PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Dinitrochlorobenzene”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1979

Ultrastructural morphometry of blastogenesis I: transformation of small lymphocytes stimulated in vivo with dinitrochlorobenzene.

Changes in the volumes and surfaces of subcellular compartments of unstimulated small lymphocytes and immunoblasts in mouse axillary lymph nodes have been established using stereological techniques. Blast transformation was induced in vivo with dinitrochlorobenzene (DNCB). Cell samples were obtained by random sampling regimes applied at light and electron microscopic levels. From electron micrographs the volume densities of euchromatin, heterochromatin, nucleoli, mitochondria, Golgi apparatus and rough endoplasmic reticulum were determined. Cell surface/volume ratios were also computed. By estimating mean nuclear volumes using light microscopy, it was possible to calculate absolute compartmental volumes and to evaluate the plasma membrane surface areas of average cells. Transformation in this model was characterized by a considerable cellular hypertrophy and a substantial increase in plasmalemma surface. Hypertrophy was the consequence of increases in the volumes of all measured intracellular compartments, notably euchromatin and "residual cytoplasm" (including ground cytoplasm and free ribosomes). These changes are discussed in the context of the altered metabolic status of cells.

Animals↗
PubMed1979

A new method for obtaining viable cells from dermal infiltrates. A study on 2,4 dinitrochlorobenzene induced contact dermatitis.

Experimental contact dermatitis has been induced in 2,4 dinitrochlorobenzene (DNCB) sensitized guinea pigs. The developing dermal infiltrate was excised and the infiltrating cells were obtained by mechanical extraction alone as well as by the combination with collagenase and elastase treatment. The most viable cells appeared in the elastase and mechanically extracted samples and the least in those subjected to mechanical treatment alone. The most cells in the enzyme-treated samples were present 24 h after re-exposure of the sensitized animals to DNCB consisting mainly of lymphocytes and of polymorphonuclear granulocytes. The optimum conditions for the action of enzymes including optimum duration of the treatment, buffer milieu, aspecific proteolytic effect on foreign substrate and action on T and B cell receptors have been elaborated. It was concluded that 80 min of collagenase treatment with gentle mechanical extraction under specified conditions does not affect any measurable immunologic properties of the liberated cells resulting in the second best yield. A comparison of these data with earlier reports and their significance is being discussed.

Animals↗
PubMed2026

Integrated Multi-omics Profiling of 2,4-dinitrochlorobenzene (DNCB)-induced Atopic Dermatitis in Mice Reveals a Coordinated Network of Barrier Dysfunction, Immune Activation, and Metabolic Reprogramming.

Atopic dermatitis (AD) is caused by a combination of epidermal barrier defect and immune imbalance. However, the molecular networks between these structural abnormalities and metabolic variations are unclear. This study aim of this research was to examine the concurrent molecular alterations in skin barrier damage and metabolic disorders in an AD-like mouse model by a multi-omics strategy. A 2,4-dinitrochlorobenzene (DNCB)-induced AD-like mouse model was established and the skin tissues were examined through the combination of transcriptomic, quantitative proteomic, and metabolomic analyses. Cross-omics correlation and network analyses were performed to identify consistently abnormal molecular pathways and crucial regulatory molecules. DNCB treatment caused severe epidermal hyperplasia, and prominent infiltration of CD3⁺ T cells, F4/80⁺ macrophages, and mast cells. Transcriptomic and proteomic analysis indicated significant disruption in keratinocyte differentiation, extracellular matrix organization, and cornified envelope formation pathways. Combined analysis detected 171 molecules which were simultaneously altered at both mRNA and protein levels, and network analysis identified FLG2 and KRT6B as central barrier-related molecules. Pathway enrichment analysis consistently showed the participation of AMPK and PPAR signaling pathways. Metabolomic analysis also revealed coordinated changes in lipid and amino acid metabolism which were closely associated with cornified envelope-associated genes and collagen-modifying enzymes. These findings indicate a close relationship between barrier, immune and metabolic regulation in DNCB-induced dermatitis and provide a multi-omics resource for future mechanistic studies of atopic skin inflammation.

Animals↗
PubMed1979

Immune reactivity of women on hormonal contraceptives: dinitrochlorobenzene sensitization test and skin reactivity to irritants.

To evaluate the influence of sex steroids on immunity in 87 women on hormonal contraceptives, sensitization tests were performed with the contact allergen, 2,4-dinitrochlorobenzene (DNCB). Forty-five women were taking oral contraceptives of combined oestrogen/progestogen of the same brand (low oestrogenic and middle range progestogenic activity); 27 had received intramuscular injections of medroxyprogesterone acetate and 15 women were using a sequential pill. The results were compared with those of 44 women not taking contraceptive steroids and matched for age. In women on the combined pill and those who had received intramuscular progesterone, the mean DNCB reactivity was significantly increased (0.02 less than p less than 0.05 and 0.001 less than p less than 0.01, respectively), whereas women using a sequential pill proved to show a decreased skin reactivity in the oestrogenic phase of this pill. (p = 0.05). The changes observed proved to be specific, since no statistically significant differences in overall skin reactivity to irritants between the four groups of women could be observed. The clinical implications of these results have been considered.

Adolescent↗
PubMed1975

Dinitrochlorobenzene sensitisation test in women on hormonal contraceptives.

Cell-mediated immunity was measured in women on hormonal contraceptives using the 2,4-dinitrochlorobenzene (D.N.C.B.) sensitisation test. Three groups of women were studied: forty-eight women were taking oral contraceptives of combined oestrogen/progestogen (thirty-seven of them had used oral contraceptives for a year or longer); twelve women were using a sequential pill (ethinyloestradiol and megestrolacetate); and sixteen women had received intramuscular injections of medroxyprogesterone acetate. The results were compared with those of a control group of twenty-nine age-matched women not taking contraceptive steroids. In women on the combined contraceptive pill and those who had received intramuscular progesterone, mean D.N.C.B. reactivity was significantly increased. The results were even more striking in women who had used combined contraceptive pills for more than one year. These results do not accord with the previously reported decrease in cell-mediated immunity in women on hormonal contraceptives.

Adolescent↗
PubMed1976

In-vitro monitoring of cell-mediated immunity to dinitrochlorobenzene.

A dinitrochlorobenzene (D.N.C.B.)/red-blood-cell conjugate inhibited migration of leucocytes which came from D.N.C.B. sensitised patients. This effect provided the basis for a rapid, sensitive, and quantitative in-vitro measure of D.N.C.B. sensitivity. Frequent serial measurement of cell-mediated immunity was possible with the test, provided D.N.C.B. sensitivity was maintained by occasional skin patch tests.

Cell Migration Inhibition↗
PubMed1979

Studies on the contact sensitization of man with simple chemicals: V. Clonal priming allows direct in vitro assessment of autologous HLA-associated factors required for immune response to dinitrochlorobenzene.

Human lymphocytes from dinitrochlorobenzene (DNCB)-sensitized human subjects primed in first culture with dinitrophenylated-antigens yield a population of cells which respond in an accelerated manner to the same or similar antigen in second culture. Using this "clonal priming" approach, we have demonstrated that such a primed population showed maximal proliferative response to dinitrophenylated autologous cells. These DNP primed clones also showed responses to some dinitrophenylated allogeneic leukocytes. The magnitude of the accelerated blastogenic response with allogeneic leukocytes varied in most instances in relation to the degree of sharing of HLA-A, B, and DRw antigens with the original autologous stimulator. These findings show that the self-specific factors recognized in conjunction with the dinitrophenyl antigen are closely but not invariably associated with established major histocompatibility (MHC)-associated serologic typing results. While DNP primed clones fail to respond to unmodified autologous leukocytes, they often show significant responses to unmodified allogeneic leukocytes. If such accelerated responses to unmodified allogeneic leukocytes are not the result of nonspecific activation of allogeneic responding lymphocyte clones, these findings further indicate that DNP modified self can resemble some alloantigens.

Dermatitis, Contact↗
PubMed1979

A new arylating agent, 2-carboxy-4,6-dinitrochlorobenzene. Reaction with model compounds and bovine pancreatic ribonuclease.

The reagent 2-carboxy-4,6-dinitrochlorobenzene (CDNCB) reacts with the imino, amino and sulfhydryl groups of model compounds. At pH 8.2, sulfhydryl groups react much faster than do amines. N alpha-Acetylhistidine, N alpha-acetyltyrosine and N alpha-acetyltryptophan do not react. Poly(L-Lysine) and poly(DL-lysine) react about 50 times as fast as does N alpha-acetyllysine. A dichloroanalog, 6-carboxy-2,4-dinitro-1,3-dichlorobenzene, shows stepwise reactivity with amines. With bovine pancreatic ribonuclease, which contains no sulfhydryl, CDNCB reacts preferentially with the epsilon-amino of Lys-41 at 450 times the rate with the epsilon-amino of N alpha-acetyllysine. The preferential reactivity at Lys-41 is discussed in relation to the pK of Ly-41, the cationic character of the active site cleft, and the mechanism of RNAase action on substrates.

Amino Acids↗
PubMed1979

Possible nonspecific immunopotentiation by 2,4-dinitrochlorobenzene sensitization in patients with Hodgkin's disease.

Various immunological parameters were evaluated in untreated Hodgkin's patients before and after sensitization with dinitrochlorobenzene (DNCB). The ratio (r) of these parameters after/before DNCB sensitization for patients and second/first samples in the controls were calculated. There were significantly more patients in the r greater than 1.1 group for PHA and Con A responses and for peripheral blood T cell percentages. These data suggest that DNCB sensitization may have a nonspecific immunopotentiation effect.

Antibody Formation↗
PubMed1979

Actinic keratoses treated with a combination of topical 5-fluorouracil and dinitrochlorobenzene.

A comparative study of topical 5-fluorouracil (5FU) alone and 5FU with dinitrochlorobenzene (DNCB) therapy in the treatment of actinic keratoses of the upper limbs is described. 5 out of 10 patients had better results with a combination of the two medications, while there was no difference in the results in 4 of the patients. Complications in the form of contact dermatitis to DNCB was experienced in 5 patients. Therapy of actinic keratoses of the upper limbs is recommended for a 6- to 8-week period with 5FU alone because of the difficulties associated with DNCB usage.

Administration, Topical↗
PubMed1978

Immunotherapy of chemically-induced tumors in the hamster cheek pouch with dinitrochlorobenzene.

Immune stimulation with an agent such as dinitrochlorobenzene (DNCB) may delay chemical carcinogenesis. Dimethylbenzanthracene (DMBA) was used to chemically induce tumors in the hamster buccal pouch. Hamsters were studied for the effect of DNCB sensitization in the buccal pouch prior to or after DMBA tumor induction. At appropriate time intervals the hamsters were sacrificed and each cheek pouch was examined histologically for the development of DMBA-induced tumors and for the presence of lymphoid cells infiltrating the tumor site. The results show that DNCB immunotherapy or immunoprophylaxis prior to or following DMBA tumor induction can alter the type of tumor produced and stimulate an infiltration of lymphoid cells into the tumor area probably invoking immune defense mechanisms.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1978

Dinitrochlorobenzene therapy for alopecia areata.

Ninety patients with alopecia areata were treated with weekly applications to one side of the head of dinitrochlorobenzene (DNCB) dissolved in acetone, the other side of the head serving as control region. In 80 patients (89%) hair regrew either exclusively on the treated side, or considerably faster and denser on this side. The difference was noted, in the majority of cases, within eight weeks. The initial response, however, could not be maintained in all of these patients. Persistent response was observed in 72 patients (80%). Peribulbar round cell infiltrates were found to be more constant and denser on the treated side, suggesting that topically applied DNCB affects the peribulbar infiltrate present in alopecia areata. Possibly, the therapeutic result is due to altered local immunoregulation.

Adolescent↗
PubMed1977

Immunological studies in psoriasis. The quantitative evaluation of cell-mediated immunity in patients with psoriasis by experimental sensitization to 2,4-dinitrochlorobenzene.

Quantitative techniques of sensitization to 2,4-dinitrochlorobenzene (DNCB) was used to determine in psoriasis the intensity and frequency of allergic reactions to DNCB following primary challenge with 2,000 microgram allergen and secondary challenge with decreasing doses of DNCB. 56 patients with psoriasis and 23 healthy volunteers were examined. Frequency of positive reactions to DNCB was similar in both groups, since all normal controls were sensitized, whereas only 8 of 56 psoriasis cases failed to develop delayed hypersensitivity to DNCB. However, the intensity of acquired contact allergy was significantly diminished in psoriasis in comparison with controls. The patients with stationary skin lesions resembled the normal population in the intensity of reaction to DNCB. Decreased intensity of DNCB sensitization seemed to be related to the activity of the disease, but not correlated with the extent of the lesions. A relationship was found between reduced reactivity to DNCB and decrease in E rosette-forming lymphocytes. The data suggest that the impaired function of T lymphocytes in active psoriasis could be responsible for both, defective recognition of contact antigens, such as DNCB, and the alteration of secondary response to DNCB.

Dinitrochlorobenzene↗
PubMed1978

Treatment of alopecia areata with dinitrochlorobenzene.

Persistent refractory alopecia areata in 26 patients was treated topically with dinitrochlorobenzene (DNCB). Sixteen patients have had excellent regrowth of hair; three patients could either not be initially sensitized or an adequate allergic contact dermatitis on the scalp did not develop. Two patients discontinued therapy within two months; hair growth did not develop in five patients despite an adequate trial. Augmentation of the T-lymphocyte pool via DNCB sensitization and challenge may become effective therapy for some patients with severe alopecia areata.

Administration, Topical↗
PubMed1976

Immunotherapy with dinitrochlorobenzene (DNCB) for recurrent squamous cell tumor of conjunctiva.

Over the course of nine years a young man sustained repeated recurrences of a squamous papillary epithelial tumor of the conjunctiva and canaliculus. Treatment had included repeated surgical excisions, fulguration, cryotherapy, and localized applications of Thiotepa. When we examined him in 1972 he had a recurrent lesion measuring about 1 cm in diameter. Because of past failures with the above-noted therapeutic modalities, we decided to treat him with immunotherapy using the immunological adjuvant DNCB (dinitrochlorobenzene). We sensitized him systemically to DNCB by applying 2,000 microng of this agent to the skin of his forearm. A spontaneous "flare" reaction, indicative of delayed hypersensitivity, developed. Delayed hypersensitivity to DNCB was confirmed by in vitro testing of his lymphocytes for their ability to produce migration inhibitory factor (MIF) in response to DNCB. Subsequent localized application of DNCB to the conjunctival tumor resulted in rapid regression of the lesion and there has been no recurrence during a follow-up period of three years. We believe this is the first time a conjunctival tumor has been successfully treated with immunotherapy.

Adjuvants, Immunologic↗
PubMed1979

The distribution of 2,4-dinitrophenyl groups in lymphoid tissue of guinea-pigs following skin painting with 2,4-dinitrochlorobenzene.

Cellular localization of 2,4-dinitrophenyl (DNP) groups in the peripheral lymphoid system of guinea-pigs was studied at various times after painting the skin with 2,4-dinitrochlorobenzene (DNCB) by the immunofluorescent method using anti-DNP antibody. The cells taking up the stain (DNP cells) were shown to be mainly lymphocytes. At 1-6 h after painting the majority of DNP cells were found in the peripheral blood and the spleen but the maximum number was reached in the lymph node draining the site of DNCB application 12 h after painting. Injecting cyclophosphamide (CY) 3 days before painting with DNCB, heightened the number of DNP cells residing in the draining node. The animals treated with the tolerogen, 2,4-dinitrobenzene sulphonic acid sodium salt (DNBSO3Na), and then painted with DNCB, had fewer DNP cells than those animals which had simply been painted once with DNCB. The culture supernatants prepared from the draining nodes of both normal and tolerant animals partially blocked the anti-DNP antibody binding with DNP cells. It is suggested that the cells associated with DNP groups residing in the draining lymph node act as immunogens in the immunizing process of contact sensitivity.

Administration, Topical↗
PubMed1978

The effect of dinitrochlorobenzene (DNCB) on dimethylbenzathracene (DMBA) carcinogenesis on hamster buccal pouch.

DNCB is an antigen that stimulates the cell-mediated response in a sensitized host. The purpose of this study was to define the effect DNCB would have on a standard model system for oral carcinogenesis, theorizing that tumorgenesis would be delayed or inhibited. Fifty-six Syrian hamsters were divided into four groups. In group A (DNCB/DMBA), the right buccal pouch of twenty animals was treated with 2% DNCB in orabase, twice a week, and 0.5% DMBA, three times a week, for 10 weeks. In group B, twenty animals received DMBA only. In group C, six animals received DMBA in Orabase. In group D, ten animals received DNCB in Orabase only. The animals were killed at 6, 12, 16, and 20 weeks. The results indicate that there were no differences in the latent period or in the histologic characteristics of the epidermoid carcinomas that developed. However, there was sensitization of the buccal pouch in pouches painted with DNCB, in that gross and histologic evidence of a delayed sensitivity reaction was demonstrated.

9,10-Dimethyl-1,2-benzanthracene↗