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Biomedical subjects

M Wilson

Publications and source records attributed to M Wilson.

At least 505 records · Page 28Linked to original sources
PubMed1991

Monocytoid B-cell lymphoma: a study of 36 cases.

We have studied 36 cases of monocytoid B-cell lymphoma (MBCL). We confirm the predilection for females (30 of 36; ratio, five women to one man). The median age was 65 years (range, 29 to 85 years). Monocytoid B-cell lymphoma characteristically involves peripheral lymph nodes (30 of 36) with a propensity for paraparotid or intraparotid nodes. Salivary glands were affected in five patients. Other extranodal sites of involvement included breast, thyroid, stomach, and soft tissue of chest wall. Eight patients manifested with Sjögren's syndrome, one had systemic lupus erythematosus, one presented initially with Raynaud's phenomenon, and two had a monoclonal gammopathy. "Composite lymphomas" were encountered in seven patients. In addition, association with or progression to a higher-grade lymphoma, ie, mixed small and large cell (one) and large cell (six), was observed in seven patients and was associated with a more aggressive behavior of the lymphoma. Immunohistochemical studies performed on biopsy sections from 20 patients confirmed the B-cell nature of MBCL. An average reactivity of less than 10% of the monocytoid B cells with the proliferation marker Ki-67 was demonstrated, in keeping with the indolent behavior of MBCL. Despite our observation of follicular lymphomas frequently accompanying MBCL, the t(14;18) chromosomal translocation does not appear to play a pathogenetic role for MBCL, as determined by molecular studies for the t(14;18) chromosomal translocation and immunologic studies for the BCL2 protein. Our observations also provide support for the proposal that there is an overlap between MBCL and "MALT lymphomas" (those arising from mucosa-associated lymphoid tissue).

Adult↗
PubMed1991

Cockroach-allergen study: allergen patterns of three common cockroach species probed by allergic sera collected in two cities.

Antigens/allergens of three common cockroach extracts, crude whole body extract of the American cockroach (CRa-A), crude whole body extract of the German cockroach (CRa-G), and crude whole body extract of the Oriental cockroach (CRa-O), were studied with crossed immunoelectrophoresis, crossed radioimmunoelectrophoresis, and Western blot analysis. Sera of cockroach-allergic patients with asthma, 10 from Chicago, Ill. (C group) and six patients from Lexington, Ky. (L group), were used; results were then compared with sera of control subjects with asthma. Qualitative differences in protein bands were noted among CRa-A, CRa-G, and CRa-O by crossed immunoelectrophoresis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Allergen bands on Western blot were analyzed for distribution by molecular weight (MW) with relative intensity scores. Results were compared by species and by geography. Two to 12 allergenic bands of variable MW (14 kd to greater than 116 kd) were identified by 13 of 16 individual sera from cockroach-allergic patients from all three extracts. CRa-A demonstrated 55 bands with an intensity score of 125; CRa-G, 58 bands with an intensity score of 100; and CRa-O, 51 bands with an intensity score of 108. Allergenic bands of CRa-A were identified by six sera of the C group and one sera of the L group, whereas bands of both CRa-G and CRa-O were noted by nine sera of the C group and four sera of the L group. All three species had an allergen band in MW range of 40 to 45 kd that reacted to most sera from cockroach-allergic patients with asthma.

Adolescent↗
PubMed1991

An unusual voltage-gated anion channel found in the cone cells of the chicken retina.

Using the whole-cell patch clamp technique, we have examined the voltage-gated currents present in adult chicken cone cells. When calcium and calcium-gated currents are blocked, hyperpolarizing voltage steps elicit slowly increasing inward currents as has been shown for photoreceptors in other species. Unlike the case for other species, chicken cones appear to lack the inward-rectifying cationic current Ih that contributes to the shaping of the photovoltage. Instead of Ih, these cones possess an anionic inward-rectifying current that in kinetics, activation range and probably function is remarkably similar to Ih. This anion channel is unusual in that both nitrate and acetate are more permanent than chloride ions.

Animals↗
PubMed1991

Safety and immunogenicity of human rotavirus vaccine strain M37 in adults, children, and infants.

Rotavirus vaccine strain M37 (serotype 1), recovered from the stool of an asymptomatic newborn infant and serially passaged in cell culture, was given orally to adults, children, and infants. Serologic responses were detected by neutralization assay or EIA in 59% of 17 adults (10(5)-pfu dose), 55%-60% of 21 infants and children (10(4)-pfu dose), and 70% of 10 infants (10(5)-pfu dose), vaccine virus was shed by 24%, 20%-36%, and 70%, respectively. In adults, neutralizing antibody rises to strain M37 and the related serotype 1 strain Wa occurred with equal frequency (41% vs. 47%). In pediatric subjects, the former were more frequent (36%-40%) than the latter (10%-18%). This was also true of 8 infants who received two doses of vaccine. Mild gastrointestinal illnesses occurred with equal frequency in pediatric subjects who received vaccine or placebo. Thus, strain M37 was well tolerated and immunogenic in young infants, but elicited primarily vaccine-strain-specific rather than serotype-specific neutralizing antibody responses.

Adult↗
PubMed1991

Clinical evaluation of the cysticercosis enzyme-linked immunoelectrotransfer blot in patients with neurocysticercosis.

During the 3 years that the enzyme-linked immunoelectrotransfer blot (EITB) assay for the diagnosis of human cysticercosis has been in use at the Centers for Disease Control, 50 patients with both pathologically confirmed neurocysticercosis and computed tomographic (CT) or magnetic resonance imaging (MRI) scan results were identified. Of 32 patients with two or more lesions, 94% had detectable antibodies by EITB compared with 28% of 18 patients with single lesions. Patients with only calcified cysts (single or multiple) were less likely to have EITB-positive results than were those with noncalcified, enhancing lesions. Antibody was detectable more frequently in serum than in cerebrospinal fluid, regardless of the number or apparent condition of the cysts. These findings confirm that the EITB assay for cysticercosis antibodies is highly sensitive in patients with multiple, enhancing intracranial lesions but is less sensitive in patients with single lesions and in those with calcified lesions.

Adolescent↗
PubMed1991

Isolation and identification of bacteria from subgingival plaque with low susceptibility to minocycline.

Twenty subgingival plaque samples from patients with chronic periodontitis were screened for the presence of three periodontal 'pathogens'--Porphyromonas gingivalis, Fusobacterium nucleatum and Eikenella corrodens. Nineteen of the samples were found to contain at least one of the three organisms and six samples contained all three. The subgingival plaque samples were cultured in the presence of various concentrations of minocycline, and those organisms which appeared to be least susceptible to the antibiotic were isolated and identified. A total of 40 isolates were obtained and these consisted of 18 different species, only one of which, Fusobacterium nucleatum, is generally recognized as being associated with chronic periodontitis. The minimum inhibitory concentrations of minocycline for many of the organisms isolated were greater than the concentration of attainable in gingival crevicular fluid following routine parenteral administration of the antibiotic.

Adult↗
PubMed1991

Comparison of basal and prandial insulin therapy in patients with secondary failure of sulphonylurea therapy.

A group of 35 normal weight patients with secondary failure of sulphonylurea therapy (fasting plasma glucose greater than 8.0 mmol l-1 on maximal dose of sulphonylurea) were randomly assigned to receive either a single injection of a basal insulin supplement (human ultralente insulin, n = 16) or three or four injections of a preprandial insulin supplement (human unmodified insulin, n = 19). Patients performed self-monitoring of capillary blood glucose and adjusted their insulin doses in an effort to achieve fasting and preprandial capillary glucose concentrations of less than 7.0 mmol l-1. Blood glucose control after 16 weeks of insulin therapy was improved to a similar extent by both regimens (HbA1 basal insulin group 12.5 +/- 1.2 (+/- SD) falling to 10.7 +/- 2.2%; preprandial group 12.0 +/- 1.6 falling to 9.5 +/- 1.6%). Preprandial insulin gave better control of daytime blood glucose levels but fasting plasma glucose did not differ between the two regimens (basal group 10.6 +/- 3.6, preprandial group 11.1 +/- 3.6 mmol l-1). Insulin dose was greater in the preprandial group (44.1 +/- 17.9 U day-1) than in the basal group (26.7 +/- 12.5 U day-1 (p less than 0.005), but there was no difference in the frequency or severity of hypoglycaemia between the two treatments. Only the preprandial therapy group showed significant weight gain (2.7 +/- 3.0 kg). While both regimens led to improvement of blood glucose control, these results suggest that neither basal nor preprandial insulin alone can achieve ideal blood glucose control through 24 h in patients with fairly severe failure of control on sulphonylurea therapy.

Blood Glucose↗
PubMed1991

Assessment of ultrasonic debridement of calculus-associated periodontally-involved root surfaces by the limulus amoebocyte lysate assay. An in vitro study.

This investigation assessed the effectiveness of an in vitro ultrasonic debridement regime on periodontally involved teeth with visually-detectable calculus deposits, using the LAL assay for lipopolysaccharides (LPS) as a marker of bacterial products. 34 single rooted teeth with extensive amounts of calcified accretions were selected, of which 10 served as uninstrumented controls for the estimation of existing LPS levels. The periodontally involved roots of the 24 experimental teeth were debrided with a Cavitron TF-10 tip for a limited time using light pressure and overlapping strokes which ensured complete surface instrumentation without reference to the presence of calculus. Marked reductions in root surface area coverage by calculus were nevertheless achieved as assessed planimetrically from photographic records of the teeth before and after debridement. The root surfaces of each tooth were then stripped away and the harvested material subjected to 'Westphal' extraction and LAL assay for LPS. The resulting LPS yields from the experimental teeth ranged from less than 0.08 to 22.387 ng compared to 1,900 to 29,200 ng from the uninstrumented controls. The extremely small residual LPS yields from the experimental teeth not only confirm the efficacy of ultrasonic debridement but, when coupled with the lack of a relationship with the widely varying amounts of the remaining calculus, support the contention that bacterial plaque rather than calculus has the greater pathogenic potential. These results reinforce the growing impression of the superficial location of bacterial toxic products associated with periodontally involved root surfaces.

Adolescent↗
PubMed1991

Dual effect of glycine on horizontal cells of the tiger salamander retina.

1. The effects of glycine on horizontal cells have been examined by microelectrode recording from superfused retinas isolated from the salamander. 2. Low concentrations of glycine (less than 50 microM) hyperpolarized horizontal cells and increased the magnitude of their light responses. Millimolar concentrations produced the opposite effect of depolarizing these cells and reducing their light response amplitudes. 3. In the presence of Co2+ and Mg2+ at concentrations sufficient to suppress the light response, millimolar glycine still exerted a depolarizing effect on horizontal cells, implying that this effect was largely a direct one on horizontal cell membranes. 4. Although both the rod and the cone contributions to horizontal cell light responses were reduced by millimolar glycine, rod input was reduced more, suggesting that millimolar glycine may also exert a presynaptic effect. 5. Strychnine (10 microns) antagonized the effects of millimolar glycine and, in the absence of exogenously applied glycine, caused horizontal cells to hyperpolarize and their light responses to increase in amplitude. This result implies that, in darkness, glycine is tonically released onto horizontal cells and maintains them in a state of partial depolarization. 6. The low-concentration effect of glycine was accompanied by an increased membrane resistance and receptive field size but no change in the balance of rod and cone input. 7. Low concentrations of glycine were often seen to cause a speeding of light responses, whereas high concentrations sometimes caused a slowing of response kinetics. Response kinetics were found to correlate with horizontal cell dark membrane potential so that, positive to -30 mV, depolarization slowed responses whereas kinetics at more negative values were largely independent of voltage.

Ambystoma↗
PubMed1991

The effects of glycine and GABA on isolated horizontal cells from the salamander retina.

1. Horizontal cells, identified by their morphology, were isolated from the salamander retina and examined in whole cell patch clamp. 2. All cells showed large outward currents activating positive to about -50 mV, and a minority of cells showed fast, tetrodotoxin-suppressible Na+ currents. Slow inward currents that might shape the light responses were never observed. 3. All cells showed conductance increases to both gamma-aminobutyric acid (GABA) and glycine that were completely blocked by bicuculline and strychnine, respectively. No cross-blocking by these antagonists was observed. Partial replacements of Cl- with large, impermeant anions indicated that both GABA- and glycine-evoked currents were carried by Cl- ions. 4. Responses to both GABA and glycine desensitized strongly with time constants of approximately 2 s. 5. Responses to glutamate were not enhanced by glycine. Similarly, responses to GABA were not enhanced by glutamate. 6. GABA-mediated synaptic interactions between horizontal cells may account for the changes in the kinetics of horizontal cell light responses seen when glycine is applied to the intact retina.

Action Potentials↗
PubMed1991

Age-related changes in the relative growth of the posterior fossa.

We have established a normative data set for the relative size of the structures of the midline posterior fossa from birth to 90 years old. Data were obtained from morphometric analysis of midsagittal magnetic resonance imaging scans of the brain utilizing a simple image analysis system. There are several significant changes in the size of these structures with an increase in chronologic age. The relative size of the cisterna magna decreases with age. Anterior cerebellar vermal lobules (I through V) appear to grow more rapidly than the rest of the cerebellum. Other, less significant, trends include a decrease in the overall size of the cerebellum, superior posterior vermal lobules (VI and VII) and inferior posterior lobule (VIII) with an increase in age. It is, therefore, necessary to use age-standardized normative data when making morphometric correlations with clinical disorders.

Adolescent↗
PubMed1991

Similar outcome of treatment of B-cell and T-cell diffuse large-cell lymphomas: the Stanford experience.

Although previous studies have suggested a relatively poor prognosis for some patients with peripheral T-cell lymphoma, the clinical significance of immunologic phenotype in diffuse large-cell lymphoma (DLCL) remains controversial. One hundred one patients with a uniform morphologic diagnosis of DLCL treated at Stanford between 1975 and 1986 with cyclophosphamide, Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH), vincristine, and prednisone (CHOP), methotrexate, bleomycin, Adriamycin, cyclophosphamide, vincristine, and dexamethasone ([M]BACOD), or methotrexate, Adriamycin, cyclophosphamide, vincristine, prednisone, and bleomycin (MACOP-B) chemotherapy were studied with regard to immunologic phenotype. Immunologic analysis, performed on frozen or paraffin-embedded tissue, identified 77 cases of B-cell origin, 21 cases of T-cell origin, and three cases that lacked B-cell or T-cell markers. Analysis of complete remission (CR) rates (84% v 95%), 5-year actuarial freedom from disease progression (38% v 53%), and 5-year actuarial overall survival (52% v 79%) showed no statistically significant differences in prognosis between B- and T-cell patients, respectively. The 5-year actuarial survival of patients with stage IV T-cell DLCL (56%) also did not differ in a statistically significant way from stage IV B-cell patients (36%). We conclude that treatment selection for DLCL should not be based on immunologic phenotype alone.

Actuarial Analysis↗
PubMed1991

Charcot foot osteoarthropathy in diabetes mellitus.

Charcot joint, a destructive bone and joint disorder of the foot, is becoming more common in long-term diabetic patients. The combination of diabetic neuropathy and painless trauma causes dislocation and collapse of the tarsal joints. The resulting soft tissue and osseous pathology easily mimics an infective episode. This report presents a review of the clinical identification, diagnosis, and treatment of this unusual diabetic complication, plus a review of three cases. Also, the pathogenesis of Charcot joint is explained in describing why surgery can be a viable treatment alternative in these patients, after careful evaluation. It is also necessary that physicians inspect the feet of their diabetic patients to rule out quiescent beginnings of Charcot joints. Referral to a podiatrist is recommended for long-term management of the Charcot foot.

Adult↗
PubMed1991

Laboratory diagnosis of toxoplasmosis.

Toxoplasmosis is usually diagnosed in the clinical laboratory by detecting antibodies to Toxoplasma gondii, and only rarely by isolating the parasites. A number of serologic tests are used; each has its own advantages and disadvantages. The methods of diagnosis and their interpretations differ for each clinical category of infection.

Acquired Immunodeficiency Syndrome↗