Missorting of cathepsin B into the secretory compartment of CI-MPR/IGFII-deficient mice does not induce spontaneous trypsinogen activation but leads to enhanced trypsin activity during experimental pancreatitis--without affecting disease severity

The lysosomal protease cathepsin B is thought to play a crucial role in the intracellular activation cascade of digestive proteases and in the initiation of acute pancreatitis. Although cathepsin B has been shown to be physiologically present in the secretory pathway of pancreatic acinar cells it has been suggested that premature activation of zymogens requires an additional redistribution of cathepsin B into the secretory compartment. Here, we studied the role of cathepsin B targeting during caerulein-induced pancreatitis in mouse mutants lacking the cation-independent mannose 6-phosphate/insulin-like growth factor II receptor (CI-MPR) which normally mediates the trafficking of cathepsin B to lysosomes. Absence of the CI-MPR led to redistribution of cathepsin B to the zymogen granule enriched subcellular fraction and to a substantial formation of large cytoplasmic vacuoles that contained both, trypsinogen and cathepsin B. However, this did not cause premature intracellular trypsin activation in saline-treated control animals lacking the CI-MPR. During caerulein-induced pancreatitis, trypsinogen activation in the pancreas of CI-MPR-deficient animals was about 40% higher than in wild-type animals but serum amylase levels were reduced and lung damage was unchanged. These data suggest that subcellular redistribution of cathepsin B, in itself, induces neither spontaneous trypsinogen activation nor pancreatitis. Furthermore, we clearly show that a marked increase in intracellular trypsinogen activation is not necessarily associated with greater disease severity.

[Carotid stenting with the new slotted tube stent--prospective multicenter study. Essen experiences]]

The indication for therapy of high degree carotid stenoses is discussed controversely in regard to new publications. Only symptomatic carotid stenoses are accepted as indication for operative therapy (arterectomy). The new method of carotid stenting was investigated in several studies and needs to be proved in controlled prospective randomized trials. The use of the self-expanding wall-stent has been established in most working groups; nevertheless some disadvantages should be considered (uncontrolled long segment stenting, covering the origin of ext. carotid artery, insufficient adaptation of struts in carotid communis). After development of a new flexible multicellular balloon-expanding stent (Jo-Carotisstent) with sufficient flexibility and compressibility and different stent lengths, the use of this stent in high degree carotid stenoses was investigated. The aim of this study was to analyze the acute and long-term quantitative stent results (angiography and duplex sonography) and clinical results periinterventionally and during follow-up (0.5-1 year).

METHODS

Selective approach from femoral, 8 Fr.-guiding catheter, canalization of stenosis with coronary guide wire (0.014 inch), primary PTA with coronary balloon.

RESULTS

In 47 of 48 patients with 49 carotid stenoses, successful stent implantation was achieved (97.9%). In 2 patients TIA of short duration (4.2%) and in 1 patient (2.1%) a minor stroke occurred. All stents could be implanted with optimal reference diameter. During follow up after 0.5 year no significant proliferative restenosis was observed. The quantitative analysis showed excellent stent-diameter after 0.5 year with only minimal recoil (< 5%) and no clinical event.

CONCLUSION

Using a new flexible and non-deforming multicellular balloon-expanded stent, selective stenting of high degree carotid artery stenoses can be realized with an excellent procedural success rate and a complication rate comparable with the results of other publicated studies. The results after 0.5 year follow-up seem to be promising.

[Interventions in carotid stenoses: carotid srugery, percutaneous transluminal balloon angioplasty and stent implantation. Indications, results of clinical studies. An overview]

Ischemic stroke is the third most reason of death and the main reason of severe disability in Western countries. The high incidence of stroke, 330 per 100,000 subjects in Germany, illustrates the importance of the disease. Generally, atherosclerotic stenosis of the proximal internal carotid artery is the responsible mechanism. The clinical efficiency of surgically performed endarterectomy has been demonstrated in several large multicenter trials. Proven indications for endarterectomy are symptomatic moderate to high-grade stenoses, rapidly progressive asymptomatic stenoses and asymptomatic patients with lesions revealing greater than sixty percent diameter stenosis under certain clinical conditions. Reduction of the incidence of cerebrovascular events, though, is only possible if a low perioperative complication rate is accomplished. Recommendations of the American Heart Association demand a total periprocedural complication rate less than six percent for symptomatic and less than three percent for asymptomatic stenoses. Implantation of stents in carotid arteries is a promising method which might expand the spectrum of indications toward stenosis morphology unfavorable for surgery and patients with significant comorbidity. Clinical results reveal primary success rates, complication rates, and restenosis rates comparable with those of surgical endarterectomy. Randomized trials, comparing both methods, are necessary and reasonable. Yet results are not available at the moment.

[Carbohydrate-deficient glycoprotein syndrome (CDGS) type Ib. A hereditary metabolic disease and its therapy]

Underlying the carbohydrate-deficient glycoprotein syndrome (CDGS) type 1b is a defect in phosphomannose isomerase (PMI), an enzyme of mannose metabolism. The clinical manifestations include exudative gastroenteropathy, thromboses and hemorrhages. In contrast to other forms of the CDGS syndrome, neurological symptoms are completely lacking. The condition responds to a simple dietetic treatment employing the monosaccharide mannose.

[Calcifying aortic valve stenosis and occult gastrointestinal hemorrhage (Heyde syndrome): description of 2 cases]

The coincidence of aortic valve stenosis and cryptogenic gastrointestinal bleeding usually from angiodysplasia of the cecum and ascending colon has been called Heyde syndrome. The pathophysiologic link between both remains unclear and may be due to subtle changes in plasmatic coagulation. There are some statistic and numerous casuistic reports, and recently the existence of the syndrome has been questioned. We describe two cases of aortic valve stenosis and cryogenic gastrointestinal bleeding in which bleeding subsided after replacement with a bioprosthesis. We give an overview of the current literature.

[IVUS-controlled aorto-ostial directional coronary atherectomy in higher grade stenosis of the central anastomosis of a sequential triple venous bypass]

Following coronary artery bypass grafting repeat ischemia mandatory for reintervention occurs in 2 to 30% of cases, depending mainly on graft age. Selection of a suitable strategy for revascularisation--transcatheter angioplasty or reoperation--depends on various parameters including coronary morphology, left ventricular performance, comorbidity and availability of graft material. Catheter-based interventions on saphenous vein bypass grafts are feasible, but lower primary success rates and a higher incidence of restenosis--compared with native coronary arteries--have to be expected. Repeat coronary artery bypass graft operations are associated with a significantly higher perioperative morbidity and mortality, patency rates are lower and late clinical outcome is worse than in primary surgery. We report on a patient who underwent coronary artery bypass grafting 4 years ago revealing a high grade ostial stenosis in a jump-graft supplying RCA, LAD and Cx sequentially, making reintervention necessary. As a prerequisite serial balloon angioplasty of two native vessels was performed prior to ostial intervention. Intravascular-ultrasound guided directional coronary atherectomy was performed with good primary and long-term result. Our case demonstrates that, if all relevant clinical parameters and different therapeutic options are taken into account, complex transcatheter angioplasty procedures are feasible and associated with a reasonable amount of risk, thus avoiding repeat coronary artery bypass graft operations.

Carbohydrate-deficient glycoprotein syndrome type Ib. Phosphomannose isomerase deficiency and mannose therapy

Phosphomannose isomerase (PMI) deficiency is the cause of a new type of carbohydrate-deficient glycoprotein syndrome (CDGS). The disorder is caused by mutations in the PMI1 gene. The clinical phenotype is characterized by protein-losing enteropathy, while neurological manifestations prevailing in other types of CDGS are absent. Using standard diagnostic procedures, the disorder is indistinguishable from CDGS type Ia (phosphomannomutase deficiency). Daily oral mannose administration is a successful therapy for this new type of CDG syndrome classified as CDGS type Ib.

Direct utilization of mannose for mammalian glycoprotein biosynthesis

Direct utilization of mannose for glycoprotein biosynthesis has not been studied because cellular mannose is assumed to be derived entirely from glucose. However, animal sera contain sufficient mannose to force uptake through glucose-tolerant, mannose-specific transporters. Under physiological conditions this transport system provides 75% of the mannose for protein glycosylation in human hepatoma cells despite a 50- to 100-fold higher concentration of glucose. This suggests that direct use of mannose is more important than conversion from glucose. Consistent with this finding the liver is low in phosphomannose isomerase activity (fructose-6-P<->mannose-6-P), the key enzyme for supplying glucose-derived mannose to the N-glycosylation pathway. [2-3H] Mannose is rapidly absorbed from the intestine of anesthetized rats and cleared from the blood with a t1/2of 30 min. After a 30 min lag, label is incorporated into plasma glycoproteins, and into glycoproteins of all organs during the first hour. Most (87%) of the initial incorporation occurs in the liver, but this decreases as radiolabeled plasma glycoproteins increase. Radiolabel in glycoproteins also increases 2- to 6-fold in other organs between 1-8 h, especially in lung, skeletal muscle, and heart. These organs may take up hepatic-derived radiolabeled plasma glycoproteins. Significantly, the brain, which is not exposed to plasma glycoproteins, shows essentially no increase in radiolabel. These results suggest that mammals use mannose transporters to deliver mannose from blood to the liver and other organs for glycoprotein biosynthesis. Additionally, contrary to expectations, most of the mannose for glycoprotein biosynthesis in cultured hepatoma cells is derived from mannose, not glucose. Extracellular mannose may also make a significant contribution to glycoprotein biosynthesis in the intact organism.

[Systemic Nocardia asteroides infection with endocardial involvement in a patient undergoing immunosuppressive therapy]

HISTORY

A 62 year-old male patient developed malaise, unproductive cough and high temperature (39.5 degrees C) during immunosuppressive therapy with methylprednisolon and cyclosporin A six months after kidney transplantation for glomerulonephritis.

INVESTIGATIONS

Clinical examination revealed an endophthalmitis and chest X ray a left-sided lobar pulmonic infiltration. Computed tomography and magnetic resonance imaging examination performed because of recurrent petit-mal-convulsions demonstrated multiple intracranial infiltrations. Transoesophageal echocardiography revealed floating vegetations up to 8 mm in diameter predominantly attached to the aortic valve. A total of 39 consecutive blood cultures drawn during several days remained sterile. However, Nocardia asteroides (Biovar A1) was isolated from a small cutaneous tumor excised from the right thigh.

TREATMENT AND COURSE

After initiation of a specific antibiotic treatment with imipenem/cilastatin (each 1 g three times daily), and doxycyclin (100 mg twice daily), computed tomography and magnetic resonance imaging showed a reduction in size and number of the intracranial infiltrations. Neurological symptoms were progressive despite maximal anticonvulsant therapy. The patient died 83 days after hospital admission from an epileptic state resistant to therapy.

CONCLUSION

Though nocardiosis is still rare, it should early be included in the differential diagnosis of infections in immunocompromised patients to allow timely diagnosis and therapy.

[Acute myocardial ischemia in spontaneous coronary artery spasm]

AIM OF STUDY

To discover what factors indicate spontaneous coronary artery spasms as a cause of myocardial ischaemia.

PATIENTS AND METHOD

In a retrospective analysis 15 of 1407 consecutive patients who had undergone coronary arteriography (six women and nine men; mean age 47 +/- 11 years) had acute ischaemia due to spontaneous coronary artery spasms. The clinical findings at the time of first investigation and during the follow-up period (mean of 29 [3-65] months) were evaluated.

RESULTS

The most common risk factors were hypercholesterolaemia (> or = 200 mg/dl) in ten patients (66%) and heavy nicotine consumption > or = 20 cigarettes per day) in eight patients (55%). Of the patients with angina at rest nine had reversible ST elevations, six had terminal T negativity in the ECG and an increased incidence of ventricular arrhythmias (n = 6). At time of hospitalization ten patients had acute myocardial ischaemia and five had signs of acute myocardial infarction (maximal creatine kinase concentration: 121-2980 U/l). Acute coronary angiography revealed circumscribed coronary artery constriction, reversible with nitroglycerin, with stenosis of < 70% in five patients and of > or = 70% in six, as well as intermittent vessel occlusion in four patients. Angiography showed smooth coronary artery walls in almost all instances. Angiographic evidence of circumscribed arteriosclerotic lesion with maximally 50% narrowing was present in six patients.

CONCLUSION

Especially in younger, male patients with hypercholesterolaemia and heavy smoking recurrent anginal pectoris at rest, with reversible ECG signs of myocardial ischaemia but without advanced coronary sclerosis, speaks for spontaneous coronary artery spasms as the cause.

Late prosthetic valve endocarditis

Prosthetic valve endocarditis remains an extremely serious complication, with a low but increasing incidence. 'Late' endocarditis, occurring more than 60 days after surgery, is relatively infrequently associated with staphylococci, Gram-negative bacteria and fungi so characteristic of the endocarditis that occurs earlier. A probable source of infection can be found in 25%-80% of patients, the most frequent causes being dental procedures, urological infections and interventions, and indwelling catheters. The most common organisms are S. epidermidis, S. aureus, viridans streptococci and enterococci. The general principles of antibiotic treatment are similar to those for native valve endocarditis, but antibiotic treatment needs to be more prolonged and dosages should be used which result in maximal, nontoxic concentrations. Oral anticoagulants should be stopped and replaced by intravenous heparins. Surgical reintervention is called for if there are large highly mobile vegetations in the mitral position or within 72 h if there are cerebral thrombo-embolic episodes.

[Repeated ingestion with suicidal intent of potentially lethal amounts of thallium]

30 minutes after drinking half a cup of rat poison a 16-year-old girl was admitted to hospital. In addition to various enteric detoxification measures forced dialysis was instituted and, after the urinary thallium level had become known (9 mg/l), haemodialysis was begun and ferric ferrocyanide (Prussian blue) administered (0.5 mg daily for six days). She had no symptoms at any time. After 10 days she was discharged. Five days after discharge she was again admitted, with colic-like abdominal pain, vomiting, paraesthesias of the hands and feet, and in a state of agitation. She had once again ingested rat poison, about one cup. Physical examination revealed little of consequence, except diffuse alopecia. Urinary thallium concentration was 37 mg/l. In the electrocardiogram the P-R interval was shortened to 0.11 s and T waves inverted in leads III and V1. Electronmicroscopy of cardiac and skeletal biopsies revealed lipid droplets, increased sarcoplasm and widening of some of the tubules. Treatment consisted of haemodialysis, forced diuresis (1 l urine/h), administration of ferric ferrocyanide, orthograde intestinal infusions and potassium substitution (serum level: 5 mmol/l). After 28 days the patient was discharged into psychiatric care.

Diagnostic and therapeutic considerations in acute, severe mitral regurgitation: experience in 42 consecutive patients entering the intensive care unit with pulmonary edema

Forty-two consecutive patients received emergency treatment for acute mitral insufficiency causing pulmonary edema between 1984 and 1992. The underlying diagnoses were acute myocardial infarction (n = 21), acute bacterial endocarditis on the native mitral valve (n = 9), prosthetic endocarditis in the mitral position (n = 4), acute failure of a replacement valve (n = 5), blunt chest trauma (n = 1) and chordal rupture in Marfan's syndrome (n = 2). Dysfunction of the subvalvular apparatus was present in 24 patients, verified by transthoracic echocardiography in 18 (75%) and by transoesophageal echocardiography in all patients in whom this technique was used. There were four cases of outflow strut fracture of a Björk-Shiley mitral prosthesis; a reliable diagnosis was made by fluoroscopy in all patients. Bedside hemodynamic monitoring was found to be unreliable both for differential diagnosis and for the quantitative assessment of the degree of mitral insufficiency. The right ventricular filling pressure was normal in 32/39 patients (82%), and the pulmonary artery and pulmonary capillary pressures elevated in 37/39 (95%). Diagnostically important, high pulmonary capillary v-waves were documented in 13 patients (33%). The left ventricular impedance could be influenced with sodium nitroprussid combined in some cases with dobutamin, and the resultant decrease of the peripheral vascular resistance from 1480 +/- 222 to 702 +/- 86 dyn x sec x cm-5 was followed by a proportionate reduction in the transmitral regurgitant fraction. Three patients died prior to the intended emergency surgical intervention. Emergency surgery was completed in 21 patients with an early mortality of 23.8% (n = 5). Ten patients underwent elective surgery within, and another three later than one year from the onset of the acute symptoms with an early mortality of 7.7% (n = 1). Four patients are alive and clinically well with medical treatment alone.

[The local lysis therapy of spontaneous renal artery dissection with arterial thrombosis]

A 33-year-old previously completely healthy man developed severe, at first colicky then persisting, pain in the left flank. The blood pressure was 190/110 mm Hg and he had pain over the left kidney on percussion. There was a mild leucocytosis (10,300/microliters), serum creatinine of 1.5 mg/dl and a rise in lactate dehydrogenase level to 395 U/l, while the urine was unremarkable. The pyelogram demonstrated on the left the upper calyceal system only and this very weakly. Colour Doppler ultrasound showed a massively reduced blood flow in the left renal vein while the artery was not visible. Digital subtraction angiography demonstrated eccentric narrowing of the left renal artery by an intravascular thrombus, providing the diagnosis of spontaneous renal artery dissection with thrombosis. Complete recanalization occurred after local thrombolysis with 500,000 IU urokinase over 7 hours, and subsequent administration of four times 40 mg tissue plasminogen activator over 4 hours. But the scintigram still demonstrated impaired renal function with decrease in clearance to 10% of total. The patient was still symptom-free on re-examination 16 months later, serum creatinine concentration was stable at 1.3 mg/dl and the blood pressure was normal.

Pathomorphological aspects, aetiology and natural history of acquired mitral valve stenosis

Commissural fusion, leaflet thickening and alteration of the subvalvular apparatus are dominant mechanisms causing clinically important mitral stenosis (MS) of rheumatic origin. Calcification and a consequent decrease in leaflet mobility are subsequent features in rheumatic MS and may be the primary mechanisms in MS of degenerative origin. In 1051 consecutive patients with pure or predominant MS requiring surgical intervention, aetiology was rheumatic in 76.9%, infective in 3.3%, degenerative (severe annular and leaflet calcification) in 2.7% and congenital (Lutembacher syndrome) in 1.2%; it was the result of systemic lupus erythematosus (n = 4), carcinoid heart disease (n = 2), endomyocardial fibrosis (n = 2) and rheumatoid arthritis (n = 2) in less than 1%, while in 14.5% of these patients aetiology remained unclassified. The natural history of rheumatic MS is characterized by an asymptomatic latent period, following the initial rheumatic fever (RF). In a prospective study of MS (n = 159) the mean interval between RF and the appearance of symptoms was 16.3 +/- 5.2 years. Twenty-five years after the initial RF 8% of the patients were still asymptomatic, 9% were class II (NYHA), 33% class III and 50% had been operated or were class IV. Progress from mild to severe disability took 9.2 +/- 4.3 years on average. When valve surgery was indicated but refused by the patients, survival with medical treatment was 0.44 +/- 0.06 after 5 years, 0.32 +/- 0.08 after 10 years and 0.19 +/- 0.09 after 15 years.(ABSTRACT TRUNCATED AT 250 WORDS)