[Clinical and fundamental studies on intravenous drip infusion of gentamicin in the pediatric field. Pediatric study group of gentamicin]

A multiclinic study of gentamicin (GM) given by intravenous drip infusion was carried out by the Gentamicin Pediatric Study Group. The results are summarized as follows: 1. Upon intravenous drip infusion of GM at a dose range of 2.0-2.5 mg/kg over a period of 0.5-1 hour, therapeutically effective serum concentrations of 4-12 micrograms/ml were obtained. These values are similar to reported values in previous studies using GM intramuscular injection. 2. High urinary concentrations were observed up to 6 hours after administration, and the urinary recovery rate was approximately 60%. 3. Of a total of 142 cases collected, 117 cases were evaluated. Efficacy rates by diseases were: 100% in pneumonia (30/30), 98.3% in urinary tract infections (59/60), and 92.3% in other infections (skin and soft tissue) (12/13), with an overall efficacy rate of 94.9% (including 77 "excellent" cases). 4. Bacteriological examinations showed high eradication rates with the use of GM; i.e., 80% with Staphylococcus aureus (8/10), 60% with Pseudomonas aeruginosa (3/5), 100% with Haemophilus influenzae (7/7) and 97.8% with Escherichia coli (44/45), achieving an overall eradication rate of 92.4%. In mixed infections, the eradication rate was 85.7% (6/7). 5. No ototoxicity, nephrotoxicity or allergic reactions was observed. Abnormal laboratory findings observed were: GOT elevation in 3.1% of cases, GPT elevation in 3.9%, platelet increase in 1.5% and eosinophil increase in 0.8%, thus an overall rate of the appearance of abnormality was 5.6%. The above results indicate that an intravenous drip infusion of GM is a useful method for treating infections in pediatrics.

Immunological studies on Crohn's disease. VII. Reduced immunologic activity in monocytes

Studies done in our laboratories showed that monocytes in Crohn's disease (CD) have an increased phagocytic activity determined using chemiluminescence assay. To further elucidate the pathogenesis of CD, we studied the monokine production activity and the proportion of HLA-DR(+) monocytes in the peripheral blood of 16 Japanese with CD. In contrast to the phagocytic function, an impaired monokine production activity and a decreased percentage of DR(+) monocytes were evident. The number of DR(+) monocytes showed a negative correlation to CRP. These findings provide additional information on the monocyte function in CD and indicate that monocyte dysfunction may be closely linked to the pathogenesis of CD.

Study on nonspecific immunity in pregnant women: increased chemiluminescence response of peripheral blood phagocytes

The total number of circulating leucocytes in the peripheral blood of pregnant women progressively increased with advance in gestation because of neutrophilia. When the phagocytic activity, representing nonspecific immunity, was estimated by a luminol-dependent chemiluminescence (CL) response during phagocytosing opsonized zymosan, we observed that the CL response of whole blood and Ficoll-Paque separated polymorphonuclear leucocytes (PMNL) significantly increased throughout the pregnancy (P less than 0.01). The CL responses of mononuclear leucocytes (MN) and monocytes also increased and reached peak levels in the third trimester (P less than 0.05). These findings suggest that the phagocytic activity in pregnant women increases, not only with regard to the number of phagocytes but also with regard to individual cell function, from a relatively early stage of the pregnancy, and that this increased nonspecific immunity may compensate in part for a weakened specific immunity of the maternal host. Attention should be directed to effects of human chorionic gonadotropin (hCG) relative to the increased CL response during pregnancy.

Immunological studies on Crohn's disease. VI. Increased chemiluminescent response of peripheral blood monocytes

Oxidative metabolic activity can be measured by a luminol-dependent chemiluminescence (CL) assay. To investigate the phagocytic activity of blood cells, CL responses were assessed in 26 patients with Crohn's disease (CD) and 26 healthy controls, using heparinized peripheral blood. Significantly (p less than 0.005) increased CL responses of whole blood cells were found in 26 patients with CD. However, CL activity was not directly related to disease activity nor to other clinical parameters. The CL responses did not correlate with the number of white blood cells, neutrophils nor monocytes. In consideration of the increased CL, there is the possibility that functional abnormalities in some components of blood cells leads to elevations in CL responses of whole blood cells. To obtain support for this proposal, blood cells were separated into neutrophils and monocytes, and CL of neutrophils or monocytes were studied, using the same number of each type of cells as that of the controls. The oxidative metabolism of monocytes from CD patients was significantly (p less than 0.005) higher than that of controls, while the phagocytic activity of neutrophils was similar to that in the controls. These data suggest that elevations in CL activity of whole blood cells were not due to alterations of the neutrophils but rather to abnormalities in the monocytes. Further attention directed to the significance of monocyte function in the pathogenesis of CD is warranted.

Role of epidermal Langerhans cells in resistance to herpes simplex virus infection

To investigate the role of epidermal Langerhans cells (LC) in resistance to herpes simplex virus (HSV) infection, nonadherent spleen cells taken from BALB/c mice immunized with HSV were cultured with syngeneic epidermal cells (EC) and ultraviolet light-inactivated HSV antigen. After five days of culture, T cell-dependent proliferative response was determined by 3H-thymidine incorporation. Treatment of EC with anti-Iad monoclonal antibody plus complement before cultivation prevented this proliferation, which suggested that LC induced stimulation of immune T cells. When these stimulated spleen cells were transferred to intracutaneously infected nude mice, the virus titer in the skin was reduced markedly and the formation of zosteriform skin lesions was completely inhibited. On the other hand, transfer of unstimulated cells, which were cultured with HSV antigen only or with HSV antigen and EC treated with anti-Iad monoclonal antibody plus complement, resulted in delayed viral clearance and development of the lesions. These results indicate that LC are of importance as accessory cells in the control of cutaneous HSV infection. Furthermore, Lyt 1+ T cells in the stimulated population were shown to have greater protective activity than Lyt 2+ T cells.

Immunological studies on Crohn's disease. IV. Decreased ADCC activity

Antibody dependent cell-mediated cytotoxicity (ADCC) activity was studied in 16 Japanese patients with Crohn's disease (CD) and 16 healthy controls. ADCC activity was assessed by measuring 51Cr release from antibody coated human B-cell line. Significantly (p less than 0.002) depressed ADCC activity was found in patients with CD, although ADCC activity was not directly related to the disease activity. To determine causative factors related to reductions in ADCC activity, circulating immune complex (CIC) was also assayed by C1q-binding method. CIC levels in patients with CD were similar to those in the control group, thereby suggesting that this impaired ADCC activity was not due to blocking of the FC-receptor on K cells by CIC. However, serum zinc concentrations did correlate to the ADCC activity. Hence, an assumption can be made that a decreased ADCC activity may be caused by malnutrition, mainly zinc deficiency, a phenomena linked to CD. The significance of serum zinc in considerations of immunological abnormalities was given attention.

Immunological studies on Crohn's disease. V. Enumeration of circulating lymphocytes subsets using monoclonal antibodies

We found normal levels of suppressor cell activity and reduced natural killer (NK) and antibody dependent cell-mediated cytotoxicity (ADCC) activities in patients with Crohn's disease (CD). To further characterize these activities, studies were carried out using monoclonal antibodies. There were no changes in the proportion of OKT4+ (helper/inducer T cells), OKT8+ or Leu 2+ (suppressor/cytotoxic T cells) and Leu 7+ (large granular lymphocytes: LGL, NK + K cells), thereby suggesting that suppressor cell activity in CD is likely to be normal both in function and in number, and that depressed NK and ADCC activities are not due to a reduction in the number of NK or K cells but rather to functional defects. Using a double staining method, we noted a low percentage of both Leu 2 and Leu 7 positive cells in CD.

Immunological studies on Crohn's disease. III. Defective natural killer activity

Natural killer (NK) activity was studied in 23 patients with Crohn's disease (CD) and 23 healthy controls, as assessed by lymphocyte cytotoxicity against K562 target cells. Severely impaired NK activity was found in patients with CD (p less than 0.001). The relationship between NK activity and disease activity was also analyzed. NK activity was not directly related to the disease activity, although NK function was lower in the patients with an active form of the disease.

The binding of a thyroid hormone metabolite, 3-monoiodo-L-thyronine, to bovine serum albumin as measured by circular dichroism

The interaction between a thyroid hormone metabolite, 3-monoiodo-L-thyronine (3-T1) and bovine serum albumin (BSA) was investigated by using the CD method. An enhanced CD band was observed at the absorption wavelength region of 3-T1 around 293 nm suggesting the binding of 3-T1 to the BSA molecule. The ellipticity at 293 nm was measured at various molar ratios of 3-T1 to BSA, and the apparent binding constant and the maximum number of binding sites could be estimated as Kapp = 8.85 +/- 1.07 X 10(4) M-1 and n = 23.8 +/- 0.9 respectively. The CD of a mixture of BSA, 3-T1 and thyroxine (T4) was also studied at various pH's. The pH profile of the two characteristic CD bands at 293 nm and 320 nm, attributed to bound 3-T1 and T4, suggested that the optimum binding condition of 3-T1 was attained at alkaline pH of around 9, while that of T4 was attained over a wide pH range between 5-10. A significant role of the ionized 4'-hydroxyl group of 3-T1 in the binding reaction with BSA is also suggested.

Immunological studies on Crohn's disease. II. Lack of evidence for humoral and cellular dysfunctions

In 16 patients with Crohn's disease, we attempted to determine possible alterations in humoral and/or cellular immunologic dysfunctions. We examined the antinuclear, antithyroglobulin and antimicrosomal autoantibodies, circulating immunoglobulin levels and complement components. To clarify the significance of cellular immunity in Crohn's disease, mitogenic lymphocyte transformation and concanavalin A-induced suppressor cell activities were studied. Evidence for humoral and cellular immunological abnormalities was not obtained. The correlation between these immunological parameters and disease activity was also nil. These results suggest that Crohn's disease may not be an immunodysfunctional disorder such as systemic lupus erythematosus, but rather a multifactorial disease. The immunological abnormalities reported in the literature may represent phenomena related to states of malnutrition, since the patients we studied were clinically not in a severe stage of the disease.

Separation of cross-linked products of rat tail tendon collagen from monomeric components by gel chromatography in the presence of Tris dodecyl sulfate at 4 degrees C

Rat tail tendon collagen can be solubilized by a neutral aqueous solution containing 2% Tris dodecyl sulfate at 4 degrees C without being unfolded to its constituent polypeptides. The solvent at this temperature is particularly suited for gel chromatographic separation of native collagen. Thus Sepharose CL-2B gel chromatography was found to separate the monomeric collagen molecule from the products of intermolecular cross-linking. The procedure can be effectively used to follow progress of intermolecular cross-linking with aging. The monomeric collagen can be subsequently applied to polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate to evaluate the mode of intramolecular cross-linking.

Detection of antibodies to human parvovirus in erythema infectiosum (fifth disease)

Two Japanese outbreaks of erythema infectiosum were investigated for evidence of human parvovirus infection by a solid phase antibody capture radioimmunoassay based on a monoclonal antibody to human parvovirus. Specific IgM and high concentrations of specific IgG were detected in 37 sera from 27 children with erythema infectiosum. No anti human parvovirus IgM was detected in a remaining case of erythema infectiosum, in five patients with Kawasaki disease, or in the 17 control children. Seven of the controls were also anti human parvovirus IgG negative, and the 10 who were seropositive had lower concentrations of anti human parvovirus IgG than the patients with erythema infectiosum. These data indicate that human parvovirus is a cause of erythema infectiosum.

Immunological studies in Crohn's disease. I. Association with HLA systems in the Japanese

We attempted to clarify the association between HLA and Crohn's disease. HLA-A, -B, -C and -DR locus antigens in 62 Japanese patients with Crohn's disease were analyzed and the results were compared with findings of 231 healthy Japanese. In the patients with Crohn's disease there was a strong association with HLA-DR4 and -DR5 (chi2 = 14 . 013, RR = 4 . 77 and chi2 = 9 . 345, RR = 5 . 04) and a weak association with HLA-Bw46 and -Bw51 (chi2 = 7 . 077, RR = 2 . 63, and chi2 = 5 . 401, RR = 2 . 52). There was a close association between HLA-DR5 in those with the ileocaecal type, and the -Bw51 and small intestine type. Therefore susceptibility to Crohn's disease may relate to specific allotypes on the human major histocompatibility complex. The correlation was weaker than the other diseases such as ankylosing spondylitis and Coeliac disease.

Effects of antithyroid drugs on Con A-induced suppressor cell activity

It is well established that Concanavalin A (Con A)-induced human peripheral blood lymphocytes exert suppressive effects on mitogen-induced proliferation of responder cells. Using peripheral blood lymphocytes from healthy individuals, effects of antithyroid drugs on Con A-induced suppressor function were studied. We found an enhancement of Con A-stimulated suppressor activity by MMI and PTU in all these subjects. In the light of these data, an enhancement in suppressor activity by antithyroid drugs may contribute, in part, to a remission of Graves' disease.