Mandibular Dysmorphology and Clinical Presentation in Treacher Collins Syndrome

INTRODUCTION

Treacher Collins syndrome is a rare congenital disease characterized by the multiple craniofacial malformations. Although the deformities affecting patients with Treacher Collins syndrome have been well characterized, the effects of these malformations to clinical severity of the syndrome are not well understood.

OBJECTIVE

To determine the association of specific Treacher Collins mandibular malformations with clinical severity.

DESIGN

A retrospective radiographic observational study.

SETTING

Study conducted at a single institution, a quaternary craniofacial care center.

PATIENTS

54 patients with Treacher Collins syndrome.

INTERVENTIONS

Computed tomography (CT), clinical photographs and medical history were included in this analysis. Mandibles were isolated from CT data and reconstructed in three dimensions using Mimics software. Cephalometric measurements were performed on CT data. Clinical severity was determined by Teber and Vincent scores. Association of craniofacial dysmorphology to clinical severity was determined by Spearman rank coefficient.

MAIN OUTCOME MEASURES

The main results obtained were the measurements of the mandibles and the quantification of the malformations of the evaluated patients.

RESULTS

Among the most frequent findings in the sample are hypoplasia of the zygomatic complex, descending palpebral cleft and mandibular hypoplasia. Patients with a lower ramus/corpus ratio had a higher (more severe) Teber and Vincent classification.

CONCLUSION

Patients with the most compromised mandible are also the patients with the highest number of malformations, thus, the most severe patients.

Growth patterns of the airway in Crouzon syndrome patients with different types of cranial vault suture synostosis

The severity of obstructive respiratory difficulty varies among affected Crouzon syndrome patients. The aim of this study was to investigate the correlation between the restricted airway volume in Crouzon syndrome and the associated type of cranial vault suture synostosis. Computed tomography scans of 68 unoperated Crouzon syndrome patients and 89 control subjects were subgrouped into four types: type I, bilateral coronal synostosis; type II, sagittal synostosis; type III, pansynostosis; type IV, perpendicular combinations of synostoses. Measurements were made using Mimics software. Of type I Crouzon patients, 42% had a restricted nasal airway (P=0.002), while the pharyngeal airway volume was not significantly reduced. Type II Crouzon patients grew normal segmental airway volumes. Crouzon patients of type III developed simultaneously reduced nasal and pharyngeal airway volumes in infancy, by 38% (P=0.034) and 51% (P=0.014), respectively. However, the nasal airway achieved a normal volume by 2 years of age without any intervention, while the pharyngeal airway remained significantly reduced up to 6 years of age, by 42% (P=0.013), compared to controls. Type IV Crouzon patients developed a reduced nasal airway volume (32%, P=0.048) and a non-significant restricted pharyngeal airway (18%, P=0.325). Airway compromise in Crouzon syndrome is variable when associated with different craniosynostosis fusion patterns. Type II (sagittal synostosis) Crouzon patients grew a normal nasopharyngeal airway volume. Those with types I (bicoronal synostosis) and IV (perpendicular synostoses) had significantly restricted nasal airways and a tendency towards a reduced pharyngeal volume. Type III (pansynostosis) Crouzon infants had the worst restriction of both airways, although there was some improvement with age.

Nasopharyngeal airway and subcranial space analysis in Pfeiffer syndrome

Tracheotomy in infancy helps patients with Pfeiffer syndrome to survive by preventing respiratory crisis, but difficulty in decannulation may consequently be a challenge. This study has investigated the regional abnormalities of the nasopharyngeal airway in children with Pfeiffer syndrome to provide an anatomical basis for the surgical treatment and decannulation of the upper airway. Seventy-two preoperative computed tomograms (CT) (Pfeiffer syndrome n=30; control n=42) were included. The airway volume, cross-sectional area, and cephalometrics were measured using Materialise software. Patients with Pfeiffer syndrome developed a 50% (p<0.001) reduction of nasal airway volume, and a 44% (p=0.003) restriction in pharyngeal airway volume. In patients with Pfeiffer syndrome the cross-sectional area at the choana was only half that of the controls (p<0.001). The posterior width of the nasal airway in patients with Pfeiffer syndrome was shortened by 13% (p=0.003), and the height reduced by 21% (p<0.001). The cross-sectional areas at the condylion and gonion levels, which indicate the calibre of the pharyngeal airway at the entrance and midsection, were reduced by 67% (p<0.001) and 47% (p<0.001), respectively, when compared with the controls. The volume of the nasal airway in patients with Pfeiffer syndrome was significantly restricted in length, height, and width, and by choanal stenosis in all cases in this cohort. The reduced anteroposterior length of the nasal airway contributed to the shortened maxilla more than the anteroposterior position. The limited height and width of the nasal pathway was the result of a hypoplastic sphenoid. Restricted mediolateral and anteroposterior dimensions were evident across the entire course of the pharyngeal airway. Mediolateral maxillary expansion in addition to maxillomandibular advancement is therefore likely to benefit these patients.

Age-adjusted D-dimer to rule out deep vein thrombosis: findings from the PALLADIO algorithm

Essentials The accuracy of the age-adjusted D-dimer in suspected venous thromboembolism is still debated. We assessed the performance of age-adjusted D-dimer combined with the PALLADIO algorithm. The age-adjusted threshold can reduce the need for imaging tests compared to the fixed cut-off. The safety of this approach should be confirmed in large management studies.

SUMMARY

Background Age-adjusted D-dimer has been proposed to increase specificity for the diagnosis of venous thromboembolism (VTE). However, the accuracy of this threshold has been recently questioned. Objectives To assess the diagnostic performance of age-adjusted D-dimer combined with clinical pretest probability (PTP) in patients with suspected deep vein thrombosis (DVT). Methods PALLADIO (NCT01412242) was a multicenter management study that validated a new diagnostic algorithm, incorporating PTP, D-dimer (using the manufacturer's cut-off) and limited or extended compression ultrasonography (CUS) in outpatients with clinically suspected DVT. Patients with unlikely PTP and negative D-dimer had DVT ruled out without further testing (group 1); patients with likely PTP or positive D-dimer underwent limited CUS (group 2); patients with likely PTP and positive D-dimer underwent extended CUS (group 3). Patients with DVT ruled out at baseline had a 3-month follow-up. In this post-hoc analysis we evaluated age-adjusted D-dimer cut-off (defined as age times 10 μg L-1 , or age times 5 μg L-1 for D-dimers with a lower manufacturer's cut-off, in patients > 50 years). Results In total, 1162 patients were enrolled. At initial visit, DVT was detected in 4.0% of patients in group 2 and 53.0% in group 3. The age-adjusted D-dimer, compared with the fixed cut-off, resulted in 5.1% (95% CI, 4.0-6.5%) reduction of CUS. The incidence of symptomatic VTE during follow-up was: 0.24% (95% CI, 0.04-1.37) in group 1; 1.12% (95% CI, 0.44-2.85) in group 2; and 1.89% (95% CI, 0.64-5.40) in group 3. Conclusions The PALLADIO algorithm using age-adjusted D-dimer slightly decreased the number of required imaging tests, but this approach should be confirmed in large management studies.

D2 dopamine receptor (DRD2) gene Taq1A polymorphism and the eating-related psychological traits in eating disorders (anorexia nervosa and bulimia) and obesity

OBJECTIVE

Food is considered a reinforcing agent, like a variety of substances such as alcohol and other drugs of abuse that produce pleasure. Psychopathological traits related to food intake are demonstrated in eating disorders as in obesity with different genetic aspects for these diseases. Recently, the prevalence of TaqA1 allele has been associated to alcohol, drug abuse and carbohydrate preference. For this reason, the aim of this study was to evaluate if the presence of A1 allele, in eating disorders and obesity, is associated with some particular psycho-pathological characteristics.

METHODS

We studied the presence of TaqA1 in Italian subjects affected by obesity (n=71), anorexia (n=28), bulimia (n=20) and in control group (n=54). The Eating Disorders Inventory (EDI test) was used to evaluate the psychological profiles. Patients without alcohol and drugs abuse were selected (>125 ml/day).

RESULTS

The A1+ allele, both in A1/A1 and A1/A2 genotypes, was not differently distributed among disease groups; on the contrary two EDI subscales (Drive for thinness and Ineffectiveness) resulted associated with A1+ allele without effect of the eating disease or obesity.

CONCLUSION

These results confirm that the presence of A1+ allele is not simply related to body weight but the A1+ allele might be a marker of a genetic psychological condition in people with high risk to develop pathological eating behaviour.

Hyaluronan Biodegradable Scaffold for Small-caliber Artery Grafting: Preliminary Results in an Animal Model

OBJECTIVE

To evaluate a new Hyaluronan-based graft.

MATERIAL AND METHODS

Hyaluronan-based grafts (HYAFF 11trade mark tube, diameter 2 mm, length 1.5 cm) were implanted in an end-to-end fashion in the abdominal aorta of 15 rats. Histology, immunohistochemistry and electron microscopy were used to evaluate the results at 7, 21, and 90 days.

RESULTS

At day 7, new tissue was observed in the graft coming from both the proximal and distal ends of the aorta. The luminal surface of the regenerating tissue was covered by endothelial cells (CD34(+), VEGFR-2(+), vWF(+)). At day 21, regenerating tissue joined at the centre of the tube. The neo-vessel was formed by smooth muscle cells (Myosin Light Chain Kinase) as well as elastic, and collagen fibres. At day 90 a stable artery segment was formed and the biomaterial was almost completely degraded. Infiltration of neutrophils and lymphocytes was not observed. All animals survived the observation period and there were no signs of stenoses or aneurysms.

CONCLUSION

The hyaluronan-based graft allowed complete regeneration of a newly formed vascular tube in which all the cellular and extracellular components are present and organized in a well defined architecture similar to native artery.

Tumor necrosis factor-alpha induces apoptosis in rat brown adipocytes

Accumulating evidence demonstrates that adipose tissue is a major site of tumor necrosis factor-alpha (TNF-alpha) gene expression, which is markedly high in obese animals and may contribute to obesity-linked insulin resistance. We now report that recombinant murine TNF-alpha triggers the apoptotic degeneration of brown adipocytes differentiated in culture. Moreover, noradrenaline, which has been described as having trophic effects on brown fat and accelerating the differentiation of brown adipocytes, is capable of dose-dependently preventing the TNF-alpha-induced apoptosis of brown fat cells. Since obesity is characterized by greatly increased TNF-alpha production and reduced catecholaminergic activity, apoptosis was studied in the brown fat of genetically obese animals. In situ DNA fragmentation analysis revealed a larger number of apoptotic cells in the brown fat of obese (fa/fa) than in that of lean (+/+) Zucker rats. The exposure of obese rats to low temperatures for 7 days, which increases the sympathetic activity of brown adipose tissue, significantly reduces the number of apoptotic brown adipocytes. We hypothesize that TNF-alpha may play a significant role in the control of brown fat homeostasis.

Human parvovirus B19 experimental infection in human fibroblasts and endothelial cells cultures

With the aim to detect what kind of cells, in addition to erythroid progenitors, could be involved in the pathogenesis of B19 infection in some connective tissue diseases, primary cultures of human fibroblasts (HF) and endothelial cells (HUVEC) were exposed to a B19 positive serum (350 genome copies/cell). The presence of NS1 and VP1 mRNA, in both HF and HUVEC cultures 1, 2 and 6 days after the exposure, indicated infection by B19 virus. However, no significant increase of B19 DNA level in the infected HF and HUVEC cultures was detectable through the entire incubation period of 6 days. It is possible that HF and HUVEC are not permissive for B19 virus replication or, alternatively, that few cells only get infected by B19 virus. HF and HUVEC stimulation with different growth factors or cytokines could be required for a B19 productive infection to occur.

Gland cell cultures into 3D hyaluronan-based scaffolds

In this study we report a preliminary investigation of the feasibility of non-woven/sponge fabrics of a hyaluronan derived biomaterials (benzyl ester of HA (HYAFF-11 FAB, Abano Terme, Italy) for the in vitro culture of rat hepatocytes and rat beta cells. Cell growth on hyaluronan derived biomaterials were tested in the presence of complete medium and in the presence of ECM (extracellular matrix) secreted by fibroblasts previously cultured into the scaffold. Hepatocytes and beta cells were extracted from rat liver/pancreas and seeded either on the HYAFF-11 scaffold alone, or on HYAFF-11 scaffold containing ECM. Direct assay of cell proliferation was performed with MTT test. For morphological observations samples were stained with hematoxylin and eosin. The results obtained by MTT test showed that hepatocytes cultivated in both the above described conditions were able to proliferate up to 14 days and Langerhans islet up to 21 days. After this time, cells started to undergo apoptosis. The morphological analyses showed cell aggregation in three-dimensional structures promoted by the fibers of the biomaterial. Our results confirmed that HYAFF-11 meshes represent a suitable scaffold for hepatocyte adhesion/Langerhans islet organization and proliferation. In particular, the presence of a fibroblast secreted extracellular matrix improves the biological property of the scaffold.

In vitro reconstruction of human dermal equivalent enriched with endothelial cells

Experiences coming from many cell-culture studies has brought about the concept that tissue and organ reconstruction should be performed in a three-dimensional environment as it normally occurs in vivo. As far as endothelial cell culture is concerned, it has been shown that angiogenesis can be successfully achieved only when cells are cultured in the presence of collagen-based matrices or basal membrane substrates. The aim of the present investigation is to demonstrate that human umbilical vein endothelial cells (HUVEC) can be grown and differentiated on an artificial dermis obtained by fibroblasts cultured on hyaluronic acid-based scaffolds. For this purpose, we have cultured HUVEC, retrieved by collagenase digestion of perfused human umbilical vein either alone and with fibroblast at 1/1 ratio into HYAFF-11 non-woven mesh. Cultures were maintained for up to 3 weeks. Samples were taken at different time points within this period for the MTT proliferation test and for immunohistochemical analysis. Our results demonstrate that hyaluronan-based biomaterials (HYAFF-11 NW mesh) represent a suitable substrate for HUVEC adhesion, proliferation and reorganization in microcapillary network.

Changes in FAT/CD36, UCP2, UCP3 and GLUT4 gene expression during lipid infusion in rat skeletal and heart muscle

OBJECTIVE

It has been reported that an increased availability of free fatty acids (NEFA) not only interferes with glucose utilization in insulin-dependent tissues, but may also result in an uncoupling effect of heart metabolism. We aimed therefore to investigate the effect of an increased availability of NEFA on gene expression of proteins involved in transmembrane fatty acid (FAT/CD36) and glucose (GLUT4) transport and of the uncoupling proteins UCP2 and 3 at the heart and skeletal muscle level.

STUDY DESIGN

Euglycemic hyperinsulinemic clamp was performed after 24 h Intralipid(R) plus heparin or saline infusion in lean Zucker rats. Skeletal and heart muscle glucose utilization was calculated by 2-deoxy-[1-(3)H]-D-glucose technique. Quantification of FAT/CD36, GLUT4, UCP2 and UCP3 mRNAs was obtained by Northern blot analysis or RT-PCR.

RESULTS

In Intralipid(R) plus heparin infused animals a significant decrease in insulin-mediated glucose uptake was observed both in the heart (22.62+/-2.04 vs 10.37+/-2.33 ng/mg/min; P<0.01) and in soleus muscle (13.46+/-1.53 vs 6.84+/-2.58 ng/mg/min; P<0.05). FAT/CD36 mRNA was significantly increased in skeletal muscle tissue (+117.4+/-16.3%, P<0.05), while no differences were found at the heart level in respect to saline infused rats. A clear decrease of GLUT4 mRNA was observed in both tissues. The 24 h infusion of fat emulsion resulted in a clear enhancement of UCP2 and UCP3 mRNA levels in the heart (99.5+/-15.3 and 80+/-4%) and in the skeletal muscle (291.5+/-24.7 and 146.9+/-12.7%).

CONCLUSIONS

As a result of the increased availability of NEFA, FAT/CD36 gene expression increases in skeletal muscle, but not at the heart level. The augmented lipid fuel supply is responsible for the depression of insulin-mediated glucose transport and for the increase of UCP2 and 3 gene expression in both skeletal and heart muscle.

Preferential channeling of energy fuels toward fat rather than muscle during high free fatty acid availability in rats

The preferential channeling of different fuels to fat and changes in the transcription profile of adipose tissue and skeletal muscle are poorly understood processes involved in the pathogenesis of obesity and insulin resistance. Carbohydrate and lipid metabolism may play relevant roles in this context. Freely moving lean Zucker rats received 3- and 24-h infusions of Intralipid (Pharmacia and Upjohn, Milan, Italy) plus heparin, or saline plus heparin, to evaluate how an increase in free fatty acids (nonesterified fatty acid [NEFA]) modulates fat tissue and skeletal muscle gene expression and thus influences fuel partitioning. Glucose uptake was determined in various tissues at the end of the infusion period by means of the 2-deoxy-[1-3H]-D-glucose technique after a euglycemic-hyperinsulinemic clamp: high NEFA levels markedly decreased insulin-mediated glucose uptake in red fiber-type muscles but enhanced glucose utilization in visceral fat. Using reverse transcriptase-polymerase chain reaction and Northern blotting analyses, the mRNA expression of fatty acid translocase (FAT)/CD36, GLUT4, tumor necrosis factor (TNF)-alpha, peroxisome proliferator-activated receptor (PPAR)-gamma, leptin, uncoupling protein (UCP)-2, and UCP-3 was investigated in different fat depots and skeletal muscles before and after the study infusions. GLUT4 mRNA levels significantly decreased (by approximately 25%) in red fiber-type muscle (soleus) and increased (by approximately 45%) in visceral adipose tissue. Furthermore, there were marked increases in FAT/CD36, TNF-alpha, PPAR-gamma, leptin, UCP2, and UCP3 mRNA levels in the visceral fat and muscle of the treated animals in comparison with those measured in the saline-treated animals. These data suggest that the in vivo gene expression of FAT/CD36, GLUT4, TNF-alpha, PPAR-gamma, leptin, UCP2, and UCP3 in visceral fat and red fiber-type muscle are differently regulated by circulating lipids and that selective insulin resistance seems to favor, at least in part, a prevention of fat accumulation in tissues not primarily destined for fat storage, thus contributing to increased adiposity and the development of a prediabetic syndrome.

Expression and distribution of heme oxygenase-1 and -2 in rat brown adipose tissue: the modulatory role of the noradrenergic system

To investigate whether brown adipose tissue (BAT) expresses the inducible (HO-1) and the constitutive (HO-2) isoform of heme oxygenase, reverse transcriptase-polymerase chain reaction, Western blotting and immunohistochemistry were performed on interscapular BAT (IBAT) from rats acclimated at environmental temperature or exposed to cold. Both HO isoforms were detected in rat IBAT. They were immunolocalized in the cytoplasm and/or nuclei of brown adipocytes, in parenchymal capillaries, arteries and in some veins and nerves. Whereas cold exposure did not affect HO-2 expression, it significantly increased the expression of HO-1, both at mRNA (about 3-fold) and protein (about 2-fold) levels, reflecting the increased expression of HO-1 in the brown adipocytes and endothelial cells of parenchymal capillaries. Western blotting of cytosolic and nuclear protein extracts from cultured differentiated brown adipocytes showed that HO-1 and HO-2 are indeed localized in the cytosol and nuclei of brown adipocytes, and that noradrenaline stimulation significantly increased their amount in cytosol but not in the nuclear fraction.

Use of dermal-like tissue in the management of chronic and acute full-thickness cutaneous wounds

This paper presents a dermal replacement technique for cutaneous wounds of diverse origin. An autologous tissue-engineered dermal-like structure was implanted in one patient with an acute surgical excision of a nevus and in another patient with a chronic post-traumatic ulcer. The dermal constructs were well integrated with the wound area, and, at 3 weeks, an epidermal covering was implanted. In both cases, 3 to 8 weeks after autografting, good integration of the transplanted epidermis with the surrounding native skin and a good take over the dermal-like tissue occurred. The use of this technology, despite its high cost, is increasing. Clinicians choose it because it helps heal critical wounds for which current therapies have failed.

Tumor necrosis factor alpha mediates apoptosis of brown adipocytes and defective brown adipocyte function in obesity

Severe quantitative and qualitative brown adipocyte defects are common in obesity. To investigate whether aberrant expression of tumor necrosis factor alpha (TNF-alpha) in obesity is involved in functional brown fat atrophy, we have studied genetically obese (ob/ob) mice with targeted null mutations in the genes encoding the two TNF receptors. The absence of both TNF receptors or p55 receptor alone resulted in a significant reduction in brown adipocyte apoptosis and an increase in beta(3)-adrenoreceptor and uncoupling protein-1 expression in obese mice. Increased numbers of multilocular functionally active brown adipocytes, and improved thermoregulation was also observed in obese animals lacking TNF-alpha function. These results indicate that TNF-alpha plays an important role in multiple aspects of brown adipose tissue biology and mediates the abnormalities that occur at this site in obesity.

Induction of fatty acid translocase/CD36, peroxisome proliferator-activated receptor-gamma2, leptin, uncoupling proteins 2 and 3, and tumor necrosis factor-alpha gene expression in human subcutaneous fat by lipid infusion

Little is known about the mechanisms involved in the preferential channeling of different fuels to fat and how the target tissue participates in this process. Dietary fatty acids have been shown to act as signaling molecules that bind and activate a new class of nuclear receptors, the peroxisome proliferator-activated receptors (PPARs). PPAR-gamma is particularly interesting because it may have the potential to link particular fatty acids with a program of gene expression involved in lipid storage and metabolism. We investigated whether a nutrient-sensing pathway is activated by an increased availability of lipid fuels in nine normal weight male volunteers. Using reverse transcriptase-polymerase chain reaction analysis, the mRNA expression of fatty acid translocase (FAT)/CD36, PPAR-gamma2, leptin, uncoupling protein (UCP)-2 and UCP-3, and tumor necrosis factor (TNF)-alpha was investigated in gluteal subcutaneous fat biopsies before and after 5 h infusions of saline or Intralipid (Pharmacia and Upjohn, Milan, Italy) plus heparin, which does not modify insulinemia. Marked increases in FAT/CD36 (724+/-18%; P < 0.05), PPAR-gamma2 (200+/-8%; P < 0.05), leptin (110+/-13%; P < 0.05), UCP-2 (120+/-7%; P < 0.05), UCP-3 (80+/-5%; P < 0.05), and TNF-alpha mRNA (130+/-12%; P < 0.05) were observed in comparison with pretreatment levels, whereas there was no change after saline infusion. These data suggest that the in vivo gene expression of FAT/CD36, PPAR-gamma2, leptin, UCP-2, UCP-3, and TNF-alpha in subcutaneous adipose tissue is regulated by circulating lipids independent of insulin and that prolonged hyperlipidemia may therefore contribute to increased fat metabolism and storage as a result of the increased expression of these proteins.

Purification and characterization of a humoral opsonin, with specificity for D-galactose, in the colonial ascidian Botryllus schlosseri

A humoral agglutinin from the hemolysate of the colonial ascidian Botryllus schlosseri was purified by affinity chromatography. This agglutinin does not require metal cations for its activity and is specific for derivatives of D-galactose. On SDS-PAGE analysis, it was resolved in two bands, of 17 and 19 kDa in reducing conditions and 15 and 16 kDa in non-reducing conditions. This behavior is due to the establishment of disulfide bridge between the thiols of cysteine, well represented in the molecule as revealed by amino acid analysis. The latter also indicated high percentages of hydrophilic residues, probably involved in sugar recognition. The lectin is an opsonin, as it increases both the phagocytic index and the number of phagocytized yeast cells. The hypothesis that this Botryllus agglutinin belongs to the galectin family of lectins is discussed.

[Surgical therapy of right colon cancer]

The debate about the management of frequent advanced right colon cancer is still opened: the opportunity of extended resections when the surrounding organs or tissues are infiltrated, the lymphadenectomy extension and its role, the possibility of identifying prognostic factors that could be useful to decide adjuvant therapy, the definition of the role of laparoscopy. Considering these problems, we have reviewed a series of 159 operations performed by the Institute of Clinical Surgery of the University of Trieste from 1980. 112 of these operations had a curative goal. The reconstruction of intestinal continuity was carried out manually in 28 cases and with mechanical stapler in 78. As far as the curative resection are concerned, in 89 of them an extended lymphadenectomy was performed (D3), while in 18 cases the lymphadenectomy was limited to the lymph nodes of first and second level due to the general bed conditions of the patient. 27 of the curative exeresis were performed in patients with T4 tumor infiltrating the nearby tissues. Referring to Dukes' classification, 8 were included in stage A, 59 in stage B and 40 in stage C, while as far as the depth of wall infiltration is concerned 2 were categorized as T1, 9 as T2, 69 as T3 and 27 as T4. The overall operative mortality was of 5 patients, the overall morbidity of 14%, that specific of 4.6%. The final incidence of local recurrences was 13.8% for Dukes A cancers, 10.9% for Dukes B and 120.5% for Dukes C (p = 0.0614). Half of the recurrences (50%) occurred in patients with a cancer infiltrating the nearby tissues. The 5 year survival rate for patients with Dukes A lesions was 100%, for patients with Dukes B lesions 73.4% and for Dukes C 52.3% (p = 0.00510). With Cox' multivariate analysis only the stage disease, T and grading showed a significative correlation with the survival rate. Our experience, therefore, suggests the execution of an exeresis with lymphadenectomy D3 in each cases where the local site of the lesion and the general conditions of the patients allow it and an extended exeresis where possible from a technical point of view and when the lymph nodes are involved.

Role of sympathetic activity in controlling the expression of vascular endothelial growth factor in brown fat cells of lean and genetically obese rats

The thermogenic activity of brown adipose tissue (BAT) is heavily dependent on high perfusion, through its dense vascular system. Angiogenesis must go hand-in-hand with BAT functions, but little is known about the factors controlling it. In the present study we demonstrate that: (a) vascular endothelial growth factor (VEGF) is synthesised and released in brown adipocytes in culture; (b) VEGF mRNA isoforms and protein appear in dispersed mature brown adipocytes and whole tissue; (c) VEGF expression is increased in BAT from cold-exposed rats, and in cultured brown adipocytes exposed to noradrenaline and the beta3-adrenoceptor agonists; (e) BAT from genetically obese (falfa) rats exhibits reduced expression of VEGF as well as a change in the ratio of mRNA isoforms. It is concluded that sympathetic control of VEGF expression via noradrenaline acting on beta3-adrenoceptors plays a major role in developmental and adaptive angiogenesis, and defects in this contribute to the reduced thermogenic capacity of BAT in genetic obesity.

Effects of nitric oxide on proliferation and differentiation of rat brown adipocytes in primary cultures

1. In the present work, we study the effect of NO on the proliferation and differentiation of brown fat cells in primary cultures. 2. Brown fat precursor cells isolated from rat brown adipose tissue were cultured for 8 days until confluence and treated daily with the NO donating agents, S-nitroso-acetyl penicillamine (SNAP) or S-nitroso-L-glutathione (GSNO). Both agents (300 microM) decreased cell proliferation approximately 8 fold on day 8. The inhibitory effect of NO was unlikely to be due to cytotoxicity since (i) cells never completely lost their proliferation capacity even after 8 days of exposure to repeated additions of SNAP or GSNO, and (ii) the inhibitory effect was reversible after removal of the media containing NO donors. 3. Daily treatment with nitric oxide synthase inhibitors, such as NG-nitro-L-arginine methyl ester (L-NAME, 300 microM), led to the stimulation of cell proliferation by 44+/-5%, n=3, suggesting that NO, endogenously produced in brown adipocytes, may be involved in modulating cell growth. 4. Daily treatment with both SNAP or GSNO induced significant mitochondriogenesis, measured as the mitochondrial conversion of 3-[4,5-dimethylthiazol-2-yl-]-2,5-diphenyl tetrazolium bromide (MTT) to formazan, whilst daily treatment with L-NAME was without effect. 5. The inhibition of cell proliferation by NO donors was accompanied by the expression of two genes coding for peroxisome proliferator activated receptor-gamma and uncoupling protein-1, which are upregulated during differentiation. 6. Increasing cyclic GMP in cells by 8-bromo-cyclic GMP (100-1000 microM) did not reproduce the observed NO effects on either cell number or gene expression. On the other hand, chronic treatment with the inhibitor of the NO-stimulated guanylyl cyclase, 1H-[1,2,4]oxadiazole[4,3-a]quinoxalin-1-one (ODQ), reduced the expression of peroxisome proliferator activated receptor-gamma and uncoupling protein-1.

[Extended resection in locally advanced colon cancer]

Colorectal malignant tumors with a mono o multivisceral involvement have a poor prognosis and surgery is the only treatment with a hope to be curative. Aggressive surgical management of locally advanced colo-rectal cancer seems to be justified by good oncological results. At the Institute of Clinica Chirurgica of the University of Trieste 58 extended resections were performed for advanced tumors of colon and rectum. The specific morbidity rate was 24% for standard and 24.1% for extended resections. Operative morality was 15.2%; hystological specimen confirmed in 31 cases neoplastic infiltration of contigous structures. The 5 year survival rate was 38.5% in right colonic tumors and 53.3% in left colonic tumors. The literature favors an aggressive approach when the tumor adhesions are suspected. The excision of adjacent organs, whether or not they are microscopically involved by the tumor, is necessary to avoid leaving potentially curable disease The authors, analyzing their results, have also reported good results by management including resection of the colon and contigous organs if involved. Palliative therapy must be performed only if liver metastases are detected or in those cases when primary resection is not thecnically feable or in patients not able to tolerate the procedure.

Bcl-2 and Bax are involved in the sympathetic protection of brown adipocytes from obesity-linked apoptosis

Obesity is linked to functional brown adipose tissue (BAT) atrophy, partially due to adipocyte apoptosis. The brown adipocytes of obese rats have lower Bcl-2/Bax mRNA and protein ratios than those of their lean littermates. Exposure to a low temperature for three days markedly increased the Bcl-2/Bax ratio, by increasing the noradrenergic output to BAT, which has previously been shown to reduce apoptotic cell death. This effect could be mimicked in vitro by the addition of noradrenaline (NA) to brown adipocytes differentiated in culture. Micromolar NA concentrations increased the Bcl-2/Bax mRNA and protein ratios, and protected against serum deprivation-induced apoptosis. We conclude that NA acts by modulating bcl-2 and bax gene expression.

SR59230A blocks beta3-adrenoceptor-linked modulation of upcoupling protein-1 and leptin in rat brown adipocytes

Experimental evidence suggests that, by stimulating energy expenditure in brown fat, selective beta3-adrenoceptor agonists can reduce body weight in obese rodents. In order to investigate further the physiological role of beta3-adrenoceptors in brown adipocytes, we analysed the effects of selective beta3-adrenoceptor agonists and antagonists on uncoupling protein-1 and leptin gene expression in culture-differentiated brown fat cells. Our main findings were that: (i) the leptin gene is expressed in brown adipocytes; (ii) the selective beta3-adrenoceptor agonist, N[(2S)-7-carbethoxy-1,2,3,4-tetrahydronaphth-2-yl]-(2R)-2-hydroxy- 2-(3-chlorophenil)ethanamine hydrochloride (SR58611A), inhibits leptin gene while inducing uncoupling protein-1 gene expression; (iii) these opposite effects of SR58611A are antagonized by the selective beta3-adrenoceptor antagonist, SS-enantiomer 3-(2-ethylphenoxy)-1-(1S),2,3,4-tetrahydronaphth-1-ylamin ol]-(2S)-2-propanol oxalate (SR59230A), but not by the selective beta1-adrenoceptor antagonist (+/-)-[2-(3-carbamoyl-4-hydroxyphenoxy)-ethylamino]-3-[4(1-methyl- 4-trifluoromethyl-2-imidazolyl)-phenoxy]-2 propanol (CGP20712A); and (iv) these effects are due to increased cyclic AMP levels. These results confirm by means of a different experimental approach that beta3-adrenoceptors play a central role in controlling the expression of genes that are important for brown fat function.

Nerve growth factor, beta3-adrenoceptor and uncoupling protein 1 expression in rat brown fat during postnatal development

An analysis was made of the expression of nerve growth factor (NGF) mRNA and protein in the brown fat of rats at different ages, and the results compared with the expression of beta3-adrenoceptor and uncoupling protein 1 (UCP1). NGF, beta3-adrenoceptor, and UCP1 messenger RNA and protein levels were measured by means of reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting in the brown fat of rats at different ages (from 20-day-old fetuses (E20) to 16-month-old rats). During the perinatal period, NGF production increased and then declined to adult levels (which are comparable with fetal levels) by eight months, and remained stable thereafter. Relatively low levels of NGF were present in the brown fat of aged rats. Taken together, these results suggest that NGF may be responsible for regulating sympathetic innervation during the perinatal and adult periods.

Inducible nitric oxide synthase in rat brown adipocytes: implications for blood flow to brown adipose tissue

Exposure of rat brown adipocytes differentiated in culture to norepinephrine (NE) results in the production of nitrites (NO2-), the breakdown product of nitric oxide (NO). This production, which is blocked by actinomycin D1 is directly related to the duration of exposure to and dose of NE. Cytosol from NE-treated brown fat cells, but not from untreated cultures, catalyzed the Ca(2+)-independent conversion of L-arginine to L-citrulline, which could be significantly blocked by the specific nitric oxide synthase (NOS) inhibitor NG-nitro-L-arginine methyl ester. Reverse transcriptase-PCR demonstrates that the addition of NE; selective beta 1-, beta 2-, or beta 3-adrenergic receptor agonists; or agents increasing cAMP production, such as forskolin, to brown adipocytes stimulates inducible NOS (iNOS) messenger RNA, which is present within 4 h after exposure. That iNOS is synthesized in brown fat cells is confirmed by immunoblotting using an antibody to the iNOS of mouse macrophages, Finally, in both brown adipose tissue (BAT) and brown adipocyte preparations from animals exposed to low temperature, iNOS messenger RNA and protein were expressed, and NOS activity was detectable; these findings were unlikely for room temperature-acclimated rats. We conclude that brown fat cells can express an inducible form of NOS similar to the iNOS of macrophages, and that its production is directly dependent on sympathetic activity in physiological conditions. NO generated by stimulation of iNOS in brown adipocytes may represent an important mechanism to modulate different BAT functions, among which is vasodilation of the BAT microcirculation.

[Evaluation of the surgical risk and preparation to major surgical intervention in geriatric surgery]

BACKGROUND

The progress in surgery, anaesthesia, pre and postoperative care improves the number of old patients undergoing major surgery. The preoperative physiologic assessment is very important to identify patients who are at higher risk group and to plan the therapeutical strategics.

METHODS

This study has been carried out on 849 patients aged 70 years and over who underwent major surgery; biliary tract surgery in 314 cases, colorectal in 279, gastroesophageal in 144, vascular in 48, jejunal in 32, pulmonary in 13, pancreatic in 11, hepatic in 8. 158 patients underwent urgency surgery. Mortality and morbidity index are related to the age of the patients, the urgency of the treatment, the time required for the operation, the preoperative physiologic assessment.

RESULTS

The overall mortality rate was 13.7%: 84 patients died for cardiovascular complications and 32 for pulmonary complications. Mortality rate was 6% after elective surgical treatment and 48% in urgency. The urgency influences considerably the mortality in the group over 80 years than in younger (p < 0.01). The difference in mortality after elective surgery was less significative (p < 0.06). The time required for the operation doesn't influence the mortality rate.

CONCLUSION

The authors emphasize that the preoperative physiologic assessment to identify patients at higher risk and an accurate preoperative care may reduce the mortality rate also in patients over 80 years undergoing major surgery. In urgency, when the patients cannot undergo a preoperative assessment and care, the postoperative mortality is higher in the group over 80 years than in younger.

Expression of nerve growth factor in brown adipose tissue: implications for thermogenesis and obesity

The presence of nerve growth factor (NGF) and the ability of adrenergic stimulation to affect the rate of its synthesis in mouse, rat, and human brown adipose tissue (BAT) were investigated. Addition of conditioned medium, obtained from preconfluent and confluent brown adipocytes, to PC12 cells induced typical morphological changes similar to those due to NGF itself. Anti-NGF antibodies blocked this action. Moreover, NGF mRNA was detected by RT-PCR both in BAT and in brown adipocyte preparations. That NGF is synthesized in and released from brown fat cells was confirmed by immunoblotting. When the animals were exposed to low temperatures, NGF production declined. The effect of cold exposure could be mimicked by the addition of norepinephrine (NE) at day 4 or 8 (preconfluent and confluent cells, respectively). NE depletion obtained by reserpine injection induced a drastic increase of BAT NGF production. In both rat and human BAT, immunohistochemistry identified distinct anatomical structures that express the low affinity neurotropin receptor, termed p75NGFR. BAT production of NGF was higher in genetically obese rats and mice than in their lean counterparts, a difference that becomes more evident with age. Prolonged exposure to low temperature significantly decreased the BAT NGF synthesis also in obese animals. We conclude that NGF is synthesized in and released from brown fat cells, its production being inversely dependent on sympathetic activity, in both physiological and pathophysiological conditions, and increased in genetic animal models of obesity.

Functional studies of the first selective beta 3-adrenergic receptor antagonist SR 59230A in rat brown adipocytes

The SS-enantiomer 3-(2-ethylphenoxy)-1-[(1S)-1,2,3,4-tetrahy dronaphth-1-ylaminol]-(2S)-2-propanol oxalate (SR 59230A) is proposed to be the first beta 3-adrenergic receptor antagonist. The present work shows that SR 59230A, unlike its inactive RR-enantiomer (SR 59483), antagonized a typical beta 3-adrenergic response in vitro, i.e., SR 58611A, the ethyl-[(7s)-7-[[(2R)-2-(3- chlorophenyl)-2-hydroxethyl]amino]-5,6,7,8-tetrahydronaphth- 2- yl]oxyacetate hydrochloride- or (-)-4-(3-t-butylamino-2-hydroxypropoxy)benzimidazol-2-one (CGP 12177)-stimulated synthesis of cAMP in rat brown adipose tissue membranes, with pKB values of 8.87 +/- 0.12 and 8.20 +/- 0.15. In addition, SR 59230A had no antagonistic effect on forskolin-induced cAMP accumulation in rat interscapular brown adipose tissue. SR 59230A, in contrast to the selective beta 1- and beta 2-adrenoceptor antagonists (+/-)[2-(3-carbamoyl-4-hydroxyphenoxy)-ethylamino]- 3-[4(1-methyl-4-trifluoromethyl-2-imidazolyl)-phenoxy]-2 propanol and erythro-(+/-)-1-(7-methylindan-4-yloxy)-3-isopropylaminob utan- 2-ol-hydrochloride did not counteract the cAMP production induced by (-)-isoprenaline or norepinephrine (NE) in rat brain areas rich in beta 1- or beta 2-adrenoceptors, such as frontal cortex and cerebellum. Moreover, in proliferating brown fat cells, in which the beta 1-adrenoceptor is the only beta-adrenergic subtype coupled to cAMP production, SR 59230A did not modify the production of cAMP induced by NE, whereas CGP 12177 did. In confluent brown fat cells, in which the beta 3-adrenoceptor is the functional beta-adrenergic subtype coupled to adenylyl cyclase, SR 59230A antagonized the NE-induced cAMP accumulation and glycerol release without affecting their basal values, whereas CGP 12177, which per se stimulated cAMP accumulation and glycerol release, did not change the NE-induced increase of either parameter. Finally, SR 59230A concentration-dependently counteracted the NE-stimulated synthesis of uncoupling protein gene in confluent brown fat cells, which is considered mainly a result of selective stimulation of beta 3-adrenoceptors. These results provide evidence that the new selective beta 3-adrenoceptor antagonist can contribute considerably to functional characterization of the beta 3-adrenoceptors.

Rat frontal cortex beta 1-adrenoceptors are activated by the beta 3-adrenoceptor agonists SR 58611A and SR 58878A but not by BRL 37344 or ICI 215,001

SR 58611A, a selective agonist of gut and brown adipose tissue beta 3-adrenoceptors (beta 3 ARs), has been reported to have antidepressant-like activity in rodents, by indicating brain beta 3ARs as the sites of this property. SR 58611A and its acid metabolite SR 58878A, as opposed to BRL 37344, ICI 215,001, and CGP 12177, increased cyclic AMP levels in rat frontal cortex. ICI 215,001, differently from BRL 37344, at concentrations in the millimolar range antagonized norepinephrine- or (-)-isoproterenol-stimulated adenylyl cyclase partially. The increase of cyclic AMP levels induced by SR 58878A was blocked selectively by beta 1AR antagonist CGP 20712A but not by beta 2AR antagonist ICI 118,551. In addition, PCR analysis did not reveal beta 3AR mRNA, and no specific beta 3AR binding sites were detected by [3H]CGP 12177 in rat frontal cortex. When down-regulation of the beta 1AR ligand binding and mRNA levels had been induced in frontal cortex by chronic administration of imipramine, SR 58878A as well as norepinephrine and (-)-isoproterenol inceased the cyclic AMP production less markedly. Our findings indicate that beta 3ARs are absent in the adult rat frontal cortex, and that various beta 3AR agonists differently affect the frontal cortex beta 1ARs, indicating that SR 58611A may exert its putative antidepressant effect acting on the frontal cortex beta 1ARS.

Differential relevance of beta-adrenoceptor subtypes in modulating the rat brown adipocytes function

The potencies and intrinsic activities on cyclic AMP accumulation and lipolysis of various selective beta 3-adrenoceptor agonists were studied in brown adipocytes and compared to those of the nonselective, (-)-isoprenaline, and conventional beta 1- (dobutamine) and beta 2-adrenoceptor (salbutamol) agonists. (-)-Isoprenaline, dobutamine and salbutamol were more potent stimulants of lipolysis than of cyclic AMP accumulation, while the selective beta 3-adrenoceptor agonists had similar potencies for these two functions. Apparent pA2 values of the selective beta 1-(CGP20712A) and beta 2-adrenoceptor (ICI118551) antagonist for inhibition of adenylyl cyclase stimulation by (-)-isoprenaline and the beta 3-adrenoceptor agonists, BRL37344, SR58611A, and ICI215001, indicated that (-)-isoprenaline can stimulate the enzyme through a relevant beta 1-adrenergic component, while the other drugs activate the enzyme mainly by acting on the beta 3-adrenoceptors. On the contrary, antagonism of the lipolysis yielded apparent pA2 values for CGP20712A and ICI118551, suggesting that (-)-isoprenaline, like all the beta 3-adrenoceptor agonists, stimulated the brown adipose tissue lipid metabolism mainly through an action on beta 3-adrenoceptors.

SR 58611A: a novel thermogenic beta-adrenoceptor agonist

N(2S)-7-carbethoxymethoxy-1,2,3,4-tetrahydronaphth-2-yl]-(2R )-2-hydroxy-2-(3-chlorophenyl)ethanamine hydrochloride (SR 58611A) increased cyclic AMP levels in membrane homogenates from rat interscapular brown adipose tissue with an EC50 of 20 +/- 2 nM. Substitution of GTP with the GDP analog, guanosine-5'-O[thiodiphosphate], in the incubation medium suppressed the stimulation of adenylyl cyclase activity by SR 58611A. This compound also stimulated glycerol release from the brown fat cells, with an EC50 of 11 +/- 0.4 nM. Only at doses higher than 10 microM did the non-selective beta-adrenoceptor antagonists, propranolol and alprenolol, as well as the selective beta 1- and beta 2-adrenoceptor antagonists, (+-)-[2-(3-carbamoyl-4-hydroxy-phenoxy)- ethylamino]-3-[4(1-methyl-4-trifluoromethyl-2-imidazolyl)-phenoxy]-2 propanol (CGP 20712A) and erythro-(+-)-1-(7-methylindan-4-yloxy)-3-iso-propylamino butan-2-ol-hydrochloride (ICI 118,551), antagonize the SR 58611A-induced stimulation of both adenylyl cyclase activity and lipid metabolism. Since, at high doses, all these beta-adrenoceptor antagonists lack selectivity for beta 1- or beta 2-adrenoceptors, these results suggest that the beta-adrenoceptor agonist, SR 58611A, activates thermogenesis by acting on brown fat cell beta 3-adrenoceptors. This implies that this compound might be useful for treatment of obesity.

[DNA ploidy and cell kinetics in cancer of the rectum]

The pathological assessment of rectal cancer remained essentially unchanged for 50 years and it is based mainly on Dukes' classification and histological granding. Alternative methods of classifications have also been developed but, actually, Dukes'taging is the most important prognostic factor. The limit of Dukes' classification is the incomplete discrimination between high risk and low risk patients into the same stages. The measurements of cellular DNA content by flow cytometry is emerging as a prognostic aid in many human tumours. Authors analyze on the basis of their experience on 116 curative operations for the cancer of the rectum, the relationship between tumour's features, CEA, symptoms, recurrences, survival, type of operation and DNA flow cytometry. In 100 cases they studied the percentage of cells in "s" phase. (SPF). Samples of flow-cytometry were prepared using paraffin-embedded tumour blocks. The authors didn't find any statistically significant relation among pathological features, staging, ploidy and SPF. Recurrences rate was 16.6% in diploid tumours and 23% in no diploid (p = 0.3). In SPF < 25% it was 18.2% (p = 0.5). 5-year survival was worse in aneuploid patients (p = 0.06). Using Cox' multivariate regression analysis, ploidy has not independent prognostic significance. In conclusion authors consider ploidy a prognostic factor in rectal cancer, but not independent. However, authors conclude that flow cytometry could help in early staging of the disease, especially in preoperative diagnosis. Flow cytometry has a prognostic significance with informations on tumoral biology and could contribute to select patients for adjuvant therapy or different surgical techniques.

Neurochemical and behavioral evidence that Ro 41-9067 is a selective presynaptic dopamine receptor agonist

(-)-2,3,4a,5,6,10b-Hexahydro-7-hydroxy-2-methylbenzo(f)-quinoline 4(1H)-ethanol (Ro 41-9067) was compared with apomorphine, 2-amino-6-allyl-5,6,7,8-tetrahydro-4H-thiazolo-[4,5-d]-azepine (B-HT 920), lisuride and other dopamine (DA) receptor agonists in a series of tests designed to characterize its pharmacological activity on DA receptors. In vitro binding studies indicated that Ro 41-9067 bound selectively to DA D2 vs. D1 receptors. It also had a moderate affinity for serotonin1A and alpha-2 adrenergic receptors. Ro 41-9067 exhibited a marked agonistic component for the presynaptic DA autoreceptors. Indeed, it caused a dose-related reduction in locomotor activity over a wide dose range and prolonged periods of observation without stimulating locomotor activity, reflecting postsynaptic DA receptor activation, even at the highest doses. Ro 41-9067 inhibited the gamma-butyrolactone-induced increase in I-dopa accumulation in the rat striatum, an effect sensitive to haloperiodol. Ro 41-9067 inhibited K(+)-induced [3H]DA release and significantly reduced the striatal contents of the DA metabolites, dihydroxyphenilacetic acid and homovanillic acid. Furthermore, the compound counteracted stereotyped behavior and locomotor stimulation induced by amphetamine. Finally, Ro 41-9067 did not appear to act on postsynaptic D2 receptors because it, similarly to B-HT 920 but differently from bromocriptine, quinpirole and lisuride, did not change basal or forskolin-stimulated adenylate cyclase activity. Only at very high concentrations Ro 41-9067 increased adenylate cyclase activity, this effect being due to a D1 agonistic component.(ABSTRACT TRUNCATED AT 250 WORDS)

Biochemical and functional identification of a novel dopamine receptor subtype in rat brown adipose tissue. Its role in modulating sympathetic stimulation-induced thermogenesis

Various dopamine (DA) agonists including propylnorapomorphine, lisuride, bromocriptine, apomorphine and quinpirole were found to reduce adenylate cyclase activity in rat brown adipose tissue homogenates. These inhibitory effects were antagonized, with a very low stereoselectivity, by DA receptor antagonists with the following rank order of potency: haloperidol > (+)-butaclamol > or = (-)-butaclamol >> clozapine > or = (-)-sulpiride > or = (+)-sulpiride > or = eticlopride, but not by the alpha-2 adrenoceptor antagonists, phenoxybenzamine and yohimbine or the serotonin receptor antagonists, ketanserin and metergoline. The selective D1 agonist, fenoldopam, was completely inactive in modifying the basal enzyme activity. DA as well as various DA agonists (lisuride > propylnorapomorphine > bromocriptine > apomorphine > quinpirole) dose-dependently reduced the stimulation of adenylate cyclase activity induced either by forskolin or by the beta adrenoceptor agonist, (-)-isoproterenol. Similar results were obtained also in dispersed brown adipocytes. We also found that DA and various DA receptor agonists induced a significant decrease of beta adrenoceptor-stimulated glycerol and nonesterified fatty acids release from brown adipocytes. This effect was selectively antagonized by haloperidol and butaclamol. Thus, the receptors present on the BAT membranes appear to be dopaminergic in nature although they differ from the classical D2 receptor for the following: 1) the low affinity for the most selective D2, D3 and D4 receptor agonist and antagonist (quinpirole, sulpiride and clozapine); 2) the absence of stereoselectivity for various DA antagonists (butaclamol and sulpiride); and 3) the lack of detectable mRNA encoding D2 or D3 DA receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

Tolerance to hypoactivity and sensitization to hyperactivity after chronic treatment with a presynaptic dose of lisuride in rats

We studied the adaptive changes of the locomotor effects of lisuride, a selective agonist for dopamine (DA) D2 receptors, and the functional state of D1 and D2 receptors after repeated administration of lisuride at a dose supposed to act preferentially on DA autoreceptors. Rats were treated daily with saline or lisuride, at a dose that causes a significant reduction in locomotor activity when given to naive rats (25 micrograms/kg i.p.), for 33 days and the effect of different challenging doses of the drug on locomotor activity was measured at different times during and after the treatment. The functional state of D1 and D2 DA receptors was evaluated by measuring SKF 82526-stimulated and LY 171555-inhibited adenylate cyclase (AC) activity in the caudatus/putamen, nucleus accumbens and substantia nigra and naive and chronically treated rats. There was a progressive decline in the ability of lisuride to decrease locomotor activity in rats given daily injections of lisuride, and there was a marked reduction in the threshold dose of lisuride for causing hypermotility. The functional state of DA receptors, positively or negatively linked to AC activity, was not modified by the treatment. The most suitable explanation of the reported adaptive behavioral changes is a down-regulation of DA autoreceptors after chronic treatment with presynaptic doses of lisuride.

Influence of meal ingestion time on pharmacokinetics of orally administered levodopa in parkinsonian patients

The influence of meal ingestion time on rate and extent of oral levodopa absorption was evaluated in a group of 17 patients, after administration of their usual second daily dose of levodopa plus carbidopa (Sinemet 10:1) or benserazide (Madopar 4:1). Standard meals were consumed by the patients after they had fasted 15-17 h, on one occasion 30 min before ingestion of the levodopa "study dose" and, at another time, 2 h after ingestion of the same dose. This study dose, ranging from 50 to 250 mg levodopa, was given to the patients at 11 a.m., 4 h after their first morning dose. Time to peak plasma levodopa concentration increased threefold (from 45 +/- 23 to 134 +/- 76 min, p less than 0.001), when levodopa was administered after meals. Area under the 6-h plasma concentration-time curve for levodopa was decreased in 10 subjects, unchanged in three and higher in four after ingestion of meals, the latter finding probably resulting from an erratic absorption even at fasting. On the whole, levodopa absorption proved significantly lower (p less than 0.01), on the average 15%. Similarly, peak plasma levodopa concentrations were lower in 12 patients, unchanged in two, and higher in three, with an overall significant decrease (p less than 0.001) of 30% on the average. The data confirm the importance of meal ingestion time in relation to levodopa dose as a determinant of drug absorption.