Relationship between serum concentration and clinical response of quetiapine in adolescents and adults with bipolar disorders in acute stage: a prospective observational study

BACKGROUND

It is found that there are great differences in the efficacy of quetiapine at the same dose in many patients with bipolar disorders. Therefore, therapeutic drug monitoring (TDM) is a valuable tool for guiding treatment with quetiapine. The aims of this study were to assess the relationship between serum concentration and clinical response of quetiapine in adolescents and adults with bipolar disorders in acute stage.

METHODS

The study design was prospective and observational. Within the naturalistic setting of a routine TDM service at the First Affiliated Hospital, Zhejiang University School of Medicine. Psychiatric symptoms were assessed using the HAMD (Hamilton Depression Scale), YRMS (Young manic rating scale) and CUDOS-M (Clinically Useful Depression Outcome Scale-Mixed Subscale). The decline of HAMD and YMRS scores was were used to assess clinical outcome of bipolar disorders respectively.

RESULTS

169 inpatients (23.7 % male, 76.3 % female) were enrolled in the study. We found that there was a strong correlation between quetiapine serum concentrations and clinical outcomes (r_s = 0.702, p < 0.001). While, quetiapine daily dose was not correlated with clinical outcome. We found that when the quetiapine serum level is >146.85 ng/ml in depression episodes patients could obtain a satisfactory treatment effect after 2 weeks of hospitalization.

CONCLUSIONS

We found a significant positive relationship between serum concentration and clinical outcome, and also determined the serum concentration of quetiapine for the treatment of bipolar depression.

Dialectical behavior therapy-based psychological intervention for woman in late pregnancy and early postpartum suffering from COVID-19: a case report

At the end of 2019, a new form of pneumonia disease known as the corona virus disease 2019 (COVID-19) rapidly spread throughout most provinces of China, and the total global number of COVID-19 cases has surpassed 500 000 by Mar. 27, 2020 (WHO, 2020). On Jan. 30, 2020, the World Health Organization (WHO) declared COVID-19 a global health emergency (WHO, 2020). COVID-19 causes most damage to the respiratory system, leading to pneumonia or breathing difficulties. The confirmed case fatality risk (cCFR) was estimated to be 5% to 8% (Jung et al., 2020). Besides physical pain, COVID-19 also induces psychological distress, with depression, anxiety, and stress affecting the general population, quarantined population, medical staff, and patients at different levels (Kang et al., 2020; Xiang et al., 2020). Previous research on patients in isolation wards highlighted the risk of depressed mood, fear, loneliness, frustration, excessive worries, and insomnia (Abad et al., 2010).

Efficacy of internet-based integrated intervention on depression and anxiety symptoms in patients with COVID-19

Public health crises, such as the outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) since Dec. 2019, are widely acknowledged as severe traumatic events that impose threats not only because of physical concerns but also because of the psychological distress of infected patients. We designed an internet-based integrated intervention and evaluated its efficacy on depression and anxiety symptoms in patients infected by SARS-CoV-2.

Relationships between dorsolateral prefrontal cortex metabolic change and cognitive impairment in first-episode neuroleptic-naive schizophrenia patients

The present study aimed to explore the possible associations between the dorsolateral prefrontal cortex (DLPFC) metabolites and the cognitive function in first-episode schizophrenia (FES).This study included 58 patients with FES (29 males and 29 females; mean age, 22.66 ± 7.64 years) recruited from the First Affiliated Hospital, College of Medicine, Zhejiang University, and 43 locally recruited healthy controls (16 males and 27 females; mean age, 23.07 ± 7.49 years). The single-voxel proton magnetic resonance spectroscopy was used to measure the levels of N-acetylaspartate (NAA); complex of glutamate, glutamine, and γ-aminobutyric acid (Glx); choline-containing compounds; and myo-inositol in the DLPFC. The ratios of metabolites to creatine (Cr) were calculated. The cognitive function was assessed by Measurement and Treatment Research to Improve Cognition in Schizophrenia Consensus Cognitive Battery (MCCB). Correlation analysis was used to assess the relationships between the DLPFC metabolites and the cognitive function.Compared with the healthy controls, the patients with FES showed significantly reduced scores in each part of the MCCB, significantly reduced NAA/Cr, and significantly increased Glx/Cr in the left DLPFC. Poor performance in verbal learning and visual learning was correlated to the reduced NAA/Cr ratio in the left DLPFC.These findings suggest that a lower NAA/Cr ratio in the left DLPFC is associated with the cognitive deficits in patients with FES, and may be an early biochemical marker for the cognitive impairment in schizophrenia.

A recombinant plasmid of composite cysteine proteinase inhibitor/glyceraldehyde-3-phosphate dehydrogenase gene of periodic Brugia malayi functions on DNA immunity in the host

OBJECTIVES

Both cysteine proteinase inhibitors (CPIs) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) play important roles in the pathogenesis of parasites and their relationship with the hosts. We constructed a new eukaryotic recombinant expression plasmid pcDNA3.1(+)-BmCPI/BmGAPDH of periodic Brugia malayi for investigation of the DNA vaccine-elicited immune responses.

MATERIALS AND METHODS

We cloned a gene encoding the CPIs and GAPDH from periodic B. malayi into vector pcDNA3.1. The composited plasmid or the control was injected into the tibialis anterior muscle of the hind leg in BALB/c mice, respectively. The target genes were detected by reverse transcription-polymerase chain reaction in muscle tissues. The stimulation index (SI) of T-lymphocyte proliferation and the levels of interferon-gamma (INF-g) and interleukin-4 ( IL-4) in serum were detected by thiazolyl blue tetrazolium blue and enzyme-linked immunosorbent assays.

RESULTS

The pcDNA3.1(+)-BmCPI/BmGAPDH was amplified from muscle tissues of the mice after immunisation. The SI of the immunised group was significantly higher than that of the two control groups (P < 0.05). The levels of INF-g and IL-4 of pcDNA3.1(+)-BmCPI/BmGAPDH group were both higher than those of the two control groups (P < 0.05). The level of INF-g of pcDNA3.1(+)-BmCPI/BmGAPDH group was significantly higher than that of pcDNA3.1(+)-BmCPI/CpG group (P < 0.05).

CONCLUSIONS

We conclude that the recombinant plasmid pcDNA3.1(+)-BmCPI/BmGAPDH could elicit specific humoural and cellular immune responses in mice.

The imaging of neuroendocrine tumors using single photon emission computed tomography/computed tomography

There have been several advances in technology over the past decade with the advent of hybrid imaging having a large impact on nuclear medicine, first with PET/CT and then more recently with SPECT/CT. Initial SPECT/CT systems used low dose but very low quality CT and except for attenuation correction offered no great advantage over reviewing SPECT and CT images side by side. More recently hybrid machines have become available and a series of studies have shown improved accuracy compared to SPECT alone with resulting changes in patient management. This has been true not only with somatostatin analogue imaging but also for demonstrating amine uptake using MIBG. Whilst PET/CT may be seen as the ideal, this may be less accessible due to the high cost and limited availability. In this case hybrid SPECT/CT offers hope for providing high quality and accurate imaging of neuroendocrine tumors.

Connexin 36 is expressed and associated with zonula occludens-1 protein in PC-12 cells

Connexin 36 (Cx36) is the predominant connexin isoform expressed in the mammalian neurons of the central nervous system (CNS). PC-12 cells, a neuronal-like cell line, are widely used for neuron functional studies. Many connexins have been shown to interact with zonula occludens-1 protein (ZO-1), a tight junction associated with protein. The present study is intended to investigate whether Cx36 is expressed in PC-12 cells and is associated with ZO-1. Cx36 transcripts were amplified and verified by RT-PCR. 2.9 kb Cx36 mRNA was detected in PC-12 cells through Northern blot hybridization. Western blotting showed a 36-kDa protein band in the homogenates of PC-12 cells. Immunofluorescence labeling revealed that Cx36 was present in cell-cell contacts of PC-12 cells and colocalized with ZO-1. The association of Cx36 and ZO-1 in PC-12 cells was also demonstrated by coimmunoprecipitation. In conclusion, PC-12 cells express Cx36 mRNA and Cx36 proteins that are associated with ZO-1. These results enhanced our understanding of the function of Cx36 in PC-12 cells.

Dosage prediction via estimation of shell thickness and concentration of drug carrier with microbubbles

For drug delivery applications, dosage prediction before release and estimation after release are required functions. In this study, we attempted to establish a method to evaluate liposome concentrations and liposome shell thickness for dosage prediction. We use the Trilling model with parameter of phospholipids bilayers to simulate the frequency responses under the different acoustic pressure and establish an experimental protocol to evaluate the liposome concentrations and the liposome shell thickness. Our results illustrate the changes on the signal strength for different concentrations and show that it is relatively stable to estimate the concentrations when the cycles are lower (15 cycles). Besides, it is verified that the second harmonic signal is more sensitive in analyzing different concentrations. On the other hand, it is proved that the liposome shell thickness affect signal strength and thinner thickness will increase the second harmonic response. Therefore, in accordance with the theoretical and experimental results, we would be able to estimate the concentration and the shell thickness of the liposomes. By numerical analysis methods, dosage prediction would be built.

Reevaluation of the role of early trypsin activity in the transcriptional activation of the late trypsin gene in the mosquito Aedes aegypti

In the female mosquito Aedes aegypti, trypsin expression is largely biphasic. Early trypsin synthesis, which is regulated at the translational level relative to feeding, peaks in the first few hours post-blood meal. Late trypsin expression is regulated at the transcriptional level, and peaks 18-24h post-blood meal. It was proposed that early trypsin activity released unknown factors during digestion of a meal that caused activation of transcription of the late trypsin gene. This connection between early trypsin activity and late trypsin expression was dependent on the fact that feeding a single trypsin inhibitor, soybean trypsin inhibitor (STI), which blocked early trypsin activity, also blocked late trypsin expression. We show in this study that feeding different trypsin inhibitors which effectively blocked early trypsin activity did not result in reduced late trypsin expression. We also found that a different lot of STI failed to cause inhibition of late trypsin transcription, although it was effective in inhibiting early trypsin activity. In addition, using RNAi methodology to reduce the level of early trypsin expression had no effect on the level of late trypsin expression. We conclude that early trypsin activity is not necessary for the transcriptional activation of late trypsin and that the previous results were due to the effect of a cytotoxic agent present in some, but not all preparations of STI.

Lineage-specific mechanism of drug and radiation resistance in melanoma mediated by tyrosinase-related protein 2

A major obstacle in the clinical management of malignant melanoma is its intrinsic resistance to chemotherapy and radiation therapy. Consequently, most patients with melanoma often do not respond to conventional anticancer therapy in a clinically significant manner. Recent advances in cancer research have provided new insights into the mechanisms of intrinsic resistance in melanomas. We have recently reported that the over-expression of tyrosinase-related protein 2 (TYRP2), an enzyme that is well characterized for its function in melanin synthesis, is associated specifically with resistance to DNA damaging drugs and radiation treatment. This review will summarize our findings as well as discuss the possible mechanisms by which TYRP2 over-expression contributes to intrinsic resistance in human malignant melanoma.

Contiguous arrangement of p45 NFE2, HnRNP A1, and HP1 alpha on mouse chromosome 15 and human chromosome 12: evidence for suppression of these genes due to retroviral integration within the Fli-2 locus

Fli-2 is a common site of proviral integration in multistage erythroleukemia cells induced by Friend murine leukemia virus (F-MuLV) or the polycythemia strain of Friend leukemia virus (FV-P). Previously, we reported that integration of Friend virus into the Fli-2 locus in CB3, an erythroleukemia cell line that harbors a homozygous inactivation of the Fli-2 locus, results in the loss of expression of two genes encoding the 45-kDa subunit of the erythroid-specific nuclear factor p45 NFE2 and the splicing factor HnRNP A1. Here, we report the identification of a third gene, Heterochromatin protein 1 (HP1alpha, also known as CBX5), which is located downstream of HnRNP A1, and p45 NFE2. Northern blot analysis revealed that the expression of HP1alpha, along with p45 NFE2 and HnRNP A1, is either undetectable or substantially reduced in CB3 cells, suggesting that HP1alpha expression is also regulated by proviral insertion within the Fli-2 locus in CB3 cells. Because p45 NFE2 was previously mapped to mouse chromosome 15, our results demonstrate that HP1alpha and HnRNP A1 are also located on mouse chromosome 15 and that the p45 NFE2, HnRNP A1, and HP1alpha genes are arranged contiguously. Contiguous arrangement of these three genes was also detected in man; this consequently localizes HP1alpha to human chromosome band 12q13.

Tyrosinase-related protein 2 as a mediator of melanoma specific resistance to cis-diamminedichloroplatinum(II): therapeutic implications

A major obstacle in the systemic treatment of advanced malignant melanoma is its intrinsic resistance to conventionally used chemotherapeutic agents. In order to investigate the mechanisms of this intrinsic resistance, we have previously utilized retroviral insertional mutagenesis on an early-stage, drug sensitive human melanoma cell line (WM35) to establish mutated cell lines that exhibited increased resistance to cis-diammi-nedichloroplatinum(II) (CDDP). Here, we demonstrate that this increased resistance to CDDP is mediated by the over-expression of tyrosinase-related protein-2 (TYRP2), an enzyme that normally functions in the biosynthesis of the pigment, melanin. Northern and Western blot analyses revealed that the expression of TYRP2 in the virally-derived cell lines as well as in a panel of human melanoma cell lines positively correlated with their levels of resistance to CDDP. Furthermore, enforced expression of TYRP2 in WM35 cells by transfection elevated their resistance to CDDP. The increased CDDP resistance in the virally-derived clones and TYRP2 transfectants was accompanied by a reduction in CDDP-induced apoptosis. Interestingly, the virally-derived CDDP-resistant clones also showed cross resistance to carboplatin and methotrexate, but not taxol, suggesting that TYRP2 over-expression may confer resistance specifically to DNA damaging agents. Overall, these results demonstrate a novel mechanism of drug resistance in human melanoma cells that is mediated by the over-expression of TYRP2. Since TYRP2 is expressed only in cells of melanocytic lineage, this may represent the first report of a lineage-specific mechanism of drug resistance. In summary, these findings suggest a significant role for TYRP2 in the intrinsic drug resistance phenotype of human melanoma cells and may have important implications in the development of chemosensitization strategies for the clinical management of this disease.

Elevated basal and thapsigargin-stimulated intracellular calcium of platelets and lymphocytes from bipolar affective disorder patients measured by a fluorometric microassay

BACKGROUND

A number of investigators have reported finding elevated basal and stimulated intracellular calcium levels in the platelets or lymphocytes of bipolar disorder patients.

METHODS

Intracellular calcium was measured by a micro fura-2 fluorometric method in the platelets and lymphocytes of 30 affective disorder patients and 14 control subjects.

RESULTS

We observed significantly elevated basal calcium concentrations in bipolar patient platelets and lymphocytes compared to control subjects. Bipolar patient platelet calcium responses to thrombin, serotonin, and thapsigargin were also significantly greater than control subjects. The peak calcium levels of lymphocytes of bipolar patients were greater than control subjects only when stimulated by thapsigargin. There were significant differences between bipolar and unipolar patients in basal and thapsigargin-stimulated calcium measures but not between bipolar I and bipolar II patients. Unmedicated versus medicated calcium measures were not significantly different. We also found little correlation between calcium measures and the severity of mood rating.

CONCLUSIONS

Using this method, we were able to confirm and extend the work of others, indicating altered intracellular calcium homeostasis in the blood cells of bipolar disorder patients. In addition, our data suggest that storage operated calcium channels may be the source of the elevated intracellular calcium in platelets and lymphocytes of bipolar patients.

Juvenile myelomonocytic leukemia (JMML) with the hematologic phenotype of severe beta thalassemia

A 3-year-old Filipino-American child with recurrent fever, splenomegaly, anemia, and thrombocytopenia, was found to have a hemoglobin F level of 76.9%. His reticulocyte count was elevated (4.3%), and erythroblasts were present in his peripheral blood. The child's erythrocytes were microcytic (MCV 66.9 fl) but his serum ferritin level was normal. His bone marrow at initial presentation demonstrated normal cellularity without an increase in blast cells. The disease progressed with worsening anemia, leukocytosis, and thrombocytopenia, with increased blasts in his marrow and the appearance of a mediastinal mass. His liver, spleen, and lymph nodes were found to be infiltrated with myeloblasts, supporting a diagnosis of juvenile myelomonocytic leukemia (JMML). Analysis of the child's Hb F showed a Ggamma/Agamma ratio of 2.2, which was within the characteristic range for JMML. A globin synthesis study using blood reticulocytes showed an alpha/non-alpha globin synthesis ratio of 2.24, typical of severe homozygous beta thalassemia. Southern blot analysis of blood-leukocyte DNA from the patient and his parents demonstrated no apparent abnormality in the beta-globin gene promoter or coding regions. The elevated level of Hb F in this child with JMML appeared to be part of an acquired Cooley's anemia-like hematologic phenotype.

A naturally occurring amino acid substitution of the human serotonin 5-HT2A receptor influences amplitude and timing of intracellular calcium mobilization

Recently, two naturally occurring amino acid substitutions were identified in the C-terminal region of the serotonin 5-HT2A receptor. One of these, His452Tyr, has a rarer allele Tyr frequency of 9%. If 452Tyr alters 5-HT2A function, it would thus be a candidate allele for human neurobehavioral variation. The present study was designed to evaluate the potential influence of the 452His and 452Tyr alleles on cellular 5-HT2A functions. Platelet 5-HT2A binding and 5-HT-induced Ca2+ response were compared in eight 452His/452His homozygous and eight 452His/452Tyr heterozygous individuals matched for sex, age, and diagnosis (all were patients with seasonal affective disorder). There was no difference in 5-HT2A binding measured using 125I-lysergic acid diethylamide. Nor were levels of G-protein subunits or PKC alpha, delta, epsilon, or zeta significantly altered. However, when Ca2+ response was stimulated by 2, 5, 10, or 25 microM 5-HT, significant differences were found. In 452His/452Tyr heterozygotes, 452Tyr was associated with both smaller peak amplitude in Ca2+ mobilization and a different time course of response, with slower peak latency and longer half-time in 452His/452Tyr heterozygotes compared with 452His/452His homozygotes. The overall difference in the response of the 5-HT2A receptor in individuals with 452Tyr was a blunting of the shape of the Ca2+ mobilization peak. The data reported here suggest that the primary sequence of this intracellular domain is important in function of the receptor and that the 452His and 452Tyr 5-HT2A alleles should be carefully evaluated for effects on human neurobehavioral variation.

Effect of dietary fat or tamoxifen on the expansion of cells harboring Ha-ras oncogenes in mammary glands from methylnitrosourea-treated rats

Diets containing high levels of fat enhance the formation of methylnitrosourea (MNU)-induced mammary gland adenocarcinomas in rats, while administration of the antiestrogen tamoxifen decreases the incidence of these tumors. It is not known, however, at what stage during tumor development the fat or tamoxifen exert their effects. Here we have used a PCR/liquid hybridization and gel retardation assay to determine the effects of dietary fat and tamoxifen on the growth rate of cells harboring an Ha-ras oncogene in the mammary glands of rats at various times following MNU administration. Glands from animals on a high-fat diet had significantly higher mutant cell fractions than those on a low-fat diet at both 30 and 75 days following MNU treatment. In contrast, there was no difference between the mutant cell fractions of tamoxifen-treated animals and controls at either 30 or 70 days. These results suggest that dietary fat promotes tumor formation early in carcinogenesis by stimulating the growth of cells harboring Ha-ras mutations, while tamoxifen delays the appearance of tumors either by acting as a tumoristatic or tumoricidal agent, or by acting to eliminate or retard the growth of preneoplastic cells just prior to the emergence of tumors.

Comparison between short-term and long-term post-operative evaluation of sleep apnoea after uvulopalatopharyngoplasty

For a long time uvulopalatopharyngoplasty (UPPP) has been used to treat the obstructive sleep apnoea syndrome (OSAS). The diverse surgical effects, the inadequate understanding of operation effect consistency, the possibility of disease progression, and the few reported papers for long-term evaluation after UPPP aroused our interest in designing this study. Fifteen OSAS patients who had undergone UPPP with pre-operative, initial post-operative and long-term post-operative polysomnographic studies were included in this study. Long-term post-operative polysomnography was undertaken more than five years after surgery. The polysomnographic evaluations included respiratory disturbance index (RDI), duration of saturation SaO2 < 85 per cent (DOS), and the lowest O2 saturation (LOS). Amongst them, 10 patients with initial post-operative RDI reduction > 50 per cent were considered responders. In these responders, the long-term follow-up results of all three parameters showed improvement compared to the pre-operative data. In a comparison between the initial and long-term post-operative sleep study results, LOS and DOS showed no significant difference. However, the long-term post-operative RDI result became significantly worse. More than 80 per cent of all cases had subjective symptomatic improvement in the long-term post-operative evaluation. The subjective improvement after operation is not adequately correlated to the polysomnographic result. We suggest that long-term follow-up for patients after UPPP is necessary.

Retroviral insertional mutagenesis as a strategy for the identification of genes associated with cis-diamminedichloroplatinum(II) resistance

Expression of resistance to cis-diamminedichloroplatinum(II) (CDDP), one of the most effective chemotherapeutic drugs used to treat a variety of malignancies, remains a serious obstacle for improving cancer treatment. To study possible genetic mechanisms underlying the development of CDDP resistance, we have adopted the approach of retroviral insertional mutagenesis. An early-stage CDDP-sensitive human melanoma cell line, WM35, was infected with a defective amphotropic murine retrovirus (murine stem cell virus), and the pooled cells were subsequently selected for CDDP-resistant variants. Nine CDDP-resistant clones independently derived from murine stem cell virus-infected WM35 cells were analyzed and it was found that five of these clones acquired an identical retroviral integration site, designated as CDDP resistance locus 1 (CRL-1), as revealed by isolation of retroviral flanking sequences. Furthermore, using the flanking sequence as probe, we have detected a 3.5-4.0-kilobase message, the expression of which is strongly increased in clones carrying a rearranged CRL-1 locus. These results strongly suggest that overexpression of CRL-1 confers resistance to CDDP in these clones. In addition, the present study indicates that retroviral insertional mutagenesis represents a potential strategy to identify genes responsible for CDDP resistance and possibly other chemotherapeutic drugs as well.

Retroviral integration within the Fli-2 locus results in inactivation of the erythroid transcription factor NF-E2 in Friend erythroleukemias: evidence that NF-E2 is essential for globin expression

Activation of either Fli-1 or Spi-1 members of the ets family of transcription factors as a result of retroviral insertion and mutational inactivation of the p53 tumor suppressor gene play essential roles in the multistage erythroleukemias induced in mice by various strains of Friend virus. We have previously identified another common site for provirus integration, designated Fli-2 (Friend leukemia integration 2), in some erythroleukemia clones induced either by Friend murine leukemia virus (F-MuLV) or by the polycythemia-inducing strain of Friend virus complex (FV-P). Here we show that genomic sequences adjacent to Fli-2 correspond to the coding region of the erythroid-specific DNA binding protein NF-E2 p45. In one erythroleukemia cell line the expression of NF-E2 p45 is undetectable due to proviral integration in one allele and loss of the other allele. The complete loss of NF-E2 p45 in this cell line is associated with a drastic reduction in expression of the alpha- and beta-globin genes that were partially restored by reintroduction of the NF-E2 p45 gene. Taken together, these results provide direct evidence that NF-E2 gene is essential for globin transcription and suggest that perturbation in expression of this transcription factor may contribute to erythroleukemia progression.

The A1 and A1B proteins of heterogeneous nuclear ribonucleoparticles modulate 5' splice site selection in vivo

Recent in vitro results suggest that the heterogeneous nuclear ribonucleoparticle (hnRNP) A1 protein modulates alternative splicing by favoring distal 5' splice site (5'SS) selection and exon skipping. We used a mouse erythroleukemia (MEL) cell line (CB3C7) deficient in the expression of hnRNP A1 to test whether variations in hnRNP A1 and AlB protein levels affected alternative splicing in vivo. In contrast to A1-expressing MEL cell lines, CB3C7 cells preferentially selected the proximal 13S and 12S 5'SS on the adenovirus E1A pre-mRNA. Transiently expressing the A1 or A1B cDNA in CB3C7 cells shifted 5'SS selection toward the more distal 9S donor site. A1 protein synthesis was required for this effect since the expression of a mutated A1 cDNA did not affect 5'SS selection. These results demonstrate that in vivo variations in hnRNP A1 protein levels can influence 5'SS selection.

Mammary tumor induction by N-methyl-N-nitrosourea in genetically resistant Copenhagen rats

The Copenhagen rat is completely resistant to mammary cancer induction by N-methyl-N-nitrosourea (MNU) when the carcinogen is administered during sexual development, a period when other strains of rats are normally susceptible to mammary gland carcinogenesis. Here we administered 30 mg/kg MNU i.p. to two groups of neonatal (2-3-day-old) Copenhagen rats. One group (group B, 18 animals) received no further treatment, while the other group (group C, 17 animals) received a second dose of 30 mg/kg MNU via the tail vein at 50 days of age. About 30% of the rats in group B and about 70% of those in group C developed mammary carcinomas before they were 1 year of age. About one-half of the tumors in both groups were cribriform adenocarcinomas and one-half were adenosquamous carcinomas. The latter tumor type has not been observed previously in susceptible rat strains. The ability to induce these mammary tumors in the Copenhagen rat suggests that the putative mammary carcinoma suppressor gene is functionally inactive in neonatal animals or is inactivated when these animals are treated with MNU.

Formation and repair of O6-methylguanine and methylation of the Ha-ras proto-oncogene by N-methyl-N-nitrosourea are not associated with mammary tumor resistance in the Copenhagen rat

A high incidence of mammary adenocarcinomas is induced in sexually immature, female Buf/N rats by a single dose of N-methyl-N-nitrosourea (MNU). The Ha-ras gene is activated in a majority of these tumors. The Copenhagen (Cop) rat is completely resistant to mammary gland carcinogenesis by a number of carcinogens, including MNU. Here we show that MNU-treated Buf/N and Cop rats do not differ in the extent of formation and rate of repair of O6-methylguanine in DNA isolated from their mammary epithelial cells. Furthermore, we show that the transcriptional activities of the Ha-ras genes are similar in the mammary glands of Buf/N and Cop rats and that the extents of methylation by MNU of restriction fragments containing the Ha-ras gene from mammary gland DNA are not different for the two strains. Resistance of the Cop rat to mammary carcinogenesis, therefore, appears not to be due to a defect in the interaction of the carcinogen with the target DNA.

Ha-ras oncogene activation in mammary glands of N-methyl-N-nitrosourea-treated rats genetically resistant to mammary adenocarcinogenesis

A single dose of N-methyl-N-nitrosourea given to sexually immature female Buf/N rats produces a high incidence of mammary adenocarcinomas. A large percentage of these tumors contain the Ha-ras oncogene, activated by a G----A transition at the second nucleotide of codon 12. Copenhagen rats, on the other hand, are completely resistant to mammary tumor induction by a number of carcinogens, including N-methyl-N-nitrosourea. Here we show, using a sensitive method involving PCR, that codon 12 Ha-ras mutations occur in the mammary glands of both Buf/N and Copenhagen rats 30 days after N-methyl-N-nitrosourea treatment. These mutations were evenly distributed among individual mammary glands and were present in purified mammary epithelial cells. In Buf/N rats, the fraction of cells containing a mutated Ha-ras allele increased by a factor of 10-100 between 30 and 60 days, whereas in Copenhagen rats, there was no such increase during this time period. We conclude that the resistance of the Copenhagen rat to mammary carcinogenesis is not due to a defect in initiation but rather appears to be due to the inability of cells containing a mutated ras allele to undergo sustained clonal expansion.

ras oncogene activation in mammary carcinomas induced by N-methyl-N-nitrosourea in Copenhagen rats

The occurrence of Ha-ras and Ki-ras oncogenes was investigated in mammary tumors produced by treating genetically resistant Copenhagen (Cop) rats with N-methyl-N-nitrosourea. G35-->A codon 12 mutations in both Ha-ras and Ki-ras genes were analyzed by a polymerase chain reaction/liquid hybridization and gel retardation assay. More than half of the adenocarcinomas analyzed contained an activated Ha-ras gene. This was also the predominant mutation in similar tumors from susceptible Buf/N rats, suggesting a common mechanism of initiation. In contrast, only two of 15 mammary adenosquamous carcinomas from the Cop rats contained an activated Ha-ras gene, suggesting a different initiation mechanism for most of these tumors. Ki-ras activation was found in none of five and one of five adenocarcinomas from Buf/N and Cop rats, respectively, and in none of 13 adenosquamous carcinomas from Cop rats. These results suggest that Ki-ras activation does not play a major role in the initiation of the mammary tumors.

Preferential methylation of the Ha-ras proto-oncogene by methylnitrosourea in rat mammary glands

Activation of the Ha-ras proto-oncogene, but not the Ki-ras or N-ras genes, has been found in mammary gland carcinomas induced in female rats by a single dose of methylnitrosourea (MNU). Here we show that a 10-kb restriction fragment containing the Ha-ras gene was extensively methylated by MNU in DNA isolated from mammary glands of female rats 4 h after carcinogen treatment. Fragments of similar size containing either the Ki-ras or N-ras genes were methylated less extensively. The extent of methylation of the three ras genes by MNU correlated with their transcriptional activity. These results suggest that the extent of interaction of a carcinogen with an oncogene, which depends on its transcriptional activity, may be a factor in determining whether the gene is mutated during the initiation of carcinogenesis.

Operative technique for carcinoma of the oesophagus after distal subtotal gastrectomy: a new method using the residual stomach to reconstruct the alimentary tract

The stomach is the organ most often chosen for substitution following resection of the oesophagus for carcinoma and this method has given good results. The mode of reconstruction of the alimentary tract in oesophageal cancer patients with previous distal gastrectomy presents a surgical problem. Usually the colon or jejunum is chosen as an alternative for substitution in such patients. We report a new technique used in our unit on 30 patients with previous distal subtotal gastrectomy. This involves using the residual stomach for reconstruction and transposing the spleen and tail of the pancreas into the left thoracic cavity in order to preserve the blood supply to the stomach. The entire procedure is performed through the left chest. We explored 35 patients originally, but five were found to be unresectable at operation. Of the remaining 30 patients, the tumour locations were: upper thoracic (1), midthoracic (24) and lower thoracic (5). The anastomotic sites were: above aortic arch (23), below aortic arch (5) and neck (2). The technical success of this procedure was good with no deaths in the immediate post-operative period. There were three anastomotic leakages which all healed after thoracic drainage and a feeding jejunostomy.

Linkage of a nasopharyngeal carcinoma susceptibility locus to the HLA region

The frequency of nasopharyngeal carcinoma is nearly 100-fold higher in southern Chinese than in most European populations. Earlier studies have suggested that an increased risk of nasopharyngeal carcinoma is associated with specific haplotypes in the HLA region: relative risks slightly over twofold were found for haplotypes A2, Bw46 and the antigen B17. We now report a linkage study based on affected sib pairs which suggests that a gene closely linked to the HLA locus confers a greatly increased risk of nasopharyngeal carcinoma. The maximum likelihood estimate is of a relative risk of approximately 21. The relationship between this suspected disease susceptibility gene (or genes) and known viral and environmental aetiological factors remains to be elucidated.

Metabolism of fusarin C by rat liver microsomes. Role of esterase and cytochrome P-450 enzymes with respect to the mutagenicity of fusarin C in Salmonella typhimurium

Fusarin C (FC) is a potent mutagen present on Fusarium moniliforme contaminated corn. This compound requires metabolic activation for which microsomes from phenobarbital-induced rats are most effective. Inhibition of the simultaneously induced esterase activity, which produced a less mutagenic metabolite, doubled the mutagenicity of FC. Carbon monoxide inhibited the mutagenicity of FC, suggesting the involvement of a heme containing enzyme. However, monoclonal antibodies specific for the phenobarbital-induced cytochrome P-450 enzymes PB-4 and PB-5, while inhibiting O-demethylation of p-nitroanisole and aflatoxin B1 mutagenicity, had not effect on FC mutagenicity. This implies that either these enzymes are not involved in the activation of FC or FC competes well with the antibodies for binding to the cytochrome P-450 enzymes. Two additional metabolites of FC were detected. One had an ultraviolet spectrum similar to FC: the other had a lambda max at 326 nm, and its retention time on reverse phase HPLC was very sensitive to changes in pH.

[Enhancing effect of danggui injection on immunologic function]

Experiments have shown that Danggui injection enhances phagocytic function of macrophage in normal mice, and antagonizes the immunosuppressive activity of macrophage by cytoxan. The injection may increase the function of B cells and the activity of serum lysozyme, thus increasing the function of humoral immunity and nonspecific immunity.

Fusarium moniliforme metabolites: genotoxicity of culture extracts

Fusarin C (FC) is a potent mutagen which has been isolated from Fusarium moniliforme culture extracts (FME). We have confirmed that the mutagenicity of these extracts is enhanced by phenobarbital- or Aroclor-induced microsomes and shown that: (i) additional, direct-acting, mutagens are present in crude extracts from F. moniliforme cultures; (ii) Salmonella typhimurium TA 100 exposed to FME in the presence of S9 mixtures shows an increased number of DNA strand breaks as detected by intercalation of ethidium bromide; (iii) exposure of polyoma-transformed rat fibroblast cells to HPLC-purified FC induced asynchronous replication of polyoma DNA sequences, a phenomenon also observed when these cells were exposed to a variety of other carcinogens; (iv) FME can alkylate 4-(p-nitrobenzyl)pyridine in the absence of S9 mix, although less efficiently than styrene oxide; and (v) these additional direct-acting mutagens, present in crude extracts from F. moniliforme cultures, may be responsible for the DNA adducts formed by reaction with calf thymus DNA in the absence of metabolic activation and detected by the 32P-postlabeling assay. All of these observations suggest that significant health effects may be associated with human exposure to F. moniliforme and that further studies on its metabolites are needed.

Effects of microwaves on three different strains of rats

Confounding factors influencing the sensitivity of biological indicators of microwave exposure--lethality, colonic temperature (Tco), decreased body mass (dW), corticosterone (CS), thyrotropin (TSH), thyroxine (T4), free thyroxine (FT4), and prolactin (PRL) concentration--were studied in Long-Evans (LE), Wistar-Kyoto (WKY), and spontaneous hypertensive (SHR) rats. The microwave signal was 2.45 GHz amplitude modulated at 120 Hz. Test power density ranged from 1 to 50 mW/cm2 for 2 h. In contrast to the LE and WKY rats, the SHR rats were characterized by intolerance (death) between 40 and 50 mW/cm2 (9.2 to 11.5 W/kg). The lowest lethal Tco was 41.1 degrees C. Survivors including all the LE and WKY rats were capable of maintaining Tco lower than 41.0 degrees C. In general, strain of rat seemed to influence other bioindicators and to interact with power density on these bioindicators. Except for Tco and PRL, baseline for the various bioindicators varied among the different strains of rats. Responses of T4 and FT4 were limited in magnitude and inconsistent among strains of rats. In general, the magnitude of Tco increase was more pronounced in SHR than in WKY. Differences between SHR and LE, however, could be noted only at 1, 10, and 50 mW/cm2. Increased Tco, increased magnitude of Dw, increased CS, decreased TSH, and increased PRL (stress reactions) could be noted in rats exposed to 30 mW/cm2 (approximately 6 W/kg) or higher, irrespective of strain. At least two of three strains of rats (WKY and SHR) exposed to 20 mW/cm2 (approximately 4 W/kg) showed changes in Tco, CS, TSH, and PRL. At 10 mW/cm2 (2 W/kg), increased Tco could be found in all three strains of rats accompanied by changes in dW and TSH in LE, TSH in WKY, and dW and CS in SHR. At 1 mW/cm2 (0.2 W/kg), increased Tco could be noted in two of three strains (LE and SHR) and increased PRL in LE only. The smallest Tco increases for a consistent response (increased magnitude of response with power density) were 1.59 degrees C for dW, 0.70 degrees C for CS, 0.24 degrees C for TSH, and 0.97 degrees C for PRL. Tentatively, the threshold intensity for response to microwave exposure for rats could be considered as 2 W/kg or a 0.24 degrees C increase at 24 degrees C ambient temperature.

Effects of microwaves on the adrenal cortex

Six-hundred-and-one male Long-Evans rats were used to study the effect of microwaves on adrenocortical secretion. Power density ranged from 0.1 to 55 mW/cm2 (SAR 0.02 to 11 W/kg). The microwave signal was 2.45 GHz amplitude modulated at 120 Hz. Serum corticosterone (CS) concentration was used as an index of adrenocortical function. Ten different exposure protocols were used to identify confounding factors influencing the sensitivity of adrenal cortex to microwave exposure. Increases in CS concentration were proportional to power density or colonic temperature and inversely proportional to the baseline CS. Increased CS concentration was never observed without increased colonic temperature and was not persistent 24 h after exposure. Acclimation (reduction in magnitude of response) could be noted after the tenth exposure. Facilitated heat loss attenuated the magnitude of CS increases by limiting the degree of hyperthermia. Ethanol enhanced the hyperthermic response and desensitized the adrenal response to microwave hyperthermia by increased baseline CS. Ether stimulated adrenal secretion irrespective of previous microwave exposure or adrenal stimulation induced by microwaves. Minor inhibition was also noted occasionally as decreased CS concentration at lower intensity (less than 20 mW/cm2) and decreased postexposure urinary CS excretion at 40 mW/cm2. Adrenal stimulation required minimally a 20 mW/cm2 (4 W/kg) or 0.7 degrees C increase in colonic temperature. An SAR lower than 4 W/kg may stimulate adrenal secretion by potentiating the hyperthermic effect if the ambient temperature is well above 24 degrees C.

Synthesis of nitrosomethylisoamylamine from isoamylamine and sodium nitrite by fungi

Nitrosomethylisoamylamine (NMIA), a carcinogenic N-nitroso compound was synthesized from isoamylamine (IAA) in a glucose-ammonium nitrate medium after several days' incubation with fungi and subsequent nitrosation with sodium nitrate. The nitrosamine was not produced by control reactions which lacked either IAA or fungi. The yield of NMIA varied with the length of incubation after inoculation with the fungi, and with the concentrations of IAA and NaNO2, the duration of nitrosation, the pH of the medium and the species of the fungi. The optimum conditions for the formation of the nitrosamine are reported.