[The role of Hong's single-stitch duct to mucosa pancreaticojejunostomy in laparoscopic pancreaticoduodenectomy].

Objective: To investigate the role of "Hong's single-stitch duct to mucosa pancreaticojejunostomy(HSDMP)" in laparoscopic pancreaticoduodenectomy (LPD). Methods: The clinical data including perioperative and short-term outcomes of 51 cases of LPD with HSDMP which performed in Zhejiang Provincial People's Hospital(33 cases) and Frist Clinical Hospital of Jilin University(18 cases) between April and October 2016 were reviewed retrospectively. There were 31 male patients and 20 female patients. The mean age was(59±11)years. Body mass index (BMI) was 18 to 28 kg/m(2) and the average BMI was (23.2±4.4)kg/m(2). Preoperative diagnosis: 18 cases with pancreatic mass, 26 cases with peri-ampullary tumor, 3 cases with intra-ductal papillary mucinous neoplasms, 2 cases with duodenal carcinoma, 2 cases with serous cystadenoma. Results: Fifty-one patients accepted LPD using HSDMP. One patient underwent LPD combined with resection of superior mesentery vein. The mean operation time was (307±69)minutes, the mean diameter of pancreatic duct for reconstruction was (3.1±1.1)mm.The mean operation time for HSDMP was (34±5) minutes, the estimated blood loss was (170±127)ml. Twelve cases(23.5%) had pancreatic fistula according to International Study Group definition, including 9 cases(17.6%) of grade A and 3 cases (5.9%) of grade B. Five cases(9.8%) had delayed gastric empty, 5 cases(9.8%) had bile leakage and 2 cases(3.9%) had pulmonary infection postoperative.All these complications were treated by non-surgical strategies. One patient(2.0%) suffered from postoperative intra-abdominal bleeding and recovered after reoperation. Pathologic results showed pancreatic ductal adenocarcinomas in 20 cases(39.2%), non-pancreatic original peri-ampullary tumors in 23 cases(45.1%), intra-ductal papillary mucinous neoplasms in 3 cases(5.9%), duodenal carcinoma in 2 cases(3.9%), serous cystadenoma in 2 cases(3.9%) and neuroendocrine tumors in one case(2.0%). Conclusions: HSDMP could not only reduce the incidence of clinical pancreatic fistula, but also save operation time. It is a feasible and safe method for pancreaticojejunostomy.

[Clinical effect of double blood supply composite tissue flap with peroneal artery perforator and sural nerve nutrient vessel carrying gastrocnemius muscle in repairing lacunar defect of ankle].

Objective: To explore the clinical effect of double blood supply composite tissue flap with peroneal artery perforator and sural nerve nutrient vessel carrying gastrocnemius muscle in repairing lacunar skin and soft tissue defect of ankle. Methods: From September 2015 to September 2017, 10 patients with lacunar skin and soft tissue defects of ankle were hospitalized in our unit, including 7 males and 3 females, aged 17-62 years, 8 traffic accident injuries and 2 heavy body pressure injuries. After debridement, the wound area ranged from 7 cm×4 cm to 15 cm×9 cm, and the lacunar area ranged from 3.0 cm×2.0 cm×1.0 cm to 7.0 cm×4.0 cm×2.0 cm. The defect was repaired with island composite tissue flap with peroneal artery perforator and sural nerve nutrient vessel and partial gastrocnemius muscle at stage Ⅰ. The area of flaps ranged from 8 cm×5 cm to 16 cm×10 cm, and the area of gastrocnemius muscle flaps ranged from 4 cm×3 cm to 8 cm×5 cm. The donor site was repaired with ipsilateral thigh intermediate split-thickness skin graft or sutured directly. The location of vascular pedicle, survival of tissue flap, follow-up, and occurrence of complications were recorded. Results: The vascular pedicle of this group of cases was located 5-15 cm above the lateral malleolus. The tissue flaps of 10 patients survived completely after operation at stage Ⅰ. Follow-up for 1-12 months showed that the area repaired with tissue flaps had good color, blood supply, and texture, without ulceration, and recovered different degrees of pain sensation and deep tactile sensation, and no short-term or long-term complications occurred. Conclusions: The double blood supply composite tissue flap with peroneal artery perforator and sural nerve nutrient vessel carrying gastrocnemius muscle has good blood supply, which can effectively fill the invalid space in repairing lacunar skin and soft tissue defect of ankle, with good effect after operation, and it is worthy of clinical application.

[Clinical effects of adjacent fasciocutaneous flaps in repairing small wounds with bone or steel plate exposure in anterior tibia].

Objective: To explore the clinical effects of adjacent fasciocutaneous flaps in repairing small wounds with bone or steel plate exposure in anterior tibia. Methods: Twelve patients with small wounds of bone or steel plate exposure in anterior tibia covering area of 2 cm×2 cm to 5 cm×3 cm were admitted to our unit from January 2014 to December 2016. A circular or elliptical adjacent fasciocutaneous flap was designed on the normal skin located at the inside or outside of the wound according to the size of wound after thorough debridement. The pedicle of the flap was located at the proximal end and transferred through the subcutaneous tunnel to cover the wound. The sizes of flaps were 3 cm×3 cm to 6 cm×4 cm. Flaps were fixed with interrupted sutures and drainage rubber sheets were placed under the flaps. The drainage rubber sheets were removed within 24 to 48 hours. The donor area was repaired by medium-thickness skin graft collected from homolateral outer thigh. Results: All the flaps of 9 patients survived. Two patients had necrosis at the distal end of the flaps and were cured by changing dressing. One patient had tension blisters on the flap and was cured by removing blisters and improving microcirculation. All patients were followed up for 3 months, and the flaps were good in blood supply, appearance, and color, with hypaesthesia. Conclusions: Repair of small wounds with bone or steel plate exposure in anterior tibia by adjacent fasciocutaneous flap is simple in surgical procedure and does not damage the well-known blood vessels, and the appearance, texture, and thickness of flaps are close to the skin of anterior tibia region. It is a good choice for repairing this kind of wounds and worth promoting in clinic.

[Analysis on treatment of extremely severe burn patients with severe inhalation injury in August 2nd Kunshan factory aluminum dust explosion accident].

Objective: To summarize the measures and experience in diagnosis and treatment of extremely severe burn patients with severe inhalation injury in dust explosion accident. Methods: The medical records of 13 patients with extremely severe burn complicated with severe inhalation injury in August 2nd Kunshan factory aluminum dust explosion accident who were treated at the First Affiliated Hospital of Soochow University (hereinafter referred to as our hospital) on August 2nd, 2014, were retrospectively analyzed. All the patients were transferred to our hospital 3-8 hours after injury under the condition of inhalation of pure oxygen. Twelve patients underwent tracheotomy within 5 hours after admission, while 1 patient underwent tracheotomy before admission. All the patients were in ventilator-assisted respiration, with synchronized intermittent mandatory ventilation combined with positive end expiratory pressure. All the patients underwent thorax or limbs escharotomy on the second day after admission, so as to reduce the restrictive ventilatory dysfunction caused by the contraction of thorax eschar and the terminal circulation disorder caused by the contraction of limbs eschar. All the patients underwent electronic bronchoscopy within 48 hours after admission, airway secretion were cleared and airway lavage were carried out under electronic bronchoscope according to the patients' condition, and the sputum, lavage solution, pathological tissue were collected for microbiological culture. All the patients underwent chest X-ray examination on the second day after admission and reexamination as required. Patients were all treated with a combination of broad-spectrum antibiotics early after admission to control lung and systemic infection. One patient was treated with extracorporeal membrane oxygenation for acute respiratory distress syndrome 1 week after admission. Results: One patient suffered from cardiopulmonary arrest during tracheotomy, which recovered autonomous respiration and cardiac impulse after cardiopulmonary resuscitation. Three patients showed decreased pulse oxygen saturation (SpO(2)) within 48 hours after injury, and the SpO(2) returned to normal after sputum aspiration, scab removal and lavage under electronic bronchoscope. During the course of disease, bacteria were cultured from wound exudate of 7 patients, bacteremia occurred in 10 patients, and sputum microbiological culture results of 13 patients were positive. Eight of the 13 patients in this group survived, and 5 died. One patient died 19 days after injury, and 4 patients died 33-46 days after injury. The main cause of death was multiple organ dysfunction syndrome induced by severe septic shock eventually. Conclusions: For this batch of patients with extremely severe burn complicated with severe inhalation injury caused by dust explosion accident, the treatment and cure measures including early definite diagnosis and timely tracheotomy, the application of effective ventilation, the effective treatment of respiratory system complications, and rational use of antibiotics for the control of lung infection obtained quite good curative effect.

[Effect of application of pulse contour cardiac output monitoring technology on delayed resuscitation of patients with extensive burn in a mass casualty].

OBJECTIVE: To investigate the effect of the application of pulse contour cardiac output (PiCCO) monitoring technology on delayed resuscitation of patients with extensive burn in a mass casualty. METHODS: The clinical data of 41 patients injured in Kunshan dash explosion hospitalized in the First Affiliated Hospital of Soochow University, the 100th Hospital of the People's Liberation Army, and Suzhou Municipal Hospital were retrospectively analyzed. The patients were divided into traditional monitoring group (T, n=22) and PiCCO monitoring group (P, n=19) according to the monitoring technic during delayed resuscitation. The input volumes of electrolyte, colloids, and water of patients in the two groups within 2 hours after admission, the first, second, and third 8 hours post injury (HPI), and the first 24 HPI were recorded. The fluid infusion coefficients of patients in the two groups within 2 hours after admission, the first, second, and third 8 HPI, and the first, second, third, and fourth 24 HPI were calculated. The urine volume, mean arterial pressure (MAP), and central venous pressure (CVP) of patients in the two groups at post injury hour (PIH) 8, 16, 24, 48, 72, and 96 were recorded. The blood lactate, base excess, hematocrit (HCT), and platelet count of patients in the two groups at PIH 24, 48, 72, and 96 were recorded. Complications and death of patients in the two groups were recorded. Data were processed with analysis of variance for repeated measurement, Chi-square test, t test, and Wilcoxon test. The deviations between figure 2 and the fluid infusion coefficients of the first or second 24 HPI, and the deviations between figure 1 and the fluid infusion coefficients of the second, third or fourth 24 HPI were calculated, and the three groups deviations were analyzed by Pearson correlation analysis. RESULTS: (1) The input volumes of electrolyte of patients in group P were significantly more than those in group T within the first 8 and 24 HPI (with Z values respectively -3.506 and -2.654, P<0.05 or P<0.01), and the input volumes of electrolyte of patients in the two groups were similar within the other time periods (with Z values from -1.871 to -0.680, P values above 0.05). The input volumes of colloid of patients in group P were significantly less than those in group T within the second, third 8 HPI, and the first 24 HPI (with Z values from -4.720 to -2.643, P<0.05 or P<0.01), and the input volumes of colloid of patients in the two groups were similar within the other time periods (with Z values respectively -2.376 and -2.303, P values above 0.05). The input volumes of water of patients in the two groups were similar within each time period (with Z values from -1.959 to -0.241, P values above 0.05). (2) The fluid infusion coefficients of patients in group T within 2 hours after admission, the first, second, and third 8 HPI, and the first, second, third, and fourth 24 HPI were respectively (0.59±0.18), (0.70±0.23), (0.94±0.24), (0.74±0.14), (2.38±0.44), (1.70±0.56), (1.35±0.67), and (0.92±0.46) mL·kg(-1)·%TBSA(-1,) and the values in group P were respectively (0.59±0.29), (0.82±0.37), (0.86±0.38), (0.59±0.24), (2.27±0.85), (2.13±0.68), (1.59±3.78), and (1.46±0.56) mL·kg(-1)·%TBSA(-1). The fluid infusion coefficients of patients in the two groups were similar within 2 hours after admission, the first, second 8 HPI, and the first, third 24 HPI (with t values from -1.262 to 0.871, P values above 0.05). The fluid infusion coefficient of patients in group P was significantly lower than that in group T within the third 8 HPI (t=2.456, P<0.05), and the fluid infusion coefficient of patients in group P were significantly higher than that in group T within the second and fourth 24 HPI (with t values respectively -2.234 and -3.370, P<0.05 or P<0.01). There was obviously negative correlation between the deviations of figure 2 and the fluid infusion coefficient of the first 24 HPI and that of the second 24 HPI (r=-0.438, P<0.01). There was no obvious correlation between the deviations of figure 1 and the fluid infusion coefficient of the second 24 HPI and that of the third 24 HPI (r=0.091, P>0.05). There was obviously positive correlation between the deviations of figure 1 and the fluid infusion coefficient of the second 24 HPI and that of the fourth 24 HPI (r=0.695, P<0.01). (3) The urine volumes and MAP of patients in the two groups were similar at each time point (with Z values from -1.884 to 0, P values above 0.05). The CVP of patients in group P were significantly higher than that in group T at PIH 16, 24, 48, and 72 (with Z values from -4.341 to -2.213, P<0.05 or P<0.01), and the CVP of patients in the two groups were similar at the other time points (with Z values respectively -0.132 and -1.208, P values above 0.05). The blood lactate of patients in group P was significantly higher than that in group T at PIH 72 (Z= -2.958, P<0.01) , and the blood lactate of patients in the two groups were similar at the other time points (with Z values from -1.742 to -0.433, P values above 0.05). The base excess of patients in group P were significantly lower than that in group T at PIH 24, 48, 72, and 96 (with Z values from -4.970 to -4.734, P values below 0.01). The HCT of patients in the two groups were similar at PIH 24, 48, 72, and 96 (with Z values from -2.239 to -0.196, P values above 0.05). There were significant differences in the platelet count of patients in the two groups at PIH 24, 72, and 96 (with Z values from -4.578 to -2.512, P<0.05 or P<0.01). (4) There were 15 cases in group T accompanied by complications, and 7 cases died, while 13 cases in group P accompanied by complications, and 9 cases died. The occurrence of complications and death of patients in the two groups were similar (with χ(2) values respectively <0.001 and 1.306, P values above 0.05). CONCLUSIONS: On the basis of traditional burn shock monitoring index, the effect of fluid resuscitation in patients with severe burn monitored by PiCCO technology is not so good and still needs further clinical research.

Cancer vaccines: the perspective of the Cancer Immunology Branch, NCI.

The Cancer Immunology Branch, NCI, is supporting a great deal of exciting research relevant to cancer vaccine development. The few areas highlighted here are representative of ongoing research opportunities, but further progress depends largely on a continued infusion of investigator-initiated ideas to realize the potential of current research areas and open new ones.

Permselectivity of neurotransmitters at overoxidized polypyrrole-film-coated glassy carbon electrodes.

The permselectivity of neurotransmitters such as dopamine, epinephrine, and norepinephrine at overoxidized polypyrrole (OPPY)-film-coated glassy carbon electrodes has been investigated. The chemically-modified electrodes exhibit attractive permselectivity and antifouling properties of rejecting anionic species, e.g. ascorbate, etc. Compared with the response of neurotransmitters at modified electrodes overoxidized in phosphate buffer solution (pH 7.4), higher sensitivity and reversibility response can be obtained at modified electrodes overoxidized in sodium hydroxide solution. The effect of film thickness on the permselective response was tested. Rotating disk electrode experiments were used to determine the apparent diffusion coefficients of several electroactive solutes in the OPPY films. The influence of the hydrophobicity of the organic ions on the permeability within the polymer films was discussed. Dopamine and epinephrine were determined at the 1 x 10(-6)-1 x 10(-4) M level by means of voltammetry after an exposure period of 2 min in 0.1 M phosphate buffer (pH 7.4) with detection limits of 8 x 10(-7) M and 6 x 10(-7) M respectively.

A selective optical chemical sensor for o-nitrophenol based on fluorescence quenching of curcumin.

An optical chemical sensor has been prepared for the selective determination of o-nitrophenol in aqueous solutions based on the fluorescence quenching of curcumin in PVC membrane. The sensing mechanism of the proposed sensor for o-nitrophenol has been discussed in detail. The fluorescence changes of sensing membrane resulted from an associated complex formation between curcumin and o-nitrophenol. In pH 4.8 buffer solution, the sensor responds linearly in the measuring range from 1.0 x 10(-2) mol 1(-1) to 1.5 x 10(-4) mol 1(-1), and the experimental detection limit is evaluated to be 8.0 x 10(-5) mol 1(-1). A stable signal was obtained within less than 1.5 min. Under the optimum conditions, the sequence of selective response to the sensing membrane is o-nitrophenol > 2,4-dinitrophenol > m-nitrophenol > p-nitrophenol > 2,4,6-trinitrophenol. Phenol, aniline as well as other ions have less effect on the fluorescence of the sensor. The reproducibility for the determination of o-nitrophenol is better than 1%, and the response is reversible. The sensor can be used for the determination of o-nitrophenol in water samples.

Chemically modified electrode based on poly[tetra(4-aminophenyl)porphyrin] as a pH sensor.

A chemically modified platinum electrode with coated poly[tetra(4-aminophenyl)porphyrin] has been used as a potentiometric pH sensor. It gives a linear response over the pH range 1.5-13.7 with a slope of 55 mV/pH (at 20 degrees ). The sensor has fair resistance to erosion of hydrofluoric acid and to interference of a coexisting redox couple. The sensor can be used for pH determination and end-point indication for potentiometric titration of hydrofluoric acid with sodium hydroxide. The a.c. impedance of the polymer membrane has also been studied.

Potentiometric pH sensors based on chemically modified electrodes with electropolymerized metal-tetraaminophthalocyanine.

Potentiometric pH sensors based on polymer film were prepared by electropolymerization of the monomer nickel(II)-4,4',4'',4'''-tetraaminophthalocyanine (NiTAPc) or copper(II)-4,4',4'',4'''-tetraaminophthalocyanine (CuTAPc) on glassy carbon (GC) electrodes. The polymer of metal tetraaminophthalocyanine (p-MTAPc) film coated electrodes show a slope of 55 +/- 1 mV/pH (at 20 degrees C) and nearly Nernstain potentiometric response to pH over the range of pH 1-13. The electrodes possess good potential reproducibility and high selectivity, and are useful sensing devices in pH determination and end-point indication of acid-base potentiometric titration.

An optical fiber sensor for berberine based on immobilized 1,4-bis(naphth[2,1-d]oxazole-2-yl)benzene in a new copolymer.

A new copolymer made of 8-quinolyl methacrylate, methyl methacrylate and n-butyl acrylate(PQMB) has been used as a solid substrate for the preparation of an optical fiber berberine sensor. The sensing is based on the fluorescence of 1,4-bis(naphth[2,1-d]oxazole-2-yl)benzene(BNOB) immobilized in the copolymer quenched by berberine with the formation of 1:1 complex between them. The membrane composition was optimized using the orthogonal experimental design. Using the sensor described above, berberine in a sample solution from 4.02x10(-7) mol l(-1) to 2.82x10(-4) mol l(-1) can be detected. The sensor has satisfactory reversibility and a short response time of less than 30 s. The relative standard deviations for repeated measurements (n=15) of 8.05x10(-6) mol l(-1) and 4.02x10(-5) mol l(-1) beberine are 0.43% and 0.33%, respectively. The sensor shows good selectivity over alkali and alkali-earth metal salts and some common pharmaceutical species and can be used for the determination of berberine in pharmaceutical preparations.

Fluorescence optical fiber sensor for tetracycline.

A new optical fiber sensor for monitoring tetracycline has been described, based on the fluorescence quenching of 1,4-bis(5,5'-dimethylbenzoxazole-1',3'-yl-2')benzene incorporated into a thin plasticized polymer film by tetracycline extracted from aqueous phase into film phase. The sensor is fully reversible and highly reproducible. Furthermore, the sensor exhibits a linear response to tetracycline in the range 6.98x10(-7)-8.73x10(-5) mol l(-1) with a detection limit of 1.06x10(-7) mol l(-1), and with the response time <30 s. The response is also selective to tetracycline, with some common pharmaceutical species, alkali and alkali-earth metal salts being highly discriminated, suggesting that the sensor can be used to monitor tetracycline in three pharmaceutical preparations. The recovery of tetracycline from commercial formulations is 95.3-98.3%.

Design of Schiff base complexes of Co(II) for the preparation of iodide-selective polymeric membrane electrodes.

The response characteristics of some iodide-selective solvent polymeric membrane electrodes based on with N,N'-bis(salicylaldehyde-n-octyl) diimine cobalt(II) (Co(II)SAODI) which is a more lipophilic substitute for a previously reported iodide-carrier are described. The electrode doped with Co(II)SAODI into a plasticized poly(vinyl chloride) membrane exhibits an anti-Hofmeister selectivity pattern with high selectivity toward iodide, long lifetime and small interference from H(+). Quartz crystal microgravimetric measurements and ac impedance experiments show that the excellent selectivity for iodide is related to the unique interaction between the carriers and iodide and steric effect associated with the structure of the Schiff base ligands.

Fluorescence spectral study of interaction of water-soluble metal complexes of Schiff-base and DNA.

The fluorescence spectral characteristics and the interaction of several water-soluble metal complexes of Schiff-base with DNA are described. Among the complexes tested, Mn-Schiff-base bound to DNA showed a marked decrease in the fluorescence intensity with a blue shift of the excitation and emission peaks. Some hypochromism in the UV absorption spectra was also observed. KI quenching and competitive binding to DNA between Mn-Schiff-base and ethidium bromide (EB) were studied in connection with other experimental observations to show that the interactive model between Mn-Schiff-base and DNA is an intercalative one. The pH and salt effect on the fluorescence properties was also investigated. The linear relationship between F/F0 and the concentration of calf thymus DNA covers 3.0 x 10(-6)-2 x 10(-4) mol L-1, which can be utilized for determining traces of calf thymus DNA with a detection limit of 8.0 x 10(-7) mol L-1 in base pairs.

Organic solvent induced quenching of porous silicon photoluminescence.

A comparison has been made for the quenching effect of three classes of organic solvents on the porous silicon photoluminescence, including hydrocarbons, solvents containing oxygen and nitrogen. Among them organoamines possess the strongest quenching effect. The experiments show that the solvent molecules interact synergistically with porous silicon and the main pathways include the surface hydrophobic interaction, dipole-dipole interaction and hole trapping, the later being the dominant pathway in quenching of porous silicon photoluminescence.

Fluorescence quenching of ethidium ion by porphyrin cations and quaternary ammonium surfactants in the presence of DNA.

Fluorescence quenching of free and DNA-bound ethidium bromide (EB) by a number of quaternary ammonium and other compounds was studied. For free EB or bound EB at lower DNA concentration the fluorescence quenching follows the Stern-Volmer equation and at higher DNA concentration follows an exponential model. At least at low quencher concentrations the quenching efficiency varies with DNA or NaCl concentrations and is about 100 times greater for bound than free EB. The quenching pathways may involve energy transfer and conformational loosening or distortion of the DNA helix in addition to possible electron transfer.

DNA binding studies of a solvatochromic fluorescence probe 3-methoxybenzanthrone.

A fluorescence probe of 3-methoxybenzanthrone (MBA) exhibits significant solvatochromic characteristics correlated with the polarity of solvents. The interaction of the solvatochromic fluorescence probe with calf thymus DNA (ct-DNA) has been investigated. In the presence of ct-DNA the fluorescence of MBA is strongly quenched with a blue-shift of emission peak and a hypochromism in absorption spectra. The absorption spectra, fluorescence quenching and fluorescence polarization experiments show that the MBA molecule as an intercalator is inserted into the base-stacking domain of the ct-DNA double helix, and the interaction of the nucleobases with the MBA molecule causes quenching of fluorescence and hypochromism in the absorption spectra. The intrinsic binding constant and the binding site number were determined to be 1.70 x 10(5) mol l-1 in base pairs and six, respectively. The I0/I versus [ct-DNA] plot shows linear relationship in the range covering 4.3 x 10(-7)-1.02 x 10(-4) mol l-1 in base pairs which can be used for ct-DNA determination. The limit of detection was found to be 4.3 x 10(-7) mol l-1 in base pairs (0.5 microgram ml-1).

[Thermotolerant kinetics of HEp-2 cells and effect of thermotolerance on cytotoxicity of nitrocaphane].

The thermotolerant kinetics of HEp-2 cells and its effect on cytotoxicity of Nitrocaphane (NC) were studied by colony formation assay. HEp-2 cells were exposed to two equal thermal doses (44 degrees C, 30 min) spaced at 0-24 hr intervals during which the cells were incubated at 37 degrees C. The maximum thermotolerance developed at the 8th hr and then gradually declined. Thermal dose survival curve even up to 2.5 hr of continuous exposure to 44 degrees C, no development of thermotolerance was demonstrated. If the cells were preheated at 44 degrees C for 30 min, and returned to 37 degrees C for 10 hr and then received the second heating at 44 degrees C for 3 hr, the slope of survival curve decreased (D0 = 2.26 hr). Thermotolerant ratio was 5.9. Thermosensitive HEp-2 cells were turned into thermotolerant cells by preheating at 44 degrees C, 30 min and returning to 37 degrees C for 10 hr. The thermotolerant cells showed resistance to drug or heat when they were exposed to NC or NC combined with heat.