Computerized quantitation of synergism and antagonism of taxol, topotecan, and cisplatin against human teratocarcinoma cell growth: a rational approach to clinical protocol design

BACKGROUND

Cisplatin-based induction chemotherapy may achieve a complete response (i.e., no sign of tumor following treatment) in 70%-80% of patients with germ cell tumors. However, only a minority of patients in whom the firstline regimens fail are cured with the salvage regimens.

PURPOSE

The aim of these studies was to identify new agents or new regimens for the treatment of germ cell tumors by carrying out quantitative assessment in vitro of two promising new antitumor agents (paclitaxel [Taxol] and topotecan) and three more established agents (cisplatin, vincristine, and etoposide). These agents were used singly or in two- and three-drug combinations and were selected because they represent five distinct categories of antineoplastic mechanisms.

METHODS

The combination index-isobologram method, which is based on the median-effect principle developed by Chou and Talalay, was used for computerized data analysis. This method was selected because it takes into account both the potencies of each drug and combinations of these drugs and the shapes of their dose-effect curves.

RESULTS

Synergism against the growth of teratocarcinoma cells resistant to cisplatin (833K/64CP10 cells) was greater than against the growth of parent 833K cells. The degrees of synergism were in the following order: cisplatin + topotecan > or = paclitaxel + cisplatin + topotecan > paclitaxel + topotecan > or = paclitaxel + etoposide > paclitaxel + cisplatin + etoposide > paclitaxel + cisplatin. All other combinations showed nearly additive effects or moderate antagonism. The degrees of antagonism were as follows: cisplatin + etoposide > or = paclitaxel + vincristine > paclitaxel + cisplatin + vincristine > cisplastin + vincristine. The combination of paclitaxel and cisplatin was synergistic against 833K/64CP10 cells and moderately antagonistic against 833K cells. Since the combination of paclitaxel, cisplatin, and topotecan and the two-component combinations of these drugs (cisplatin + topotecan and paclitaxel + topotecan) showed synergism stronger than that of other combinations, these three drugs were selected for illustrating detailed data analysis, using a computer software program developed in this institute.

CONCLUSIONS AND IMPLICATIONS

Our findings suggest that, as a result of synergy, the doses of these agents needed to achieve an antitumor effect may be reduced by twofold to eightfold when these agents are given in combination. The present quantitative data analyses for synergism or antagonism provide a basis for a rational design of clinical protocols for combination chemotherapy in patients with advanced germ cell tumors.

Localization of diazepam-binding inhibitor and peripheral type benzodiazepine binding sites in the rat ovary

Diazepam-binding inhibitor (DBI) is the precursor of a family of peptides, including an octadecaneuropeptide (ODN), that share with DBI the ability to specifically displace benzodiazepines (BZD) from their receptors. An association of ODN with the peripheral type BZD receptors (PBR) has been reported in the brain and a few peripheral tissues. In order to investigate whether DBI and PBR are present in ovarian tissue, we have localized DBI by means of immunocytochemistry, in situ hybridization and autoradiography of PBR in the rat ovary. Immunocytochemical localization was achieved by means of rabbit antibodies developed against rat ODN. Immunostaining was located in the cytoplasm of the theca interna, corpus luteum and interstitial gland cells, but not in the granulosa cells. Hybridization signal obtained following in situ hybridization with a [35S]-labelled single-stranded RNA probe complementary to DBI mRNA was observed in all the steroid-secreting cells, including granulosa cells of developing and mature follicles. Autoradiographic localization of PBR obtained by incubating ovary sections with [3H] PK11195, a ligand selective for PBR, revealed the presence of specific labelling in all the steroid-secreting cells. These results, which demonstrate for the first time that the ovarian steroid-secreting cells contain both PBR and its endogenous ligand, suggest that the BZD receptor might be involved in the regulation of ovarian function.

The value of duplex scanning in surveillance of infra-inguinal vein and synthetic grafts

The contribution of duplex scanning to improving early diagnosis of graft stenosis was evaluated in 195 patients after infrainguinal bypass procedures. Over a 31 month period. 406 duplex scans were obtained on 232 limbs with 191 vein and 41 polytetrafluoroethylene (PTFE) grafts. Peak systolic velocities > 200 cm/s with spectral broadening and lumen reduction on B-mode image were the criteria adopted for identification of a haemodynamically significant (> 50%) stenosis. Sixty-one stenoses were identified in 55 of the grafted limbs. Thirty-three of the 55 limbs had a subsequent angiogram. The angiogram showed graft occlusion in six limbs, graft stenosis in 18, and native artery stenosis in four. Twenty-one of the grafts had the angiogram within 1 month after the duplex had detected graft stenosis, and one (4.76%) became occluded in this interval. Seven had an angiogram more than 1 month after the duplex study, and five (71.4%) had become occluded. The angiographic study did not confirm a graft stenosis in five limbs. Three were submitted to operation and stenosis was confirmed. Seventeen graft thromboses were detected by duplex scanning. Graft thrombosis was demonstrated following a previous negative duplex scan in one of the 106 vein grafts (0.94%), and in four of 30 PTFE grafts (13.3%). Duplex scanning is effective in the detection of graft stenosis. The precise anatomical location is less accurate when in the region of an anastomosis. Early attention should be taken when duplex studies suggest critical stenosis because there is a high risk of occlusion. Polytetrafluoroethylene grafts tend to thrombose without a precursory focal stenosis.

An anatomic source of false venous reflux with continuous wave Doppler

BACKGROUND

The limitations of continuous wave (CW) Doppler have been recognized in the assessment of venous reflux since CW Doppler is not able to distinguish reflux signals from more than one vein. In our experience, some regions with venous reflux suggested by CW Doppler were noted to have no reflux in any individual vein during duplex studies.

OBJECTIVE

The aim of the study was to assess the anatomic source of the venous reflux suggested by CW Doppler but not confirmed by duplex ultrasound.

METHODS

Five hundred and fifty-one consecutive lower limbs with primary or recurrent varicose veins were examined with CW Doppler and subsequently by color-coded duplex ultrasound to assess the source of venous reflux.

RESULTS

The duplex ultrasound study revealed no reflux in 44 specific regions (8%) where reflux had been indicated by CW Doppler. Two types of anatomy were noted. Two or more superficial veins joined the deep venous system via a common junction in 25 cases. A descending vein joined the deep venous system in 19 cases.

CONCLUSION

A bidirectional Doppler signal in a region of venous junction without any incompetent veins can be misinterpreted as venous reflux. A careful examination of veins not only at the region of the junction, but also at some distance down the stem of the vein is important during CW Doppler or duplex assessment.

Transfection of a nonactive site mutant murine DHFR cDNA (the tryptophan 15 mutant) into Chinese hamster ovary and mouse marrow progenitor cells imparts MTX resistance in vitro

Chinese hamster ovary (CHO) DHFR-cells were converted to the DHFR+ (dihydrofolate reductase) phenotype when transfected with a mammalian expression vector containing the murine mutant Trp15 DHFR cDNA. Transfection of the Trp15 DHFR cDNA into wild-type CHO cells resulted in resistance to high levels of methotrexate (MTX) in vitro indicating that this mutant DHFR cDNA can act as a dominant marker. Southern and Northern blot analyses of transfected cells indicated that the transfected mutant DHFR cDNA was integrated and expressed. Gene copy number analysis showed that the Trp15 cDNA was amplifiable in increasing concentrations of MTX. Transfection of murine bone marrow progenitor cells with the Trp15 mutant DHFR cDNA resulted in MTX resistant colony forming units-granulocyte macrophage.

The mitochondrial DNA mutation at position 11778 in Chinese families with Leber's hereditary optic neuropathy

We amplified the 340 bp of mitochondrial DNA (mtDNA) by PCR including the recognized sequence of restriction enzyme of SfaN I. After amplification and digestion of SfaN I, two bands of 190 bp and 150 bp appeared in the mtDNA of four normal individuals but only one band of 340 bp appeared in the mtDNA with the mutation of G to A at the site of the nucleotide 11778 because such mutation destroyed the recognized sequence of SfaN I. We studied the mtDNAs of the patients with Leber's hereditary optic neuropathy from 19 Chinese families and their maternal relatives as well as the normal individuals i. e. the husbands of the female members of the pedigrees. The results show that 66.7% of the patients (30/45) and 54.7% of the maternal relatives (29/53) have such a mutation, while no such a mutation exists in the four normal individuals. So, we conclude that the mutation of mitochondrial DNA at position 11,778 is also a major cause of LHON in China.

Percutaneous transluminal angioplasty: follow-up with treadmill exercise testing

Between 1986 and 1992, 308 percutaneous transluminal angioplasties in 252 patients were reviewed in the vascular laboratory of the Austin Hospital. The follow-up period ranged from 1 month to 6 years. Treadmill exercise testing was used as an additional mode of assessment to resting ankle/brachial pressure indices in monitoring outcome. Early haemodynamic improvement rate was 86.7%. In 267 successful cases, 199 had increased the mean(s.d.) resting ankle/brachial pressure index from 0.68(0.15) to 0.96(0.14) (P < 0.05) and another 68 with normal or unchanged resting ankle/brachial pressure indices after the procedure increased the mean(s.d.) post-exercise pressure index from 0.45(0.24) to 0.82(0.23) (P < 0.05). The primary haemodynamic improvement rate of initially successful percutaneous transluminal angioplasties was 80.1% at 1 year and was maintained in 46.1% of cases 5 years after. Treadmill exercise testing revealed reduction of the ankle/brachial pressure index in 69 patients during follow-up, indicating restenosis of the dilated lesion or development of a new arterial stenosis. Fifty-two of the 69 patients exhibited a significant drop in the resting pressure index. However, in the 17 remaining patients, only the post-exercise index decrease indicated haemodynamic deterioration. Treadmill exercise testing proved to be valuable adjunct in detecting haemodynamic changes after percutaneous transluminal angioplasty.

Synergistic reversal of multidrug-resistance phenotype in acute myeloid leukemia cells by cyclosporin A and cremophor EL

Cremophor (Crem) EL, the vehicle for intravenous delivery of cyclosporin A (CsA), has been reported to counteract multidrug resistance (MDR) in P-glycoprotein (Pgp)-over-expressing cell lines. Because of this, we sought to determine whether Crem functions independently as a modulator of MDR in blast cells obtained from acute myelogenous leukemia (AML) patients, and the nature of its interaction in combination with CsA in reversing an MDR phenotype. In the phenotypically classical MDR AML cell lines HL-60/Vinc (overexpresses Pgp) or HL-60/AR (does not overexpress Pgp), the dose causing half-maximum enhancement (D50) of daunorubicin (DNR, 1 micrograms/mL, 3 hours) accumulation was achieved by the combination of CsA and Crem (CsA/Crem) at 1.2 mumol/L CsA. In contrast, the D50 for Crem alone was approached at an amount that would be needed to suspend 6.2 mumol/L CsA for HL-60/Vinc, and 81 mumol/L CsA for HL-60/AR. The D50 concentrations for CsA alone (dissolved in ethanol, which does not alter DNR accumulation) were also higher than those for CsA/Crem, being 6.5 mumol/L for HL-60/Vinc, and 3.1 mumol/L for HL-60/AR. The maximum absolute level of enhancement of DNR accumulation (Emax) in each cell line was approximately equivalent for CsA/Crem or CsA alone, and was equal to the 3 hr intracellular DNR accumulation observed in parental, drug sensitive HL-60/W cells. For Crem alone, HL-60/AR and HL-60/Vinc cells showed markedly different responses: HL-60/Vinc cells attained intracellular DNR content comparable to HL-60/W, whereas HL-60/AR cells achieved only approximately 35% of this level. Multiple-drug effects were analyzed by calculation of the Combination Index (Chou and Talalay, Adv Enzyme Regul 22:27, 1984), which indicated that CsA and Crem are synergistic in causing enhancement of DNR accumulation in these MDR HL-60 cell lines. In blasts from AML patients, 5 mumol/L CsA/Crem or an equivalent amount of Crem alone each caused significant (P < .001) enhancement of DNR accumulation (60 AML-patient marrow samples) or DNR retention (51 AML-patient marrows). Similarly, CsA/Crem or Crem alone caused significant (P < .01) enhancement of the cytotoxicity of DNR in 36 AML blast cell specimens. The degree of enhancement of accumulation/retention or cytotoxicity by CsA/Crem was approximately equivalent to that obtained with Crem alone. These studies indicate that Crem can reverse an MDR phenotype in patient AML blast cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Characterization of the gene encoding dihydroflavonol 4-reductase in tomato

A cDNA clone (DFR) encoding dihydroflavonol 4-reductase was identified from tomato hypocotyls. Nucleotide and amino acid sequence comparisons to Petunia hybrida, Antirrhinum majus and Zea mays DFR sequences confirmed that the cDNA encodes the structural DFR gene. In tomato, the DFR sequence appeared to be present as a single gene and mapped to a region on chromosome 2 near two loci affecting anthocyanin pigmentation, are and aw. DFR was expressed in both leaf and hypocotyl tissue. Sequencing data from two DFR cDNA clones indicated there are alternative polyadenylation sites on DFR.

Duplex scanning and light reflection rheography in the assessment of the severity of short saphenous vein incompetence

BACKGROUND

Duplex ultrasound assessment of veins in the popliteal fossa is an accepted alternative to venography. Light reflection rheography provides additional quantitative information on venous reflux in chronic venous insufficiency.

OBJECTIVE

To use duplex ultrasound and light reflection rheography to study the venous reflux patterns in the popliteal fossa in a group of patients.

METHODS

Duplex ultrasound examination and light reflection rheography were used in the assessment of the severity of short saphenous vein incompetence.

RESULTS

The study revealed that any associated deep venous reflux which was detectable beyond the saphenopopliteal junction represented a more advanced stage of superficial venous insufficiency.

CONCLUSIONS

Light reflection rheography, as a semiquantitative test, provided useful additional information to duplex scan findings in assessing venous reflux of the popliteal fossa. Short saphenous vein reflux with functional deep venous incompetence was associated with shorter venous refilling times and clinically represented a more advanced stage of primary varicose vein disease.

Normal human skin lymphocytic and Langerhans' cell responses to intradermal interferon alpha-2 beta injections

The effects of intradermal injection of interferon alpha-2 beta on normal human skin were studied in 12 healthy adult volunteers using 500,000 international units recombinant human interferon alpha-2 beta, 3 times a week for five injections (n = 6) and nine injections (n = 6). Saline injections served as control sites. Lymphocytic infiltrates and the population of epidermal Langerhans' cells in the injection areas were observed. The results showed that epidermal Langerhans' cells (both adenosine triphosphatase positive and CD-1+) decreased significantly whereas human leukocyte antigen-DR expression in keratinocytes was enhanced. Dermal CD-3+ (Pan T cells), CD-4+ (T helper cells) and human leukocyte antigen DR+ cells increased. No significant differences in the number of CD-19+ (B cells) and CD-57+ (NK cells) were observed. There were no significant differences between the five-injection and nine-injection groups.

p53 point mutations in dysplastic and cancerous ulcerative colitis lesions

BACKGROUND

The molecular basis of colorectal dysplasia and carcinoma arising in ulcerative colitis is poorly understood. Loss of heterozygosity involving the tumor suppressor gene p53 occurs frequently in neoplastic ulcerative colitis lesions. Point mutation affecting p53 is associated with loss of heterozygosity in other cancers. Therefore, it was determined whether p53 point mutation occurs in ulcerative colitis-associated neoplasia.

METHODS

Single-strand conformation polymorphism analysis, DNA sequencing, and loss of heterozygosity studies were performed on 45 patients with ulcerative colitis-associated dysplasia and carcinoma.

RESULTS

Point mutations were detected in 26 lesions from 20 patients, including 18 carcinomas, 6 dysplasia-associated masses, 1 flat dysplasia, and 1 lymph node metastasis. In two cases, identical p53 mutations were observed in both carcinoma and adjacent dysplasia. Missense mutations causing amino acid substitutions as well as nonsense mutations resulting in premature stop codons were seen. Tandem mutations, in which more than 1 sequence alteration occurred on the same allele of p53, were also detected. Point mutation was accompanied by loss of the other p53 allele in 8 of 10 patients informative for both loss of heterozygosity and mutation assays.

CONCLUSIONS

These findings suggest that inactivation of p53 by mutation and loss of heterozygosity is a common mechanism of malignant transformation in ulcerative colitis. They also imply that in contrast to sporadic colorectal carcinoma, ulcerative colitis-associated neoplastic progression may involve p53 inactivation at relatively early, noninvasive stages.

Altered messenger RNA and unique mutational profiles of p53 and Rb in human esophageal carcinomas

Seventy-nine esophageal carcinoma patients were studied for genetic abnormalities in the p53 and Rb tumor suppressor genes. Single-strand conformation polymorphism analysis and DNA sequencing were used to detect p53 point mutations, Northern blotting was used to examine abnormal expression of p53 and Rb, and polymerase chain reaction and Southern blotting were used to analyze allelic loss. Twenty-five cases were analyzed by DNA sequencing to detect mutations in p53. Fourteen samples contained mutations within exons 5 through 9 of p53; seven had missense mutations giving rise to single amino acid substitutions. The remaining seven (50%) contained nonsense mutations leading to premature termination, five due to single base pair substitutions, and two that were the result of frameshift mutations. In other human tumors, p53 mutations are predominantly missense mutations, but our data as well as those from other groups show that nonsense mutations are common in human esophageal cancer. All but one of the constitutionally heterozygous samples containing mutations also manifested loss of the normal p53 allele; the one exception without allelic loss contained a silent mutation, which should not have had any affect on the p53 protein product. In addition, Northern blotting analysis revealed abnormalities (altered transcript size or mRNA levels) in 5 of 7 cases involving p53 and in 2 of 7 cases analyzed for Rb. Thirty-four cases were informative for allelic loss studies of both p53 and Rb; of these, 25 (74%) lost heterozygosity of p53, Rb, or both. When point mutations and mRNA expression abnormalities were also considered, 33 of 45 (73%) tumors informative for allelic loss assays of both genes as well as for mRNA or point mutation studies showed one or more abnormalities in p53 or Rb. Our results strongly suggest that a unique profile of molecular alterations involving p53 and Rb characterizes human esophageal cancer and that these specific genetic lesions are important in the development and/or progression of most human esophageal carcinomas.

[An observation of the effects of rat's condylar cartilage after application of retractive force on the mandible]

The changes of histologic structure and matrix secreting of rat's condylar cartilage after application of upward retractive force to the mandible were investigated by means of histology and histochemistry. After the force application, the condylar cartilage became thinner, the amount of the cells in the germ zone decreased, and that in the transition and transform zone were extremely or even disappeared. Sometimes a calcification zone was discovered in the cartilage and some cells of the mature zone were embed in it. The amount of acid mucopolysaccharide in the matrix also decreased. The result indicated that the retractive force inhibited the proliferation and differentiation of condylar cartilage remarkedly. This was the mainly morphologic bases of the shorted mandible which as a result of the retractive force applied to the mandible.

Loss of heterozygosity involves multiple tumor suppressor genes in human esophageal cancers

Loss of heterozygosity occurring on various chromosomes has been described in the majority of human tumors. The targets of frequent or consistent subchromosomal deletions are believed to be tumor suppressor genes. We examined 72 esophageal tumors (46 squamous cell carcinomas and 26 adenocarcinomas) for loss of heterozygosity at the p53, Rb, APC, MCC, and DCC loci. Inclusion of these tumor suppressor genes in the allelic deletions was directly ascertained by performing polymerase chain reaction at polymorphic sites within the genes. Loss of heterozygosity occurred in 55% of informative cases at p53, in 48% of informative cases at Rb, in 66% at APC, in 63% at MCC, and in 24% at DCC. Ninety-three % of tumors informative at all loci (fully informative) lost heterozygosity of at least one locus. A high percentage of fully informative tumors (71%) also lost heterozygosity at more than one locus. There were no significant differences among histological types in the prevalence of loss of heterozygosity at any locus. There were correlations of losses involving MCC versus DCC, Rb, and p53. These data suggest that (a) allelic deletions including these tumor suppressor genes are important in the formation and/or progression of most esophageal cancers; (b) allelic deletions involving MCC may not occur independently of deletions involving other tumor suppressor genes; and (c) the accumulation of multiple allelic deletions involving specific tumor suppressor genes may be important in most esophageal tumorigenesis or tumor evolution.

Prolactin regulation of pro-opiomelanocortin gene expression in the arcuate nucleus of the rat hypothalamus

It is well known that the opiate peptides, especially the pro-opiomelanocortin (POMC)-related peptide beta-endorphin, stimulate the release of prolactin (PRL) in the rat. In order to evaluate the involvement of PRL on the activity of POMC neurons in the arcuate nucleus, we have studied the effects of the injection of PRL into the third ventricle of intact and hypophysectomized rats as well as the effects of hyperprolactinemia induced by pituitary implants under the kidney capsule on POMC gene expression. The amounts of POMC mRNA in the arcuate nucleus were measured by in situ hybridization using a [35S]-labelled cDNA probe encoding for POMC. Hypophysectomy performed 2 weeks previously decreased by 24% the number of silver grains/unit of surface of labelled neurons. Intracerebroventricular injection of 3 micrograms of PRL 4 h before sacrifice induced a significant decrease in the hybridization signal of 32 and 20% in the intact and hypophysectomized rat, respectively. Hyperprolactinemia achieved by pituitary implants also led to a significant decrease in POMC mRNA levels. The present data show that hypophysectomy depresses hypothalamic POMC mRNA levels and that this effect is not related to the suppression of PRL secretion since this hormone exerts an inhibitory action on POMC gene expression. They suggest that the regulation of PRL secretion by short loop feedback mechanism might be well mediated by beta-endorphin which has already been shown to inhibit dopaminergic neuron activity in the arcuate nucleus.

Role of dopamine in the regulation of proopiomelanocortin (POMC) mRNA levels in the arcuate nucleus and pituitary gland of the female rat as studied by in situ hybridization

The effects of the dopaminergic antagonist haloperidol (HAL) as well as the D2 dopamine receptor agonist bromocriptine (BRO) on proopiomelanocortin (POMC) mRNA levels in the female rat arcuate nucleus and pituitary were investigated by quantitative in situ hybridization. Since we had already shown that sex steroids could induce a decrease in POMC mRNA levels in the arcuate nucleus of castrated rats, the involvement of the dopaminergic system in the inhibitory effect of estradiol (E2) was also investigated. In situ hybridization was performed on paraformaldehyde-fixed cryostat sections through the arcuate nucleus and whole pituitary gland using a 35S-labelled cDNA probe encoding for POMC. In the arcuate nucleus of intact animals, a 14-day treatment with BRO increased by 54% the number of silver grains/unit of surface of labelled neurons while HAL decreased by 30% the value of this parameter. Hypophysectomy which induced a 20% decrease in the hybridization signal could not prevent the effects of BRO or HAL. Ovariectomy performed 14 days earlier increased by 20% the number of silver grains while a 14-day treatment of ovariectomized animals with E2 decreased the hybridization signal by 32%. On the other hand, the concomitant administration of HAL and E2 did not induce significant variations in POMC mRNA levels compared to those obtained following HAL administration, but slightly decreased the hybridization signal by 20% compared to that induced by E2 alone. In the intermediate lobe of the pituitary, BRO markedly depressed (30% of control values) and HAL increased by 50% the levels of POMC mRNA. The present data clearly demonstrate that POMC mRNA levels are differently regulated by dopamine in the intermediate lobe of the pituitary and the arcuate nucleus and that the effects of BRO and HAL on arcuate POMC mRNA are not mediated by the pituitary gland. They do not allow to draw any definite conclusion about the possible involvement of the dopaminergic system in the inhibitory role of E2 on POMC gene regulation.

[Anti-inflammatory effect of differently processed rhizoma Typhon] off

Rat was employed to study the anti-inflammatory effect of Rhizoma Typhon processed by different methods. The result showed that processed and raw Rhizoma Typhon had similar action. With the new processing method similar anti-inflammatory effect was obtained compared with the old processing method.

Regulation of Prolactin Messenger Ribonucleic Acid Levels by Estradiol and Dihydrotestosterone as Evaluated by in situ Hybridization Performed on Implanted Pituitary Glands and Anterior Pituitary Cells in Culture in the Male Rat

We have recently demonstrated that 17ß-estradiol (E(2) ) administration increases protactin (PRL) mRNA levels in the male rat anterior pituitary gland and that this stimulatory effect is partially inhibited by concomitant administration of dihydrotestosterone. In order to gain more information about the site(s) of action of E(2) and dihydrotestosterone on PRL gene expression, we have studied the effects of these two hormones in pituitaries implanted under the kidney capsule as well as in anterior pituitary cells in culture. In implanted pituitaries, PRL mRNA levels were increased by 90% as compared to values obtained in the stalk-connected pituitaries from the same animals. Administration of E(2) induced a further increase of PRL mRNA levels in implanted pituitaries, while dihydrotestosterone did not produce any change in animals which had been treated or not with E(2) . In anterior pituitary cells in culture, addition of E(2) to the culture medium resulted in a 60% increase of PRL mRNA levels over control values. Supplementation with dihydrotestosterone did not induce any variation in the concentration of PRL mRNA in cells which were treated or not with E(2) . These results indicate that E(2) exerts a direct action on PRL cells at the pituitary level and strongly support the key role of the hypothalamus in the inhibitory effect of androgens on estrogen-induced stimulation of PRL mRNA in the male rat pituitary.

Loss of heterozygosity involving the APC and MCC genetic loci occurs in the majority of human esophageal cancers

The tumor suppressor gene APC was recently identified, and the cDNA was cloned from chromosome 5q21. Point mutations affecting APC are seen in the hereditary syndrome familial adenomatous polyposis, and point mutations in APC and a closely linked gene, MCC, as well as loss of heterozygosity involving chromosome 5q have been reported in sporadic colon cancer. To our knowledge, loss of heterozygosity involving APC or MCC or both has not yet been described in any other human cancer besides lung cancer. We used the polymerase chain reaction and DNA content flow cytometric nuclear sorting to examine 30 primary human esophageal cancers for loss of heterozygosity of APC or MCC or both. Loss of one allele was detected in 77% of 26 informative cases. These data suggest that loss of heterozygosity of regions on 5q including the APC and MCC genetic loci is involved in the development and/or progression of most human esophageal cancers. They imply that inactivation of APC, MCC, and/or a linked gene on chromosome 5q plays a role in the pathogenesis of some cancers of the upper gastrointestinal tract, as well as in colon cancer and familial adenomatous polyposis.

Loss of heterozygosity affecting the p53, Rb, and mcc/apc tumor suppressor gene loci in dysplastic and cancerous ulcerative colitis

Allelic deletions of tumor suppressor genes have been observed frequently in a variety of human tumors. These losses are believed to contribute to the development of human cancer. Three of the most frequently deleted chromosomal loci contain the tumor suppressor genes p53, retinoblastoma (Rb), and mcc/apc. In order to detect loss of heterozygosity (LOH) within these genes in dysplastic and cancerous ulcerative colitis, we used an application of the polymerase chain reaction. LOH affecting p53 was observed in 8 of 17 (47%) of heterozygous patients, while LOH of Rb and the mcc/apc locus was observed in 9 of 27 (33%) and 13 of 39 (33%) of heterozygotes, respectively. Among 35 patients heterozygous at 2 or more loci, LOH of p53, Rb, and/or mcc/apc was observed in 18 (51%). LOH was more common in left-sided neoplasms. These data suggest that allelic deletion of p53, Rb, mcc, and/or apc is involved in the pathogenesis and/or progression of at least a subset of colonic dysplasias and carcinomas occurring in the setting of ulcerative colitis.

Venous reflux patterns in the popliteal fossa

Incompetent veins in the popliteal fossa were assessed with duplex ultrasound in 123 legs of 104 patients. In 91 cases the venous reflux was the result of a single incompetent vein draining into the deep system. In 32 cases duplex ultrasound demonstrated a combination of incompetent veins. With the exception of 3 patients duplex scanning accurately localised the incompetent veins and their "junctions" with the deep system. In 48 legs the reflux signal, detected in the surface vein, extended back beyond the "junction" into a proximal segment of the popliteal vein or superficial femoral vein; in most cases the distal popliteal vein remained competent. Six distinct venous reflux patterns were identified in the popliteal fossa, which seemed to correlate with the severity of related clinical symptoms.

In vivo Regulation of Prolactin Gene Expression in the Male Rat: Role of Sex Steroids and Dopamine

Abstract The influence of sex steroids and the dopaminergic system on the in vivo modulation of prolactin (PRL) mRNA levels was investigated by quantitative in situ hybridization in the male rat anterior pituitary gland. In situ hybridization was performed using a [(35)S]-labeled cDNA probe encoding PRL. Orchiectomy performed 14 days earlier did not modify PRL mRNA levels. In orchiectomized rats treatment with the dopaminergic agonist bromocriptine for 14 days decreased PRL mRNA levels by 30%, while in intact animals the same treatment did not induce any changes in PRL mRNA levels. Administration of the dopamine D(2) receptor antagonist haloperidol in both intact and orchiectomized rats induced a 4-fold increase in mRNA levels. Administration of dihydrotestosterone to orchiectomized animals which had been treated or not with haloperidol or bromocriptine did not modify PRL mRNA levels. In orchiectomized animals administration of 17ss-estradiol (0.25 mug twice daily) for 14 days caused a 4-fold increase in amounts of PRL mRNA. Administration of bromocriptine to 17ss-estradiol-treated animals induced a 15% decrease of PRL mRNA levels compared to those obtained by 17ss-estradiol administered alone. The concomitant administration of 17ss-estradiol and haloperidol resulted in a 50% increase in PRL mRNA levels compared to those measured in animals treated with haloperidol alone. The present results clearly demonstrate that in vivo estrogen as well as dopamine-mediated mechanisms play a regulatory role in PRL mRNA levels in the male rat.

Distribution and characterization of endogenous benzodiazepine receptor ligand (endozepine)-like peptides in the rat gastrointestinal tract

Endozepine is the generic name for a family of peptides that are capable of displacing benzodiazepines and the 3-carboxylate ester of beta-carboline from their specific binding sites on synaptosomal membranes. The 104-amino acid polypeptide diazepam-binding inhibitor (DBI) and the octadecaneuropeptide (ODN) generated by tryptic digestion of DBI are two members of the endozepine family. In the present study we have used RIA, HPLC, in situ hybridization, and immunohistochemical techniques to identify and localize endozepine-like molecules in the rat gastrointestinal tract. Significant amounts of endozepine-like immunoreactivity (LI) were detected throughout the gut; the highest concentrations were found in the duodenum and antrum. HPLC analysis revealed that the immunoreactive material eluted as a major peak with a higher retention time than that of synthetic ODN. The distribution of the immunoreactive peptide(s) was studied using the peroxidase-antiperoxidase technique at the light microscope level. Endozepine-LI was localized only in the epithelial cell layer of the intestine in both goblet cells and enterocytes. In the stomach, endozepine-LI appeared to be restricted to deep layer of the epithelial cells. The diffuse neuroendocrine cells (amine precursor uptake and decarboxylation system) as well as myenteric and neuronal cells were devoid of immunoreactivity. A good correlation was observed between RIA and immunocytochemical data, in that the esophagus, which contained very low concentrations of endozepine-LI, also exhibited weak immunostaining of secretory cells. In situ hybridization using a 35S-labeled cRNA probe showed that endozepine mRNA was located in the mucosa. Taken together, these results show that in the rat, epithelial cells synthesize endozepine-LI material. Since epithelial cells also contain a high density of peripheral-type benzodiazepine-binding sites, our data indicate that endozepines may play a role in water, electrolyte, and/or mucus regulation in the rat gastrointestinal tract. The occurrence of high levels of endozepine-LI in the rat stomach also suggests that endozepines can be involved in the regulation of gastric acid secretion through modulation of local gamma-aminobutyric acid-ergic neurotransmission.

[Anti-inflammation and toxicity of radix Aconiti coreni and rhizoma Tyhon]

Rats, mice, pigeons and rabbits were employed to study the anti-inflammatory and toxic actions of Radix Aconiti coreni and rhizoma Tyhon. The result shows that Radix Aconiti coreni and rhizoma Tyhon have similar anti-inflammatory action. rhizoma Tyhon has an obvious stimulating effect on eye conjunctiva as well as throat and stomach mucosa, while Radix Aconiti coreni does not.