Impacts of extreme summers on European ecosystems: a comparative analysis of 2003, 2010 and 2018.

In Europe, three widespread extreme summer drought and heat (DH) events have occurred in 2003, 2010 and 2018. These events were comparable in magnitude but varied in their geographical distribution and biomes affected. In this study, we perform a comparative analysis of the impact of the DH events on ecosystem CO2 fluxes over Europe based on an ensemble of 11 dynamic global vegetation models (DGVMs), and the observation-based FLUXCOM product. We find that all DH events were associated with decreases in net ecosystem productivity (NEP), but the gross summer flux anomalies differ between DGVMs and FLUXCOM. At the annual scale, FLUXCOM and DGVMs indicate close to neutral or above-average land CO2 uptake in DH2003 and DH2018, due to increased productivity in spring and reduced respiration in autumn and winter compensating for less photosynthetic uptake in summer. Most DGVMs estimate lower gross primary production (GPP) sensitivity to soil moisture during extreme summers than FLUXCOM. Finally, we show that the different impacts of the DH events at continental-scale GPP are in part related to differences in vegetation composition of the regions affected and to regional compensating or offsetting effects from climate anomalies beyond the DH centres. This article is part of the theme issue 'Impacts of the 2018 severe drought and heatwave in Europe: from site to continental scale'.

Prolonged biphasic response of plasma testosterone to single intramuscular injections of human chorionic gonadotropin.

The response of plasma testosterone to varying doses of hCG (0--6000 IU) given as a single im injection has been evaluated in normal men. After an initial rise at 2 h, the levels of testosterone demonstrated a secondary rise, reaching a peak 48 h after the im injection. The magnitude of the response varied directly with the dose of hCG used, and at the highest dose (6000 IU) testosterone levels were still elevated 6 days after administration. Plasma estradiol levels showed a dose-dependent rise, with peak levels being attained 24 h after hCG. The prolonged response of plasma testosterone to a single injection of hCG should prompt a reevaluation of diagnostic and therapeutic regimens using this agent.

Lipids and testicular function.

We studied 19 male patients with primary hyperlipoproteinaemia, a control group of 28 healthy men and 44 infertile males before any treatment was undertaken. Spermiogram, seminal biochemical studies, measurements of plasma hormone levels and lipid determinations were carried out. Most hyperlipoproteinaemic patients showed abnormalities in the spermiograms and the mean values were lower than in the controls except for semen volume. Seminal biochemical determinations were normal in the majority and the hormone profile showed some abnormal values, mainly for E2. Lipid abnormalities were more common in azoospermic infertile men and mean lipid levels were higher. Correlation studies suggest that high levels of C and/or Tg are associated with poor semen quality and higher FSH levels. The results of our studies suggest that high lipid levels exert adverse direct effects at the testicular level.

Semen biochemistry studies in men with macro-orchidism.

Biochemical analysis of semen was performed in six men with bilateral macro-orchidism. It has been shown that marker levels of the seminal vesicle secretion (fructose) are higher, whereas marker levels of prostatic secretion (citric acid and calcium) are lower, in these men than in those of a control group of normal men. Whether the pathogenesis of these findings was due to a benign enlargement of the accessory sex glands or not remains to be elucidated.

Familial bilateral vas deferens agenesis.

Two brothers with bilateral vas deferens agenesis are described, one of them with a chromosome mosaicism (46,XX/47,XXY). To our knowledge, there are not any previous reports of both conditions existing simultaneously. The patients consulted us because of infertility; they have normal sexual function, normal physical examination, but typical semen analyses with azoospermia, low semen volume, low pH, and negative fructose test. It appears to us that bilateral vas deferens agenesis may be genetic in origin in some patients.

Effects of amitriptyline on semen of infertile men.

A clinical evaluation of the effects of the antidepressive drug amitriptyline on the semen of 20 infertile men with oligoasthenozoospermia was carried out. Quantitative assessment of semen in the whole group showed significantly higher sperm counts, an increased proportion with normal sperm morphology and an increased semen volume after treatment, with a high positive correlation between sperm count before and after treatment. Individual qualitative evaluation showed an increased sperm count in 50% and increased motility in 35% of patients. It would seem that amitriptyline has a beneficial effect on semen in some of these patients.

Sterility caused by functional absence of ejaculatory ducts.

Five patients with functional absence of genital excretory ducts are presented, with emphasis on the scarcity of physical and complementary data obtained. The low impairment of spermatogenesis is pointed out. Seminal characteristics are analysed and the diagnostic importance of spermogram data stressed. The importance of the qualitative determination of fructose for the diagnosis of this syndrome is noted, as well as the incidence of this syndrome as the cause of azoospermia and sterility. The existence of a unilateral congenital absence of ejaculatory ducts is demonstrated. Cases of this sort cannot be detected unless a contralateral acquired lesion occurs.

Testicular response to human chorionic gonadotrophin in men with non-tumoural hyperprolactinaemia.

The change in plasma levels of testosterone and oestradiol-17-beta following a single intramuscular injection of 6000 IU hCG was studied in 7 men with non-tumoural hyperprolactinaemia and who were without clinical and/or laboratory evidence of hypogonadotrophism. These values were compared to the response of normal males to hCG. Plasma samples were obtained at 0, 2, 4, 24, 48, 96, 144, 192 and 240 h after hCG injection. The early and late phases of the plasma testosterone to hCG in hyperprolactinaemic patients were comparable to those of the controls, although the maximum and relative increment was somewhat diminished (5.0 +/- 1.2 vs 7.2 +/- 2.1 ng/ml; P less than 0.05, and 1.8 +/- 0.2 vs 2.3 +/- 0.5 ng/ml; P less than 0.02, respectively). The plasma oestradiol response to hCG was not different between the two groups, but the maximum and relative incement was higher in the hyperprolactinaemic patients (135.9 +/- 20.6 vs 97.1 +/- 11.9 pg/ml; P less than 0.05, and 4.9 +/- 0.6 vs 3.1 +/- 0.5 pg/ml; P less than 0.01, respectively. These findings suggest that the testosterone response to exogenous gonadotrophin is impaired in patients with non-tumoural hyperprolactinaemia. Whether this impairment is related to the higher increment in plasma levels of oestradiol remains to be elucidated. The data presented favour the hypothesis that in hyperprolactinaemic men, the prolactin exerts a direct action at the testicular level.

Semen analyses in adolescent diabetic patients.

We studied the semen quality and plasma testosterone levels (T) in 32 adolescent patients with insulin-dependent diabetes mellitus and in an aged-matched control group. Semen volume, motility and morphology were significantly lower in diabetics whereas seminal fructose and glucose were significantly higher. Even though the sperm count was lower in these adolescent diabetics, the difference was not significant when compared to the control group. No difference was observed in plasma testosterone levels. Patients were divided into two groups according to the presence of retinopathy and neuropathy, and degree of metabolic control. Spermiogram parameters, seminal fructose and glucose were lower in diabetics with neuropathy. No difference was observed in spermiogram parameters between diabetic patients with or without retinopathy, but seminal fructose, and glucose were lower in the former. All spermiogram parameters, as well as seminal fructose were lower in diabetics with poor metabolic control but seminal glucose was higher. No correlation was detected between clinical parameters (age at onset and duration of diabetes mellitus and time since first ejaculation), semen parameters, plasma T, glycemia and glycosuria. In conclusion, a deterioration of the quality of human semen occurs in adolescent diabetic patients. Neuropathy and poor metabolic control seem to be important factors of this deterioration. The presence of retinopathy does not correlate with T and semen quality.

Transferrin in seminal plasma of fertile and infertile men.

The levels of transferrin in seminal plasma of a large sample of infertile men (n = 287) were measured by radioimmunoassay. A group of recently pregnancy-proven fertile men (n = 20) was used as control and a small group (n = 6) of vasectomized men was studied to determine the origin of seminal transferrin. Infertile men had lower transferrin values than fertile men, although the difference was not significant in the case of normozoospermic infertile men (0,05 less than p less than 0,1); in the case of oligozoospermic infertile men the difference was highly significant (p less than 0,001). The values of transferrin in severely oligozoospermic, azoospermic and vasectomized subjects suggested that 60% of seminal transferrin could be of testicular origin. In infertile patients transferrin fall along with sperm count; there is a strong correlation between transferrin and sperm density. FSH levels were measured in a group of severely oligozoospermic and azoospermic patients (n = 41); although the patients with elevated FSH had lower transferrin levels than the patients with FSH within the normal range, the difference was not significant. The results of this study show that transferrin could be a useful marker of seminiferous tubular function but more work is needed to assess its relevance for clinical practice.

Semen analyses in men with asymptomatic genital gonorrhoea.

Thirty asymptomatic men with gonorrhoea were studied. No significant difference was seen in spermiogram (semen volume, sperm count, motility, velocity and normal morphology) and most of the seminal constituents studied (fructose, ascorbic acid, calcium, sodium, potassium, chlorides and magnesium) between this group of men and those of a normal control group. Citric acid levels were significantly lower in men with gonorrhoea (P less than 0.002). suggesting a non-acute prostatitis. No significant difference was observed in the studies before and after treatment.

Diabetes mellitus and vasopressin sensitive diabetes insipidus.

The rare association of diabetes mellitus and vasopressin sensitive diabetes insipidus found in 5 patients attending the Institute of Endocrinology and Metabolic Diseases in a ten-year period is reported. Suspicious signs and criteria for diagnosis were discussed and a brief review made on the pathogenesis and treatment of this association.

Una nueva prueba para el diagnostico de la diabetes insipida. / New test for the diagnosis of diabetes insipidus

Se utilizo la carbamazepina en una nueva prueba para el diagnostico de la diabetes insipida parcial o incompleta.La prueba se basa en la accion antidiuretica rapida y potente del medicamento cuando hay secrecion de ADH endogena. El estudio se realizo en nueve pacientes con diabetes insipida vasopresin sensible (dos de causa organica y el resto idiopaticos) y en tres con polidipsia psicogenica. Se hallo respuesta antidiuretica practicamente en todos los casos, lo que demuestra que el deficit parcial de ADH es mucho mas frecuente que el total, y que la carbamazepina puede disminuir la diuresis en la polidipsia psicogenica. Durante la prueba pueden presentarse sitnomas de sobrehidratacion, por el aumento de la accion hormonal mientras se mantiene una ingestion aumentada de liquidos, en especial en los pacientes con potomania y en los que presentan diabetes insipida de causa organica. Los resultados demuestran que la prueba propuesta permite el reconocimiento de la diabetes insipida parcial e incompleta, aun en medio con escasos recursos tecnicos y que su aplicacion facilitara el estudio del sindrome poliurico-polidipsico