Peroxidase activity and thyroglobulin iodination activity of thyroid peroxidase in non-functioning thyroid tumours

Both lesion (L) and adjacent normal (N) thyroid tissue from 48 patients with non-functioning adenomas and adenomatous goitres were assayed for peroxidase activity by the 'mini' assay method employing guaiacol or iodide as the second substrate. A considerable proportion of thyroids (46% of adenomas and 22% of adenomatous goitres) demonstrated no iodide oxidation activity in L although they had guaiacol oxidation activity, and these were grouped as subgroups A. The rest of these non-functioning tumours, termed subgroups B, had both guaiacol and iodide oxidation activity which was higher (3.0-4.6 times in guaiacol assay and 7.3-14.1 times in iodide assay) in L than in N. These data indicate that the non-functioning in subgroups A may be due to a lack of iodide oxidation activity and that some other defects such as an iodide transport defect may be involved in subgroups B. Furthermore, a precise and rapid assay method for thyroglobulin iodination activity of thyroid peroxidase was developed, with modifications of previous methods. On the basis of this method, we found that there is a good correlation (r = 0.94) between iodide oxidation assay and thyroglobulin iodination assay, leading to the conclusion that thyroglobulin iodination assay can be replaced by iodide oxidation assay.

Effect of thyroid hormone on the phosphorylation of 110k proteins and the activity of protein kinase NII of rat liver nucleoli

When rat liver nucleoli were incubated with [gamma-32P] ATP, it was found that 110k proteins were predominantly phosphorylated. The phosphorylation of 110k proteins was decreased by thyroidectomy to about 80% of the normal level and restored 12 h after the injection of triiodothyronine. The activity of nucleolar protein kinase NII which is responsible for phosphorylation of 110k proteins was also increased by about 20-50% after injecting triiodothyronine into thyroidectomized rats. The hormone-stimulated enhancement in the phosphorylation of 110k proteins and protein kinase NII in nucleoli were abolished within 1 h after an injection of cycloheximide, without any change in the amount of the proteins.

Enhanced thyroid iodine metabolism in patients with triiodothyronine-predominant Graves' disease

Some patients with hyperthyroid Graves' disease have increased serum T3 and normal or even low serum T4 levels during treatment with antithyroid drugs. These patients with elevated serum T3 to T4 ratios rarely have a remission of their hyperthyroidism. The aim of this study was to investigate thyroid iodine metabolism in such patients, whom we termed T3-predominant Graves' disease. Mean thyroid radioactive iodine uptake was 51.0 +/- 18.1% ( +/- SD) at 3 h, and it decreased to 38.9 +/- 20.1% at 24 h in 31 patients with T3-predominant Graves' disease during treatment. It was 20.0 +/- 11.4% at 3 h and increased to 31.9 +/- 16.0% at 24 h in 17 other patients with hyperthyroid Graves' disease who had normal serum T3 and T4 levels and a normal serum T3 to T4 ratio during treatment (control Graves' disease). The activity of serum TSH receptor antibodies was significantly higher in the patients with T3-predominant Graves' disease than in control Graves' disease patients (60.5 +/- 19.2% vs. 20.4 +/- 18.2%; P less than 0.001). From in vitro studies of thyroid tissue obtained at surgery, both thyroglobulin content and iodine content in thyroglobulin were significantly lower in patients with T3-predominant Graves' disease than in the control Graves' disease patients. Thyroid peroxidase (TPO) activity determined by a guaiacol assay was 0.411 +/- 0.212 g.u./mg protein in the T3-predominant Graves' disease patients, significantly higher than that in the control Graves' disease patients (0.129 +/- 0.112 g.u./mg protein; P less than 0.01). Serum TPO autoantibody levels determined by immunoprecipitation also were greater in T3-predominant Graves' disease patients than in control Graves' disease patients (52.6 +/- 27.7% vs. 32.4 +/- 11.4%; P less than 0.05). Binding of this antibody to TPO slightly inhibited the enzyme activity of TPO, but this effect of the antibody was similar in the two groups of patients. The data suggest enhanced iodine metabolism in the thyroid gland of patients with T3-predominant Graves' disease, which may relate to the discordant T3 overproduction in patients with this type of Graves' disease.

Proton and iodine-127 nuclear magnetic resonance studies on the binding of iodide by lactoperoxidase

Interaction of an iodide ion with lactoperoxidase was studied by the use of 1H NMR, 127I NMR, and optical difference spectrum techniques. 1H NMR spectra demonstrated that a major broad hyperfine-shifted signal at about 60 ppm, which is ascribed to the heme peripheral methyl protons, was shifted toward high field by adding KI, indicating the binding of iodide to the active site of the enzyme; the dissociation constant was estimated to be 38 mM at pH 6.1. The binding was further detected by 127I NMR, showing no competition with cyanide. Both 1H NMR and 127I NMR revealed that the binding of iodide to the enzyme is facilitated by the protonation of an ionizable group with a pKa value of 6.0-6.8, which is presumably the distal histidyl residue. Optical difference spectra showed that the binding of an aromatic donor molecule to the enzyme is slightly but distinctly affected by adding KI. On the basis of these results, it was suggested that an iodide ion binds to lactoperoxidase outside the heme crevice but at the position close enough to interact with the distal histidyl residue which possibly mediates electron transport in the iodide oxidation reaction.

Change in the amount of rRNA precursor synthesized in rat ventral prostates after administration of androgen and cycloheximide: application of quantitative S1 nuclease mapping

The change in amount of pre-rRNA was observed by the use of total cellular RNA isolated from rat ventral prostates and quantitative S1 nuclease mapping. The amount of pre-rRNA from castrated rats was about 20% of that of normal rats, and increased to the normal level 24h after administration of testosterone. Cycloheximide caused a rapid decrease in the amount of pre-rRNA in normal and testosterone-treated castrated rats, to about 20% and 10% of that of normal rats, respectively, 2h after the administration of the drug. These results support the view that the androgen-stimulated initiation of the rRNA gene transcription is mediated by a hormone-dependent short-lived protein(s).

[Clinico-pathological study of atypical adenomas of the thyroid]

A total of five cases of atypical adenomas of the thyroid were clinicopathologically examined to clarify their malignant potential and incidence. These adenomas showed both structural and cellular atypia when compared with follicular adenoma of the usual type, A follow-up study after surgery revealed neither metastasis nor postoperative recurrence. Therefore it has been concluded that an atypical adenoma of the thyroid can be regarded as a benign neoplasm.

In vivo effects of dexamethasone and cycloheximide on the phosphorylation of 110-kDa proteins and the protein kinase activities of rat liver nucleoli

In vivo effects of dexamethasone and cycloheximide on the phosphorylation of nucleolar proteins and the activities of nucleolar protein kinases of rat livers were studied. Phosphorylation of nucleolar proteins was accomplished by incubation of isolated nucleoli with [gamma-32P]ATP at 37 degrees C for 10 min followed by electrophoretic separation and autoradiographic demonstration of phosphorylated proteins. Of several nucleolar phosphoproteins observed in the liver of adrenalectomized rats, the incorporation of 32P into nucleolar 110-kDa proteins was rapidly increased, reaching about 1.8-fold of the adrenalectomized level at 12 h after administration of dexamethasone. In addition, the activities of liver nucleolar protein kinases which were measured using casein or phosvitin as substrates were stimulated similarly by the administration of dexamethasone. It was found by DEAE-Sephadex column chromatography that nucleolar protein kinases were separated into NI and NII, the activities being increased about 35 and 80% by dexamethasone treatment (12 h), respectively, and that the enhancements were completely abolished by 1-h treatment of cycloheximide. The injection of cycloheximide also suppressed the hormone-induced enhancement of 32P incorporation into 110-kDa proteins but did not reduce the amount of the proteins at least until 2 h. Evidence was obtained indicating that the phosphorylation of the nucleolar 110-kDa proteins is accomplished primarily by protein kinase NII. These results suggest that continuous synthesis of protein(s) is necessary for glucocorticoid-induced enhancement of phosphorylation of 110-kDa proteins of liver nucleoli and that the nucleolar protein kinase NII is involved in the glucocorticoid-induced short-lived protein(s).

Effects of glucocorticoids and cycloheximide upon transcription of ribosomal RNA gene in rat liver: application of quantitative S1 nuclease mapping analysis

The change in the amount of pre-rRNA synthesized in rat liver was examined by S1 nuclease mapping analysis using the probe containing the 5' end of the rat 45S rRNA gene. It was found that the amount of pre-rRNA of adrenalectomized rats, which was about half of the normal level, was increased after administration of dexamethasone attaining to the normal level at 12 h, and that the hormone-induced pre-rRNA synthesis was completely abolished within 1 h after injection of cycloheximide. These results indicate that the glucocorticoids-stimulated initiation of rRNA transcription is mediated by the hormone-dependent short-lived protein(s).

[A case of malignant melanoma, axillary lymph node metastasis proved by fine needle aspiration biopsy cytology]

We report the case of a 57-year-old man with a malignant melanoma in the subunguinal region of his right thumb associated with the palpable axillary lymph nodes. Its metastasis was confirmed by fine needle aspiration biopsy cytology. Prognosis if a malignant melanoma is protean by its stage. Thus information regarding the axillary metastasis is mandatory for deciding the therapeutic plan. Fine needle aspiration biopsy cytology is a useful technique for diagnosing lymph node metastasis.

Proton nuclear magnetic resonance studies on the iodide binding by horseradish peroxidase

Binding of an iodide ion to horseradish peroxidase was studied by following the hyperfine-shifted proton nuclear magnetic resonance signals of the enzyme. For the enzyme in an iodide-free solution, the spectra of hyperfine-shifted methyl region were only slightly affected by varying pH. In the presence of iodide (200 mM), however, both chemical shifts and line widths of the heme peripheral 1- and 8-methyl proton signals were markedly affected by the pH change from 7 to 4 and broadened at pH 4. From the change in peak heights of these signals at various concentrations of iodide, the dissociation constant of the iodide to the enzyme was calculated to be about 100 mM at pH 4.0. The peak derived from the proximal histidyl imidazole N epsilon-H proton was not perturbed by the addition of 200 mM iodide at pH 4.0 and 7.1. The rate of oxidation of iodide with hydrogen peroxide catalyzed by the enzyme was increased with decreasing pH, indicating the participation of an ionizable group with the pKa value of 4.0. Optical difference spectrum studies showed that iodide exerts no effect both at pH 4.0 and 7.4 on the binding affinity of resorcinol which is associated with the enzyme in the vicinity of the heme peripheral 8-CH3 group. These results suggest that an iodide ion binds to the enzyme at almost equal distance from the heme peripheral 1- and 8-methyl groups at the distal side of the heme and that the interaction becomes stronger in acidic medium with protonation of the ionizable group with the pKa value of 4.0.

Relationship between RNA polymerase I activity and ornithine decarboxylase in rat liver tissues

In order to examine the relationship between RNA polymerase I and ornithine decarboxylase (ODC), three lines of experiments were performed, with the following results. The glucocorticoid-induced increase of RNA polymerase I in rat liver nuclei was not abolished by administration of inhibitors of ODC synthesis and activity, namely 1,3-diaminopropane and 2-difluoromethylornithine respectively. Anti-ODC antibody did not cross-react with RNA polymerase I solubilized from rat liver nucleoli, indicating the absence of a common protein sequence in these enzymes. The ODC preparation which was treated with transglutaminase in the presence of putrescine could not stimulate the activity of RNA polymerase I in nuclei of liver and prostate. All these results suggest that the increases in ODC protein or activity are not a prerequisite to the increase in RNA polymerase I after hormonal or physiological stimuli, but rather that the increases in both enzymes are separate responses to the primary stimuli.

Autoantibodies to thyroid peroxidase in patients with chronic thyroiditis: effect of antibody binding on enzyme activities

Using thyroid peroxidase (TPO), which was purified from the thyroid of patients with Graves' disease, we attempted to determine whether sera from patients with chronic thyroiditis contained antibodies to the enzyme. When the binding was tested by ELISA, sera from patients with chronic thyroiditis revealed high binding activities to TPO. When TPO was incubated with IgG from sera followed by treatment with protein A-Sepharose and centrifugation, the remaining TPO activities in the supernatant fraction were lower in most of the patients, as compared to normal controls. Moreover, IgG purified by DEAE-cellulose chromatography from sera in patients interfered with the TPO activities. Titres of anti-TPO antibodies correlated well with those of anti-microsome antibodies. These results indicate the presence of autoantibodies to TPO in sera of most patients with chronic thyroiditis and that TPO may be one component of microsome antigen complexes recognized by the autoantibodies. Studies on the inhibition of TPO by IgG isolated from sera of patients using guaiacol and iodide assays revealed that at least three epitopes of TPO molecule were recognized by autoantibodies and that the antigenic determinants on TPO molecule recognized by autoantibodies could be heterogeneous in patients.

Nuclear magnetic resonance studies on the spatial relationship of aromatic donor molecules to the heme iron of horseradish peroxidase

The geometry of hydrogen donor molecules bound to horseradish peroxidase was investigated using nuclear magnetic resonance techniques. Between resorcinol and 2-methoxy-4-methylphenol which showed different optical difference spectra, little difference was observed in the orientation of the molecules bound to horseradish peroxidase: the minimal distances between the enzyme iron and the protons of the phenol rings are in the range of 8.4-11.0 A. This situation was not greatly different for the third compound studied in this paper, benzhydroxamic acid, providing evidence against the view that its side chain coordinates to the heme iron. Furthermore, it was found that transferred nuclear Overhauser effect for the signals of these compounds was observable only when the heme peripheral 8-methyl proton signal was irradiated. These results, together with a hypothetical model of the enzyme structure obtained by computer-aided simulation procedures, suggest that the binding of these donor molecules and competitive inhibitors occur in the vicinity of the heme peripheral 8-methyl group, with hydrophobic interactions probably with Tyr-185 and with hydrogen bond with adjacent amino acid residues such as Arg-183.

[Breast cancer associated with other organ cancer reviewed from cancer family history]

Double cancers and related family histories were studied in eight patients who had developed cancers in the breasts and other organs. The incidence of double cancer among patients with breast cancer was 1.7% (8/472), and the age at first onset averaged 48. The organs involved were mainly the digestive system, thyroid and female sexual organs. The incidence of cancer was higher in the pedigree of double breast cancer patients than in those with solitary cancer. In follow-up study, it is necessary to elucidate the difference in characteristics between double and solitary breast cancer.

Effects of glucocorticoid and cycloheximide on the activity and amount of RNA polymerase I in nuclei of rat liver

The activity of the template-engaged form of RNA polymerase I from livers of adrenalectomized rats was about 50-60% of that of normal control rats, and increased about 2-fold at 6 h after the administration of dexamethasone. However, no change was found in the activity of the 'free' form of RNA polymerase I or the template-engaged form of RNA polymerase II. Immunochemical studies using guinea-pig anti-(RNA polymerase I) serum disclosed that the total number of RNA polymerase I molecules did not vary during the treatment with dexamethasone. Cycloheximide caused a rapid decrease in the template-engaged form of RNA polymerase I activity in normal rats and in dexamethasone-treated (6 h) adrenalectomized rats, to the value in adrenalectomized rats, but affected it only slightly in adrenalectomized rats. The elongation rate of rRNA-precursor synthesis in liver nuclei was not affected by a change in the concentration of circulating dexamethasone. From these results, it is concluded that about half the rRNA-precursor synthesis in rat liver is regulated by glucocorticoids, probably through the synthesis of short-lived protein(s) which may play a role in conversion of the 'dormant' form of RNA polymerase I into the 'engaged' form.

Effect of androgen on ornithine decarboxylase activity in androgen-dependent mouse mammary tumor (Shionogi Carcinoma 115) and its androgen-independent subline (CS 2)

The activity of ornithine decarboxylase in androgen-dependent mouse mammary tumor (Shionogi Carcinoma 115) was reduced to 25% by castration of tumor-bearing mice and restored to the normal level 12 h after administration of testosterone or 5 alpha-dihydrotestosterone. Administration of estradiol-17 beta to the tumor-bearing castrated mice also stimulated the enzyme activity while progesterone and cortisol had little effect. On the other hand, the enzyme activity was affected by neither castration nor androgen injection to CS 2, which is a subline of SC 115 and completely independent of androgen for growth. The inhibition of ornithine decarboxylase activity in SC 115 by injecting alpha-difluoromethylornithine did not affect the enhancement of RNA polymerase I activity by androgen, showing independent elevation of the levels of the two enzymes by androgen.

[Vascular invasion, lymph node metastasis and extraglandular extension of well-differentiated carcinoma of the thyroid]

Forty-five surgically removed thyroid glands with well-differentiated carcinoma were histologically analyzed to clarify the relationships among vascular invasion, lymph node metastasis and extraglandular extension. Using Victoria blue-HE stain, vascular invasion can be detected as the evident finding of circular elastic fibers surrounding the cancer cluster. In our series, 60% of the subjects were positive for vascular invasion. Patients with vascular invasion tend to show lymph node metastasis and/or extraglandular extension. This correlation was statistically significant. Therefore, in a patient with lymph node metastasis and/or extraglandular extension, there is a greater possibility of vascular invasion being present as well.

Fat in the normal cavernous sinus

The cavernous sinuses of 17 patients examined by metrizamide CT cisternography with 1.5 mm-thick slices were reviewed. Most of the cavernous sinuses contained fatty components. Anterior lateral end and posterior end of the cavernous sinus are the common sites where the fat is visible.

Human bone matrix gelatin as a clinical alloimplant. A retrospective review of 160 cases

Bone matrix gelatin, prepared by sequential chemical treatment including decalcification with 0.6 N hydrochloric acid [9], was used as an alloimplant for the treatment of benign bone tumours, tumorous conditions of bone, acetabular dysplasia, delayed union, traumatic bone defects and other disorders. The bone matrix gelatin implanted into bone defects was incorporated successfully in 98% of implantations, excluding cases of infection, tumour recurrence and recurrence of tumorous conditions. The material was also implanted into ten bone sites as an onlay but in five it was resorbed without new bone formation. The incorporation of the bone matrix gelatin into the recipient bed was completed from 6 to 33 months (average 14.9 months) after implantation. Wound infection complicated 5 of 165 implantations (3%) in previously uninfected sites. Low grade fever persisting after the tenth post-operative day (a probable sign of immunological reaction) occurred in 4 of 160 implantations (2.5%), excluding cases of infection. Alloimplants of bone matrix gelatin are thus effective in the treatment of bone defects. The risk of complication such as rejection or infection is low.

An improved assay method for thyroid peroxidase applicable for a few milligrams of abnormal human thyroid tissues

A peroxidase assay method (Mini assay method) which is applicable for a minute amount (as small as a few mg) of thyroid tissue was developed, employing guaiacol or iodide as the second substrate. This method is a modification of the previous one (Ordinary assay method): the volume of the reaction mixture was reduced to about one-tenth with prior solubilization of the enzyme. The correlation between the Mini assay and Ordinary assay methods, and between the guaiacol and iodide assays by both methods were satisfactorily good, but the iodine content of thyroglobulin was found to be not directly correlated to the peroxidase activities. Protein-based specific activities of peroxidase from normal human thyroid tissue were about 0.030 guaiacol units/mg protein and 0.0066 iodide units/mg protein, which were slightly higher than those of porcine thyroid tissue. The Mini assay method developed in the present study was used for the determination of peroxidase activity in a small amount (1-8 mg) of thyroid tissue obtained by means of a needle biopsy from patients with thyroid disorders. One specimen (goitrous cretinism) showed no peroxidase activity in both the guaiacol and iodide assays, and three specimens (two chronic thyroiditis, one familial nontoxic goiter) possessed no ability to catalyze the oxidation of iodide in spite of the high reactivity towards guaiacol, suggesting the presence of an abnormal peroxidase in these tissues.

Effects of androgen and polyamines on the phosphorylation of nucleolar proteins from rat ventral prostates with particular reference to 110-kDa phosphoprotein

The effects of testosterone (in vivo) and polyamines (in vitro) on the phosphorylation of nucleolar proteins of rat ventral prostates were studied. Phosphorylation of nucleolar proteins was accomplished by incubation of isolated nucleoli with [gamma-32P]ATP at 37 degrees C for 10 min followed by electrophoretic separation and autoradiographic demonstration of phosphorylated proteins. Of several nucleolar phosphoproteins observed in ventral prostates of castrated rats, the incorporation of 32P into 110-kDa protein was remarkably augmented by the testosterone treatment. The stimulation became evident as early as 4 h after the injection of the hormones, reaching 3-4-fold of the control level and was efficiently prevented by cycloheximide injection 3 h before killing. 5 alpha-Dihydrotestosterone gave similar results to testosterone, but estradiol-17 beta failed to stimulate the phosphorylation of 110-kDa protein. Polyamines and cyclic nucleotides did not affect the phosphorylation, but, when phenylmethanesulfonyl fluoride was omitted from the standard medium, spermine and spermidine showed a distinct effect: 110-kDa phosphoprotein was completely abolished with a concomitant increase of 59-kDa phosphoprotein in both cases of castrated and testosterone-primed rats. The effect of polyamines seems to be due to the stimulation of degradation of the protein which is presumably catalyzed by a serine protease.

Biochemical studies on the purine metabolism of four cases with hereditary xanthinuria

The purine metabolism of four cases with marked hypouricemia (serum uric acid concentration of less than 0.018 mmol/l) from three Japanese families was investigated. Erythrocyte adenosine deaminase (EC 3.5.4.4) and purine-nucleoside phosphorylase (EC 2.4.2.1) activities of the patients were within the normal ranges. Urinary hypoxanthine and xanthine concentrations were 0.096-0.397 mmol/l and 0.743-1.717 mmol/l, respectively. Xanthine oxidase (EC 1.2.3.2) activities in the jejunal mucosa of the two normal controls were 0.257 and 0.283 units/g protein, while those of three of the patients were extremely low and could not be determined. The findings of these biochemical features may indicate that the four patients have hereditary xanthinuria. In order to study the purine metabolism in the hypouricemic condition of this disorder, a single oral dose of allopurinol (4-hydroxypyrazolo[3,4-d]pyrimidine) was administered in one case. The excretion pattern of allopurinol and oxypurinol (4,6-dihydroxypyrazolo[3,4-d]pyrimidine) in the urine of the patient was similar to that of a normal control male. These data suggest that some residual enzyme activity may be functioning in vivo, although the presence of xanthine oxidase could not be detected.

Plate-like atelectasis at the corticomedullary junction of the lung: CT observation and hypothesis

A concept of plate-like atelectasis in the corticomedullary junction of the lung is presented with illustrative case reports. Two processes can be considered as contributory causes: air trapping in the cortex of the lung and decreased distensibility of the whole lung due to interstitial infiltration.

In vitro effect of androgen on RNA synthesis in nuclei from androgen-independent subline of Shionogi carcinoma (CS 2)

By serial transplantation of CS 1, a subline of Shionogi carcinoma SC 115, to female mice, another subline was obtained and designated CS2. The subline showed a complete loss of androgen dependency on the growth of the tumor. When male mice bearing the tumor were castrated and treated with testosterone, the activity of RNA polymerase I in isolated nuclei from the tumor hardly varied during the period of the experiments (36 h), while the activity of RNA polymerase II exhibited a transient increase (about 40%) at 6 h after the testosterone injection. The results, together with the previous ones showing 80% and 40% increases in RNA polymerase I activity at 24 h after testosterone administration in the case of SC 115 (androgen-dependent tumor) and CS 1 (less androgen-dependent tumor), respectively, indicate that the stimulation of RNA polymerase I activity by androgen in the tumor tissues is closely related to the androgen dependency on the growth of the tumors.

[Nodal psammoma body in thyroid cancer as an indicator of cancer metastasis to the lymph node]

A 64-year-old woman underwent subtotal thyroidectomy and cervical lymphadenectomy for thyroid carcinoma. In 5 of 15 resected nodes, histologic examination revealed metastasis. The other 10 nodes showed no metastasis, though psammoma bodies were seen in 3 nodes. To clarify the relationship between psammoma bodies and metastasis, 10 cancer-negative nodes were serially sectioned (4 microns in thickness). This disclosed cancer cells and psammoma bodies in 2 to 3 psammoma body-positive nodes. We suggest that the presence of psammoma bodies in the lymph node may indicate metastasis.

Distinct heme-substrate interactions of lactoperoxidase probed by resonance Raman spectroscopy: difference between animal and plant peroxidases

Resonance Raman scattering from cow milk lactoperoxidase (LPO) and its complexes with various electron donors and inhibitors was investigated. The Raman spectrum of LPO is strikingly close to that of hog intestinal peroxidase but distinctly dissimilar to that of horseradish peroxidase (HRP). The v10 frequency suggested the six-coordinate high-spin structure of heme for native LPO in contrast with the five-coordinate high-spin structure for HRP. For the v10 band, benzohydroxamic acid caused a frequency shift with HRP but not with LPO. Guaiacol, o-toluidine, and histidine brought about a frequency shift of the v4 mode for LPO but not for HRP. The frequency shift was restored upon removal of the substrate or inhibitor by dialysis. The down shift of the v4 frequency is considered to represent an appreciable donation of electrons from the substrate or inhibitor to the porphyrin LUMO and thus their direct interaction with the heme group. From the relative intensity of the shifted and unshifted v4 lines, the dissociation constant was determined to be Kd = 52 mM for guaiacol and Kd = 87 mM for histidine at pH 7.4. The binding of histidine was relatively retarded in the presence of sulfate anion (Kd = 150 mM for 0.53 M sulfate present), and imidazole alone yielded no frequency shift, indicating the binding of the carboxyl group of histidine to the protein cationic site on one hand and a weak charge-transfer interaction between the imidazole group and the heme group on the other.

Changes in cytosolic androgen receptor after administration of testosterone of androgen-dependent mouse mammary tumor (Shionogi carcinoma) and its sublines of altered androgen dependency

The effect of testosterone treatment on the cytosolic androgen receptor in an androgen-dependent tumor (Shionogi Carcinoma 115, SC 115) and its sublines of altered hormone-dependency (CS 1, less androgen-dependent, and CS 2, androgen-independent) was examined. In all tumors examined a single, high-affinity binding to 3H-R 1881 was detected in cytosols. The size of the maximum binding sites was in the order SC 115, CS 1 and CS 2. Inhibition experiments revealed that the binding to 3H-R 1881 in cytosols of these tumors was attributable to the androgen receptor. The amount of the androgen receptor in cytosols was decreased at 1 hr after testosterone injection, then replenished gradually towards the pretreatment level. Depletion of the androgen receptor was dependent on the dose of testosterone administered. Multiple injections of testosterone depressed the replenishment of the receptor. Treatment with actinomycin D or cycloheximide did not alter the dynamics of the androgen receptor. Therefore, it was concluded that the depletion and replenishment of the androgen receptor in cytosols of the tumors were caused by receptor recycling. Because a similar pattern of depletion and replenishment of the androgen receptor was also observed in the less androgen-dependent tumors, the growth of tumors was felt to be unrelated to the receptor dynamics.

[Glucagon-producing carcinoid of the rectum--report of a case]

A 22-year-old male who had been receiving insulin therapy to treat uncontrollable hyperglycemia, was diagnosed to have a carcinoid in the lower rectum. The excised tumor was 1.5 cm in diameter, and showed a yellowish-white cut surface. It did not invade into the proper muscle. Numerous glucagon immunoreactive cells were found. The tumor cells contained many rounded neurosecretory granules. After tumor excision, the patient's hyperglycemia did not return in the absence of insulin administration. We suggest that the tumor may have secreted glucagon which may have acted as an antagonist against insulin in the circulation.

Effect of sex hormones on RNA synthesis of androgen-dependent mouse mammary tumor (Shionogi carcinoma)

To observe the effect of sex hormones on RNA synthesis of androgen-dependent tumors, mice of DD/S strain bearing androgen-dependent mouse mammary tumor (SC 115) were treated with the hormones, and RNA polymerase activities in isolated nuclei of the tumor were measured. The activity of RNA polymerase I in SC 115 was diminished to approximately 60% of the control level by castration, and it was restored to the precastrated level 12 hr after treatment with 0.2 mg of testosterone. While the activity of RNA polymerase II in the tumor was scarcely influenced by castration, it reached 150% of the castrated level 24 hr after administration of testosterone. In CS 1, a subline of SC 115 with partial loss of androgen dependency on growth, castration and testosterone treatment caused similar but less prominent effects on the activities of RNA polymerase. Administration of estradiol-17 beta to castrated animals also increased the activity of RNA polymerase I, but to a lesser degree than testosterone, in both SC 115 and CS 1. However, only SC 115 demonstrated an increase in RNA polymerase II after estrogen treatment.

Partial purification of estrogen-dependent peroxidase of rat uterus and comparison of the properties with those of other animal peroxidases

An attempt was made to solubilize a peroxidase from the uterine tissue of estrogen-primed rats using various detergents, and the best result was obtained by incubation with 4% cetyltrimethylammonium bromide at 37 degrees C for 60 min. The solubilized material was then dialyzed and subjected to gel filtration on Sephacryl S-200 followed by CM-cellulose chromatography, resulting in a 50-250-fold increase in specific activity over the detergent extract. Some properties of the partially purified uterine tissue peroxidase were studied in comparison with those of other animal peroxidases. The absorption spectra, molecular weight, and isoelectric point are very similar to those of lactoperoxidase. However, the oxidation rates of various hydrogen donor substrates by the uterine peroxidase were not parallel to those of lactoperoxidase and other animal peroxidases and the affinities for cyanide and azide of these enzymes were somewhat different from each other. The uterine peroxidase was inhibited by histidine and excess hydrogen peroxide competitively with respect to guaiacol, suggesting an important role of an amino acid residue in the protein moiety.

The repair process in experimentally induced avascular necrosis of the femoral head in dogs

Total necrosis of the femoral head was experimentally produced in dogs by freezing. The healing process was observed in a time sequence. There was a dense fibrous layer at the boundary between the necrotic bone mass and living bone tissue, in each dog which survived for 18 months after the surgery. The layers were similar to that commonly found in avascular necrosis of the femoral head in humans. Histological observation revealed that the establishment of the dense fibrous layer was the final result of three time dependent changes in biological potencies of granulation tissue, i.e., decreasing proliferating and differentiating potencies and increasing osteoclastic potency of mesenchymal cells within the granulation tissue.

Spectroscopic and kinetic properties of the estrogen-induced peroxidase in rat uterine fluid

Uterine fluid was collected from estrogen-primed rats which had each previously been subjected to an operation to close the cervical junction of the uterus. Starting from the uterine fluid, uterine fluid peroxidase was purified by carboxymethyl cellulose column chromatography followed by gel filtration on Sephacryl S-200. The purity of the enzyme preparation, as estimated by microelectrophoresis on polyacrylamide gel, was found to be 70-95%. Absorption spectra of the peroxidase and its derivatives resembled those of lactoperoxidase. The pyridine hemochromogen spectrum of the enzyme was also very similar to that of lactoperoxidase. The apparent molecular weight of the enzyme was estimated to be 90,000, being similar to that of lactoperoxidase (78,000). Uterine fluid peroxidase has, however, distinctly different properties from lactoperoxidase, for example, in substrate specificity, pH optimum, inhibition by excess hydrogen peroxide, and isoelectric point.

Thyrotropin-dependence of the distribution of peroxidase in rat thyroid gland

After male rats were injected daily with propylthiouracil, whale thyrotropin, or thyroxine for several days, the thyroid glands were examined for their ultrastructural localization of peroxidase. The propylthiouracil treatment caused a marked increase in the number of round, peroxidase-positive vesicles in the apical and middle regions of cytoplasm, and brought about a formation of granular reaction products in the colloid lumen adjacent to the elongated microvilli. Such changes became evident after 2 days of the drug treatment and increased with the time of the effect, until the whole colloid lumen was filled with the reaction products and very elongated microvilli. The effect of exogenous thyrotropin was essentially similar, to a lesser degree, to the drug effect mentioned above. The thyroxine treatment diminished the population of the small vesicles, as usually seen in the case of normal rat thyroids. When the thyroids of thyrotropin-stimulated and unstimulated rats were homogenized and fractionated into particulates fractions and a soluble fraction, almost all the peroxidase activity was contained in the former in both cases. Based on these results, the dynamics and the physiological role of the intracellular peroxidase are discussed.

Comparative studies on estrogen-dependent peroxidases contained in uterine microsomes and fluid of rats and pigs

1. The uterine peroxidase activity of rats was determined quantitatively at each stage of the estrous cycle, and it was found that the protein-based and DNA-based specific activities in proestrus and estrus are 4-5 times higher than those in diestrus. Ovariectomy caused a marked decrease in the activity in the uterus, and the administration of estrogen, but not other steroids, restored the activity. Of many organs in normal rats, the uterus had the greatest peroxidase activity. The peroxidase activity of pig uterus varied from animal to animal and the mean specific activity was about one-hundredth of that of rats. 2. The peroxidase activity of uterine tissue was mainly associated with subcellular particulates, especially microsomal fractions. The membrane-bound peroxidase showed a cyanide-difference spectrum which was very similar to those of lactoperoxidase and thyroid peroxidase. 3. Rat uterine fluid peroxidase was also found to be estrogen-dependent and to exhibit a similar cyanide-difference spectrum. 4. On the basis of spectroscopic, kinetic, and other properties, the relationship between the uterine tissue peroxidase, uterine fluid peroxidase and eosinophil peroxidase is discussed.