Update on paediatric tracheostomy tubes.

In the recent past there has been a significant expansion in the range of paediatric tracheostomy tubes available. This has mainly been in response to clinicians' requests. This article reviews those now available and the situations in which they are useful.

Molecular cloning and functional characterization of a rat somatostatin sst2(b) receptor splice variant.

1. The mouse somatostatin (SRIF) sst2 receptor exists in two splice variants, sst2(a) and sst2(b), which differ in their intracellular carboxy-termini only. The murine sst2(b) receptor was reported to be less prone to agonist-induced desensitization as compared with the sst2(a) receptor.

Mammalian 3-methyladenine DNA glycosylase protects against the toxicity and clastogenicity of certain chemotherapeutic DNA cross-linking agents.

DNA repair status is recognized as an important determinant of the clinical efficacy of cancer chemotherapy. To assess the role that a mammalian DNA glycosylase plays in modulating the toxicity and clastogenicity of the chemotherapeutic DNA cross-linking alkylating agents, we compared the sensitivity of wild-type murine cells to that of isogenic cells bearing homozygous null mutations in the 3-methyladenine DNA glycosylase gene (Aag). We show that Aag protects against the toxic and clastogenic effects of 1,3-bis(2-chloroethyl)-1-nitrosourea and mitomycin C (MMC), as measured by cell killing, sister chromatid exchange, and chromosome aberrations.

Aortoiliac aneurysm with arteriocaval fistula treated by a bifurcated endovascular stent-graft.

A 71-year-old patient with high-output cardiac failure was found to have an aneurysmal distal aorta with evidence of an arteriocaval fistula on ultrasound scanning. CT demonstrated an aneurysm of the distal aorta and right common iliac artery and an intraarterial digital subtraction angiogram confirmed an arteriocaval fistula. In view of the patient's cardiac failure and general condition an endovascular stent was considered.

Kaposi's sarcoma masquerading as pyogenic granuloma of the nasal mucosa.

Kaposi's sarcoma (KS) is a neoplastic vascular disorder characterized by multiple reddish blue nodules which, according to the original description (Kaposi, 1872), usually present on the skin of the upper and lower extremities. It is not until the disease progresses that nodules appear on the skin of the head and neck, on mucosal membranes and as visceral lesions. However, with the large increase in the incidence of this tumour associated with the acquired immune deficiency syndrome (AIDS) epidemic, there have been increasing numbers of cases of Kaposi's sarcoma presenting primarily on the skin or mucosa of the head and neck.

Identification of amino acid residues associated with modulation of flavin-containing monooxygenase (FMO) activity by imipramine: structure/function studies with FMO1 from pig and rabbit.

The activity of the flavin-containing monooxygenase (FMO) can be modulated by a number of nitrogen-containing compounds in a manner that is both isoform and modulator-dependent. We now show that the direction (activation or inhibition) and extent of modulation can also be dependent on substrate concentration. Imipramine activates methimazole metabolism catalyzed by rabbit FMO1 or FMO2 at methimazole concentrations greater than 50 or 100 microM, respectively, and inhibits at lower methimazole concentrations.

Psoas release at the pelvic brim in ambulatory patients with cerebral palsy: operative technique and functional outcome.

Seventeen patients with cerebral palsy (29 hips) underwent psoas recession at the pelvic brim. The operative technique was a direct anterior approach, lateral to the femoral sheath. There were no infections or nerve or arterial injuries.

Kinematic and kinetic analysis of distal derotational osteotomy of the leg in children with cerebral palsy.

Patients with cerebral palsy often develop rotational deformities of the lower extremities. These deformities may be caused by abnormal muscle tone, soft-tissue contractures, or bony malalignment. When rotational deformity persists after correction of the soft-tissue components, bony-realignment procedures are warranted to improve gait in ambulatory patients.

Base excision repair deficient mice lacking the Aag alkyladenine DNA glycosylase.

3-methyladenine (3MeA) DNA glycosylases remove 3MeAs from alkylated DNA to initiate the base excision repair pathway. Here we report the generation of mice deficient in the 3MeA DNA glycosylase encoded by the Aag (Mpg) gene. Alkyladenine DNA glycosylase turns out to be the major DNA glycosylase not only for the cytotoxic 3MeA DNA lesion, but also for the mutagenic 1,N6-ethenoadenine (epsilonA) and hypoxanthine lesions.

The sequence specificity of alkylation for a series of benzoic acid mustard and imidazole-containing distamycin analogues: the importance of local sequence conformation.

The covalent sequence specificity of a series of nitrogen mustard and imidazole-containing analogues of distamycin was determined using modified sequencing techniques. The analogues tether benzoic acid mustard (BAM) and possess either one, two or three imidazole units. Examination of the alkylation specificity revealed that BAM produced guanine-N7 lesions in a pattern similar to conventional nitrogen mustards.

Critical and subcritical ischaemia.

Objectives: To stratify leg ischaemia into high and low risk groups with respect to outcome.

Methods: An evaluation of 20 recent publications, reporting the results of 6118 patients with critical ischaemia. Low and high risk patient groups are identified by the definition of critical ischaemia.

Prospective study of zero drift in fiberoptic pressure monitors used in clinical practice.

One hundred and one fiberoptic pressure transducers (59 subdural and 42 ventricular) were studied in 86 patients (some in whom more than one device had been inserted). Only four complications occurred: two transient cerebrospinal fluid leaks after removal and two clinically insignificant intracerebral hematomas. No intracranial infections could be attributed to the devices.

Neonatal and paediatric fibre-optic laryngoscopy and bronchoscopy using the laryngeal mask airway.

Endoscopy of the upper airways in neonates and infants was traditionally been accomplished using rigid laryngoscopes and bronchoscopes. The laryngeal mask may be used both to control the airway for anaesthetic ventilation and to guide a fibre-optic endoscope to the laryngeal inlet and beyond. We report our experience with five neonatal and paediatric cases where fibre-optic laryngoscopy and bronchoscopy were performed through the laryngeal mask airway.

Involvement of DT-diaphorase (EC 1.6.99.2) in the DNA cross-linking and sequence selectivity of the bioreductive anti-tumour agent EO9.

The chemistry of the mitomycin C-related drug indoloquinone EO9 would suggest that its mechanism of action is likely to involve DNA damage after reductive activation. The ability of this agent to induce DNA damage in intact cells has been examined using alkaline filter elution. After treatment with pharmacologically relevant concentrations of EO9, both DNA strand breaks and interstrand cross-links were detected in rat Walker tumour cells and human HT29 colon carcinoma cells.

Alkylation specificity for a series of distamycin analogues that tether chlorambucil.

The sequence specificity of alkylation for a series of pyrrole- and imidazole-containing analogues of distamycin that tether the nitrogen mustard chlorambucil (CHL) was determined using modified sequencing techniques. Examination of the sequence specificity of alkylation for the imidazole-CHL conjugates using a Taq polymerase stop assay revealed that although the doses required to produce similar amounts of damage were at least 10-fold lower, the sequence specificity of alkylation was essentially identical to that seen for CHL. The guanine-N7 alkylation pattern, which consisted of guanines within runs of guanines, was confirmed using a piperidine cleavage assay.

Structural characteristics of flavin-containing monooxygenase genes one and two (FMO1 and FMO2).

As a first step in understanding the regulation of the expression of flavin-containing monooxygenases (FMOs), we have isolated the FMO genes from the rabbit and characterized the gene for FMO1. Probes based on the 3', middle and 5' regions of the cDNAs encoding FMO1, FM02, FM03, and FM05 were generated by polymerase chain reaction. A mixture of the 5' probes was used to screen a genomic library, and isolated clones were identified by hybridization with individual 5' probes.

Somatostatin sst2 receptor-mediated inhibition of parietal cell function in rat isolated gastric mucosa.

1. The aim of this study was to determine the location and functional characteristics of the somatostatin (SRIF) receptor type(s) which mediate inhibition of acid secretion in rat isolated gastric mucosa. 2.

Clinical use of prediction regions for motion analysis.

This study assesses the diagnostic capability of statistically defined prediction regions, developed by a 'bootstrap' method, for assessing the curves of angular rotation of joints in children as they walk. The prediction regions had been previously developed in the authors' laboratory from a study of 309 normal children. The goal of the present study was to determine whether these computer-generated prediction regions could be used as a screen in clinical gait analysis, to determine whether a movement falls outside the normal range of variability.

Isolated tibial vessel disease: treatment options and outcome.

Tibial vessel disease is an important cause of limb ischaemia, particularly in diabetics. Revascularisation by angioplasty and bypass is increasingly feasible. The aim of this study was to review treatment and outcome in patients with this patterns of disease.

Femorotibial bypass: the learning curve.

Femorotibial bypass is still infrequently performed in many district hospitals, because it is time consuming and the risk of failure is high, especially during the learning curve. This article reviews the results of a single consultant surgeon and his team after starting femorotibial bypass de novo in a district general hospital. During the period 1987 to 1992, 85 femorotibial grafts were performed in 76 patients for ulceration and gangrene (57), rest pain (19) and severe claudication (9).