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Biomedical subjects

A Mellon

Publications and source records attributed to A Mellon.

13 recordsLinked to original sources
PubMed2006

Prospective randomised study of urgent haemorrhoidectomy compared with non-operative treatment in the management of prolapsed thrombosed internal haemorrhoids.

OBJECTIVE: To compare the outcome of urgent haemorrhoidectomy with conservative treatment for prolapsed thrombosed internal haemorrhoids. METHODS: A prospective randomised study of 50 patients with prolapsed thrombosed internal haemorrhoids was carried out using clinical and ultrasonic outcome measures. Peri-operative bed occupancy and the presence of symptoms at 6 and 24 months were compared. Endoanal ultrasonic scanning was carried out to investigate anal sphincter integrity in those patients willing to be studied. RESULTS: The median length of hospital stay for the group treated conservatively; 2 nights (range 1-9 nights) was significantly shorter than for the group treated by urgent haemorrhoidectomy; 4 nights (range 1-12 nights, P < 0.01). There was no difference between treatment groups in the number of patients with symptoms at six or 24 months. Urgent haemorrhoidectomy was associated with a significantly higher incidence of endosonographically detected anal sphincter damage in 18 patients: 66%vs 0% (P = 0.009). CONCLUSION: Conservative treatment for prolapsed thrombosed internal haemorrhoids is associated with shorter in patient stay and less anal sphincter damage compared with operative treatment.

Adult↗
PubMed2005

Effects of a course in neonatal resuscitation--evaluation of an educational intervention on the standard of neonatal resuscitation.

BACKGROUND: Appropriate assessment and resuscitation is an important part of neonatal care provided during the first minutes of life. Midwifery and junior medical staff are often in the frontline of neonatal resuscitation. Appropriate education and training of midwifery staff is therefore essential if the standard of care delivered to babies in the delivery suite is to be improved and maintained. Evaluation of any such educational interventions is necessary to assess their effectiveness. AIM: To assess the effect of a course in neonatal resuscitation introduced in 1995 aimed at midwifery staff, on the standard of care provided to babies immediately after birth. Prior to this, training in neonatal resuscitation was largely theoretical. METHODS: Naturalistic design observational study conducted in a maternity unit with a tertiary neonatal intensive care unit in the North of England. We compared two groups of babies born before and after the course was introduced. Use of naloxone in the delivery suite and appropriateness of its use, and temperature on admission to neonatal intensive care unit were used as proxy markers for standard of care and compared in the two groups. We also looked at the use of mask intermittent positive pressure ventilation (IPPV) and tracheal intubation in the delivery suite. RESULTS: Use of naloxone fell dramatically from 13.2% of all babies born in 1994 to 0.5% in 2003. Inappropriate use of naloxone before other resuscitation measures were initiated declined from 75% of babies given naloxone in 1994 to 10% in 2003. The incidence of hypothermia (<35 degrees C) on admission to neonatal unit declined from 9% of all admissions to 2.3% in 2003. There was a trend towards increased use of mask ventilation in the delivery suite with a corresponding trend towards less tracheal intubation. CONCLUSION: We have shown that the intervention has been related temporally to an improvement in the quality of care delivered by midwifery staff to newborn babies. Practical courses in neonatal resuscitation can contribute to improvements in the quality of care provided to babies immediately after birth. These courses are more effective than theoretical teaching alone.

Drug Utilization↗
PubMed2000

Light ethanol consumption enhances liver regeneration after partial hepatectomy in rats.

BACKGROUND & AIMS: The effects of "social drinking" on the liver have yet to be fully documented. The aim of this study was to document the effects of daily light, moderate, and heavy ethanol exposure on hepatic regenerative activity in the rat. METHODS: Adult male Sprague-Dawley rats underwent daily gavages with 1.0 (light), 2. 0 (moderate), or 4.0 (heavy) g/kg of ethanol or tap water (controls) for 30 days before 70% partial hepatectomy (PHx). Hepatic regenerative activity was then documented on days 1, 3, 5, and 7 after PHx. RESULTS: Compared with controls, restitution of liver mass, [(3)H]thymidine incorporation, and proliferating cell nuclear antigen expression were decreased in the heavy (-10%, -60%, and -36%, respectively), unchanged in the moderate (-4%, -8%, and -16%, respectively), and increased in the light (+6%, +38%, and +29%, respectively) ethanol groups. Messenger RNA differential display of resected livers at PHx identified a band present only in the light ethanol group that encodes a unique 47-kilodalton protein with growth-promoting features designated light ethanol-induced stimulatory protein. CONCLUSIONS: The results indicate that light ethanol consumption enhances hepatic regenerative activity after PHx in rats. Further studies are required to determine the mechanism involved and whether social drinking has beneficial or adverse effects on the natural history of acute or chronic liver disease in humans.

Alcohol Drinking↗
PubMed1992

Amyloid beta-peptide is produced by cultured cells during normal metabolism.

Alzheimer's disease is characterized by the extracellular deposition in the brain and its blood vessels of insoluble aggregates of the amyloid beta-peptide (A beta), a fragment, of about 40 amino acids in length, of the integral membrane protein beta-amyloid precursor protein (beta-APP). The mechanism of extracellular accumulation of A beta in brain is unknown and no simple in vitro or in vivo model systems that produce extracellular A beta have been described. We report here the unexpected identification of the 4K (M(r) 4,000) A beta and a truncated form of A beta (approximately 3K) in media from cultures of primary cells and untransfected and beta-APP-transfected cell lines grown under normal conditions. These peptides were immunoprecipitated readily from culture medium by A beta-specific antibodies and their identities confirmed by sequencing. The concept that pathological processes are responsible for the production of A beta must not be reassessed in light of the observation that A beta is produced in soluble form in vitro and in vivo during normal cellular metabolism. Further, these findings provide the basis for using simple cell culture systems to identify drugs that block the formation or release of A beta, the primary protein constituent of the senile plaques of Alzheimer's disease.

Amyloid beta-Peptides↗
PubMed1992

Targeting of cell-surface beta-amyloid precursor protein to lysosomes: alternative processing into amyloid-bearing fragments.

Progressive cerebral deposition of the amyloid beta-peptide is an early and invariant feature of Alzheimer's disease. The beta-peptide is released by proteolytic cleavages from the beta-amyloid precursor protein (beta APP), a membrane-spanning glycoprotein expressed in most mammalian cells. Normal secretion of beta APP involves a cleavage in the beta-peptide region, releasing the soluble extramembranous portion and retaining a 10K C-terminal fragment in the membrane. Because this secretory pathway precludes beta-amyloid formation, we searched for an alternative proteolytic processing pathway that can generate beta-peptide-bearing fragments from full-length beta APP. Incubation of living human endothelial cells with a beta APP antibody revealed reinternalization of mature beta APP from the cell surface and its targeting to endosomes/lysosomes. After cell-surface biotinylation, full-length biotinylated beta APP was recovered inside the cells. Purification of lysosomes directly demonstrated the presence of mature beta APP and an extensive array of beta-peptide-containing proteolytic products. Our results define a second processing pathway for beta APP and suggest that it may be responsible for generating amyloid-bearing fragments in Alzheimer's disease.

Alzheimer Disease↗
PubMed1975

A comparison of methods for the measurement of cardiac output and blood oxygen content.

A comparison has been made between the recently introduced thermal dilution method for measurement of cardiac output and the standard dye dilution technique. Two relatively new methods of measurement of blood oxygen content, one involving the measurement of oxygen tension after release of oxygen by carbon monoxide, and the other the measurement of current flow upon reduction of oxygen in a galvanic cell, have been compared with a standard indirect method of measurement of blood oxygen content. All three new methods fulfilled the criteria of accuracy and simplicity and compared favourably with the standard methods. Of the two new methods for measurement of oxygen content, that involving reduction of oxygen in a galvanic cell was superior by virtue of compactness and speed of operation.

Animals↗
PubMed1975

Ventricular function in experimental hemorrhagic shock.

Hemorrhagic shock was induced in 20 spontaneously breathing adult greyhounds by lowering the mean arterial pressure to 40 millimeters of mercury. In the first group of six dogs, reinfusion was carried out without delay; in a second group of six dogs, hypovolemia was continued for two hours, during which time the arterial pressure was permitted to rise in response to intact cardiovascular reflexes; in a third group of eight dogs, the mean arterial pressure was artificially maintained at 40 millimeters of mercury for two hours, initially by further bleeding. In all dogs in the latter group, take-up of blood from the reservoir was required during the second hour to maintain the arterial pressure, this being indicative of irreversible shock. In two of this group, fatal arrhythmias developed during reinfusion. All three groups showed evidence of ventricular dysfunction during and immediately after reinfusion, as indicated by disproportion between left ventricular stroke work and left ventricular end diastolic pressure, these data being used to construct ventricular function curves. Measurement of dP/dt maximum suggested that this dysfunction was due to impairment of myocardial contractility. The first two groups recovered normal function within one hour; the third group failed to have such a recovery. Evidence indicates that generalized tissue hypoxia, in addition to myocardial hypoxia, is important in the cause of cardiac dysfunction in irreversible shock.

Animals↗
PubMedDate not supplied

Cytomegalovirus infection after liver transplantation in children.

Post-liver transplant cytomegalovirus (CMV) infection (seroconversion or virus isolation) and CMV disease (infection plus clinical signs and symptoms) were studied in relation to pretransplant recipient and donor serology, age, nutritional status and the effect of paediatric versus adult (reduced size) grafts. Of 70 children receiving 79 transplants, 26 (37%) had evidence of CMV infection, and eight (11.5%) had evidence of CMV disease, four of whom died. The primary infection rate (where the recipients were CMV negative) was 71% with mortality of 7% with most receiving a CMV-positive graft. The active secondary infection rate (reactivation or reinfection, where the recipients were CMV positive) was 60% with mortality of 12.5%. No significant differences in infection or disease rates were found comparing malnourished versus well-nourished patients, or between those who received whole or reduced-size grafts. The high prevalence of CMV infections supports the view that clinical signs alone are inadequate to direct investigations for CMV. Both primary and active secondary CMV infection can result in serious morbidity and mortality in children receiving liver transplants. These data do not support the strategy of providing immunoprophylaxis to seronegative recipients only, at least in paediatric liver transplantation.

Adolescent↗