Mutation analysis of the putative tumor suppressor gene PTEN/MMAC1 in hepatocellular carcinoma

Loss of heterozygosity of chromosome 10q has been reported in hepatoma. Areas with a high rate of loss of genetic material could harbor putative tumor suppressor genes. PTEN/MMAC1, a candidate tumor suppressor gene located at chromosome 10q23.3, has recently been identified and found to be homozygously deleted or mutated in several different types of human tumors. To determine whether the PTEN/MMAC1 gene is a target of 10q loss of heterozygosity in hepatoma, we examined 42 primary hepatomas for mutations in PTEN/MMAC1 by using nested reverse transcriptase polymerase chain reaction (RT-PCR) of the RNA and single-stranded conformation polymorphism (SSCP) analysis of all genomic exons. Although 2 of 42 hepatoma tissues had aberrant transcripts, 5 matched noncancerous liver tissues also had aberrant transcripts. Southern blot analysis of the entire genomic DNA revealed no genomic change. Therefore, like the TSG101 or FHIT gene, aberrant transcripts of PTEN/MMAC1 using the nested RT-PCR method were a common phenomenon for both cancerous and noncancerous liver tissues, which may not be related to oncogenesis. None of the 42 cases had small deletions, point mutations, or insertions. Our results suggest that the PTEN/MMAC1 gene may not play a role in the pathogenesis of hepatoma.

The effects of antagonizing residual neuromuscular blockade by neostigmine and glycopyrrolate on nausea and vomiting after ambulatory surgery

The effects of neostigmine on the incidence of postoperative nausea and vomiting (PONV) are controversial. In this study, we evaluated the effects of neostigmine and glycopyrrolate on the incidence of PONV and the need for antiemetics in patients undergoing ambulatory surgery. One hundred healthy patients undergoing outpatient surgical procedures were included in the study. A standardized anesthetic technique was used for all patients. Patients were randomized to receive either mivacurium (n = 50) or rocuronium (n = 50) to achieve muscle paralysis. Bolus doses of mivacurium 2-4 mg or rocuronium 5-10 mg were administered to maintain one or two twitches of the train-of-four stimulation of the ulnar nerve at the wrist. After surgery, residual neuromuscular blockade was reversed with neostigmine 2.5 mg i.v. and glycopyrrolate 0.5 mg i.v. only if clinically deemed necessary (i.e., fade on train-of-four stimulation, inadequate tidal volume, reduced hand grip, or inability to maintain head lift). The incidence of PONV and the need for antiemetics were recorded in the post-anesthesia care unit (PACU), in the phase II unit, and 24 h after surgery. We compared patients who received neostigmine (n = 40) for reversal of residual neuromuscular blockade with those who did not (n = 60). More patients receiving rocuronium required reversal drugs than those receiving mivacurium (68% vs 10%). There were no differences in the incidence of nausea (18% vs 15%), vomiting (8% vs 12%), and the need for antiemetics (13% in both the groups) in the PACU between patients who received neostigmine and those who did not. In addition, the duration of PACU stay and the time to home-readiness were also similar between the groups. We conclude that, compared with rocuronium, the use of mivacurium decreases the need for reversal drugs. In addition, reversal of residual neuromuscular blockade with neostigmine does not increase the incidence of PONV or the need for antiemetic medications in patients undergoing ambulatory surgery.

IMPLICATIONS

In this study, we showed that the incidence of postoperative nausea and vomiting and the need for antiemetics do not increase with the use of neostigmine and glycopyrrolate for reversal of residual muscle paralysis.

Mutation analysis of the putative tumor suppression gene PTEN/MMAC1 in sporadic breast cancer

PTEN/MMAC1, a potential human tumor suppressor gene, has been found to have inactivating mutations in several types of cancer, including breast cancer. The incidence of breast cancer in Chinese is quite low in comparison with Caucasians, and genetic factors may play some roles. To further determine the role of PTEN/MMAC1 in breast cancer in Chinese, we used loss of heterozygosity (LOH), single strand conformation polymorphism (SSCP) with direct sequencing of variant bands, and Southern blot analysis methods to analyze mutations in PTEN/MMAC1 in 52 cases of breast cancer. None had LOH at chromosome 10q23.3. One mutation was identified, a somatic 3-base deletion, in one case. Our results suggest PTEN/MMAC1 does not play a major role in the development of sporadic breast cancer.

CT features of systemic lupus erythematosus in patients with acute abdominal pain: emphasis on ischemic bowel disease

PURPOSE

To evaluate the computed tomographic (CT) features of systemic lupus erythematosus (SLE) in patients with acute abdominal pain. Special emphasis was placed on the analysis of ischemic bowel disease.

MATERIALS AND METHODS

The authors retrospectively reviewed the images from 39 abdominal CT examinations performed in 33 patients with SLE and acute abdominal pain. Images were evaluated for bowel wall changes, mesenteric changes, fluid collection, retroperitoneal lymphadenopathy, peritoneal enhancement, and hepatomegaly as well as for changes in other abdominal organs. Ischemic bowel disease was diagnosed if at least three of the following signs were seen: bowel wall thickening, target sign, dilatation of intestinal segments, engorgement of mesenteric vessels, and increased attenuation of mesenteric fat.

RESULTS

Thirty-one (79%) of the 39 examinations had CT findings diagnostic of ischemic bowel disease, including symmetric bowel wall thickening (n = 29), target sign (n = 26), and mesenteric vascular engorgement and haziness (n = 31). In 24 cases, bowel wall thickening was multifocal, with variable length, and did not appear to be confined to a single vascular territory.

CONCLUSION

The most common CT finding in patients with SLE and acute abdominal pain is ischemic bowel disease. CT is useful for detecting the primary cause of gastrointestinal symptoms, planning treatment, and monitoring for infarction or perforation.

Several levels of EGF receptor signaling during photoreceptor specification in wild-type, Ellipse, and null mutant Drosophila

Dominant Ellipse mutant alleles of the Drosophila EGF receptor homologue (DER) dramatically suppress ommatidium development in the eye and induce ectopic vein development in the wing. Their phenotype suggests a possible role for DER in specifying the founder R8 photoreceptor cells for each ommatidium. Here we analyze the basis of Ellipse mutations and use them to probe the role of DER in eye development. We show that Elp mutations result from a single amino acid substitution in the kinase domain which activates tyrosine kinase activity and MAP kinase activation in tissue culture cells. Transformant studies confirmed that the mutation is hypermorphic in vivo, but the DER function was elevated less than by ectopic expression of the ligand spitz. Ectopic spi promoted photoreceptor differentiation, even in the absence of R8 cells. Pathways downstream of DER activation were assessed to explore the basis of these distinct outcomes. Elp mutations caused overexpression of the Notch target gene E(spl) mdelta and required function of Notch to suppress ommatidium formation. The Elp phenotype also depended on the secreted protein argos and was reverted in Elp aos double mutants. Complete loss of DER function in clones of null mutant cells led to delay in R8 specification and subsequently to loss of mutant cells. The DER null phenotype was distinct from that of either spitz or vein mutants, suggesting that a combination of these or other ligands was required for aspects of DER function. In normal development DER protein was expressed in most retinal cells, but at distinct levels. We used an antibody specific for diphospho-ERK as well as expression of the DER target gene argos to assess the pattern of DER activity, finding highest activity in the intermediate groups of cells in the morphogenetic furrow. However, studies of mutant genotypes suggested that this activity may not be required for normal ommatidium development. Since we saw distinct phenotypic effects of four different levels of DER activity associated with wild-type, null mutant, Elp mutant, or fully activated DER function, we propose that multiple thresholds separate several aspects of DER function. These include activation of N signaling to repress R8 specification, turning on argos expression, and recruiting photoreceptors R1-R7. It is possible that during normal eye development these thresholds are attained by different cells, contributing to the pattern of retinal differentiation.

Cell death and proliferation and its relation to collagen degradation in uterine involution of rat

Collagen concentration, procollagenase localization, and their association with cell proliferation and apoptosis during postpartum involution, were investigated biochemically and histochemically in postpartum day 1, 3, 5, and 7 rat uterine tissues. In control animals, uterine wet weight, soluble protein, and collagen decreased rapidly during days 1 to 3 postpartum, and the DNA concentration in the uterine horn rapidly decreased, as noted by others. Simultaneously, both apoptosis and cell proliferation were observed in these tissues. These processes were highest in smooth muscle cells on day 3 postpartum. Procollagenase was found in the cell cytoplasm through days 1 to 3 postpartum, was highest on the third day postpartum, and appeared to gradually diminish by day 5 postpartum. Disorganization of collagen fibers was observed, under polarized microscopy by a strong birefringence of collagen fibers of the circular smooth muscle cell layers. However, this disorganization of the uterine collagen diminished progressively from day 3 to day 7. Treatment with estradiol or a combination of estradiol and progesterone suppressed cellular turnover and attenuated the changes in DNA, total amino acids, and collagen on day 3 postpartum. In this study, cellular turnover and biochemical and morphological changes appeared to be closely associated. Gonadal steroid hormones appear to influence these changes and retard uterine involution. This study suggests that a dynamic turnover of the cellular population takes place during uterine involution. It is possible that other factors, in addition to steroid hormones, contribute to uterine involution. It is to be postulated that these factors either are themselves decreased or, alternatively, may increase the inhibition of other unknown factors by an indirect mechanism.

Functional analysis of the fibrinogen-related scabrous gene from Drosophila melanogaster identifies potential effector and stimulatory protein domains

The scabrous (sca) gene encodes a secreted dimeric glycoprotein with putative coiled-coil domains N-terminally and a C-terminal region related to the blood clot protein fibrinogen. Homozygous sca mutants have extra bristle organs and rough eyes. We describe a GAL4-based expression system for testing rescue of the sca mutant phenotype by altered SCA proteins and for misexpression. We find that deletion of the fibrinogen-related domain (FReD) greatly decreases SCA function, confirming the importance of this conserved region. SCA function could not be restored by FReDs from human fibrinogen chain genes. However, proteins lacking any FReD still showed some function in both rescue and misexpression experiments, suggesting that putative effector-binding regions lie outside this domain. Consistent with this, proteins expressing only the FReD had no rescuing activity but were recessive negative; i.e., they enhanced the phenotype of sca mutations but had no phenotype in the presence of a wild-type sca allele. This suggests that the FReD contributes to SCA function by binding to other components of the bristle determination pathway, increasing the activity of the linked N-terminal region.

Antiemetic activity of propofol after sevoflurane and desflurane anesthesia for outpatient laparoscopic cholecystectomy

BACKGROUND

Controversy exists regarding the effectiveness of propofol to prevent postoperative nausea and vomiting. This prospective, randomized, single-blinded study was designed to evaluate the antiemetic effectiveness of 0.5 mg/kg propofol when administered intravenously after sevoflurane- compared with desflurane-based anesthesia.

METHODS

Two hundred fifty female outpatients undergoing laparoscopic cholecystectomy were assigned randomly to one of four treatment groups. All patients were induced with intravenous doses of 2 mg midazolam, 2 microg/kg fentanyl, and 2 mg/kg propofol and maintained with either 1-4% sevoflurane (groups 1 and 2) or 2-8% desflurane (groups 3 and 4) in combination with 65% nitrous oxide in oxygen. At skin closure, patients in groups 1 and 3 were administered 5 ml intravenous saline, and patients in groups 2 and 4 were administered 0.5 mg/kg propofol intravenously. Recovery times were recorded from discontinuation of anesthesia to awakening, orientation, and readiness to be released home. Postoperative nausea and vomiting and requests for antiemetic rescue medication were evaluated during the first 24 h after surgery.

RESULTS

Propofol, in an intravenous dose of 0.5 mg/kg, administered at the end of a sevoflurane-nitrous oxide or desflurane-nitrous oxide anesthetic prolonged the times to awakening and orientation by 40-80% and 25-30%, respectively. In group 2 (compared with groups 1, 3, and 4), the incidences of emesis (22% compared with 47%, 53%, and 47%) and requests for antiemetic rescue medication (19% compared with 42%, 50%, and 47%) within the first 6 h after surgery were significantly lower, and the time to home-readiness was significantly shorter in duration (216 +/- 50 min vs. 249 +/- 49 min, 260 +/- 88 min, and 254 +/- 72 min, respectively).

CONCLUSIONS

A subhypnotic intravenous dose of propofol (0.5 mg/kg) administered at the end of outpatient laparoscopic cholecystectomy procedures was more effective in preventing postoperative nausea and vomiting after a sevoflurane-based (compared with a desflurane-based) anesthetic.

A subset of notch functions during Drosophila eye development require Su(H) and the E(spl) gene complex

The Notch signalling pathway is involved in many processes where cell fate is decided. Previous work showed that Notch is required at successive steps during R8 specification in the Drosophila eye. Initially, Notch enhances atonal expression and promotes atonal function. After atonal autoregulation has been established, Notch signalling represses atonal expression during lateral specification. In this paper we investigate which known components of the Notch pathway are involved in each signalling process. Using clonal analysis we show that a ligand of Notch, Delta, is required along with Notch for both proneural enhancement and lateral specification, while the downstream components Suppressor-of-Hairless and Enhancer-of-Split are involved only in lateral specification. Our data point to a distinct signal transduction pathway during proneural enhancement by Notch. Using misexpression experiments we also show that particular Enhancer-of-split bHLH genes can differ greatly in their contribution to lateral specification.

The R8-photoreceptor equivalence group in Drosophila: fate choice precedes regulated Delta transcription and is independent of Notch gene dose

It has been suggested that lateral specification of cell fate by Notch signaling depends on feedback on Notch (N) and Delta (Dl) transcription to establish reciprocal distributions of the receptor and its ligand at the protein level. In Drosophila neurogenesis the predicted reciprocal protein distributions have not been observed. Either this model of lateral specification or the description of N and/or Dl protein distributions must be incomplete. We have reexamined R8 photoreceptor specification in the developing eye to resolve this question for this example of lateral specification. N and Dl protein levels were assessed in the cell as a whole and at the cell surface, where these proteins were mostly found at the intercellular cell junctions. Protein levels did not correspond to Notch signaling in wild type. However, Dl transcription and protein levels did correlate with altered N signaling in mutant genotypes. Our findings suggest the difference relates to the speed of lateral specification in vivo. The time required for N signaling to inhibit ato expression was at most 90 min, but changes in the Dl protein distribution in mutant genotypes arose more slowly. N expression was little regulated by N signaling, but protein encoded by the Nts1 allele was temperature-sensitive for appearance at the cell surface. Some aspects of the pattern of Dl protein appeared to be due to endocytosis. We conclude that feedback of N signaling on Dl transcription does occur but is too slow to account for the pattern of R8 specification. Studies of ommatidia mosaic for a Notch duplication, or for the Nts1 allele at semi-restrictive temperatures, found that cells beginning with less N activity were not necessarily predisposed to be selected for R8 differentiation. Our data argue that other signals may be responsible for the pattern of R8 cell fate allocation by N. Potential relevance to other neurogenic regions is discussed.

Mast cell collagenase correlates with regression of pulmonary vascular remodeling in the rat

Pulmonary vascular remodeling, produced by cell hypertrophy and extracellular matrix protein synthesis in response to hemodynamic stress, regresses after reduction of blood pressure, possibly by proteolysis of structural proteins. To test this postulate, we assessed the breakdown of extracellular matrix proteins and expression of collagenase and elastase in pulmonary arteries of rats exposed to hypoxia (10% O2 for 10 d) followed by normoxia. During hypoxia, contents of collagen and elastin increased in pulmonary arteries and latent rat interstitial collagenase was expressed without increased collagenolytic activity or mRNA levels. At 3 days after normoxia, collagen and elastin contents decreased coincident with the new appearance of activated collagenase and transient increases in collagenolytic and elastolytic activities. The amount of immunoreactive collagenase, localized predominately in connective tissue-type mast cells, was increased in the adventitia and media of hypertensive vessels. We conclude that mast cells containing latent collagenase are recruited into the outer walls of pulmonary arteries during remodeling. It is possible that mast cell-derived collagenase contributes to collagen breakdown in pulmonary arteries during early recovery from hypoxia and plays a role in restoration of vascular architecture.

Detection of elastin in the human fetal membranes: proposed molecular basis for elasticity

The human fetal membranes provide a sterile biomechanical container which adjust by growth to mid-pregnancy to the increase in fetal size, and by elasticity to the forceful movements of the fetus. The molecular basis for this elasticity is not known, yet reduced elasticity may lead to their premature rupture and preterm birth, a major problem in perinatal medicine. Classically, elastin confers the property of elastic recoil to elastic fibres which are assembled from a family of tropoelastin precursors. These are covalently cross-linked to form insoluble elastin by formation of desmosine and isodesmosine, catalysed by the enzyme lysyl oxidase. The amnion, chorion and decidua were shown by Northern analysis and RT-PCR to contain detectable levels of tropoelastin mRNA and the mRNA encoding lysyl oxidase. The proteins encoded by these mRNAs were also identified by Western blotting and immunolocalization. Further, insoluble elastin was extracted from the human fetal membranes and shown by comparison to elastin preparations from other elastic tissues to have a reasonable desmosine content. Finally, scanning electron microscopy confirmed the presence of multiple layers of an apparently very thin elastic system in this tissue. This biochemical and histopathologic study has demonstrated therefore that the human fetal membranes synthesize and deposit a novel elastic fibre. The presence of such an elastic system in these tissues provides, for the first time, a probable molecular basis for the elastic properties of this tissue.

Diagnostic laparoscopy: indication and benefit

BACKGROUND

Patients with an obscure and unrelievable abdominal condition may be forced to receive open laparotomy for diagnosis. Diagnostic laparoscopy has been suggested as an alternative to diagnostic laparotomy in selected cases. The aim of this article is to evaluate the circumstances suitable for laparoscopic diagnosis of certain abdominal conditions and the possible advantages of that approach.

METHODS

Among 256 patients undergoing elective laparoscopic operations using conventionally pneumoperitoneal techniques from January 1994 to June 1995, twenty patients received diagnostic laparoscopy. The correlation between preoperative diagnosis, laparoscopic diagnosis and pathologic diagnosis as well as the outcome of laparoscopic diagnosis and treatment have been assessed.

RESULTS

Major indications for diagnostic laparoscopy included acute abdominal pain (n = 4), chronic abdominal pain (n = 6), differentiating intraabdominal tumor (n = 4), staging known malignancy (n = 3) and evaluating intraperitoneal implantation (n = 3). Two of the four patients with acute abdominal conditions, one of the six patients with chronic abdominal pain. Four of the seven patients with undifferentiated/unstaged abdominal tumors and all of the three patients with intraperitoneal-implanted drainage tubes had no reasons for a further exploratory procedure, thus preventing the morbidity or mortality which might occur after unnecessary laparotomy. The duration of operation and hospitalization was shorter than the group without laparotomy.

CONCLUSIONS

Diagnostic laparoscopy benefits patients by avoiding unnecessary surgery, avoiding unnecessary delay in diagnosis and treatment and shortening the operative and hospitalized period. However, it provides only an alternative not a substitute for traditional diagnostic procedures and will never lessen the importance of conventional laparotomy.

Proneural function of neurogenic genes in the developing Drosophila eye

BACKGROUND

. Intercellular signals are major determinants of cell fate during development. Certain signals and receptors are important for many different cell-fate decisions, suggesting that cellular responses to similar signals change during development. Few transitions between such distinct cellular responses have been studied. The Drosophila genes Notch and hedgehog function during intracellular signaling at various stages of development. In the specific case of development of the Drosophila eye, expression of the proneural gene atonal is induced in response to Hedgehog signaling and then becomes subject to autoregulation. The receptor protein Notch has previously been reported to function in the selection of single founder photoreceptor cells (R8 cells) by inhibiting atonal expression. On this basis, complete elimination of Notch gene function would be expected to cause neural hyperplasia in the eye.

RESULTS

. Contrary to expectation, we detect a reduction in neural differentiation both in cells expressing a conditional Notch allele and in those lacking expression of either Notch or its ligand Delta. We show here that Notch signaling acts after the initial Hedgehog-driven expression of atonal to enhance proneural competence of the atonal-expressing cells and also to terminate their response to the Hedgehog signals. This occurs before the Notch-induced lateral inhibition of atonal expression within the same cells.

CONCLUSION

. Notch has sequentially opposite effects on the same cells, by first promoting and then inhibiting proneural gene function. This apparently paradoxical sequence of events has two possible consequences. Firstly, coupling of alternative cellular responses to the same receptor may prevent them from occurring simultaneously. Secondly, consecutive regulatory processes become temporally coupled, so that these events follow on from each other, without gaps or overlaps.

Protective role of selenium against hepatitis B virus and primary liver cancer in Qidong

High rates of hepatitis B virus (HBV) infection and primary liver cancer (PLC) are present in Qidong county. Epidemiological surveys demonstrated an inverse association between selenium (Se) level and regional cancer incidence, as well as HBV infection. Four-year animal studies showed that dietary supplement of Se reduced the HBV infection by 77.2% and liver precancerous lesion by 75.8% of ducks, caused by exposure to natural environmental etiologic factors. An intervention trial was undertaken among the general population of 130,471. Individuals in five townships were involved for observation of the preventive effect of Se. The 8-yr follow-up data showed reduced PLC incidence by 35.1% in selenized table salt supplemented vs the nonsupplemented population. On withdrawal of Se from the treated group, PLC incidence rate began to increase. However, the inhibitory response to HBV was sustained during the 3-yr cessation of treatment. The clinical study among 226 Hepatitis B Surface Antigen (HBsAg)-positive persons provided either 200 micrograms of Se in the form of selenized yeast tablet or an identical placebo of yeast tablet daily for 4 yr showed that 7 of 113 subjects were diagnosed as having PLC in the placebo group, whereas no incidence of PLC was found in 113 subjects supplemented with Se. Again on cessation of treatment, PLC developed at a rate comparable to that in the control group, demonstrating that a continuous intake of Se is essential to sustain the chemopreventive effect.

Decreased endurance to cold water swimming and delayed sexual maturity in the rat following neonatal lead exposure

The effects of neonatal lead (Pb) exposure on ability to endure stress and on the onset of sexual maturity were investigated using rats. Sprague-Dawley dams (n = 17/treatment) were treated with or without lead acetate (0.3%) in drinking water from parturition until postnatal day (PND) 21, at which time the pups were weaned. A set of sex-balanced pairs of pups (24 male and 24 females/treatment) from randomly selected control and Pb-treated dams was tested for cold water (4 degrees C) swimming-endurance on PND 15, 21, 25 and 30. Lead treated-female pups showed significantly (P < 0.05) lower endurance on PND 21 and 30, while Pb-treated males exhibited lower (P < 0.05) endurance on PND 21 compared to their respective controls. The results of this study indicate that neonatal exposure to Pb decreased cold water swimming-endurance. Neonatal exposure to either Pb or swimming stress delayed (P < 0.002) the onset of sexual maturity in both sexes. However, exposure to both treatments masked the effect of swimming stress on the onset of maturity in females but not in males.

The scabrous gene encodes a secreted glycoprotein dimer and regulates proneural development in Drosophila eyes

R8 photoreceptor cells play a primary role in the differentiation of Drosophila eyes. In scabrous (sca) mutants, the pattern of R8 photoreceptor differentiation is altered. The sca gene is predicted to encode a secreted protein related in part to fibrinogen and tenascins. Using expression in Drosophila Schneider cells, we showed that sca encoded a dimeric glycoprotein which was secreted and found in soluble form in the tissue culture medium. The sca protein contained both N- and O-linked carbohydrates and interacted with heparin. This Schneider cell protein was similar to protein detected in embryos. We showed that sca mutations, along with conditional alleles of Notch (N) and Delta (Dl), each affected the pattern of cells expressing atonal (ato), the proneural gene required for R8 differentiation. In normal development, about 1 cell in 20 differentiates into an R8 cell; in the others, ato is repressed. N and Dl were required to repress ato in the vicinity of R8 cells, whereas sca had effects over several cell diameters. Certain antibodies detected uptake of sca protein several cells away from its source. The overall growth factor-like structure of sca protein, its solubility, and its range of effects in vivo are consistent with a diffusible role that complements mechanisms involving direct cell contact. We propose that as the morphogenic furrow advances, cell secreting sca protein control the pattern of the next ommatidial column.

Collagen changes in rat cervix in pregnancy--polarized light microscopic and electron microscopic studies

The structural arrangement of collagen fibers in cervical ripening was studied in normal pregnant rats by picrosirius red staining and polarized light microscopy. The macromolecular arrangement of collagen fibers in the cervices of nonpregnant controls and in firm and rigid cervices of rats in early pregnancy (1-10 days of gestation) were optically anisotropic and had birefringence and a positive sign of elongation when examined by polarized light microscopy. The findings indicated that the structure of these collagen fibers was assembled from well-packed parallel collagen molecules. The direction of fibrous formation was arranged with regularity. In contrast, most of the collagen fibers in the soft cervices were optically isotropic. The fibers were fragmented and had a structure with discontinuous birefringence. Disarray and disorientation of the collagen fibers was found in the soft cervices. These collagen fibers changed their direction of formation. The disorganization of these collagen fibers might have a major impact on weakening the tensile strength of the cervix. Thus, we conclude that the processes of rearrangement of collagen fibers might be an important process in the cervical ripening. Electron microscopic studies suggest that in the focal hydrolytic processes of collagen and other matrix components degradation by lysosomal and phagosomal vesicles were associated with atrophic smooth muscle cells and fibroblasts of the cervices. Hydrolases released from lysosomes from these apoptotic cells may presumably be one of the processes in the remodeling of collagen structure.

Inhibitory effect of rikkunshi-to, a traditional Chinese herbal prescription, on tumor promotion in two-stage carcinogenesis in mouse skin

We report the inhibitory effect of topical application of extracts of a traditional Chinese herbal prescription on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation in mice. Methanol and water extracts obtained from 22 traditional Chinese herbal prescriptions were assayed and their inhibition ratios calculated. In general, the methanol extracts produced more effective inhibition than the water extracts. Of the various traditional Chinese herbal prescriptions, the methanol extract of Rikkunshi-to was more effective than other prescriptions as far as inhibition of TPA-induced inflammation was concerned. Hoelen, Glycyrrhizae Radix, Atractylodis Rhizoma, components of Rikkunshi-to markedly inhibited the inflammatory activity involved by TPA in mice. Furthermore, topical application of the methanol extract of Rikkunshi-to markedly inhibited TPA-induced tumor promotion in two-stage carcinogenesis in mouse skin.

Improvement on performance of modified Hopfield neural network for image restoration

By analyzing the same inequality ||u*||(1)=/<(1/2)trace(T), the authors conclude that a severely blurred image is generally restored less accurately than a mildly blurred one by the modified Hopfield neural network. This conclusion is the opposite of the statement made in Paik and Katsaggelos (1992). The authors also propose an improved new algorithm. Simulation results show that the SNRs of the images restored by the algorithm are higher by 3 to 8 db than those restored by the algorithm in Paik and Katsaggelos and the streaks in the restored images are obviously suppressed by the algorithm.

[Amplification of C-erB2 gene in ovarian cancer]

In the present report, amplification of C-erbB2 proto-oncogene in ovarian cancer was studied with Southern Blot technique. There were 14 cases to occur amplification of C-erbB2 oncogene in 50 cases with ovarian cancer. Among 14 ovarian cancer cases with amplification of C-erbB2, 2 of 20 cases were detected in stage I and II respectively, while 12 of 30 cases were from stage III/IV (P < 0.05). These results showed that amplification of C-erbB2 proto-oncogene is associated with advanced ovarian cancer. Therefore, it is suggested that C-erbB2 gene amplification may deserve further evaluation as a prognostic marker in ovarian cancer.

Apoptosis in the cervix of pregnant rats in association with cervical softening

Cervical ripening in gestation occurs spontaneously in a timely but species-specific fashion as if it were genetically programmed. This study shows that the numbers of dying smooth muscle cells in the cervix increased along with cervical softening in pregnant rats from day 12 of gestation to day 21. The morphological characteristics of the chromatin cleavage in apoptosis are identified. Internucleosomal DNA fragments in the DNA preparations as well as the ladder pattern of double-stranded DNA observed on gel electrophoresis are observed. The deletion and decrease of the cell population in the cervices was demonstrated by a decrease of total DNA in these tissues. The interesting possibility is raised that programmed smooth muscle cell death in the cervix may be involved in the processes of the cervical ripening.

Multiple lymphomatous polyposis of the gastrointestinal tract--a report of two cases with immunohistochemical studies

We describe two cases of multiple lymphomatous polyposis in the gastrointestinal tract from the esophagus to the rectum. Clinical findings, histopathologic and immunohistochemical findings in paraffin embedded tissue are discussed. It is important to recognize this rare form of gastrointestinal lymphoma because of the prognostic and therapeutic implications.

[Cerebrospinal fluid rhinorrhea due to sinus surgery: a case report]

Cerebrospinal fluid rhinorrhea is an uncommon but dangerous disease. Many lethal complications, such as bacterial meningitis and pneumoencephalus, may be the result of cerebrospinal fluid rhinorrhea. Otolaryngologist, neurosurgeons and radiologists must know how to diagnose, how to localize the site of leakage and how to choose the best method of treatment. A case of cerebrospinal fluid rhinorrhea and meningitis due to improper sinus surgery is presented. Satisfactory result, such as avoidance of unnecessary brain tissue damage, can be obtained by extracranial endonasal repairing of the fistula with a composite septal flap.

Comparative direct-acting mutagenicity of 1- and 2-nitropyrene: evidence for 2-nitropyrene mutagenesis by both guanine and adenine adducts

The mutations and DNA adducts produced by the environmental pollutant 2-nitropyrene were examined in Salmonella typhimurium tester strains. 2-Nitropyrene was a stronger mutagen than its extensively studied structural isomer 1-nitropyrene in strains TA96, TA97, TA98, TA100, TA102, TA104 and TA1538. Both 1- and 2-nitropyrene were essentially inactive in TA1535. The mutagenicity of 1- and 2-nitropyrene in TA98 was much higher than in TA98NR and the activity of these compounds in TA100 was much higher than in TA100NR. While 1-nitropyrene exhibited similar mutagenicity in strains TA98 and TA98/1,8-DNP6, the mutagenicity of 2-nitropyrene in TA98/1,8-DNP6 was much lower than in TA98. Analysis of DNA from TA96 and TA104 incubated with 2-nitropyrene indicated the presence of two adducts, N-(deoxyguanosin-8-yl)-2-aminopyrene and N-(deoxyadenosin-8-yl)-2-aminopyrene. The results suggest that 2-nitropyrene is metabolized by bacterial nitroreductase(s) to N-hydroxy-2-aminopyrene, and possibly by activation to a highly mutagenic O-acetoxy ester. DNA adduct formation with deoxyguanosine and deoxyadenosine correlates with the mutagenicity of 2-nitropyrene in tester strains possessing both G:C and A:T mutational targets.

A preliminary report on the intervention trials of primary liver cancer in high-risk populations with nutritional supplementation of selenium in China

The purpose of this study was to evaluate the effect of selenium (Se) in the prevention of human primary liver cancer. Three intervention trials were conducted among the residents at high risk to primary liver cancer (PLC) in Qidong county, Jiang-su province, the People's Republic of China. This area has the second highest rate of PLC in China. One trial was undertaken among the general population in a township with supplement of table salt fortified with 15 ppm anhydrous sodium selenite (Se-salt) for 5 y and the other four townships with similar PLC incidence rate served as the controls using normal table salt. The second trial was undertaken among hepatitis B virus surface antigen carriers (HBVsAg+) receiving supplement of 200 micrograms Se in form of selenized yeast (Se-yeast) daily vs placebo for 4 y. The third trial was carried out in members of families with high PLC incidence using Se-yeast (200 micrograms of Se daily) vs placebo for 2 y. The results showed that nutritional supplement of Se could reduce the PLC incidence significantly.

Dialectic classification of syndrome diagnosis in traditional Chinese medicine used as new criterion for evaluating prognosis of patients with cervical cancer

254 patients with cervical cancer were treated by radiotherapy from Jan 1979 to Dec 1984. All the patients were followed up at least for more than 3 years, of them 180 for over 5 years. According to various symptoms, picture of the tongue and pulse condition, the disease was classified into 4 types, namely: 1) deficiency of liver-yin and kidney-yin, 2) deficiency of splenic qi, 3) internal retention of damp-heat, and 4) stagnation of qi and blood or stagnation of liver qi. The survival rate of the various types was quite different. The patients of type 4 had the worst prognosis. The prognosis of patients with type 1 was significantly better than that of patients with type 4. The difference was of statistical significance (P less than 0.01).

[Study on mutagenicity of size-fractionated air particles]

Ames Salmonella assay and sister chromatid exchanges in CHO cells were used to study the mutagenic activity of size-fractionated air particles from outdoor air in Beijing, Taiyuan, Wuhan, Shenyang and the areas with high incidence of lung cancer in Xuanwei county. Five size particles were collected from each sampling points. The results indicate that: 1. The results of organic matter content in particles. 2. All of the samples have mutagenicity. There was negative correlation between mutagenicity and particle sizes, mutagenicity was increased with particle size reduced. The maximum mutagenicity was at the particle size less than 1.1 microns. So it is especially hazardous to human health. There was logarithmic correlation between organic matter content and revertants. Correlation coefficient was 0.98. Regression equation was gamma = 0.23 + 1.01 X. 3. The results showed that of the five sampling points air pollution at the high lung cancer incidence area of Xuanwei county was the most severe.

Three-dimensional structures of uterine elastic fibers: scanning electron microscopic studies

We report findings that demonstrate for the first time that the structure of the elastic fibers of the uterus and cervix are characteristic to these tissues. Elastic fibers of the uterine corpus and cervix were studied by scanning electron microscopy (SEM). Elastic tissues were prepared from non-pregnant human uteri and pregnant rat uteri by three different methods: extraction from the tissue homogenates, in situ digestion by autoclaving of sliced tissue, and in situ formic acid digestion of sliced tissue. In addition, in situ formic acid digestion of the glutaraldehyde-fixed uterine wall of pregnant rats was done. Under SEM, the uterine elastic fibers revealed two distinct structures--fibrils and thin sheets of elastic membranes. Isolated fibers and membranes ranged in thickness from 0.1 to 0.4 micron which is thinner than aortic elastic lamellae (1-2.5 microns in thickness). These thin sheets of elastic membranes and elastic fibrils probably allow the uterus to maintain its elasticity without exerting excess pressure on the growing fetus. Formic acid digestion of fixed uterine walls of pregnant rats preserved the structural organization of elastic tissues near in vivo conditions. In these tissues, the fibers were arranged in a honeycomb structure made up largely of membranes, although sparse fibrils were present. These elastic, membranous sheets were arranged parallel to the plane of the uterine surface and interconnected with the threads of the membranes or fibrils. In the rat uterine wall, at least 12 parallel layers of elastic sheets were present. In contrast, at low magnification, the elastic tissues in the non-pregnant human uterus had no specific architectural arrangement and exhibited a sponge-like structure. Elastic fibers of the cervix were also made up of membranes and fibrils, and these fibers were organized into fishnet-like structures. These cervical membranes had fenestrations and pits with a diameter of 3-5 microns. In these studies, the concentrations of insoluble elastin in human uteri were found to be 1.38 and 1.32-1.41% of dry-defatted tissues for uterine body and cervix, respectively. The concentrations of total collagen were 38.8 and 64.3-72.4% of dry-defatted tissues for uterine body and cervix, respectively.

[Diagnosis of pancreatic cancer with simultaneous detection of a pancreatic-cancer-associated antigen and pancreas-specific antigen]

We reported the purification and characterization of a pancreatic cancer-associated antigen from normal colonic mucosa (PCAAc) and pancreas-specific antigen (PaA) according to Kitada's and Loor's methods as well as the established method of double antibody enzyme-linked immunoassay for the detection of serum PaA and PCAAc; respectively. In our study, 155 serum samples were detected (including normal controls 40; pancreatic cancer 31; other malignant disease 56 and benign diseases 28). The results indicated that the overall sensitivity and specificity of a single PCAAc test for pancreatic cancer were calculated to be 70.98% and 96.43%; a single PaA to be 80.65% and 95.23%, respectively. Furthermore, the sensitivity and specificity of combined tests (PCAAc and/or PaA) for pancreatic cancer were calculated to be 96.77% and 90.91%. The diagnostic efficiency was 90.91%. None of 84 cases of nonpancreatic cancer and benign diseases has been found elevated PCAAc and PaA simultaneously. The results suggest that simultaneous detection of PCAAc and PaA would have increased the sensitivity of diagnosis for pancreatic cancer.

Collagen and elastin metabolism in hypertensive pulmonary arteries of rats

We evaluated the processes controlling the accumulation of collagen and elastin in main pulmonary arteries of rats during an episode of hypoxic pulmonary hypertension. Explant cultures of main pulmonary arteries were incubated with [3H]proline to measure collagen and protein synthesis and percent collagen synthesis. Elastin synthesis was measured by [14C]valine incorporation into insoluble elastin. Relative collagen synthesis increased twofold (from 1.1 +/- 0.2 x 10(3) to 2.0 +/- 1.0 x 10(3) disintegrations per minute [14C]hydroxyproline/vessel/hr/mg protein), relative collagen synthesis doubled (from 2% to 4-5% of total protein synthesis), and elastin synthesis increased ninefold (from 0.4 +/- 0.2 x 10(4) to 3.6 +/- 0.6 x 10(4) dpm [14C]valine/vessel/hr/mg protein) in early hypertension. The level of pro alpha l(I) collagen RNA paralleled the relative collagen synthetic rate during the study period. Within 7 days of recovery from hypoxia, collagen and elastin contents were normal. We conclude that collagen and elastin in main pulmonary arteries are synthesized rapidly during an episode of hypoxic pulmonary hypertension and that collagen and elastin are rapidly removed from the hypertensive vessel during normoxic recovery.

Intervention trial with selenium for the prevention of lung cancer among tin miners in Yunnan, China. A pilot study

This pilot study evaluated the feasibility and effectiveness of conducting a double-blind clinical trial for the prevention of lung cancer with selenium (Se) in Yunnan Tin Corporation, the People's Republic of China, where the incidence rates of lung cancer are extraordinarily high among the miners. Forty healthy miners were randomized to either 300 micrograms of Se in high Se malt cakes or an identical placebo of malt cakes daily for one year. Subjects consumed their usual daily diet. The low Se concentrations in plasma (0.05 +/- 0.008 microgram/mL) and hair (0.442 +/- 0.085 microgram/g) reflected their low dietary Se intake in the control subjects. In Se-supplemented group, the Se status was increased by 178% for serum and 194.8% for hair. The serum GSHpx activity was increased by 155.7%, whereas the lipid peroxide level was reduced by 74.5% compared to the placebo. The results of UDS assay indicated that the lymphocyte DNA damage induced by ultraviolet irradiation and carcinogen 3,4-benzpyrene could be protected by Se supplementation. Se-supplementation did not affect the liver function test (SGPT), as well as the concentrations of hemoglobin, albumin, and cholesterol. Thus, daily intake of 300 micrograms Se in form of Se-malt as a chemopreventive measure is safe and effective to humans with low Se status.

Strain specific respiratory air space enlargement in aged rats

We studied lung structure and function in Fischer-344 and Sprague Dawley rats to compare the pathophysiologic features of the aged lung in animal strains. Both strains were maintained under identical conditions of minimal exposure to injurious environmental agents. We measured the number, size, and surface area of alveoli, pressure-volume characteristics and connective tissue content of lungs at midlife (12 or 14 months of age) and old age (24 months of age). Results showed differences in the older versus younger group of the Sprague Dawley strain as indicated by enlarged air spaces [154 +/- 21 (SEM) versus 118 +/- 13 micromicroliter] (p less than 0.05), increased collagen (hydroxyproline content 4.1 +/- 0.1 versus 3.0 +/- 0.1 mg/lung) (p less than 0.05), and a leftward shifted pressure-volume curve. There was no change in surface area or alveolar number. The structural lesions are consistent with air space enlargement with fibrosis and not emphysema. In contrast, no major changes were found in the lungs with age in Fischer-344 rats. We hypothesize that in the Sprague Dawley strain the aging process impairs the ability of the lung to maintain normal structure and function. Two strains of rats which differ pathologically in old age may be useful in the study of the effects of aging on the lung.

Changes in vascular extracellular matrix accumulation reflect phenotypic differences between the arterial wall of pigeons resistant and susceptible to the development of spontaneous atherosclerosis

White Carneau pigeons have previously been shown to be genetically susceptible to the development of spontaneous atherogenesis. The severity of development of atheromatous lesions is considerably greater than a more resistant breed of Show Racer pigeons. Analysis of levels of total hydroxyproline and isodesmosine in the thoracic aorta and celiac bifurcation of prelesion, six-week-old White Carneau and Show Racer pigeons, revealed an increased accumulation of total collagen and cross-linked elastin in the White Carneau arterial tissue. Using dot blot hybridization, measurements of steady state levels of several mRNAs in total RNA extracted from pigeon aortic tissue were also determined. While the increased deposition of extracellular matrix proteins was paralleled by a significantly greater recovery of mRNAs coding for pro alpha 1(1) collagen and elastin, in RNA extracted from White Carneau aortal tissue, increased recovery of mRNAs coding for an intracellular protein, gamma-actin were also observed in White Carneau aortal tissue. No differences in steady state levels of mRNAs coding for pro alpha 1(1) collagen and elastin were observed in RNA extracted from pigeon liver, suggesting a tissue specific increase in the mRNAs coding for these connective tissue proteins in aorta. A markedly reduced cell population however, was responsible for this overall increase in biosynthetic activity in White Carneau pigeon aortic tissue. This was demonstrated by a reduced cell count and by the recovery of reduced levels of total DNA in the thoracic aorta and celiac bifurcation of the White Carneau pigeon. The cell population in White Carneau aortic tissue exhibits therefore a markedly different phenotype with respect to a capacity for the biosynthesis of extracellular and intracellular proteins.

[Study of factors affecting prognosis of cervical cancer using a microcomputer]

We set up a software system which can store, retrieve and handle the data for cervical cancer. The data of 526 patients with cervical cancer have been stored. The correlation between various prognostic factors and 5-year survival was studied by means of stepwise analysis. It was found that such factors as macroscopic type of tumor, hemoglobin, peritumoral lymphocytic infiltration and age of the patients influenced prognosis significantly. The best regression equation to predict the 5-year survival of patients was established by this method. It was proved that the calculated survival rate in correspondence with the real 5-year survival rate was 83.6%-99.55%. This study was important to us. We could then take appropriate therapeutic measures in the treatment of patients with cervical cancer.

Chemoprevention trial of human hepatitis with selenium supplementation in China

A three-year study has been conducted for prevention of infectious hepatitis with supplementation of table salt fortified with 15 ppm anhydrous sodium selenite to the general population of 20,847 persons in a township M.Z. at Qidong County, Jiangsu Province, China. The results showed that the incidence of virus hepatitis infection in the test township was significantly lower than that of controls provided with normal table salt. The incidence rate of infectious hepatitis in the treated township M.Z. was 1.20 and 4.52 per 1,000, whereas the average incidence in the 6 surrounding control townships was 2.96 and 10.48 per 1,000 in 1986 and 1987, respectively. The incidence of hepatitis B surface antigen (HBsAg+) was 13.2% vs 19.23% for males and 10.42% vs 12.24% for females in the supplemented vs nonsupplemented neighboring township, respectively. Epidemiological studies have demonstrated that a low grain Se content is associated with a high regional incidence of hepatitis B virus infections.

Serum ribonuclease and its isoenzymes for diagnosis of pancreatic cancer

Serum ribonuclease (RNase) activity and its isoenzymes were determined by biochemical and PAGE electrophoretic separation technique in 20 patients with pancreatic cancer, in 27 with other gastroenterologic malignant tumors, 8 with acute pancreatitis, 7 with chronic pancreatitis, 5 with leukemia, 3 with chronic uremia of glomerulonephritis, and in 30 adult normal controls. Serum A1AT rocket immunoelectrophoresis and carcinoembryonic antigen (CEA) radioimmunoassay were also carried out simultaneously.

Connective tissue, mechanical, and morphometric changes in the lungs of weanling rats fed a low protein diet

We studied the effect of low-protein diet (8% casein) on lung growth in rats from 3 to 7 weeks of age. Their diet was isocaloric with that of control animals fed a diet of 20% casein. The calorie intake of experimental animals was increased during the first 3 weeks of the experiment, but they increased less (about 10%) in body weight, had less protein and less water when the whole body was examined, and had lower serum proteins and decreased urinary hydroxyproline. The experimental animals remained in positive nitrogen balance by maintaining low urinary nitrogen excretion. The lungs of the experimental animals were abnormal, with decreased absolute amounts of hydroxyproline and desmosine and of these relative to unit lung weight. The lungs contained more air per gram of lung tissue, and the volume of air in the lung was increased at all transpulmonary pressures above zero. When corrected for increased total lung capacity, there was a loss of recoil at mid-lung volumes. Saline-filled volume-pressure curves, corrected for lung volume, showed similar loss of recoil. Alveolar multiplication was quantitatively normal, but the experimental animals had larger alveoli. We conclude that the protein deprivation in isocalorically fed animals has a specific effect on lung scleroprotein content, which may be due to diminished synthesis, and this results in both structural and functional abnormalities in the lung. Our results indicate the importance of dietary protein in lung development and possibly as one of the causes of emphysema. Further studies are needed to know whether this would be a problem in infants of Kwashiokor.

Diagnostic value of plasma PABA level in pancreatic diseases

NBT-PABA test was performed in 72 subjects with simultaneous determination of the plasma PABA time-concentration curve. The curve in 25 controls after oral administration of N-benzoyl-L-tyrosyl-P-aminobenzoic acid (NBT-PABA) peaked (3.88 +/- 0.78 micrograms/ml, M +/- SD) at the third hour. In patients with chronic pancreatitis (24) and pancreatic carcinoma (6), the curves were flattened, and peaked at the fifth hour (2.7 +/- 1.4 micrograms/ml, M +/- SD), and fourth hour (3.14 +/- 2.26 micrograms/ml, M +/- SD), respectively. The discrimination between the controls and patients with chronic pancreatitis was most significant in the third-hour plasma PABA concentration (P less than 0.0001). This study shows that determination of the third-hour plasma PABA concentration is better in sensitivity and specificity than the 6-hour urinary excretion of PABA, suggesting that the third-hour plasma PABA concentration after oral administration of NBT-PABA might be a sensitive index of exocrine pancreatic function test.

Acute myocardial infarction in elderly Chinese. A clinical analysis of 631 cases and comparison with 389 younger cases

The purpose of this study was to define the clinical features of acute myocardial infarction in a group of elderly Chinese. The presenting symptoms, complications and mortality of acute myocardial infarction were compared in 631 patients (430 men and 201 women) aged 60 and over and 389 patients (333 men and 56 women) whose ages were under 60 years. The incidence of painless myocardial infarction was 17.6% in the elderly versus 5.9% in the younger group. Typical chest pain was present in 63.1% of the elderly and 84.3% of the younger Chinese. However, the incidence of other nonspecific presenting symptoms was higher in the elderly group. Likewise, the major complications in the elderly group were more severe than those in the younger group. For example, the incidences of cardiogenic shock, heart failure, arrhythmia, pulmonary infection and cardiac rupture in the older group were 19.8, 24.2, 77.2, 22.0 and 4.4%, versus 15.1, 19.5, 48.1, 9.5 and 1.1% in the younger group, respectively. The immediate (4 week) mortality rate of the older group was 21.9% (over 80 years 51.5%), but was only 11.0% in the younger group. Although the incidences of hypertension and pulmonary disease were significantly greater in the elderly group, these diseases alone did not account for the higher mortality rate in the elderly.

Selenium chemoprevention of liver cancer in animals and possible human applications

An inverse correlation between geographic distribution of liver cancer incidence and the selenium (Se) contents of whole blood and grains was observed in Qidong county, Jiangsu province, a high liver cancer area of the People's Republic of China. Animal experiments demonstrated that supplementation of Se reduced the incidence of liver cancer in rats exposed to aflatoxin B1. Se was also shown to inhibit the growth of transplanted tumors. A lower incidence of liver preneoplastic alterations and reduction of hepatitis B virus infection in ducks by Se-supplementation was observed, and three pilot studies for a Se-intervention trial on human liver cancer were carried out on the residents of Qidong county. A protective effect on the cellular DNA damage induced by aflatoxin B1 was observed in lympocytes from human with Se-supplements.

Biochemical and cellular aspects of the anticancer activity of selenium

Aberrant differentiation is a frequent hallmark of tumors, suggesting that modulators for differentiation and proliferation play a role in multistage carcinogenesis and that their use can also be exploited in cancer chemoprevention and therapy. We have demonstrated that selenium (Se) may be a modulator for the differentiation and proliferation of tumor cells. Evidence has been obtained that Se exerts the following effects: reversing changes of biochemical phenotypes toward normal levels, including reduction of cGMP level and cAMP-dependent protein kinase isozyme type I; increase in cAMP level and cAMP-dependent protein kinase isozyme type II, and altering membrane properties. Furthermore, we have obtained support for this hypothesis utilizing experiments on cultured human liver cell lines. It is demonstrated that Se can lead to the following changes: a. reduction of mitotic index; b. increase in the adhesiveness of cells; c. decrease in confluent saturation density and induction of an early contact inhibition; and d. decrease in tumorigenicity. For the purpose of comparison, the effects of Se on the normal counterparts was also studied. Contrary to what was observed above, there was no significant change in both biochemical and cellular aspects of normal cells treated analogously.

Decreased elastic fibers and desmosine content in incompetent cervix

Incompetence of the uterine cervix is a syndrome of painless, progressive dilatation and effacement occurring between the sixteenth and twenty-fourth weeks of gestation that represents abnormal functioning. It may serve as a model to elucidate normal function. Because the incompetent cervix results in painless opening of this organ without uterine contraction before term gestation, it is considered one of the causes of midtrimester spontaneous abortion, habitual spontaneous abortion, and early preterm labor. Untreated, it leads to rapid expulsion and often death of the fetus. We used light microscopy to compare decreased elastic fibers in incompetent cervices with those of normal nonpregnant and pregnant cervices. Morphologic analysis of this difference was extended to biochemical quantification of elastin content in one patient with cervical incompetence. The decrease in elastin suggests that one function of cervical elastin may be to maintain a closed and undilated cervix throughout gestation. There may be a relationship between changes in cross-linked elastin and the incompetent cervix; further studies are therefore indicated.

[Different effects of selenium on proliferation of human lung adenocarcinoma cells and human embryonic lung diploid cells in vitro]

After treating human lung adenocarcinoma cells by Na2SeO3 (1 microgram/ml) for 24 hours, its mitotic index decreased by 50%. The reduction rate was directly proportional to selenite concentration (1-5 micrograms/ml). In the meantime, the labelling index, growth rate and progression of the cell cycle were also inhibited. In contrast to the above observation, there was no marked change in the cell count, mitotic index, labelling index and the average silver granule number in the human embryonic lung diploid cells treated by Na2SeO3 (1-5 micrograms/ml) for 1-3 days. When human embryonic lung diploid cells were mix-cultured with human lung adenocarcinoma cells in the presence of 5 micrograms/ml Na2SeO3 for 24 hours, the former maintained a normal morphology, while the lung cancer cells showed heavily vacuolated cytoplasms and distorted nuclei.

Differential Effects of selenium on the proliferation of human pulmonary adenocarcinoma cells and human embryonic lung diploid cells in vitro

The effect of different concentrations of Na2SeO3 on human pulmonary adenocarcinoma cells and human embryonic lung diploid cells in vitro was investigated. For human pulmonary adenocarcinoma cells, mitotic index and cell count decreased with increasing selenium concentrations. At 1 μg/mL sodium selenite, mitotic activity and growth of human lung cancer cells were partially inhibited, and the progression of human lung cancer cell cycle was partially arrested. When human embryonic lung diploid cells were treated with 1 μg/mL sodium selenite for five continuous days, cell counts of the treated group were closely parallel to those of the control group. After treating human embryonic lung diploid cells with 1-5μg/mL sodium selenite for 1-3 d, the mitotic index (MI), labeled index (LI), and average silver grain (SG) number per 20 labeled nuclei were the same as those of the control. In mixed cultures of human embryonic lung diploid cells and human pulmonary adenocarcinoma cells, treated with 3 and 5 μg/mL sodium selenite for 24 h, the lung diploid cells showed a normal fusiform morphology, whereas the lung cancer cells showed heavily vacuolated cytoplasms and distorted nuclei.