Differences between intravenous iron products: focus on treatment of iron deficiency in chronic heart failure patients

Iron deficiency is the leading cause of anaemia and is highly prevalent in patients with chronic heart failure (CHF). Iron deficiency, with or without anaemia, can be corrected with intravenous (i.v.) iron therapy. In heart failure patients, iron status screening, diagnosis, and treatment of iron deficiency with ferric carboxymaltose are recommended by the 2016 European Society of Cardiology guidelines, based on results of two randomized controlled trials in CHF patients with iron deficiency. All i.v. iron complexes consist of a polynuclear Fe(III)‐oxyhydroxide/oxide core that is stabilized with a compound‐specific carbohydrate, which strongly influences their physico‐chemical properties (e.g. molecular weight distribution, complex stability, and labile iron content). Thus, the carbohydrate determines the metabolic fate of the complex, affecting its pharmacokinetic/pharmacodynamic profile and interactions with the innate immune system. Accordingly, i.v. iron products belong to the new class of non‐biological complex drugs for which regulatory authorities recognized the need for more detailed characterization by orthogonal methods, particularly when assessing generic/follow‐on products. Evaluation of published clinical and non‐clinical studies with different i.v. iron products in this review suggests that study results obtained with one i.v. iron product should not be assumed to be equivalent to other i.v. iron products that lack comparable study data in CHF. Without head‐to‐head clinical studies proving the therapeutic equivalence of other i.v. iron products with ferric carboxymaltose, in the highly vulnerable population of heart failure patients, extrapolation of results and substitution with a different i.v. iron product is not recommended.

Beyond the cardiorenal anaemia syndrome: recognizing the role of iron deficiency

Growing awareness that heart failure, renal impairment, and anaemia are frequent co-morbidities which can exacerbate one another in a vicious circle of clinical deterioration has led to the concept of the cardiorenal anaemia syndrome (CRAS). The role of iron deficiency within this complex interplay has been less well examined. Scrutiny of data from the recent FAIR-HF trial raises a new hypothesis: is it time for ‘CRAS’ to be supplemented with new acronyms such as CRIDS (cardiorenal–iron deficiency syndrome) or even CRAIDS (cardiorenal–anaemia–iron deficiency syndrome)? Iron deficiency occurs frequently in heart failure patients with or without anaemia. It not only impairs oxygen transport through reduced erythropoiesis, but adversely affects oxidative metabolism, cellular energetics, and immune mechanisms, and the synthesis and degradation of complex molecules such as DNA. One large observational study in patients with heart failure found iron deficiency to be an independent predictor of death or urgent heart transplantation (hazard ratio 1.58, 95% confidence interval 1.14–2.17, P = 0.005). In the FAIR-HF trial, i.v. iron therapy was associated with significant improvements in physical functioning in iron-deficient patients with heart failure, even in non-anaemic patients in whom haemoglobin levels did not change following i.v. iron administration. Key questions regarding the use of i.v. iron supplementation in the setting of heart failure merit exploration and could readily be answered by appropriately designed clinical trials. It is to be hoped that these important clinical trials are conducted, to permit a more subtle characterization of the patient's pathological condition and interventional requirements.

Positional therapy for obstructive sleep apnea patients: A 6-month follow-up study

BACKGROUND

Approximately half of obstructive sleep apnea (OSA) patients are positional (i.e., the majority of their breathing abnormalities during sleep appear in the supine posture). Little information exists as to whether avoiding the supine posture during sleep (positional therapy) is a valuable form of therapy for these patients.

AIM

To assess the use of positional therapy (by the tennis ball technique [TBT]) during a 6 month period in 78 consecutive positional OSA patients.

METHODS

Demographic, polysomnographic, and self-reported questionnaire data on the use of the TBT were analyzed.

RESULTS

Of the 50 patients who returned the questionnaire, 19 (38%) (group A) said they were still using the TBT, and 12 (24%) (group B) said they used it initially and stopped using it within a few months but were still avoiding the supine position during sleep. Nineteen patients (38%) (group C) stopped using the TBT within a few months but did not learn how to avoid the sleep supine posture. Patients still using the TBT showed a significant improvement in their self-reported sleep quality (P < .005) and daytime alertness (P < .046) and a decrease in snoring loudness (P < .001). Patients of groups A and B were older than patients who did not comply with this therapy (P < .001). The main reason for patients stopping the use of the TBT in group C was that using it was uncomfortable.

CONCLUSIONS

Positional therapy appears to be a valuable form of therapy mainly for some older aged positional OSA patients.

Erythropoietin improves anemia exercise tolerance and renal function and reduces B-type natriuretic peptide and hospitalization in patients with heart failure and anemia

BACKGROUND

Anemia is now recognized as being a common finding in CHF and is associated with increased mortality and morbidity. However, it is uncertain whether the anemia is actually causing the worse prognosis or is merely a marker of more severe cardiac disease. Previous intervention studies with subcutaneous (s.c.) beta-EPO in combination with iron have either been uncontrolled or case-controlled studies. We report a randomized, double-blind, placebo-controlled study of the combination of s.c. EPO and oral iron versus oral iron alone in patients with anemia and resistant CHF.

OBJECTIVES

The present study examines, in patients with advanced congestive heart failure (CHF) and anemia, the effects of beta-erythropoietin (EPO) and oral iron on the anemia and on cardiac and renal functional parameters.

METHODS

Forty consecutive subjects with moderate to severe CHF and anemia (hemoglobin [Hb] <11 g/dL) were studied. They were randomized to receive, in a double-blind fashion, either (a) (group A, the treatment group, 20 patients) s.c. beta-EPO for 3 months twice weekly, in addition to daily oral iron, or (b) (group B, the placebo group, 20 patients) normal saline in s.c. injections and daily oral iron. Two patients in group B were eventually excluded because of a fall of Hb <8 g/dL requiring transfusion, leaving 18 patients in group B. After the 3-months study, the group A patients were maintained on the same treatment for an additional 9 months, whereas in Group B, the placebo and oral iron were stopped.

RESULTS

In group A, after a mean of 3.5 +/- 0.8 months of treatment, there was a significant increase in Hb from 10.4 +/- 0.6 to 12.4 +/- 0.8 g/dL (P < .01); a significant improvement in New York Heart Association functional class from 3.5 +/- 0.6 to 2.8 +/- 0.5 (P < .05); a longer endurance time on exercise testing, from 5.8 +/- 2.2 to 7.8 +/- 2.5 minutes (P < .01); a greater distance walked on exercise testing, from 278 +/- 55 to 356 +/- 88 meters (P < .01); a significant increase in the peak oxygen consumption (VO2) from 12.8 +/- 2.8 to 15.1 +/- 2.8 mL/kg per minute (<.05); and the VO2 at the anaerobic threshold, from 9.2 +/- 2.0 to 13.2 +/- 3.6 mL/kg minute (P < .01). There was also a significant fall in plasma B-type natriuretic peptide levels from 568 +/- 320 to 271 +/- 120 pg/mL (P < .01), a significant reduction in serum creatinine (P < .01), and an increase in estimated creatinine clearance (P < .05). In group B, there were no significant changes in any of the above parameters over the study period. At the end of the 1-year study, the Hb was still higher in group A than group B, and the rate of hospital admissions/patients over the year averaged 0.8 +/- 0.2 in group A and 1.7 +/- 0.8 in group B (P < .01).

CONCLUSIONS

In anemic CHF patients, correction of anemia with EPO and oral iron leads to improvement in New York Heart Association status, measured exercise endurance, oxygen use during exercise, renal function and plasma B-type natriuretic peptide levels and reduces the need for hospitalization.

Preoperative gemcitabine (G) and docetaxel (D) in patients (pts) with stage IB, II, or III non-small cell lung cancer (NSCLC): A phase II trial of the Minnie Pearl Cancer Research Network

17007

Background: Preoperative chemotherapy may improve outcomes for pts with resectable NSCLC compared with surgery alone. This multicenter community-based phase II trial examined the role of preoperative G/D for pts with resectable NSCLC. Methods: The primary endpoint was to assess the response rate (RR) of G/D in pts with potentially resectable clinical stages IB, II, and selected III NSCLC [T3N1, T1–3N2 (1 nodal station ≤2 cm), T4N0, T4N1 excluding vascular, tracheal, esophageal, vertebral disease, or malignant effusions]. Treatment included: D 30 mg/m2 IV and G 1000 mg/m2 IV D1,8 Q 21D × 3 cycles. Pts were restaged after treatment and resected 3–6 weeks later. Eligibility included: measurable disease, ECOG PS 0–1, adequate organ function, informed consent. Analysis was by intent to treat. Results: Fifty-four pts were enrolled between 4/04 and 9/05. Baseline features include: median age 62 years (42–82); male/female, 44%/56%; ECOG PS 0/1: 50%/50%; adenocarcinoma (28%), squamous (43%), large cell (9%), mixed/not specified (20%); IB (30%), IIA (5%), IIB (19%), IIIA (33%), IIIB (13%). Forty-eight pts (91%) completed preoperative treatment and 32 pts (60%) underwent resection. Grade 3/4 hematologic and non-hematologic toxicities were limited to neutropenia (20%) and infection (8%), respectively. All other toxicities were <5%. There were no treatment-related deaths. Complete/partial responses for all pts were observed in 1 pt/16 pts, respectively, for an overall RR of 31% (95% CI 20%–44%). Twenty-five pts (46%) had stable disease, and 11% had progression (6 pts were unevaluable.) No pathological complete responses were observed in 32 resected pts. After a median follow-up of 12 months, actuarial 1-year progression-free survival and overall survival (OS) are 54% and 79%, respectively. Median OS has not been reached. Conclusions: G/D is a well-tolerated preoperative regimen for pts with resectable NSCLC with activity rivaling platinum-based regimens. Further follow-up and additional studies comparing preoperative and adjuvant treatment are needed to assess the benefit of this regimen.

[Table: see text]

Iron deficiency is a common cause of anemia in chronic kidney disease and can often be corrected with intravenous iron

BACKGROUND

There is some epidemiological and clinical evidence that the anemia seen in chronic kidney disease (CKD) in patients not on dialysis could be due to a significant extent to iron deficiency, and that adequate iron replacement could cause a marked improvement in the anemia even without the use of erythropoietin (EPO). The purpose of this work was to study the effects of intravenous (i.v.) iron administration (ferric gluconate - Ferrlecit) on hemoglobin (Hb) of patients with CKD.

METHODS

Forty-seven consecutive patients with CKD with Hb <12 g/dL in whom no underlying cause for the anemia could be found underwent sternal bone marrow biopsy and had their red cell and blood iron parameters measured. They then received 250 mg of ferric gluconate (Ferrlecit) intravenously twice monthly for 3 months, and had their blood parameters measured 1 month later. No patient received erythropoietin (EPO).

RESULTS

Forty-six patients had no evidence of any iron deposits in the bone marrow - consistent with the presence of severe iron deficiency. The mean serum ferritin and %transferrin saturation prior to treatment were 235.9 +/- 54.3 ug/L and 13.5 +/- 4.1%, respectively, and both increased significantly with the iron treatment. Mean Hb increased from 10.16 +/- 1.32 to 11.96 +/- 1.52 g/dL, an increase of 1.80 +/- 1.72 g/dL (p<0.01). Twenty-six patients (55.3%) reached the target Hb of 12 g/dL. Ten patients (21.3%) had an increase of 0.1-0.9 g/dL, nine patients (19.1%) had an increase of 1-1.9 g/dL and 23 patients (48.9%) had an increase of >or= 2 g/dL.

CONCLUSIONS

Iron deficiency is frequently seen in anemic CKD patients not on dialysis and its correction with i.v. iron will often cause a marked increase in the Hb level, and the achievement of the target Hb of 12 g/dL even without EPO.

Anaemia as a contributor to morbidity and mortality in congestive heart failure

Anaemia is present in approximately 40% of cases of congestive heart failure (CHF) and is associated with a higher mortality, a lower left ventricular ejection fraction, a lower cardiac functional status, a higher rate of hospitalization, signs of malnutrition, a lower exercise capacity, a progressive fall in renal function, an increased need for high dose diuretics, hyponatraemia, an increased plasma volume, a reduced red cell volume and a lower quality of life. In both uncontrolled and controlled studies, correction of the anaemia with subcutaneous erythropoietin and, in some cases, with the addition of intravenous iron, has been shown to improve these parameters. A vicious circle is present between CHF, chronic kidney insufficiency (CKI) and anaemia, each capable of causing or being caused by the other, the so-called cardio renal syndrome. If larger randomized, controlled, double-blind studies confirm these observations, correction of the anaemia may prove to be a useful addition to the prevention and progression of both CHF and CKI. Cooperation between nephrologists, cardiologists and other internists to identify and treat these anaemic CHF patients early will help prevent progression of both the cardiac and renal disease.

Prevalence of anemia in patients admitted to hospital with a primary diagnosis of congestive heart failure

OBJECTIVES

To find the prevalence of anemia in patients hospitalized with the primary diagnosis of congestive heart failure (CHF).

BACKGROUND

There is growing evidence that anemia is common in CHF and may contribute to the high morbidity and mortality associated with this condition. However, there is considerable disagreement about the prevalence of anemia in this condition.

METHODS

In 338 consecutive patients who were admitted to the medical wards with a primary diagnosis of CHF we extracted from the charts the hemoglobin (Hb), serum creatinine, age, sex, New York Heart Association (NYHA) functional class, presence of smoking, diabetes, hypertension, hyperlipidemia and the primary cardiac etiology of the CHF. Anemia was considered to be present when the Hb on admission was <12 g/dl.

RESULTS

All the patients were NYHA functional class III-IV. One hundred seventy seven (52.4%) of the 338 patients had a Hb on admission that was <12 g/dl. The mean Hb for the entire group was 12.0+/-1.8 g/dl. One hundred three (51.0%) of the 202 males were anemic compared to 74 (54.4%) of the 136 women. The mean serum creatinine was 1.7+/-1.1 mg/dl. The prevalence of renal insufficiency (serum creatinine >1.5 mg%) was 47.6%. There was a negative correlation between the level of serum creatinine and Hb (r=-0.294) P<0.00001. Of the 177 patients who were anemic, most of 114 (64.4%) had a serum creatinine >1.5 mg/dl.

CONCLUSIONS

Anemia is a common finding in patients hospitalized with CHF and most anemic CHF patients have some degree of renal insufficiency. In view of the negative effect of anemia on cardiac function, it may be a common and important contributor to the mortality and morbidity of CHF in these patients.

The cardio-renal anaemia syndrome: does it exist?

Many patients in our nephrology department who have anaemia and chronic kidney insufficiency (CKI) show evidence of congestive heart failure (CHF). This triad of anaemia, CKI and CHF is known as the cardio-renal anaemia syndrome. The three conditions form a vicious circle, in which each condition is capable of causing or being caused by another. Anaemia can increase the severity of CHF and is associated with a rise in mortality, hospitalization and malnutrition. Anaemia can also further worsen renal function and cause a more rapid progression to dialysis than is found in patients without anaemia. Uncontrolled CHF can cause rapid deterioration of renal function and anaemia. CKI can also cause anaemia, as well as worsen the severity of CHF, and is associated with increased mortality and hospitalization in patients with CHF. Aggressive therapy against CHF with all the conventional medications at the accepted doses often fails to improve the CHF if anaemia is also present but is not treated. In studies in which the anaemia was corrected with s.c. erythropoietin and, in some cases, with i.v. iron, however, the cardiac function improved, as assessed by measurement of the left ventricular ejection fraction and oxygen utilization during maximal exercise. Symptomatic patient functioning improved, as monitored by shortness of breath and fatigue on exertion, and the need for hospitalization and oral and i.v. diuretics markedly decreased. The quality of life, as judged by different criteria, also improved. The glomerular filtration rate, which fell rapidly when the anaemia was untreated, stabilized in patients when their anaemia was treated. Nephrologists need to assess the cardiac status of all patients with CKI carefully, and this includes an echocardiogram along with possibly measuring the levels of B-type natriuretic peptide. Nephrologists also need to use the indicated agents for CHF at the recommended doses, while cardiologists and internists need to be more aware of the importance and lethal effects of even mild anaemia and the benefits of its treatment in CHF and CKI. Cooperation between these specialists will allow better and much earlier treatment of the anaemia, CHF and CKI, and prevent the deterioration of all three conditions.

The association between congestive heart failure and chronic renal disease

PURPOSE OF REVIEW

Recent findings on the relationship between congestive heart failure and renal failure are summarized in this review.

RECENT FINDINGS

Congestive heart failure is found in about one-quarter of cases of chronic kidney disease. The most common cause of congestive heart failure is ischemic heart disease. The prevalence of congestive heart failure increases greatly as the patient's renal function deteriorates, and, at end-stage renal disease, can reach 65-70%. There is mounting evidence that chronic kidney disease itself is a major contributor to severe cardiac damage and, conversely, that congestive heart failure is a major cause of progressive chronic kidney disease. Uncontrolled congestive heart failure is often associated with a rapid fall in renal function and adequate control of congestive heart failure can prevent this. The opposite is also true: treatment of chronic kidney disease can prevent congestive heart failure. There is new evidence showing the cardioprotective effect of carvedilol in patients on dialysis, and of simvastatin and eplerenone in patients with congestive heart failure. Use of non-steroidal anti-inflammatory drugs doubles the rate of hospitalization in patients with congestive heart failure. Anemia has been found in one-third to half the cases of congestive heart failure, and may be caused not only by chronic kidney disease but by the congestive heart failure itself. The anemia is associated with worsening cardiac and renal status and often with signs of malnutrition. Control of the anemia and aggressive use of the recommended medication for congestive heart failure may improve the cardiac function, patient function and exercise capacity, stabilize the renal function, reduce hospitalization and improve quality of life. Congestive heart failure, chronic kidney disease and anemia therefore appear to act together in a vicious circle in which each condition causes or exacerbates the other. Both congestive heart failure and anemia are often undertreated. Cooperation between nephrologists and other physicians in the treatment of patients with anemic congestive heart failure may improve the quality of care and the subsequent prognosis for both congestive heart failure and chronic kidney disease.

SUMMARY

Adequate and early detection and aggressive treatment of congestive heart failure and chronic kidney disease and the associated anemia may markedly slow the progression of both diseases.

Outcomes of anaemia management in renal insufficiency and cardiac disease

Cardiac disease represents a major cause of morbidity and mortality in dialysis patients, and is also a well-established feature of chronic kidney disease (CKD). Anaemia has also been shown to be a key component not only of dialysis and CKD but also of cardiac disease, including congestive heart failure (CHF). Furthermore, published clinical and laboratory data suggest that anaemia, CHF and CKD are interrelated, each causing the other to worsen and thus resulting in a 'vicious cycle' of disease progression which we have called the Cardio-Renal Anaemia syndrome. In this syndrome anaemia may cause CKD or be caused by CKD, anaemia may cause CHF or be caused by CHF and CHF may cause CKD or be caused by CKD. Numerous publications have borne out the fact that anaemia correction through epoetin treatment provides great benefit to CKD patients. Additionally, there is evidence to suggest that these benefits may be extended to patients with cardiac disease. Uncontrolled and controlled studies of the effect of subcutaneous epoetin treatment in anaemic patients with both CHF and CKD show significant improvements in both cardiac and renal function. Despite these findings, however, it is apparent that anaemia correction is not implemented rigorously within both CHF and CKD populations. Greater awareness of the need for early anaemia correction therapy is therefore required. Cooperation between nephrologists and others who are caring for CHF patients, especially cardiologists, is crucial.

The effect of articular malposition after total shoulder arthroplasty on glenohumeral translations, range of motion, and subacromial impingement

The articular surface of the normal humeral head has a variable posterior and medial offset with respect to the central axis of the humeral shaft. Recreation of the normal humeral head shaft offset is postulated to be an important consideration during shoulder arthroplasty. However, the effect of humeral head malposition is unknown. The purpose of this study was to determine the effect of articular malposition after total shoulder arthroplasty on glenohumeral translation, range of motion, and subacromial impingement. Twenty-one human cadavers were dissected and tested with the use of an active or passive shoulder model. Range of motion and translation were recorded by means of an electromagnetic tracking device. The experiment was performed in 2 phases. For kinematics study, 11 cadaver shoulders were positioned both passively and actively from maximum internal rotation to maximum external rotation at 90 degrees of total elevation in the scapular plane. Three rotator cuff and 3 deltoid muscle lines of action were simulated for active joint positioning. Passive joint positioning was accomplished with the use of a torque wrench and a nominal centering force. The testing protocol was used for the natural joint as well as for 9 prosthetic head locations: centered and 2- and 4-mm offsets in the anterior, posterior, inferior, and superior directions. Repeated-measures analysis of variance was used to test for significant differences in the range of motion and translation between active and passive positioning of the natural joint as well as all prosthetic head positions. (2) For impingement study, 10 cadaver shoulders were used in a passive model, loading the tendons of the rotator cuff with a 30-N centering force. The humerus was passively rotated from maximum internal rotation (1500 Nmm) to maximum external rotation (1500 Nmm) by means of a continuous-recording digital torque wrench. Trials were performed with the use of centered, 4-, 6-, and 8-mm offset heads in the anterior, posterior, superior, and inferior positions before and after removal of the acromion and coracoacromial ligament. The relation between change in mean peak torque (with and without acromion), passive range of motion, and humeral head offset was analyzed by means of repeated-measures analysis of variance. In the kinematics study, total range of motion and all humeral translations were greater with passive joint positioning than with active positioning (P =.01) except for total superior-inferior translation and superior-inferior translation in external rotation. Anterior to posterior humeral head offset was associated with statistically significant changes in total range of motion (P =.02), range of internal rotation (P =.02), range of external rotation (P =.0001), and total anterior-posterior translation (P =.01). Superior to inferior humeral head offset resulted in statistically significant changes in total range of motion (P =.02), range of internal rotation (P =.0001), anterior-posterior translation during external rotation (P =.01), and total superior-inferior translation (P =.03). In the impingement study, there was a significant increase in torque from centered to 4-mm inferior offset (P =.006), 6-mm inferior offset (P <.001), and 8-mm inferior offset (P <.001). There was no significant increase in torque with superior, anterior, and posterior offsets. Glenohumeral motion significantly decreased from 129 degrees for centered head to 119 degrees for 8-mm superior (P =.002), 119 degrees for 8-mm anterior (P =.014), 118 degrees for 8-mm inferior (P <.001), and 114 degrees for 8-mm posterior (P =.001). Humeral articular malposition of 4 mm or less during prosthetic arthroplasty of the glenohumeral joint may lead to small alterations in humeral translations and range of motion. Inferior malposition of greater than 4 mm can lead to increased subacromial contact; offset of 8 mm in any direction results in significant decreases in passive range of motion. Therefore if subacromial contact is to be minimized and glenohumeral motion maximized after shoulder replacement, anatomic reconstruction of the humeral head-humeral shaft offset to within 4 mm is desirable.

Obstructive sleep apnea and hypertension: from correlative to causative relationship

Sleep-disordered breathing, manifested by repetitive episodes of partial or complete cessation of breathing during sleep associated with brief arousal and autonomic activation, is estimated to affect as many as 4% of adult men and 2% of adult women. Studies conducted during the 1980s revealed a strong association between sleep-disordered breathing and hypertension. The results of these early studies, which relied on relatively small samples of patients, have been confirmed in recent years by large-scale epidemiologic studies that are controlled for all possible confounding factors. This paper reviews the evidence suggesting a causative relationship between hypertension and disordered breathing in sleep. The authors discuss the possible underlying mechanisms of the two entities and address the clinical implications of this relationship. They conclude by recommending a proactive approach to the diagnosis of breathing disorders in sleep, in order to prevent the cardiovascular sequelae of this syndrome.

[Acute colonic pseudo-obstruction]

Colonic Pseudo-obstruction is a poorly understood syndrome. It was first described by Ogilvie in 1948 and is characterized by signs of large bowel obstruction with a non-mechanical etiology. The suggested cause of this pathophysiology is an imbalance in the autonomic nerve supply to the colon. The syndrome affects mainly old, bedridden patients, usually hospitalised for non-colonic causes. The actual incidence of this syndrome is unknown, mainly due to the fact that spontaneous recovery may occur. When massive abdominal distention is apparent, diagnosis and treatment are usually problematic and other causes of obstruction must be ruled out. It is usually managed by water soluble contrast administered orally or rectally, or by colonic decompression. In extreme cases surgical treatment is required with significant morbidity and mortality. Pharmacologic management with parasympathomimetic drugs has been suggested recently. We describe the successful treatment of a patient with neostigmine and review the current literature.

Methylene blue, a nitric oxide inhibitor, prevents haemodialysis hypotension

BACKGROUND

Plasma nitric oxide (NO) levels have been found to be high in haemodialysis (HD) patients, especially in those prone to hypotension in dialysis. The aim of the study was to prevent dialysis hypotension episodes by i.v. administration of methylene blue (MB), an inhibitor of NO activity and/or production.

METHODS

MB was given i.v. in 18 stable HD patients with hypotensive episodes during almost every dialysis, in 18 HD patients without hypotension during dialyses, and in five healthy controls. MB was given as a bolus of 1 mg/kg bodyweight followed by a constant infusion of 0.1 mg/kg bodyweight lasting 210 min until the end of the dialysis session and only as a bolus on a non-dialysis day. Systolic and diastolic blood pressures (BP) were measured at 10-min intervals during HD sessions with or without MB and on a non-dialysis day with MB.

RESULTS

In hypotension-prone patients, MB completely prevented the hypotension during dialysis and increased both systolic and diastolic BP on non-dialysis days. In normotensive patients, MB increased BP during the first hour of dialysis and for 90 min on the non-dialysis day. The BP in the healthy controls remained unchanged. Plasma and platelet NO(2)+NO(3) (stable metabolites of NO) levels were determined. The NO(2)+NO(3) generation rate in the first post-dialysis day was calculated. The plasma and platelet NO(2)+NO(3) were higher in the hypotensive group than in the normotensive dialysis group. The generation rate of nitrates was higher (P<0.01) in the hypotensive group (1.21+/-0.13 micromol/min and 0.74+/-0.16 after MB) than in the normotensive patients (0.61+/-0.11 micromol/ min and 0.27+/-0.14 after MB). No side-effects were recorded.

CONCLUSIONS

MB is an efficient therapy in the prevention of dialysis hypotension.

Low nitric oxide production in patients with chronic renal failure

BACKGROUND

Rats with chronic renal failure have a low nitric oxide (NO) production and a diminished NO excretion. The supplementation of L-arginine has an inhibitory effect on the progression of renal insufficiency.

METHODS

The present study was designed to determine whether chronic renal failure patients have a low NO production. Plasma and urine nitrate (NO3) and nitrite (NO2), stable metabolites of NO, were measured in 83 consecutive patients with chronic renal failure. The 83 chronic renal failure patients were divided into three groups: group 1, mild renal failure (creatinine clearance >60 ml/min/1.73 m2); group 2, moderate renal failure (creatinine clearance >30 <60 ml/min/1.73 m2), and group 3, severe renal failure (creatinine clearance <30 ml/min/1.73 m2). Thirty-three healthy volunteers served as controls.

RESULTS

The daily urinary NO excretion was significantly lower in patients with moderate and severe renal failure as compared with those with mild renal failure and normal controls. The lowest values were found in the severe renal failure group. When the 24-hour urinary NO excretion or NO per milligram creatinine and the NO clearance were correlated with the renal function in all patients as a group, these parameters were directly correlated with the creatinine clearance and inversely correlated with the serum creatinine level. The plasma NO concentration was not different between the three chronic renal failure groups, but higher than in the controls. Plasma NO in renal failure patients was not correlated with the creatinine clearance or serum creatinine levels.

CONCLUSIONS

Chronic renal failure is a state of NO deficiency. Treatment strategies to increase NO production (L-arginine supplementation or other NO compounds) may prove to be useful in maintaining the renal function and slow the progression of renal disease.

Treatment of acute colonic pseudo-obstruction with neostigmine

BACKGROUND

Colonic pseudo-obstruction is a poorly understood syndrome, described by Ogilvie, and characterized by signs of large-bowel obstruction, without a mechanical cause. An imbalance in the autonomic nerve supply to the colon has been suggested as the pathophysiology. Recently, promising results with pharmacologic manipulation with neostigmine have been described.

STUDY DESIGN

A prospective study was undertaken with 11 consecutive patients with clinical and radiologic signs of colonic pseudo-obstruction, in one general hospital, over a 1-year period. Patients were treated primarily with 2.5 mg of neostigmine in 100 mL of saline for 1 hour, under cardiac monitoring. Results were assessed by the clinical and radiologic responses.

RESULTS

Rapid and effective spontaneous decompression of the colon was achieved in 8 patients after a single dose of neostigmine, within a mean of 90 minutes from the beginning of treatment. In another two patients decompression occurred only after a second dose was administered 3 hours after the first dose. In one patient, no changes were observed and colonoscopic decompression was performed. No significant bradycardia was observed in any of the patients.

CONCLUSIONS

Neostigmine is a simple, safe, and effective therapy for treatment of colonic pseudo-obstruction.

Pregnancy decreases immunoreactive parathyroid hormone level in rats with chronic renal failure

Normal pregnancy is associated with an increase in serum parathyroid hormone and 1,25-dihydroxyvitamin D3 (calcitriol). The effect of pregnancy on these hormones in chronic renal failure (CRF) is unknown. The present work was undertaken to study the changes of serum immunoreactive parathyroid hormone (iPTH) and calcitriol in pregnant rats with CRF. The following experimental groups were studied: CRF1 (5/6 nephrectomized virgin female rats), CRF2 (5/6 nephrectomized pregnant rats at day 20-21 of pregnancy), CRF3 (5/6 nephrectomized rats 2 weeks after delivery) and their respective sham-operated control groups: N1, N2 and N3. The 5/6 nephrectomy (CRF1) resulted in renal failure with very high serum iPTH (100+/-18 pg/ml) and low calcitriol levels (10.6+/-4.3 pg/ml) compared with normal rats [N1: 14+/-2.5 pg/ml (P<0.001) and 18.2+/-4.2 pg/ml (P<0.01) respectively]. The pregnancy in CRF rats (CRF2) resulted in normalization of serum iPTH levels (18.2+/-5.41 pg/ml), which was associated with a parallel increase in serum calcitriol (29.4+/-8.0 pg/ml) similar to that in pregnancy of normal rats (N2). Two weeks after delivery the CRF rats (CRF3) once again had high serum iPTH (87+/-17 pg/ml) and low calcitriol levels (9.3+/-1.2 pg/ml), similar to those observed in non-pregnant uraemic rats (CRF1). It is concluded that pregnancy decreases serum iPTH in 5/6 nephrectomized CRF rats most probably by the increased level of calcitriol synthesized by the feto-placental unit.

Randomised crossover trial of naltrexone in uraemic pruritus

BACKGROUND

Most dialysis patients develop pruritus, for which current treatment is unsatisfactory. Endogenous opioids may be involved in this pruritus. We studied the effect of the opioid antagonist naltrexone on the pruritus of haemodialysis patients.

METHODS

Naltrexone 50 mg per day by mouth was given to 15 haemodialysis patients with severe resistant pruritus in a randomised, double-blind, placebo-controlled crossover trial. The naltrexone or placebo periods lasted 7 days each with a 7-day washout between the two periods. Pruritus was assessed by the patients on a visual analogue scale from 0 (no pruritus) to 10 (maximum), and mean daily scores were calculated. Plasma histamine and beta-endorphin levels were measured, and spontaneous and stimulated basophil histamine-release were determined.

FINDINGS

The median pruritus scores at the end of the naltrexone treatment were 2.1 (interquartile range 1.5-2.15) for the naltrexone-placebo sequence and 1.0 (0.4-1.15) for the placebo-naltrexone sequence. The respective values before naltrexone was given were 9.9 (9.85-9.95) and 9.9 (9.3-10.0). Plasma beta-endorphin levels were normal and remained unchanged during the study. Plasma histamine levels were high (mean 2.32 [SD 0.11] ng/mL, normal < 1.0) and decreased after naltrexone (to 1.8 [0.09], p < 0.01). Basophils from haemodialysis patients stimulated by interleukin-3 plus IgE antibodies released high amounts of histamine. The increase was 78.3 (19.3)% compared with 26.6 (16.3)% for five normal controls (p < 0.01). Incubation of the basophils with naloxone, another opioid antagonist, prevented this effect.

INTERPRETATION

Our data suggest short-term efficacy with few side-effects for the amelioration of uraemic pruritus with naltrexone.

Nitric oxide in ischaemic acute renal failure of streptozotocin diabetic rats

Changes in nitric oxide (NO) levels were determined in ischaemic acute renal failure in streptozotocin-induced diabetes mellitus rats. Two weeks after streptozotocin administration and immediately after right nephrectomy, the left renal artery was occluded for 60 min. Similar procedures were carried out in non-diabetic rats. The nitrite (NO2) + nitrate (NO3) levels were measured in plasma and urine. The effects of chronic oral supplementation with L-arginine and an NO synthase inhibitor (N-omega-nitro-L-arginine) were also studied in both diabetic and non-diabetic rats before and after renal artery clamping. The rats with diabetic acute renal failure had a much lower creatinine clearance (90 +/- 22 microliters.min-1. 100g body weight-1, p < 0.005), and higher fractional excretion of sodium (FENa)% (10.90 +/- 4.2, p < 0.001) and protein excretion (2078 +/- 69 micrograms/ml creatinine clearance, p < 0.001) compared with the respective values in the non-diabetic groups (163 +/- 30; 1.46 +/- 86; 453.3 +/- 31). The plasma and urine NO2 + NO3 levels were significantly higher in the untreated diabetic rats compared with the untreated normal rats before ischaemia (p < 0.001). The ischaemic acute renal failure in non-diabetic rats increased the plasma and urinary NO2 + NO3 excretion after ischaemia. The urinary excretion of these metabolites decreased significantly and their plasma levels remained unchanged in the ischaemic diabetic rats. The L-arginine administration resulted in a small but significantly higher creatinine clearance after clamping in the non-diabetic rats. The NO synthase inhibitor caused deterioration in renal function in all ischaemic and non-ischaemic groups. In summary, the greater vulnerability to ischaemia of the diabetic kidney seems to be associated with both impaired response to and impaired production of NO.

Oral administration of L-arginine and captopril in rats prevents chronic renal failure by nitric oxide production

The effect of oral supplementation of L-arginine, the substrate of nitric oxide, (1.25 g/liter water) and captopril (15 mg/liter water) was studied in 5/6 nephrectomized rats for a period of three months. N-omega-nitro L-arginine, a nitric oxide synthase inhibitor, was given orally (70 mg/liter water) with or without L-arginine or captopril. The urinary excretion of nitrite (NO2) + nitrate (NO3), the known metabolites of nitric oxide, was taken as an index of nitric oxide production. Chronic renal failure rats were characterized by a low creatinine clearance, high FENa%, proteinuria, hypertension and a low urinary excretion of NO2 + NO3; 0.152 +/- 0.06 (P < 0.001) nmol/micrograms creatinine compared with 0.481 +/- 0.004 (P < 0.001) in normal rats and 0.479 +/- 0.11 (P < 0.001) in untreated sham-operated rats. Both L-arginine and captopril were effective in the normalization of all these parameters. The combination of L-arginine and captopril had no additive effects. The nitric oxide synthase inhibitor significantly diminished the captopril beneficial effect. It is concluded that chronic renal failure in rats is a low nitric oxide production state. The supplementation of L-arginine is shown to overcome this condition. It is suggested that the beneficial effect of captopril on chronic renal failure is through a specific L-arginine--nitric oxide synthase--nitric oxide pathway.

Head injuries after serious bicycle accidents

Between 1987 and 1988 there were 47 serious or fatal injuries among bicycle riders in the city of Tel Aviv-Yafo (Serious injury was defined as being hospitalized for at least 24 hours). Collisions with vehicles, mostly cars, were responsible for about 80% of these cases. Two-thirds of the accidents occurred in adults aged 20 and over. We were able to trace the records of 24 of the 47 who were injured. Head trauma was the most common form of severe injury, occurring in 11 of the 24 cases. Two of the 11 died instantly and one died after 14 days of hospitalization, all from severe brain damage. Eight suffered severe head trauma, 7 of which had brain injury and 2 of the 7 were left with severe residual brain damage. In view of the efficacy of bicycle helmets in preventing head trauma there is a great need to expand their use among bicyclists in Israel.

Blood pressure measurement in children aged 6 to 15 years--the Nahariya Study

A total of 5,323 school students aged 6 to 15 years in the city of Nahariya, Israel, had their blood pressure measured during the 1981-82 school year. Height, weight, sex, region of birth and parent's region of birth were also recorded. Charts containing selected percentiles of blood pressure were developed, and distribution curves were drawn. Mean systolic blood pressure increased with age in both sexes. The diastolic pressure, however, remained unchanged. The mean systolic pressures were slightly higher than those found in Bogalusa and than the pooled means published in the recent report of the Task Force on Blood Pressure Control in Children, but lower than those of most other studies. The diastolic pressures were higher than those of the Bogalusa study; they were slightly higher than the pooled means reported by the Task Force for children aged 6 to 9, and for above these ages they were lower by 3 to 7 mm Hg. The selected percentiles of both systolic and diastolic blood pressure in both sexes were lower than those in the charts published initially by the Task Force in 1977 but were very close to those published in their second report in 1987. The mean blood pressure levels were not associated with the parents' region of birth. A highly significant correlation between systolic blood pressure and body mass (as expressed by weight or Quetelet's index) was found.

Cultured mouse marrow cell lines: interactions between fibroblastoid cells and monocytes

Continuous cell lines were derived from primary cultures of adherent bone marrow cells from SJL/J, BALB/c, C3H/eb, RF, and nude-ICR mice. All these lines readily assumed a pure fibroblastoid appearance with the exception of the BALB/c line (MBA-14), which retained both fibroblastoid and monocytoid cells. This particular line could promote the proliferation of myeloid progenitors (CFU-C) in short-term bone-marrow cultures. The two cell types that composed the MBA-14 cell line were successfully isolated and grown separately; the monocytes as the 14M and 14M1 cell lines and the fibroblastoid cells as the 14F clones. The latter were found to be preadipocytes and accumulated fat in the absence of added hydrocortisone, in medium supplemented with fetal calf serum. Growth of the monocyte lines (14M and 14M1) was dependent upon the mononuclear phagocyte stimulator CSF-1. In the parent MBA-14 cell line the growth of monocytes seemed to depend upon stimulating factor(s) produced by the fibroblastoid cells. The 14M1 monocytes were able to process and degrade antigen as efficiently as primary macrophages. Furthermore, processed antigen produced by 14M1 cells evoked proliferative response by antigen-primed lymph-node cells. In addition to these immunological functions the 14M1 cells were capable of modulating the colony-stimulating activity and degree of adipogenesis exhibited by the fibroblastoid cells. These interactions between monocytes and fibroblastoid cells may constitute part of the mechanism controlling the activity of the hematopoietic microenvironment.