Subduction and collision processes in the Central Andes constrained by converted seismic phases.

The Central Andes are the Earth's highest mountain belt formed by ocean-continent collision. Most of this uplift is thought to have occurred in the past 20 Myr, owing mainly to thickening of the continental crust, dominated by tectonic shortening. Here we use P-to-S (compressional-to-shear) converted teleseismic waves observed on several temporary networks in the Central Andes to image the deep structure associated with these tectonic processes. We find that the Moho (the Mohorovicic discontinuity--generally thought to separate crust from mantle) ranges from a depth of 75 km under the Altiplano plateau to 50 km beneath the 4-km-high Puna plateau. This relatively thin crust below such a high-elevation region indicates that thinning of the lithospheric mantle may have contributed to the uplift of the Puna plateau. We have also imaged the subducted crust of the Nazca oceanic plate down to 120 km depth, where it becomes invisible to converted teleseismic waves, probably owing to completion of the gabbro-eclogite transformation; this is direct evidence for the presence of kinetically delayed metamorphic reactions in subducting plates. Most of the intermediate-depth seismicity in the subducting plate stops at 120 km depth as well, suggesting a relation with this transformation. We see an intracrustal low-velocity zone, 10-20 km thick, below the entire Altiplano and Puna plateaux, which we interpret as a zone of continuing metamorphism and partial melting that decouples upper-crustal imbrication from lower-crustal thickening.

B lymphocyte antigen D8/17 and repetitive behaviors in autism.

OBJECTIVE: Monoclonal antibody D8/17 identifies a B lymphocyte antigen with expanded expression in rheumatic fever, Sydenham's chorea, and subgroups of obsessive-compulsive disorder and Tourette's syndrome with repetitive behaviors. The authors examined the rate of D8/17 expression in children with autism and its correlation with severity of repetitive behaviors. METHOD: Blood samples from 18 patients with autism and 14 comparable medically ill children were evaluated for percentage of D8/17-positive B cells by immunofluorescence and for streptococcal antibodies. Severity of repetitive behaviors was also determined. RESULTS: The frequency of individuals with > or =11% D8/17-positive cells was significantly higher in the autistic patients (78%) than the comparison subjects (21%), severity of repetitive behaviors significantly correlated with D8/17 expression, and D8/17-positive patients had significantly higher compulsion scores than D8/17-negative patients. CONCLUSIONS: D8/17 expression is high in patients with autism and may serve as a marker for compulsion severity within autism.

Autoantigen-specific T cell proliferation induced by the ribosomal P2 protein in patients with systemic lupus erythematosus.

A role for helper T cells in the induction of pathogenic lupus autoantibodies is increasingly supported by data from studies of murine lupus and patients with systemic lupus erythematosus (SLE). However, the poor in vitro function of SLE T cells has hampered the identification and characterization of autoantigen-specific T cells. We used recombinant fusion proteins to study the T cell proliferative response of 31 lupus patients and 27 healthy subjects to a well-characterized SLE autoantigen, the ribosomal P2 protein. Although PBMC from SLE patients showed marked impairment in the proliferative response to the common recall antigen tetanus toxoid when compared with normal subjects, a significantly greater proportion of SLE patients (32%) than normal individuals (0%) showed a T cell response to a recombinant P2 fusion protein. When the SLE patients were subgrouped according to the presence of serum anti-P autoantibody, 7 of 10 anti-P antibody-positive patients, but 0 of 20 anti-P antibody-negative SLE patients, demonstrated > 2,000 cpm [3H]thymidine incorporation and a P2 stimulation index > 5. The specificity of the T cell proliferative response for the P2 protein was confirmed by studies using a second recombinant human P2 fusion protein and by the specific activation of P2-primed T cells by recombinant P2 in secondary cultures. Moreover, the T cell proliferative response to the P2 autoantigen was mediated by CD4-positive T cells and was inhibited by anti-MHC class II antibodies. These data demonstrate the presence of autoantigen-specific T helper cells in patients with SLE and suggest that these T cells drive the production of autoantibodies by B lymphocytes.

[Ossification after transplantation of model cartilage in the rat patella]. / Recherches sur l'ossification après transplantation d'ébauches cartilagineuses de rotule chez le rat.

The cartilage model of the rat's patella constitutes a formation susceptible of inducing ossification, following its transplantation in a variety of sites (muscle, thyroïd, testis, ovary, anterior chamber of the eye, etc.), including those considered inappropriate in other experiments of induced ossification (liver, kidney). So we have an experimental model allowing the influence on the osteogenesis of various factors, local or general, natural or experimental, to be studied. Ossification occurs in this model only in cases of histocompatibility between donor and recipient. It is constant after autotransplantation or isotransplantation. It is never seen after heterotransplantation. In cases of homotransplantation its frequency varies: this is not influenced by the technical conditions of implantation but by tissue compatibility and the age of the animals giving and receiving. A private perichondrium cartilage retains its osteogenic potency. A cartilage killed by alcohol or cold no longer demonstrates its osteoformative capacities, even when put into contact with a living cartilage. Our findings are difficult to reconcile with the hypotheses invoking the osteogenic potency of the periosteum, or the intervention of substances either inducing osteoformation or inhibiting vascular invasion, for the explanation of endochondral ossification. However, they lead one to the opinion that chondrocytes play an active role in its release.

Performance and sensitivity of modern home pregnancy tests.

We have studied the performance of three currently available home pregnancy tests. The Advance is a test based on monoclonal antibodies in an enzyme immunoassay format that specifically detects hCG in urine. The positive results are determined by the presence of a blue color in a color stick (30 minutes). The Daisy 2 and FACT are tests based on monoclonal antibodies that specifically detect hCG in urine in a hemagglutination inhibition assay; positive results are demonstrated by the deposition of a dot ring at the bottom of the test tube (45 minutes). Thirty-five patients who eventually became pregnant in that cycle collected the first morning urine specimens from day of ovulation (determined by ultrasound) in artificial insemination donor (AID) cycles, or from the date of gamete intrafallopian transfer (GIFT) for 16 consecutive days. In each specimen, the Advance, Daisy 2, and FACT tests were performed; in addition, beta-hCG levels were determined by radioimmunoassay. All the home pregnancy tests studied can detect pregnancy as early as 9 or 10 days post-conception, and they give positive results at the time of the expected onset of menses in 70%, 95%, and 88% of cases for Daisy 2, Advance, and FACT, respectively. The sensitivity of the these home pregnancy tests was determined to be about 200 mIU/mL of urine after correlating their positive or negative results with the concentrations of urinary beta-hCG determined by radioimmunoassay.

[Experimental studies on the factors of osteogenesis by transplantation of patellar cartilage framework in rats]. / Recherches expérimentales sur les facteurs de l'ostéogenèse par transplantation d'ébauches cartilagineuses de rotule chez le rat.

The cartilage framework of the patella in rats is capable of inducing ossification after homotransplantation in many various sites: muscle, thyroid, testicle, ovary, kidney, anterior chamber of the eye, etc. The frequency of ossification does not depend on the technical conditions of the transplant, but on the age of the donors and receivers; it approximates 84 p. cent when the two rats are three weeks old. It is close to 100 p. cent in case of autotransplant. It is non-existent in case of heterotransplantation. A cartilage that is killed by alcohol or cold, has no longer osteogenetic abilities, even if it is placed in contact with live cartilage. The transplant of patellar cartilaginous framework represents a model which may be used to study the factors responsible for physiological ossification as well as the effect of various experimental conditions on osteogenesis.

[Urinary calcium and phosphate during fasting. Effect of various hormonal factors (author's transl)]. / Calciurie et phosphaturie au cours du jeûne. Action des divers facteurs hormonaux.

Obese patients who fasted during seven days were divided into four groups according to whether they received triiodothyronine (100 to 150 microgram per day), calcitonin (1 MRC unit per day), both T3 and calcitonin, or neither of these two hormones. Urinary calcium and phosphate were increased in patients receiving T3 or calcitonin. T3 given with calcitonin did not increase the calcitonin-induced calciuria but did increase the phosphaturia. The authors suggest a possible explanation for these findings. No changes in serum parathormone were recorded during fasting acidosis.

[Mechanism of fasting hyperuricemia]. / Recherche sur le mécanisme de l'hyperuricémie du jeûne.

The authors followed up 73 obese patients submitted to fasting for 7 days; 46 of them took nos drugs (control subjects); the others took daily 100 to 200 mg of benzbromarone. The average serum uric acid of the controls rose from 49.37 mg to 90.52 mg per litre. Their uric acid clearance during the week of fasting fell to 4.67 ml per minute. The uric acid turnover was multiplied by two and the mixable pool by 3.5. These results that the hyperuricemia of fasting is due both to a fall in uric acid clearance and increased catabolism of cellular nucleic acid.

[Action exerted by atropine sulfate on the luteinization phenomenon induced by a total gonadotropic preparation of prehypophysis at several stages of the estrus cycle in the rat]. / Action exercée par le sulfate d'atropine sur les phénomènes de lutéinisation suscités par une préparation gonadotrope totale de préhypophyse à divers stades cu cycle oestral chez la ratte.

PIP: These experiments explored the effect of 70 mg atropine sulfate, and several doses of Gonadormone Byla, given at 1700 on diestrous I or at 1700 on diestrous II in the strains WI and WII rats derived in the authors' laboratory from Wistar rats. In Experiment 1 300 rats, 30 per group, received 2.5 or 5.0 mouse units of Gonadormone per 100 gm body weight at 1700 of diestrous I, with or without atropine, and were killed for serial ovarian sections at 1100 of proestrus. The 2.5 unit experime nt generated significant differences in frequency of luteinization between season of the year (p less than .001), between atropine and no atropine treatment (p less than .001), and season of atropine administration (p less than .05). Atropine decreased frequency of luteinization defined as proportion of a group having luteinized with or without retained ova. There were no differences in mean coefficients of ovulation, i.e., mean proportion of ovulated corpora lutea in each rat among all luteinized follicles, between rat strains or atropine treatments. The 5 unit dose of gonadotropin per 100 gm body weight increased luteinization 100% over the 2.5 unit dose. In the 2nd series of 180 rats, the frequency of luteinization induced by 1.25 units of gonadotropin was decreased by atropine (p less than .01), but the frequency of ovulation and response in the 2 rat strains did not differ. The results were interpreted as due in part to endogenous gonadotropin release, although atropine was thought to act directly on the ovary.^ieng

[Effect of atropine sulfate on the phenomena of follicular growth induced by a total anterior pituitary gonadotropic preparation during the estrus cycle in the rat]. / Action exercée par le sulfate d'atropine sur les phénomènes de croissance folliculaire suscités par une préparation gonadotrope totale de préhypophyse au cours du cycle oestral chez la ratte.

PIP: The question whether atropine inhibits follicular growth in rats induced by Gonadormone Byla was tested. 52 rats of strain WI, and 48 WII rats about 20 gm heavier, were injected at 1700 in diestrous I with 2.5 mouse units of gonadotropin per 100 gm body weight and 28 of each group also with 70 mg atropine sulfate sc, then serial ovarian sections were prepared at 1700 of proestrus. Atropine reduced the mean number of follicles 400 mcm in diameter or above (p less than .02), but did not affect their size distribution. A 2nd series of 48 rats were injected at 1700 of diestrous II with 1.5 units of gonadotropin per 100 gm body weight and half the rats with atropine. Again, atropine reduced the number of developing follicles (p less than .05) without affecting their mean diameter or size distribution.^ieng