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Biomedical subjects

K McClellan

Publications and source records attributed to K McClellan.

15 recordsLinked to original sources
PubMed1999

Squamous cell carcinoma with necrotizing scleritis.

PURPOSE: To report on a case of limbal squamous cell carcinoma (SCC) with necrotizing scleritis in a young, previously healthy, white Australian male. METHODS: A 31-year-old man presented with a left limbal lesion intermittently causing a red eye and foreign body sensation. He had enjoyed surfing for many years. Repeat HIV tests were negative and the lesion was biopsied. RESULTS: Biopsy showed a well-differentiated SCC apparently arising in an intra-epithelial (in situ) carcinoma of the conjunctiva. The lesion was excised and a corneoscleral graft repair was performed. CONCLUSION: The present case highlights the potential for a significant increase in the prevalence of ocular surface neoplasia in healthy young people who have had excessive UV-B exposure.

Adult↗
PubMed1998

Sudden loss of vision.

BACKGROUND: Sudden loss of vision is an ophthalmological emergency. OBJECTIVE: This article explains how history and examination, particularly ophthalmoscopy, will greatly assist the general practitioner to diagnose the cause. DISCUSSION: Vision loss may be transient or prolonged. It is important to consider whether the eye is painful or comfortable, inflamed or not. An accurate diagnosis will direct the emergency management, which frequently determines the prognosis for vision.

Eye Diseases↗
PubMed1994

Suppurative corneal ulceration in Bangladesh. A study of 142 cases examining the microbiological diagnosis, clinical and epidemiological features of bacterial and fungal keratitis.

Suppurative keratitis is an important preventable cause of blindness, particularly in the developing world. This study analyses 142 cases of suppurative keratitis referred to Chittagong Eye Infirmary Bangladesh. Some 53.5% of cases were bacterial and 35.9% were fungal. The five most common pathogens were: Pseudomonas sp. 24%, Streptococcus pneumoniae 17%, Aspergillus sp. 13%, Fusarium sp. 7% and Curvularia sp. 6%. Gram stain and culture results were consistent in 62.6% of cases. Previous antibiotic treatment was a significant factor for failure of culture isolation and less so for Gram stain failure. On Gram stain, 55.9% of pseudomonal cases were missed, but only 2% of fungal cases were missed. Over all, Gram stain had a sensitivity of 62% and positive predictive value of 84% for bacterial cases, and 98% and 94% for fungal cases, respectively. Fungal ulcers were typically filamentous, but an antecedent history of trauma was not common. The most frequent injury was due to rice grains, but the inoculum appeared to be introduced during eye washing with contaminated water. Pseudomonal ulcers occurred most frequently in the monsoon season, and Fusarium cases were seen only in the hot, dry season.

Adolescent↗
PubMed1991

Suppurative keratitis in rural Bangladesh: the value of gram stain in planning management.

External eye disease which result in corneal scarring are an important cause of blindness in Bangladesh and at the Chittagong Eye Infirmary and Training Complex (EITC) over 200 cases of suppurative keratitis are managed each year. We reviewed the records of 127 cases of microbial keratitis to determine the relative contributions of Gram stain and culture to diagnosis of the causative organism. There were 107 culture-proven cases of microbial keratitis amongst the 127 patients in this study. Gram stain was positive in 89 cases which represents 70% of the total and 83% of all culture-proven cases. Streptococcus pneumoniae and Pseudomonas sp were the commonest bacteria isolated and Aspergillus sp and Fusarium sp the commonest fungi. In 20 cases (16%) no organism was isolated on Gram stain or culture. Our results support the use of both Gram stain and culture in isolation of the causative organism in cases of suppurative keratitis in Bangladesh. However the low cost of Gram stain and its useful recovery rates for both bacteria and fungi support its use as an initial investigation for microbial keratitis at the secondary level of eye care in rural Bangladesh.

Anti-Bacterial Agents↗
PubMed1987

Endophthalmitis following cataract extraction.

We describe a case of bacterial endophthalmitis complicating routine cataract extraction and intraocular lens implantation in a 91-year-old woman. The ocular and systemic factors that may have predisposed to intraocular infection in this case, and the possibility of predicting these pre-operatively, are discussed.

Adenocarcinoma↗
PubMed1987

Acanthamoebic keratitis diagnosed by paracentesis and biopsy and treated with propamidine.

A previously healthy 53-year-old man had keratitis of the right eye for six months, unresponsive to topical medical therapy. Acanthamoeba was grown from tissue obtained by corneal biopsy and from aqueous from an anterior chamber tap. The patient was treated with propamidine isethionate 0.1% drops and dibromopropamidine isethionate 0.15% ointment, and after two and a half months the ocular inflammation was continuing to resolve. This case supports a role for the diamidines in the treatment of acanthamoebic keratitis.

Acanthamoeba↗
PubMed1987

Microbiological diagnosis of suppurative keratitis in Bangladesh.

Experience in setting up an inexpensive microbiology laboratory in the Bangladesh National Society for the Blind Eye Hospital and Training Complex at Chittagong is presented, together with the results of a pilot study to identify organisms responsible in 33 consecutive cases of suppurative keratitis in the Chittagong area of Bangladesh. Of the 33 cases 21 were positively identified by means of Gram stain and/or culture. Two-thirds of the responsible organisms were bacteria, and one-third were fungi. The bacterial causes included Streptococcus pneumoniae and Pseudomonas aeruginosa. The fungi isolated were Aspergillus fumigatus, Aspergillus ochraceus, and Fusarium solani. Among the causes of failure to diagnose the organism was chronicity of infection and previous treatment. The value of the study in the planning of future treatment regimens, and the implications of setting up similar relatively cheap microbiology laboratory facilities in developing countries, are discussed.

Bacteria↗
PubMed1985

Concurrent pineoblastoma and unilateral retinoblastoma: a forme fruste of trilateral retinoblastoma?

A 10-month-old boy who presented with strabismus and symptoms of intracranial hypertension was found to have a pineoblastoma and a unilateral ocular retinoblastoma. Despite enucleation of the eye, subtotal removal of the pineoblastoma, and craniospinal axis irradiation, the patient died 6 months later from disseminated intracranial neoplasm. As there was no clinical evidence of bilateral retinoblastoma, this case may represent a forme fruste of the trilateral retinoblastoma complex. The clinicopathological features of this unusual syndrome are reviewed.

Brain Neoplasms↗
PubMed1984

Anemia of prematurity: determinants of the erythropoietin response.

This study was undertaken to determine the factors that are important in determining the erythropoietin response in low-birth-weight infants during the period of so-called anemia of prematurity. In the first weeks of life oxygen consumption in a group of 21 infants gradually increased as hemoglobin level fell. The magnitude of the erythropoietin response inversely varied with the central venous oxygen tension (P-vO2) (r = -0.55, P less than 0.001). When the P-vO2 declined to less than 30 torr, erythropoietin values were uniformly increased above the "normal" range (defined as the values associated with P-vO2 greater than 38 torr). Erythropoietin values varied inversely with hemoglobin but in general did not exceed the values observed for normal adult men. The erythropoietin values in the infants were remarkably lower at any given hemoglobin level when compared with those of older children with anemia resulting from bone marrow failure. In general, elevations of erythropoietin were seen when the hemoglobin concentration declined to less than 10.0 gm/dl. Change in heart rate did not appear to be a reliable indicator of the presence of anemia; rather, it correlated best with oxygen consumption.

Adult↗
PubMed1979

Dextran 40-containing incubation media: effect on lens electrolyte and water balance.

The effect of dextran 40 on lens swelling and electrolyte balance in lenses stressed by incubation in Ca++-free media was studied. Dextran 40 substantially inhibited lens swelling, Na+ gain, and K+ loss caused by six-hour incubation in Ca++-free media. After an additional 12-hour incubation in Ca++-enriched media, the water and electrolyte balance in the dextran 40-incubated group was essentially the same as that of lenses that were never exposed to a Ca++-free media. Those lenses that were not incubated in dextran 40 demonstrated significant residual lens swelling and electrolyte imbalance. It is concluded that dextran 40, by virtue of its oncotic effect, inhibits colloidal osmotic swelling and exerts a protective effect on lens function under a stress situation.

Animals↗