Myxoma of the skin of a finger

A case of a true myxoma of the fingertip is presented. The lesion was removed by simple shave excision. Reports of myxoma of the skin are reviewed, and the differential diagnosis of this rare tumor is discussed.

Aspergillosis of the paranasal sinuses--diagnostic significance of the computed tomography

Aspergillosis of the paranasal sinuses appears to be relatively rare in occurrence, but there is a growing incidence of it in accordance with the increasing use of antibiotics, steroid hormones, anticancer drugs, and radiation therapy. We have seen 15 cases of aspergillosis of the paranasal sinuses in which computed tomography (CT) was helpful for diagnosis. The characteristic feature of CT findings was the intermixture of high and low density areas in the affected paranasal sinuses, apparently caused by increased X-ray absorption due to calcification. These findings indicate that CT is useful in the preoperative diagnosis of aspergillosis of the paranasal sinuses.

Testosterone metabolism by microsomal cytochrome P-450 in liver of rats treated with some inducers

1. The stereoselective hydroxylation of testosterone by microsomal cytochrome P-450 and the changes in level of components participated in the microsomal electron transport system were observed in the microsomes induced unique P-450 isozymes. 2. Flavone- and hesperetin-inducible P-450 catalyzed the hydroxylation of testosterone more effectively than other chemicals-inducible ones. 3. The P-450 in all the microsomal preparations tested most rapidly oxidized testosterone to 6 beta-monohydroxy form. 4. Particularly, MC- and BNF-inducible P-450 showed high stereoselectivity on C6-position of testosterone, and PB-, flavone- and hesperetin-inducible one showed that on C2-position of this compound, respectively. 5. This specificity of two flavonoid-inducible P-450 for the formation of 2 alpha- and 2 beta-epimer of monohydroxytestosterone was opposite to each other. 6. The content of P-450 and the activity of NADPH-cytochrome P-450 reductase were high in PB-, MC- and BNF-microsomes, whereas NADH-cytochrome b5 reductase activity was high in two flavonoid-microsomes and the content of cytochrome b5 was not changed except the PB-treated rats. 7. It is suggested that the increasing activities of testosterone hydroxylases in flavonoid-microsomes seems to be closely related to NADH-cytochrome b5 reductase.

Adult Wilms' tumor--a case report

A case of Wilms' tumor in a 67 year-old female is presented. The tumor totally replaced the left kidney with extension to Gerota's fascia, the adrenal gland and ureter, with tumor thrombi in the left renal vein. Multiple bony metastases to the skull, shoulder, rib, ilium, acetabulum and femur were noted also. Microscopically, the tumor was composed predominantly of blastemal tissue with diffuse anaplasia with areas of tubular differentiation and chondroid elements. Clear cell nests were found in the proximal ureter with gradual maturation downward.

Modulation of glycoprotein hormone alpha-subunit levels, alkaline phosphatase activity, and DNA replication by antimetabolites in HeLa cultures

Synthesis of the glycoprotein hormone common alpha-subunit and alkaline phosphatase (placental isozyme) has been examined in HeLa S3 cells. A variety of compounds that inhibit DNA synthesis lead to the increased production of both proteins. Experiments presented in this communication were undertaken to determine whether protein induction and DNA synthesis inhibition are coordinated. In general, nucleoside analogs and compounds that alter deoxynucleotide metabolism were good inducers of these ectopic products, whereas agents that altered DNA by intercalation, crosslinking, and covalent modification were poor inducers. The former class of effectors includes 5-bromo-2'-deoxyuridine, 5-fluoro-2'-deoxyuridine, 2'-deoxythymidine, 1-beta-D-arabinofuranosylcytosine, methotrexate, hydroxyurea, N-phosphonoacetyl-L-aspartic acid, and sodium butyrate; and the latter class of compounds includes ethidium bromide, acridine, bleomycin, mitomycin C, cesalin, macromomycin, and cis-diamminedichloroplatinum(II). A direct correlation between protein induction and DNA synthesis inhibition is unlikely based on the following observations: (i) for some effectors, the concentrations required to induce alpha-subunit and PAP were significantly different from those necessary to inhibit DNA synthesis; (ii) several agents inhibit DNA replication but do not enhance hormone or enzyme production; (iii) the kinetics of ectopic protein induction were similar for a number of inducers whereas the kinetics of DNA synthesis inhibition elicited by the same compounds were quite different. It is difficult from the data obtained, however, to rule out the possibility that inhibition of DNA synthesis may be required but is not sufficient for protein induction.

Gonadotropin and prolactin secretion increases during sleep during the puerperium in nonlactating women

To investigate the neuroendocrine changes that regulate initiation of normal menstrual function after parturition, serum LH, FSH, and PRL concentrations were determined at 20-min intervals for 12-24 h in eight nonlactating postpartum women on a weekly basis between postpartum days 10-26. Sleep was monitored by EEG. On postpartum day 10, serum LH concentrations were similar to early follicular phase levels in normal cycling women, while FSH concentrations were lower than early follicular phase levels. Mean LH pulse frequency during each postpartum interval was 3.6 +/- 0.6 (+/- SE), 4.4 +/- 0.6, and 4.1 +/- 0.8 pulses/12 h on postpartum days 10-11, 17-21, and 24-26, respectively. Because mean serum LH levels and LH pulse frequency did not change significantly between postpartum days 10 and 26, the results from the two or three studies in each woman were combined for the purpose of comparing LH pulse characteristics during the waking and sleeping periods. During the waking hours, mean LH pulse frequency (6.1 +/- 0.5 pulses/12 h) was significantly greater than during sleep (4.1 +/- 0.4 pulses/12 h; P less than 0.02). The amplitude of the serum immunoreactive LH pulses (P less than 0.05) and bioactive LH levels (P less than 0.05) were significantly higher during sleep than during the waking period, with five of the eight women having higher sleep-associated immunoreactive LH and bioactive LH levels between postpartum days 17-26. These changes were associated with an increase in the bioactive to immunoactive LH ratio from 3.3 +/- 0.4 (awake) to 4.5 +/- 0.5 (sleep; P less than 0.05). Although serum PRL levels remained elevated during the puerperium, the diurnal pattern of PRL secretion was conserved. With each successive week postpartum, serum PRL concentrations declined. These results suggest that the increment in LH secretion (and, by inference, increased GnRH secretion) during sleep is a feature of postpartum pituitary-ovarian reactivation. Although the mechanism(s) responsible for the increase in GnRH secretion is not known, this hormonal pattern is analogous to that during early puberty and during recovery from anorexia nervosa and hypothalamic amenorrhea. Taken together, these findings provide evidence to support the concept of a centralized preprogrammed scheme for pituitary-gonadal reactivation.

Purification of heat-labile enterotoxin from an enterotoxin from an enterotoxigenic Escherichia coli of human origin by monoclonal immunoaffinity chromatography

Heat-labile enterotoxin (LT) was purified from an enterotoxigenic Escherichia coli 015H11 of human origin. The purification steps included French pressure cell disruption of the bacteria, salting-out, DEAE-Sephacel on chromatography. Application of this procedure resulted in a 95.1-fold purification of LT with a yield of 19.9% as determined by rabbit ileal loop assay. The final LT preparation showed only one protein-staining band on polyacrylamide gel electrophoresis, indicating that the purified LT was homogeneous.

Maximum entropy image reconstruction for an object with opaque obstructions

In the case of image reconstruction from missing projection data such as imaging an object with opaque obstructions, the conventional maximum entropy technique reconstructs a degraded image, which results from missing projection data. In this paper, we propose an improved maximum entropy technique based on a good estimation of missing projection data. Computer simulation using the proposed algorithm shows a significant improvement in image quality and convergence behavior over the conventional algorithms. This algorithm is also applied successfully to ultrasound attenuation CT (computed tomography) using a sponge phantom.

The effects of conditioned media on spinal neurites: substrate-associated changes in neurite direction and adherence

The effects of conditioned media and other growth factors on spinal cord neurite adherence, growth rate, and direction were studied. Skeletal muscle-conditioned medium (SMCM) significantly increased neurite adherence and altered the direction of elongation. Lung- and skin-conditioned media, nerve growth factor, and polyornithine binding neurite promoting factor did not affect neurite adherence or direction. The positive effects of SMCM on neurite adherence and direction may be due to substrate-bound substances, since SMCM depleted of poly-L-lysine-adsorbable materials decreased neurite adherence and direction, and the directional response was greatly diminished on SMCM-conditioned substrate. Haptotaxis may be the basis of the turning response, since it appears to involve substrate-bound molecules which slightly increase adherence. It was also observed that the measured length of neurite involved in a turn toward SMCM was much greater than the calculated length of neurite (based on neurite elongation rates). Therefore, it appears as if the growth cone has been displaced, dragging the attached neurite with it. These observations suggest that the growth cone may have extensive locomotive capabilities which affect growth cone migration.

[The reaction of holo-, apo- and coenzyme of the peroxidase to heating (author's transl)]

The thermal reaction of the two components of the horseradish peroxidase--the apoenzyme and the prosthetic group--with that of the holoenzyme were compared. From this we conclude that the thermal inactivation of the peroxidase in aqueous solution is not caused by a change of the apoprotein alone, but rather by participation of the entire three-dimensional structure including the prosthetic group. Spectrophotometric studies of the inactivation process in the holoenzyme revealed that the absorbance of the Soret band changes parallely to a reduction of the enzyme activity during heating. Since it has been found that the Soret absorption increases again during storage and simultaneously the enzyme activity regenerates, the change of the Soret absorption during heating can be regarded as the result of both reversible and irreversible denaturation processes.

[Thermal inactivation and storage behavior of technologically important enzymes. III. Effect of reagents added to peroxidase and lipoxygenase]

The influence of milieu factors on the thermal inactivation of peroxidase and lipoxigenase was investigated. Cationogenic, anionogenic, non-ionogenic and amphoteric tensides were more or less effective in inactivating horseradish peroxidase. Most effective in this respect were lecithine and monoglyceride, both capable of swelling in water. In presence of lecithine, peroxidase was inactivated already at 0 degrees C and pH 4.0. Linoleic acid was more efficient in an oxygen stream than in presence of nitrogen, in a stream of nitrogen its influence was comparable to oleic acid. This suggests an additional effect by lipid peroxides which are formed of linoleic acid under the heating process. Tensides prevented the regeneration of the heated peroxidase. In the case of lipoxigenase, the authors investigated the influence of lecithine and various fatty acids on the thermal inactivation at 60 degrees and pH 7.0. Lecithine accelerated the inactivation less distinctly than with peroxidase. The accelerated the inactivation less distinctly than with peroxidase. The accelerating effect of the fatty acids decreased in the order oleic acid, linoleic acid, palmitic acid, myristic acid and stearic acid.

[Thermal inactivation and storage behavior of technologically important enzymes. II. Lipase from Geotrichum candidum and lipoxygenase from soybeans]

The thermal inactivation of lipase out of Geotrichum candidum and of lipoxigenase out of soybeans was investigated in phosphate buffer solution. Comparable to peroxidase, a sharp bend was observed in the inactivation curves of both enzymes. The z-value of 19 degrees C for lipase out of Geotrichum candidum was higher than the values indicated in the pertinent literature for pancreas lipase and milk lipase. The z-value for soy lipoxigenase was found to be 9.8 degrees C.

[Thermal inactivation and storage behavior of technologically important enzymes. I. Horseradish and spinach peroxidase]

The thermal inactivation and storage behaviour for horseradish and spinach peroxidases were investigated in defined systems, in spinach also within its natural environment. The inactivation curves of either enzyme show a sharp bend which is clearly visible at low, but not at higher temperatures. The D-values were taken from the inactivation curves. z-values resulting from the D-values were 25.5 degrees C for horseradish peroxidase, 13 degrees C for isolated peroxidase and 18 degrees C for peroxidase in spinach extract. Horseradish peroxidase was relatively heat-resistent at pH 6.0, spinach peroxidase at pH 5.0-6.0; both enzymes were found to be highly susceptible to heat at pH 4.0. Peroxidase isolated from spinach responded differently to heating than the enzyme in spinach extract or suspension. This discrepancy indicates that certain model experiments cannot be transferred to foods. Heated peroxidase from horseradish and spinach were found to regenerate during storage; the extent of regeneration depended on the pH.

[Digital densimetric method for the determination of enzymatic reaction rates (author's transl)]

A new digital method of density measurement has been developed for the determination of enzymatic reaction rates. The method by means of which reaction kinetics can be pursued in a very easy way is particularly suited for hydrolases. The results obtained in studies on invertase and lipase are reported in this paper.

[A modified hydroxamic acid method for the estimation of the activity of lipase (E.C. 3. 1. 1. 3)]

Optimal conditions for a modified hydroxymic acid method have been worked out with respect to the stability of the substrate emulsion; by systematically varying the ratios of the components of the solutions it was possible to develop a homogeneous reaction system which could be directly measured by spectrophotometry.