Adenovirus-mediated expression of human prorelaxin promotes the invasive potential of canine mammary cancer cells

This study reports the characterization of a recombinant adenoviral vector containing a tetracycline-regulatable promoter, driving the bicistronic expression of the human H2 preprorelaxin (hH2) cDNA and enhanced green fluorescent protein, via an internal ribosomal entry site. An hH2 ELISA was used to measure the secreted levels of recombinant hH2 in transfected canine (CF33.Mt) and human (MDA-MB-435) mammary cancer cell lines over a 6-d period; secreted peptide peaked on d 2 and 4 for the canine and human cell types, respectively. An unprocessed hH2 immunoreactive form of approximately 18 kDa was identified by Western blotting analysis and confirmed by mass spectrometry, suggesting that prorelaxin remains unprocessed in these cell types. The biological activity of the adenovirally expressed human prorelaxin was measured in the established human monocytic cell line THP-1 cAMP ELISA and in an in vitro Transwell cell migration system. Exogenous recombinant hH2 and adenovirally-mediated delivery of prorelaxin to CF33.Mt cells conferred a significant migratory action in the cells, compared with controls. Cell proliferation assays were performed to discount the possibility that the effect of relaxin was mitogenic. Thus, we have demonstrated that prorelaxin has the ability to facilitate cell migration processes exclusive of its ability to stimulate cell proliferation. In validating this adenovirus-based system, we have created a potential tool for further exploration of the physiology of relaxin in mammalian systems.     

The perceived risk of variant Creutzfeld-Jakob disease and the effect of additional delay in tonsillectomy: a questionnaire based parents perspective

OBJECTIVES: In February 2001 the United Kingdom Department of Health in conjunction with the British Association of Otolaryngology, Head and Neck Surgeons decreed that all non-emergency tonsillectomies should be performed using disposable instruments because of the theoretical risk of transmission of variant Creutzfeld-Jakob disease (vCJD). There was an understandable delay in the provision of these instruments by the various manufacturers, leading to an increase in waiting time for surgery. It was decided to assess parental attitudes to the risk of vCJD, and assess the effect the additional delay had on their child. METHOD: A questionnaire was sent to the parents of all 249 children on the waiting list for tonsillectomy. RESULTS: Seventy percent replied, and of these, 37% felt there was a risk of reusing instruments, only 10% felt there was no risk, and the remaining 53% did not know if there was any risk. Nevertheless 41% of parents would have gone ahead using old instruments if allowed. All parents of the 73 children waiting greater than 6 months were questioned on the effect of the additional delay. Only 7% reported improvement in symptoms, and 68% felt the additional delay had badly affected their child's health and wellbeing. Ninety percent of parents felt their child's symptoms still warranted tonsillectomy. CONCLUSION: There is an awareness of risk of vCJD among parents whose children await tonsillectomy, although understandably the level of risk they feel is hard to quantify. The rate of symptom resolution whilst on the waiting list was very low.     

Patient eligibility for day case paediatric adenotonsillectomy

There is a growing trend towards day case surgery and departments are constantly under pressure from Health Trusts to perform more day case procedures. Adenoidectomy and tonsillectomy are being performed as day case procedures in many centres and literature has suggested that it is safe to do so, provided the population characteristics are favourable. A prospective study of 100 consecutive patients presenting to our department for tonsillectomy or adenotonsillectomy was undertaken to assess the eligibility of our patient group for day surgery. Medical and social history was obtained as per recommended guidelines. Only 27% of our patients were eligible for day surgery and only 17% of parents preferred the option of day case adenotonsillectomy. There is a marked difference between our group and those previously reported in the literature. This regional variation has implications in the safe expansion of day surgical procedures.     

The role of fibreoptic laryngoscopy in infants with stridor

Stridor in infants may be potentially serious and would require further investigations in all cases. Laryngomalacia is the most common cause of congenital stridor. This is a self-limiting condition with a good prognosis but other causes of stridor should be excluded to enable the surgeon to plan further intervention if needed. Traditionally microlaryngoscopy and bronchoscopy under a general anaesthetic is performed to evaluate the airway. We have investigated the use of the flexible fibreoptic laryngoscope under local anaesthetics in infants with inspiratory stridor. The procedure was performed in the day surgery unit on a non-fasting, non-sedated child. A retrospective analysis of procedures performed between January 1998 and August 1999 was carried out. Of the 43 patients studied, laryngomalacia was diagnosed in 35, vocal cord palsies in six and two infants had a normal larynx. There were no complications during the procedure and only one child required further intervention. The results showed that the combination of fibreoptic laryngoscopy under local anaesthetic with follow-up is a safe, effective and cost effective method of assessing stridor in this group of patients.     

Cationic lipid-mediated gene transfer to the growing murine and human airway

Gene therapy in patients with cystic fibrosis may need to be commenced before the onset of lung disease which may be evident as early as 4 weeks after birth. We assessed the efficacy of cationic lipid-mediated transfer of a reporter gene, chloramphenicol acetyltransferase, in the growing murine and human respiratory tract. Gene expression was greater in adult mice (greater than 8 weeks old) compared with 9- and 16-day-old animals, despite a relatively greater proportion of complex delivered to the younger mice. Subsequent experiments compared 16-day-old and adult mice. Whilst higher gene expression occurred in the parenchyma compared with conducting airways in both groups, significantly greater expression was seen in the conducting airway of adult mice compared with 16-day-old animals. This expression persisted beyond 18 days in the adults but was undetectable in the younger group at this time-point. In an ex vivo model there was no difference in gene expression between the two groups. Further, no differences were observed in gene expression between growing (age 5 weeks to 14 years 8 months) and adult human lung tissue in either parenchyma or conducting airway. These data suggest age-dependent differences in gene transfer in vivo, which are not seen in an ex vivo setting. Proof-of-principle has been demonstrated for cationic-lipid mediated gene transfer to the growing human lung. Gene Therapy (2000) 7, 273-278.     

Hypercalcemia in patients with esophageal cancer.

Hypercalcemia is a paraneoplastic syndrome that is associated with squamous cell cancers and which may be of life-threatening proportions. We investigated the incidence and prognostic importance of hypercalcemia in patients with esophageal cancer at the Department of Veterans Affairs Medical Center, Washington, DC, USA. The medical records of 170 patients with esophageal cancer from January 1988 to January 1998 were examined. Of the 170 patients with esophageal cancer, 47 (27.6%) had hypercalcemia during the course of their disease. Five (10.6%) of the 47 hypercalcemic patients were found to have hypercalcemia at the time of diagnosis. Forty-six of the 47 hypercalcemic patients had squamous cell carcinoma and 1 had adenosquamous cell carcinoma. Seven (14.8%) had bony metastasis. The median survival of patients with hypercalcemia and esophageal cancer was 12.4 months and 12.6 months for patients without hypercalcemia. Hypercalcemia is a common complication of squamous cell esophageal carcinoma. The survival of patients with or without this complication is similar; thus, it may not be a poor prognostic factor.     

Altered distribution of excitatory amino acid receptors in temporal lobe epilepsy

In temporal lobe epilepsy, excitatory amino acid receptors in the hippocampus and temporal lobe may contribute to both increased excitability and vulnerability to excitotoxic damage. We used receptor autoradiography to examine the density of N-methyl-D-aspartate (NMDA) and kainic acid (KA) receptors in the hippocampus and parahippocampal gyrus obtained from five patients who had undergone anterior temporal lobectomy for the treatment of intractable seizures and from six control individuals, in which the hippocampus was obtained postmortem. Within the hippocampal formation, loss of [3H]KA and NMDA-sensitive L-[3H]glutamate binding was apparent in the sclerotic regions CA3, hilus, and CA1. In the subiculum and molecular layer of the denate gyrus, binding densities were maintained or even increased in some of the epileptic patients. A two-fold increase in L-[3H]glutamate binding, along with an increase in [3H]KA binding, was observed in the parahippocampal gyrus obtained from the epileptic patients. The results suggest that the vulnerability of the hippocampus in temporal lobe epilepsy may result, at least in part, from the presence of aberrant excitatory circuits in the parahippocampal gyrus.