Sleep deprivation as a model experimental antidepressant treatment: findings from functional brain imaging

This paper reviews the functional brain imaging studies in depressed patients treated with sleep deprivation. Sleep deprivation is an excellent experimental model of antidepressant treatments which offer new opportunities to understand the basic neural mechanisms. Its antidepressant effects are efficacious and rapid; sleep deprivation is easy to administer, inexpensive, and relatively safe; it can be studied in patients, normal controls, and animals; and it may lead to new treatments and new paradigms for antidepressant therapies. Seven published papers, coming from five different research centers, using either positron emission tomography (PET) with 18fluorodeoxyglucose (FDG) or single photon emission computerized tomography (SPECT) with Technetium-99-bexamethyl propyleneamine oxime (HMPAO) have relatively consistent findings. First, before sleep deprivation, responders have significantly elevated metabolism compared with non-responders, and usually the normal controls, in the orbital medial prefrontal cortex, and especially in the ventral portions of the anterior cingulate cortex. Secondly, after sleep deprivation, these hyperactive areas normalize in the responders. The magnitude of the clinical improvement was significantly correlated with decreased local glucose metabolic rate or cerebral blood flow in three studies. The results are consistent with some but not all functional brain imaging studies of antidepressant medications in depressed patients. Finally, a SPECT study using a radioactively labeled D2 receptor antagonist suggests that the antidepressant benefits of sleep deprivation are correlated with endogenous release of dopamine.

New sunscreens confer improved protection for photosensitive patients in the blue light region

BACKGROUND

Some patients with photosensitivity disorders are sensitive to visible radiation. As current commercial sunscreens do not significantly absorb in this region, there is a lack of effective topical photoprotection. To meet this need a new range of sunscreens has been developed incorporating zinc oxide and pigmentary grade titanium dioxide as active ingredients.

OBJECTIVES

To determine the effectiveness of the new sunscreens in providing protection for patients with visible radiation photosensitivity.

METHODS

In the first part of this study, an in vitro transmission spectrum was obtained. The properties of the new sunscreens, as well as a range of commercial agents, were compared, and a new parameter, photosensitivity protection factor (PPF), was developed. This was used to predict the likely degree of protection the various sunscreens would provide for patients with photosensitivity extending into the visible region. In the second in vivo part of the study, patients with known visible (blue) light photosensitivity were tested using light at 430 +/- 30 nm and the protection factor (PF) at this wavelength was determined.

RESULTS

Mean +/- SD PPFs for the new sunscreens were between 5.4 +/- 0.3 and 9.6 +/- 0.3, compared with 4.1 +/- 0.1 for Sun E45 (sun protection factor, SPF 25) and 4.2 +/- 0.1 for RoC Total (SPF 25). The derived in vivo PF for Sun E45 ranged between 1 and 4 (median 2). For the new sunscreens the range was 3 to > 10 (median 8).

CONCLUSIONS

This study demonstrates that the new sunscreens do provide protection for patients with sensitivity to visible light (blue light region).

Characterization of Salmonella associated with pig ear dog treats in Canada

In the summer of 1999, the incidence of Salmonella enterica serotype Infantis infections in Alberta rose dramatically. Subsequent laboratory and epidemiological investigations established that an outbreak of human disease caused by this organism was occurring across Canada and was associated with pet treats for dogs produced from processed pig ears. Laboratory investigations using phage typing and pulsed-field gel electrophoresis (PFGE) established that isolates of Salmonella serotype Infantis from pig ear pet treats and humans exposed to pig ear pet treats comprised a well-defined subset of all isolates analyzed. Of the 53 subtypes of Salmonella serotype Infantis obtained around the time of the outbreak as defined by PFGE and phage typing, only 6 subtypes were associated with both human infection and isolation from pig ears. Together with information from epidemiological studies, these investigations established pig ear pet treats as the cause of the Salmonella serotype Infantis outbreak. The results are consistent with a model in which contaminated pig ear pet treats constitute a long-term, continuing vehicle for infection of the human population rather than causing temporally delimited point-source outbreaks. During the course of this outbreak, several other Salmonella serotypes were also isolated from pet treats, suggesting these products may be an important source of enteric infection in both humans and dogs. Though isolates of Salmonella serotypes other than Salmonella serotype Infantis from pet treats were also subjected to PFGE and phage typing, no link with human disease could be definitively established, and the contribution of pig ear pet treats to human disease remains unclear. Elimination of bacterial contamination from pet treats is required to reduce the risk of infection from these products.

Variables influencing end-of-life care in children and adolescents with cancer

BACKGROUND

The purpose of this study was to describe the variables influencing end-of-life care in children and adolescents dying of cancer.

MATERIALS AND METHODS

Records of 146 children with cancer who died at Children's Hospital were reviewed for demographics, diagnosis, location of death, withdrawal of life support, use of "do not resuscitate" (DNR) orders, and the length of time that those orders were in effect.

RESULTS

Ninety-five patients were evaluated. Fifty-nine died of progressive disease and 36 deaths were therapy-related. Sixty-four percent of disease-related deaths occurred at home with support from home care or hospice. Only 10% of all patients died while receiving maximal aggressive support in the intensive care unit. Age, diagnosis (solid tumor vs. leukemia), cause of death, length of last hospital admission, and the duration of DNR orders had a significant correlation with the place of death and referral to and use of hospice. Thirty-five percent of all patients had hospice support.

CONCLUSIONS

Most children who die of cancer die because of progressive disease at home with hospice support. Do not resuscitate orders were written for most patients who died. End-of-life decisions are influenced by patient diagnosis, cause of death, and age.

Osteogenesis imperfecta: an overview

Osteogenesis imperfecta (brittle bone disease) is a rare hereditary disorder with an increased tendency to fracture. Chris Clark highlights the management needs of people with this condition.

Toxic effects in dairy cattle following the ingestion of a large volume of canola oil

The clinical and laboratory findings of a group of 9 dairy cattle that accidentally ingested large volumes of canola oil are described. Four of the animals died, and 3 were necropsied. No specific cause of death was found, although a number of theories are advanced. This is the first report of such an occurrence.

Toxicity evaluation of petroleum blending streams: inhalation subchronic toxicity/neurotoxicity study of a light catalytic cracked naphtha distillate in rats

A 15-week, whole-body inhalation study of the vapors of a distillate (LCCN-D) of light catalytic cracked naphtha (CAS no. 64741-55-5, LCCN) was conducted with Sprague-Dawley rats. Target exposure concentrations were 0, 750, 2500, and 7500 ppm for 6 hours/day, 5 days/week. Over the course of the study, animals received at least 65 exposures. For a portion of the control and 7500-ppm groups, a 4-week postexposure period was included in the study. Subchronic toxicity was evaluated using standard parameters. During life, neurotoxicity was evaluated by motor activity assessment and a functional observational battery. Selected tissues from animals in all exposure groups were examined microscopically. Neuropathologic examination of selected neuronal tissues from animals in the control and high-exposure groups was also conducted. No compound-related effects were seen on survival, clinical chemistry, food consumption, or physical signs. No evidence of neurotoxicity was seen at any exposure level. Slight decreases in hematocrit and hemoglobin concentrations were seen in male rats at the end of exposure to 7500 ppm LCCN-D. However, values were within normal physiological ranges and recovery occurred. Slight decreases in mean body weights and body weight gain were observed in high-exposure females during the first 7 weeks of exposure, but this decrease was not seen during the second half of the study. Male rat nephropathy involving hyaline droplet formation and alpha-2micro-globulin accumulation was seen in mid- and high-exposure males, an effect not relevant to humans. The incidence and severity of goblet cell hypertrophy/hyperplasia and respiratory epithelium hyperplasia in nasoturbinal tissues were greater in high-exposure animals, but recovery occurred. None of the effects observed were considered toxicologically significant. The no-observable-adverse-effect level (NOAEL) for subchronic and neurotoxicity of LCCN-D was > or = 7500 ppm.

Solid phase assay of urine cystine supersaturation in the presence of cystine binding drugs

PURPOSE

We report a new kind of assay system for urine cystine supersaturation that is accurate in the presence of cystine binding thiol drugs. We measured the molar ratio of cystine dissolved per mole of drug.

MATERIALS AND METHODS

Measured amounts of cystine crystals were incubated in buffer or urine for 48 hours with stirring. The solid phase remaining was pelleted by centrifugation, extracted into a high pH buffer and measured. D-penicillamine, tiopronin and captopril were added to determine their effect on solid phase dissolution.

RESULTS

Total cystine calculated from urine and solid measurements closely matched the amounts of cystine weighed in, meaning that the assay system successfully recovered the total cystine from the 2 phases. Each drug dissolved solid cystine in a specific and fixed proportion to its molar concentration in the range of 0.2 to 0.4 mM. dissolution per mM. of drug. Solution measurements were not a reliable gauge to the actual amounts of cystine dissolved.

CONCLUSIONS

Changes in solid phase cystine accurately reflect buffer or urine supersaturation when thiol drugs are present. The solid phase assay is a technically straightforward and reliable way of assessing cystine movement into and out of urine that avoids complexity of measurement and distortions of assay systems by drugs. This assay enables one to assess the level of drug effect and the need for a change in dosing.

Conjunctivitis due to Chlamydophila felis (Chlamydia psittaci feline pneumonitis agent) acquired from a cat: case report with molecular characterization of isolates from the patient and cat

Conjunctivitis due to Chlamydiaceae other than Chlamydia trachomatis is rarely reported because of infrequent occurrence or inadequate investigation. A case of chronic non-trachomatis chlamydial conjunctivitis is described. After full clinical information was supplied to the laboratory, a non-trachomatis chlamydia was recovered from the patient's eye. This organism, and a subsequent isolate from one of the patient's cats, were shown to be indistinguishable examples of the recently described species Chlamydophila felis. The infection was most likely acquired from the patient's cats. A prolonged course of doxycycline was required to eradicate the infection.

Mammalian expression and hollow fiber bioreactor production of recombinant anti-CEA diabody and minibody for clinical applications

Genetically engineered radiolabeled antibody fragments have shown great promise for the radioimmunoscintigraphy of cancer. Retaining the exquisite specificity of monoclonal antibodies yet smaller in molecular size, antibody fragments display rapid tumor targeting and blood clearance, a more uniform distribution in the tumor, and present a lower potential to elicit an immune response. However, one of the factors that has limited clinical evaluation of these antibody-derived proteins has been the difficulty in expressing and purifying the quantities necessary for clinical trials. This study outlines the capability of mammalian expression for the production of recombinant antibody fragments intended for clinical use. Two anti-carcinoembryonic antigen antibody fragments, the T84.66/212 Flex minibody (scFv-C(H)3) and the T84.66 diabody (scFv dimer) have been previously expressed and have shown excellent radioimaging properties in tumor bearing animals. To proceed toward human studies, these high affinity recombinant fragments and a second minibody version, the T84.66/GS18 Flex minibody, were expressed using a high-level mammalian expression system. Production of all three antibody fragments in a small-scale hollow fiber bioreactor resulted in 137-307 mg of crude antibody harvest. A purification protocol that employed ceramic hydroxyapatite and anion exchange chromatography resulted in 50-150 mg of purified T84.66 diabody and T84.66 minibody. The development of this level of research grade material established conditions for clinical production as well as provided material to complete pre-clinical studies and undertake protein crystallization studies. Scale-up for clinical studies produced 3.4 g of the T84.66 minibody in the harvest. A portion of this material was purified yielding 180 mg of highly purified T84.66 minibody intended for pilot radioimmunoscintigraphy studies of carcinoembryonic antigen (CEA) positive disease.

Regional cerebral glucose metabolism in never-medicated patients with schizophrenia

OBJECTIVE

The purpose of this study was to assess regional cerebral glucose metabolism in patients with schizophrenia who had never received antipsychotic medication and whose olfactory identification ability had been assessed. Two hypotheses were examined. First, the patients were compared with normal controls to determine whether differences in regional cerebral metabolism were apparent. Second, regional rates of metabolism were correlated with olfactory ability and the relation between them determined.

METHODS

The patient (n = 26) and control (n = 32) subjects were scanned at rest using positron emission tomography (PET) after administration of 18F-fluorodeoxyglucose (FDG). In addition, the University of Pennsylvania Smell Identification Test was administered to each patient.

RESULTS

Patients with schizophrenia had reduced rates of glucose metabolism in the right and left thalamus that reached significance if not corrected for multiple comparisons. However, if a Bonferroni correction was applied over the 27 regions of interest, the differences were not significant. Scores on the Smell Identification Test were negatively correlated with 8 regions of interest. When scores were analyzed using multiple regression, the left frontal cortex and the medial parietal cortex were significant predictors.

CONCLUSIONS

The finding of reduced metabolism in the thalami is consistent with some of the previous literature, whereas the negative correlations between specific regions and olfactory function are not consistent with studies using activation paradigms.

Flow mixing and fluid residence times in a model of a ventricular assist device

To provide a reliable tool for predicting the flow in a clinical sac-type ventricular assist device (VAD), a simplified model VAD was developed prior to this study for the purpose of experimental validation of computer simulations of the time-varying flow on a moving grid. At selected locations in the flow field, flow patterns, vortex core trajectories and velocities were compared between the numerical and physical models during one full pumping cycle. The computer simulations showed qualitatively very good agreement with the experiment. Quantitatively, the agreement was less favourable. In order to investigate flow mixing and to evaluate fluid residence times in the model VAD a new tool has been developed: the numerical simulations were extended by injecting a scalar into the flow domain. These simulations allow investigation of the flow mixing qualitatively by visualisation and quantification of fluid residence times. Experimental assessment of the numerical results using dye injection proved to be favourable. The numerical results have been extended to include some prediction of pressure which have been compared with experimental measurements.

Lowest hematocrit on bypass and adverse outcomes associated with coronary artery bypass grafting. Northern New England Cardiovascular Disease Study Group

BACKGROUND

Cardiac surgery patients' hematocrits frequently fall to low levels during cardiopulmonary bypass.

METHODS

We investigated the association between nadir hematocrit and in-hospital mortality and other adverse outcomes in a consecutive series of 6,980 patients undergoing isolated coronary artery bypass graft surgery. The lowest hematocrit during cardiopulmonary bypass was recorded for each patient. Patients were divided into categories based on their lowest hematocrit. Women had a lower hematocrit during bypass than men but both sexes are represented in each category.

RESULTS

After adjustment for preoperative differences in patient and disease characteristics, the lowest hematocrit during cardiopulmonary bypass was significantly associated with increased risk of in-hospital mortality, intra- or postoperative placement of an intraaortic balloon pump and return to cardiopulmonary bypass after attempted separation. Smaller patients and those with a lower preoperative hematocrit are at higher risk of having a low hematocrit during cardiopulmonary bypass.

CONCLUSIONS

Female patients and patients with smaller body surface area may be more hemodiluted than larger patients. Minimizing intraoperative anemia may result in improved outcomes for this subgroup of patients.

Product development of branded, packaged household goods in Britain, 1870-1914: Colman's, Reckitt's, and Lever Brothers

The three companies whose history forms the subject of this article became leaders in a sector of the British economy—consumer goods—generally regarded as one of the most successful in the late nineteenth and early twentieth centuries. Product innovation and development, achieved internally or through acquisition, enabled these firms to become market leaders. We therefore analyze the processes of product development within the three firms, using a systematic framework that allows us to offer generalizations about the process of product innovation and development in the consumer goods sector in Britain. We conclude that gradual modification, rather than revolutionary innovation, was characteristic of product development in the household goods trade, and that technology was less important for success than marketing skill.

Multiculturalism as a concept in nursing

This article focuses on the theoretical processes of identifying and evaluating concepts in the public domain and the subsequent practical application of such concepts to the provision of nursing care. More specifically, this article identifies the concept of "multiculturalism" as a valuable one for nursing, and then evaluates it via the methodology developed by nursing theorists Wilson (1969) and Meleis (1997).

Clinical and physiological consequences of rapid tryptophan depletion

We review here the rapid tryptophan depletion (RTD) methodology and its controversial association with depressive relapse. RTD has been used over the past decade to deplete serotonin (5-hydroxy-tryptamine, or 5-HT) in humans and to probe the role of the central serotonin system in a variety of psychiatric conditions. Its current popularity was stimulated by reports that RTD reversed the antidepressant effects of selective serotonin reuptake inhibitors (SSRIs) and monoamine oxidase inhibitors (MAOIs) in remitted patients with a history of depression but not in patients treated with antidepressants which promote catecholaminergic rather than serotonergic neurotransmission (such as tricyclic antidepressants or buproprion). However, RTD has inconsistent effects in terms of full clinical relapse in depressed patients. Pooling the data from all published reports, patients who are either unmedicated and/or fully remitted are much less likely to experience relapse (7 of 61, or approximately 9%) than patients who are recently medicated and partially remitted (63 of 133, or approximately 47%; although, the numbers here may reflect patient overlap between reports). Recently remitted patients who have been treated with non-pharmacological therapies such as total sleep deprivation, electroconvulsive therapy, or bright light therapy also do not commonly show full clinical relapse with RTD. We briefly review RTD effects in other psychiatric disorders, many of which are treated with SSRIs. There is accumulating evidence to suggest that RTD affects central serotonergic neurotransmission. Nevertheless, many questions remain about the ability of RTD to reverse the beneficial effects of SSRIs or MAOIs, or to induce symptoms in unmedicated symptomatic or asymptomatic patients.

Partner violence and medical encounters: African-American women's perspectives

OBJECTIVE

To examine the relationship between intimate partner violence (IPV) victimization and patient satisfaction with medical encounters among an African-American population.

DESIGN

Cross-sectional, self-administered, anonymous survey.

SETTING

Community-based, primary care center.

PATIENTS

Consecutive African-American women recruited from an urban health center. A total of 102 women provided sufficient information to reveal whether they were currently experiencing IPV and to allow us to assess their experiences in their most recent primary care encounter.

MEASUREMENTS

Patients' perceptions of their most recent encounter using questions adopted from the Medical Interview Satisfaction Scale and Consultation Satisfaction Questionnaire. We used the Conflicts Tactics Scale, supplemented with questions measuring sexual violence and emotional abuse, to assess IPV "in the past year."

RESULTS

Women who reported current IPV rated several aspects of the encounter more negatively than did women who did not report current abuse. The IPV victims were less likely to report that they felt respected and accepted during the encounter, and they provided lower ratings of the quality of communication with their providers.

CONCLUSIONS

It is unclear why victims of partner violence experience medical encounters as less satisfactory. Researchers need to expand studies of medical encounters as experienced by abused women to determine whether IPV status adversely affects general medical care.