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Biomedical subjects

S M Murphy

Publications and source records attributed to S M Murphy.

At least 19 recordsLinked to original sources
PubMed2006

How many types of cholinergic sympathetic neuron are there in the rat stellate ganglion?

Sympathetic cholinergic postganglionic neurons are present in many sympathetic ganglia. Three classes of sympathetic cholinergic neuron have been reported in mammals; sudomotor neurons, vasodilator neurons and neurons innervating the periosteum. We have examined thoracic sympathetic ganglia in rats to determine if any other classes of cholinergic neurons exist. We could identify cholinergic sudomotor neurons and neurons innervating the rib periosteum, but confirmed that cholinergic sympathetic vasodilator neurons are absent in this species. Sudomotor neurons contained vasoactive intestinal peptide (VIP) and calcitonin gene-related peptide (CGRP) and always lacked calbindin. Cholinergic neurons innervating the periosteum contained VIP and sometimes calbindin, but always lacked CGRP. Cholinergic neurons innervating the periosteum were usually surrounded by terminals immunoreactive for CGRP. We conclude that if any undiscovered populations of cholinergic neurons exist in the rat thoracic sympathetic chain, then they are indistinguishable in size, neurochemistry and inputs from sudomotor or cholinergic neurons innervating the periosteum. It may be that the latter two populations account for all cholinergic neurons in the rat thoracic sympathetic chain ganglia.

Acetylcholine↗
PubMed2006

Incentives for voluntary HIV testing in NHS staff.

BACKGROUND: HIV seroprevalence is rising in the United Kingdom. While acceptability of HIV testing has been explored among many groups there is a paucity of data regarding voluntary HIV counselling and testing (VCT) among NHS staff. AIMS: To understand the barriers to HIV testing among NHS employees. To observe how these may be overcome. To assess which factors would motivate staff to undergo VCT and which would be a disincentive. METHODS: Completion of a cross-sectional anonymous postal questionnaire survey of new employees at a London district general hospital. Demographic and attitudinal factors were collected. Respondents were able to give multiple responses to questions regarding reasons for and against VCT. Those unable to communicate in English were excluded. RESULTS: There was a 63% response rate; of 69 respondents, 76% were female, 72% had English as their first language and 30% self-identified as white British. Thirty-nine percent were nurses, 19% doctors and the remainder a variety of professions. Of these, 41% had had a previous HIV test; none were known positive. Sixty-two percent would consider future testing. The commonest reasons to consider testing were knowledge of status (79%), treatment benefit (40%) and to inform family members (44%). The commonest reasons not to test were already tested negative (30%) and rather not know (26%). CONCLUSIONS: Since the NHS is recruiting staff from areas of high HIV prevalence, VCT should be encouraged. NHS staff require information on how to access testing as well as the benefits of early detection of blood-borne viruses.

AIDS Serodiagnosis↗
PubMed2005

CT cystography and virtual cystoscopy in the assessment of new and recurrent bladder neoplasms.

OBJECTIVE: To determine if CT cystography and virtual cystoscopy have a role in the assessment of neoplasms of the urinary bladder. MATERIAL AND METHODS: Twenty five adults suspected of having bladder tumours underwent CT cystography. Twenty three had subsequent virtual cystoscopic reconstructions from the axial data. The examinations were reviewed by two radiologists and the findings were correlated with those at conventional cystoscopy. RESULTS: Seventeen masses larger than 0.5 cm were identified by CT cystography in 16 patients. Two patients had normal CT cystography, but one had small recurrent neoplasms on conventional examination. Seven patients had nodular mucosal irregularities which were subsequently shown to be neoplastic in three. Accuracy for diagnosis of neoplasm in all patients was 88%. CONCLUSION: CT cystography is very accurate at identifying masses larger than 0.5 cm and can show mucosal abnormalities as small as 2 mm. It is minimally invasive and can be diagnostic when conventional cystoscopy is inconclusive. It can indicate appropriate areas for assessment and biopsy at conventional examination. Virtual cystoscopy gave comparable views to conventional cystoscopy, but did not add diagnostic information. It is not likely to replace conventional cystoscopy, but may be helpful in occasional circumstances where the latter is inconclusive, or can not be performed.

Adult↗
PubMed2004

The effect of the transplanted pineal gland on the sympathetic innervation of the rat sublingual gland.

We investigated the effect of the pineal on sympathetic neurons that normally innervate the sublingual gland of the rat. When the pineal gland was transplanted into the sublingual gland, it remained as a distinct mass that was innervated by sympathetic axons. Injection of the retrograde tracer, Fast Blue, into the sublingual gland labelled sympathetic neurons in the ipsilateral superior cervical ganglion (SCG). Thirty per cent of all neurons labelled retrogradely by Fast Blue injection into transplanted pineal glands were immunoreactive for both neuropeptide Y (NPY) and calbindin. This combination is characteristic of sympathetic neurons innervating the pineal gland in its normal location, but not the sympathetic vasoconstrictor neurons normally innervating the sublingual gland. This, and our previous study in which the pineal gland was shown to similarly influence the phenotype of salivary secretomotor neurons, suggests that a range of different functional classes of sympathetic neuron are able to change their phenotype in response to signals released by the pineal gland.

Amidines↗
PubMed2004

Patients' recall of clinical information following laparoscopy for acute abdominal pain.

BACKGROUND: Failures in doctor-patient communication and patients' understanding continue to confound improvements in the delivery of quality healthcare. In the context of acute abdominal pain managed by means of laparoscopy, it was hypothesized that patients are either not adequately informed, or do not reliably retain simple relevant information transmitted at the time of the procedure. This study was designed to evaluate the reliability of information transfer between doctor and patient in this setting, including the diagnosis and whether or not the appendix was removed. METHODS: A retrospective study of 350 consecutive patients who had undergone laparoscopy for acute abdominal pain over 3.5 years was designed. Each patient completed a telephone questionnaire that was used to evaluate the accuracy of patients' information. RESULTS: In total, 26.9 per cent of patients did not know or were incorrect regarding the surgical procedure performed. Similarly, 20.0 per cent of all patients did not know or were incorrect regarding the status of their appendix after surgery and 30.0 per cent of patients were incorrect regarding the diagnosis. Despite all of these statistics, 91.4 per cent of patients were happy with the information they had received regarding the procedure. CONCLUSION: Some 26.9 per cent of patients who underwent laparoscopy for acute abdominal pain were incorrect or did not know about the procedure that had been performed. This could lead to a further unnecessary operation should they re-present with similar symptoms.

Abdominal Pain↗
PubMed2003

Re-establishment of neurochemical coding of preganglionic neurons innervating transplanted targets.

We investigated the effect on neurochemical phenotype of changing the targets innervated by sympathetic preganglionic neurons. In neonatal rats, the adrenal gland was transplanted into the neck, to replace the postganglionic neurons of the superior cervical ganglion. Transplanted adrenal glands survived, and contained noradrenergic and adrenergic chromaffin cells, and adrenal ganglion cells. Retrograde tracing from the transplants showed that they were innervated by preganglionic neurons that would normally have supplied postganglionic neurons of the superior cervical ganglion. The neurochemical phenotypes of preganglionic axons innervating transplanted chromaffin cells were compared with those innervating the normal adrenal medulla or superior cervical ganglion neurons. As in the normal adrenal gland, preganglionic nerve fibres apposing transplanted chromaffin cells were cholinergic. The peptide and calcium-binding protein content of preganglionic fibres was similar in normal and transplanted adrenal glands. In both cases, cholinergic fibres immunoreactive for enkephalin targeted adrenergic chromaffin cells, whilst cholinergic fibres with co-localised calretinin-immunoreactivity innervated noradrenergic chromaffin cells and adrenal ganglion cells. In contrast to the innervation of normal adrenal glands, these axons lacked immunoreactivity to nitric oxide synthase. In a set of control experiments, the superior cervical ganglion was subjected to preganglionic denervation in rat pups the same age as those that received adrenal transplants, and the ganglion was allowed to be re-innervated over the same time course as the adrenal transplants were studied. When the superior cervical ganglion was re-innervated by preganglionic nerve fibres, we observed that all aspects of chemical coding were restored, including cholinergic markers, nitric oxide synthase, enkephalin, calcitonin gene-related peptide and calcium binding proteins in predicted combinations, although the density of nerve fibres was always lower in re-innervated ganglia. These data show that the neurochemical phenotypes expressed by preganglionic neurons re-innervating adrenal chromaffin cells are selective and similar to those seen in the normal adrenal gland. Two explanations are advanced: either that contact of preganglionic axons with novel target cells has induced a switch in their neurochemical phenotypes, or that there has been target-selective reinnervation by pre-existing fibres of appropriate phenotype. Regardless of which of these alternatives is correct, the restoration of normal preganglionic codes to the superior cervical ganglion following denervation supports the idea that the target tissue influences the neurochemistry of innervating preganglionic neurons.

Adrenal Glands↗
PubMed2003

Ireland in the World Cup: trauma orthopaedic workloads.

To determine if whether there were any changes in numbers of orthopaedic injuries at the emergency/ orthopaedic trauma department requiring treatment that could be related to televised home matches during World Cup 2002. Numbers of patients attending with musculoskeletal injuries directly attributable to world cup celebrations were collected during the four home matches. Attendances from midnight before the match until midday the day after the match were recorded. Control groups were matched from the previous month of May, and matched with the same day of the week for each of the four groups. Significantly more patients were admitted to the trauma service, referred to orthopaedic outpatients, and referred to the minor trauma clinic in the match versus control groups. 280 patients required onward referral during the match period compared with 233 during the control period. Televised Irish matches during the World Cup significantly increased the workload of the trauma orthopaedic service with musculoskeletal injuries. This should be taken into account when planning for such events in the future.

Adolescent↗
PubMed2002

Control of postganglionic neurone phenotype by the rat pineal gland.

As neurones develop they are faced with choices as to which genes to express, to match their final phenotype to their role in the nervous system. A number of processes can guide these decisions. Within the autonomic and sensory nervous systems, there are a handful of examples that suggest that one mechanism that may match phenotype to function is the presence of target-derived differentiation factors. We tested whether the rat pineal gland controls the expression of a neuropeptide (neuropeptide Y) and a calcium-binding protein (calbindin) in sympathetic postganglionic neurones that innervate it. We first showed that the chemical phenotype of sympathetic neurones innervating the rat pineal includes the expression of both neuropeptide Y and the calcium-binding protein, calbindin. After transplanting the pineal gland of neonatal rats into the submandibular salivary gland of neonatal hosts, it was innervated by sympathetic axons from the surrounding salivary gland tissue, which do not normally express neuropeptide Y and calbindin. The presence of the pineal gland led to the appearance of neuropeptide Y and calbindin in many of the postganglionic neurones that innervated the graft. From these findings we suggest that, like the rodent sweat gland, the pineal gland generates a signal that can direct the neurochemical phenotype of innervating sympathetic neurones.

Animals↗
PubMed2001

Computed tomography-based spectral imaging for fluorescence microscopy.

The computed tomography imaging spectrometer (CTIS) is a non-scanning instrument capable of simultaneously acquiring full spectral information (450-750 nm) from every position element within its field of view (75 microm x 75 microm). The current spatial and spectral sampling intervals of the spectrometer are 1.0 microm and 10 nm, respectively. This level of resolution is adequate to resolve signal responses from multiple fluorescence probes located within individual cells or different locations within the same cell. Spectral imaging results are presented from the CTIS combined with a commercial inverted fluorescence microscope. Results demonstrate the capability of the CTIS to monitor the spatiotemporal evolution of pH in rat insulinoma cells loaded with SNARF-1. The ability to analyze full spectral information for two-dimensional (x, y) images allows precise evaluation of heterogeneous physiological responses within cell populations. Due to low signal levels, integration times up to 2 s were required. However, reasonable modifications to the instrument design will provide higher system transmission efficiency with increased temporal and spatial resolution. Specifically, a custom optical design including the use of a larger format detector array is under development for a second-generation system.

Animals↗
PubMed2001

GCP5 and GCP6: two new members of the human gamma-tubulin complex.

The gamma-tubulin complex is a large multiprotein complex that is required for microtubule nucleation at the centrosome. Here we report the purification and characterization of the human gamma-tubulin complex and the identification of its subunits. The human gamma-tubulin complex is a ring of ~25 nm, has a subunit structure similar to that reported for gamma-tubulin complexes from other species, and is able to nucleate microtubule polymerization in vitro. Mass spectrometry analysis of the human gamma-tubulin complex components confirmed the presence of four previously identified components (gamma-tubulin and gamma-tubulin complex proteins [GCPs] 2, 3, and 4) and led to the identification of two new components, GCP5 and GCP6. Sequence analysis revealed that the GCPs share five regions of sequence similarity and define a novel protein superfamily that is conserved in metazoans. GCP5 and GCP6, like other components of the gamma-tubulin complex, localize to the centrosome and associate with microtubules, suggesting that the entire gamma-tubulin complex takes part in both of these interactions. Stoichiometry experiments revealed that there is a single copy of GCP5 and multiple copies of gamma-tubulin, GCP2, GCP3, and GCP4 within the gamma-tubulin complex. Thus, the gamma-tubulin complex is conserved in structure and function, suggesting that the mechanism of microtubule nucleation is conserved.

Amino Acid Sequence↗
PubMed2000

Rodent noradrenergic chromaffin cells contain calbindin D28K immmunoreactivity.

The calcium binding protein calbindin D28K is heterogeneously distributed in neurons throughout the body. We have investigated the distribution of calbindin in the chromaffin cells of the adult rodent adrenal medulla, which share the same developmental origin as peripheral sensory and autonomic neurons. Calbindin immunoreactivity was present in all noradrenergic chromaffin cells (defined by their lack of the adrenaline synthesizing enzyme, phenylethanolamine N-methyl transferase) in both the rat and mouse. It was also present in a very few adrenergic chromaffin cells in both rat and mouse. Calbindin-immunoreactivity is present in rat noradrenergic chromaffin cells from the day of birth and so is a useful marker for identifying rodent noradrenergic chromaffin cells.

Adrenal Medulla↗