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Biomedical subjects

R M Walsh

Publications and source records attributed to R M Walsh.

At least 91 records · Page 5Linked to original sources
PubMed1995

Biliary alpha 1-acid glycoprotein concentrations in gallstone-free controls and in patients with multiple or solitary cholesterol gallstones.

We recently identified a promoting glycoprotein in the concanavalin A-bound fraction of gallbladder bile as a biliary form of alpha 1-glycoprotein (AAG). The concentration of biliary AAG appears to exert an important promoting effect on the speed of cholesterol nucleation in many patients with cholesterol gallstone disease. In the current study, we provide information about the biliary concentration of AAG as well as the amount and comparative potency of its subfractions in patients with and without cholesterol gallstone disease. The amount of total biliary AAG and the amounts of its different isoforms separated by concanavalin A affinity chromatography were measured by ELISA. Estimates of absolute concentrations of AAG for each sample were normalized to the sample total protein content to give relative AAG values. The promoting activity (potency) of immunopurified biliary AAG from gallstone patients and gallstone-free controls on cholesterol crystallization was compared by a crystal growth assay. The mean absolute concentration of AAG in gallstone-free controls was not significantly different from multiple stone patients. The relative concentration of AAG (micrograms per milligram total protein) was significantly increased in patients with multiple stones when compared to controls (P < 0.05), and both the absolute and relative concentrations of AAG (micrograms per milligram bile), were three- and to five fold higher in a number of these patients. The functional activity and distribution of AAG in different subfractions was similar in gallstone patients and gallstone-free controls. The relative concentration of biliary AAG is significantly greater in cholesterol gallstone patients with multiple stones than in gallstone-free controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Bile↗
PubMed1995

Management of retraction pockets of the pars tensa in children by excision and ventilation tube insertion.

Retraction pockets of the pars tensa in children can result in erosion of the ossicles leading to hearing loss and eventually cholesteatoma formation. Several different types of treatment for the more severe grades of retraction pocket have been described. The aim of this pilot study was to assess the outcome following simple excision and ventilation tube insertion of grade II, III and IV retraction pockets of the pars tensa. The eardrums were graded according to Sadé's classification (1979). There were seven grade II and four grade III retractions. Ten eardrums healed completely in a mean time of 3.6 months (mean follow-up 16 months) and there was one residual perforation. Two retractions recurred and both of these were only grade I. Clinically, an improvement in hearing was reported in seven children (eight ears) and the average air conduction threshold gain for these patients was 16 dB. A larger prospective study is currently underway.

Auditory Threshold↗
PubMed1995

Comparison of the otoendoscopic and microscopic anatomy of the middle ear cleft in canal wall-up and canal wall-down temporal bone dissections.

This study was designed to compare the accessibility of particular anatomical sites in the middle ear cleft in five canal wall-up and five canal wall-down temporal bone dissections, using 0 and 70 degree otoendoscopes and the microscope. In all five canal wall-up dissections, otoendoscopy gave good visualization of all sites of the middle ear cleft whereas microscopy failed to give adequate visualization of the sinus tympani and protympanum. In all five canal wall-down dissections otoendoscopy again allowed good visualization of all sites whereas microscopy did not permit visualization of the sinus tympani. It is well known that residual cholesteatoma is most frequently found in the sinus tympani, therefore this makes the otoendoscope an essential adjunct to the microscope in canal wall-up and canal wall-down surgery.

Cholesteatoma, Middle Ear↗
PubMed1995

Bomb blast injuries to the ear: the London Bridge incident series.

Twelve patients who were treated for ear injuries at Guy's Hospital following the London Bridge bomb blast in February 1992 were reviewed. Among three there were four perforated eardrums, two of which closed spontaneously (50%). All three patients had a persistent mixed hearing loss. The remaining nine patients had acute sensorineural hearing loss and/or tinnitus only. Four of these had resolved completely by 4h, another one by 48h, and two by 4 weeks. Two patients had a residual high frequency hearing loss. In total, five patients (42%) have a persistent hearing loss. None of the patients suffered from balance problems. In summary, the ear is very susceptible to bomb blast injury, but there is a high rate of spontaneous closure of perforations and improvement of sensorineural hearing loss and tinnitus.

Adult↗
PubMed1995

The use of Davis pinch grafts to promote epithelialization in a post- mastoidectomy cavity.

Otorrhoea following open mastoid cavity surgery is common and is estimated to occur in 10 to 35% of patients. It is usually due to failure of epithelialisation of the mastoid cavity for a variety of reasons. Even in the ideal cavity, which is small with a low facial ridge and large meatus, 10% discharge recurrently. Various techniques designed to promote epithelialisation have been proposed including cavity revision with or without a meatoplasty, cavity obliteration by different methods and partial or total reconstruction of the cavity. No single technique has proved superior. Other approaches that directly address the problem of epithelialisation have been used, including partial thickness skin grafting, autologous and indeed synthetic epidermal cell grafting, with varying degrees of success. We describe the Davis pinch graft technique, as devised by Holsted and popularized by Davis for venous ulcers. Free pinch grafts consisting of epidermis and small amounts of dermis are taken from the anterior abdominal wall and inserted into the revised mastoid cavity. We present a retrospective study of 15 patients who underwent revision mastoidectomy and Davis pinch grafting for persistent ottorrhoea, and discuss the results with respect to patient symptomatology and the surgeons assessment of the cavity. In conclusion, we believe that the Davis pinch graft has a proven beneficial effect in the management of post-mastoidectomy otorrhoea.

Adolescent↗
PubMed1994

Massive epistaxis following sphenoid sinus exploration.

Internal carotid artery trauma is a rare but potentially disastrous complication of surgery to the sphenoid sinus and pituitary gland. Emergency and elective procedures to establish haemostasis are discussed.

Aneurysm, False↗
PubMed1994

Angioedema secondary to angiotensin-converting enzyme inhibitors.

Angioedema secondary to angiotensin-converting enzyme (ACE) inhibitors is rare, but it is a side effect which is likely to be seen more frequently because of the increased use of these drugs to treat cardiac failure and hypertension. Presentation is variable and the diagnosis may go unrecognized for many months or years. The cases reported illustrate problems both in the diagnosis and management of this life-threatening condition.

Adult↗
PubMed1994

Impaired high-intensity cycling performance time at low levels of dehydration.

On two separate occasions six trained subjects (peak oxygen consumption [VO2peak] 4.41/min) rode for 60 min at 70% of VO2peak and then to exhaustion at 90% of VO2peak to determine the effects of mild dehydration on high-intensity cycling performance time in the heat (32 degrees C, 60% relative humidity, wind speed 3 km/h). In one trial (F) subjects ingested a 400 ml bolus of 20 mmol/l NaCl immediately before, and then as repetitive 120 ml feedings every 10 min during the first 50 min of exercise. In the other trial they did not ingest fluid (NF) either before or during exercise. The order of testing was in a counter-balanced random sequence. For the first 60 min of exercise mean (+/- SD) VO2 (2.90 +/- 0.39 vs 2.93 +/- 0.38 l/min) and respiratory exchange ratio (RER; 0.95 +/- 0.03 vs 0.94 +/- 0.04) values were similar between F and NF trials. However, weight loss was significantly reduced during F compared to NF (0.16 +/- 0.39 vs 1.30 +/- 0.22 kg; p < 0.005) and high-intensity cycling time to exhaustion was significantly increased (9.8 +/- 3.9 vs 6.8 +/- 3.0 min; p < 0.005). Increased cycling times to exhaustion in the F trial were not associated with any measurable differences in heart rate (HR), body temperature, respiratory gas exchange, leg muscle power over 5 sec, or the degree to which fluid ingestion reduced the level of dehydration within the group. Only the ratings of perceived exertion (RPE) and plasma anti diuretic hormone (ADH) concentrations were significantly increased in the NF trial compared to the F trial.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Sudden contralateral deafness following cerebellopontine angle tumor surgery.

Sudden hearing loss in the contralateral ear is a rare but catastrophic complication of acoustic tumor surgery. The seventh case in the literature is reported. Hearing can return, but this is less likely when the tumor was large or a suboccipital approach was used. A short course of corticosteroids, carbogen, and histamine cannot be shown to be effective but is probably worthy of consideration. Cochlear implantation may have a role if irreversible hearing loss persists 18 months after surgery.

Adult↗
PubMed1993

Jugular bulb phlebectasia.

Phlebectasia of the internal jugular vein (IJV) is a rare venous anomaly that usually presents in young children as a soft cystic swelling in the neck and represents a pathologically enlarged vein. We present a case of jugular bulb phlebectasia in a 4-year-old boy. He presented with a blue pulsatile swelling arising from the floor of the left middle ear cleft. The venous phase of digital subtraction vertebral arteriography (DSVA) and computerised axial tomography (CT) with contrast confirmed a diagnosis of phlebectasia of the lateral sinus and proximal part of the left IJV, with a complete bony defect in the floor of the middle ear. The child did not have any neck symptoms or signs. No active treatment was required. To our knowledge, this is the first case of jugular bulb phlebectasia presenting in the middle ear.

Angiography, Digital Subtraction↗
PubMed1992

Bilateral internal jugular phlebectasia.

Internal jugular phlebectasia is a venous anomaly commonly presenting as a unilateral neck swelling in children. The clinicopathology, aetiology and management are discussed. Bilateral doppler ultrasonography is the diagnostic investigation of choice and should be performed in all suspected cases. Conservative management of the bilateral case is recommended.

Child, Preschool↗
PubMed1992

Does oxygen supply improve graft viability in liver preservation?

While the clinical results of orthotopic liver transplantation have greatly improved, the viability of liver grafts and extension of the safe time for preservation are necessary factors in need of improvement. The liver is one of the organs most sensitive to anoxia. The addition of an oxygen carrying agent to the preservation solution was evaluated. Pyridoxalated hemoglobin-polyoxyethylene conjugate (PHP) is used as an oxygen carrier. Viaspan (UW) served as a control solution. Test solution (PHP+UW) composition was composed of a 1:1 mixture of PHP and UW solutions with hemoglobin 4.0g%, hydroxyethyl starch 2.5g%, osmolality 320 mOsm/kg H2O, and colloidal osmotic pressure 33 mmHg. The oxygen carrying capacity of PHP+UW solution is about 10 times higher than UW solution at 4 degrees C. Male Lewis rats (BW: 250-300 g) were divided into five groups. After flushing the solution via the portal vein, rat livers were harvested. Two preservation methods, simple storage and perfusion (0.1 ml/min/g liver), were studied at 4 degrees C for 24 or 48 hours. OxyHb, MetHb, pO2, pH, Na, K, GOT, and GPT of perfusate, hepatic mitochondrial functions after preservation, and tissue adenine nucleotides by HPLC were measured. Light microscopy on the tissue was also performed. No significant differences were noted in perfusate biochemical parameters. Oxygen consumption during the perfusion was significantly higher in the PHP+UW than in the UW group. Hepatic mitochondrial functions and tissue ATP levels were better preserved in perfusion than in simple storage, and in PHP+UW than in UW at 48 hours. The oxygen carrying agent, PHP, can provide significantly higher levels of oxygen to liver grafts and improve graft viability.

Adenosine Triphosphate↗
PubMed1990

Mortality and quality of life after total abdominal colectomy.

We have reviewed the results of 107 consecutive total abdominal colectomies performed at our institutions during the past 10 years. Indications for surgery were carcinoma of the colon (60), multiple polyps (nine), diverticular disease (31), and other conditions (seven). Seven (6.5%) were emergency operations. All patients had anastomosis of the terminal ileum into the lower rectum or distal sigmoid colon no more than 25 cm above the anus. Thirty days after surgery, two patients (1.8%) had died of complications of anastomotic leaks. Both were poor candidates for primary reanastomosis. Morbidity was low, occurring in 11 patients (10.3%). Follow-up evaluation of bowel function revealed satisfactory results in 102 patients (95%). Five patients (5%) had experienced chronic debilitating diarrhea. Unfavorable results were more common with diverticular disease than with neoplasia.

Adult↗
PubMed1989

Effects of a task-specific warm-up on anaerobic power.

Twenty-four untrained (UT) males (age 21 +/- 2.5 yr, height 1.77 +/- 0.05 m, weight 75.3 +/- 10.1 kg, values mean +/- SD) performed the Wingate Anaerobic Test (WT) under two conditions, cold (C) and following a warm-up (WU). Trials were separated by a minimum of 48 h. A modified Monark 818 cycle ergometer was interfaced with an Apple IIE microcomputer and peak power (PEAK), mean power (MEAN) and fatigue index (FI) determined. The WU trial consisted of an 8 min incremental continuous cycling bout (cadence 90 rev.min-1) with 5 min rest before the WT. During the C trial subjects completed only the WT. A repeated measures design was employed with order of trials counterbalanced. ANOVA revealed no significant differences for PEAK or MEAN between WU or C conditions. However FI was significantly greater (p less than 0.05) following the WU. A significant correlation (r = 0.45, p = 0.03) was obtained between WU intensity and FI. These findings suggest that our UT subjects were fatiguing themselves during the WU. Future studies are needed to assess whether a task-specific WU in which FI is not impaired would lead to improvements in PEAK and MEAN. Investigators should be aware that a self-spaced WU may increase FI in the WT in UT subjects.

Adult↗
PubMed1984

Morphometric evaluation of lipid droplet associations with secretory vesicles, mitochondria and other components in the lactating cell.

The size, cellular location, and identity of surface-associated components were determined for lipid droplets in lactating cells. Transmission electron-microscopic measurements were made involving 3801 droplets in approximately 211 cells from three rats and 1197 droplets in 66 cells from a mouse. For the purposes of droplet evaluation, cells were divided into seven locations ranging from basal to secreting positions. Droplets were also categorized with respect to contact with other droplets, basolateral plasma membrane, mitochondria, Golgi apparatus, secretory vesicles, and endoplasmic reticulum-cytoplasm (ERC). Data on droplet size showed that droplet growth occurs mainly in the secretory position, confirming previously published findings. Lipid droplets from mouse tissue, although somewhat smaller in size showed similar growth trends to those of the rat. Data on numbers of droplet contacts and percentages of droplet circumferences involved in associations with other cell components showed that the dominant interaction of lipid droplets was with the ERC. However, intimate association of droplets with mitochondria was noted in all cellular locations. In addition, nursed animals exhibited a greater proportion of droplet surface association with secretory vesicles and less in contact with mitochondria in comparison to those not nursed. The significance of these relationships to milk synthesis and secretion is discussed.

Animals↗
PubMedDate not supplied

Laparoscopic cryoablation of hepatic metastases.

Cryosurgery for liver metastases may improve survival for unresectable hepatic metastases. The laparoscopic approach to managing these tumors is a novel method fostered by increasing surgeon and patient interest in minimally invasive surgical techniques and the development of laparoscopic ultrasound and cryoprobes. A retrospective review of our patients who underwent laparoscopic cryoablation of hepatic tumors from April 1996 to December 1997 was conducted. We report on this experience and comment on the feasibility and safety of the procedure based on this early trial.

Cryosurgery↗
PubMedDate not supplied

Endoscopic resection of large sessile colorectal polyps.

Colonoscopic removal of large, sessile polyps is difficult, but can be successfully carried out by experienced endoscopists. "Piecemeal" resection with an electrocautery snare was performed at our institution in 108 patients with 132 such lesions. The mean size of the unresected polyps was 3.0 cm. Complications occurred in 3.0% of polypectomies (3.8% of patients), with bleeding necessitating transfusion in 2.3% of polypectomies (2.8% of patients), and microperforation (probable) in the remainder. No patient required emergency surgery due to a complication. In 65 patients (60%), colonoscopic resection and follow-up alone was carried out. Of these, adenomas recurred/persisted in 28%, most of which were successfully re-resected. Nearly half of all recurrent polyps occurred after at least one negative intervening examination. Carcinoma later appeared in 17% of the recurrences despite apparent initial complete resection of a previously benign polyp. Cure was ultimately achieved in 88% of endoscopically managed patients. Surgical resection was required in 27% of patients, mostly following the initial polypectomy when invasive carcinoma was found in the specimen. No residual tumor was later found in 41% of the colon specimens from these patients. Ninety-one percent of cancers were favorable stage, whether discovered early or late. Follow-up colonoscopy was achieved in 77% of patients over an average of 3.7 years. Metachronous polyps were excised in 52 patients (63%) and metachronous carcinoma was diagnosed in 3 patients (3.6%). An aggressive regimen of surveillance colonoscopy is warranted in these patients to detect and manage local recurrences and to remove subsequent adenomas. Endoscopic resection of large sessile adenomas can be safe and effective.

Aged↗