Heritability estimate of erythrocyte Na-K-Cl cotransport in normotensive and hypertensive families

Na-K-Cl cotransport was measured in 209 essential hypertensive patients (EH) and in 114 normotensive controls (NT). The distribution of Na-K-Cl cotransport was bimodal in EH and unimodal in NT. The EH with higher Na-K-Cl cotransport values had increased passive permeability to Na in fresh erythrocytes and increased Li-Na countertransport compared to NT. Li-Na countertransport was significantly increased in the EH as a whole, but the increase was accounted for by some EH individuals with elevated Na-K-Cl cotransport values. A simple biometric analysis of the Na-K-Cl cotransport was performed for 287 individuals of 86 families with different prevalence of hypertension (neither parent hypertensive, 39 families; one, 31 families; or both, 16 families). Na-K-Cl cotransport was not correlated between spouses, but was correlated highly significantly between the average value of the two parents (mid-parent) and offspring. The polygenic additive heritability (h2) was about 50% for all families considered together. It increased slightly for the hypertensive families analyzed alone (no significant correlation was found, and hence genetic heritability, in the normotensive families). Finally, after applying arbitrary cut-off points to the Na-K-Cl cotransport values, segregation analysis showed that some major gene, recessive for the high allele, also contributes to the phenotypic value of Na-K-Cl cotransport.

Uralic genes in Europe

We have analysed data of three European populations speaking non-Indoeuropean languages: Hungarians, Lapps, and Finns. Principal coordinate analysis shows that Lapps are almost exactly intermediate between people located geographically near the Ural mountains and speaking Uralic languages, and central and northern Europeans. Hungarians and Finns are definitely closer to Europeans. An analysis of genetic admixture between Uralic and European ancestors shows that Lapps are slightly more than 50% European, Hungarians are 87% European, and Finns are 90% European. There is basic agreement between these conclusions and historical data on Hungary. Less is known about Finns and very little about Lapps.

Regional distribution of cystic fibrosis linked DNA haplotypes in Italy, a collaborative study

In view of the reported variations of cystic fibrosis (CF) associated haplotypes among populations, a detailed analysis of the distribution of two tightly linked DNA markers (Xv-2c and KM.19) in 18 Italian regions was performed. Haplotypes were determined for 405 CF chromosomes carrying the mutation, and showed significant heterogeneity between the North, Center, and South of Italy and the island of Sardinia. KM.19/PstI Restriction Fragment Length Polymorphism (RFLP) showed significant heterogeneity in these four areas, and was statistically correlated with the geographic distribution of the disease, while Xv-2c/TaqI polymorphism, like the haplotypes of normal chromosomes, was more uniformly distributed over the same four areas. Correlation coefficients between the markers and the mutation have been used to obtain additional indications on the physical distance between the markers and the fibrosis locus.

[Effects of chronic administration of nifedipine on echo-Doppler parameters of left ventricular filling in hypertensive patients]

This study aimed determining the chronic effects of nifedipine (N) on left ventricular filling in 25 patients (mean age 55) with mild to moderate arterial hypertension. M-mode, B-mode and pulsed Doppler measurements were performed at baseline, after 30 min from administration of sublingual N (10 mg) and after 6 months of therapy with slow release N (max dose: 60 mg die). Acute and chronic N reduced significantly both systolic (p less than 0.001) and diastolic pressure (p less than 0.001). At the end of the treatment with slow release N, and septal wall thicknesses had a slight but significant decrease (p less than 0.01). Diastolic and systolic dimension were not modified. Left ventricular mass index decreased significantly from 141 +/- 34 to 130 +/- 31 g/m2 (p less than 0.05). The Doppler-derived diastolic filling indexes (peak E, ratio peak E/A,E deceleration) were abnormal at baseline, and had a significant increase after sublingual and chronic therapy. Changes in left ventricular mass index and diastolic filling indexes were not correlated. A significant correlation was found between peak E changes after acute and chronic N administration (r = 0.732 and p less than 0.001). The results of this study demonstrate that both acute and chronic administration of N modify transmitral flow velocity pattern, suggesting that, in hypertensive patients, left ventricular filling abnormalities are partly dynamic and reversible. Our findings also demonstrate that acute N effects may predict the chronic results.

The distribution of HLA antigens in Italy

Human histocompatibility (HLA) gene frequencies were studied in the Italian population. A random sample of healthy individuals born in several Italian regions and provinces was studied to estimate HLA-A, -B, -C and -DR gene frequencies using the maximum likelihood method. The goodness of fit to Hardy-Weinberg proportions was evaluated by the likelihood ratio statistics. Different Italian regions and provinces show significant differences in the HLA alleles, providing further evidence for the genetic heterogeneity in the Italian population. This heterogeneity is also displayed by a synthetic geographical representation which uses colour to map the most informative gene differences. Statistically significant gametic associations between HLA-A, -B, -C and -DR loci are reported. The difference between northern and southern Italy and between continental Italy and Sardegna is clearly shown also by their heterogeneous linkage disequilibria.

The distribution of some polymorphisms in Italy

A wide data collection on blood group gene frequencies in Italian regions and provinces is presented. This report is the result of a joint collaboration of human geneticists and forensic haematologists started in 1979 and updates a previous work by the same group. The following genetic polymorphisms have been examined: red-cell antigens (ABO, FY, Kell, Kidd, Lewis, Lutheran, MNSs, P, Rhesus), red-cell enzymes (ACP1, ADA, AK1, ESD, GLO1, GPT, PGD, PGM1), plasma proteins (BF, C3, GC, HP, IGK, PI, TF). Data have been classified according to genetic systems, Italian regions and provinces. Gene frequencies were estimated by the maximum likelihood method. The goodness of fit to Hardy-Weinberg proportions has been evaluated by the likelihood ratio statistics. Genetic heterogeneity of provinces and regions is reported.

Cytotoxic effectors in human peripheral blood mononuclear cells induced by a mannoprotein complex of Candida albicans: a comparison with interleukin 2-activated killer cells

In this study, the major histocompatibility complex-unrestricted cytotoxic effectors elicited in human peripheral blood mononuclear cells (PBMC) by a mannoprotein (MP) component from the cell wall of the human indigenous microorganism Candida albicans have been compared with those obtained by stimulation with interleukin 2. (Interleukin 2-activated killer cells: LAK). It has been found that MP-induced lytic effectors were substantially similar to LAK in potency, target specificity, and type of precursor/effector cells. In both cases, natural killer (NK)-susceptible and NK-resistant targets as well as fresh tumor (glioma) cells were efficiently killed by a population of effectors showing a predominant CD3-, CD16+ phenotype. However, the precursors of MP-induced killers were highly sensitive to the lysosomotropic toxic drug L-leucine methyl ester (Leu-OME) whereas the generation of LAK cells was unaffected by this drug. The Leu-OME sensitivity of MP-induced cytotoxicity generation was not due to a nonspecific effect on antigen-presenting cells or inhibition of cell proliferation. In addition, the generation of MP-induced killer cells was totally abrogated by treatment with CD16 antibodies and complement, whereas a minor but significant fraction of LAK precursors was not susceptible to the above treatment. These results indicate that a defined component(s) of the cell wall of C. albicans has some properties of biological response modifiers in cultures of human PBMC in vitro.

B cells from chronic lymphocytic leukemia (CLL) patients are strong inducers of proliferation and major histocompatibility complex (MHC)-unrestricted [natural killer (NK)-like] cytotoxicity in normal T-lymphocytes

We studied the ability of chronic lymphocytic leukemia (CLL) B cells to stimulate proliferation and major histocompatibility complex (MHC)-unrestricted [natural killer (NK)-like] cytotoxicity in a mixed lymphocyte tumor-cell culture (MLTC). CLL-derived B cells induced a significantly higher proliferative response than did B cells from healthy normal donors. Comparable levels of interferon and interleukin-2 production were detected in the mixed lymphocyte cultures (MLC) set up with normal B cells from healthy donors and in MLTC. Higher levels of NK-like cytotoxic activity were induced after stimulation with CLL than with normal B cells in nonlytic precursors. Inhibition experiments with specific monoclonal antibodies indicate that the NK-like response in MLTC is attributable to HLA class II antigens, which are expressed at comparable levels on CLL and normal B cells. Percoll gradient centrifugation of the MLC and MLTC recovered cells demonstrated that the NK-like effectors in both types of cultures were blast-transformed, highly mitotic cells.

[Effects of digitalis on the left ventricular filling phase in the normal and ischemic heart. Angiographic study in man]

The effects of digitalis on the left ventricular diastolic phase are very scant. In order to gain a better insight into this problem, we measured the hemodynamic effects of an intravenous injection of K-strophantidin (0.005 mg/kg in a bolus given within 5-10 min) during the diastolic phase in 9 normal male subjects and in 9 male patients with coronary artery disease (CAD), maintaining a normal overall ejection fraction despite of the presence of some hypokinetic segments. Administration of K-strophantidin decreased significantly in normal controls the left ventricular volumes at 1/3, 1/2, 2/3 of the diastolic phase, whereas it did not produce significant change in CAD patients. Digitalis decreased the first and increased the second filling peak of the volumetric variable dV/dt in the normal controls, but not in the CAD patients. In the latter group the 2 peaks before digitalis administration were similar. The effects of digitalis on the dV/dt measured during the second filling peak were significantly different in the 2 groups. The increments of pressure in middle and end diastole in CAD patients were significantly greater than those observed in normal controls. Results of the present study suggest that digitalis has a negative influence on the left ventricular filling phase both in normal and CAD subjects. In fact digitalis modifies in normals the pattern of the left ventricular filling phase whereas it induces an untoward increase in the middle and end diastolic pressure in CAD patients.

[Modification of left ventricular filling after acute administration of nifedipine in hypertensive patients. Doppler echocardiographic study]

This study was undertaken to determine the acute effects of nifedipine on left ventricular filling, examined by Doppler echocardiography in patients with arterial hypertension and normal left ventricular systolic function. Twenty-seven patients with mild to moderate systemic hypertension, and 18 normotensive subjects were studied. Pulsed Doppler, M-mode and B-mode measurements were performed before and 30 min after sublingual nifedipine administration (10 mg). Peak E, peak A, area A, area E, ratio area A/area E, E deceleration and E acceleration time were measured. Before administering nifedipine, some of these diastolic filling parameters were significantly different in the hypertensive patients as compared with normal subjects. After nifedipine, in patients with arterial hypertension, peak E and area E increased significantly (p less than 0.01), while ratio peak A/E and ratio area A/area E showed a significant decrease (p less than 0.001). No significant changes were observed in normal subjects. The result of this study demonstrates that the acute administration of nifedipine modifies transmitral flow velocity pattern in hypertensive patients, suggesting that the left ventricular filling abnormalities are in part dynamic and reversible.

Changes of immunological patterns of human cancer cells treated in vitro with a triazene compound

Previous experimental evidence indicates that immunogenicity of mouse tumor cells can be increased by treatment with dacarbazine and other triazene compounds. The present studies have been conducted on the human cell lines H125 (lung cancer), 1246 (melanoma), X3 (EBV-immortalized B cells) subjected to in vitro treatment with 4 (3-methyl-1-triazeno) benzoic acid potassium salt (MTBA). Untreated or drug-treated sublines were tested for susceptibility to allogeneic NK effector cells, either non-stimulated or pretreated with beta-Interferon. In the case of X3 cell line and its MTBA-treated subline the expression of the EBV-associated antigens and the capability of eliciting autologous cytotoxic T lymphocytes (CTL) were also investigated. The results suggest that a modification of membrane antigenic pattern could be induced by MTBA treatment in terms of changes of cell susceptibility to cell-mediated lysis, expression of EBV-related antigens and capability to elicit autologous CTL.

HLA antigens and neuroleptic response in clinical subtypes of schizophrenia

The frequency of HLA antigens of A and B loci was examined in a carefully selected sample of 91 schizophrenic patients from central Italy. This population showed no increase in antigens compared with the control group. However, in agreement with previous studies, a slight increase in A1 was observed in the hebephrenic subgroup and, in a lesser extent, an increase of A2 was found in the paranoid subgroup. Although these increases are more prominent when the subgroups are compared and tend to support the case for genetic heterogeneity, they fail to reach statistical significance. Response to neuroleptic treatment was studied in an attempt to further subdivide the clinical subgroups. A1-negative and A2-positive paranoid patients demonstrated a statistical better response to neuroleptics. The findings suggest that schizophrenia should be considered a heterogenous disease and that response to neuroleptics can be employed as an instrument of biological subclassification.

Mitochondrial DNA polymorphism in four Sardinian villages

Polymorphism of mitochondrial DNA has been studied in two highland (Desulo, Tonara) and in two lowland (Galtellì, Orosei) Sardinian isolates, formerly subjected to different selective pressure due to malaria, and in 103 individuals from Northern Italy (Bergamo area), where malaria never appeared to be endemic. Two mitochondrial restriction endonuclease patterns (morphs) never described before have been found, one in the Bergamo and Orosei samples, and the other one only in Orosei. Four new mitochondrial types (mitotypes) due to different combinations of morphs have been identified; two of them have been found only in Sardinia, but with such a low frequency that they cannot be defined as typical Sardinian mitotypes. One mitotype (BamHI-morph 3, MspI-morph 4, AvaII-morph 9 and HaeII-morph 1) showed a significantly higher frequency in the highland rather than in the lowland Sardinian villages or in the Bergamo area. Since this mitotype has been found at a relatively high frequency in Central and Southern Italy, while it has been reported to be rare in Caucasians of Central European origin and absent in other ethnic groups (Africans, Chinese, Japanese and Israeli Jews), we suggest it may represent an ancient Mediterranean type. The analysis of these data suggests that drift or other evolutive forces different from malaria might be the major cause of mitochondrial DNA variation in Sardinia.

Reconstruction of human evolution: bringing together genetic, archaeological, and linguistic data

The genetic information for this work came from a very large collection of gene frequencies for "classical" (non-DNA) polymorphisms of the world aborigines. The data were grouped in 42 populations studied for 120 alleles. The reconstruction of human evolutionary history thus generated was checked with statistical techniques such as "boot-strapping". It changes some earlier conclusions and is in agreement with more recent ones, including published and unpublished DNA-marker results. The first split in the phylogenetic tree separates Africans from non-Africans, and the second separates two major clusters, one corresponding to Caucasoids, East Asians, Arctic populations, and American natives, and the other to Southeast Asians (mainland and insular), Pacific islanders, and New Guineans and Australians. Average genetic distances between the most important clusters are proportional to archaeological separation times. Linguistic families correspond to groups of populations with very few, easily understood overlaps, and their origin can be given a time frame. Linguistic superfamilies show remarkable correspondence with the two major clusters, indicating considerable parallelism between genetic and linguistic evolution. The latest step in language development may have been an important factor determining the rapid expansion that followed the appearance of modern humans and the demise of Neanderthals.

A genetic history of Italy

Statistical techniques for displaying the geographical distribution of many genes in few synthetic images have been used to represent the various patterns of gene frequencies in Europe and in the world (Menozzi et al. 1978; Piazza et al. 1981 a). It has also been shown that such synthetic displays are particularly useful in detecting clines of genetic differentiation associated with movements of populations like those accompanying the Neolithic expansion of farmers from the Near East or, in more recent times, the putative diffusion of Indo-European-speaking populations (Ammerman & Cavalli-Sforza, 1984; Gimbutas, 1973). In this paper we use the same combination of statistical and graphical techniques to study the genetic structure of Italy, a European country whose unity of people and cultures was quite a recent event. The possibility of studying genetic differentiation in a small geographical area is tested and trends of genetic differences are tentatively interpreted in terms of historic and linguistic knowledge. The few demographic pieces of information taken from historical sources and compared with linguistic records support the hypothesis that the genetic structure of Italy still reflects the ethnic stratification of pre-Roman times.