Biomedical subjects

A Torres

Publications and source records attributed to A Torres.

At least 289 records · Page 16Linked to original sources

PubMed1998

An in vitro validation of a commercially available metabolic cart using pediatric ventilator volumes.

Our objective was to determine the validity of the SensorMedics 2900 Metabolic Measurement Cart (SensorMedics Corp., Yorba Linda, CA) for use at pediatric ventilator volumes by designing an in vitro validation study. The study was performed using a previously described nitrogen dilution, carbon dioxide infusion technique in which known amounts of nitrogen (N2) and carbon dioxide (CO2) are infused while a test lung is ventilated. Metabolic measurements were made at tidal volumes (Vt) varying from 50-500 mL at a peak end-expiratory pressure (PEEP) of 0 and 12 cm H2O and at inspiratory oxygen fractions (Fi,O2s) ranging from 0.21-0.60. Each study was repeated six times to assess reproducibility of measurements. At a PEEP of 0 cm H2O, the measurement of oxygen consumption (V'O2), carbon dioxide production (V'CO2), and minute ventilation (V'E) were all within +/-10% of predicted values at all Fi,O2S except when Vt(t) was 50 mL. When PEEP was increased to 12 cm H2O, error in measurement of V'O2 increased and became unacceptably large as Fi,O2 was increased. Each study consisted of six trials, and results showed acceptable reproducibility as demonstrated by narrow 95% confidence intervals. For V(t)s of 100-500 mL, the metabolic monitor provided accurate and reproducible results under in vitro testing conditions when PEEP was low. Accurate results could not be obtained with a Vt of 50 mL or at elevated PEEP.

Calorimetry, Indirect↗

PubMed1998

Protein coding gene trees in ciliates: comparison with rRNA-based phylogenies.

We have reexamined the phylogeny of the ciliates using alpha-tubulin and phosphoglycerate kinase gene sequences. For alpha-tubulin, we have compared the amino acid and nucleotide sequences of 20 species representing seven of the nine classes of the phylum (Karyorelictea, Heterotrichea, Hypotrichea, Oligohymenophorea, Colpodea, Nassophorea, and Litostomatea). The phylogenetic tree resembles a bush from which three monophyletic lineages can be distinguished which correspond to the three classes Hypotrichea, Oligohymenophorea, and Litostomatea. For phosphoglycerate kinase, we have compared the amino acid sequences from 7 species representing three classes (Heterotrichea, Hypotrichea, and Oligohymenophorea). The branching pattern is resolved in three deeply separated branches with an early emergence of the heterotrich. Our comparative analysis shows that if alpha-tubulin phylogeny is not informative at the interclass level, the preliminary data from the phosphoglycerate kinase molecule appear more promising. Nevertheless, at low taxonomic level and at the class level, the resolved phylogenetic relationships inferred from both protein and rRNA sequence data are congruent.

Amino Acid Sequence↗

PubMed1998

Quantitative exposure of humans to an octamethylcyclotetrasiloxane (D4) vapor.

There is potential for human exposure to cyclic siloxanes by the respiratory route. To determine the pharmacokinetics of octamethylcyclotetrasiloxane (D4), a material commonly found in personal care products, the respiratory intake and uptake of D4 were measured in 12 healthy volunteers (25-49 years) on two occasions. Subjects inhaled 10 ppm D4 (122 micrograms/liter) or air (control) during a 1-h exposure via a mouthpiece in a double-blind, randomized fashion. Inspiratory and expiratory D4 concentrations were continuously measured. Exhaled air and plasma D4 levels were measured before, during, and after exposures. Individual D4 uptakes were measured under steady-state conditions during three rest periods (10, 20, and 10 min, respectively) alternating with two 10-min exercise periods. Mean D4 intake was 137 +/- 25 mg (SD) and the mean deposition efficiency was equivalent to 0.74/(1 + 0.45 VE), where VE is the minute ventilation. No changes in lung function were induced by the D4 vapor. Plasma measurements of D4 gave a mean peak value of 79 +/- 5 ng/g (SEM) and indicated a rapid nonlinear blood clearance. Using lung volume and respiratory surface area estimates based on functional residual capacity measurements, we developed a model and determined that the effective mass transfer coefficient for D4 was 5.7 x 10(-5) cm/s from lung air to blood. In an additional eight subjects, we compared D4 deposition with mouthpiece and nasal breathing at resting ventilations. For these individuals, mean deposition was similar for the two exposure protocols, averaging 12% after correction for exposure system losses. These are the first data describing the intake and absorption of D4 and they should contribute to a meaningful safety assessment of the compound.

Adult↗

PubMed1998

[Use of growth factors in therapy of chronic wounds. Experimental, clinical and financial aspects].

Clinical trials on exogenous application of polypeptide growth factors in chronic wounds have not fulfilled the high expectations derived from results of experimental studies. There is no convincing evidence that growth factors may substitute for good wound care and efficient surgical approaches to wound closure. The ultimate goal of treatment of chronic ulcerations remains reconstitution of a durable skin envelope without unstable scarring. Therefore, optimization of current methods of wound therapy, including reconstructive vascular and plastic surgery and adequate metabolic and wound control, should be employed before any adjuvant growth factor therapy is attempted. As long as efficient and inexpensive therapy of chronic wounds by growth factors has not been demonstrated, empincal growth factor treatment should be rejected on scientific and economic grounds. Current use appears to be reasonable only under a regime of controlled clinical studies comparing growth factor treatment with conventional wound therapy and operative measures according to the rules of "good clinical practice".

Administration, Topical↗

PubMed1998

Q-type Ca2+ channels are located closer to secretory sites than L-type channels: functional evidence in chromaffin cells.

This study uses a new strategy to investigate the hypothesis that, of the various Ca2+ channels expressed by a neurosecretory cell, a given channel subtype is coupled more tightly to the exocytotic apparatus than others. The approach is based on the prediction that the degree of inhibition of the secretory response by various Ca2+ channel blockers will differ at low (0.5 mM) and high (5 mM) extracellular Ca2+ concentrations ([Ca2+]o). So, at low [Ca2+]o the K+-evoked catecholamine release from superfused bovine chromaffin cells was depressed 60-70% by 2 microM omega-agatoxin IVA (P/Q-type Ca2+ channel blockade), by 3 microM omega-conotoxin MVIIC (N/P/Q-type Ca2+ channel blockade), or by 3 microM lubeluzole (N/P/Q-type Ca2+ channel blockade); in high [Ca2+]o these blockers inhibited the responses by only 20-35%. At 1-3 microM omega-conotoxin GVIA (N-type Ca2+ channel blockade) or 3 microM furnidipine (L-type Ca2+ channel blockade), secretion was inhibited by 30 and 50%, respectively; such inhibitory effects were similar in low or high [Ca2+]o. Combined furnidipine plus omega-conotoxin MVIIC, omega-agatoxin IVA or omega-conotoxin GVIA exhibited additive blocking effects at both Ca2+ concentrations. The results suggest that Q-type Ca2+ channels are coupled more tightly to exocytotic active sites, as compared to L-type channels. This hypothesis if founded in the fact that external Ca2+ that enters the cell through a Ca2+ channel located near to chromaffin vesicles will saturate the K+ secretory response at both [Ca2+]o, i.e. 0.5 mM and 5 mM. In contrast, Ca2+ ions entering through more distant channels will be sequestered by intracellular buffers and, thus, will not saturate the secretory machinery at lower [Ca2+]o.

Animals↗

PubMed1998

Constant bright light (LL) during lactation in rats prevents arrhythmicity due to LL.

Light has a strong effect on the circadian system. Light-dark (LD) cycles are the main zeitgebers for practically all organisms, and the exposure of animals to constant bright light (LL) alters the manifestation of circadian rhythms. In rats, exposure to LL in adulthood produces an arrhythmic pattern in their motor activity, with a large number of ultradian components. In previous experiments, we found that rats born and kept under LL during lactation develop, after weaning, a circadian rhythm which is maintained for at least a couple of months. Here, we examined motor activity rhythms under LL of two groups of rats which differed in the lighting conditions under which they were kept during lactation: 1) rats kept under LL during lactation (LL-rats), which manifested a circadian rhythm after weaning, and 2) rats kept under constant darkness (DD-rats), which were arrhythmic after weaning. We investigated whether the presence of rhythmicity under LL in LL-rats is a transitory effect or whether it persists throughout most of the life of the rat. Moreover, we examined motor activity rhythms of both groups of rats under different lighting conditions to find out other possible differences in the manifestation of their circadian rhythms. Results showed that there are no differences in the capacity of entrainment of both groups of rats to LD cycles or in the rhythm that rats show under DD. Most of the LL-rats maintained their circadian rhythms for the duration of the experiment (1 year), although we found differences in the rhythms manifested between males and females. We found that most of the LL-males became arrhythmic; consequently, at the end of the experiment, there were no differences in the number of males showing circadian rhythm in the LL- and DD-groups. Most of the females in the LL-group showed a clear circadian rhythm under LL during the entire experiment. Thus, LL during lactation has a protective effect against the disruptive effect of LL on the circadian rhythm, although it is only clearly manifested in females.

Aging↗

PubMed1998

Glyceraldehyde-3-phosphate dehydrogenase from Tetrahymena pyriformis: enzyme purification and characterization of a gapC gene with primitive eukaryotic features.

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH, EC.1.2.1.12) was purified to electrophoretic homogeneity from an amicronucleated strain of the ciliate Tetrahymena pyriformis using a three-step procedure. The native enzyme is an homotetramer of 145 kDa exhibiting absolute specificity for NAD. In its catalytic properties it is similar to other glycolytic GAPDHs. Chromatofocusing analysis showed the presence of only one basic GAPDH isoform with an isoelectric point of 8.8. Western blots using a monospecific polyclonal antibody raised against the T. pyriformis GAPDH showed a single 36-kDa band corresponding to the enzyme subunit in the cytosolic protein fraction of this strain and the closely related species, both from the class Oligohymenophorea, Paramecium tetraurelia. No bands were immunodetected in the ciliate Colpoda inflata (class Colpodea) and in the diverse eukaryotes and eubacteria tested. A 0.5-kb DNA fragment which corresponds to an internal region of a gapC gene was generated by polymerase chain reaction using cDNA of T. pyriformis as template. This gene codes for a basic GAPDH protein with eukaryotic-diplomonad signatures and exhibits a codon usage biased in the manner typical for T. pyriformis genes. Southern blots performed both under homologous and heterologous conditions using this amplified cDNA fragment as a probe, indicated that it should be the only gapC gene present in the macronuclear genome of this ciliate, its expression being confirmed by Northern blot analysis. These results are discussed in connection with the peculiar genomic organization of ciliates and in the context of protist evolution.

Amino Acid Sequence↗

PubMed1998

Invasive diagnostic techniques for pneumonia: protected specimen brush, bronchoalveolar lavage, and lung biopsy methods.

We suggest the following strategy for managing patients with pneumonia. For nonventilated patients with either CAP or HAP, empiric antibiotic treatment should be started according to approved guidelines, and if the clinical evolution of the patient is not adequate, fiberoptic bronchoscopy including PSB and BAL could be considered, with modification of the antibiotic treatment accordingly. In ventilated patients with either CAP or HAP, respiratory secretion sampling using noninvasive techniques should be conducted upon clinical suspicion of VAP and before starting a new antibiotic treatment. Antibiotic therapy according to approved guidelines should be started as soon as possible and maintained during the first 48 hours if the patient's evolution is satisfactory and condition has stabilized. Then, initial antibiotic treatment should be adjusted according to cultures. If there is a clear diagnostic alternative to VAP and cultures are negative, this is the only case in which antibiotic treatment could be withdrawn. If the patient's clinical evolution is inadequate (persistence of fever, leukocytosis, increasing infiltrates, and respiratory failure), fiberoptic bronchoscopy with PSB and BAL and modification of the initial antibiotic regimen should be sought. Open lung biopsy may be indicated in patients with diffuse pulmonary infiltrates in whom a diagnosis has not been achieved by other methods, including bronchoscopy. Transbronchial lung biopsy should not be viewed as a diagnostic technique for pneumonia except in immunosuppressed patients with diffuse alveolar infiltrates.

Anti-Bacterial Agents↗

PubMed1998

saliva, a new Drosophila gene expressed in the embryonic salivary glands with homologues in plants and vertebrates.

saliva (slv) transcription begins at the salivary gland placodes and continues on throughout development as salivary glands invaginate and reach their final location and morphology. saliva is located cytogenetically in 76A/B, and encodes a 226-amino-acid protein with four hydrophobic domains. A Northern blot detects a 1.6-kb transcript throughout development. Database similarity searches reveal homology to proteins from Caenorhabditis, Lilium, Medicago and mouse.

Amino Acid Sequence↗

PubMed1998

Mechanisms in progestin antagonism of pituitary tumorigenesis.

Chronic exposure of F344 rats to diethylstilbestrol (DES) induces pituitary tumors (DES-T) composed of proliferating lactotrophs. Presently, we studied the effect of progestins on parameters related to tumor growth and function, due to previous evidences of progesterone antagonism of pituitary tumorigenesis acting at pituitary and hypothalamic levels [Piroli, G., Grillo, C., Ferrini, M., Lux-Lantos, V. and De Nicola, A. F., Antagonism by progesterone of diethylstilbestrol-induced pituitary tumorigenesis in Fischer 344 rats: Effects on sex steroid receptors and tyrosine hydroxylase mRNA, Neuroendocrinology, 1996, 63, 530-539]. In search of a quantitatively more important effect, animals bearing DES-T were treated with synthetic progestins. Competition assays using DES-T as source of progestin receptors indicated that levonorgestrel (LNG), gestodene and R5020 showed higher affinities (IC50 1-2 nM) than progesterone, norethisterone and medroxyprogesterone (IC50 10-25 nM). Treatment with LNG reduced DES-T weight by 45%, and serum PRL by one half. Small (monomeric) and big (polymeric) PRL increased 5- and 2.5-fold, respectively, in DES-T in comparison with pituitaries of ovariectomized (OVX) rats. However, LNG produced no changes indicating that synthesis and storage of PRL was conserved in rats receiving both hormonal treatments. DES induced a 15-fold increase in cell proliferation, measured as bromodeoxyuridine incorporation into cell nuclei, in comparison to OVX rats, while LNG treatment of DES-T bearing rats reduced this index by 72%. Electron microscopic images showed that LNG markedly reduced hypertrophy and hyperplasia of lactotropes, increasing the proportions of degenerating cells and cells of high electronic density with alterations of cytoplasmic organelles. However, histopathological signs of apoptosis were absent. Therefore, reduced cell proliferation and non-apoptotic cell death are part of the mechanisms employed by progestins to antagonize tumorigenesis at the pituitary level. The results may open a new therapeutic strategy for treatment of PRL secreting adenoma in humans.

Animals↗

PubMed1998

Autologous peripheral blood stem cell transplantation (PBSCT) mobilized with G-CSF in AML in first complete remission. Role of intensification therapy in outcome.

In order to determine if peripheral blood stem cells (PBSC) collected after priming with G-CSF in AML in first complete remission (CR) can be used for autologous transplantation and to evaluate the efficacy of early intensification therapy as in vivo purging, we studied 35 consecutive patients with AML in first CR. After standard induction and consolidation chemotherapy, 24 of them were treated with one (10 patients) or two (14 patients) cycles of high-dose cytarabine plus etoposide prior to PBSC collection. G-CSF was used as the priming agent. Of the 35 patients scheduled for peripheral blood stem cell transplantation (PBSCT), three relapsed before transplantation, and the 32 remaining underwent PBSCT. High-dose therapy consisted of either total body irradiation plus cyclophosphamide or busulphan plus cyclophosphamide. The median number of CD34+ cells infused was 3.24 x 10(6)/kg (range 0.15-14). The median times to reach a PMN count of 0.5 x 10(9)/l and a platelet count of 50 x 10(9)/l were 12 (8-28) and 30 (11-345) days, respectively. There was no transplant-related mortality. Twelve patients relapsed between 2 and 21 months post-PBSCT. With a median follow-up of 28 months, actuarial disease-free survival (DFS) is 52.41 +/- 9% in the intent-to-treat group and 57.4 +/- 9.8% in patients who underwent PBSCT. The probability of DFS is significantly higher for patients who receive early intensification therapy prior to both PBSC collection and PBSCT as compared with patients that do not: 68.8 +/- 10.27% vs 35.5 +/- 12.6%, P = 0.0418. These results indicate the feasibility of PBSCT in AML using G-CSF-mobilized PBSC. The use of intensification treatment as 'purging in vivo' prior both to collection of PBSC and PBSCT significantly reduces the risk of relapse in this group of patients.

Adolescent↗

PubMed1998

Autologous reconstitution with BCR-ABL-negative haematopoiesis after T cell-depleted allogeneic BMT for CML.

We report a patient with Ph chromosome-positive CML who underwent an HLA-identical T cell-depleted BMT from a sibling donor. DNA polymorphism analysis showed complete donor chimaerism after BMT, followed by mixed chimaerism of granulocytes, natural killer cells and B lymphocytes, with T lymphocytes host-derived at day +120 post BMT. From month +20 haematopoiesis was exclusively of host origin in all cell lineages. RT-PCR was used in order to detect residual disease, but at the time, analysis did not show BCR-ABL transcripts. This case is unusual in that non-malignant stem cells of recipient origin survived the transplant and reconstituted haematopoiesis after BMT. Two years post transplant, no molecular or haematological relapse was documented. The observation that subsequent recipient recovery without molecular relapse implies that, at least in this case, the GVL effect can occur in the absence of donor T cells.

Bone Marrow Purging↗

PubMed1998

Epidermal growth factor protects against carbon tetrachloride-induced hepatic injury.

1. Epidermal growth factor (EGF) is known to protect the gastrointestinal tract against various noxious agents. Its potential value in preventing/ treating hepatic injury is, however, largely unexplored. We therefore examined whether EGF could influence CCl4-induced hepatic injury. 2. Female Sprague-Dawley rats (8 per group) received saline or recombinant EGF (500 or 750 micrograms/kg, intraperitoneal) 30 min before CCl4 (20% v/v, in olive oil, intraperitoneal). Eighteen hours later, animals were killed, serum was collected for assay of biochemical markers of hepatic injury and livers were removed for histological analyses. 3. Administration of CCl4 resulted in severe hepatic necrosis and caused a 10-fold rise in plasma alanine aminotransferase levels compared with levels seen in control animals (218 +/- 15 compared with 23 +/- 9 mumol/l in controls, mean +/- SEM, P < 0.01). Serum malondialdehyde levels, used as a marker of lipid peroxidation, showed a 2-fold rise in response to CCl4 treatment (median 4.0, quartile range 3.3-5.8 units/l compared with median 2.3, quartile range 2.1-2.5 units/l in controls, P < 0.05). Administration of EGF at 500 micrograms/kg, before the CCl4, did not protect against injury, as assessed by histology or rise in plasma alanine aminotransferase levels. In contrast, animals given EGF at 750 micrograms/kg, before the CCl4, had only minimal changes in histology, with only a minor rise in alanine aminotransferase levels (37 +/- 4 compared with 23 +/- 9 mumol/l in animals not given CCl4) and had no significant rise in malondialdehyde levels. 4. EGF protects against CCl4-induced hepatic injury and may provide a novel approach to the treatment of liver damage.

Animals↗

PubMed1998

Residual effects of thyroid hormone on secretory activity of somatotroph population.

In the present experiments the effects of the interruption of a prolonged T3 treatment on somatotroph population and GH synthesis and secretion were studied. The treatment with pharmacological doses of T3 provokes marked ultrastructural changes in somatotrophs compatible with a stimulated synthesis of GH. These results can be correlated with the significant increase in pituitary GH content and the normal values of serum GH. Twenty-four hours after T3 withdrawal, somatotrophs exhibited a marked depletion of secretory granules by exocytosis. These changes were concurrent with a significant discharge of pituitary GH and a two-fold increase in GH serum levels. The serum concentrations attained the highest values on the second and the third day after the T3 suppression, while the pituitary GH contents recovered the control levels. Morphometry of somatotroph population revealed a clear proliferation of cells and increased areas immunostained for GH, 24 h after withdrawal of the T3 treatment. The effects of T3 on somatotrophs were persistent for several days and at least five days were required for all parameters to return to control values. These results provide a new insight on the residual activity of thyroid hormones on both functional activity and morphological organization of somatotrophs.

Animals↗

PubMed1998

Production of alternariol and alternariol mono-methyl ether by isolates of Alternaria spp. from Argentinian maize.

Alternaria cultures (87 isolates of Alternaria alternata, four of A. tenuissima, two of A. radicina, and three of Alternaria state of Pleospora infectoria respectively, from maize) were screened to determine their ability to produce alternariol (AOH) and alternariol monomethyl ether (AME) on maize and rice. Only 28 A. alternata stains had toxigenic capacity. When maize was used as substrate 21 of 28 isolates produced AOH and AME, and 23 of 28 strains produced AOH and 22 of 28 produced AME when rice was used. The level of AOH produced by the isolates ranged from 0.3 to 2.1 mg/kg on maize and from 0.4 to 9.9 mg/kg on rice. The AME production by the stains ranged between 0.3 and 3.3 mg/kg both on maize and on rice. These results could indicate a low probability of AOH and AME occurring naturally on maize in Argentina.

Alternaria↗

PubMed1998

The effect of a high phosphorus diet on the parathyroid cell cycle.

High extracellular phosphorus directly increases parathyroid hormone (PTH) secretion and gene transcription. The present study evaluates the effect of high phosphorus diet on the parathyroid cell cycle in rats with normal renal function. Rats were divided into two groups, receiving either a high phosphorus diet (HPD, P=1.2%) or a normal phosphorus diet (NPD, P=0.6%). The dietary calcium content was 0.6% in both diets. Rats were pair fed and sacrificed on days 0, 1, 5, 10 and 15 after initiation of the diet. The parathyroid glands were removed and parathyroid cells dispersed for evaluation of cell cycle and apoptosis by flow cytometry. Serum calcium, phosphorus, PTH and calcitriol were measured. As compared with NPD, the ingestion of a HPD resulted in an increased number of cells in the S phase of the cell cycle from day 1 to 10 (1.2+/-0.09% vs 0.6+/-0.04% for day 1, 1.2+/-0.11% vs 0.6+/-0.06% for day 5 and 1.0+/-0.09% vs 0.5+/-0.04% for day 10, P<0.01). By day 15, the percentage of cells in the S phase in NPD and HPD were not different. In the rats fed the HPD, serum PTH increased significantly from day 5 through 15 (P<0.01). Parathyroid cell apoptosis was minimal and unaffected by the diet. At day 15, the parathyroid gland size in HPD was increased by 27% as compared with NPD (P<0.05). This increase should be attributed to cell proliferation since parathyroid cell size remained unchanged. Serum calcitriol and calcium were not significantly different in the two groups. In HPD, an increase in serum phosphorus was observed only on day 1. The results show that an HPD results in the stimulation of the parathyroid cell cycle independently of changes in calcium and calcitriol.

Animals↗

PubMed1998

Is it possible to control hyperphosphataemia with diet, without inducing protein malnutrition?

Dietary intervention, phosphate (P) removal during dialysis and, especially, phosphate binders are current methods for the management of hyperphosphataemia. Ideally, the amount of P absorbed from the diet should equal the amount of P removed during dialysis, and this must occur in the context of an adequate protein intake. We evaluated the relationship between P intake and protein intake in 60 stable chronic uraemic patients (mean age 55+/-15 years, 25% diabetics, 68% males) on standard 4 h haemodialysis. The dietary counselling was relatively free for protein and calories. Nutrient intake was recorded during a 5 day period, and average daily ingestion of P and proteins was calculated using a computerized diet analysis system. A highly significant correlation was observed between protein and P intake. The mean daily ingestion of P and proteins was 998+/-316 mg and 64+/-19 g (1+/-0.4 g/kg/day), respectively. For an optimal protein diet of 1-1.2 g/kg/day, the P intake was 778-1444 mg. The amount of P removed by haemodialysis, extrapolated to an average week, is 250-300 mg/day. Since approximately 40% of P ingested is absorbed from the gut by uraemic patients treated with intestinal P binders, 750 mg of P intake should be the critical value above which a positive balance of P may occur. This value corresponds to a protein intake of 45-50 g per day (>0.8 g/kg body weight/day for a 60 kg patient). In patients undergoing standard chronic haemodialysis, a neutral P balance is difficult to achieve, despite phosphate binder therapy, when protein intake is >50 g. Additional protein restriction, in order to obtain a neutral balance, may impose the risk of protein malnutrition.

Adult↗

PubMed1998

Parathyroid function in long-term renal transplant patients: importance of pre-transplant PTH concentrations.

Lack of resolution of hyperparathyroidism after long-term renal transplantation is common. The relative roles of the graft function attained and the degree of pre-transplant hyperparathyroidism have not been established. Intact parathyroid hormone (iPTH) and several clinical parameters were studied before and 68.6+/-26.8 months (range: 30-124) after renal transplantation in 62 patients (20 females/42 males) with good renal function (creatinine <2 mg/dl). iPTH decreased from 214+/-229 pre-transplantation to 116+/-70 pg/ml post-transplantation (P<0.01). However, only 22.6% of patients had PTH concentrations in the normal range, and values greater than twice the upper normal limit were not uncommon (27.4%). Of the many variables analysed, creatinine (r=0.43; P=0.001) and pre-transplant PTH (r=0.31; P=0.02) significantly correlated with post-transplant PTH. After selecting patients with serum creatinine <1.5 mg/dl (n=46), pre-transplant PTH emerged as the more important predictor of post-transplant PTH (r=0.58; P<0.0001). After controlling for creatinine, the partial correlation was r=0.53, P<0.0001. We concluded that spontaneous resolution of hyperparathyroidism after renal transplantation is uncommon. In addition, the magnitude of pre-transplant hyperparathyroidism and the renal function determine the long-term post-transplant parathyroid function.

Adult↗