Early diastolic filling dynamics in diastolic dysfunction

BACKGROUND

The aim of the study was to determine the relationship between the rate of peak early mitral inflow velocity and the peak early diastolic mitral annular tissue velocities in normal controls and to compare them with subjects with diastolic dysfunction.

METHODS

The relationship between early passive diastolic transmitral flow and peak early mitral annular velocity in the normal and in diastolic dysfunction was studied. Two groups comprising 22 normal controls and 25 patients with diastolic dysfunction were studied.

RESULTS

Compared with the normal group, those with diastolic dysfunction had a lower E/A ratio (0.7 +/- 0.2 vs. 1.9 +/- 0.5, p < 0.001), a higher time-velocity integral of the atrial component (11.7 +/- 3.2 cm vs. 5.5 +/- 2.1 cm, p < 0.0001), a longer isovolumic relaxation time 73 +/- 12 ms vs. 94 +/- 6 ms, p < 0.01 and a lower rate of acceleration of blood across the mitral valve (549.2 +/- 151.9 cm/sec2 vs. 871 +/- 128.1 cm/sec2, p < 0.001). They also had a lower mitral annular relaxation velocity (Ea) (6.08 +/- 1.6 cm/sec vs 12.8 +/- 0.67 cm/sec, p < 0.001), which was positively correlated to the acceleration of early diastolic filling (R = 0.66), p < 0.05.

CONCLUSIONS

This investigation provides information on the acceleration of early diastolic filling and its relationship to mitral annular peak tissue velocity (Ea) recorded by Doppler tissue imaging. It supports not only the premise that recoil is an important mechanism for rapid early diastolic filling but also the existence of an early diastolic mechanism in normal.

Audit of acute myocardial infarctions at Saint James's Hospital, Dublin, from 1996 to 1999

Saint James' Hospital is a 650-bed tertiary referral hospital. An audit was performed of acute transmural myocardial infarctions for the years 1996 to 1999 inclusive. On average there were 2043 cardiology admissions annually, 9.8% of all hospital admissions. Acute transmural myocardial infarction was diagnosed in 178 patients annually, and was less common during the summer. The figure of 72% receiving revascularisation therapy (thrombolysis 67%, primary angioplasty 5%) compares favourably with 35% in 1992. The main reason for not receiving thrombolysis was late presentation (15%) with contraindications present in only 5%. The case fatality rate was 16% confirming the higher mortality in clinical practice than that of thrombolytic trials. The prescription of aspirin or warfarin (99%) and betablockers (67%) was in line with international trials. The use of angiotensin converting enzyme inhibitors (34%) and statins (28%) is similar to other studies but less than would be expected according to trial evidence.

Endothelial inflammation and thrombolysis resistance in acute myocardial infarction

BACKGROUND

Despite recent refinements to thrombolysis for acute myocardial infarction, a significant minority of patients still fail to reperfuse. There is no reliable predictor of this state of "thrombolysis resistance", but platelet and endothelial factors are believed to be important. Cell adhesion molecules are expressed by the endothelium when activated and their shed or soluble portion can be quantified in the peripheral serum, where they may be taken as a measure of endothelial activation. We sought to find a link between markers of endothelial inflammation at time of infarction and failure to reperfuse as measured by vessel occlusion at angiography.

METHODS

Patients presenting with their first acute myocardial infarction had levels of soluble adhesion molecules, C-reactive protein and monocyte chemotactic protein-1 measured prior to thrombolysis. An angiogram on day five after admission was performed to establish patency of the index vessel.

RESULTS

Levels of soluble vascular adhesion molecule-1 (sVCAM-1) taken prethrombolysis were significantly elevated compared to those with a patent vessel (620+/-90 vs. 418+/-28 ng/ml, P<0.03. The positive predictive value of sVCAM-1 for vessel patency was 88%.

CONCLUSIONS

We found elevated serum levels of the adhesion molecule soluble vascular adhesion molecule-1 (sVCAM-1) at presentation in patients with acute myocardial infarction who did not respond to thrombolysis. Endothelial activation may be important in thrombolysis resistance.

Autosomal dominant chorea-acanthocytosis with polyglutamine-containing neuronal inclusions

BACKGROUND

The term chorea-acanthocytosis describes a heterogeneous group of neurodegenerative disorders with variable clinical features and modes of inheritance. The characteristic acanthocytic appearance of red blood cells is attributed to abnormalities of a membrane protein, band 3, although the relationship between this and the neurodegenerative process has yet to be determined.

OBJECTIVE

To describe features of phenotype, inheritance, and neuropathological findings in a family with this disorder.

METHODS

Clinical and hematologic evaluations were performed on all available family members and neuropathological examination was performed on one case.

RESULTS

Autosomal dominant inheritance was evident, with variable clinical features of chorea or parkinsonism, marked cognitive changes, but no seizures or peripheral neurologic abnormalities. Abnormalities of band 3 were demonstrated on gel electrophoresis of red blood cell membranes. Neuropathological examination revealed severe neuronal loss of the caudate-putamen and intranuclear inclusion bodies in many areas of the cerebral cortex. These inclusion bodies were immunoreactive for ubiquitin, expanded polyglutamine repeats, and torsinA.

CONCLUSIONS

This family extends the genetic spectrum of chorea-acanthocytosis to include autosomal dominant inheritance, possibly due to expanded trinucleotide repeats. Intraneuronal inclusion bodies have recently been associated with a wide range of inherited neurodegenerative disorders and may provide a clue to etiopathogenesis, in addition to potentially indicating a function of torsinA.

L-H transition in the mega-amp spherical tokamak

H-mode plasmas have been achieved on the MAST spherical tokamak at input power considerably higher than predicted by conventional threshold scalings. Following L- H transition, a clear improvement in energy confinement is obtained, exceeding recent international scalings even at densities approaching the Greenwald density limit. Transition is accompanied by an order-of-magnitude increase in edge-density gradient, a marked decrease in turbulence, the efficient conversion of internal electron Bernstein waves into free space waves, and the onset and saturation of edge poloidal rotation.

Ethics seminars: HIV testing, consent, and physician responsibilities

Emergency physicians constantly have multiple ethical obligations in the emergency department. They must understand these sometimes conflicting obligations and learn to prioritize. A case discussion is presented that exemplifies the conflict between patient privacy and society's right to know. Specific aspects of HIV testing and obtaining patient consent are presented. Teaching physicians are encouraged to use such common cases for "ethics case discussion."

Preclinical pharmacokinetics of SB-203580, a potent inhibitor of p38 mitogen-activated protein kinase

1. SB-203580 (4-(4-fluorophenyl)-2-(4-methylsulphinylphenyl)-5-(4-pyridyl)imidazole) is a potent, selective inhibitor of p38 MAP kinase used extensively as a tool inhibitor in various pharmacological and toxicological models. This study was designed to evaluate the pharmacokinetics of SB-203580 in several preclinical species, both to assist with the interpretation of existing studies and to aid in the design of future studies with this inhibitor. 2. In vitro, SB-203580 was stable in mouse, rat, dog, monkey and human plasma over 24 h. However, species differences in plasma protein binding were observed; SB-203580 was 96-97% bound in human plasma and 78-92% bound in other species. These data suggest that protein binding may influence the results of in vitro studies using SB-203580, particularly when comparing results from different in vitro systems that incorporate plasma components. In vivo, SB-203580) demonstrated moderate to high clearance in all species tested, with non-linear elimination observed in the rat at plasma concentrations > 1,000 ngml(-1). Although good solution bioavailability was observed in non-rodents (78% in dog, 32% in monkey), lower and more variable bioavailability was observed in the rat and mouse (3 -48%). 3. These interspecies differences in bioavailability, and the non-linear pharmacokinetics observed in rat, highlight the importance of monitoring SB-203580 systemic exposure in parallel witb the pharmacological endpoint during in vivo pharmacology

Faculty triage shortens emergency department length of stay

OBJECTIVE

To determine whether faculty triage (FT) activities can shorten emergency department (ED) length of stay (LOS).

METHODS

This was a comparison study measuring the impact of faculty triage vs no faculty triage on ED LOS. It was set in an urban county teaching hospital. Subjects were patients presenting to the registration desk between 9 AM and 9 PM on 16 consecutive Mondays (August 2 to November 15, 1999). On eight Mondays, an additional faculty member was stationed at the triage desk. He or she was asked to expedite care by rapid evaluation orders for diagnostic studies and basic therapeutic interventions, and by moving serious patients to the patient care areas. He or she was not provided with detailed instructions or protocols. The ED LOS, time of registration (TIMEREG), inpatient admission status (ADMIT), x-ray utilization (XRAY), total patients registered each day between 9 AM and 9 PM (TOTREG), and patients who left without being seen (LWBS) were determined using an ED information system. The LOS was analyzed in relation to FT, ADMIT, and XRAY by the Mann-Whitney U test. The LOS was related to TIMEREG and TOTREG by simple linear regression. Stepwise multiple linear regression models to predict LOS were generated using all the variables.

RESULTS

Patients without FT (n = 814) had a mean LOS of 445 minutes. Patients with FT (n = 920) had a mean LOS of 363 minutes. Mean difference in LOS was -82 minutes (95% CI = -111 to -53), a reduction of 18%. The LOS was also related to: ADMIT +203 minutes (95% CI = 168 to 238), TOTREG -2.7 min/additional patient registered (95% CI = -1.15 to -4.3), and TIMEREG +0.14 min/min since 9 AM (95% CI = 0.07 to 0.21). The LWBS was reduced by 46% with FT. In multiple regression analysis, ADMIT, FT, TIMEREG, and XRAY were all related to LOS, but the model explained only a small part of variance (adjusted R(2) = 0.093). The faculty cost is estimated to be $11.98/patient.

CONCLUSIONS

Faculty triage offers a moderate increase in efficiency at this ED, albeit with relatively high cost.

Impact of preexisting statin use on adhesion molecule expression in patients presenting with acute coronary syndromes

Of 147 patients admitted with acute coronary syndromes, 17 were taking statins at the time of presentation. These were matched with 17 subjects not taking statins. We found that statin therapy was associated with lower levels of sP-selectin, a marker of platelet and vascular endothelial activation. This provides further insight into the extralipid effect of statins in clinical practice and may help explain the greater-than-expected benefits of statin therapy in ischemic heart disease.

Intravenous Lorazepam versus dimenhydrinate for treatment of vertigo in the emergency department: a randomized clinical trial

STUDY OBJECTIVE

To determine whether lorazepam is more effective than dimenhydrinate in relieving the symptom of vertigo in the emergency department setting.

METHODS

A prospective, randomized, double-blind trial of intravenous lorazepam versus dimenhydrinate therapy was conducted in the ED of a county-owned, university-affiliated hospital. All adult patients who presented between January 24, 1998, and May 23, 1999, with the symptom of vertigo were eligible for inclusion. The intervention was varying the intravenous treatment between lorazepam, 2 mg, and dimenhydrinate, 50 mg. All patients received intravenous infusion of Ringer's lactate solution at a rate of 100 mL/h. Adequacy of randomization to the 2 treatment groups was assessed by comparing the patients' relevant baseline history, physical examination, and symptoms. The predetermined primary outcome measurement was the patient's sensation of "vertigo with ambulation" 1 and 2 hours after treatment. Secondary outcome measurements included vertigo while lying, sitting, and turning the head, ability to ambulate as judged by the enrolling physician, and sensation of nausea and drowsiness 1 and 2 hours after treatment, and whether the patient was "ready to go home" per patient report or physician assessment 2 hours after treatment. All patient symptoms were reported on 10-point scales. Outcome measurements were compared between the 2 treatment groups with a 2-way repeated-measures analysis of variance, Student's t test, Mann-Whitney U, and chi(2) test as appropriate.

RESULTS

Ten patients refused entry into the study, 16 were excluded, and 74 were enrolled, treated, and included in the analysis. One enrolled patient had evidence of vertigo of central origin. The pretreatment values of vertigo with ambulation were strongly correlated with the patient's ability to ambulate (P <.001), suggesting good internal validity. The patients randomly assigned to the lorazepam group were sicker based on their pretreatment symptoms and ability to ambulate, and this may have biased the study results. The patients' symptom of "vertigo with ambulation" decreased 1.5 units more (95% confidence interval [CI] 0 to 3.0) on average on a 10-point scale 2 hours after treatment in the dimenhydrinate group. All other measures of vertigo also decreased more in the dimenhydrinate group, although the differences were not statistically significant. At 2 hours after treatment, the patients' ability to ambulate was better in the dimenhydrinate group (P <.001), and 17% (95% CI -2 to 36) more patients in this group were "ready to go home." Patients in the lorazepam group experienced a 1.8-unit (95% CI 0.2 to 3.4) greater increase in drowsiness 2 hours after treatment.

CONCLUSION

Our results suggest that dimenhydrinate was more effective in relieving vertigo and less sedating than lorazepam at the intravenous doses administered in this study. Dimenhydrinate appears to be the preferred medicine for patients who present to the ED with vertigo likely to be of peripheral origin.

Regulation of the homeodomain CCAAT displacement/cut protein function by histone acetyltransferases p300/CREB-binding protein (CBP)-associated factor and CBP

The CCAAT displacement protein/cut homologue (CDP/cut) is a divergent homeodomain protein that is highly conserved through evolution and has properties of a potent transcriptional repressor. CDP/cut contains three conserved cut-repeat domains and a conserved homeobox, each involved in directing binding specificity to unique nucleotide sequence elements. Furthermore, CDP/cut may play a role as a structural component of chromatin through its direct interaction with nucleosomal DNA and association with nuclear matrix attachment regions. CDP/cut is cell-cycle regulated through interactions with Rb, p107, specific kinases and phosphatases directing the transcriptional activity of CDP/cut on such genes encoding p21(WAF1,CIP1), c-myc, thymidine kinase, and histones. Our previous studies indicate that CDP/cut is associated with histone deacetylase activity and is associated with a corepressor complex through interactions with histone deacetylases. Here, we report the interaction of CDP/cut with CBP and p300/CREB-binding protein-associated factor (PCAF) along with the modification of CDP/cut by the histone acetyltransferase PCAF. Acetylation of CDP/cut by PCAF is directed at conserved lysine residues near the homeodomain region and regulates CDP/cut function. These observations are consistent with the ability of CDP/cut to regulate genes as a transcriptional repressor, suggesting acetylation as a mechanism that regulates CDP/cut function.

H-Mode operation in the START spherical tokamak

H-mode operation has been achieved in high current (I(p)>200 kA) plasmas in the START spherical tokamak for both neutral-beam-injection-heated and Ohmic discharges. The transition to H mode features the development of well-defined edge pedestals in density and temperature, which signifies the formation of an edge-transport barrier, and associated edge-localized modes. Recent operation at plasma currents exceeding 250 kA shows that these features are accompanied by increases in energy confinement time. This is the first clear demonstration of the H-mode regime in a spherical tokamak.

A randomized, placebo-controlled clinical trial on the efficacy of chiropractic therapy on premenstrual syndrome

OBJECTIVE

To evaluate the efficacy of chiropractic therapy on the treatment of symptoms associated with premenstrual syndrome.

DESIGN

A prospective, randomized, placebo-controlled, crossover clinical trial.

SETTING

Multicenter private clinics.

SUBJECTS

Twenty-five subjects with diagnosed premenstrual syndrome (with a Moos premenstrual syndrome questionnaire plus daily symptom monitoring).

INTERVENTION

After randomization, 16 of the subjects received high-velocity, low-amplitude spinal manipulation plus soft tissue therapy 2 to 3 times in the week before menses for at least 3 cycles. The remaining 9 subjects received a placebo treatment with a spring-loaded adjusting instrument wound down for minimum force. After a 1-cycle washout, the 2 groups changed over.

OUTCOME MEASURE

Daily rating of symptom level, comparing total scores for premenstrual week with baseline for treatment and placebo phases.

DATA ANALYSIS

The data were analyzed with paired Student t tests and Wilcoxon signed rank tests, with the statistical significance set at P < .05.

RESULTS

There was a significant decrease in scores after treatment compared with baseline scores (P = .00001) and a statistically significant decrease in scores for the treatment phase compared with the placebo (P = .006). For group 1 (n = 16), there was a significant decrease in scores after treatment compared with baseline scores (P = .0001) and a statistically significant decrease in scores for the treatment phase compared with the placebo (P = .041). For group 2 (n = 9), there was a significant decrease in scores during treatment compared with the baseline (P = .01); however, there was no difference at the P = .05 level between treatment and placebo scores.

CONCLUSIONS

Within the limitations of the study, the results support the hypothesis that the symptoms associated with PMS can generally be reduced by chiropractic treatment consisting of adjustments and soft-tissue therapy. However, the role of a placebo effect needs further elucidation, given that the group receiving the placebo first, although improving over the baseline, showed no further improvement when they had actual treatment.

Helicobacter pylori serology in patients with angiographically documented coronary artery disease

We studied the relation between angiographically defined coronary artery disease and serologic evidence of Helicobacter pylori infection in 488 patients undergo ing elective coronary angiography. There was no association between Helicobacter pylori infection and coronary artery disease (odds ratio 1.3, 95% confidence interval 0.83 to 2.16).

The frequency of positive common spinal clinical examination findings in a sample of premenstrual syndrome sufferers

OBJECTIVE

As part of a randomized clinical trial to determine the efficacy of chiropractic therapy on premenstrual syndrome (PMS), subjects were evaluated for initial underlying spinal dysfunction.

SUBJECTS

Fifty-four subjects with diagnosed PMS (using a Moos PMS questionnaire plus daily symptom monitoring) and 30 subjects with no diagnosable PMS were recruited by newspaper advertising and referrals.

DESIGN

All subjects underwent a full history and physical and chiropractic examination carried out by 1 of 2 fully qualified and registered chiropractors, each with a minimum of 10 years experience. The results of the assessment for the PMS group were compared with those of the non-PMS group.

SETTING

RMIT teaching clinics.

DATA ANALYSIS

The data collected were entered into a spread sheet and contingency tables were created. The data were analyzed by use of chi-squared tests, with the statistical significance being set at P < .05.

RESULTS

The PMS group had a higher percentage of positive responses for each of 12 measured spinal dysfunction indexes except for range of motion of the low back. The indexes where the increase was statistically significant (P < .05) were cervical, thoracic, and low back tenderness, low back orthopedic testing, low back muscle weakness, and the neck disability index. An average of 5.4 of the 12 indexes were positive for the PMS group compared with 3.0 for the non-PMS group.

CONCLUSIONS

A relatively high incidence of spinal dysfunction exists in PMS sufferers compared with a comparable group of non-PMS sufferers. This is suggestive that spinal dysfunction could be a causative factor in PMS and that chiropractic manipulative therapy may offer an alternative therapeutic approach for PMS sufferers.

Transcriptional repression of the cystic fibrosis transmembrane conductance regulator gene, mediated by CCAAT displacement protein/cut homolog, is associated with histone deacetylation

Human cystic fibrosis transmembrane conductance regulator gene (CFTR) transcription is tightly regulated by nucleotide sequences upstream of the initiator sequences. Our studies of human CFTR transcription focus on identifying transcription factors bound to an inverted CCAAT consensus or "Y-box element." The human homeodomain CCAAT displacement protein/cut homolog (CDP/cut) can bind to the Y-box element through a cut repeat and homeobox. Analysis of stably transfected cell lines with wild-type and mutant human CFTR-directed reporter genes demonstrates that human histone acetyltransferase GCN5 and transcription factor ATF-1 can potentiate CFTR transcription through the Y-box element. We have found 1) that human CDP/cut acts as a repressor of CFTR transcription through the Y-box element by competing for the sites of transactivators hGCN5 and ATF-1; 2) that the ability of CDP/cut to repress activities of hGCN5 and ATF-1 activity is contingent on the amount of CDP/cut expression; 3) that histone acetylation may have a role in the regulation of gene transcription by altering the accessibility of the CFTR Y-box for sequence-specific transcription factors; 4) that trichostatin A, an inhibitor of histone deacetylase activity, activates transcription of CFTR through the Y-box element; 5) that the inhibition of histone deacetylase activity leads to an alteration of local chromatin structure requiring an intact Y-box sequence in CFTR; 6) that immunocomplexes of CDP/cut possess an associated histone deacetylase activity; 7) that the carboxyl region of CDP/cut, responsible for the transcriptional repressor function, interacts with the histone deacetylase, HDAC1. We propose that CFTR transcription may be regulated through interactions with factors directing the modification of chromatin and requires the conservation of the inverted CCAAT (Y-box) element of the CFTR promoter.

Enhancement of electrolaryngeal speech by adaptive filtering

Artificial larynges provide a means of verbal communication for people who have either lost or are otherwise unable to use their larynges. Although they enable adequate communication, the resulting speech has an unnatural quality and is significantly less intelligible than normal speech. One of the major problems with the widely used Transcutaneous Artificial Larynx (TAL) is the presence of a steady background noise caused by the leakage of acoustic energy from the TAL, its interface with the neck, and the surrounding neck tissue. The severity of the problem varies from speaker to speaker, partly depending upon the characteristics of the individual's neck tissue. The present study tests the hypothesis that TAL speech is enhanced in quality (as assessed through listener preference judgments) and intelligibility by removal of the inherent, directly radiated background signal. In particular, the focus is on the improvement of speech over the telephone or through some other electronic communication medium. A novel adaptive filtering architecture was designed and implemented to remove the background noise. Perceptual tests were conducted to assess speech, from two individuals with a laryngectomy and two normal speakers using the Servox TAL, before and after processing by the adaptive filter. A spectral analysis of the adaptively filtered TAL speech revealed a significant reduction in the amount of background source radiation yet preserved the acoustic characteristics of the vocal output. Results from the perceptual tests indicate a clear preference for the processed speech. In general, there was no significant improvement or degradation in intelligibility. However, the processing did improve the intelligibility of word-initial non-nasal consonants.

Dual implication of 2',3'-cyclic nucleotide 3' phosphodiesterase as major autoantigen and C3 complement-binding protein in the pathogenesis of multiple sclerosis

Multiple sclerosis (MS) is characterized by intra-blood-brain barrier immunoglobulin synthesis that persists lifelong. Subcellular fractionation and two-dimensional electrophoresis were used in conjunction with immune precipitation and immunoblotting to identify antigenic determinants for this immunoglobulin. We report that 2', 3'-cyclic nucleotide 3'-phosphodiesterase (CNP), a protein associated with oligodendrocyte/myelin membranes, also present in lymphocytes and retina, is one major target for the humoral response. Antibodies to CNP are detected in sera of 74% of MS patients. The antibodies are IgM and are present in serum in high titer as well as in cerebrospinal fluid. The antibody response is temporally persistent, consistent with systemic immune activation and persistent antigenic stimulation. Moreover, CNP is isolated as an immune complex from MS brain. CNP is expressed as two isoforms, with CNPII identical to CNPI but with a 20-amino acid extension at the amino terminus of CNPII; however, the antibody response is exclusively restricted to CNPI. In contrast, both isoforms bind the C3 complement, providing a plausible mechanism in MS central nervous system (CNS) for opsonization of myelin membrane CNP, mediated via the C3 receptor, and phagocytosis of CNP-Ig immune complexes, mediated by membrane Ig Fc receptors of macrophages and CNS microglia.

Evaluation of orthopedic testing of the low back for nonspecific lower back pain

OBJECTIVE

To assess the value of some commonly used orthopedic tests used in evaluating nonspecific lower back pain where there are no demonstrable pathological or neurological deficits.

DESIGN

Retrospective analysis of patient files.

SETTING

Chiropractic teaching clinic, Royal Melbourne Institute of Technology.

SUBJECTS

Five hundred sixty-four files of patients presenting to the above clinic with nonspecific lower back pain were analyzed.

DATA ANALYSIS

The data were entered into a spreadsheet, contingency tables were created, and the data were analyzed using chi 2 tests. Statistical significance was set at p < .05.

RESULTS

Kemp's and Yeoman's tests were most commonly positive, whereas Bonnet's, supported Adams' and axial compression tests showed relatively low positive results. The factors studied that affected the rate of positive responses were age, gender, pain site, duration and cause. The number of previous episodes of lower back pain had no effect on the positive test rates.

CONCLUSION

For cases of nonspecific, mechanical lower back pain, orthopedic testing has limited clinical value once nerve root problems and pathologies have been ruled out. Kemp's and Yeoman's tests were the most frequently positive, and seemed to be the most useful in diagnosing nonspecific lower back pain. When selecting the most appropriate tests to use, one needs to take into account the patient profile and history.

Functional outcomes following treatment for advanced laryngeal cancer. Part I--Voice preservation in advanced laryngeal cancer. Part II--Laryngectomy rehabilitation: the state of the art in the VA System. Research Speech-Language Pathologists. Department of Veterans Affairs Laryngeal Cancer Study Group

This two-part investigation assessed functional outcomes related to communication (including amount of speech therapy), swallowing and eating, and employment status for patients who received one of the two treatment modalities for advanced laryngeal cancer (stage III or IV laryngeal squamous cell carcinoma) in Veterans Administration Cooperative Study #268. One hundred sixty-six patients were randomized to primary surgery (laryngectomy) and radiotherapy (RT), and 166 to induction chemotherapy (CT) and RT. The first investigation dealt with examining and comparing functional outcomes for patients in the two treatment arms of the main study. Results showed clearly that patients with advanced laryngeal cancer are better off from the standpoint of speech communication if they can be treated for this disease without removal of the larynx. In contrast, there were few significant differences between patient groups for other non-speech-related measures. The second investigation focused on communication-related outcomes associated with the rehabilitation of total laryngectomy patients. Results revealed that only relatively small percentages of total laryngectomy patients (6%) developed usable esophageal speech or remained nonvocal (8%), and that a majority of patients ended up as users of artificial electrolarynx (55%) or tracheoesophageal (31%) speech. The results from both investigations are discussed with respect to factors that can influence the rehabilitation process and long-term outcome status of patients who are treated for advanced laryngeal cancer with these two strategies.

Transventricular pressure-velocity wave propagation in diastole: adherence to the Moens-Korteweg equation

In the latter half of the diastolic phase of the cardiac cycle, the left atrium contracts and generates a pressure-velocity wave which enters the left ventricle. The wave moves through the inflow tract of the ventricle, reflects off the apex and heads towards the aortic valve. The time taken for the pressure-velocity wave to propagate through the ventricle, referred to as the A-Ar interval, may be measured using pulsed Doppler echocardiography and occurs in the range 20-80 ms. It has been shown previously that there is a significant negative linear correlation between the A-Ar interval and the passive elastic modulus of the ventricular wall (r = -0.782, p < 0.001). This relationship may be explained by modelling the left ventricle as a folded-over elastic tube through which the pressure-velocity wave is propagated according to the principles of the Moens-Korteweg equation.

Immunohistochemical localization of the neuron-specific glutamate transporter EAAC1 (EAAT3) in rat brain and spinal cord revealed by a novel monoclonal antibody

Neuronal regulation of glutamate homeostasis is mediated by high-affinity sodium-dependent and highly hydrophobic plasma membrane glycoproteins which maintain low levels of glutamate at central synapses. To further elucidate the molecular mechanisms that regulate glutamate metabolism and glutamate flux at central synapses, a monoclonal antibody was produced to a synthetic peptide corresponding to amino acid residues 161-177 of the deduced sequence of the human neuron-specific glutamate transporter III (EAAC1). Immunoblot analysis of human and rat brain total homogenates and isolated synaptosomes from frontal cortex revealed that the antibody immunoreacted with a protein band of apparent Mr approximately 70 kDa. Deglycosylation of immunoprecipitates obtained using the monoclonal antibody yielded a protein with a lower apparent Mr (approximately 65 kDa). These results are consistent with the molecular size of the human EAAC1 predicted from the cloned cDNA. Analysis of the transfected COS-1 cells by immunocytochemistry confirmed that the monoclonal antibody is specific for the neuron-specific glutamate transporter. Immunocytochemical studies of rat cerebral cortex, hippocampus, cerebellum, substantia nigra and spinal cord revealed intense labeling of neuronal somata, dendrites, fine-caliber fibers and puncta. Double-label immunofluorescence using antibody to glial fibrillary acidic protein as a marker for astrocytes demonstrated that astrocytes were not co-labeled for EAAC1. The localization of EAAC1 immunoreactivity in dendrites and particularly in cell somata suggests that this transporter may function in the regulation of other aspects of glutamate metabolism in addition to terminating the action of synaptically released glutamate at central synapses.