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Biomedical subjects

M B Moore

Publications and source records attributed to M B Moore.

At least 37 records · Page 2Linked to original sources
PubMed1990

The effect of currently available contact lens disinfection systems on Acanthamoeba castellanii and Acanthamoeba polyphaga.

Contact lens disinfection systems were evaluated for their effectiveness in killing Acanthamoeba castellanii and Acanthamoeba polyphaga trophozoites and cysts. Amoebae were inoculated into commercially available contact lens cleaning and soaking solutions. At intervals varying from 30 minutes to 24 hours, solutions were filtered. The filters were removed and cultured for Acanthamoeba organisms. Striking differences were observed in the abilities of the different disinfecting solutions to kill the organisms. Solutions containing chlorhexidine were effective at very short exposure times. Solutions containing benzalkonium chloride required slightly longer exposure times but were faster than solutions containing only thimerosal. Solutions containing sorbate, polyaminopropyl biguanide, or polyquaternium-1 were not effective at killing Acanthamoeba organisms in the time allotted for the experiment. Solutions containing hydrogen peroxide were quite effective if the agent was not prematurely catalyzed. A. polyphaga generally required longer exposure to disinfectants than did A. castellanii for complete inhibition to occur.

Acanthamoeba↗
PubMed1990

Acanthamoeba keratitis and contact lens wear: the patient is at fault.

The avoidance of nonsterile solutions is important to curtailing Acanthamoeba keratitis, a serious infection that has been found to occur with all types of contact lens (CL) wear. Increased patient education, revised recommendations regarding the use of tap and distilled water, and improved disinfecting systems are vital to preventing infection. These precautions are particularly important since it appears that Acanthamoeba, unlike Pseudomonas, may not require an epithelial defect to establish corneal infection and, once in the cornea, may not respond to drug therapy or surgical extirpation. Unfortunately, many patients receive poor lens care instructions or cannot be relied on to follow appropriate routines. Finding a foolproof means of lens disinfection for them is critical. Recently, several disinfection systems were tested against Acanthamoeba castellanii and Acanthamoeba polyphaga cysts and trophozoites to see which might prove most effective. Effective systems included heat disinfection at 70 to 80 degrees C for 10 min, 3% hydrogen peroxide for 2-3 h, 0.001% thimerosal with edetate for 4 h, 0.005% benzalkonium chloride with edetate and reagent for 4 h, and either 0.001% chlorhexidine for 4 h or 0.004% chlorhexidine for 1 h. Thus, for patients who are careless or persist in using nonsterile rinsing solutions, it appears that at least some methods of disinfection will help prevent Acanthamoeba infection.

Acanthamoeba Keratitis↗
PubMed1990

Illustrated print materials for health and family planning education.

Printed materials meant to convey health messages are apt to make a more striking and lasting impression on their audience if they are well illustrated. But coming up with good illustrations takes time, effort and care. The Program for Appropriate Technology in Health (PATH) has found that the best way of ensuring that illustrations will be understood and accepted is to develop them with the help of representatives of the target audience.

Books, Illustrated↗
PubMed1989

Acanthamoeba keratitis associated with contact lenses: six consecutive cases of successful management.

We examined and treated six patients with acanthamoeba keratitis associated with contact lens wear from 1981 to 1988. Five patients were treated with topical neomycin-polymyxin B-gramicidin (Neosporin) and propamidine isethionate (Brolene) drops. The patients were followed up for an average of 32 months (range 16-75 months). Two patients underwent penetrating keratoplasty at 22 and 26 months after the onset of symptoms and have maintained clear grafts with no evidence of recurrence. In four patients corneal infiltrates cleared on topical medication. All six patients have 6/6 best corrected vision. Early diagnosis and medical treatment alone can result in resolution of corneal infiltrates due to acanthamoebae. With this initial therapy we have had no treatment failures.

Acanthamoeba↗
PubMed1987

Corneal biopsy in chronic keratitis.

Failure to identify the causative agent makes the treatment of chronic keratitis difficult. Inability to obtain a definitive diagnosis may be related to the depth of the pathogen within the cornea, partial or inappropriate treatment that interferes with diagnostic cultures, or fastidious growth characteristics of the organism in culture. Biopsy by lamellar keratectomy provides sufficient tissue for culture and for histopathologic evaluation by histochemistry, immunohistopathology, and, if necessary, electron microscopy. Consultation with an ophthalmic pathologist before biopsy can prevent inappropriate handling of the specimen, which may preclude essential diagnostic procedures. Many studies can be done within 24 hours of biopsy, often permitting rapid identification of the pathogen and prompt institution of appropriate therapy.

Biopsy↗
PubMed1987

The rapid detection of Acanthamoeba in paraffin-embedded sections of corneal tissue with calcofluor white.

Acanthamoeba keratitis is a difficult diagnosis to make with routine stains and cultures. Gram's, Giemsa, and hematoxylin-eosin stains do not differentially stain Acanthamoeba, making the detection of organisms difficult. Trophozoite and cyst forms in paraffin-embedded corneal tissue sections can be rapidly and differentially stained with calcofluor white. Under the fluorescence microscope, the trophozoites are bright red-orange, and cyst cell walls fluoresce bright apple-green with red-orange cytoplasm. Retrospective identification can be made by destaining hematoxylin-eosin-stained sections. Digesting background corneal tissue with trypsin or collagenase and hyaluronidase solutions helps to more readily identify trophozoites.

Acanthamoeba↗
PubMed1987

Acanthamoeba keratitis. A growing problem in soft and hard contact lens wearers.

Eleven contact lens-wearing patients presented with Acanthamoeba keratitis. Eight cases were culture- and/or stain-positive for Acanthamoeba and three were presumed to have Acanthamoeba keratitis based on history and clinical findings. Six wore daily wear soft contact lenses, two wore extended-wear soft contact lenses, one wore a polymethylmethacrylate hard contact lens, one wore a gas-permeable hard contact lens, and one wore a Saturn lens (combined hard and soft lens). Four patients used distilled water and salt tablet saline, three used tap water and salt tablet saline, two used tap water rinse, two used well water rinse or storage, and one used intravenous (IV) saline. It is apparent that all contact lens wearers are at some risk for Acanthamoeba keratitis developing if proper contact lens care is not maintained. Of great concern is the inability of most current chemical sterilization methods to kill the organism if the lens becomes contaminated. Heat disinfection will kill Acanthamoeba trophozoites and cysts but the lens must not be placed into contaminated solutions afterward. Prevention is very important because medical and surgical treatment failures are frequent. Eye care practitioners who fit contact lenses are advised to use heat disinfection for low-water content stock soft contact lenses, and to use hydrogen peroxide without a catalyst for a minimum of 6 hours for all other stock lens fitting sets, to specifically inquire about contact lens care habits used by their patients, and to discourage the use of homemade saline solutions.

Acanthamoeba↗
PubMed1987

Fate of lyophilized xenogeneic corneal lenticules in intrastromal implantation and epikeratophakia.

The antigenicity of intrastromal and epikeratophakia xenografts of lyophilized corneal tissue was evaluated in nonimmune and immune recipients. Lyophilized feline lenticules were implanted into intrastromal pockets in unsensitized rabbits and rabbits sensitized to the donor cat. In both cases, the grafts remained clear. Sensitized rabbits with clear intrastromal grafts received fresh tissue penetrating keratoplasty grafts from the same donor cat, placed adjacent to the intrastromal grafts. The fresh tissue penetrating keratoplasty grafts were rapidly rejected, while the lyophilized intrastromal grafts remained clear. Cats sensitized to rabbits received lyophilized and rehydrated epikeratophakia grafts shaped from rabbit cornea; these lyophilized grafts also remained clear for the 3-month period of the study. The results indicate that lyophilized and rehydrated corneal stroma, which is devoid of living cells, is not antigenic and is not subjected to immunologic attack, even in cases where the donor and host are of different species and the host has been previously immunized to the donor.

Animals↗
PubMed1986

Chronic keratitis caused by Mycobacterium gordonae.

We treated a patient with chronic keratitis caused by Mycobacterium gordonae, a slow-growing, atypical mycobacterium not previously reported as a cause of corneal infection. The patient was a 34-year-old man who was hit in the eye with some vegetable matter while gardening. Initially, the patient was treated for a presumptive diagnosis of herpes simplex keratitis. Because of progression of the keratitis, a lamellar corneal biopsy was performed 3 1/2 years later and the definitive diagnosis was made. Subsequently, a penetrating keratoplasty was performed and the patient's condition then remained stable. The diagnosis of atypical mycobacterium should be considered in a patient with an indolent corneal ulcer. Lamellar corneal biopsy may disclose the pathogen when the infection is deep, chronic, or partially treated.

Adult↗
PubMed1986

Radial keratoneuritis as a presenting sign in Acanthamoeba keratitis.

Three myopic patients who wore soft contact lenses developed unilateral Acanthamoeba keratitis that presented with unusual infiltrates that appeared to be located along the corneal nerves. These infiltrates were found in the midstroma, beginning paracentrally, and extending to the limbus in a radial pattern. The epithelium overlying these infiltrates was intact. In two patients, the central epithelium had a stippled, almost dendritiform appearance leading to the misdiagnosis of herpes simplex keratitis. Cultures from corneal scrapings of two patients and cultures of a corneal biopsy from one patient, which included an area of presumed neural involvement, grew Acanthamoebae. All three patients used homemade saline solutions (salt tablets dissolved in distilled water). In one patient, Acanthamoebae were found in the contact lens case solution. In our recent experience, Acanthamoebae have also been found in the distilled water bottle and the saline solution made from distilled water and salt tablets in two additional patients with A. keratitis. Distilled water, which is not sterile, has proven to be one potentially avoidable source of A. keratitis in contact lens wearers.

Adult↗
PubMed1986

Floppy eyelid syndrome. Management including surgery.

Six overweight patients, five men and the first woman to be reported, are described with floppy eyelid syndrome. Five patients had bilateral ocular involvement. Only two patients were free of other ocular surface problems. Concurrent diagnoses included blepharitis, keratoconjunctivitis sicca, lagophthalmos, medicamentosal conjunctivitis, molluscum contagiosum, and masquerade syndrome. Five patients responded to appropriate therapy, which included shielding the eyes during sleep. Three patients underwent a horizontal lid tightening procedure, which resulted in permanent correction of their floppy eyelids and resolution of their ocular signs and symptoms.

Adult↗
PubMed1985

Acanthamoeba keratitis associated with soft contact lenses.

Three patients (a 13-year-old girl, a 25-year-old man, and a 22-year-old woman) who used daily-wear soft contact lenses, sterilized with saline made from distilled water and salt tablets, developed Acanthamoeba keratitis. Acanthamoeba was cultured from the contact lens solution of one patient. This patient, in whom the diagnosis was made by corneal biopsy early in the clinical course, was successfully treated with topical neomycin-polymyxin, miconazole, and propamidine isethionate. The other two patients underwent penetrating keratoplasty. One of these patients, who received a graft early in the clinical course, developed a recurrence of disease in the graft, whereas the other, who received the graft 18 months after the initial symptoms, has maintained a clear corneal transplant with useful vision.

Adolescent↗
PubMed1985

Mucus fishing syndrome.

Twenty-five patients are described with a variety of external ocular diseases including keratoconjunctivitis sicca, blepharitis, and allergic conjunctivitis, who presented with persistence of symptoms of irritation, foreign body sensation, and apparent excessive mucus production, with mild conjunctival inflammation despite appropriate treatment of the underlying disease. All patients were found to have evidence of trauma to the conjunctival epithelium due to mechanical removal of the excess mucus from the surface of the globe or inferior cul-de-sac. The surface irritation created by the mechanical damage led to a further increase in mucus production, creating a cycle that we have termed mucus fishing syndrome. Cessation of this behavior coupled with ongoing therapy of the underlying disease led to resolution of signs and symptoms in all patients.

Adult↗
PubMed1984

Donor-to-host transmission of streptococcal infection by corneas stored in McCarey-Kaufman medium.

Two patients developed streptococcal endophthalmitis following penetrating keratoplasty. These cases may represent the third and fourth cases of donor-to-host transmission of streptococcal infection by corneas stored in McCarey-Kaufman (M-K) medium. Streptococcal agents now account for 50-59% of the total number of reported cases of M-K medium contamination by donor tissue with resultant infection in the host. Gentamicin sulfate, the sole antibiotic used in the M-K medium in all cases, has poor activity against most streptococci. The addition of a second antibiotic to the M-K medium to provide an improved spectrum of antimicrobial activity should be considered.

Aged↗
PubMed1980

The spinal cord ventral root: an afferent pathway of the hind-limb pressor reflex in cats.

1. In anaesthetized cats the sciatic nerve was cut and the central end was stimulated at a high frequency and voltage. This caused an increase in arterial blood pressure and a rise in heart rate. The pressure response was diminished by dorsal root section but not completely eliminated until ventral root section (L4-S3). The tachycardia response was abolished by dorsal root section alone. 2. In other cats capsaicin was injected intra-arterially into the hind limb, causing elevations in both blood pressure and heart rate. Similar to the sciatic nerve stimulation experiments, the pressor response was principally reduced by dorsal root section but was further significantly decreased by ventral root section (L1-S3). The rise in heart rate was prevented by dorsal root section alone. 3. It is concluded that, in cats, the afferent pathway of the pressor response to sciatic nerve stimulation and to hind-limb capsaicin injection are conducted principally in the dorsal roots but also to a small extent in the ventral roots of the spinal cord. Although the tachycardia response appears to be conducted only through the dorsal roots, it is possible that at lower resting heart rates and by stimulation of a large population of the unmyelinated skeletal muscle afferents, the ventral root is a functional pathway.

Afferent Pathways↗