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Biomedical subjects

A R Harrison

Publications and source records attributed to A R Harrison.

At least 19 recordsLinked to original sources
PubMed2004

Doxycycline and intracranial hypertension.

The authors report seven patients from six neuro-ophthalmology referral centers who developed pseudo-tumor cerebri during treatment with doxycycline. All four female patients and one of three male patients were obese. Vision was minimally affected in most patients, but two had substantial visual acuity or visual field loss at presentation. Discontinuation of doxycycline, with or without additional intracranial pressure-lowering agents, yielded improvement, but permanent visual acuity or visual field loss occurred in five patients.

Acne Vulgaris↗
PubMed2003

Myotonic dystrophy type 2: molecular, diagnostic and clinical spectrum.

BACKGROUND: Myotonic dystrophy types 1 (DM1) and 2 (DM2/proximal myotonic myopathy PROMM) are dominantly inherited disorders with unusual multisystemic clinical features. The authors have characterized the clinical and molecular features of DM2/PROMM, which is caused by a CCTG repeat expansion in intron 1 of the zinc finger protein 9 (ZNF9) gene. METHODS: Three-hundred and seventy-nine individuals from 133 DM2/PROMM families were evaluated genetically, and in 234 individuals clinical and molecular features were compared. RESULTS: Among affected individuals 90% had electrical myotonia, 82% weakness, 61% cataracts, 23% diabetes, and 19% cardiac involvement. Because of the repeat tract's unprecedented size (mean approximately 5,000 CCTGs) and somatic instability, expansions were detectable by Southern analysis in only 80% of known carriers. The authors developed a repeat assay that increased the molecular detection rate to 99%. Only 30% of the positive samples had single sizeable expansions by Southern analysis, and 70% showed multiple bands or smears. Among the 101 individuals with single expansions, repeat size did not correlate with age at disease onset. Affected offspring had markedly shorter expansions than their affected parents, with a mean size difference of -17 kb (-4,250 CCTGs). CONCLUSIONS: DM2 is present in a large number of families of northern European ancestry. Clinically, DM2 resembles adult-onset DM1, with myotonia, muscular dystrophy, cataracts, diabetes, testicular failure, hypogammaglobulinemia, and cardiac conduction defects. An important distinction is the lack of a congenital form of DM2. The clinical and molecular parallels between DM1 and DM2 indicate that the multisystemic features common to both diseases are caused by CUG or CCUG expansions expressed at the RNA level.

Adolescent↗
PubMed2003

Identification of a mutation associated with erythromycin resistance in Bordetella pertussis: implications for surveillance of antimicrobial resistance.

Erythromycin treatment failures and in vitro resistance of Bordetella pertussis have been reported on several occasions in the past few years, but the mechanism of resistance has not been described. One potential mechanism, genetic modification of the erythromycin-binding site on the 23S rRNA of the 50S ribosomal subunit, has been observed in other bacteria. To explore this possibility, we amplified the portion of the 23S rRNA gene encoding the central loop of domain V. DNA sequencing and restriction fragment length polymorphism of the PCR products showed that each of the four erythromycin-resistant B. pertussis strains tested contained an A-to-G transition mutation at position 2058 (Escherichia coli numbering) of the 23S rRNA gene. The mutation was not found in seven erythromycin-susceptible isolates tested. Two of the resistant isolates were heterozygous, containing at least one mutant copy and one wild-type copy of the 23S rRNA gene. These results indicate that erythromycin resistance in these strains is likely due to a mutation of the erythromycin-binding site in the 23S rRNA gene. Identification of the resistance mechanism will facilitate development of molecular susceptibility testing methods that can be used directly on clinical specimens in the absence of an isolate.

Anti-Bacterial Agents↗
PubMed1999

Isolated inferior rectus paresis secondary to a mesencephalic cavernous angioma.

PURPOSE: To report a case of recurrent binocular, vertical diplopia presenting as an isolated, unilateral inferior rectus paresis occurring in a patient with a mesencephalic tegmental cavernous angioma. METHOD: Case report. A 30-year-old man with recurrent vertical diplopia underwent neuro-ophthalmic examination, laboratory examination, pharmacologic testing, and magnetic resonance imaging and angiography. RESULTS: Magnetic resonance imaging disclosed a lesion in the mesencephalon consistent with a cavernous angioma. Magnetic resonance angiography was negative. CONCLUSIONS: Isolated inferior rectus paresis is a rare phenomenon. This unique case involved a patient with recurrent inferior rectus paresis secondary to a mesencephalic cavernous angioma. The disparity between the extent of the lesion and the neuro-ophthalmologic consequences is remarkable.

Adult↗
PubMed1999

Levator aponeurosis disinsertion in congenital entropion of the upper eyelid.

PURPOSE: To present a patient with congenital entropion of the upper eyelid caused by levator aponeurosis disinsertion. METHODS: Case report. RESULTS: Surgical correction of the levator aponeurosis disinsertion corrected the upper eyelid entropion. CONCLUSIONS: Congenital upper eyelid entropion may be caused by levator aponeurosis disinsertion and treated effectively by repairing the anatomic defect.

Entropion↗
PubMed1998

Etiology of immune stromal (interstitial) keratitis.

PURPOSE: We compared the etiologies of immune stromal keratitis (ISK), also known as interstitial keratitis (IK), in a recent group of patients with active and inactive ISK. METHODS: We reviewed the charts of 97 patients seen in the cornea clinic at the University of Minnesota from 1985 through 1994. Fifty-five patients were classified as having active ISK, defined by stromal inflammation without ulceration within 1 year of presentation. Forty-two patients were identified as having inactive ISK, defined by evidence of past stromal inflammation including stromal scarring, stromal thinning, ghost vessels, and reduplication of Descemet's membrane without active inflammation for the 1 year before presentation. We determined the etiology of the ISK by careful review of the patient's ocular examination, as well as medical and laboratory workup. Patients were labeled with the diagnosis of idiopathic ISK if no identifiable etiology was found. RESULTS: Herpes simplex virus (HSV) accounted for 71.4% of unilateral active ISK. Idiopathic accounted for 14.3%, and varicella-zoster virus accounted for 8.6% in this group. HSV was the etiologic factor of 50.0% of inactive unilateral cases, whereas 33.3% were idiopathic. Sixty percent of cases of bilateral, active ISK were from idiopathic causes. Syphilis was the cause of 48.5% of bilateral inactive cases. In this group, 33.3% were from idiopathic causes. CONCLUSION: Although syphilis has been recognized for many years as the cause of 90% of cases of ISK, this is no longer true. We demonstrated that active ISK is most commonly caused by HSV or is idiopathic and that, although syphilis is the leading cause of inactive, bilateral ISK, it is responsible for only 18.6% of total cases.

Antibodies, Antinuclear↗
PubMed1997

Ocular neuromyotonia in a patient with cavernous sinus thrombosis secondary to mucormycosis.

PURPOSE: To report a case of ocular neuromyotonia occurring after cavernous sinus thrombosis secondary to mucormycosis. METHODS: Case report. We performed serial comprehensive neuro-ophthalmologic examinations. RESULTS: Fifteen months after initial total ophthalmoplegia of the right eye and complete right upper eyelid ptosis, isolated ocular neuromyotonia, characterized by episodic upward jerking movements of the right upper eyelid, was noted. CONCLUSION: Ocular neuromyotonia, which usually manifests in patients with a history of intracranial tumors and cranial radiation, may also be secondary to infectious cavernous sinus thrombosis.

Adult↗
PubMed1983

Cardiac arrhythmias during outpatient dental anaesthesia: comparison of halothane with enflurane.

In 75 young female patients undergoing extraction of 3rd molar teeth during halothane or enflurane anaesthesia, the electrocardiogram was recorded on magnetic tape and analysed subsequently for arrhythmias, using a high-speed analyser. Enflurane induced a much lower frequency of arrhythmia during surgery than halothane, but there was otherwise little difference between the two drugs in the quality of anaesthesia or recovery. Many arrhythmias occurred before exposure of the patient to enflurane or halothane; the significance of this is discussed.

Adolescent↗
PubMed1981

An outbreak of Nocardia asteroides infection in a renal transplant unit.

An outbreak of Nocardia asteroides infection occurred in the nephro-urological intensive care unit, St. Peter's Group of Hospitals, London in 1979. In is suggested that the outbreak has been due to patient-to-patient transmission. Five months before the outbreak. N. asteroides was first isolated from nephrostomy urine from an asymptomatic patient who had undergone several urological operations. Subsequently six of the seven patients admitted for renal transplant over a three month period developed proven infections. The first transplant patient had an abdominal abscess and the other five had only pulmonary disease with obvious radiological lesions. Bacteriological diagnosis was made in three patients by examination of sputum and in the other three from bronchoscopic specimen, pleural fluid and pus from an abscess respectively. Five of the six renal transplant patients were treated with amoxycillin and erythromycin. Clinical and radiological improvement was observed and no patient died as a result of the infection. In the intensive care unit air and dust samplings were positive for N. Asteroides. The unit was closed and fumigated with formaldehyde and when the air sampling continued to be negative the unit was then re-opened.

Adult↗