Pathogenetic aspects of the L-arginine-NO metabolic pathway in arteriosclerosis and possible therapeutic aspects

A yearly pattern in the occurrence of uterine cervical cancer (UCC), obtained from cytological examinations reported as type V (cases concluding a malignant alteration), has been previously shown for data obtained in the Monterrey Metropolitan Area (state of Nuevo Leon, Mexico) for a span of 10 years (1978-1987), with a peak of relative incidence in the month of February being high stable for consecutive years. With the aim of extending and validating those results, we analyzed the monthly totals of positive detected cases of UCC in the states of Nuevo Leon, Chihuahua, Coahuila, and Tamaulipas (covering most of Northern Mexico) during the same period. To eliminate bias due to the seasonal variation in the number of screening smears, data were first expressed in relation to the number of cytological examinations done the same month. The least-squares fit of a 1-year cosine curve to the data of relative incidence in the four states reveals a statistically significant yearly pattern (p = .008), with a maximum of relative incidence in February almost double that during the rest of the year. Results indicate that the relative incidence of UCC is higher than the yearly average during the winter, with secondary peaks in May and October. In view of the nonsinusoidal waveform in the incidence of UCC, we undertook a multiple-component analysis, allowing several cosine functions to be simultaneously fitted to the data. Results indicate that the yearly pattern in the relative incidence of UCC can be represented by a model that includes two components with periods of 12 and 4 months (p = .004). The same model can be documented as statistically significant independently for each of the four states. These results, summarizing over 2200 positive cases of UCC detected in more than 1,100,000 screening smears, are in full agreement with those found previously for part of the state of Nuevo Leon and reveal a highly stable and predictable yearly pattern of variation in the relative incidence of UCC in Northern Mexico.     

Fatty diet and multiple sclerosis]

INTRODUCTION AND DEVELOPMENT: Multiple sclerosis (ME) is an inflammatory disease of the myelin of the central nervous system, the origin of which is still unknown. Genetic, infectious, immunological and environmental factors have all been blamed, but none of these factors on their own can explain the whole spectrum of this disease. Of the environmental factors, fat in the diet has given rise to most discussion. At the present time, it is known that polyunsaturated essential fatty acids form a part of biological membranes. A relationship has been found between the dietary fat consumed and the plasma levels and cell membrane content. CONCLUSIONS: The possible immuno-modulation function of these fatty acids justify rigorous evaluation of this hypothesis.     

Sources of GABAergic input to the inferior colliculus of the rat

We have studied the GABAergic projections to the inferior colliculus (IC) of the rat by combining the retrograde transport of horseradish peroxidase (HRP) and immunohistochemistry for gamma-amino butyric acid (GABA). Medium-sized (0.06-0.14 microliter) HRP injections were made in the ventral part of the central nucleus (CNIC), in the dorsal part of the CNIC, in the dorsal cortex (DCIC), and in the external cortex (ECIC) of the IC. Single HRP-labeled and double (HRP-GABA)-labeled neurons were systematically counted in all brainstem auditory nuclei. Our results revealed that the IC receives GABAergic afferent connections from ipsi- and contralateral brainstem auditory nuclei. Most of the contralateral GABAergic input originates in the IC and the dorsal nucleus of the lateral lemniscus (DNLL). The dorsal region of the IC (DCIC and dorsal part of the CNIC) receives connections mostly from its homonimous contralateral region, and the ventral region from the contralateral DNLL. The commissural GABAergic projections originate in a morphologically heterogeneous neuronal population that includes small to medium-sized round and fusiform neurons as well as large and giant neurons. Quantitatively, the ipsilateral ventral nucleus of the lateral lemniscus is the most important source of GABAergic input to the CNIC. In the superior olivary complex, a smaller number of neurons, which lie mainly in the periolivary nuclei, display double labeling. In the contralateral cochlear nuclei, only a few of the retrogradely labeled neurons were GABA immunoreactive. These findings give us more information about the role of GABA in the auditory system, indicating that inhibitory inputs from different ipsi- and contralateral, mono- and binaural auditory brainstem centers converge in the IC.     

Traumatic myocardial infarction caused by lead shot

The authors report the case of a 32 year old woman who was shot with a shotgun. Acute inferior wall infarction was detected fortuitously on electrocardiography and coronary angiography showed occlusion of the right coronary artery with lead shot. The single coronary lesion, absence, of other cardiac complications (haemopericardium, cardiac perforation, ...) and the favourable outcome with conservative medical treatment has not been previously reported to the authors' knowledge.     

Dyslipemia in a population with a high rate of cardiovascular mortality

The activity of N-acetyltransferase (NAT) and catalase was measured in the tissues of placenta, full venous blood and full umbilical cord blood in 141 complicated pregnancies. The control group consisted of 34 physiological pregnancies. The enzymes activity was marked by use of biochemical methods. It has been shown that NAT and catalase is the most active in the group of physiological pregnancies. The decrease of NAT and catalase in venous and umbilical cord blood is correlated with the decrease of the activity these enzymes in placenta.     

Three-week hepatitis B vaccination provides protective immunity

To determine whether a 3-week hepatitis B (HB) vaccination could achieve protective immunity, 89 healthy non-immunized young adults received three doses of 20 micrograms each of HBs antigen (GenHevac B, Pasteur) and were randomly assigned to schedule A (n = 44): two doses at day 0, one dose at day 21; or schedule B (n = 45): one dose at days 0, 10 and 21. Seroprotection rates (anti-HBs > or = 10 mIU ml-1) for groups A and B respectively were: 23 and 40% at day 21; and 77 and 91% at day 82 (not significant). Anti-HBs geometric mean titres were higher in group B than in group A (p < 0.05) at days 21 (6.4 versus 3.8) and 82 (77.6 versus 33.5). One year after primary vaccination, the seroprotection rate remained as high as 90% in the vaccinees of group B; after boosting all vaccinees had protective levels of anti-HBs antibodies. Thus 3-week HB vaccination with GenHevac B allowed early and durable protective immunity.     

Effect of guanine nucleotides and temperature on calcitonin gene-related peptide receptor binding sites in brain and peripheral tissues

Recent data have suggested the existence of at least two major classes of calcitonin gene-related peptide (CGRP) receptors in brain and peripheral tissues [Henke et al., Brain Res., 410 (1987) 404-408; Dennis et al., J. Pharmacol. Exp. Ther., 251 (1989) 718-725; ibid, 254 (1990) 123-128; Quirion et al., Ann. NY Acad. Sci., 657 (1992) 88-105]. However, little is currently known in the structure characteristics of CGRP receptors as cloning as yet to be reported. In the present study, the sensitivity of [125I]humanCGRP alpha binding to guanine nucleotides and temperature was investigated in guinea pig atria (prototypical CGRP1 tissue) guinea pig vas deferens (prototypical CGRP2 tissue) and in the rat brain and cerebellum (mixed assay). Binding isotherms of [125I]hCGRP alpha in those four tissue preparations were curvilinear and best fitted to a two-site model under most assay conditions. The high affinity binding component was highly temperature-sensitive and accounted, under experimental conditions, for up to 18% of the total population of receptors. Moreover, these high affinity sites were also highly sensitive to guanine nucleotides (Gpp(NH)p, 100 microM) in all preparations although to a different extend depending upon assay temperatures. Taken together, this suggests that the different CGRP receptor subtypes present in these tissue all belong to a G-protein coupled receptor family.     

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