Effects of intra-arterial prostaglandin E1 in patients with peripheral arterial occlusive disease

The effects of intraarterially administered prostaglandin E1 (PGE1) on macrocirculatory, microcirculatory and metabolic parameters in patients with peripheral arterial occlusive disease were studied. Nutritive calf muscle blood flow, as determined with the xenon-clearance technique, and muscle tissue oxygen pressure increased markedly in patients with obliterations of the femoral artery. Transcutaneous PO2 as indicator for cutaneous blood flow increased in prestenotic regions dose-dependently whereas there was a clear poststenotic decrease during the infusion period. High lactate/pyruvate ratios in the femoral vein were significantly decreased by PGE1 treatment. PO2 in the femoral vein increased significantly. Thus, PGE1 has some beneficial effects on muscle circulation in these patients.

[Radiologic diagnosis of thoracic outlet syndrome and its vascular complications]

The term "Thoracic Outlet Syndrome" (TOS) applies to all neurological and vascular symptoms caused by compression of the nerves and vessels situated in the outlet (inlet) of the thorax and the costoclavicular area. The clinical and radiological results of 20 patients with acquired and congenital TOS are presented and the relevant literature is reviewed. The different radiological findings of plain chest X-ray, phlebography, intravenous DSA and arteriography are demonstrated with special emphasis on the vascular complications of TOS.

[Oxygen pressure fields in ulcers of the lower leg]

Using a multi-wire surface electrode, oxygen pressure fields were determined in leg ulcers of 11 patients with chronic venous insufficiency (cvi). In three of them, cvi was combined with arterial occlusive disease. The histograms of all patients with very low PO2 values revealed microcirculatory disturbances of the ulcer tissue. The influence of leg position is reflected in the histograms. Patients with cvi showed higher PO2 values when the leg was raised in comparison with when it was in the hanging position. The patients with mixed ulcerations showed a significant increase in tissue PO2 when the leg was in the hanging position, which shows the importance of arterial perfusion pressure. After a compression bandage had been applied to the legs with cvi, the tissue oxygen pressure of the ulcers increased markedly, probably as a result of diminished blood stasis. These results can be explained either by a rarefaction of capillaries in the ulcer tissue or by fibrin diffusion barriers around the capillaries. The changes in the histograms after bandaging are thought to be caused by an improvement in venous circulation.

Reproducibility of carotid artery Doppler frequency measurements

Doppler sonography of 29 extracranial carotid arteries was performed twice within three days or less. Angiography revealed stenoses with from 10 to 95% diameter reduction in 25 internal carotid arteries whereas four vessels were found to be normal. The systolic peak frequency of the internal carotid artery read from the Doppler spectrum (n = 29) could be reproduced very well. This was shown by a linear regression nearest the line of identical values with a coefficient of correlation r = 0.97 (p less than 0.001). Other values derived from the spectral analysis of the Doppler shift signal were not so well reproduced including the peak frequency ratio (systolic peak frequency of the internal carotid artery/systolic peak of the common carotid artery) (n = 22; r = 0.81; p less than 0.001). The mean frequencies read from the zero-crossing detector recordings (n = 20) could not be reproduced as demonstrated by a linear regression far away from the line of identical measurements with a coefficient of correlation r = 0.43 (p less than 0.05).

Doppler frequency spectrum analysis and digital subtraction angiography in carotid artery disease

The aim of the study was to evaluate the diagnostic accuracy of frequency spectrum analysis complementary to direct Doppler sonography in comparison to conventional biplane arteriography and transvenous digital subtraction angiography in internal carotid artery stenosis. In a group consisting of 229 carotid arteries visualized by conventional biplane arteriography, Doppler frequency spectrum analysis had a specificity of 97% and concerning all stenoses and occlusions, a sensitivity of 89%. In a second group consisting of 198 carotid arteries imaged by transvenous digital subtraction angiography, Doppler sonographic examination had a specificity of 65% only, and concerning all categories of stenoses and occlusions a sensitivity of 85%. These differences concerning specificity are not interpreted as false positive diagnoses in Doppler spectrum analysis but are considered to be due to false negative findings of digital subtraction angiography in stenoses of less than 50% vessel diameter reduction.

Influence of contralateral obstructions on Doppler-frequency spectral analysis of ipsilateral stenoses of the carotid arteries

Contralateral obstructions have been suggested to be responsible for inaccuracy in Doppler sonographic diagnosis and estimation of severity of internal carotid artery stenoses. Therefore correlations of the systolic peak frequency of the internal carotid artery (Doppler-Frequency-Spectrum-Analysis) and severity of stenoses found by angiography have been compared in subgroups with (n = 36) and without (n = 48) additional contralateral obstructions. The linear regressions in both subgroups were found to be very similar (Y = 0.0098X - 12.4 and Y = 0.0099X - 14.0), the coefficients of correlation identical (r = 0.83). In 26 patients, the systolic peak frequency of the internal carotid artery did not demonstrate a significant change due to operation of the contralateral vascular lesion; thus indicating that contralateral obstructions do not influence CW-Doppler sonographic findings of an ipsilateral vessel wall lesion concerning diagnostic accuracy and non-invasive estimation of the severity of stenoses.

Effects of different living settings on the performance of mentally retarded individuals

Motivation for adult attention and support, wariness, and expectancy of success over a 2-year period were assessed for 58 mentally retarded individuals residing in either large central institutions, regional centers, or group homes. Males were found to be more responsive to social reinforcement than were females in all living settings. Wariness was found to increase over time in the large central institutions, whereas it decreased in the smaller settings. Individuals with greater preinstitutional social deprivation had a lower expectancy of success. In addition, over the 2-year period, the expectancy of success of individuals from high-deprived backgrounds remained low, whereas it increased for individuals from less socially deprived preinstitutional backgrounds.

[Ergotamine-induced disorders of the peripheral blood circulation--a case report]

Ergotism with severe arterial circulatory disorders, sometimes leading to amputation of the leg, is a severe complication following application of drugs containing ergotamine. Often the diagnosis is made by the typical angiographic findings. The history, clinical course and a new treatment in a very severe case is reported.

Topical nitroglycerin ointment in Raynaud's phenomenon

The purpose of the study was to evaluate the hemodynamics of nitroglycerin ointment in Raynaud's phenomenon. 22 patients (15 women and 7 men aged 25-75 years) suffering from Raynaud's phenomenon were investigated in a double-blind paradigm. Blood flow measurements were performed by venous occlusion plethysmography. Cardiac output was registered by means of impedance cardiography. 800 mg nitroglycerin ointment 2% was applied on one hand only. In the placebo group, finger blood flow, blood pressure, heart rate, and cardiac output did not change significantly. In the group receiving nitroglycerin, finger blood flow increased significantly from 21.6 +/- 6.0 to 31.7 +/- 7.0 ml/100 ml/min. Systolic blood pressure decreased from 126 +/- 4 to 118 +/- 3 mmHg. Cardiac output significantly decreased from 7.3 +/- 0.8 to 6.3 +/- 0.5 l/min. It is concluded that nitroglycerin ointment in Raynaud's phenomenon has a local and a systemic effect as well, because, on the one hand, cardiac output and blood pressure decreased whereas, on the other hand, the increase in finger blood flow was more marked in the treated hand than in the contralateral control fingers.

Muscle tissue oxygen pressure in patients with arterial occlusive disease

Oxygen pressure histograms were determined with the multiwire surface electrode from the gastrocnemius muscle in patients with arterial occlusive disease and compared with those of healthy volunteers. Seven out of 22 patients had normally distributed histograms like volunteers, but the mean PO2 values were lower than the total mean value of the volunteers. Fifteen patients showed scattered histograms with dominating low PO2 values. Ten out of 11 patients suffering from diabetes mellitus had scattered histograms. When perfusion pressure was impaired by elevating the leg or the musculature was stressed in 7 patients the histograms' form of all these patients changed significantly. Median PO2 fell in all cases with clinically decompensated occlusive disease. Percutaneous transluminal angioplasty of an occlusion of the superficial femoral artery led to a significant shift of the histogram to higher PO2 values. The scattered histograms of patients suffering from arterial occlusive disease are thought to be caused by an inhomogeneous blood flow probably induced by the closure of arterioles.

Studies of tibial subchondral bone density and its significance

We examined the relationships between the density of the subchondral bone of the proximal end of the tibia and the location and condition of the overlying articular cartilage and menisci. We took coronal sections of the tibial plateaus and of the overlying articular cartilage and menisci from human knee joints that were grossly free of osteoarthritis. The specimens were examined for the presence of cartilage fibrillation using the India-ink technique of Meachim. Bone density was determined using the Quantimet picture-point analyzer. Fibrillation of articular cartilage was observed only in the articular cartilage that was not covered by meniscus and lying mesial to it, which supports the concept that the meniscus confers a protective effect on the articular cartilage. The density of the bone underlying the meniscus was lower, and was inversely related to the thickness of the meniscus and directly related to the thickness of the articular cartilage. In four knees from which the menisci were absent, the bone density was increased at the periphery. We suggest that there is a trinitarian relationship between the meniscus, cartilage, and subchondral bone, in which structural changes in any one of the three causes secondary pathological adaptive changes in the other two.

Near-UV radiation from the operating microscope and pseudophakic cystoid macular edema

We performed a prospective randomized study of 297 patients to determine the effect of a UV-blocking filter on the operating microscope on the angiographic incidence of cystoid macular edema in patients undergoing extracapsular surgery with implantation of a posterior chamber lens. Patients were randomly allocated preoperatively to two groups undergoing surgery with or without a UV filter in place. Of the 297 patients, 205 had angiograms readable for the presence or absence of cystoid macular edema. The incidence of aphakic cystoid macular edema in patients without the filter was 21% v 17.3% in the group with a filter. This difference was not significant. The presence of a UV-blocking filter on the operating microscope makes no difference in the angiographic incidence of cystoid macular edema or the visual outcome in these cases.

[Heart and skeletal muscle scintigraphy with thallium 201]

The regional uptake of Thallium-201 is correlated with the regional distribution of cardiac output in the myocardium as well as in skeletal muscle. Thallium-201 perfusion scans will detect peripheral occlusive arterial disease (POAD) as well as coronary heart disease (CHD). In a prospective study we examined POAD patients and CHD patients by both myocardial and leg stress scintigraphy. In normals the uptake ratio of both calves was 1.03 +/- 0.05 (mean +/- SD), while in all patients with proven POAD the ratio was higher than 1.2. In 12 of 16 patients with myocardial infarction the high ratio indicated a coincidence of POAD and CAD, confirmed by other techniques in all but one patient. In patients with suspected CHD there was an increased ratio in 8 of 21;6 of these patients also had an abnormal myocardial stress scan, while there were only 4 abnormal scans in the 13 patients with normal leg uptake. In 19 of 26 patients with known POAD the myocardial stress scan was abnormal, indicating CHD in 75% of this group. This was confirmed in most patients by coronary angiography. The combination of myocardial and leg stress scan can be carried out without further radiation exposure to the patient and in a few minutes. It is a new approach to determine the possible coincidence between POAD and CHD; it should be performed in all patients referred for TI-201 myocardial stress scintigraphy.

[Incidence of peptic ulcer in an inpatient angiologic patient sample]

Incidence of peptic ulcers in hospitalized patients with arterial occlusive disease without history or clinical symptoms of ulcer disease was 32% and four times higher than in patients with acute phlebothrombosis. Possible etiological factors could be: decreased blood perfusion of gastric or duodenal mucosa because of generalized arteriosclerosis, intake of ulcerogenic drugs, chronic abuse of nicotine, and stress due to the underlying arterial occlusive disease. Patients with inflammatory vascular disease are affected as often as are patients with arteriosclerotic disease. Routine endoscopic examination of the upper GI-tract should be performed in such patients in order to exclude potential bleeding sources before treatment with fibrinogen lowering drugs is started.

[Doppler frequency spectrum analysis of extracranial carotid artery lesions]

Signals registered from the extracranial carotid artery by direct Doppler-ultrasound with a MHz transducer were subjected to real-time frequency spectrum analysis. A systolic maximal frequency over 3500 Hz was considered abnormal, together with a broadened spectrum. The study was made on 157 subsequently operated carotid arteries, not all of which had previous angiographic studies. Of 47 with a normal angiogram 45 were correctly classified non-invasively (specificity 96%). The non-invasive diagnosis was correct in 16 of 17 occlusions of the internal carotid artery demonstrated angiographically. An abnormal Doppler frequency analysis was present in only 7 of 14 stenoses with a decreased vessel lumen below 25%. An abnormal Doppler frequency analysis was present in 78 of 79 stenoses with more than 25% reduction in lumen diameter, diagnostic sensitivity for all stenoses being 91%.

Endemic Lassa fever in Liberia. I. Clinical and epidemiological aspects at Curran Lutheran Hospital, Zorzor, Liberia

In a study to assess the epidemiological and clinical aspects of endemic Lassa fever (LF) in Liberia at Curran Lutheran Hospital (CLH), 44 cases were diagnosed by virological and serological techniques over a 22-month period. During one calendar month, testing of febrile patients admitted to the medical-surgical ward revealed six cases of LF, 13% of all febrile cases and 17% of those who were tested. As the study progressed the diagnostic skills of the hospital staff improved. The most common mistake was the diagnosis of a case of LF as pneumonia; the most potentially serious diagnostic problem was differentiating LF from typhoid fever, a readily treatable infection. LF may also mimic other diseases such as aseptic meningitis, pelvic inflammatory disease, gastroenteritis or arbovirus infection. We found a previously unreported symptom of LF, rib tenderness typical of costochondritis. The mortality rate in the medical-surgical ward was 5.4%; the over-all case-fatality rate was 13.6%. Women outnumbered men by nearly three to one, and had a higher mortality particularly noted in the pregnant. LF is common at CLH, and as many as 100 cases may occur annually at this hospital.

[Percutaneous transluminal angioplasty of the lower extremities in the elderly]

Results of percutaneous transluminal angioplasty (PTA) for peripheral arterial occlusion were compared between a group of 41 patients aged over 60 years and one of 39 patients under 60 years. In the older patients the proportion of those in a decompensated state was 61%, more than double that in the younger ones. 54% of the older patients were diabetics with a poor peripheral vascular outflow bed; conservative treatment failed in them and surgical intervention was not possible. A primary success rate of PTA was 87% in the older patients, no worse than in the younger ones. Long-term follow up of both groups indicated that PTA in the compensated stage achieved prolongation of pain-free walking distance or absence of symptoms in 74%. Threatened leg amputation could be avoided in 80% of the younger and 60% of the older patients. Limited amputation was performed in 20% of the older patients with decompensated vascular disorders. The most frequent complication of PTA was embolization into the small vessels of the lower leg, in nearly 30% of patients. But only once did this worsen the clinical state, and this was transitory.

Effect of treadmill exercise on blood gases and acid-base balance in patients with intermittent claudication

Blood gases and lactate and pyruvate concentration were measured in arterial and popliteal venous blood in 6 control subjects and 34 patients with intermittent claudication before, during, and after treadmill exercise of 10 min duration. Oxygen saturation, oxygen extraction, base excess, and standard bicarbonate were calculated. The transition from resting supine position to upright position on the treadmill caused the popliteal venous oxygen saturation to fall from 49.4% to 26.3%. In patients, during exercise a further decrease (to 11%) was observed. During treadmill exercise the popliteal venous PO2 did not fall below 16.5 +/- 1.1 mm Hg in the controls. Individual values during exercise varied between 6.4 mm Hg and 17.9 mm Hg in patients. A critical oxygen pressure was reached in 10 patients. Lactate concentration was found to increase to values as high as 14 mmol/l in popliteal venous blood. The lactate-pyruvate ratio varied between 12.9 and 106.3 during exercise, and the corresponding values for venous blood pH were 7.38 and 6.92. Changes in the PCO2, lactate, and pH in arterial and popliteal venous blood showed a significant correlation. The decrease in the base excess was greater than the corresponding increase in the blood lactate concentration. It is concluded that analysis of the acid-base balance in patients with intermittent claudication is best carried out by the regional catheterization technique.

Effects of ethanol on cultured human fibroblasts

The effects of ethanol on cellular functions of growth and low density lipoprotein uptake were studied with cultured human fibroblasts, WI-38. Cells were grown in basal medium for 24 hr, then incubated in medium containing 0, 100, or 500 mM ethanol for various times. Growth in 100 mM ethanol had little effect, but growth in 500 mM ethanol for 24 or more hours significantly decreased the number of cells per dish and increased the protein, but not the DNA, content, per cell. Exposure to 500 mM ethanol had little effect on protein synthesis but significantly depressed DNA synthesis. It was also evident from microscopy that fewer but larger cells were present. There appeared to be no consistent acute effects of 500 mM ethanol on the uptake of lipoproteins by confluent monolayers of cells. After chronic exposure, uptake was comparable to that of 0 or 100 mM ethanol when expressed as nanogram of lipoprotein/mg of cell protein but higher when expressed as picograms/cell. The results suggest that 500 mM ethanol decreased the rate of cell division but resulted in enlargement of cells.

Women's preferences for gynecological examiners: sex versus role

Preferences for gynecological examiners are studied in a cervical cancer screening program. Sex appears to be a more important factor in preference than the professional level of the examiner. Female health professionals were preferred by a majority of patients; the distinction between physicians and nurse practitioners was a much less important factor. Female examiners were particularly important to low-income and Mexican-American participants, and to women who were reluctant to participate in screening programs.

Lactate and pyruvate changes during treadmill exercise in patients with intermittent claudication

Exercise and post-exercise metabolism was studied in the legs of 6 healthy individuals without arterial occlusive disease and in 34 patients with intermittent claudication. Venous blood from the popliteal vein was taken intermittently by regional catheterization during and after an exhaustive constant load exercise on a treadmill. Change of lactate and pyruvate was studied in arterial and popliteal venous blood. The mean arterial concentration of pyruvate during exercise was increased less in patients and controls as compared to the lactate concentration in both groups. There was a continuous rise of the arterial pyruvate concentration after exercise in patients in contrast to the controls. During exercise, the difference between the arterio-popliteal venous blood samples in lactate concentrations was significantly higher in patients than in the controls. In general, patients had a significantly higher lactatepyruvate ratio in the popliteal venous blood than in the arterial blood. It is concluded that the onset and degree of anaerobic work is best studied by the regional catheterization technique. This new technique permits to study the spontaneous and reactive metabolic changes in the legs during and after treadmill exercise in patients with intermittent claudication.

[Carotid auscultation and Doppler sonography of the A. supratrochlearis in cerebral ischemias]

72 patients (117 angiographies ) suffering from transient ischemic attacks or prolonged reversible ischemic neurological deficits have been examined to study the diagnostic accuracy of the Doppler-sonography of the supratrochlear artery and of neck bruits. The specificity and sensitivity of the Doppler examination were 91 and 81%. The specificity and sensitivity of carotid bruits were 80 and 60%. The sensitivity increased to 94% when either a neck bruit or a pathological Doppler-test were interpreted to be indicative of carotid occlusive disease.

The distribution of a specific HLA-B27-associated cell surface component on the tissues of patients with ankylosing spondylitis

In this paper, we report the presence on Epstein-Barr virus-transformed lymphoblastoid cell lines on platelets and on fibroblasts of an HLA-B27-associated cell surface complex (antigenically related to some antigens of Klebsiella K43 and K21) which is identical to or cross-reactive with the determinant present on the peripheral blood lymphocytes (PBL) of B27-positive patients with ankylosing spondylitis (AS). By contrast, no Klebsiella K43 markers could be demonstrated on the spermatozoa of B27+ AS+ individuals even though these cells expressed the HLA-B27 alloantigen. No B27-associated K43 antigen was detected on the erythrocytes of patients or of normal controls. The B27-associated membrane marker is still detectable on lymphoblastoid cell lines after 20 generations and on fibroblasts after about 10 generations. This finding implies that the continued expression of Klebsiella-modified B27 structure is generally determined and does not require the repeated exposure of the cell surface to Klebsiella antigen. These data suggest that certain non-lymphoid as well as lymphoid cells may be involved in the complex sequence of events leading to the clinical manifestation of AS.

Application of marketing principles to improve participation in public health program

The application of marketing principles to develop a program aimed at increasing participation in a cervical screening program appears to be more effective than the use of sales techniques. Standard methods of promotion such as posters, direct mail, and flyers were generally ineffective. Direct personal contact produced the majority of program participants, and mass media approaches also resulted in significant participant response. A consumer orientation led to development of effective program features designed to satisfy specific consumer needs. Use of female health practitioners, for example, reduced cultural barriers to participation and insured adequate screening in Mexican-American populations.

Search for Klebsiella cell wall components cross-reactive with lymphocytes of B27+ AS+ individuals

It has been suggested that some Klebsiella sp may cross-react with a cell surface determinant on the lymphocytes of B27+AS+ individuals. Studies were undertaken to identify culture filtrates capable of rendering the lymphocytes of B27-positive healthy controls susceptible to lysis by the anti-Klebsiella antiserum. Polyacrylamide gel electrophoresis of cell wall material of Klebsiella K43 prepared by sonication, high-speed centrifugation, and nonidet solubilization, demonstrated the presence of four major protein bands. When antisera raised in rabbits to each of these were tested for their cytotoxic effect on the lymphocytes of B27+AS+ individuals, an antiserum to one component only, of 40-52 K daltons molecular weight, reproduced the activity of the whole serum. Studies on the K43 filtrate indicated that the 'modifying' factor appeared to reside in a 25-50 K dalton component. Immunoelectrophoresis against anti-K43 serum demonstrated overlapping bands in the culture filtrate and the 40-52 K dalton cell wall fraction and these appeared to be identical on immunodiffusion. Antibody to the cell wall component removed both the 'modifying' activity and the appropriate protein band from the filtrate. The results suggest that a 40-52 K dalton component of the Klebsiella K43 cell wall is cross-reactive with a determinant on the lymphocytes of B27+AS+ individuals and is similar to or identical with a modifying factor in K43 culture filtrate which renders the lymphocytes of B27-positive healthy controls susceptible to lysis by anti-Klebsiella antiserum.

Local cerebral blood flow following transient cerebral ischemia. I. Onset of impaired reperfusion within the first hour following global ischemia

Using the hydrogen clearance technique, local cerebral blood flow (LCBF) in 22 dogs was estimated at 6 parietal sites prior to and following 5 min of total global ischemia. Ischemia was immediately followed by an initial reactive hyperemia during which the electrocorticogram (ECoG) usually began to recover, and within the first 30 min, most of the LCBF's decreased to subnormal values. This onset of hypoperfusion was accompanied by a concomitant decrease in ECoG activity. Two animals that maintained normal local perfusion after the initial hyperemia recovered ECoG activity quickly. These results suggest that the subsequent poor reperfusion was caused by an increased microvascular resistance rather than by blood aggregates, increased blood viscosity, or a variety of other mechanism which have been proposed. Increased vascular tonus was, at least, partly responsible for the increased vascular resistance. This report supports the hypothesis that impaired reperfusion (which occurs some time after an initial hyperemia) may be responsible for ultimate neuronal death, rather than the period of global ischemic hypoxia per se.

Local cerebral blood flow following transient cerebral ischemia. II. Effect of arterial PCO2 on reperfusion following global ischemia

Following 5 minutes of global ischemia, local cerebral blood flow (LCBF) was shown to have an initial reactive hyperemia that was followed, within the first hour, by persistent hypoperfusion (Part I). Intracranial pressure (ICP) was never elevated during the period of poor reperfusion. These experiments attempted to reverse the state of subnormal LCBF by inducing hypercarbia or hyocarbia or maintaining normocarbia. Although hypocarbia did increase LCBF at several electrode sites, neither the intracerebral steal syndrome nor the "squeeze" syndrome are a dominant consequence of hypercarbia in this model of global ischemia. Hypercarbia was consistently more effective in elevating LCBFs and in recovery of the electrocorticogram. It appears that, in the absence of raised ICP, hypercarbia may be preferred to normal or low PACO2,. Even though hypercarbia was superior to normocarbia or hypocarbia, hypercarbia was not a completely satisfactory regimen for reversing the state of poor reperfusion.

Characterization of a factor(s) present in Klebsiella culture filtrates that specifically modifies an HLA-B27-associated cell-surface component

It has been shown that HLA-B27 lymphocytes from healthy individuals (B27+ ankylosing spondylitis [AS]-), which are not lysed by an antiserum against Klebsiella K43, can be rendered susceptible to lysis after incubation in the culture filtrate of Klebsiella K43. This finding is compatible with a specific modification by a Klebsiella K43-derived soluble factor of a B27-associated lymphoid cell component. Preliminary characterization of the factor has indicated that it is nondialyzable, but it is heat labile at 56 degrees C for 30 min and has a 35,000-50,000 mol wt. The modifying factor activity of the filtrate is destroyed by neuraminidase but not by trypsin and alpha-chymotrypsin. Furthermore, the ability of the factor to convert B27+AS- lymphocytes can be specifically absorbed by B27+AS- lymphocytes, but not by B27+AS+, B27-AS+, or by B27-AS- lymphocytes, which suggests that B27+AS- cells carry a hypothetical receptor which can specifically bind a Klebsiella K43 antigenic determinant. These results imply that the modification by environmental agents of specific major histocompatibility complex-associated gene products may be an important element in the pathogenesis of the HLA-B27-linked seronegative arthropathies.

[Evaluation of neck bruits by directional Doppler sonography (author's transl)]

Neck bruits were noticed 86 times in 60 patients. A hemodynamic obstruction of the carotid artery was diagnosed in 22% by Doppler sonography of the supratrochlear artery. The diagnostic directions in case of neck bruits are suggested: 1. In patients with a history of neurological symptoms a pathological Doppler test will be the indication for cerebral angiography. If obstruction of the carotid artery is suspected by clinical examination cerebral angiography should be done in spite of a normal directional Doppler sonography. 2. Cerebral angiography must be done in patients with asymptomatic neck bruits and a pathological Doppler sonography if the patient will undergo a great operation.

Alternative hydroxylases for the aerobic and anaerobic biosynthesis of ubiquinone in Escherichia coli

The synthesis of ubiquinone under anaerobic conditions was examined in a variety of strains of Escherichia coli K12. All were shown to synthesize appreciable quantities of ubiquinone 8 when grown anaerobically on glycerol in the presence of fumarate. Under these conditions, ubiquinone 8 was in most cases the principal quinone formed, and levels in the range 50--70% of those obtained aerobically were observed. Studies with mutants blocked in the various reactions of the aerobic pathway for ubiquinone 8 synthesis established that under anaerobic conditions three alternative hydroxylation reactions not involving molecular oxygen are used to derive the C-4, -5, and -6 oxygens of ubiquinone 8. Thus, mutants blocked in either of the three hydroxylation reactions of the aerobic pathway (ubiB, ubiH, or ubiF) are each able to synthesize ubiquinone 8 anaerobically, whereas mutants lacking the octaprenyltransferase (ubiA), carboxy-lyase (ubiD), or methyltransferases (ubiE or ubiG) of the aerobic pathway remain blocked anaerobically. The demonstration that E. coli possesses a special mechanism for the anaerobic biosynthesis of ubiquinone suggests that this quinone may play an important role in anaerobic metabolism.

Three hydroxylations incorporating molecular oxygen in the aerobic biosynthesis of ubiquinone in Escherichia coli

The biosynthetic origin of the oxygen atoms of ubiquinone 8 from aerobically grown Escherichia coli was studied by 18O labeling. An apparatus was developed which allowed the growth of cells under a defined atmosphere. Mass spectral analysis of ubiquinone 8 from cells grown under highly enriched 18O2 showed that three oxygen atoms of the quinone are derived from molecular oxygen. It was established that the molecular oxygen is incorporated into the two methoxyl groups (at C-5 and C-6) and one of the carbonyl positions of the ubiquinone molecule by demonstrating that only one of the incorporated oxygens will exchange with water under acidic conditions that specifically catalyze the exchange of carbonyl, but not methoxyl, oxygens. That the C-4 carbonyl oxygen is derived from molecular oxygen was shown by the incorporation of three atoms of 18O2 into ubiquinone 8 biosynthesized from added 4-hydroxybenzoic acid. Comparison of ubiquinone 8 and menaquinone 8 from E. coli grown under 18O2 confirmed that the labeled carbonyl oxygen of the [18O2]ubiquinone 8 is incorporated biosynthetically and not by chemical exchange in the cell. It is concluded that the three hydroxylation reactions involved in the pathway for the aerobic biosynthesis of ubiquinone are all catalyzed by monooxygenases. The implications of this study for the anaerobic biosynthesis of ubiquinone 8 in E coli are discussed.

Chemical and enzymic studies on the characterization of intermediates during the removal of the 14alpha-methyl group in cholesterol biosynthesis. The use of 32-functionalized lanostane derivatives

By using cell-free preparations of rat liver it was shown that the removal of the 14alpha-methyl group (C-32) of steroids containing either a delta7(8) or a delta8(9) double bond is attended exclusively by the formation of the corresponding 7,14- and 8,14-dienes respectively (structures of types III and VIII). Cumulative evidence from a variety of experimental approaches had led to the deduction that delta8(14)-steroids are not involved as intermediates on the major pathway of cholesterol biosynthesis. The metabolism of [32-3H]lanost-7-ene-3beta,32-diol (structure of type I) results in the formation of radioactive formic acid, no labelled formaldehyde being formed. By using appropriately labelled species of the compound (I) it was found that the release of formic acid and the formation of 4,4-dimethylcholesta-7,14-dien-3beta-ol (strurcture of type III) were closely linked processes, and that in the conversion of compound (I) into compound (III), 3-beta-hydroxylanost-7-en-32-al (II) is an obligatory intermediate. Both the conversion of lanost-7-ene-3beta,32-diol (I) into 3beta-hydroxylanost-7-en-32-al (II) and the further metabolism of the latter (II) to 4,4-dimethylcholesta-7,14-dien-3beta-ol (III) exhibited a requirement for NADPH and O2. This suggests that the oxidation of the 32-hydroxy group of compound (I) to the aldehyde group of compound (II) does not occur by the conventional alcohol dehydrogenase type of reaction, but may proceed by a novel mechanism involving the intermediacy of a gem-diol. A detailed overall pathway for the 14alpha-demethylation in cholesterol biosynthesis is considered, and proposals about the mechanism of individual steps in the pathway are made.