PubMed Health⌕ Search

Biomedical subjects

C L Olsen

Publications and source records attributed to C L Olsen.

36 records · Page 2Linked to original sources
PubMed1991

Care of diabetic patients by optometrists in New York State.

OBJECTIVE: This study was undertaken to learn about the involvement of optometrists in the eye care of diabetic patients in New York and to collect baseline data for planning intervention programs in diabetic eye disease. RESEARCH DESIGN AND METHODS: This study was conducted by a mail survey being sent to all optometrists in New York whom we could identify through state sources (n = 2270). Three follow-up mailings were conducted. RESULTS: Eighty-six percent who received our mailing responded, 87% of whom reported that they see diabetic patients. Analysis was confined to this 87%. Routine retinal examinations were provided by 68% of the respondents who see diabetic patients, 62% of whom dilate the pupils. Sixty-eight percent who see diabetic patients diagnose retinopathy solely by their own examination, and 60% of these dilate. Follow-up of retinopathy was provided by 15% of optometrists who see diabetic patients, 90% of whom dilate the pupils of their diabetic patients. Twenty-five percent of respondents who see diabetic patients refer them to an ophthalmologist for diagnosis of retinopathy, and 67% refer all retinopathy patients to an ophthalmologist for follow-up. Although 91% of respondents recommended eye examinations at least annually for diabetic patients, only 68% specifically recommended annual examinations through dilated pupils. Those who dilate were significantly more likely to recommend annual dilated examinations than those who do not dilate, regardless of practice setting. CONCLUSIONS: These findings indicate that optometrists as a group see many diabetic patients. Intervention strategies should include increased emphasis on the use of dilation when examining diabetic patients and annual dilated retinal examinations.

Attitude of Health Personnel↗
PubMed1989

The care of diabetic patients by ophthalmologists in New York State.

All ophthalmologists in New York State whom the authors could identify through state sources and professional societies (n = 1655) were surveyed about eye care of diabetic patients. Over 90% recommended at least annual retinal examinations for the presented hypothetical patients. Ninety-four percent said they "usually" (31%) or "almost always" (63%) recommend laser treatment for proliferative retinopathy, while 6% said they "occasionally" or "almost never" recommend such treatment. Almost all the latter physicians were general ophthalmologists. The decision to treat macular edema was highly dependent on the quality of the patient's vision. The percentage who "usually" or "almost always" recommend laser treatment for macular edema was 24% when the patient's vision was excellent, 63% when vision was mildly compromised, but 73% when vision was significantly compromised. General ophthalmologists and retina specialists differed significantly in their recommendations for follow-up and treatment of diabetic retinopathy. Ophthalmology 96:739-745, 1989.

Diabetes Complications↗
PubMed1986

Requisites for growth and myelination of urodele sensory neurons in tissue culture.

We describe a system for long-term culture of adult salamander dorsal root ganglia and present initial observations on the regulation of nonneuronal cell proliferation in this system. Observations of the region of axonal outgrowth in these cultures indicated that, on the one hand, fibroblasts proliferate equally well with neurons present or absent. Schwann cells, on the other hand, require not only the presence of neurons but also proximity to or contact with their neurites. These results indicate that neural tissue is not mitogenic for all cell types represented in the limb regeneration blastema. Further, we describe, for the first time, myelination of salamander axons in vitro. The critical factors found to be required for this high degree of differentiation were the use of long culture periods and addition to the culture medium of ascorbic acid, which is shown to promote extracellular matrix deposition. These observations correlate with extensive observations made on mammalian tissues in vitro, indicating a linkage between deposition of extracellular matrix and full expression of other Schwann cell functions. We anticipate this culture system will be useful in studies of limb blastema cell proliferation.

Ambystoma↗
PubMed1986

Nausea and vomiting of pregnancy and association with pregnancy outcome.

The pattern of nausea and/or vomiting of pregnancy were investigated in a group of 414 predominantly white, upper middle-class women in Albany, New York; patterns were ascertained before their eighty-eighth day of gestation and followed up to the end of pregnancy. Of these, 89.4% reported at least some symptoms. This frequency is higher than reported previously, perhaps in part because extensive attempts were made in this study to ascertain symptoms. The incidence of vomiting was about 55%. Women with no symptoms of nausea and/or vomiting of pregnancy experienced a significantly greater proportion of nonviable pregnancy outcomes (fetal death). Increased intake of niacin during the first trimester was associated with decreased infant birth weight. This may be the result of quicker fetal maturation due to increased levels of protein intake.

Female↗
PubMed1985

Application of image analysis for quantitative immunoperoxidase detection of IgE containing cells in lymphoid tissues.

Methods for the quantitation of antigen or antibody specific cells within lymphoid structures rely on the laborious and often inaccurate counting of stained cells visually under the microscope. To circumvent these problems we used a combination of computer-linked image analysis, with the Quantimet 720 and specific staining for IgE by immunoperoxidase, to produce a relatively easy, accurate method for the quantitation of specifically stained cells within tonsils and lymph nodes. Frozen sections of bovine lymph nodes and tonsils were stained in an indirect immunoperoxidase technique with either rabbit anti-bovine IgE or normal rabbit serum as the primary reagent. Examination of the stained slides on the Quantimet 720 image analyzing computer revealed cells that were sufficiently dark to be considered above the 'threshold level' of background staining. These were counted as positive picture points. A quantitative evaluation of the relative number of IgE containing cells within the particular lymphoid tissue was arrived at by determining the difference between the percent positive picture in the control tissue incubated with normal rabbit serum (background) and in the sample treated with rabbit anti-IgE. Using this method, it was readily possible to quantitate the presence of IgE containing cells in the tonsils of calves; the highest percentage of positive tissue was present in the tonsils of calves exposed to ovalbumin. Image analysis is a useful technique for quantitative evaluation of any immunoperoxidase stained tissues.

Animals↗
PubMed1985

Quantitation and localization of immunoglobulin E containing cells in bovine lymphoid tissues.

Although recent studies have begun to describe and quantify IgE responses in bovine serum and secretions, little is known about the distribution and quantity of IgE containing cells in cattle. In the present study, cells with cytoplasmic IgE were quantitated in bovine lymphoid tissues, using immunoperoxidase staining and evaluation by an image analysing computer (Quantimet). Frozen sections from retropharyngeal, bronchial and mesenteric lymph nodes, tonsil and spleen were stained from 11 calves, some of which had been exposed to antigen by aerosol or injection. Although individual variability was considerable, bronchial and mesenteric lymph nodes generally contained the greatest percentage of IgE containing cells, while retropharyngeal lymph node, tonsil, and spleen had less. Parenteral immunization with ovalbumin appeared to increase the splenic percentage, while aerosol exposure to ovalbumin was associated with a greater percentage of IgE containing cells in bronchial lymph nodes. Comparison of the present results with those reported for other species shows some similar trends in IgE localization.

Aerosols↗
PubMed1984

Cell cycle and histological effects of reinnervation in denervated forelimb stumps of larval Ambystoma.

Although nerves are a requirement for regeneration of a salamander limb, denervation of an amputated larval Ambystoma forelimb does not permanently prevent the limb from regenerating. When nerves grow back into the distal stump in sufficient numbers, regeneration occurs. In this study we examined histological and cell cycle events in denervated limb stumps of Ambystoma as they became reinnervated and began to regenerate. Prior to reinnervation and regeneration, dedifferentiated cells are present in the distal stump but are rarely synthesizing DNA or undergoing mitosis and are densely packed. About 2 days after the distal tip of the stump becomes reinnervated, the limb tip appears to "expand" as cells become less densely packed, and cell cycle activity begins. Mitotic index (MI) and labeling index (LI) increase slowly compared to MI and LI in control amputated limbs. Evidence for the localization of cycling activity is presented. In reinnervated stumps, the increase in LI precedes the increase in MI, suggesting that most of the cells are initiating cycling from the G1 phase.

Ambystoma↗
PubMed1984

Rescue of blocked cells by reinnervation in denervated forelimb stumps of larval Ambystoma.

Cells of amputated, denervated larval Ambystoma forelimbs dedifferentiate and enter the cell cycle but do not subsequently proliferate sufficiently to form a blastema. The denervated limb stump resorbs slowly until reinnervation stimulates regeneration. We used this system to investigate the fate of cells in denervated limbs which undergo early but limited cycling in response to amputation. In Experiment 1, cells were labeled with [3H]thymidine (3H-T) on Day 4 postamputation (PA)/Day 3 postdenervation (PD). Labeled cells were still present on Day 7 PA, but were less frequently observed on Day 13 PA when the limbs were reinnervated and beginning to regenerate. In Experiment 2 we denervated 1 day preamputation to obtain earlier reinnervation and prevent loss of Day 4 PA labeled cells. Cells labeled with 3H-T on Day 4 PA/Day 5 PD were present throughout the denervation period and most were still present on Day 13 PA. Little or no mitotic activity was found among the labeled cells after the initial round of cycling. The apparent cell cycle block was released upon reinnervation on Days 12 and 13 PA when cycling resumed. Labeled mitotic figures were present on Day 13 PA, and the mitotic index of the labeled population increased as a result of reinnervation. These results demonstrate that blocked cells are rescued by nerves, re-enter the cell cycle, and thus contribute to the reinnervation blastema.

Ambystoma↗
PubMed1984

Humoral response of cattle to aerosolized Micropolyspora faeni.

Calves (7) were exposed to antigens of Micropolyspora faeni by the aerosol route for 9 weeks. The humoral immune response of calves to M faeni antigens was studied; immunoglobulins (Ig) E, G1, G2, A, and M were measured weekly in serum and nasal secretions by enzyme-linked immunosorbent assay (ELISA). Intradermal injection of antigen was performed during the 6th and 9th weeks; responses were evaluated at 30 minutes, 6 to 8 hours, 24, and 48 hours after injection. Total IgE levels in serum and nasal secretions, evaluated weekly, did not show any elevation. Micropolyspora faeni-specific IgE, IgA, IgG1, and IgG2, but not IgM, were produced by calves exposed to the antigen by the aerosol route; individual variability in magnitude of the response was marked. Thirty-minute skin tests were positive for cytotropic antibody in 2 of 3 aerosol-exposed calves by the 9th week, but delayed-type reactivity was not present. The ELISA test results were compared with those from sera of saline solution aerosol-exposed calves and from a parenterally immunized calf. Comparison of isotype-specific ELISA results obtained from M faeni aerosol-exposed calves with ELISA results from calves exposed to aerosolized ovalbumin according to a similar procedure indicated inherent problems in evaluating immune responses to environmental antigens. Aerosolized M faeni elicited a substantial antibody response. In particular, it is noteworthy that antigen-specific IgE responses were detected.

Aerosols↗
PubMed1984

Immunologic responses of calves to aerosolized antigen: humoral response to ovalbumin.

The humoral response of cattle to ovalbumin (OA), a nonenvironmental well-defined antigen, was studied. During 9 weeks of aerosolization, weekly serum and nasal secretion concentrations of immunoglobulin (Ig)G1, IgG2, IgM, IgA, and IgE were determined by enzyme-linked immunosorbent assay (ELISA) for OA specific antibody. Data from 3 calves given aerosol OA were compared and contrasted with data from 3 calves given aerosol saline solution and 1 calf given parenteral OA. The presence of cytotropic (skin sensitizing) antibody was evaluated during weeks 6 and 9 by direct skin testing with OA. A humoral response was induced in all 3 calves given aerosol OA. Serum IgG1 and IgG2 titers reached a maximum of 64,000 and 2,000, respectively, in calves given aerosol OA compared with 521,000 and 16,000, respectively, in the calf given parenteral OA. The ELISA did not detect an OA-specific IgM response. In contrast, all 3 calves given aerosol OA had serum IgA concentrations that increased to a peak by week 9. The mean IgA absorbance value for the 3 calves given aerosol OA was slightly greater than 5 times that of the calf given parenteral OA. Similarly, nasal secretions from calves given aerosolized OA had absorbance values that were 15-fold greater than that from the calf given parenteral OA. Calves given aerosol OA had antigen-specific IgE responses during weeks 6 to 8. The ELISA results were compared with results of passive cutaneous anaphylaxis tests. The presence of skin-sensitizing antibody was indicated by positive skin tests in the calves given aerosol OA and the calf given parenteral OA by week 9.

Aerosols↗
PubMed1982

Higher vertebrates do not regenerate digits and legs because the wound epidermis is not functional. A hypothesis.

The necessity of injury, nerves, and wound epidermis for urodele limb regeneration is well accepted. Whether one or more of these three factors is limiting in amputated nonregenerating limbs of other vertebrates is a problem area in need of resolution. One view, that higher vertebrates possess inadequate innervation for limb regeneration to occur, is not strongly supported by experimental results. Superinnervation of lizard and mammalian limbs fails to elicit limb regeneration. Furthermore, in the well-known cases of mammalian regeneration, deer antlers and rabbit ears, a nerve requirement has not been demonstrated. In urodeles, the wound epidermis has recently been shown to have the role of maintaining dedifferentiated cells of the amputated limb stump in the cell cycle. The result of this wound epidermal stimulus is a sufficient number of cell divisions such that blastema formation occurs. We postulate that in amputated limbs of higher vertebrates, the wound epidermis is nonfunctional. Dedifferentiated or undifferentiated cells are not maintained in the cell cycle and blastema formation therefore does not occur. Instead, tissue regeneration occurs precociously due to lack of a cycling stimulus. The scar tissue which forms at the limb tips of nonregenerating vertebrates is the result of a nonfunctional wound epidermis.

Animals↗
PubMed1980

Cellular events in denervated limb stumps of Ambystoma larvae during re-innervation and subsequent regeneration.

Amputated, denervated Ambystoma forelimbs undergo cellular dedifferentiation and slight resorption through 12 days post-amputation. Subsequently, as limb stumps become re-innervated, there occur mitosis, blastema formation, and regeneration. The initial increase in the mitotic index in once-denervated limb stumps is closely correlated with the presence of ingrowing nerve fibres.

Ambystoma↗
PubMed1980

Cancer mortality in a human isolate.

Cancer mortality (1965--77) among 12,652 members of an inbred human religious isolate, the Hutterites, was compared with expectations based on mortality rates for the U.S. white population in 1970. Overall, Hutterites had significantly fewer deaths from cancer than expected (P < 0.01), due primarily to fewer lung cancers among males. Smoking is prohibited for this religious group. The most frequent types of cancers were leukemia and cancers of the digestive system, the prostate gland, and the female breast. Preliminary results suggest an association between recessive alleles and childhood leukemia. More stomach and rectal cancers were observed than expected, but differences were generally not significant. Familial aggregates of cancers of the stomach and breast are being investigated. The low frequency of cervical cancer is consistent with current evidence for an association of cervical cancer with early age at first intercourse and promiscuity, neither of which is characteristic of this population.

Canada↗
PubMedDate not supplied

The community ecology of diabetes patient classification and practice characteristics.

We examined the clinical and epidemiologic characteristics of diabetic subjects ascertained from five different sources (hospital, private practice, specialist practice, nursing home, and prevalence survey) in a medium-sized upstate New York community. Patients were categorized using the National Diabetes Data Group classification (based on weight and insulin requirement) and using an alternative clinical classification scheme based on age at onset and insulin use. Both classifications demonstrate marked differences in the distribution of diabetic subjects. Those seen in general medical practice reflect the prevalent population and tend to have fewer complications and less insulin requirement. Those seen in specialist practice or in hospital have higher complication frequencies. Thus, the source of patients may determine the epidemiologic picture of the disease, as well as the practitioners' perceptions. Use of the clinical classification scheme helps to identify a subgroup of diabetic subjects--those with onset past the age of 25 yr who use insulin--at greatest risk of complications. Further investigation of high-risk groups is warranted, particularly for the implementation and evaluation of diabetes control programs.

Adolescent↗