Inhibitory role of sex steroid in the regulation of ovarian follicle-stimulating hormone receptors during pregnancy

The present study was conducted to determine the role of sex steroids in the regulation of FSH receptors in pregnant rats. In the normal physiological condition, FSH bindings per unit ovarian weight (density of binding) and per 2 ovaries (total binding) increased during days 14-21 gestation. Scatchard plot analyses of the binding suggested that the increase in FSH binding was due to an increase in the number of FSH-binding sites. The plasma FSH concentration in pregnant rats was stable during the receptor change. In contrast, the plasma estradiol-17 beta concentration continuously increased from gestation day 14 to 21, and the testosterone level showed a large peak on gestation day 18. Estradiol-17 beta (one silastic plate containing 13 mg crystal)-implanted pregnant rats during 14-21 days of gestation induced significant decreases in the total FSH binding and ovarian weight on gestation day 21. Estradiol administration increased the plasma estradiol level 2.3-fold but did not change the FSH level. Testosterone or 5 alpha-dihydrotestosterone, a nonaromatizable androgen, did not influence the binding level under the same dose treatment. In contrast, continuous treatment with aminoglutethimide (2 plates containing 20 mg crystal), an inhibitor of adrenocortical steroidogenesis, for 7 days significantly increased the total FSH binding without a significant change in the ovarian weight. The plasma titers of estradiol and testosterone in pregnant rats treated with aminoglutethimide were reduced by 37% and 51%, respectively. Aminoglutethimide did not influence plasma FSH levels. These results suggest that circulating estradiol acts as a negative factor in the regulation of ovarian FSH receptors, at least during the second half of pregnancy. Other factor(s) that is (are) independent of sex steroids and FSH may contribute to FSH receptor induction.

[Pharmacokinetic study and side effects of chronic daily administration of oral etoposide]

Eleven inoperable patients with non-small cell lung cancer were treated as a maintenance therapy with oral etoposide 25 mg daily. The toxicity appeared during the chemotherapy were assessed in all cases, but the blood concentration of the drug were measured in 5 cases on the first and the seventh day of treatment. While the peak plasma level (Cmax) was 0.92 +/- 0.43 microgram/ml on the first day and 1.02 +/- 0.30 micrograms/ml on the seventh day of chemotherapy, AUC was 12.3 +/- 5.41 micrograms.hr/ml and 11.9 +/- 4.52 micrograms.hr/ml on the first and the seventh day, respectively. Cumulative effect of the drug did not exist, since in any of these two measurements there was no significant statistical difference between values obtained on the first and on the seventh day. Regarding the toxicity of the drug, bone marrow suppression with abnormal reduction of peripheral white blood cells was observed. Though grade 2 adverse reaction was found in 6 cases, stopping drug administration for 2 weeks, enabled to re-administer the drug. Alopecia and liver or renal injury were not observed, and in spite of the presence of nausea and anorexia in one case, maintenance therapy could continue in all cases. Based on these results we concluded that etoposide can be safely administered as a maintenance therapy on out-patient basis.

[Obstructive pneumonitis in lung cancer patients--a retrospective study]

We evaluated the frequency and the backgrounds of lung cancer patients with obstructive pneumonitis. Among 84 cases of lung cancer, 35 presented with bronchial obstruction at bronchoscopy or on radiological studies. Of these 35 cases, 8 had infectious obstructive pneumonitis. This complication was observed more commonly in patients with squamous cell carcinoma. A comparative analysis of the immunological and nutritional states before the occurrence of bacterial complication was performed on patients with infectious obstructive pneumonitis and those with non-infectious obstructive pneumonitis. The serum concentration of total protein, albumin and total cholesterol was significantly lower in patients who subsequently developed bronchial obstruction and bacterial infection, compared to concentrations in patients with non-infectious obstructive pneumonitis. Similarly, there was significant decrease in the number of peripheral lymphocytes, and neutrophils as well as a significant reduction of the serum concentration of IgM in the group of patients with infectious complications. These results suggest that nutritional and immunological deficiencies, in association with local airway obstruction, may be determining factors in the occurrence of infectious obstructive pneumonitis in patients with lung cancer.

Bronchopulmonary disease in ulcerative colitis

Two cases of ulcerative colitis are described: a 33-year-old woman who developed widespread bronchiectasis 7 months after undergoing colectomy, and a 72-year-old man whose colonic disease began coincidentally with the appearance of diffuse interstitial pulmonary infiltrates. In both cases, clinical correlation and common patterns of response of lung and bowel diseases suggested that the co-existence of these two pathologies might not be merely a casual relation.

Purification and biochemical characterization of squirrel monkey retrovirus-H produced in a human lymphoblastoid cell line

We found a type D retrovirus in a human lymphoblastoid cell line of B-cell lineage. Molecular cloning and nucleotide sequencing of the provirus genome revealed that this virus was closely related to squirrel monkey retrovirus (SMRV), and we designated this virus as SMRV-H. To investigate the relationship between these retroviruses, SMRV-H was purified from the virus-producing cells, and its biochemical properties were characterized. The cell-adhesive virus particles were successfully separated from the cell by a brief trypsin treatment and purified by velocity sedimentation. The purification of the virus was confirmed by electron microscopy. Major gag protein of the virus is phosphorylated, and has a molecular weight of 34 kDa. The virion-associated reverse transcriptase prefers Mg2+ to Mn2+. These properties of SMRV-H were almost the same as those of SMRV.

cDNA cloning, sequencing, expression and possible domain structure of human APEX nuclease homologous to Escherichia coli exonuclease III

cDNA encoding the human homologue of mouse APEX nuclease was isolated from a human bone-marrow cDNA library by screening with cDNA for mouse APEX nuclease. The mouse enzyme has been shown to possess four enzymatic activities, i.e., apurinic/apyrimidinic endonuclease, 3'-5' exonuclease, DNA 3'-phosphatase and DNA 3' repair diesterase activities. The cDNA for human APEX nuclease was 1420 nucleotides long, consisting of a 5' terminal untranslated region of 205 nucleotide long, a coding region of 954 nucleotide long encoding 318 amino acid residues, a 3' terminal untranslated region of 261 nucleotide long, and a poly(A) tail. Determination of the N-terminal amino acid sequence of APEX nuclease purified from HeLa cells showed that the mature enzyme lacks the N-terminal methionine. The amino acid sequence of human APEX nuclease has 94% sequence identity with that of mouse APEX nuclease, and shows significant homologies to those of Escherichia coli exonuclease III and Streptococcus pneumoniae ExoA protein. The coding sequence of human APEX nuclease was cloned into the pUC18 SmaI site in the control frame of the lacZ promoter. The construct was introduced into BW2001 (xth-11, nfo-2) strain and BW9109 (delta xth) strain cells of E. coli. The transformed cells expressed a 36.4 kDa polypeptide (the 317 amino acid sequence of APEX nuclease headed by the N-terminal decapeptide derived from the part of pUC18 sequence), and were less sensitive to methylmethanesulfonate and tert-butyl-hydroperoxide than the parent cells. The N-terminal regions of the constructed protein and APEX nuclease were cleaved frequently during the extraction and purification processes of protein to produce the 31, 33 and 35 kDa C-terminal fragments showing priming activities for DNA polymerase on acid-depurinated DNA and bleomycin-damaged DNA. Formation of such enzymatically active fragments of APEX nuclease may be a cause of heterogeneity of purified preparations of mammalian AP endonucleases. Based on analyses of the deduced amino acid sequence and the active fragments of APEX nuclease, it is suggested that the enzyme is organized into two domains, a 6 kDa N-terminal domain having nuclear location signals and 29 kDa C-terminal, catalytic domain.

Mechanism of induction of cellular DNA synthesis by the adenovirus E1A 12S cDNA product

The mechanism of induction of DNA synthesis in quiescent rat 3Y1 cells by the adenovirus E1A gene was investigated using the 3Y1 derivative cell lines g12-21, gn12RB1, and gn12RB2. The g12-21 cells express the E1A 12S cDNA and the latter two cells express both the E1A 12S cDNA and the human retinoblastoma susceptibility (Rb) gene at different levels in response to dexamethasone (dex). The cDNA sequences of E1A-inducible cell cycle-dependent genes, clone 3 and clone 16, were isolated by differential screening of a cDNA library constructed from dex-treated g12-21 cells. The quiescent 3Y1 cells induced c-fos and c-myc expression within 2 h after serum stimulation and expressed clone 16 and clone 3 transiently at around 8 h before the onset of DNA synthesis (10 h). In contrast, the quiescent g12-21 cells treated with dex expressed a high level of E1A at 6 to 8 h after treatment and expressed clone 16 and clone 3 at around 8 h without stimulation of c-fos and c-myc expression, suggesting that E1A bypasses the cell cycle early in G1. The half-maximal rate of DNA synthesis was reached in a much shorter time in dex-treated g12-21 cells (12 h) than in serum-treated 3Y1 cells (18 h), suggesting that E1A also bypasses the cell cycle at the G1/S boundary. The gn12RB1 and gn12RB2 cells were unable to induce DNA synthesis in response to dex presumably due to lower levels of E1A expression, although gn12RB2 but not gn12RB1 cells could express clone 16 and clone 3. These results suggest that the level of E1A required for bypass at the G1/S boundary is higher than that required early in G1.

cDNA and deduced amino acid sequence of a mouse DNA repair enzyme (APEX nuclease) with significant homology to Escherichia coli exonuclease III

We purified a mouse DNA repair enzyme having apurinic/apyrimidinic endonuclease, DNA 3'-phosphatase, 3'-5'-exonuclease and DNA 3' repair diesterase activities, and designated the enzyme as APEX nuclease. A cDNA clone for the enzyme was isolated from a mouse spleen cDNA library using probes of degenerate oligonucleotides deduced from the N-terminal amino acid sequence of the enzyme. The complete nucleotide sequence of the cDNA (1.3 kilobases) was determined. Northern hybridization using this cDNA showed that the size of its mRNA is about 1.5 kilobases. The complete amino acid sequence for the enzyme predicted from the nucleotide sequence of the cDNA (APEX nuclease cDNA) indicates that the enzyme consists of 316 amino acids with a calculated molecular weight of 35,400. The predicted sequence contains the partial amino acid sequences determined by a protein sequencer from the purified enzyme. The coding sequence of APEX nuclease was cloned into pUC18 SmaI and HindIII sites in the control frame of the lacZ promoter. The construct was introduced into BW2001 (xth-11, nfo-2) strain cells of Escherichia coli. The transformed cells expressed a 36.4-kDa polypeptide (the 316 amino acid sequence of APEX nuclease headed by the N-terminal decapeptide of beta-galactosidase) and were less sensitive to methyl methanesulfonate than the parent cells. The fusion product showed priming activity for DNA polymerase on bleomycin-damaged DNA and acid-depurinated DNA. The deduced amino acid sequence of mouse APEX nuclease exhibits a significant homology to those of exonuclease III of E. coli and ExoA protein of Streptococcus pneumoniae and an intensive homology with that of bovine AP endonuclease 1.

Effects of tumor necrosis factor and hyperthermia on Meth-A tumors

The combined effects of purified human natural tumor necrosis factor (TNF) and hyperthermia were investigated in a transplanted TNF-sensitive Meth-A tumor model. We assessed the sequence and interval for the two treatments, the temperature that caused maximal heat sensitization, and the effects of pH modification on this combination therapy. Tumor response was evaluated by means of a tumor growth delay assay. TNF at a dose of 50 JRU/g caused significant tumor growth delay. A synergistic effect of TNF and hyperthermia was observed when TNF was administered 10 min before heating. This thermal enhancement of the action of TNF became more prominent with an increase in the heating temperature. Tumor growth delay was maximal when TNF was given immediately before or after hyperthermia. However, after an increase in the time interval to more than 2 h, there was no enhancement of growth delay. Injection of glucose (5 g/kg) caused a significant fall in pH at 10 and 30 min after administration. Further enhancement in tumor growth delay was seen with the trimodality of glucose, TNF, and heat compared to combined treatment with heat and either TNF or glucose at a hyperthermia of 42 degrees C. This effect was not obtained with heating to 40 degrees C. TNF appears to be a potent heat sensitizer when an appropriate temperature and time interval between hyperthermia and TNF administration are used. Trimodality treatment with hyperthermia, TNF, and glucose may be a new method of anticancer therapy.

A mouse DNA repair enzyme (APEX nuclease) having exonuclease and apurinic/apyrimidinic endonuclease activities: purification and characterization

A mouse repair enzyme having priming activity on bleomycin-damaged DNA for DNA polymerase was purified to apparent homogeneity and characterized. The enzyme extracted from permeabilized mouse ascites sarcoma (SR-C3H/He) cells with 0.2 M potassium phosphate buffer (pH 7.5) was purified by successive chromatographies on phosphocellulose, DEAE-cellulose, phosphocellulose (a second time), Sephadex G-100, single-stranded DNA cellulose and hydroxyapatite. The purified enzyme has an Mr of 34,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Enzymatical studies indicated that it is a multifunctional enzyme having exonuclease, apurinic/apyrimidinic endonuclease and phosphatase activities, similar to Escherichia coli exonuclease III. This enzyme is tentatively designated as APEX nuclease for apurinic/apyrimidinic endonuclease and exonuclease activities. The amino acid composition, amino-terminal amino acid sequence and an internal amino acid sequence of APEX nuclease are determined.

A radiotherapeutic experience for localized extranodal non-Hodgkin's lymphoma: prognostic factors and re-evaluation of treatment modality

Between 1966 and 1988, 149 patients were treated with radiotherapy for localized extranodal lymphoma. The average total dose given was 39.8 Gy for low grade disease and 48.7 Gy for all other disease. Of the 149 patients, 60 also received adjuvant chemotherapy. Twenty-four had low grade lymphoma, 109 had intermediate grade disease, and 16 had high grade disease, histologically. The distribution of histological grade and T/B phenotype varied with the primary site. Low grade lymphomas were found mainly in the orbit, and T-cell lymphomas were found in the nasal cavity and nasopharynx. The 5-year survival rates according to tumor location were 89% for oral cavity, 86% for paranasal sinus, 83% for thyroid, 69% for orbit, 47% for Waldeyer's ring (WAR), 44% for testis, 23% for CNS, 21% for nasal cavity and 60% for other sites. Histological grade and T/B phenotype both had prognostic importance. Combined chemotherapy significantly improved the survival rate only for disease with intermediate or high grade histology. Other prognostic factors according to the primary site were the bulk of lymph node for WAR disease, the radiation dose for CNS disease, bone erosion for orbital disease, stridor for disease of the thyroid, and the tumor stage for disease of both the testis and the thyroid.

MR imaging of gynecologic lymphoma

We present a case of solitary secondary gynecologic lymphoma, in which MR imaging contributed to the diagnosis. The finding was a region of uterine enlargement consisting of ill-defined nodules of variable signal intensity diffusely mixed with the myometrium.

Peplomycin-induced DNA repair synthesis in permeable mouse ascites sarcoma cells

DNA repair synthesis induced in permeable mouse ascites sarcoma cells by peplomycin, an antitumor antibiotic, was studied. Mouse ascites sarcoma (SR-C3H/He) cells were permeabilized with a low concentration of Triton X-100 in an isotonic condition. Permeable cells were treated with an appropriate concentration of peplomycin to introduce single-strand breaks in permeable cell DNA. DNA repair synthesis in peplomycin-treated permeable cells was measured by incubating the cells with four deoxynucleoside triphosphates in an appropriate buffer system. The DNA repair synthesis was enhanced by ATP and NaCl at near physiological concentrations. More than 90% of DNA synthesis in the present system depended on the peplomycin-treatment. The repair nature of the DNA synthesis was confirmed by a BrdUMP density shift technique. The repair patches were largely completed and ligated in the presence of ATP. Analyses using selective inhibitors for DNA polymerases showed that both DNA polymerase Beta and aphidicolin-sensitive DNA polymerases (DNA polymerase alpha and/or delta) were involved in the repair DNA synthesis.

Adenohypophysectomy in the zebra finch

Castration and replacement of gonadal steroids have been used extensively in order to examine the hormonal regulation of song and sexual behaviors in passerine birds. However, recent studies have reported that levels of gonadal hormones may remain high following castration. In order to circumvent this problem, adenohypophysectomy might be advantageous. In this study we describe a technique for removing the anterior pituitary gland in a small passerine species (the zebra finch, Poephila guttata) using a parapharyngeal approach. The completeness of the adenohypophysectomy in individual male and female birds was examined by measuring gonadal weights as well as plasma levels of luteinizing hormone. The results indicate that this technique can be successfully applied to zebra finches. Removal of the anterior pituitary gland may represent a more effective means than gonadectomy for lowering circulating levels of gonadal hormones.

Pituitary and gonadal hormone-dependent and -independent induction of follicle-stimulating hormone receptors in the developing testis

The number of FSH receptors increases during testicular development in several species of mammals. Hypophysectomy and hormonal replacement were performed to identify the factors that induce developmental changes in testicular FSH receptors. Male rats of the Wistar/Tw strain were hypophysectomized at 9, 16, 23, or 30 days or 3 months of age. These rats were killed 10 days after surgery along with intact control rats, and the testes were removed for receptor assay. A group of intact rats was killed on the day of surgery as initial controls. All of the hypophysectomized immature rats showed a higher density of FSH binding (FSH binding per unit weight) and a lower total FSH binding (FSH binding per two testes) compared with each of the matched intact control rats. In contrast to FSH binding, not only the total LH binding but also the density of LH binding were invariably lower in the hypophysectomized rats than in the intact control rats. Unlike hypophysectomy at other immature ages, surgery at 9 days of age was followed by significant increases in testicular weight, density of FSH binding, and total FSH binding compared with those values in the initial control rats. There was no significant effect of hypophysectomy on total FSH binding in adult animals, in contrast to the marked decrease in total LH binding. When male rats hypophysectomized at 25 days of age were injected with FSH for 5 days beginning on the 11th day after surgery, dose-dependent increases in total FSH binding and testicular weight were observed. Testosterone treatment induced an increase only in the total FSH binding, but its effect was less potent. Scatchard plot analyses of the binding suggested that changes in FSH binding with age, after hypophysectomy, and after hormonal administration were due to changes in the number of binding sites. Plasma FSH concentrations in all postoperative rats were below or at the level of detectability, indicating that hypophysectomy was successful. In normal immature rats, a significant increase in the plasma FSH level was detected only from 9-19 days of age, in contrast to the continuous increase in total FSH binding during testicular development. These results suggest that FSH and testosterone act as hormonal factors to induce an increase in the number of FSH receptors in the developing testis. Other factors that are independent of pituitary and sex hormones may also contribute to FSH receptor induction.

[A case of symmetrical and bilateral tuberculoma of both lung apices]

A 28-year-old man with solitary nodular shadows in both lungs was admitted. The erythrocyte sedimentation rate was accelerated, with elevation of the serum IAP values, and the tuberculin reaction was strongly positive. The X-Ray film of the chest revealed symmetrical and bilateral nodular shadow in both lung apices. Both nodular lesions revealed a tendency to grow, pleural indentation and spiculated margins. Moreover, the tomogram film showed convergence of the pulmonary vein branch in the central part of the left apex nodule. Since it was extremely difficult to distinguish these lesions from malignant nodules based on just radiographic findings, an exploratory thoracotomy was carried out. The histologic diagnosis of both nodules was tuberculoma. Currently, the radiologic criteria used to distinguish between benign and malignant lesions are assessment of size, contour, absence or presence of tumor growing tendency by serial radiographs, calcification as well as the relation between the lesion with the pulmonary vasculature. It was concluded that, as was shown by this case, the radiographic criteria appear to be insufficient to categorize the nature of a lesion into benign or malignant. Consequently, more reliable non-invasive techniques would be desirable for the accurate diagnosis of tuberculosis.

Detection of possible DNA repair enzymes on sodium dodecyl sulfate-polyacrylamide gels by protein blotting to damaged DNA-fixed membranes

A novel method for detecting possible DNA repair enzymes on sodium dodecyl sulfate-polyacrylamide gels by blotting them onto a damaged DNA-fixed membrane is presented. To prepare the membrane, highly polymerized calf thymus DNA immobilized on a nylon membrane is damaged chemically. Enzymes, either homogeneous or crude, that are possibly involved in the priming step of DNA repair are fractionated by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and are renatured to active form by incubating the gel in an appropriate buffer. The renatured enzyme is then blotted onto the damaged DNA-fixed membrane, a process during which incision and/or excision are introduced to the damaged DNA by the enzymes. The incision and/or excision provide priming sites for repair DNA synthesis in the subsequent step in which the membrane is incubated with DNA polymerase in the presence of alpha-32P-labeled substrate. The site of substrate incorporation on the membrane reflecting the molecular weight of the repair enzyme is finally visualized by autoradiography. The present technique is established using Escherichia coli exonuclease III and a DNA-fixed membrane treated with bleomycin or acid-depurinated. By application of this method, a priming factor (an exonuclease) involved in the initiation of bleomycin-induced DNA repair is detected in the extract of mouse ascites sarcoma cells, and thus the molecular weight of the enzyme is estimated. Some apurinic/apyrimidinic endonucleases of mammals are also detected by the present procedure.

[Cell kinetic effects of a single PUVA treatment on rapidly proliferating epidermis of the stripped skin of guinea pigs]

This study investigated the cell kinetic effects of a single treatment with PUVA on guinea pig epidermis after tape stripping. Flow cytometry was used to determine the proportion of cells in S phase and G2 + M phase. Bromodeoxyuridine incorporation was used to determine the labeling index. Conventional histological techniques were used to observe the mitotic index. An initial decrease followed by a subsequent significant increase compared to the non-PUVA-treated controls was observed in all parameters studied except the mitotic index, which was below or around the control level until 168 hours after the treatment with PUVA. The results obtained in this study suggest that PUVA induces a partial blocking at G1-S boundary for short duration, and that when the partial G1 block is released, then the cells of stimulated epidermis enter DNA synthesis and pass through the S phase to the G2 phase in partial synchrony. It is also suggested that PUVA blocks the passage of cells from the G2 phase to mitosis, resulting in an long-lasting accumulation of cells in the G2 phase.

Effects of prolactin and bromocryptine on the regulation of testicular luteinizing hormone receptors in mice

The binding of luteinizing hormone (LH) to testicular homogenates increased gradually in mice from 15 to 60 days of age, while the level at 90 days was almost the same as that at 60 days. The plasma concentration of prolactin (PRL) increased significantly from 15 to 40 days and thereafter remained constant. In order to ascertain the influence of PRL on testicular receptors for LH, bromocryptine was injected subcutaneously for 10 days into immature (20-day-old) and adult (90-day-old) mice. In 20-day-old mice, treatment with bromocryptine significantly reduced the plasma levels of PRL but had no significant effects on the binding of LH to receptors in 30-day-old mice. However, in 90-day-old mice, treatment with bromocryptine led to a significant reduction in numbers of receptors for LH 10 days later. There was no difference in dissociation constants (Kd) between groups of oil-injected (Kd = 6.5 x 10(-10) M) and bromocryptine-injected (Kd = 4.6 x 10(-10) M) mice. The reduction in binding of LH per testis of 100-day-old mice after treatment with bromocryptine was eliminated by the simultaneous administration of ovine (o) PRL. The plasma level of follicle-stimulating hormone (FSH) in 100-day-old mice, which tended to be decreased as a result of treatment with bromocryptine, was markedly increased by treatment with oPRL. There were no distinct changes in binding of FSH in any of the groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Extranodal non-Hodgkin's lymphoma of the head and neck. A clinicopathologic study in the Kyoto-Nara area of Japan

The clinicopathologic features of 114 Japanese patients with extranodal non-Hodgkin's lymphoma of the head and neck region were analyzed. The median age was 60.5 years and the male:female ratio was 1.5:1. The most common site of involvement was Waldeyer's ring, followed by the oral cavity, thyroid gland, paranasal sinuses, nasal cavity, and larynx. Seventy-five percent of the patients were in Stage I or Stage II at admission. Histologically, diffuse lymphoma accounted for 94% and follicular lymphoma for 6% of cases. The histologic grade according to the Working Formulation System of the National Cancer Institute was low in 11%, intermediate in 75%, and high in 14% of cases. Immunohistochemical study showed that the majority of the cases were of B-cell type and only 13 cases (11%) were of the T-cell type. Peripheral T-cell lymphomas (eight cases) mainly occurred in the nasopharynx and nasal cavity, whereas four of five thymic T-cell lymphomas were found in the palatine tonsil. The over-all 5-year survival rate was 54%, and the factors affecting survival were sex, histologic grade, T/B phenotype, clinical stage, and the site of initial presentation. Five-year survival with nasal cavity and Waldeyer's ring lymphoma was 24% and 46%, respectively. The poor prognosis of lymphomas at these sites might result from the predominance of T-cell lymphoma, the paucity of low grade lymphoma, and the relatively high incidence of cases that were in an advanced stage at presentation. In Stage II, patients treated with combined therapy tended to have a better 5-year survival rate than those treated with radiotherapy alone.

Two-step transformation of rat 3Y1 cells by the adenovirus E1A and E1B genes

The transformation of rodent cells by the adenovirus E1A and E1B genes was very efficient when these genes were physically linked. When they were cleaved, the transformation became very inefficient. To clarify this difference, the chimeric E1B genes in which either the adenovirus enhancer or the human beta-actin promoter was linked to the 5' side of the E1B gene were introduced into rat 3Y1 cells. The saturation density of these cell lines (eB or APrB) was similar to that of parental 3Y1 cells. When eB or APrB cell lines were supertransfected with the E1A gene, discrete dense foci were developed after 5-6 weeks, while the supertransfection of 3Y1 derivative cell lines, in which the enhancer-unlinked E1B gene was introduced, did not develop any dense foci. Analysis of the E1A and E1B transcripts in these cell lines indicated that the E1B gene is efficiently expressed in the presence of the E1A gene products if the enhancer is linked to the E1B gene and that an increased level of E1B proteins is required for an efficient expression of the E1A gene. These results indicated that E1A and E1B genes in separate pieces of DNA are capable of cooperatively transforming 3Y1 cells if appropriate cis-acting elements are attached and high-level expressions are achieved.

Improved survival rate in primary intracranial lymphoma treated by high-dose radiation and systemic vincristine-doxorubicin-cyclophosphamide-prednisolone chemotherapy

Thirty patients with histologically proven primary intracranial non-Hodgkin's lymphoma were treated at Kyoto University. Ten of them were treated prospectively with a radiation-chemotherapy protocol. All but four specimens were recently reexamined and classified according to the Working Formulation system. The predominant histologic types were diffuse large cell type, large cell immunoblastic type, and diffuse mixed small and large cell type, seen in 38%, 21%, and 21% of cases, respectively. Before 1980, 16 patients were treated with postoperative radiation without definite chemotherapy, and only one has survived more than 5 years. Local recurrence was the most common cause of failure. In 1981, the authors started a protocol in which four to six courses of systemic chemotherapy with vincristine, doxorubicin, cyclophosphamide, and prednisolone (VEPA) was given after whole brain radiation (30-40 Gy) with a local boost up to 50 to 60 Gy. Eight patients completed this protocol, and all of them are alive at 16 to 100 months after diagnosis, with three patients surviving more than 5 years. Only one patient developed recurrence. On the other hand, six patients who did not complete or receive chemotherapy after 1981 are dead or alive with recurrence. Correlation between the Working Formulation subtype and prognosis was not clear because of the variety of treatment. Two patients receiving chemotherapy developed brain necrosis, which was fatal in one case, and the other two patients treated with the protocol are in a poor state without signs of recurrence. Chemotherapy may enhance the radiation effect on normal brain tissue as well as tumor. Combination of radiotherapy and chemotherapy can improve the survival rate, but the optimal dosage needs to be investigated further.

Effects of PRL and FSH on LH binding and number of Leydig cells in hypophysectomized mice

The effects of PRL and FSH on testicular LH receptors were studied in hypophysectomized (hypox) mice. From the eleventh day after hypophysectomy, they were given 100 micrograms ovine (o) PRL and/or 2 micrograms oFSH in two injections per day for 10 days. Hypophysectomy reduced the weight of testis, epididymides and seminal vesicles, and the LH binding to the testis. Treatment with oPRL and/or oFSH in hypox mice resulted in an increase in the weight of testis and epididymides, and the LH binding per testis. There was no difference between the testicular LH binding in oFSH- and oPRL-treated mice. Histological examination showed that oPRL and/or oFSH treatment in hypox mice restored normal spermatogenesis. Administration of oFSH to hypox mice led to an increase in the number of typical Leydig cells, whereas oPRL was not effective. These results suggest that either PRL or FSH stimulates the LH binding to the testis, but that the action of PRL and FSH on the increase in testicular LH binding is different.

[Radiographic staging procedures and radiotherapy of malignant lymphoma]

Radiographic studies play an important role in the clinical staging of malignant lymphoma (ML). Conventional procedures are plain chest X-ray, lymphangiography, gastrointestinal series, and 67Ga scintigraphy. Gastro-intestinal series is essential in non-Hodgkin's lymphoma (NHL) of Waldeyer's ring and thyroid. 67Ga scintigraphy is a non-invasive procedure useful in the screening of ML. Recently marked improvements have been made in the diagnostic modalities. CT scan and NMR have made it very easy to diagnose ML of the central nervous system and detect the extension of tumors at all sites. In some cases with Hodgkin's disease (HD), staging laparotomy is necessary, but not in cases with NHL. If tumors are localized, subtotal or total nodal irradiation is performed for patients with HD, and generous involved field is employed for NHL with or without combined chemotherapy at our department. Good local control is obtained except for NHL of the central nervous system at a total dose of 40-50 Gy. NHL is prone to relapse outside the radiation field. Therefore we consider that combined chemotherapy is indicated for NHL such as T-cell lymphomas, those with high grade histology classified according to the Working Formulation, and with involvement of lymph nodes larger than 6 cm in diameter.

[Clinical results of conventional fractionation radiotherapy for glottic and supraglottic laryngeal cancers--the usefulness of hyperfractionation for these cancers]

Ninety patients with glottic and eighteen patients with supraglottic laryngeal cancer (anyN, M0) were treated by conventional fractionation radiotherapy between July, 1963 and August, 1988. Tumor control and cause specific survival were evaluated according to tumor location (glottic or supraglottic) and tumor size (T1, T2, T3, or T4). As a result, the steepness of dose-response curve for the tumor control in T1-2 glottic and T2 supraglottic tumors was more slanting upwards than that in other laryngeal tumors, and the patients whose tumors were irradiated at larger doses had a tendency to survive longer. These results suggested that T1-2 glottic and T2 supraglottic laryngeal tumors can have a good application for hyperfractionation radiotherapy which is a radiation therapy with multiple fractions per day with a small fraction size and with which tumors can receive larger radiation doses than with conventional fractionation radiotherapy. Five patients with glottic or supraglottic tumors treated by hyperfractionation radiotherapy obtained CR, and now show no recurrence. We are going to investigate the usefulness of hyperfractionation radiotherapy after treating more patients with Twice-A-Day fractionation radiotherapy.

Effect of recombinant human granulocyte colony-stimulating factor on granulocytopenia in mice induced by irradiation

We report the effect of human granulocyte colony-stimulating factor (hG-CSF) on the recovery from granulocytopenia induced by irradiation. Female 9-week old C3H/He mice were used. The irradiation schedule was as follows: Group 1 and 2 received whole-body irradiation of 1 Gy and 5 Gy, respectively, on day 0; Group 3 and 4 received whole-body irradiation of 0.5 and 1.0 Gy, respectively, for 5 consecutive days; Group 5 received upper hemibody irradiation of 3 Gy for 5 consecutive days. Daily subcutaneous injections of G-CSF (3 x 10(5) Unit/mouse) or 0.3 ml of saline to each group were started from the day after the first irradiation and continued for 18 days. Mice were sampled randomly from each group, and the total number of leukocytes, erythrocytes of peripheral blood, nucleated cells in femur, and spleen weight were counted and measured, respectively, on day 0, 3, 5, 7, 9, 12, and 18. The leukocyte counts decreased with an increase in radiation doses. In Group 1 and 2 mice, G-CSF enhanced the leukocyte count more than saline. In Group 3 mice, the recovery of leukocytopenia was facilitated by G-CSF, but in Group 4 mice, G-CSF had no effect on the leukocyte count decrease or on leukocytopenia recovery. In Group 5 mice, G-CSF greatly affected leukocytopenia recovery. Increase in spleen weight paralleled the peripheral leukocyte count. Daily administration of recombinant hG-CSF accelerated the granulocytopenia recovery which was induced by irradiation, and it may be a useful therapeutic agent for treating myelosuppressive cases.

Combined effect of radiation and YM-881 (SMANCS) on murine tumors and bone marrow

The combined effect of radiation and YM-881 (SMANCS) was studied in vitro and in vivo. When 0.25 microgram/ml of YM-881 was simultaneously combined with radiation, during and after irradiation for 30 min in total, Dq decreased from 3.3 Gy to 1.4 Gy without changing D0 in the dose-survival curve of exponentially growing SCC VII tumor cells. Five or ten times administrations of 0.1 mg/kg YM-881 at an interval of 24 h did not inhibit tumor growth. However, administration of 0.1 mg/kg YM-881 just before every irradiation which was repeated five times at an interval of 24 h yielded dose modifying factors (DMFs) of 1.8-1.2 when the tumor response to treatment was evaluated by the time for the tumors to regrow to three times the original volume. Administration of YM-881 ten times just before every irradiation yielded DMFs of 1.3-1.2. Adverse effects of the combination on bone marrow were examined by spleen colony assay. After five injections of 0.1 mg/kg YM-881, the mean number of CFU-S per femur decreased to 77% of the pretreatment level, but this was not significant statistically (0.1 greater than p greater than 0.05). The slope of radiation response curve for CFU-S per femur was not affected by the combination.

[Results of radiation therapy for medulloblastoma]

Results of radiation therapy for cerebellar medulloblastoma at Kyoto University Hospital were reviewed. Between 1962 and 1988, 30 patients with histologically-proven medulloblastoma completed radiotherapy. Before 1971, the treatment volume was either the posterior fossa only or posterior fossa plus spinal axis, but after 1972, it was extended to include the entire neuraxis. The mean dose was 48 Gy to the posterior fossa, 36 Gy to the whole brain, and 25 Gy to the spinal axis. The 5-year survival rate and 5-year relapse-free survival rate estimated by the Kaplan-Meier's method were 36% and 37%, respectively, for total cases, but were as high as 79% and 80%, respectively, for the recent 10 patients. This improvement in the treatment results appeared to be due to extensive tumor resection and improved radiotherapy technique, and not to the use of chemotherapy. The prognosis was significantly better in patients treated with craniospinal irradiation than in those otherwise treated. There was a trend towards better survival in patients who received 50 Gy or more to the posterior fossa or 24 Gy or more to the spinal axis, compared to the patients who received lower doses to each site. No significant morbidity of radiotherapy was seen. Four of the six surviving patients who were treated below age 12 have a mental retardation and/or a short stature, but one patient treated at age 5 has a normal growth and a good intelligence. From these analysis, it is recommended to irradiate craniospinal axis and posterior fossa up to 25-35 Gy and 50-55 Gy, respectively.

The correlation between cell survival curve and dose response curve of micronucleus (MN) frequency

The correlation between cell survival curve and dose response curve of MN frequency following irradiations was studied using cytokinesis-block method. Both dose response curves were analyzed by linear quadratic model, i.e. SF = exp (-alpha D-beta D2) and MN frequency = aD + bD2 + C. A good correlation between alpha/beta and a/b ratios was observed in repeated paired experiments (= 0.97). When the cells were treated with BUdR, alpha-type radiosensitizer, a value in dose response curve of MN frequency increased but b value did not. These data present that MN frequency assay using cytokinesis-block method is available as a tool of rapid assay of radiosensitivity of cells.

Combined effects of radiation and IUdR on experimental liver tumors and hepatocytes

IUdR, a thymidine analogue, increased the radiosensitivity of SCC VII tumor cells. A decrease in Dq value of cell survival curve was more prominent compared with that in D0 value. However, in experimental liver tumors made by transplanting SCC VII tumors, the decrease in D0 value was apparent. Proportion of IUdR incorporated tumor cells in the liver increased with an increase in number of IUdR injections, and reached 52% after five administrations of the drug at an interval of twelve hours. However, few hepatocytes incorporated IUdR. The response of hepatocytes to radiation was evaluated by micronucleus appearance frequency. To accelerate the appearance of micronucleus in hepatocytes, partial hepatectomy was performed immediately after irradiations. No differences in micronucleus frequency were observed between the treated and untreated with IUdR.

Changes in the testicular binding of luteinizing hormone and plasma testosterone concentrations in the Djungarian hamster subjected to different photoperiods and temperatures and effects of long-term testosterone treatment on the binding

The effects of artificial photoperiod, temperature, and long-term testosterone treatment on testicular luteinizing hormone (LH) binding were studied in adult male Djungarian hamsters. In hamsters transferred to long-day (LD; 16 hr light, 8 hr dark) photoperiod 8 weeks after adaptation in short-day (SD; 8 hr light, 16 hr dark) photoperiod of 25 degrees C, testicular growth was associated with an increase in the total LH binding per two testes and a decrease in LH binding per unit testicular weight. Plasma testosterone levels reached a peak 47 days after transfer to LD and tended to decrease thereafter, while the testes continued growing. In contrast, when hamsters reared under LD conditions at 25 degrees C for 12 weeks were transferred to SD, testicular regression was associated with a decrease in plasma testosterone and the total LH binding per two testes and an increase in LH binding per unit testicular weight. A significant decrease in LH binding per unit weight compared to SD controls was observed in those hamsters exposed to SD with continuous testosterone treatment. The testosterone treatment tended to induce decrease in the total LH binding. Scatchard plot analyses of the binding suggested that changes in LH binding were due to changes in the number of binding sites. When sexually mature male hamsters were subjected for 8 weeks to two different ambient temperatures (7 degrees C and 25 degrees C) and photoperiods (LD and SD), the difference between the two temperature groups was statistically not significant regarding the weights of testes, epididymides, and prostates; plasma testosterone levels; and LH binding in either LD or SD group. These results suggest that photoperiod is a more important environmental factor than temperature for the regulation of testicular activity and LH receptors and that testosterone reduces the number of LH receptors per unit testicular weight in adult male Djungarian hamsters.

Unique features of monoclonal IgG2b in the cleavage reaction with pepsin

Preparations of IgG2b purified from several mouse hybridoma clones were highly susceptible, compared to other subclasses, to peptic digestion under conditions usually used to prepare F (ab')2 fragments. Analyses of the digestion products revealed that no F (ab')2 was produced and that the main product was a Fab-like fragment. Demonstration of the hinge disulfides in the Fc portion clearly indicated that in IgG2b the primary peptic cleavage occurs on the NH2-terminal side of the inter-heavy chain disulfide bridge. The resulting Fab failed to bind with antigen, suggesting the importance of the CH1-hinge region in maintaining the native conformation of the antigen-binding site.

The effect of arterial oxygen content on the results of radiation therapy for epidermoid bronchogenic carcinoma

Anemia is believed to be an important prognostic factor in treating cancer patients by radiation therapy. One possible explanation for this is tumor oxygenation. With respect to tumor oxygenation, the arterial oxygen content (CaO2) may be of more importance than the hemoglobin (Hb) level. This study shows the relationship between the CaO2 and tumor response to radiation therapy. Forty-two patients with epidermoid bronchogenic carcinoma, treated by irradiation alone between April 1982 and March 1986, were reviewed. Regression of the tumor after radiation therapy was calculated as a percent change in the tumor area. Arterial oxygen partial pressure (PaO2), Hb level, and percent oxygen saturation of Hb in arterial blood (SaO2) were measured within 2 weeks of commencement of radiation therapy and the CaO2 was calculated. The rank correlation coefficients between the maximum percent regression of the tumor and the PaO2, the Hb level and the CaO2 were 0.36, 0.34, and 0.46, respectively. Statistical analyses of the data indicate that the group of patients with CaO2 over 14.5 ml/dl exhibited greater tumor regression and longer survival periods than the group of patients with CaO2 below 14.5 ml/dl. Similarly patients with PaO2 over 90 mmHg or Hb level over 11 g/dl, exhibited significantly greater tumor regression and longer survival periods than those with PaO2 below 90 mmHg and Hb level below 11 g/dl. There were no significant differences in the length of survival periods with respect solely to the Hb level or the PaO2. It was concluded that the CaO2 is more important than the Hb level in determining tumor response to radiation therapy. This is considered as important indirect evidence of the existence of hypoxic fractions of cells in human tumors.

Incorporation of exogenous circular DNA into large catenated networks in isolated nuclei. Evidence for involvement of the nuclear scaffold

Circular plasmid DNA was efficiently converted into huge catenated intranuclear networks by incubation with isolated nuclei in the presence of ATP. The network production is abolished by omission of ATP, strongly inhibited by etoposide (VP-16), but only slightly inhibited by antibody to topoisomerase I, indicating that the major enzyme responsible for catenation is DNA topoisomerase II. Under optimal conditions, a single nucleus incorporates about 4.2 x 10(4) DNA rings into its networks. Under the light microscope, networks retrieved from nuclei appear like spheres of various sizes. Sedimentation analysis showed that most of the networks are composed of thousands of catenated rings, which was confirmed by electron microscopy. Data from experiments that caused partial disruption of the networks were submitted to analysis based on probable models of catenane structure. The results suggest that the predominant pattern is a linear alignment of catenated rings. Similar networks are formed when the nuclear scaffold is incubated with circular DNA in the presence of nuclear extract containing topoisomerase II. Titration experiments showed that the scaffold binds a stoichiometric amount of the substrate and that a critical level of DNA is required for network formation. The results are consistent with the idea that DNA-binding sites are fixed on the scaffold and mediate catenation of bound DNA circles by holding them in close proximity to each other. We propose that catenation by the nuclear scaffold also occurs in intact nuclei, suggesting additional roles for the scaffold in vivo.

Variation in tumor response to fluosol-DA (20%)

The effects of Fluosol-DA 20% (FDA) and carbogen (95% O2/5% CO2) on radiosensitivity of the three experimental tumors, SCC VII tumor, RIF-I tumor, and transplanted mammary tumor of C3H/He mouse, subcutaneously inoculated in the leg were examined. The effect of FDA plus carbogen, and carbogen alone on radiosensitivity of SCC VII and RIF-I tumors was tested using the in vivo-in vitro assay. The growth curves were obtained for both SCC VII tumor and transplanted mammary tumor. The effect of the combination of FDA and carbogen was only observed in the transplanted mammary tumor. In the other two tumors, only the effect of inspiring carbogen was observed. We concluded that the effect of FDA on the radiosensitivity of experimental tumors varies with the kind of tumor systems.

Rapid purification of squirrel monkey retrovirus-H major gag protein by high performance liquid chromatography

The major gag protein (p34) of squirrel monkey retrovirus-H was purified in one chromatographic step by anion-exchange high performance liquid chromatography. The virus in a crude fraction was disrupted with Brij 35 in the presence of three kinds of protease inhibitors. The soluble virus lysate was injected into a Polyanion SI column, and p34 was eluted with a linear salt gradient. The recovery of the protein was about 60%. The purified p34 was nearly homogenous as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and silver staining.

Interleukin-1 inducing activity of a streptococcal preparation OK-432 and its fractions by human monocytes

Interleukin-1 (IL-1) inducing activity of a streptococcal preparation OK-432 and its fractions by monocytes were investigated in patients with lung cancer and healthy subjects. The results showed that cell free extracts and cell wall fractions of OK-432 were the strong IL-1 inducing fractions. IL-1 activity released by OK-432-stimulated monocytes of patients with lung cancer fell within normal range. OK-432 stimulated intracellular IL-1 synthesis as well as extracellular release by monocytes. These results, therefore, suggested that OK-432 immunotherapy in patients with malignant diseases might be effective by increasing IL-1 production of monocytes.

Properties of follicle-stimulating hormone receptors and changes during annual breeding cycle in the testis of short-tailed bandicoot rat, Nesokia indica

Some properties and seasonal changes of follicle-stimulating hormone (FSH) receptors in the testis of short-tailed bandicoot rat, Nesokia indica, were studied. The binding of FSH was highly specific for mammalian FSHs and located primarily in the testis. The Scatchard plot analyses of the binding of FSH to the testicular preparations of N. indica showed straight lines similar to those of albino Wistar rats, suggesting the presence of a single class of FSH-binding sites. The mean dissociation constants (Kds) for FSH receptors of N. indica were 1.416 (0.964-2.667, 95% confidence interval) nM in December, 1986; 1.348 (0.885-2.849) nM in April, 1987; and 3.039 (1.678-16.127) nM in August to October, 1987. No significant differences were found among the three groups, but they were all significantly greater than those in Wistar rats. The FSH binding per unit weight of tissue during non-breeding phase (June, 1987) was lower than those during other phases (December, 1986; April and August-October, 1987). Calculated numbers of FSH-binding sites showed no statistically significant differences among the latter three phases. In June preparations the number of binding sites was not determined due to their extremely low binding capacity.

Blastogenic responses of human lymphocytes to a streptococcal preparation OK-432 and its fractions

This study was undertaken to examine the blastogenic responses of PBL to Streptococcal preparation OK-432 and its fractions. The results showed that OK-432 and its fractions, Su-PR and PM, have the mitogenic activity against human lymphocytes. The demonstration that PBL which had been cultured with OK-432 expressed IL-2 receptors and the blastogenic responses of PBL to OK-432 were inhibited by anti-IL-2 antibody suggested that IL-2 and IL-2 receptors might play a central role in OK-432-induced proliferation of human lymphocytes.

Single-strand DNA cleavages by eukaryotic topoisomerase II

A new purification method for eukaryotic type II DNA topoisomerase (EC 5.99.1.3) is described, and the avian enzyme has been purified and characterized. An analysis of the cleavage reaction has revealed that topoisomerase II can be trapped as a DNA-enzyme covalent complex containing DNA with double-stranded and single-stranded breaks. The data indicate that DNA cleavage by topoisomerase II proceeds by two asymmetric single-stranded cleavage and resealing steps on opposite strands (separated by 4 bp) with independent probabilities of being trapped upon addition of a protein denaturant. Single-strand cleavages were directly demonstrated at both strong and weak topoisomerase II sites. Thus, a match to the vertebrate topoisomerase II consensus sequence (sequence; see text) (N is any base, and cleavage occurs between -1 and +1) [Spitzner, J.R., & Muller, M.T. (1988) Nucleic Acids Res. 16, 5533-5556)] does not predict whether a cleavage site will be single stranded or double stranded; however, sites cleaved by topoisomerase II that contain two conserved consensus bases (G residue at +2 and T at +4) generally yield double-strand cleavage whereas recognition sites lacking these two consensus elements yield single-strand cleavages. Finally, single-strand cleavages with topoisomerase II do not appear to be an artifact caused by damaged enzyme molecules since topoisomerase II in freshly prepared, crude extracts also shows the property of single-strand cleavages.

Treatment results of intracranial germinoma as a function of the irradiated volume

Between 1962 and 1986, 70 patients were treated with radiation for confirmed or suspected intracranial germinoma at our hospital. The diagnosis was based on histology in 30 cases, cerebrospinal fluid (CSF) cytology in 12 cases, and on clinical and radiological findings in the remaining 28 cases. The target of radiation was the primary tumor site in 34 cases (Group A), the entire neuraxis in 22 cases (Group B), the whole brain in 4 cases (Group C), and the ventricle plus spine in 6 cases (Group D). Four patients were not included in the above groups for various reasons. The average radiation dose was 50-55 Gy to the tumor, 30 Gy to the whole brain, and 24 Gy to the spinal axis. The 5- and 10-year survival rates of the 68 primary cases in which radiotherapy was completed were 86% and 79%, respectively. The survival and relapse-free survival rates for the above 4 groups did not differ significantly, although slightly better results were seen in Groups B and C. Five cases in Groups A and D developed intracranial recurrence, 4 adjacent to the primary site but 1 distant from it, whereas no intracranial recurrence was found in the whole-brain-treated groups (B and C). One patient in Group B developed spinal metastasis, which was possibly due to inadequate radiation fields, and another in Group B developed abdominal metastasis via the shunt tube. Craniospinal irradiation should be administered to the patients with demonstrated meningeal seeding or with a positive CSF cytology. For cytology-negative cases with no evident metastasis, irradiation of the tumor plus a wide margin is usually sufficient, but craniospinal irradiation should be considered when the disease extends along the ventricular walls or is present in both pineal and suprasellar regions.

The nuclear scaffold exhibits DNA-binding sites selective for supercoiled DNA

Binding of exogenous DNA to the nuclear scaffold was investigated using a plasmid DNA (pBR322, EcoRI site deleted) of various topological forms and nuclear subfractions with different levels of nuclear DNA depletion. When supercoiled DNA was incubated with histone-depleted nuclei (nuclear halo), a dose-dependent binding of the DNA occurred, whereas no binding was observed with relaxed and linear forms of DNA. The bound DNA was released upon linearization with BamHI or digestion of the scaffolding structure with proteinase K. Extensive digestion of the halo with micrococcal nuclease generated additional sites which bind both relaxed and linear DNA. In the presence of a large excess of calf thymus DNA, these sites were effectively blocked and the specificity to supercoiled DNA was restored. The binding of all forms of DNA was abolished by heat-denatured DNA. There was no detectable change in linking number of the scaffold-associated supercoils. Competitive binding was observed between supercoiled DNAs with unrelated sequences, indicating that no specific nucleotide sequence is required for the binding. RNA was found to be a weak competitor. A DNA binding assay performed on electrophoretic blots of solubilized nuclear scaffold revealed a protein component with apparent molecular weight of 120,000 which retained selective binding to supercoils. These results suggest that the nuclear scaffold possesses DNA-binding sites for torsionally strained domains of chromatin and that an integral protein factor is involved in the binding. Implications of the findings are discussed in connection with proposed functions of the nuclear scaffold and topoisomerase II.

Inhibitory effect of Sertoli cell-cultured media on LH binding to mouse Leydig cells in culture

The aim of this study is to examine the influence of Sertoli cells on LH binding to Leydig cells in culture in immature mice. Leydig cells and Sertoli cells were obtained from the testes of immature C57BL/6Ncrj mice and were cultured in serum-free medium for 7 days. The LH binding to Leydig cells and the FSH binding to Sertoli cells were dependent on incubation time, the number of cells, and the amount of labelled hormone added. The dissociation constant for LH binding to Leydig cells was 7.3 x 10(-10) M. Co-culture of Leydig cells with Sertoli cells for 7 days decreased LH binding to Leydig cells. The binding was 34.9% of that to Leydig cells cultured alone. After cultivation of Leydig cells with spent Sertoli cell-cultured medium (SM) for the last 4 days of the 7-day culture period, LH binding to Leydig cells decreased to as low as 17.4% of that of the controls. For the controls, LH binding was measured in Leydig cells cultured in spent Leydig cell-cultured medium (LM). There was no difference between SM- and LM-cultures in the final survival rate or the percentage of cells showing histochemically demonstrated 3 beta-hydroxysteroid dehydrogenase activity. These data suggest that some factor or factors are secreted from the cultured Sertoli cells and inhibit the binding of LH to Leydig cells in culture.

Effects of photoperiod and temperature on the binding of follicle-stimulating hormone (FSH) to testicular preparations and plasma FSH concentration in the Djungarian hamster, Phodopus sungorus

The effects of artificial photoperiod and temperature on testicular FSH binding and plasma FSH levels were studied in adult male Djungarian hamsters. In Exp I, hamsters were transferred to long day (LD) photoperiods (16-h light, 8-h dark) after 8 weeks of adaptation in short day (SD) photoperiods (8-h light, 16-h dark), but the ambient temperature was maintained at 25 C throughout the experiments. A marked increase in the total FSH binding per two testes occurred between 10 and 47 days after transfer to LD, a change that was accompanied by testicular growth. Binding of FSH per testicular weight decreased during the same period. Scatchard plot analyses of the parameters indicated that LD decreased both the concentration of FSH binding sites and the equilibrium dissociation constant (Kd). Plasma FSH levels increased between 10 and 47 days after transfer to LD. In contrast, when hamsters reared under LD for 12 weeks were transferred to SD (Exp II), FSH binding per unit weight basis increased 19 weeks after transfer to SD, but the total binding per two testes decreased markedly. In Exp III, sexually mature male hamsters were subjected to different ambient temperature and photoperiods. There were no significant effects of different ambient temperatures on the testicular weight and testicular FSH binding in animals exposed for 8 weeks to either LD or SD. However, plasma FSH levels of hamsters maintained at 25 C under LD was significantly higher than FSH levels at 7 C under LD. A similar effect of temperature on plasma FSH levels was observed in hamsters under SD. The present study indicates that photoperiod is a more important environmental factor than temperature for the regulation of FSH receptor in the Djungarian hamster.