Applicability of laser to assist coronary balloon angioplasty

Severe atherosclerotic obstructed coronary artery disease (CAD) may preclude passage of a balloon catheter for transluminal coronary angioplasty (TCA). Since lasers have been shown to effectively vaporize CAD plaque, the initial application of laser to effect a lumen large enough to accommodate the angioplasty catheter for further dilatation was explored. Eleven postmortem human CAD segments which did not permit passage of a 1.33 mm shaft diameter angioplasty catheter were studied. Argon laser radiation (14 to 90 J) transmitted via 400 micron core diameter quartz fiber onto the stenotic channel of 0.58 mm created a vaporized lumen of 1.77 mm (mean increase of 1.31 +/- 0.25 mm, p less than 0.001). The laser procedure allowed the balloon angioplasty catheter to be pushed into the stenosis. TCA was then performed (7 atm, 45 seconds) and expanded the channel to 2.12 mm (additional mean increase of 0.38 +/- 0.07 mm, p less than 0.001). In terms of percent luminal narrowing, laser radiation reduced obstruction from 80% to 45% (mean difference of -38.7 +/- 4.6%, p less than 0.001), and TCA caused a further decrease to 37% (mean difference of -9.3 +/- 1.9%, p less than 0.001). Thus, in tight atherosclerotic lesions, the laser may be useful in creating an initial opening enabling the placement of the balloon angioplasty catheter which, in turn, can further dilate the lased stenotic coronary lumen.

Portal versus systemic venous drainage for small-bowel allografts

The effect of portal venous drainage (PV-D) on the survival of accessory small-bowel allografts was studied in a rat model. In the LBN-F1----LEW combination (rejection reaction only), grafts with caval venous drainage (CV-D) were rejected acutely (mean 11.8 days) and those with PV-D were rejected chronically (mean, 22.8 days). In the LEW----LBN-F1 combination, the survival of recipients subject perforce to a fatal graft-versus-host reaction was not influenced by the type of venous drainage used (CV-D: 14.1 days; PV-D: 14.8 days). These findings suggest that the delaying influence of the liver on the rejection process is not due to unspecific filtration of antigens but must involve their specific recognition or alteration. In the BN----LEW combination, in which rejection and the graft-versus-host reaction occur simultaneously, the type of venous drainage used did not influence graft survival (CV-D: 16.2 days; PV-D: 15.5 days), nor did it modify the rejection process. This indicates that the liver has a minor effect on the rejection process, sufficient to inhibit the rejection of semiallogeneic LBN-F1 grafts but insufficient to alter the rejection of allogeneic BN grafts by LEW recipients. With CV-D, LBN-F1 grafts were rejected as rapidly as were BN grafts. This unexpected finding may be explained by the fact that in the LBN-F1----LEW combination only rejection occurs, unimpeded by a graft-versus-host reaction, which is known to impair the immune system of the recipient; in the BN----LEW combination, however, the graft-versus-host reaction temporarily opposes the rejection reaction, thereby allowing prolonged graft survival.

Argon laser radiation of human clots: differential photoabsorption in red cell rich and red cell poor clots

Since argon laser radiation (454-514 nm) can vaporize human clots, we determined whether the absorption of laser energies can differ among different types of blood clots. Thus we performed spectrophotometric studies and examined the ability of this laser to penetrate red cell rich and red cell poor clots. Fifty-four red cell rich and red cell poor clot samples, varying in depth from 1.8 to 5.0 mm, were subjected to 3, 5 and 7 watts from an argon laser beam. At a given power intensity, the deeper the red cell rich clot, the longer was the time needed to penetrate the clot. The higher the power used, the shorter was the red clot penetration time. In contrast, all power levels used up to 5 minutes did not penetrate any of the varying depths of red cell poor clots. Spectrophotometrically, the red cell rich clot had an absorption curve typical of hemoglobin pigment while the red cell poor clot, in the absence of hemoglobin, had poor absorption between 350 and 600 nm and was unable to absorb argon laser energies. Thus, the argon laser provides a therapeutic modality for human red cell rich clot dissolution but the present approach does not appear to be effective against red cell poor clots.

In vitro allograft irradiation prevents graft-versus-host disease in small-bowel transplantation

In small-bowel transplantation, the transfer of large numbers of donor lymphocytes with the intestinal allograft may provoke a lethal graft-versus-host reaction. The effectiveness of allograft irradiation in vitro as a method of preventing graft-versus-host disease (GVHD) was studied in a rat model of small-bowel transplantation, with the Lewis----Lewis X Brown Norway F1 hybrid strain combination. Cold harvested small-bowel allografts were irradiated immediately prior to heterotopic or orthotopic transplantation. Animals that had received heterotopic allografts irradiated with 0, 250, or 500 rad all died of GVHD after 14.4 +/- 3.0, 15.0 +/- 1.3, and 14.2 +/- 1.9 days, respectively. None of the animals that had received allografts treated with 1000 rad developed clinical or pathologic evidence of GVHD, however, and all survived for more than 6 months (P less than 0.001). Allograft function was studied in animals that underwent orthotopic transplantation. Recipients of nonirradiated orthotopic allografts all died of GVHD after 14.0 +/- 0.7 days, whereas recipients of allografts irradiated with 1000 rad all survived for more than 5 months (P less than 0.001). After 120 days, weight gain (51.8 +/- 11.7%), serum albumin (3.9 +/- 0.7 g/dl), serum triglycerides (67.0 +/- 24.3 mg/dl), CBC, and differential in these animals were not statistically different from those in either age-matched isograft recipients or normal animals, and when the rats were sacrificed, irradiated allografts showed no changes suggestive of radiation injury. These results indicate that irradiation of small-bowel allografts in vitro prevents development of GVHD, and that this can be achieved at a dose which does not cause injury to or malfunction of the allograft.

Riboflavin use as a drug marker in Veterans Administration cooperative studies

Most Veterans Administration (VA) cooperative studies have used only the pill count method to measure and describe patient adherence to a drug regimen. The use of a drug marker is considered when adherence is expected to be a problem in a study, especially if the therapeutic drug or metabolite cannot be measured in the blood or urine of all patients or if reliability of pill counts is open to serious question. In a VA-NHLBI hypertension study using riboflavin as a marker for assessing patient adherence, group data suggest that similar adherence scores can be expected when comparing pill counts and urine tests. However, when an individual patient's adherence was examined by each method at a particular visit, discrepancies were noted. In a VA cooperative study on disulfiram for the treatment of alcoholism, riboflavin used as a marker provided additional information that was needed to assess the adherence of the study population. By employing this second measure of adherence in this study, we were able to obtain at least one measure of adherence at 84% of all clinic visits. If the pill count method had been the sole adherence measure, only 60% of visits would have produced an adherence score. At 65% of clinic visits, the pill count and urine test were in agreement. Results of urine tests taken in the interval between visits were similar to those taken at the clinic visit. Patient cooperation in providing urine specimens or in returning pills to the clinic was slightly associated with positive adherence scores.(ABSTRACT TRUNCATED AT 250 WORDS)

Veterans Administration cooperative study of disulfiram in the treatment of alcoholism: study design and methodological considerations

Disulfiram treatment of alcoholism has been difficult to evaluate in controlled studies because the study design must contend with problems unique to this drug. The therapeutic effect may be a result of the patient's fear of the disulfiram-ethanol reaction rather than a direct pharmacological effect on the craving for alcohol. Good outcome may not be directly related to compliance with the drug regimen; a patient may remain abstinent even if he does not take his medication. The Veterans Administration Cooperative Study "Disulfiram in the Treatment of Alcoholism," is a multicenter, randomized, blinded, controlled clinical trial designed to evaluate the efficacy of disulfiram while addressing these issues. Two control groups are used. The members of one control group will not receive disulfiram and will be told they are not receiving disulfiram. The members of the other control group will be given disulfiram and will be told they are receiving disulfiram; however, the dose of their disulfiram will be measured by doing pill counts and obtaining urine specimens at each clinic visit and measuring urinary diethylamine, a metabolite of disulfiram, and riboflavin (a medication marker).

Reduction of ferric leghemoglobin in soybean root nodules

Reduction of ferric leghemoglobin to ferrous leghemoglobin in soybean nodules (Glycine max [L.] Merr. cv Woodworth) was studied using a spectrophotometer equipped with an in-cell space diffuse reflectance accessory. Nodule slices prepared and scanned under nitrogen gas showed a ferrous leghemoglobin absorption spectrum. Nodule slices equilibrated with 100% O(2) or air exhibited two absorption bands characteristic of oxygenated leghemoglobin. The addition of CO shifted those bands to CO leghemoglobin absorption bands. Potassium ferricyanide was not effective in oxidizing ferrous to ferric leghemoglobin in nodule slices. However, ferric leghemoglobin was formed by treating the nodule slices with hydroxylamine, and this was confirmed by complexing the ferric leghemoglobin to acetate, fluoride, or nicotinic acid. The diminution of ferric leghemoglobin was monitored as a function of time, and in the presence of nicotinic acid, the conversion of ferric to ferrous leghemoglobin was monitored by the appearance of ferrous leghemoglobin nicotinate complex as a function of time. Ferric leghemoglobin reduction was also confirmed by direct transmission spectrophotometry. The evidence presented here suggests that ferrileghemoglobin reduction occurs in nodule slices.

Diagnostic value of gallium and bone scans in evaluation of extrapulmonary coccidioidal lesions

The value of 67Ga and methylene diphosphonate labeled with 99mTc in detecting extrapulmonary lesions was evaluated in 12 patients win whom disseminated nonmeningeal coccidioidomycosis developed after a single epidemic exposure in December 1977. Studies were performed with each radionuclide from 4 to 9 months after infection. Comparison of scintigraphy with radiography showed that eight of 14 osteolytic lesions identified by radiography were present on the bone and gallium scans; four were present only on the gallium scan, and two were undetected. Of 15 additional lesions present in both scanning procedures, eight were not present in matching roentgenograms and seven were in unstudied areas. Gallium scans detected seven of 14 soft tissue lesions. Few diagnostically confusing noninfectious lesions were observed. Because nuclear scanning detected almost all lesions present in radiographs and demonstrated otherwise unrecognized lesions, scans should be performed in all patients in whom coccidioidal dissemination is suspected.

Autopsy study of small cardiac scars in Japanese men who lived in Hiroshima, Japan and Honolulu, Hawaii

Japanese men long resident in Honolulu, Hawaii have significantly more ischemic heart disease but significantly fewer small cardiac scars than men in Hiroshima, Japan. These scars occur in three forms:(1)small scars in the mural myocardium which account for the difference in frequency of small lesions in the two cities and are of uncertain etiology; (2)areas of diffuse fibrosis in the papillary muscles. These are equally frequent in the two cities and are associated with advancing age and sclerosis of papillary muscle arteries; and(3)focal scars in the papillary muscles. These are more frequent in Honolulu than Hiroshima. They are healed infarcts due to ischemic heart disease and are associated with a severe degree of extramural coronary artery atherosclerosis. Small mural myocardial scars, when present, are usually found in multiple sites. Their increased frequency in Hiroshima is not explained by differences in age or heart weight. They are more common in the presence of sclerosis of intramural small arteries, but this association also fails to explain the intercity difference. It is supected that the excess of these small cardiac scars in Hiroshima males reflects past privation. There is no evidence that is is related to A-bomb radiation exposure.

In vitro susceptibilities of Naegleria fowleri strain HB-1 to selected antimicrobial agents, singly and in combination

The overall prognosis of primary amoebic meningoencephalitis remains poor. The results of this study support previous finding that amphotericin B is the most efficacious drug against the Naegleria species in in vitro testing. In addition, the methyl ester of amphotericin B, a new derivative, also appears to be an effective agent. Of the drug combinations studied, amphotericin B plus minocycline and amphotericin B plus tetracycline showed synergy. The clinical significance of these findings remains to be determined.

Autopsy study of cerebrovascular disease in Japanese men who lived in Hiroshima, Japan, and Honolulu, Hawaii

Evidence of cerebrovascular disease at autopsy was compared in 2 groups of men: 186 long-time residents of Hiroshima, Japan, and 253 men of Japanese ancestry long resident in Honolulu, Hawaii. They were 45 to 71 years-of-age at death. Atherosclerosis of the circle of Willis and its major branches, sclerosis of the intraparenchymal arteries and the frequency of cerebral hemorrhage and cerebral infarct were compared in the 2 populations. The Honolulu subjects had significantly more atherosclerosis of the circle of Willis, but less intraparenchymal artery sclerosis and less cerebral infarction. Cerebral hemorrhage was equally frequent in the 2 cities. It was concluded that cerebral infarction is more frequent in Japanese men in Hiroshima than Honolulu, and that men of Japanese ancestry in Honolulu are spared an appreciable risk of cerebral infarction through decreased frequency of intraparenchymal arterial sclerosis despite higher levels of atherosclerosis of large intracranial arteries.

Small cardiac lesions. Fibrosis of papillary muscles and focal cardiac myocytolysis

Three types of small cardiac lesions were described and illustrated: (1) focal type of papillary muscle fibrosis, evidently a healed infarct of the papillary muscle present in 13% of autopsies, is a histologically characteristic lesion associated with coronary artery disease and healed myocardial infarction, (2) diffuse type of papillary muscle fibrosis, probably an aging change present in almost half of the autopsies, is associated with sclerosis of the arteries in the papillary muscle, is identifiable histologically, and apparently is not associated with any cardiac abnormality, and (3) focal cardiac myocytolysis, a unique histologic lesion, usually multifocal without predilection for any area of the heart, is associated with ischemic heard disease, death due to cancer complicated by nonbacterial thrombotic endocarditis and microthrombi in small cardiac arteries as well as with other diseases. Differentiation of the 2 types of papillary muscle fibrosis is important in the study of papillary muscle and mitral valve dysfunction. Focal cardiac myocytolysis may contribute to the fatal extension of myocardial infarcts.

Light and electron microscopic studies of megakaryocytes in Korean epidemic hemorrhagic fever

A retrospective study was devised to determine the correlation between myelography and computed tomography (CT) in the recognition of abnormalities of the lumbar intervertebral disk. A group of 106 patients was studied who had had both myelography and CT within a 6 week period. Each examination was interpreted separately by a neuroradiologist who had no access to the patients' clinical findings or the results of any radiologic studies. On comparison of 290 interspace levels, there was agreement in definite abnormalities in 70%. Most discrepancies were due to suspicious findings and inconclusive studies of both kinds. In particular, there was poor correlation between the two examinations in the diagnosis of a slightly bulging disk. The major discrepancy rate was less than 5% overall and less than 1% among patients without prior surgery. On the basis of these findings, a diagnostic algorithm is suggested that would facilitate the workup of a similar group of patients.