Adenosine-induced coronary vasodilation during transesophageal Doppler echocardiography. Rapid and safe measurement of coronary flow reserve ratio can predict significant left anterior descending coronary stenosis

BACKGROUND

Less invasive methods are replacing traditional invasive means of measuring coronary flow reserve (CFR). Transesophageal echocardiography (TEE) is becoming a useful tool for evaluation of coronary artery disease and has recently been used to measure CFR. This has always been done using dipyridamole, but adenosine has a greater vasodilator potency and more favorable kinetics than dipyridamole. This study was done to evaluate the hypothesis that adenosine is safe, rapid, and accurate in measuring coronary blood flow reserve by TEE Doppler.

METHODS AND RESULTS

Forty-nine patients who had recently undergone angiography had a transesophageal echocardiogram with visualization of the coronary arteries and measurement of blood flow velocity in the left anterior descending coronary artery (LAD) during adenosine infusion of 0.14 mg/kg per minute. Angiograms were analyzed by quantitative coronary angiography, and significant stenosis was defined as > 70% lumenal diameter narrowing. Thirty-nine of the 49 patients did not have a significant LAD stenosis (group 1); the remainder had significant disease (group 2). Good spectral Doppler recordings of blood flow velocity in the LAD were obtained in 41 of 46 patients (89%). There were no significant differences in baseline coronary blood flow velocities between the two groups. Hyperemic to baseline flow ratios were significantly higher in patients without significant LAD stenosis for peak (2.83 +/- 1.04 versus 1.78 +/- 0.36) and mean (2.68 +/- 0.96 versus 1.75 +/- 0.39) diastolic velocity. A CFR ratio > 2.1 had a sensitivity of 86%, a specificity of 79%, a positive predictive value of 46%, and a negative predictive value of 96% for the absence of critical LAD stenosis. The infusion was well tolerated. It had to be prematurely terminated in only 3 patients (6.5%), and they were asymptomatic. No patient experienced chest pain, palpitations, or flushing. Intraobserver and interobserver variabilities were low, and reproducibility of data was good (< 4%).

CONCLUSIONS

Adenosine Doppler TEE is an effective, rapid, safe, and superior means of measuring CFR ratio. This method is convenient for serial measurements of CFR as well as in clinical settings such as evaluation of syndrome X, cardiomyopathy, and aortic regurgitation.

Predictors for altering caffeine consumption during stress

The present study investigated whether or not those who self-report increasing use of caffeine when under stress consume caffeine more for the drug (e.g., stimulant) effects. A three-part questionnaire assessing demographic information, caffeine use patterns, and reasons for use was completed by 182 females and 106 males (mean age, 22.4 years; range, 9 to 59). Consistent with earlier research, nearly 50% of the sample reported increasing consumption of coffee or soft drinks when under stress. Hierarchical multiple regression analyses showed drinking for relief reasons as the most consistent predictor for altering caffeine use when under stress. Understanding differences in use patterns will likely help strengthen the ability to describe the extent to which caffeine use contributes to cardiovascular and other disorders.

Gender differences in onset of illness, treatment response, course, and biologic indexes in first-episode schizophrenic patients

OBJECTIVE

Gender differences in onset of illness, response to treatment, course, and biologic measures have been consistently reported in patients with chronic schizophrenia. Patients with first-episode schizophrenia were examined to determine whether gender differences also occur in these patients.

METHOD

Fifty-four neuroleptic-naive schizophrenic patients (29 men and 25 women) were studied beginning in an initial stage of the first hospitalization for psychosis while undergoing treatment with a standardized medication regimen. Before antipsychotic drug treatment and during 1 year of follow-up each patient was rated on the Schedule for Affective Disorders and Schizophrenia--Change Version (psychosis and disorganization items), Scale for the Assessment of Negative Symptoms, Clinical Global Impression, modified Simpson Tardive Dyskinesia Scale, and Simpson-Angus Rating Scale for extrapyramidal side effects. Methylphenidate challenge testing was done at study entry. Plasma neuroleptic, homovanillic acid (HVA), and prolactin levels were determined weekly for the first 6 weeks.

RESULTS

The female schizophrenic patients had a later onset and better treatment response than the men. Plasma HVA levels at baseline and week 1 and changes in prolactin levels from baseline to weeks 1 through 6 were greater among the women.

CONCLUSIONS

Gender differences in onset and degree of treatment response in first-episode schizophrenic patients are similar to those of chronic patients and are apparent at early stages of the illness. The greater pharmacologic responsivity of the female patients, as indicated by the neuroendocrine results, is consistent with the gender difference in degree of symptom improvement with medication.

Rural Minnesota family physicians' attitudes toward telemedicine

This study reports the results of an assessment of the attitudes and opinions of rural Minnesota family physicians toward telemedicine. The results of 52 mail surveys and 32 telephone interviews were compiled to determine existing attitudes and levels of awareness concerning aspects of telemedicine. Surveyed physicians overwhelmingly agreed that they do not have sufficient information about telemedicine. Their awareness of telemedicine's applications and capabilities is minimal. Also, responding physicians indicated little knowledge regarding such important issues as cost-effectiveness, reimbursement, liability, and potential primary care benefits. In general, however, physicians' attitudes toward telemedicine were favorable. This information should be important to funders, suppliers, and potential users of telemedicine. This study suggests a need to educate medical students, residents, and practicing physicians about telemedicine and issues related to its use.

Application of the API YeastIdent system in determining the enzymatic profiles of Nocardia asteroides isolates

Glucose represses production of ammonium in many clinical isolates of Nocardia asteroides growing on bromcresolpurple casein glucose agar. Strains exhibiting this property are designated as group A, while group B represents isolates showing a high degree of proteolytic activity and a resulting rapid increase in pH. Twenty isolates of N. asteroides were characterized as group A or B. Enzymatic profiles obtained using the API YeastIdent system showed significant enzymatic variation between 12 group B and 8 group A isolates. Proteolytic enzymes which most varied in activity between groups were glycine aminopeptidase, histidine aminopeptidase and leucyl glycine aminopeptidase. As some of the N. asteroides isolates were isolated from asymptomatic patients, it is of interest to consider the possibility of one group being of low virulence while the other is more strongly associated with infection.

A prospective study of the prevalence of clear-cut endocrine disorders and polycystic ovaries in 350 patients presenting with hirsutism or androgenic alopecia

OBJECTIVE

To determine the frequency of polycystic ovaries (PCO) on ultrasound and the incidence of clearcut endocrine disorders leading to virilization in patients complaining of hirsutism or androgenic alopecia. The major purpose was to determine a coherent policy for the routine biochemical assessment of such women.

DESIGN

A prospective study of women attending a joint skin/endocrine clinic complaining of these problems.

PATIENTS

Three hundred and fifty consecutive women with hirsutism and/or androgenic alopecia were assessed.

MEASUREMENTS

Baseline endocrine screens were conducted on two occasions and included measurement of serum testosterone, androstenedione, dehydroepiandrosterone sulphate, sex hormone binding globulin, LH, FSH, 17-hydroxyprogesterone and PRL. The ovaries were visualized by high-resolution pelvic ultrasound scanning.

RESULTS

Eight women were identified with relevant endocrine disorders; of these, one was acromegalic and one had a microprolactinoma--in both cases the association may have been fortuitous. Three had clear-cut 21-hydroxylase deficiency, one a rare hepatic enzyme deficiency (11-reductase), one a virilizing adrenal carcinoma and one a Leydig cell tumour. The latter six cases all had persistently elevated levels of serum testosterone (> 5 nmol/l). In all, 13 women had baseline testosterone levels in excess of 5 nmol/l. Polycystic ovaries were present in 81% of the cases who had erratic cycles and 52% of those with regular cycles; PCO were present in two of the women with 21-hydroxylase deficiency and in the woman with 11-oxoreductase deficiency. The Leydig cell tumour (1.2 cm diameter) was not detected on ultrasound or CT scan.

CONCLUSIONS

For the exclusion of enzyme deficiencies and virilizing tumours clinical assessment and a single serum testosterone measurement will suffice.

Neural modulation of muscle contractile properties during fatigue: afferent feedback dependence

H reflex amplitudes, an indirect measure of the excitability of the alpha motoneuron pool, were recorded from 10 males during fatigue induced by submaximal, isotonic, voluntary contractions of the soleus muscle. H reflex changes were correlated with electromyographic changes (mean power frequency (MPF); root mean square (rms EMG)), under ischemic and non-ischemic conditions. The purpose of the ischemia was to block transmission of Ia and possibly Ib afferents to assess whether changes in sensory feedback had any effect on alpha motoneuron and EMG activity during fatigue. Significant interactions were found between ischemic and non-ischemic conditions. After an initial decrease (1.21 +/- 0.56 mV to 0.54 +/- 0.39 mV), H reflex amplitudes increased during non-ischemic trials (0.54 +/- 0.39 mV to 1.13 +/- 0.84 mV). Under ischemic conditions H reflex amplitudes decreased (2.11 +/- 1.10 mV to 0.70 +/- 0.74 mV; P < 0.003). During non-ischemic conditions, MPF decreased across 5 consecutive trials (157.7 +/- 17.9 Hz to 124.7 +/- 17.2 Hz), as compared to an increase under ischemic conditions (132.8 +/- 21.2 Hz to 197.1 +/- 53.6 Hz; P < 0.001). Root mean square amplitude decreased during the non-ischemic trials (31.07 +/- 14.62 mV to 25.98 +/- 8.26 mV). A greater decrease was noted during the ischemic trials (34.00 +/- 23.61 mV to 4.95 +/- 3.77 mV; P < 0.001). Data suggest that the CNS modulates muscle contraction in order to preserve force output and neuromuscular transmission during fatigue. This modulation appears dependent on Ia and/or Ib afferent feedback.

Relation of plasma fluphenazine levels to treatment response and extrapyramidal side effects in first-episode schizophrenic patients

OBJECTIVE

The aim of this study was to determine the relation between plasma fluphenazine levels and clinical response in first-episode schizophrenic patients.

METHOD

Data from 36 first-episode schizophrenic or schizoaffective inpatients diagnosed according to the Research Diagnostic Criteria were evaluated. The patients received open, standardized treatment with fluphenazine, 20 mg/day, for at least 4 weeks. Psychopathology was assessed biweekly, and plasma fluphenazine levels were ascertained weekly. Patients were classified as responders or nonresponders, and correlations between their neuroleptic levels and ratings of psychopathologic and extrapyramidal symptoms were computed.

RESULTS

Plasma fluphenazine levels for weeks 1 through 4 were significantly correlated with each other but were not correlated with age, gender, diagnosis, or race. Mean neuroleptic levels (weeks 3 and 4) were not different between responders and nonresponders and were not correlated with measures of psychopathology or extrapyramidal symptoms.

CONCLUSIONS

These results do not indicate an association between plasma fluphenazine levels and response to treatment or extrapyramidal side effects in first-episode schizophrenia. The disparity between the results of this study and those of previous studies may be due to methodological differences or to a biologically based difference between first-episode and chronic patients.

Early results with cryopreserved saphenous vein allografts for infrainguinal bypass

PURPOSE

Cryopreserved saphenous vein allografts (CSVA) are available for use in arterial reconstructions; however, patency rates in the infrainguinal position are not well described.

METHODS

We reviewed our experience with 38 patients who underwent 43 infrainguinal bypasses with CSVA as the conduit. The group includes 21 women and 17 men with a mean age of 69 +/- 11 years. Mean follow-up is 8.2 +/- 5.5 months. Logistic regression was used to analyze five variables in an attempt to identify predictors of success or failure: distal anastomosis to the popliteal artery versus a crural artery, one-vessel versus two- or three-vessel runoff, postoperative anticoagulation versus none, primary reconstructions versus reoperations, and one segment versus two segments of CSVA required.

RESULTS

The cumulative patency rate at 12 months by life-table analysis is 66%. Logistic regression revealed that primary reconstructions were more likely to succeed than reoperations (p = 0.03) and operations completed with one segment of CSVA were more likely to succeed than those requiring more than one segment of vein (p = 0.03).

CONCLUSIONS

We conclude that (1) the short-term patency of infrainguinal bypasses with CSVA suggests that they may be acceptable alternatives to prosthetic grafts in the below-knee position, and (2) primary reconstructions performed with one segment of CSVA are more likely to succeed.

Use of lateral heel and sole wedges in the treatment of medial osteoarthritis of the knee

The authors discuss the use of lateral heel wedges in the treatment of medial osteoarthritis of the knee in 121 knees in 85 patients. Follow-up was an average of 12 months after the insertion of the wedge. Patients' roentgenograms were graded according to the Ahlback classification, and various improvements were noted. Overall, 38% of patients improved to a Hospital for Special Surgery pain score of 25 or 30, which corresponds to an excellent result from total knee arthroplasty. Fifty percent of patients improved to a pain score of 20 or higher, which corresponds to a good result from total knee arthroplasty. The patients with milder osteoarthritis received greater pain relief. However, even patients with complete loss of joint space and bony erosion showed some improvement. It appears that the use of lateral wedges has a place in the conservative treatment of medial osteoarthritis.

Octreotide changes serum thyrotropin (TSH) glycoisomer distribution as assessed by lectin chromatography in a TSH macroadenoma patient

A 28-yr-old woman with hyperthyroidism due to a TSH/GH-secreting macroadenoma was treated preoperatively with octreotide to attain euthyroidal status. Lectin chromatography, performed on her immunopurified serum TSH obtained at baseline and 1 week after 50 micrograms three times daily octreotide therapy, revealed a significant increase in ricin binding after octreotide. This result is consistent with increased amounts of TSH isoforms with more exposed galactose residues. Further clinical studies to elucidate the effects of pharmacological agents on serum TSH isoforms and TSH bioactivity are needed.

Role of the gamma component of preprotoxin in expression of the yeast K1 killer phenotype

K1 killer strains of Saccharomyces cerevisiae secrete a polypeptide toxin to which they are themselves immune. The alpha and beta components of toxin comprise residues 45-147 and 234-316 of the 316-residue K1 preprotoxin. The intervening 86-residue segment is called gamma. A 26-residue signal peptide is removed on entry into the endoplasmic reticulum. The Kex2 protease excises the toxin components from the 290-residue glycosylated protoxin in a late Golgi compartment. Expression of a cDNA copy of the preprotoxin gene confers the complete K1 killer phenotype on sensitive cells. We now show that expression of immunity requires the alpha component and the N-terminal 31 residues of gamma. An additional C-terminal extension, either eight residues of gamma or three of four unrelated peptides, is also required. Expression of preprotoxin terminating at the alpha C-terminus, or lacking the gamma N-terminal half of gamma causes profound but reversible growth inhibition. Inhibition is suppressed in cis by the same 31 residues of gamma required for immunity to exocellular toxin in trans, but not by the presence of beta. Both immunity and growth inhibition are alleviated by insertions in alpha that inactivate toxin. Inhibition is not suppressed by kex2, chc1 or kre1 mutations, by growth at higher pH or temperature, or by normal K1 immunity. Inhibition, therefore, probably does not involve processing of the alpha toxin component at its N-terminus or release from the cell and binding to glucan receptors. Some insertion and substitution mutations in gamma severely reduce toxin secretion without affecting immunity. They are presumed to affect protoxin folding in the endoplasmic reticulum and translocation to the Golgi.

High plasma clozapine levels in tardive dyskinesia

Studies in the literature that attempt to relate neuroleptic plasma levels to the development of tardive dyskinesia (TD) report inconsistent findings. As part of an open, long-term study, 60 schizophrenic and schizoaffective patients were started gradually on a b.i.d. schedule of the atypical antipsychotic drug clozapine. Blood samples were drawn weekly for 6 weeks and analyzed for a variety of constituents including clozapine plasma levels. Patients with higher levels of TD were found to have significantly higher levels of plasma clozapine and a higher ratio of plasma/dose than those with lower levels of TD. Our data suggests that schizophrenics with TD may have different pharmacokinetics, drug metabolism, and elimination processes than those without TD. Higher typical plasma neuroleptic levels may increase susceptibility to TD development. A second hypothesis implies that it is not the higher mean plasma level of a neuroleptic that is associated with TD but the greater fluctuations of plasma levels over time (i.e., a higher variance). This hypothesis is discussed in the context of our data.

The dopamine-serotonin relationship in clozapine response

The effects of clozapine on the dopamine and serotonin systems may underlie its atypical pharmacologic and clinical profile. To examine this hypothesis, we measured dopamine and serotonin plasma and cerebrospinal (CSF) metabolites and the relationship of these values to treatment response in 19 neuroleptic refractory and intolerant schizophrenic patients. Only a small change in the CSF and plasma homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5HIAA) levels was found. However, the pretreatment CSF HVA/5HIAA ratio and, to a lesser extent, the CSF HVA level predicted treatment response. These results suggest that the modest relationship between HVA and 5-HIAA and treatment response supports the involvement of both neurotransmitters in the pathophysiology of schizophrenia.

Ricin and lentil lectin-affinity chromatography reveals oligosaccharide heterogeneity of thyrotropin secreted by 12 human pituitary tumors

Some patients with thyrotropin (TSH)-producing pituitary tumors are more hyperthyroid than others despite similar TSH levels in serum, suggesting that qualitatively different TSH molecules with differing bioactivities may be secreted by different tumors. We used ricin and lentil lectin-affinity chromatography to test whether the TSH oligosaccharides varied among 12 patients with TSH-producing tumors. We found that each tumor secreted heterogeneous isoforms of TSH that differed in their extents of exposed galactose (Gal) residues, and their degrees of sialylation and core fucosylation. These biochemical parameters also varied markedly for TSH secreted by different tumors. Isoforms appeared to reflect poor sialyltransferase activity in two tumors and efficient sialyltransferase in the remainder. TSH secreted by tumors was more fucosylated than TSH secreted by control euthyroid persons. There was an inverse relationship between the sialylation and fucosylation of tumor TSH. No simple relationship between TSH oligosaccharide structures and bioactivity was evident, although mixtures of isoforms having the least and most sialylated TSH seemed to be the most bioactive clinically. In three patients from whom serum and medium TSH were both available, TSH in serum was more sialylated than TSH secreted by the tumor in vitro, perhaps reflecting slow clearance of sialylated isoforms from the circulation. Core fucosylation of serum TSH was less than that of medium TSH. These data prove that human tumors secrete TSH with heterogeneous oligosaccharide structures.

The Structured Clinical Interview for DSM-III-R (SCID). II. Multisite test-retest reliability

A test-retest reliability study of the Structured Clinical Interview for DSM-III-R was conducted on 592 subjects in four patient and two nonpatient sites in this country as well as one patient site in Germany. For most of the major categories, kappa s for current and lifetime diagnoses in the patient samples were above .60, with an overall weighted kappa of .61 for current and .68 for lifetime diagnoses. For the nonpatients, however, agreement was considerably lower, with a mean kappa of .37 for current and .51 for lifetime diagnoses. These values for the patient and nonpatient samples are roughly comparable to those obtained with other structured diagnostic instruments. Sources of diagnostic disagreement, such as inadequate training of interviewers, information variance, and low base rates for many disorders, are discussed.