Are apolipoprotein E alleles correlated with semen quality?

Apolipoproteins have a unique role in lipoprotein metabolism regulation, aiding lipid transport and acting as a cofactor of the enzymes involved in metabolism. There are three co-dominant alleles, APOE*2, APOE*3 and APOE*4, which encode three protein isoforms, apoE2, apoE3 and apoE4. APOE*3 is the most frequent in all populations thus far investigated, ranging from 50 to 90%. Some studies have tried to resolve a genetic 'dilemma' by evaluating the cause of the frequency and survival of the three alleles. Genetic drift, migration or natural selection could explain the current distribution of APOE gene frequencies worldwide. If APOE*4 is the ancestral allele, APOE*3 must have offered a considerable selective advantage, perhaps consisting of a positive effect during the reproductive period. Given this, there is a need to understand if APOE gene polymorphism might affect reproductive capacity. Few studies have been conducted in this area, and they generally correlate APOE polymorphism with reproductive efficiency in terms of number of children. The aim of our study was to look for correlations between APOE polymorphism in humans and semen quality, to establish if APOE genotypes have any demonstrable effect on spermatogenesis. In conclusion, our data show that APOE polymorphism is not associated with semen quality, as it is present to a similar extent in both normal and impaired or absent spermatogenesis. This demonstrates once again that the use of number of children as an index of fertility is not indicative of real male reproductive capacity.

Outcome of occupational asthma due to cobalt hypersensitivity.

We performed a follow-up study on nine subjects with occupational asthma due to cobalt hypersensitivity confirmed by a specific bronchial provocation test. Both at diagnosis and at the two follow-up visits (1 and 3 years after the diagnosis, respectively), we graded the severity of asthmatic symptoms and the need for antiasthma treatment and performed lung function tests, measurement of airways responsiveness to methacholine (PD15) and skin tests. The evolution of the disease was established on the basis of the increase or decrease in asthmatic symptoms and the requirements for medication, FEV1 and PD15. After cessation of exposure, two subjects recovered, five improved and one remained stable; the subject who carried on working in the same environment deteriorated. The improvement in symptoms, medication need and lung function occurred earlier and in a larger number of patients than the improvement in methacholine hyperreactivity. At follow-up, the inhalation test with cobalt was repeated on three subjects who had stopped exposure and were asymptomatic and again they had bronchoconstriction. Our data show that early diagnosis and early removal from exposure after the onset of asthma are important factors for a favourable evolution of the disease and that specific and non-specific bronchial hyperresponsiveness can persist even in asymptomatic subjects no longer exposed to the sensitizing agent.

Toluene diisocyanate induced asthma: outcome according to persistence or cessation of exposure.

Sixty patients with occupational asthma due to exposure to toluene diisocyanate (TDI) were re-evaluated, five years after the initial diagnosis had been confirmed by a specific bronchial provocation challenge. During both examinations the severity of asthmatic symptoms and the need for antiasthma treatment were graded and lung function tests, measurement of airway responsiveness to methacholine (PD15), and skin tests with common inhalant allergens were carried out. The evolution of the disease was established on the basis of the increase or decrease in asthmatic symptoms, requirements for medication, and FEV1 and PD15 methacholine between the two examinations. At follow up 17 patients (group A, 28.3%) had carried on working in the same environment after relocation to jobs with only occasional exposure to TDI; 15 of them used protective respiratory devices. The remaining 43 (group B, 71.7%) avoided further inhalation of TDI by moving to another sector. Group A showed a significant decrease in FEV1 and PD15 methacholine and significant increases in the severity of symptom score and requirement for medication; 13 subjects (76.5%) were worse, four (23.5%) were stable, and no one had recovered or improved. Group B showed significantly less severe symptoms and a threefold increase in PD15 methacholine; 12 subjects (28.2%) totally recovered, 10 (23.2%) improved, 16 (37.2%) were stable, and five (11.6%) were worse. In group B the duration of exposure to TDI and of symptoms before the initial diagnosis delineated the patients who recovered from those who did not improve; intermediate values in these features characterised the subjects who improved but did not recover. It is inferred that complete removal from exposure is the only effective way of preventing deterioration in patients with occupational asthma due to TDI. Early diagnosis and early removal from exposure after the onset of asthma are important factors for a favourable outcome of the disease.

One- and two-dimensional 1H-NMR analysis of lipids extracted from erythrocytes and plasma of humans.

A combination of established lipid extraction procedures and high-resolution 1D and 2D NMR spectroscopic methods has been used to analyze qualitatively and quantitatively the lipid composition of human erythrocytes and plasma. The major lipids present in each structural class were identified and quantified. Considerable information on the composition of unsaturated fatty acid chains were obtained for the intact lipids without resort to hydrolysis.

Subclinical inorganic mercury neuropathy: neurophysiological investigations in 17 occupationally exposed subjects.

17 workers in a thermometer factory exposed to mercury for periods ranging from 1 to 40 years all had high urine and blood mercury levels on undergoing electromyographic examination. All were clinically free from central and peripheral nervous symptoms. 88% had subclinical neuropathy, mainly distal and axonal. There was no correlation between severity of the neuropathy and blood and urine mercury levels or between severity of neuropathy and duration of exposure to mercury. The presence of a subclinical neuropathy in symptomless workers exposed to mercury is perhaps the most reliable index for the detection of the early toxic effects of mercury on the peripheral nerve fiber when it is probably still reversible.

Toxicity in man due to stain removers containing 1,2-dichloropropane.

There are reports that 1,2-dichloropropane, a constituent of many commercial solvents and stain removers in Italy, has caused severe liver damage and, sometimes, acute renal failure. Between 1980 and 1983 three cases of 1,2-dichloropropane intoxication (1 by ingestion, 2 by inhalation) were observed. Clinical features included severe liver damage, acute renal failure (2 patients), haemolytic anaemia, and disseminated intravascular coagulation. The most surprising features were haemolytic anaemia and disseminated intravascular coagulation which have not been reported before. The clinical picture was similar despite different modes of exposure.

AK and ADA polymorphisms in South Sardinia.

A sample of the South Sardinia population was studied with respect to adenylate kinase (AK) and adenosine deaminase (ADA) enzymes. The gene frequencies were: AK1 0.975 and ADA1 = 0.933. The results were compared with those of other Italian populations.

Occupational type test for the etiological diagnosis of asthma due to toluene di-isocyanate.

An occupational type exposure-test to toluene di-isocyanate (TDI) for the diagnosis of specific respiratory sensitization is proposed. The subjects were tested by exposure to a two-pot polyurethane varnish with and without TDI activator, using a paint-spraying system under standard and controlled conditions, so as not to exceed the threshold limit value of TDI. Forced expiratory volume per second and specific airway resistance (plethysmographic method) were measured before each exposure and during the following 24 h. 47 subjects with clinical symptoms of asthma were examined during their hospital care. For the purpose of this study they were divided into two groups: 42 workers exposed to TDI and 5 not exposed. The preliminary control test, using polyurethane varnish without TDI activator, was always negative and no significant changes in ventilatory parameters were recorded. The spray-painting test, with the same varnish and TDI activator, gave positive responses in 35 out of the 42 exposed workers and negative findings in the group not exposed. This method permits to formulate an accurate diagnosis of TDI respiratory sensitization in the majority of cases (83%). Immediate asthmatic reactions were frequently observed in the exposed subjects with high acetylcholine reactivity. Ten subjects showed a late bronchial reaction (3 h or more after TDI exposure).

Pathology produced by isocyanates: methods of immunological investigation.

A group of 182 workers exposed to diisocyanates (varnishers, carpenters, producers of polyurethane resins and expanded plastic) were examined to study the immunogenic capacity of these substances. The skin tests, particularly the intradermal tests, revealed reactions of the immediate, accelerated and/or delayed types due to the presence of IgE and IgG, in addition to responses of the cellular type. This was confirmed by passive transfer in guinea-pigs and man and immunohaematological tests such as passive haemagglutination and lymphocyte transformation. In 4 cases it was possible to demonstrate thermoresistant, homocytotropic immunoglobulins, that were not dependent on complement and behaved like reagins (i.e. short-term anaphylactic IgG). Exposure tests were performed on 45 cases; the results are analyzed and compared with those of the skin tests. It is concluded that both these groups of tests are of value in investigating the aetiopathogenesis of the pathology of the isocyanates: the skin tests for initial screening, and then the exposure tests for resolving doubtful diagnoses. Cross-reactions were also demonstrated between toluene-diisocyanate and methylene-diisocyanate. Two phases could be considered in the pathogenesis; in the first phase, signs of inflammation appeared at the primary sites of contact with the irritant, then the ability of the diisocyanates to form a conjugate with organic proteins results in the production of a complete antigen and consequent sensitization of the exposed person. The appearance of symptoms naturally depends on subsequent exposure and the immunogenic capacity of the patient: the response is mainly of the reagin type in atopic patients and of type 3 in non-atopic patients.