Surgical strategy in lithium-associated hyperparathyroidism: A population-based study.

BACKGROUND: The extent of parathyroidectomy (PTX) recommendation in patients with lithium-associated hyperparathyroidism (LAH) remains controversial. The primary objectives of this study were to analyze extent of surgery, complications, and long-term outcomes. METHODS: A population-based study, including all primary hyperparathyroidism (PHPT) patients who underwent PTX in Sweden between 2008 and 2017. Data on exhibited lithium prescriptions, morbidity, surgical approach, and outcomes were collected from relevant national registers and the Scandinavian Quality Register of Thyroid, Parathyroid, and Adrenal Surgery. Patients with lithium exposure before PTX were defined as having LAH. Descriptive summary statistics and regression models were used to evaluate differences in comorbidities, surgical approach, and outcomes between LAH and PHPT not exposed to lithium (non-LAH). RESULTS: Lithium exposure was significantly more common among PHPT (n = 202, 2.3%) than in controls (n = 416, 0.5%); OR 5.0 (95% CI 4.2-5.9). The risk of LAH correlated to the length of lithium exposure. In the LAH-group, the surgical procedures were more extensive and associated with a higher risk of postoperative bleeding, wound infections, persistent hypercalcemia, and hypocalcemia that remained after adjustment for the higher percentage of multiglandular disease. However, the cumulative risk of re-admission for PHPT was similar the first years after PTX and primarily elevated for patients with >5 years duration of lithium exposure prior to surgery. CONCLUSIONS: The findings support the perception of LAH as a complex entity. We recommend a functionally oriented approach, aimed to obtain and maintain normocalcemia for as long as possible, minimizing the risk of permanent hypoparathyroidism, and accepting some risk of recurrence.

Neuropsychiatric Comorbidity in Primary Hyperparathyroidism Before and After Parathyroidectomy: A Population Study.

BACKGROUND: Primary hyperparathyroidism (PHPT) is often accompanied by neuropsychiatric symptoms. This study aimed to map out psychiatric comorbidity as reflected by medical treatment for psychiatric symptoms. METHODS: A retrospective case-control analysis and a prospective cohort analysis of psychotropic drug utilization before and after PTX. A total of 8279 PHPT patients treated with parathyroidectomy in Sweden between July 1, 2008 and December 31, 2017 compared to a matched control cohort from the total population (n = 82,790). Information on filled prescriptions was collected from the Swedish Prescribed Drug Register (SDR). Socioeconomic data and diagnoses were added by linkage to national patient and population registers. Regression analyses were used to calculate relative drug utilization (OR) within 3 years prior to PTX and relative incidence of drug treatment (RR) within 3 years postoperatively. RESULTS: Utilization of antidepressant, anxiolytic and sleep medication was more comprehensive in PHPT patients compared with the controls prior to PTX. The most common were benzodiazepines [OR 1.40 (95% CI: 1.31-1.50)] and selective serotonin reuptake inhibitors [SSRI; OR 1.38 (95% CI: 1.30-1.47)]. Postoperatively, the excess prescription rate for anxiolytic benzodiazepines decreased within three years from a 30 to 19% excess and for benzodiazepines for sleep from 31 to 14%. No corresponding decrease in excess prescription rate was observed for SSRI. CONCLUSION: PHPT is associated with increased utilization of antidepressive medications and benzodiazepines before PTX. This study implies that psychiatric symptoms should be considered in PHPT patients and continuous medication should be reevaluated after PTX.

Prediction of cognitive response to surgery in elderly patients with primary hyperparathyroidism.

BACKGROUND: Primary hyperparathyroidism (pHPT) can be associated with potentially reversible cognitive impairment, which is occasionally mistaken for natural ageing and dementia. The aim was to evaluate short-term medical normalization of hypercalcaemia in surgical decision-making for elderly patients with mild cognitive deficiency. METHODS: Patients with pHPT were included in a prospective observational study. A test panel including the Montreal Cognitive Assessment (MoCA) and validated tools for estimation of psychological status (Hospital Anxiety and Depression Scale, HADS), and muscle strength (timed-stands test, TST) was applied at baseline, after 4 weeks of calcimimetic treatment, and after parathyroidectomy. Mild cognitive impairment was defined by a MoCA score below 26. A longitudinal increase in MoCA score of at least 2 points 6 months after surgery was considered clinically meaningful. RESULTS: Of 110 patients who underwent testing, 35 aged 50 years or more were identified to have mild cognitive dysfunction, including 19 who were aged at least 70 years (median MoCA score 23, i.q.r. 21-24). Calcimimetic treatment resulted in normalization of calcium levels, and improvements in MoCA and HADS scores, and TST time. Normal MoCA scores (at least 26) were reached in 17 patients by 6 months after surgery, of whom 10 were aged 70 years or older. Long-term increase in MoCA score correlated with the decrease in ionized calcium concentration (r = -0.536, P = 0.022). Baseline calcium concentration and improvement in MoCA with calcimimetic treatment were identified as independent predictors of favourable outcome after parathyroidectomy. CONCLUSION: Medical normalization of hypercalcaemia can aid in predicting outcome after parathyroidectomy.

Increased risk for tooth extraction in primary hyperparathyroidism and hypercalcemia: a population study.

The aim of this study was to analyze dental comorbidities in untreated primary hyperparathyroidism (pHPT). Patients with pHPT subjected to parathyroidectomy (PTX) at Karolinska University Hospital, Stockholm, during 2011-2016 (n = 982) were selected from the Scandinavian Quality Register of Thyroid, Parathyroid and Adrenal surgery and compared to a general population cohort (n = 2944), matched for age and gender. Dental data was obtained from the Swedish Dental Health Registry for the 3 years prior to PTX. The incidence rate ratios (IRRs) of tooth loss by extraction, periodontal interventions, and dental visit rate were analyzed by Poisson regression models. In order to analyze the impact of disease severity, the PHPT cohort was sub-grouped based on preoperative serum levels of ionized calcium (S-Ca2+). The total number of tooth extractions, periodontal interventions, and number of visits were similar in the cohorts. PHPT patients belonging to the quartile with the highest S-Ca2+ (≥ 1.51 mmol/L) had increased risk for tooth extraction (IRR 1.85; 95% CI 1.39-2.46). Female gender independently amplified the risk (IRR 1.341, P < 0.027). This study indicates an association between pHPT and oral disorders reflected by increased tooth loss by extraction related to high S-Ca2. Increased awareness of dental comorbidity in primary hyperparathyroidism may benefit a large group of patients with a common disease through earlier detection and prevention.

Short-term medical treatment of hypercalcaemia in primary hyperparathyroidism predicts symptomatic response after parathyroidectomy.

BACKGROUND: Primary hyperparathyroidism is often associated with non-disease-specific symptoms. The aim of this study was to evaluate whether normalization of hypercalcaemia with short-term medical treatment can be used to predict the effects of parathyroidectomy and guide in surgical decision-making. METHODS: This observational study included patients who received calcimimetic treatment for 4 weeks before parathyroidectomy (30-60 mg daily). A panel of tests was used to assess various aspects of quality of life (European Organisation and Treatment of Cancer QLQ-C30 core questionnaire, Hospital Anxiety and Depression Scale and Positive State of Mind questionnaire), cognitive function (Montreal Cognitive Assessment) and muscle strength (timed-stands test). The tests were carried out at baseline, after 4 weeks of calcimimetic treatment, and at 6 weeks and 6 months after parathyroidectomy. The predictive values of changes during calcimimetic treatment were determined for each test. RESULTS: The study included 110 patients of median age 62 years (91 women). Calcimimetic treatment resulted in normalization of calcium levels and improvements in quality-of-life parameters. The time spent on the timed-stands test was significantly shortened. Eleven of 38 participants with a baseline Montreal Cognitive Assessment score below 26, indicating mild cognitive impairment, reached scores of at least 26 during treatment with calcimimetic. Improvements during treatment with calcimimetic correlated well with postoperative outcomes (positive predictive values 74-96 per cent). CONCLUSION: The method described in this study may be used to aid surgical decision-making for patients with primary hyperparathyroidism and non-disease-specific symptoms by predicting the effects of normalization of hypercalcaemia.

ANTECEDENTES: El hiperparatiroidismo primario (pHPT) a menudo se asocia con síntomas no específicos de la enfermedad. El objetivo de este estudio fue evaluar si la normalización de la hipercalcemia a corto plazo con tratamiento médico se podría usar para predecir los efectos de la paratiroidectomía y guiar la toma de decisiones quirúrgicas. MÉTODOS: Estudio observacional (ClinicalTrials.gov, registro NCT02227264) que incluyó 110 pacientes programados para paratiroidectomía (mediana de edad 62 años; 91 mujeres). Intervención: tratamiento calcimimético, cuatro semanas, 30-60 mg al día. Medidas de resultado: Un panel de pruebas para evaluar los aspectos de la calidad de vida (cuestionario de calidad de vida core 30, QLQ-C30; escala hospitalaria de ansiedad y depresión (HAD) y estado mental positivo (PSOM); función cognitiva (evaluación cognitiva de Montreal, MoCa) y fuerza muscular (Timed-Stands Test, TST). Las pruebas se realizaron cuatro veces: al inicio del estudio (basal), después de cuatro semanas de tratamiento calcimimético, a las seis semanas y seis meses después de la paratiroidectomía. Para cada prueba se determinaron los valores predictivos de los cambios durante el tratamiento calcimimético. RESULTADOS: El tratamiento con fármacos calcimiméticos determinó una normalización en los niveles de calcio y una mejoría en los parámetros de calidad de vida. El tiempo del TST se redujo significativamente. Once de los 38 participantes con una puntuación MoCa basal < 26, definida como deterioro cognitivo leve, alcanzaron puntuaciones ≥ 26 durante el uso de la medicación. Las mejoras observadas durante el tratamiento mostraron una buena correlación con el resultado postoperatorio (valores predictivos positivos 74-96%). CONCLUSIÓN: Este estudio presenta un método basado en la predicción de los efectos de la normalización de la hipercalcemia para ayudar en la toma de decisiones quirúrgicas en pacientes con pHPT y síntomas no específicos de la enfermedad.

Mrp1 multidrug resistance-associated protein and P-glycoprotein expression in rat brain microvessel endothelial cells.

Two membrane glycoproteins acting as energy-dependent efflux pumps, mdr-encoded P-glycoprotein (P-gp) and the more recently described multidrug resistance-associated protein (MRP), are known to confer cellular resistance to many cytotoxic hydrophobic drugs. In the brain, P-gp has been shown to be expressed specifically in the capillary endothelial cells forming the blood-brain barrier, but localization of MRP has not been well characterized yet. Using RT-PCR and immunoblot analysis, we have compared the expression of P-gp and Mrp1 in homogenates, isolated capillaries, primary cultured endothelial cells, and RBE4 immortalized endothelial cells from rat brain. Whereas the mdr1a P-gp-encoding mRNA was specifically detected in brain microvessels and mdr1b mRNA in brain parenchyma, mrp1 mRNA was present both in microvessels and in parenchyma. However, Mrp1 was weakly expressed in microvessels. Mrp1 expression was higher in brain parenchyma, as well as in primary cultured brain endothelial cells and in immortalized RBE4 cells. This Mrp1 overexpression in cultured brain endothelial cells was less pronounced when the cells were cocultured with astrocytes. A low Mrp activity could be demonstrated in the endothelial cell primary monocultures, because the intracellular [3H]vincristine accumulation was increased by several MRP modulators. No Mrp activity was found in the cocultures or in the RBE4 cells. We suggest that in rat brain, Mrp1, unlike P-gp, is not predominantly expressed in the blood-brain barrier endothelial cells and that Mrp1 and the mdr1b P-gp isoform may be present in other cerebral cells.

Molecular characterization and in vitro biological activity of placentin, a new member of the insulin gene family.

Insulin and insulin-like growth factors belong to a family of polypeptides involved in essential physiological processes. Placentin, a new member of the insulin family, was recently identified as a 139-amino acid open reading frame from a cDNA clone isolated from a subtracted library of first trimester human placenta. Tris/Tricine/SDS-polyacrylamide gel electrophoresis and immunoblot analyses of histidine-tagged recombinant placentin indicate that it is composed of two peptide chains of apparent molecular masses of 4 and 13 kDa. Conditioned media produced by recombinant expression of placentin cDNA in the placental 3AsubE cell line were assayed for biological activity and found to stimulate tyrosine phosphorylation and DNA synthesis. While these effects closely mimicked those of insulin, they were not mediated by the insulin receptor as shown by the lack of tyrosine phosphorylation of this receptor upon placentin treatment. Moreover, in cytotrophoblast primary culture, production of chorionic gonadotropin, a marker of trophoblast differentiation, was increased upon treatment with placentin-conditioned media, while unaffected by insulin. These results suggest that placentin might participate in the cellular proliferation and/or differentiation processes during placental development.

Cloning and sequencing of the equine testicular follitropin receptor.

To investigate the possibility that specific structural determinants within the equine follitropin receptor (eFSHR) are critical to the enhanced specificity of this receptor compared to other FSHRs, we used the RACE-PCR technique to clone the eFSHR from equine testis. Sequence analysis revealed that the eFSHR is highly homologous to other mammal FSHRs, but it presents 10 unique amino acid residue replacements in the extracellular domain. Furthermore, a potential N-glycosylation site was detected at a position not encountered in other receptors. Northern blot analysis identified three transcripts of 4.2 kb, 2.3 kb and 1.0 kb in horse testis.

Expression of the human follicle-stimulating hormone receptor in the baculovirus system.

Human follitropin receptor (hFSHR) cDNA was inserted into the genome of Autographa californica nuclear polyhedrosis virus under the control of the polyhedrin promoter. Spodoptera frugiperda (Sf9) insect cells expressed the hFSHR at the membrane level, 2-3 days after infection. Ligand binding analysis demonstrated saturable, high-affinity binding of 125I-labeled recombinant hFSH (Kd = 0.17 nM) as well as binding specificity for both human and equine FSH. Interestingly, a highly purified preparation of equine choriogonadotropin was found to compete with the binding of 125I-rhFSH. Finally, Western-blot analysis, using a monoclonal antipeptide antibody directed to the 178-206 region of the hFSHR, revealed two bands migrating at M(r) 77 and 130 kDa.

Different regulatory patterns of M1 and M2 muscarinic receptor subtype RNA in SH-SY5Y human neuroblastoma induced by phorbol ester or DMSO.

The human neuroblastoma cells SH-SY5Y were treated with the differentiation agents 12-O-tetradecanoyl-phorbol-13-acetate (TPA) or dimethyl sulfoxide (DMSO) and the muscarinic receptor subtype M1 and M2 RNA levels analyzed. After a decrease induced by both agents, the M1 level gradually returned to normal in the presence of TPA but remained minimal with DMSO. As for M2, several phases were observed with TPA, while DMSO caused a drastic increase. The data obtained with TPA were tentatively correlated with the amounts of immunoreactive PKC alpha. In conclusion, our results reveal: (a) differential regulation of M1 and M2 muscarinic receptor subtypes by either treatment; (b) opposing effects of TPA and DMSO on both subtypes.

Modulation of muscarinic-receptor expression in human embryonic lung fibroblasts by platelet-derived growth factor.

Platelet-derived growth factor (PDGF) is known to have regulatory control of a large number of cellular components, including various receptors. We show that muscarinic acetylcholine receptors of the m2 subtype on CCL 137 human fibroblasts in culture are affected by PDGF treatment. A time-dependent down-regulation is observed in steady-state RNA levels, followed by a decrease in ligand-binding capacity. Minimum RNA levels are attained at 11 h; minimum binding capacity is observed after 24 h of treatment. To our knowledge, this is the first example of negative gene control by PDGF.

Modulation of both interleukin 2 receptor expression and interleukin 2 production during experimental murine Trypanosoma cruzi infection.

A massive activation of T cells takes place during the early stages of a Trypanosoma cruzi infection in mice. We present data indicating that substantial amounts of interleukin 2 (IL-2) are secreted and IL-2 receptors are expressed during the period of increased proliferation (4-7 days post infection). Both concanavalin A-induced proliferation and IL-2 production are markedly decreased later in the acute infection (around 3 weeks post infection). This proliferation cannot be restored by externally added IL-2. Simultaneously, there is a drastic reduction in the number of both high- and low-affinity IL-2 receptors. The reduction is not attributable to the elimination of a particular T-cell population. In vivo administration of recombinant IL-2 failed to improve resistance to T. cruzi parasites as measured by parasitaemia and mortality.

Improved method for multisample evaluation of ligand binding to cells. Application to IL-2 receptor measurement.

A newly developed assay using microtitre plates with removable wells permits rapid measurements of IL-2 receptors. Triplicate or quadruplicate samples of several ligand dilutions are easily handled, thus giving more reliable results. In addition, measurement of binding parameters may be accomplished simultaneously on several cell lines. Results are presented which show that the binding assay may also be used for measuring binding constants of antibodies.

A naloxone-steroid hybrid azine with selective and long-acting opioid antagonism at delta receptors in vitro.

The interaction of naloxone estrone azine (N-EH) with various opioid receptor types was studied in vitro. Its potency as an antagonist of opioid effects was compared to that of naloxone on the electrically evoked contractions of mouse vas deferens (Mvd) and guinea pig ileum myenteric plexus longitudinal muscle (Gpi) preparations. N-EH was found to be 9-fold more potent than naloxone in antagonizing the effects of D-Ala2-Leu5-enkephalin in the Mvd and 22-fold less potent in antagonizing normorphine in the Gpi. In the Mvd, the recovery half-time for N-EH was longer than 1000 min. Neither compound showed agonism. The two compounds were also compared for their capacity to displace the binding of 3H-D-Ala2-Leu5-enkephalin, 3H-dihydromorphine, and 3H-ethylketocyclazocine to rat brain membranes under conditions where delta, mu, and kappa sites were labeled. The relative affinities were 0.70, 0.16, and 0.14 for N-EH and 0.05, 0.87, and 0.08 for naloxone, respectively. Thus, compared to naloxone, which is mu selective, N-EH is a delta-selective antagonist.

Prolonged receptor blockade by opioid receptor probes.

Opioid receptor interactions of morphinan-type opioids derivatized at the C-6 carbon were investigated. The compounds, designed as probes for studying opioid receptors, were characterized with regard to affinity for the rat brain mu receptor by competition with tritium-labeled dihydromorphine ((3)H-DHM). All compounds were also screened for prolonged receptor blockade by preincubation of rat brain membranes with the compounds alone, followed by extensive washing, and incubation with (3)H-DHM. The apparent dissociation profiles of congeners with prolonged blockade were further studied in the presence and absence of physiological concentrations of salts. Under conditions that completely dissociate the parent opioids, naltrexone, naloxone, and oxymorphone, the derivative l-(N-fluoresceinyl naltrexone thiosemicarbazone (6-FNX) and the opioid-steroid hybrids naloxone estrone azine (N-EH) and androstene bisoxymorphone azine (O-AD-O) showed more persistent receptor blockade than the bivalent opioid naloxonazine (NAz). Neither chemical reactivity nor a bivalent opioid structure was found to be a prerequisite for prolonged receptor blockade.

Agonist-antagonist properties of fluorescent opioid probes in the guinea-pig myenteric plexus-longitudinal muscle preparation.

The opioid activity of a series of fluorescent derivatives of oxymorphone, naloxone and naltrexone, were characterized on the electrically stimulated guinea-pig myenteric plexus-longitudinal muscle preparation. In all compounds the fluorescent moiety, fluorescein or tetramethylrhodamine B, is attached to the C-6 carbon of the morphinan. Mu-receptor affinity was well retained and there was a good correlation between capacity to displace [3H]-dihydromorphine from binding sites in rat brain membranes and apparent receptor affinity in the myenteric plexus measured as antagonism of normorphine effects. Fluorescein conjugated oxymorphone showed mainly agonist activity. Certain derivatives of the antagonists naloxone and naltrexone showed partial agonism. One compound, 1-(N)-fluoresceinyl naloxone thiosemicarbazone, was an antagonist.

Synthesis and pharmacological characterization of fluorescent opioid receptor probes.

A series of five fluorescent opioid receptor probes was synthesized by coupling naloxone, oxymorphone or naltrexone with fluorescein or tetramethylrhodamine B. The series was characterized for capacity to displace (3)H-dihydromorphine from rat brain opioid receptors. All compounds showed receptor binding, and 1-(N)-fluoresceinyl naltrexone thiosemicarbazone displayed the highest mu-receptor affinity with a Ki value of 3 nM. l-(N)-fluoresceinyl naloxone thiosemicarbazone was a morphine antagonist in vivo, approximately 6 % as potent as naloxone and naloxonazine in the mouse hot-plate test.

Fluorescent probes for opioid receptors.

Naloxone, naltrexone and oxymorphone were labeled in position 6 with fluorescein by coupling their hydrazone analogs with fluorescein isothiocyanate. Naloxone was also coupled in a similar way with rhodamine-B. The compounds thus obtained were: "6-FN", [1-(N)-fluoresceinyl naloxone thiosemicarbazone]; "6-FNX", [1-(N)-fluoresceinyl naltrexone thiosemicarbazone]; "6-FO", [1-(N)-fluoresceinyl oxymorphone thiosemicarbazone]; "6-RN", [1-(N)-tetramethylrhodaminyl-B naloxone thiosemicarbazone]. These compounds were tested for opioid receptor binding in rat brain synaptosomal plasma membranes and for biological activity on the guinea pig ileum. All compounds retained activity, showing some changes in affinity and binding profile compared to their parent compounds. "6-FN", for example, showed decreased (approximately 10x) affinity compared to naloxone in opiate displacement analysis but retained potency in displacement of opioid peptides. Antagonist activity of "6-FN" in the guinea pig ileum bioassay was about ten-fold less than that of naloxone.