Identification of sulfhemoglobinemia after surgical polypectomy

Sulfhemoglobinemia (SHb) is an uncommon cause of cyanosis that is predominantly drug-induced in adults. We report an unusual case of sodium sulfate-induced sulfhemoglobinemia in a 61-year-old woman after surgical polypectomy. Fractional hemoglobin derivates were assayed by spectrophotometry and high-performance liquid chromatography. The SHb ratio was 8.6% in the first sample and 3.77% a month later measured by spectrophotometry. In the blood hemolysate, a new peak was identified as SHb with high-performance liquid chromatography (HPLC). HPLC showed the presence of 9.37% SHb in the first sample and 4.88% a month later. After removing the suspected toxic agent the cyanosis decreased significantly. The findings underline the importance of routine SHb detection in cyanosis of unknown origin especially in emergency cases.     

Clinical review: Drug metabolism and nonrenal clearance in acute kidney injury

Decreased renal drug clearance is an obvious consequence of acute kidney injury (AKI). However, there is growing evidence to suggest that nonrenal drug clearance is also affected. Data derived from human and animal studies suggest that hepatic drug metabolism and transporter function are components of nonrenal clearance affected by AKI. Acute kidney injury may also impair the clearance of formed metabolites. The fact that AKI does not solely influence kidney function may have important implications for drug dosing, not only of renally eliminated drugs but also of those that are hepatically cleared. A review of the literature addressing the topic of drug metabolism and clearance alterations in AKI reveals that changes in nonrenal clearance are highly complicated and poorly studied, but they may be quite common. At present, our understanding of how AKI affects drug metabolism and nonrenal clearance is limited. However, based on the available evidence, clinicians should be cognizant that even hepatically eliminated drugs and formed drug metabolites may accumulate during AKI, and renal replacement therapy may affect nonrenal clearance as well as drug metabolite clearance.     

Molecular charge heterogeneity of human serum erythropoietin

The charge heterogeneity of human serum erythropoietin (S-Epo) was studied in 89 serum specimens from 78 subjects by zone electrophoresis in 0.17% agarose suspension at pH 8.6. The electrophoretic elution profiles of S-Epo were determined with a radioimmunoassay for Epo. The number of Epo peaks indicated that at least 20-30 different forms of Epo were present in a single serum specimen. The median charge of Epo, estimated as its median electrophoretic mobility, was determined for each serum specimen. This median charge was measured in 10 healthy adults, 46 patients with anaemia, six patients with secondary polycythaemia, one patient with polycythaemia vera treated by phlebotomy, and six healthy newborn infants (cord sera). Forty-four of the patients with anaemia had a median charge of S-Epo within the reference range for healthy adults, while all the patients with polycythaemia and the newborn infants had less negatively charged forms of S-Epo. In nine patients in whom the S-Epo level had a circadian rhythm, the forms of S-Epo in the evening were less negative than those in the morning. The median charge of recombinant preparations was much less negative than that of S-Epo in healthy individuals, while that of the 2nd International Reference Preparation was more negative than in any of the 78 subjects analysed. A significant change to less negatively charged S-Epo forms was observed 24 h after a subcutaneous injection of recombinant Epo in one patient, who before the injection had a normal median charge and concentration of S-Epo. In conclusion, Epo exhibits a considerable charge heterogeneity in individual serum specimens, the forms of S-Epo in the morning may differ from those in the evening, those in adults differ from those in newborn infants, and those in patients with anaemia differ from those in polycythaemia. The results also suggest that the methods used in this study may be useful for detecting the presence of injected recombinant Epo in the blood in persons with a normal endogenous Epo production.     

Multiple endocrine neoplasia type 1: a 10-year prospective screening study in four kindreds.

A total of 80 individuals in 4 kindreds with multiple endocrine neoplasia type 1 (MEN 1) have been subjected to repeated biochemical screening during a 10-yr period with the principal aim being to analyze characteristics of the developing pancreatic lesion. Age at presentation of the MEN 1 trait averaged 18 yr in 7 previously unaffected individuals, and this effect of the screening procedure represented a lowering by almost 2 decades. Pancreatic endocrine involvement was recognized at a mean age of 25 yr and constituted the presenting lesion in a majority of the patients. A standardized meal test and basal values of serum pancreatic polypeptide, insulin, proinsulin, and gastrin were the most efficient markers for the pancreatic lesion and preceded signs of pancreatic tumors upon radiological examinations by a mean of 3.5 yr. A 75% penetrance of the islet cell disease and 90% for primary hyperparathyroidism within the affected individuals equalled the prevalences reported in autopsy studies. Two of the kindreds showed signs of intrafamilial homogeneity with respect to the profile of peptide excess (P less than 0.05) and considerable discrepancy in the malignant potential of the pancreatic lesions. The results of early detection and surgical intervention of the pancreatic tumors in MEN 1 suggested an impact on morbidity, while any effect on the mortality of these individuals remains to be clarified.     

Median charge and charge heterogeneity of human pituitary FSH, LH and TSH. I. Zone electrophoresis in agarose suspension

The charge and charge heterogeneity of FSH, LH and TSH in 63 extracts of individual human pituitaries were investigated by use of zone electrophoresis in 0.17% agarose suspension in veronal buffer at pH 8.6 followed by hormone analyses by radioimmunoassay. The migration velocities are similar to those in free solution and directly proportional to differences in charge in the buffer. The technique gave highly reproducible results and the recovery of hormone activity after electrophoresis was about 100%. Methods for estimation of median charge, expressed as median migration rate, and of degree of charge heterogeneity are described. Each pituitary contained a sequence of different forms, estimated at 20 or more, of each of the three hormones, with minor differences in charge. The degree of charge heterogeneity within the pituitary was similar for FSH, LH and TSH. The distribution curves of radioimmunological activity in relation to migration rate were close to normality for the three glycoprotein hormones. This was in contrast to that found for Prl and GH. The merits of the electrophoretic technique are discussed.     

Nursing research in heart failure care: a position statement of the american association of heart failure nurses (AAHFN)

Background

Heart Failure (HF) is a public health problem globally affecting approximately 6 million in the United States.