Two novel HLA-DRB1 alleles identified using a sequence-based typing: HLA-DRB1*1443 and HLA-DRB1*1351*

Two novel HLA-DRB1 alleles, DRB1*1443 and DRB1*1351, were identified using a sequence-based typing protocol. DRB1*1443 differed from DRB1*140501 by one single-nucleotide substitution in exon-2 (codon 77, ACC-->GCC), which corresponded to an amino acid change of threonine to alanine. DRB1*1351 was identical to DRB1*1301 but differed by a single-nucleotide substitution at codon 50 (GTG-->TTG), resulting in an amino acid change of valine to leucine. Both new alleles present unique polymorphisms, which have not been seen among other DRB1 alleles and which have no known effect on peptide binding.

Space spraying of bacterial and chemical insecticides against Anopheles balabacensis Baisas for the control of malaria in Sabah, East Malaysia

A pilot study was undertaken to determine the effectiveness of space application of insecticides for the control of malaria in Ranau, a district in Sabah. A village each was treated monthly: with chemical adulticide--alpha cypermethrin (Fendona SC(R)/10SC(R)) at 2 g a.i./10,000 m2 in Pahu; with biological larvicides--Bacillus thuringiensis israelensis (Vectobac 12AS(R)) at 500 ml/10,000 m2 or B. sphaericus (Vectolex WG(R)) at 500 g/10,000 m2 in Pinawantai; and with a mixture of chemical adulticide and biological larvicide in Togop Laut. All sprayings were conducted using a portable mist blower. During the study period all villages, including Tarawas the untreated village, received the conventional malaria control measures. Entomological and epidemiological surveillance was used to measure the effectiveness of the space application. The entomological surveillance indicated that the An. balabacensis population was significantly reduced by alpha cypermethrin in Pahu and Togop Laut and B. sphaericus in Pinawantai; but was not reduced by B.t.i. in Pinawantai. There was a significant reduction in the number of malaria cases and in the slide positivity rate in the treated villages during the study period. The pilot study does indicate that space application of larvicides/adulticides or a mixture of both is able to reduce the malaria vector population and the malaria transmission. A larger scale study needs to be undertaken in a malarious village/province to determine whether space application of insecticides together with other malaria control measures will be able to eradicate malaria.

Identification of a new HLA-DRB1 allele, HLA-DRB1*0436

Anovel allele, HLA-DRB1*0436, was identified in a Taiwan indigenous individual by sequence-based typing. DRB1*0436 was identical to DRB1*0403 in exon2 but differed at codons 67-74 with five nucleotide substitutions. This corresponded to three amino acid changes within the P4 peptide-binding pocket of the DR molecule. These substitutions constitute a motif that is also seen in other DRB1*11 alleles. It is possible that the new allele resulted from a gene conversion event.

Properties of 137Cs in marine sediments off Yangnam, Korea

Concentrations of 137Cs in sediment and seawater samples in the East Sea (Japan Sea) adjacent to Yangnam, Korea were measured and data on the physical and chemical properties of the sediments were collected. The concentrations of 137Cs in the sediment samples were in the range of less than the minimum detectable activity (MDA)-7.19 Bq/kg-dry, and the values were linearly correlated with particle size, total organic carbon (TOC), H, N or S content of the sediment. The 137Cs concentrations in the sediment samples were well fitted to a multiple regression equation with TOC contents and particle size distributions. The distribution coefficients, which indicate the degree of adsorption, of 137Cs to the sediments were strongly dependent on particle size and TOC content.

hMLH1 and hMSH2 mutations in families with familial clustering of gastric cancer and hereditary non-polyposis colorectal cancer

The pattern of hMLHI and hMSH2 mutations was assessed to identify the genetic correlation between hereditary gastric and colorectal cancers. Four disease groups and their healthy family members were assembled according to the presentation of gastric cancer: FG, familial clustering of gastric cancer (n = 32); CG, family with one or more colorectal and gastric cancers in first-degree relatives (n = 22); HS, seven HNPCC families corresponding to the Amsterdam criteria (AMS+) and 12 suspected HNPCC families which did not satisfy one of the criteria (AMS-), but no gastric cancer among first- and second-degree relatives (n = 19); and SG, sporadic gastric cancer (n = 33). In the CG group, three were included in AMS + and six in AMS- criteria. Peripheral blood was obtained from them to detect hMLHI and hMLH2 mutations using PCR-SSCP analysis and direct sequencing. The incidence of mutations was 9.4% in the FG group, 54.5% in the CG group, 31.6% in the HS group, and none in the SG group. The incidence, type, and number of the mutation were not different between the CG and HS groups. Thirty-four different mutations included 19 in hMLH1 and 15 in hMSH2. Gastric cancer was the most common extracolonic malignancy in HNPCC and suspected HNPCC families (9/28, 32.1%). The hMLH1 or hMSH2 mutation occurred in seven of 10 families with AMS+, whereas it occurred in four of 18 with AMS- (70% vs. 22.2%, P = .013). Five mutations in the hMLH1 and six mutations in the hMSH2 were exclusively found in families with gastric cancer. All three mutations in the FG group were in hMLHI and there was no mutation in their healthy family members. This study demonstrates that some familial clustering type of gastric cancer appears to be associated with hMLHI mutations thereby indicating a difference from the hereditary gastric cancer studies previously reported. In addition, hMLHI and hMSH2 mutations may impact the gastric cancer carcinogenesis in HNPCC or suspected HNPCC.

Modeling fish community dynamics in the Florida Everglades: role of temperature variation

Temperature variation is an important factor in Everglade wetlands ecology. A temperature fluctuation from 17 degrees C to 32 degrees C recorded in the Everglades may have significant impact on fish dynamics. The short life cycles of some of Everglade fishes has rendered this temperature variation to have even more impacts on the ecosystem. Fish population dynamic models, which do not explicitly consider seasonal oscillations in temperature, may fail to describe the details of such a population. Hence, a model for fish in freshwater marshes of the Florida Everglades that explicitly incorporates seasonal temperature variations is developed. The model's main objective is to assess the temporal pattern of fish population and densities through time subject to temperature variations. Fish population is divided into 2 functional groups (FGs) consisting of small fishes; each group is subdivided into 5-day age classes during their life cycles. Many governing sub-modules are set directly or indirectly to be temperature dependent. Growth, fecundity, prey availability, consumption rates and mortality are examples. Several mortality sub-modules are introduced in the model, of which starvation mortality is set to be proportional to the ratio of prey needed to prey available at that particular time step. As part of the calibration process, the model is run for 50 years to ensure that fish densities do not go to extinction, while the simulation period is about 8 years. The model shows that the temperature dependent starvation mortality is an important factor that influences fish population densities. It also shows high fish population densities at some temperature ranges when this consumption need is minimum. Several sensitivity analyses involving variations in temperature terms, food resources and water levels are conducted to ascertain the relative importance of temperature dependence terms.

The use of genotyping to predict the phenotypes of human platelet antigens 1 through 5 and of neutrophil antigens in Taiwan

BACKGROUND

The human platelet antigen (HPA) 1 through 5 and the human neutrophil antigen (HNA-1) systems are relevant to immune-related thrombocytopenia and neutropenia. The alloantigen distribution profiles in the population will aid in estimating the risk of alloimmunization.

STUDY DESIGN AND METHODS

Genotyping of the genes that control the expression of the HPA-1 through -5 and HNA-1 systems in Taiwanese (n = 326) and Taiwan's indigenous peoples (n = 608) was performed by PCR with the sequence-specific primer (PCR-SSP) method.

RESULTS

In the HPA system, HPA-1b and HPA-4b were absent among Taiwan's indigenous tribes and detected among other Taiwanese only with frequencies of <0.2 percent and <0.5 percent, respectively. The GP1BA*2 (HPA-2b) and GP1A*2 (HPA-5b) allele frequencies range from 1 percent to 7 percent and 0.4 percent to 3.5 percent among the two ethnic groups, respectively. GP2B*1 (HPA-3a) and GP2B*2 (HPA-3b) showed similar allele frequencies. In the HNA-1 system, the FCGR3B*1 (HNA-1a) allele frequency was about twice that of FCGR3B*2 (HNA-1b) in Taiwanese and also in most of the indigenous tribes. Three FCGR3B (HNA-1) null persons were found in one indigenous tribe (Ami tribe), for an FCGR3B null frequency of 19.8 percent. However, no FCGR3B*3 (HNA-1c) allele was detected in Taiwan.

CONCLUSION

The frequencies of HPA-1b, -2b, and -5b in the Taiwanese population were much lower than those among whites. In Taiwan, all of the HNA-1 null found was due to the deletion of the FCGR3B gene, and this deletion may be widely distributed in the Ami tribe.

Polymorphism and distribution of the Secretor alpha(1,2)-fucosyltransferase gene in various Taiwanese populations

BACKGROUND

The Secretor gene (Se or FUT2), which produces alpha(1,2)-fucosyltransferase, exhibits extensive polymorphism. Six Se genes, including the weak Se (Se(w) or Se385) and three nonsecretor alleles (se571, se685, and se849) have been detected in various populations of Taiwan. The distribution of various Lewis phenotypes among the Taiwanese population groups has been shown to vary considerably.

STUDY DESIGN AND METHODS

A PCR-RFLP analysis system, which was based on the nucleotide polymorphism variation of the different Se alleles and which can reveal the Se genotype of an individual easily and accurately, was developed. The distribution of the Se alleles among Taiwanese population groups, including the two major populations, Minnan and Hakka Taiwanese, and 11 indigenous groups, was analyzed by the method.

RESULTS

Frequencies of the Se alleles among the Taiwanese populations were revealed. The distribution of the nonsecretor alleles, especially se849, showed a marked variation. A good correlation was observed between a person's Se genotype and Lewis phenotype.

CONCLUSION

The Se genes have a polymorphic distribution among various Taiwanese populations, and this agrees with previous results for Lewis phenotype distributions. The Se(w) allele and the three se alleles are responsible for the Le(a+b+) and Le(a+b-) phenotypes, respectively.

Inadvertent hypothermia causes pulseless electrical activity in a patient during cervical spine surgery--a case report

Recent studies have shown that hypothermia triples the incidence of major cardiac events. We present a happening in which a 71-year-old patient developed pulseless electrical activity (PEA) while he was undergoing cervical laminectomy for spinal stenosis in the sitting position. Thromboembolism or venous air embolism and acute myocardial infarction were respectively excluded by transesophageal echocardiography and cardiac enzymes analysis to be the causes of the cardiac event. The abnormal finding that stood out was low nasopharyngeal temperature (31 degrees C) during the procedure, which was thought to contribute to the development of the PEA episode.

Histone H1 phosphorylation by Cdk2 selectively modulates mouse mammary tumor virus transcription through chromatin remodeling

Transcriptional activation of the mouse mammary tumor virus (MMTV) promoter by ligand-bound glucocorticoid receptor (GR) is transient. Previously, we demonstrated that prolonged hormone exposure results in displacement of the transcription factor nuclear factor 1 (NF1) and the basal transcription complex from the promoter, the dephosphorylation of histone H1, and the establishment of a repressive chromatin structure. We have explored the mechanistic link between histone H1 dephosphorylation and silencing of the MMTV promoter by describing the putative kinase responsible for H1 phosphorylation. Both in vitro kinase assays and in vivo protein expression studies suggest that in hormone-treated cells the ability of cdk2 to phosphorylate histone H1 is decreased and the cdk2 inhibitory p21 protein level is increased. To address the role of cdk2 and histone H1 dephosphorylation in the silencing of the MMTV promoter, we used potent cdk2 inhibitors, Roscovitine and CVT-313, to generate an MMTV promoter which is associated predominantly with the dephosphorylated form of histone H1. Both Roscovitine and CVT-313 block phosphorylation of histone H1 and, under these conditions, the GR is unable to remodel chromatin, recruit transcription factors to the promoter, or stimulate MMTV mRNA accumulation. These results suggest a model where cdk2-directed histone H1 phosphorylation is a necessary condition to permit GR-mediated chromatin remodeling and activation of the MMTV promoter in vivo.

Relative language proficiency modulates BOLD signal change when bilinguals perform semantic judgments. Blood oxygen level dependent

The effect of relative language proficiency on the spatial distribution and magnitude of BOLD signal change was evaluated by studying two groups of right-handed English-Mandarin bilingual participants with contrasting language proficiencies as they made semantic judgments with words and characters. Greater language proficiency corresponded to shorter response times and greater accuracy in the semantic judgment task. Within the left prefrontal and parietal regions, the change in BOLD signal was smaller in a participant's more proficient language. The least proficient performance was associated with right, in addition to left, inferior frontal activation. The results highlight the importance of taking into consideration nature of task and relative language proficiency when drawing inferences from functional imaging studies of bilinguals.

Diversity of HLA among Taiwan's indigenous tribes and the Ivatans in the Philippines

Taiwan's indigenous tribes, especially the east coast tribes are not only closely related to Oceania but also with the Australian aborigines. The Ivatans of the Batan Islands in the Philippines are closely related to the Yami tribe of Taiwan as cultural and anthropological studies have shown. Many DRB1 alleles (*15021, *16021, *0404, *04051, *11011, *12021, *1401, *08032) have high allele frequencies (>20%) in certain tribes, suggesting Taiwan's indigenous tribes are homogeneous populations. These high frequency DRB1 alleles and also some HLA-A-B-DR haplotypes found in Taiwan's indigenous tribes are also found in Oceania, Australian aborigines, south and north east Asians and American Indians, lending further support to our previous findings that Taiwan's indigenous tribes are more or less genetically related to both northern and southern Asians, possibly as well as Amerindians. HLA-A*2402 with a remarkably high frequency among Taiwan's indigenous tribes (52.1% approximately 86.3%), especially the central mountain tribes, possibly represents not only founder effects and population bottlenecks, but also positive selection of the allele. Although the Ami tribe has the highest ever reported frequencies of the DRB1*0404 and DRB1*0405, these alleles have not been found to be associated with rheumatoid arthritis as previously described for Caucasians. In addition, DRB1*1401 has a high frequency in most tribes but is not associated with psoriasis as previously indicated in some studies, suggesting the involvement of some additional genetic and/or environmental factors mechanism in the development of these diseases.

Natural history of low-grade squamous intraepithelial lesion

OBJECTIVE

To determine guidelines for management of CIN1 by evaluating its natural history.

METHODS

One hundred fifty-eight patients were diagnosed with CIN1 had colposcopy follow-up with or without cytology every three months.

RESULTS

Colposcopically directed biopsy confirmed progression to CIN2 or CIN3 in 17 of 158 (10.7%) patients, persistence of CIN1 in 87 (55%) patients, regression to normal in 54 (34.2%) patients during the 5-year follow-up period. The percentage of abnormal Pap tests were 39%, 64%, and 71% in the regression, persistent, and progression groups, respectively. The percentage of HPV-positive tests were 16%, 29%, 65% in regression, persistent, and progression groups, respectively.

CONCLUSIONS

Of the patients who were diagnosed with CIN1 and monitored by colposcopy for 60 months, 34% had disease regression, 55% had persistent disease, and 11% had progressive disease. HPV DNA testing is more informative than the Pap test in the prediction of disease progression.

Factors related to quality of life in breast cancer patients receiving chemotherapy

This descriptive correlation study investigated the relationship among individual characteristics, disease characteristics, psychological factors (anxiety, depression, self-esteem), social support, and quality of life in patients with breast cancer receiving chemotherapy. One hundred and fifty women from nine Taipei area hospitals were surveyed with a structured questionnaire. The total quality of life index for breast cancer patients was about average (M = 19.88). The family factor scored highest for importance and satisfaction with quality of life. Patients showed the most dissatisfaction with the health factor. Of the individual characteristics affecting patient quality of life, number of children and social status were statistically significant (p < .05). Of the disease characteristics, the stage of the disease, the commencement of chemotherapy, and the number of chemotherapy treatments were statistically significant (p < .05). The psychological factors were significantly related to patients' quality of life (p < .05). Social support of both relatives and health professionals was significantly related to patients' quality of life (p < .01). Of the four independent variables (individual characteristics, disease characteristics, psychological factors and social support), the most influential factor affecting breast cancer patients' total quality of life was the psychological factor of self-esteem (p < .001). The findings can assist nurses to plan and improve the quality of breast cancer care in terms of understanding the factors affecting patients' quality of life.

Modulation of the levels of NMDA receptor subunit mRNA and the bindings of [3H]MK-801 in rat brain by chronic infusion of subtoxic dose of MK-801

The effects of continuous infusion of NMDA receptor antagonist MK-801 on the modulation of NMDA receptor subunits NR1, NR2A, NR2B, and NR2C were investigated by using in situ hybridization study. Differential assembly of NMDA receptor subunits determines their functional characteristics. Continuous intracerebroventricular (i.c.v.) infusion with MK-801 (1 pmol/10 microl/h) for 7 days resulted in significant modulations in the NR1, NR2A, and NR2B mRNA levels without producing stereotypic motor syndromes. The levels of NR1 mRNA were significantly increased (9-20%) in the cerebral cortex, striatum, septum, and CA1 of hippocampus in MK-801-infused rats. The levels of NR2A mRNA were significantly decreased (11-16%) in the CA3 and dentate gyrus of hippocampus in MK-801-infused rats. In contrast to NR2A, NR2B subunit mRNA levels were increased (10-14%) in the cerebral cortex, caudate putamen, and thalamus. However, no changes of NR2C subunits in cerebellar granule layer were observed. Using quantitative ligand autoradiography, the binding of NMDA receptor ligand [3H]MK-801 was increased (12-25%) significantly in almost all brain regions except in the thalamus and cerebellum after 7 days infusion with MK-801. These results suggest that region-specific changes of NMDA receptor subunit mRNA and [3H]MK-801 binding are involved in the MK-801-infused adult rats.

Population genetics of the hypervariable locus D12S391 in Koreans

The hypervariable short tandem repeat (STR) locus D12S391 was investigated in a Korean population and 34 fragments were sequenced to confirm the structure of alleles. From these sequenced fragments an allelic ladder containing 13 sequenced alleles was constructed. From 595 unrelated Koreans, 14 alleles were detected and one variant allele 19.3 was observed. The observed heterozygosity was 0.795 and no deviation from Hardy-Weinberg equilibrium was observed in the Korean population (p = 0.606). The allele frequency distribution in the Korean population was not similar to other racial or ethnic groups except for Egyptians, Yemenis, Japanese and Caucasoids from the Rhine area. No mutations were observed in the 702 meioses from 144 Korean families. This study demonstrates that the STR locus D12S391 is a useful tool for forensic identification and parentage testing.

A Korean population study of the nine STR loci FGA, VWA, D3S1358, D18S51, D21S11, D8S1179, D7S820, D13S317 and D5S818

DNA typing was performed on 379 randomly selected unrelated Koreans using the nine short tandem repeat loci FGA, VWA, D3S1358, D18S51, D21S11, D8S1179, D7S820, D13S317 and D5S818 present in the AmpF/STR Profiler Plus PCR amplification kit. Allele frequencies, heterozygosity, power of discrimination, mean exclusion chance, and polymorphism information content of each locus were calculated by statistical analysis. All nine loci were in Hardy-Weinberg equilibrium. The combined discrimination index and the combined mean exclusion chance in Koreans was 2.31 x 10(-12) and 0.99983, respectively. By evaluation of 297 children from 128 families, 2 mutations were found at the FGA locus and 1 each at the D18S51 and D13S317 loci. This study demonstrates that this multiplex system is a useful and convenient tool for forensic identification and parentage testing in Korea.

The origin of Minnan and Hakka, the so-called "Taiwanese", inferred by HLA study

The Minnan and Hakka people groups, the so-called "Taiwanese", are the descendants of early settlers from the southeast coast of China during the last few centuries. Genetically they showed affinities to southern Asian populations, as determined by phylogenetic trees and correspondence analysis calculated from HLA allele frequencies. This corresponds historically with the fact that they are the descendants of the southeast coastal indigenous population (Yueh) of China and should therefore not be considered as descendants of "pure" northern Han Chinese. A33-B58-DRB1*03 (A33-Cw10-B58-DRB1*03-DQB1*02), the most common HLA haplotype among "Taiwanese", with a haplotype frequency of 6.3%, has also been found to be the most common haplotype among Thai-Chinese and Singapore Chinese, two other populations also originating from the southeast coast of China. These observations suggests that this haplotype is the most well-conserved ancient haplotype of the Yueh.

Hyperthermic pretreatment decreases microvascular protein leakage and attenuates hypotension in anaphylactic shock in rats

Systemic anaphylaxis is a life-threatening allergic reaction and its pathologic conditions, such as edema, bronchospasm, and hypotension, have been attributed to release of vasoactive mediators. Heat shock protein (HSP) is known to play a protective role in living cells under various stresses. In these studies, we investigated the protective role of heat shock response in anaphylactic shock, focusing on changes of blood pressure (BP) and vascular permeability. Adult sensitized rats were injected intravenously with Evans blue (EB) and challenged with bovine serum albumin (BSA). The rats were treated with whole-body hyperthermia at 41.5 +/- 0.5 degrees for 15 min 24 h before BSA challenge. Vascular protein leakage in tissues was analyzed with the EB technique. The results showed that BSA challenge induced EB extravasation in all sensitized rats. EB values (EB/tissue; microg/g) in heart and lung (112.3 +/- 41 and 244.4 +/- 90.6; mean +/- SD; n = 6) in the nonheated rats were significantly higher than those (33.4 +/- 23.3 and 103.4 +/- 63.9; n = 9) in the heated rats (P < 0.05). The results showed that BSA challenge caused BP to fall drastically in the sensitized rats. BP in the heated rats was significantly higher than BP in the nonheated rats from 4 to 15 min during anaphylactic shock (P < 0.001). Inducible HSP72 appeared overexpressed in heart, lung, and liver tissue in the heated rats tested by Western immunoblotting. The results indicate that reduction of increased protein leakage and attenuation of hypotension may result from induction of HSP by whole-body hyperthermia.

Characteristics of repeated ambulance use in an urban emergency medical service system

BACKGROUND AND PURPOSE

Although many studies have examined the reasons for repeated use of emergency medical service (EMS), little information is available concerning repeated ambulance use in Taiwan. This study evaluated the characteristics of repeated EMS ambulance use in an urban EMS system in Taiwan.

METHODS

Data from a local EMS computerized database for the period from January 1996 through December 1998 were collected for analysis. All calls to the dispatch center that resulted in EMS transports were included. Repeat users were identified by matching the user name, sex, age, and home address. Transports were categorized according to how many times the patient was transported by ambulance during the 3-year period: single use, one time; repeated use, two or three times; or frequent use, more than three times.

RESULTS

During the 36-month study period, there were 41,792 calls, with 13,076 non-transports (a non-transport rate of 31.3%). Of the 28,716 transports during the study period, 2,101 represented repeated or frequent use (7.3%); the rate of frequent use was 1.4% (406/28,716). The frequency of repeated use reached a daily first peak at 8:00 AM, with the second and third peaks at 1:00 PM and 7:00 PM. The mean age increased with increasing repeated use of transport (37.25 +/- 0.24 vs 41.55 +/- 1.03 vs 46.23 +/- 1.57 years, respectively; p < 0.001). The percentage of non-trauma missions increased with increasing repeated use of transport (26.3% vs 55.6% vs 73.2%; p < 0.001). Response time significantly increased for repeated use (analysis of variance [ANOVA], p < 0.001). The on-scene interval (time from arrival until departure) in the single-use group was shorter than in the repeated and frequent use groups (ANOVA, p < 0.005).

CONCLUSIONS

The results of this study indicate that the characteristics of repeat users of EMS transport differ from those of single users. Characteristics of service time, reason for transport, and interval to each subsequent call varied among different groups of users. Studies of repeat use under a wider range of conditions such as in rural EMS systems and after implementation of a priority-dispatch system are needed to determine the implications of repeated ambulance use.

Nitrogen regulatory protein C-controlled genes of Escherichia coli: scavenging as a defense against nitrogen limitation

Nitrogen regulatory protein C (NtrC) of enteric bacteria activates transcription of genes/operons whose products minimize the slowing of growth under nitrogen-limiting conditions. To reveal the NtrC regulon of Escherichia coli we compared mRNA levels in a mutant strain that overexpresses NtrC-activated genes [glnL(Up)] to those in a strain with an ntrC (glnG) null allele by using DNA microarrays. Both strains could be grown under conditions of nitrogen excess. Thus, we could avoid differences in gene expression caused by slow growth or nitrogen limitation per se. Rearranging the spot images from microarrays in genome order allowed us to detect all of the operons known to be under NtrC control and facilitated detection of a number of new ones. Many of these operons encode transport systems for nitrogen-containing compounds, including compounds recycled during cell-wall synthesis, and hence scavenging appears to be a primary response to nitrogen limitation. In all, approximately 2% of the E. coli genome appears to be under NtrC control, although transcription of some operons depends on the nitrogen assimilation control protein, which serves as an adapter between NtrC and final sigma(70)-dependent promoters.