Continuous renal replacement therapy: the treatment of choice for acute renal failure

The health care issues facing society today are complex. Access to care, quality of life, relative value scales, diagnosis related groups, and cost containment demands have had an impact on the decision-making processes of health care professionals. The availability of alternative therapeutic treatment modalities adds additional considerations when prescribing medical therapy. This is especially true when a patient is diagnosed with renal failure. In the past, either peritoneal dialysis or hemodialysis have been the only therapies for supporting patients with acute renal failure. This article explores continuous renal replacement therapy for the management of acute renal failure: what it is, when and where it should be used, and the responsibilities of nephrology and critical care nurses and physicians.     

Ongoing pregnancies after intracytoplasmic injection using cryopreserved testicular spermatozoa

We report two clinical pregnancies occurring after intracytoplasmic sperm injection (ICSI) using cryopreserved spermatozoa obtained from testicular biopsy, made in two different infertility situations in our clinic. The first patient showed a secretory azoospermia associated with elevated serum follicular stimulating hormone (FSH) level and spermiogenesis maturation arrest. The second patient was affected by azoospermia resulting from bilateral epididymal obstruction. Spermatozoa present in the wet preparation of testicular biopsy made on the day of scrotal exploration were cryopreserved within the testicular tissue for both men. Intracytoplasmic injections were performed at a later date, using spermatozoa prepared from frozen-thawed tissues. In each case, three embryos were obtained and transferred in utero. The transfers resulted in a twin pregnancy for the first case, and in a singleton pregnancy for the second. Living foetuses were seen in the ultrasound scan at the 7th week and both pregnancies are proceeding to date beyond 30 weeks without complications.      

Correction of distal femoral deformity

This retrospective study reviews 12 distal femoral osteotomies in nine patients performed for angular and rotational deformities, using the Orthofix external fixator. All osteotomies progressed to solid union with reliable correction of the deformity. Few complications were encountered. Simultaneous lengthening was performed on one patient successfully. This method proved to be a safe and precise means of correcting distal femoral deformity with the option of simultaneous correction of length discrepancy.     

The distinction of bone and liver isoenzymes of alkaline phosphatase in serum using a monoclonal antibody

Out of 31 mouse monoclonal antibodies to human liver and bone ALP, one antibody coded BAP 1/9, showing a preference for binding the bone isoenzyme, and one antibody coded LAP 1/5, showing no preference, were selected to study binding of the serum forms of ALP. Using a plate capture assay format BAP 1/9 showed a 1.8-fold preference for binding purified bone versus liver ALP in the presence of 10% ALP-free serum compared with 2.1- to 2.25-fold preference in buffered salt solution. BAP 1/9 showed a preference for binding ALP from serum samples containing predominantly bone ALP compared to those containing predominantly liver ALP. Using predefined mixtures of serum forms of bone and liver ALP a linear relationship between ALP bound to BAP 1/9 and the fraction of bone ALP was obtained.     

Relationships between tumour necrosis factor, eicosanoids and platelet-activating factor as mediators of endotoxin-induced shock in mice.

1. The toxicity of intravenous recombinant human tumour necrosis factor (rhTNF), a TNF fragment (TNF114-130), endotoxin and combinations of rhTNF or TNF114-130 were tested in mice. Neither rhTNF nor TNF114-130 was lethal alone, but when combined with a non-lethal dose of endotoxin, rhTNF provoked dose-dependent mortality, as did higher doses of endotoxin alone. 2. Both the toxicity and the vasopermeability changes induced by endotoxin alone were blocked by the platelet-activating factor (PAF) antagonist BN52021, indomethacin or the dual cyclo-oxygenase/lipoxygenase inhibitor BW755C. 3. The lethality of the combined low dose endotoxin/rhTNF challenge was unaffected by pretreatment with BN52021, indomethacin or BW755C, or by treatment at 6 h intervals with BN52021 or BW755C. 4. The results of these studies suggest that TNF, a putative, early mediator of septic or endotoxin shock, cannot by itself mimic all of the effects of bacterial endotoxin in the model used in this study. Apparently, TNF works synergistically with other mediators whose release is stimulated by endotoxin. 5. The results also suggest that the mechanism of shock production by the rhTNF/endotoxin combination in mice is not dependent on the early stimulation of eicosanoid or PAF synthesis by rhTNF.     

Evidence that the earliest generated cells of the murine cerebral cortex form a transient population in the subplate and marginal zone.

We used bromodeoxyuridine to label the earliest generated cells of the murine cerebral cortex while they were dividing, and then observed their distributions at several instances later in development. Shortly before birth, many of the labelled cells were either above the cortical plate, in the marginal zone, or below it, in the region known as the subplate in other species. These cells had disappeared by postnatal day 21.     

Measurement of diet in a large national survey: comparison of computerized and manual coding of records in household measures

A diary method using household measures was employed to obtain dietary records in a large national prospective survey and a computer program, DIDO (Diet In Data Out), was designed for direct entry of the diaries. The accuracy of this computerized coding system was examined alongside that of the manual coding used for a similar diary in a previous wave, 7 years earlier, of the same survey. Accuracy was assessed by analysis of the errors in the coded and checked records by stringent re-checking of nominal 2% random subsamples of the diet diaries coded by each method. The mean time to code and check each of the 2086 7-day records in the whole survey using DIDO was 58 minutes (SD 30) compared with reported results of 1–4 hours for manual methods. The mean error rate of computerized coding and checking with DIDO was 2.3% (SD 2.1; range 0–8.9) per diary in the subsample. Correcting these mistakes made insignificant changes to the calculated mean energy and nutrient intakes for the subsample. The percentage of individuals changing to an adjacent third of nutrient distribution after correcting unambiguous errors ranged from none (for alcohol) to 11% (for carbohydrate and calcium intake). The mean error rate on a similar subsample of diaries from the earlier survey which had been coded manually was significantly higher at 5.9% (SD 4.1; range 0–17) per diary. Emphasis is laid on the importance, in coding, of dealing with ambiguities in the subjects' records, since this can affect the accuracy and the precision of the nutrient results obtained. We conclude that the DIDO coding method has the advantages of greater accuracy, speed, consistency and efficient data handling, and affords greater data accessibility for checking, compared with manual systems.     

Phytochelatin production by marine phytoplankton at low free metal ion concentrations: laboratory studies and field data from Massachusetts Bay.

Phytochelatins are small metal-binding polypeptides synthesized by algae in response to high metal concentrations. Using a very sensitive HPLC method, we have quantified phytochelatins from phytoplankton in laboratory cultures at environmentally relevant metal concentrations and in marine field samples. Intracellular concentrations of phytochelatin, in the diatom Thalassiosira weissflogii, exhibit a distinct dose-response relation with free Cd2+ concentration in the medium--not with total Cd(2+)--and are detectable even when the free Cd2+ concentration is less than 1 pM. In Massachusetts Bay, phytochelatin levels (normalized to chlorophyll a) in the particulate fraction are similar to those measured in laboratory cultures exposed to picomolar free Cd2+ concentrations and exhibit a decreasing seaward trend. Incubations of natural samples with added Cd2+ confirmed the induction of the peptides by this metal. Ambient phytochelatin concentrations thus appear to provide a measure of the metal stress resulting from the complex mixture of trace metals and chelators in natural waters.