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Central effects associated with DDP-induced early polyuria are described. Male Sprague-Dawley rats injected intraperitoneally with DDP (5 mg/kg) have a threefold increase in urine volume in the first 24 hr after treatment. This is accompanied by a corresponding decrease in Uosm but no decrease in renal function as indicated by serum creatinine or GFR. Treated animals having free access to water have reduced levels of plasma AVP, 1.42 +/- 0.14 pg/ml compared to 2.63 +/- 0.47 for control, at 8 hr after injection, and treated animals deprived of water have decreased plasma AVP at 12 and 24 hr after injection. The early polyuria in DDP-treated animals can be prevented by the administration of exogenous AVP. At 8 hr after DDP injection, posterior pituitary AVP content is identical in treated and control rats. In vitro studies with isolated pituitaries show that DDP, either 0.85 and 1.7 mM, in the medium inhibits AVP release by 60% to 90% during two successive 10 min incubation periods. These results suggest that DDP inhibits AVP release from the posterior pituitary but has no effect on AVP synthesis. This inhibition of AVP release results in lowered plasma AVP levels, which reduces water reabsorption and causes polyuria.

We performed a randomized trial comparing intracoronary administration of streptokinase versus dextrose placebo within six hours after the onset of symptoms of acute myocardial infarction in 40 patients. The base-line clinical, hemodynamic, and angiographic findings were similar in the control and streptokinase-treated groups. Reestablishment of flow occurred in 12 of 20 patients treated with streptokinase and in 2 of 20 given placebo (P less than 0.05). Left ventricular function, angiographic ejection fraction, and regional wall motion, measured before and immediately after intervention, and serial radionuclide ejection fractions, measured at treatment, at 12 days, and at 5 months, were compared according to type of treatment (streptokinase vs. placebo) and outcome of therapy (reperfusion vs. no reperfusion). No statistically significant differences between groups were found. Thus, although streptokinase was more effective than placebo in achieving reperfusion, we detected no improvement of left ventricular function as a result of reestablished coronary flow.

Assessment of percutaneous transluminal coronary angioplasty (PTCA) by early radionuclide exercise test was evaluated for 11 arteries undergoing a successful procedure. Exercise thallium-201 (Tl-201) and radionuclide ventriculography (RNV) were performed within 3 days before and after PTCA and compared to % diameter stenosis, % translesional gradient and regional coronary flow reserve (CFR) determined by digital coronary angiography. Primary success of the procedure was gauged by reduction in % stenosis from 80 +/- 12% to 31 +/- 12% (residual stenosis less than 50% in all cases) and reduction in % gradient less than 25% in all cases). Before PTCA, Tl-201 and/or RNV were abnormal in all cases. After PTCA, radionuclide exercise tests improved but remained abnormal in 4 instances. No relationship was found between residual % gradient or stenosis and pathological Tl-201 or RNV following PTCA, but abnormal tests were observed among 4 out of the 5 vessels with the lowest CFR (less than 1.69). In one case CFR remained depressed despite good angiographic, hemodynamic and scintigraphic results, this patient had unstable angina before the procedure. Among patients with stable symptoms, CFR of arterial distributions with positive Tl-201 or RNV after PTCA was significantly lower than that with negative tests (1.58 +/- 0.05 as compared to 1.90 +/- 0.25, P less than 0.02). Early radionuclide stress tests results thus reflect the physiologic improvement of coronary circulation. They may reflect the persistence of coronary flow abnormalities despite the relief of the epicardial stenosis.

A 26-year-old man who had had a successful cadaveric renal transplant six months previously was admitted for evaluation of fever and dysuria. Chest x-ray revealed a new left pleural effusion, bilateral nodular parenchymal densities, and an anterior mediastinal mass. A biopsy of the mediastinal mass to exclude concurrent malignancy and positive AFB stains from pleural fluid and urine confirmed a diagnosis of disseminated tuberculosis.

A patient with acute monocytic leukemia and fibrosis presented with severe hypocalcemia producing tetany, myocardial failure, and ventricular tachycardia with torsades de pointes configuration. Hypophosphatemia, hypomagnesemia, an elevated alkaline phosphatase level, and osteosclerosis were also present. Bone marrow biopsy samples showed fibrosis and thickened bony trabeculae lined with large osteoblasts. Tetracycline labeling showed an increased rate of calcification. Complete remission of the leukemia and fibrosis was achieved with a single 3-week course of low-dose cytarabine and hydroxyurea, with resolution of the hypocalcemia and hypophosphatemia. Calcitriol and etidronate disodium were also administered. The calculated left ventricular ejection fraction increased from 15% to 55% with correction of the hypocalcemia. The hypocalcemia and hypophosphatemia in this patient probably resulted from accelerated bone formation stimulated by the leukemic cells. The high dose of calcitriol that this patient received may have contributed to the remission of the leukemia.

To determine the risk of arterial reocclusion or recurrent ischemia after acute intervention in myocardial infarction, we analyzed the results of coronary arteriography performed acutely and at 1 week in 50 consecutive patients who received acute intervention. Successful recanalization of the infarct vessel was achieved in 46 (92%) patients after therapy with intravenous tissue plasminogen activator, percutaneous coronary angioplasty, or both. Follow-up angiography in 44 showed early reocclusion in 10 patients (23%). Intermittent patency during acute arteriography was always associated with reocclusion; suboptimal (Thrombolysis in Myocardial Infarction [TIMI] class 2) flow was associated with a 50% rate of reocclusion. Although residual stenosis of greater than 50% alone was not predictive of rethrombosis, 90% of all reocclusions were associated with either stenosis greater than 50%, TIMI 2 flow, or intermittent patency. Absence of these angiographic risk factors predicted a 95% patency rate at follow-up. In-hospital cardiac complications occurred in 17 of 23 (74%) patients with residual stenosis of greater than 50% (death in four, ischemia in 13), and late revascularization was required in 53% of survivors. Only 15% of the group with less than 50% stenosis had an in-hospital ischemic event (p less than 0.001). Thus, after acute intervention, an infarct vessel with intermittent patency or suboptimal flow is associated with a high rate of reocclusion. Residual stenosis greater than or equal to 50% appears to predict a high incidence of negative in-hospital clinical outcomes and the need for subsequent revascularization.

The representation in the inferior colliculus of the frequency modulated (FM) components of the first (25-30 kHz) and second (50-60 kHz) harmonic of the sonar signal of the mustached bat, which may be important for target range processing, was investigated by using the 2-deoxyglucose (2-DG) technique and single-unit mapping. In the 2-DG experiments, bats presented with second harmonic FM stimuli alone showed uptake of label in specific regions of the central nucleus and dorsal cortex of the inferior colliculus, and the nucleus of the brachium. In the central nucleus, a dorsoventrally and mediolaterally elongated slab at the caudal border of the anterolateral division was observed. Labeling in the dorsal cortex was contiguous with this band. Bats stimulated with pairs of first and second harmonic FM stimuli separated by short time delays showed similar patterns of labeling, with the addition of another dorsoventrally elongated region of uptake in the more rostral part of the anterolateral division, associated with label in the dorsal cortex. By comparison to control cases exposed to delayed pairs of first and third harmonic signals, or to a second harmonic constant-frequency tone burst at the bat's reference frequency (ca. 60 kHz), we deduced that this additional region of uptake was attributable to the first harmonic FM component. To elucidate further the details of the tonotopic organization and to correlate the frequency representation with anatomical features of the IC, fine-grained maps of single-unit best frequencies were obtained in the central nucleus. Isofrequency contours were reconstructed by computer from five bats after focal, iontophoretic injection of horseradish peroxidase to locate the penetrations and trace connections of the FM2 area. We found that the tissue volume representing FM2 frequencies (50-60 kHz) showed approximately a sixfold overrepresentation for this frequency band. This region occupied most of the caudal portion of the anterolateral division of the central nucleus. Only a single tonotopic representation was found in the central nucleus, consistent with the pattern seen in other mammals. However, isofrequency contours in the anterolateral division were oriented dorsoventrally, approximately parallel to the coronal plane. The small band of frequencies (ca. 60-62 kHz) associated with the dominant constant-frequency component of the biosonar signal was even more dramatically overrepresented (40x) and was confined to the dorsoposterior division, as previously reported by Zook et al. (1985, 530-456).(ABSTRACT TRUNCATED AT 400 WORDS)

High-frequency rotation atherectomy of an occluded left circumflex coronary artery was performed in a 45-year-old man. Over a 0.009 inch flexible tip steel wire a diamond-coated brass burr fastened to a flexible drive shaft that rotates and tracks was advanced. The drive shaft was connected to a turbine and driven by compressed air with 150,000 rpm. After rotablation of the posterior lateral branch over 3 cm with a 1.5 mm burr and rotablation with a 1.75 mm burr of the posterior branch of the left circumflex coronary artery the vessel was reopened with a smooth surface without perforation and dissection. 24 h control and 6 mo control revealed an open coronary vessel. High frequency rotating coronary angioplasty seems to be a promising alternative method to PTCA in opening totally occluded coronary arteries.

Assessment of the functional significance of anatomically defined coronary stenoses has been hampered by the lack of clinically applicable techniques of measuring coronary blood flow or flow ratios. A digital angiographic technique is reported that allows rapid analysis of relative regional coronary blood flow during routine cardiac catheterization. This technique was validated in dogs by comparing digital flow ratio estimates with electromagnetic-flow (EMF) ratio measurements. Fourteen open-chest dogs had EMF probes placed on the proximal left anterior descending artery before selective coronary angiography. Electrocardiographically gated images were acquired directly by a digital radiographic system during both baseline blood flow and either contrast or papaverine-induced hyperemia. Dual-parameter functional images were generated using color and intensity coding to represent contrast arrival time and contrast density, respectively. For analysis, myocardial areas of interest were created over the distal perfusion bed of the left anterior descending coronary artery. Mean contrast density/appearance time (CD/AT) values were computer calculated as the mean density divided by the mean arrival time for each. Coronary flow reserve was determined as the ratio of the CD/AT value for a hyperemic image divided by the CD/AT value for the corresponding baseline image. CD/AT ratios correlated well (r = 0.92) with actual EMF ratios (CD/AT Ratio = 0.90 EMF Ratio +0.12, n = 48 ratios). Reproducibility was +/- 13%. Interobserver (r = 0.99) and intraobserver (r = 0.98) variability was excellent. Thus, rapid, accurate and reproducible estimates of relative regional coronary blood flow are possible using digital radiography.

After an operation upon the abdomen, certain patients have a high risk of developing acute respiratory failure or the adult respiratory distress syndrome. These patients at high risk have been mechanically ventilated during the postoperative period in an attempt to prevent the onset of respiratory insufficiency. As a method of prophylaxis, continuous positive airway pressure has the advantages of increasing the functional residual capacity with minimal effects on the cardiac output, low potential for barotrauma and simplicity of equipment. Alternate patients at risk following an operation on the upper part of the abdomen were placed on 8 centimeters of water continuous positive airway pressure for the first 24 hours postoperatively. Fifty-six controls and 56 patients receiving continuous positive airway pressure were studied. In ten controls, adult respiratory distress syndrome developed, and three died in respiratory failure. Only one of the group receiving continuous positive airway pressure met standard criteria for the diagnosis of adult respiratory distress syndrome. In addition, in 25 patients serving as controls, respiratory complications other than adult respiratory distress syndrome developed compared with the development in only 11 receiving continuous positive airway pressure9

The auditory cortex of the mustache bat, Pteronotus parnellii rubiginosus, is composed of functional divisions which are differently organized to be suited for processing the elements of its biosonar signal according to their biological significance. Unlike the Doppler-shifted-CF (constant frequency) processing area, the area processing the frequency-modulated components does not show clear tonotopic and amplitopic representations, but consists of several clusters of neurons, each of which is sensitive to a particular combination (or combinations) of information-bearing elements of the biosonar signal and echoes. The response properties of neurons in the major clusters indicate that processing of information carried by the frequency-modulated components of echoes is facilitated by the first harmonic of the emitted biosonar signal. The properties of some of these neurons suggest that they are tuned to a target which has a particular cross-sectional area and which is located at a particular distance.

The wide variety of reperfusion strategies now available has led to confusion regarding the optimal therapy of patients with acute myocardial infarction. In assessing the comparative efficacy of reperfusion strategies, safety factors, recanalization rates, reocclusion rates, myocardial salvage and improvement in survival must be compared. In this analysis, primary percutaneous transluminal coronary angioplasty (PTCA) compares favorably to intravenous thrombolytic therapy or combination PTCA and thrombolytic therapy as a reperfusion strategy. Primary PTCA has not been reported to cause intracerebral hemorrhage, whereas thrombolytic strategies are associated with an incidence of a 0.2 to 1.4% rate of intracerebral bleeding. Strategies using PTCA have recanalization rates of only 33 to 75%. Disappointingly, a major failure of all reperfusion strategies (including primary PTCA) is a high rate of reocclusion and reinfarction. Primary PTCA is associated with a 7 to 16% increase in global ejection fraction. Similar improvement in ejection fraction has not been demonstrated in patients treated with thrombolytic therapy alone. Although in-hospital mortality is improved, a substantial 1-year mortality persists for intravenous thrombolytic therapy. Long-term survival is greater when PTCA therapy is used. In addition, PTCA does favorably improve survival in high-risk patients with cardiogenic shock. Although it is unlikely that most patients with acute myocardial infarction will have primary PTCA as a treatment option, this therapy remains extremely attractive for centers where primary PTCA is readily available.

Experiment 1 demonstrated that delayed matching-to-sample in the capuchin monkey was superior when the delay interval was spent in darkness rather than in moderate illumination. In contrast with previous studies in which the delayed-matching ability of primates appeared limited to 60 sec or less, in the dark condition all subjects showed above-chance matching at a 120-sec delay interval. Experiment 2 verified that darkness during the delay interval can facilitate delayed matching and provided evidence that the effective variable was the illumination level of the delay interval rather than change in illumination, which in Exp. 1 was confounded with illumination level.