A diagenetic control on the Early Triassic Smithian-Spathian carbon isotopic excursions recorded in the marine settings of the Thaynes Group (Utah, USA).

In the aftermath of the end-Permian mass extinction, Early Triassic sediments record some of the largest Phanerozoic carbon isotopic excursions. Among them, a global Smithian-negative carbonate carbon isotope excursion has been identified, followed by an abrupt increase across the Smithian-Spathian boundary (SSB; ~250.8 Myr ago). This chemostratigraphic evolution is associated with palaeontological evidence that indicate a major collapse of terrestrial and marine ecosystems during the Late Smithian. It is commonly assumed that Smithian and Spathian isotopic variations are intimately linked to major perturbations in the exogenic carbon reservoir. We present paired carbon isotopes measurements from the Thaynes Group (Utah, USA) to evaluate the extent to which the Early Triassic isotopic perturbations reflect changes in the exogenic carbon cycle. The δ(13) Ccarb variations obtained here reproduce the known Smithian δ(13) Ccarb -negative excursion. However, the δ(13) C signal of the bulk organic matter is invariant across the SSB and variations in the δ(34) S signal of sedimentary sulphides are interpreted here to reflect the intensity of sediment remobilization. We argue that Middle to Late Smithian δ(13) Ccarb signal in the shallow marine environments of the Thaynes Group does not reflect secular evolution of the exogenic carbon cycle but rather physicochemical conditions at the sediment-water interface leading to authigenic carbonate formation during early diagenetic processes.

Influence of neoadjuvant chemotherapy on serum tumor markers CA 15-3, MCA, CEA, TPS and TPA in breast cancer patients with operable disease.

Serum levels of CA 15-3, mucinous-like cancer antigen, carcinoembryonic antigen, tissue polypeptide antigen and tissue polypeptide-specific antigen (TPS) have been determined in 99 patients with T2-4 N0-1 M0 breast cancer (BC) before and after primary (neoadjuvant) chemotherapy and after surgery. As a whole, no difference in marker levels was apparent according to tumor and patient characteristics, with the only exception of TPS values, which showed an inverse relationship with the histologic grade. Serum marker levels did not substantially change with respect to baseline either after chemotherapy, despite the high response rate obtained, or after surgery. These data indicate a limited contribution of the primary tumor to the serum marker levels and are consistent for the scarce usefulness of marker evaluation in BC patients with an early stage of disease. Interestingly, pretreatment elevated CA 15-3 levels were correlated with a higher recurrence rate, further supporting the prognostic significance of this tumor marker.

Acute myeloblastic leukemia associated with mediastinal nonseminomatous germ cell tumors. Report on two cases.

The demonstrated association with hematologic neoplasms may partially account for the poor survival of patients with mediastinal nonseminomatous germ cell tumors (MNSGCT) compared to patients with testicular and retroperitoneal counterparts. It has been shown that the median interval from the diagnosis of MNSGCT to the diagnosis of the hematologic disorders is 6 months, which contrasts sharply with the average time of 2 to 3 years for the development of therapy-related leukemias. The 2 cases herein described, 1 male and 1 female, developed acute M2 leukemia 4 and 2 years after the diagnosis of MNSGCT. In the second patient (the first female ever described), we cannot exclude a pathogenetic role of the PEB regimen (platinum, etoposide, bleomicin), even though the total dose of etoposide administered has been demonstrated to have a mild leukemogenic potential. This is not the case of the first patient, who did not receive adjuvant chemotherapy after the radical resection of primary MNGSCT and developed the hematologic disorder a few months after local recurrence. In conclusion, the time elapsed from chemotherapy administration does not discriminate the hematologic neoplasms associated to MNGSCT from those related to therapy.

Occurrence and significance of vascular invasion in multinodular adenomatous goiter.

Solitary follicular neoplasms of the thyroid gland are usually classified as adenomas or carcinomas according to two main criteria: vascular invasion and capsular penetration. No information is available on the occurrence of vascular invasion in multinodular goiter lesions, except for the case of a follicular carcinoma within a goiter. One thousand consecutive cases of multinodular adenomatous goiter were reviewed. After screening all H&E-stained slides, 5 patients with histological features typical of adenomatous goiter but displaying foci of vascular invasion at the periphery of the nodes were selected. A single vessel (2 patients) and 2-4 vessels (3 patients) at the periphery of different nodules were involved, with clusters of follicular cells lined by endothelium and partly filling the lumen. Clinical information was obtained from all patients: No recurrences or progressive disease were reported 14 to 16 years after operation. These findings indicate that presence of minimal vascular invasion, although a valuable criterion of differentiation in solitary follicular lesions of the thyroid, has little diagnostic importance in the setting of multinodular adenomatous goiter. It does not appear to justify a diagnosis of malignancy and does not indicate a need for further therapy.

A study of capillary morphology in the digits of patients with acquired clubbing.

We sought to determine the capillary morphology in patients with clubbing to compare it with that in subjects without clubbing. Subjects were placed in the clubbed or nonclubbed groups on the basis of caliper measurements of their index fingers. In each subject, photomicrographs of eight fingers were done focusing on the dorsal skin just proximal to the base of the nail. Each photomicrograph was randomly graded with respect to the presence and extent of plexus formation, the presence of arborized loops, and the presence of splayed loops. Comparison of the plexus score, presence of arborized loops, and presence of splayed loops were significantly different between the clubbed and nonclubbed groups (p less than 0.001 in all three analyses). Only a plexus score of 2 or greater demonstrated a useful degree of sensitivity and specificity (89 and 90%, respectively). We concluded that a significant difference in the morphologic features of the capillaries existed between nonclubbed subjects and those with acquired clubbing.