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Biomedical subjects

K Mayer

Publications and source records attributed to K Mayer.

At least 163 records · Page 9Linked to original sources
PubMed1986

Group A streptococcal pharyngitis and bacteremia associated with a Ludwig's angina-like syndrome.

Ludwig's Angina (LA) is an infection of the submandibular and sublingual spaces usually initiated by abscesses of the inferior molars due to mixed oral flora. Pharyngitis due to group A beta-hemolytic streptococci (GABHS) rarely results in bacteremia. A patient presented with the classical findings of LA, and had no odontogenic focus but had GABHS pharyngitis and bacteremia. Attempts to isolate other microbiological organisms from the submandibular and sublingual spaces were unsuccessful. The patient required emergent tracheostomy and was treated with penicillin G for 4 wk with complete resolution of his clinical illness. The case demonstrates a previously unreported association between GABHS pharyngitis and the development of LA.

Arthritis, Infectious↗
PubMed1986

Techniques for measuring red cell, platelet, and WBC survival.

Blood cell survival studies yield valuable information concerning production and destruction of cells circulating in the bloodstream. Methodologies for the measurement of red cell survival include nonisotopic methods such as differential agglutination and hemolysis. The isotopic label may be radioactive or, if not, will require availability of a mass spectrograph. These methods fall into two categories, one where red cells of all ages are labeled (51Cr, DFP32, etc.) and those employing a cohort label of newly formed cells (14C glycine, 75Se methionine, etc.). Interpretation of results for methodology employed and mechanism of destruction, random or by senescence, are discussed. A similar approach is presented for platelet and leukocyte survival studies. The inherent difficulties and complications of sequestration, storage, and margination of these cells are emphasized and discussed.

ABO Blood-Group System↗
PubMed1985

Evaluation of the S-Plus IV.

An evaluation of a Coulter Counter Model S-Plus IV hematology analyzer was undertaken at Memorial Sloan-Kettering Cancer Center to assess performance characteristics and to determine accuracy in analyzing both normal and clinical specimens. Special emphasis was placed on the platelet parameter. Precision, linearity, and carryover were found to be well within the manufacturer's specifications. A total of 222 patient samples were analyzed in the routine laboratory and on the Model S-Plus IV. Coefficients of correlation of 0.99 or higher were obtained for white blood cell count (WBC), red blood cell count (RBC), hemoglobin (Hgb), platelets (Plt), except mean cell volume (MCV) (r = 0.93). Results from 99 selected normal samples were compared with those from manual reference methods. Coefficients of correlation of 0.98 or higher were obtained for WBC, RBC, and Hgb. For MCV, the correlation coefficient was 0.85 and for Plt, 0.89 was obtained. The lower coefficient of correlation for these two parameters may be a function of the imprecision of the manual reference methods. In a previous study with an original Model S-Plus, the Plt parameter occasionally exhibited spuriously high counts. With the advent of third-generation S-Plus instruments, represented by the Model S-Plus IV, the possibility of reporting aberrant Plt values virtually has been eliminated. Data from the current study verify this. However, 93% of the flagged Plt results proved to be accurate, checking slides on these introduced inefficiencies in the laboratory.

Evaluation Studies as Topic↗
PubMed1985

Results of a screening method used in a 12-month stool survey for Escherichia coli O157:H7.

Escherichia coli serotype O157:H7 has been epidemiologically linked to outbreaks of hemorrhagic colitis associated with fast-food restaurants and nursing homes. Sporadic cases now exceed those associated with outbreaks. The incidence of the organism in patients with common diarrhea syndromes and in asymptomatic persons is unknown. Routine serotyping of E. coli isolates is impractical for most clinical microbiology laboratories. We developed a screening plate by utilizing sorbitol fermentation as a biochemical marker to identify organisms for serotyping. A total of 2,552 stool samples were screened. In 106 (4.1%), sorbitol-negative E. coli were identified. Of these, two were serotype O157:H7, and both produced a Vero cell toxin. One patient had hemorrhagic colitis and the other a mild, febrile, self-limited diarrhea with no other bacterial pathogen identified. This plate provides an easy, effective method of screening for sorbitol-negative E. coli, a process facilitating the selection of organisms for serotyping and one that may help clarify this organism's role in human disease.

Canada↗
PubMed1985

Presence of abnormal cells.

Automated WBC differential counters will identify only a limited number of cells but may do this very precisely and accurately. In a cancer center and in an orthopedic center, 10% and 6%, respectively, of all admissions will have circulating "abnormal" cells that might be missed by the automated instruments. Abnormal cells include blasts, promyelocytes, myelocytes, metamyelocytes, bands, reactive and immature lymphocytes and nucleated red cells. Eosinophilia and basophilia also have clinical implications. The argument is made that a screening method that fails to detect such cells may be inadequate and a simple practical solution is proposed. This will not eliminate the need for a stained smear but will reduce the call for a labor intensive manual differential count.

Automation↗
PubMed1984

Use of sodium chromate Cr51 in diagnosing childhood idiopathic pulmonary hemosiderosis.

The diagnosis of idiopathic pulmonary hemosiderosis (IPH) may be elusive. A 6-year-old boy had microcytic hypochromic anemia and a hemolytic component. Hemosiderin-laden macrophages were not found in the gastric aspirate. He had no pulmonary signs or symptoms. Extensive hematologic and roentgenologic investigations failed to reveal the cause of the anemia. Quantitative serial scintigraphic scanning showed significant (35%) pulmonary sequestration of autologous erythrocytes labeled with sodium chromate Cr51. The half-life of the RBCs was moderately decreased (half-life, 15 days; normal, 25 to 35 days). An open-lung biopsy specimen confirmed the diagnosis of IPH. A diagnosis of IPH should be considered when children have iron deficiency anemia and pulmonary signs or symptoms. Organ sequestration studies may be helpful in equivocal cases.

Anemia, Hypochromic↗
PubMed1984

Decreased expression of human class II antigens on monocytes from patients with acquired immune deficiency syndrome. Increased expression with interferon-gamma.

The expression of HLA-DR (a class II histocompatibility antigen) on monocytes isolated from the peripheral blood of normal individuals and patients with acquired immune deficiency syndrome (AIDS) was investigated by the use of dual fluorescent staining and cytofluorometry. In animal models the absence of class II positive monocytes is linked to a failure of T cells to respond to antigens. We now report that patients with AIDS have a paucity of HLA-DR+ monocytes. The percentage of HLA-DR+ monocytes among eight normal individuals ranged from 49.3 to 95.0%+, and only one individual had less than 50% HLA-DR+ monocytes. HLA-DR expression on monocytes from homosexual male patients with lymphadenopathy was similar to that of normal subjects (range, 58.0 to 97.4%+). In contrast, seven of nine patients with AIDS had less than 50% HLA-DR+ monocytes (range, 13.4 to 78.8%+). The in vitro incubation of monocytes from AIDS patients with cloned human interferon-gamma resulted in an increase of the expression of HLA-DR to near normal levels.

Acquired Immunodeficiency Syndrome↗
PubMed1982

Combination chemotherapy of advanced chronic lymphocytic leukemia: the M-2 protocol (vincristine, BCNU, cyclophosphamide, melphalan, and prednisone).

The M-2 protocol (vincristine, cyclophosphamide, BCNU, melphalan, and prednisone) was administered monthly to 63 evaluable patients with advanced chronic lymphocytic leukemia. Complete remission (absence of all clinical and bone marrow evidence of leukemia) and partial response (greater than 50% decrease in organ enlargement and reduction of WBC count to below 15,000 x 10(6)/liter) were achieved in 17% and 44%, respectively, for a total response rate of 61%. The median survivals from therapy of patients achieving a CR, RR, or no response were 73+, 40, and 14 mo respectively. The median survival time from onset of treatment for stages II, III, and IV disease were 47, 20 and 19 mo, respectively, which was not statistically different from historical controls. However, when untreated patients are compared to this latter group, a significant survival advantage from diagnosis was found (p = 0.01), stressing the importance of prior therapy as the only unfavorable prognostic factor. Although complete remissions in CLL, as reflected in apparently normal bone marrow B-lymphocyte markers, can be induced wih acceptable morbidity, the majority of patients relapse after cessation of therapy. An alternative approach to the M-2 protocol will be needed to eradicate the disease.

Antineoplastic Agents↗