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In the present paper, the phenomenon of vibrational resonance in a time-varying delayed FitzHugh- Nagumo system that is driven by two-frequency periodic signals is reported. Via a numerical simulation, the periodic vibrational resonances are found to be induced by the time-varying delay feedback under the condition that the delayed feedback strength is small, and then along with the increase of the delayed feedback strength K within the slow period (i.e., the period of low-frequency signal), the single resonance turns into multiple resonances. However, if the delayed feedback strength K is big enough, the resonance no longer occurs. More interestingly, the multiple resonances can also turn into a single resonance in a cycle by modulating the amplitude F of high-frequency signal. Furthermore, both the resonance region and the resonance amplitude are found to be able to be controlled by the time-varying delay. Finally, it is found that the regular motion of the system can be enhanced by the time-varying delay feedback and then more regular motion will present if the resonance does not occur. [ABSTRACT FROM AUTHOR]

1. The aim of the study was to determine the pharmacokinetics of losartan in relation to the CYP2C9*13 allele. 2. A single oral dose of 50 mg losartan was administrated to each of the 16 healthy male volunteers with a different genotype (CYP2C9*1/*1, n = 6; CYP2C9*1/*13, n = 4; and CYP2C9*1/*3, n = 6). Blood samples were collected from pre-dose up to 24 h after the drug administration. Plasma losartan and E3174 (an active metabolite of losartan) were assayed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). 3. All the subjects finished the study without adverse drug effects. In the present study, the frequencies of CYP2C9*13 and *13 alleles were 0.6% and 2.6% in Chinese healthy volunteers, respectively, and both alleles were in Hardy-Weinberg equilibrium. Compared with the subjects in the CYP2C9*1/*1 group, individuals carrying the CYP2C9*1/*13 genotype showed significantly a longer t1/2 of losartan and E3174 and markedly increased the area under the curve (AUC) of losartan. Meanwhile, the CYP2C9*1/*3 genotype group had significant differences in t1/2 and Cmax of E3174 compared with the CYP2C9*1/*1 group. The ratio of AUCE3174/AUClosartan after losartan administration in the CYP2C9*1/*13 and CYP2C9*1/*3 groups was also statistically different from that in the CYP2C9*1/*1 group. 4. The data indicate that the presence of the CYP2C9*13 allele results in poor metabolism of losartan after a single oral dose. [ABSTRACT FROM AUTHOR]

The authors investigated the effect of herbal medicine Schisandra chinensis extract (SchE) and Ginkgo biloba extract (GBE) on the oral pharmacokinetics of P-glycoprotein substrate talinolol in humans. Twelve healthy male volunteers took a single 100-mg oral dose of talinolol either alone or after pretreatment with 300 mg SchE twice daily or with 120 mg GBE three times daily for 14 days. On day 14, a single 100-mg oral dose of talinolol was administered. Plasma concentrations of talinolol from zero to 24 h were measured by high-performance liquid chromatography. SchE increased the area under the curve (AUC)0-24 of talinolol by 47% (90% confidence interval (CI), 18-84%; p = 0.010), and GBE by 21% (90% CI = 11-32%; p = 0.002). The Cmax of talinolol increased by 51% (90% CI = 21-89%; p = 0.007) with SchE treatment and by 33% (90% CI = 18-51%; p = 0.002) with GBE treatment, respectively. The t1/2 of talinolol increased by 7% (90% CI = -4% to 19%; p = 0.320) with SchE treatment and by 11% (90% CI = -12% to 38%; p = 0.436) with GBE treatment, respectively. The results suggest that both SchE and GBE significantly inhibited P-glycoprotein in humans. Patients receiving either SchE or GBE may require dose adjustments when treated with drugs primarily transported by P-glycoprotein. [ABSTRACT FROM AUTHOR]

Objective: To analyze the diagnosis and treatment of a patient with glufosinate-ammonium poisoning after total gastrectomy. Methods: The clinical data of a patient with oral glufosinate-ammonium poisoning after total gastrectomy in the First Affiliated Hospital of Nanjing Medical University in August 2020 were analyzed. Results: After total gastrectomy, the patient took about 200 ml of glufosinate-ammonium orally, and the plasma glufosinate-ammonium concentration was 816.8 ng/ml 6.5 h after poisoning. After symptomatic treatment such as promoting poison excretion, rehydration, anti infection and protecting important organs, the patient improved and discharged. Conclusion: The clinical manifestations of patients with glufosinate-ammonium poisoning after total gastrectomy are still mainly neurological symptoms, with delayed effect. Whether total gastrectomy will affect the distribution and toxic effect of the poison still needs further exploration.

Objective: To analyze the amino acid polymorphism of truncated Staphylococcal enterotoxin-like toxin X (tSElX), and to evaluate its related emetic activities. Methods: Sequence of tselx was compared with both the genome sequence of 145 CC398 strains completed in our research group and the NCBI database. Primers were designed to amplify the target gene of tselx , and the fragment was recombined into pMD18-T vector and sequenced. PCR product was digested with BamH Ⅰ and EcoR Ⅰ, and constructed into plasmid pGEX-6P-1 and pET-28a (+). After recombinant plasmid was identified, the protein expression was induced by IPTG. Proteins expressed in the form of inclusion bodies were denatured and renatured, then purified by affinity chromatography and ultrafiltration. Purified tSElX protein was then fed to common marmosets with the dose of 250 μg/kg to observe the vomiting reaction. Results: tselx gene was present in 145 strains of CC398 strains from the different origins (patients, healthy people and animals) in China. Homology of the amino acid sequence of the protein from the Chinese strains appeared 100.0 % , while the homology with the four American strains were 97.8 % (1) and 98.9 % (3), respectively. Through two sets of expression systems and different induction conditions, tSElX was expressed in the form of inclusion bodies. The high purity soluble recombinant tSElX was thus obtained by denaturated and renaturated processes. At the dose of 250 μg/kg, tSElX protein did not cause vomiting in common marmosets. Conclusions: Results of this study showed that the amino acid sequence of tSElX was highly conserved and was universally present in a particular clone group. We obtained soluble recombinant tSElX protein with high purity. We also noticed that tSElX did not have the animal emetic activity at a dose of 250 μg/kg.

Objective: To analyze the reasons for failure of Meek micro-skin grafting in children with severe burns and to observe the clinical effects of the treatment measures. Methods: Thirty children with severe burns hospitalized in the First Affiliated Hospital of Anhui Medical University (hereinafter referred to as the author's affiliation) from January 2012 to January 2018, conforming to the inclusion criteria were included to failed skin graft group. Children in failed skin graft group were performed with Meek micro-skin grafting operation and the operation failed, including 17 males and 13 females aged 1 to 12 year(s). Thirty children with severe burns hospitalized in the author's affiliation during the same period of time, conforming to the inclusion criteria, were included to successful skin graft group. Children in successful skin graft group were performed with Meek micro-skin grafting operation and the operation succeeded, including 16 males and 14 females aged 1 to 12 year(s). Main treatment measures and effects before operation, area and survival rate of Meek micro-skin graft, infected pathogens status, selection status of sensitive antibiotics, preoperative nutrition status, and wound infection status in plum rain season of children in the two groups, and nutritional status before and after strengthening nutritional support of postoperative surviving children in failed skin graft group were analyzed retrospectively. Data were processed with chi-square test and t test. Results: (1) The numbers of children in the two groups performed with main treatment measures of dilatation and anti-shock, tracheotomy intubation, ventilator-assisted respiration, and limb incision decompression after admission were close ( χ (2)=0, 0.016, 0.025, 0.009, P >0.05). After taking the above-mentioned main treatment measures, effects of correcting shock, preventing asphyxia, correcting breathing difficulty, and improving peripheral circulation of limb were achieved. (2) The area of Meek micro-skin grafting of children in successful skin graft group was (20.6±2.5)% total body surface area (TBSA), close to (21.2±2.2)% TBSA in failed skin graft group ( t =0.534, P >0.05). The survival rate of Meek micro-skin graft of children in successful skin graft group was (79±5)%, significantly higher than (26±3)% in failed skin graft group ( t =2.956, P <0.01). (3) The microbial culture of wound secretion of 5 (16.67%) children in 30 patients in successful skin graft group was positive, with Pseudomonas aeruginosa of 2 children, and Escherichia coli, Staphylococcus aureus, and Aspergillus of one patient respectively. As children in successful skin graft group were with no symptom of systemic infection, no blood microbial culture was done. The microbial culture of wound secretion of 30 (100.00%) children in 30 patients in failed skin graft group was positive, and blood microbial culture of 8 (26.67%) children was positive. The main pathogen was Pseudomonas aeruginosa of 11 (36.67%) children in 8 pathogens caused infection with gram-negative bacteria of 22 (73.33%), gram-positive bacteria of 11 (36.67%) children, and fungi of 6 (20.00%) children. (4) Ten kinds of sensitive antibiotics such as cephalosporins, glycopeptides, carbapenems, and tetracyclines antibiotics were used in children in failed skin graft group, of which the use rate of imipenem of 9 (30.00%) was the highest. Only 4 kinds of sensitive antibiotics such as ceftazidime were used in 30 children in successful skin graft group. (5) The preoperative levels of albumin and prealbumin of children in successful skin graft group were (32±4) g/L and (133±41) mg/L respectively, significantly higher than (27±4) g/L and (93±35) mg/L in failed skin graft group ( t =5.090, 4.064, P <0.01). The albumin and prealbumin levels of postoperative surviving children in failed skin graft group after nutritional support treatment were (35±4) g/L and (168±49) mg/L, significantly higher than (27±4) g/L and (94±38) mg/L before nutritional support treatment ( t =6.911, 6.315, P <0.01). (6) Wound infection of 9 children in 30 children with wound infection in failed skin graft group happened in the plum rain season, and fungi infection of 3 children in 6 children with fungi infection happened in the plum rain season. Wound infection of 2 children in 5 children with wound infection in successful skin graft group happened in the plum rain season, and the only one children with fungi infection happened in the plum rain season. Conclusions: The main reasons for the failure of Meek micro-skin grafting in children with severe burns include infection, nutrition, and season factors, etc. Measures of strengthening wound dressing change, reasonable use of sensitive antibiotics to control infection, internal and external intestinal nutritional support, and reducing disturbance of the plum rain season by enhancing ventilation are effective and worthy of clinical promotion.

Objective: To investigate the regulation of hypoxia-inducible factor-1α (HIF-1α) on permeability of rat vascular endothelial cells and the mechanism. Methods: Twelve male Sprague-Dawley rats aged 35 to 38 days were collected and vascular endothelial cells were separated and cultured. The morphology of cells was observed after 4 days of culture, and the following experiments were performed on the 2nd or 3rd passage of cells. (1) Rat vascular endothelial cells were collected and divided into blank control group, negative control group, HIF-1α interference sequence 1 group, HIF-1α interference sequence 2 group, and HIF-1α interference sequence 3 group according to the random number table (the same grouping method below), with 3 wells in each group. Cells in negative control group, HIF-1α interference sequence 1 group, HIF-1α interference sequence 2 group, and HIF-1α interference sequence 3 group were transfected with GV248 empty plasmid, recombinant plasmid respectively containing HIF-1α interference sequence 1, interference sequence 2, and interference sequence 3 with liposome 2000. Cells in blank control group were only transfected with liposome 2000. After transfection of 24 h, expression levels of HIF-1α mRNA and protein of cells in each group were respectively detected by reverse transcription real-time fluorescent quantitative polymerase chain reaction and Western blotting (the same detecting methods below) . The sequence with the highest interference efficiency was selected. (2) Another batch of rat vascular endothelial cells were collected and divided into blank control group, negative control group, and HIF-1α low expression group, with 3 wells in each group. Cells in blank control group were only transfected with liposome 2000, and cells in negative control group and HIF-1α low expression group were respectively transfected with GV248 empty plasmid and low expression HIF-1α recombinant plasmid selected in experiment (1) with liposome 2000. After 14 days of culture, the mRNA and protein expressions of HIF-1α in each group were detected. (3) Another batch of rat vascular endothelial cells were collected and divided into blank control group, negative control group, and HIF-1α high expression group, with 3 wells in each group. Cells in blank control group were transfected with liposome 2000, and cells in negative control group and HIF-1α high expression group were respectively transfected with GV230 empty plasmid and HIF-1α high expression recombinant plasmid with liposome 2000. After 14 days of culture, the mRNA and protein expressions of HIF-1α of cells in each group were detected. (4) After transfection of 24 h, cells of three groups in experiment (1) and three groups in experiment (2) were collected, and mRNA and protein expressions of myosin light chain kinase (MLCK), phosphorylated myosin light chain (p-MLC), and zonula occludens 1 (ZO-1) of cells were detected. Data were processed with one-way analysis of variance and t test. Results: After 4 days of culture, the cells were spindle-shaped, and rat vascular endothelial cells were successfully cultured. (1) The interference efficiencies of HIF-1α of cells in HIF-1α interference sequence 1 group, HIF-1α interference sequence 2 group, and HIF-1α interference sequence 3 group were 47.66%, 45.79%, and 62.62%, respectively, and the interference sequence 3 group had the highest interference efficiency. After transfection of 24 h, the mRNA and protein expression levels of HIF-1α of cells in interference sequence 3 group were significantly lower than those in blank control group ( t =18.404, 9.140, P <0.01) and negative control group ( t =15.099, 7.096, P <0.01). (2) After cultured for 14 days, the mRNA and protein expression levels of HIF-1α of cells in HIF-1α low expression group were significantly lower than those in blank control group ( t =21.140, 5.440, P <0.01) and negative control group ( t = 14.310, 5.210, P <0.01). (3) After cultured for 14 days, the mRNA and protein expression levels of HIF-1α of cells in HIF-1α high expression group were significantly higher than those in blank control group ( t =19.160, 7.710, P <0.01) and negative control group ( t = 19.890, 7.500, P <0.01). (4) After transfection of 24 h, the mRNA expression levels of MLCK and p-MLC of cells in HIF-1α low expression group were significantly lower than those in blank control group ( t =2.709, 4.011, P <0.05 or P <0.01) and negative control group ( t =2.373, 3.744, P <0.05 or P <0.01). The mRNA expression level of ZO-1 of cells in HIF-1α low expression group was significantly higher than that in blank control group and negative control group ( t =4.285, 5.050, P <0.01). The mRNA expression levels of MLCK and p-MLC of cells in HIF-1α high expression group were significantly higher than those in blank control group ( t =9.118, 11.313, P <0.01) and negative control group ( t =9.073, 11.280, P <0.01). The mRNA expression level of ZO-1 of cells in HIF-1α high expression group was significantly lower than that in blank control group and negative control group ( t =2.889, 2.640, P <0.05). (5) After transfection of 24 h, the protein expression levels of MLCK and p-MLC of cells in HIF-1α low expression group were significantly lower than those in blank control group ( t =2.652, 3.983, P <0.05 or P <0.01) and negative control group ( t =2.792, 4.065, P <0.05 or P <0.01). The protein expression of ZO-1 of cells in HIF-1α low expression group was significantly higher than that in blank control group and negative control group ( t =3.881, 3.570, P <0.01). The protein expression levels of MLCK and p-MLC of cells in HIF-1α high expression group were 1.18±0.24 and 0.68±0.22, which were significantly higher than 0.41±0.21 and 0.35±0.14 in blank control group ( t =5.011, 3.982, P <0.05 or P <0.01) and 0.43±0.20 and 0.36±0.12 in negative control group ( t = 4.880, 3.862, P <0.05 or P <0.01). The protein expression level of ZO-1 of cells in HIF-1α high expression group was 0.08±0.06, which was significantly lower than 0.20±0.09 in blank control group and 0.19±0.09 in negative control group ( t =4.178, 3.830, P <0.05 or P <0.01). Conclusions: HIF-1α up-regulates expressions of MLCK and p-MLC and down-regulates expression of ZO-1, thereby increasing the permeability of rat vascular endothelial cells.

Objective: To explore the influence of three-level collaboration network of pediatric burns in Anhui province on treatment effects of burn children. Methods: The data of medical records of pediatric burn children transferred from Lu'an People's Hospital and Fuyang People's Hospital to the First Affiliated Hospital of Anhui Medical University from January 2014 to December 2015 and January 2016 to September 2017 (before and after establishing three-level collaboration network of pediatric burns treatment) were analyzed: percentage of transferred burn children to hospitalized burn children in corresponding period, gender, age, burn degree, treatment method, treatment result, occurrence and treatment result of shock, and operative and non-operative treatment time and cost. Rehabilitation result of burn children transferred back to local hospitals in 2016 and 2017. Data were processed with t test, chi-square test, Mann-Whitney U test, and Fisher's exact test. Results: (1) Percentage of burn children transferred from January 2014 to December 2015 was 34.3% (291/848) of the total number of hospitalized burn children in the same period of time, which was close to 30.4% (210/691) of burn children transferred from January 2016 to September 2017 ( χ (2)=2.672, P >0.05). (2) Gender, age, burn degree, and treatment method of burn children transferred from the two periods of time were close ( χ (2)=3.382, Z =-1.917, -1.911, χ (2)=3.133, P >0.05). (3) Cure rates of children with mild, moderate, and severe burns transferred from January 2016 to September 2017 were significantly higher than those of burn children transferred from January 2014 to December 2015 ( χ (2)=11.777, 6.948, 4.310, P <0.05). Cure rates of children with extremely severe burns transferred from the two periods of time were close ( χ (2)=1.181, P >0.05). (4) Children with mild and moderate burns transferred from the two periods of time were with no shock. The incidence of shock of children with severe burns transferred from January 2014 to December 2015 was 6.0% (4/67), and 3 children among them were cured. The incidence of shock of children with severe burns transferred from January 2016 to September 2017 was 3.9% (2/51), and both children were cured. The incidences and cures of shock of children with severe burns transferred from the two periods of time were close ( χ (2)=0.006, P >0.05). Incidence of shock of children with extremely severe burns transferred from January 2014 to December 2015 was 57.1% (32/56), significantly higher than that of burn children transferred from January 2016 to September 2017 [34.5% (10/29), χ (2)=3.925, P <0.05]. Shock of 25 children with extremely severe burns transferred from January 2014 to December 2015 were cured, and shock of 9 children with extremely severe burns transferred from January 2016 to September 2017 were cured. The cures of shock of children with extremely severe burns transferred from the two periods of time were close ( χ (2)=0.139, P >0.05). (5) Time of operative treatment of children with moderate, severe, and extremely severe burns transferred from January 2014 to December 2015 was obviously longer than that of burn children transferred from January 2016 to September 2017 ( t =2.335, 2.065, 2.310, P <0.05). Time of operative treatment of children with mild burns transferred from the two periods of time was close ( Z =-0.417, P >0.05). Costs of operative treatment of children with moderate and severe burns transferred from January 2014 to December 2015 were significantly more than those of burn children transferred from January 2016 to September 2017 ( Z =-3.324, t =2.167, P <0.05). Costs of operative treatment of children with mild and extremely severe burns transferred from the two periods of time were close ( t =0.627, 0.808, P >0.05). (6)Time of non-operative treatment of children with mild, moderate, and severe burns transferred from January 2014 to December 2015 was obviously longer than that of burn children transferred from January 2016 to September 2017 ( t =2.335, Z =-2.095, t =2.152, P <0.05). Time of non-operative treatment of children with extremely severe burns transferred from the two periods of time was close ( t =0.450, P >0.05). Costs of non-operative treatment of children with moderate and severe burns transferred from January 2014 to December 2015 were obviously higher than those of burn children transferred from January 2016 to September 2017 ( Z =-2.164, t =2.040, P <0.05). Costs of non-operative treatment of children with mild and extremely severe burns transferred from the two periods of time were close ( t =0.146, 1.235, P >0.05). (7) Sixty-seven burn children transferred from January 2016 to September 2017 were transferred back to local hospitals for rehabilitation under the guidance of experts of the First Affiliated Hospital of Anhui Medical University, with 25 patients in 2016 and 42 patients in 2017. Effective rehabilitation rates of burn children transferred back to local hospitals for rehabilitation in 2016 and 2017 were both 100%. Conclusions: The three-level collaboration network of pediatric burns treatment in Anhui province can effectively increase cure rate of children with mild, moderate, and severe burns, reduce incidence of shock of children with extremely severe burns, shorten time of operative treatment of burn children with moderate, severe, and extremely severe burns, and time of non-operative treatment of children with mild, moderate, and severe burns, reduce treatment costs of children with moderate and severe burns, and improve rehabilitation effectiveness of children transferred from Lu'an People's Hospital and Fuyang People's Hospital to the the First Affiliated Hospital of Anhui Medical University.

To identify which region of staphylococcal enterotoxin A (SEA) is responsible for the emetic activity, twelve synthetic peptides corresponding to the entire SEA amino acid sequence and their respective anti-peptide antibodies were prepared and tested. The anti-peptide antibodies were tested for neutralization of SEA-induced emesis in Suncus murinus (Shrew mouse). The results indicate that SEA-induced emesis was neutralized by the mixture of three anti-peptide antibodies to A-7 (corresponding to amino acid residues 121-140), A-8 (141-160) and A-9 (160-180). These findings suggest that the regions corresponding to residues 121-180 may be the epitopes responsible for the emetic activity of SEA.

Peroral and intraperitoneal administration of staphylococcal enterotoxin A (SEA) to Suncus murinus elicited an emetic response. The 50% emetic dose of SEA by peroral administration was found to be 32 microg per kg of body weight, whereas that by intraperitoneal administration was 3 microg per kg. Multiple emetic responses occurred 70 to 108 min after peroral administration of an emetic dose of SEA. Similar responses occurred 65 to 102 min after intraperitoneal injection of an emetic dose of SEA. No significant difference in vomiting was observed between male and female animals. Anti-SEA serum neutralized SEA-induced emesis in S. murinus. These findings indicate that S. murinus may serve as a suitable animal model to study the enterotoxigenicity of SEA.

The authors carried out a descriptive analysis of acute chemical intoxication in a large petrochemical corporation with 38,000 employees, located in a suburban district of Shanghai, China, to determine the chemicals involved and the primary causes of the incidents. Between 1977 and 1997, 350 cases of acute chemical-intoxication were recorded, resulting in a total of 541 workers with symptoms. Of these, 483 were male and 58, female, with over half the victims under 30 years old. Two hundred and seventy-five cases were serious enough to necessitate hospital admission. There were 266 cases of chemical irritation or inhalation responses (49.2%), 215 cases of mild chemical poisoning (39.7%), 31 cases of moderate poisoning (5.7%), and 29 cases resulting in critical injury (5.4%), including eight deaths (1.5%). The main causes of injury reported by patients were lack of training about safety (63%) and equipment failure (23%). The chemicals involved were asphyxiating gases (302 cases; 55.8%), irritating gases (111 cases; 20.5%), and other toxins. Intervention strategies for the prevention of acute chemical exposures were suggested to the corporation.

To identify the functional region(s) associated with induction of gamma interferon on the staphylococcal enterotoxin A molecule, native staphylococcal enterotoxin A molecules and 12 various synthetic peptides corresponding to different regions of entire staphylococcal enterotoxin A were compared to induce gamma interferon production in murine spleen cells. The native staphylococcal enterotoxin A molecule induced gamma interferon production, whereas all of the 12 synthetic peptides did not. Pre-treatment of the murine spleen cells with synthetic peptide A-9 (corresponding to amino acid residues 161-180) significantly inhibited the staphylococcal enterotoxin A-induced gamma interferon production, whereas those with other synthetic peptides did not. When native staphylococcal enterotoxin A was pre-treated with either anti-staphylococcal enterotoxin A serum or anti-peptide sera, anti-staphylococcal enterotoxin A serum and antisera to peptides A-1 (1-20), A-7 (121-140), A-8 (141-160), A-9 (161-180) and A-10 (181-200) inhibited the staphylococcal enterotoxin A-induced gamma interferon production. From these findings, the amino acid residues 161-180 on the staphylococcal enterotoxin A molecule may be an essential region for murine gamma interferon production. Furthermore, the neutralizing epitopes may be also located on regions of amino acid residues 1-20, 121-140, 141-160 and 181-200 on the staphylococcal enterotoxin A molecule.

The antigenic determinants (or epitopes) of staphylococcal enterotoxin A (SEA) were analyzed using synthetic peptides and rabbit antibodies to their corresponding peptides. Of 12 different synthetic peptides tested, peptides A-1 (corresponding to the amino acid sequence 1-20), A-5 (81-100), and A-8 (141-160) were reactive with anti-SEA antibodies. However, all synthetic peptides were found to elicit antibodies reactive with native SEA molecule. These findings suggest that native SEA molecule contains at least 3 different antigenic determinants.

The genes AldP and AldC-a, encoding the rice chloroplastic (cp) and cytoplasmic (ct) types of aldolase, respectively, were isolated and sequenced, and their transcription start points (tsp) were determined. Organization of the two genes was found to differ greatly; AldP consisted of six exons while AldC-a consisted of two exons. The deduced amino acid (aa) sequence of AldP contained a cp stromal targeting signal, followed by a sequence that matches the experimentally determined N-terminal sequence of mature AldP. The two enzymes share only 55% aa identity. However, rice AldP had about 73% homology with the cp aldolase of spinach. Also, the homology of AldC-a with maize, spinach and Arabidopsis thaliana cytoplasmic aldolases ranged from 70 to 90%. Southern blot analyses indicated that AldP is encoded at a single locus, whereas the gene encoding the ct counterpart is distributed at three loci on the genome. This feature is quite different from those of maize and spinach, in which only one locus was found for the ct aldolase.