Biomedical subjects

A Conti

Publications and source records attributed to A Conti.

At least 55 records · Page 3Linked to original sources

PubMed2001

The recovery of Senegalese African blacks from intravenous anesthesia with propofol and remifentanil is slower than that of Caucasians.

UNLABELLED: Differences in sensitivity to anesthetic drugs have already been described among races. This study was designed to comparatively investigate the anesthetic requirements of two different ethnic groups: Caucasians and African blacks. Forty-five Caucasians from Italy and 45 African blacks from Senegal, who underwent general IV anesthesia with propofol and remifentanil, were comparatively evaluated for anesthetic depth and time lapsed before recovery. We used an electroencephalographic-derived index of depth of anesthesia, the bispectral index (BIS), and evaluation of clinical variables to assess the depth of anesthesia and the recovery trend. Mean BIS values from Caucasians after propofol discontinuation returned to baseline (92-100) in approximately 8 min, whereas in African blacks BIS values remained <80 for some 30 min. Time to eye opening was 10.6 +/- 4.8 min in Caucasians versus 16.9 +/- 8.8 min in African blacks (P < 0.001). Time to respond to loud verbal commands was 14.8 +/- 9.1 min in African blacks versus 9.1 +/- 4.2 min in Caucasians (P < 0.01). During anesthetic induction, the mean arterial pressure decreased by 20% in Caucasians and by only 10% in African blacks. We conclude that the recovery from general anesthesia with propofol was slower in African blacks compared with Caucasian patients. IMPLICATIONS: This study demonstrates statistically significant differences between Caucasians and African blacks in the arousal time from IV anesthesia with propofol and remifentanil. The authors conclude that the recovery from general anesthesia was slower in African blacks compared with Caucasian patients.

Adult↗

PubMed2001

Prospective evaluation of adenosine-induced proarrhythmia in the emergency room.

The arrhythmogenic hazard of adenosine treatment in an emergency room (ER) has not been established. Thus, in this study, we set out to prospectively determine the prevalence and clinical consequences of the arrhythmogenic effects associated with urgent adenosine treatment in the ER. One hundred and sixty consecutive patients treated with adenosine for regular wide or narrow complex tachyarrhythmias at our ER were included in the study. An initial bolus of 3 mg of adenosine was used, up to a maximum dose of 18 mg (mode 6 mg). Proarrhythmia was defined as the new appearance of any brady- or tachyarrhythmia within 1 minute from the bolus administration of adenosine. Of the 160 study patients, 84% had narrow complex tachycardia and 16% had wide complex tachycardia. Adenosine was effective in the diagnosis and/or treatment of the underlying arrhythmia in 92%. The overall prevalence of adenosine-induced proarrhythmia was 13%, including prolonged AV block inducing asystole > 4 seconds (7%), paroxysmal atrial fibrillation (1%) and non-sustained ventricular tachycardia (5%). All adenosine-induced arrhythmias were transient and subsided spontaneously. It is concluded, firstly, that adenosine-induced proarrhythmia proved to be frequent in a consecutive ER series, and included potentially dangerous arrhythmias. Secondly, nevertheless, all adenosine-induced arrhythmias subsided spontaneously and did not require treatment. Therefore, urgent adenosine treatment is safe and can be recommended in an emergency setting, provided a strict protocol of administration under close monitoring by highly trained personnel.

Adenosine↗

PubMed2001

Antigenic determinants of bovine serum albumin.

BACKGROUND: Bovine serum albumin (BSA) is one of the most widely studied proteins; its structure is well known and its antigenic characteristics have been described in several papers. The aim of this research was the identification of the BSA antigenic determinants. METHODS: This study was performed using limited proteolysis and an immunoblotting technique, in which a commercial murine antibody and sera from children sensitized to BSA were used. RESULTS: Findings suggest amino acids (aa) 524-598 as an epitopic area for human species. The most critical sequence seems to be aa 524-542, even if it must be included in a longer fragment to be recognized by antibodies. Murine IgG antibodies also recognize fragments contained in the first half (NH(2)-terminal portion) of BSA. CONCLUSIONS: The results presented in this study indicate that the epitopic sites of an antigenic protein can be different when different species are considered, so that data obtained with antibodies from animal species cannot be directly extrapolated to the behavior of human IgEs.

Amino Acid Sequence↗

PubMed2001

The catechol 1,2 dioxygenase system of Acinetobacter radioresistens: isoenzymes, inductors and gene localisation.

Two different isozymes (Iso A and Iso B) of catechol 1,2 dioxygenase (C1,2O) were isolated from cultures of A. radioresistens grown in two different media, containing phenol and benzoate respectively. In the phenol medium the bacteria expressed about 90% of Iso A, whereas in the benzoate medium the Iso A/Iso B ratio was 40:60. The two proteins have different molecular masses, isoelectric points and N-terminal sequences that are not consistent with simple post-translational modifications. Furthermore, their behaviour differs at high temperatures (42 degrees C-47 degrees C) and at moderately acidic pH (pH 6.0): Iso A proved to be the more stable under conditions of environmental stress. Hybridisation analysis with an A. calcoaceticus catA-derived probe revealed that A. radioresistens C1,2O proteins are encoded by two chromosomally located genes. Bidimensional electrophoresis (2DE) maps of crude extracts of cells grown in different carbon sources (phenol, benzoate and acetate) clearly demonstrated a differential induction pattern for the two proteins. The hypothesis of a double set of genes, one for benzoate catabolism and the other for phenol catabolism, is discussed, and analogies are drawn with other known C1,2Os.

Acinetobacter↗

PubMed2001

Proteolysis of beta-casein as a marker of Grana Padano cheese ripening.

Proteolysis has a critical role in defining the typical organoleptic characteristics of Grana Padano, a well-known Italian cheese. During the ripening process, hydrolysis of beta-casein produces different fragments, the most abundant and widely studied of which are gamma-caseins, three polypeptides containing the HOOC-terminal portion of beta-casein. By sodium dodecyl sulfate-PAGE and a specific anti-beta-casein monoclonal antibody, two beta-casein-derived bands were identified in Grana Padano cheese: betaa and betab. Thanks to the identification of the amino acid sequences, it was shown that: a) betaa contains gamma1-casein [beta-casein (29-209)] and the correlated peptide [beta-casein (30-209)]; b) betab contains gamma2-casein [beta-casein (106-209)] and gamma3-casein [beta-casein (108-209)]. The production of betaa and betab by the three enzymes most involved in cheese proteolysis (pepsin, chymosin, and plasmin) was evaluated by performing in vitro digestions. A significant correlation between abundance of some polypeptides and ripening process was shown.

Amino Acid Sequence↗

PubMed2001

Efficacy of monochemotherapy with docetaxel (taxotere) in relation to prolactin secretion in heavily pretreated metastatic breast cancer.

OBJECTIVES: Recent data have suggested that the efficacy of cancer chemotherapy does not depend only on tumor-related characteristics, but also on patient biological status, namely immune and endocrine functions. In particular, it has been shown that prolactin (PRL) is a growth factor for breast cancer, and abnormally high blood levels of PRL have been described in metastatic breast cancer patients. The present study was performed to evaluate the efficacy of chemotherapy with taxanes in relation to PRL blood levels in metastatic breast cancer. MATERIAL & METHODS: The study included 20 metastatic breast cancer patients, who were treated with taxotere (100 mg/mq I.V. every 21 days) for at least 3 consecutive cycles. Serum levels of PRL were measured by RIA before the onset of treatment and at 21-days intervals. RESULTS: The clinical response consisted of partial response (PR) in 6, stable disease (SD) in 7 and progressive disease (PD) in the remaining 7 patients. Abnormally high pre-treatment levels of PRL were seen in 7/20 patients. The percent of patients who had PD in response to chemotherapy was significantly high in patients with pre-treatment hyperprolactinemia than in those with normal blood levels of PRL before therapy. CONCLUSIONS: This study shows that the evidence of abnormally high serum levels of PRL correlates with resistance to chemotherapy with taxanes in metastatic breast cancer. Therefore, a concomitant administration of anti-prolactinemic agents, such as bromocriptine, could enhance the efficacy of chemotherapy itself.

Adult↗

PubMed2001

Anti-angiogenic activity of melatonin in advanced cancer patients.

OBJECTIVES: The anticancer activity of the indole melatonin has been explained to be due to its immunomodulatory, anti-prolferative and anti-oxidant effects, whereas at present no data are available about its possible influence on the angiogenesis, which has been shown to be one of the main biological mechanisms responsible for tumor dissemination. Vascular endothelial growth factor (VEGF) is the most active angiogenic factor, and the evidence of abnormally high blood levels or VEGF has been proven to be associated with poor prognosis in cancer patients. To investigate the influence of melatonin on angiogenesis, in this preliminary study we have evaluated the effects of melatonin therapy on VEGF blood levels in advanced cancer patients. MATERIAL & METHODS: The study included 20 metastatic patients, who progressed on previous conventional antitumor therapies and for whom no other effective treatment was available. Melatonin was given orally at 20 mg/day in the evening for at least 2 months. Serum levels of VEGF were measured by an enzyme immunoassay on venous blood samples collected at 15-day intervals. RESULTS: The clinical response consisted of minor response (MR) in 2, stable disease (SD) in 6 and progressive disease (PD) in the remaining 12 patients. VEGF mean levels decreased on therapy, without, however, statistical differences with respect to the pre-treatment values. In contrast, by evaluating changes in VEGF levels in relation to the clinical response, non-progressing patients (MR + SD) showed a significant decline in VEGF mean concentrations, whereas no effect was achieved in progressing patients. CONCLUSIONS: This study, by showing that melatonin-induced control or the neoplastic growth is associated with a decline in VEGF secretion, would suggest that the pineal hormone may control tumor growth at least in part by acting as a natural anti-angiogenic molecule, with a following opposition or angiogenesis-dependent cancer proliferation.

Adult↗

PubMed2001

A study of light/dark rhythm of melatonin in relation to cortisol and prolactin secretion in schizophrenia.

OBJECTIVES: Recent studies have suggested the involvement of the pineal gland and its main hormone melatonin (MLT) in the pathogenesis of psychiatric disturbances, namely the depressive syndrome. In contrast, the behavior of MLT secretion in schizophrenia is still controversial. MATERIAL & METHODS: The present study was carried out to analyze light/dark rhythm of MLT secretion in relation to that of cortisol and prolactin (PRL) in schizophrenic patients. The study included 13 schizophrenic patients, 8 of whom were untreated, while the other 5 patients were on neuroleptic therapy. Serum levels of MLT, PRL and cortisol were measured by RIA on venous blood samples collected at 8 A.M., 12 A.M., 8 P.M. and 1 A.M. The control group consisted of 20 age-matched healthy subjects. RESULTS: A physiological nocturnal increase in MLT levels occurred in 6/13 patients, whereas the other 7 patients showed an abnormally low MLT peak during the night. Moreover, both light and night mean levels of MLT were significantly lower in patients than in controls. In addition, mean nocturnal levels of MLT were significantly lower in chronic patients than in those evaluated at the onset of disease. Cortisol rhythm was normal in 11/13 patients, whereas PRL levels were abnormally high in 10/13 patients. CONCLUSIONS: This preliminary study would suggest that schizophrenia may be associated with a diminished secretion of MLT from the pineal gland, and pineal deficiency would be more evident in the chronic disease. Finally, pineal alterations have appeared to be associated with an altered secretion of PRL and cortisol, by suggesting that the schizophrenic disease may be characterized by marked neuroendocrine disturbances, whose physio-pathological and prognostic significance needs to be established by successive clinical investigations.

Adult↗

PubMed2001

A review on cancer--psychospiritual status interactions.

With the advances in the knowledge of neuroimmunomodulation, a new era of investigations about the chemical basis of the state of mind has been initiated. Both emotions and states of spiritual consciousness may influence immune functions and cancer growth. Stress, anxiety and depressive states are associated with immunosuppression and enhanced frequency of tumors. On the other hand, the states of sexual pleasure and spiritual joy enhance the immune efficacy, by counteracting tumor onset and dissemination. The biochemistry of pleasure and immunostimulation is mainly mediated by pineal indoles and cannabinergic substances, whereas that of stress, anxiety and depression is associated with enhanced production of adrenal steroids, opioids and catecholamines. The sexual repression would allow a progressive immunosuppression through a profound damage in the biochemistry of pleasure. Therefore, a better definition of psychospiritual status-associated neuroimmunochemistry could allow us to improve the immune dysfunction by acting on the same neuroendocrine secretions which are involved in mediating the psychic influence on the immunity, including that against cancer.

Emotions↗

PubMed2000

HPLC-ED measurement of endogenous catecholamines in human immune cells and hematopoietic cell lines.

A rapid and simple HPLC-ED method is described to identify and measure catecholamines (CTs) and their major metabolites in immune cells. Using this method, intracellular CTs were quantified in human peripheral blood mononuclear cells (PBMCs), T and B lymphocytes, monocytes and granulocytes. Immune cell subsets were separated by density gradient centrifugation and immunomagnetic cell sorting. CTs were also found in the human hematopoietic cell lines NALM-6 (pre-B) and (in smaller amounts) in Jurkat (T lymphoblastoid) and U937 (promonocytic). In cultured PBMCs, intracellular CTs were reduced by both the tyrosine hydroxylase inhibitor alpha-methyl-p-tyrosine and the chromaffin granule depletant reserpine. In NALM-6 cells, both alpha-methyl-p-tyrosine and the dopamine-beta-hydroxylase inhibitor disulfiram reduced intracellular CTs, supporting the presence of active synthetic pathways in these cells. Since sympathoadrenergic mechanisms play a key role in the interactions between the immune system and the nervous system, these findings may be relevant for a better understanding of the neuro-immune network.

B-Lymphocytes↗

PubMed2000

Short-term clinical outcome of patients with acute pulmonary embolism, normal blood pressure, and echocardiographic right ventricular dysfunction.

BACKGROUND: The role of echocardiographic right ventricular (RV) dysfunction in predicting clinical outcome in clinically stable patients with pulmonary embolism (PE) is undefined. In this study, we assessed the prevalence and clinical outcome of normotensive patients with RV dysfunction among a broad spectrum of PE patients. METHODS AND RESULTS: This prospective clinical outcome study included cohort of 209 consecutive patients (age, 65+/-15 years) with documented PE. Acute RV dysfunction was diagnosed in the presence of >/=1 of the following: RV dilatation (without hypertrophy), paradox septal systolic motion, and Doppler evidence of pulmonary hypertension. Four groups were identified: 28 patients presenting with shock or cardiac arrest (13%), 19 hypotensive patients without shock (9%), 65 normotensive patients with echocardiographic RV dysfunction (31%), and 97 normotensive patients without RV dysfunction (47%). Among normotensive patients with RV dysfunction, 6 (10%) developed PE-related shock after admission: 3 of these patients died, and 3 were successfully treated with thrombolytic agents. In comparison, none of the 97 normotensive patients without RV dysfunction developed shock or died as a result of PE. CONCLUSIONS: A significant proportion (31%) of normotensive patients with acute PE presents with RV dysfunction; these patients with latent hemodynamic impairment have a 10% rate of PE-related shock and 5% in-hospital mortality and may require aggressive therapeutic strategies. Conversely, normotensive patients without echocardiographic RV dysfunction have a benign short-term prognosis. Thus, early detection of echocardiographic RV dysfunction is of major importance in the risk stratification of normotensive patients with acute PE.

Acute Disease↗

PubMed2000

Properties of ryanodine receptor in rat muscles submitted to unloaded conditions.

Unloading of skeletal muscles by hindlimb unweighting is known to induce muscle atrophy and a shift toward faster contractile properties associated with an increase in the expression of fast contractile proteins, particularly in slow soleus muscles. Contractile properties suggest that slow soleus muscles acquire SR properties close to those of a faster one. We studied the expression and properties of the sarcoplasmic reticulum calcium release (RyR) channels in soleus and gastrocnemius muscles of rats submitted to hindlimb unloading (HU). An increase in RyR1 and a slight decrease in RyR3 expression was detected in atrophied soleus muscles only after 4 weeks of HU. No variation appeared in fast muscles. [(3)H]Ryanodine binding experiments showed that HU neither increased the affinity of the receptors for [(3)H]ryanodine nor changed the caffeine sensitivity of [(3)H]ryanodine binding. Our results suggested that not only RyR1 but also RyR3 expression can be regulated by muscle activity and innervation in soleus muscle. The changes in the RyR expression in slow fibers suggested a transformation of the SR from a slow to a fast phenotype.

Animals↗

PubMed2000

Use of antihypertensive drugs in the Italian hospitals. GIFA group. Gruppo Italiano di Farmacoepidemiologia nell'Anziano.

Calcium channel blockers and ACE-inhibitors are among the most common drugs prescribed for the initial treatment of hypertension. While their ability to control surrogate outcomes, such as blood pressure and left ventricular hypertrophy, is proven, there is limited evidence of their prevention of major cardiovascular events, including mortality. The aim of our work was to assess the use of these drugs in Italy in comparison with beta-blockers and diuretics. We examined the consumption of the four main antihypertensive classes of drugs (beta-blockers, diuretics, calcium channel blockers and ACE- inhibitors). In-hospitalization data from the GIFA (Gruppo Italiano di Farmacoepidemiologia nell'Anziano) database were used. During the period from 1988 to 1995, the most frequently prescribed antihypertensive drugs were calcium channel blockers (47%) followed by diuretics (37%), ACE-inhibitors (33%) and beta-blockers (5.5%). Changes over time in the use of these drugs were analysed: ACE-inhibitors had the greatest increase in use over time. Calcium channel blockers, ACE-inhibitors and beta-blockers were usually prescribed to the youngest patients (aged <65 years), while diuretics to the oldest. Calcium channel blockers were prescribed to 60% of patients with myocardial infarction and to 55% of those with congestive heart failure. In conclusion, our study demonstrates that the Italian physicians very often prescribe drugs like calcium channel blockers and ACE-inhibitors. Among these pharmacological agents, enalapril (twice per day) and slow release calcium channel blockers are the most frequently prescribed drugs.

Adrenergic beta-Antagonists↗

PubMed2000

Effects of 12 months rec-GH therapy on bone and collagen turnover and bone mineral density in GH deficient children with thalassaemia major.

Children suffering from thalassaemia major are reported to have growth delay and bone alterations even when well transfused and chelated. In the present study we evaluated bone and collagen turnover (bone Gla-protein, BGP; carboxyterminal telopeptide of type I collagen, ICTP; aminoterminal propeptide of type III procollagen, PIIINP, respectively) and bone mineral density (BMD) in 5 pre-pubertal GH deficient thalassaemic children before and during rec-GH treatment (0.6 IU/kg/week). Data were compared with those recorded in an age- and sex-matched control group. Before treatment, serum BGP and ICTP levels were significantly lower (p<0.0001) in children with thalassaemia (9.3+/-0.7 ng/ml and 5.3+/-0.5 ng/ml, respectively) than in healthy controls (18.9+/-0.9 ng/ml and 14.4+/-0.6 ng/ml, respectively), while serum PIIINP levels did not significantly differ in the two groups (6.7+/-0.7 ng/ml vs 6.7+/-0.7 ng/ml). Mean lumbar BMD values of patients (0.62+/-0.05 g/cm2) were significantly lower (p<0.05) than those recorded in healthy controls (0.78+/-0.01 g/cm2), while femoral BMD values were similar in the two groups (patients: 0.70+/-0.08 g/cm2 vs controls: 0.74+/-0.01 g/cm2). One-year GH therapy significantly increased height velocity (from 2.3+/-0.2 cm/year to 6.1+/-0.4 cm/yr, p<0.0001) and IGF-I levels (from 61.6+/-15.4 to 342+/-38.5 ng/ml, p<0.005). Serum BGP (basal: 9.3+/-0.7 ng/ml, 6th month: 10.8+/-0.6 ng/ml, 12th month: 14.9+/-1.4 ng/ml), ICTP (basal: 5.3+/-0.5 ng/ml, 6th month: 7.9+/-0.8 ng/ml, 12th month: 10.9+/-1.7 ng/ml) and PIIINP levels (basal: 6.7+/-0.7 ng/ml, 6th month: 9.9+/-1.0 ng/ml, 12th month: 9.6+/-1.4 ng/ml) significantly increased (p<0.05), while no significant effects were observed on lumbar and femoral BMD values. Although the GH-induced stimulation of bone turnover markedly increased BGP (+60%) and ICTP (+105%) levels, one-year GH therapy was not sufficient to completely normalize these parameters, which remained significantly lower than in healthy controls. In conclusion, our study shows that pre-pubertal GH deficient children with thalassaemia major have reduced bone turnover (both bone formation and resorption) and lumbar BMD values, thus indicating that bone metabolism should be monitored and improved even in well-transfused patients. One-year GH treatment is able to increase, but not normalize, bone turnover, this effect being insufficient to improve BMD values. More prolonged periods of GH therapy are probably requested to positively affect both bone turnover and BMD values in GH deficient thalassaemic patients, as occurs in children and adults with GH deficiency.

Adolescent↗

PubMed2000

Evidence for a lipid transfer protein as the major allergen of apricot.

BACKGROUND: Apricots are widely grown in Europe, and allergic reactions are becoming more common, especially oral allergy syndrome. Apricot belongs to the botanical subfamily of Prunoideae, which includes peach, the major allergen of which was identified as a 9-kd protein, a lipid transfer protein (LTP). OBJECTIVE: The aim of the study was to evaluate the IgE reactivity pattern to an apricot extract in subjects with allergic reactions to apricot, as demonstrated by a positive oral challenge response. METHODS: Thirty patients were investigated. All the patients displayed oral allergy syndrome (2 with systemic reactions) to apricot, with positive open food challenge responses, skin prick test responses, and serum-specific IgE antibodies to apricot. The IgE reactivity pattern to apricot extract was identified by using SDS-PAGE and immunoblotting. The major allergen, a 9-kd protein, was then purified by HPLC and characterized by periodic acid-Schiff stain, isoelectric point determination, and N-terminal amino acid sequencing. RESULTS: The sera from all patients allergic to apricot recognized the 9-kd protein, whereas none of the other allergens, with molecular weights from 15 to 80 kd, acted as a major allergen. The 9-kd allergen has an isoelectric point of 8.7 and is not glycosylated. Determination of the N-terminal 34 amino acid sequence showed that it belongs to the LTP family, with a 94% homology with the LTP from peach. IgE blotting of the apricot extract was completely inhibited by the 9-kd purified LTP from peach. CONCLUSIONS: The major allergen of apricot is an LTP, which is highly cross-reactive with the LTP from peach.

Adolescent↗

PubMed2000

Identification of the human beta-casein C-terminal fragments that specifically bind to purified antibodies to bovine beta-lactoglobulin.

The presence of foreign proteins in human milk after the ingestion of bovine dairy products is thought to be one of the possible causes of allergic sensitization in exclusively breast-fed predisposed infants. The immunologic determination of bovine beta-lactoglobulin (LG) concentration in human milk has been reported by several researchers, but the results are conflicting. Moreover, a strong cross-reactivity between antibodies to bovine beta-LG and human milk proteins and peptides was reported, throwing doubt on the reliability of radioimmunoassay and enzyme-linked immunosorbent assay detection and quantification assays for bovine beta-LG in human milk. Thus, the goal of this study was to isolate human milk peptides with a molecular mass >or= 1,000 Da cross-reactive with antibodies to bovine beta-LG in order to identify possible common epitopes between human and bovine milk proteins. The proteins were first isolated by affinity chromatography with purified polyclonal antibodies to bovine beta-LG, followed by gel filtration fast phase liquid chromatography and reverse phase-high performance liquid chromatography purification of the components specifically bound in the affinity separation step. Affinity-bound peptides were identified by determining their amino acid sequence. All the sequenced peptides belonged to the C-terminal part of human beta-casein, which confirms the cross-reactivity of human milk proteins and peptides with antibodies to bovine beta-LG and allows the identification of possible common epitopes between the two proteins. No bovine beta-LG peptides with a molecular mass >or= 1,000 Da were found in our milk samples from healthy mothers on a diet rich in bovine milk and dairy products.

Journal Article↗

PubMed2000

Evidence for melatonin synthesis in mouse and human bone marrow cells.

Recently, it was demonstrated that inbred strains of mice have a clearcut circadian rhythm of pineal and serum melatonin. Moreover, it is known that melatonin is involved in many immunoregulatory functions. Among them, hematopoiesis is influenced by the action of melatonin via melatonin-induced opioids on kappa-opioid receptors, which are present on stromal bone marrow cells. Therefore, the present study was carried out to investigate the presence of melatonin in the bone marrow in which immunocompetent cells are generated. Specifically, we aimed at answering the following question: are bone marrow cells involved in melatonin synthesis? In the present study, we demonstrate that (1) bone marrow cells contain high concentrations of melatonin; (2) bone marrow cells have a N-acetyltransferase activity and they express the mRNA encoding hydroxy-O-methyltransferase and (3) bone marrow cells cultured for a prolonged period exhibited high levels of melatonin. Results presented here suggest that mouse and human bone marrow and bone marrow cells are capable of de novo synthesis of melatonin, which may have intracellular and or paracrine functions.

Acetylserotonin O-Methyltransferase↗

PubMed2000

The maize major allergen, which is responsible for food-induced allergic reactions, is a lipid transfer protein.

BACKGROUND: Cereals are the most important nutritional component in the human diet. Food-induced allergic reactions to these substances therefore have serious implications, and exhaustive diagnosis is required. Such diagnosis is still difficult because of the incomplete knowledge about major cereal allergens. In particular, few food-induced allergic reactions to maize have been reported, and no information on the allergenic proteins is available. OBJECTIVE: Having observed several anaphylactic reactions to maize, we planned a study to identify maize major allergens and cross-reactivity with other cereals, as well as to peach because the majority of patients also reacted to Prunoideae fruits. METHODS: Twenty-two patients with systemic symptoms after maize ingestion and positive skin prick test responses and serum-specific IgE antibodies to maize were selected. The IgE-reactivity pattern was identified by SDS-PAGE and immunoblotting. The major allergen identified was then purified by HPLC and characterized by mass spectrometry, determination of the isoelectric point value, and N-terminal amino acid sequencing. RESULTS: Sera from 19 (86%) of the 22 patients recognized a 9-kd protein, thus confirming this as the maize major allergen. This protein had an isoelectric point of greater than 9, a molecular mass of 9047.0 d, and no glycosylation. Determination of its N-terminal sequence showed that it was a lipid transfer protein (LTP). By using immunoblotting-inhibition experiments, we demonstrated that the LTP cross-reacts completely with rice and peach LTPs but not with wheat or barley LTPs. N-terminal sequence of the 16-kd allergen (recognized by 36% of patients) showed it to be the maize inhibitor of trypsin. This protein cross-reacts completely with grass, wheat, barley, and rice trypsin inhibitors. CONCLUSION: The major allergen of maize is an LTP with a molecular weight of 9 kd that is highly homologous with the peach LTP, the major allergen of the Prunoideae subfamily.

Adolescent↗