Renal thrombotic microangiopathy associated with interferon-alpha treatment of chronic myeloid leukemia

Recent reports have documented the development of renal thrombotic microangiopathy in patients with chronic myeloid leukemia (CML) who have undergone treatment with interferon-alpha. The pathogenesis of the renal lesion in such cases remains unclear. We report the case of a patient with chronic myeloid leukemia who developed renal failure and nephrotic syndrome while being treated with hydroxyurea and interferon-alpha. The renal biopsy showed features of chronic thrombotic microangiopathy. The patient had serologic and functional evidence of anti-phospholipid antibody. Interferon-alpha is known to cause induction of multiple autoantibodies. We propose that in the context of CML, interferon-alpha treatment can induce pathogenic anti-phospholipid antibodies that result in renal thrombotic microangiopathy. This has important implications for patients with CML receiving immune-stimulating therapy because it suggests that prospective monitoring of such patients for anti-phospholipid antibody might identify those at risk of developing thrombotic microangiopathy. Furthermore, patients with established anti-phospholipid antibody syndrome in this context might benefit from intervention such as early anticoagulation.

Determination of threshold energy dose for ultrasound-induced transdermal drug transport

Low-frequency (20 kHz) ultrasound has been shown to enhance transdermal transport of drugs, a phenomenon referred to as sonophoresis. In this paper, we report the threshold energy dose for ultrasound-induced transdermal drug transport. The threshold was determined by in vitro measurements of the dependence of sonophoretic enhancement on ultrasound parameters, including intensity, duty cycle, and exposure time. While the enhancement varies linearly with ultrasound intensity and exposure times, it is independent of the duty cycle in the range of parameters studied. The enhancement is also directly proportional to the ultrasound energy density once the threshold value is crossed. For full thickness pig skin, the threshold value is about 222 J/cm(2). The overall dependence of transport enhancement on ultrasound parameters is similar to that of cavitation measured in a model system, pitting of aluminum foil. Specifically, the extent of pitting is proportional to ultrasound intensity and exposure time and is independent of duty cycle. Furthermore, the extent of pitting is also proportional to the ultrasound energy density. The similarity between the parametric dependence of transport enhancement and cavitation is consistent with previous findings that cavitation plays the dominant role in sonophoresis.

Are bilateral fetal lung masses double trouble?

OBJECTIVES

To examine the perinatal natural history of bilateral fetal cystic lung masses.

METHODS

The records of a tertiary medical center over a 3-year period were reviewed for cases of fetal bilateral pulmonary masses.

RESULTS

Three of 98 fetuses referred for evaluation over a 3-year period from September of 1995 to August of 1998 had bilateral lung lesions. Two of these cases resulted in live births, while one, associated with hydrops, resulted in death after preterm delivery.

CONCLUSIONS

Similar to prenatally diagnosed unilateral lung lesions, hydropic fetuses with bilateral cystic lung lesions have a poor prognosis. Nonhydropic fetuses, however, may be asymptomatic despite persistent lesions on postnatal CT scan. These observation may prove helpful for prenatal counseling for these rare lesions.

Enhancing perioperative nursing practice: developing a course for the surgeon's assistant

This article describes the development of a new English National Board (ENB) course for nurses wishing to adopt the role of the surgeon's assistant. The original request for a course of this nature came from the clinicians working in hospitals in the Manchester area, including not only theatre nurses and managers but also surgeons and individuals already practising as surgeon's assistants. This course has been designed with the support of the nursing and medical staff in local trusts, who have been widely consulted. It was developed collaboratively with nurse educationalists, in order to standardise training and education for nurses in practice who wished to adopt this expanding role.

The value of a phenol red impregnated thread for differentiating between the aqueous and non-aqueous deficient dry eye

To determine the clinical viability of a phenol red impregnated cotton thread in differentiating between normal, aqueous deficient and non-aqueous deficient dry eyes. Subjects were recruited on the basis of subjective symptoms, tear stability, rose bengal staining, Schirmer test, conjunctival hyperaemia, patency and number of meibomian glands, presence of mucin strands, appearance of lower tear meniscus. Based on the outcome of the tests, subjects were categorised as either aqueous deficient dry eyes, non-aqueous dry eyes or normals. Subjects were randomised and a thread was applied by inserting into the lower fornix of the right eye and leaving the thread in place for 120 sec. All data was collected under similar ambient conditions. After gathering all the data, the codes were broken. Mean (+/- S.D.) thread wetting values were, all dry eyes (n = 59) 18.4 mm (5.9). Aqueous deficient dry eyes (n = 35), 15.5 mm (4.6). Non-aqueous deficient dry eyes [n = 24], 22.7 mm (5.0). For the normals (n = 38), 19.4 mm (5.0). Differences between (i) normals and aqueous deficient dry eyes and (ii) aqueous deficient and non-aqueous deficient dry eyes were significant (p = 0.01). Difference between all dry eyes and normals was not significant. For the aqueous deficient and non-aqueous deficient dry eyes only, using a cut-off value of 20 mm the calculated sensitivity and specificity values were 86% and 83% respectively. This cotton thread test can effectively differentiate between aqueous deficient and non-aqueous deficient dry eye.

Complications associated with insertion of jugular venous catheters for hemodialysis: the value of postprocedural radiograph

It is routine in hemodialysis units to require a chest radiograph after the insertion of an internal jugular line for venous access before dialysis is commenced. There are two principal reasons for this: (1) to ensure that no procedural complications have occurred and (2) to verify correct catheter placement. Knowledge of the time delay involved may prompt nephrologists to opt for femoral access (with increased hemodialysis recirculation and need for repeated line placement). The benefit of the postprocedural chest radiograph has never been evaluated in the hemodialysis population. We retrospectively reviewed the data on internal jugular access placement from two large nephrology training centers. Over a 36-month period, 460 internal jugular dialysis catheters were placed in 312 patients. Wherever possible, 15-cm lines were used for the left internal jugular vein and 12-cm lines for the right internal jugular vein. Ultrasound guidance was used in 105 cases (22.8%). There were a total of 90 (19.6%) clinical complications in 62 patients (13.5%). These consisted of carotid artery puncture (n = 35, 7.6%) and hematoma (n = 55, 12%). All of these patients had a normal post-internal jugular chest radiograph. Carotid artery puncture did not occur if ultrasound guidance was used. There was no case of associated pneumothorax. Of the 370 line insertions in 250 patients in whom it was believed clinically that no complication had occurred, the chest radiograph only showed unsuspected line malposition in four cases (1.08%). Routine chest radiographs rarely contribute to the diagnosis of any procedural complications and are of little value after internal jugular access placement, especially if it is believed clinically that no complication occurred.

Paracetamol-induced pancreatitis and fulminant hepatitis in a hemodialysis patient

The occurrence of hepatotoxicity and acute renal dysfunction following an acute paracetamol overdose has been well documented. Acute pancreatitis, however, has been rarely described. We would like to report a hemodialysis patient who developed acute pancreatitis and hepatic failure from acute paracetamol toxicity. To our knowledge, this represents the first description in a dialysis patient of paracetamol induced pancreatitis. Given the frequency of paracetamol usage in these patients, we believe that it is important to consider this diagnosis in patients with unexplained acute pancreatitis, particularly if there is associated hepatic dysfunction.

Ultrasound-guided cannulation versus the landmark-guided technique for acute haemodialysis access

BACKGROUND

The correct placement of large-bore venous catheters plays an important role in the management of haemodialysis patients. Whilst the procedure for landmark-based placement of these catheters is well known, the technique is not without significant morbidity and mortality. Complications include arterial puncture, haematoma, and pneumothorax. The procedure may be further complicated in these patients by venous thrombosis and abnormal vein position from multiple previous attempts at venous access.

METHODS

Data on the use of ultrasound guidance versus anatomical landmarks for the placement of internal jugular vein (n = 69) and femoral vein (n = 30) dialysis access was retrospectively analysed over a 13-month period. Data collected included age, sex, duration on dialysis, number of vein cannulation sets required, number of attempts for successful cannulation, salvage of failed cannulation using landmark-based technique by ultrasound guidance, and the complication rate.

RESULTS

Internal jugular vein cannulation using ultrasound was ultimately successful in 96.7% compared to 82% in the landmark group. The vein was entered on the first attempt in 83.3% of patients with ultrasound compared to 35.9% of the landmark group (P < 0.0001). Seven patients in whom the landmark technique was unsuccessful had access placed under ultrasound guidance. There were fewer carotid artery punctures in the ultrasound group (7.7 versus 0%, P = n.s.). In the femoral vein group, the vein was entered on the first attempt in 85.7% of patients with ultrasound compared to 56.25% of the landmark group (P = n.s.).

CONCLUSIONS

The use of ultrasound guidance is associated with fewer complications and is more likely to lead to cannulation of the vein at the first attempt in haemodialysis patients.

Beta 2-microglobulin amyloidosis in chronic dialysis patients: a case report and review of the literature

Dialysis-related amyloidosis secondary to beta-2-microglobulin (beta 2m) deposits is a common complication of long-term dialysis patients and is responsible for significant morbidity with potential mortality. Beta 2m amyloid has a propensity to deposit in the osteoarticular tissues, particularly in large bones close to the joint spaces, and in synovial membranes and carpal tunnel tissue. Older age at the onset of dialysis and the duration of dialysis are two important risk factors for development of this disease. The high-flux, more biocompatible membranes have been shown to remove and adsorb beta 2m more efficiently than the cellulosic membranes. This study presents the case of a chronic dialysis patient who developed recurrent arthritis of the left knee, followed by carpal tunnel syndrome; biopsy of the patient's knee showed very large aggregates of beta 2m amyloid deposits in the tendon sheets. A brief review of the literature on this subject is also presented.

HELLP syndrome: a condition of varied presentation

Three cases of HELLP syndrome are presented which illustrate its varied clinical presentation, the difficulty in making a diagnosis and the management problems. The cases varied in severity; all showed thrombocytopenia and abnormal liver function tests, but in one case the blood pressure remained within "normal limits" whereas another patient suffered grand mal seizures due to hypertensive encephalopathy.

Long-term successful management of refractory congestive cardiac failure by intermittent ambulatory peritoneal ultrafiltration

Despite advances in the pharmacological management of cardiac failure, some patients remain refractory to this therapy. However, improved understanding of the physiology and technique of peritoneal dialysis has recently allowed ambulatory peritoneal ultrafiltration to be applied to the treatment of patients with intractable heart failure. We report the management of three such patients with New York Heart Association (NYHA) class IV cardiac failure, each with a left ventricular ejection fraction < 20%. They had become unresponsive to maximum pharmacological management with inotropes, diuretics and ACE inhibitors. All patients had biochemical evidence of pre-renal azotemia. Initially, patients received aggressive ultrafiltration by continuous veno-venous haemofiltration (CVVH) or one- to two-hourly peritoneal dialysis exchanges until they achieved an optimal dry body weight. Once stabilized, they were converted to an intermittent ambulatory peritoneal ultrafiltration (IAPU) regimen of one to three exchanges per 24 h according to their individual needs. During an 18 +/- 10-month follow-up, their duration of hospital confinement was reduced by 85% and all three patients improved from class IV to class II cardiac failure. IAPU may have a useful role in the long-term management of intractable heart failure in a selected group of patients.

Hydration of single-stranded phosphodiester and phosphorothioate oligodeoxyribonucleotides

Infrared spectroscopy was used to identify hydration-sensitive structural differences between single- stranded phosphorothioate (PS) and phosphodiester (PO) oligodeoxyribonucleotides. Spectra were recorded in the mid-infrared region, 500-1800 cm-1, at relative humidities between 0 and 98%; the PS and PO spectra are substantially different. The hydration effects on spectral bands in these single-stranded oligodeoxyribonucleotides is markedly different from such behavior in double- and triple-stranded oligodeoxyribonucleotides. A strong absorption occurs at 656 cm-1 in the phosphorothioate sample which is completely absent from the PO spectra. Gravimetric measurements were carried out on one PS and one PO sample to monitor and confirm hydration. The calculated BET adsorption constants [Brunauer, S., Emmett, RH. and Teller, E. (1938) J. Am. Chem. Soc., 60, 309-319] are 1.2 and 1.4 water molecules per nucleotide in the first hydration layer of PS and PO respectively. While the gravimetric data indicate that the single-stranded oligodeoxyribonucleotides hydrate very similarly to duplex DNA, the mid-infrared conformational marker bands are strikingly different from those observed for duplex DNA. In particular, the Vas of the phosphate group (PO2) at 1222 cm-1 in the single-stranded PO spectra is independent of relative humidity.

The rapid reversal of profound hypothermia using peritoneal dialysis

Severe hypothermia is associated with serious patient morbidity and mortality. The groups most frequently affected are the elderly, the very young and substance abusers. We describe three such cases which were successfully treated using warmed peritoneal dialysis. Two patients recovered completely and were left with no long term deficits. The third patient recovered from the acute event, but succumbed later to an underlying medical condition. Warmed peritoneal lavage is an efficient, cost effective approach which is easily performed without specialist equipment, and involves minimal risk to the patient.