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.