Biomedical subjects

A Peri

Publications and source records attributed to A Peri.

At least 19 recordsLinked to original sources

PubMed2006

Antineoplastic effects of rosiglitazone and PPARgamma transactivation in neuroblastoma cells.

Neuroblastoma (NB) is the most common extracranial solid tumour in infants. Unfortunately, most children present with advanced disease and have a poor prognosis. In the present study, we evaluated the role of the peroxisome proliferator-activated receptor gamma (PPARgamma) agonist rosiglitazone (RGZ) in two NB cell lines (SK-N-AS and SH-SY5Y), which express PPARgamma. Rosiglitazone decreased cell proliferation and viability to a greater extent in SK-N-AS than in SH-SY5Y. Furthermore, 20 microM RGZ significantly inhibited cell adhesion, invasiveness and apoptosis in SK-N-AS, but not in SH-SY5Y. Because of the different response of SK-N-AS and SH-SY5Y cells to RGZ, the function of PPARgamma as a transcriptional activator was assessed. Noticeably, transient transcription experiments with a PPARgamma responsive element showed that RGZ induced a three-fold increase of the reporter activity in SK-N-AS, whereas no effect was observed in SH-SY5Y. The different PPARgamma activity may be likely due to the markedly lower amount of phopshorylated (i.e. inactive) protein observed in SK-N-AS. To our knowledge, this is the first demonstration that the differential response of NB cells to RGZ may be related to differences in PPARgamma transactivation. This finding indicates that PPARgamma activity may be useful to select those patients, for whom PPARgamma agonists may have a beneficial therapeutic effect.

Antineoplastic Agents↗

PubMed2006

Specific features of differentiated thyroid carcinoma in patients over 70 years of age.

BACKGROUND AND OBJECTIVES: Among the geriatric population, there is a lower incidence of thyroid carcinoma (TC), but it accounts for 30% of all thyroid disorders compared to 6-8% in younger subjects. Prognosis, moreover, is worse in the elderly, as demonstrated by the fact that 81% of deaths related to these tumors occur in patients over 55. The aim of this retrospective study was to identify the characteristics of differentiated thyroid carcinoma (DTC) peculiar to the elderly. METHODS: Of 638 patients who underwent surgery for DTC over a period of 30 years, 46 were more than 70 years old. All the elderly patients had undergone radioioidine and TSH-suppression therapy following surgical resection. RESULTS AND CONCLUSIONS: Despite these measures, the rate of recurrence was 26.5% at 5 years and 63.6% at 10 years. The 5- and 10-year disease-specific survival rates were 87.8% and 63.6%, respectively. On an average, survival was 55.1 months when death was disease-related, and with regard to histological type, it was longer in papillary carcinoma than in the follicular variant, and longest of all in occult sclerosing carcinoma. Survival was greatest in patients with tumors less than 2 cm in diameter, characterized by the absence of extraglandular spread and by lymph node metastasis.

Adolescent↗

PubMed2006

Multi-step approach in a complex case of Cushing's syndrome and medullary thyroid carcinoma.

The diagnosis of Cushing's syndrome (CS) may sometimes be cumbersome. In particular, in ACTH-dependent CS it may be difficult to distinguish between the presence of an ACTH-secreting pituitary adenoma and ectopic ACTH and/or CRH secretion. In such instances, the etiology of CS may remain unknown despite extensive diagnostic workout, and the best therapeutic option for each patient has to be determined. We report here the case of a 54-yr-old man affected by ACTH-dependent CS in association with a left adrenal adenoma and medullary thyroid carcinoma (MTC). He presented with clinical features and laboratory indexes of hypercortisolism associated with elevated levels of calcitonin. Ectopic CS due to MTC was reported previously. In our case hypercortisolism persisted after surgical treatment of MTC. Thorough diagnostic assessment was performed, in order to define the aetiology of CS. He was subjected to basal and dynamic hormonal evaluation, including bilateral inferior petrosal sinus sampling. Extensive imaging evaluation was also performed. Overall, the laboratory data together with the results of radiological procedures suggested that CS might be due to inappropriate CRH secretion. However, the source of CRH secretion in this patient remained unknown. It was then decided to remove the left adenomatous adrenal gland. Cortisol level fell and has remained within the normal range nine months after surgery. This case well depicts the complexity of the diagnostic workout, which is needed sometimes to correctly diagnose and treat CS, and suggests that monolateral adrenalectomy may represent, at least temporarily, a reasonable therapeutic option in occult ACTH-dependent hypercortisolism.

Calcitonin↗

PubMed2006

Hyponatremia and pituitary adenoma: think twice about the etiopathogenesis.

Pituitary adenomas may be the cause of the syndrome of inappropriate secretion of antidiuretic hormone (SIADH), although few cases have so far been reported. We described a case of hypotonic hyponatremia in a 76-yr-old man with a pituitary macroadenoma. He had a recent history of two syncopal attacks which had occurred in the last two months. Baseline assessment demonstrated a sodium serum level of 114 mEq/l. Clinically, the patient appeared euvolemic. Thyroid and adrenal function testing did not show any abnormality. Plasma and urinary osmolality (238 and 186 mOsm/kg, respectively) were in agreement with the diagnosis of SIADH. Accordingly, 3% hypertonic saline solution was started, followed by water intake restriction when natremia reached 126 mEq/l. A computed tomography (CT) scan of the chest revealed the presence of a 2-cm lesion in the azygos-esophageal recess. Because the nature of the lesion appeared uncertain, antibiotic therapy was initiated. After one month, a new CT scan did not show any evidence of the mediastinic mass. Sodium serum level was within the normal range (141 mEq/l) and remained stable thereafter, without fluid restriction. This case very well demonstrates that, in the presence of hyponatremia due to SIADH, more frequently associated co-morbidities (ie mediastinic diseases) have to be searched, even in the presence of a possible, yet rare, cause of this syndrome (ie pituitary adenoma).

Aged↗

PubMed2006

Octreotide promotes apoptosis in human somatotroph tumor cells by activating somatostatin receptor type 2.

Somatostatin analogs currently used in the treatment of acromegaly and other neuroendocrine tumors inhibit hormone secretion and cell proliferation by binding to somatostatin receptor type (SST) 2 and 5. The antiproliferative pathways coupled to these receptors have been only partially characterized. The aim of this study was to evaluate the effect of octreotide and super selective SST2 (BIM23120) and SST5 (BIM23206) analogs on apoptotic activity and apoptotic gene expression in human somatotroph tumor cells. Eight somatotroph tumors expressing similar levels of SST2 and SST5 evaluated by real-time PCR and western blot analyses were included in the study. In cultured cells obtained from these tumors, octreotide induced a dose-dependent increase of caspase-3 activity (160+/-20% vs basal at 10 nM) and cleaved cytokeratin 18 levels (172+/-25% vs basal) at concentrations higher than 0.1 nM. This effect was due to SST2 activation since BIM23120 elicited comparable responses, while BIM23206 was ineffective. BIM23120-stimulated apoptosis was dependent on phosphatases, since it was abrogated by the inhibitor orthovanadate, and independent from the induction of apoptosis-related genes, such as p53, p63, p73, Bcl-2, Bax, BID, BIK, TNFSF8, and FADD. In somatotroph tumors, both BIM23120 and BIM2306 caused growth arrest as indicated by the increase in p27 and decrease in cyclin D1 expression. In conclusion, the present study showed that octreotide-induced apoptosis in human somatotroph tumor cells by activating SST2. This effect, together with the cytostatic action exerted by both SST2 and SST5 analogs, might account for the tumor shrinkage observed in acromegalic patients treated with long-acting somatostatin analogs.

Acromegaly↗

PubMed2005

Analysis of somatostatin receptors 2 and 5 polymorphisms in patients with acromegaly.

OBJECTIVE: The aim of the study was to investigate the possible correlation of single nucleotide polymorphisms in somatostatin receptor (SSTR)2 and SSTR5 genes with the responsiveness to somatostatin analogs in a cohort of acromegalic patients. STUDY DESIGN: Three single nucleotide polymorphisms (a-83 g, c-57 g, and t80c) of SSTR2 and three (t-461c, c325t, and c1004t) of SSTR5 were analyzed in 66 acromegalic patients with different responsiveness to somatostatin analogs and 66 healthy controls. RESULTS: Allele frequencies in patients and controls were similar. No association between SSTR2 genotypes and GH and IGF-I levels was found. When considering SSTR5 variants, patients homozygous or heterozygous for the substitution c1004 (P+) showed basal IGF-I levels significantly lower than patients homozygous for 1004t (P-). Moreover, serum GH levels were lower in patients with P+/T- haplotype (having c1004 allele and no t-461 allele) than in those with P-/T+. No correlation between SSTR2 and SSTR5 genotypes, responsiveness to somatostatin therapy, and mRNA expression in the removed adenomas (n = 10) was found. CONCLUSIONS: These data suggest a role for SSTR5 t-461c and c1004t alleles in influencing GH and IGF-I levels in patients with acromegaly, whereas SSTR2 and SSTR5 variants seem to have a minor role in determining the responsiveness to somatostatin analogs.

5' Untranslated Regions↗

PubMed2005

Seladin-1 as a target of estrogen receptor activation in the brain: a new gene for a rather old story?

Experimental evidence indicates that estrogen exerts neuroprotective effects. According to the fact that Alzheimer's disease (AD) is more common in post-menopausal women, estrogen treatment has been proposed. However, the beneficial effect of estrogen or selective estrogen receptor modulators (SERMs) in preventing or treating AD is a controversial issue, which will be summarized in this review. Recently, a novel gene, named selective AD indicator-1 (seladin-1), has been isolated and found to be down-regulated in brain regions affected by AD. Seladin-1, which is considered the human homolog of the plant protein DIMINUTO/DWARF1, confers protection against beta-amyloid-mediated toxicity and from oxidative stress and is an effective inhibitor of caspase 3 activity, a key mediator of apoptosis. This review will present the up-to-date findings regarding seladin-1 and DIMINUTO/DWARF1. In addition, the possibility that seladin-1 may be a downstream effector of estrogen receptor activation in the brain, based on our recent experimental findings using a human fetal neuronal model, will be addressed.

Alzheimer Disease↗

PubMed2004

Loss of heterozygosity at the SS receptor type 5 locus in human GH- and TSH-secreting pituitary adenomas.

SS receptor types 2 and 5 (sst2 and sst5) are involved in the control of secretion and proliferation of normal and tumoral somatotrophs and thyrotrophs. The mechanisms leading to reduced responsiveness to SS analogues in patients with pituitary tumors are poorly understood. The aim of the study was to verify the possible loss of heterozygosity (LOH) at the sst5 gene locus in somatotroph and thyrotroph adenomas by screening leukocyte and tumor DNA for two single nucleotide polymorphisms, i.e. C1004T leading to P335L change and T-461C in the 5'-upstream region. Among the 13 informative samples, 1 GH- and 1 TSH-secreting adenoma showed LOH at sst5 gene locus with the retention of Leu335 variant. By analyzing other polymorphic markers spanning from telomere to 16p13.3-13.2 boundaries, DNA deletion of at least 1 megabase was found in both tumors. LOH in thyrotroph adenoma was associated with unusual tumor aggressiveness that required a second surgery and resistance to SS analogs, while no obvious phenotype was identified in the case of the somatotroph adenoma. In conclusions, LOH at the sst5 gene locus is a rare phenomenon, occurring in about 10% of pituitary tumors, that seems to be associated with an aggressive phenotype, at least in thyrotroph adenomas. Further studies are required to confirm this association and to identify the genes, in addition to sst5, lost in these tumors.

Adenoma↗

PubMed2003

Reduced sympathetic outflow and adrenal secretory activity during a 40-day stay in the Antarctic.

Human adaptation to unknown and extreme environments requires changes in the psychological and physical homeostasis. We previously reported a significant decrease of anterior pituitary and adrenal hormonal levels and a significant modification of psychophysiological correlates of stress, such as galvanic skin response, after exposure to Antarctica, suggesting a possible decrease of individual arousal. The latter was hypothesized to be correlated with a modification of autonomic balance, mainly represented by a possible reduction of adrenergic output. The aim of the present study was to assess the patterns of hormonal circadian rhythms and the autonomic nervous system balance by means of spectral analysis of heart rate variability (HRV). These parameters were evaluated during 3 sessions (baseline, session 1 and session 2), before, at the beginning and after a 40-day stay in Antarctica (Station of Terra Nova Bay; average temperature in the study period: -11 degrees C, 24 h of light, sea level). In each of the sessions, 6 healthy male subjects underwent a 24-h electrocardiogram and blood sampling (08.00, 12.00, 16.00, 20.00, 24.00 and 08.00 h) for hormonal determinations. The data showed a remarkable decrease of hormonal levels without significant changes in circadian rhythms. Spectral analysis of HRV showed an imbalance of the autonomic nervous system with a relative significant decrease of the low frequency band (0.1 Hz) in session 1 and 2 compared to baseline, which can be functionally interpreted as a relative decrement of the sympathetic component. In conclusion, the exposure to a cold and extreme environment seems to affect autonomic balance over a 40-day period. This is followed by a significant reduction of the anterior pituitary and adrenal hormonal secretory patterns with preserved hormonal circadian rhythms (within the same time period of 40 days). This pattern is suggestive of a trophotropic neurovegetative adaptive process.

Adrenal Glands↗

PubMed2001

Variable expression of the transcription factors cAMP response element-binding protein and inducible cAMP early repressor in the normal adrenal cortex and in adrenocortical adenomas and carcinomas.

The molecular mechanisms leading to adrenocortical tumorigenesis have been only partially elucidated so far. Because the pituitary hormone ACTH, via activation of the cAMP pathway, regulates both cell proliferation/differentiation and steroid synthesis in the adrenal cortex, in this study we focused on the cAMP-dependent transcription factors cAMP responsive element modulator (CREM) and cAMP responsive element binding protein (CREB). We studied CREM and CREB expression by RT-PCR in human normal adrenal cortex (n = 3), adrenocortical adenomas (n = 8), and carcinomas (n = 8). We found transcripts corresponding to the isoforms alpha, beta, gamma, and tau2 of the CREM gene in all of the normal adrenal tissues, in the adenomas, and in seven of eight carcinomas. On the other hand, mRNA for the inducible cAMP early repressor isoforms, which derive from an internal promoter of CREM gene, was detected in the normal adrenal and in seven of eight adenomas, but in only three of eight carcinomas. Similarly, CREB transcripts were readily detectable in all normal adrenals and adenomas, whereas they were not found in four of eight adrenal carcinomas. To further characterize the carcinomas, telomerase activity and the expression of the ACTH receptor gene were determined. Telomerase activity in the carcinomas resulted in levels significantly higher than in the adenomas, whereas the levels of ACTH receptor mRNA were lower in the carcinomas. No correlation was found in the carcinomas between the levels of the ACTH receptor transcript and the loss of expression of CREB/inducible cAMP early repressor, suggesting that this alteration is not secondary to an upstream disregulation at the receptor level. In conclusion, our results suggest that an alteration in cAMP signaling may be associated with malignancies of the adrenal cortex.

Adenoma↗

PubMed2001

Expression of cyclic adenosine 3',5'-monophosphate (cAMP)-responsive element binding protein and inducible-cAMP early repressor genes in growth hormone-secreting pituitary adenomas with or without mutations of the Gsalpha gene.

In about 30-40% of GH-secreting adenomas, gain-of-function mutations of the Gsalpha gene, which convert this gene into an oncogene termed gsp, occur. Gsalpha mutations have been related to pituitary tumorigenesis. We focused on 2 nuclear transcription factors that are final targets of the cAMP-dependent pathway and are positively regulated by cAMP signaling, i.e. the cAMP-responsive element binding protein (CREB) and the inducible cAMP early repressor (ICER), that derives from alternative splicing of cAMP-responsive element modulator gene. We examined 21 GH-secreting adenomas, 8 with (gsp(+)) and 13 without (gsp(-)) a mutated Gsalpha. Analysis of CREB and ICER I/II messenger RNA revealed that the levels of both transcripts were higher in gsp(+) than in gsp(-) tumors (CREB/glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mean optical density +/- SE, 2.34 +/- 0.36 in gsp(+) vs. 0.99 +/- 0.22 in gsp(-), P = 0.003; ICER I/GAPDH, 0.53 +/- 0.15 in gsp(+) vs. 0.14 +/- 0.07 in gsp(-), P = 0.01; ICER II/GAPDH, 1.5 +/- 0.21 in gsp(+) vs. 0.83 +/- 0.13 in gsp(-), P = 0.01), although a few cases in both groups did not display this pattern of expression. Moreover, no positive correlation between the levels of CREB and ICER transcripts was observed, suggesting the possible presence of alterations in the mechanisms by which cAMP signaling directs the expression of CREB and/or ICER genes. Our results indicate a complex pattern of expression of nuclear transcription factors that mediate cAMP action in both gsp(+) and gsp(-) tumors, suggesting that, beside Gsalpha gene mutations, different and partially unknown molecular events may contribute to the pathogenesis of these tumors.

Adenoma↗

PubMed2001

Cushing's syndrome due to intermittent ectopic ACTH production showing a temporary remission during a pulmonary infection.

OBJECTIVES: In about 15-20% of patients with ACTH-dependent Cushing's syndrome the source of ACTH is outside the pituitary gland. Pulmonary tumours are the most frequent, yet not unique, source of ectopic ACTH. In some instances the localisation of an ACTH-secreting tumour may be problematic. Occult ectopic ACTH secretion indicates the occurrence of ACTH-dependent hypercortisolism with an unknown origin. Another peculiarity of Cushing's syndrome may reside in the episodic cortisol hypersecretion, which can determine a pattern characterised by hypercortisolism together with periods of remission (cyclic Cushing's syndrome). We describe a very challenging case of Cushing's syndrome due to ectopic ACTH hypersecretion, showing virtually all of the most unusual features of the disease. DESIGN: A 55-year-old woman affected by Cushing's syndrome, presenting with biochemical features of ectopic ACTH secretion, has been followed for 7 years. METHODS: Thorough basal and dynamic hormonal assessment through the past 7 years is reported. In addition, the results of extensive imaging studies are presented. RESULTS: The source of ACTH secretion has not been identified so far, and hypercortisolism has been controlled by octreotide treatment. In addition, the patient showed a cyclic pattern of hypercortisolism with a long-term remission period. A unique feature of this case is represented by the fact that we observed a temporary, yet dramatic, short-lasting remission of ACTH and cortisol hypersecretion during a pulmonary infection, which occurred while the patient was hospitalised for a periodic hormonal assessment. CONCLUSIONS: This case well represents the wide spectrum of clinical variability of Cushing's syndrome. Most interestingly, to our knowledge, this is the first report of a case of Cushing's syndrome showing a remission during an acute infection.

Adrenocorticotropic Hormone↗

PubMed2000

Uteroglobin reverts the transformed phenotype in the endometrial adenocarcinoma cell line HEC-1A by disrupting the metabolic pathways generating platelet-activating factor.

Uteroglobin, originally named blastokinin, is a protein synthesized and secreted by most epithelia, including the endometrium. Uteroglobin has strong anti-inflammatory properties that appear to be due, at least in part, to its inhibitory effect on the activity of the enzyme phospholipase A(2). In addition, recent experimental evidence indicates that uteroglobin exerts antiproliferative and antimetastatic effects in different cancer cells via a membrane receptor. The human endometrial adenocarcinoma cell line HEC-1A does not express uteroglobin. Thus, we transfected HEC-1A cells with human uteroglobin cDNA. The transfectants showed a markedly reduced proliferative potential as assessed by impaired plating efficiency as well as by reduced growth in soft agar. Cytofluorimetric analysis clearly indicated that in uteroglobin-transfected cells the time for completion of the cell cycle was increased. We previously demonstrated that HEC-1A cells actively synthesize platelet-activating factor, one of the products of phospholipase A(2) activity. In addition, we demonstrated that platelet-activating factor stimulates the proliferation of these cells through an autocrine loop. In uteroglobin transfectants, the activity of phospholipase A(2) and platelet-activating factor acetyl-transferase, which are involved in the synthesis of platelet-activating factor, was significantly reduced compared with wild-type and vector-transfected cells (p < 0.05). Our results indicate that enforced expression of uteroglobin in HEC-1A cells markedly reduced their growth potential and significantly impaired the synthesis of platelet-activating factor, an autocrine growth factor for these cells. These data suggest that one possible mechanism for the recently observed antineoplastic properties of uteroglobin may be the inhibition of the synthesis of platelet-activating factor.

Acetyltransferases↗

PubMed2000

The CREM system in human spermatogenesis.

Spermatogenesis is a multi-step process, regulated by endocrine, paracrine and autocrine signals, through which immature germ cells differentiate into spermatozoa. The cAMP-dependent transcription factor CREM directs in the testis the expression of genes related to the structuring of mature spermatozoa. CREM gene expression originates different isoforms, which in turn can be divided into activators or repressors of gene expression. Whereas only CREM repressors are expressed in pre-meiotic germ cells in mice, a switch to the expression of the CREM activator tau occurs in post-meiotic germ cells. In addition, mice lacking CREM gene are infertile and present an arrest of germ cell maturation at the stage of round spermatid. We have demonstrated that CREM gene is expressed also in human germ cells and that a switch from the expression of repressors to activators is present in normospermic men. In particular, CREM tau mRNA is located in the cytoplasm of round spermatids. Conversely, in patients showing a testicular pattern of round spermatid maturation arrest only CREM repressors are expressed. Other reports have confirmed our data, supporting the hypothesis that CREM plays a role also in human spermatogenesis and that the absence of "the CREM switch" can be associated to spermatogenic arrest.

Animals↗

PubMed2000

Preliminary studies on the psychological adjustment in the Italian Antarctic summer campaigns.

Up until now, no significant emotional or cognitive modifications have been found in psychological studies performed during Italian Antarctic summer campaigns, which last from 2 to 5 months. A substantial emotional stability and a general satisfactory adjustment of the expedition participants emerged in the research. To investigate the coping strategies used to deal with the Antarctic environment, the Profile of Mood States (POMS) and the Ways of Coping Inventory were administered to a group of 11 Italian expeditioners before leaving and before returning from the campaign. The results confirm the emotional stability found in the previous studies and show a decrease of several ways of coping. Particularly, there was a decrease in seeking social support and in problem-focused coping. The discussion and interpretation of the findings are reported, and the hypothesis of a frozen reactivity mediated by a possible perceptual defense is suggested.

Adaptation, Psychological↗

PubMed1999

Loss of transformed phenotype in cancer cells by overexpression of the uteroglobin gene.

Uteroglobin (UG) is a multifunctional, secreted protein that has receptor-mediated functions. The human UG (hUG) gene is mapped to chromosome 11q12.2-13.1, a region frequently rearranged or deleted in many cancers. Although high levels of hUG expression are characteristic of the mucosal epithelia of many organs, hUG expression is either drastically reduced or totally absent in adenocarcinomas and in viral-transformed epithelial cells derived from the same organs. In agreement with these findings, in an ongoing study to evaluate the effects of aging on UG-knockout mice, 16/16 animals developed malignant tumors, whereas the wild-type littermates (n = 25) remained apparently healthy even after 11/2 years. In the present investigation, we sought to determine the effects of induced-expression of hUG in human cancer cells by transfecting several cell lines derived from adenocarcinomas of various organs with an hUG-cDNA construct. We demonstrate that induced hUG expression reverses at least two of the most important characteristics of the transformed phenotype (i.e., anchorage-independent growth on soft agar and extracellular matrix invasion) of only those cancer cells that also express the hUG receptor. Similarly, treatment of the nontransfected, receptor-positive adenocarcinoma cells with purified recombinant hUG yielded identical results. Taken together, these data define receptor-mediated, autocrine and paracrine pathways through which hUG reverses the transformed phenotype of cancer cells and consequently, may have tumor suppressor-like effects.

Adenocarcinoma↗

PubMed1999

Laparoscopic extraperitoneal inguinal hernia repair with spinal anesthesia and nitrous oxide insufflation.

BACKGROUND: Laparoscopic repair of inguinal hernia is traditionally performed under general anesthesia mainly because of the adverse effects that carbon dioxide pneumoperitoneum has on awake patients. Since a mandatory use of general anesthesia for all hernia repairs is questionable, the feasibility of laparoscopic extraperitoneal herniorraphy using spinal anesthesia combined with nitrous oxide insufflation was investigated. METHODS: Over a 4-month period, February to May 1998, we performed 35 consecutive total extraperitoneal inguinal hernia procedures (24 unilateral, 11 bilateral) using spinal anesthesia and nitrous oxide extraperitoneal gas. Data on operative findings, self-reported operative and postoperative pain and discomfort (visual analog pain scale), procedure-related hemodynamics, and complications were collected prospectively. RESULTS: All 35 procedures were completed laparoscopically without the need to convert to general anesthesia. Mean operative time was 39 +/- 7 min for unilateral hernia and 65 +/- 10 min for bilateral hernia. Incidental peritoneal tears occurred in 22 patients (63%) resulting in nitrous oxide pneumoperitoneum, which was well tolerated. The patients remained hemodynamically stable throughout the procedure, and operative conditions and visibility were excellent. Complications at a mean of 4 months after the procedure included seven uninfected seromas (20%), three patients with transient testicular pain, and one (3%) recurrence. CONCLUSIONS: Laparoscopic total extraperitoneal hernia repair can be safely and comfortably performed using spinal anesthesia with extraperitoneal nitrous oxide insufflation gas. This method provides a good alternative to general anesthesia.

Aged↗

PubMed1999

Endocrine and psychophysiological aspects of human adaptation to the extreme.

Human beings need to adapt to any extreme, unknown, or isolated environment. This adaptation requires changes in the normal regulation of psychophysiological homeostasis, as described in terms of stress reaction. The aim of the present study was to monitor the processes of human adaptation to cold and isolated areas in Antarctica during the 12th expedition of the Italian National Research Program. Nine healthy subjects (experimental subjects), members of the expedition, and nine controls in Italy, were studied over a period of 2 months. Anterior pituitary hormone secretion, insulin, and melatonin, plus routine blood test, blood pressure, and ECG were performed. In addition, psychophysiological correlates were also recorded before and after the expedition period. In experimental subjects results of metabolic data suggested the presence of an increased peripheral insulin sensitivity at the end of the permanence in the station and a significant increased of total cholesterol. Hematocrit also significantly increased due to the conditions of hypobaric hypoxia. Results of endocrine data showed a significant decrease (p < 0.05) of hormone levels, which was associated with a significant decrement of the Galvanic Skin Response (GSR) activity to a standardized cognitive stress. No significant differences were reported in the controls. The data suggest that the exposure to the extreme environment develops a possible psychophysiological mechanism(s) that decreases the individual arousal.

Acclimatization↗