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Biomedical subjects

C M Rotella

Publications and source records attributed to C M Rotella.

At least 109 records · Page 6Linked to original sources
PubMed1982

Parathyroid hormone bioassay using human kidney cortical cells in primary culture.

The biological activity of parathyroid hormone (PTH) has been investigated by measuring intracellular accumulation of cyclic AMP (cAMP) in human kidney cortical cultures. Enzyme dispersed cortical cells from non-invaded kidney poles of patients undergoing nephrectomy for cancer were used after 5 days of primary culture. Bovine PTH (1-84) produced a significant increase of cAMP accumulation in cultured cells at a dose (53.7 ng/ml) 10-fold lower than that found for the minimal stimulatory effect when using preparations of human purified plasma membranes. The action of bovine PTH (1-84) was very rapid, a response was detected after 5 min and a ceiling effect after 30 min. Cortical cells showed a slightly lower sensitivity to synthetic bovine PTH (1-34) (half maximal increase dose: 0.66 microgram/ml), compared to bovine PTH (1-84) (half maximal increase dose: 0.32 microgram/ml), but revealed a higher sensitivity to human PTH purified from the medium of parathyroid cell cultures (half maximal increase dose: 11.2 ng/ml). Arginine-vasopressin (AVP) also increased the cAMP accumulation of kidney cortical cultured cells, with a potency and efficacy lower than that of human 'culture' PTH, while in kidney medullary cells in primary culture AVP exerted a strong response and the effect of PTH was poor or absent. Calcitonin and glucagon were weak stimulators of kidney cortical cell cAMP accumulation.

Adenylyl Cyclases↗
PubMed1982

Studies on thyroid cell surface antigens using cultured human thyroid cells.

Human thyroid cells in primary culture were used for studies of thyroid cell surface antibodies in patients with thyroid autoimmune disorders. Radioiodinated IgG preparations containing thyroid microsomal antibody (TMAb), thyroid stimulating antibody (TSAb) and/or thyroglobulin antibody (TgAb) were tested for binding to thyroid cells. Binding was observed with radioiodinated IgG from patients with Graves' disease, Hashimoto's thyroiditis and idiopathic myxoedema containing TMAb, irrespective of the presence of TSAb and TgAb, while negative results were obtained with normal IgG. A dose-dependent inhibition of binding to thyroid cells was produced by the addition of the corresponding unlabelled IgG preparations. Evidence for tissue specificity was provided by the absence of binding to human skin fibroblasts used as controls. Preabsorption with human thyroid microsomes completely abolished the binding to thyroid cells of a radioiodinated TMAb positive IgG preparation, while only incomplete removal of the reactivity to thyroid microsomes was produced by preabsorption with thyroid cells. These data suggest that some but not all microsomal antigenic determinants are expressed on the thyroid cell surface. Binding to thyroid cells was also observed with purified TgAb, indicating that thyroglobulin antigenic determinants are present on the surface of thyroid cells. No evidence of binding was obtained with a TSAb positive Graves' IgG preparation with undetectable TMAb and TgAb. Unlabelled IgG preparations containing TMAb from patients with either Hashimoto's thyroiditis or idiopathic myxoedema were shown to inhibit the binding to thyroid cells of radioiodinated TMAb positive Graves' IgG and vice versa. These data indicate that antibodies present in these thyroid autoimmune disorders share common thyroid cell surface antigens. However, the binding of radioiodinated IgG from a patient with idiopathic myxoedema was only partially inhibited by Graves' or Hashimoto's IgG, suggesting that some of the thyroid cell surface antibodies of idiopathic myxoedema may not be detectable in other thyroid autoimmune disorders.

Antibodies↗
PubMed1981

Dissociation in the response of the adenylate cyclase system to thyrotropin and prostaglandin E2 in human thyroid carcinoma tissue.

Because the existence of a damaged thyrotropin (TSH) receptor in thyroid tumors may be relevant in the perspective of a correct postsurgical therapy, the effect of TSH on cAMP intracellular accumulation in thyroid carcinoma (N = 16), follicular adenoma (N = 27) and normal tissue (N = 30) slices was studied and compared with that of nonspecific stimulus of thyroid adenylate cyclase-cAMP system, such as prostaglandin E2 (PGE2). While in all follicular adenomas a normal behavior of basal and post-TSH and -PGE2 stimulated cAMP accumulation was observed, basal cAMP levels were generally higher than in controls in 14 differentiated carcinomas, responses to TSH were reduced or absent, and response to PGE2 was close to normal. On the contrary, in two anaplastic carcinomas, both TSH and PGE2 produced a negligible modification of cAMP levels. Thus, in undifferentiated carcinomas, the adenylate cyclase-cAMP system seems to be altered; in differentiated carcinomas, the catalytic part of the system appears unaffected as it is PGE2-responsive. Therefore, some hypotheses are ruled out as an explanation for decreased sensitivity to TSH of differentiated carcinomatous cells.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1981

Prostacyclin stimulates the adenylate cyclase system of human thyroid tissue.

Since Prostacyclin (PGI2) is a major product of arachidonic acid metabolism in the human thyroid, we have studied the effects of PGI2 on cAMP accumulation in human thyroid slices and cultured thyrocytes. In both systems, PGI2 caused a dose- and time-dependent increase of cAMP accumulation with higher potency and efficacy than PGE2. Two optically active isomers of 5,6-dihydro-PGI2, i.e. stable synthetic analogs of PGI2, had qualitatively similar effects to PGI2. The relative potency ratio between the alpha- and beta- isomer as well as their potency compared to PGI2 were substantially similar to their potency in inhibiting human platelet aggregation. In thyroid slices, PGI2 and its stable analogs had a greater effect than TSH in causing cAMP accumulation; however, in contrast to TSH, this effect was not associated with increased iodothyronine release except at maximal PGI2 concentrations. TSH had no detectable effect on thyroidal PGI2 synthesis and release. In cultured thyrocytes the effects of PGI2 and its stable analogs were considerably less than those obtained with TSH and required higher concentrations. Such a discrepancy was not found in the case of PGE2. These findings suggest the existence of a specific PGI2-responsive adenylate cyclase system in human thyroid cells other than thyrocytes, of possible physiologic significance.

6-Ketoprostaglandin F1 alpha↗
PubMed1981

Reduced mitogenic action of insulin evaluated as 3H-thymidine uptake in diabetic cultured fibroblasts.

As cultured diabetic fibroblasts have a shorter lifespan than normal subjects, the mitogenic activity of foetal calf serum (FCS) and insulin have been studied by taking skin biopsies from 5 patients with juvenile onset diabetes (JODM), 8 with adult onset diabetes (AODM) and 5 with chemical (latent) diabetes (CDM). In controls a high dose of insulin (20 microgram/ml) produced a tritiated thymidine uptake lower than 10% FCS. At lower doses (0.1 to 1.0 microgram/ml) a dose-dependent uptake was observed. In diabetic fibroblasts 10% FCS produced a lower 3H-thymidine uptake than in controls, with p less than 0.005 in JODM, p less than 0.01 in AODM and p less than 0.01 in CDM. A high dose of insulin produced a lower uptake in patients with JODM (p less than 0.01), AODM (p less than 0.01) and CDM (p less than 0.05) when compared with controls. However, when lower doses of insulin were used, 2 out 5 cases of JODM and 4 out of 8 cases of AODM showed a similar response to controls, while 3H-thymidine uptake was low or absent in the remaining cases, including all those with CDM. This study indicates that a reduced mitogenic action of FCS and insulin exists in many patients affected by clinical or chemical diabetes. Our results suggest, however, that the sensitivity to the two mitogenic factors seems to be dissociated: in fact, while a reduced response to FCS is present in all patients, the response to insulin seems to be correlated to the patient's equilibrium at the time of skin biopsy.

Adolescent↗
PubMed1979

Thyrotrophin-responsive adenylate cyclase activity in thyroid toxic adenoma.

The adenylate cyclase system was studied in hyperfunctioning autonomous nodules in comparison with normal thyroid tissue. The basal, TSH- and NaF-stimulated adenylate cyclase activities were tested in purified plasma membrane preparations. Basal enzyme activity in membranes from hyperfunctioning nodules was variable and the response to TSH was either normal, low or absent. The present study demonstrates that an intact adenylate cyclase activity, hyporesponsive to TSH, may exist in the cell membrane of the adenoma.

Adenoma↗
PubMed1977

Plasma proinsulin-like components and insulin in chronic liver disease.

In order to explain the increase of total IRI frequently observed at basal status, and after glucose administration, in patients with chronic liver disease, plasma proinsulin-like component and insulin levels have been studied in fourteen patients with liver cirrhosis associated or not with clinical or subclinical diabetes mellitus. A significative increase of plasma insulin was observed at basal status and after a glucose load not only in subjects with clinical or subclinical diabetes but also in those patients without carbohydrate abnormalities. This increase is apparently not correlated to any clinical characteristic and is associated in fasting and after glucose load with increased proinsulin-like component levels especially in patients with clinical or subclinical diabetes.

Aged↗
PubMedDate not supplied

Increased retinal endothelial cell monolayer permeability induced by the diabetic milieu: role of advanced non-enzymatic glycation and polyol pathway activation.

BACKGROUND: Increased vascular permeability could be involved in the pathogenesis of diabetic retinopathy. The present study was aimed at assessing whether high glucose concentrations can impair retinal endothelial cell barrier function directly, irrespective of changes in other determinants of permeability, and the role of non-enzymatic glycation and polyol pathway activation in these alterations. METHODS: Bovine retinal endothelial cells (BREC) were exposed for various periods to high glucose vs iso-osmolar mannitol and normal glucose containing media+/-agents mimicking or inhibiting advanced glycation end product (AGE) formation and polyol pathway activation. Monolayer permeability was assessed by measuring the transendothelial passage of (125)I-labeled proteins. RESULTS: Permeability increased significantly (up to +70%) in BREC exposed to high glucose, but not to mannitol, for 1-30 days, vs normal glucose control cells. Exposure to AGE-modified bovine serum albumin (BSA) (> or = 90%) and, to a lesser extent, sorbitol (+28%) mimicked the high glucose effect. The AGE formation and nitric oxide synthase (NOS) inhibitor aminoguanidine significantly reduced (by 60%) changes induced by 30-day exposure to high glucose, whereas methylguanidine, which inhibits only NOS activity, did not affect permeability. Aldose reductase or sorbitol dehydrogenase inhibitors decreased (by approximately 40%) the enhanced leakage produced by 1-day, but not 30-day, incubation in high glucose. CONCLUSIONS: The present results indicate that high glucose is capable of impairing retinal endothelial cell barrier function directly and that non-enzymatic glycation and polyol pathway activation may mediate these changes, with AGEs participating in the long-term alterations and increased flux through the sorbitol pathway in the short-term effect.

Animals↗
PubMedDate not supplied

Measurement of thyroid cell surface antibodies by radioassay using human cultured thyroid cells.

The present report describes a sensitive and quantitative binding radioassay for measurement of thyroid cell surface antibodies (TCSAb). Enzyme-dispersed thyroid cells from surgical specimens of human normal thyroid tissue were used after 7 days of culture. 125I-labelled Graves' IgG was shown to bind to cultured thyroid cells. The binding was time-and temperature-dependent and increased linearly with the number of thyroid cells. Evidence for specificity was provided by the lack of binding of radioiodinated Graves' IgG to human fibroblasts and by the negligible binding of 125I-labelled normal IgG to thyroid cells. A dose-dependent inhibition of binding of 125I-labelled Graves' igG to thyroid cells was produced by the addition of graded amounts of the unlabelled original Graves' IgG preparation, but not by normal IgG. Assays for TCSAb were performed on IgG preparations from patients with and without thyroid autoimmune disorders using the original Graves' IgG preparation as reference standard. Results were expressed in terms of arbitrary units/100 microgram IgG, 1 unit corresponding to the minimum amount of the standard IgG producing a significant inhibition of binding. Negative tests were found in most normal subjects (15/18) while low TCSAb levels (less than or equal to 1.8 U/100 microgram IgG) were detected in 3 cases. Increased TCSAb levels were found in the majority of the patients wit Graves' disease (14/21), in most of the patients with idiopathic myxedema (9/10) and in all of those with Hashimoto's thyroiditis (10/10).

Autoantibodies↗
PubMedDate not supplied

TSH-responsive adenylate cyclase activity in thyroid tissue from patients with Graves' disease.

Basal adenylate cyclase activity of thyroid plasma membranes obtained from six patients with Graves' disease was slightly but not significantly lower than normal (83.3 +/- 13.9 pmol cAMP/10 min/mg of protein versus 120.9 +/- 19.5 pmol cAMP/10 min/mg of protein). In five of these patients the adenylate cyclase activity was stimulated by bovine TSH with an apparent Km value similar to that of normal thyroid (3.1 +/- 0.5 X 10-9 M versus 3.4 +/- 0.6 X 10-9 M). The response to prostaglandin E2 was also normal. In the sixth patient adenylate cyclase activity was stimulated by prostaglandin E2 but not by bovine TSH. The distribution of basal adenylate cyclase activity in various gradient layers was studied in two TSH-responsive patients. A relative increase of this activity was found in the denser layer when compared to normal thyroid tissue. This could be the expression of an altered ratio between the protein and lipid components of the plasma membranes in patients with Graves' disease.

Adenylyl Cyclases↗
PubMedDate not supplied

Monoclonal antibodies to the thyrotropin receptor: the identification of blocking and stimulating antibodies.

Monoclonal antibodies to the thyrotropin (TSH) receptor have been obtained from fusions of mouse myeloma cells with spleen cells immunized with solubilized thyroid membrane preparations. Two monoclonal antibodies which inhibit 125I-TSH binding and are reactive with the glycoprotein component of the bovine TSH receptor (11E8 and 13D11), are shown to inhibit basal and TSH stimulated adenylate cyclase activity in bovine thyroid membranes and human thyroid cells. Both antibodies also inhibit 125I-TSH binding in vitro, whether binding is measured at pH 6.0 in low salts and at 0-4 C or at pH 7.4 in 50 mM NaCl and at 37 C. The glycoprotein component is thus a portion of the physiologic TSH receptor in vivo and 125I-TSH binding studies apparently measure the high affinity glycoprotein component under nonphysiologic conditions and conditions more representative of the physiologic milieu. A third monoclonal antibody whose interaction with thyroid membranes is prevented by TSH is shown to stimulate adenylate cyclase activity in bovine thyroid membranes and human thyroid cells. This stimulating antibody only weakly inhibits 125I-TSH binding to thyroid membranes or to the glycoprotein component of the TSH receptor. The 22A6 antibody does, however, immunoprecipitate mixed brain gangliosides, in distinct contrast to the monoclonal antibodies to the glycoprotein receptor component, i.e., 11E8 and 13D11. The results support the speculation that autoimmune antibodies which inhibit TSH binding to thyroid membranes are not necessarily identical to antibodies which stimulate function; that antibodies directed at the high affinity initial site of TSH interaction with a cell can behave as blocking rather than stimulating antibodies and that a possible relationship exists between stimulating antibodies and the low affinity TSH binding sites (gangliosides) on thyroid membranes.

Animals↗
PubMedDate not supplied

Screening for binge eating disorder in obese outpatients.

The prevalence of binge eating disorder (BED) in clinical samples of obese patients is controversial, and sensitive diagnostic protocols for use in routine clinical practice need to be further defined. Three hundred forty-four obese (body mass index [BMI] > or =30 kg/m2) patients were studied with the Structured Clinical Interview for DSM-III-R to investigate the lifetime prevalence of mental disorders. The current prevalence of BED was assessed using DSM-IV criteria. Eating attitudes and behavior were investigated with the Bulimic Investigation Test, Edinburgh (BITE) and the Binge Eating Scale (BES). The Beck Depression Inventory (BDI) and Spielberg's State-Trait Anxiety Inventory (STAI) were also applied. The prevalence of BED was 7.5%. Patients with BED had a higher BMI compared with obese patients without BED. Differences in the lifetime prevalence of mental disorders in patients with and without BED were not statistically significant. Using the BES as a screening instrument for BED with a threshold of 17, the sensitivity was 84.8%, specificity 74.6%, positive predictive value 26.2%, and negative predictive value 97.9%. Using the BITE with a threshold of at least 10, the sensitivity was 91%, specificity 51.4%, positive predictive value 71.8%, and negative predictive value 98.2%. The BITE can be a valid alternative to the BES as a screening method for BED in obese patients.

Adult↗
PubMedDate not supplied

Quality of life and overweight: the obesity related well-being (Orwell 97) questionnaire.

The development and validation of a self-reported measure of obesity-related quality of life, the Obesity Related Well-Being (ORWELL 97), were undertaken to examine the intensity and the subjective relevance of physical and psychosocial distress. The questionnaire was validated in a sample of 147 obese patients (99 females, 48 males). The Eating Disorder Examination 12.0D interview, a structured diagnostic interview for DSM-III-R (DSM-IV criteria for binge eating disorder), Beck Depression Inventory, Binge Eating Scale, and the State-Trait Anxiety Inventory 1 and 2 scales were also applied. Internal consistency and test-retest reliability were satisfactory. Factor analysis allowed the identification of two subscales: ORWELL 97-1 related to psychological status and social adjustment, and ORWELL 97-2 related to physical symptoms impairment. Obese female patients showed a lower quality of life, and the severity of obesity appeared to interfere with physical functioning rather than psychological status and social adjustment. The ORWELL 97 questionnaire appears to be a simple and reliable measure of obesity-related quality of life, which can be used in current clinical practice.

Adolescent↗
PubMedDate not supplied

Cognitive-behavioural therapy for bulimia nervosa and binge eating disorder. A review.

Cognitive-behavioural therapy (CBT) programmes for bulimia nervosa (BN) have been considerably refined during the last 2 decades, and such a treatment is now extensively used. The present paper describes the treatment rationale and structure, and reviews the available evidence on its efficacy. Compared to any other psychological or pharmacological treatment for which controlled studies have been published, CBT is reported to be more effective (the majority of studies), or at least as effective. A CBT programme for binge eating disorder (BED) has been created by adapting that of BN, but it has been less extensively evaluated in field trials. Even here, however, no other treatment has proven to be of greater efficacy than CBT. Various methodological limitations reduce the possibility of generalizing these findings. Moreover, CBT was found to be completely satisfactory neither for BN nor for BED, with moderate effectiveness and some limits. However, at the present state of treatment, no other therapeutical procedure seems to be more effective, more specific or more promising. It is speculated therefore that CBT could be presently considered the first-choice remedy for these severely disabling disorders.

Bulimia↗
PubMedDate not supplied

Fluoxetine and fluvoxamine combined with individual cognitive-behaviour therapy in binge eating disorder: a one-year follow-up study.

BACKGROUND: : The treatment of binge eating disorder (BED) is still the object of debate. In the present study, the effectiveness of antidepressant drugs (fluoxetine - FLX - 60 mg/day, fluvoxamine - FLV -300 mg/day), cognitive-behavioural therapy (CBT) and combined treatments (CBT + FLX, CBT + FLV) has been evaluated in a randomized, clinical trial. Results at the end of the active treatment (in the 24th week) and 1-year follow-up outcomes have been evaluated. METHODS: One hundred eight (44 M, 64 F) BED patients were randomly assigned to either CBT, FLX (60 mg/day), FLV (300 mg/day), CBT + FLX or CBT + FLV, for 24 weeks. At the beginning (T0), at the end (T1) of treatment and after 1 year (T2), body mass index (BMI) and eating attitude and behaviours (by EDE 12.0D) were assessed. RESULTS: At T1, BMI and EDE scores were significantly reduced in CBT, CBT + FLX and CBT + FLV, but not in the FLX and FLV treatment groups. In the CBT + FLV group, a greater (p < 0.05) reduction of EDE total scores was observed, when compared to CBT + FLX or CBT treatment groups. At T2, BMI was significantly higher than at T1, but still significantly lower than at T0 in the CBT, CBT + FLX and CBT + FLV groups, while EDE scores remained unchanged from T1 in all treatment groups. CONCLUSIONS: CBT was more effective than FLX or FLV in the treatment of BED. The addition of FLX to CBT does not seem to provide any clear advantage, while the addition of FLV could enhance the effects of CBT on eating behaviours. Modifications of eating behaviours are maintained at the 1-year follow-up, although the lost weight was partly regained.

Adult↗
PubMedDate not supplied

Interaction between iodothyronines and thyrotropin receptor in human cultured thyroid cells.

In order to verify the existence of a "short-loop" negative feedback between iodothyronines and adenylate cyclase system of human thyroid, we have studied the effect of preincubation with iodothyronines, iodotyrosines, iodothyronine analogues and iodide on TSH-induced cAMP cellular accumulation in normal human thyroid cells in primary culture. Iodide did not produce an inhibitory effect on TSH-dependent adenylate cyclase system both in normal human thyroid plasma membranes and cultured cells. Iodothyronines at a 30-40 microM concentration did not inhibit the TSH-dependent adenylate cyclase activity of human thyroid plasma membranes; however at a 1 microM concentration they were able to inhibit the TSH-dependent cAMP accumulation by cultured cells. Preincubation with iodotyrosines and iodothyronine analogues failed to inhibit the TSH-responsive cAMP accumulation in human thyroid cultured cells.

Adenylyl Cyclases↗