[Morphological basis of atherosclerosis]

The lesions of atherosclerosis are initiated as a response to some form of injury to arterial endothelium. Increase in plasma levels of low-density lipoproteins or some components of hyperlipidemic serum may increase the rate of penetration into the artery wall. Monocytes adhere to endothelium, emigrate into the intima and transform into lipid-laden macrophages. The second component of atherogenesis is smooth muscle proliferation in the intima. The proliferating cells originate from cells migrating from the media and from myointimal cells. After adhesion to foci of injury, platelets release platelet-derived growth factor, a potent mitogen for intimal smooth muscle cells. The plaque is increasing, the lumen narrowing. A plaque consisting mainly of yellow, grumous fluid is called an atheroma. The oily content of this plaque is covered by a fibrous cap that is often thin and prone to rupture. An occluding thrombus may result. Lipids and crystalline cholesterol initiate a foreign-body reaction, an inflammatory process. Older lesions are calcified. Examples from the daily work in the mortuary demonstrate the pathogenetic relevance of hypertension, thrombocytes and endothelium.

[Comparison of vaginal and abdominal ultrasound measurements with embryologic growth curves in early pregnancy]

Body lengths and chorionic diameters of 225 early pregnancies with known fertilisation age, measured by transvaginal sonography (TVS), were compared with measuring results of measurements from abdominal ultrasound and of embryological specimen from the literature. The TVS measuring results were made according to the Carnegie classification. It is shown that the growth curve obtained by TVS is very similar to valid embryological growth curves, although the "Greatest Length" (GL) is measured by sonography not the Crown-Rump-Length (CRL). Between the sixth and eighth gestational week, the TVS curve shows strong resemblance to abdomino-sonographical curves. After that period, the TVS results tend to be systematically lower. The earliest TVS measurement of the human embryo in possible in the sixth gestational week, one week earlier than with abdominal ultrasound. There is a good correlation between the development of a structure and its earliest detection by TVS, active movements of the embryo can even be shown earlier than assumed by embryologists (stage 20/ninth week of gestation). Due to terminological reasons, in ultrasound the established term "Crown-Rump-Length" should be replaced by "Greatest Length". In a TVS-examination of an embryo (gestational weeks 4 to 11), morphological criteria must be additional contributions to the determination of maturity and integrity of a pregnancy. The application of the specimen-derived Carnegie classification to TVS measurements seem to be possible, as well as the utilization of TVS results in embryology.

Fibrin-specific lysis of microthrombosis in endotoxemic rats by saruplase

The dissolution by the fibrinolytic agent saruplase of microthrombi due to disseminated intravascular coagulation (DIC) has been studied in anesthetized rats. The intravenous infusion of E. coli lipopolysaccharide (endotoxin) for 4 hours (total dose: 25 mg/kg) induced marked thrombocytopenia and hypofibrinogenemia. DIC-related microthrombosis, detected as increased deposition of 125I-labelled human fibrin, was found in the liver and the kidneys, but not in the lungs, the heart, the mesenterium, the spleen and the M. rectus abdominis of endotoxemic rats. Treatment with 1-20 micrograms/kg.min saruplase, that was infused concomitantly with endotoxin, dose-dependently and significantly reduced endotoxin-induced microthrombosis in the liver and the kidneys by 85 resp. 88%. When saruplase (20 micrograms/kg.min) was administered only during the last two hours of endotoxin infusion, liver microthrombosis was still significantly dissolved by 69%, whereas renal microthrombosis was insignificantly reduced by 34%. The inhibition of endotoxin-induced microthrombosis took place in the same dosage range as the shortening of the euglobulin clot lysis time in normal rats by saruplase as a measure of its fibrinolytic activity. Saruplase did not modify thrombocytopenia and hypofibrinogenemia in endotoxemic rats. Saruplase per se did not affect plasma fibrinogen levels. Thus, in a fibrin-selective dose range saruplase is able to dissolve microthrombosis associated with DIC in endotoxemic rats.

Paraanastomotic aneurysms of the abdominal aorta

PURPOSE

Aneurysm formation after abdominal aortic bypass reconstruction is an infrequent but underestimated complication. Aneurysms may occur after aortic prosthetic reconstruction for both occlusive and aneurysmal disease, may occur early or late, and may be classified as a pseudoaneurysm or true aneurysm.

METHODS

Thirty-one cases in 29 patients treated at a tertiary referral center from 1980 to 1992 were retrospectively reviewed. Iliac and femoral aneurysms were excluded. The indication for initial abdominal aortic grafting had been aneurysmal disease in 19 patient and occlusive disease in 10 patients.

RESULTS

There were 25 pseudoaneurysms and six true aneurysms, the latter followed grafting for aneurysmal disease. The current aneurysm (mean size 7.1 cm) was at the proximal aortic anastomosis in 27 cases and at the distal aortic anastomosis in two cases. Symptoms at presentation included abdominal pain (14), mass (12), claudication (9), back pain (6), and gastrointestinal bleeding (3). Surgical management included interposition tube grafting (16), aortoiliofemoral bypass (9), and graft removal with extraanatomic bypass (3). The overall operative morbidity rate was 73%, and mortality rate was 21%.

CONCLUSIONS

Paraanastomotic aortic aneurysms are being increasingly recognized and are associated with high morbidity and mortality rates. Patients should be periodically studied after aortic grafting with abdominal ultrasonography for early detection of this potentially serious complication. Elective surgical repair is advocated in the effort to minimize morbidity rates.

[Left ventricular arrhythmogenic dysplasia]

The present rare case study of left ventricular dysplasia attempts to improve understanding of the clinical picture of arrhythmogenic right ventricular dysplasia (ARVD), based on additional facts concerning this clinical picture which has been increasingly diagnosed over the last few years in the investigation of sudden death in adolescents.

[Right ventricular dysplasia (right ventricular cardiomyopathy). Clinical aspects, diagnosis and course in 15 patients from the Zurich area]

Fifteen patients (8 men, 7 women) with right ventricular dysplasia (RVS) from the greater Zürich area are described. Two thirds of these patients were younger than 30 years at first manifestation. 12 presented with ventricular tachycardia of left bundle branch block type. Other forms of arrhythmia (supraventricular tachycardia, sinus node dysfunction) or condition disturbances were documented in 9 subjects. 6 patients had additional symptoms of congestive heart failure; in 3 of them this was the only symptom. 12-lead ECG at rest showed precordial T-negativity (1 pacemaker ECG not interpretable) in 14/15 subjects. Signal averaged ECG revealed late potentials as well as spectral turbulence in the Y or Z leads. Echocardiography yielded typical local abnormalities in the whole study cohort and all but 2 patients showed decreased right ventricular ejection fraction and right heart dilatation. Moreover, left ventricular ejection fraction was concomitantly impaired in 6 subjects. 4 of these 6 individuals suffered from further impairment of left ventricular function within a time period of 19 to 47 months. Recurrent ventricular tachycardia was documented in 11 patients. 2 subjects underwent heart transplantation because of severe progressive right heart failure. One subject died shortly after diagnosis and autopsy confirmed nearly total absence of right ventricular myocardium. This extreme form of right ventricular dysplasia corresponds to Uhl's anomaly. Thus, recurrent ventricular arrhythmias, in particular ventricular tachycardia of left bundle branch block type, together with precordial T-negativity without signs of ischemic heart disease, is highly suggestive of RVD. Echocardiography allows reliable diagnosis. Concomitant left ventricular involvement is frequent. Considering that the etiology and pathogenesis of this disease are unknown, the term right ventricular cardiomyopathy, rather than right ventricular dysplasia, seems more accurate.

Acute lower extremity ischemia after cardiac surgery

A retrospective review during a 5-year period (1987 to 1992) was conducted of all patients manifesting leg ischemia after major cardiac surgery. There were 7,620 procedures performed, and 65 (0.85%) patients (mean age: 65 years) were identified with acute ischemia. Diagnosis was made by physical examination, during which a cool pulseless extremity without pedal Doppler signals was noted in 63 of 65 patients (97%). An intra-aortic balloon pump (IABP) was inserted in 56 patients (86%). Treatment regimens included medical management (17), IABP removal (4), IABP removal and thromboembolectomy (24), thromboembolectomy and endarterectomy with patch angioplasty (10), femoral-femoral bypass (17), other bypasses (6), fasciotomy (10), and amputation (16). Morbidity was 92% and mortality was 46%. Mortality was 11% in those patients developing ischemia without an IABP. Acute leg ischemia after cardiac surgery is predictive of high morbidity and mortality. This reflects the compromised cardiac status and multi-system disease. Treatment alternatives are based on the overall clinical status, degree of arterial insufficiency, and distribution of pre-existing peripheral vascular disease. However, ultimate limb salvage had no influence on overall patient survival in our study.

Neuronal metabolism of catecholamines: plasma DHPG, DOMA and DOPAC

Pre-synaptic endings of the sympathetic nervous fibers control the metabolism of catecholamines, particularly inactivating norepinephrine after its neuronal recapture. The present study was carried out to investigate this segment of the metabolism of catecholamines through measurements of DHPG, DOMA and DOPAC concentrations in plasma. A sensitive and specific radio-enzymatic assay was developed of which the major characteristic is to include the plasma sample in the incubation mixture without initial extraction of the deaminated metabolites. In the rat, there was a statistically significant correlation between norepinephrine and DHPG in both anesthetized and conscious conditions and after clonidine or guanethidine induced reduction of sympathetic activity; thus it can be suggested that plasma DHPG is a good index of neuronal metabolism of norepinephrine in this animal. In humans, our data indicate an interesting correlation between norepinephrine and DOMA concentrations in plasma in resting conditions and within three hours after clonidine. Further studies need to be carried out to establish whether DOMA is a better index of neuronal metabolism of norepinephrine than DHPG.

[Disseminated toxoplasmosis in AIDS]

Within one year a 46-year-old HIV-positive man developed Pneumocystis carinii pneumonia, candida oesophagitis and recurrent mucocutaneous herpes simplex infections. He finally developed a constant fever without any infection-localizing features. There was pancytopenia, increased activities of the transaminases, lactate dehydrogenase, amylase and lipase, as well as diffuse ST-segment changes in the ECG and discrete pulmonary infiltrates. The anti-toxoplasmosis titre was 8 IU/ml. Despite extensive diagnostic tests no firm diagnosis could be established. The pulmonary infiltrate and the fever regressed under antibiotic treatment with co-trimoxazole. Two months later his general condition deteriorated again with some disorientation and subfebrile temperature, epididymitis and renewed rise in abnormal laboratory values. For the first time computed tomography showed some punctate contrast-medium concentrations in the subcortical area and the medulla. The patient died on the same day. Histological material obtained at the time of autopsy revealed pseudocysts with Toxoplasma gondii and necrotizing inflammation in the brain, myocardium and lungs, as well as the entire gastrointestinal and urogenital tracts. In addition, cytomegalovirus infection of the lung and adrenals was demonstrated. Anti-toxoplasmosis IgG titre, determined postmortem, again registered a marked rise to 251 IU/ml. This suggests that there was reactivation of the toxoplasmosis as part of the immunosuppression process.

The effect of transforming growth factor-beta 2-specific phosphorothioate-anti-sense oligodeoxynucleotides in reversing cellular immunosuppression in malignant glioma

This in vitro study was aimed at restitution of transforming growth factor (TGF)-beta 2-mediated suppression of T-lymphocyte activation within malignant gliomas. In early-passage tumor cell cultures of two glioblastomas (HTZ-153 and HTZ-209) and one malignant astrocytoma classified as World Health Organization Grade III (HTZ-243), autologous peripheral blood mononuclear cells were activated by interleukin-1 alpha and interleukin-2 in vitro (lymphokine-activated killer cells) and tested for cytotoxic and proliferative activity. In expression studies (Western blot and Northern hybridization) of all three tumors, TGF-beta could be detected at the protein and messenger ribonucleic acid (mRNA) levels. A polyclonal anti-TGF-beta neutralizing antibody did not enhance lymphocyte proliferation upon stimulation with tumor targets (3H-thymidine incorporation) and slightly stimulated lymphocyte cytotoxicity against autologous target cells. Preincubation of target cells for 12 hours with TGF-beta 2-specific phosphorothioate-anti-sense oligodeoxynucleotides (S-ODN's) did, however, enhance lymphocyte proliferation up to 2.5-fold and autologous tumor cytotoxicity up to 60%, compared to controls not treated with S-ODN's. Incubation of tumor cells with TGF-beta 2-specific S-ODN's resulted in decreased TGF-beta-specific immunoreactivity in cultured glioma cells, in reduced TGF-beta 2 protein concentration (Western blot), and in a change in the expression pattern of TGF-beta 2 mRNA's. These observations may have implications for in vivo and in vitro activation of a cellular immune response against autologous malignant glioma cells.

Rapid administration of multiple cycles of high-dose myelosuppressive chemotherapy in patients with metastatic breast cancer

PURPOSE

To determine the feasibility and safety of a rapidly cycled sequence of high-dose myelosuppressive chemotherapy courses.

PATIENTS AND METHODS

Seventeen patients with metastatic breast cancer were treated with two courses of cyclophosphamide (CPA; 3.0 g/m2) supported by granulocyte colony-stimulating factor (G-CSF). Following the first CPA treatment, peripheral-blood leukaphereses commenced when the leukocyte count recovered to 1.0 x 10(9)/L. After hematologic recovery from the second dose of CPA, patients were treated with carboplatin 1,500 mg/m2, etoposide 1,200 mg/m2, and CPA 5.0 g/m2 administered over 3 days. The peripheral-blood progenitors (PBPs) were reinfused 3 days later, and G-CSF was recommenced.

RESULTS

All patients received the three courses. The median interval between treatments was 14 days (range, 13 to 21). Sixteen of the 34 courses of CPA resulted in admissions for fever. Following the third course, neutrophil counts recovered to 0.5 x 10(9)/L at a median of 9 days (range, 8 to 18) after PBP reinfusion and platelets recovered to 50 x 10(9)/L at a median of 12 days (range, 9 to 102). There were no treatment-related deaths. Flow-cytometric analysis was performed on the leukapheresis collections of eight patients. Seven patients with at least 2.0 x 10(6) CD34+ CD33- cells per kilogram body weight exhibited prompt hematologic recovery. One patient with 0.03 x 10(6) CD34+ CD33- cells was still cytopenic on day 21, and required reinfusion of her back-up marrow. Among seven patients with measurable or assessable disease, there were two complete responses (CRs) and four partial responses (PRs).

CONCLUSION

These preliminary results suggest that multiple, rapidly cycled courses of high-dose myelosuppressive chemotherapy can be administered. PBPs, harvested during the G-CSF-augmented rebound from CPA-induced cytopenia, produce rapid hematologic recovery in patients undergoing high-dose chemotherapy (HDC). Further follow-up will be necessary to assess the efficacy of this specific regimen in the treatment of metastatic breast cancer.

Clinical application of a noninvasive multi-electrode array EMG for the recording of single motor unit activity

Using a recently developed noninvasive EMG recording technique with multi-electrode arrays we investigated the pattern and distribution of motor unit action potentials (MUAP) following maximal voluntary contraction of the musculus abductor pollicis brevis. An additional parameter, i.e. muscular conduction velocity (CV) in single motor units, was calculated from the multi-electrode array EMG recordings. From 63 healthy children of various age the normal EMG pattern and CV were derived and compared to the EMG of diagnosed patients known to suffer from Duchenne muscular dystrophy and from spinal muscular atrophy. In normal individuals the muscular CV in neonates was lowest at 1-2 m/s and gradually reached a plateau of 2.9-4 m/s from the age of 4 years onwards. The EMG in 31 children with Duchenne muscular dystrophy showed an abnormal pattern with low amplitude action potentials. In 30 out of 31 patients a significantly lower muscular CV was found. In 10 children with spinal muscular atrophy the EMG showed action potentials of abnormally large amplitude and a reduced recruitment of firing motor units. The muscular CV remained within the normal range. Compared to classical needle EMG the application of this new noninvasive EMG technique in children is painless and offers an easy-to-handle diagnostic tool to differentiate between neuromuscular diseases of denervating or of myopathic origin.

Acetylation of phenolic derivatives of 7H-dibenzo[c,g]carbazole: identification and quantitation of major metabolites by rat liver microsomes

Acetylation stabilized the phenolic metabolites of 7H-dibenzo[c,g]carbazole (DBC) and made it possible to accumulate greater amounts of metabolites for comprehensive chemical structural elucidation and quantification without the use of radiolabeled DBC. High-resolution mass spectral data and 1H NMR and fluorescence spectra were used to confirm the existence of 5-OH-DBC, 3-OH-DBC, 1-OH-DBC, and the oxidative dimer, 6,6'-bis-(5-OH-DBC), in the acetylated metabolite mixture formed in vitro by 3-methylcholanthrene-induced rat liver microsomes. Using the synthesized acetoxy-DBC derivatives as standards, the HPLC external standard method was employed for quantitation of the major DBC metabolites after acetylation. The quantities of 5-OH-DBC, 3-OH-DBC, 1-OH-DBC, and DBC in the metabolite mixture determined using the external standard method were found to agree with those calculated using the radiometric method. Acetylation is a promising nonradiometric qualitative and quantitative technique for further metabolism studies of DBC and analogues which produce unstable monohydroxylated metabolites.

[Antibody detection after antepartal rhesus prophylaxis: normal values or sensitization]

Antibody screening tests were performed in 29 unsensitized pregnant women after antepartum Rh immune prophylaxis, using the indirect Coombs test (ICT) and a more sensitive ID-microtyping-system (IDM). With the ICT, anti-D antibodies were detected in 85% for at least 4 weeks and at most 8 weeks after immunisation. The maximum titer was 1:8. With the IDM, 97% showed antibodies against 'D' for at least 4 weeks and at most 11 weeks with a maximum of 1:16. The IDM titer was always 1 to 3 steps more sensitive than the ICT. After postpartum Rh immune prophylaxis, anti-D titers were again positive in many of the patients (ICT: 42%; IDM: 60%). In conclusion, it is nearly always possible to measure antibodies against 'D' after antepartum Rh immune prophylaxis and IDM was superior in comparison to ICT. However, maternal isoimmunisation to the rhesus antigen cannot be excluded for sure and patients have then to be controlled. As isoimmunisation could not be confirmed in any of our patients, postpartum Rh immune prophylaxis has to be administered even after detection of an antibody titer against 'D' after antepartum Rh prophylaxis.

Endocarditis in intravenous drug addicts and HIV infected patients: possibilities and limitations of surgical treatment

The incidence of infective endocarditis in drug addicts is increasing with the spread of intravenous drug abuse. The tricuspid valve is involved most commonly, followed by the mitral. We evaluated 22 patients prospectively with a mean age of 23 years, presenting with addiction-associated endocarditis and referred to our institution during a three-year period. The tricuspid valve was involved in 13 instances, the mitral in four, mitral plus tricuspid valves in five patients and the aortic valve in one. Staphylococcus aureus was the most frequent infective organism (15 cases), followed by streptococci (4 cases), corynebacteria (2 cases) and one case with a mixed infection. Six patients were HIV positive and 17 had evidence of chronic viral hepatitis. Ten patients (three of them HIV positive) were treated surgically. Resection of the tricuspid valve with (one case) or without replacement (four cases), resection of vegetations and tricuspid repair (two cases), mitral valve replacement (2 cases) and aortic valve replacement (one case) were performed. Operative mortality (< 30 days) was high (2/10, 20%); one patient died from cerebral hemorrhage and another from multi-organ failure. Another three patients died after a mean follow up of 10 months. In 12 patients, surgery was not attempted because of still existing intravenous drug abuse or renal and liver failure. Five of these patients died after a mean follow up of 13 months, two from septicemia, two from AIDS-related complications and one from drug overdose. The prognosis of drug-associated endocarditis treated with antibiotics is generally good.(ABSTRACT TRUNCATED AT 250 WORDS)

[Rupture of an aneurysm of the common hepatic artery with pancreatic necrosis]

A male patient known to have hemophilia A was operated on twice (1990, 1991) in the Department of Surgery, University Hospital, Zurich, first because of severe intraabdominal hemorrhage from a liver artery aneurysm, and then because of a ruptured common hepatic artery aneurysm. The second surgical intervention revealed necrosis of the head and body of the pancreas. We consider that the pancreatic necrosis had resulted from the aneurysm, in view of the patient's history of silent pancreatitis and the uncomplicated postoperative course. Immediate reconstruction of the common hepatic artery aneurysm (in the presence of an occluded gastroduodenal artery) was performed with saphenous vein interposition. Because visceral aneurysms may be multiple, further aneurysms must be sought at the time of the first diagnosis. Elective surgery is the method of choice, because 40-80% of visceral aneurysms rupture spontaneously, with a high mortality rate. The mortality rate for elective surgery is now low.

Association of tRNA(Gln) acceptor identity with phosphate-sugar backbone interactions observed in the crystal structure of the Escherichia coli glutaminyl-tRNA synthetase-tRNA(Gln) complex

We isolated several mutants with nucleotide substitutions in alanine tRNA (tRNA(Ala)) that resulted in glutamine tRNA (tRNA(Gln)) acceptor identity in Escherichia coli. These substitutions were in three regions of tRNA structure not previously associated with tRNA(Gln) acceptor identity. Only the phosphate-sugar backbone moieties of these nucleotides interact with the enzyme in the previously determined X-ray crystal structure of the complex between tRNA(Gln) and glutaminyl-tRNA synthetase. We conclude that these sequence-dependent phosphate-sugar backbone interactions contribute to tRNA(Gln) identity, and argue that the interactions help communicate enzyme recognition of the anticodon to the acceptor end of the tRNA and the catalytic center of the enzyme.