Cloning and pharmacological characterization of the guinea pig P2X7 receptor orthologue.

BACKGROUND AND PURPOSE: The human, rat, and mouse P2X(7) receptors have been previously characterized, and in this study we report the cloning and pharmacological properties of the guinea pig orthologue. EXPERIMENTAL APPROACH: A cDNA encoding for the guinea pig P2X(7) receptor was isolated from a guinea pig brain library. The receptor was expressed in U-2 OS cells using the BacMam viral expression system. A monoclonal antibody was used to confirm high levels of cell surface expression and the functional properties were determined in ethidium bromide accumulation studies. KEY RESULTS: The predicted guinea pig protein is one amino acid shorter than the human and rat orthologues and over 70% identical to the rat and human receptors. In contrast to human and rat P2X(7) receptors, 2'-&3'-O-(4benzoylbenzoyl)ATP (BzATP) was a partial agonist of the guinea pig P2X(7) receptor when compared to ATP and acted as an antagonist in some assays. However, as at other species orthologues, BzATP was more potent than ATP. The guinea pig P2X(7) receptor possessed higher affinity for 1-[N,O-bis(5-isoquinoline sulphonyl)-N-methyl-L-tyrosyl]-4-phenylpiperazine (KN62), suramin and Coomassie Brilliant Blue than human or rat P2X(7) receptors suggesting that it is pharmacologically different to other rodent or human P2X(7) receptors. CONCLUSIONS AND IMPLICATIONS: The guinea pig recombinant P2X(7) receptor displays a number of unique properties that differentiate it from the human, rat and mouse orthologues and this structural and functional information should aid in our understanding of the interaction of agonists and antagonist with the P2X(7) receptor.

Repeatability of the sonographic assessment of fetal sucking and swallowing movements.

OBJECTIVE: To test the repeatability of sonography in the assessment of fetal sucking and swallowing movements. METHODS: Eighty normal fetuses of pregnant women with no systemic abnormalities were examined sonographically at 30-38 weeks of gestation. Sucking and swallowing movements were observed for 15 min and the face was visualized in frontal and lateral views. The examinations were recorded for later analysis by two independent observers and the 95% limits of agreement (Bland and Altman) method was used for inter- and intraobserver comparison. RESULTS: The mean +/- SD number of swallowing movements, sucking bursts and total sucking movements recorded by Observer 1 were 8.3 +/- 4.7, 9.9 +/- 9.3 and 35.8 +/- 48.0 and the equivalent values for Observer 2 were 8.2 +/- 4.8, 9.8 +/- 9.3 and 36.4 +/- 49.0, respectively. The mean (95% limits of agreement) interobserver difference was 0.1 (-1.4; 1.6), 0.1 (-2.2; 2.3) and -0.6 (-9.0; 7.9), and the mean (95% limits of agreement) intraobserver difference was 0.4 (-3.1; 3.9), 0.1 (-2.0; 2.2) and 1.0 (-10.7; 12.7) for swallowing movements, sucking bursts and total sucking movements, respectively. CONCLUSIONS: The high degree of intra- and interobserver repeatability disclosed in the sonographic analysis of fetal sucking and swallowing movements supports the applicability of sonographic assessment in normal fetuses.

Molecular cloning and functional characterization of MCH2, a novel human MCH receptor.

Melanin-concentrating hormone (MCH) is involved in the regulation of feeding and energy homeostasis. Recently, a 353-amino acid splice variant form of the human orphan receptor SLC-1 () (hereafter referred to as MCH(1)) was identified as an MCH receptor. This report describes the cloning and functional characterization of a novel second human MCH receptor, which we designate MCH(2), initially identified in a genomic survey sequence as being homologous to MCH(1) receptors. Using this sequence, a full-length cDNA was generated with an open reading frame of 1023 base pairs, encoding a polypeptide of 340 amino acids, with 38% identity to MCH(1) and with many of the structural features conserved in G protein-coupled receptors. This newly discovered receptor belongs to class 1 (rhodopsin-like) of the G protein-coupled receptor superfamily. HEK293 cells transfected with MCH(2) receptors responded to nanomolar concentrations of MCH with an increase in intracellular Ca(2+) levels and increased cellular extrusion of protons. In addition, fluorescently labeled MCH bound with nanomolar affinity to these cells. The tissue localization of MCH(2) receptor mRNA, as determined by quantitative reverse transcription-polymerase chain reaction, was similar to that of MCH(1) in that both receptors are expressed predominantly in the brain. The discovery of a novel MCH receptor represents a new potential drug target and will allow the further elucidation of MCH-mediated responses.

Herpesvirus antibody levels in the etiologic diagnosis of the acute retinal necrosis syndrome.

Quantitative antibody levels to three herpesviruses in acute and chronic sera from six patients with clinical signs of the acute retinal necrosis syndrome were consistent with a specific etiologic diagnosis only in the two cases associated with cutaneous herpes zoster. Available data on acute and convalescent antibody titers to herpes group viruses from these six patients in addition to data from 27 acute retinal necrosis cases from the literature disclosed that only 13 of the 33 patients (39%) had a diagnostic increase or decrease in herpes group viral antibody levels on serial sampling. Three patients had nondiagnostic changes in viral antibody levels despite positive vitreous cultures for herpesviruses. In contrast, a review of 25 cases from the literature with paired antiviral serum and intraocular fluid antibody levels suggested a more promising approach to the etiologic diagnosis of the acute retinal necrosis syndrome. By calculating the ratio of antiviral antibodies in intraocular fluid and serum, an etiologic diagnosis could be made in 12 of 14 (86%) of subacute and convalescent samples. The sensitivity of this method decreased to 72% (13 of 18) when fluids were obtained earlier in the course of the disease.

Cardiac arrest associated with halothane anesthesia in a patient receiving theophylline.

A case of a 10-year-old asthmatic patient who had cardiac arrest during induction for elective ear surgery is presented. The patient's serum theophylline level was 21.6 micrograms/mL one hour after surgery. It is likely that, since other factors that can contribute to cardiac arrest during the perioperative period were not present, the combined use of aminophylline and halothane was responsible.

The adverse effects of cervical cancer treatment on bladder function.

Bladder dysfunction is a recognized complication following radical hysterectomy, however, the effect of radiation alone or in combination with surgery on bladder function has received little attention. Thirty patients who underwent radical hysterectomy with postoperative whole pelvis radiation (RH + RT) were matched for age, stage of disease, and time interval since therapy, with 30 patients who had radical hysterectomy alone (RH) and 30 patients who were treated with pelvic radiotherapy (RT). Bladder function was assessed by symptoms and urodynamic evaluation. Altered bladder sensation and voiding problems were associated with surgery, and were more frequent after RH or RH + RT than RT (P = 0.002). fifty percent of RH patients voided by abdominal straining compared to 10% who had only RT. No greater problem was seen after RH + RT compared to RH. Urinary incontinence was present in 15% of patients prior to therapy. After treatment, incontinence requiring protection developed in 23% of RT patients, 26% of RH patients, and 63% of RH + RT patients. The severity of the incontinence was greater after RH + RT. Bladder neck and urethral function was similar in all groups, however, bladder compliance was reduced in RT patients and significantly (P = 0.0001) reduced after RH + RT compared to RH alone. This reduction was related to the bladder dose of external radiation and was a factor in the etiology of the urinary incontinence seen in RH + RT patients.

Uterine perforation during intracavitary application. Prognostic significance in carcinoma of the cervix.

All cases of uterine perforation occurring during intracavitary application for carcinoma of the cervix over a 13-year period (1968-1981) were reviewed. There were 14 perforations out of 799 applications in 622 patients, for an incidence of 2.25% of patients and 1.75% of applications. In most cases, it is sufficient to halt the application and carefully monitor the patient, as supported by the uneventful post-perforation course in 12 cases. Nine patients (64%) underwent subsequent intracavitary application without further complications; of these, 8 are still living or died without evidence of tumor. In the other 5, it was impossible to locate the cervical canal on subsequent applications. Alternative treatments, results of therapy, and analysis of failures are presented. The authors conclude that there is no direct evidence that uterine perforation alters the prognosis following radiation therapy for carcinoma of the cervix.

Metastatic carcinoma to the tongue: a report of two cases and a review of the literature.

Metastatic tumors of the oral cavity are uncommon. Most of them are located in the mandible while only a small percentage are found within the soft tissues. Two cases of metastatic bronchogenic carcinomas to the tongue are described. Review of the literature showed that cancer of the lung was the most common primary lesion that metastasized to the soft tissues of the oral cavity. The base of the tongue was the most prevalent site of metastases to soft tissue within the oral cavity.

Postoperative irradiation in the prevention of keloids.

Low dose superficial x-irradiation to the incisional site after surgical excision of a keloid prevented keloid or hypertrophic scar formation in 31 of 35 patients evaluated (88%). The clinical manifestation of keloids, physiology of wound healing, pathophysiology of keloid formation, and the radiation technique utilized are presented. This study shows that the method is well tolerated, easily administered, and efficient in inhibiting recurrence of keloid or hypertrophic scar formation.