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Biomedical subjects

H G Herrod

Publications and source records attributed to H G Herrod.

At least 19 recordsLinked to original sources
PubMed1999

Breast-feeding initiation: predictors, attitudes, and practices among blacks and whites in rural Mississippi.

OBJECTIVES: We attempted to determine the incidence, predictors, attitudes, and practices of breast-feeding initiation among women in a low-income rural Mississippi community. METHODS: We interviewed 420 new mothers regarding breast-feeding. RESULTS: Ninety-six women (24%) initiated breast-feeding. More whites (44%) than blacks (20%) initiated breast-feeding. Of those 96, 59% planned to breast-feed for <6 months and 38% for 6 to 12 months. Among women who breast-fed, 78% said they did so because it was healthier. Among those not breast-feeding, most (48%) specifically stated, "I have no reason," while 20% hated the idea and 19% lacked time. About 73% of all women had been encouraged to breast-feed by nonphysicians (83%). For both races, the most significant predictor was a breast-feeding friend or relative. CONCLUSION: Breast-feeding rates in the Mississippi Delta are low, especially among blacks. Effective education programs are needed to increase these rates, and such programs should include friends, spouses, relatives, and significant others.

Adult↗
PubMed1997

Repeated invasive pneumococcal infections in young children without apparent underlying immunodeficiency.

During a 30-month interval at LeBonheur Children's Medical Center, 394 patients had a blood or cerebrospinal fluid culture positive for Streptococcus pneumoniae. Sixteen of these episodes (4%) were repeated infections; 6 of these 16 patients had sickle cell disease. Six of the remaining 10 patients had immunologic evaluations of varying completeness; no immunodeficiency was identified by these tests or on follow-up. Nine of the ten previously healthy patients with repeated pneumococcal disease were less than 2 years of age. In our experience, repeated invasive pneumococcal infections in otherwise healthy young children were relatively common (10/394, or 2.5% of patients with invasive pneumococcal infections) and did not indicate the presence of an unsuspected immunodeficiency.

Bacteremia↗
PubMed1997

Follow-up of pediatric patients with recurrent infection and mild serologic immune abnormalities.

BACKGROUND: Children with recurrent infections significant enough to warrant referral to an immunologist frequently have mild abnormalities of the humoral immune system. Parents of these children are generally reassured that their child will outgrow the clinical problems that prompted their referral. OBJECTIVE: This is a retrospective study with the objective being to evaluate changes in immune measurements and clinical status of children with recurrent infections followed in an immunology clinic. METHODS: Forty-two patients (mean age 60 months) previously evaluated for recurrent infections were re-evaluated after at least 12 months (mean 37 months). Initial evaluation studies included quantitative immunoglobulins in all patients and IgG subclass determinations and pre- and postvaccination pneumococcal polysaccharide antibody titers in a subpopulation of patients. RESULTS: Patients were assigned to one of two categories: those with initial laboratory abnormalities (27 patients) and those with normal initial studies (15 patients). Among the patients with initial abnormalities, partial IgA deficiency was most commonly seen (20/27). It persisted in 15. Only 6/27 patients had studies that were completely normal on follow-up. Among patients with no initial abnormality, 9/15 developed a partial deficiency of at least one immunoglobulin isotype or IgG subclass. Eighty-six percent of the patients were clinically improved at the time of their last follow-up visit regardless of their laboratory values. CONCLUSIONS: A high proportion of children with recurrent infection have persistent, partial immunoglobulin deficiencies lasting in some cases for years. Despite this finding almost all patients demonstrate clinical improvement with time.

Antibody Formation↗
PubMed1996

Antibody response to unconjugated Haemophilus influenzae b and pneumococcal polysaccharide vaccines in children with recurrent infections.

BACKGROUND: Increasingly, antibody testing is being used to evaluate the status of humoral immunity in patients with recurrent infection and suspected immunodeficiency. In the past, we had been impressed that immunization with unconjugated Haemophilus influenzae b (uHib) vaccine provided useful information about the ability to produce antibody to polysaccharides and that the use of pneumococcal polysaccharide (PPS) vaccine frequently produced results that were difficult to interpret. OBJECTIVE: The study was carried out to compare antibody responsiveness to vaccination with uHib with the response seen after PPS vaccination. METHODS: Twenty children (ages, 2 to 13 years; 11 male) who were referred to our immunology clinic because of recurrent infections were immunized with both uHib vaccine and PPS vaccine. Nine children had previously received conjugated Hib vaccine. RESULTS: All 20 children either responded with a twofold or greater increase in antibody titer after uHib vaccine or had preimmunization antibody concentrations of greater than 400 nanograms antibody nitrogen per milliliter (ng Ab N/ml). All of the children responded to PPS-3 with postimmunization antibody concentrations greater than 400 ng Ab N/ml. Three children had an increase in titer to PPS-7 of less than twofold, seven did not have a twofold increase in titer to PPS-9, and 15 had an increase in titer to PPS-14 of less than twofold. CONCLUSION: Unconjugated Hib vaccine is a potent immunogen in children over 2 years of age. Prior immunization with the conjugate vaccine did not prevent a response to unconjugated vaccine. Unconjugated Hib vaccine appears to be at least as immunogenic as PPS-3 when used as an assessment vaccine for evaluating antibody responsiveness.

Adolescent↗
PubMed1996

Practice parameters for the diagnosis and management of immunodeficiency. The Clinical and Laboratory Immunology Committee of the American Academy of Allergy, Asthma, and Immunology (CLIC-AAAAI)

In this brief review, only the most useful immunologic tests available for defining host defects that lead to susceptibility to infection have been emphasized. It should be pointed out that those evaluations and tests ordered by the physician will rule out the vast majority of the currently recognized defects. Finally, it is important that any patients identified as abnormal by these screening tests be characterized as fully as possible in centers specializing in these diseases before therapy is initiated, since what may appear to be a simple diagnosis on the surface may be an indicator of more complex underlying problems.

Antibody Formation↗
PubMed1995

Cell-mediated immune status of children with recurrent infection.

OBJECTIVE: To evaluate the cell-mediated immune status of children with recurrent respiratory tract infections. DESIGN: We evaluated the cell-mediated immune status of 76 patients referred because of recurrent infection. Patients were divided into those with serologic abnormalities and those without such findings. Twenty-three healthy children served as control subjects. Studies of lymphocyte phenotype included CD4+ CD29+ cells (an immunologically mature phenotype), lymphocyte proliferation studies, cytokine production including interleukin-2 (IL-2), IL-4, IL-6, and interferon gamma), and measurement of in vitro IgM and IgG synthesis. RESULTS: Lymphocyte proliferation and T-cell phenotype were similar in both patient groups as well as in control subjects. The proportions of CD4+ CD29+ cells at different ages were similar in all groups. Patients with serologic abnormalities (e.g., partial IgA deficiency, partial IgG subclass deficiency) produced more IL-2 and IL-4 than did other patients. The control population had greater spontaneous IgM and IgG synthesis than the patient groups. CONCLUSION: Routine studies of T-cell function of patients with recurrent infection provide little information useful in making clinical decisions.

Antigens, Bacterial↗
PubMed1995

Immunization status of hospitalized preschool children: risk factors associated with inadequate immunization.

OBJECTIVES: The purposes of this study were to determine the accuracy of the immunization histories of hospitalized preschool children, assess the sociodemographic factors associated with delayed immunizations, and interview parents or guardians concerning their views on ways of improving immunization delivery. METHODS: The immunization status of 215 preschool children admitted to a pediatric hospital was determined by interviewing parents or guardians regarding their children's immunization histories. The patient's immunization records were subsequently reviewed for confirmation. The admitting physician's history also was reviewed to determine whether the patient's immunization status had been noted. Finally, parents or guardians of all children studied were interviewed to assess their views on ways of improving the delivery of immunization services. RESULTS: Only 44% of the 215 preschoolers evaluated were adequately immunized. Among those between 2 and 5 years of age, 52% were fully immunized. Only 17% of those who were inadequately immunized could have been completely updated if given an immunization at discharge. The admitting physician failed to document the immunization status of 22% of the patients. Thirty percent of the parents gave inaccurate information concerning the immunization status of their children. Most parents felt that the provision of transport (30%) or formal remainders (21%) would enhance immunization rates. Multiple regression analysis showed that a history of missed opportunity to immunize, male gender, lack of transportation, and lack of day care attendance were significant predictors of delayed immunization. CONCLUSIONS: Resident physicians should be more stringent in documenting the immunization status of all admitted preschoolers so that those found to be delayed could be updated before discharge. A hospital policy of updating underimmunized children at discharge and reporting the immunization status of all discharged patients to their primary care provider could help improve the immunization coverage in this population. Transportation for routine health maintenance and telephone or mailed remainders might further improve the immunization status of inner-city children.

Adolescent↗
PubMed1994

Hyper IgM syndrome associated with defective CD40-mediated B cell activation.

Recent studies show that most patients with X-linked hyper IgM syndrome have defects in the gene for CD40 ligand. We evaluated 17 unrelated males suspected of having X-linked hyper IgM syndrome. Activated T cells from 13 of the 17 patients failed to bind a soluble CD40 construct. In these patients, the sequence of CD40 ligand demonstrated mutations. By contrast, T cells from the remaining four patients exhibited normal binding to the CD40 construct. Sequencing of the cDNA for CD40 ligand from these patients did not show mutations. The possibility that hyper IgM syndrome in these four patients was due to abnormalities in the B cell response to CD40-mediated signals was examined. Peripheral blood lymphocytes were stimulated with anti-CD40 alone, IL4 alone or anti-CD40 plus IL4. In comparison with B cells from controls or patients with hyper IgM syndrome and mutant CD40 ligand, B cells from the patients with hyper IgM syndrome and normal CD40 ligand were defective in their ability to secrete IgE (P < 0.02) or express activation markers, CD25 and CD23 (P < 0.02) in response to stimulation with anti-CD40. The failure of these B cells to respond to CD40-mediated activation could not be attributed to a generalized deficiency in B cell activation because IL4 induced normal up-regulation of CD23 and CD25 expression. These findings indicate that hyper IgM syndrome may result from defects in expression of CD40 ligand by activated T cells or defects in CD40-mediated signal transduction in B cells.

Antigens, CD↗
PubMed1994

Elevated in vitro IL-4 production in a patient with elevated serum IgE.

BACKGROUND: We have cared for an unusual patient with serum IgE concentrations of up to 150,000 IU/mL who did not have the hyper-IgE syndrome. OBJECTIVE: Our objective in this study was to compare the regulation of in vitro IgE synthesis in this patient with results reported for in vitro IgE production by patients with the hyper-IgE syndrome. METHODS: We utilized an enzyme-linked immunosorbent assay to measure in vitro IgE production under varying conditions. In vitro cytokine production including IL-2, IL-4, IL-6, and interferon-gamma also was evaluated as was expression of the IgE receptor molecule CD23. RESULTS: B cells from this patient produced high concentrations of IgE. The patient was found to produce very high levels of interleukin-4 (IL-4) in vitro, to have high levels of soluble CD23 in his serum, and to have cells that were inconsistently responsive to the effect of IL-4 on IgE synthesis. CONCLUSIONS: Patients with elevated production of IL-4 may have increased serum IgE concentrations without having the hyper-IgE syndrome syndrome.

Adult↗
PubMed1993

Thoracic aortic calcification in 3 children with candidiasis-endocrinopathy syndrome.

Three cases are reported of the association of childhood onset of thoracic aortic calcification with mucocutaneous candidiasis, endocrine dysfunction and recurrent non-fungal pulmonary disease. The aortic calcification affects the thoracic aorta and the low lumbar aorta and common iliac arteries, sparing the mid-lumbar aorta and its major branches. Ischemic signs and symptoms of the head and neck and lower limbs are absent. This peculiar, slowly progressive vascular calcification, although unexplained to date, appears to be a non-random part of the more common candidiasis-endocrinopathy syndrome.

Adolescent↗
PubMed1993

Oral dehydroepiandrosterone in physiologic doses modulates immune function in postmenopausal women.

OBJECTIVE: This study tests the hypothesis that dehydroepiandrosterone or its metabolic products are immunomodulatory in postmenopausal women with relative adrenal androgen deficiency. STUDY DESIGN: A prospective, randomized, double-blind, crossover study of 11 subjects with 3-week treatment arms separated by a 2-week washout period was performed. Immunologic evaluation at the beginning and end of the treatment arms consisted of flow cytometry to delineate T-cell populations, in vitro T-cell mitogenic response and cytokine production, and natural killer cell cytotoxicity. Statistical analysis was based on a split-plot design with analysis of variance with repeated measures. RESULTS: Dehydroepiandrosterone supplementation decreased CD4+ (helper) T cells and increased CD8+/CD56+ (natural killer) cells. Although T-cell mitogenic and interleukin-6 responses were inhibited, natural killer cell cytotoxicity increased dramatically. CONCLUSIONS: These data provide the first in vivo evidence in human for an immunomodulatory effect of dehydroepiandrosterone. The salutary immune changes could account for clinical and experimental evidence of antioncogenic effects of this steroid. This study provides a strong rationale for further clinical studies on dehydroepiandrosterone supplementation in adrenal androgen-deficient states.

Aged↗
PubMed1993

Clinical significance of IgG subclasses.

IgG subclass deficiency has been noted in association with a variety of clinical conditions. It's relative importance as a contributing factor to these conditions is unclear. Despite reservations about the importance of partial IgG subclass deficiency, evidence is beginning to emerge that suggests that in select patients with recurrent infection and subclass deficiency, gamma globulin therapy may be beneficial.

Child↗
PubMed1992

Role of immunoglobulin subclasses and specific antibody determinations in the evaluation of recurrent infection in children.

We studied humoral immune function in 267 children with recurrent respiratory infections referred to our immunology clinic to determine the most appropriate immunologic studies for evaluating recurrent infections in children. Of this highly selected population, 58% had a partial deficiency in one or more of the major immunoglobulin isotypes or IgG subclasses (defined as at least 2 SD below the normal age-adjusted mean). In none of the patients was there a total absence of an immunoglobulin isotype. The most common abnormality was partial IgA deficiency, which was found in one third of the patients. Twenty-six patients had only partial IgG subclass deficiencies, of which 20 were deficiencies of a single subclass. IgG1 was an isolated partial defect in three patients, IgG3 in five patients, and IgG2 and IgG4 were selective partial defects in six patients each. Tetanus toxoid and pneumopolysaccharide type 3 were the most immunogenic of the immunogens tested; hyporesponsiveness to pneumococcal polysaccharide types 7, 9, and 14 was common. Nineteen percent of the patients with normal immunoglobulin concentrations who were tested had lower-than-expected antibody titers; 42% of those tested with partial isotype deficiencies had deficient antibody responses. Of 25 patients with selective partial IgG subclass deficiencies or combined IgG subclass deficiencies, eight had antibody deficiencies. Our findings indicate that a high proportion of children referred to immunology clinics for recurrent infection have a demonstrable immunologic abnormality. Selective IgG subclass deficiency or a combined IgG subclass deficiency without an associated deficiency in a major immunoglobulin isotype is unusual. Identification of such patients is not predictive of the capacity to form antibodies to the antigens tested in this study and, in our opinion, adds little to the initial evaluation of immune function in such children.

Adolescent↗
PubMed1992

Formation of pseudoislets from human pancreatic cultures.

We have successfully developed a technique for culturing human islet cells obtained from the cadaveric pancreata of children. Within 24-48 h of in vitro culture, collagenase-digested human pancreatic tissue formed epithelioid monolayers. Scattered within these monolayers were insulin-positive cells, as detected by immunocytochemical and dithizone staining. Treatment of the beta cell-containing epithelioid-cell monolayers with EDTA resulted in the formation of spherical cellular clusters, i.e., pseudoislets. These pseudoislets differed from isolated islets of Langerhans in that they showed a more peripheral distribution of insulin-positive cells. Our studies have demonstrated that insulin-positive cells can be detected in monolayers obtained from human pancreata 3-4 weeks after culture. When exposed to varying concentrations of glucose, these cells secreted insulin. The development of this in vitro technique for culturing human pancreatic islet tissue could provide a model for systematically studying in vitro islet function.

Cells, Cultured↗
PubMed1992

Natural killer cell activity in very low birth weight infants.

The exact role of natural killer (NK) cells in host defense is unclear, but they may be important as an early response to certain infections. We evaluated NK cell phenotype and activity in premature very low birth weight infants (VLBWI) (n = 52) with an average gestational age of 29.3 wk (24-35 wk) and an average birth weight of 1124 g (537-1480 g). All patients initially were evaluated within 7 d of birth. Samples also were obtained at 2, 4, and 6 wk in some infants. The proportion of mononuclear cells expressing the phenotypic marker of NK cells (NKH-1; CD56) was significantly lower in VLBWI than in adults (2.5 +/- 1.4 versus, 12.5 +/- 7.8%, p less than 0.0001) or term infants (2.5 +/- 1.4 versus 9.5 +/- 7.1%, p less than 0.0001). VLBWI also had significantly diminished NK activity expressed as the percentage of specific lysis compared with adults (4.7 +/- 4.4 versus 32.3 +/- 14.5%, p less than 0.0001) or term infants (4.7 +/- 4.4 versus 15.5 +/- 10.8%, p less than 0.0001). Both the number of cells expressing the NK phenotype and the NK lytic activity in VLBWI increased in the 6 wk after birth. NK activity in VLBWI was enhanced by IL-2 and in most cases by interferon-gamma.

Adult↗