PubMed Health⌕ Search

Biomedical subjects

D A Snyder

Publications and source records attributed to D A Snyder.

At least 19 recordsLinked to original sources
PubMed1999

Effectiveness of monitored anesthesia care in cataract surgery.

OBJECTIVE: To determine the need for monitored anesthesia care in cataract surgery by evaluating the incidence of intervention by anesthesia personnel and by looking for associated risk factors. DESIGN: Nonrandomized, prospective case series with analysis of consecutive cataract surgery cases. PARTICIPANTS: A total of 1006 consecutive cataract surgery patients at an ambulatory surgery center over a 6-month period. METHODS: Routine cataract surgery was performed with the patient under local anesthesia. A detailed questionnaire was completed by the anesthesia personnel at the conclusion of each phase (before, during, and after) of cataract surgery. MAIN OUTCOME MEASURES: Age, medical history, and preoperative electrocardiogram (EKG) were analyzed as predictors for intervention by anesthesia personnel. The nature of the patient's problem and the type of intervention by anesthesia personnel were recorded. RESULTS: In 1006 consecutive cataract surgery cases, intervention by anesthesia personnel was required in 376 (37.4%) cases. No preoperative identifying characteristics were found to be reliable predictors of the need for intervention. There were no statistically significant differences in preoperative EKG and some medical conditions such as heart disease, diabetes, and thyroid disease between patients who received intervention and those who did not. Certain subgroups of patients did show a statistically significantly greater incidence of intervention, including systemic hypertensives (41.4%) versus nonhypertensives (34.5%) (P = 0.030), patients with pulmonary disease (49.3%) versus no pulmonary disease (36.5%) (P = 0.043), patients with renal disease (68.8%) versus no renal disease (36.9%) (P = 0.019), and patients with cancer (61.9%) versus no cancer (36.3%) (P = 0.001). Intervention was also required in 61.1 % of patients younger than 60 years of age compared to 36.5% of those patients 60 years of age and older (P = 0.005). CONCLUSIONS: Because intervention is required in more than one third of cataract surgery cases and the authors cannot reliably predict those patients at risk, monitored anesthesia care seems justified in cataract surgery with the patient under local anesthesia.

Adult↗
PubMed1996

Randomized double-blind prospective trial to evaluate the effects of sargramostim versus placebo in a moderate-dose fluorouracil, doxorubicin, and cyclophosphamide adjuvant chemotherapy program for stage II and III breast cancer.

PURPOSE: To determine the effects of sargramostim (recombinant human granulocyte-macrophage colony-stimulating factor [rhu GM-CSF]) on the incidence, duration, and complications of myelosuppression after moderate-dose fluorouracil, doxorubicin, cyclophosphamide (FAC) adjuvant chemotherapy in patients with node-positive breast cancer. PATIENTS AND METHODS: In this randomized, double-blind, placebo-controlled study, 142 women with stage II and III breast cancer were to receive four 21-day cycles of chemotherapy that consisted of fluorouracil 600 mg/ m2 intravenously (IV), doxorubicin 60 mg/m2 IV, and cyclophosphamide 750 mg/m2 IV on day 1, followed by placebo or GM-CSF 250 micrograms/m2/d daily subcutaneously (SC) on days 3 through 15. All patients received prophylactic ciprofloxacin by mouth when the absolute neutrophil count (ANC) was less than 1,000/microL. RESULTS: Eighty-six percent of GM-CSF patients (n = 62) and 96% of placebo patients (n = 69) completed four assessable cycles of treatment on study. Overall, the median duration of severe neutropenia (ANC < 500/microL) was 2.8 days with GM-CSF and 6.8 days with placebo (P < .001); the duration of ANC less than 1,000/microL was 6.0 versus 9.1 days, respectively (P < .001). Hospitalizations for febrile neutropenia were uncommon in either group: GM-CSF, six; placebo, eight. The only other difference in hematologic toxicity was grade 3/4 thrombocytopenia observed with greater frequency in GM-CSF patients than placebo patients in cycles 3 and 4. GM-CSF increased mean the FAC dose-intensity among patients who completed two or more cycles (P < .001). GM-CSF was generally well tolerated and associated with more injection-site reactions, but less mucositis than placebo. There were no deaths on study. CONCLUSION: GM-CSF significantly enhanced ANC recovery after FAC chemotherapy; it decreased the incidence and duration of associated neutropenia and moderately increased the dose-intensity of adjuvant chemotherapy. Whether these effects will ultimately translate into improved long-term outcome remains to be determined.

Adolescent↗
PubMed1991

Olfactomedin: purification, characterization, and localization of a novel olfactory glycoprotein.

We have identified a novel glycoprotein expressed exclusively in frog olfactory neuroepithelium, which we have named "olfactomedin". Olfactomedin is a 57-kDa glycoprotein recognized by seven monoclonal antibodies, previously shown to react solely with proteins of olfactory cilia preparations. It undergoes posttranslational modifications, including dimerization via intermolecular disulfides and attachment of complex carbohydrate moieties that contain N-acetylglucosamine and beta-D-galactoside sugars. Olfactomedin strongly binds to Ricinus communis agglutinin I and has been purified to homogeneity by lectin affinity chromatography. Polyclonal rabbit antiserum raised against purified olfactomedin confirmed that it is expressed only in olfactory tissue. Immunohistochemical studies at the light microscopic and electron microscopic level show that olfactomedin is localized in secretory granules of sustentacular cells, in acinar cells of olfactory glands, and at the mucociliary surface. The massive production of olfactomedin and its striking deposition at the chemosensory surface of the olfactory neuroepithelium suggest a role for this protein in chemoreception.

Animals↗
PubMed1991

Transhiatal esophagectomy in the management of perforated esophageal cancer.

Instrumental perforation of esophageal malignancy is best managed by immediate esophagectomy. Transthoracic esophagectomy has been the technique most described in the management of patients with this injury. A recent series reported the successful use of transhiatal esophagectomy with primary cervical esophagogastrostomy in four patients with perforated esophageal cancers. We have also used this technique to treat a patient with instrumental perforation of a distal esophageal cancer. This case is presented to add to the published experience using transhiatal esophagectomy in the management of perforated esophageal malignancy. The merits of transhiatal esophagectomy warrant consideration of this approach as a useful alternative to transthoracic resection in the management of selected patients with perforated esophageal cancer.

Adenocarcinoma↗
PubMed1990

Intermittent claudication caused by atherosclerosis in patients aged forty years and younger.

Intermittent claudication may represent a severe limitation in daily life-style for young, active patients and may result in loss of professional career for members of the armed forces. Our recent experience with young patients with atherosclerotic claudication was reviewed to determine whether more liberal use of angioplasty and surgery is warranted in these patients to salvage their military careers and improve their life-styles. A systemic review was made of patients aged 40 years and younger with atherosclerosis who have undergone arteriography at our institution during the past 67 months. From this study, 22 patients were found with the initial complaint of intermittent claudication. Fifteen of these patients (68%) had occlusive disease confined to the iliac arteries, and six (27%) had single-level occlusive disease in a femoropopliteal distribution. Only one patient had multilevel disease. Symptoms of coronary occlusive disease developed in five patients (23%) within 38 months of the onset of claudication, and two of these patients died of myocardial infarctions. Of 19 patients who underwent interventions to correct symptoms of claudication, 16 (85%) had complete relief of symptoms at the end of follow-up, ranging from 6 months to 7 years. Ten of these patients remained symptom free after a single intervention, but six patients had rapid progression of disease and required secondary procedures. These results indicate that a majority of young patients with claudication caused by atherosclerosis can be returned to full active-duty status in the military after angioplasty or surgery. However, some patients may require secondary procedures to relieve recurrent symptoms caused by rapid progression of disease. We believe that an aggressive interventional approach is warranted in the evaluation and treatment of young patients with work-limiting claudication caused by atherosclerosis. These patients are at significant risk of developing premature coronary occlusive disease and should be monitored closely.

Adult↗
PubMed1981

Humoral and cellular immunity studies in patients with Vogt-Koyanagi-Harada syndrome and pars planitis.

We performed a comprehensive immunologic assessment of 17 patients with Vogt-Koyanagi-Harada syndrome (VKH) and nine with pars planitis (PP). Several variations in humoral and cellular immunity were found when the patients were compared with normal controls. Elevated serum IgD levels, positive results from various autoimmune profile assays, and deviations from normal levels of viral antibody titers were noted in both groups of patients. However, only some VKH patients had elevated beta 2 microglobulin, total complement level and E-active and EA rosette counts. HLA haplotype typing revealed no distinct correlation between patients when compared with a normal population.

Antibodies, Viral↗
PubMed1980

Vogt-Koyanagi-Harada syndrome.

We studied 20 patients with Vogt-Koyanagi-Harada syndrome. They represented 3.7% of referred patients with uveitis. American Indian ancestry appears to be the link to Oriental racial type. Five patients had a forme fruste retinal detachment. After extensive treatment with corticosteroids, detachments flattened within an average of two to three months. Anterior inflammation continued to persist chronically. Seven of our patients had retinal vasculitis. Pregnancy had a beneficial effect on disease activity. Those patients with diabetes mellitus and sickle cell hemoglobin did not have an adverse effect. Visual outcome was good; of 20 patients, 16 had visual ascuity of 6/21 (20/70) in at least one eye.

Adolescent↗
PubMed1979

Follicular and gonadotrophic changes during transition from ovulatory to anovulatory seasons.

Observations of follicular and gonadotrophic changes were conducted on 14 Pony mares for 31-day periods beginning at the penultimate (second last) ovulation and at the last ovulation of the season. There were no main effects or interaction of day or period on the numbers of small follicles (less than 20 mm). Concentrations of FSH, numbers of large follicles (greater than 20 mm), and oestrous behaviour each showed an effect of day (P less than 0.01), but no effect of period. Concentrations of LH and diameter of the largest follicle each showed an interaction (P less than 0.01) between day and period attributable primarily to smaller values on Days 18--24 after the last ovulation than after the penultimate ovulation. It was concluded that, of the factors considered, failure of ovulation at the onset of the anovulatory season was due to lack of an adequate ovulatory LH surge and final growth of a preovulatory follicle.

Animals↗
PubMed1979

An unusual presentation of pseudotumor cerebri.

A 25-year old grossly obese woman presented with decreased visual acuity. She had bilateral total (internal and external) ophthalmoplegia, a left-sided seventh cranial nerve palsy, and florid bilateral papilledema. The diagnosis of pseudotumor cerebri was made on the basis of high cerebrospinal fluid pressure and the absence of other abnormalities on systemic, neurologic, and neuroradiologic examination. The patient responded favorably to corticosteroid treatment; however, bilateral optic atrophy occurred with persistent loss of visual field and acuity.

Adult↗
PubMed1978

Vitelliform lesions associated with retinal pigment epithelial detachment.

Two patients with bilateral vitelliform macular lesions had normal electro-oculogram findings. The fluorescein angiograms showed retinal pigment epithelial detachment. Detachment of the retinal pigment epithelium associated with lipid and/or protein accumulation within the subpigment epithelial space represents another mechanism by which a lesion ophthalmoscopically similar to that seen in classical Best's disease can be produced.

Adult↗
PubMed1977

A civilian case of fatal meningococcemia due to Neisseria meningitidis, group Y.

The present report is that of a civilian episode of fatal, fulminant group Y meningococcemia in a previously healthy adolescent, who denied prior vaccination against group C meningococcus. The patient suffered abrupt onset of purpura, hypotension and cardiopulmonary arrest. A detailed clinical and pathologic report is included.

Adolescent↗
PubMed1976

Effects of laser photocoagulation on adenine nucleotides in rabbit retinas.

High-pressure liquid chromatography was used to provide a qualitative biochemical assessment of laser effects on retinal metabolism. The adenosine triphosphate-adenosine diphosphate ratio and the Atkinson energy charge are considerably increased in laser-treated rabbit retinas compared to the contralateral untreated retinas.

Adenosine Diphosphate↗