The L-3,4-dihydroxyphenylalanine transporter in human and rat epithelial intestinal cells is a type 2 hetero amino acid exchanger

Information on the intestinal transport of L-3,4-dihydroxyphenylalanine (L-DOPA) is scarce. We present here the functional characteristics and regulation of the apical inward L-DOPA transport in two intestinal epithelial cell lines (human Caco-2 and rat IEC-6). The inward transfer of L-DOPA and L-leucine was promoted through an energy-driven system but with different sensitivity to extracellular Na(+) concentration: a minor component of L-leucine uptake (approximately 25%) was found to require extracellular Na(+) in comparison with L-DOPA transport which was Na(+)-independent. L-DOPA and L-leucine uptake was insensitive to N-(methylamino)-isobutyric acid, but competitively inhibited by 2-aminobicyclo(2,2,1)-heptane-2-carboxylic acid (BCH). L- and D-neutral amino acids, but not acidic and basic amino acids, markedly inhibited L-DOPA and [(14)C]L-leucine accumulation in both cell lines. The [(14)C]L-DOPA and [14C]L-leucine outward were markedly increased by L-leucine and BCH present in extracellular medium, but not by L-arginine. In both cell lines, L-DOPA transport was stimulated by acidic pH in comparison with [(14)C]L-leucine inward which was pH-independent. In conclusion, it is likely that system B(0) might be responsible for the Na(+)-dependent uptake of L-leucine in Caco-2 and IEC-6 cells, whereas sodium-independent uptake of L-leucine and L-DOPA may include system type 1 and type 2 L-amino acid transporter (LAT1 and LAT2), the activation of which results in trans-stimulation of substrates outward transfer.     

Synthesis and evaluation of analogues of 5'-([(Z)-4-amino-2-butenyl]methylamino)-5'-deoxyadenosine as inhibitors of tumor cell growth,trypanosomal growth,and HIV-1 infectivity

A well-defined series of 5'-([(Z)-4-amino-2-butenyl]methylamino)-5'-deoxyadenosine analogues was designed and synthesized in order to further ascertain the optimal structural requirements for S-adenosylmethionine decarboxylase inhibition and potentially to augment and perhaps separate their antiproliferative and antitrypanosomal activities. Most structural modifications had a deleterious affect on both the antitrypanosomal and antineoplastic activity of 5'-([(Z)-4-amino-2-butenyl]methylamino)-5'-deoxyadenosine. However, di-O-acetylation of the parent compound produced a potential prodrug that caused markedly pronounced inhibition of trypanosomal and neoplastic cell growth and viability. Moreover, the acetylated derivative of 5'-([(Z)-4-amino-2-butenyl]methylamino)-5'-deoxyadenosine did inhibit HIV-1 growth and infectivity, whereas the parent compound did not.     

Aging and intestinal motility: a review of factors that affect intestinal motility in the aged

Normal aging is associated with significant changes in the function of most organs and tissues. In this regard, the gastrointestinal tract is no exception. The purpose of this review is to detail the important age-related changes in motor function of the various parts of the gastrointestinal tract and to highlight some of the important motility changes that may occur, either in relation to common age-related disorders, or as a result of certain drugs commonly prescribed in the aged. A major confounding factor in the interpretation of motor phenomena throughout the gastrointestinal tract in this age group is the frequent coexistence of neurological, endocrinological and other disease states, which may be independently associated with dysmotility. Overall, current data are insufficient to implicate normal aging as a cause of dysmotility in the elderly. Normal aging is associated with various changes in gastrointestinal motility, but the clinical significance of such changes remains unclear. More important is the impact of various age-related diseases on gastrointestinal motility in the elderly: for example, long-standing diabetes mellitus may reduce gastric emptying in up to 50% of patients; depression significantly prolongs whole-gut transit time; hypothyroidism may prolong oro-caecal transit time; and chronic renal failure is associated with impaired gastric emptying. In addition, various, frequently used drugs in the elderly cause disordered gastrointestinal motility. These drugs include anticholinergics, especially antidepressants with an anticholinergic effect, opioid analgesics and calcium antagonists.     

Neodymium YAG contact laser in the treatment of cancer of the mobile tongue

The aim of this study was to evaluate the usefulness of a contact neodymium YAG laser for the treatment of squamous cell carcinoma (SCC) of the mobile tongue in 35 patients. The TNM stage and histologic grade were as follows: T1, n = 20; T2, n = 11; T3, n = 4; and N0, n = 33; N1, n = 2; G1, n = 20; G2, n = 10; and G3, n = 5. The surgical treatment consisted of a hemiglossectomy or resection with adequate margins in 28 cases, and an ipsilateral neck dissection was also performed in 7 patients. Radiotherapy to a mean tumor dose of 62-64 Gy and an elective dose of 50 Gy to the cervical lymph nodes was given to 14 patients. The radiotherapy was preoperative in 12 patients and postoperative in 2. Tongue resection was easily performed using the contact neodymium YAG laser, with a mean operation time of 31 min and intraoperative bleeding varying from negligible to 100 cm3. During postoperative follow-up no major complications occurred: cases with minor hemorrhage were easily controlled on the ward and 1 patient had a bleed on the 14th postoperative day necessitating hospitalization. The resection was histologically radical in all cases. During follow-up one patient had a local recurrence (T2N0, G3) and four failed in the neck (T1N0 G2, T1N0 G2, T1N0 G2, T2N0 G2), three of whom were successfully salvaged with a neck dissection and radiotherapy. One patient with osteoradionecrosis was diagnosed and treated curatively. Two patients died of their tongue cancer (T2N0 G3, T2N0 G2), 1 died from a second primary tumor (T2N0 G1) and 2 of intercurrent disease with no evidence of cancer; 30 patients (86%) are still alive with no evidence of disease. The function of the tongue in all patients in this sample was good to satisfactory. The major complaint was xerostomia in the irradiated patients. In conclusion, the contact neodymium YAG laser appears to be suitable for resection of T1-T2 SCCs of the oral tongue. In this limited patient sample T stage or grade did not predict failures in the neck. Biologic predictive markers need to be evaluated.     

Behavioral avoidance test for childhood obsessive-compulsive disorder: a home-based observation

Obsessive-compulsive disorder (OCD) is one of the most debilitating of the anxiety disorders. As our knowledge about this childhood condition continues to grow, there is a need for controlled treatment-outcome trials with precise assessments that are sensitive to treatment change, to guide the development of effective interventions. To evaluate the efficacy of a treatment protocol, it is necessary to have reliable and sensitive measures of OCD symptoms, including measures of obsessions, compulsions, and related levels of distress and avoidance. Whilst structured diagnostic interviews, semistructured clinical interviews, and self-report measures have been widely used in the assessment of childhood OCD, related levels of behavioral distress and avoidance have not been measured in treatment-outcome trials. This study investigated the sensitivity of a behavioral avoidance test (BAT), conducted in the home environment, in assessing treatment-outcome effects for children and adolescents with OCD following a 14-week cognitive-behavioral therapy (CBT) family intervention, in comparison to children in an 8-week "waitlist" control group. The results of the current study strongly support the sensitivity of a standardized BAT in assessing treatment-related changes in children and adolescents with OCD. Implications and future directions for research are discussed.     

Diagnostic concordance of ICD-10 personality and comorbid disorders: a comparison of standard clinical assessment and structured interviews in a clinical setting

OBJECTIVE: The diagnosis of personality disorders is one of the most problematic areas in psychiatric diagnosis. Diagnoses are usually made by standard clinical interview, but they have poor reliability. The aim of this study was to compare the concordance in diagnosis between structured assessment tools and assessment as usual in a clinical setting. METHOD: Diagnosis of 33 patients on the International Personality Disorder Examination (IPDE) and the Mini International Neuropsychiatric Interview (MINI) was compared to diagnosis made by standard assessment through clinical interview. RESULTS: There was poor concordance between structured measures and standard assessment by clinical interview, and poor levels of diagnostic sensitivity and specificity on standard assessment. CONCLUSION: Structured measures were more comprehensive, sensitive and specific in diagnosis than standard clinical assessment. Increased diagnostic accuracy is needed for effective understanding and treatment planning for personality disorders.     

Myopathy of distal lower limbs: the clinical variant of Miyoshi

Miyoshi distal dystrophy is a rare myopathy characterized by an autosomal recessive pattern of inheritance and it is prevalent in Japan. Onset of disease is in early adult life with weakness and atrophy of the leg muscles. Recently gene linkage to chromosome 2p12-14 has been established. We report three sisters, born of consanguineous parents. All of them noticed weakness and atrophy of leg muscles, and could not walk on their heels. In all of them the creatine kinase concentrations were very high. The electromyography showed myopathic patterns and the muscle biopsy disclosed dystrophic changes and an absence of dysferlin. There are few cases reported of Miyoshi distal dystrophy in Latin America. The Miyoshi myopathy may be distinct among the hereditary distal myopathies.     

Hypobaric hypoxia modifies constitutive nitric oxide synthase activity and protein nitration in the rat cerebellum

Ischemic hypoxia provokes alterations in the production system of nitric oxide in the cerebellum. We hypothesize that the nitric oxide system may undergo modifications due to hypobaric hypoxia and that may play a role in high altitude pathophysiology. Therefore, changes in the nitric oxide system of the cerebellum of rats submitted to acute hypobaric hypoxia were investigated. Adult rats were exposed for 7 h to a simulated altitude of 8235 m (27000 ft.) and then killed after 0 h or 1, 3, 5 and 10 days of reoxygenation. Nitric oxide synthase calcium-dependent and -independent activity, immunoblotting and immunohistochemistry of neuronal, endothelial, and inducible nitric oxide synthase, and nitrotyrosine were evaluated. Immunoreactivity for neuronal nitric oxide synthase slightly increased in the baskets of the Purkinje cell layer and in the granule cells, after 0 h of reoxygenation, although no changes in neuronal nitric oxide synthase immunoblotting densitometry were detected. Calcium-dependent activity significantly rose after 0 h of reoxygenation, reaching control levels in the following points, and being coincident with a peak of eNOS expression. Nitrotyrosine formation showed significant increments after 0 h and 1 day of reoxygenation. Nitrotyrosine immunoreactivity showed an intracellular location change in the neurons of the cerebellar nuclei and in addition, an appearance of nitration in the soma of the Purkinje cells was detected. No changes in inducible nitric oxide synthase activity, immunoblotting or immunohistochemistry were detected. We conclude that at least part of the nitric oxide system is involved in cerebellum responses to hypobaric hypoxia.