Solubilization and characterization of cardiac sarcolemmal taurine-binding proteins

Cardiac sarcolemma preparations of both pig and rat ventricles were found to possess two sets of taurine-binding components. The two proteins from pig heart were solubilized with the detergent Ammonyx-Lo. Characterization of these solubilized proteins revealed that both components are glycoproteins and retain the binding properties observed for the membrane isolate. However, the characterization also revealed several differences between the proteins including their binding specificities, their affinities for taurine, their binding isotherms, and their molecular sizes. Possible functions of these two taurine-binding proteins are discussed.     

Fine needle aspiration cytology of neoplasms metastatic to the breast

The fine needle aspiration (FNA) cytologic findings in 18 cases of metastatic neoplasms of the breast are reported. The cases were encountered in a combined series of 2,529 FNA breast biopsies, of which 666 were malignant; the metastatic neoplasms of the breast thus constituted 2.7% of all the malignant breast tumors. The series consists of 15 women and 3 men, with a mean age of 48 years (range of 11 to 73 years). Sixteen biopsies confirmed metastatic malignancy in patients with known extramammary primaries; the prebiopsy clinical diagnoses in six of the patients were benign breast lesions. In eight patients, the clinical differential diagnosis was either a benign or malignant primary breast lesion versus a metastatic malignancy. In two additional patients, the FNA biopsy identified metastatic neoplasms from unsuspected extramammary primaries. The metastatic neoplasms included three small-cell carcinomas of the lung, one squamous-cell carcinoma of the lung, two malignant melanomas, three ovarian malignancies, including a dysgerminoma, and one each of carcinoma of the fallopian tube, endometrial carcinoma, transitional-cell carcinoma of the urinary bladder, prostatic carcinoma, acute granulocytic leukemia, lymphoma, mycosis fungoides, hepatoma and neuroblastoma of the retroperitoneum. Recognition of unusual cytologic patterns raised the suspicion of, or confirmed the diagnosis of, malignancy in all cases, with no false-negative diagnoses. None of the cases were cytologically interpreted as a primary breast malignancy. Ancillary studies performed on the FNA material, including immunocytochemistry, contributed to a definitive diagnosis in three cases. FNA diagnosis of metastatic malignancy of the breast is essential in order to avoid unnecessary mastectomy and to ensure appropriate chemotherapy and/or irradiation treatment.     

T wave changes in humans and dogs during experimental dives.

Electrocardiogram (ECG) analysis was performed in three human divers studied at 21 and 23.5 ATA while they breathed various gas mixtures containing H2 and/or He (COMEX HYDRA IX experiment) and in five dogs exposed to 91 ATA of He-O2 or He-N2-O2. In all cases, the O2 partial pressure was slightly higher than its physiological value. These human and animal studies reveal that elevated pressure of different inert gases did not change the resting heart rate or its respiratory fluctuation. However, the T wave amplitude increased in proportion to the gas density in the three divers; this was also found in four of the five dogs studied. Changes in peak T wave configurations were also observed in the dog experiments. Positional changes in QRS or T vectors cannot explain these T wave changes.     

Preliminary X-ray study of p-cresol methylhydroxylase (flavocytochrome c) from Pseudomonas putida N.C.I.B. 9869

Single crystals of p-cresol methylhydroxylase, a flavocytochrome c from Pseudomonas putida, have been prepared. The crystals are orthorhombic, space group P212121 with unit cell parameters; a = 140.3 A, b = 130.6 A and c = 74.1 A. They contain a single non-symmetric dimer per asymmetric unit and diffract to at least 2.5 A resolution.     

Microvascular pressures measured by micropuncture in isolated perfused lamb lungs

To investigate the influence of vasomotor tone and vessel compliance on pulmonary segmental vascular resistance, we determined the longitudinal distribution of vascular pressures in 15 isolated blood perfused lungs of newborn lambs. We measured pulmonary arterial and left atrial pressures and by micropuncture the pressures in 20- to 80-micron-diam subpleural arterioles and venules, both before and after paralyzing the vasculature with papaverine hydrochloride. In five lungs we also determined the microvascular pressure profile during reverse perfusion. In lungs with baseline vasomotor tone, approximately 32% of the total pressure drop was in arteries, approximately 32% in microvessels, and approximately 36% in veins. With elimination of vasomotor tone, arterial and venous resistances decreased to one-fifth and one-half of base-line values, respectively, indicating that vasomotor tone contributed mainly toward arterial resistance. During reverse perfusion, the pressure drop in veins was similar to that in arteries during forward perfusion, suggesting that the compliance of arteries and veins is comparable. We conclude that vascular tone and compliance are important factors that determine the distribution of segmental vascular resistance in lungs of the newborn.     

Glucocorticoid-mediated degradation of DNA in thymocytes of rats with transplantable Zajdela ascites hepatoma

Tumour growth was shown to be associated with DNA breakdown in thymocytes of rats bearing Zajdela ascites hepatomas. The tumour action on the thymus is mediated through adrenal glands since bilateral adrenalectomy completely prevents DNA breakdown in thymocytes. Using Southern hybridization of DNA genome with probes for histone, ribosomal and heat shock gene (hsp 70), it was shown that the degradation products of specific DNA sequences are as heterogenous as those of total DNA, although marked differences in appearance of nucleosomal ladder were seen. These data were interpreted to indicate different patterns of DNA breakdown in dying thymocytes. DNA breakdown in thymocytes in vivo and in isolated rat liver nuclei in vitro seems to proceed by similar mechanisms.     

Ontogenesis of TRH mRNA in the rat pancreas

The rapid changes in TRH levels in the rat pancreas during the neonatal period make this organ an interesting model for the study of the regulation of TRH biosynthesis. Pancreatic RNAs were isolated by the guanidinium thiocyanate method and layered onto CsCl cushion. Northern blot preparations were hybridized with 32P labeled TRH cDNA probe. Pancreatic TRH mRNA was first detected in 19-day old fetuses and reached the highest level on day 0, then decreased, being barely detectable 14 days after birth. The neonatal injection of streptozotocin induced a dramatic drop of TRH mRNA levels 24 hours later. This result suggests that the peculiar evolution of TRH level in pancreas is partly due to the evolution of the expression of the TRH gene.     

Factors influencing the efficiency of T-DNA transfer during co-cultivation of Antirrhinum majus with Agrobacterium tumefaciens

Summary The effects of varying the pH of the cocultivation medium, additons of vir-inducing phenolic compounds and the strains of wild-type agrobacteria on transformation rates of a number of different varieties of Antirrhinum majus were studied. In general, optimal transformation was found with strains C58 or A281 and was favoured by low pH and the inclusion of acetosyringone in the co-cultivation medium. However, maximal transformation of the least susceptible variety was achieved at high pH and in the presence of syringaldehyde. This demonstrates the need for the optimization of a wide range of culture conditions when working with new genotypes and offers a rational approach towards the development of Agrobacterium-mediated transformation of new species or varieties.Abbreviations BAP 6-benzylaminopurine - MS Murashige and Skoog medium (Murashige and Skoog, 1962) - NOA naphthoxyacetic acid