Ornithine transcarbamylase deficiency: neonatal diagnostic

OBJECTIVE: To drive pediatrician's attention to a urea cycle enzyme deficiency. The prognosis is directly related to the early diagnosis and treatment. METHODS: We describe a newborn patient who present lethargy, vomitus and seizures 48 hours afther birth. We investigated this patient and the diagnosis of ornithine transcarbamylase deficiency was made. Treatment was started immediately. RESULTS: We followed the patient until he was 1 year old, when he had liver transplant with a good outcome of the disease. CONCLUSION: The ornithine transcarbamylase deficiency is a rare and very serious disease. Any newborn whose evolution is similar to that of a septic patient without any infection must be investigated for this disease. The prognosis is directly related to the early diagnosis and treatment.     

The surgical risk in sleep apnea: the implications for tonsillectomies

Hypertrophy of tonsils or adenoids is the commonest cause of obstructive sleep apnea (OSA) in children. Adenotonsillectomy (AT) is frequently curative in children with OSA but riskier than the same procedure without OSA. It is crucial to identify OSA among the patients programmed for AT because they require a detailed evaluation, frequently including total or limited polysomnogram. Patients with OSA need a continuous surveillance before, during, and after surgery, ideally in a referral hospital.     

The salivary amylase, lactate and electromyographic response to exercise

Twelve trained young males (age: 24 +/- 5 years) performed an incremental test to exhaustion during which capillary blood and saliva samples were obtained to determine the blood lactate (LT) and salivary amylase (T(sa)) thresholds. The root mean-square voltage of electromyographic activity (rms-EMG) of the vastus lateralis muscle was also recorded to detect the electromyographic threshold (EMG(T)). No significant difference was found between the exercise intensity corresponding to the LT, T(sa) or EMG(T).     

Clinicopathological characteristics of breast carcinomas with allelic loss in the p73

p73, a new member of the p53 family, has been mapped to chromosome 1p36, a region where loss of heterozygosity (LOH) is frequently observed in primary human tumors. Allelic loss studies involving the 1parm in breast carcinomas offer rates ranging from 13% to 75%, depending on the genetic interval being studied. We investigated LOH in an intragenic microsatellite marker, and those centromerically flanking the p73 gene, at 1p36, and their correlations with patient age and 10 pathologic parameters in a series of 193 breast carcinomas. The LOH analysis was performed by amplifying DNA by PCR, using five markers of the 1p36 region (p73P1, D1S2694, D1S214, D1S2666 and D1S450). LOH was found in at least one of these markers in 27% of tumors. When we established the comparison between tumors with and without LOH and the distribution of the 10 pathologic parameters considered, we observed statistically significant differences in association with higher histologic grade (p=0.02), more advanced pathological stage (p=0.02), peritumoral vessel involvement (p=0.04) and poorly differentiated carcinomas (p=0.01), as well as in tumors that concomitantly exhibited lymph node metastases, peritumoral vessel involvement and absence of steroid receptors (p=0.02). These data suggest that LOH in the p73 region could be pathogenically related to breast cancer and possibly to a poor tumor prognosis.     

An evaluation of tissue polypeptide antigen (TPA) in the two bronchoalveolar lavage fractions of lung cancer patients

BACKGROUND: It has been proven that cytokeratins (CKs) are useful tumor markers for the follow-up, treatment monitoring and prognosis evaluation of lung cancer and among these, tissue polypeptide antigen (TPA) plays an important role. Nevertheless, only a small number of studies have been reported about their diagnostic capacity. Bronchoalveolar lavage (BAL) can be divided into two fractions: bronchiolar (BF) and alveolar (AF). For the above reasons, our aims were (1) to analyze the diagnostic usefulness of TPA in the BAL of lung cancer patients and (2) to observe if, in lung cancer patients, TPA levels in the two BAL fractions are different. This should mean that the study of tumor markers in the BAL should be carried out in both fractions to increase their diagnostic capacity. METHODS: We studied 289 BALs divided into two phases. In phase I, TPA was analyzed in the BAL of six groups of subjects (healthy persons, chronic bronchitis, asthma, respiratory infections, diffuse interstitial pulmonary diseases and lung cancer). In phase II, TPA was studied in both BAL fractions of a group of patients with lung cancer. RESULTS: We observed that TPA levels were significantly higher in the BAL of patients with bronchogenic neoplasias. In these patients, TPA was increased in the BF of the lavage in relation to the AF. In smoker patients with pulmonary carcinomas, TPA was higher in the AF of the BAL than in the lavage of non-smokers. This did not occur in the BF. We found no relation between the TPA concentrations and cancer histology. CONCLUSIONS: We believe that TPA is a useful tumor marker with diagnostic capacity and this capacity is increased when it is studied in the two BAL fractions. Smoking habit may play a role in the secretion of tumor markers by the tumor cells.     

Molecular Mechanisms of the Inhibitory Effects of Propofol and Thiamylal on Sarcolemmal Adenosine Triphosphate-sensitive Potassium Channels

Background: Both propofol and thiamylal inhibit adenosine triphosphate-sensitive potassium (KATP) channels. In the current study, the authors investigated the effects of these anesthetics on the activity of recombinant sarcolemmal KATP channels encoded by inwardly rectifying potassium channel (Kir6.1 or Kir6.2) genes and sulfonylurea receptor (SUR1, SUR2A, or SUR2B) genes.

Methods: The authors used inside-out patch clamp configurations to investigate the effects of propofol and thiamylal on the activity of recombinant KATP channels using COS-7 cells transfected with various types of KATP channel subunits.

Results: Propofol inhibited the activities of the SUR1/Kir6.2 (EC50 = 77 [mu]m), SUR2A/Kir6.2 (EC50 = 72 [mu]m), and SUR2B/Kir6.2 (EC50 = 71 [mu]m) channels but had no significant effects on the SUR2B/Kir6.1 channels. Propofol inhibited the truncated isoform of Kir6.2 (Kir6.2[DELTA]C36) channels (EC50 = 78 [mu]m) that can form functional KATP channels in the absence of SUR molecules. Furthermore, the authors identified two distinct mutations R31E (arginine residue at position 31 to glutamic acid) and K185Q (lysine residue at position 185 to glutamine) of the Kir6.2[DELTA]C36 channel that significantly reduce the inhibition of propofol. In contrast, thiamylal inhibited the SUR1/Kir6.2 (EC50 = 541 [mu]m), SUR2A/Kir6.2 (EC50 = 248 [mu]m), SUR2B/Kir6.2 (EC50 = 183 [mu]m), SUR2B/Kir6.1 (EC50 = 170 [mu]m), and Kir6.2[DELTA]C36 channels (EC50 = 719 [mu]m). None of the mutants significantly affects the sensitivity of thiamylal.