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1.
J Nat Prod ; 80(12): 3128-3135, 2017 12 22.
Article in English | MEDLINE | ID: mdl-29148767

ABSTRACT

The binding properties toward the human telomeric G-quadruplex of the two natural alkaloids coptisine and chelerythrine were studied using spectroscopic techniques, molecular modeling, and X-ray diffraction analysis. The results were compared with reported data for the parent compounds berberine and sanguinarine. Spectroscopic studies showed modest, but different rearrangements of the DNA-ligand complexes, which can be explained considering particular stereochemical features for these alkaloids, in spite of the similarity of their skeletons. In fact, the presence of a dioxolo moiety rather than the two methoxy functions improves the efficiency of coptisine and sanguinarine in comparison to berberine and chelerythrine, and the overall stability trend is sanguinarine > chelerythrine ≈ coptisine > berberine. Accordingly, the X-ray diffraction analysis confirmed the involvement of the benzodioxolo groups in the coptisine/DNA binding by means of π···π, O···π, and CH···O interactions. Similar information is provided by modeling studies, which, additionally, evidenced reasons for the quadruplex vs double-helix selectivity shown by these alkaloids. Thus, the analyses shed light on the key role of the benzodioxolo moieties in strengthening the interaction with the G4-folded human telomeric sequence and indicated the superior G4 stabilizing properties of the benzophenanthridine scaffold with respect to the protoberberine one and conversely the better G4 vs dsDNA selectivity profile of coptisine over the other alkaloids.


Subject(s)
Alkaloids/chemistry , Benzodioxoles/chemistry , Benzophenanthridines/chemistry , Berberine/analogs & derivatives , DNA/chemistry , Berberine/chemistry , Berberine Alkaloids/chemistry , Crystallography, X-Ray/methods , G-Quadruplexes , Humans , Isoquinolines/chemistry , Ligands
3.
J Eur Acad Dermatol Venereol ; 29(3): 574-80, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25200134

ABSTRACT

BACKGROUND: Patients who develop cutaneous melanoma are at increased risk of developing a second primary melanoma. There are many aetiological reasons by which the risk of a second melanoma increases. Among others, genetic factors may contribute to modulating this risk. The risk of identifying a CDKN2A germline mutation increases with the number of primary melanomas and with the presence of familial history of melanoma. Patients with melanoma are especially encouraged to have regular follow-up visits with their dermatologist to perform clinical and dermatoscopic examination. In particular, dermoscopy could be very useful in multiple primary melanoma (MPM) patients. OBJECTIVES: To analyse the clinical and dermatoscopic features of multiple melanomas, focusing on those features that are more frequently found in the same patient to recognize them earlier and understand whether they appear with the similar peculiar dermatoscopic features, especially in CDKN2A carriers. METHODS: Medical records of MPM patients were selected from a database including 1065 patients with histopathologically proven melanoma diagnosis, all treated at the dermatology clinic of the University of Florence from 2000 to 2013. Pictures of melanoma were independently and blindly administered to three dermatologist experts in dermoscopy to evaluate the presence or absence of ABCD criteria for each clinical image, and the main pattern for the dermoscopic images. The results were then analyzed and crossed to rate the clinical and dermoscopic features of MPM. RESULTS: Seventy five (7.0%) of 1065 patients included in our database were found to carry an MPM disease. Among them, we selected 12 (16%) patients with three or more MPMs. The presence of the CDKN2A melanoma susceptibility gene was observed in 4/12 (33.33%) patients; two patients presented the C500G and c.5 + 1delG polymorphisms in the CDKN2A gene. In CDKN2A carriers, each patient showed a similar and specific dermatoscopic pattern in their lesions. CONCLUSIONS: Even being aware of the limitations of this study, according to hereditary characters and their modes of transmissions, we could speculate that for each patient with a CDKN2A germline mutation, it is possible to find the same kind of dermoscopical pattern among their melanocytic tumours.


Subject(s)
Dermoscopy , Genes, p16 , Melanoma/diagnosis , Mutation , Skin Neoplasms/diagnosis , Adult , Aged , Female , Humans , Male , Melanoma/genetics , Middle Aged , Skin Neoplasms/genetics
4.
Clin Exp Dermatol ; 40(1): 27-30, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25252087

ABSTRACT

An 85-year-old woman presented with a lesion on the sole of her right foot, which was histologically confirmed as acral lentiginous melanoma. Because of the large field involved and because the patient refused any invasive or painful treatment, topical treatment with imiquimod was commenced. At the 20-month follow-up, the patient was still continuing treatment with topical imiquimod, and no metastases to the lymph nodes or viscera were found, either clinically or in imaging studies. We believe that the success of the treatment cannot be explained only by the stimulation of the immune system induced by imiquimod. A possible explanation might be 'tumour dormancy', where a tumour grows very slowly because of a balance between the neoplasia and the immune (and nonimmune) mechanisms of tumour control. The use of imiquimod has so far allowed our patient to avoid surgery, and perturbation of the mechanisms of tumour regulation, such as local immunity and angiogenesis, has not taken place.


Subject(s)
Aminoquinolines/administration & dosage , Antineoplastic Agents/administration & dosage , Melanoma/drug therapy , Skin Neoplasms/drug therapy , Administration, Topical , Aged, 80 and over , Female , Foot , Humans , Imiquimod , Melanoma/immunology , Skin Neoplasms/immunology , Treatment Outcome
6.
Br J Dermatol ; 168(3): 513-9, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23013061

ABSTRACT

BACKGROUND: Oncological research has focused on evaluating oestrogen receptors (ERs) in oestrogen-related tumours, and understanding the potential role of ERs in the pathophysiology of cancer. OBJECTIVES: To investigate the significance of oestrogen receptor beta (ERß) in melanoma. METHODS: We prospectively evaluated ERß expression in malignant melanoma (MM) tissue and adjacent healthy skin by quantitative immunohistochemistry at the Department of Dermatology of the University of Florence, from 1998 to 2010. RESULTS: ERß was detected with varying staining intensity in the 66 malignant melanocytic lesions. After adjusting for age and sex, we found that ERß expression was significantly lower in melanoma tissue compared with adjacent healthy skin (P < 0·0001). We also found significantly lower ERß levels in thick melanoma tissue compared with thin melanoma tissue. In addition, there was a positive association between Breslow thickness and the difference of ERß expression between healthy tissue and melanoma tissue (P = 0·0004). Consistent with sex differences in melanoma survival, men showed significantly lower levels of ERß than women in both melanoma (P = 0·05) and healthy tissues (P = 0·02). CONCLUSIONS: ERß expression is inversely associated with Breslow thickness and is significantly influenced by sex in MM.


Subject(s)
Estrogen Receptor beta/physiology , Melanoma/etiology , Skin Neoplasms/etiology , Analysis of Variance , Estrogen Receptor beta/metabolism , Female , Humans , Male , Melanoma/metabolism , Overweight/metabolism , Postmenopause/metabolism , Premenopause/metabolism , Prospective Studies , Sex Factors , Skin Neoplasms/metabolism
8.
Clin Exp Dermatol ; 36(3): 255-9, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21091756

ABSTRACT

BACKGROUND: According to the literature, dermatoscopy can improve diagnostic accuracy for melanoma. However, a weak point of the studies in the literature is that most were carried out in a 'privileged' setting of dermatologists who are expert in dermato-oncology, and who work in departments specializing in screening pigmented lesions. This study was set up to specifically evaluate whether the use of dermatoscopy by general dermatologists would also improve accuracy. AIM: To analyse the effect on intention to excise lesions (intervention yes/no) of adding either dermatoscopy (20 years after the advent of the method) or detailed lesion classification (melanoma yes/no) to clinical examination by the naked eye. More specifically, we evaluated whether the current practice of general dermatologists using dermatoscopy improves the sensitivity and specificity values, and thus the diagnostic accuracy. METHODS: Eight general dermatologists examined separately clinical images and combined (clinical and dermatoscopic) images of 200 melanocytic lesions that had been excised (64 melanomas and 136 melanocytic naevi). RESULTS: Focusing on intention to excise (intervention yes/no), addition of dermatoscopy to naked eye examination resulted in an increase in sensitivity for all observers (average gain +4.5%) but an overall nonsignificant reduction in specificity (-4.5%, P=0.10). Diagnostic accuracy, which increased when examination was focused on melanoma (yes/no) classification (+4.1%, P<0.05) remained unchanged (-1.62%; P=0.36). CONCLUSIONS: The effect of adding dermatoscopy to naked eye examination of melanocytic lesions on 'general dermatologists' changes according to the aim of the examination. Dealing with the intention to excise, the increase of sensitivity associated with dermatoscopy (lower risk of leaving a melanoma unexcised) is obtained at the expense of specificity (higher number of melanocytic naevi excised) without improving overall diagnostic accuracy.


Subject(s)
Dermoscopy/standards , Melanoma/diagnosis , Skin Neoplasms/diagnosis , Clinical Competence , Diagnosis, Differential , Humans , Melanoma/surgery , Nevus, Pigmented/diagnosis , Nevus, Pigmented/surgery , Physical Examination , Sensitivity and Specificity , Skin Neoplasms/surgery
9.
Br J Dermatol ; 163(6): 1319-22, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20670298

ABSTRACT

BACKGROUND: Patients with melanoma are especially encouraged to have regular follow- up visits with their dermatologist and to perform total-body skin examination on a routine basis to identify new pigmented lesions or detect significant changes in existing naevi. OBJECTIVES: To identify main risk factors (sex, age, number of common and atypical naevi, family history, phototype) associated with multiple primary melanomas (MPM) and to investigate the association between regular follow up and tumour thickness of a second primary melanoma. METHODS: We performed a retrospective analysis of patients with MPM in order to evaluate risk factors for developing a second primary melanoma. Medical records of patients with melanoma who developed a second primary melanoma were selected from a database of all patients with histopathologically confirmed melanoma treated at the dermatology clinic of the University of Florence, Italy, from 2000 to 2004. Medical data culled from the patient records were as follows: medical history, number of typical naevi, presence of atypical naevi, Breslow thickness, Clark level and histotype of the melanomas, site of the melanomas and patient adherence to 6-month follow-up examinations. RESULTS: The presence of atypical naevi was associated with a higher risk of developing MPM (adjusted odds ratio 3·28, 95% confidence interval 1·35­7·44). Moreover, in the subjects who did not attend follow up, we noted that the thickness of the second melanoma was significantly higher, with a mean thickness of 1·22 mm, in comparison with patients with a careful adherence to follow up in whom the mean thickness was 0·36 mm (P = 0·0189). CONCLUSIONS: For the first time, the validity of this clinical approach has been supported by real comparison of thickness levels of second melanoma in patients with or without periodical follow up. Results obtained from this analysis show that follow up is an effective method for early detection of melanoma.


Subject(s)
Melanoma/pathology , Neoplasms, Multiple Primary/pathology , Nevus/pathology , Skin Neoplasms/pathology , Adult , Age Factors , Aged , Aged, 80 and over , Female , Humans , Italy/epidemiology , Long-Term Care/methods , Male , Middle Aged , Odds Ratio , Patient Compliance , Retrospective Studies , Risk Factors , Sex Factors , Young Adult
10.
Clin Exp Dermatol ; 34(6): 688-93, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19508580

ABSTRACT

AIM: To evaluate the effectiveness of a silicone gel in treating surgical wounds compared with a control group of the same phenotype and same scar site for which a placebo was advised. METHODS: This was a randomized controlled trial, carried out in a dermatology department of a university hospital. In total, we studied 110 patients (55 men, 55 women) who had undergone outpatient surgery at the Department of Dermatology, University of Florence, between May and July 2005. The patients were divided into two groups: a treatment group (group A) and a control group (group B). Subjects (n = 65) in group A were prescribed silicone gel to be applied to the wound twice a day for 60 days after the removal of stitches. Subjects (n = 45) in group B were prescribed the use of zinc oxide cream. All subjects, in both study and control groups, were examined by the same dermatologists every month for 3 months after surgery, then every 2 months for a total follow-up of 8 months from the date of surgery. RESULTS: In the treatment group, only 18 patients (27%) had formation of a nonphysiological scar: diastasic scar in 10 patients (15%), hypertrophic scar in 6 (9%) and atrophic scar in 2 (3%). No keloid scars were recorded. In the control group, 25 (55%) had an altered scar: keloid scars in 5 patients (11%), hypertrophic scar in 10 (22%), diastasic scar in 8 (18%) and atrophic scar in 2 (4%). CONCLUSIONS: The results of this study indicate that silicone gel is able to reduce the formation of keloid and hypertrophic scars and the signs/symptoms associated with the healing process (paraesthesia, pulling sensation, alterations in colour).


Subject(s)
Cicatrix, Hypertrophic/drug therapy , Keloid/drug therapy , Silicone Gels/administration & dosage , Skin Neoplasms/surgery , Wound Healing/drug effects , Administration, Topical , Adult , Aged , Aged, 80 and over , Cicatrix, Hypertrophic/pathology , Female , Humans , Keloid/pathology , Male , Middle Aged , Patient Compliance , Skin Absorption , Treatment Outcome , Wound Healing/physiology , Young Adult
13.
Clin Exp Dermatol ; 33(3): 309-11, 2008 May.
Article in English | MEDLINE | ID: mdl-18201260

ABSTRACT

It is a common experience that many Spitz naevi deviate from the idealized or stereotypical representation found in the literature, often causing considerable difficulties in distinguishing them from melanoma. The diagnostic term 'atypical Spitz naevus' is used to describe lesions that deviate from the typical appearance of Spitz naevi and which have an uncertain biological significance and prognosis. The term 'Spitz tumour' has been proposed for these lesions, as the term 'naevus' indicates a lesion that is completely benign and presents no risk to the patient. We present a case of atypical Spitz tumour with peculiar atypical clinical and dermatoscopic features. The difficulty in managing this Spitz tumour was aggravated by the clinical diagnosis. In fact, the lesion appeared as a benign and nonmelanocytic lesion, a pigmented dermatofibroma. Our case underlines the difficulties present in the controversial chapter of spitzoid melanocytic lesions. The atypical Spitz tumour is a 'chameleon' lesion that can mimic not only melanocytic, but also nonmelanocytic lesions.


Subject(s)
Melanoma/pathology , Nevus, Epithelioid and Spindle Cell/pathology , Pregnancy Complications, Neoplastic/pathology , Skin Neoplasms/pathology , Adult , Diagnosis, Differential , Female , Humans , Hyperpigmentation/pathology , Melanocytes/pathology , Pregnancy , Risk Factors , Treatment Outcome
14.
Diabet Med ; 23(6): 660-5, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16759309

ABSTRACT

AIM: To determine the influence of Type 1 diabetes mellitus on circulating adipocytokines in children. METHODS: The circulating concentrations of leptin, adiponectin, resistin and tumour necrosis factor (TNF)-alpha were measured in 91 children, aged 11.1 +/- 2.7 years, with Type 1 diabetes mellitus (T1DM). Ninety-one healthy children were selected as control subjects. RESULTS: Body mass index-adjusted leptin concentrations were higher in the pubertal diabetic children compared with the control children. There was a significant positive correlation between leptin and daily insulin dose in the diabetic group. Circulating adiponectin concentrations were higher in the prepubertal diabetic children and were positively associated with HbA(1c). Resistin concentrations were lower in the prepubertal non-diabetic subjects compared with the pubertal non-diabetic children, whose values were higher than those of the diabetic children. TNF-alpha concentrations were similar in non-diabetic and diabetic children. CONCLUSIONS: Circulating concentrations of adipocytokines are abnormal in Type 1 diabetic children, although the direction of change differs by cytokine. Pubertal development, in addition to insulin treatment and glycaemic control, also influences the concentrations.


Subject(s)
Cytokines/blood , Diabetes Mellitus, Type 1/blood , Insulin/therapeutic use , Puberty , Adiponectin/blood , Adolescent , Analysis of Variance , Blood Glucose/analysis , Body Mass Index , Case-Control Studies , Child , Diabetes Mellitus, Type 1/drug therapy , Diabetes Mellitus, Type 1/physiopathology , Female , Glycated Hemoglobin/analysis , Humans , Insulin/blood , Leptin/blood , Male , Resistin/blood , Tumor Necrosis Factor-alpha/analysis
15.
Clin Endocrinol (Oxf) ; 63(2): 139-45, 2005 Aug.
Article in English | MEDLINE | ID: mdl-16060906

ABSTRACT

OBJECTIVE: To study the circulating levels of two gut-derived peptides in children with type 1 (insulin-dependent) diabetes mellitus (IDDM). RESEARCH DESIGN AND METHODS: Plasma levels of ghrelin, both total ghrelin (TG) and the acylated form (AG), and galanin and their relationships with insulin dosage, metabolic control, IGFBP-1, body mass and pubertal development were evaluated in 91 children, aged 11.1 +/- 2.7 years, affected by IDDM and treated with insulin. Ninety-one healthy children were selected as controls. RESULTS: Body mass index (BMI)-adjusted levels of both forms of ghrelin were reduced in IDDM compared with healthy subjects, with greater values in prepubertal than pubertal IDDM subjects. A negative association was found between AG and fasting insulin serum levels and insulin resistance [measured by using the homeostasis model assessment of insulin resistance (HOMA IR)] among the healthy children. IDDM children showed a negative association of their plasma ghrelin (both acylated and total) with daily insulin dosage, and the three adiposity indices (BMI, skinfold thickness and percentage fat mass). IGFBP-1 levels were higher among the IDDM children without any association with ghrelin serum values. BMI-adjusted plasma levels of galanin were higher among IDDM compared to healthy subjects, irrespective of sex or pubertal development. Greater values for galanin were found among pubertal than prepubertal subjects in both groups without any significant differences between the genders. A positive association was found between galanin and BMI in both groups and between galanin and haemoglobin A1c (HbA1c) among the IDDM children. No relationship existed between either galanin and fasting serum insulin among the healthy subjects or galanin and both insulin dosage or duration of treatment among the IDDM subjects. CONCLUSIONS: The associations found between both ghrelin and galanin with adiposity indices could be considered as an indirect signal of involvement of the two peptides in the development of the nutritional status of the IDDM adolescents. The reduction in both forms of ghrelin could be involved in the development of the body mass increase of IDDM subjects with opposite effects, either influencing insulin sensitivity or exerting a compensatory restraint of feeding.


Subject(s)
Diabetes Mellitus, Type 1/metabolism , Galanin/analysis , Insulin/administration & dosage , Peptide Hormones/analysis , Acylation , Adolescent , Blood Glucose/analysis , Body Mass Index , Child , Child, Preschool , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 1/drug therapy , Drug Administration Schedule , Female , Galanin/blood , Ghrelin , Humans , Insulin/blood , Insulin Resistance/physiology , Leptin/blood , Male , Peptide Hormones/blood , Puberty/blood , Puberty/metabolism , Sex Factors
16.
J Pediatr Endocrinol Metab ; 18(12): 1399-408, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16459466

ABSTRACT

In order to define serum leptin values in children, its concentration was assayed in 3,453 children, 5-14 years old, and body mass index (BMI) and pubertal development were recorded. Insulin, testosterone (in males) and 17beta-estradiol (in females), the sum of four skinfold thicknesses (SST), waist-to-hip ratio, and body fat mass were also determined in 1,601 children. Analysis of multicollinearity effects on estimated models demonstrated a quasi-linear correlation between SST and BMI, the former being prevalent. Although other variables were strongly correlated with leptin, assuming only SST as predictor, R2 yielded a value of 0.711 in males and 0.607 in females. When the other variables were added, R2 increased by about 0.03 in both sexes. BMI and SST were the most important of all the predictors and each can act as a sort of proxy for the others. When the z-scores of BMI of all 3,453 children were subdivided into deciles, any correlation with leptin was no more significant inside each BMI z-score range. This study demonstrates that subcutaneous fat mass may be considered the prevalent determinant factor. The adopted statistical procedure furnished results useful for reference values based on BMI z-score as a simple and appropriate evaluation for serum leptin concentrations in children.


Subject(s)
Body Mass Index , Leptin/blood , Adolescent , Child , Child, Preschool , Estradiol/blood , Female , Humans , Insulin/blood , Male , Testosterone/blood
17.
Proc Biol Sci ; 270 Suppl 2: S129-32, 2003 Nov 07.
Article in English | MEDLINE | ID: mdl-14667360

ABSTRACT

While the long-distance movements of pelagic vertebrates are becoming known thanks to satellite telemetry, the factors determining their courses have hardly been investigated. We have analysed the effects of oceanographic factors on the post-nesting movements of three satellite-tracked leatherback turtles (Dermochelys coriacea) moving in the southwest Indian Ocean. By superimposing the turtle tracks on contemporaneous images of sea-surface temperatures and sea height anomalies, we show that currentrelated features dominate the shape of the reconstructed routes. After an initial offshore movement, turtles moved along straight routes when in the core of the current, or executed loops within eddies. Large parts of the routes were strikingly similar to those of surface drifters tracked in the same region. These findings document that long-lasting oceanic movements of marine turtles may be shaped by oceanic currents.


Subject(s)
Animal Migration/physiology , Geography , Movement/physiology , Turtles/physiology , Water Movements , Animals , Indian Ocean , Oceanography , Satellite Communications
18.
Diabetes Nutr Metab ; 16(5-6): 306-11, 2003.
Article in English | MEDLINE | ID: mdl-15000442

ABSTRACT

BACKGROUND: Leptin concentrations as a predictor of weight excess (WE) variations in obese children continue to be controversial. AIM AND DESIGN: To evaluate the relationship between fasting leptin serum concentrations and the ability to maintain loss of WE during obesity treatment, 172 (82 males and 90 females) overweight children and adolescents (OW), 6-16 yr old, were recruited. The subjects were retrospectively selected among those who had demonstrated a reduction of their WE during an initial phase of 12 months of a WE reduction programme (WERP). Fasting serum levels of leptin were assayed, together with insulin, triacylglycerol and cholesterol, before (time 0) and at the end of the first phase of WERP (time 1), and BMI (Z-score) was determined at time 0, time 1 and at the end (time 2) of a subsequent second phase of 12 months. OW were subdivided according to wether their Z-BMI showed a persistent reduction also during the second phase (maintaining WE reduction subjects or MS) or showed a subsequent increase after the reduction observed during the first phase (relapsing WE subjects or RS). RESULTS: A significant reduction in serum levels of leptin, insulin and lipids, paralleling Z-BMI reduction, was observed at the end of the first phase of WERP, during which we found a correlation between the decrease in serum leptin concentrations and the decrease in Z-BMI. The decrease in RS during the first phase ((deltalgL(0-1) was significantly greater when compared to that observed in MS (p < 0.05). In two different multiple logistic regression analyses, where RS = 0 and MS = 1, serum leptin at time 1 [odds ratio (OR) = 1.08; 95% confidence interval (CI) = 1.04-1.13] and deltalgL(0-1) (OR = 0.48; 95% CI = 0.25-0.92), together with final pubertal stage (OR = 0.78; 95% CI = 0.63-0.96), were significantly associated with final subject status. CONCLUSIONS: Leptin serum levels after a previous WE reduction and its parallel decline are related to subsequent adiposity outcome. The lower the leptin serum concentration after previous WE reduction and/or the greater its decrease, the greater was the probability of WE relapse.


Subject(s)
Leptin/blood , Obesity/blood , Weight Loss , Adolescent , Body Mass Index , Child , Cholesterol/blood , Confidence Intervals , Diet, Reducing , Fasting , Female , Humans , Insulin/blood , Lipids/blood , Logistic Models , Longitudinal Studies , Male , Obesity/therapy , Odds Ratio , Puberty , Recurrence , Retrospective Studies , Triglycerides/blood , Weight Loss/physiology
19.
J Exp Biol ; 204(Pt 23): 4093-8, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11809783

ABSTRACT

Satellite telemetry was used to record the submergence duration of green turtles (Chelonia mydas) as they migrated from Ascension Island to Brazil (N=12 individuals) while time/depth recorders (TDRs) were used to examine the depth distribution and dive profiles of individuals returning to Ascension Island to nest after experimental displacement (N=5 individuals). Satellite telemetry revealed that most submergences were short (<5 min) but that some submergences were longer (>20 min), particularly at night. TDRs revealed that much of the time was spent conducting short (2-4 min), shallow (approximately 0.9-1.5 m) dives, consistent with predictions for optimisation of near-surface travelling, while long (typically 20-30 min), deep (typically 10-20 m) dives had a distinctive profile found in other marine reptiles. These results suggest that green turtles crossing the Atlantic do not behave invariantly, but instead alternate between periods of travelling just beneath the surface and diving deeper. These deep dives may have evolved to reduce silhouetting against the surface, which would make turtles more susceptible to visual predators such as large sharks.


Subject(s)
Animal Migration , Behavior, Animal/physiology , Diving/physiology , Turtles/physiology , Animals , Brazil , Female , Immersion , Satellite Communications , Telemetry , Time Factors
20.
Int J Obes Relat Metab Disord ; 24(12): 1586-91, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11126210

ABSTRACT

BACKGROUND: A role for leptin to predict weight gain is still controversial. OBJECTIVE AND DESIGN: To determine the relationship between baseline serum leptin values and responsiveness to an educational-based weight excess reduction program (WERP), 418 (241 males and 185 females) obese subjects, aged 9-15 y, were recruited. WERP required 2 y of follow-up. Body mass index (BMI) was evaluated at baseline and at each semester of follow-up. The obese subjects were subdivided into responsives and non-responsives, according to reduction or not of their BMI Z-scores during the WERP. Leptin concentrations were assayed at baseline and were included together with other independent variables in statistical multiple regression analysis. RESULTS: At a preliminary multiple regression analysis, a significant positive correlation between leptin values and BMI Z-score reduction at the second, third and fourth semester of follow-up was registered. To determine the odds ratio of the subjects who were responsive or non-responsive at the various semesters of WERP follow-up, a stepwise logistic regression was used incorporating the same predictors, with the serum leptin values subdivided into quintiles and responsiveness and non-responsiveness as a binary outcome variable. The model offered a satisfying goodness of fit as shown by the sensitivity and specificity. The odds ratio of being responsive were significantly increased by greater quintiles of leptin serum concentrations. Furthermore, such odds ratios were much higher in pubertal than in prepubertal subjects. CONCLUSIONS: These findings support a significant role for serum leptin concentration in predicting BMI changes as a response to an educational excess weight reduction program.


Subject(s)
Leptin/analysis , Obesity/blood , Obesity/therapy , Weight Loss , Adolescent , Behavior Therapy , Body Mass Index , Child , Exercise , Female , Humans , Linear Models , Male , Odds Ratio , Patient Education as Topic , Treatment Outcome
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