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Biomedical subjects

R H Kobayashi

Publications and source records attributed to R H Kobayashi.

16 recordsLinked to original sources
PubMed1992

Antibody responses to bacteriophage phi X174 in patients with adenosine deaminase deficiency.

Adenosine deaminase (ADA) deficiency and its biochemical consequences cause severe combined immunodeficiency (SCID). Treatment strategies, designed to correct the biochemical abnormalities, include transplantation of matched bone marrow or haploidentical bone marrow stem cells, repeated partial exchange transfusions with frozen irradiated human red blood cells (RBC), or weekly injection of polyethylene glycol-modified bovine ADA (PEG-ADA). To evaluate the effect of these therapeutic options, we studied in vitro T-cell function and in vivo antibody responses to the T-cell-dependent neoantigen, bacteriophage phi X174, in 10 children with ADA-deficient SCID. In untreated patients, T-cell function was severely depressed, and only minute amounts of antibacteriophage antibody were produced. Transplantation of bone marrow from a matched sibling (one patient) or a phenotypically matched parent (one patient) resulted in a stable graft, normal T-cell function, and substantial but subnormal antibody titers to bacteriophage, with reduced memory and impaired switch from IgM to IgG. Patients receiving T-cell-depleted haploidentical bone marrow stem cells had markedly depressed antibody responses for as long as 3 years posttransplantation, despite rapidly improving T-cell function that became normal in two of four patients. Two methods of enzyme replacement were explored. During treatment with human RBC transfusions, antibody responses to bacteriophage were as severely depressed as in untreated ADA-deficient patients. Treatment with weekly injections of PEG-ADA resulted in normalization of T-cell numbers in all four patients, normal or near-normal T-cell function in two, and mildly but variably improved T-cell function in the other two patients. Quantitatively and qualitatively normal antibody responses to bacteriophage were observed in three of four patients. Assessment of antibody responses to immunization with bacteriophage phi X174 is a useful method to monitor humoral immune function in treated ADA-deficient patients and can be used to estimate when intravenous immunoglobulin (IVIG) prophylaxis may be safely discontinued.

Adenosine Deaminase↗
PubMed1992

Exercise-induced asthma.

Exercise-induced asthma affects approximately 10 percent of the exercising population but often goes undiagnosed. Diagnosis is generally simple if the physician is aware of the subtle symptoms that may present during or after exercise. Preventive treatment, using a combination of exercise strategies and inhaled medications, is often successful. For patients with underlying chronic asthma that is exacerbated by exercise, long-term medication with preexercise doses is recommended.

Adrenergic alpha-Agonists↗
PubMed1991

Exercise-induced asthma, anaphylaxis, and urticaria.

Exercise-induced asthma is a common but frequently undiagnosed problem. The patient may not wheeze, but rather have shortness of breath, chest tightening, and coughing. The coach and the physician must be particularly alert to the signs and symptoms of exercise-induced asthma to recognize this syndrome. Proper conditioning, warming up, inducing refractoriness, participating in sports less likely to provoke exercise-induced asthma, and the aggressive use of appropriate medications allow patients to enjoy sports and compete effectively. A rare but potentially fatal syndrome is exercise-induced anaphylaxis. Accurate diagnosis and differentiation from other exertion-related syndromes are critical, and appropriate precautions are necessary. A third clinical entity, exercise-induced cholinergic urticaria, although not life-threatening, can be quite annoying. Aggravating factors, such as increased heat, compound the problems. In summary, exercise-induced allergic phenomena are common and should be recognized by the practicing physician.

Anaphylaxis↗
PubMed1991

Home-based immunoglobulin infusion therapy: quality of life and patient health perceptions.

Thirty-seven antibody-deficient patients who were participating in a multicenter trial evaluating home-based, self-administered IVIG therapy anonymously completed questionnaires regarding beliefs concerning health control, quality of life, and attitudes toward active participation in medical care. Their responses were compared with a group of 29 patients undergoing traditional IVIG therapy in a medical clinic setting. A subsample of the home-based group who later returned to clinic-based IVIG therapy allowed comparison of responses given by the same patients in both settings. Home-based therapy was preferred to clinic-based therapy. Independence, convenience, comfort, decreased disruption of activities, travel time, and costs were specific factors rated most favorably. On the Health Belief Questionnaires, patients preferred informed, self-involved medical care regardless of the setting for their IVIG treatments.

Adult↗
PubMed1990

Home self-administration of intravenous immunoglobulin therapy in children.

Twelve children with primary immunodeficiency, aged 2 to 17 years (mean +/- 1 SD = 9.8 +/- 5.3), were enrolled in a 9-month study to evaluate the feasibility and safety of home self-infusion of intravenous immunoglobulin (IVIg). An initial 2-month training and supervisory period was followed by a 6- to 7-month period during which the children or their parents infused IVIg in a home setting. Eight children received an average dose of 204 +/- 12 mg/kg every 2 weeks, two children received a dose of 400 mg/kg every month, and an additional two children received 240 to 250 mg/kg every 10 days. Peak and trough levels varied from 946 +/- 20 mg/dL and 627 +/- 16 mg/dL, respectively, in children receiving IVIg every 2 weeks. The peak-trough values for the children receiving IVIg every month were 1105 +/- 94 mg/dL and 457 +/- 78 mg/dL, while those of children receiving IVIg every 10 days were 840 +/- 24 mg/dL and 553 +/- 109 mg/dL. A total of 224 infusions were administered, with only two minor reactions occurring (reaction rate of 0.9%). There was no difference in the frequency of infections and antibiotic use during the study compared with the previous phase. The results demonstrate that home self-infusion of IVIg in children is safe and feasible.

Adolescent↗
PubMed1989

Interferon-gamma in a family with X-linked lymphoproliferative syndrome with acute Epstein-Barr virus infection.

A 20-month-old male with fulminant infectious mononucleosis and the X-linked lymphoproliferative syndrome (XLP) was studied. Epstein-Barr virus (EBV)-determined nuclear antigen (EBNA) and EBV DNA were detected in various tissues. Despite a combined treatment with acyclovir, immunoglobulin, and methylprednisolone, the patient deteriorated rapidly. Following treatment with recombinant interferon-gamma (IFN-gamma), defervescence occurred and circulating EBNA-positive cells markedly decreased. IFN-gamma prior to treatment ranged from 10.8 to 24.5 U/ml in the patient's serum and increased linearly post exogenous IFN-gamma treatment. His natural killer (NK)-cell activity remained in the normal range throughout his illness but autologous EBV-infected cells were not killed in vitro by his peripheral blood lymphocytes (PBL). These results suggest that patients with the fatal infectious mononucleosis phenotype of XLP may produce endogenous IFN-gamma. Defective cytotoxic T cells against EBV-infected cells seem to be responsible for the fulminant infectious mononucleosis in this patient.

Acute Disease↗
PubMed1989

Beclomethasone dipropionate aqueous nasal spray for seasonal allergic rhinitis in children.

A 3-week double-blind, parallel group study comparing the effectiveness and safety of an aqueous formulation of beclomethasone dipropionate (BDP-AQ) versus placebo was undertaken in 101 patients. Children aged 5 to 13 years with a diagnosis of seasonal allergic rhinitis received one spray in each nostril twice daily of either BDP-AQ (42 micrograms/spray) or an identical placebo spray. Patient assessment at the end of treatment indicated statistically significant improvement in nasal symptoms for BDP-AQ patients. The physicians overall evaluation of treatment indicated that the BDP-AQ-treated patients experienced significantly greater (P = .012) improvement as compared with placebo-treated patients. There was no difference in the incidence of adverse events between the two treatments. The results demonstrate the effectiveness and safety of BDP-AQ nasal spray in the treatment of seasonal allergic rhinitis in children.

Adolescent↗
PubMed1987

Treatment of adenosine deaminase deficiency with polyethylene glycol-modified adenosine deaminase.

We treated two children who had adenosine deaminase deficiency and severe combined immunodeficiency disease by injecting bovine adenosine deaminase modified by conjugation with polyethylene glycol. The modified enzyme was rapidly absorbed after intramuscular injection and had a half-life in plasma of 48 to 72 hours. Weekly doses of approximately 15 U per kilogram of body weight maintained plasma adenosine deaminase activity at two to three times the level of erythrocyte adenosine deaminase activity in normal subjects. The principal biochemical consequences of adenosine deaminase deficiency were almost completely reversed. In erythrocytes, adenosine nucleotides increased and deoxyadenosine nucleotides decreased to less than 0.5 percent of total adenine nucleotides. The activity of S-adenosylhomocysteine hydrolase, which is inactivated by deoxyadenosine, increased to normal in red cells and nucleated marrow cells. Neither toxic effects nor hypersensitivity reactions were observed. In vitro tests of the cellular immune function of each patient showed marked improvement, along with an increase in circulating T lymphocytes. Clinical improvement was indicated by absence of infection and resumption of weight gain. We conclude that from the standpoints of efficacy, convenience, and safety, polyethylene glycol-modified adenosine deaminase is preferable to red-cell transfusion as a treatment for adenosine deaminase deficiency. Patients with other inherited metabolic diseases in which accumulated metabolites equilibrate with plasma could benefit from treatment with the appropriate polyethylene glycol-modified enzyme.

Adenosine Deaminase↗
PubMed1986

Circulating immune complexes in cystic fibrosis and their correlation to clinical parameters.

Circulating immune complexes (CIC) have been found to be elevated in individuals with cystic fibrosis (CF). Previous investigators, using a variety of assays, have reported high levels of CIC in as many as 86% of these patients. Our study followed the progress of 25 patients with CF over a period of 10 months to determine which, if any, clinical parameters correlated with the occurrence and/or concentration of CIC. Immune complex determinations were performed using a coprecipitation method with equine rheumatoid-complement complex. One hundred percent of the CF patients had CIC elevated above normal levels, however, levels of CIC did not correlate with the severity of an individual's acute exacerbation. Clinical parameters including pulmonary function tests, vital signs, total serum IgG levels, and other laboratory studies, were obtained on each individual and analyzed with respect to their relationship to CIC. Only four of 38 parameters examined had p less than 0.05. Factors that showed significant correlation to elevated CIC's in the highly elevated portion of our CIC population were poor NIH score, increased patient age, low peak expiratory flow rate, and elevated total serum IgG. These clinical values are associated more with the measurement of chronic disease. These data suggest that CICs cannot be used as an indication of short-term prognosis or as a monitor to follow the course of acute severe lung infections in the CF patient. Of interest was the observation that all patients who died during the course of the investigation had CIC levels greater than 80 micrograms/ml.

Adolescent↗
PubMed1985

Evaluation of a sustained-release theophylline tablet in young asthmatics.

A sustained-release theophylline (SRT) tablet was evaluated in 15 children with moderately severe asthma between the ages of 3 and 5 years (4.2 +/- 0.83 years). They received a mean daily dose of 20.4 mg/kg given q12h for 3 or more weeks with daily symptom scores and twice daily peak flow rates (PFR) measured. Serum theophylline levels (STL) were then obtained at 0, 1, 2, 4, 6, 8, 10, and 12 hr (eight children had 24-hr samples obtained), along with PFRs every 3 hr. The mean peak STL (x +/- SD) was 16.6 +/- 4.4 and the trough was 5.9 +/- 2.8, with a peak-trough difference of 10.6 +/- 3.9. The average time to peak level was 3.9 hr. The mean +/- SD clearance was 1.42 +/- 0.63 ml/kg per min and the apparent T1/2 was 5.11 +/- 1.34 hr. The average weekly morning PFR for the 3-week period ranged from 116.8 +/- 41.2 to 127.4 +/- 37.4 L/min, and the evening PFT ranged from 126.5 +/- 38.4 to 137.0 +/- 40.9 L/min. In conclusion, the SRT tablet is effective in treating many young asthmatics on a 12-hr dosage schedule. For some children who experience excessive peak-trough differences, an 8-hr dosage schedule may be indicated.

Asthma↗
PubMed1978

Ovarian teratomas in early childhood.

The ovary is second only to the sacroccygeal area as the commonest anatomic site for the occurrence of teratomas (including dermoid cysts) in infancy and childhood. While virtually all sacrococcygeal teratomas are present at birth or appear within the first 24 mo of life, ovarian teratomas are quite rare within the first 24 mo of life and seldom appear before 6 yr of age. Teratomas comprise half the surgically significant lesions of the ovary in infancy and childhood and carry a mean malignancy incidence of approximately 14% in this age group. Seven cases of ovarian teratoma in the first 2 yr of life have been reported. All of these have been seen in the second 12 mo of life. They differ from those occurring after 2 yr of age in the lesser incidence of abdominal pain, the higher incidence of an abdominal mass and the absence of reported malignancy.

Age Factors↗