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Biomedical subjects

M Cuevas

Publications and source records attributed to M Cuevas.

104 records · Page 6Linked to original sources
PubMed1977

Cell-mediated immunity in an ageing population.

Eight hundred and eighty patients hospitalized in a geriatric hospital were routinely tested with 2, 10, 30 and 100 i.u. tuberculin. Among these, fifty-four patients were selected on the basis of negative skin tests and absence of evident diseases interfering with the function of the immune apparatus. A battery of tests analysing cell-mediated immunity was applied to those fifty-four patients. It appears that elderly patients having a negative test to 100 i.u. tuberculin show very infrequent sensitization to three other thymus-dependent antigens. The capacity of this selected population to become sensitized to DNCB is poor (20%). Furthermore they exhibit a low per cent of peripheral blood T cells (36%) and a poor capacity to respond in vitro to mitogens such as PHA. Testing the in vitro response to a battery of antigens demonstrates a good correlation with the results of the skin tests. Finally the leucocytes of 25% of this selected population failed to produce LIF in vitro in the presence of PHA. These results suggest not only an absolute decrease in the population of circulating T lymphocytes in those elderly humans; but very likely, at least in some cases, a functional impairment of T cells.

Adult↗
PubMed1976

[Diagnosis of drug allergies related to anesthesia and surgery].

Drug allergies are increasingly common. They may occur in 5-10 p. 100 of patients treated with drugs. From a diagnostic standpoint, the problem is a complex one, many aspects of which are still poorly understood. This is particularly true with regard to the nature of the antigenic determinants and their vectors. Allergic reactions in patients submitted to anaesthesia and surgery represent a very particular case of the situation. A study of the immune status of such patients was undertaken and revealed that T lymphocyte depression, lasting from one to three weeks, often occurs. It is important to take this concept into account when choosing laboratory tests designed to substantiate the diagnosis. Several examples are presented and discussed.

Adult↗
PubMed1976

Immunological mechanisms and diagnostic tests in allergic drug reactions.

Current knowledge about the immunological mechanisms involved in drug hypersensitivity is reviewed, with comments on the major conditions which favour the development of reactions to drugs. In spite of the numerous tests available to establish the in vitro diagnosis of allergic reactions to drugs, it is often very difficult to relate the clinical picture to the laboratory findings. The results of various tests of antibody and cell-mediated responses are presented and discussed.

Antigen-Antibody Reactions↗
PubMed1975

[Clinical and immunological analysis of 1,047 allergic reactions to penicillin].

Of 1047 patients who had had an allergic reaction to penicillin established by clinical and laboratory findings, 224 were given penicillin therapy again later. One third of these patients developed a second allergic reaction to penicillin. In patients experiencing a second allergic reaction the most striking feature is a dramatic increase in the immediate reactions and especially of the anaphylactic type, and less markedly, an increase in the serum-sickness type of reaction. All the patients were skin tested with penicilloyl-polylysine (PPL) and benzylpenicillin (BPO). Circulating hemagglutinating antibodies were determined and in vitro stimulation of peripheral blood lymphocytes was performed in all cases. Skin tests show little change for several years. In contrast, circulating hemagglutinating antibodies disappear in half the cases within 6 months. Finally, lymphocyte stimulation with penicillin was positive in only 50% three months after onset of the allergic reaction, whereas one year later there was a 73% positive response. The best test for prediction of an allergic reaction to penicillin appears to be determination of the (high) and (low) reactors among patients with a positive skin test to PPL and BPO.

Anaphylaxis↗
PubMed1975

Immune response in the guinea pig to penicillin-autologous carrier proteins.

The spontaneous fixation of penicillin G on guinea pig serum protein was studied. Serum albumin and Ig were shown to fix firmly over 95% of penicillin. Therefore, guinea pigs were immunized with penicillin alone or penicillin-autologous carrier protein conjugates. The production of hemagglutinating antibody, of MIF and the in vitro stimulation of lymphocytes were analyzed as immunological parameters. The results showed that in all cases the strongest immunological response was obtained with animals immunized with the protein-hapten conjugates, whereas no response could be obtained with the carrier protein alone. Finally it was shown that the conjugates significantly stimulated purified T cell population. These results suggest that the antigenic recognition of penicillin involves the participation of lymphocytes.

Animals↗
PubMedDate not supplied

Anaphylaxis to Linum.

BACKGROUND: Flax (Linum usitatissimum) seeds are increasingly used in bread and as laxatives. Hypersensitivity to linseeds has been infrequently described, and we report a case of anaphylaxis induced by linseed ingestion in a 39-year-old woman. METHODS AND RESULTS: The clinical course, as well as positive skin prick tests and histamine release tests performed with linseed extracts, suggested a type I hypersensitivity as the underlying cause for the patient's multisystemic involvement. The presence of linum-specific IgE in her serum was confirmed by immunoCAP assay. CONCLUSION: Linum seeds might be a source of allergic sensitization that should be taken into account due to its widespread distribution at health food stores.

Adult↗
PubMedDate not supplied

Phase III randomized pilot study comparing interferon alpha-2b in combination with radiation therapy versus radiation therapy alone in patients with stage III-B carcinoma of the cervix.

This randomized pilot study was designed to determine whether the addition of interferon alpha-2b to standard radiation therapy offered an advantage in loco-regional control and survival over radiation therapy alone in a homogeneous group of patients with stage IIIB carcinoma of the cervix. Thirty-six patients were treated with a combination of interferon alpha-2b plus radiation therapy, and 38 patients were treated with radiation therapy alone. Patients with evidence of ureteral obstruction were excluded from the study. Evaluation of loco-regional response was determined by pelvic examination, cervical cytology, biopsies and CT scans when indicated. Survival time was measured from initiation of treatment to date of death or last follow-up. Patient characteristics were comparable between both study arms. The objective complete response rate was 67% in the combined therapy group and 55% in the radiation alone group (P = 0.454). With a median follow-up of 17 months for all patients and 31 months for live patients, 50% of the combined group survived vs. 39.5% of the radiation alone group (P = 0.424). We conclude that the addition of interferon alpha-2b to standard radiation therapy did not significantly improve loco-regional response or survival, although such a trend was noted. We encourage the design of a larger randomized study with sufficient power to detect meaningful differences to prove whether the tendency observed in the present investigation holds any promise to improve the outcome of these patients.

Adult↗
PubMedDate not supplied

Anaphylaxis to calcitonin.

BACKGROUND: The calcitonin is an hormone produced by the thyroid gland C cells. The salmon calcitonin is used in some osteomuscular diseases. There are few references of allergic reaction to this hormone. We introduce a case of a sixty years old woman with several previous episodes of rhinitis, conjunctivitis and perspiration immediately after the administration of salmon calcitonin with nasal spray or intramuscular administration (Calsynar). There were some temporal periods of good tolerance between these episodes. METHODS: Skin prick test (SPT), nasal and intramuscular challenge test with commercial salmon calcitonin (Miacalcic) were performed. Leukocyte histamine release test with salmon calcitonin and serum tryptase levels at baseline and after intramuscular challenge test were performed. RESULTS: The patient skin prick test with commercial calcitonin (Miacalcic. 50 UI/ml) was positive and negative in controls. The nasal challenge test with a calcitonin nasal spray, up to 150 UI, was negative. The intramuscular challenge test with 25 UI of Miacalcic was positive with an immediate anaphylactic reaction. Whole blood histamine release studies were negative. Serum tryptase levels after intramuscular challenge did not increase significantly with regard to the basal levels. CONCLUSION: We have introduced a case of anaphylaxis by calcitonin that suggest an IgE mediated hypersensitivity reaction.

Anaphylaxis↗
PubMedDate not supplied

A placebo controlled double-blind trial of beclomethasone dipropionate in the treatment of allergic rhinitis.

Beclomethasone dipropionate aerosol, administered intransally, 50 mcg into each nostril four times a day, was compared to placebo aerosol therapy in a three-week, double-blind trial of 30 patients with allergic rhinitis. Evaluation of efficacy, derived from patient scoring on daily diary cards and a weekly evaluation of signs and symptoms by a physician, showed a statistically significant difference in favor of the beclomethasone dipropionate aerosol. The 400 mcg/day dosage did not provide for systemic absorption as determined by measurements of plasma cortisol levels and circulating eosinophils. The only side effects consisted of mild to moderate burning and stinging or drying of the nasal mucosa.

Adolescent↗
PubMedDate not supplied

Analysis of serum-mediated immunosuppression in normal pregnancy, abortion and contraception.

Blood samples were obtained from pregnant women, threatened pregnancies, abortions, from women taking oral contraceptive drugs and normal controls. The measurement of immunoglobulins, G, A, M and E was done in all samples. The mean levels were normal in all cases, excepting the IgG levels which in normal pregnancies were decreased. Analysing the effect of these sera on the "in vitro' response of peripheral blood lymphocytes to PHA, a strong inhibition could be observed with the serum of normal pregnant women, with that of aborted pregnancies, that of women taking oral contraceptives and to a lesser extent with that of threatened pregnancies. Abortion experiments demonstrate that a large part of this inhibitory effect was attributable to the PZP factor. On the other hand, inhibitory sera failed to inhibit the "in vitro' production of MIF or the capacity of lymphocytes to form E-rosettes. A specific effect of PZP on the release of mitogenic factor by stimulated lymphocytes is suggested.

Abortion, Spontaneous↗
PubMedDate not supplied

Susceptibility of a grass-pollen oral immunotherapy extract to the saliva and gastric fluid digestive process.

The oral and sublingual immunotherapy is still a controversial therapeutic procedure. One of the problems is knowing how much allergenic activity could the extracts loss due to the digestive process into the mouth and stomach. Using a grass-pollen oral and sublingual immunotherapy extract, we studied its degradation until reaching the small intestine. For this purpose we employed an in vitro model using the RAST-inhibition assay. We observed a 3.8 fold loss of allergenic activity after a 30 sec-incubation with saliva; a subsequent 5 min-incubation with gastric fluid got a final loss of allergenic activity of 10.3 fold. The incubation times were those expected occurring during the ingestion of the extract. It was surprising that after the enzymatic and acid actions of the gastric fluid, an important degree of allergenic activity still remained in the extract. This issue should be taken into account when considering the dose to be administered in oral and sublingual immunotherapy.

Administration, Oral↗
PubMedDate not supplied

Shellfish hypersensitivity: clinical and immunological characteristics.

Shellfish is one of the most frequent causes of food allergy. We studied 48 patients (25 male and 23 female) with a mean age of 24.2 +/- 1.8 with shellfish hypersensitivity. A clinical questionnaire was carried out and prick tests were performed using a series of aeroallergens and a battery of extracts of squid, shrimp, lobster, crab, mussel and clam. Prick tests were also performed using raw and boiled extracts from fresh squid, octopus and limpet. Total and specific IgE to these allergens were determined. The most frequent causes of symptoms were shrimp (33 cases) and squid (24 cases). The most frequently found symptoms were Urticaria/angioedema (39 patients), asthma (18 patients) and rhinitis (14 patients). Clinical association was found between Cephalopoedae and Lamelibranquiae (p < 0.05 for clam and p < 0.01 for mussel), but not among both groups and Crustaceans. Association between history and Prick was statistically significant for Crustaceae and Cephalopoedae (p < 0.01) but not for Lamalibranquiae. Association between history and CAP was not found for shellfish. Significant differences among prick-tests with raw and boiled extracts were not found. These results suggest that prick test yields better results than CAP does it, in shellfish hypersensitivity, that clinical association among shellfish hypersensitivity can occurs within the same and different Phylum reflecting common epitopes and that squid, octopus and limpet extracts contain a large amount of heat-stable allergens.

Adolescent↗
PubMedDate not supplied

Specific IgE antibody response to human insulin in diabetic subjects.

Treatment with heterologous insulin preparations induce insulin antibody formation in most of the patients. A hundred of diabetic individuals in treatment with human insulin (HI) for at least 6 months at the time of the study and without any clinical immunological reaction, were selected in order to study the development of specific IgE antibodies against HI by in vivo and in vitro methods. Serologic specific IgE antibodies to HI were measured by RAST (Pharmacia) and 5 RAST-positive subjects were found. The specificity of these results were confirmed in 4 of the 5 subjects by RAST-inhibition. Thus, the prevalence of specific serologic IgE to HI in our study was 4% (1.1%-9.9%, p < 0.05). Only two of the RAST-positive subjects had cutaneous reactivity to HI by intradermal technique and one of the RAST-negative subjects presented also insulin skin reactivity. HI skin reactivity was found in 3% (0.6%-8.5%, p < 0.05) of the 100 diabetic subjects. These results differ from others obtained with heterologous insulins.

Adolescent↗