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Biomedical subjects

N Young

Publications and source records attributed to N Young.

At least 73 records · Page 4Linked to original sources
PubMed1994

Technetium-99m DTPA renography and angiography in renal artery stenosis of varying severity.

Thirty-five hypertensive patients, consecutively studied between 1986 and 1991, were retrospectively reviewed, to compare Technetium-99m (99mTc) DTPA renal scanning for renal artery stenosis with angiography. Ten patients were on chronic angiotensin converting enzyme (ACE) inhibitor medication and 20 underwent angioplasty of their stenoses. In patients not on ACE inhibitors the renal scan specificity was 83%, sensitivity 82%, negative predictive value 89% and positive predictive value 74%. In the 10 patients on ACE inhibitors the specificity was 67% (relatively more stenoses of < 50% were reported in this group), sensitivity 100%, negative predictive value 100% and positive predictive value 60%. Low levels of function (< 10 mL/min/1.73m2) in 9 kidneys did not militate against diagnoses that correlated well with angiography. Hence, renal scanning, particularly with ACE inhibition, is efficacious in the evaluation of possible renal artery stenosis. With a mean follow-up period of 29 months after percutaneous transluminal angioplasty (PTA), four patients had clinical improvement of hypertension control. Each had pre-PTA total glomerular filtration rates (GFR) of approximately 75 mL/min/1.73m2. No improvement was detected in cases with pre-PTA total GFR of < 50 mL/min/1.73m2. This may be the level of renal function below which PTA therapy or surgery will not provide benefit.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1994

Imaging of thoracic aortic dissection.

Acute thoracic aortic dissection has a high mortality if untreated, so the diagnosis must be rapidly made if mortality is to be lowered significantly. Multiple imaging techniques are often used. This retrospective study from 1988 to 1993 assesses the usefulness in diagnosis of chest X-rays, computed tomography (CT) scanning, aortography, magnetic resonance imaging (MRI), trans-thoracic (TTE) and trans-oesophageal (TOE) echocardiography. Forty-two patients with a final clinical diagnosis of dissection were studied. The diagnosis was confirmed in 16 (13 at surgery and three at autopsy). Three died with dissection given as the only cause for death. Chest X-ray abnormalities were seen in all 19 patients with surgery or death from dissection, with a widened mediastinum and/or dilated aorta being present in 17. In the group of 16 patients with surgery or autopsy proof, CT scans found dissections in 9 of 12 patients studied and correctly classified the type in only five. Aortography was performed in five, with accurate depiction of dissection and type in all. TTE found dissections in three of eight patients imaged by this method. MRI and TOE were performed each on two patients, with accurate depiction of dissection and type in each. Because of the relatively low sensitivity of CT scanning in defining aortic dissections Westmead Hospital is currently assessing the use of TOE as the prime imaging modality prior to surgical intervention.

Acute Disease↗
PubMed1994

Bronchial artery embolization to control haemoptysis.

This is a retrospective study of 15 patients who had bronchial artery angiography and embolization for life-threatening haemoptysis in the period January 1986 to March 1993. Eight were male and seven were female, in the age range 32-77 years. Massive haemoptysis has a 50-100% mortality if treated conservatively and surgery has an up to 35% mortality in this high-risk group. Nine patients had advanced tumours. Seven had technically successful procedures, with haemoptysis being controlled in six and one patient dying from post-procedural massive haemoptysis. One of the patients with failed embolization died from massive haemoptysis and the other had spontaneous settling of bleeding. The other six patients suffered from bronchiectasis (2), aspergilloma involving tuberculous cavity (2), active tuberculosis (1), and abscess cavity presumably due to vasculitis (1). Technically successful embolizations were achieved in all six; three had control of haemoptysis, one required successful re-embolization after massive bleeding following initial embolization, one suffered continuing non-massive bleeding and one died soon afterwards from massive haemoptysis.

Adult↗
PubMed1994

Leaking mycotic abdominal aortic aneurysm.

A case of leaking mycotic abdominal aortic aneurysm is reported, with a brief review of the literature. A 58 year old female presented with shoulder and abdominal pain associated with diarrhoea, vomiting and fever with leucocytosis. Computed tomography of the abdomen showed pooling of contrast in the retroperitoneum anterior to a non-dilated abdominal aorta. There was considerable retroperitoneal blood accumulating in a mass-like lesion in the right lower abdomen and pelvis obstructing the right renal collecting system. Laparotomy revealed a 4 cm diameter saccular aneurysm of the abdominal aorta, with a 1 cm diameter neck. Culture of the thrombus grew Streptococcus pyogenes.

Aneurysm, Infected↗
PubMed1994

Bone density at weight-bearing and nonweight-bearing sites in ballet dancers: the effects of exercise, hypogonadism, and body weight.

Exercise is recommended as a means of preventing osteoporosis. When intensive, weight-bearing exercise is often associated with hypogonadism. As weight-bearing exercise is likely to be more beneficial at weight-bearing than nonweight-bearing sites, and hypogonadism is likely to be more detrimental to trabecular than cortical bone, we tested the hypothesis that exercise and hypogonadism result in differing regional effects: net benefits at weight-bearing, predominantly cortical sites, and net deficits at nonweight-bearing trabecular-rich sites. Bone density (grams per cm2), body fat, and fat-free mass (kilograms) were measured using dual x-ray absorptiometry in 44 ballet dancers, aged 17.0 +/- 0.2 yr (mean +/- SEM), 18 sedentary amenorrheic girls with anorexia nervosa, and 23 girls of comparable age with regular menstrual cycles. Bone density, expressed as a percentage above or below the mean in the girls with regular menstrual cycles, was normal or elevated at weight-bearing sites in dancers [femoral neck, 3.1 +/- 1.7% (P = NS); Wards triangle, 4.1 +/- 2.3% (P = NS); trochanter, 5.9 +/- 1.9% (P < 0.05)] and normal or reduced at these sites in girls with anorexia nervosa [-10.5 +/- 3.8% (P < 0.05), -7.8 +/- 4.3% (P = NS), and -8.7 +/- 4.0% (P < 0.05), respectively]. By contrast, deficits similar to those in girls with anorexia nervosa were found in dancers at nonweight-bearing sites [ribs, -5.7 +/- 0.8% (P < 0.01); arms, -4.6 +/- 1.1% (P < 0.01); skull, -5.9 +/- 1.3% (P < 0.01)] before, but not after, correcting for fat mass. Fat mass was 7.8 +/- 0.4 kg in dancers, similar to that in girls with anorexia nervosa (6.3 +/- 0.7 kg) and lower than that in girls with regular menstrual cycles (16.8 +/- 1.6 kg; P < 0.01). The net result of vigorous exercise, hypogonadism, and leanness in athletic amenorrhea may not be generalized osteoporosis. Weight-bearing exercise may offset the effects of hypogonadism at predominantly cortical weight-bearing sites, such as the proximal femur. Non-weight-bearing sites and weight-bearing sites containing substantial amounts of trabecular bone, such as the lumbar spine, may be adversely affected by hypogonadism while benefiting little from weight-bearing exercise. Deficits at nonweight-bearing sites may be attenuated by maintenance of body weight.

Absorptiometry, Photon↗
PubMed1994

Bone mass during growth: the effects of exercise. Exercise and mineral accrual.

Intense exercise during childhood and adolescence may result in primary amenorrhea and low peak bone mineral density (BMD). After puberty, exercise may result in secondary amenorrhea and bone loss. Higher BMD in amenorrheic athletes than amenorrheic sedentary persons suggests that exercise may partly offsets the effects of amenorrhea. To examine this possibility, we measured BMD (g/cm2) by dual x-ray absorptiometry in 32 ballet dancer and 23 healthy controls of comparable age with regular menstrual cycles, 34 pre-pubertal female gymnasts bone age 8.9 +/- 0.2 years and 37 girls matched by bone age. Dancers had normal BMD at the weight bearing sites, not low, despite having oligomenorrhea, not high despite 32 hours of week dancing. BMD was lower by 4-6 percent at the non-weight bearing sites. BMD diminished in the dancers at the weight bearing femoral neck (r = -0.29, P = 0.1) and trochanter (r = -0.31, P = 0.09), and at the non-weight bearing arms (r = -0.29, P = 0.09) with increasing duration of amenorrhea. Dancers with less than 40 months amenorrhea had 5 to 7% higher BMD at the weight bearing, but not non-weight bearing sites. Dancers with more than 40 months amenorrhea had normal, not higher BMD at weight bearing sites and deficits of about 5 percent at non-weight bearing sites. In gymnasts, BMD was 10-15 percent (or 1 SD) higher than the bone age-predicted mean. Exercise may not offset the effects of amenorrhea. Bone loss may continue but from a higher level, perhaps attained prior puberty.

Adolescent↗
PubMed1993

Symptom relief and survival after chemo-embolization with adriamycin, lipiodol and gelfoam for hepatocellular carcinoma.

This is a retrospective study to evaluate the ability of arterial chemo-embolization with Adriamycin, Lipiodol and Gelfoam to relieve symptoms, primarily abdominal pain, and to prolong survival in patients with hepatocellular carcinoma. Twenty patients were referred from 1986 to 1991 and in 18 the chemo-embolization procedure was successful. In the follow-up period to March 1992, 17 patients had died. Their survival times were not found to be significantly different from the reported rates of survival in patients given no therapy. In only one of 10 patients followed with computed tomography was a reduction in tumour size seen. Nine of 11 patients with pain reported significant relief from pain following treatment. Six patients had repeat embolizations that successfully relieved recurrent pain. In the authors' experience chemo-embolization was helpful in relieving pain, but did not prolong life.

Adult↗
PubMed1993

Acute intracerebral haematomas: assessment for possible underlying cause with MRI scanning.

Forty-seven patients presenting with acute intracerebral haematomas between 1989 and 1992 were retrospectively examined to assess the role of Magnetic Resonance Imaging (MRI) in identifying any underlying lesion. None had any prior known intracerebral pathology. Magnetic resonance imaging scans were done on a 0.5 T unit. Ten patients with an average age of 35 years had angiographically occult vascular malformations (AOVM) found by MRI (one with biopsy confirmation). One of three cases of glioma, three of three cases with secondary tumour, one case of superior sagittal sinus thrombosis with haemorrhagic infarction, one of two cases of venous angioma and one case of arteriovenous malformation were detected by MRI. Progress computed tomography scans discovered two cases of glioma and angiography found a venous angioma and an arterial aneurysm, all undetected by MRI. It is concluded that MRI scanning is helpful in detecting underlying AOVM as a cause of intracerebral haemorrhage but its role in imaging haemorrhagic tumours remains unclear.

Acute Disease↗
PubMed1992

Comparison of duplex ultrasound with angiography in assessment of carotid bifurcation disease.

This is a study comparing duplex ultrasound against the "gold standard" of angiography in assessing atherosclerotic disease of the carotid bifurcation, prior to prospective endarterectomy surgery. Thirty-nine patients were studied with both sonography and angiography studies being performed within one month of each other. Plaques were described by sonography as being "smooth" or "irregular" in surface and "homogeneous" or "heterogeneous" in composition. Ultrasound showed an overall 92% sensitivity, against the standard of angiography, in its ability to assess the degree of internal carotid stenosis. There was only a 63% sensitivity with the common carotid arteries and only a 65% sensitivity with the external carotid arteries. Ultrasound did not show a high accuracy in detecting plaque ulceration when compared against angio-graphy.

Adult↗
PubMed1992

Use of percutaneous transluminal balloon angioplasty to treat renovascular disease.

This is a retrospective study of the ability of percutaneous transluminal balloon angioplasty (PTA) to treat hypertension and renal impairment in patients with haemodynamically significant renal artery stenoses (those over 50%). Thirty-two patients underwent PTA procedure in a 4 year study period. Seventeen were male, 15 female, with an average age of 61 years. Thirty patients had atherosclerosis and 2 had fibromuscular hyperplasia (FMH) lesions. The procedure was technically unsuccessful in 28% of 37 arteries attempted, primarily in the > 80% stenosis group. The mean clinical follow-up period was 20 months. In those patients with technically successful PTAs, none was cured, with no change in the status of hypertension or medication required. Clinical improvement was seen in 37% (7 of 19) patients with atherosclerotic disease and who had PTA of significant unilateral lesions or of the haemodynamically significant side in cases of bilateral disease. Two patients with FMH lesions had improvement. Five patients with PTA of only one side in cases of significant bilateral disease gained no benefit. Nine patients with pre-existent renal insufficiency and technically successful PTAs had no improvement of renal function. No mortality or any significant morbidity resulted from the procedure. These results are more compatible with more recent than the earlier literature.

Adult↗
PubMed1992

Multiple use of cycler set in cycler peritoneal dialysis.

STUDY OBJECTIVE: To evaluate the multiple use of cycler set with universal connector set. DESIGN: The study was designed to reuse the cycler set for two to three treatments, each of 16-24 hours using Pac-X or Pac-Xtra cycler and to continue to use the same set if the patient was disconnected for any reason. SETTING: Tertiary-referral university hospital. PATIENTS AND METHODS: 204 ESRD patients on peritoneal dialysis (PD) admitted to University Hospital from January 1989 to July 1991 were studied. The patients were disconnected and reconnected in between or during PD treatments. Five-liter dialysate bags were used. All the fluid was either set initially or added as clinically indicated. RESULTS: 2491 cycler PD treatments were performed with Pac-X and Pac-Xtra cyclers using 940 cycler tubing sets. 1624 disconnections were made in between and 336 were made for radiological investigations, special procedure, physical therapy and surgery during PD treatments. No episode of peritonitis or mechanical failure occurred. The multiple use resulted in 62% reduction in cycler sets thereby reducing the disposable supplies and a substantial saving in the nursing time. CONCLUSIONS: The multiple use of cycler set with universal connector and manifold set was safe and economical in the patients undergoing cycler PD in the hospital setting.

Humans↗
PubMed1991

Positive role of Clostridium difficile infection in diarrhea in infants and children.

A retrospective review of children with Clostridium difficile infection and diarrhea identified 43 patients. Fifteen (35%) had immunoglobulins below the normal range for age, and typified those with transient hypogammaglobulinemia of infancy, because all increased their levels over the following 12 months. The age of those with hypogammaglobulinemia was significantly younger (p less than 0.01), averaging 18.8 months, than those with normal immunoglobulins who had a mean age of 4.6 yr. The number with recurrent C. difficile infection was significantly greater (p less than 0.001) in the hypogammaglobulinemic group than in those with normal immunoglobulins (46% vs 18%). Eleven children were identified who had C. difficile toxin in the stool after antibiotic therapy, but who had no diarrhea at the time of study. All had normal immunoglobulins. Control patients (20 without and 40 with diarrhea) had no evidence of C. difficile infection, and all but three had normal immunoglobulins. Three (7%) of those with diarrhea had IgA deficiency, and all had a diagnosis of milk protein allergy. These data suggest that immunoglobulin values be obtained in infants and children who have problematic C. difficile diarrhea in order to identify disorders of immunoglobulin synthesis which may be the underlying cause of repeated upper respiratory disease requiring antibiotic usage.

Adolescent↗