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Biomedical subjects

J Gardner

Publications and source records attributed to J Gardner.

At least 271 records · Page 15Linked to original sources

Alphavirus-specific cytotoxic T lymphocytes recognize a cross-reactive epitope from the capsid protein and can eliminate virus from persistently infected macrophages.

Persistent alphavirus infections in synovial and neural tissues are believed to be associated with chronic arthritis and encephalitis, respectively, and represent likely targets for CD8+ alphabeta cytotoxic T lymphocytes (CTL). Here we show that the capsid protein is a dominant target for alphavirus-specific CTL in BALB/c mice and that capsid-specific CTL from these mice recognize an H-2Kd restricted epitope, QYSGGRFTI. This epitope lies in the highly conserved region of the capsid protein, and QYSGGRFTI-specific CTL were cross reactive across a range of Old World alphaviruses. In vivo the acute primary viraemia of these highly cytopathic viruses was unaffected by QYSGGRFTI-specific CTL. However, in vitro these CTL were able to completely clear virus from macrophages persistently and productively infected with the arthrogenic alphavirus Ross River virus.

Alphavirus↗

Intravenous drug use and glomerular deposition of lipid-like material.

UNLABELLED: We present a series of 5 intravenous drug users (4 male, age range 24-47 years) with glomerular deposition of a lipid-like material. Three patients presented with the nephrotic syndrome, 1 with acute renal failure and 1 with hypertension and an active urinary sediment. All were continuing to use opiates intravenously (mixed with lemon juice or acetic anhydride and sodium bicarbonate). INVESTIGATIONS: plasma creatinine 0.10-0.30 mmol/l, urinary protein excretion 1.0-6.75 g/24 h, hepatitis C antibody positive (4), all seronegative for hepatitis B and HIV. Renal biopsy showed large vacuolated areas consistent with heavy deposition of lipid-like material in all glomerular cells and infiltrating macrophages. Two showed ATN and another FGS. We suggest that these changes are due to the pattern of illicit drug availability and preparation peculiar to these users.

Acute Kidney Injury↗

Illicit drug-associated ischemic stroke in the Baltimore-Washington Young Stroke Study.

BACKGROUND: Limited information exists on the frequency, trends in occurrence, risk factors, mechanisms, and outcome of ischemic stroke associated with illicit drug use among young adults in a geographically defined population. METHODS: We reviewed ischemic stroke in young adults (aged 15 to 44 years) in 46 regional hospitals for 1988 and 1991. We examined stroke mechanisms and outcome in patients with recent drug use. RESULTS: Recent illicit drug use was noted in 51/422 (12.1%) stroke patients. Patients with drug use were more likely than other stroke patients to be black (p=0.01), aged 25 to 39 years (p=0.004), and smokers (p=0.006), and were less likely to have hypertension (p=0.004) or diabetes mellitus (p=0.004). Drug use was the probable cause of stroke in 20 (4.7%) patients. Among 31 (7.3%) patients with drug use as a possible stroke mechanism, more likely diagnoses included cardioembolic stroke in 18, hematologic/collagen vascular in 6, nonatherosclerotic vasculopathy in 5, and atherosclerosis in 3. There was no difference in outcome between drug-associated and non-drug associated stroke. CONCLUSIONS: Recent illicit drug use occurs in 12.1% of young adult stroke patients. Drug-associated young adult stroke seems to relate to vascular mechanisms other than those related to hypertension or diabetes. Case-control studies are needed.

Adolescent↗

Stroke in children and sickle-cell disease: Baltimore-Washington Cooperative Young Stroke Study.

BACKGROUND/PURPOSE: The Baltimore-Washington Cooperative Young Stroke Study is the largest biracial urban-suburban population-based study to examine the etiology of strokes in children. METHODS: We identified all children aged 1 to 14 years discharged from all 46 hospitals in central Maryland and Washington, DC with a diagnosis of ischemic stroke and intracerebral hemorrhage in the years 1988 and 1991. Each medical record was reviewed by two neurologists for appropriateness of the diagnosis of stroke and for information on the patient's history, clinical presentation, pertinent investigations, hospital stay, and outcome at time of discharge. RESULTS: Eighteen children with ischemic infarction and 17 with intracerebral hemorrhage were identified. The most common cause of ischemic stroke was sickle-cell disease (39%), followed by vasculopathic (33%) and indeterminate (28%) causes. Causes of intracerebral hemorrhages were arteriovenous malformation (29%), hematologic (23%), vasculopathy (18%), surgical complication (12%), coagulopathy (6%), and indeterminate (12%). The overall incidence for childhood stroke was 1.29 per 100,000 per year, with ischemic stroke occurring at a rate of 0.58 per 100,000 and intracerebral hemorrhage occurring at a rate of 0.71 per 100,000. The incidence of stroke among children with sickle-cell disease was estimated to be 0.28% or 285 per 100,000 per year. CONCLUSION: Sickle-cell disease plays a disproportionately high role in childhood stroke when a biracial population is surveyed.

Adolescent↗

Clinical audit of the use of renal biopsy in the management of isolated microscopic hematuria.

Whether renal biopsies are indicated for the investigation of microscopic hematuria is a subject of debate. In this retrospective study we evaluated our use of renal biopsy in patients who presented between 1985 and 1995 with microscopic hematuria but without proteinuria, hypertension or renal insufficiency. Of 111 patients, 75 had a renal biopsy. Histological diagnoses included thin membrane nephropathy (TMN) (36%), IgA nephropathy (IgAN) (23%), non-IgA mesangioproliferative glomerulonephritis (MPGN) (9%), mild glomerular abnormalities (11%), focal global glomerulosclerosis (FGS) (4%) and normal (17%). After 85 patients had been followed for a mean of 43 months there were no deaths, 3 patients had proteinuria (IgAN 2, no biopsy 1), 1 had proteinuria and renal insufficiency (immune negative MPGN) and 11 were hypertensive (TMN 3, IgAN 2, normal 2, FGS 1, no biopsy 3). Hematuria resolved in 23 patients. Only 11 patients were still attending the nephrology clinic and 27% of the patients who were advised to continue annual follow-up with family doctors had not done so. In summary, the information obtained from renal biopsy rarely altered clinical management. Hypertension developed in 13% of the patients followed but it was not predicted by the biopsy result. Although a renal biopsy will usually be diagnostic it is difficult to justify in patients who have isolated microscopic hematuria.

Adult↗