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Biomedical subjects

J R Humbert

Publications and source records attributed to J R Humbert.

At least 37 records · Page 2Linked to original sources
PubMed1984

Neutrophil bactericidal dysfunction towards oxidant radical-sensitive microorganisms during experimental iron deficiency.

We developed a clear-cut nutritional iron deficiency anemia without concomittant malnutrition in rats given a low iron diet, and we restored normal iron and hemoglobin levels in these same animals with iron dextran injections. The neutrophil function studies performed during and after a period of iron deficiency showed the following: Phagocytosis of Staphylococcus aureus 502A, Streptococcus pneumoniae, and Salmonella typhimurium was not altered by iron deficiency or by the administration of iron; phagocytosis of Candida albicans was moderately abnormal during iron deficiency, and became normal with the restoration of iron sufficiency. Microbicidal activity towards Staphylococcus aureus 502A and Candida albicans, two catalase-positive microorganisms, was markedly decreased (to 50% of control values) and returned to normal when iron sufficiency was restored. Killing of a catalase-negative organism, Streptococcus pneumoniae was normal in iron-deficient rats. This pattern of differential bactericidal activities suggested an abnormality of the oxidant radical-generating machinery in neutrophils of iron-deficient animals. Indeed, iron deficiency caused a marked decrease of neutrophil nitroblue tetrazolium dye reduction, which disappeared after iron administration. Neutrophil myeloperoxidase activity was slightly decreased in iron deficient rats and returned to normal after iron administration. Microbicidal activity towards a gram-negative, catalase-positive organism, Salmonella typhimurium, was equal in iron deficient and iron sufficient animals. Our combined results suggest that a definite microbicidal defect is the consequence of nutritional iron deficiency, apart from any protein-calorie malnutrition. This defect affects the disposal in PMNs of two catalase-positive microorganisms (which require intracellular production of oxidant radicals for their destruction) but not of a catalase-negative bacterial species.(ABSTRACT TRUNCATED AT 250 WORDS)

Anemia, Hypochromic↗
PubMed1982

Newborn screening for hemoglobinopathies in New York State: experience of physicians and parents of affected children.

Responses of physicians and parents to New York State-mandated newborn screening for sickle cell disease were solicited and evaluated. The index group comprised 25 infants born in western upstate New York. Each was found to have either sickle cell disease, hemoglobin SC disease, sickle beta-thalassemia, or hemoglobin C disease. In nondirective interviews the following factors were assessed: clinical course, the physician's policies of disease treatment and family counseling, the parents' reactions to the diagnosis and their level of understanding and compliance with medical recommendations, and the physicians' and parents' views on newborn screening. Newborn screening for sickle hemoglobin makes early prophylaxis and prompt treatment possible. Some morbidity may have been averted, judging from parental understanding of medical needs. Parents and physicians agreed that newborn screening for hemoglobinopathies is a valuable public health program. Suggestions for improving the New York state program included a need to increase communication among the screening laboratory, the hospital, and the physician; encouraging physicians to educate parents more fully, provide genetic counseling, and test parents and siblings of the identified neonate; and, most important, provide a well-delineated mechanism for follow-up of every infant with a potentially symptomatic hemoglobinopathy.

Age Factors↗
PubMed1980

Cystadenocarcinoma of the ovary in a 4-year-old: benign transformation during therapy.

Ovarian tumors comprise only 1% of all tumors in females below the age of 17 years. Of these, the epithelial tumors are the least common, being particularly rare before puberty and then increasing in frequency with advancing age after puberty. The youngest girl previously reported in the literature with an epithelial ovarian tumor was a 9-year-old child with an ovarian papillary cystadenocarcinoma. This is the only case thus far reported of a malignant ovarian epithelial tumor occurring before puberty. Only histologically benign appearing glands were detected in the resected tumor masses, on a second-look laparotomy following the use of multiagent chemotherapy.

Antineoplastic Agents↗
PubMed1980

Phagocytic function in Down syndrome--I. Chemotaxis.

Defects in host defences may provide a partial explanation for the increased incidence of infection in individuals with Down syndrome. Neutrophil and monocyte cellular and humoral chemotaxis were evaluated to explore phagocytic function. Fourteen individuals with Down syndrome and fifteen matched institutionalised controls were studied. In addition, a non-matched comparison normal group was investigated, representing a non-institutionalised young adult population. Neutrophil chemotaxis in institutionalised individuals (both Down syndrome and matched controls) was significantly impaired. Monocyte chemotaxis in this group was lower than in comparison normals. Evaluation of humoral components of neutrophil chemotaxis revealed no significant differences between individuals with Down syndrome and those with no known chromosomal abnormality. Down syndrome subjects had diminished humoral monocyte chemotactic responses compared with institutionalised controls and normal subjects.

Chemotaxis, Leukocyte↗
PubMed1980

Phagocytic function in Down syndrome--II. Bactericidal activity and phagocytosis.

Bactericidal capacity was investigated to delineate the impairment of phagocytic function. Fourteen individuals with Down syndrome and fifteen matched institutionalised controls were studied. A non-matched comparison normal group was also evaluated, representing a non-institutionalised young adult population. Neutrophil bactericidal capacity was impaired in institutionalised subjects, the defect being most apparent in Down syndrome. Monocyte bactericidal capacity was identical in institutionalised and non-institutionalised subjects. Humoral functions revealed no differences. Neutrophil phagocytosis was diminished in institutionalised individuals, Down syndrome subjects being the least effective. Monocytes had normal phagocytosis, but opsonisation was defective in both the Down syndrome and matched institutionalised groups. Neutrophils were more efficient at phagocytosis than monocytes. No physiologically significant differences were noted in neutrophil or monocyte intracellular killing.

Blood Bactericidal Activity↗
PubMed1979

Fanconi's anemia with growth hormone deficiency.

The association of Fanconi's anemia (FA) and growth hormone (-gh) deficiency is not commonly reported. These children may have the typical features of the FA syndrome, or may exhibit much variability in clinical and hematological findings. In a single family, members may have FA with or without GH deficiency. The genetic basis for this heterogeneity is unknown. We describe here two siblings with FA, one of whom had dwarfism due to GH deficiency. Combined treatment with GH and androgen (oxymetholone) resulted in strikingly greater acceleration of growth than did the use of GH alone. Pancytopenia was not influenced by hormone therapy.

Anemia, Aplastic↗
PubMed1979

Transcutaneous leukocyte migration in vivo: cellular kinetics, platelet and C5a dependent activity.

A simple quantitative method for the measurement of leukotaxis in vivo is described. Duplicate skin chambers are placed over tape-stripped skin with 50% autologous serum--50% Hank's balanced salt solution as the attractant. Neutrophils predominate throughout 24 hr in this method with no change to mononuclear cells. A recommended modification of our original method is that chambers are sampled and removed after 8 hr rather than 24 hr since the majority of leukocyte migration occurs within the first 8 hr. Analysis of serum factors showed that heat-inactivation of the serum (56degreesC for 30 min) had no effect. However, depleting platelets or C5 from the serum removed approximately 90% of chemotactic activity for human neutrophils in vivo. Platelets, presumably through activity of their granules, enzymatically cleaves C5a from C5 in plasma. We conclude that C5a, after cleavage from C5, accounts for the majority of chemattractant activity in vivo.

Blood Platelets↗
PubMed1979

A simple microchromatographic column for determination of hemoglobins A1a + b and A1c.

A simple microchromatographic homemade column was devised for the measurement of glycosylated minor hemoglobin fractions. The mean and one standard deviation of hemoglobins A1a + b, A1c and A1a + b + c determined by the homemade column in 150 nondiabetic controls and 56 juvenile onset insulin-dependent diabetics were 2.6 +/- 0.5%, 6.0 +/- 1.0%, 8.6 +/- 1.1%, 3.3 +/- 0.9%, 13.7 +/- 2.2% and 16.9 +/- 2.8% respectively. A twofold increase in hemoglobins A1c and A1a + b + c levels was observed in the diabetics as compared to the non-diabetic controls suggesting that the homemade column is valid for the measurement of all three glycosylated hemoglobin fractions and assessment of blood glucose control in diabetic patients. The homemade column procedure yields accurate and reproducible results, is simple to perform, inexpensive, relatively rapid and may be used in the routine clinical laboratory. Hemoglobin A1a + b + c levels measured by a commercial column in 35 non-diabetic controls and in 56 diabetics showed good correlation (R = 0.91) with hemoglobin A1a + b + c levels determined by the homemade column. The commercial column is valid for the measurement of the combined glycosylated hemoglobin A1a + b + c fraction and may be used in the routine clinical laboratory to assess diabetic control.

Adolescent↗
PubMed1979

Host defense in infantile osteopetrosis.

Since infants with malignant osteopetrosis often die from infection at an early age, we studied several aspects of host defense in five such infants. No consistent abnormality was found in cellular or humoral immunity. Monocyte cellular chemotaxis and phagocytosis were normal in four tested infants. However, all four of these infants had decreased intracellular bacterial killing by monocytes. Neutrophil function tests in five infants showed that two had defective bacterial phagocytosis and four had reduced cellular chemotaxis, decreased nitroblue tetrazolium reduction, and decreased intracellular bacterial killing. The severity of the decreased bactericidal capacity of granulocytes did not correlate with the number of circulating immature granulocytes. Our data suggest that abnormal function of circulating monocytes and granulocytes may contribute to impaired host resistance to infection. We postulate that this defect may reflect a more generalized inherited abnormality of phagocytic cells and perhaps osteoclasts that plays a role in the pathogenesis of infantile osteopetrosis.

Blood Bactericidal Activity↗
PubMed1978

Remission of relapsed leukaemia during a graft-versus-host reaction. A "graft-versus-leukaemia reaction" in man?

Acute lymphoblastic leukaemic in two boys relapsed after engraftment of marrow from siblings identical at HLA A, B, and D loci but went into remission during subsequent graft-versus-host reactions without specific anti-leukaemia therapy. Later leukaemic relapse was primarily in extramedullary sites, with little or no involvement of bone-marrow, liver, or spleen. Cytogenetic studies in both cases showed that the relapsed leukaemic blasts were those of the recipients while marrow cells and blood lymphocytes detected during marrow remission originated from the female donors. Blood lymphocytes from one of the recepients kiled. 51Cr-labelled autologous lymphoblast. The prolonged bone-marrow remission in the face of active and even massive extramedullary leukaemia suggests a graft-versus-leukaemia reaction in these two patients.

Adolescent↗
PubMed1978

Pyoderma gangrenosum. Abnormal monocyte function corrected in vitro with hydrocortisone.

A 34-year-old man with chronic active hepatitis and pyoderma gangrenosum demonstrated abnormalities in neutrophil and monocyte function. Monocytes from this man had diminished chemotaxis and bacterial phagocytosis. These functions were significantly improved in vitro after one hour of incubation of monocytes with 10(-5) hydrocortisone. Neutrophil function was nornal for bactericidal activity and phagocytosis, but neutrophil chemotaxis was diminished. A plasma inhibitor was not found to explain these phagocyte alterations.

Adult↗
PubMed1978

Non-leukemic dividing cells in the blood of leukemic patients.

Spontaneous mitoses in the blood of 67 patients with acute leukemia were enumerated and their identity determined by cytogenetic methods. Most patients were children with acute lymphoblastic leukemia. Simultaneous 16- to 20-hour cultures of blood leukocytes (Bu) and of bone marrow (BM) cells were performed without phytohemagglutinin (PHA). Blood leukocytes were also cultured with PHA for 72 hours (BPHA). Mitoses in Bu cultures were counted, and karyotypic analysis performed on cells from the three culture types. In 21 control subjects, Bu cultures usually yielded no mitoses. Relapse and remission patients both displayed significantly more Bu mitoses than the controls. The karyotypes of Bu, BPHA, and BM mitoses in remission patients were normal. Fifty percent of relapse patients displayed cytogenetically abnormal leukemia cell lines; the percentage of their abnormal karyotypes was significantly higher in BM cells than in Bu or BPHA cells. The majority of the mitotic cells in Bu cultures from both relapse and remission patients appear to be of a nonleukemic origin. The number of mitoses could not be correlated with type of leukemia, hematologic parameters, or prognosis.

Adult↗