A Dosimetric Comparison of Breast Radiotherapy Techniques to Treat Locoregional Lymph Nodes Including the Internal Mammary Chain

AIMS

Radiotherapy target volumes in early breast cancer treatment increasingly include the internal mammary chain (IMC). In order to maximise survival benefits of IMC radiotherapy, doses to the heart and lung should be minimised. This dosimetry study compared the ability of three-dimensional conformal radiotherapy, arc therapy and proton beam therapy (PBT) techniques with and without breath-hold to achieve target volume constraints while minimising dose to organs at risk (OARs).

MATERIALS AND METHODS

In 14 patients' datasets, seven IMC radiotherapy techniques were compared: wide tangent (WT) three-dimensional conformal radiotherapy, volumetric-modulated arc therapy (VMAT) and PBT, each in voluntary deep inspiratory breath-hold (vDIBH) and free breathing (FB), and tomotherapy in FB only. Target volume coverage and OAR doses were measured for each technique. These were compared using a one-way ANOVA with all pairwise comparisons tested using Bonferroni's multiple comparisons test, with adjusted P-values ≤ 0.05 indicating statistical significance.

RESULTS

One hundred per cent of WT(vDIBH), 43% of WT(FB), 100% of VMAT(vDIBH), 86% of VMAT(FB), 100% of tomotherapy FB and 100% of PBT plans in vDIBH and FB passed all mandatory constraints. However, coverage of the IMC with 90% of the prescribed dose was significantly better than all other techniques using VMAT(vDIBH), PBT(vDIBH) and PBT(FB) (mean IMC coverage ± 1 standard deviation = 96.0% ± 4.3, 99.8% ± 0.3 and 99.0% ± 0.2, respectively). The mean heart dose was significantly reduced in vDIBH compared with FB for both the WT (P < 0.0001) and VMAT (P < 0.0001) techniques. There was no advantage in target volume coverage or OAR doses for PBT(vDIBH) compared with PBT(FB).

CONCLUSIONS

Simple WT radiotherapy delivered in vDIBH achieves satisfactory coverage of the IMC while meeting heart and lung dose constraints. However, where higher isodose coverage is required, VMAT(vDIBH) is the optimal photon technique. The lowest OAR doses are achieved by PBT, in which the use of vDIBH does not improve dose statistics.

Vitamin D receptor variants and uncontrolled asthma

Summary

Background. Asthma is a common childhood respiratory disease, affecting around 20% of Irish children. In other populations, vitamin D receptor (VDR) polymorphisms have been associated with asthma risk. We aimed to investigate the association between 2 VDR polymorphisms and uncontrolled paediatric asthma. Methods. 44 asthmatic children and 57 healthy volunteers were studied. The VDR TaqI gene variant in exon 9 (T/C) (rs731236) and ApaI (rs7975232) in intron 8 (C/T) were determined, using TaqMan® Assays. The lung function, serum 25-hydroxyvitamin D (25OHD) levels and other biomarkers of allergy, immunity, airway and systemic inflammation were as-sessed. Results. The distribution of T and C alleles and genotype frequencies differed significantly between asthmatics and controls for both polymorphisms (p < 0.05). A significant association was found between both TaqI [OR = 2.37, 95% CI (1.27 - 4.45), p = 0.007] and ApaI polymorphisms, and asthma risk [OR = 2.93, 95% CI (1.62 - 5.3), p = 0.0004]. No association was observed between genotypes and 25OHD levels, lung function and other biomarkers, with the exception of Interleukin-10 (IL-10) and white blood cells count (WBC). IL-10 levels were lower in asthmatics with TC genotype for TaqI polymorphism (p < 0.01) and were higher in patients with TT genotype for ApaI (p < 0.01). WBC were higher in patients with TC and CC genotypes for TaqI (p < 0.05) and lower in TT genotype for ApaI (p < 0.05). Conclusion. TaqI and ApaI polymorphisms are associated with asthma in Irish children. Further studies are warranted to investigate the importance of decreased IL-10 levels in paediatric asthmatics with specific genotypes.

The Association Between 25 Hydroxyvitamin D and Airway Obstruction in Asthma

Since Vitamin D has anti-inflammatory effects we wondered whether the association between low serum 25OHD and airway obstruction in moderate persistent asthma might be explained by inflammatory pathways that worsen asthma. All subjects examined were Irish Caucasians with moderate persistent asthma and none took systemic steroid therapy. In addition to computerized spirometry, we measured BMI, serum 25-hydroxyvitamin D (25OHD), total IgE, Eosinophil Cationic Protein (ECP), and high sensitive C- reactive protein (hs-CRP). One hundred (47 male) subjects completed the testing. Within single level of asthma severity, 25OHD levels were related to post-bronchodilator FEV1/FVC (r = 0.26, p< 0.01), but multiple linear regression analysis demonstrated that the association was not explained by obesity or inflammatory markers. We find a relationship exists between airway obstruction and 25OHD levels in asthmatic adults, and the effect is not explained by the presence of potential confounders such as obesity, allergy and systemic inflammation.

Final results of a multicenter phase II study of the purine nucleoside phosphorylase (PNP) inhibitor forodesine in patients with advanced cutaneous T-cell lymphomas (CTCL) (Mycosis fungoides and Sézary syndrome)

BACKGROUND

Forodesine is a potent inhibitor of purine nucleoside phosphorylase (PNP) that leads to intracellular accumulation of deoxyguanosine triphosphate (dGTP) in T and B cells, resulting in apoptosis. Forodesine has demonstrated impressive antitumor activity in early phase clinical trials in cutaneous T-cell lymphoma (CTCL).

PATIENTS AND METHODS

In this phase II study, patients with CTCL who had already failed three or more systemic therapies were recruited. We investigated the response rate, safety and tolerability of oral forodesine treatment in subjects with cutaneous manifestations of CTCL, stages IB, IIA, IIB, III and IVA. The safety population encompassing all stages was used for analysis of accountability, demographics and safety. The efficacy population differed from the safety population by exclusion of stage IB and IIA patients.

RESULTS

All 144 patients had performance status 0-2. The median duration of CTCL from diagnosis was 53 months (5-516 months). The median number of pretreatments was 4 (range: 3-15). No complete remissions were observed. In the efficacy group of patients, 11% achieved partial remission and 50% had stable disease. The median time to response was 56 days and the median duration of response was 191 days. A total of 96% of all treated patients reported one or more adverse events (AEs) and 33% reported a serious AE. The majority of AEs were classified as mild or moderate in severity. The most commonly reported AEs (>10%) were peripheral edema, fatigue, insomnia, pruritus, diarrhea, headache and nausea. Overall eight patients died during the study: five due to sepsis and infections, one due to a second malignancy (esophageal cancer), one due to disease progression and one due to liver failure.

CONCLUSION

Oral forodesine at a dose of 200 mg daily is feasible and shows partial efficacy in this highly selected CTCL population and some durable responses.

Diet selection and productivity of sheep grazing contrasting pastures

A grazing experiment was conducted at the Big Ridge 2 site CSIRO, Chiswick (30˚31′S, 151˚39′E), 20 km south of Armidale, New South Wales, Australia. The site was established in 1955. In March 1966, phalaris and white clover were sown and pastures were fertilised annually with superphosphate until 1993. There were 3 pasture treatments, each with 2 replicates: degraded pasture (low phalaris content), phalaris-dominant, and phalaris–white clover. The effect of pasture type on animal production (liveweight gain and wool) was only significant in 1996, when there were large differences in pasture composition and production between the 3 pasture types. n-Alkane based estimates showed that pasture degradation affected diet selection and nutrient intake and thus sheep production. The estimates in this study also showed no clear preference for a single pasture species over time and lack of strong preferential selection for clovers when sheep were grazing 3 contrasting pastures. Preferential selection of a particular species varied over time depending on the presence and availability of alternative species. Although there were large differences in total N and S intake and faecal output between the 3 pastures, the proportion of the dietary nutrient used for production was similar. This observation reveals the importance of further improving pasture and grazing management, particularly in productive phalaris–white clover pasture with high nutrient flux, to improve nutrient recycling through plant uptake and retention by animals in the grazing ecosystem, and reduce losses.

Restored to life, and power, and thought

This paper describes the personal experiences of a nurse working on a hospital ward in England during the Second World War.

Depression, mood state, and back pain during microgravity simulated by bed rest

OBJECTIVE

The objective of this study was to develop a ground-based model for spinal adaptation to microgravity and to study the effects of spinal adaptation on depression, mood state, and pain intensity.

METHODS

We investigated back pain, mood state, and depression in six subjects, all of whom were exposed to microgravity, simulated by two forms of bed rest, for 3 days. One form consisted of bed rest with 6 degrees of head-down tilt and balanced traction, and the other consisted of horizontal bed rest. Subjects had a 2-week period of recovery between the studies. The effects of bed rest on pain intensity in the lower back, depression, and mood state were investigated.

RESULTS

Subjects experienced significantly more intense lower back pain, lower hemisphere abdominal pain, headache, and leg pain during head-down tilt bed rest. They had higher scores on the Beck Depression Inventory (ie, were more depressed) and significantly lower scores on the activity scale of the Bond-Lader questionnaire.

CONCLUSIONS

Bed rest with 6 degrees of head-down tilt may be a better experimental model than horizontal bed rest for inducing the pain and psychosomatic reactions experienced in microgravity. Head-down tilt with balanced traction may be a useful method to induce low back pain, mood changes, and altered self-rated activity level in bed rest studies.

Urban outpost nursing: the nature of the nurses' work in the AIDS prevention street nurse program

The AIDS Prevention Street Nurse Program in Vancouver, Canada focuses on HIV and sexually transmitted diseases (STD) prevention within a context of harm reduction and health promotion targeted at marginalized, hard to reach, high-risk populations. As part of a large evaluation project that included interviews with street nurses, clients, and other service providers together with document analysis, the nature of the street nurses' work and its fit within the provision of health care were described. The street nurses' work reflected the following themes: reaching the marginalized high-risk populations for HIV/STDs; building and maintaining trust, respect, and acceptance; doing HIV/AIDS and STD prevention, early detection, and treatment work; helping clients connect with and negotiate the health care system; and influencing the system and colleagues to be responsive. The findings and their implications for community health nursing practice are examined.

A comparison of spinal quantitative computed tomography with dual energy X-ray absorptiometry in European women with vertebral and nonvertebral fractures

Quantitative computed tomography (QCT) was compared to dual X-ray absorptiometry (DXA) measured in the lumbar spine of 508 European women defined as normal without fracture (NoF), or osteoporotic (OP), with either vertebral fracture (VF), or peripheral fracture (PF). The correlations between QCT and DXA BMD measurements were significantly different in normal and in osteoporotic patients, indicating that the two exams do not measure the same bone aspects. According to ROC curves results, QCT Z-scores separate OP from NoF with better sensitivity than all other measurements. A threshold to differentiate OP from NoF was chosen at Z-score = -1 for DXA-BMD and -1.5 for QCT-BMD. VF patients showed a highly significant decrease in BMD by DXA or QCT. PF patients revealed measurements lower than those of normal subjects but greater than those of VF, calling into question the idea of a diffuse osteoporosis causing nonvertebral fractures that is measurable by spinal DXA or QCT. DXA is weakly dependent upon age, and T-score or Z-score are equivalent for evaluating osteoporosis. QCT depends greatly upon age, and Z-score appears to be more efficient.

Recurrent ischemic strokes in a patient with Medtronic-Hall prosthetic aortic valve and valve strands

Fine strands associated with prosthetic heart valves have been demonstrated with transesophageal echocardiography, but the pathologic identity of these strands is unclear. A case of a man with a prosthetic aortic Medtronic-Hall valve with prominent valve strands and recurrent strokes is discussed. The patient underwent valve replacement surgery, and histopathologic examination of the strands identified them as Lambl's excrescences.

Immunoglobulin G crystalline keratopathy associated with monoclonal gammopathy

PURPOSE

Two cases of corneal crystal deposition are reported, both caused by a benign monoclonal gammopathy

METHODS

Similar corneal pathology is identified in these two patients, both of whom presented with visual acuities of 6/6 or better Consideration of possible causes involved biochemical and haematological testing and assessment.

RESULTS

Potential for malignant transformation of monoclonal gammopathy was recognized, hence the need for ongoing haematological follow-up.

CONCLUSION

Corneal crystals may be the initial presentation in a patient with monoclonal gammopathy, a rare, but significant, clinical finding.

Morphine and dextrorphan lose antinociceptive activity but exhibit an antispastic action in chronic spinal rats

Within 3-4 weeks after spinal transection, morphine-induced antinociception, assessed with the tail flick reflex in rats, is profoundly reduced. The cause of this decrement is unknown. The present studies were conducted to determine whether this phenomenon reflects a general loss in opiate activity or a selective decline in opiate antinociception. This was accomplished by assessing the effect of morphine on two different responses, the tail flick reflex and the hindlimb spasticity that develops in chronic spinal rats. Because excitatory amino acid antagonists are also antinociceptive in acute spinal rats, the effect of one such drug, dextrorphan, on these two behaviors was also evaluated in chronic spinal animals. The antinociceptive and antispastic effect of subcutaneous (6 mg/kg) and intrathecal (5 micrograms) morphine injections were assessed in intact and chronic (21-28 days) spinal rats, whereas the effect of subcutaneous (25 and 40 mg/kg) and intrathecal (350 micrograms) dextrorphan was assessed in acute (1 day) and chronic spinal rats. The antinociceptive effect of both drugs was significantly reduced in chronic spinal animals, relative to saline controls. However, each drug treatment produced a significant antispastic effect in the same animals, indicating a selective decline in opiate action. This outcome also suggests that excitatory amino acid antagonists may be useful as adjunct antispastic agents.

A computer program that periodically monitors the ability to interpret the antinuclear antibody test

Our laboratory has been developing computer programs that help medical technologists improve their performance of the microscope-based immunofluorescence assay for antinuclear antibodies (ANA). This image-based laboratory test has been associated with poor reproducibility. We have previously described our first program, ANA-Tutor, which systematically teaches the ANA test by using approximately 150 processed digital images of ANA test results. The program we describe here, Pattern Plus Auditor, is a logical extension to ANA-Tutor. Pattern Plus Auditor tests the ability of laboratory personnel to interpret the ANA test, and tracks individual and laboratory performance over time. The program consists of image-based questions that test a variety of ANA staining patterns, including homogeneous, speckled, centromere, nucleolar, mixed patterns, and rare patterns. For each question, the program provides correct answers with explanations and color overlays that highlight key image features. By entering the proper password, users gain access to exam results for individuals and for the laboratory as a whole. Results are available for the current exam, any previous exam, or cumulatively on all exams to date. Intralaboratory testing with computer programs such as Pattern Plus Auditor might be a useful part of quality-assurance procedures for many image-based laboratory tests.

A computer program that periodically monitors the ability to interpret the antinuclear antibody test

Our laboratory has been developing computer programs that help medical technologists improve their performance of the microscope-based immunofluorescence assay for antinuclear antibodies (ANA). This image-based laboratory test has been associated with poor reproducibility. We have previously described our first program, ANA-Tutor, which systematically teaches the ANA test by using approximately 150 processed digital images of ANA test results. The program we describe here, Pattern Plus Auditor, is a logical extension to ANA-Tutor. Pattern Plus Auditor tests the ability of laboratory personnel to interpret the ANA test, and tracks individual and laboratory performance over time. The program consists of image-based questions that test a variety of ANA staining patterns, including homogeneous, speckled, centromere, nucleolar, mixed patterns, and rare patterns. For each question, the program provides correct answers with explanations and color overlays that highlight key image features. By entering the proper password, users gain access to exam results for individuals and for the laboratory as a whole. Results are available for the current exam, any previous exam, or cumulatively on all exams to date. Intralaboratory testing with computer programs such as Pattern Plus Auditor might be a useful part of quality-assurance procedures for many image-based laboratory tests.

Patterns of coordinated multi-joint movement

In multi-joint reaching movements, the motor system may choose any one of an infinite set of possible joint rotations to move the hand between given start and target positions. In order to find out whether reaching movements are represented in Cartesian hand coordinates or in joint coordinates, it is necessary to measure whether hand paths or joint paths have lower variability. We have measured hand paths and rotations of shoulder, elbow and wrist joints simultaneously in five subjects reaching in four orientations in the horizontal plane. As in earlier studies, we found a preference for nearly straight hand paths, despite different patterns of joint rotation for different orientations of movement. However, movements in three of four orientations showed a single principal joint, which rotated essentially without reversals. This may reflect optimisation in the motor system, preferring the simplest pattern of joint control for a desired hand path. We used generalised Procrustes analysis to quantify the variability in shape of repeated paths in hand space and joint space. Results showed that hand paths were less variable than the joint angles used to realise them, due to the kinematic redundancy of the limb, suggesting that hand paths, rather than joint angles, are directly represented by the motor system. Nevertheless, movements with straighter hand paths, on average, and those requiring coordinated activity at both shoulder and elbow joints also showed more variability in the shape of the hand path. Other orientations such as movement across the body use primarily a single joint and are less variable at the cost of a slightly curved path. These results suggest that coordinating multiple joints to produce a straight hand path has a definite computational cost. The motor system may perform a trade-off between the benefits of planning reaching movements as straight hand paths and the computational simplicity of executing them using patterns of joint rotation which simplify multi-joint coordination.

Cytoplasmic tutor: a program for teaching interpretation of a microscope-based laboratory test

Antibodies to cytoplasmic antigens can be identified with a microscope-based indirect immunofluorescence assay that uses a mouse stomach-kidney substrate. The antibodies are diagnostic markers in chronic active hepatitis, primary biliary cirrhosis, pernicious anemia, and other autoimmune diseases. We describe the development and features of an image-based computer program for teaching medical technologists and other health care workers the proper interpretation of cytoplasmic fluorescence staining patterns. The program, called Cytoplasmic Tutor, is written in Microsoft Visual Basic for Windows and runs on an 80486 microcomputer. it is based on a library of digital images, with key features described by overlays of text. The images were collected and processed with a computer-based fluorescence video microscopy system assembled in our laboratory.

The Homeless Prenatal Program: a model for empowering homeless pregnant women

The Homeless Prenatal Program (HPP) is one of the first programs in the country to provide comprehensive prenatal services to homeless pregnant women. A formative evaluation was conducted in 1992, indicating that HPP is achieving its program goals of improving birth outcomes and transforming the lives of its clients. Results of the qualitative evaluation are presented, including HPP's service model and approach to empowerment. In this model, empowerment has two central tenets, derived from the special needs of women who are pregnant and homeless: the "mother-child connection," and the principle of "giving back."

A mutant baculovirus with a temperature-sensitive IE-1 transregulatory protein

We have mapped the mutation responsible for the temperature-sensitive (ts) phenotype of tsB821, a mutant of the baculovirus Autographa californica nuclear polyhedrosis virus (H. H. Lee and L. K. Miller, J. Virol. 31:240-252, 1979), to a single nucleotide which changes alanine 432 of the multifunctional regulatory protein IE-1 to a valine. Mapping was done with a combination of marker rescue and transient expression assays, hybrid gene construction by overlap PCR gene splicing, and nucleotide sequence analysis. Cells infected with tsB821 at high multiplicities of infection showed a spectrum of responses from severe cytopathic effects, including apoptosis, to a lack of obvious signs of infection. Protein synthesis in tsB821-infected cells at the restrictive temperature appeared similar to uninfected cell protein synthesis, but viral DNA replication and budded virus production were observed, albeit in a delayed manner. The dependence of early and late promoter activity on the wild-type IE-1 gene, ie-1, was observed in transient expression assays. However, the dependence of early promoter activity on ie-1 was strongest in the absence of other viral genes. Thus, other viral genes appear to be able to compensate, at least in part, for the lack, or low levels, of ie-1 in transient expression assays using early promoters. The mutant should prove useful in further defining the function(s) of IE-1.

Trade union recognition

An increasing number of organizations are addressing the issue of trade union recognition, particularly NHS trusts considering introducing local pay determination. Burnley NHS Trust developed a strategic approach to the issue, establishing pre-determined outcomes and measurable criteria to determine which organizations--if any--would have recognition extended for the purpose of local pay determination. The staff side case is examined in detail along with three other options: a staff association, recognition for some and recognition for none. Four organizations--representing 95 per cent of the unionized workforce--accepted recognition, with safeguards for 14 others.

Identification and characterization of tox21A: a mite cDNA encoding a paralytic neurotoxin related to TxP-I

A cDNA library established from polyadenylated RNA isolated from the predatory mite Pyemotes tritici was screened for cDNAs homologous to tox34, a cDNA encoding an insect-selective paralytic neurotoxin known as TxP-I. Most of the cDNA inserts of homologous clones were shorter or of equal length to tox34 but a few were longer. Further investigation into the nature of these longer clones led to the identification, sequencing and expression of a distinct cDNA referred to as tox21A. This cDNA is predicted to encode a polypeptide which shares approximately 83% amino acid identity with TxP-I. Larvae infected with a recombinant baculovirus expressing tox21A are paralyzed during infection in a manner similar to larvae infected with tox34-expressing recombinants. The tox21A cDNA may represent a duplicated and diverged copy of the TxP-I gene.

The time course of action of three differing doses of noberastine, a novel H1-receptor antagonist, on histamine-induced skin wheals and the relationship to plasma drug concentrations in normal human volunteers

1. The time course and magnitude of effect of the novel H1-receptor antagonist noberastine, structurally modified from astemizole to achieve a more rapid onset while retaining a good duration of action, has been investigated using histamine-induced skin wheals in healthy volunteers. 2. The pharmacokinetics and pharmacodynamics of three doses (10, 20 and 30 mg) have been studied in a double-blind, placebo controlled, randomised cross-over trial involving 12 healthy male volunteers. 3. All doses of noberastine caused inhibition of histamine-induced skin wheals, which were significantly different from placebo (P < 0.0001) when assessed as the area under the percent inhibition of the response vs time curves. 4. Following single dose administration of 10, 20 and 30 mg noberastine significant inhibition of histamine-induced skin wheals occurred and this effect persisted beyond 24 h. 5. At the higher (20 and 30 mg) doses studied significant inhibition of the histamine-induced skin wheal occurred by 1 h of dosing, whereas this did not occur until 2 h following the 10 mg dose. 6. An increase in plasma concentrations of noberastine was seen after administration of all doses, with mean (s.d.) concentrations of 4.14 (3.70), 8.38 (7.81) and 12.66 (11.82) ng ml-1 1 h following administration of 10, 20, and 30 mg respectively. 7. Visual analogue scale measurements of drowsiness identified no sedative effects above those of placebo at any of the dose levels. 8. We conclude that noberastine is an effective H1-receptor antagonist in the human as assessed by its effect on histamine-induced skin wheals.

Implementing a health care assistant strategy

All nursing auxiliaries with over five years service were given the opportunity to receive both NVQ training and assessment to level 2 and a small financial inducement. New job descriptions, pay and grading systems have been introduced resulting in considerable progress towards changing the culture of the organization.

Thermal stabilities of globular proteins

Statistical thermodynamic theory has recently been developed to account for the stabilities of globular proteins. Here we extend that work to predict the dependence on temperature. Folding is assumed to be driven by solvophobic interactions and opposed by the conformational entropy. The temperature dependence of the solvophobic interaction is taken from the transfer experiments on amino acids by Tanford and Nozaki and on model solutes by Gill and Wadsö. One long-standing puzzle has been why proteins denature upon heating, since the solvophobic force to fold strengthens with increasing temperature. This is resolved by the theory, which predicts two first-order phase transitions. "Cold denaturation" is driven principally by the weakening of the solvophobic interaction, but normal denaturation is driven principally by the gain of conformational entropy of the chain. Predictions of the thermodynamic state functions are in reasonable agreement with the calorimetric experiments of Privalov and Khechinashvili. Comparison of the theory with experiments suggests that there may be an additional enthalpic driving force toward folding which is not due to the solvophobic interactions.

Topically applied tetracaine, adrenalin, and cocaine in the repair of traumatic wounds of the head and neck

TAC is an effective topically applied anesthetic agent for repair of nonmucosal soft tissue injuries of the head and neck. It seems to be well accepted by patients--particularly pediatric patients and their parents. The incidence of toxic reactions and wound infections is low.

Ultrastructural changes in V79 hamster lung fibroblasts during hypoxic exposure

Cells in tumors that are deprived of their blood supply become hypoxic. These stressed cells adapt to their new environments by altering their metabolic regimen which in time induces cellular structure changes. The morphologic make-up of these O2-deprived cells is the focal point of this electron microscopy study. V-79 hamster lung fibroblast cells grown as monolayer cultures were examined under controlled culture density and oxygen tensions - normal aerobia (2.1 X 10(5) ppm O2), and extreme hypoxia (less than 10 ppm O2). Electron micrographs of these cells demonstrated a loss of structural mitochondrial integrity accompanied with large increases in both mitochondrial and lipid vacuole size following exposure to extreme hypoxia. When these cells were reoxygenated, those mitochondria which had not become degenerate returned to their normal state however, lipids still continued to accumulate in vacuoles for a further 6 h. Addition of 1 mM palmitic acid to aerobic cultures evoked similar lipid and mitochondrial irregularities as were observed in hypoxic cells although, the latter were not as marked. When this saturated fatty acid was added to hypoxic cells no further structural alterations were seen. The cellular changes manifested during this study were subjected to quantitative measurements and these results have given an insight into the scope and variety of ultrastructural changes which have resulted from exposure of cultured cells to hypoxic conditions.

Effects of dietary manipulation on vascular status of patients with peripheral vascular disease

In a one-year, double-blind clinical trial, 45 patients with peripheral vascular disease (PVD) were randomly assigned to either the American Heart Association Hyperlipidemia Diet C (n = 20) or a low-fat, high-fiber, complex carbohydrate diet similar to the Pritikin Maintenance Diet (n = 25). Vascular status and blood lipid levels were monitored at 0, 2, 4, 6, and 12 months. Walking distance increased significantly in both groups, with no difference between groups. No vascular parameters changed significantly, suggesting that increased walking distance was due to improved metabolic capacity of the muscle. A trend toward lower blood lipid values was observed, with no significant differences within or between groups. We conclude that while patients with PVD benefit from a program of diet and exercise, there is no apparent advantage to the more difficult complex carbohydrate diet.

Symptom changes in chronic schizophrenic patients on a token economy: a controlled experiment

An 18-month controlled experiment was conducted into the effects of a token economy programme on the ward behaviour and symptoms of chronic schizophrenic patients. An experimental group received tokens dependent upon appropriate behaviour, while a matched control group on the same ward received every aspect of the ward programme similarly except that tokens were not dependent upon their behaviour. Regular assessment showed that both groups improved substantially in social withdrawal. Over twelve months of treatment the experimental group improved no more than the control group. There were no symptomatic changes. The conclusions were that token economy is a treatment affecting withdrawl and social behaviour rather than symptomatology, and that factors other than reinforcement by tokens were responsible for the main changes.

A token economy project with chronic schizophrenic patients

The token economy is an application of operant conditioning theory which is particularly relevant to the treatment of patients in institutions. The basic idea is to motivate the patient to behave more appropriately and constructively by giving him tokens whenever he behaves in such a way. The tokens have an incentive function, as the patient can cash them in for a number of different things, such as pleasant single room accommodation, cigarettes, magazines, TV viewing, drinks etc., depending upon what is programmed into the token economy. The theory of operant conditioning is that not only does the token motivate the patient to behave in certain ways, but ‘reinforces' his behaviour. Such reinforced behaviour should eventually become an integral part of the ‘way he is', continuing even when the token is removed.