Hypernatremia in hospitalized patients

OBJECTIVE

To determine the incidence, clinical characteristics, and outcome for general medical-surgical hospital patients with hypernatremia.

DESIGN

A prospective cohort study.

SETTING

A 942-bed urban university hospital.

PATIENTS

All patients who developed a serum sodium concentration of 150 mmol/L or greater during a 3-month observation period.

MEASUREMENTS

Daily fluid balance, mental status, and serum and urine electrolytes and osmolality.

RESULTS

103 patients were identified. Eighteen patients were hypernatremic on hospital admission, and 85 developed hypernatremia during hospitalization. Patients who developed hypernatremia during hospitalization were younger than patients who developed hypernatremia before hospital admission (mean age +/- SD, 58.9 +/- 19.2 years compared with 76.6 +/- 16.6 years; P < 0.01) but did not differ in age from the patients of the general hospitalized population. Eighty-nine percent of patients who developed hypernatremia during hospitalization had urine concentrating defects, primarily as the result of the use of diuretics or of solute diuresis, whereas only 50% of patients who were hypernatremic on admission could be shown to have concentrating defects (P < 0.01). Fifty-five percent of all hypernatremic patients had increased insensible water losses, and 35% had increased enteral water losses. Eighty-six percent of patients with hospital-acquired hypernatremia lacked free access to water, 74% had enteral water intake of less than 1 L/d, and 94% received less than 1 L of intravenous electrolyte-free water per day during the development of hypernatremia. No supplemental electrolyte-free water was prescribed during the first 24 hours of hypernatremia in 49% of patients. The duration of hypernatremia was shorter in patients who were hypernatremic on admission (median duration, 3 days) than in patients with hospital-acquired hypernatremia (median duration, 5 days; P < 0.05). Mortality was 41% for all patients, but hypernatremia was judged to have contributed to mortality in only 16% of patients.

CONCLUSIONS

Although the development of hypernatremia before hospital admission occurs primarily in geriatric patients, hospital-acquired hypernatremia was more common in our cohort and had an age distribution similar to that of the general hospitalized population. Hospital-acquired hypernatremia was primarily iatrogenic, resulting from inadequate and inappropriate prescription of fluids to patients with predictably increased water losses and impaired thirst or restricted free water intake or both. Treatment of hypernatremia is often inadequate or delayed. Efforts to manage hypernatremia better and altogether avoid hospital-acquired hypernatremia should focus on both physician education and the development of hospital systems to prevent errors in fluid prescription.

Clinical similarity and biological diversity in the response to alprazolam in patients with panic disorder and generalized anxiety disorder

Thirty-six patients with panic disorder (PD) and 35 patients with generalized anxiety disorder (GAD) participated in an open alprazolam treatment phase that preceded controlled withdrawal from alprazolam. Clinical ratings, blood pressure and heart rate were obtained along with plasma measurements of cortisol, ACTH, growth hormone and catecholamines. A similar clinical response profile was evident in both groups with rapid onset of improvement within the first week. The two diagnostic groups differed in their biological response to alprazolam. PD patients had a significant reduction in blood pressure, plasma cortisol and a trend toward significant reduction in plasma epinephrine, which were not seen in the GAD patients. GAD patients showed a significant reduction in plasma norepinephrine. These findings provide further evidence that PD and GAD are biologically distinct syndromes.

Failure of low molecular weight dextran to prevent clotting during continuous renal replacement therapy

Clotting of the extracorporeal circuit during continuous renal replacement therapy results in decreased ultrafiltration rates, impaired solute clearance and, ultimately, occlusion of the extracorporeal circuit. The authors conducted an open-label randomized controlled trial to determine whether low molecular weight dextran could prevent hemofilter clotting in patients undergoing continuous venovenous hemodialysis. Eleven patients were randomized to receive a continuous infusion of 10% low molecular weight dextran at 25 mL/hr; 8 patients served as control subjects. No differences in the frequency of hemofilter clotting or hemofilter lifespan were detected. The authors concluded that continuous infusion of low dose low molecular weight dextran is not effective in preventing clotting during continuous renal replacement therapy.

An assessment of a urinary biomarker for total human environmental exposure to benzo[a]pyrene

Urinary banzo[a]pyrene (BaP) metabolite levels were compared to human environmental exposure to BaP through inhalation and dietary ingestion to assess the predictive validity of the exposure biomarker. These measurements were made for 14 adult volunteers over 14 consecutive days, once during summer/fall, again during winter periods. Based on personal air monitoring, median potential inhalation doses of 11.0 and 2.3 ng/day were estimated for the winter and summer/fall studies, respectively. A median potential ingested dose of 176 ng/day, estimated from "duplicate plate" sampling, exceeded inhalation by 6- and 122-fold for the winter and summer/fall studies, respectively. "Total" urinary BaP metabolites were measured using a published "reverse metabolism" (BaP) method of analysis. Median rates of urinary BaP metabolite elimination for the winter and summer/fall studies were 121 and 129 ng/day, respectively. The changes in inhaled and ingested potential doses were regressed on the change in urinary metabolite elimination from week 1 to week 2 to test the predictive validity of the biomarker measurement. The regression was statistically significant (r = 0.620, p = 0.015, n = 25) when body weight was included and two extreme values were removed. Consistent with the exposure measurements showing diet as the dominant route of exposure, most of the variation in urinary metabolite elimination was explained by the ingested dose. It is concluded that the measurement of urinary BaP by "reverse metabolism" is qualitative and of marginal predictive validity as an exposure biomarker due to the method's low recoveries and the large unexplained variance.

Interindividual differences in the concentration of 1-hydroxypyrene-glucuronide in urine and polycyclic aromatic hydrocarbon-DNA adducts in peripheral white blood cells after charbroiled beef consumption

Biological markers of internal dose and macromolecular dose from PAHs provide a potential means of assessing environmental exposure to PAHs through inhalation, ingestion and percutaneous absorption. In this study we examined the time course and interindividual variation of 1-hydroxypyrene-glucuronide (1-OHP-gluc) excretion in urine and PAH-DNA adduct formation in peripheral white blood cells (WBCs) after charbroiled (CB) beef consumption. As a marker of internal dose, 1-OHP-gluc was measured in human urine using immunoaffinity chromatography and synchronous fluorescence spectroscopy. PAH-DNA adducts were measured in WBCs by enzyme-linked immunosorbent assay (ELISA) in order to assess macromolecular dose. Ten healthy non-smoking males consumed identical amounts of CB beef on five consecutive days. Multiple blood and urine samples were collected before, during, and after the feeding period. The morning after the first day of CB beef consumption, individual urinary concentrations of 1-OHP-gluc increased 10- to 80-fold (range: 2.0-16.6 pmol/ml urine) above pre-feed baseline concentrations (0.23 +/- 0.11 pmol/ml) in the 10 subjects. 1-OHP-gluc concentration decreased to near baseline levels by 24-72 h after CB beef consumption ended. In contrast, PAH-DNA adducts in WBCs increased markedly in only four of 10 subjects during or after CB beef consumption. Significant interindividual variation was observed for both urinary 1-OHP-gluc concentration (P < 0.001 by Kruskal-Wallis) and PAH-DNA adduct levels (P < 0.005) during the feeding period. The mean urinary 1-OHP-gluc concentration for each subject during and immediately after (days 2-8) the feeding period was significantly correlated with their mean PAH-DNA adduct level in WBCs during the same time period (Spearman r = 0.79, P < 0.01). Evidence of segregation of the subjects into separate response groups based on level of urinary 1-OHP-gluc was observed, suggesting that discrete determinants may regulate the absorption, metabolism and/or excretion of ingested pyrene.

Assessment of renal function during pregnancy using a random urine protein to creatinine ratio and Cockcroft-Gault formula

The current standard for assessment of renal function in pregnant women is a 24-hour urine collection to determine creatinine clearance and proteinuria. It is easier to use the random urine protein to creatinine (P:C) ratio and the Cockcroft-Gault (CG) formula to estimate protein excretion and glomerular filtration rate, but the reliability of these formulae in combination for assessing renal function in pregnant women with renal disease is unknown. We compared the results of the P:C ratio with the 24-hour urinary protein excretion and the results of the CG clearance estimate with the 24-hour urine creatinine clearance in 34 pregnant women with underlying renal disease. Comparisons were made once in each trimester and postpartum. Prepregnancy weights were used in the CG formula: (140 - age x weight [kg] x 0.85)/72 x serum creatinine (mg/dL). Twenty-six first trimester, 33 second trimester, 21 third trimester, and 15 postpartum comparisons were made for creatinine clearance and 16 first trimester, 29 second trimester, 15 third trimester, and 15 postpartum comparisons were made for protein excretion. Measured creatinine clearance for the three trimesters combined (105 +/- 40 mL/min [mean +/- SD]) correlated significantly with CG clearances (113 +/- 52 mL/min; r = 0.87). The mean P:C values (2.03 +/- 3.15) for the three trimesters combined correlated significantly with 24-hour urine protein (2.25 +/- 4.21 g; r = 0.92). Our study demonstrates excellent correlations between the CG formula using prepregnancy weights and 24-hour creatinine clearance and between the P:C and 24-hour urinary protein in this population.(ABSTRACT TRUNCATED AT 250 WORDS)

An ab initio computational molecular orbital study of the conformers of muconaldehyde, and the possible role of 2-formyl-2H-pyran in bringing about the conversion of a (Z,Z)-muconaldehyde structure into an (E,Z)-muconaldehyde structure

To determine whether conformers of 2-formyl-2H-pyran (2F2HP) can serve as intermediates in the isomerization (Z,Z)-muconaldehyde-->(E,Z)-muconaldehyde--an essential step in the metabolic oxidation of benzene in which (E,E)-muconic acid is formed--we have carried out ab initio molecular orbital calculations at the MP2/6-31G* (frozen core, valence orbitals active) level with full geometry optimization at the RHF/6-31G* level. Taking account of the configuration about the carbon-carbon single bonds as well as that about the double bonds, the six conformers of (Z,Z)-muconaldehyde have been characterized, as well as the eight conformers of (E,Z)-muconaldehyde. Axial and equatorial conformers of 2F2HP have been identified, which exist in stable syn or anti forms depending on the relative position of the pyran and carbonyl O-atoms. Each step in the metabolic pathway is stereospecific. The initial ring opening in 2,3-epoxyoxepin gives (eZzZz)-muconaldehyde, which then undergoes ring closure to give anti-axial-2F2HP (step a). Inversion of the ring gives anti-equatorial-2F2HP, which upon ring opening gives (zEzZz)-muconaldehyde (step b). An alternative pathway links (zZzZz)-muconaldehyde with syn-axial-2F2HP (step a'), and syn-equatorial with (eEzZz)-muconaldehyde (step b'). Half-reaction times, taking into account the fractional representation of each reacting conformer in rapidly established equilibrium mixtures, suggest that the operative pathway is via step a, with little to choose between steps b and b'.

Cost-benefit analysis of a national screening programme for cystic fibrosis in an Israeli population

The recently acquired ability to identify 97% of CF carriers in an Israeli Ashkenazi population, prompts an evaluation of a nationwide screening programme. In 1993, the programme would first screen and counsel 9,261 parents, then 396 spouses of carrier parents and finally screen 16.5 fetuses where both parents are carriers. Assuming 92% of screened parents choose abortion of fetus screened positive, 2.33 cases of CF will be prevented in 1993 at a direct cost of $781,000. The $326,000 direct costs of preventing a CF case, exceed the lifetime excess direct costs per case of $297,000. However, benefits of screening also accrue to subsequent pregnancies, resulting in a direct benefit ($14.45 million) to cost ($10.39 million) ratio of 1.39/1 for the period 1993-2032. When benefits and costs resulting from mortality changes, work absences and transport costs are included, the benefit ($15.95 million) to cost ($13.88 million) ratio falls to 1.15/1. Benefit-cost ratios are lower for other ethnic groups in Israel, due to lower carrier rates and lower mutation detection abilities. A CF screening programme will increase the freedom of individuals choice, but should be carried out carefully in order to minimize stigmatization and even discrimination against CF carriers.

Regulation of alveolar macrophage transforming growth factor-beta secretion by corticosteroids in bleomycin-induced pulmonary inflammation in the rat

In a model of pulmonary inflammation and fibrosis induced by the antineoplastic antibiotic, bleomycin, we previously demonstrated that TGF-beta was markedly elevated within 7 d of bleomycin administration. At the time of maximal TGF-beta production, TGF-beta 1 was localized by immunohistochemistry to be present almost exclusively in alveolar macrophages. In this study, we have demonstrated that alveolar macrophages stimulated by bleomycin-induced injury secrete large quantities of biologically active TGF-beta 1 when explanted into tissue culture. However, alveolar macrophages from normal saline-treated rats secrete small quantities of biologically inactive TGF-beta. In contrast, splenic macrophages secrete large quantities of inactive TGF-beta and are unaffected by the intratracheal bleomycin treatment. High doses of the corticosteroid methylprednisolone given intramuscularly before and concomitantly with bleomycin administration prevented the influx of alveolar macrophages into the lungs, diminishing both the number of macrophages present in the alveoli and the total lung content of TGF-beta. However, the rate of secretion of TGF-beta by alveolar macrophages recovered from the alveoli was unchanged after corticosteroid treatment. When activated alveolar macrophages were cultured in the presence of several concentrations of dexamethasone that completely suppressed IL-1 secretion, little effect on TGF-beta secretion was observed. The findings in this study demonstrate that during bleomycin-induced injury, alveolar macrophages not only secrete large quantities of active TGF-beta 1, but are a predominant source of the enhanced TGF-beta response seen in this model. Furthermore, the alveolar macrophage secretion of TGF-beta is not inhibited by the presence of high concentrations of corticosteroids.

Energetics of the metabolic production of (E,E)-muconaldehyde from benzene via the intermediates 2,3-epoxyoxepin and (Z,Z)- and (E,Z)-muconaldehyde: ab initio molecular orbital calculations

To assess the feasibility of the pathway set out in the title, we have carried out ab initio molecular orbital calculations of the energies of cisoid- and transoid-2,3-epoxyoxepin and the eZzZz-, eZeZz-, eEeZz-, eEeEz-, and eEeEe-conformers of muconaldehyde at the MP2/6-31G* (frozen core, valence orbitals active) level with full geometry optimization using the split-valence RHF/6-31G* basis set. Including thermal energies, derived from vibrational frequencies obtained at the RHF/6-31G*//RHF/6-31G* level, reaction energies (that would correspond to gas phase data at 298 K) have been evaluated. The muconaldehyde conformers are lower in energy than the epoxyoxepin, i.e., are formed exothermically, and in accord with experiment, the Z,Z-conformers are less stable than the E,Z, and the E,Z less stable than the E,E. In addition, we have characterized the transition state for the fission of the C-O bond in the epoxy ring and the C-O bond in the oxepin ring of transoid-2,3-epoxyoxepin, thereby generating (eZzZz)-muconaldehyde. With an activation energy of 16.5 kcal mol-1 the half-life of the epoxyoxepin is very short at the temperatures employed in the experiments, less than 1 min, which explains why it has not been detected. To gain some insight into the isomerization about the carbon-carbon double bonds in the muconaldehyde conformers, we have examined the possible involvement of 2-formyl-2H-pyran and cyclobutene-3,4-dicarboxaldehyde as intermediates. In model reactions simulating the microsomal monooxygenase system, the formation of benzene oxide and of the epoxyoxepin are found to be very favorable exothermic processes.

Assessment of carcinogenic risk from personal exposure to benzo(a)pyrene in the Total Human Environmental Exposure Study (THEES)

The Total Human Environmental Exposure Study (THEES) was an investigation of multimedia exposure to the ubiquitous environmental carcinogen, benzo(a)pyrene (BaP). The three-phase study was conducted in Phillipsburg, New Jersey and involved the participation of 14-15 individuals (8-10 homes) during each 14-day monitoring period. Microenvironmental sampling of air, food, water and soil indicated that environmental exposure to BaP was primarily through air and food. Exposure and risk estimates were, therefore, based on the results of personal monitoring of breathing zone air and prepared food samples. Based on a comparison of the range and magnitude of inhalation and dietary BaP exposures, food ingestion was clearly the predominant exposure to pathway. The relative contributions of other potential sources of community exposure to BaP (e.g., soil and drinking water ingestion) were also assessed. The excess cancer risk estimates for food ingestion were consistently greater than those for personal air, reflecting both the predominantly higher BaP exposures through the diet and the higher carcinogenic potency value for oral exposure. Overall, the total lifetime risk from personal exposure to BaP for nonsmokers in the community was estimated at 10(-5). In identifying risk reduction options, it is important to account for the observation that personal activities, lifestyle, and diet strongly influenced individual exposures to BaP.

Effect of sustained pyridoxine treatment on seizure susceptibility and regional brain amino acid levels in genetically epilepsy-prone BALB/c mice

Epilepsy-prone and epilepsy-resistant substrains were selectively bred from a strain of BALB/c mice; audiogenic-sensitive epilepsy-prone animals showed enhanced sensitivity to chemical convulsants. Treatment with pyridoxine (100 mg/L in drinking water) initiated at mating and continued throughout pregnancy and the life of the offspring abolished the enhanced sensitivity to chemical convulsants and reduced the severity of audiogenic seizures. Withdrawal of pyridoxine restored the enhanced seizure sensitivity. [1H] Nuclear magnetic resonance (NMR) spectroscopy of perchloric acid extracts of tissue was used to determine the concentrations of several compounds [N-acetylaspartate (NAA), GABA, glutamate, aspartate, alanine, taurine, creatine, cholines, inositol] in the hippocampus, neocortex, brainstem, and cerebellum of untreated and pyridoxine-treated 6-week-old female animals. The ratios of the concentrations of excitatory to inhibitory putative neurotransmitter amino acids tended to be higher in epilepsy-prone animals, with the most pronounced difference being a significantly elevated glutamate/GABA ratio in every brain region examined. Pyridoxine treatment abolished this imbalance in the hippocampus, brainstem, and cerebellum, but not in the neocortex. Treatment of epilepsy-resistant animals with pyridoxine using the same protocol decreased the glutamate/GABA concentration ratio in the hippocampus, brainstem, and neocortex and resulted in impaired development of the animals. The amino acid imbalance and the accompanying seizure susceptibility in these genetically epilepsy prone mice may originate from an inborn error in pyridoxine metabolism or in a pyridoxine-dependent enzyme system.

Phase II trial of fludarabine phosphate for adenocarcinoma of the pancreas. An Illinois Cancer Center study

We have conducted a phase II trial of fludarabine phosphate for advanced measurable adenocarcinoma of the pancreas. The drug was administered every 4 weeks by a daily-times-5 bolus schedule beginning at 20 mg/m2/day. No responses were observed in 20 evaluable patients, 18 of whom were previously untreated. Dose-limiting toxicity was leukopenia, and gastroenterologic side effects were frequent. Life-threatening or fatal renal dysfunction occurred in 3 patients. In this schedule fludarabine phosphate is ineffective against adenocarcinoma of the pancreas and appears to have unpredictable severe renal toxicity.

Dialysate and blood flow dependence of diffusive solute clearance during CVVHD

To define the flow dependence of diffusive solute clearance (Kd) during continuous venovenous hemodiafiltration (CVVHD), urea, creatinine, and phosphate clearance were measured during CVVHD, while ultrafiltration was minimized. Studies were performed using AN69, polyacrylonitrile (PAN), and polyamide (PA) hollow fiber hemofilters. To assess the dialysate flow dependence of Kd, clearances were measured at constant blood flow (QB), while dialysate inflow (QDi) was increased incrementally from 8.3 to 33.3 ml/min. Kd increased linearly for all three solutes using all membranes. To assess its blood flow dependence, Kd was measured at blood flows of 50, 75, 100, and 150 ml/min, while QDi was held constant at 33.3 ml/min. The PA membrane showed no flow dependence; for the other membranes, Kd was flow independent for QB > 100 ml/min. At all values of QB and QDi, clearances for the AN69 and PAN membranes were two to three times that of the PA membrane (p < 0.01). Lactate uptake increased with increasing QDi for all three membranes, but did not result in blood lactate accumulation. It is concluded that: 1) small molecule clearance is dialysate flow limited during CVVHD; 2) increasing QB beyond 100 ml/min is unnecessary for maintaining solute clearance; and 3) the PA membrane is unsuitable for CVVHD because of its low diffusive solute clearance.

Hemoperitoneum complicating chronic peritoneal dialysis: single-center experience and literature review

Hemoperitoneum is a well-recognized, if uncommon, complication of chronic peritoneal dialysis. In this review of 424 patients maintained on peritoneal dialysis at a single center during an 11-year period, 26 patients (6.1%) developed one or more episodes of hemoperitoneum. Three patients had hemoperitoneum on two separate occasions with different etiologies. One additional patient was seen on a hospital consultative service. Three types of bleeding episodes were observed. Twenty-one of 30 (70%) were benign, consisting of pink-tinged dialysate with little clinical consequence (group 1). Three (10%) consisted of minor hemoperitoneum associated with significant intra-abdominal pathology (group 2), and six (20%) required active intervention (group 3). The most frequent cause of hemoperitoneum was bleeding related to menstruation or ovulation; hemoperitoneum was more common in women than in men. Two patients had hemoperitoneum occurring after more than 6 years on dialysis. In both, the etiology was sclerosing peritonitis, an association not previously noted. The less common etiologies of hemoperitoneum encountered in our patients were similar to those in reports from other centers and are compiled here.

Suppression of the translocated myc gene and expression of intracisternal A-particle genes in tumorigenic and non-tumorigenic hybrids between murine myeloma and normal fibroblasts

We have studied the tumorigenic potential of a series of independent intraspecies hybrid clones derived from fusion of murine myeloma (BALB/c) and normal fibroblasts (C3H). All of these hybrids grew as adherent cells and thus resembled the fibroblast phenotype. As judged by chromosome enumeration, these hybrids appear to retain the full complement of their parental cells. Three out of 4 hybrids tested were able to form colonies in soft agar and to grow as tumors in either nude or (BALB/c x C3H) F1 mice, albeit at a reduced rate. The 4th hybrid did not grow in agar, was non-tumorigenic and may have had a 2:1 fibroblast to myeloma genomic equivalence ratio. In contrast to the parental myeloma cells, all the hybrids exhibited restricted growth rates in serum-free medium. As in our previous sets of hybrids formed between myeloma and L-cells, expression of the Ig genes was inhibited in the new hybrids and the derived tumors. The constitutive expression of the translocated myc gene in the myeloma parental cells was decreased in the hybrids and in all their derived tumors. In contrast, all of the hybrid cell lines and the tumors express high levels of the intracisternal A particle mRNAs. Our results show that the tumorigenic phenotype of myeloma cells is either fully or partially suppressed in myeloma x fibroblast hybrids and that this may be due to the fact that expression of the translocated c-myc is suppressed. We suggest that, in addition to the translocated myc gene, myeloma cells contain other activated oncogene(s), and that the latter are responsible for the residual tumorigenic potential of the myeloma x fibroblast hybrids.

Resolution of cirrhotic glomerulonephritis following successful liver transplantation

A 38-year-old man with liver failure due to Laennec's cirrhosis developed nephrotic range proteinuria and hematuria. Renal biopsy showed membranoproliferative glomerulonephritis with 2+ staining for IgA and complement consistent with cirrhotic glomerulonephritis. After orthotopic liver transplantation, proteinuria and hematuria rapidly resolved. This case indicates that glomerulonephritis associated with cirrhosis may be successfully treated with hepatic transplantation. Whether the improvement in glomerular abnormalities resulted from immunosuppression therapy or from restoration of normal hepatic function is unknown.

Bulimia in opiate-addicted women: developmental cousin and relapse factor

There has been a growing awareness that eating disorders and substance abuse may coexist in the same individual. While several studies have documented the prevalence of these problems, few have addressed their relationship in the recovering patient. In the present study, the charts and hospital course of all female patients admitted to an inpatient treatment program for opiate dependency were reviewed. Approximately 20% of the patients had bulimic pathology that predated the drug abuse and re-emerged during detoxification. A theoretical model is presented which examines the possible developmental interplay between the two disorders and the role that renewed food problems may serve as a prodrome for relapse. The difficulty in addressing these issues during both the assessment and treatment phases of recovery is also discussed.

Catecholamine determination in sequential urine voiding: a method for detecting pheochromocytoma in patients without elevated urinary catecholamines

The biochemical diagnosis of pheochromocytoma is based on the demonstration of increased amounts of catecholamines, or catecholamine metabolites, in 24-h urine samples. In patients whose 24-h urine catecholamines are within normal limits, and in whom short duration catecholamine elevations are suspected, timed urine collections have been used to detect these elevations. In this study, determination of catecholamines in sequential urine voidings and consideration of their relative values are suggested as a further method to detect pheochromocytomas, especially in cases without extended elevation of urinary catecholamine levels. The use of this method is demonstrated in three cases in which pheochromocytoma would not otherwise have been proven by laboratory determination.

Cyclosporine nephrotoxicity in cardiac allograft patients--a seven-year follow-up

Renal function was observed retrospectively in a population of 228 adults who underwent a cardiac allograft at the University of Pittsburgh from June 1980 through June 1987, survived a minimum of one year, and received cyclosporine. Renal function was determined by serial measurement of serum creatinine concentration. Serum creatinine rose from 1.2 +/- 0.0 mg/dl at time of hospital discharge to 2.0 +/- 0.0 mg/dl at two and four years and 3.3 +/- 0.1 mg/dl at seven years. The fall in renal function was biphasic, with a rapid decline (reciprocal creatinine slope -0.018 dl/mg-mo) through 24 months and a slower decline thereafter -0.0036 dl/mg/month). This occurred despite a progressive decrease in cyclosporine levels from 668 +/- 23 ng/ml (whole blood RIA) to 380 +/- 12 ng/ml at seven years. Three of 222 patients (1.6%) developed end-stage renal disease within 18 months of initiation of cyclosporine therapy. Only one additional patient of 26 followed through 54 months (3.8%) developed end-stage disease thereafter. The decline in renal function seen with cyclosporine is rapid in the first 18 months, with a slower but continuing decline seen with later follow up. At least in heart transplantation, the risk of end-stage renal disease is significant, but not prohibitive.

Biological monitoring for occupational cadmium exposure: the urinary metallothionein

The relationship between urinary metallothionein and kidney and liver cadmium levels was examined in 68 active and retired smelter workers. Metallothionein was analyzed by a radioimmunoassay and liver and kidney cadmium levels were determined by in vivo neutron activation. Four workers suffered from severe renal dysfunction and excreted high amounts of total protein and beta 2-microglobulin and greater than 1 mg metallothionein/g creatinine. In the remaining 64 workers the urinary metallothionein levels correlated significantly with the cadmium levels in both liver and kidney. Similarly, in these individuals urinary metallothionein was significantly related to cadmium in blood and urine. These results demonstrate that urinary metallothionein is a sensitive biological indicator of cadmium exposure and body burden, before the onset of severe renal dysfunction.

Hyperkalemia associated with intravenous labetalol therapy for acute hypertension in renal transplant recipients

Three renal transplant recipients developed potentially life-threatening hyperkalemia after receiving intravenous labetalol for postoperative hypertension. Even as beta-adrenergic agonists find increasing use in the therapy of acute hyperkalemia, physicians should be aware of the potential of beta blockers to cause profound elevations of serum potassium.