A Preliminary Study of Stress, Mental Health, and Pain Related to the COVID-19 Pandemic and Odds of Persistent Prescription Opioid Use

BACKGROUND

The COVID-19 pandemic has been associated with increased opioid prescribing. It is not known if perceived COVID-19 related stress is associated with increased odds of long-term opioid use.

OBJECTIVE

To determine if greater COVID-19-related stress and worsening pain attributed to the pandemic was associated with LTOT over a 6-month observation period.

DESIGN

Longitudinal cohort.

PARTICIPANTS

Patients (n=477) from two midwestern health care systems, with any acute or chronic non-cancer pain, starting a new period of 30-90-day prescription opioid use, were invited to participate in the Prescription Opioids and Depression Pathways Cohort Study, a longitudinal survey study of pain, opioid use, and mental health outcomes.

MAIN MEASURES

Baseline and 6-month follow-up assessments were used to measure the association between perceived COVID-19 stressors, the perception that pain was made worse by the pandemic and the odds of persistent opioid use, i.e., remaining a prescription opioid user at 6-month follow-up. Multivariate models controlled for demographics, opioid dose, and change in pain characteristics, mental health measures, and social support.

KEY RESULTS

Participants were, on average, 53.9 (±11.4) years of age, 67.1% White race, and 70.9% female. The most frequently endorsed COVID-19 stressor was "worry about health of self/others" (85.7% endorsed) and the least endorsed was "worsened pain due to pandemic" (26.2%). After adjusting for all covariates, "worsened pain due to pandemic" (OR=2.88; 95%CI: 1.33-6.22), change in pain interference (OR=1.20; 95%CI: 1.04-1.38), and change in vital exhaustion (OR=0.90; 95%CI: 0.82-0.99) remained significantly associated with persistent opioid use.

CONCLUSIONS

Patients who attribute worsening pain to the COVID-19 pandemic are more likely to be persistent opioid users. Further research is warranted to identify mechanisms underlying this association. Clinicians may consider discussing pain in the context of the pandemic to identify patients at high risk for persistent opioid use.

Adult Asthma Diagnosis: Physician Reported Challenges in Alberta-Based Primary Care Practices

Introduction

An estimated 8.1% of Canadians adults have asthma. While there are challenges associated with the use of objective measurement of lung function in the diagnosis of asthma, we are uncertain of the barriers that impact the use of objective measures, and have limited understanding of the challenges experienced by primary care providers in diagnosis of asthma. The objectives of this quality improvement initiative were to identify primary care providers’ methods of diagnosing asthma and to identify challenges with diagnosis.

Methods

An online survey was disseminated using a snowball methodology.

Setting

Primary care practices in Alberta, Canada.

Participants

A total of 84 primary care providers completed the survey.

Main Outcome Measures

Participants were asked their ideal and sufficient methods for diagnosing asthma and to identify challenges in their practice related to asthma diagnosis.

Results

They identified full pulmonary function testing (54%), pre- and postbronchodilator spirometry (54%), complete history and physical (42%), peak flow measurement overtime (26%), pulmonary consult (26%), and trial of asthma medication(s) (23%), as ideal methods of diagnosing asthma. The most significant barriers to diagnosis included episodic care–care provided typically during times of worsening symptoms without ongoing preventative/maintenance care (55%), patient follow-up (44%), conflict between clinical impression and pulmonary function results (43%), patient already on asthma medications (43%), and interpreting spirometry/pulmonary function results (39%).

Conclusion

The results of this survey indicate that the majority of primary care providers would choose full pulmonary function testing or pre- and postbronchodilator spirometry as the ideal methods of diagnosing asthma. However, barriers related to the nature of asthma care, patient factors, and challenges with diagnostic testing create challenges. This study also highlights that primary care providers have adapted to challenges in leveraging objective measurement and may rely upon other methods for diagnosis such as trials of medications.

Cystic and necrotic papillary renal cell carcinoma: prognosis, morphology, immunohistochemical, and molecular-genetic profile of 10 cases

Conflicting data have been published on the prognostic significance of tumor necrosis in papillary renal cell carcinoma (PRCC). Although the presence of necrosis is generally considered an adverse prognostic feature in PRCC, we report a cohort of 10 morphologically distinct cystic and extensively necrotic PRCC with favorable biological behavior. Ten cases of type 1 PRCC with a uniform morphologic pattern were selected from the 19 500 renal tumors, of which 1311 were PRCCs in our registry. We focused on precise morphologic diagnosis supported by immunohistochemical and molecular-genetic analysis. Patients included 8 men and 2 women with an age range of 32-85 years (mean, 62.6 years). Tumor size ranged from 6 to 14 cm (mean, 9.4 cm). Follow-up data were available in 7 patients, ranging from 0.5 to 14 years (mean, 4 years). All tumors were spherical, cystic, and circumscribed by a thick fibrous capsule, filled with hemorrhagic/necrotic contents. Limited viable neoplastic tissue was present only as a thin rim in the inner surface of the cyst wall, consistent with type 1 PRCC. All cases were positive for AMACR, OSCAR, CAM 5.2, HIF-2, and vimentin. Chromosome 7 and 17 polysomy was found in 5 of 9 analyzable cases, 2 cases demonstrated chromosome 7 and 17 disomy, and 1 case showed only chromosome 17 polysomy. Loss of chromosome Y was found in 5 cases, including 1 case with disomic chromosomes 7 and 17. No VHL gene abnormalities were found. Papillary renal cell carcinoma type 1 can present as a large hemorrhagic/necrotic unicystic lesion with a thick fibroleiomyomatous capsule. Most cases showed a chromosomal numerical aberration pattern characteristic of PRCC. All tumors followed a nonaggressive clinical course. Large liquefactive necrosis should not necessarily be considered an adverse prognostic feature, particularly in a subset of type 1 PRCC with unilocular cysts filled with necrotic/hemorrhagic material.

Utility of peritoneal washing cytology in staging and prognosis of ovarian and fallopian tube neoplasms: a 10-year retrospective analysis

The prognostic significance of peritoneal washing cytology in gynecologic neoplasms is controversial. The presence of neoplastic cells in peritoneal washings is currently part of the Federation of Gynecology and Obstetrics and American Joint Committee on Cancer TNM staging systems in cases of ovarian and fallopian tube neoplasms without metastasis beyond the pelvis. In this study, we retrospectively reviewed all cases of ovarian and fallopian tube neoplasms in which cytologic studies were performed. The utility of cytology in tumor staging and the relationship between cytology results and patient outcome are studied. All cases of ovarian and fallopian tube neoplasms in our institution between July 2002 and July 2012 were reviewed. Primary tumor characteristics including type and pelvic extension were collected, categorized, and correlated with peritoneal washing cytology. Final tumor staging was reviewed and the impact of positive cytology was evaluated. A total of 120 cases of ovarian and fallopian tube neoplasms without extrapelvic metastasis were identified within the study period. Peritoneal washing cytology was positive in 24% (29/120) of neoplasms and upstaged the tumor 83% (24/29) of the time when positive. Overall, 20% (24/120) of reviewed cases were upstaged based on positive cytology results. Peritoneal washing cytology remains a useful staging tool for ovarian and fallopian tube neoplasms limited to the pelvic cavity. Positive cytology results in upstaging in a significant proportion of the cases regardless of the tumor type. A larger study is needed to analyze follow-up data to determine if upstaging based on positive cytology adversely affects outcome.

Mucinous spindle and tubular renal cell carcinoma: analysis of chromosomal aberration pattern of low-grade, high-grade, and overlapping morphologic variant with papillary renal cell carcinoma

The chromosomal numerical aberration pattern in mucinous tubular and spindle renal cell carcinoma (MTSRCC) is referred to as variable with frequent gains and losses. The objectives of this study are to map the spectrum of chromosomal aberrations (extent and location) in a large cohort of the cases and relate these findings to the morphologic variants of MTSRCC. Fifty-four MTSRCCs with uniform morphologic pattern were selected (of 133 MTSRCCs available in our registry) and divided into 3 groups: classic low-grade MTSRCC (Fuhrman nucleolar International Society of Urological Pathology grade 2), high-grade MTSRCC (grade 3), and overlapping MTSRCC with papillary renal cell carcinoma (RCC) morphology. Array comparative genomic hybridization analysis was applied to 16 cases in which DNA was well preserved. Four analyzable classic low-grade MTSRCCs showed multiple losses affecting chromosomes 1, 4, 8, 9, 14, 15, and 22. No chromosomal gains were found. Four analyzable cases of MTSRCC showing overlapping morphology with PRCC displayed a more variable pattern including normal chromosomal status; losses of chromosomes 1, 6, 8, 9, 14, 15, and 22; and gains of 3, 7, 16, and 17. The group of 4 high-grade MTSRCCs exhibited a more uniform chromosomal aberration pattern with losses of chromosomes 1, 4, 6, 8, 9, 13, 14, 15, and 22 and without any gains detected. (1) MTSRCC, both low-grade and high-grade, shows chromosomal losses (including 1, 4, 6, 8, 9, 13, 14, 15, and 22) in all analyzable cases; this seems to be the most frequent chromosomal numerical aberration in this type of RCC. (2) Cases with overlapping morphologic features (MTSRCC and PRCC) showed a more variable pattern with multiple losses and gains, including gains of chromosomes 7 and 17 (2 cases). This result is in line with previously published morphologic and immunohistochemical studies that describe the broad morphologic spectrum of MTSRCC, with changes resembling papillary RCC. (3) The diagnosis of MTSRCC in tumors with overlapping morphology (MTSRCC and PRCC) showing gains of both chromosomes 7 and 17 remains questionable. Based on our findings, we recommend that such tumors should not be classified as MTSRCC but rather as PRCC.

Surveillance of parapoxvirus among ruminants in Virginia and Connecticut

In 2008, two deer hunters in Virginia and Connecticut were infected with a unique strain of pseudocowpox virus, a parapoxvirus. To estimate the prevalence of this virus, and in an attempt to define the reservoir, Parapoxvirus surveillance was undertaken between November 2009 and January 2010. 125 samples from four ruminant species (cows, goat, sheep and white-tailed deer) were collected in Virginia, and nine samples from white-tailed deer were collected in Connecticut. We found no evidence that the parapoxvirus species that infected the deer hunters is circulating among domesticated ruminants or white-tailed deer. However, parapoxvirus DNA of a different parapoxvirus species, bovine papular stomatitis virus (BPSV), was detected in 31 samples obtained from asymptomatic cattle in Virginia. Parapoxvirus DNA-positive cattle originated from the same counties indicating probable transmission among animals. Molecular analysis identified BPSV as the parapoxvirus affecting animals. Asymptomatic parapoxvirus infections in livestock, particularly young animals, may be common, and further investigation will inform our knowledge of virus transmission.

Galantamine in frontotemporal dementia and primary progressive aphasia

BACKGROUND/AIMS

The treatment of frontotemporal dementia (FTD) has been mainly symptomatic. Small randomized or open-label case control studies of neurotransmitters have been inconclusive. We tried galantamine in the 2 most common varieties of FTD.

METHOD

Thirty-six behavioral variety FTD and primary progressive aphasia (PPA) patients were treated in an open-label period of 18 weeks and a randomized, placebo-controlled phase for 8 weeks with galantamine. The primary efficacy measures were the Frontal Behavioral Inventory, the Aphasia Quotient of the Western Aphasia Battery, the Clinical Global Impression of Severity and the Clinical Global Impression of Improvement.

RESULTS

No significant differences in behavior or language were found for the total group. A treatment effect (p = 0.009), in a subgroup of subjects with PPA in the global severity score, in favor of galantamine was detected in the placebo-controlled withdrawal phase but was not considered significant after correction for multiple comparisons. The language scores for the treated PPA group also remained stable compared to the placebo group, which showed deterioration.

CONCLUSION

Galantamine is not effective in the behavioral variety of FTD, but a trend of efficacy is shown in the aphasic subgroup, which may be clinically significant. Galantamine appeared safe in FTD/PPA.

Wood smoke exposure induces a pulmonary and systemic inflammatory response in firefighters

Epidemiological studies report an association between exposure to biomass smoke and cardiopulmonary morbidity. The mechanisms for this association are unclear. The aim of the present study was to characterise the acute pulmonary and systemic inflammatory effects of exposure to forest fire smoke. Seasonal forest firefighters (n = 52) were recruited before and/or after a day of fire-fighting. Exposure was assessed by questionnaires and measurement of carbon monoxide levels (used to estimate respirable particulate matter exposure). The pulmonary response was assessed by questionnaires, spirometry and sputum induction. Peripheral blood cell counts and inflammatory cytokines were measured to define the systemic response. Estimated respirable particulate matter exposure was high (peak levels >2 mg x m(-3)) during fire-fighting activities. Respiratory symptoms were reported by 65% of the firefighters. The percentage sputum granulocytes increased significantly from 6.5 to 10.9% following fire-fighting shifts, with concurrent increases in circulating white blood cells (5.55x10(9) to 7.06x10(9) cells x L(-1)) and band cells (0.11x10(9) to 0.16x10(9) cells x L(-1)). Serum interleukin (IL)-6, IL-8 and monocyte chemotactic protein-1 levels significantly increased following fire-fighting. There were no changes in band cells, IL-6, and IL-8 following strenuous physical exertion without fire-fighting. There was a significant association between changes in sputum macrophages containing phagocytosed particles and circulating band cells. In conclusion, acute exposure to air pollution from forest fire smoke elicits inflammation within the lungs, as well as a systemic inflammatory response.

Impact of continuous positive airway pressure therapy on blood pressure in patients with obstructive sleep apnea hypopnea: a meta-analysis of randomized controlled trials

Patients with untreated obstructive sleep apnea hypopnea (OSAH) are predisposed to developing hypertension, and therapy with continuous positive airway pressure (CPAP) may reduce blood pressure (BP). The purpose of this study was to assess the impact of CPAP therapy on BP in patients with OSAH. We performed a comprehensive literature search up to July 2006 [Medline, PubMed, EMBASE, Cochrane Database of Systematic Reviews (CDSR), Cochrane controlled trials register (CCTR), and Database of Abstract and Reviews of Effect (DARE)] to identify clinical studies and systemic reviews that examined the impact of CPAP on BP. Studies were included if they (1) were randomized controlled trials with an appropriate control group, (2) included systolic and diastolic BP measurements before and after CPAP/control in patients with OSAH, and (3) contained adequate data to perform a meta-analysis. To calculate pooled results, studies were weighted by inverse variances, with either a fixed or a random effects model used depending on the presence of heterogeneity (assessed with Q test). Ten studies met our inclusion criteria (587 patients): three studies were crossover (149 patients) and seven were parallel in design. Seven studies (421 patients) used 24-h ambulatory BP and three used one-time measurements. Two studies were of patients with heart failure (41 patients). Overall, the effects of CPAP were modest and not statistically significant; CPAP (compared to control) reduced systolic BP (SBP) by 1.38 mmHg (95% CI: 3.6 to -0.88, p = 0.23) and diastolic BP (DBP) by 1.52 mmHg (CI: 3.1 to -0.07; p = 0.06). Six of the trials studied more severe OSAH (mean AHI > 30/h, 313 patients); in these six trials, CPAP reduced SBP by 3.03 mmHg (CI 6.7 to -0.61; p = 0.10) and DBP by 2.03 mmHg (CI: 4.1 to -0.002; p = 0.05). There was a trend for SBP reduction to be associated with CPAP compliance. In unselected patients with sleep apnea, CPAP has very modest effects on BP. However, we cannot exclude the possibility that certain subgroups of patients may have more robust responses-this may include patients with more severe OSAH or difficult-to-control hypertension. Future randomized controlled trials in this area should potentially concentrate on these subgroups of patients.

Experiences from the structure determination of human cytomegalovirus protease

Several obstacles were encountered and overcome during the structure determination of human cytomegalovirus protease. Dehydration of crystals, by exposing them to higher concentrations of the precipitant, reduced the mosaicity of the crystals and may have also resolved their microscopic twinning. The initial phase information was obtained with the selenomethionyl multiple-wavelength anomalous diffraction technique. However, site-specific mutagenesis was required to introduce extra Met residues into the protease. The phase information had to be improved by non-crystallographic symmetry averaging, initially among three 'crystal forms'. A change in the composition of the artificial mother liquor led to a significant improvement, from 3.0 and 2.0 A resolution, in the diffraction quality of the crystals. The experiences reported here may prove useful to structure determination of other proteins.

Estimation of total body water from bioelectrical impedance analysis in patients with pancreatic cancer -- agreement between three methods of prediction

INTRODUCTION

Bioelectrical impedance analysis (BIA) is a useful field measure to estimate total body water (TBW). No prediction formulae have been developed or validated against a reference method in patients with pancreatic cancer. The aim of this study was to assess the agreement between three prediction equations for the estimation of TBW in cachectic patients with pancreatic cancer.

METHODS

Resistance was measured at frequencies of 50 and 200 kHz in 18 outpatients (10 males and eight females, age 70.2 +/- 11.8 years) with pancreatic cancer from two tertiary Australian hospitals. Three published prediction formulae were used to calculate TBW - TBWs developed in surgical patients, TBWca-uw and TBWca-nw developed in underweight and normal weight patients with end-stage cancer.

RESULTS

There was no significant difference in the TBW estimated by the three prediction equations - TBWs 32.9 +/- 8.3 L, TBWca-nw 36.3 +/- 7.4 L, TBWca-uw 34.6 +/- 7.6 L. At a population level, there is agreement between prediction of TBW in patients with pancreatic cancer estimated from the three equations. The best combination of low bias and narrow limits of agreement was observed when TBW was estimated from the equation developed in the underweight cancer patients relative to the normal weight cancer patients. When no established BIA prediction equation exists, practitioners should utilize an equation developed in a population with similar critical characteristics such as diagnosis, weight loss, body mass index and/or age.

CONCLUSIONS

Further research is required to determine the accuracy of the BIA prediction technique against a reference method in patients with pancreatic cancer.

Development of a standardized, comprehensive "ideal drug detail"

OBJECTIVES

To develop a standardized, comprehensive ideal drug detail for use in face-to-face education about individual drugs.

METHODS

A random sample of 603 physicians and pharmacists was selected and stratified to include input from each of the following specialties: family practice, internal medicine, surgery, pediatrics, psychiatry, obstetrics/gynecology, geriatric medicine and clinical pharmacology. Thirty-one potential items were generated by the investigators from a preliminary survey of a local convenience sample of physicians and pharmacists. A modified Delphi consensus process was used in the large sample to determine which items should be included in the ideal drug detail. In each round of the Delphi process, respondents rated each item on a seven-point scale of importance and were then given feedback of the cumulative ratings for each item. Rounds were continued until consensus was obtained on all items.

RESULTS

The response rate to the first round was 55.3%; 85.5% of these respondents responded to the second round. Response rates varied between specialties from 44% to 70%. Attempts to contact nonresponders to measure potential nonrespondent bias were unsuccessful. Consensus was obtained on 19 items after the first round, and on the remaining 12 items after the second round. Four items were dropped because they were unimportant. There was variation in modal response between specialties on eight items.

CONCLUSIONS

Consensus was obtained among a sizable and interested sample of Canadian physicians and pharmacists on the items of information needed to prescribe a drug appropriately. Subsequent work will refine this list into a usable template to develop ideal drug details for specific drugs, to develop an assessment process to measure quality of information, and to assess the impact of this program on prescribing and patient outcomes.

Binding site elucidation of hydantoin-based antagonists of LFA-1 using multidisciplinary technologies: evidence for the allosteric inhibition of a protein--protein interaction

The binding site on the lymphocyte function-associated antigen-1 (LFA-1) of a class of hydantoin-based antagonists of leukocyte cell adhesion has been identified. This site resides in the inserted-domain (I-domain) of the CD11a chain at a location that is distal to residues known to be required for interactions with the intercellular adhesion molecules. This finding supports the hypothesis that the molecules are antagonizing cell adhesion via an allosteric modification of LFA-1. The binding site was identified using an integrated immunochemical, chemical, and molecular modeling approach. Antibodies that map to epitopes on the I-domain were blocked from binding to the purified protein by the hydantoins, indicating that the hydantoin-binding site resides on the I-domain. Photoaffinity labeling of the I-domain followed by LC/MS and LC/MS/MS analysis of the enzymatic digest identified proline 281 as the primary amino acid residue covalently attached to the photoprobe. Distance constraints derived from this study coupled with known SAR considerations allowed for the construction of a molecular model of the I-domain/inhibitor complex. The atomic details of the protein/antagonist interaction were accurately predicted by this model, as subsequently confirmed by the X-ray crystal structure of the complex.

Death the Fas way: regulation and pathophysiology of CD95 and its ligand

Apoptotic cell death mediated by the members of the tumor necrosis factor receptor family is an essential process involved in the regulation of cellular homeostasis during development, differentiation, and pathophysiological conditions. Among the cell death receptors comprising the tumor necrosis factor receptor superfamily, CD95/APO-1 (Fas) is the best characterized. The specific interaction of Fas with its cognate ligand, Fas ligand (FasL), elicits the activation of a death-inducing caspase (cysteine aspartic acid proteases) cascade, occurring in a transcription-independent manner. Caspase activation executes the apoptosis process by cleaving various intracellular substrates, leading to genomic DNA fragmentation, cell membrane blebbing, and the exposure of phagocytosis signaling molecules on the cell surface. Recent studies have shown that the Fas/FasL pathway plays an important role in regulating the life and death of the immune system through activation-induced cell death. In addition, these molecules have been implicated in aging, human immunodeficiency virus infection, drug abuse, stress, and cancer development. In this review, we will focus on the mechanisms that regulate Fas and FasL expression, and how their deregulation leads to diseases.

The corticobasal degeneration syndrome overlaps progressive aphasia and frontotemporal dementia

OBJECTIVE

To provide evidence for the hypothesis that the corticobasal degeneration syndrome (CBDs) overlaps significantly with primary progressive aphasia and frontotemporal dementia, and that CBDs is part of the Pick complex.

BACKGROUND

Corticobasal degeneration has been mainly described as a movement disorder, but cognitive impairment is also increasingly noted.

METHODS

Thirty-five cases of clinically diagnosed CBDs were followed-up with clinical, neuropsychological, and neuroimaging investigations. Twenty-nine patients were seen prospectively in movement disorder and cognitive neurology clinics; five of these came to autopsy. Six other autopsied cases that fulfilled the clinical criteria of CBDs were added with retrospective review of records.

RESULTS

All 15 patients presenting with movement disorders developed behavioral, cognitive, or language deficits shortly after onset or after several years. Patients presenting with cognitive problems (n = 20), progressive aphasia (n = 13), or frontotemporal dementia (n = 7) developed the movement disorder subsequently. Eleven cases with autopsy had CBD or other forms of the Pick complex.

CONCLUSIONS

There is a clinical overlap between CBD, frontotemporal dementia, and primary progressive aphasia. There is also a pathologic overlap between these clinical syndromes. The recognition of this overlap will facilitate the diagnosis and avoid consideration of CBD as "heterogenous."

Are there gender differences in starting protease inhibitors, HAART, and disease progression despite equal access to care?

OBJECTIVES

To describe gender differences in starting and response to treatment regimens and long-term clinical outcome in a well-characterized regional population from the Southern Alberta HIV Clinic (SAC) of 1403 patients, where all medical care for HIV, including physician fees, laboratory tests, and antiretroviral drug costs is provided free of charge.

DESIGN

Observational cohort study.

METHODS

Cox proportional hazards models were used to examine the relative risk of starting treatment regimens and disease progression (new AIDS-defining illness or death).

RESULTS

There are 126 women in the SAC (9.0%). The median CD4 lymphocyte count at first visit among all patients was 350 cells/mm3, and was significantly higher among women than men (428 cells/mm3 versus 345 cells/mm3, respectively; p = 0.0024). Participating women were less well educated than participating men; 29% of women did not proceed beyond a tenth grade education compared with 13% of men; only 28% of women went to college or received a degree in contrast to 40% of men (p <. 001). The proportion of women in the cohort has increased over the past 5 years (p <.001). During a median follow-up period of 35 months that dates back as far as 1985, 572 patients (40.8%) died or progressed to a new AIDS-defining illness, of whom 30 were women (5. 2%). In a multivariate Cox model stratified by calendar quartile of first visit and adjusted for latest CD4, AIDS status, age, exposure group, education, and prior treatment, women were significantly less likely to start highly active antiretroviral therapy (HAART; defined as at least three antiretrovirals taken consecutively; relative hazard [RH], 0.69; 95% confidence interval [CI], 0.49-0.98; p =.033), significantly less likely to start a protease inhibitor containing treatment regimen (RH, 0.71; 95% CI, 0.52-0.98; p =.040) and significantly less likely to start a HAART regimen including a protease inhibitor (RH, 0.69; 95% CI, 0.48-1.00; p =.049). After adjustment for potentially confounding variables such as CD4 lymphocyte count and treatment regimen, no difference in disease progression was found between men and women (RH, 0.77; 95% CI, 0. 49-1.19; p =.24). Among patients who started HAART, the CD4 lymphocyte count and viral load at starting treatment regimens was similar between men and women, as were the immunologic and virologic response following initiation of treatment.

CONCLUSIONS

Despite free access to antiretrovirals, women in the SAC were significantly less likely to start HAART treatment regimens, and the reasons for this need further investigation. Response to treatment was similar between genders. No evidence was found for a poorer long-term clinical outcome in women, but given the proven large clinical benefits of HAART, this may change in the future.

B-cell receptor and Fas-mediated signals for life and death

A series of B-cell lymphoma lines with an immature phenotype has been used as a model system to study molecular events associated with receptor ligation induced death. B-cell receptor (BCR) cross-linking with antibodies to membrane IgM (but not with anti IgD) induces c-Myc downregulation via nuclear factor kappaB inactivation and p27(Kip1) accumulation in these B lymphomas. Anti-mu-treated cells then undergo G1 arrest and die by apoptosis independent of Fas. Steroids and retinoids similarly downregulate c-Myc and induce apoptosis in these B cells and synergize with anti-mu. Rescue from apoptosis induced by anti-mu or steroids occurs with T-cell signals, like CD40L, or a broad-range caspase inhibitor, but only CD40L prevents the loss of c-Myc, p27 accumulation and growth arrest. Both IgM and IgD signaling lead to modulation of phosphatidylinositol 3-kinase (PI3K) signals, including the activation of p70(S6K), but this pathway recovers under anti-IgD treatment. Blockade of the PI3K pathway augments anti-mu-induced death and converts anti-delta to an apoptotic signal. Resistance to Fas-mediated death may be an important factor in B-cell transformation in vivo. Many of our panel of lymphomas are insensitive to Fas-mediated death signals, although all can form a death-inducing signaling complex (DISC). Additional studies suggest that some lymphomas can be blocked at the DISC complex by anti-apoptotic proteins, whereas others are inhibited downstream of caspase 8 activation. Anti-Ig treatment of a Fas-sensitive line, A20.2J, activated a number of genes whose products may block apoptosis proximally (like FLICE-inhibitory protein (FLIP1)) or at late points, such as bcl-2-family members. Our data suggest that B lymphomas develop multiple pathways of resistance to Fas-mediated signals during lymphomagenesis, in part via signaling through the BCR.

The Frontal Behavioral Inventory in the differential diagnosis of frontotemporal dementia

A personality and behavioral disorder is an important and defining feature of frontal lobe dementia (FLD) or frontotemporal degeneration (FTD). The diagnosis usually depends on the progressive development of various behavioral symptoms rather than a set of neuropsychological measures. Quantification of the personality-behavior disorder is important for standardizing the diagnosis. An inventory was constructed to capture the major positive and negative behaviors and personality change, and it was administered prospectively to caregivers of 108 patients in a cognitive neurology clinic, at the time of first diagnostic assessment. The prevalence and extent of behavioral abnormality was quantitated in the clinic population of FLD, vascular dementia (VaD), Alzheimer's disease (AD), primary progressive aphasia (PPA), and depressive disorder (DD) patients. The mean scores of FLD patients were significantly above all other groups. Scores in VaD were also higher than in AD, PPA, and DD. Interrater reliability (Cohen's kappa of .90) and item consistency (a Cronbach alpha of .89) were both high. Perseveration, indifference, inattention, inappropriateness, and loss of insight rated highest in FLD, significantly different from all other groups. Apathy, aspontaneity, inflexibility, disorganization, impulsivity, personal neglect, and poor judgment were also significantly higher in FLD. Discriminant function correctly classified 92.7% versus all other patients (NON-FLD) in the study. A total of 18.8% of VaD patients were misclassified as FLD. Indifference, alien hand, and inappropriateness were the highest discriminant functions. Perseveration and verbal apraxia were important discriminatory items for FLD and PPA, respectively. The FBI is a standardized behavioral inventory useful to diagnose FLD, to differentiate it from other dementias, and to quantify the behavior disorder.

Clinical and pathological overlap between frontotemporal dementia, primary progressive aphasia and corticobasal degeneration: the Pick complex

A substantive overlap between the clinical syndromes of frontal lobe dementia (FLD), frontotemporal dementia (FTD), or primary progressive aphasia (PPA), and corticobasal degeneration syndrome (CBDS) has been demonstrated in a population of 55 patients followed for more than 3 years in a cognitive neurology clinic. Patients presenting with the personality behavior disorder (FLD) often develop progressive aphasia (PA) and vice versa. CBDS is often associated with FLD and PA, and the extrapyramidal-apractic syndrome of CBDS often appears in FLD and PPA. The histopathological variations do not predict the clinical phenotype. The term Pick complex is suggested to indicate that these clinical and pathological variations are related and they were first described by Pick as clinical manifestations of fronotemporal atrophy. This term will avoid the confusion of using FLD or FTD or for the whole complex and also for the personality behavioral presentation. The relationship of the various clinical presentations has been strengthened by the discovery of chromosome 17 linkage in families manifesting them.

Predictors of a viral response and subsequent virological treatment failure in patients with HIV starting a protease inhibitor

OBJECTIVES

To investigate the factors related to viral load becoming undetectable among patients from Southern Alberta who started a protease inhibitor for the first time, and to determine the factors related to subsequent re-emergence of detectable viral load amongst those patients whose viral load initially became undetectable.

SUBJECTS AND METHODS

A total of 243 patients from the Southern Alberta Clinic had started a protease inhibitor for the first time and had been followed up for a median time of 32 weeks. Standard survival techniques including Kaplan-Meier techniques and Cox proportional hazards models were used to determine which factors were related to viral load becoming undetectable.

RESULTS

At 24 weeks after first exposure to a protease inhibitor, 52.8% of the patients [95% confidence interval (Cl), 45.2-56.6] had achieved an undetectable viral load. In a multivariate analysis, those with a higher initial viral load were less likely to become undetectable [relative hazard (RH), 0.50; 95% Cl, 0.35-0.70; P < 0.0001], whereas those starting more new drugs (RH per new drug, 1.54; 95% Cl, 1.01-2.11; P = 0.048) were significantly more likely to achieve an undetectable viral load. Amongst 111 patients whose viral load became undetectable, Kaplan-Meier analysis indicated that 15.5% of patients experienced re-emergence of detectable viral load at 24 weeks after the first undetectable viral load. A higher CD4 cell count was associated with a lower risk of viral load becoming detectable (RH, 0.73; 95% Cl, 0.53-1.00; P = 0.049), as was treatment with indinavir (versus any other protease inhibitor RH, 0.17; 95% Cl, 0.03-0.86; P = 0.033).

CONCLUSIONS

A significant proportion of patients in a routine clinic setting achieved an undetectable viral load measurement after first starting a protease inhibitor; viral load in patients with a higher CD4 cell count was more likely to become and stay undetectable. There was no evidence that patients who were drug-naive experienced significantly worse virological effects than drug-experienced patients, as long as the same number of new drugs was started at the date of first exposure to a protease inhibitor. Further follow-up of these patients is warranted to study the longer term effects of treatment with protease inhibitors.

Prediction of axillary lymph node involvement of women with invasive breast carcinoma: a multivariate analysis

BACKGROUND

The increasing use of systemic therapy for women with lymph node negative breast carcinoma and earlier stage of disease at mammographic detection raises questions regarding the need for routine axillary lymph node dissection. Predictive modeling for lymph node involvement may be one way to reduce the need for axillary lymph node dissection and its morbidity.

METHODS

A multivariate analysis of 12 factors predictive of axillary lymph node involvement was conducted in a population-based cohort of 4312 women with invasive breast carcinoma diagnosed between January 1, 1993 and December 31, 1996.

RESULTS

Clinical palpability, lymphatic or vascular invasion, lesion size, margin status, histology, and patient age were independent predictors of axillary lymph node involvement. The model correctly identified lymph node status in 76.6% of cases. Model accuracy and fit were equally high when applied to randomly selected halves of the study subjects. Approximately 32.0% of the patients in the study sample (1363/4312) were identified as having an extremely high (91%; n = 1102) or low (10%; n = 261) risk of lymph node involvement. In a second analysis, a clinically useable, three-variable model identified a very low risk group of patients (n = 147) with a 4.8% risk of lymph node metastasis and a high risk group of patients (n = 1008) with a 74.2% risk of lymph node metastasis. Greater than 90% of subjects in the high risk group received adjuvant systemic therapy even if they were lymph node negative pathologically.

CONCLUSIONS

A clinically useable, three-variable model employing tumor and lymph node palpability, size, and lymphatic or vascular invasion can identify women with invasive breast carcinoma in whom axillary lymph node dissection is very unlikely to alter recommendations regarding adjuvant systemic therapy.

A comparison of physiological responses and rating of perceived exertion between high-impact and low-impact aerobic dance sessions

The aim of this study was to compare the exercise intensity and rating of perceived exertion (RPE) of a high-impact (HIP) and a low-impact (LIP) university aerobic dance session. Ten women [mean (SD) age 22.9 (2.6) years] took part in the study. An incremental treadmill test was performed by each subject to determine maximum oxygen consumption (VO2max) and maximum heart rate (HRmax). The measured VO2max [mean (SD)] was 49.0 (7.5) ml x kg(-1) x min(-1). The subjects were randomly assigned to LIP and HIP sessions (i.e. five of the subjects participated in the HIP session first, and the other five participated in the LIP session first). In a laboratory, heart rate, oxygen uptake and RPE were measured throughout each session for each subject. Expired air was collected continuously throughout the sessions using Douglas bags (ten bags over a 30-min period). The sessions consisted of 20 min of aerobic exercise (bags 1-7) followed by 5 min of local muscular endurance exercise (bags 8 and 9) and 5 min of flexibility exercises (bag 10). The mean intensity of the aerobic section of the LIP and HIP sessions was 51.6% and 64.7% VO2max, respectively. Ninety-five percent confidence intervals for the average difference between the HIP and LIP sessions demonstrate that the %VO2max was between 12% and 14% higher for the HIP session. The mean %HRmax for the LIP and HIP sessions was 71.4% and 76.7%, respectively, with the %HRmax in the HIP session being between 5.4% and 7.2% higher on average than that of the LIP session. On average, the RPE for the aerobic section of the HIP session (12.1) was consistently higher than that of the LIP session (11.1). HIP activity has the potential to maintain/improve the aerobic fitness of its participants. According to the literature, the exercise intensity elicited by LIP activity may have a limited training effect for the population utilised in this study, and for some individuals may result in detraining. Conversely, LIP activities may be an appropriate mode of exercise for overweight and unfit individuals.

Primary progressive semantic aphasia: a case study

A longitudinal case study of a patient with a progressive loss of meaning of objects with preserved phonology and syntax is presented. Repeated measures of language, praxis, visual cognition, and semantic processing were carried out. The patient still has preserved conversational speech, social skills, and orientation in her 8th year of her illness, but shows severe anomia and comprehension deficit in all modalities of stimulus presentation. In addition to standardized tests of language, cognition, and memory, specific experiments of categorization, modalities of word access, item consistency, category specificity, and definition of words were carried out. Results indicate a frequency dependent loss of meaning that was consistent in all modalities and throughout all object categories. However, the relative preservation of visual categorization of all categories tested and the language based categorization of animals suggested some fractionation of semantic memory. Relative preservation of autobiographical and personal memories versus semantic memory was a striking observation. Evidence for selective impairment of central semantic processing was obtained from experiments indicating item consistency of loss and the lack of semantic cuing. Neuroimaging evidence of left temporal lobe atrophy and the classical picture is compatible with similar cases published under the term semantic dementia or "transcortical sensory aphasia with visual agnosia" and suggest the diagnosis of Pick's disease.

Frontal behavioral inventory: diagnostic criteria for frontal lobe dementia

OBJECTIVE

To utilize the diagnostic criteria of frontal lobe dementia (FLD).

METHODS

We studied 12 patients with FLD diagnosed clinically, with radiological confirmation in 10 and autopsy confirmation in 2; sixteen patients with Alzheimer's disease matched for stage and severity to FLD and 11 patients with depressive dementia were used as control groups. A 24-item Frontal Behavioral Inventory (FBI) using the most relevant behavioral manifestations of FLD was administered in these populations.

RESULTS

FLD patient scores on the FBI were much higher compared with control groups (AD and DD). Item analysis showed loss of insight, indifference, distractibility, personal neglect and apathy as the most frequent negative symptoms. Perseveration, disinhibition, inappropriateness, impulsivity, and irresponsibility were the most significant positive symptoms. An operational definition of FLD included a minimum FBI score of 27. Only one false positive was shown in the depressive group and none among the AD group, indicating little overlap between patient groups, and a high discriminating value of the FBI.

CONCLUSIONS

The FBI appears to be a useful diagnostic instrument and a method to operate the behavioral criteria of FLD. Further prospective studies are warranted to establish validity.

Crystallization and preliminary crystallographic analysis of recombinant human P38 MAP kinase

The recombinant human p38 MAP kinase has been expressed and purified from both Escherichia coli and SF9 cells, and has been crystallized in two forms by the hanging drop vapor diffusion method using PEG as precipitant. Both crystal forms belong to space group P2(1)2(1)2(1). The cell parameters for crystal form 1 are a = 65.2 A, b = 74.6 A and c = 78.1 A. Those for crystal form 2 are a = 58.3 A, b = 68.3 A and c = 87.9 A. Diffraction data to 2.0 A resolution have been collected on both forms.

National survey on the attitudes of Canadian physicians towards drug-detailing by pharmaceutical representatives

OBJECTIVE

Our objective was to study the attitudes of Canadian physicians toward product presentations by pharmaceutical representatives (PRs), the use of inducements by the pharmaceutical industry, and methods to improve the quality of prescribing information provided to physicians.

DESIGN

We used a mailed survey.

PARTICIPANTS

A random sample of 550 Canadian physicians in all settings was chosen.

OUTCOME MEASURES

The main outcome measure was the proportion of respondents agreeing with a series of statements.

RESULTS

The response rate was 262 of 525 deliverable surveys (50 per cent). Respondents had a mean of 4.2 interactions per week with PRs. Of the 262 respondents (5.8 per cent of data were incomplete), 193 (80 per cent) believed that PRs overemphasize their products' effectiveness, 108 (45 per cent) thought PRs do not present fairly the drugs' negative aspects, and 223 (92 per cent) felt that PRs have production promotion as a goal. Most, 175 (70 per cent), believe that drug-detailing affects physicians' prescribing behavior. Most, 210 (86 per cent), considered drug samples acceptable, but fewer agreed that other inducements were acceptable. Of the respondents, 183 (74 per cent) agreed that PRs should be required to use guidelines for standardized, comprehensive drug-detailing, and 165 (65 per cent) agreed that face-to-face drug-detailing by PRs using standardized guidelines would be an effective way to receive information.

CONCLUSIONS

There is dissatisfaction among Canadian physicians about the quality of information provided by the pharmaceutical industry. Standardized, comprehensive guidelines would be accepted by physicians as one improvement.

Physician characteristics and prescribing for elderly people in New Brunswick: relation to patient outcomes

OBJECTIVE

To examine the relation between physician characteristics, prescribing behaviour and patient outcomes.

DESIGN

Descriptive study linking four provincial databases.

SETTING

New Brunswick.

PARTICIPANTS

All 366 general practitioners (GPs) (accounting for 40% of all physicians with a general licence in New Brunswick) who ordered at least 200 prescriptions for elderly beneficiaries of the New Brunswick Prescription Drug Program and saw at least 20 elderly patients in an office setting between Apr. 1, 1990, and Mar. 31, 1991. Physicians with palliative care practices were excluded.

OUTCOME MEASURES

GPs' personal, professional and practice characteristics, their prescribing patterns, and mortality, morbidity (number of days in hospital per patient) and hip-fracture rates among their elderly patients.

RESULTS

Compared with the GPs who had a lower mortality rate, those with a higher mortality rate prescribed more drugs overall (p < 0.001), specifically antidepressants, bronchodilators, cholesterol-lowering agents, gastrointestinal drugs, neuroleptics and nonsteroidal anti-inflammatory drugs (NSAIDs). They also were more likely to be male (p < 0.01), had larger practices (p < 0.001), saw more patients per day (p < 0.05) and billed more per year (p < 0.001). Compared with the GPs who had a lower morbidity rate, those with a higher morbidity rate prescribed more drugs overall (p < 0.005), specifically bronchodilators, gastrointestinal drugs and NSAIDs. They also were more likely to be younger (p < 0.005) and male (p < 0.01), had fewer years in practice (p < 0.001), saw more patients per day (p < 0.05) and billed more per patient (p < 0.01). The GPs who had a higher hip-fracture rate prescribed more drugs overall (p < 0.001), notably antihypertensives, bronchodilators, cholesterol-lowering agents, gastrointestinal drugs and NSAIDs, than those who had a lower hip-fracture rate. They also had a larger practice (p < 0.001), practised more days per year (p < 0.005), had more patient visits per year (p < 0.05) and billed more per year (p < 0.001). Younger male GPs who practised with relatively more intensity and prescribed more drugs per patient had practices with higher morbidity, mortality and hip-fracture rates among their elderly patients than the other GPs.

CONCLUSIONS

There is a significant relation between certain physician characteristics, their prescribing behaviour and patient outcomes. Further study is required to determine what physician characteristics and prescribing behaviours for specific illnesses contribute to patient outcomes. Regional differences should also be examined, as should incentives in this fee-for-service system. Linkage of these types of provincial databases may help in the evaluation of physicians' performance and in the development of strategic interventions and practice guidelines.

Relation between physician characteristics and prescribing for elderly people in New Brunswick

OBJECTIVE

To determine whether there is a relation between physician characteristics and prescribing for elderly patients.

DESIGN

Descriptive study linking two provincial databases.

SETTING

New Brunswick.

PARTICIPANTS

All general practitioners (GPs) in New Brunswick who ordered at least 200 prescriptions for elderly beneficiaries of the New Brunswick Prescription Drug Program between Apr. 1, 1990, and Mar. 31, 1991; eligible GPs accounted for 376 (40%) of all physicians with a general licence in New Brunswick.

MAIN OUTCOME MEASURES

GPs' personal and professional characteristics (age, sex, family practice accreditation, country of training and number of years in practice), practice characteristics (number of practice days, number of patients seen and medical services provided per day, average amount of billing per patient, total number of patients seen and their average age, and total amount of billings) and number of prescriptions by category of drug.

RESULTS

High prescribers and low prescribers did not differ significantly in age, number of years in practice, mean practice size or patient age. Compared with the low prescribers the high prescribers were more likely to be male, have been trained in Canada and be qualified by the Canadian College of Family Physicians. Also, they had more practice days, saw more patients per day, performed more services per day, billed more per patient and billed on average 30% more during the study period. Overall, the high prescribers ordered on average 45% more prescriptions than the low prescribers.

CONCLUSION

There is a significant relation between certain physician characteristics and prescribing behaviour. Further study is required to examine the relation between these variables and patient outcomes.

High dose rate intraluminal radiation in a combined modality treatment plan for carcinoma of the esophagus

We have previously reported results for treatment of adenocarcinomas and squamous cell carcinomas of the mid and distal esophagus as well as the use of intraluminal high-dose rate radiation (HDR-RT) for palliation of carcinoma of the esophagus. In this report we describe the results of a chemotherapy/HDR-RT/esophagectomy management program. Examination of the surgical specimens revealed a complete response in only 13% of patients and locoregional recurrence was disappointing. There were no operative deaths nor were there major complications attributable to the preoperative treatment. Two-year survival was 33%, only slightly better than that previously achieved by us with either primary surgery or primary external beam radiation among "curative" candidates with locoregional disease. HDR in combination with our selected chemotherapy regimen is insufficient for locoregional control and must be supplemented either by esophagectomy or external beam radiation for even modest long-term survival.

Arteriovenous malformation of scrotum: a case report

Arteriovenous malformations of the scrotum are rare. We report a case of arteriovenous malformation involving the scrotal vessels. The patient presented with painful scrotal swelling, which was mainly in the skin and the Dartos layers. Vascular lesions of the scrotum are rare. By far the most common condition is varicocele. Our patient was examined by 2 other urologists before us and no one made the diagnosis of arteriovenous malformation on clinical examination. Diagnosis was made by auscultation with the Doppler stethoscope. We suggest that the possibility of a scrotal arteriovenous malformation and hemangiomas should be entertained in patients with unilateral scrotal swelling.

Squamous carcinoma of the mid-esophagus. A survival study

A survival study for squamous carcinomas of the mid-esophagus treated by Southern California Permanente Medical Group in the interval of 1954 to 1988 was undertaken. Radiation therapy and surgery were equally efficacious in terms of 5-year survival for patients without distant disease and performance status sufficient to tolerate treatment (11% and 16%, respectively). There was no survival benefit for patients treated with palliative surgery. Less invasive endoscopic means along with chemotherapy and radiation for palliation are recommended except for special circumstances. Optimal treatment combinations remain to be discovered.

Acute myeloid leukemia induction by amphotropic murine retrovirus (4070A): clonal integrations involve c-myb in some but not all leukemias

Amphotropic murine retrovirus 4070A was demonstrated to be highly leukemogenic when inoculated intravenously into adult DBA/2 mice that were undergoing an intense chronic inflammatory response, but was nonleukemogenic in the absence of inflammation. The virus-induced promoonocytic leukemias, designated AMPH-ML, are similar morphologically and in cell surface marker expression to monocytic leukemias, called MML and MF-ML, previously shown to be induced by Moloney murine leukemia virus and MF-3 virus (a recombinant between Friend murine leukemia virus and Moloney murine leukemia virus) and resemble certain mature acute monocytic leukemias in humans (AML subtype M5). Approximately two-thirds of the AMPH-MLs (subgroup I) were demonstrated to have alterations in the 5' end of the c-myb locus, an event which occurs in 100% of MML and MF-ML. Data indicate that proviral insertions in AMPH-ML subgroup I resulted in aberrant c-myb mRNA expression and truncation of its translation product at the amino terminus. Approximately one-third of the AMPH-MLs (subgroup II) had not undergone any DNA rearrangements at the c-myb locus. In addition, their transcripts and protein products were of normal size. These latter leukemias also had not undergone DNA rearrangements in c-myc, although retroviruses expressing myc have previously been shown to induce monocyte-macrophage tumors in mice undergoing a chronic inflammation. That subgroup II leukemias had at least one clonal viral insertion suggests that there may be other sites in the cellular genome that can be activated by insertional mutagenesis in these murine acute monocytic leukemias.

Squamous carcinoma of the distal esophagus: a survival study

A survival study for squamous carcinomas of the distal esophagus treated by the Southern California Permanente Medical Group in the interval of 1954 to 1988 was undertaken. We found radiation therapy and surgery equally efficacious in terms of cure for patients without distant disease and performance status sufficient to tolerate treatment. We did not find survival benefit for patients treated with palliative surgery, and plan less invasive endoscopic means along with chemotherapy and radiation for palliation, reserving surgery for special circumstances.

The characterization of crude products from solid-phase peptide synthesis by mu-HPLC/fast atom bombardment mass spectrometry

Crude product mixtures from the solid-phase synthesis of a series of peptides were analyzed by on-line packed, fused silica column mu-HPLC/Continuous Flow Fast Atom Bombardment Mass Spectrometry (mu-HPLC/CF-FABMS). The technique is superior to the direct FAB analysis of crude product mixtures since competitive ionization and suppression effects are not generally observed. Positive correlation between a chromatographic peak and the desired synthetic product may be obtained. An accurate assessment of peptide deprotection can be made without ambiguity arising from the MS fragmentation of the more labile t-butyl and BOC protecting groups used in FMOC-based solid-phase peptide synthesis strategies. mu-HPLC combined with in-line UV detection and MS analysis allows the use of minimum sample and injection volumes, typically 10-50 pmol contained in 0.2-0.5 microliters.

Adenocarcinoma of the esophagus: a survival study

A 35 year review of adenocarcinomas of the esophagus was undertaken. We found the disease to be one of increasing incidence afflicting white males disproportionately. Risk factors remain to be clarified. Radiation therapy in curative doses and complete resection were competitively effective in terms of long-term survival. No survival advantage was found with palliative surgery compared with other means of therapy. Optimal combinations of treatment remain to be discovered.

Studies on measurement of plasma magnesium: application of the Magon dye method to the "Monarch" centrifugal analyzer

The "Magnesium Liquid Stable Reagent Set" from Medical Analysis Systems, Inc., is evaluated. The method, which involves Magon dye binding and bichromatic absorbance measurements, was used in a Monarch centrifugal analyzer. Results were compared with those by atomic absorption spectrometry. The calibration curve for the Magon method is linear to 2.5 mmol/L, with a 2-microL sample volume. Analytical recovery of magnesium added to human plasma ranged from 95 to 102%. The working reagent is stable for at least five days at 15 degrees C. At concentrations of 0.54 and 1.20 mmol/L, the respective CVs were 2.15 and 3.60% within batch, and 3.13 and 3.24% between batch. We analyzed 150 clinical samples for magnesium by both methods. Absorbance readings at 520/600 nm rather than 520/690 nm improved the correlation (r = 0.9777 and r = 0.9428, respectively). Calcium, albumin, phosphate, or bilirubin did not significantly interfere.

Studies on measurement of plasma magnesium: application of the Magon dye method to the "Monarch" centrifugal analyzer

The "Magnesium Liquid Stable Reagent Set" from Medical Analysis Systems, Inc., is evaluated. The method, which involves Magon dye binding and bichromatic absorbance measurements, was used in a Monarch centrifugal analyzer. Results were compared with those by atomic absorption spectrometry. The calibration curve for the Magon method is linear to 2.5 mmol/L, with a 2-microL sample volume. Analytical recovery of magnesium added to human plasma ranged from 95 to 102%. The working reagent is stable for at least five days at 15 degrees C. At concentrations of 0.54 and 1.20 mmol/L, the respective CVs were 2.15 and 3.60% within batch, and 3.13 and 3.24% between batch. We analyzed 150 clinical samples for magnesium by both methods. Absorbance readings at 520/600 nm rather than 520/690 nm improved the correlation (r = 0.9777 and r = 0.9428, respectively). Calcium, albumin, phosphate, or bilirubin did not significantly interfere.

Conservation surgery for T2 and T3 carcinomas of the supraglottic larynx

The treatment of choice for supraglottic carcinomas of intermediate size (stages T2 and T3) remains controversial. Between 1974 and 1983 in our institution, 139 patients with supraglottic carcinoma of intermediate size were judged retrospectively to have been technically amenable to conservation surgery. Primary disease control at three years was achieved in 100% of the patients treated by supraglottic laryngectomy, 91% (34 patients) of those treated by total laryngectomy, and 69% (81 patients) of those treated by radiotherapy. Of the latter group, 62% were salvaged by total laryngectomy yielding a net three-year local control of 85%. Determinate five-year survival rates were 89% for supraglottic laryngectomy, 78% for total laryngectomy, and 70% for radiotherapy. Significant problems with aspiration occurred in four patients (16%) who were treated by conservation surgery, and two patients (8%) required a permanent tracheostomy. The results of this study show that supraglottic laryngectomy with postoperative radiotherapy as indicated is a highly effective method for the local control of supraglottic carcinoma of intermediate size that is amenable to conservation surgery.

Pharmacological evaluation of an intra-oral fluoride-releasing device in adolescents

The purpose of this study was to quantify fluoride (F) concentrations in body fluids of adolescents wearing two intra-oral fluoride-releasing devices (IFRDs) designed to release 0.10 mg F/day. Fluoride concentrations were determined potentiometrically. No significant increases occurred in urine or serum F concentrations during the 26-week device phase. Elevated salivary F concentrations were maintained throughout the device phase when broken or depleted IFRDs were replaced. However, salivary F concentrations returned to pre-device phase values by 26 weeks when the original IFRDs were maintained. These findings suggest that IFRDs can significantly elevate salivary F concentrations of adolescents without significant elevations in systemic F concentrations.

A GABA cardiovascular mechanism in the dorsal raphe of the rat

An injection of gamma-aminobutyric acid (GABA) and the GABA agonist, muscimol, into the dorsal raphe reduced both heart rate and blood pressure in the urethane-anesthetized rat. Picrotoxinin (3.4 nmol) did not affect blood pressure and slightly reduced the heart rate when injected into the dorsal raphe, but it blocked the decrease in both cardiovascular responses produced by GABA. These decreases in heart rate and blood pressure most likely result from stimulation of a GABAA receptor, as the GABAB agonist, baclofen, appeared to elevate heart rate and blood pressure by a mechanism occurring outside the dorsal raphe area. The changes in blood pressure and heart rate induced by muscimol occurred whether or not respiration was supported. Finally, it can be inferred that these GABAergic actions on blood pressure and heart rate probably involve both an inhibition of central sympathetic outflow and an excitation of parasympathetic outflow, as the quaternary muscarinic blocker, atropine methyl nitrate, blocked the decrease in heart rate induced by muscimol, but not the decrease in blood pressure.