The effect of sodium restriction on iodine prophylaxis: a review.

PURPOSE: Sodium is essential to life. However, its dietary excess is detrimental to the cardiovascular system, and sodium restriction is a crucial step in cardiovascular prevention. Iodine deficiency has been fought worldwide for decades, and substantial success has been achieved introducing the use of iodine-enriched salt. Nevertheless, areas of iodine deficiency persist around the world, both in developing and industrialized countries, and a major concern affecting dietary sodium reduction programs is represented by a possible iodine intake deficiency. There are substantial differences in the source of alimentary iodine among countries, such as iodized salt added, household tap water, seafood, or salt employed in packaged food. It is clear that a sodium-restricted diet can induce differences in terms of iodine intake, depending on the country considered. Moreover, iodine status has undergone relevant changes in many countries in the last years. METHODS: Systematic review of literature evidence about the possible effects of sodium restriction on population iodine status. RESULTS: To date, the available results are conflicting, depending on country, salt iodization policy, as well as time frame of data collection. However, to ensure an optimal iodine supply by salt fortification, without exceeding the current recommendation by World Health Organization for salt intake, seems to be an achievable goal. CONCLUSION: A balanced approach may be obtained by an adequate iodine concentration in fortified salt and by promoting the availability of iodized salt for household consumption and food industry use. In this scenario, updated prospective studies are strongly needed.

Recommendations for the Use of Tryptase in the Diagnosis of Anaphylaxis and Clonal Mastcell Disorders.

Summary: Tryptase is a serin-protease produced and released by mast cells after IgE-mediated or non-IgE mediated stimuli. We here review the various aspects related to the molecular characteristics of the enzyme and its biological effects, the genetic basis of its production and the release kinetics. Recommendations for the clinical use of tryptase measurement developed by a task force of Società Italiana di Patologia Clinica e Medicina di Laboratorio and Associazione Allergologi Immunologi Italiani Territoriali e Ospedalieri are given on the best procedure for a correct definition of the reference values in relation to the inter-individual variability and to the correct determination of tryptase in blood and other biological liquids, in the diagnosis of anaphylaxis (from drugs, food, insect sting, or idiophatic), death from anaphylaxis (post mortem assessment) and cutaneous or clonal mastcell disorders.

Reference intervals for thyrotropin in an area of Northern Italy: the Pordenone thyroid study (TRIPP).

PURPOSE: Thyrotropin (TSH) is the most accurate marker of thyroid dysfunction in the absence of pituitary or hypothalamic disease. Studies on TSH reference intervals (RIs) showed wide inter-individual variability and prompted an intense debate about the best estimation of TSH RIs. DESIGN: We performed a population study on TSH RIs, using current data stored in the laboratory information system (LIS), at the Hospital Department of Laboratory Medicine, Pordenone (Italy), historically an area of mild-moderate iodine deficiency with a relatively high goiter prevalence. METHODS: 136,650 individuals constituted the final sample. A TSH immunoassay was performed on fasting serum samples with the Dimension Vista 1500 analyzer (Siemens Healthineers). We adopted the Kairisto's procedure to analyze TSH data downloaded by the LIS, applying the indirect strategy for deriving RIs. RESULTS: TSH RIs of the entire population were 0.32-3.36 mIU/L with a distribution skewed towards higher values. RIs were 0.26-3.61 mIU/L for females, and 0.32-3.01 mIU/L for males. Unlike other studies, TSH median levels progressively decreased from 0-4 to 85-104 years in the overall population, both in male and in female subgroups, showing an inverse correlation between TSH and age in all groups. CONCLUSIONS: This study is the first to analyze a high percentage (40%) of individuals from an ethnically homogenous Caucasian population. The results obtained emphasize the opportunity to define the TSH RIs according to age, gender and race, in addition to assay methods, and provide further insight about the possible role of iodine status.

Relationship between circulating anti-thyroglobulin antibodies (TgAb) and tumor metabolism in patients with differentiated thyroid cancer (DTC): prognostic implications.

PURPOSE: TgAb have been proposed as tumor markers in DTC. Recent evidence links TgAb levels with DTC aggressiveness. We aimed to evaluate the relationship between TgAb and tumor glucose metabolism in DTC patients. METHODS: Seventy-one DTC patients who underwent 18F-FDG PET/CT were included. According to TgAb value and trends, patients were divided into TgAb positive (TgAb+) or negative (TgAb-) as well as in patients with increasing (Inc-TgAb) or decreasing (Dec-TgAb) trend. On the basis of the results of FDG-PET, post-therapy 131I and Tg levels, patients were divided into two groups according to the evidence (ED) or absence (NED) of disease. ED patients were further divided into three subgroups: 1. radioiodine avid with positive 18F-FDG PET/CT (PET+/131I+), 2. radioiodine refractory with positive 18F-FDG PET/CT (PET+/131I-) and 3. radioiodine avid with negative 18F-FDG PET/CT (PET-/131I+). MeanSUV of FDG-avid lesions was assessed and averaged for each patient (SUVmean-pt). T test was performed to assess the difference between SUVmean in TgAb-, TgAb+ and in Inc-TgAb and Dec-TgAb subgroups. Difference in TgAb between ED and NED patients as well as between ED patients and PET+/131I+, PET+/131I- and PET-/131I+ subgroups was compared. RESULTS: SUVmean was significantly higher in Inc-TgAb with respect to Dec-TgAb subgroup (5.2 ± 1.5 vs. 2.9 ± 1.1, p < 0.05). TgAb were higher only in the ED PET+/131I+ subgroup with respect to NED patients (p < 0.01). CONCLUSIONS: The relationship between higher tumor metabolism and trend of TgAb supports a prognostic relevance of TgAb in DTC patients. Significantly higher TgAb in radioiodine avid tumors with positive 18F-FDG PET/CT further testify the role of TgAb as surrogate tumor marker in DTC.

[Radiometabolic therapy for metastatic thyroid carcinoma: overview of the literature and rational bases for the use of recombinant human TSH]. / La terapia radiometabolica del carcinoma della tiroide metastatico: overview della letteratura e basi razionali all'utilizzo del TSH umano ricombinante.

The established treatment for differentiated thyroid carcinoma (DTC) is founded on total thyroidectomy and subsequent administration of radioiodine (131I) to ablate the thyroid remnant and to treat the metastatic disease. In the case of metastatic or recurrent disease, further cycles of 131I therapy are often necessary. The condition for maximizing the effectiveness of the treatment is to have an adequate stimulation from TSH, which must be >25-30 mIU/L. This elevation is achieved either discontinuing the hormone suppression therapy for an appropriate period, or administering recombinant human TSH (rhTSH). The latter has shown good clinical efficacy in patients with residual thyroid gland and is nowadays commonly employed since it is easy to use and allows to avoid the side effects of hypothyroidism. It thus represents a good alternative to thyroid hormone withdrawal for the remnant ablation, while is still open the question if its efficacy on the management of metastatic disease is superimposable to thyroid hormone withdrawal. To this purpose, a Panel of expert reviewed the literature, assessing the advantages and disadvantages for the patient, as well as the impact in terms of cost and benefit to the National Health Service. The work of the Panel concluded with a proposal for the use of rhTSH in selected patients with metastatic DTC, in which is considered the efficacy and safety of the product and is examined its use in terms of costs; this proposal was accepted by the Italian Drug Agency resulting in an update of the indications for rhTSH.

A study of the efficacy of radioiodine therapy with individualized dosimetry in Graves' disease: need to retarget the radiation committed dose to the thyroid.

Although Iodine-131 (131I) therapy is fully validated for Graves' disease (GD), there is debate about radioiodine amount to be administered (prescribed activity), as well as the use of individualized dosimetry vs fixed 131I activity. The clinical outcome of 119 GD patients treated with 131I from 2003 to 2008 has been evaluated. The prescribed activity was calculated according to a dosimetric protocol taking into account several variables, including thyroid volume reduction during treatment. In addition, we performed a simulation according to other dosimetric protocols, by calculating the corresponding prescribed activities. The patients were followed up for at least 12 months after treatment. In the first period of observation (2003), a 120-200 Gray (Gy) radiation dose to the thyroid was prescribed, according to the guidelines published by the Italian Societies of Endocrinology, Nuclear Medicine and Medical Physics: hyperthyroidism cure with a single radioiodine administration was obtained in 53% of patients. This outcome raised up to 89% when a higher radiation dose to the target (200- 250 Gy) was prescribed, although the administered activities were still lower, as a rule, than the most commonly employed fixed activities (400-600 Mega-Becquerel--MBq). Our method showed a high level of individual dose optimisation, particularly when compared to simplified methods. In conclusion, the protocol adopted in this study ensures a satisfactory rate of hyperthyroidism cure, while administering quite low 131I activities, provided that an adequate committed radiation dose to the thyroid is prescribed. In this context, the dose indication given by the aforementioned guidelines should probably be revised.

Thyrotropin receptor autoantibody measurement following radiometabolic treatment of hyperthyroidism: comparison between different methods.

BACKGROUND: TSH receptor antibodies (TRAb) play a crucial role in the pathogenesis of Graves' disease (GD). The use of human recombinant TSH-receptor far improved the analytical performance of TRAb assays (2nd-generation assays). The 3rd-generation assay is based on the inhibition of binding of a human biotin-labeled monoclonal thyroid- stimulating antibody (M22) to TSH-receptor by the autoantibodies present in the serum. AIM: We aimed to assess the ability of the 2nd- and 3rd-generation assays to detect serum TRAb following radioiodine therapy for hyperthyroidism. METHODS: Sera from 47 hyperthyroid (25 autoimmune, 22 non-autoimmune) patients were tested using the two different assays before and at different time intervals after radioiodine therapy. The modifications of TRAb were evaluated, as well as the correlation between the two methods. RESULTS: The results obtained by the two methods proved to be closely correlated. A rise in TRAb was invariably observed in GD patients following radioiodine, with a median peak at 6 months, irrespective of their initial clinical status, presence of ophthalmopathy, smoking habits or other variables. Such a rise was nearly superimposable using both methods. No TRAb appearance was observed in patients with non-autoimmune hyperthyroidism. CONCLUSIONS: The use of methods of higher sensitivity with respect to that formerly used indicate that nearly all GD patients develop TRAb following radioiodine, and that this phenomenon is transient and not related to baseline conditions and clinical outcome/efficacy of treatment.

Pain and ketoprofen: what is its role in clinical practice?

Ketoprofen is a drug belonging to the family of non-steroidal anti-inflammatory drugs (NSAIDs). The present review examines the main available clinical evidence of ketoprofen in the treatment of acute and chronic pain, of both rheumatic and traumatic origin, as well as postoperative pain. Ketoprofen has shown to be an excellent choice of drug for the treatment of chronic pain in patients with osteoarthritis, rheumatoid arthritis or gout, demonstrating a high level of efficacy with good tolerability also in elderly patients. Even in the treatment of acute forms of pain such as bursitis, tendinitis and back pain, ketoprofen compares favourably to other NSAIDs (e.g., ibuprofen and diclofenac) in terms of efficacy. Ketoprofen has been shown to be effective also for the treatment of post-operative pain, particularly in the orthopaedic field, with an efficacy similar to opioids in some studies. In this setting, some evidence indicates that ketoprofen exhibits additional important benefits, showing to be effective in the prophylaxis of heterotopic calcification following hip or pelvic major intervention, without affecting the bone healing process. Moreover, the use of ketoprofen in elastomeric pump in combination with opioids or other NSAIDs has proven to be effective and safe. In conclusion, available data confirm that ketoprofen is effective and well tolerated, through different administration routes, for the treatment of various forms of rheumatic, traumatic and post-surgical pain, and may therefore be considered as a valid therapeutic option for these patients.

Potential involvement of Fas and its ligand in the pathogenesis of Hashimoto's thyroiditis.

The mechanisms responsible for thyrocyte destruction in Hashimoto's thyroiditis (HT) are poorly understood. Thyrocytes from HT glands, but not from nonautoimmune thyroids, expressed Fas. Interleukin-1beta (IL-1beta), abundantly produced in HT glands, induced Fas expression in normal thyrocytes, and cross-linking of Fas resulted in massive thyrocyte apoptosis. The ligand for Fas (FasL) was shown to be constitutively expressed both in normal and HT thyrocytes and was able to kill Fas-sensitive targets. Exposure to IL-1beta induced thyrocyte apoptosis, which was prevented by antibodies that block Fas, suggesting that IL-1beta-induced Fas expression serves as a limiting factor for thyrocyte destruction. Thus, Fas-FasL interactions among HT thyrocytes may contribute to clinical hypothyroidism.

Prevalence of post-partum thyroiditis in Liguria (Italy): an observational study.

BACKGROUND: Post-partum thyroiditis (PPT) is an autoimmune disorder occurring within the first year following delivery. A variable prevalence has been reported in different surveys. We prospectively evaluated PPT prevalence and outcome in a cohort of pregnant women living in a well-defined geographic area. AIM: A subset from a group of healthy women consecutively evaluated for thyroid function and thyroid autoimmunity during pregnancy, referring to the same obstetric unit, were followed up at 4-6 months and 1 yr after delivery. MATERIALS/SUBJECTS AND METHODS: Follow-up for PPT was performed in 258 pregnant women. Control data were obtained in a comparable group of healthy non-pregnant women. Free T3 (fT3), free T4 (fT4), TSH thyroglobulin/thyroid peroxidase autoantibodies (TgAb/TPOAb), and urinary iodine excretion were measured. RESULTS: Autoantibody positivity was observed in 9.3% of pregnant, similar to control women. Forty-three out of 59 autoantibody-positive women were followed up; 23 showed PPT at the first control, 18 had hypothyroidism at 1 yr (5 had not shown PPT at the first control). Among 215 out of 584 autoantibody-negative women followed up, 27 developed PPT (15 of them without thyroid autoantibodies); 16 developed thyroid autoantibodies without PPT. After 1 yr, 9 women had hypothyroidism: only 1 of them was autoantibody-negative at the former control. Urinary iodine was increased in several pregnant women. CONCLUSIONS: An overall PPT prevalence of about 18% may be estimated. PPT was also observed in autoantibody- negative women. Differences with other surveys may be related to both study protocol and characteristics of the population studied.

Diagnostic accuracy of IgA anti-tissue transglutaminase antibody assays in celiac disease patients with selective IgA deficiency.

Clinical studies have estimated a 10- to 20-fold increased risk for celiac disease (CD) in patients with selective IgA deficiency (SIgAD). For this reason, screening for CD is mandatory in SIgAD patients, but it represents a special challenge since the specific IgA class antibodies against gliadin (AGA), endomysium (EMA), and tissue-transglutaminase (tTG) are not produced in patients with CD. IgG class counterparts of these antibodies may be informative; in particular IgG EMA has been demonstrated to be a valid marker for diagnosing CD in SIgAD cases, but it is not used much in clinical laboratories, because it is cumbersome and involves some technical difficulties. Even if it was widely used in clinical laboratories, the measuring of IgG AGA has shown a less-than-optimum diagnostic accuracy, so that now it tends to be substituted by tests for anti-tTG IgG, for which the few available studies have shown diagnostic performances superior to AGA. Since it is not known whether various available methods for measuring IgG anti-tTG antibodies offer similar diagnostic performances, we have compared the results obtained from nine second-generation commercial methods (D-tek, Phadia, Immco, Orgentec, Radim, Euroimmun, Inova, Aesku, Generic Assays), measuring IgG anti-tTG antibodies in 20 patients with CD and SIgAD and in 113 controls (9 patients with SIgAD without CD, 54 patients with chronic liver disease, and 50 healthy individuals). Diagnostic sensitivity, calculated by means of ROC plot analysis, ranged between 75% and 95%, and specificity ranged from 94% to 100%. In the same population, the diagnostic sensitivity and specificity of AGA IgG were 40% and 87%, respectively. Even though they perform differently, all IgG anti-tTG methods evaluated are reliable serological assays for the diagnosis of CD in SIgAD patients, with diagnostic accuracy superior to the AGA IgG method. The methods that use a mix of tTG and gliadin peptides as the antigenic preparation have a specificity slightly lower than that of the methods that use only tTG.

Ultrasonography thyroid volume estimation in hyperthyroid patients treated with individual radioiodine dose.

Radioiodine (RAI) therapy is a safe and effective treatment for hyperthyroidism and individual doses are frequently administered. Initial thyroid volume (TV) is an important parameter for RAI therapy. Ultrasonography (US) is considered the most reliable method of determining TV. The aim of this study was to evaluate TV by means of US in a cohort of 75 hyperthyroid patients before and after RAI therapy. According to clinical examination, thyroid US and technetium-99m (99mTc)-pernechnetate scintiscan, the diagnosis of hyperthyroidism was multinodular goiter (MNG) in 27, diffuse goiter (DG) in 32 and uninodular goiter (UNG) in 16 patients. The RAI dose to be administered was calculated according to TV and RAI uptake, up to a maximum of 600 MBq. TV was further evaluated 1, 3 and 6-12 months after RAI therapy. The initial TV was 42.3+/-4.0 ml for MNG, 29.7+/-2.8 ml for DG and 34.5+/-3.7 ml for UNG. After 6-12 months a non-significant TV reduction was observed in the MNG group even though the fraction of initial TV was 53.3+/-6.5%. Moreover, a significant TV reduction was noticed in the DG group (8.8+/-2.3 ml; p<0.001). In this group the fraction of initial TV was 28.6+/-3.2% at 6-12 month evaluation. A less marked, though still significant (p=0.04) TV reduction (19.6+/-3.2 ml) was also observed in the UNG group, the fraction of initial TV being 57.8+/-5.3% 6-12 months after RAI. In the whole patient population there was no significant correlation between TV reduction or TV at the last examination and initial TV, RAI dosage, baseline free T4 and TSH levels. No correlation was found between clinical condition at the last examination and TV reduction. In conclusion, these data justify TV estimation by means of US in the protocol of individual RAI dose for the therapy of hyperthyroidism. Our follow-up documents a poorly predictable TV reduction in all clinical conditions, but this is more pronounced and predictable in patients with diffuse toxic goiter.

Occurrence of overt celiac disease in the elderly following total thyroidectomy.

We report the case of a female patient in whom gluten-induced entheropathy was revealed at the age of 71 yr by resistance to treatment with levothyroxine (L-T4), calcium carbonate and alfacalcidol. Hypothyroidism and hypoparathyroidism were the consequence of a total thyroidectomy performed at the age of 65 yr for a large multinodular goiter. Six months after thyroid ablation the patient started to complain of abdominal pain, diarrhea and weight loss. Following, anemia and osteopenia were documented. A progressive increase of replacement therapy for hypothyroidism and hypoparathyroidism was necessary. The clinical presentation suggested a malabsorption syndrome: celiac disease (CD) was diagnosed by serological markers and duodenal biopsy. Following gluten-free diet a normalization of clinical and serological findings was observed, bone mass density improved and a reduction of L-T4, calcium and vitamin D requirements was observed.

Chemoprevention of carcinogen-DNA adducts and chronic degenerative diseases.

Molecular dosimetry techniques were exploited in order to assess the efficacy of experimental chemoprevention assays and to evaluate the involvement of DNA alterations, not only in cancer but also in other chronic degenerative diseases. In agreement with other protective effects previously observed in the same animal models, the thiol N-acetylcysteine (NAC) totally prevented or significantly reduced the formation of carcinogen-DNA adducts in three experimental systems in rats. Thus, as assessed by 32P postlabeling, supplement of the diet with NAC decreased both deoxyguanosine-C8-aminofluorene adducts (butanol enrichment) and deoxyguanosine-N2-acetylaminofluorene adducts (nuclease P1 enrichment) formed in rat liver following dietary administration of 2-acetylaminofluorene for 3 weeks. DNA adducts were detected by synchronous fluorescence spectrophotometry in rat liver, lung, heart, and testis following a daily i.t. instillation of benzo(a)pyrene for 3 consecutive days. The whole-body exposure of rats to mainstream cigarette smoke for 40 consecutive days resulted in the appearance of DNA adducts in heart, lung, and aorta, whereas no adduct was detected by synchronous fluorescence spectrophotometry in liver, brain, and testis. Multiple DNA adducts in the aorta were also measured by 32P postlabeling. Administration of NAC by gavage inhibited the formation of DNA adducts in all organs of rats treated with benzo(a)pyrene or exposed to cigarette smoke. It is of interest that a single chemopreventive agent can display a broad-spectrum protective ability. The selective localization of DNA adducts in different organs depends on pharmacokinetics, metabolic capacity, DNA repair efficiency, and cell proliferation rate. Whereas inhibition by NAC of DNA adducts in testis can be correlated with its demonstrated ability to prevent dominant lethal mutations, we raise the hypothesis that DNA adducts in lung, heart, and aorta may be pathogenetically associated with lung cancer, cardiomyopathies, and arteriosclerosis, respectively. In order to explore the involvement of molecular and biochemical alterations in human arteriosclerosis, we started an extensive collaborative project and report here preliminary data showing the presence of DNA adducts in aorta smooth muscle cells obtained from arteriosclerotic patients.

Therapeutic Strategies and Clinical Outcome in Papillary Thyroid Microcarcinoma: A Multicenter Observational Study.

PURPOSE: Papillary thyroid microcarcinoma (MPTC) has an excellent prognosis. We aimed to evaluate the evolution of therapeutic strategies over time and the clinical outcome of MPTC. METHODS: In this retrospective multicenter observational study in a northwest Italian region, patients with intrathyroidal, unifocal tumor ≤1 cm in size, incidentally found at histology or preoperative cytology diagnosis, were included. Exclusion criteria were a previous head-and-neck irradiation and/or node metastases. RESULTS: From 1985 to 2012, 437 patients had an MPTC diagnosis, which was incidental in 85% and preoperative in 15%. Patients with a preoperative diagnosis were younger at the time of diagnosis (47.6 ± 12.7 years, p < 0.01) and had a larger tumor (7.0 ± 2.5 mm, p < 0.0001) than patients with an incidental diagnosis (age 52 ± 13.5 years, size 4.4 ± 2.8 mm), but there were no differences in clinical outcome between both groups. We observed a significant (p < 0.001) reduction in radioiodine remnant ablation during the years. TSH levels were: <0.1 mIU/l in 27.5%, 0.1-0.5 mlU/l in 33.7%, 0.5-2.5 mlU/l in 32.6%, 2.5-4.2 mlU/l in 3.9%, and >4.2 mlU/l in 2.3% of patients. Six patients (1.37%) had nodal recurrence; 5 of them were cured after therapy. MPTC-linked mortality was null. CONCLUSIONS: We confirmed the favorable clinical outcome of MPTC. Despite the reduction in radioiodine ablation, overtreatment of MPTC is still observed.

HPLC investigated physicochemical compatibility between Artrosilene injectable solution and other pharmaceutical products frequently used for combined therapy into elastomeric Baxter LV5 infusion devices.

Ketoprofen lysine salt(Artrosilene injectable solution) is a non-steroidal anti-inflammatory agent frequently administered by slow intravenous infusion with portable elastomeric infusion systems in association regimen with other analgesic drugs. The aim of this study was to investigate the physicochemical compatibility between ketoprofen lysine salt(Artrosilene injectable solution) and other injectable drugs frequently used in association, such as tramadol hydrochloride, keterolac tromethamine and morphine hydrochloride, into the Infusor LV5, Baxter elastomeric infusion system. Physicochemical properties of drug mixture, including colour, clarity, pH and drug content were observed or measured by a reversed-phase HPLC method with UV detection, before and after (up to 7 days) mixing at room temperature and under light protection. The results obtained demonstrated the physicochemical compatibility of ketoprofen lysine salt(Artrosilene injectable solution) with all drug formulations at every tested mixing ratios into Baxer Infusor LV5 infusion devices.

Dissociation between early and late events in T cell activation mediated through CD28 surface molecule.

The regulation of early and late events of T cell activation via the CD28 molecule has been investigated, using as an indicator system the differentiated leukemic T cell line Jurkat. Both CD3 and CD28 mAbs induced an increase in (Ca2+)i in Jurkat cells, although with different kinetics, the latter being slower than the former. CD28-mediated (Ca2+)i mobilization was highly sensitive to cholera toxin (ID50 25 ng/ml, vs 300 ng/ml for CD3 stimulation). The inhibitory action of cholera toxin was neither merely due to the increase in intracellular cAMP concentrations, nor to decrease in cell surface expression of the CD28 molecule. To evaluate the effects of cholera toxin on late events of Jurkat cell activation induced by CD28 and CD3 mAbs, the action of cholera toxin and cAMP and CD3- and CD28-mediated IL-2 secretion was analyzed. CD3-induced IL-2 secretion was highly sensitive to cholera toxin (ID less than 5 ng/ml); on the other hand, CD28-induced IL-2 secretion was poorly sensitive to cholera toxin, in sharp contrast to (Ca2+)i mobilization. On the basis of these data, it is hypothesized that the CD28 pathway could be associated with at least two distinct transduction mechanisms, one responsible for the (Ca2+)i rise in Jurkat cells and highly sensitive to cholera toxin, and the other, whose second messenger is unknown, resistant to cholera toxin and responsible for IL-2 secretion.

Evidence for the existence of distinct central appetite, energy expenditure, and ghrelin stimulation pathways as revealed by hypothalamic site-specific leptin gene therapy.

To identify the specific hypothalamic sites in which leptin acts to decrease energy intake and/or increase energy expenditure, recombinant adeno-associated virus vector-encoding leptin was microinjected bilaterally into one of four hypothalamic sites in female rats. Leptin transgene expression in the ventromedial nucleus and paraventricular nucleus induced comparable decreases in daily food intake (FI; 18-20%) and body weight (BW; 26-29%), accompanied by drastic reductions in serum leptin (81-97%), insulin (92-93%), free fatty acids (35-36%), and normoglycemia. Leptin transgene expression in the arcuate nucleus (ARC) decreased BW gain (21%) and FI (11%) to a lesser range, but the metabolic hormones were suppressed to the same extent. Leptin transgene expression in the medial preoptic area (MPOA) decreased BW and metabolic hormones without decreasing FI. Finally, leptin transgene expression in all four sites augmented serum ghrelin and thermogenic energy expenditure, as shown by uncoupling protein-1 mRNA expression in brown adipose tissue. Proopiomelanocortin gene expression in the ARC was up-regulated by leptin expression in all four sites, but neuropeptide Y gene expression in the ARC was suppressed by leptin transgene expression in the ARC but not in the MPOA. Thus, whereas leptin expression in the paraventricular nucleus, ventromedial nucleus, or ARC suppresses adiposity and insulin by decreasing energy intake and increasing energy expenditure, in the MPOA it suppresses these variables by increasing energy expenditure alone.