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Biomedical subjects

A S Baker

Publications and source records attributed to A S Baker.

At least 37 records · Page 2Linked to original sources
PubMed1995

Effect of intravitreal dexamethasone in treatment of pneumococcal endophthalmitis in rabbits.

PURPOSE: To investigate whether corticosteroid therapy would decrease the inflammation and tissue damage associated with pneumococcal endophthalmitis. METHODS: Albino rabbits were injected intravitreally with 1000 live organisms of Streptococcus pneumoniae and randomized after 24 hours to treatment with intravitreal vancomycin hydrochloride alone (n = 10), combination intravitreal vancomycin and intravitreal dexamethasone (n = 10), or no treatment (n = 10). After 2 weeks, the eyes were examined clinically and enucleated for histopathologic examination. RESULTS: Eyes treated with vancomycin and dexamethasone had significantly less intraocular inflammation and more preservation of retinal tissue than untreated eyes or eyes treated with vancomycin alone (P < .05, Fisher's exact test). Untreated and vancomycin-treated eyes were indistinguishable on clinical and histologic examination. Marked anterior and posterior segment inflammation with total retinal necrosis was noted in eyes from both groups. CONCLUSION: Intravitreal corticosteroid therapy may play an important role in minimizing the inflammation and tissue damage associated with pneumococcal endophthalmitis.

Animals↗
PubMed1995

Relapse of Mycobacterium leprae infection with ocular manifestations.

A case of ocular leprosy as the manifestation of persistent or relapsed Mycobacterium leprae infection approximately 20 years following treatment is reported. The clinical and pathological features of this case are described, and the molecular methods needed to arrive at the definitive diagnosis are examined. If blindness is to be averted, clinicians must have a high index of suspicion for the diagnosis of ocular leprosy when anterior segment changes are noted during ophthalmologic examination of a patient from an area in which M. leprae is endemic. The indolent nature of ocular leprosy may require lifelong surveillance and therapy to insure sight preservation.

Adult↗
PubMed1995

Lateral sinus thrombosis associated with otitis media and mastoiditis in children.

Lateral sinus thrombosis (LST) is an infrequent complication of otitis media and mastoiditis in the antibiotic era. A recent case of LST in a 7-year-old boy, the third such case at our institutions in the past 5 years, prompted a review of the modern day English literature concerning LST in pediatric patients. Our goal was to highlight the clinical findings suggestive of LST in the antibiotic era as well as to analyze retrospectively the diagnostic and therapeutic modalities of greatest benefit based on the outcomes reported in the reviewed studies.

Anti-Bacterial Agents↗
PubMed1995

Treatment of exogenous Candida endophthalmitis in rabbits with oral fluconazole.

We investigated the efficacy of oral fluconazole, alone or in combination with oral flucytosine (5FC), in treating Candida endophthalmitis using a rabbit model. Albino rabbits were infected with an intravitreal inoculation of 1,000 CFU of susceptible Candida albicans and randomized 5 days later to receive treatment with oral fluconazole alone (80 mg/kg of body weight per day), a combination of fluconazole and 5FC (100 mg/kg/12 h), or no treatment. The treatment effect was assessed at 2 and 4 weeks after therapy by funduscopy, quantitative vitreous culture, and histopathology. Intravitreal levels of fluconazole, 2 to 24 h after the first dose, were measured to be > 10 times the MIC of the drug for C. albicans. Among rabbits treated with fluconazole for 2 weeks, 67% had a > 90% reduction in fungal load (P < 0.05) and 33% were sterile. After 4 weeks, all had a > 99% reduction in fungal load (P < 0.05) and 75% were sterile (P = 0.01). This treatment effect was unchanged 4 weeks after discontinuation of fluconazole. Among rabbits treated with fluconazole and 5FC for 2 weeks, 67% died during therapy. Among the surviving rabbits, 75% had a > 90% reduction in fungal load (P < 0.05) and 25% were sterile. We conclude that oral fluconazole may be useful for treatment of Candida endophthalmitis. Addition of 5FC was associated with high toxicity and minimal additional antifungal effect in our rabbit model.

Administration, Oral↗
PubMed1995

Rhinoscleroma treated with ciprofloxacin: a case report.

Rhinoscleroma, a chronic progressive infection of the nose and associated structures caused by Klebsiella rhinoscleromatis, has posed a therapeutic dilemma since its identification in the late 1800s. Although a number of antibiotics have been found to be effective in this relapsing disorder, the lengthy duration of treatment can lead to problems with adverse effects and compliance, especially with the traditional therapies of streptomycin and tetracycline. We report on a patient with extensive nasal rhinoscleroma who achieved pathologic and bacteriologic resolution during treatment with oral ciprofloxacin after previous courses of tetracycline and trimethoprim-sulfamethoxazole. Ciprofloxacin may prove to be useful in the therapy of rhinoscleroma because it is convenient for oral administration, achieves good tissue levels, is concentrated in macrophages, and is generally well tolerated as long-term therapy. As mentioned in a recent review of patients with rhinoscleroma at the Mayo Clinic, the fluoroquinolones deserve further study as potentially highly effective agents for this uncommon but significant infectious condition.

Adult↗
PubMed1995

Infections of the head and neck in diabetes mellitus.

Patients with diabetes mellitus exhibit particular susceptibility to three severe infections of the head and neck: rhinocerebral mucormycosis, postoperative endophthalmitis, and malignant otitis externa. Rhinocerebral mucormycosis is an extensive life-threatening infection beginning in the nasal passages and sinuses and extending often into the orbit and the cerebrum. Endophthalmitis, which is infection of the vitreal contents, can occur secondary to bacteremia, trauma, or postoperatively. Invasive external otitis or malignant otitis externa is an invasive infection beginning in the adjacent soft tissue and into bone. It is usually secondary to Pseudomonas aeruginosa and occurs almost exclusively in diabetics. These will all be discussed in this article.

Brain Diseases↗
PubMed1995

The UNOS OPTN waiting list: 1988-1995.

On November 30, 1995, the combined waiting list contained 43,370 registrants, a 15.1% increase from the 37,684 registrations as of December 31, 1994. Kidney registrations accounted for the majority (70.9%) of registrations. The predominant characteristics of the registrants on the combined waiting list as of November 30, 1995 are as follows: 57.6% were male; 59.2% were White; 57% were between 18-49 years of age; 51.4% were of blood type 0; and 82% had no previous transplant. The majority of kidney registrants (68.1%) had a current PRA value of 0-19%. The number of new registrations increased 69.6% from 17,441 additions in 1988 to 29,402 in 1994. The waiting lists with the highest percentage increase in additions over this period were the lung waiting list, ranging from 125 additions in 1988 to 1,544 additions in 1994, and the liver waiting list, ranging from 2,140 additions in 1988 to 6,211 additions in 1994. Since 1992, additions to the kidney-pancreas waiting list ranged from 743 to 1,222, a 64.5% increase. Over the 1988-1992 time period, the rate of transplantation as a percentage of total waiting list registrations declined, decreasing approximately 1% per year. Meanwhile, the death rate per patient registered remained fairly stable, averaging 5.6% each year. The death rate for patients on the heart-lung waiting list decreased each year since 1989. Median waiting times increased annually for patients awaiting kidney and liver transplantation. For those registrants on the heart waiting list, median waiting times increased from 1988-1992, but decreased over the last 2 years. In contrast, lung registrants experienced decreasing median waiting times from 1988-1990, but median waiting times for lung registrants have increased since 1991. Patients awaiting heart-lung transplantation experienced the longest median waiting time in each year except 1993, when the median waiting time for kidney waiting list registrants surpassed that of heart-lung registrants. Patients awaiting liver transplantation experienced the shortest median waiting times each year except 1992. Of those patients added to the combined waiting list in 1993, patients with blood type O on the kidney, liver, heart, lung and heart-lung waiting lists had longer median waiting times than those with blood types A, B or AB. In general, patients having a previous transplant waited longer than those who had not had a previous transplant, with the exception of patients awaiting liver and pancreas transplantation. Females on the kidney, kidney-pancreas, liver, lung and heart-lung waiting lists experienced longer median waiting times than males. Median waiting times were shorter for females on the pancreas (278 vs 436 days) and heart (144 vs 240 days) waiting lists. Median waiting times were shortest for Whites registered on the kidney and lung waiting lists, for Hispanics on the liver list and for Asians on the heart and heart-lung waiting lists. Patients of ¿other¿ racial backgrounds experienced the shortest median waiting time on the kidney-pancreas waiting list. In general, pediatric patients experienced the shortest median waiting times of patients added to the waiting lists in 1993: Kidney and heart registrants less than one year of age had a median waiting time of 90 days and 47 days, respectively. Kidney-pancreas, lung and heart-lung registrants aged 1-5 years had a median waiting time of 81.5 days, 220 days, and 153 days, respectively. Conversely, older patients typically waited the longest for an organ transplant. Patients over 50 years of age experienced the longest median waiting times of patients registered on the kidney, kidney-pancreas, pancreas and heart waiting lists.

Adolescent↗
PubMed1994

Endogenous bacterial endophthalmitis. Report of a ten-year retrospective study.

PURPOSE: The purpose of this study is to report the predisposing factors, timing of symptoms, timing of diagnosis, causative organisms, source of infection, and visual outcome in cases of endogenous bacterial endophthalmitis. METHODS: The records of 28 patients with endogenous bacterial endophthalmitis who presented to our combined ophthalmology and medicine services over a 10-year period were reviewed. RESULTS: Ninety percent of the patients had prior medical conditions, including diabetes mellitus, gastrointestinal disorders, hypertension, cardiac disorders, and malignancy. Acute ocular symptoms were the most common reasons why the patient went to the physician (usually an ophthalmologist) rather than systemic symptoms. A correct initial diagnosis was made in 50% of patients, with a delay in diagnosis of 4 days or more in 29% of patients. Organisms were identified in 27 of the 28 patients (96% identification rate), two thirds of which were gram-positive organisms. Streptococcal species were the most common group (32% of patients), although the single most common organism was Staphylococcus aureus (25% of patients). Sources of infection were identified in 93% of patients, with endocarditis and the gastrointestinal tract being the most common. In the majority of patients, visual outcome was poor. However, six eyes that received intravenous and intravitreal antibiotics, as well as therapeutic vitrectomy, achieved visual acuities of 20/50 or better. CONCLUSION: These results provide a further understanding of the manner of presentation, organisms involved, and sources of infection in endogenous bacterial endophthalmitis. They also suggest that improved outcome may be associated with early initiation of combined medical and surgical treatment.

Adult↗
PubMed1993

Proton magnetic resonance spectroscopy of vitreal changes in experimental streptococcal endophthalmitis.

We used magnetic resonance spectroscopy to examine endophthalmitis in rabbits inoculated with a virulent strain of Streptococcus pneumoniae. On different days after infection, the animals were sacrificed and the vitreous isolated and examined with water-suppressed proton magnetic resonance spectroscopy. A broad resonance corresponding to the methyl envelope of lipoprotein lipids appeared 2 days after infection and persisted until the eyes developed phthisis (around 10 days postinfection). This resonance was absent in the control eye and the bacterial culture; it could be used as the marker of breakdown of blood-vitreous barrier and onset of endophthalmitis-induced changes.

Animals↗
PubMed1993

Endophthalmitis caused by the coagulase-negative staphylococci. 2. Factors influencing presentation after cataract surgery.

PURPOSE: This study, comprising 60 patients with coagulase-negative staphylococcal endophthalmitis which occurred after cataract surgery, was designed to define the variation in disease presentation and visual outcome and to evaluate statistically the role of the primary surgery and its management. METHODS: An intensive evaluation of microbiological, inpatient, outpatient, and cataract surgery charts was made retrospectively using a standardized protocol. The predictive value of surgical, iatrogenic, and clinical factors was analyzed for their influence on defined aspects of the disease pattern and of the visual results using multiple regression models, via a stepwise technique. RESULTS: There was commonly a significant asymptomatic latent period after cataract surgery. The median diagnostic delay was 7 days; 22% of patients presented after 2 weeks and 12% after 1 month. Symptoms progressed longer than 3 days in 25% of patients. Ten percent had no pain. Clinical variation proved largely unrelated to cataract surgery events and postoperative management; bacterial factors were implicated. Good visual outcome was associated statistically with intensive topical corticosteroid in the symptomatic period, but was negatively associated with operative subconjunctival corticosteroid. CONCLUSIONS: The clinical variation in cases of postoperative coagulase-negative staphylococcal endophthalmitis poses particular problems for diagnosis in the outpatient setting. Surgical and perioperative events (except corticosteroid use) probably can be disregarded in studies of endophthalmitis management.

Adult↗
PubMed1992

Microbial contamination of in-use ocular medications.

Two hundred twenty in-use medications from 101 patients with nonmicrobial ocular surface disease were studied by culturing the bottle caps, a drop produced by simple inversion, and the interior contents removed sterilely. Conjunctival cultures were taken from these patients and 50 age-matched controls. Pathogenic organisms were harvested from conjunctivae significantly more frequently (P less than .01) from cases (34 of 101) than from controls (five of 50). Sixty-four medications (29%) had microorganisms cultured from at least one medication site. Gram-negative organisms were significantly more likely (P less than .00001) to be isolated from all medication sites than gram-positive organisms. Additionally, when isolated from medication sites, the gram-negative organisms were highly likely to be cultured from the conjunctiva as well. This was not true for pathogenic gram-positive organisms. We conclude that a cycle of contamination between in-use medications and conjunctivae may represent an important risk factor for microbial keratitis in patients with ocular surface disease.

Conjunctiva↗
PubMed1992

Fine-needle aspiration cytology of an endometrioid-like variant of yolk sac tumor.

A 36-year-old male with a history of immature teratoma and embryonal carcinoma of the testis was admitted to the hospital for abdominal pain and fever. A CT scan revealed a large right abdominal mass. The patient's serum alpha-fetoprotein (AFP) was 46.8 ng/ml (reference < 25 ng/ml). Fine-needle aspiration (FNA) of the mass revealed malignant glandular cells. Chemotherapy was instituted, followed by resection of the large abdominal mass. The tumor was grossly encapsulated, consisting of large areas of necrotic, hemorrhagic tissue surrounded by smaller, multiloculated cysts. Microscopically, the tumor had a villoglandular pattern and variably stratified tall columnar cells. A prominent feature of the columnar cells was supranuclear and subnuclear vacuolization. Intracytoplasmic PAS-positive, diastase-resistant hyaline globules were occasionally present. AFP by immunoperoxidase was prominent within the tumor. This recurrence of the previously diagnosed testicular teratoma with embryonal carcinoma represents a yolk sac tumor with components strongly resembling endometrioid carcinoma, a variant only recently described in eight cases of ovarian origin (Clement et al.: Am J Surg Pathol 1987; 11(10):767-778). We believe this is the first reported case of an endometrioid-like variant of testicular yolk sac tumor and also the first report of the FNA cytology findings in this variant.

Adenocarcinoma↗
PubMed1992

Aging in humans: a continuous 20-year study of physiologic and dietary parameters.

The old adage, "You are what you eat," is not always reliable, as demonstrated in this mixed-longitudinal study of men that began in 1969. Mean values of percent body fat, total body potassium (TBK), and total serum cholesterol (SCHOL) did not show changes that correlated with any studied nutrient from repeated 4-day diet records. Mean blood pressure increased with increased body weight as age increased. High-density lipoprotein cholesterol decreased when polyunsaturated fat intake increased. The men had decreased mean height, TBK and increase in percent body fat as age increased. Food energy intake decreased equally from carbohydrates, protein and fat as age increased. Large standard deviations of mean values of measured parameters document heterogeneity of these subjects. A subset of 144 male cohorts was studied serially for 20 years in time-age, cross-sectional and longitudinal series. As they aged, height and TBK decreased (p < or = 0.05), percent body fat and blood pressure increased (p < or = 0.04) and SCHOL had no significant change. Intake of all nutrients decreased significantly (p < or = 0.03) longitudinally and with time, showing a time effect.

Adipose Tissue↗