Magnetic resonance imaging of flow dynamics in the circle of Willis

Magnetic resonance angiography was applied to the study of blood flow dynamics in the circle of Willis in nine patients with cerebrovascular disease and two normal volunteers. In conjunction with two-dimensional or three-dimensional gradient-echo acquisitions, selective presaturation of individual vessels was used to determine the direction of blood flow and the origin of the vascular supply. Presaturation causes signal loss within the territory supplied by the presaturated artery, without affecting vessels not crossing the presaturation slab. The results were correlated with those from transcranial Doppler sonography and conventional angiography. Magnetic resonance angiography was able to demonstrate the direction of blood flow, the presence or absence of collateral blood flow, and the blood supply to the pericallosal arteries, as well as the presence of a fetal posterior circulation. Magnetic resonance angiography is a noninvasive means for imaging the blood supply of the major intracranial arteries.

Intracerebral arteriovenous malformations: evaluation with selective MR angiography and venography

Magnetic resonance (MR) angiography and spin-echo methods were used to evaluate intracerebral arteriovenous malformations (AVMs) in 10 patients. Spin-echo images obtained with flow presaturation demonstrated the nidus of the AVM in all cases, but it was difficult to determine feeding vessels. These vessels were directly visualized with three-dimensional MR angiography; their presence could be indirectly determined by means of selective presaturation of individual vessels, which resulted in a marked decrease in signal within the portion of the AVM supplied by that vessel. Vascular supplies from the internal carotid artery and anterior, middle, or posterior cerebral arteries were detected in all cases, but in three large malformations it was not possible to demonstrate small feeding vessels. MR angiograms were also helpful for further defining the nidus. The combination of MR angiographic and spin-echo methods provides information useful for therapeutic planning not provided by either technique alone.

Nosocomial Legionnaires' disease

The first proved outbreak of nosocomial Legionnaires' disease occurred in a psychiatric hospital in Washington D.C. in 1965, but the diagnosis was not established until determination of serum antibodies against Legionella pneumophila by the indirect fluorescent antibody (IFA) test was undertaken, using the bacterial antigen isolated from patients with Legionnaires' disease in the 1976 outbreak in Philadelphia. The second nosocomial outbreak of Legionnaires' disease occurred in three immunocompromised patients who received renal transplantation at the University of Kansas Medical Center and died of extensive lobar pneumonia in 1975. The direct fluorescent antibody (DFA) test revealed L. pneumophila in the lungs of all three patients after the Legionnaires' disease agent was identified. The lack of prospective surveys using sensitive diagnostic procedures by various types has limited our knowledge on the extent of the problem caused by legionella. In fact, nosocomial Legionnaires' disease is a worldwide problem, and control of this disease requires thorough cooperation of physicians, epidemiologists, microbiologists and expert engineers.

MR angiography and dynamic flow evaluation of the portal venous system

We studied the value of MR angiographic techniques in imaging the portal venous system. Projection angiograms were created by postprocessing a series of two-dimensional, flow-compensated gradient-echo images. Flow velocity was determined by a bolus-tracking method with radiofrequency tagging and multiple data readout periods. Each image was acquired during a breath-hold. MR angiography was applied to six normal subjects and four patients with abnormal hemodynamics in the portal venous system. Flow velocity determined by MR was correlated with the results of duplex sonography. The main portal vein and intrahepatic branches were shown in all cases. Portosystemic collaterals were identified in all patients with portal hypertension. In normal subjects, peak flow velocities (17.9 +/- 2.8 cm/sec) on MR correlated well with values determined by duplex sonography (17.5 +/- 2.2 cm/sec) (r = .846, p less than .04). Reversed portal blood flow was shown in two patients. One patient with portal vein thrombosis had no evidence of flow by MR angiography. Our results indicate that MR angiography can provide a three-dimensional display of normal and abnormal vascular anatomy as well as functional information in the portal venous system.

Projection arteriography and venography: initial clinical results with MR

Motion currently limits the applications of magnetic resonance (MR) angiography in certain regions of the body. To overcome this problem, a series of breath-hold, two-dimensional, flow-compensated gradient-echo images were acquired. These images were then processed by means of the maximum intensity projection algorithm to produce projection angiograms. The method was evaluated in 10 healthy subjects and in 12 patients and validated by comparing conventional angiograms, contrast material-enhanced computed tomographic scans, and duplex sonograms with MR projection arteriograms and venograms of the chest, abdomen, and pelvis. The aorta and pulmonary arteries and their branches were demonstrated, as was detailed anatomy of the hepatic and portal venous systems and inferior vena cava. Renal arteries and veins could be studied in both native and transplanted kidneys. The method permits determination of flow direction and differentiation of arteries and veins and is superior to three-dimensional acquisition techniques for imaging slow blood flow. Initial results suggest that the method may have clinical applications for a variety of vascular disorders.

[Correlation of syndrome types in traditional Chinese medicine and insulin release curves in pre-aged and aged diabetics--an analysis of 142 cases]

This paper deals with the correlation between insulin release curves and syndrome types of TCM in 142 cases of diabetes. The syndromes were divided into 3 types: I, Qi-Yin deficiency, 94 cases; II, Yin deficiency with interior heat overabundance, 36 cases; and III, deficiency of both Yin and Yang, 12 cases. The results showed that fasting for 60 min, the postprandial (M +/- SD) of serum insulin were 18.27 +/- 1.10 mu/L and 45.21 +/- 2.82 mu/L in type I 25.47 +/- 1.88 mu/L and 60.53 +/- 0.25 mu/L in Type II; 8.29 +/- 0.93 mu/L and 19.20 +/- 1.67 mu/L in type III respectively. It was obvious that serum insulin level was Type II greater than Type I greater than Type III. But there was no difference between the aged and the pre-aged with diabetes (P greater than 0.05); even though the former was lower than the latter. According to the analysis of insulin release curve types (insulin secretion level and peak time), there were 39 cases (41.5%) of the low secretion type, 7 cases (7.5%) of the high secretion type among the 94 cases of Type I. Of the 36 cases of Type II, there were 7 cases (19.4%) of high secretion, more than that of Type I, and the highest value reached 155-106 mu/L. The 12 cases of Type III are all of the lower secretion type, with the fasting mean value being 47.5 mu/L and 10.93 mu/L and the postprandial highest value 21.69 mu/L and 20.73 mu/L, much lower than those of Types I and II. The results also showed that correlation between insulin secretion level and blood glucose value was significantly negative. The paper also discussed the mechanism of insulin secretion condition of 3 syndrome types according to the theory of TCM.

Intra-articular amphotericin B treatment of Sporothrix schenckii arthritis

Arthritis caused by Sporothrix schenckii may not respond satisfactorily to a full course of intravenous amphotericin B therapy. Left untreated, the fungus continues to be recovered from cultures of joint fluid, and the patient typically has serious joint disability. We have shown in one patient with sporotrichosis of the knee that direct low-dose injections of amphotericin B can be performed safely, resulting in eradication of the fungus. The patient has had continued useful range of motion and weight bearing on the involved knee.

Kinetics of trypsin inhibition by its specific inhibitors

The kinetics of inhibition of trypsin by its specific inhibitors, pancreatic trypsin inhibitor, ovomucoid trypsin inhibitor, and soybean trypsin inhibitor, has been studied by following the hydrolysis of benzoylarginine ethyl ester in the presence of the inhibitor, and the results have been analyzed with the method described previously [Tian & Tsou (1982) Biochemistry 21, 1028]. The results obtained are consistent with the following: (a) The enzyme binds with the pancreatic inhibitor irreversibly to form an inactive complex. (b) The binding with the ovomucoid inhibitor to form the inactive complex is reversible. (c) An intermediate is formed before the relatively stable inactive complex with the soybean inhibitor, and both steps are reversible. The respective microscopic rate constants are determined by suitable plots of the apparent rate constants under different substrate and inhibitor concentrations. The second-order rate constants for the initial binding step thus obtained are in accord with the apparent inactivation rate constants determined by measuring the activity remaining with a stopped-flow apparatus equipped with a multimixing system after the enzyme-inhibitor mixture has been incubated for different time intervals.

Successful treatment of progressive disseminated histoplasmosis with amphotericin B methyl ester

Amphotericin B methyl ester (AME) has been used to treat fungal infections, most often those caused by Coccidioides immitis. We describe the only patient with disseminated histoplasmosis who has been treated with AME. After having had alarming reactions to amphotericin B, the patient was treated and cured with AME without adverse drug effect or later relapse.

Embolization: an adjunctive measure for removal of carotid body tumors

Small carotid body tumors that do not encircle the internal carotid artery are excised with relative ease and minimal risk by the conventional subadventicial approach. Large carotid body tumors frequently encircle the internal and external carotid arteries, and extensive bleeding often complicates the resection, increasing the risk of carotid artery rupture and damage to major cranial nerves. Recent improvements in surgical techniques and selective embolization have lessened the risks of surgical excision, decreased the blood loss, and diminished the time required for resection. Experiences in the resection of carotid tumors with and without embolization are compared. Early resection of carotid body tumors, before involvement of the internal carotid artery and carotid bulb, is advocated.

Inhibition of growth of early passage normal rat liver epithelial cell lines by epidermal growth factor

The proliferation of newly derived or early passage nonparenchymal rat liver epithelial cell lines in serum-containing medium was inhibited consistently by epidermal growth factor (EGF). Inhibition of proliferation by EGF was a dominant effect which could not be overcome by insulin, phorbol ester or substances which raised the intracytoplasmic concentration of cyclic-AMP (cholera toxin and dibutyryl cyclic-AMP). EGF has a heterogeneous effect on colony formation by individual cells of early passage cell lines. Whereas the colony-forming ability of a majority of these cells was inhibited by EGF, a small fraction of the cells resisted this effect and formed colonies in the presence of EGF. Clonal strains of EGF-inhibited and EGF-stimulated cells were isolated. Measurement of 125I-EGF binding capacity of these cell strains revealed no significant differences between the EGF-inhibited and EGF-stimulated cells. In general, EGF-stimulated cell strains demonstrated faster growth rates and higher colony-forming efficiencies than EGF-inhibited strains. EGF-induced growth inhibition however, was an unstable phenotype that might be diminished or lost after multiple passages, especially when cells were allowed to remain confluent for many days between passages. These observations may explain the consistent findings that in late passage, rat liver epithelial cell lines in which the conditions for culture and times of subcultures have not been controlled rigorously, the inhibitory effect of EGF usually is not observed.

Cure of brain abscess caused by Nocardia asteroides resistant to multiple antibiotics

A 29-year-old man with pulmonary infiltrates due to pulmonary alveolar proteinosis had Nocardia asteroides pneumonia and brain abscess. The nocardial infections persisted after therapy with sulfonamides, minocycline, and cefotaxime. Based on the susceptibility studies and serum antibiotic concentrations, he was treated with minocycline, 400 to 600 mg daily, cefotaxime, 12 to 30 gm daily, and probenecid for 15 months. Proteinuria observed near the completion of therapy was transient. Three years after therapy, the infections appear to have been cured.

Transforming growth factors produced by normal and neoplastically transformed rat liver epithelial cells in culture

The secretion of transforming growth factors (TGFs) alpha and beta by normal, chemically transformed, and malignant rat liver epithelial cell lines was investigated. The WB-F344 normal cultured rat liver epithelial cell line does not secrete an epidermal growth factor-like (putatively TGF-alpha) activity, but several clonal cell strains derived from WB-F344 cells which had been treated with N-methyl-N'-nitro-N-nitrosoguanidine, especially those that expressed high levels of gamma-glutamyl transpeptidase, secreted TGF-alpha-like activity into their conditioned media. Cell lines obtained from tumors which were produced by these cell strains varied in their abilities to secrete TGF-alpha, even though they all expressed high levels of gamma-glutamyl transpeptidase activity. When two of the non-TGF-alpha-secreting tumor cell lines were transplanted into isogeneic rats, the tumors that formed contained high levels of TGF-alpha-like activity. Although epidermal growth-factor (hence, TGF-alpha also) inhibited the proliferation of several of these tumor cell lines in monolayer cultures, this growth factor often paradoxically stimulated the anchorage-independent growth of the same cell lines. In contrast to TGF-alpha-like activity, all cell lines/strains released TGF-beta activity into their conditioned media. However, while both normal or chemically transformed cell strains typically produced the inactive form of TGF-beta, the tumor cell lines tended to produce activated TGF-beta de novo. Anchorage-independent growth of cell lines that produced active TGF-beta was either stimulated, inhibited, or unaffected by TGF-beta. Cell lines that were inhibited by TGF-beta concurrently produced TGF-alpha which was usually able to overcome the negative "autocrine" effect of TGF-beta. We conclude that both TGF-alpha and TGF-beta, singly or in combination, are variously involved in the growth of transformed rat liver epithelial cells. TGF-alpha has a predominantly positive autocrine action on the growth of rat liver epithelial tumor cell lines. The "paracrine" effect of TGF-beta may be at least as important as its autocrine effect in the growth of these transformed epithelial cell lines.