Randomised placebo-controlled study of stopping second-line drugs in rheumatoid arthritis

BACKGROUND

A favourable benefit/risk ratio for treatment of rheumatoid arthritis (RA) with second-line drugs has been established only in short-term studies. The present investigation addresses the question of whether RA patients with a good response to long-term treatment with second-line drugs benefit from continuation of such treatment.

METHODS

A 52-week randomised double-blind placebo-controlled multicentre study was conducted to assess the effect of stopping second-line therapy in 285 RA patients with a good long-term therapeutic response. The patients either continued the second-line drug (n = 142) or received a placebo (n = 143). The endpoint was a flare, defined as recurrence of synovitis.

FINDINGS

At entry into the study median duration of second-line drug therapy was 5 years (range 2-33). At 52 weeks the cumulative incidence of a flare was 38% for the placebo group and 22% for the continued therapy group (p = 0.002). The risk of a flare was 2.0 times higher for patients receiving placebo than for those continuing the second-line drug (95% CI 1.27 to 3.17). The same trend was found for each second-line drug separately, with the exception of d-penicillamine. Side-effects that necessitated dose reduction or discontinuation occurred in 2 patients in each group.

INTERPRETATION

Second-line drugs continue to be effective in RA patients who have responded well to initial treatment.

Effects of fast clinostat treatment and microgravity on Vicia faba L. mesophyll cell protoplast ubiquitin pools and actin isoforms

With parabolic rocket flights and fast clinostat treatments, the effect of microgravity on ubiquitin, ubiquitin-protein conjugates, and actin isoforms of Vicia faba mesophyll protoplasts was studied. Western immunoblotting with ubiquitin antibodies revealed that simulated and particularly, real microgravity influenced the amount of free ubiquitin and of 18, 19, and 40 kD ubiquitin conjugates by inducing strong oscillations in the proteins concentrations over time. Simulated microgravity and microgravity-phase during parabolic rocket flights resulted in a decrease of actin isoforms. Results obtained support the assumption, that microgravity and fast clinostat treatment have a direct effect on Vicia faba mesophyll protoplast metabolic activities.

Alpha-hemolytic streptococci: a major pathogen of iatrogenic meningitis following lumbar puncture. Case reports and a review of the literature

Iatrogenic meningitis following lumbar puncture is a rare complication of myelography, spinal anesthesia, intrathecal chemotherapy, and epidural anesthesia. Sporadic cases and clusters of iatrogenic meningitis have been reported after intrathecal therapy, but most incidental cases are reported after myelography. Four cases of iatrogenic meningitis caused by viridans streptococci and a review of the literature are presented here. Observations and a case control study implicated a single anesthesiologist as the source. Probable cause of this cluster is non-observance of infection control measures as to the routine wearing of masks during the procedure. New infection control guidelines were implemented. A review of the literature on iatrogenic meningitis is given. Viridans streptococci have emerged as major pathogens of this complication. These findings underline the need to wear face masks since these bacteria are commensals of the oral cavity.

Interaction of glucagon-like peptide-I (GLP-I) and galanin in insulin (beta TC-1)- and somatostatin (RIN T3)-secreting cells and evidence that both peptides have no receptors on glucagon (INR1G9)-secreting cells

The interaction of glucagon-like peptide-I (GLP-I) and galanin in clonal endocrine pancreatic cells was characterized. By Northern blot analysis the presence of GLP-I receptor mRNA was shown in B (beta TC-1 cells) and D (RIN 1048-38) cells but not in A (INR1 G9) cells, thus confirming functional data demonstrating the absence of active GLP-I receptors on glucagon-producing cells. Galanin receptors were detected on B and D cells but not on A cells. In B and D cells galanin inhibited the GLP-I stimulated adenylate cyclase activity. Treatment of insulin- and somatostatin-producing cells with GLP-I increased intracellular cAMP levels, and this was dampened by galanin, GLP-I stimulated the activity of protein kinase A in B and D cells, which was also inhibited by galanin. Galanin alone did not influence B- and D-cell function. These data show that in the endocrine pancreas B and D cells but not A cells express GLP-I and galanin receptors. The interaction of GLP-I and galanin might act in the endocrine pancreas as a physiological inhibitor of the potent incretin hormone GLP-I. Therefore, we suggest galanin is a 'decretin'.

Temporal location of unsignaled food deliveries: effects on conditioned withdrawal (inhibition) in pigeon signtracking

Standard models of Pavlovian conditioning neglect local effects of unsignaled unconditioned stimuli (USs) on learning and performance. Using the approach-withdrawal behavior of pigeons toward keylights as conditioned stimuli (CSs), the authors varied the specific times (5-110 s) that USs occurred before or after a CS. Withdrawal from a CS generally increased as the time between a US before and/or after the CS was lengthened. Combinations of 2 distant USs produced more withdrawal from the CS than either US alone, whereas combinations of a distant and a nearby US yielded behavior intermediate between that for either US alone. Postacquisition retardation tests supported similar conclusions. Based on the temporal isolation of CSs and USs, a tentative model was offered to summarize these data. The results and the model suggest that a more molecular, possibly perceptual approach to Pavlovian excitation and inhibition is needed.

Selective enhancement of alpha 2-adrenoceptor-mediated vasoconstriction in insulin-dependent diabetic patients with microalbuminuria

1. Microalbuminuria, the earliest clinical marker of microvascular disease, is an important predictor of early death in insulin-dependent diabetes, and abnormal vascular reactivity may contribute to microvascular disease. We have previously found that vasoconstrictive responses to noradrenaline are exaggerated in insulin-dependent diabetic patients with microalbuminuria as compared with both normoalbuminuric insulin-dependent diabetic patients and non-diabetic control subjects. 2. To determine whether this is due to increased sensitivity at alpha 1- or alpha 2-adrenergic receptors, we compared vascular responses to the alpha 1-adrenergic agonist phenylephrine and the alpha 2-adrenergic agonist clonidine. 3. We studied 15 insulin-dependent diabetic patients with microalbuminuria, 15 insulin-dependent diabetic patients with normal urinary albumin excretion and 14 non-diabetic subjects. Vascular constrictive responses were measured in dorsal hand veins. 4. No difference in vasoreactivity to phenylephrine was demonstrated between any of the three groups. However, enhanced vascular responsitivity to clonidine at infusion rates of 16-2048 ng/min (analysis of variance, P < 0.001) was found in insulin-dependent diabetic patients with microalbuminuria as compared with both non-diabetic control subjects and normoalbuminuric insulin-dependent diabetic patients. There were no significant differences between the dose-response curves of the diabetic group with normal urinary albumin excretion and the non-diabetic group. 5. Vasoconstriction mediated by alpha 2-adrenergic receptors is therefore enhanced in normotensive insulin-dependent diabetic patients with microalbuminuria. If also present at the level of the peripheral resistance arterioles or the efferent glomerular arterioles, this could lead to systemic and intraglomerular hypertension, factors which may contribute to the development of diabetic nephropathy.

NMR evaluation of changes in myocardial high energy metabolism produced by repeated short periods of ischemia

Following our previous results which demonstrated that repeated short periods (2 min) of ischemia are capable of protecting the isolated rat heart from a subsequent global ischemia (30 min), in the present study we have concentrated on the metabolic changes occurring in rat hearts during six 2 min ischemia/3 min reperfusion cycles. Cardiac high-energy phosphates were monitored using 31P-NMR. Phosphocreatine levels fell (50-60%) during each ischemic period, and recovered to 70-80% of their initial values during reperfusion. P(i) rose by 59% during the first ischemic period, but increased less during subsequent ischemias (30% during the 6th occlusion, P < 0.05 vs. the first ischemic period) returning to baseline levels after each reperfusion. [ATP], pH, and [Mg2+] remained almost unaffected, but there was a decrease in HPLC-determined effluent ATP catabolites. The first occlusion led to a 95% drop in contractile function (P < 0.001 vs. baseline), but this recovered to 73% upon reperfusion (P < 0.02 vs. baseline), and was 65% at the end of the protocol. Phosphorylation potential (PP = [ATP]/([ADP].[P(i)]) correlated exponentially with total purine (r = 0.90) and with adenosine + inosine release (r = 0.81), and by the 6th ischemia/reperfusion cycle, exceeded that observed in controls by 21% (P < 0.05). We conclude that repeated short periods of ischemia do not lead to any significant alteration in the absolute myocardial ATP, but are associated with an enhanced cytosolic energy state in the heart, that enables the myocardium to reach a steady albeit lower functional state. Adenosine (+inosine) release may be involved in the regulation of the energy supply-demand balance.

Intermittent v continuous ischemia decelerates adenylate breakdown and prevents norepinephrine release in reperfused rabbit heart

Myocardium tolerates intermittent ischemia followed by short reperfusions better than continuous ischemia of the same duration. We attempted to delineate the differential mechanism(s) involved in intermittent v continuous ischemia. Isolated, paced rabbit hearts were perfused at 22 ml/min. Coronary flow was stopped intermittently 12 x for 2 or 4 min, with 3-min reperfusions (total reperfusion period: 36 min). In two other groups, flow was stopped continuously for 24 or 36 min followed by a flat 36-min reperfusion. Following the first intermittent 2-min ischemia, adenosine efflux increased ninefold; in all subsequent ischemia/reperfusion cycles, adenosine and total purine releases were substantially less despite identical heart rates, coronary flows and ischemic periods. The rate-pressure product prior to the intermittent ischemias exhibited exponential correlations with total purine efflux during the 3 min of reperfusion. When intermittent ischemia was extended to 4 min, the initial attenuation of ATP breakdown during the prior 2-min occlusions was overcome, but during subsequent 4-min ischemia/reperfusion cycles, ATP breakdown was again attenuated relative to the first 4-min ischemia. After the prolonged continuous ischemias, purine efflux was up to 6 x higher than with intermittent ischemias of the same total time of zero flow. Lactate release and hence cellular H+ export after intermittent ischemias remained consistently elevated, but following the continuous ischemia of 36 min, release of lactate, and thus H+, was subsequentially decreased. Glycogen mobilization occurred regardless of the ischemia's nature, but it was markedly enhanced during continuous ischemias, where no fall in proglycogen levels occurred. Similarly, myocardial norepinephrine release increased substantially only during the prolonged continuous ischemias. Thus short intermittent ischemia attenuates cardiac adenylate degradation and glycogen mobilization; such ischemic insult also provides for better lactate and H+ washouts immediately upon reperfusion. Another beneficial effect of intermittent ischemia was the near-complete absence of free interstitial norepinephrine, which exacerbates myocardial ischemic insults. In addition, the exponential correlations between preischemic rate-pressure product and postischemic purine release suggest that preischemic energy demand may determine ATP breakdown in ischemic rabbit myocardium.

Serum values of pepsinogens and antibodies to Helicobacter pylori in relation to a history of peptic ulcer disease and NSAID use

The present study was undertaken to investigate whether patients with a history of peptic ulcer disease (PUD) have serological features indicative of the presence of more severe gastritis, compared to patients without a history of PUD. In addition we investigated whether current chronic use of non steroidal anti-inflammatory drugs (NSAIDs) was associated with serological features indicative of a chemical (type C) gastritis. In total 850 consecutive outclinic patients were interviewed by a standard questionnaire with emphasis on demographic data, diagnosis, chronic use of NSAID, and history of PUD. Serum pepsinogen A (PgA) and pepsinogen C (PgC), the PgA:PgC ratio, and IgA and IgG antibodies to H. pylori were measured in all patients. After controlling for age, sex, H. pylori seropositivity, and presence of RA, a correlation was found between a decreased pepsinogen A:C ratio and the use of NSAID. Patients with a history of PUD have serological features indicative of a persistently more severe gastritis. Secondly we found serological evidence for the existence of a chemical (type C) gastritis in NSAID users.

NSAID-associated upper gastrointestinal damage in patients with rheumatoid arthritis

AIM OF THE STUDY

The main aim of the present study was to identify the patient with rheumatoid arthritis (RA) taking non-steroidal anti-inflammatory drugs (NSAIDs) at risk for peptic ulcer disease (PUD) and its life-threatening complications.

PATIENTS AND METHODS

During a retrospective study in which more than 1000 patients were interviewed, current gastrointestinal (GI) complaints were of no use in detecting current PUD.

RESULTS

A history of PUD was an important predictor of current PUD, while the predictive value of serologic parameters, such as serum values of pepsinogen and antibodies to Helicobacter pylori, was disappointingly low. A prospective study in which 81 consecutive RA patients underwent a gastroscopy revealed 16% PUD; again a history of PUD was the most important predictive parameter. Since no study had been undertaken into the effects of a NSAID on intragastric pH we performed such a study, the main conclusion being that indomethacin does not influence the intragastric pH of RA patients. A placebo-controlled study of ranitidine 300 mg b.i.d. for the prevention of recurrent PUD in RA patients on NSAIDs is underway.

Adenosine, added to St Thomas' Hospital cardioplegic solution, improves functional recovery and reduces irreversible myocardial damage

St Thomas' Hospital cardioplegic solution is commonly used to arrest hearts during surgery. Pursuing the hypothesis that the cardioprotective properties of adenosine could be a beneficial adjunct to a solution containing high K+ and Mg2+, we tested a low and a high adenosine concentration added to this cardioplegic solution, aiming at improved recovery of function and energy status. We arrested 18 working rat hearts by a 3-minute infusion with the solution without or with 50 microM or 5 mM adenosine. We induced 30 minute stop-flow ischemia at 37 degrees C, followed by 10 minute washout (Langendorff mode) and 20 minute reperfusion (working heart). Control cardioplegia induced electrical arrest in 19.8 +/- 5.5 s. This took 9.1 +/- 0.9* and 12.7 +/- 1.8 s in the presence of 50 microM and 5 mM adenosine, respectively (*p < 0.05 vs no adenosine). During reperfusion a regular electrocardiogram appeared after 1.9 +/- 0.3 minutes in controls, after 1.0 +/- 0.0* and 1.7 +/- 0.2 minutes in hearts treated with low and high-dose adenosine, respectively (*p < 0.05 vs no adenosine). After 20 minute reperfusion, the pressure-rate product had recovered to 65 +/- 17% in controls, and to 107 +/- 11** and 72 +/- 11% of preischemic values in hearts treated with 50 microM and 5 mM adenosine, respectively (**p < 0.05 vs other groups). There was a good correlation between reperfusion function recovery and the postischemic release of creatine kinase, an index for irreversible cellular damage. This association was absent with ATP content, which increased with the adenosine concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Loss of elastic recoil in postischemic myocardium induces rightward shift of the systolic pressure-volume relationship

Ischemia-induced systolic dysfunction has been ascribed to changes in cellular excitation-contraction coupling and diastolic dysfunction because of disruption of the extracellular collagen matrix. Therefore, systolic and diastolic pressure-volume relationships and O2 consumption were determined before and after 5 min of global ischemia in isolated blood-perfused porcine hearts. The slope of the systolic pressure-volume relationship was 7.2 +/- 0.6 (SE) mmHg.ml-1.100 g-1 (n = 18) at baseline and did not change during reperfusion, but the systolic volume intercept shifted from 1.0 +/- 0.4 ml/100 g at baseline to 3.7 +/- 1.4, 4.1 +/- 1.1, and 4.2 +/- 0.9 ml/100 g at 15, 30, and 60 min of reperfusion, respectively (all P < 0.05). The diastolic volume intercept was 8.2 +/- 0.7 ml/100 g at baseline and remained unchanged during reperfusion. Therefore, the difference of the systolic-diastolic volume intercepts, an index of elastic recoil forces, was decreased to 57 +/- 8, 49 +/- 7, and 47 +/- 9% of baseline values (P < 0.05). The shift of the systolic pressure-volume relationship was accompanied by a transient decrease of contractile efficiency (slope of O2 consumption-pressure-volume-area relationship) at 15 min of reperfusion (from 43 +/- 6 to 27 +/- 7%). We hypothesize that the rightward shift of the systolic pressure-volume relationship was compatible with a decrease of elastic-restoring forces, probably induced by alterations in the extracellular collagen matrix and/or the cytoskeleton, and thereby our data imply that left ventricular dysfunction of postischemic myocardium does not result solely from disturbances in excitation-contraction coupling.

Teratozoospermia and in-vitro fertilization: a randomized prospective study

A prospective randomized study was conducted to assess the prognostic value of sperm morphology in an in-vitro fertilization (IVF) programme, using strict criteria. The first group (T, teratozoospermic) included 32 couples with an isolated teratozoospermia in the male partner (morphology < 9% normal). The second group (C, control) contained 36 couples with normal semen parameters, including morphology (> 9% normal, strict criteria). In both groups, 50 IVF cycles were performed. Patients were matched for indication for IVF. There was no difference between the two groups regarding age, duration of infertility, stimulation protocol, catheter used for embryo transfer and different sperm parameters. A statistically significant difference between the T and C groups respectively was observed regarding the fertilization rate (69.2 and 79.4%, P < 0.05), pregnancy rate per cycle (12.0 and 42%, P < 0.001), the pregnancy rate per transfer (13.9 and 42.0%, P < 0.01) and per embryo transferred (6.1 and 14.8%, P < 0.05). No pregnancy occurred in the poor prognosis group (morphology < 5% normal). In cases of moderate teratozoospermia, the fertilization rate appeared normal (78.6%) but the conception rate remained low. We concluded that the use of strict criteria in the assessment of sperm morphology is useful in predicting fertilization and pregnancy rate in the human in-vitro model.

No effect of intramuscular gold therapy on serological parameters of Helicobacter pylori infection in patients with rheumatoid arthritis: a 12 month prospective study

OBJECTIVES

To assess prospectively the influence of intramuscular gold therapy on Helicobacter pylori serology in patients with rheumatoid arthritis (RA).

METHODS

Fifty patients with RA were started on intramuscular gold or chloroquine, as the control group and were followed serologically for H pylori infection for 12 months.

RESULTS

Twelve patients treated with gold and eight control patients treated with chloroquine, all with serological evidence for H pylori infection, showed no significant decline of IgA and IgG anti-H pylori antibody levels or serum pepsinogen A and C levels. Total serum IgA and IgG levels declined significantly during gold therapy, while they remained unchanged during chloroquine therapy.

CONCLUSIONS

Intramuscular gold therapy in patients with RA does not influence the serological parameters of H pylori infection.

A gastroscopic study of the predictive value of risk factors for non-steroidal anti-inflammatory drug-associated ulcer disease in rheumatoid arthritis patients

Peptic ulcer disease (PUD) in RA patients is associated with NSAID use. This study aimed to validate the predictive value of presumed risk factors for NSAID-associated PUD in a prospective gastroscopic study in RA patients. Eighty-one NSAID using RA patients were prospectively divided into four presumed risk groups according to Helicobacter pylori status and history of PUD. As additional risk factors the following were analysed: upper gastrointestinal GI complaints; disability; daily dose of NSAID and antral gastritis. The presence of PUD in the four risk groups did not differ. Additionally it was found that a history of PUD was predictive for current PUD [odds ratio (OR) 3.9; 95% CI 1.1-14]. H. pylori status was not predictive. Transformation from one ulcer type to another was rare. NSAID dose was not a risk factor, while disability was of borderline importance (OR 2.1; 95% CI 1-4.8). Current upper GI complaints were bad predictors. PUD only occurred with a concomitant antral gastritis. A history of PUD, disability and antral gastritis were the most important predictors for current PUD. When an ulcer relapsed it was of the same ulcer type as had been present earlier. This may have practical implications for prophylaxis enabling stratification by previous ulcer type.

A prospective, randomized study of pefloxacin versus teicoplanin in the treatment of gram-positive coccal infections in cancer patients: early termination due to emergence of resistance to fluoroquinolones

A randomized prospective study comparing pefloxacin to teicoplanin in the treatment of gram-positive infections in cancer patients was prematurely terminated because of the emergence of pefloxacin resistance associated with oxacillin resistance in Staphylococcus aureus and coagulase-negative staphylococci. Among 56 patients evaluated for efficacy (26 pefloxacin and 30 teicoplanin) and infected with bacteria susceptible to both antibiotics, the clinical cure and eradication rates were similar for pefloxacin (80.5% and 77.3% respectively) and teicoplanin (66.6% and 52.2% respectively). The relapse rates (15% and 10% for pefloxacin and teicoplanin respectively) and the overall mortalities within 1 month (42% and 31%) were similar.

P-31 MR spectroscopy of skeletal and cardiac muscle metabolism in patients with systemic sclerosis: a multiple case study

Three-dimensionally localized proton-decoupled phosphorus-31 magnetic resonance (MR) spectroscopy of skeletal and cardiac muscle was performed in six patients with systemic sclerosis. Cardiac (n = 9) and skeletal (n = 6) spectra were also obtained in healthy volunteers. Metabolite ratios and intracellular pH were determined from the spectra of skeletal and cardiac muscle. The phosphocreatine-to-adenosine triphosphate ratio was normal for both skeletal and cardiac muscle in patients with systemic sclerosis. The pH values of skeletal muscle were similar in patients and control subjects (7.13 +/- 0.02 vs 7.12 +/- 0.01, respectively). In skeletal muscle, the inorganic phosphate-to-phosphocreatine ratio in patients was increased relative to that of control subjects (0.106 +/- 0.014 vs 0.086 +/- 0.006, respectively; P = .02). P-31 MR spectroscopy showed no abnormalities in the myocardium of patients with systemic sclerosis. Assessment of the inorganic phosphate-to-phosphocreatine ratio in peripheral skeletal muscle may be helpful for assessing disease activity.

Achlorhydria does not protect against benign upper gastrointestinal ulcers during NSAID use

It is widely accepted that the absence of acid-peptic activity excludes the presence of a benign upper gastrointestinal ulcer. We assessed the frequency of a history of benign upper gastrointestinal ulcer disease in patients with and without serological evidence of achlorhydria with reference to the use of nonsteroidal antiinflammatory drugs (NSAIDs). In total 857 patients were interviewed, using a standard questionnaire with emphasis on demographic data, chronic use of NSAID, and history of upper gastrointestinal ulcers. The frequency of achlorhydria was determined by extremely low serum levels of pepsinogen A (PgA < 17 micrograms/liter). Of the total group of patients, 36 patients (4.2%; 95% CI 2.9-5.5) had a PgA lower than 17 micrograms/liter. A history of benign upper gastrointestinal ulcer was found in 57/827 (6.9%) of patients with serum PgA higher than 17 micrograms/liter and in 3/36 (8.3%) of patients with serum PgA lower than 17 micrograms/liter (NS). The three patients with upper gastrointestinal ulcer and PgA lower than 17 micrograms/liter were known to have pernicious anemia (PA) before (two patients) or simultaneously (one patient) with the diagnosis of the upper gastrointestinal ulcer and were using NSAIDs at that time. The presence of gastric acid is not obligatory for the development of ulcers during NSAID use.

Primary femoral shortening osteosynthesis in the management of comminuted supracondylar femoral fractures

Supracondylar fractures are most often the result of high-energy vehicular trauma in the young population, and the result of low-energy injuries in the elderly. Therefore, these fractures are generally associated with comminution or osteoporosis. Anatomic reconstruction with stable medial buttressing is often not possible. Utilization of AO principles and techniques with anatomic reduction and internal fixation often fails to yield sufficient stability. We have developed a technique for the treatment of these distal femoral fractures which involves shortening by impaction. Rather than achieving anatomic reduction, the femur is shortened by telescoping the fragments to reestablish inherent stability of the bone prior to internal fixation. Over a 20-year period we treated 25 comminuted supracondylar femoral fractures with primary shortening osteosynthesis in 24 patients. Sixteen patients were available for review at an average follow-up of 10 years (range 4-24 years). Ninety-four percent of the patients demonstrated complete radiographic consolidation by 14 weeks after the operative intervention. One patient required secondary bone grafting and reached consolidation at 30 weeks. Primary cancellous grafting was utilized in only 25% of the patients. One-third of the patients in review were given a heel lift; the average shortening in these patients was 2.6 cm (range 2.1-5 cm). Two-thirds of the patients did not require a heel lift, the average shortening in this group of patients being 1.2 cm (range 0.8-2.0 cm). At follow-up the average range of motion of the knee was 114 degrees (range 90 degrees-130 degrees).(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of subtrochanteric fractures of the femur: reduction on the traction table and fixation with dynamic condylar screw

In the subtrochanteric region of the femur high tensile forces are active in the lateral cortex and even higher compressive forces in the medial cortex. Subtrochanteric fractures are often comminuted. The implant of choice for osteosynthesis of subtrochanteric femoral fractures is the condylar plate. Usually the various fragments are dissected intraoperatively and the medial cortex is reconstructed anatomically for improved abutment. This devitalizing of fragments leads to disturbed healing, so that failure are frequent despite cancellous bone grafting. The osteosynthesis technique introduced by Mast and Ganz of indirect reduction by distractor without dissection of the fragments and the medial cortex allowed the complication rate to be reduced to 0%. We have modified this technique in that we performed closed reduction on the traction table rather than using the distractor to achieve axial and rotational alignment, after which the fracture is stabilized with dynamic condylar screw (DCS) under image intensifier control. The proximal femur is dissected only laterally and only in so far as in necessary to place the DCS. We never use cancellous bone grafting. From 1988 to 1990 this technique was used in 12 patients. All fractures had healed uneventfully after 4 months.

Antioxidant defences in rat, pig, guinea pig, and human hearts: comparison with xanthine oxidoreductase activity

OBJECTIVE

Cardiac injury, related to ischaemia and reperfusion, may be caused by the action of oxygen free radicals. Xanthine oxidoreductase activity may be an important free radical source. During cardiac ischaemia, the native dehydrogenase form may be converted to the oxidase form, which uses molecular oxygen to form superoxide radicals. Superoxide dismutase converts the radicals to H2O2, which is detoxified by catalase and glutathione peroxidase. In view of the large differences in xanthine oxidoreductase in various species, the activity of these antioxidant enzymes was investigated.

METHODS

Normal rodent and porcine as well as explanted human hearts were perfused according to Langendorff. After a 30 minute stabilisation period, hypoxanthine was added to the perfusion buffer to estimate xanthine oxidoreductase. Hearts or biopsies were freeze clamped after 90 minutes. Effluent xanthine and urate were assayed with high performance liquid chromatography; tissue reduced glutathione content and the activity of superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase were determined spectrophotometrically. Apparent xanthine oxidoreductase was calculated as xanthine +2 x urate production.

RESULTS

Xanthine oxidoreductase was (mU.g-1 protein, mean(SEM), n = 5-7): rat, 470(40); guinea pig, 270(41); pig < 1.5; and human, 5.4(1.0). Superoxide dismutase activities were (U.g-1 protein): rat, 13,370(1030); guinea pig, 10,100(1110); pig, 12,800(450); and human, 7400(450). Catalase activity (k < or = 10.g-1 protein) was low in all species studied. Glutathione peroxidase activity was 93(7) U.g-1 protein in rat heart, and 10 x lower in the other species. Glutathione reductase activity was (U.g-1 protein): rat, 15.0(1.6); guinea pig, 10.4(1.3); pig, 16.0(1.5); and human, 26.6(2.0). Tissue reduced glutathione concentrations were (mumol.g-1 protein): rat, 13.5(0.8); guinea pig, 18.5(0.9); pig, 11.1(2.9); and human 17.2(1.7).

CONCLUSIONS

Considerable species differences in xanthine oxidoreductase activity exist, contrasting with the smaller variations in antioxidant enzyme activities. In the species examined catalase activities were very low. Rat hearts are far better protected against H2O2 than the other three species. Xanthine oxidoreductase induced free-radical damage probably plays a minor role in pig and human hearts. Human myocardium seems less protected against superoxide radicals.

Impact of innovative techniques on the waiting list and results in pediatric liver transplantation

The wide application of liver transplantation in children is hampered by the shortage of size-matched pediatric donors; this results in high mortality rate on the waiting list, a long waiting time, worsening of the clinical condition of the waiting patient, deterioration of the overall results, and an increase in the cost. Reduced-size liver transplants have been shown to be a safe way to alleviate the shortage of size-matched organs. We have retrospectively analyzed the impact of the reduced-size liver transplants on the waiting list and the results in a consecutive series of 314 transplants performed in 261 children over an 8-year period (1984-1991). Among these 314 grafts, 160 (51%) were innovative techniques including 86 reduced livers (stricto senso), 66 partial livers (with preservation of the recipient vena cava), and 8 split livers. Such an extensive use of these technical variants allowed a sharp decrease in the waiting list mortality: from 14.9% between 1984 and 1989 to 6.6% in 1990 and 5% in 1991; the corresponding figures for infants registered under the age of 1 year were 25%, 13.3%, and 8.3%, respectively. Results obtained with a full-size graft or a technical variant were similar regarding surgical complications (with a significantly lower incidence of arterial thrombosis for the reduced transplants), graft loss, and patient survival. The 5-year survival of the whole group was 78.1% without any significant difference regarding type of transplant, indications (with the best results: 89.4% 5-year survival obtained in 41 children grafted for metabolic diseases), or age (the 5-year survival was 82.2% for the 41 infants transplanted under the age of 1 year, 78.9% for the 124 children transplanted between 1 and 3 years, and 81.3% for the 96 children transplanted between 6 and 15 years). This series of reduced-size liver transplants, which is the largest worldwide single institutional experience, confirms that the extensive use of reduced transplants in children is safe; this study also shows that innovative techniques, including the split liver, allow a drastic decrease of the waiting list mortality of candidates in the pediatric age range without alterations of the results.

Malondialdehyde and glutathione production in isolated perfused human and rat hearts

A number of studies show the relation between oxygen-derived free radicals and cardiac ischemia/reperfusion injury. However, little is known about oxidative stress in the human heart, which can be measured by oxidized glutathione (GSSG) and malondialdehyde (MDA) formation. Furthermore, data on MDA production by rat hearts are controversial, possibly because of the use of the aspecific thiobarbituric acid assay. Therefore, GSSG and MDA were measured, with colorimetric and high-performance liquid chromatographic assays, respectively, in buffer-perfused explanted human hearts and normal rat hearts made temporarily ischemic. Human hearts received cardioplegia; rat hearts were studied in a control and an ischemic group with or without cardioplegia. Baseline GSSG release was < 0.01 nmol.min-1.g wet wt-1 in both species. During reperfusion, GSSG release from human hearts and from ischemic and cardioplegic/ischemic rat hearts peaked at 0.24 +/- 0.12, 1.1 +/- 0.4, and 0.19 +/- 0.04 nmol.min-1.g-1, respectively. MDA was undetectable (< 0.02 nmol.min-1.g-1) in the effluent of both species and in human hearts (< 4 nmol/g protein). Rat heart reduced glutathione levels decreased 32% as a consequence of cardioplegia and ischemia. Cardioplegia induced a 41% (P = .08) decrease in rat heart MDA content, whereas cumene hydroperoxide increased it 3.6 times (P < .01). Thus, after ischemia human and rat hearts release GSSG, indicating that oxidative stress has occurred. Apparently, lipid peroxidation takes place in normal rat hearts, decreases after cardioplegia, but does not increase after ischemia/reperfusion. Human hearts lack MDA under normoxic and ischemic conditions. This novel finding seems to reflect a low MDA-forming potential in both situations.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of indomethacin on intragastric pH and meal-stimulated serum gastrin secretion in rheumatoid arthritis patients

The effects of oral indomethacin on intragastric pH and serum gastrin were investigated in rheumatoid arthritis patients. Nine patients (1 male, 8 female) without a history of peptic ulcer disease and 6 patients with a history of peptic ulcer disease (5 male, 1 female) were studied. To obviate Helicobacter pylori infection as a confounding factor, only patients with positive H. pylori serology were included. After a 5-day period of placebo treatment and after a 5-day period of indomethacin (50 mg t.d.s.; total dose 750 mg), 24-h intragastric pH and basal and meal-stimulated serum gastrin levels were measured in a double-blind placebo controlled cross-over study. There were no differences in the median 24-h pH values between placebo and indomethacin users irrespective of peptic ulcer disease history. Indomethacin resulted in a higher basal and stimulated gastrin response than placebo in patients with a history of peptic ulcer disease. The basal and incremental responses were lower in patients with a history of peptic ulcer disease than in patients without a history of peptic ulcer disease, both during indomethacin and placebo. The same basal and stimulated incremental serum gastrin responses were found during placebo and indomethacin treatment in patients without a history of peptic ulcer disease. No correlation was established between median 2-h post-prandial intragastric pH and post-prandial incremental serum gastrin concentration. We conclude that indomethacin does not influence the intragastric pH of rheumatoid arthritis patients irrespective of history of peptic ulcer disease.

The frequency of extremely low serum pepsinogen, indicative of corpus gastritis with severe atrophy, in rheumatoid arthritis, other chronic rheumatic diseases and non-rheumatic diseases

The aim of this study was to assess the frequency of corpus gastritis with severe atrophy (CGA), pernicious anaemia and combined severe atrophy of antrum and corpus by non-invasive methods (i.e. determination of low serum pepsinogen A (PgA) and serum gastrin) in outpatients with RA (n = 249), compared to outpatients with other rheumatic diseases (n = 181) and outpatients with chronic non-rheumatic diseases (n = 429). In addition we investigated whether NSAIDs could cause or prevent CGA. A low serum PgA level (< 17 micrograms/l), indicating pentagastrin-refractory achlorhydria in patients without gastric resection, was found in 13 patients (5.2%; 95% Confidence Interval (CI) 2.4-8.0) with RA, in 11 (6.1%; 95% CI 2.6-9.5) with other rheumatic diseases and in 12 patients (2.8%; 95% CI 1.2-4.4) with chronic non-rheumatic diseases (NS). Low serum PgA values were more frequent in older patients (P < 0.005) and females (P < 0.05). Pernicious anaemia occurred in RA in 1.2% (95% CI 0-2.6) of the patients while for other rheumatic diseases the frequency was 1.7% (95% CI 0-3.5) and for chronic non-rheumatic diseases 0.2% (95% CI 0-3.6) (NS). In patients with a serum PgA below 17 micrograms/l, normal serum gastrin levels (< 90 ng/l) as an indication of combined severe atrophy of antrum and corpus, were found in 1/13 patients with RA, in 3/11 with other rheumatic diseases and 2/12 with chronic non-rheumatic diseases (NS). The frequency of low serum PgA levels was no different between patients on NSAIDs 17/355 (4.8%) and those without NSAIDs 19/502 (3.8%).(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro and ex vivo xanthine oxidoreductase activity in rat and guinea-pig hearts using hypoxanthine or xanthine as substrate

Through oxyradical formation xanthine oxidoreductase (XOD) could play a role in the etiology of cardiac damage. Its measurement poses problems, due to little substrate specificity, self-inactivation and endogenous inhibitors. Perfusion of guinea-pig hearts with hypoxanthine gave rise to only little xanthine release; in contrast rat hearts showed vivid xanthine production. Therefore, xanthine breakdown was hypothesized to exceed its formation in guinea-pig hearts. The kinetics of both substrates for XOD in cardiac homogenates were therefore compared with those obtained in perfused hearts. Oxypurine contents and effluent catabolites were determined by HPLC. Regardless of substrate, Vmax values in homogenates were about 38 and 13 mU/g for rat and guinea-pig heart, respectively. Km values were in the 3-5 microM range; therefore the hypothesis concerning the low xanthine release in guinea-pig hearts must be rejected. Activities in hearts perfused with hypoxanthine (50 microM) were 40 and 18 mU/g for rat and guinea pig, respectively; perfusion with xanthine produced < 50% of the activities observed with hypoxanthine (p < 0.002). Intracellular xanthine concentration, estimated from sorbitol distribution space and myocardial xanthine content was negative in both species, contrasting intracellular hypoxanthine levels, which approached extracellular concentrations. This disparate distribution indicates that hypoxanthine transport across the cell membrane far exceeds that of xanthine. Consequently, hypoxanthine is preferable to xanthine as substrate in perfused hearts to estimate XOD activity in situ.

Temperature dependence of glucocorticoid binding in sensitive and refractory murine leukaemia cells

The validity of in vitro assays in predicting the susceptibility of leukaemic cells to glucocorticoid-mediated lysis was evaluated in a panel of six murine leukaemia cell lines. In this panel susceptibility to glucocorticoids ranged from highly sensitive to fully resistant. The panel was screened for specific 3H-dexamethasone binding in whole cells and for activation of cytosolic receptors in cell lysates. Specific binding of 3H-dexamethasone was strongly affected by the incubation temperature. In all cell lines, rapid and reversible changes were observed in the stability of agonist-receptor association with a transition temperature of 28 degrees C. Below this temperature, intracellular receptors were found to be in a stable-binding, high-affinity configuration, masking differences in receptor status among the various cell lines. When assayed at 37 degrees C, refractory and fully resistant cells revealed nonsaturating, low-affinity binding of steroid. Saturating, high-affinity binding was, however, restored in these cells by the drug meta-iodobenzylguanidine with concomitant sensitization to dexamethasone-induced lysis. Contrary to observations with intact cells, heat-induced agonist-receptor dissociation in cytosols caused irreversible loss of (re)binding capacity. Activation of cytosolic receptors only recognized fully resistant cell lines as being deficient in the transformation of liganded receptors into a DNA-binding configuration. The assay, however, could not discriminate between three cell lines with highest but varying degrees of sensitivity because of maximal activation. The results indicate that non-physiological temperature and cell disruption strongly and differentially affect steroid binding and receptor activation, respectively. The observations may account for the poor correlation between conventional predictive assays and steroid responsiveness in clinical leukaemia.

Myocardial xanthine oxidoreductase activity in hypertensive and hypercholesterolemic rats

In several species, xanthine oxidoreductase activity seems to be a major source of free radicals in myocardial tissue. Its activity changes during development and aging, at least in the rat heart. Hardly any data are available about its activity in two important diseases, hypertension and hypercholesterolemia, in which the production of free radicals induced by xanthine oxidoreductase activity could play a role. Therefore we measured the activity of xanthine oxidase and dehydrogenase in myocardial tissue of spontaneously hypertensive. Wistar (control hypertensive), Yoshida (hypercholesterolemic) and Brown Norway (control hypercholesterolemic) rats of various ages. Cytosolic fractions were incubated at 30 degrees C, pH 8.3, with 60 microM xanthine, and the formation of urate was measured with high performance liquid chromatography. In the Wistar group, xanthine oxidoreductase activity was relatively constant during aging (about 1.8 U/g protein). In the hypertensive group, the activity increased gradually from 1.7 to 2.3 U/g at 18 months (p < 0.05 compared with Wistar at 18 months). Xanthine oxidase was about twice as high in both groups at 18 months (p < 0.001 compared with 2 and 6 months). The ratio of xanthine dehydrogenase to xanthine oxidase had decreased 42% at this age (p < 0.001). In the Yoshida and Brown Norway groups, xanthine oxidoreductase activity was similar, with a peak at 6 months. These data suggest that the hypercholesterolemic state does not influence xanthine oxidoreductase activity. In contrast, in hypertrophied myocardium, xanthine oxidoreductase activity was higher than in the control, suggesting a different potential for free-radical generation.(ABSTRACT TRUNCATED AT 250 WORDS)

Formation and breakdown of uridine in ischemic hearts of rats and humans

In contrast to cardiac purine metabolism, little is known about pyrimidine catabolism in heart. We therefore investigated uridine and uracil formation in ischemic rat and human hearts. Human donor hearts accumulated uridine 3 x (P < 0.05) before implantation. Hearts released this pyrimidine during implantation or correction of cardiac defects. During the former systemic blood uridine rose 38% (P < 0.05). In explanted human hearts, uridine was the only pyrimidine released during reperfusion; isolated, perfused rat hearts produced initially 3 x more uracil than uridine. Uridine phosphorylase activity in human heart homogenate was 3.4 mU/g wet weight, i.e. 60 x lower than that in rat myocardium (198 mU/g, P < 0.02); its purine counterpart, nucleoside phosphorylase, differed much less in activity (0.32 and 1.12 U/g, respectively; P < 0.001). Thus human heart is virtually devoid of uridine phosphorylase, contrasting rat heart. Consequently uridine accumulates in ischemic human heart while uracil production predominates in rat heart.

Virus-induced airway hyperresponsiveness in guinea pigs in vivo: study of broncho-alveolar cell number and activity

Recently, we demonstrated that an increased airway responsiveness in vitro can be measured 4, 8, and 16 days, but not 2 days, after intratracheal inoculation of parainfluenza-3 (PI-3) virus to guinea pigs. In the present study airway responsiveness was measured in vivo, and the number, types and activity of broncho-alveolar cells was determined. A significant increase in airflow resistance was measured in spontaneously breathing anesthetized guinea pigs in response to histamine and methacholine, 4 and 8 days after PI-3 virus inoculation. 2 days after inoculation with control solution or PI-3 virus, no difference in the total number of inflammatory cells was observed in the broncho-alveolar lavage fluid. In contrast, on days 4, 8, and 16 after infection a significant increase in the number of alveolar macrophages (102%, 76%, 68%, respectively), monocytes (552%, 374%, 360%, respectively), and lymphocytes (253%, 675%, 396%, respectively) was found. The number of eosinophils was increased as well, but faded with time (378%, 312%, 63%, respectively). PI-3 virus was found to be a very potent activator of broncho-alveolar cells as measured by chemiluminescence. The increase in chemiluminescence production in response to PI-3 virus was reduced in cells obtained from PI-3 virus pretreated animals (day 2, 42%; day 4, 65%; day 8, 22%; and day 16, 30%). In conclusion, PI-3 virus can stimulate broncho-alveolar cells and the virus-induced airway hyperresponsiveness is associated with an influx of inflammatory cells in the respiratory tract.

Upper gastrointestinal complaints and complications in chronic rheumatic patients in comparison with other chronic diseases

The aim of this study was to compare the frequency of upper gastrointestinal (GI) complaints and complications between chronic rheumatic patients who are most often non-steroidal anti-inflammatory drugs (NSAIDs) users and patients with other chronic conditions. In this comparison we took into account known risk factors for upper GI disease. To achieve the study aims we performed a combined cross-sectional and retrospective study. We therefore interviewed by means of a standard questionnaire, an index and a reference group, about current upper GI complaints and previous complications. The former group comprises 578 outpatients of the Department of Rheumatology, the latter of 531 outpatients of the Departments of Internal Medicine, Pulmonology, and Cardiology. Although the number of patients in the index group being chronically treated with NSAIDs was very high (62% versus 9% in the reference group: P < 0.00001), no between-group differences were found for the frequency of several current upper gastrointestinal complaints or for the number of upper gastrointestinal investigations ever performed (35% and 37%: NS) or for the use of gastric drugs (14% and 10%: NS). Risk factors for upper GI complaints were not related to NSAID use but with the use of prednisolone, history of duodenal ulcer disease, family history of peptic ulcer disease and female sex. For peptic ulcer disease, bleeding, and gastric surgery, the only difference between the index and reference groups concerned the frequency of gastric ulcers (6.7% and 2.8%: P < 0.005), which was highest in patients with rheumatoid arthritis. Upper GI bleeding had more often been present in male seropositive rheumatoid arthritis patients (13.2% [corrected] and 4.5%: P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Purification and characterization of an antithrombin III inactivating enzyme from the venom of the African night adder (Causus rhombeatus)

A serine proteinase was isolated from the venom of the night adder (Causus rhombeatus) by fast protein liquid chromatography (anion-exchange, gel filtration and hydrophobic interaction). The protein (termed CR-serpinase) had an estimated mol. wt of 45,500 as determined by SDS-PAGE, pI of 4.7 and a carbohydrate content of 18.9%. Incubation of CR-serpinase with purified human antithrombin III at a molar ratio of 1:66 resulted in a loss of more than 90% of the initial AT III activity within 10 min. The reaction was dependent on heparin. In SDS-PAGE inactivation of human antithrombin III was correlated with the occurrence of two cleavage products. The cleavage site in the antithrombin III molecule was determined to be Arg 393-Ser 394 by amino-terminal sequencing. CR-Serpinase had no thrombin-like activity since no fibrinogen conversion was induced and had no procoagulant activity. CR-Serpinase activity was not inhibited by antithrombin III-heparin and was not decreased by a 10-min preincubation in normal human plasma. Inactivation of antithrombin III by CR-serpinase appeared to be very specific.

Virus-induced airway hyperresponsiveness in the guinea pig can be transferred by bronchoalveolar cells

For the investigation of whether inflammatory cells were responsible for virus-induced airway hyperresponsiveness, tracheal spirals from healthy guinea pigs were incubated in organ baths with different numbers of bronchoalveolar cells obtained from guinea pigs 4 days after their inoculation with parainfluenza-3 (P-3) virus or control solution. Airway responsiveness was measured by performance of histamine concentration/response (C/R) curves on the tissues. Preparations incubated with 5 x 10(5) cells/ml obtained from guinea pigs treated with P-3 virus demonstrated a significant upward shift of the histamine C/R curve. The maximal contraction was increased by 26% as compared with the tissues incubated with the same number of cells from animals inoculated with control solution. When the number of cells was increased further to 5 x 10(6) cells/ml, no additional upward shift of the C/R curve was seen; the increase in maximal contraction was 24%. Tracheal spirals incubated with 5 x 10(4) cells/ml did not affect the histamine C/R curves. Addition of P-3 virus to the organ bath during the incubation period with the cells did not affect the histamine C/R curve either, irrespective of the inoculation solution or the number of bronchoalveolar cells used. The relative number of alveolar macrophages in bronchoalveolar lavage fluid decreased significantly from 86.3% +/- 2.6% in the control group to 71.8% +/- 3.3% in the P-3 virus group as a consequence of a significant increase in the percentage of monocytes, lymphocytes, and eosinophils. These results suggest that bronchoalveolar cells are causally involved in the virus-induced airway hyperresponsiveness.

Decreased level of antibodies against Helicobacter pylori in patients with rheumatoid arthritis receiving intramuscular gold

BACKGROUND

Sodium aurothiomalate has been reported to have in vitro activity against Helicobacter pylori. Intramuscular gold, as given to patients with rheumatoid arthritis (RA), may therefore influence the colonisation of the gastric mucosa with H pylori.

METHODS

Two groups were compared. One group of 42 patients was treated with intramuscular gold; the other group of 58 patients was treated with antimalarial drugs. Antibodies to H pylori (IgA and IgG) were assessed by an enzyme linked immunosorbent assay (ELISA) and total IgA and IgG were measured by nephelometry.

RESULTS

IgA and IgG antibody titres against H pylori and total IgA and IgG levels were lower in the patients treated with gold than in the group treated with antimalarial drugs. The ratio of IgA antibodies to H pylori to total IgA antibodies and the ratio of IgG antibodies to H pylori to total IgG antibodies were lower in the group treated with gold. The percentage of seropositivity to H pylori was significantly lower in the group treated with gold than in the group treated with antimalarial drugs for the two IgA antibodies (35 and 55% respectively) and IgG antibodies to H pylori (40 and 65% respectively).

CONCLUSIONS

Although this study cannot completely exclude the possibility that a suppressive effect of intramuscular gold on total immunoglobulin production plays a part in the decrease in the titres of IgA antibodies to H pylori and IgG antibodies to H pylori, the lower ratios of antibodies to H pylori to total immunoglobulin antibodies and the lower percentages of seropositivity to H pylori in the group treated with gold suggests that treatment with intramuscular gold decreases H pylori colonisation.

Intra-articular rheumatoid nodules and triggering of the knee joint

Rheumatoid nodules are a common extra-articular manifestation in rheumatoid arthritis. Intra-articular localisation of these nodules is rare and may produce clinical symptoms. Seven patients with walking problems due to an intra-articular rheumatoid nodule, which became entrapped on the ridge of the tibial plateau of the knee joint resulting in a phenomenon referred to as trigger knee, are described. After excision of the nodules all symptoms completely disappeared.

Pharmacokinetics and intracellular distribution of the tumor-targeted radiopharmaceutical m-iodo-benzylguanidine in SK-N-SH neuroblastoma and PC-12 pheochromocytoma cells

Radiodinated meta-iodobenzylguandine (MIBG) is increasingly used for the diagnosis and targeted radiotherapy of neuro-adrenergic tumors. We have investigated various conditions for specific tumor loading and prolonged retention of this radiopharmaceutical in poorly differentiated SK-N-SH neuroblastoma and highly differentiated PC-12 pheochromocytoma cells. At a constant value of drug concentration x incubation time, short incubations were superior to protracted incubations for maximal cell loading. This effect was most pronounced in the SH-N-SH neuroblastoma cells. In highly differentiated pheochromocytoma cells, the levels of MIBG storage remained high and unchanged during incubations up to 46 hr in label-free medium, while primitive SK-N-SH cells lost 40-50% of accumulated drug by diffusion. In PC-12 cells, susceptibility of stored MIBG to exocytotic release induced by acetylcholine or K+ was similar to that of natural norepinephrine (NE) and prevented by the Ca(++)-channel blockers verapamil and nifedipine. Conversely, granule-poor SK-N-SH cells were insensitive to exocytotic release of MIBG. Uptake and retention capacities were minimally impaired by an externally delivered radiation dose of 5 Gy to mimic the radiobiological effect of 131I-MIBG in tumors. In pre-irradiated cultures, drug uptake was even stimulated, probably due to enrichment in non-proliferating cells. An autoradiographic comparison of the (sub)cellular distributions of 3H-norepinephrine and 125I-MIBG showed that routine conditions of cell fixation and sample processing do not yield reliable results regarding localization of MIBG.

Muscle cramps in the calf as presenting symptom of sarcoidosis

A patient is described, who presented with pain in the calf due to a palpable nodule as the presenting symptom of sarcoidosis. The patient was treated with rest and diclofenac, followed by intralesional injections with triamcinolone hexacetonide and became free from pain.

Disseminated lung cancer or extragonadal germ cell tumour?

Two patients are reported in whom an initial diagnosis of disseminated non small cell bronchogenic carcinoma was subsequently changed into a final diagnosis of extragonadal germ cell tumour. The clinical importance of the differential diagnosis between these two malignancies is highlighted and the management of extragonadal germ cell tumours is discussed.

Effects of metformin on haemorheology, lipid parameters and insulin resistance in insulin-dependent diabetic patients (IDDM)

We have evaluated the effect of metformin on haemorheology, lipid levels and insulin resistance in insulin-dependent diabetic patients over a 6-week period. Rheological parameters remained unaltered except for the whole blood clogging rate which decreased significantly. No effect on lipid levels was seen. The main effect of metformin was limited to daily insulin requirement and insulin units/kg bw. Bearing in mind the negative effects of high insulin levels, metformin could be useful in the prevention of atherogenesis in insulin-dependent diabetic patients.

Disseminated lung cancer or extragonadal germ cell tumour?

Two patients are reported in whom an initial diagnosis of disseminated non small cell bronchogenic carcinoma was subsequently changed into a final diagnosis of extragonadal germ cell tumour. The clinical importance of the differential diagnosis between these two malignancies is highlighted and the management of extragonadal germ cell tumours is discussed.

Intracellular inhibition of mono(ADP-ribosylation) by meta-iodobenzylguanidine: specificity, intracellular concentration and effects on glucocorticoid-mediated cell lysis

meta-Iodobenzylguanidine (MIBG) is a high-affinity substrate for mono(ADP-ribosyl)transferase of cholera toxin and turkey erythrocyte membranes (Loesberg, C., Van Rooij, H. and Smets, L.A.(1990) Biochim. Biophys. Acta 1037, 92-99). In the present study the drug was investigated as a potential inhibitor of intracellular ribosyltransferases by competition with endogenous acceptors. To this end, MIBG was compared with the conventional ADP-ribosylation inhibitors nicotinamide and 3-aminobenzamide in cell-free ribosylation systems and in intact L1210 leukemia cells. Poly(ADP-ribose)polymerase (poly-ADPRP) was assayed by the DNAse-I-induced incorporation of [14C]NAD in nuclei of permeabilized L1210 cells. Mono(ADP-ribosyl)transferase (mono-ADPRT) was assayed as NAD linkage to [125I]iodoguanyltyramine catalysed by turkey erythrocyte membranes or activated cholera toxin. Poly-ADPRP was inhibited by nicotinamide (IC50 = 0.03 mM) and by 3-aminobenzamide (IC50 less than or equal to 0.03 mM) but was insensitive to MIBG. Conversely, mono-ADPRT was inhibited by MIBG (IC50 = approx. 0.1 mM) but not by 3-aminobenzamide and only weakly so by nicotinamide in high concentration (10 mM). In L1210 cells, intracellular levels of nicotinamide equilibrated at 60-70% of the extracellular drug concentrations assayed at 1 and 10 mM. In contrast, MIBG was concentrated 15-fold by nonspecific uptake. The preferential interference of the drugs with endogenous mono- or poly-ADP ribosylations, predicted from inhibitory capacity in vitro and intracellular concentrations, was confirmed by their effect on dexamethasone-induced lysis of L1210 cell lines. Inhibition of endogenous mono-ADPRT with 0.03 mM MIBG or 10 mM nicotinamide induced sensitivity to glucocorticoids in refractory L1210-wt cells. In contrast, inhibition of poly-ADPRP by 3-aminobenzamide or nicotinamide (1 mM each) did not confer susceptibility to refractory cells but enhanced the lytic process in the sensitive subline L1210-H7 or in L1210-wt cells sensitized by MIBG. These results indicate that MIBG is the first substrate for guanidino-specific mono-ADPRT which accumulates in intact mammalian cells and effectively competes with intracellular acceptors for endogenous enzymes.

Extragranular storage of the neuron blocking agent meta-iodobenzylguanidine (MIBG) in human neuroblastoma cells

Human SK-N-SH neuroblastoma cells accumulate and store the adrenal imaging agent metaiodobenzylguanidine (MIBG) with minor involvement of specialized cytoplasmic storage granules (Smets LA et al., Active uptake and extravesicular storage of meta-iodo-benzylguanidine in human neuroblastoma SK-N-SH cells. Cancer Res 49: 2941-2944, 1989). In the present study the mechanism of extravesicular MIBG retention was investigated and compared with granular storage of MIBG and norepinephrine (NE) in PC-12 pheochromocytoma cells. SK-N-SH cells concentrated both MIBG and NE by neuron-specific Uptake-1 but long-term retention was only observed with MIBG. Retention of accumulated NE was, however, promoted by inhibition of intracellular catecholamine degradation with pyrogallol. Drug release by controlled cell permeabilization and by KCl-induced exocytosis indicated that MIBG was mainly stored as freely diffusible, cytoplasmic molecules. SK-N-SH cells were depleted from stored MIBG by the Uptake-1 inhibitor imipramine but poorly so by the granule-depleting drug reserpine. Conversely, PC-12 cells were depleted by reserpine but insensitive to imipramine. The data suggest that extravesicular retention of MIBG in SK-N-SH cells is not based on intracellular sequestration but is solely due to efficient re-uptake of accumulated drug after leaking from the cells. The accumulation of MIBG in SK-N-SH cells, reflecting "pure" Uptake-1, appears to be a powerful system for exploring various cellular and molecular aspects of catecholamine uptake.

Parainfluenza-3 induced hyperreactivity of the guinea pig trachea coincides with an increased number of bronchoalveolar cells

Guinea pigs were inoculated intra-tracheally with bovine parainfluenza type 3 virus (PI-3) to investigate whether airway hyperreactivity was associated with an increase in the number of broncho-alveolar cells. Two days after saline or PI-3 inoculation no difference in histamine reactivity of the isolated tracheal spirals was observed. The number of broncho-alveolar cells was also not changed. However, 4 days after PI-3 inoculation the histamine-induced contraction of the tracheal spirals was increased by 45% and the number of inflammatory cells in the airways by 150% as compared with the control group. In conclusion, PI-3 infection of the guinea pig respiratory airways induces tracheal hyperreactivity which is associated with an increase in broncho-alveolar cells.

Antigenic relationship between the venom of the night adder Causus maculatus and venoms of other viperids

Monovalent antivenoms were raised in mice against the venoms of Causus maculatus, Vipera ammodytes, Echis carinatus, Cerastes cerastes, Bitis arietans, Agkistrodon rhodostoma and Bothrops atrox. These antivenoms as well as four commercially available antivenoms were tested against the venoms of 15 viperid species by means of immunoelectrophoresis and/or ELISA. Cross-reactive protein bands were determined by immunoblot. ELISA cross-reactions of C. maculatus antivenom were low with all heterologous venoms. When investigating the other viperine antivenoms in ELISA stronger cross-reactions were observed with several heterologous venoms. In immunoblot, two heterologous antivenoms cross-reacted with one or two protein bands of C. maculatus venom whereas there were at least four heterologous antivenoms cross-reacting with each of the other venoms. The findings indicate that there is little antigenic affinity between C. maculatus venom and the other venoms investigated. Broad in vitro cross-reactions between viperine antivenoms and Causus venom which were reported in literature seem to be attributable to the use of antivenoms of commercial grade. Specificity of commercially produced, mono- or polyvalent antivenoms may not be strictly limited to those venoms, against which potency is claimed on the label of the product.