Metabolic Syndrome, a Real Barrier for Living Kidney Donor Transplant.

INTRODUCTION: Renal transplantation is the optimal renal replacement therapy. In Mexico, most of the kidney transplants are from living donors. It is essential to identify conditions that increase the risk of developing chronic kidney disease (CKD) in donors, such as metabolic syndrome (MS). MATERIALS AND METHODS: In retrospect from January 2008 to December 2018, the donation protocols for renal transplantation of the Hospital Central Sur Alta Especialidad "Picacho" were reviewed, classifying all the cases of donors by nephrectomy or no nephrectomy and describing the demographic characteristics, prevalence of metabolic diseases, and cause of rejection of the protocol. RESULTS: A total of 178 donors were studied: 82 women (46%), 96 men (54%), mean age of 42 years, average body mass index (BMI) 27.9 kg/m2, glomerular filtration rate (GFR) by Chronic Kidney Disease Epidemiology Collaboration 99 mL/min, 59 patients with grade I and II obesity (BMI ≥ 30 kg/m2), and 1 patient with morbid obesity (BMI ≥ 40 kg/m2). A total of 39 patients (22%) underwent nephrectomy and 139 (78%) did not. The following characteristics and alterations were found: Of the 139 patients who did not undergo nephrectomy, 91 had metabolic disorders, 20 had low GFR, 21 had albuminuria, and 4 recipients received cadaveric transplants, 3 due to critical conditions of the recipient. The metabolic alterations in the rejected donors were as follows: MS 54 (59%), prediabetes 55 (39%), newly diagnosed hypertension 70 (76%), diabetes mellitus 20 (14%), obesity 47 (51.6%), dyslipidemia 76 (83%), hyperuricemia 17 (12%). DISCUSSION: The prevalence of MS in apparently healthy donors is similar to that of other studies in Mexico. Both MS and its components are independently associated with an increased risk of cardiovascular disease and CKD. It has been shown that these donors have a greater degree of glomerular and interstitial fibrosis; therefore, diagnosis, prevention, and timely treatment in this group are important.

TNFR1-383 A˃C polymorphism association with clinical manifestations in primary Sjögren's syndrome patients.

Primary Sjögren's syndrome is an autoimmune disease affecting the function of exocrine glands. Tumor necrosis factor receptor-1 (TNFR1) is involved in apoptosis through extrinsic pathway initiation. The level of soluble TNFR1 is reported increased in rheumatoid arthritis, systemic lupus erythematosus, and primary Sjögren's syndrome patients. The TNFR1 gene contains a polymorphism that replaced an adenine with a cytosine at the -383 in promoter region position. The TNFR1-383 A˃C polymorphism has been associated with rheumatic diseases. We examined the association between the TNFR1-383 A˃C polymorphism and TNFR1 soluble (sTNFR1) levels and laboratory and clinical characteristics in primary Sjögren's syndrome patients. Eighty-two patients with primary Sjögren's syndrome classified using the American-European criteria and 84 healthy subjects were studied. Sjögren's Syndrome Disease Activity Index (SSDAI) and Sjögren's Syndrome Disease Damage Index were performed for all patients. Genotypic and allelic frequencies were similar in both groups (P = 0.317 and P = 0.329, respectively). sTNFR1 levels were similar in patients and healthy subjects (P = 0.051). High levels of C-reactive protein (P = 0.045) and rheumatoid factor (P = 0.040) in patients with the A˃C genotype were observed. In these patients, the SSDAI score was higher than in A˃A genotype carriers (P = 0.045). This is the first study that to examine the TNFR1-383 A˃C polymorphism in primary Sjögren's syndrome patients. Clinical parameters and SSDAI index were associated in A˃C genotype carriers. However, further studies with a larger sample are necessary to verify the association between primary Sjögren's syndrome and the TNFR1-383 A˃C polymorphism.

FAS -670A>G promoter polymorphism is associated with soluble Fas levels in primary Sjögren's syndrome.

Primary Sjögren's syndrome (pSS) is a chronic systemic autoimmune disease characterized by lymphocytic infiltration of exocrine glands. Soluble Fas receptor (sFas) has been suggested as a Fas-mediated apoptosis blocker that could impair clonal deletion in infiltrated autoreactive cells. The FAS -670A>G promoter polymorphism has been studied in pSS. However, a relationship between FAS -670A>G promoter polymorphism and sFas levels in pSS had not been found. We examined this relationship in 77 Mexican pSS patients and 84 healthy subjects were included. Genotypes were identified by PCR-RFLP, and Fas soluble levels were quantified by ELISA. No significant differences between allele and genotype frequencies were found between these two groups. The sFas levels in the serum of pSS patients were significantly higher than in controls (9961 vs 8840 pg/mL, respectively). In addition, AA genotype carriers had significantly higher levels of sFas than GG carriers (pSS: 10,763 and 9422 pg/mL; controls: 9712 and 8305 pg/mL, respectively). An additive model analysis between genotypes (AG+GG vs AA) in both groups, demonstrated a significant association between carriers of the A allele and high sFas levels. In conclusion, carrying the double dose of A allele of FAS -670A>G polymorphism is associated with high levels of sFas in pSS, but it is not a susceptibility marker for pSS.

Macrophage migration inhibitory factor (MIF): genetic evidence for participation in early onset and early stage rheumatoid arthritis.

Macrophage migration inhibitory factor (MIF) is an upstream pro-inflammatory cytokine that is associated with the pathogenesis of autoimmune inflammatory diseases including rheumatoid arthritis (RA). Two polymorphisms in the upstream region exist in the MIF gene and are associated with RA susceptibility or severity in different populations. In this case-control study, we investigated whether MIF polymorphisms are associated with RA susceptibility or activity in a western Mexican population .The relationship of MIF levels with clinical features of disease also was assessed. Genotyping of the -794 CATT5-8 (rs5844572) and the -173 G>C (rs755622) polymorphisms was performed by PCR and PCR-RFLP respectively on 226 RA patients and 210 healthy subjects. Serum MIF levels were determined by ELISA. We found a significant association between the -794 CATT5-8 6,7 MIF genotype with RA. Moreover, we detected an association between the -794 CATT7 allele with early onset RA. The -794 CATT7 and -173(*)C alleles, which are in linkage disequilibrium, were associated with high disease activity on RA patients. A positive correlation between circulating MIF levels and C-reactive protein, erythrocyte sedimentation rate, rheumatoid factor, anti-citrullinated protein/peptides antibodies and TNFα was detected. MIF levels appear to be associated with disease progression rather than disease activity, which is distinct from the established relationship between disease activity and TNFα levels. In conclusion, the MIF gene and protein are associated with RA in a western Mexican population, with a main contribution onto early onset and early stages of disease.

Dhrs3a regulates retinoic acid biosynthesis through a feedback inhibition mechanism.

Retinoic acid (RA) is an important developmental signaling molecule responsible for the patterning of multiple vertebrate tissues. RA is also a potent teratogen, causing multi-organ birth defects in humans. Endogenous RA levels must therefore be tightly controlled in the developing embryo. We used a microarray approach to identify genes that function as negative feedback regulators of retinoic acid signaling. We screened for genes expressed in early somite-stage embryos that respond oppositely to treatment with RA versus RA antagonists and validated them by RNA in situ hybridization. Focusing on genes known to be involved in RA metabolism, we determined that dhrs3a, which encodes a member of the short-chain dehydrogenase/reductase protein family, is both RA dependent and strongly RA inducible. Dhrs3a is known to catalyze the reduction of the RA precursor all-trans retinaldehyde to vitamin A; however, a developmental function has not been demonstrated. Using morpholino knockdown and mRNA over-expression, we demonstrate that Dhrs3a is required to limit RA levels in the embryo, primarily within the central nervous system. Dhrs3a is thus an RA-induced feedback inhibitor of RA biosynthesis. We conclude that retinaldehyde availability is an important level at which RA biosynthesis is regulated in vertebrate embryos.

Circulating TNFRI and TNFRII levels correlated with the disease activity score (DAS28) in rheumatoid arthritis.

OBJECTIVE: To measure levels of soluble tumour necrosis factor alpha (TNFalpha) receptor type I (sTNFRI) and type II (sTNFRII) in order to correlate them with C-reactive protein (CRP), rheumatoid factor (RF), erythrocyte sedimentation rate (ESR), and disease activity score (DAS28) in RA patients. METHODS: We recruited 41 RA patients classified according to American College of Rheumatology (ACR) criteria and 38 healthy subjects (HS). sTNFRI and sTNFRII were measured using an enzyme-linked immunosorbent assay (ELISA) kit. Clinical activity in RA patients was evaluated using the Disease Activity Score using 28 joint counts (DAS28). The statistical analysis was realized using SPSS version 10.0. RESULTS: Soluble TNFRI and TNFRII levels were higher in RA patients (p = 0.04 and 0.001, respectively) than HS. Serum levels of sTNFRI correlated with sTNFRII (r = 0.699, p < 0.0001). sTNFRII correlated with DAS28 (r = 0.375, p = 0.017), RF (r = 0.505, p = 0.004), and ESR (r = 0.323, p = 0.042). CONCLUSION: The increased levels of both sTNFRI and sTNFRII suggest a secondary event related to the inflammatory state observed in RA, whereas the correlation of sTNFRII with RF, ESR, and DAS28 reflects the preferential TNFRII shedding induced by TNFalpha. sTNFRII may be useful as an additional inflammatory marker in RA.

El Burnout médico: la ansiedad y los procesos de afrontamiento como factores intervinientes / The Medical Burnout: anxiety and doping process as relevant factors

Actualmente, no existen muchas investigaciones donde se consideren variables tanto ambientales como de personalidad en el estudio del burnout como proceso. La presente investigación plantea dos objetivos centrales: evaluar el nivel de significación de la ansiedad y las estrategias de afrontamiento en el proceso de burnout, y clarificar la relación empírica entre ellas. En una muestra de 130 profesionales médicos de ocho hospitales públicos de Madrid se les administró los cuestionarios Maslach Burnout Inventory (Maslach y Jackson, 1986), State-Trait Anxiety Inventory (Spielberger, Gorsuch y Lushene, 1988), Ways of Coping Checklist (Lazarus y Folkman, 1984) y el Cuestionario de Afrontamiento Médico Situacional (Moreno-Jiménez y Seminotti, 1998). Las variables independientes fueron: género, estado civil, grupo médico, experiencia clínica, edad y especialidad. Los resultados mostraron una relación significativa entre las variables dependientes y el género, grupo médico y la edad mediante análisis multivariante MANOVA. El análisis de regresión por pasos mostró resultados relevantes para determinar un modelo teórico situacional del proceso de Burnout

To date there are not many studies focused on burnout like a process, where both environment and personality variables are considered. The present study had two central aims: to test what variables significantly effect the burnout process, and to clarify the empirical relationship between anxiety, coping styles and burnout. The Maslach Burnout Inventory (Maslach y Jackson, 1986), the State-Trait Anxiety Inventory (Spielberger, Gorsuch y Lushene, 1988), the Ways of Coping Checklist (Lazarus y Folkman, 1984) and the Situational Medical Coping (Moreno-Jimenez y Seminotti, 1998) were administered to a sample of 130 physicians who work in eight public hospitals in Madrid. The independent variables were gender, marital status, medical group, clinical experience, age and speciality. Results showed a strong relationship among the dependent variables in gender, medical group and age through the GLM Multivariate MANOVA. A stepwise regression analysis provided relevant results to determine the theoretical situational model in Burnout process

Massive myeloid sarcoma affecting the central nervous system, mediastinum, retroperitoneum, liver, and rectum associated with acute myeloblastic leukaemia: a case report.

Myeloid sarcomas are extramedullary tumours with granulocytic precursors. When associated with acute myelogenous leukaemia (AML), these tumours usually affect no more than two different extramedullary regions. This report describes a myeloid sarcoma associated with AML with tumour formation at five anatomical sites. The patient was a 37 year old man admitted in September 1999 with a two month history of weight loss, symptoms of anaemia, rectal bleeding, and left facial nerve palsy. The anatomical sites affected were: the rectum, the right lobe of the liver, the mediastinum, the retroperitoneum, and the central nervous system. A bone marrow smear was compatible with AML M2. Flow cytometry showed that the peripheral blood was positive for CD4, CD11, CD13, CD14, CD33, CD45, and HLA-DR. A karyotypic study of the bone marrow revealed an 8;21 translocation. The presence of multiple solid tumours in AML is a rare event. Enhanced expression of cell adhesion molecules may be the reason why some patients develop myeloid sarcomas.

Polymorphism of the beta3-adrenergic receptor and lipid profile in patients with rheumatoid arthritis and systemic lupus erythematosus treated with chloroquine.

We investigated the effect of beta 3-adrenergic receptor (beta(3)AR) polymorphism on lipid profiles in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) treated with chloroquine. One hundred sixty-eight subjects were classified into three groups: 61 RA patients, 57 SLE patients, and 50 healthy subjects. All patients fulfilled the 1987 and 1982 classification criteria for RA and SLE, respectively, of the American College of Rheumatology. Demographic data and clinical characteristics of the patients were registered. Fasting lipid profile determination and leukocyte genomic DNA isolation from peripheral blood was performed in all the participants. Screening of the beta(3)-AR gene polymorphic region (exon 1) was done by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Quantitative and qualitative variables were analyzed using analysis of variance (ANOVA) with the LSD and chi(2) tests, respectively. An association between the arg64/arg64 beta(3)-AR genotype and high levels of triglycerides (TG) and very low-density lipoprotein cholesterol (VLDL-c) was found in three RA patients ( P=0.01), two of them taking chloroquine. Arg64/arg64 beta(3)-AR polymorphism may contribute to increased TG and VLDL-c in RA patients, independently of chloroquine treatment.

Zebrafish Meis functions to stabilize Pbx proteins and regulate hindbrain patterning.

Homeodomain-containing Hox proteins regulate segmental identity in Drosophila in concert with two partners known as Extradenticle (Exd) and Homothorax (Hth). These partners are themselves DNA-binding, homeodomain proteins, and probably function by revealing the intrinsic specificity of Hox proteins. Vertebrate orthologs of Exd and Hth, known as Pbx and Meis (named for a myeloid ecotropic leukemia virus integration site), respectively, are encoded by multigene families and are present in multimeric complexes together with vertebrate Hox proteins. Previous results have demonstrated that the zygotically encoded Pbx4/Lazarus (Lzr) protein is required for segmentation of the zebrafish hindbrain and proper expression and function of Hox genes. We demonstrate that Meis functions in the same pathway as Pbx in zebrafish hindbrain development, as expression of a dominant-negative mutant Meis results in phenotypes that are remarkably similar to that of lzr mutants. Surprisingly, expression of Meis protein partially rescues the lzr(-) phenotype. Lzr protein levels are increased in embryos overexpressing Meis and are reduced for lzr mutants that cannot bind to Meis. This implies a mechanism whereby Meis rescues lzr mutants by stabilizing maternally encoded Lzr. Our results define two functions of Meis during zebrafish hindbrain segmentation: that of a DNA-binding partner of Pbx proteins, and that of a post-transcriptional regulator of Pbx protein levels.

Osseointegration treatment of transverse root fractures in the region of the alveolar crest.

A method of using osseointegrated implants as an alternative treatment modality for transverse root fractures near the osseous crest is presented. A 15-mm Branemark implant was placed immediately after extraction of a maxillary central incisor with transverse root fracture. Five months after stage I surgery, the implant was uncovered. Custom fabrication of a substructure core cast directly to the titanium single tooth abutment was necessary due to the palatal inclination of the fixture. An overcasting porcelain fused to gold crown was fabricated to avoid an unesthetic labial access for the abutment screw. This treatment indicates that the use of osseointegrated implants seems to provide an effective solution to replacing teeth with transverse root fractures.

Effects of ventilation style on surfactant metabolism and treatment response in preterm lambs.

We investigated whether the style of ventilation would influence respiratory physiology or surfactant metabolism in surfactant-treated preterm lambs. Preterm lambs were delivered at 131 +/- 1 d gestation and treated with an organic solvent extract of sheep surfactant (100 mg/kg). The lambs were randomized to ventilation peiods of 2 h, 5 h, 10 h, or 24 h, and to ventilation with a low rate (15 breaths/min) and high VT (15 ml/kg), with a high rate (50 breaths/min) and low VT (8 ml/kg), or with high-frequency oscillatory ventilation (HFOV). Gas exchange and lung volumes were similar across time and for the different ventilation styles. Saturated phosphatidylcholine (SatPC) in alveolar lavage was lower for the HFOV group than for the other ventilation groups at 10 h and 24 h. The rate of loss of surfactant protein B (SP-B) from these preterm animals' lungs was slow and not influenced by ventilation style. The percentages of surfactants in large-aggregate forms were not changed by style of ventilation, and the large-aggregate surfactants had excellent function when tested in surfactant-deficient preterm rabbits. Alveolar lavage protein was low (30 ml/kg), and tissue hyaluronan did not change with time or ventilation style. In preterm lambs ventilated without causing injury, the extreme styles of ventilation examined in the study had minimal effects on lung function, surfactant function, or surfactant metabolism.

Surfactant protein-B and lung function in surfactant-treated preterm lambs.

We asked if the amount of SP-B (range 37-410 micrograms/ml) in surfactants used to treat preterm lambs at 123 days of gestation correlated with postnatal lung function or the SP-B content of surfactant recovered by alveolar washes after 10 h ventilation. Ventilation was initiated using a low tidal volume strategy to minimize early lung injury. There were small increases in compliance for the lambs treated with surfactants containing more than 37 micrograms/ml SP-B and an increased lung volume for lambs treated with a surfactant containing 385 micrograms/ml/ml relative to the surfactant containing 37 micrograms/ml SP-B. The amount of SP-B in the surfactant used for treatment correlated linearly with the amount of SP-B in the surfactant recovered from the lambs (r = 0.95, p < 0.001). Albumin leak from the vasculature to the airspace was low as was total protein in alveolar washes, indicating minimal lung injury. The SP-B content of surfactant (from 37 to 410 micrograms/ml) had minimal effects on postnatal lung function over a 10-hour study period in lambs ventilated in a manner to minimize lung injury.

A comparative study of one implant versus two replacing a single molar.

A comparative study between one and two Brånemark implants replacing a single molar was conducted. Forty-seven individuals comprised two groups of 22 patients treated with one implant and 25 with two implants. A total of 72 implants were placed, 66 (92%) in the mandible and six (8%) in the maxilla. After the first year of function, the success rate was 99%, with only one implant lost. Between the second- and third-year follow-ups, 100% of the implants continued to function in the remaining 46 patients, giving a 3-year cumulative success rate of 99%. The marginal bone loss between 1 and 3 years of function was 0.10 mm (SD 0.20) for the group with one implant and 0.24 mm (SD 0.20) for the group with two implants. No changes were observed in the Sulcus Bleeding Index during the 3-year follow-up. Prosthesis mobility or screw loosening was the most frequent complication and was predominant in the group using one implant (48%), but was substantially reduced in the group using two implants (8%). These mechanical problems, using one implant only, seem to be preventable using a stronger screw joint (CeraOne abutment). Precise centric occlusal contact was established and maintained over the study period, which was thought to contribute to the very high success rate for the single-implant-supported molars, despite their high degree of mechanical problems. This study suggests that implant-supported molars can be effective therapy, and the results confirm the biomechanical analysis that two implants provide more advantageous support than does one.

The use of pterygomaxillary implants in the partially edentulous patient: a preliminary report.

One hundred eighty-seven implants were placed in the maxillary posterior areas of 44 partially edentulous patients (29 female; 15 male). The mean age was 62 years (range 36 to 82 years). Fifty-one of the 187 implants were placed in the pterygomaxillary area and further restored with fixed prostheses. The mean number of implants per prosthesis was 3.7 (range 1 to 6) for the maxillary posterior area. These 51 implants are the subject of this report. During stage II surgery and before loading, six implants were not osseointegrated and were removed. After a mean loading period of 12.6 months (range 1 to 63 months), one additional implant was lost. Seven of 51 implants were removed (13.7%). Failure rates according to implant size and bone quality were also analyzed. The average loss of marginal bone height was 1.3 mm on the mesial and 1.1 mm on the distal surfaces between 1 and 3 years of loading. This study demonstrates the possible and successful use of the pterygomaxillary site for implant placement.

[Diabetes mellitus and hypertension, clinical and epidemiological aspects in the population of La Plata]. / Diabetes mellitus e hipertensión arterial. Aspectos clínicos y epidemiológicos en la población de La Plata.

The purpose of this study was to determine socio-demographic characteristics, habits, most frequent morbid associations and degree of compliance with the control and treatment of their illness in a population of diabetic and hypertense patients of the La Plata area. A representative sample (890 people) was selected through a home survey (413 housing units). The results obtained show that diabetic and hypertense people a) are in average older than the general population and that the percentage of sedentary habits among them is also higher; b) show multiple typical symptoms of the illness but do not identify them as such and consequently diagnosis is frequently haphazardous; c) have a higher frequency of association with other risk factors, intercurrencies and hospitalization; d) are treated mainly by giving priority to drugs over changes in their detrimental habits; e) tend to ignore those indications that prescribe a change in their habits and f) control their illness at an inadequate periodicity. Consequently, it would be advisable to emphasize the incorporation of education strategies into the treatment of these patients in order to give more importance to preventive and health promoting actions. Education programmes should include not only patients and their families but also members of the health team and the community in general.

Diabetes mellitus e hipertensión arterial. Aspectos clínicos y epidemiológicos en la población de La Plata. / [Diabetes mellitus and hypertension, clinical and epidemiological aspects in the population of La Plata]

The purpose of this study was to determine socio-demographic characteristics, habits, most frequent morbid associations and degree of compliance with the control and treatment of their illness in a population of diabetic and hypertense patients of the La Plata area. A representative sample (890 people) was selected through a home survey (413 housing units). The results obtained show that diabetic and hypertense people a) are in average older than the general population and that the percentage of sedentary habits among them is also higher; b) show multiple typical symptoms of the illness but do not identify them as such and consequently diagnosis is frequently haphazardous; c) have a higher frequency of association with other risk factors, intercurrencies and hospitalization; d) are treated mainly by giving priority to drugs over changes in their detrimental habits; e) tend to ignore those indications that prescribe a change in their habits and f) control their illness at an inadequate periodicity. Consequently, it would be advisable to emphasize the incorporation of education strategies into the treatment of these patients in order to give more importance to preventive and health promoting actions. Education programmes should include not only patients and their families but also members of the health team and the community in general.

Extracorporeal shock-wave lithotripsy and ursodiol versus ursodiol alone in the treatment of gallstones.

The efficacy and occurrence of adverse effects after two forms of treatment were compared in 111 patients with biliary colic and radiolucent gallstones in this prospective, nonrandomized study. Fifty-four patients received extracorporeal shock-wave lithotripsy (ESL) plus ursodiol, and 57 patients received ursodiol alone. Among patients with a single stone (5-20 mm in size), no patient treated with ursodiol alone had a stone-free gallbladder at 6 or 12 months after treatment; of those treated with ESL plus ursodiol, 15 of 24 patients (63%) had a stone-free gallbladder at 6 months and 17 of 20 patients (85%) at 12 months. For patients with multiple stones (with an aggregate diameter of less than or equal to 30 mm), the incidence of a stone-free gallbladder was 2 of 43 patients (5%) at 6 months and 8 of 35 patients (23%) at 12 months in the ursodiol treatment group. In the ESL plus ursodiol group, the incidence of a stone-free gallbladder was 7 of 22 patients (32%) at 6 months and 9 of 20 patients (45%) at 12 months. Two patients in the ESL plus ursodiol group (4%) and 13 patients in the ursodiol group (24%) underwent cholecystectomy. Both patients in the ESL plus ursodiol therapy and 4 patients in the ursodiol group had emergency cholecystectomies because of acute cholecystitis. The remaining 9 patients in the ursodiol group had elective cholecystectomies. In this nonrandomized, prospective study, ESL plus ursodiol treatment produced stone-free gallbladders at a faster rate than ursodiol alone in patients with either single or multiple gallstones.

Treatment of osseous defects using Vicryl mesh (polyglactin 910) and the Brånemark implant: a case report.

The effectiveness of using Vicryl mesh (polyglactin 910) in combination with a Brånemark titanium implant is described. A maxillary central incisor with an apical osseous defect resulting from endodontic failure was treated with the Brånemark method of osseointegration for single tooth replacement. Vicryl mesh was used over the osseous defect site and uncovered 5 months later. New bone formation filling the defect and around the implant was observed.

Dietary potassium influences kidney maintenance of serum phosphorus concentration.

In studying the metabolic effects of diet potassium (K+) variation in normal humans, we noted that varying diet K+ within its normal range influenced inorganic phosphorus (Pi) homeostasis and serum calcitriol (1,25-dihydroxyvitamin D) levels. In six men who ingested a constant whole-foods diet containing (per 70 kg body wt) 27 mmol/day Pi and 52 mEq/day K+, we increased diet K+ to 156 mmol/day with supplements first of potassium bicarbonate (KHCO3) alone and then of potassium chloride (KCL) alone, each for eight days interrupted by an eight-day recovery period of no K+ supplement. Urine Pi decreased promptly with either K(+)-salt, each inducing a persisting retention of 7 to 10 mmoles Pi, which was dumped during recovery. Fasting serum [Pi] increased with either K+ supplement (P = 0.022, repeated measures analysis of variance); the composite mean serum [Pi] for the two K(+)-supplement periods exceeded that for the two periods without supplements (P less than 0.01, paired t-test). Conversely, the concentrations of serum calcitriol decreased with either K+ supplement (P = 0.020). Among subjects, the diet K(+)-induced increases in serum [Pi] correlated with those in plasma [K+] (r = 0.64, P = 0.027); the decreases in serum calcitriol concentration correlated with the increases in serum [Pi] (r = -0.69, P = 0.014). There were no significant differences among periods in serum parathyroid hormone, ionized calcium, urine cyclic AMP excretion, plasma renin activity, body weight, serum albumin, or creatinine clearance; plasma volume decreased slightly during KCL but not during KHCO3 periods.(ABSTRACT TRUNCATED AT 250 WORDS)