Liver Assessment in Patients with Ataxia-Telangiectasia: Transient Elastography Detects Early Stages of Steatosis and Fibrosis.

Background: Ataxia-telangiectasia (A-T) is a rare autosomal-recessive multisystem disorder characterized by pronounced cerebellar ataxia, telangiectasia, cancer predisposition, and altered body composition. Liver diseases with steatosis, fibrosis, and hepatocellular carcinoma are frequent findings in older patients but sensitive noninvasive diagnostic tools are lacking. Objectives: To determine the sensitivity of transient elastography (TE) as a screening tool for early hepatic tissue changes and serum biomarkers for liver disease. Methods: Thirty-one A-T patients aged 2 to 25 years were examined prospectively from 2016-2018 by TE. In addition, we evaluated the diagnostic performance of liver biomarkers for steatosis and necroinflammatory activity (SteatoTest and ActiTest, Biopredictive, Paris) compared to TE. For calculation and comparison, patients were divided into two groups (<12, >12 years of age). Results: TE revealed steatosis in 2/21 (10%) younger patients compared to 9/10 (90%) older patients. Fibrosis was present in 3/10 (30%) older patients as assessed by TE. We found a significant correlation of steatosis with SteatoTest, alpha-fetoprotein (AFP), HbA1c, and triglycerides. Liver stiffness correlated significantly with SteatoTest, ActiTest, HbA1c, and triglycerides. Conclusion: Liver disease is a common finding in older A-T patients. TE is an objective measure to detect early stages of steatosis and fibrosis. SteatoTest and ActiTest are a good diagnostic assessment for steatosis and necroinflammatory activity in patients with A-T and confirmed the TE results.

Secondary malignancies in chronic myeloid leukemia patients after imatinib-based treatment: long-term observation in CML Study IV.

Treatment of chronic myeloid leukemia (CML) has been profoundly improved by the introduction of tyrosine kinase inhibitors (TKIs). Long-term survival with imatinib is excellent with a 8-year survival rate of ∼88%. Long-term toxicity of TKI treatment, especially carcinogenicity, has become a concern. We analyzed data of the CML study IV for the development of secondary malignancies. In total, 67 secondary malignancies were found in 64 of 1525 CML patients in chronic phase treated with TKI (n=61) and interferon-α only (n=3). The most common malignancies (n⩾4) were prostate, colorectal and lung cancer, non-Hodgkin's lymphoma (NHL), malignant melanoma, non-melanoma skin tumors and breast cancer. The standardized incidence ratio (SIR) for all malignancies excluding non-melanoma skin tumors was 0.88 (95% confidence interval (0.63-1.20)) for men and 1.06 (95% CI 0.69-1.55) for women. SIRs were between 0.49 (95% CI 0.13-1.34) for colorectal cancer in men and 4.29 (95% CI 1.09-11.66) for NHL in women. The SIR for NHL was significantly increased for men and women. An increase in the incidence of secondary malignancies could not be ascertained. The increased SIR for NHL has to be considered and long-term follow-up of CML patients is warranted, as the rate of secondary malignancies may increase over time.

Integrating novel agents into multiple myeloma treatment - current status in Switzerland and treatment recommendations.

The treatment of multiple myeloma has undergone significant changes in the recent past. The arrival of novel agents, especially thalidomide, bortezomib and lenalidomide, has expanded treatment options and patient outcomes are improving significantly. This article summarises the discussions of an expert meeting which was held to debate current treatment practices for multiple myeloma in Switzerland concerning the role of the novel agents and to provide recommendations for their use in different treatment stages based on currently available clinical data. Novel agent combinations for the treatment of newly diagnosed, as well as relapsed multiple myeloma are examined. In addition, the role of novel agents in patients with cytogenetic abnormalities and renal impairment, as well as the management of the most frequent side effects of the novel agents are discussed. The aim of this article is to assist in treatment decisions in daily clinical practice to achieve the best possible outcome for patients with multiple myeloma.

Randomized trial of daily versus weekly administration of 2-chlorodeoxyadenosine in patients with hairy cell leukemia: a multicenter phase III trial (SAKK 32/98).

Daily administration of 2-chlorodeoxyadenosine (Cladribine, CDA) is a standard treatment for hairy cell leukemia, but may cause severe neutropenia and neutropenic fever. This trial compared toxicity and efficacy of weekly versus daily CDA administration. One hundred patients were randomized to receive standard (CDA 0.14 mg/kg/day day 1-5 [Arm A]) or experimental treatment (CDA 0.14 mg/kg/day once weekly for 5 weeks [Arm B]). The primary endpoint was average leukocyte count within 6 weeks from randomization. Secondary endpoints included response rates, other acute hematotoxicity, acute infection rate, hospital admission, remission duration, event-free, and overall survival. There was no significant difference in average leukocyte count. Response rate (complete + partial remission) at week 10 was 78% (95% confidence interval (CI) 64-88%) in Arm A and 68% (95% CI 54-80%) in Arm B (p = 0.13). Best response rates during follow-up were identical (86%) in both arms. No significant difference was found in the rate of grade 3+4 leukocytopenia (94%vs. 84%), grade 3+4 neutropenia (90%vs. 80%), acute infection (44%vs. 40%), hospitalization (38%vs. 34%), and erythrocyte support (22%vs. 30%) within 10 weeks. Overall, these findings indicate that there are no apparent advantages in toxicity and efficacy by giving CDA weekly rather than daily.

TNF-alpha alters visfatin and adiponectin levels in human fat.

Adiponectin and visfatin are newly discovered adipokines that are strongly expressed in human visceral adipose tissue. To identify new regulatory mechanisms in fat, the effect of TNF-alpha (TNF) on adiponectin, on its two receptors, and on visfatin was investigated by incubating human visceral adipose tissue from patients without diabetes mellitus with TNF for 24, 48 and 72 hours. The mRNA expression of visfatin, adiponectin, and its two receptors, as well as the protein expression of adiponectin were determined. A decrease of adiponectin mRNA expression of 97% after incubation with TNF (5.75 nmol/l) for 24 hours, a decrease of 91% after 48 hours, and a decrease of 96% after 72 hours were measured. The reduction of protein expression was measured to be 42% after 24 hours, 28% after 48 hours, and 39% after 72 hours of incubation with TNF (5.75 nmol/l). The mRNA level of adiponectin receptor 1 (AdipoR1) was elevated about 72% after 48 hours of incubation and 67% after 72 hours of incubation, whereas the mRNA expression of adiponectin receptor 2 (AdipoR2) was not altered significantly. The visfatin mRNA level was found to be highly increased by 255% after 24 hours and 335% after 48 hours and 341% after 72 hours of incubation with TNF (5.75 nmol/l). Our results support the concept of visceral adipose tissue as an endocrine organ. We demonstrate that TNF has regulatory functions on adiponectin, AdipoR1 and on visfatin in human visceral adipose tissue. TNF levels are elevated in states of obesity and insulin resistance. Due to this fact TNF could be the reason that there is a decrease in the level of adiponectin, whereas there is an increase in the level of visfatin in states of obesity and insulin resistance.

[The plasma cell myeloma--molecular pathogenesis and target therapies]. / Das Plasmazell-Myelom--von der molekularen Pathogenese zu neuen gezielten Therapien.

The cells of the malignant clone of plasmacell myeloma have cytogenetic aberrations in a substantial number of cases. Many of these abnormal karyotypes are predictive for an unfavorable outcome. Gene mutations and abnormal gene expression, particularly of oncogenes and tumor suppressor genes, are often observed in myeloma cells. The cross talk between the myeloma cells and the bone marrow microenvironment plays an important role for growth and survival of the tumor cells. As a consequence of this cell-to-cell-interaction, several cytokines are secreted. The intracellular signaling, evoked by these cytokines, leads to continuous growth and proliferation and inhibition of apoptosis. Since these molecular pathways have been defined, many new targets for therapeutical interventions become obvious. Some molecules, directed against cytokines, are under early clinical investigation. Medicaments intervening in the cross talk between the myeloma cell and the bone marrow stroma as Thalidomide, Lenalidomide or Bortezomib are already available. Many of the myeloma patients suffer from bone disease. Some new drugs inhibiting the differentiation and activation of osteoclasts are evaluated in clinical trials. These molecules will be an important contribution against the painful bone disease of plasmacell myeloma.

Combination of broad molecular screening and cytogenetic analysis for genetic risk assignment and diagnosis in patients with acute leukemia.

We evaluated the impact of genetic analysis combining cytogenetics and broad molecular screening on leukemia diagnosis according to World Health Organization (WHO) and on genetic risk assignment. A two-step nested multiplex RT-PCR assay was used that allowed the detection of 29 fusion transcripts. A total of 186 patients (104 males (56%), 174 adults (94%), 12 children (6%), 155 AML (83%), 31 ALL (17%)) characterized by morphology and immunophenotyping were included. Of these 186 patients, 120 (65%) had a genetic abnormality. Molecular typing revealed a fusion transcript in 49 (26%) patients and cytogenetic analysis revealed an abnormal karyotype in 119 (64%). A total of 27 (14%) cases were genetically classified as favorable, 107 (58%) intermediate and 52 (28%) unfavorable. For 38 (20%) patients, there was a discrepancy in the genetic risk assignments obtained from broad molecular screening and cytogenetics. Cryptic fusion transcripts in nine (5%) patients changed the genetic risk assignment in four and the WHO classification in four patients. In 34 patients (18%), cytogenetics defined the risk assignment by revealing structural and numerical chromosomal abnormalities not detected by molecular screening. Broad molecular screening and cytogenetics are complementary in the diagnosis and genetic risk assignment of acute leukemia.

Venous thromboembolism prophylaxis in acutely ill medical patients: definite need for improvement.

AIM OF THE STUDY: To examine the frequency and adequacy of thromboprophylaxis in acutely ill medical patients hospitalized in eight Swiss medical hospitals. METHODS: A cross-sectional study of 1372 patients from eight Swiss hospitals was carried out. After exclusion of patients (275) given therapeutic anticoagulation, 1097 patients were audited. The adequacy of thromboprophylaxis was assessed by comparison with predefined explicit criteria. RESULTS: Of 1097 patients, 542 (49.4%) received thromboprophylaxis. According to the explicit criteria, 644 (58.7%) should have been on prophylaxis (P < 0.001, when compared with the rate observed). The rate of prevention differed widely between hospitals (from 29.4 to 88.6%) with no difference between teaching and nonteaching hospitals. According to the explicit criteria, a substantial proportion (44.9%) of the patients who should have been treated were not. Conversely, 41.3% of the patients were unnecessarily treated. CONCLUSIONS: Even though the appropriateness of the explicit criteria used could be challenged, our data suggest that the current practice is associated with important uncertainty leading to both overuse and underuse of thromboprophylaxis in patients hospitalized in medical wards. More efforts are urgently needed to develop new or endorse existing explicit, evidence-based criteria and guidelines for thromboprophylaxis in this population of patients.

[Monoclonal gammopathies--from MGUS to myeloma]. / Monoklonale Gammopathien--vom MGUS zum Myelom.

Monoclonal gammopathies are characterized by the overproduction of a monoclonal immunoglobulin (M-Protein), which may be detected in serum or urine by protein electrophoresis and immunofixation. The presence of an M-Protein results from the proliferation of a single abnormal clone of differentiated B lymphocytes or plasma cells, and is associated with a variety of clinical conditions, ranging from asymptomatic to malignant disease. Recent years have witnessed considerable advances in the treatment of plasma cell myeloma, the most common malignant disorder of the monoclonal gammopathies. As compared with conventional-dose treatments, high-dose chemotherapy with autologous stem-cell transplantation increases response rates and overall survival of patients with myeloma who are younger than 65 years of age. Progress in supportive therapies and the development of promising new drugs such as proteasome inhibitors and thalidomide analogues may provide further benefits for myeloma patients in the future.

Subthalamic nucleus stimulation induces deficits in decoding emotional facial expressions in Parkinson's disease.

BACKGROUND: Bilateral subthalamic nucleus (STN) stimulation is recognised as a treatment for parkinsonian patients with severe levodopa related motor complications. Although adverse effects are infrequent, some behavioural disturbances have been reported. OBJECTIVE: To investigate the consequences of STN stimulation on emotional information processing in Parkinson's disease by assessing the performance of an emotional facial expression (EFE) decoding task in a group of patients before and after surgery. METHODS: 12 non-demented patients with Parkinson's disease were studied. They were assessed one month before surgery and three months after. Their ability to decode EFEs was assessed using a standardised quantitative task. Overall cognitive function, executive function, visuospatial perception, depression, and anxiety were also measured. Twelve healthy controls were matched for age, sex, and duration of education. RESULTS: Before surgery, the patients showed no impairment in EFE decoding compared with the controls. Their overall cognitive status was preserved but they had a moderate dysexecutive syndrome. Three months after surgery, they had significant impairment of EFE decoding. This was not related to their overall cognitive status or to depression/anxiety scores. Visuospatial perception was not impaired. There was no change in the extent of the dysexecutive syndrome except for a reduction in phonemic word fluency. CONCLUSIONS: Bilateral STN stimulation disturbs negative emotional information processing in Parkinson's disease. The impairment appears specific and unrelated to certain secondary variables. This behavioural complication of STN may have implications for the patient's social life.

Ampakines reduce methamphetamine-driven rotation and activate neocortex in a regionally selective fashion.

It has been proposed that glutamatergic and dopaminergic systems are functionally opposed in their regulation of striatal output. The present study tested the effects of drugs that enhance AMPA-receptor-mediated glutamatergic transmission (ampakines) for their effects on dopamine-related alterations in cortical activity and locomotor behavior. Rats with unilateral 6-hydroxydopamine lesions of the ascending nigro-striatal dopamine system were sensitized to methamphetamine and then tested for methamphetamine-induced circling behavior in the presence and absence of ampakines CX546 and CX614. Both ampakines produced rapid, dose-dependent reductions in circling that were evident within 15 min and sustained through 1 h of behavioral testing. In situ hybridization maps of c-fos mRNA expression showed that in the intact hemisphere, ampakine cotreatment markedly increased c-fos expression in parietal, sensori-motor neocortex above that found in rats treated with methamphetamine alone. Ampakine cotreatment did not augment c-fos expression in frontal, sensori-motor cortex or striatum. Still larger ampakine-elicited effects were obtained in parietal cortex of the dopamine-depleted hemisphere where labeling densities were increased by approximately 60% above values found in methamphetamine-alone rats. With these effects, the hemispheric asymmetry of cortical activation was less pronounced in the ampakine-cotreatment group as compared with the methamphetamine-alone group. These results indicate that positive modulation of AMPA-type glutamate receptors 1) can offset behavioral disturbances arising from sensitized dopamine receptors and 2) increases aggregate neuronal activity in a regionally selective manner that is probably dependent upon behavioral demands.

Acute pericarditis and pleural effusion complicating cytarabine chemotherapy.

BACKGROUND: Pericarditis is a rare but possibly severe complication of treatment of acute leukemia with cytarabine. CASE REPORT: We report a possibly cytarabine-induced acute pericarditis and pleuritis with a rapid onset. A patient with acute myelomonocytic leukemia developed an isolated pericarditis 3 weeks after the first course of chemotherapy with cytarabine and idarubicin. The second course of chemotherapy with cytarabine and amsacrine was started after clinical improvement; 3 days later an acute pericarditis with a large pericardial effusion accompanied by a left pleural effusion developed. A pericardio- and pleuracentesis was performed and the symptoms improved rapidly without reaccumulation of the fluid. The third course of chemotherapy with mitoxantrone and etoposide was completed without further cardiopulmonary complications. CONCLUSION: The differential diagnosis of pericarditis in the setting of chemotherapy with cytarabine should include cytarabine- induced pericarditis. The pathogenesis remains unclear, directly toxic and immunological mechanisms are suggested. Severe progression with massive pericardial effusion necessitating risky pericardiocentesis can occur and therefore a therapy with high-dose corticosteroids should be considered early.

The presence of an HLA-identical sibling donor has no impact on outcome of patients with high-risk MDS or secondary AML (sAML) treated with intensive chemotherapy followed by transplantation: results of a prospective study of the EORTC, EBMT, SAKK and GIMEMA Leukemia Groups (EORTC study 06921).

This report used the framework of a large European study to investigate the outcome of patients with and without an HLA-identical sibling donor on an intention-to-treat basis. After a common remission-induction and consolidation course, patients with an HLA-identical sibling donor were scheduled for allogeneic transplantation and patients lacking a donor for autologous transplantation. In all, 159 patients alive at 8 weeks from the start of treatment were included in the present analysis. In total, 52 patients had a donor, 65 patients did not have a donor and in 42 patients the availability of a donor was not assessed. Out of 52 patients, 36 (69%) with a donor underwent allogeneic transplantation (28 in CR1). Out of 65 patients, 33 (49%) received an autograft (27 in CR1). The actuarial survival rates at 4 years were 33.3% (s.e. = 6.7%) for patients with a donor and 39.0% (s.e. = 6.5%) for patients without a donor (P = 0.18). Event-free survival rates were 23.1% (s.e. = 6.2%) and 21.5% (s.e. = 5.3%), respectively (P = 0.66). Correction for alternative donor transplants did not substantially alter the survival of the group without a donor. Also, the survival in the various cytogenetic risk groups was not significantly different when comparing the donor vs the no-donor group. This analysis shows that patients with high-risk myelodysplastic syndrome and secondary acute myeloid leukemia may benefit from both allogeneic and autologous transplantation. We were unable to demonstrate a survival advantage for patients with a donor compared to patients without a donor.

Treatment of hairy cell leukemia with cladribine (2-chlorodeoxyadenosine) by subcutaneous bolus injection: a phase II study.

BACKGROUND: To assess the activity and toxicity of 2-chlorodeoxyadenosine (cladribine, CDA) given by subcutaneous bolus injections to patients with hairy cell leukemia (HCL). PATIENTS AND METHODS: Sixty-two eligible patients with classic or prolymphocytic HCL (33 non-pretreated patients, 15 patients with relapse after previous treatment, and 14 patients with progressive disease during a treatment other than CDA) were treated with CDA 0.14 mg/kg/day by subcutaneous bolus injections for five consecutive days. Response status was repeatedly assessed according to the Consensus Resolution criteria. RESULTS: Complete and partial remissions were seen in 47 (76%) and 13 (21%) patients, respectively, for a response rate of 97%. All responses were achieved with a single treatment course. Most responses occurred early (i.e. within 10 weeks) after start of CDA therapy, but response quality improved during weeks and even months after treatment completion. The median time to treatment failure for all patients was 38 months. Leukopenia was the main toxicity. Granulocyte nadir (median 0.2 x 10(9)/l) was strongly associated with the incidence of infections (P = 0.0013). Non-specific lymphopenia occurred early after CDA treatment, and normal lymphocytes recovered slowly over several months. No significant associations were found between infections and nadir count of lymphocytes or any lymphocyte subpopulation. No opportunistic infections were observed. CONCLUSIONS: One course of CDA given by subcutaneous bolus injections is very effective in HCL. The subcutaneous administration is more convenient for patients and care providers, and has a similar toxicity profile to continuous intravenous infusion. The subcutaneous administration of CDA is a substantial improvement and should be offered to every patient with HCL requiring treatment with CDA.

[Electrochemical reduction of pentaerythrityltetranitrate (PETN) and metabolites]. / Elektrochemische Reduktionen von Pentaerythrityltetranitrat (PETN) und seinen Metaboliten im Kontext pharmakologischer Wirkungen.

The reduction-cascade of PETN is described as a combination of cyclic-voltammetric measurements and analytical results together with synthesis of PETN-metabolites; furthermore the electroreduction of pentaerythityldinitrate (PEDN) in the presence and absence of cystine as well as cystine and electrogenerated superoxide-radicalanions to elucidate the interaction of PETN with thiol-species. PETN was recognized as precursor for a initial radicalic process, followed by intermediate formation of pentaerythityltrinitratealdehyde (PENA) inside a self-reducing nitrate-system with NO as final product, which may explain its special position in comparison with other pharmaceutically applied nitratestructures. It could be proved, that a cystine-pool reacts as a selective moderator inside the reduction of PEDN without being interfered by O2.-, yielding pentaerythitylmononitrate (PEMN) meanwhile in the absence of cystine only pentaerythrite (PE) is formed.

Weekly x 4 induction therapy with the anti-CD20 antibody rituximab: effect on circulating t(14;18)(+) follicular lymphoma cells.

Rituximab 375 mg/m(2) weekly x 4 has been reported to induce a 60% response rate in patients with relapsed follicular lymphomas (FL). Our aim was to examine the effect of this rituximab schedule on circulating FL cells in an ongoing multicenter study. One hundred fifty-four patients with FL were examined by nested polymerase chain reaction (PCR) at baseline for the presence of t(14;18) translocation-carrying lymphoma cells in bone marrow and/or blood. Sixty-four patients (42%) had PCR-detectable t(14;18)(+) FL cells. Pretreatment characteristics of these 64 patients were as follows: one had stage I, nine had stage II, 14 had stage III, and 40 had stage IV disease. Thirty-five patients had bulky disease (> or = 5 cm) and 25 patients had an elevated serum lactate dehydrogenase (LDH) level. Bone marrow was morphologically assessed in 64 patients, and 39 of these patients had an infiltration with FL cells. Blood samples from 51 patients were available for PCR analysis between weeks 8-12 after induction therapy, and 28 of these patients (55%) were PCR negative. Paired blood and bone marrow samples were available for PCR analysis from 39 patients between weeks 8-12 after induction therapy with rituximab. Thirteen of these patients (33%) did not have PCR-detectable cells in blood and bone marrow, while 26 patients (67%) still had circulating t(14;18)(+) cells in either bone marrow (eight patients), blood (one patient), or both (17 patients). PCR negativity in blood and bone marrow in 13 patients was statistically significantly associated with partial or complete response after induction therapy with rituximab (P = 0.006). However, clearance of PCR-detectable t(14;18)(+) cells in bone marrow and/or blood could not be associated with any low tumor burden pretreatment characteristics such as stages I/II, absence of morphological bone marrow infiltration or tumor bulk of > or = 5 cm, and normal serum LDH.

Deficits in recognition of emotional facial expression are still present in alcoholics after mid- to long-term abstinence.

OBJECTIVE: Emotional facial expression (EFE) decoding skills play a key role in interpersonal relationships. Decoding errors have been described in several pathological conditions, including alcoholism. The aim of this study was to investigate whether EFE decoding skill deficits persist after abstention from alcohol of at least 2 months. METHOD: Alcoholic patients abstinent for at least 2 months (n = 25) were compared with 25 recently detoxified patients and with 25 normal controls matched for age, gender and educational level. Subjects were presented with 40 photographs of facial expressions portraying happiness, anger, sadness, disgust and fear. Each emotion was displayed with neutral, mild, moderate and strong emotional intensity. Each facial expression was judged successively on eight scales labeled happiness, sadness, fear, anger, disgust, surprise, shame and contempt. For each scale, subjects rated the estimated intensity level. A complementary scale assessed the self-estimated difficulty in performing the task. RESULTS: Recently detoxified alcoholics were significantly less accurate than controls, making more EFE labeling errors and overestimating the intensity of the portrayed emotions. Deficits in decoding accuracy for anger and disgust were present in mid- to long-term abstinent patients; intensity overestimation was present in the former and absent in the latter. CONCLUSIONS: Deficits in decoding accuracy for anger and disgust, and to a lesser degree sadness, persist with an abstinence of 2 months and beyond. Right frontotemporal regions and cingulate could be implicated. These deficits may contribute to the social skills deficits frequently encountered in alcoholic patients.

Potentiation of sildenafil-induced hypotension is minimal with nitrates generating a radical intermediate.

Recently the new specific phosphodiesterase-5 inhibitor sildenafil was introduced into therapy for erectile dysfunction. Because of the phosphodiesterase-5 inhibitor-induced increases of cyclic GMP in the vasculature, vasodilation in various vascular beds is induced, which in combination with various nitrovasodilators (e.g., when used simultaneously for the treatment of coronary artery disease), may lead to excessive hypotension. Thus nitrovasodilators are contraindicated when sildenafil may be used and reports of a number of accidents have recently been published. We therefore studied the acute interactions of glyceryl trinitrate (GTN), pentaerythritol tetranitrate (PETN), and isosorbide dinitrate (ISDN) with sildenafil in six chronically instrumented conscious dogs for each nitrate to assess the magnitude of blood pressure drops (and compensatory increases in heart rate) during a 24-h nitrate administration (infusion into the pulmonary artery). Sildenafil (3 mg/kg) was given orally (after a 24-h fast) 30 min after start of nitrate infusion. GTN, PETN, or ISDN (which follow different steps of metabolic conversion to nitric oxide) were applied at submaximal dosages leading to 90% of maximal coronary artery dilation at 1.5 microg/kg per min, 0.75 microg/kg per min, or 6 microg/kg per min, respectively. During GTN infusion sildenafil caused a maximum drop in mean blood pressure of 21 +/- 3 mm Hg (rise in heart rate from 117.0 +/- 7.2 to 126.0 +/- 6 .0/min) and during ISDN infusion of 18 +/- 3 mm Hg (rise in heart rate from 115.0 +/- 7.0 to 125 +/- 6/min), which was significantly less (p < 0.01) during PETN (only 6 +/- 1 mm Hg with a rise in heart rate from 107.0 +/- 5.0 to 122.0 +/- 7.0/min). When sildenafil is used during exposure to nitrates (e.g., in coronary artery disease), the PETN-induced drop in blood pressure at equi-effective dosages (with regard to coronary dilation) is substantially smaller compared with that of GTN or ISDN, which is probably because of lesser potentiation of phosphodiesterase-5 inhibitor-induced effects in the arteriolar bed, thus minimizing critical drops in blood pressure.