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Biomedical subjects

F Balsano

Publications and source records attributed to F Balsano.

At least 91 records · Page 5Linked to original sources

Inflammatory changes in conjunctival scrapings after allergen provocation in humans.

This study was performed to investigate the inflammatory changes occurring in the human conjunctiva at different time periods after allergen provocation. Twenty-three ryegrass-sensitive patients with allergic conjunctivitis (19 with hayfever and four with vernal conjunctivitis) were challenged by topical administration of ryegrass antigen to the eye. Allergen concentrations were increased in increments until an immediate ocular allergic reaction was elicited. Numbers of various inflammatory cells (neutrophils, eosinophils, lymphocytes, and monocytes) found in conjunctival scrapings were quantified and correlated with the clinical profile, total serum IgE, and serum IgE to Rye I antigen. Twenty minutes after some level of antigen topical challenge to the eye, all patients had ocular redness, tearing, and itching. Compared with findings in seven control subjects, significant inflammatory cells were found in the conjunctival scrapings of patients before challenge (p less than 0.05) and 20 minutes (p less than 0.001) and 6 hours (p less than 0.002) after effective challenge. Significant increases in neutrophils of patients occurred after 20 minutes (p less than 0.001), and in eosinophils at 6 hours (p less than 0.005), compared with values of control subjects. When each case was evaluated individually, nine of the 23 patients had highly evident inflammatory changes 6 hours after allergen provocation. The levels of total serum IgE and serum IgE to Rye I antigen of these nine patients did not differ significantly from the other patients in the study. Our data provide the first evidence in humans that significant inflammatory changes in conjunctival scrapings are present long after allergen exposure has ended.

Adolescent↗

Increased number of CD4 cells able to bind to natural killer cell targets in the peripheral blood of AIDS related complex patients.

CD4 cells forming conjugates with natural killer target cells (K562 cells) were measured in the peripheral blood of anti-HIV antibody positive AIDS related complex (ARC) patients and in three control groups (asymptomatic individuals at risk, normal healthy people and patients with acute hepatitis B). These CD4 cells, which are unable to kill K562 cells, were significantly increased in ARC patients as compared to the control groups. Our data indicate that classical CD4 cells are partially replaced, in ARC patients, by a population of natural killer-target binding granular CD4 lymphocytes, and suggest that the functional abnormalities of helper T cells in these patients may be in part a consequence of the relative predominance of these non IL-2 and BCGF producing cells within the circulating CD4 population.

AIDS-Related Complex↗

Influence of hydroxyl radical scavengers on platelet function.

The influence of four hydroxil radical (OH.) scavengers on platelet function was investigated. OH. scavengers inhibited ADP, collagen, arachidonic acid, PAF-induced platelet aggregation, and platelet cyclooxygenase pathway activation, which was studied by evaluating platelet malondialdehyde and serum thromboxane A2 formation. The latter was not affected by superoxide dismutase, catalase, or metal ion chelants such as desferioxamine or DETAPAC. The detection of deoxyribose degradation by stimulated platelets suggested that platelets produce OH.. This study shows that activated platelets produce free radicals and that antioxidant agents such as OH. scavengers inhibit platelet function.

Adult↗

Leukocyte response in patients suffering from acute stroke.

The oxidation of adrenaline to adrenochrome has been shown to reflect the activation of leukocytes in vivo. We tested the in vivo activation of leukocytes by measuring plasma oxidation of adrenaline to adrenochrome in patients suffering from cerebral ischemia, cerebral hemorrhage, and transient ischemic attacks and in healthy subjects. Patients with cerebral ischemia and cerebral hemorrhage had significantly higher values than healthy subjects, while patients with transient ischemic attacks had values similar to those of healthy subjects. In some patients with cerebral ischemia, the test was repeated 4 and 15 days after the acute event, but the follow-up data did not differ from baseline values. Our study shows that leukocyte activation occurs in cerebral ischemia and cerebral hemorrhage.

Acute Disease↗

The majority of the activated T cells in the blood of insulin-dependent diabetes mellitus (IDDM) patients are CD4+.

Twenty-five recently diagnosed insulin-dependent diabetic patients were screened for the presence of activated T lymphocytes using the anti-IL-2 receptor monoclonal antibody; thirteen had elevated levels of activated T lymphocytes. The activated cells were mostly confined to the CD4 subset, with the CD4/CD8 ratio in IL-2 receptor expressing cells averaging 5 +/- 1 (s.d.) compared with 1.3 +/- 0.3 for all T cells. In recent onset insulin-dependent diabetes blood there was no lack of CD4 CD45R+ (suppressor/inducer) T cells. The activated IL-2 receptor, expressing cells belonged to both CD4 subsets, 'helper inducer' (CD44B4) and 'suppressor inducer', (CD42H4).

Adolescent↗

Captopril does not alter metabolic control in elderly hypertensive diabetics during secondary failure.

In elderly patients diabetes and hypertension play an important and synergistic role in the development of cardiovascular complications. For this reason therapy must reduce blood pressure without compromising blood glucose control. We investigated the question of whether captopril, an angiotensin converting enzyme inhibitor, can be used without interference to glucose metabolism in diabetics with secondary failure. Ten elderly hypertensive diabetics (diastolic blood pressure greater than 95 mmHg), maintained in good metabolic control using oral hypoglycaemic agents and insulin, were studied before and after 30 days of captopril at 100 mg/day. We measured the following parameters: blood pressure, heart rate, fructosamine and a daily profile for blood glucose and c-peptide. There was a statistically significant reduction in systolic and diastolic blood pressure. No difference was observed in the levels of blood glucose and fructosamine. Insulin secretion as determined by c-peptide levels was not modified, in contrast with findings reported for the use of beta-blockers, diuretics or nifedipine. It seems that captopril is useful and without side effects, even in secondary-failure diabetic patients characterized by unstable metabolic control.

Aged↗

Effect of nicardipine on angiotensin II platelet content.

We evaluated the effect of nicardipine treatment on platelet angiotensin II content in 18 essential hypertensive patients. Nicardipine induced a decrease in platelet angiotensin II content in all patients (-14%), but particularly in 10 (P less than 0.05; -20.5%). No other differences were found between these patients and the others. Further investigations are required to determine whether platelet angiotensin II content reduction contributes to the prophylactic and therapeutic effects of calcium antagonists on atherosclerosis.

Aged↗

Blood platelets and angiotensin II: angiotensin II release after platelet aggregation.

Recent studies have demonstrated the presence of angiotensin II (Ang II) in human platelets. The aim of the present study was to determine whether in vitro platelet aggregation induces Ang II release. We studied 20 healthy volunteers, and found that some aggregant stimuli can cause the platelet to release this peptide. Release of Ang II was greater with thrombin (40.7%) than with ADP (29%), while N-ethylmaleimide was almost ineffective. The release of Ang II following in vitro aggregant stimuli suggests that this may be one of the mechanisms through which platelets can locally modulate vascular tone and perhaps promote atherogenesis.

Adenosine Diphosphate↗

A calf thymus acid lysate improves clinical symptoms and T-cell defects in the early stages of HIV infection: second report.

Thymomodulin is a calf thymus acid lysate capable of inducing T lymphocyte maturation. Fifteen patients with HIV infection at different stages according to the Walter Reed classification were treated with 60 mg/day of thymomodulin syrup for more than 50 days. Two WR6B subjects had clinical and immunological parameters unchanged and died, while the patient suffering from Kaposi's sarcoma presented an evident clinical and laboratory improvement with remission of the neoplasia. The other 12 patients ranging from WR2 to WR5B showed an improvement of clinical symptoms after thymomodulin therapy accompanied by the normalization of CD4/CD8 ratio (P less than 0.001). This helpers/suppressors increase was due to a significant increase of CD4 cells (P less than 0.01) and also to a decrease of the CD8 lymphocytes (P less than 0.05). Thymomodulin administration did not cause an enhancement of the urinary levels of neopterin, a marker of T-cell activation.

Acquired Immunodeficiency Syndrome↗

In vitro induction of HBsAg-specific CD8 CD11 human suppressor T cells.

Anti-hepatitis B surface (HBs) antibodies have been induced in vitro by human peripheral blood mononuclear cells (PBMC) from individuals immunized with hepatitis B surface antigen (HBsAg). Anti-HBs antibody production is antigen-specific, T-cell dependent, class II MHC-restricted and requires de novo synthesis. Furthermore, HBsAg-specific CD8 suppressor cells can also be induced in vitro after challenge with high antigen doses. Antigen presenting cells (APC) are required for the induction of suppression. These suppressor cells are antigen-specific since they do not suppress the antibody response to tetanus toxoid. Antigen-specific suppression is inhibited by cytotoxic treatment of CD8 CD11 cells with OKM1 monoclonal antibody (MoAb) and complement, suggesting that these suppressor CD8 cells may represent granular lymphocytes. Addition to cultures of high concentrations of a recombinant human IL-2 dose not affect suppression, ruling out the adsorption of IL-2 by suppressor cells as a possible mechanism for suppression.

Cells, Cultured↗

In vitro anti-HBs antibody synthesis from anti-hepatitis B vaccine recipients.

Peripheral blood mononuclear cells (PBMC) from 'responders' recently boosted with hepatitis B vaccine, were studied for synthesis in vitro of antibody to hepatitis B surface antigen (anti-HBs Ab) when stimulated with pokeweed mitogen (PWM) or HBsAg. HBsAg alone can induce an antigen-specific anti-HBs Ab response in vitro; this antibody synthesis is T cell-dependent. In some responders both allogeneic T4+ cells (in absence of PWM or HBsAg) and mixed leucocyte culture supernatants (MLC/SN) (without T cells and antigen) can help responder B cells to produce anti-HBs Ab. Thus, in some immunized subjects, B lymphocytes involved in anti-HBs Ab synthesis are in an advanced phase of differentiation and require only non-antigen specific T cell signals (B cell growth factor or B cell differentiation factor or interleukin 2, etc) to differentiate into antibody-secreting cells. Moreover, the concentration of the antigen necessary to suppress anti-HBs Ab production induced by HBsAg was five times lower than that necessary to suppress antibody production induced by PWM. T cell help for antigen induced anti-HBs Ab could be different from T cell help for the PWM-induced anti-HBs Ab response. Moreover, the finding that the low HBsAg doses inhibiting specific response did not affect the PWM-driven anti-HBs response suggests that antigen-specific T suppressor cells could play a role in this context.

B-Lymphocytes↗

"Anti-Ia reactivity in sera from patients with chronic active hepatitis (CAH)".

Anti-Ia reactivity in sera from patients with chronic active hepatitis (CAH) were characterized by determining cross-reacting specificities with the antigen defined by anti-Ia monoclonal antibody (MoAb) and by studying the effect of CAH sera on the autologous mixed leukocyte reaction (MLR). Preincubation with autoimmune CAH sera lowered the percentage of Ia+ non-T cells stained by anti-Ia MoAb. HBsAg+ve/HBeAg+ve sera did not exert any blocking activity while 4 out of 11 HBsAg+ve/anti-HBe+ve sera exerted a significant blocking effect. Preincubation of cells with normal human serum (NHS) plus aggregated IgG did not block the binding of MoAb anti-Ia. Sera from patients with autoimmune or HBsAg+ve/anti-HBe+ve CAH, that blocked the binding of anti-Ia MoAb to Ia positive target cells by more than 20%, clearly inhibited the autologous mixed lymphocyte reaction (MLR). Both IgG and IgM fractions obtained by affinity chromatography from CAH sera inhibited the autologous MLR and blocked the binding of anti-Ia antibody to Ia positive target cells. A significant positive correlation (p less than 0.001) between serum anti-Ia reactivity and serum liver membrane antibodies (LMA) was observed. In 4 "autoimmune" CAH patients, steroid treatment induced a dramatic decrease in the anti-Ia reactivity.

Antigen-Antibody Reactions↗

Use of monoclonal antibodies to identify shared idiotypes on anticardiolipin and anti-DNA antibodies in human sera.

Using hybridoma technology we produced monoclonal antibodies (MoAb) to idiotypic determinants on human anti-cardiolipin antibodies purified from a patient with SLE. Hybridomas were screened by inhibition of cardiolipin binding activity of sera from patients with SLE. Seven hybridomas were selected, two of which were studied extensively. Sera from a number of patients with SLE were found to share idiotypic determinants. This cross-reacting idiotype was not detectable on anti-cardiolipin antibodies in syphilis sera. The cross-reacting idiotype was present in sera with anti-ssDNA antibodies even though some of these sera had no anti-cardiolipin antibodies. We propose that these MoAb may recognize a regulatory idiotype.

Animals↗