Assessing coronary blood flow dynamics with the TIMI frame count method: comparison with simultaneous intracoronary Doppler and ultrasound.

This study compared the TIMI frame count (TFC), which has been proposed as a method for quantifying coronary blood flow, with coronary flow and microvascular function measured with intracoronary Doppler and intracoronary ultrasound. Coronary blood flow volume was calculated from coronary blood velocity (by intracoronary Doppler) and lumen area (by intracoronary ultrasound) in the LAD in 46 post-heart transplant patients at baseline and after intracoronary adenosine. TFC correlated significantly with average peak coronary blood velocity (r = -0.42; P = 0.004) and coronary lumen area (r = 0.39; P = 0.008), but not with coronary blood flow volume (r = -0.01; P = 0.96) or the coronary flow reserve response to adenosine (r = 0.09; P = 0.58). In conclusion, TFC is a simple method of assessing coronary blood velocity but not volumetric flow. While TFC does not predict coronary flow reserve, as a measure of velocity it does provide an assessment of basal microvascular tone, information that is complementary to that afforded by flow reserve measurements.

Circadian rhythms in the suprachiasmatic nucleus are temperature-compensated and phase-shifted by heat pulses in vitro.

Temperature compensation and the effects of heat pulses on rhythm phase were assessed in the suprachiasmatic nucleus (SCN). Circadian neuronal rhythms were recorded from the rat SCN at 37 and 31 degrees C in vitro. Rhythm period was 23.9 +/- 0.1 and 23.7 +/- 0.1 hr at 37 and 31 degrees C, respectively; the Q(10) for tau was 0.99. Heat pulses were administered at various circadian times (CTs) by increasing SCN temperature from 34 to 37 degrees C for 2 hr. Phase delays and advances were observed during early and late subjective night, respectively, and no phase shifts were obtained during midsubjective day. Maximum phase delays of 2.2 +/- 0.3 hr were obtained at CT 14, and maximum phase advances of 3.5 +/- 0.2 hr were obtained at CT 20. Phase delays were not blocked by a combination of NMDA [AP-5 (100 microM)] and non-NMDA [CNQX (10 microM)] receptor antagonists or by tetrodotoxin (TTX) at concentrations of 1 or 3 microM. The phase response curve for heat pulses is similar to ones obtained with light pulses for behavioral rhythms. These data demonstrate that circadian pacemaker period in the rat SCN is temperature-compensated over a physiological range of temperatures. Phase delays were not caused by activation of ionotropic glutamate receptors, release of other neurotransmitters, or temperature-dependent increases in metabolism associated with action potentials. Heat pulses may have phase-shifted rhythms by directly altering transcriptional or translational events in SCN pacemaker cells.

Simultaneous intracoronary ultrasound and Doppler flow studies distinguish flow-mediated from receptor-mediated endothelial responses.

Abnormalities in vascular endothelial function, which occur early in atherosclerosis, may play an etiologic role in the development of the disease or represent a marker for the extent of atherosclerosis. Endothelial dysfunction, usually characterized by demonstration of decreased endothelium-dependent vasorelaxation, may be a sensitive and specific method to detect vascular disease in its earliest stages. In this context, separation of abnormalities in receptor-mediated and flow-mediated endothelium-dependent vasodilatory responses may allow for the most accurate characterization of endothelial dysfunction. In 35 patients undergoing routine annual cardiac catheterization after heart transplantation, changes in epicardial lumen area and coronary blood flow in response to intracoronary administration of adenosine, acetylcholine, and nitroglycerin were measured simultaneously using an intravascular ultrasound (IVUS) catheter positioned over a Doppler flow wire in the left anterior descending coronary artery. The combination of these techniques allowed for distinction between receptor-mediated and flow-mediated endothelium-dependent vascular responses. Peak flow with the endothelium-independent resistance vessel dilator adenosine occurred at 18+/-2 sec; the maximal lumen area response occurred later, at 43+/-11 sec (P < 0.001). Acetylcholine, an endothelium-dependent small- and large-vessel vasodilator, caused an immediate increase in both flow and lumen area, but a second peak of dilation was observed, and maximal area occurred 46 sec after maximal flow (54+/-14 vs. 100+/-26 sec, P < 0.001). Simultaneous IVUS and Doppler flow measurements after infusion of vasoactive agents allows for distinction between and evaluation of the relative contribution of agonist-mediated and flow-mediated responses, which may offer important and unique insights into coronary endothelial function.

Autoantibodies in patients with silicone implants.

We assessed the prevalence of autoantibodies in women with silicone implants and controls. Five hundred consecutive patients with silicone implants, 25 age-matched normal women, 25 women with silicone implants and no rheumatic symptoms, and 100 women with fibromyalgia were tested. Immunofluorescence antinuclear antibodies (ANA) were performed using HEp-2 cells. Subtype autoantibodies were performed by enzyme-linked immunoassay and Western blot. ANA tests were positive in 30% of patients with silicone implants and rheumatic symptoms, 8% of age-matched normal women, 28% of women with silicone implants without clinical symptoms, and 25% of women with fibromyalgia and no silicone implants. The predominant ANA pattern was speckled (55%). ANA subtype testing was positive in 4.8% of patients and none of the controls. We conclude that a larger proportion of women with silicone implants have autoantibodies compared to age-matched asymptomatic women suggesting immune activation in women with silicone implants.

Noncardiac pulmonary edema, newer environmental aspects. An update.

Accidental spread of potentially toxic gases, fumes, and particulate chemicals has been reported recently in various cities throughout the country and appears to be on the increase throughout the world in the past few years. Moreover, cerebral trauma, septic shock (ARDS), and environmental pulmonary edema from drug intoxication have been commonly encountered. Newer modalities of treatment include selective [corrected] fiber optic bronchoscopy, constant positive airway pressure mask, administration of surfactant, pentoxifylline, and use of newer experimental agents such as nitrous oxide, antitumor necrosis factor (ATNF), and extracorporeal carbon dioxide with low-frequency positive pressure (ECCO2R-LFPPV). The future holds promise for probable reductions in both morbidity and mortality rates of this ubiquitous occupational and environmental health problem, which is of global importance.

Beguiled by the gallium. Thymic rebound in an adult after chemotherapy for Hodgkin's disease.

An 18-year-old woman was diagnosed as having Hodgkin's disease involving the mediastinal lymph nodes and lung parenchyma. A pretreatment gallium 67 scan showed increased uptake in the mediastinum. Chest radiograph and chest computed tomographic (CT) scans after chemotherapy demonstrated resolution of disease, and a repeated gallium scan was normal. Four months later, a surveillance gallium scan showed increased activity in the mediastinal and hilar regions with corresponding chest CT and magnetic resonance imaging (MRI) showing a retrosternal mass. Prior to committing the patient to aggressive treatment for presumed disease relapse, a biopsy of the mass was performed and a specimen showed normal thymus tissue. The patient has continued in remission without further therapy 3 years after her initial treatment, with subsequent normal gallium scans and a stable mass on CT and MRI. Thymic enlargement following chemotherapy can occur with Hodgkin's disease in young adults, and interpretation of imaging studies, including gallium scanning, must be made with this consideration in mind.

A clinical and immunologic evaluation of women with silicone breast implants and symptoms of rheumatic disease.

OBJECTIVE: To describe the clinical and serologic features of women with silicone breast implants who were referred for symptoms of rheumatic disease. DESIGN: A case series. SETTING: University and private rheumatology practices. PATIENTS: A total of 156 women with silicone breast implants and rheumatic disease complaints. Controls for the serologic studies included women with silicone implants and no rheumatic symptoms (n = 12) and women with fibromyalgia without silicone implants (n = 174). MEASUREMENTS: Complete physical examination and testing for immunoglobulins; complement; C-reactive protein; rheumatoid factor; and autoantibodies by indirect immunofluorescence, immunodiffusion, and Western blot. RESULTS: Three subgroups of patients were defined based on clinical and laboratory findings: joint and muscle pain (n = 95), joint swelling (n = 32), and connective tissue disease (n = 29). Most women had normal immunologic studies. The patients with joint swelling had mild, asymmetric, rheumatoid-factor-negative synovitis that did not meet American College of Rheumatology criteria for rheumatoid arthritis. Fourteen patients had a scleroderma-like illness and anti-centromere or anti-PM-Sci antibodies by Western blot. Ten patients had a positive Western blot for BB' polypeptide, a small nuclear ribonucleoprotein (snRNP), but did not meet criteria for systemic lupus erythematosus. No autoantibodies to known disease-related polypeptides were detected on Western blot in the control groups. CONCLUSION: Most women with silicone implants and rheumatic complaints had normal results of serologic tests and nonspecific symptoms, suggesting no serious connective tissue disease. However, a subset of women had clinical signs and serologic tests that were unusual even for referred patients. These observations suggest, but cannot establish, that some women with silicone breast implants may develop atypical immunologic reactions.

Reduced vascular compliance as a marker for essential hypertension.

In 38 patients with established essential hypertension and 32 age-matched normotensive control subjects proximal and distal arterial compliance were determined by computer-based assessment of the diastolic decay of a brachial arterial tracing and a modified Windkessel model of the circulation. In the hypertensive subjects compared to the normotensive subjects mean arterial pressure was 25% higher (P less than .001), systemic vascular resistance 23% higher (P less than .01), proximal compliance 19% lower (P less than .01), and distal compliance 72% lower (P less than .001). The reduction in distal compliance was highly age-dependent. In the youngest age range (45 to 54 years) little overlap appeared between hypertensive and normotensive groups, whereas in the oldest subjects studied (65 to 75 years) distal compliance was comparably low in the two groups. Thus, distal vascular compliance provides a sensitive and specific marker for the abnormal vasculature associated with hypertension and may be particularly useful in identifying the disease in young individuals with borderline blood pressure.

A surgical approach to a displaced ankle fracture.

The goal of reduction in displaced ankle fractures is the restoration of normal function in the involved extremity. This can be accomplished only by restoring the normal anatomy of the involved joints. Closed reduction is not always successful or indicated if vascular compromise, interspersed soft tissue, or osseous fragments are present. Open reduction with internal fixation allows for direct visualization of the involved parts and an accurate and rigid form of fixation. A case report of a displaced ankle fracture treated with open reduction and internal A-O fixation is presented.

The Wilson bunion procedure modified for improved clinical results.

The Wilson procedure for correction of hallux abducto valgus is modified for use in three specific clinical conditions. The modifications are outlined and demonstrated in the preoperative conditions of 1) juvenile hallux abducto valgus, 2) functional hallux limitus, and 3) postoperative metatarsus primus elevatus. The rationale and biomechanical considerations for the modified Wilson bunion procedure are discussed.

The mucin clot test and the synovial fluid rheumatoid factor as diagnostic criteria in rheumatoid arthritis.

We evaluated the diagnostic usefulness of 2 synovial fluid (SF) tests viz the mucin clot test (MCT) and the rheumatoid factor (RF) test in rheumatoid arthritis (RA). SF was obtained from 140 patients, 60 with RA, 80 with other articular diseases. The sensitivity and specificity of the MCT in RA were 76% and 49%, respectively; the positive and negative predictive values (PPV, NPV) were 52% and 73%. The sensitivity and specificity of SF RF were 63% and 91% respectively compared with corresponding values of 75% and 87% for serum RF; PPV and NPV were 89% and 69%, and differed little from values obtained for serum RF. Our results suggest that RA diagnostic criteria should be revised to exclude the MCT, and that the detection of RF in SF in addition to its determination in serum is unnecessary in establishing a diagnosis of RA.