibition. In future, the task could be used in conjunction with non-alcohol-related sentence completion tasks to investigate general and alcohol-specific processes of disinhibition.

Rapid pre-screening: a validated quality assurance measure in cervical cytology

We present the results of 3 years' experience of rapid pre-screening in cervical cytology. In our laboratory we rapidly pre-screen all smears. The performance of each primary screener can be assessed. In addition, the relative sensitivity and specificity of each rapid pre-screener can itself be continuously monitored using the final report as a yardstick. In our laboratory individual sensitivity of rapid pre-screening for the detection of high-grade abnormalities was in the range of 44-90% with an overall laboratory sensitivity of 69%. Specificity was in the range of 94-99% with an overall laboratory specificity of 98%. Rapid pre-screening allows checking of the checkers and pathologists and tends to promote uniformity in the assessment of smear adequacy. This form of continuous quality assurance is practical, convenient and acceptable to staff.

Health information: an evaluation of the use of touch screen kiosks in two hospitals

An exit questionnaire survey of 150 hospital users of a touch screen health information kiosk was undertaken. It was compiled by Royal Cornwall Hospitals NHS to evaluate kiosk use and was reanalysed by researchers at City University to determine whether the information obtained went anyway to meeting patients' information needs. The study established two effective outcome variables on kiosk use: whether the information found answered the users' questions and if users intended, after using the kiosk, to find more information elsewhere. Two-thirds of respondents said that the information found had answered their question, whilst 16% said that after using the kiosk they still had further questions and intended to talk to a health professional to obtain this information. The variables found to have an impact on the information outcome included: gender, navigational ease, object of search, and ease of reading and understanding the information.

Intubation success rates by air ambulance personnel during 12-versus 24-hour shifts: does fatigue make a difference?

OBJECTIVES

To determine whether the skill performance and psychomotor agility, as measured by the endotracheal intubation success rate, of air ambulance medical personnel would be affected by the potential fatigue incurred when increasing the length of their shifts from 12 to 24 hours.

METHODS

This was a retrospective review of all flight and intubation records from a large air medical transport system from 1997, when 24-hour shifts were in place, and six months (March-August) of 1996, during which 12-hour shifts were scheduled. Records of all intubation efforts during both periods, including multiple attempts per patient, and outcomes of all attempts, were recorded. Results of successes and failures were tabulated for both ultimate intubation outcome per patient and all attempts per patient for each calendar day and for the 12 hours between 19:00 and 07:00 when fatigue might play a role. Results from the two study periods were compared using Fisher's exact test.

RESULTS

During the six months of 1996, 190 of 199 (95.5%) patients were ultimately successfully intubated. These patients required 237 attempts (80.1% successful). During 1997, 362 of 376 (96.3%) patients were successfully intubated, and required 438 attempts (82.6% successful). There was no statistically significant difference in the number of ultimately successful intubations (p = 0.66) or total intubation attempts (p = 0.37) between 1996 and 1997. Analysis of intubations between 19:00 and 07:00 revealed 81 of 84 (96.4%) patients successfully intubated in 1996, with 81 of 103 (78.6%) attempts successful. During 1997, 173 of 180 (96.1%) patients were ultimately successfully intubated, with 173 of 212 (81.6%) attempts successful. Again, there was no significant difference in the number of successful intubations (p = 0.99) or intubation attempts (p = 0.55) between 1996 and 1997.

CONCLUSION

Psychomotor agility of air ambulance medical personnel, as measured by the success rate of endotracheal intubation, was not affected by the potential additional fatigue incurred as a result of increasing shift length from 12 to 24 hours.

Comparing Web and touch screen transaction log files

BACKGROUND

Digital health information is available on a wide variety of platforms including PC-access of the Internet, Wireless Application Protocol phones, CD-ROMs, and touch screen public kiosks. All these platforms record details of user sessions in transaction log files, and there is a growing body of research into the evaluation of this data. However, there is very little research that has examined the problems of comparing the transaction log files of kiosks and the Internet.

OBJECTIVES

To provide a first step towards examining the problems of comparing the transaction log files of kiosks and the Internet.

METHODS

We studied two platforms: touch screen kiosks and a comparable Web site. For both of these platforms, we examined the menu structure (which affects transaction log file data), the log-file structure, and the metrics derived from log-file records.

RESULTS

We found substantial differences between the generated metrics.

CONCLUSIONS

None of the metrics discussed can be regarded as an effective way of comparing the use of kiosks and Web sites. Two metrics stand out as potentially comparable and valuable: the number of user sessions per hour and user penetration of pages.

Partial genetic characterization of West Nile virus strains, New York State, 2000

We analyzed nucleotide sequences from the envelope gene of 11 West Nile (WN) virus strains collected in New York State during the 2000 transmission season to determine whether they differed genetically from each other and from the initial strain isolated in 1999. The complete envelope genes of these strains were amplified by reverse transcription-polymerase chain reaction. The resulting sequences were aligned, the genetic distances were computed, and a phylogenetic tree was constructed. Ten (0.7%) of 1,503 positions in the envelope gene were polymorphic in one or more sequences. The genetic distances were 0.003 or less. WN virus strains circulating in 2000 were homogeneous with respect to one another and to a strain isolated in 1999.

Development of a quality-of-life index for pediatric inflammatory bowel disease: dealing with differences related to age and IBD type

BACKGROUND

A child- and adolescent-generated IBD quality-of-life index was designed to be descriptive (to be used to assess the overall impact of IBD on individual patients), and evaluative (to be used as an outcome measure in clinical trials).

METHODS

Item-generation and item-reduction interviews with 82 patients with IBD aged 8 to 17 years (61 with Crohn's disease, 21 with ulcerative colitis; 36 girls, 45 boys) generated a list of ways in which their lives were affected by IBD. These issues were incorporated into an item-reduction questionnaire, which was administered to 117 patients (87 Crohn's disease, 30 ulcerative colitis). Patients indicated on a visual analog scale how important an item was to them and how often it bothered them. Mean and median importance-plus-frequency scores for each issue were calculated for the entire group and among patients in subgroups according to age and IBD type.

RESULTS

Ulcerative colitis and Crohn's disease affect the lives of children and adolescents differently. Bowel symptoms are more troubling and disabling to patients with ulcerative colitis, whereas systemic symptoms and body image concerns are greater for patients with Crohn's disease. The impact of Crohn's disease on ability to function in school and leisure activities is greater. Worries about future health problems and about the effects of IBD on the family are shared. Crohn's disease and ulcerative colitis trigger emotional responses of unfairness and frustration, but anger and embarrassment are more prevalent in ulcerative colitis. Disparities between age groups are fewer and less marked than those between types of IBD.

CONCLUSION

In selection of items to be retained in a pediatric IBD quality-of-life measure, the variation in concerns with disease type must be considered. A single index to assess IBD-related quality of life must include items of major importance to one subgroup of patients, even if not important to all. Alternately, a core of common concerns could be supplemented by disease-specific modules, thereby increasing the content validity of the tool for all patients.

Perceived outcome of social work intervention: beyond consumer satisfaction

This study identified and measured the predictive value of specific indicators of consumers' overall perception of a hospital-based social work service. A review of the health and social work literature revealed a number of distinct "components" which predict overall satisfaction with the service a patient receives. A questionnaire evaluating client perceptions of each component was developed and administered to 83 randomly selected respondents. The study also gathered information about perceptions of patients/families regarding the reason for social work involvement and the corresponding outcome measured on a goal attainment scale. Findings were positive concerning the value of social work. The results suggest that the "components" of satisfaction that were tested were relevant as they were positively and significantly associated with patients' overall rating of the social work service. Implications for practice are discussed.

External radiation protection audit in National Health Service hospitals. Radiation protecgtion advisors (RPA) of the Nottingham City Hospital NHS Trust and the Oxford Radcliffe Hospital NHS Trust

Radiation protection advisers are accustomed to carrying out internal audit in organizations for which they provide services but, traditionally, external audit has not been a part of the radiation protection adviser function. To provide an external audit function, two teams of radiation protection advisers undertook external radiation protection audits of their respective organizations, including the radiation protection adviser function itself. These audits were more representative of audits or inspections carried out by government agencies, for example the Health and Safety Executive and the former Inspectorate of Pollution, now the Environment Agency. Subsequently, reports, including recommendations for remedial action, were prepared for each management by the external auditors. The process of setting up and carrying out the external audits is described. Guidelines are suggested for those seeking to carry out an external audit.

High-altitude pulmonary edema at a ski resort

Medical records of 150 patients with high-altitude pulmonary edema seen over a 39-month period in a Colorado Rocky Mountain ski area at 2,928 m (9,600 ft) (mean age 34.4 years; 84% male) were reviewed. The mean time to the onset of symptoms was 3 +/- 1.3 days after arrival. Common symptoms were dyspnea, cough, headache, chest congestion, nausea, fever, and weakness. Orthopnea, hemoptysis, and vomiting were rare, occurring in 7%, 6%, and 16%, respectively. Symptoms of cerebral edema occurred in 14%. A temperature exceeding 100 degrees F occurred in 20%, and 17% had a systolic blood pressure of 150 mm of mercury or higher. Blood pressures were higher in patients older than 50 years (142 mm of mercury). Rales were present in 85%, and a pulmonary infiltrate was present in 88%; both were most commonly bilateral or on the right side. The amount of infiltrate was mild. Men appeared to be more susceptible than women to high-altitude pulmonary edema. Pulse oximetry in 45 patients showed a mean oxygen saturation of 74% (38% to 93%). Treatment methods depended on severity and included a return to quarters for portable nasal oxygen, an overnight stay in the clinic for continuing oxygen, or a descent to Denver for recovery or admission to a hospital. All patients received oxygen for 2 to 4 hours in the clinic. There were no deaths or complications.

Attitudes of dialysis patients and caregivers regarding advance directives

OBJECTIVE

The objective of this study was to describe and compare the attitudes of dialysis patients, their relatives/friends, primary nephrologists, and nurses regarding advance directives.

DESIGN

A descriptive comparative design was used.

SAMPLE/SETTING

A total of 50 dialysis patients from a large teaching hospital in western Canada participated in the study. For every patient who responded, a relative/friend, physician, and nurse completed the questionnaire.

METHODS

The questionnaires were designed for the purposes of the study. These questionnaires were mailed to dialysis patients, who were asked to identify a relative/friend to complete a similar questionnaire. Nurses and physicians also completed questionnaires.

RESULTS

Overall, 84% of patients indicated that they believed that it was important to leave a living will, but only 18% of these patients had actually left an advance directive. However, 52% of patients and relatives/friends believed that major treatment decisions should be left to the physician, a perception that was not shared by physicians and nurses.

CONCLUSIONS

It appears that patients, family/friends, nurses, and physicians in this study had differing perceptions regarding advance directives. It is important that health care professionals realize that these differences may exist and that further research should address strategies to increase our understanding of patient decisions in this area.

Costing medical libraries: the feasibility of functional cost analysis

As a result of organizational changes in the National Health Service (NHS) there is a need for a coherent costing model for NHS libraries, particularly for the smaller libraries based in postgraduate medical centres. One possible model is functional cost analysis, whereby all costs are assigned to library functions representing services to users, such as loans from stock, interlibrary loans, enquiry services, etc. Using data from a 1991 survey of postgraduate centre-based libraries in the North West Thames (NWT) Region of the NHS, the feasibility and appropriateness of functional cost analysis is examined.

Clinical application of an electronic imaging device for assisting patient set-up in radiotherapy

As radiotherapy treatment set-ups are becoming more complicated and a greater emphasis is placed on accuracy, there is an increasing need to verify and record the actual treatments being given. A direct electronic imaging device is currently marketed by Varian (the DYNARAY ID), which uses the latest technology in detection and image processing to obtain digital images of the patient's anatomy using the actual treatment beam. At Norwich we have been using a prototype machine in a busy district radiotherapy centre and have examined over 50 patients. We have found the images easy to obtain and the technique superior to the standard practice of using verification radiographs. The role of this device lies in aiding quality assurance of treatments whilst generating a permanent record of the actual treatment given.

Quantitative assessment of lung damage due to bleomycin using computed tomography

Visual assessment and density measurements of the lung using computed tomography (CT) were made in 18 patients undergoing treatment with bleomycin for malignant teratoma of the testis. The results of both visual assessment and density measurements were compared with changes in gas transfer per unit lung volume (KCO). Visual assessment of severity of damage to the lungs caused by bleomycin is unrelated to changes in KCO but is characteristic of bleomycin damage and allows a confident diagnosis to be made. Quantitative density measurement by CT, however, is inversely related to changes in KCO and may therefore be used to monitor the physiological effect on the patient. Examination of the lung by CT in these patients can not only characterise and define the extent of lung damage due to bleomycin but can be used to give a quantitative measurement on which to monitor treatment.

Comparison of computed tomography and conventional radiology in the assessment of treatment response of lytic bony metastases in patients with carcinoma of the breast

Full skeletal survey, localised radiographs and computed tomography (CT) examinations were compared with clinical assessment in the evaluation of treatment response of bony metastases in 20 patients with carcinoma of the breast. Conventional radiology, skeletal survey and localised views compared poorly with clinical assessment agreeing in only 35% and 50% respectively. CT concurred with the clinical assessment in 65% of patients, particularly with respect to healing (86%). CT predicted the effect of treatment in six additional patients and this was confirmed on follow-up assessment. It is suggested that the use of skeletal surveys in monitoring treatment response is limited and that for critical evaluation of treatment CT should be the method of choice.

Prognosis following chemotherapy for metastatic malignant teratoma

A multiple regression analysis was performed of factors affecting the prognosis of 93 patients with metastatic malignant teratoma treated at the Royal Marsden Hospital between 1979 and 1981. In a subgroup of 53 patients, where exact tumour bulk could be calculated from sequential CT scan slices, a correlation was seen between tumour marker level and volume of metastatic disease. On analysis of the risk of relapse after initial chemotherapy, the independent adverse influence was detected of serum AFP greater than 500 micrograms/l and of bulky disease defined by clinical staging. An adverse influence of high serum HCG levels was not seen, probably due to the small number of patients in this series with this presenting feature.

Benign thymic enlargement in adults after chemotherapy: CT demonstration

Serial computed tomographic (CT) scans of 200 patients with malignant testicular teratomas were reviewed. Of the 200 patients, 120 were treated with chemotherapy for metastatic disease; 80 patients with no evidence of metastases (stage I disease) received no treatment and served as a control group. CT was performed at regular intervals for ongoing follow-up in both groups. Thymic enlargement occurred 3-14 months after initiation of treatment in 14 of the 120 patients (11.6%) who received chemotherapy but in only one patient in the control group. Histologic examination in one patient who received chemotherapy revealed that the thymic enlargement represented true hyperplasia. Thirteen of the 14 patients (93%) with thymic enlargement after chemotherapy were well and disease free on mean follow-up of 45 months, compared with 78% of the group that did not show thymic enlargement after chemotherapy (P less than .02). Rebound thymic hyperplasia in adults after chemotherapy for metastatic testicular teratoma may be a good prognostic feature and should be considered when an anterior mediastinal mass develops after chemotherapy for metastatic malignancy.

Lung damage after hemithoracic irradiation: dependence on mouse strain

A comparative study was performed on CBA, C57Bl mice and their F1 hybrid cross (CBBF1) after right hemithorax irradiation using doses ranging from 15 to 35 Gy. A dose-dependent increase in breathing rate was observed, corresponding to the expression of radiation pneumonitis in the irradiated lung. The use of hemithoracic irradiation enabled this to be observed without any lethality. Results obtained from X-ray computerized tomography (CT), lung weight and histology complemented the breathing rate studies. CBA mice showed a peak response at 16 weeks followed by a decline in breathing rate coincident with a compensatory hypertrophy of the shielded left lung. The manifestation of radiation pneumonitis in C57Bl mice was considerably delayed, supporting previous findings on whole-thorax irradiated animals. The latent period in CBBF1 hybrid mice was intermediate between the parent strains.

The assessment of early and late radiation injury to the mouse lung using X-ray computerised tomography

X-ray computerised tomography (CT) was performed on the lungs of CBA and C57Bl mice at varying time intervals after 13 and 16 Gy irradiation to the whole thorax. With careful consideration of artefacts associated with lung cross-sectional area and breathing rate, the mean density of the lung was evaluated in Hounsfield units (CT number). In CBA mice, this parameter showed a biphasic increase in lung density with time from irradiation, corresponding to an early phase of radiation pneumonitis and a late phase dominated by pleural effusions. Reduced lung volumes were also seen during the late response and lung compression due to accumulations of pleural fluid is considered a major factor in these observations. C57Bl mice did not develop radiation pneumonitis but appeared to be equally responsive to later radiation-induced increases in lung density. The results obtained from CT-derived densitometry compared well with measurements gained from functional and survival endpoints. X-ray CT provides a sensitive and informative technique for assessing the extent of radiation injury to the mouse lung and is potentially useful for quantifying the counterpart in patients.

Autonomic neuropathy and hypertrophic osteoarthropathy in association with malignancy

A case of autonomic neuropathy and hypertrophic osteoarthropathy in association with metastatic giant cell carcinoma of the lung and leiomyosarcoma of the stomach is reported. The link between these conditions is discussed and the role of pancreatic polypeptide as a possible marker for hypertrophic osteoarthropathy reported.

Two-dimensional diffraction scanning of normal and cancerous human hepatic tissue in vitro

A technique and associated equipment are described which investigate the acoustic signals backscattered from small tissue volumes and interrogated over a solid angle of transmitter/receiver positions. This two-dimensional diffraction technique produces acoustic scatter maps termed, by us "interferograms", which are analysed to determine their usefulness in discriminating between normal, freshly excised liver tissue and cancerous tissue within the intact organ. The "interferograms" are collected at three different narrow-band frequencies and have been used in investigating 26 normal liver and 13 liver tumour samples. The preliminary results indicate that this novel technique has a 97% success in discriminating normal liver from tumour, compared to an 87% success achieved by two observers when scoring conventional sector B-scan images of the same tissue regions.

B-scan texture classification: a study using physical and theoretical models

Recent clinical trials, in our own centre and elsewhere, have demonstrated the ability of A- and B-scan texture analysis techniques to provide useful in vivo separation of certain disease conditions. The present paper reports studies, using physical and theoretical models of tissues, aimed at identifying the particular sets of textural features which are most effective in achieving such separations. Using a 3.5 MHz, single element manual scanner, a total of 300 B-scans have been collected from four physical models consisting of gel-embedded 'point' scatterers, with differing mean separations. Additionally, computer modelling has been used to obtain a further 500 B-scans from 14 statistically different scattering situations. The total set of B-scans thus obtained has been subjected to a variety of texture classification procedures which have previously been developed for application in other imaging fields, such as cytology and aerial photography. The results are discussed in terms of: i) the features which are best suited to the classification of B-scans, and ii) the manner in which the resulting classification schemes are sensitive to variables of the ultrasonic scanning instrumentation.

The binding of tetanus toxin to retinal cells

An indirect immunofluorescence assay demonstrated intense binding of tetanus toxin to a minority of cells cultured from neonatal rat retina. These labelled cells were typically spheroid cells bearing long processes. Flat cells and smaller spheroid cells without long processes were essentially unlabelled. A similar assay performed on frozen sections of rat retina showed that tetanus toxin bound intensely to the inner plexiform layer, moderately to the outer plexiform and inner nuclear layers, and only very slightly to the outer nuclear layer. The localization of tetanus toxin bound to frozen sections was confirmed by autoradiography of [125I]tetanus toxin binding. In contrast, the monoclonal antibody A4 bound to all layers of the retina (except that of the outer segments). In cell cultures the monoclonal antibody Ran-2 bound to the flat cells but to neither class of spheroid cells. These data imply that tetanus toxin binds more intensely to retinal neurones than to photoreceptors and other retinal cell types. By assisting identification of cells dissociated from retina, assays of tetanus toxin binding should prove useful in the isolation of specific retinal cell-types.

Time-frequency-domain analysis: one-dimensional phantom studies

Two methods have been adopted to date for investigating the interference effects resulting from the scattering of ultrasound by soft mammalian tissues; one involves the conversion of time-domain signals into the frequency-domain, where the broad spectral characteristics of a short acoustic pulse are utilised, whilst the other varies the orientation of the specimen with reference to the incident beam and analyses the interference effects at a specific frequency. It is shown both theoretically and experimentally that the two techniques are equivalent though the former is more seriously restricted by the equipment features. Results are presented on simple linear arrays of nylon monofilaments which indicate the ability of the respective techniques to evaluate scatterer separation. Furthermore a detailed examination of the limitations of the techniques concludes that the monofrequency orientation method is to be preferred and allows for the more accurate determination of scatterer separation. The significance of these findings is discussed with reference to the usage of these techniques for tissue characterisation.