[Spectrophotometric assay of polyethyene glycol in urine using ammonium ferrothiocyanate aqueous-chloroform system]

A spectrophotometric method for the quantitative determination of polyethylene glycol-600 (PEG-600) in urine is based on partitioning a chromophore present in ammonium ferrothiocyanate reagent into an aqueous phase and a chloroform phase in the presence of PEG. The method is simple and reproducible, and can detect PEG in a concentration of 0.25 g/L. It gives a linear response over a range of 0.25-2.5 g/L. The recovery of PEG-600 in urine is 107% and relative standard deviation is less than 5%.

[Secondary glaucoma after anterior chamber intraocular lens implantation]

OBJECTIVE

To investigate the intraocular pressure level, the change of anterior chamber angle and the occurrence of secondary glaucoma after anterior chamber intraocular lens (AC-IOL) implantation.

METHODS

Sixty-two AC-IOL implanted eyes were followed up postoperatively for 3 months to 7 years (mean 31 months). The examination of anterior chamber angle was emphasized. The type of cataract mainly included senile and traumatic. The operation performed were lensectomy with anterior vitrectomy or extracapsular cataract extraction (ECCE) combined with primary or secondary AC-IOL implantation.

RESULTS

The incidence of postoperative peripheral anterior synechia (PAS) of iris was 87.1% and that of the secondary glaucoma (mainly the angle-closure) was 11.3%. The incidence of the glaucoma after ECCE with primary or secondary implantation was 17.4%, while that after ECCE combined with anterior vitrectomy was 0%.

CONCLUSION

The main causes of the secondary glaucoma are possibly the rupture of posterior capsule and vitreous loss during the surgery leading to postoperative severe uveitis and pupillary block. To prevent its occurrence, it is important to combine ECCE with anterior vitrectomy.

Hypermethylation of the hMLH1 gene promoter in human gastric cancers with microsatellite instability

Human gastric carcinoma shows a higher prevalence of microsatellite instability (MSI) than does any other type of sporadic human cancer. The reasons for this high frequency of MSI are not yet known. In contrast to endometrial and colorectal carcinoma, mutations of the DNA mismatch repair (MMR) genes hMLH1 or hMSH2 have not been described in gastric carcinoma. However, hypermethylation of the hMLH1 MMR gene promoter is quite common in MSI-positive endometrial and colorectal cancers. This hypermethylation has been associated with hMLH1 transcriptional blockade, which is reversible with demethylation, suggesting that an epigenetic mechanism underlies hMLH1 gene inactivation and MMR deficiency. Therefore, we studied the prevalence of hMLH1 promoter hypermethylation in a total of 65 gastric tumors: 18 with frequent MSI (MSI-H), 8 with infrequent MSI (MSI-L), and 39 that were MSI negative. We found a striking association between hMLH1 promoter hypermethylation and MSI; of 18 MSI-H tumors, 14 (77.8%) showed hypermethylation, whereas 6 of 8 MSI-L tumors (75%) were hypermethylated at hMLH1. In contrast, only 1 of 39 (2.6%) MSI-negative tumors demonstrated hMLH1 hypermethylation (P<0.0001 for MSI-H or MSI-L versus MSI-negative). Moreover, hypermethylated cancers demonstrated diminished expression of hMLH1 protein by both immunohistochemistry and Western blotting, whereas nonhypermethylated tumors expressed abundant hMLH1 protein. These data indicate that hypermethylation of hMLH1 is strongly associated with MSI in gastric cancers and suggest an epigenetic mechanism by which defective MMR occurs in this group of cancers.

Quantitative intracellular kinetics of HIV type 1

Although our knowledge of HIV-1 growth, from a molecular mechanistic perspective, has rapidly increased, we do not yet know how the overall growth rate of HIV-1 depends on its constituent biochemical reactions. Such an understanding would be of fundamental importance and potentially useful for designing and evaluating anti-HIV strategies. As a first step toward addressing this need we formulate and implement here a global computer simulation for the intracellular growth of HIV-1 on a CD4+ T lymphocyte. Our simulation accounts for the kinetics of reverse transcription, integration of proviral DNA into the host genome, transcription, mRNA splicing and transport from the nucleus, translation, feedback of regulatory proteins to the nucleus, transport of viral proteins to the cell membrane, particle assembly, budding, and maturation. The simulation quantitatively captures the experimentally observed intracellular dynamics of viral DNA, mRNA, and proteins while employing no "fudge factors." Moreover, it provides an estimate of the intracellular growth rate of HIV-1 and enables evaluation of mono- and combined anti-HIV strategies.

[Modification of N-terminal cDNA of hGM-CSF and high-expression in E. coli]

OBJECTIVE

N-terminal cDNA of human granulococyte-macrophage colony stimulating factor(GM-CSF) was designed to be modified and highly-expressed in E. coli.

METHODS

A pair of oligo-nucleotide primers were used to modify the mature N-terminal cDNA sequence of hGM-CSF with the method of PCR. the modified cDNA of hGM-CSF was cloned into E. coli. expressive vector PBV220 and expressed in E. coli DH5 alpha strain, the biological activities of the recombinant protein was identified by means of cell colony formation and TF-1 cell growth assay in vitro.

RESULTS

The expression level of modified hGM-CSF cDNA was higher than that of unmodified native type. SDS-PAGE revealed that expressed protein of hGM-CSF accounted for about 25% of total bacterial cell protein. The biological activity of recombinant protein was about 1.5 x 10(7) U/mg protein. The sequence of 1-16 amino acid of N-terminal of the recombinant protein was same with native hGM-CSF.

CONCLUSIONS

Modification of the N-terminal cDNA of hGM-CSF could dramatically enhance the expression level in E. coli system.

Determination of hexamethylene diisocyanate-based isocyanates in spray-painting operations. Part 2. Comparison of high performance liquid chromatography with capillary zone electrophoresis

A capillary zone electrophoresis (CZE) approach was developed for the determination of hexamethylene diisocyanate (HDI) monomer and HDI-based oligomers. A comparison of CZE with high performance liquid chromatography (HPLC) indicates that the CZE separation completely isolates isocyanates from excess solvent, derivatizing reagent and pigment while offering a fivefold increase in sensitivity. The CZE approach allows for the quantification of HDI monomer and oligomer within a 1 min time window under the run conditions selected. For the determination of HDI-based oligomer, provided that the relative response with respect to HDI monomer is calculated, there is no significant difference (p < 0.05, n = 10) in the isocyanate air concentration when using either HPLC or CZE. The results are significant because they indicate that CZE has advantages for the determination of both HDI-based oligomer and HDI monomer generated during spray-painting operations.

[Characters of two gravity-related esterases in carrot callus cells]

On the basis of identification of two gravity-related esterases (grEST1 and grEST2) in carrot callus cells (Cai et al. 1998), we continued the study of the characteristics of these two esterases. They have the very special characteristic of SDS resistance. Their activities could be inhibited partially by deoxycholate. beta-Phenylpropionic acid, AgNO3 and CuSO4 had no inhibitory effect on their activities. The activities of grEST1 and grEST2 could be decreased by ascorbic acid and cysteine, and the influence by cysteine was particularly obvious. The molecular weights of grEST1 and grEST2 were shown to be near the ranges of 49-66 kD and 43-59 kD respectively by non-denaturing electrophoresis containing deoxycholate, Triton X-100 and SDS respectively, and the isoelectric points were approximately pH 5.4 and 4.9 respectively. Besides, grEST1 and grEST2 were found in the fraction precipitating at value between 30% and 40% saturation with (NH4)2SO4.

Subsurface oxidation of polyethylene

Since the 1960s ultrahigh molecular weight polyethylene has been a primary bearing material in orthopedic prostheses. Most polyethylene components have been sterilized by exposure to gamma radiation, but in the presence of oxygen this promotes degradation and correlates with component failure in the body. To better understand the mechanism of degradation, we measured oxidation profiles for components shelf aged 5.8 and 10.9 years. Microtomed sections from each component were analyzed for ketones, which are the primary oxidation products, by FTIR spectroscopy. Maximum ketone concentrations in both cases were found several millimeters below the surface. We propose a model to explain the profiles. Alkyl radicals, which are uniformly generated in the polyethylene during irradiation, react with peroxyl radicals, which are produced by alkyl radicals with oxygen to form ketones. At the component surface ketone levels are low because high oxygen concentrations deplete alkyl radicals, creating an excess of peroxyl radicals. In the bulk material ketones are low because low oxygen concentrations limit the formation of peroxyl radicals. However, just below the surface the concentrations of alkyl and peroxyl radicals balance, promoting ketone production. A computer simulation that accounts for the coupling of these reactions with the diffusion of oxygen shows a good agreement with the measured profiles.

Sequence alterations of insulin-like growth factor binding protein 3 in neoplastic and normal gastrointestinal tissues

Insulin-like growth factor binding protein 3 (IGFBP-3) is an important regulator of normal and malignant cell growth. It modulates the mitogenic effects of insulin-like growth factors (IGFs) by inhibiting growth through mechanisms both dependent on and independent of IGF binding. IGF-I and IGF-II levels are regulated by binding to the IGF-II receptor, which is inactivated by mutation in human gastrointestinal (GI) tumors. We have previously demonstrated elevated IGF-II ligand expression in IGF-II receptor-mutant GI tumors, implicating the IGF signaling system in GI tumorigenesis. Therefore, to investigate the potential involvement of IGFBP-3 in human GI carcinogenesis, direct DNA sequencing of exons 1-4 and intron-exon boundaries of the IGFBP-3 gene was performed in 10 colorectal cancers, 10 gastric cancers, and 10 esophageal cancers. Four distinct sequence alterations were identified: (a) in one gastric and one esophageal tumor, an A to C transversion occurred at nucleotide 5795 (CAC-->CCC), leading to a His-->Pro substitution at codon 179; (b) a second esophageal tumor had a C to T transition at nucleotide 8291 (ACC-->ATC), leading to a Thr-->Ile substitution at codon 277 of IGFBP-3; (c) one alteration comprised a G to C transversion in exon 1 at nucleotide 2132 (GGG-->GCG), leading to a Gly-->Ala substitution at codon 32 in two gastric cancers, seven esophageal cancers, and nine colon cancers; and (d) a C to G transversion located 17 nucleotides from the 3' splice site in intron 1 was observed in three colon cancers and four esophageal cancers. All of these DNA sequence alterations were present in matched normal DNA from the same subjects, which suggests that some or all of them may represent polymorphisms. However, we cannot exclude the possibility that the germ-line nonconservative amino acid substitutions predicted to occur as a result of these alterations result in subtle changes to IGFBP-3 protein function and a predisposition to developing GI malignancy.

Structural and kinetic evidence for strain in biological catalysis

A classic hypothesis for enzyme catalysis is the induction of strain in the substrate. This notion was first expressed by Haldane with the lock and key analogy-"the key does not fit the lock perfectly but exercises a certain strain on it" (1). This mechanism has often been invoked to explain the catalytic efficiency of enzymes but has been difficult to establish conclusively (2-7). Here we describe X-ray crystallographic and mutational studies of an antibody metal chelatase which strongly support the notion that this antibody catalyzes metal ion insertion into the porphyrin ring by inducing strain. Analysis of the germline precursor suggests that this strain mechanism arose during the process of affinity maturation in response to a conformationally distorted N-alkylmesoporphyrin.

Effects of the estrous cycle and early pregnancy on uterine expression of Mx protein in sheep (Ovis aries)

Conceptuses of ruminant ungulates produce large amounts of a type I interferon, interferon-tau (IFNtau), which is the signal for maternal recognition of pregnancy. Induction of cellular Mx proteins is an important component of the response to type I interferon in the immune system, but Mx regulation and function have not been studied in the uterus. This study examined temporal and spatial alterations in ovine uterine Mx expression during the cycle and early pregnancy using immunohistochemistry, in situ hybridization, and Northern and slot-blot analysis. Sheep uterine endometrium expressed a single approximately 2.5-kilobase Mx mRNA transcript that was detectable at all stages of the estrous cycle and early pregnancy examined. In cyclic ewes, mRNA abundance in endometrium increased from Day 1 to peak levels at Day 13 and then declined to Day 15. In pregnant ewes, steady-state levels of Mx mRNA were first detected above the level in cyclic ewes at Day 13 postmating, were greater than 10-fold higher at Day 15, and remained elevated at Day 19. Expression of Mx mRNA in the myometrium did not change during the estrous cycle but increased approximately 23-fold between Days 11 and 15 of pregnancy. Immunohistochemical and in situ hybridization analysis revealed a similar temporal pattern of Mx expression. In cyclic ewes, Mx protein and mRNA were initially localized to the luminal epithelium at Days 1 and 3, increased from Days 5 to 13, especially in the shallow uterine glands, and then declined at Day 15. Pregnancy resulted in up-regulation of Mx expression in the luminal and glandular epithelium, stroma, and myometrium. Punctate Mx immunostaining and Mx mRNA concentrations were greatest when progesterone production was maximal during the estrous cycle and were strongly up-regulated by the conceptus across the entire uterine wall. It is suggested that a cascade of induction of Mx gene expression proceeds from the luminal epithelium to the outer longitudinal myometrium and that transcriptional activation of the promoter may involve both soluble cytokines (i.e., IFNtau) and steroid hormones (i.e., progesterone).

Determination of hexamethylene-based isocyanates in spray-painting operations. Part 1. Evaluation of a polyurethane foam sponge sampler

A polyurethane foam (PUF) sponge was mounted in a cassette sampler and evaluated as a sorbent for the collection of hexamethylene diisocyanate (HDI) monomer and HDI-based oligomers. Recovery studies indicated 112 +/- 34% average recovery of HDI monomer and 92 +/- 9% and 97 +/- 25% average recovery of HDI-based oligomers when using impregnated PUF sponges. The PUF sponge was also evaluated during actual spray-painting operations. In a series of side-by-side sampling events, an impinger filled with 1-(2-methoxyphenyl)piperazine (MOP) in toluene was compared directly with a cassette sampler containing a PUF sponge impregnated with MOP or 1-(9-anthracenylmethyl)piperazine (MAP) in dimethyl sulfoxide (DMSO). For the analysis of HDI-based oligomer, there is no significant difference (p < 0.05, n = 7) in the air concentration when sampling with either the PUF sponge cassette or the impinger. The results are significant because they indicate that a PUF sponge, which is more convenient than an impinger, may be used for the collection of HDI-based oligomer generated during spray-painting operations.

[Investigation on the epidemiology of Histoplasma capsulatum infection in Nanjing district]

Two hundred and ninety-two permanent or temporary residents in Nanjing district were tested with histoplasmin (Histolyn-CYL, ALK/Berkeley Laboratories, USA) and PPD. Forty-nine (16.78%) subjects reacted to histoplasmin with 5.0-23.0 (9.5 +/- 4.2) mm induration. Positive reaction rate among people without pulmonary diseases (normal group) was 15.10% comparing to 17.74% to patients with pulmonary diseases. Positive reaction to PPD with 5-50 (14.2 +/- 4.7) mm induration was 56.16%, with 59.43% in normal group and 54.30% in patients with pulmonary diseases while 8.90% subjects reacted to both histoplasmin and PPD, 7.88% of the research subjects reacted to histoplasmin but not to PPD. Result suggested that there was herd infection of Histoplasma capsulatum in Nanjing district.

Hyperoxia-induced lung injury in premature rat: description of a suitable model for the study of lung diseases in newborns

OBJECTIVE

To provide suitable animal model (hyperoxia-induced premature rat lung damage) for research of bronchopulmonary dysplasia (BPD) and to better understand pathogenesis of BPD and look for effective drugs to prevent and treat BPD.

METHODS

Rat litters delivered prematurely at 21-day gestation by hysterotomy. Vigorous resuscitation at birth resulted in a high survival rate. Surfactant and antioxidant enzyme (AOE) system were measured. The model was tested in an experiment of hyperoxia-induced lung injury.

RESULTS

Compared to litters delivered spontaneously at term (gestation 22 days), these preterm rats had immature pulmonary surfactant composition with low total phospholipid (x +/- s: 10.09 +/- 1.49 micrograms/mg wet weight vs 12.04 +/- 1.31 micrograms/mg wet weight; P = 0.0367) and phostidylcholine (5.06 +/- 1.82 micrograms/mg wet weight vs 8.28 +/- 2.35 micrograms/mg wet weight; P = 0.0238) levels. The concentrations of AOE enzymes, superoxide dismutase (11.40 +/- 2.04 mu/mg DNA vs 15.78 +/- 1.84 mu/mg DNA; P < 0.01) and catalase (92.81 +/- 62.25 mu/mg DNA vs 412.24 +/- 117.50 mu/mg DNA; P < 0.01) were also significantly lower. Animals exposed to hyperoxia had a significantly higher mortality. Pulmonary edema and histological features of lung damage were observed in the pups exposed to hyperoxia.

CONCLUSIONS

The premature rat model is relatively cheap, readily available and has a high survival rate. Pulmonary surfactant and AOE systems are immature. These properties make them a suitable model for the study of acute and chronic lung damage related to prematurity and O2 toxicity.

[An ELISA assay for humulus scandens specific IgE antibodies]

OBJECTIVE

Humulus scandens pollen (HSP) has been proved to be the one of the most important causative factors of autumnal hay fever in China. We established an enzyme immunoassay for specific IgE against HSP by using monoclonal anti-IgE antibody to detect sIgE in 143 patients with autumnal hay fever and 30 healthy volunteers.

METHODS

An indirect method of ELISA was developed. The optimal conditions for the test were: coating the allergen at 4 degrees C overnight with a concentration of 12 micrograms/ml; the test serum was diluted 1:16 and incubated with allergen overnight at 37 degrees C; the most suitable dilution and incubative time of the peroxidase-conjugated mouse anti-human IgE antibody were 1:3,000 and 2 hours respectively.

RESULTS

The patients' serum level of sIgE was significantly higher than controls (P < 0.001) and correlated significantly with the degree of skin test reaction (P < 0.01). The concordance between the results of skin test and ELISA was 74%-83%. The specificity of the assay was confirmed by heat inactivation and multiple absorption experiments. The coefficients of variation for the intraassay and interassay reproducibility ranged from 1.20%-8.30% and 8.63%-9.22% respectively.

CONCLUSIONS

Determination of specific HSP IgE with ELISA assay shows good specificity, sensitivity and reproducibility. It favours clinical practice due to its lower cost.

In situ PCR for in vivo detection of foreign genes transferred into rat brain

Here we describe the use of in situ PCR to detect a viral transgene in rat brain. Previously, we have reported in vivo gene transfer by using a defective herpes simplex viral vector in mammalian brain (Kaplitt, M.G., Pfaus, J.G., Kleopoulos, S.P., Hanlon, B.A., Rabkin, S.D., Pfaff, D.W., Mol. Cell. Neurosci. 2 (1991) 320-330). For detection of the LacZ transgene, we have used histochemical staining for the protein product, beta-galactosidase, and in situ hybridization for its mRNA, but the DNA itself cannot be reliably detected with conventional methods. Therefore we have adapted the technique of in situ PCR, so that we may detect minute quantities of transgenic vector DNA following in vivo gene. The brain sections, prefixed, were treated with PBS-detergent before PCR amplification to increase permeability for peptides and oligonucleotides across cellular barriers in brain tissue. Pretreatment with detergent retained better brain morphology than the more widely used proteinase treatment. The PCR mixture containing dNTPs, primers, digoxigenin-dUTP (Dig-dUTP) and buffer was loaded onto each brain section. Slides containing brain sections were placed in an aluminum boat and then on the block of the thermal cycler. Temperature was brought to 82 degrees C before adding Taq polymerase ('hot start' method). Dig-labeled PCR amplified fragments were then detected by alkaline-phosphatase-linked anti-digoxigenin-antibody. Positive signals were seen within the nucleus of transduced neurons, indicating presence of viral DNA. Enhanced specificity was observed with the use of Dig-labeled primers which eliminates the possibility of non-specific viral DNA detection through primer-independent reactions. Overall, this technique can serve not only as an internal control for transgene presence during comparisons of experimental groups of animals, but may also have clinical applications including the detection of viral infection in human brain such as HIV in pathology specimens.

Synthesis and immobilization of ceramide analogs on silica particles

Ceramides are the major lipid components of the stratum corneum, the major permeability barrier of the skin. Here we report a chemical synthesis of ceramide analogs covalently bonded on the silica particles, that can be used to predict the skin permeability of chemicals via HPLC methods.

Mutation of hMSH3 and hMSH6 mismatch repair genes in genetically unstable human colorectal and gastric carcinomas

Mutations within microsatellite sequences, consisting of additions or deletions of repeat units, are known as the replication/repair error positive (RER+) phenotype or micorsatellite instability (MI). Microsatellite instability has been demonstrated in hereditary and sporadic colorectal carcinomas and is usually observed in noncoding regions of genomic DNA. However, relatively few coding region targets of MI have been identified thus far. Using PCR, we amplified regions encompassing (A)8 and (C)8 microsatellite tracts within hMSH3 and hMSH6 from 31 RER+ sporadic colorectal tumors, 8 hereditary colon cancers, 23 RER+ gastric carcinomas, and 32 RER- gastric tumors. Mutations were found in 11 (36%) of 31 sporadic colon carcinomas, 4 (50%) of 8 hereditary colorectal cancers, and 5 (22%) of 23 RER+ gastric carcinomas, but in only 2 (6%) of 32 RER- gastric carcinomas. These frameshift mutations cause premature stop codons downstream that are predicted to abolish normal protein function. Our results and those of others suggest that DNA mismatch repair genes, such as hMSH3 and hMSH6, are targets for the mutagenic activity of upstream mismatch repair gene mutations and that this enhanced genomic instability may accelerate the accumulation of mutations in RER+ tumors.

Some changes of receptor and postreceptor signal transduction regulated by somatostatin in pituitary hGH-secreting adenomas

OBJECTIVE

To investigate the disturbance in the function of SRIF receptor, Gi protein and Ca2+ channel in hGH adenoma cells and to evaluate their significance in the pathogenesis of pituitary hGH adenomas.

METHODS

All 25 patients with pituitary hGH adenoma who were involved in this study had typical acromegalic manifestation and high fasting serum hGH levels of > 5.0 micrograms/L which were not suppressed to < 3.0 micrograms/L by oral glucose tolerance test. The pituitary hGH adenoma tissue obtained from transphenoidal operation was digested by collagenase and the dispersed adenoma cells were cultured in the monolayer. The effects of octreotide (SMS), a long-acting agonist of somatostatin, on hGH secretion and intracellular cAMP level were observed and the influences of pertussis toxin (PT), an inhibitor of Gi protein, and Ca2+ ionophore A23187 or KCl on the inhibitory action of octreotide on hGH secretion were also investigated in the cultured pituitary hGH adenoma cells.

RESULTS

A total of 16.0% (4/25) of cultured pituitary hGH adenomas did not respond to octreotide (100 nmol). The inhibitory effect of octreotide on hGH secretion was not blocked by PT (50 ng/ml) and A23187 (10 mumol) or KCl (22.5 nmol) in 31.6% (6/19) and 35% (7/20) of hGH adenomas, respectively. The effects of octreotide on hGH secretion and intracellular cAMP levels were studied in 10 cultured hGH adenomas. Octreotide suppressed both hGH secretion and cAMP levels in 5 cases; inhibited only hGH secretion or the cAMP level in 3 cases and 1 case respectively; and affected neither hGH secretion nor cAMP level in the last case.

CONCLUSION

There were abnormalities in the SRIF receptor and/or postreceptor signal transduction in 16.0% of hGH adenomas which did not respond to octreotide. The defects in Gi and/or Ca2+ channels were found in 52.4% (11/21) of hGH adenomas which had responded to octreotide. These defects might induce diminution of the inhibitory action of SRIF on hGH secretion and might be the causes of hypersecretion in some pituitary hGH adenomas.

[Determination of minor flavor components in Chinese spirits by direct-injection technique with capillary columns]

Chinese spirits are among the best-known distilled alcoholic beverages in the world. Because of the longer multiple-strain fermentation, Chinese spirits are richer than yeast fermented western liquors in fragrance and mellow. The complex nature of Chinese spirits often makes it difficult to separate, identify and quantify major and minor flavor components. Among the several analytical methods for flavor components in Chinese spirits developed in recent years, the direct-injection technique using capillary columns is by far the best. In this study of direct injection with crosslinked PEG 20M, HP-INNOWax and bonded SGE BP21 columns, up to 68 flavor components including alcohols, organic acids, esters, acetals, carbonyl and heterocyclic compounds were identified with fine-tuning separation and followed by GC/MS to identify. The gas chromatographic separation of flavour components of Maotai Liquor by the method on PEG 20M, SGE BP21 and HP-INNOWax are shown. The compounds of the numbered peaks in the chromatograms are listed. Three compounds of, ie., amyl acetate, t-pentanol and 2-ethyl butyric acid, were used as internal standards to minimize discrimination in quantitative determination. The operation procedures for these tests were provided. The application identities of three capillary columns for the analysis of minor flavor components with direct injection were summarized respectively.

FHIT gene alterations in esophageal cancer and ulcerative colitis (UC)

FHIT (fragile histidine triad gene), a candidate tumor suppressor gene, was recently identified and cloned at chromosome 3p14.2. Alterations of this gene have been reported in a number of primary human tumors, including colorectal, esophageal, gastric and lung carcinomas. However, some reports have found no abnormalities in this gene. We investigated a total of 63 primary esophageal tumors, nine esophageal cancer cell lines and 17 ulcerative colitis-associated neoplasms (UCANs) for alterations of FHIT. In 13 esophageal tumors, we employed overlapping reverse transcriptase-PCRs (RT-PCRs) to amplify and sequence the complete open reading frame of FHIT. One of 13 primary esophageal tumors analysed by RT-PCR expressed no detectable FHIT transcript; the remaining 12 expressed normal-sized transcripts with wild-type open reading frame sequences. In an additional 50 esophageal tumors, the polymorphic microsatellite loci D3S1300 and D3S1313 were used to evaluate loss of heterozygosity (LOH) at 3p14.2. Eleven of these 50 tumors showed LOH at one or both loci. In all these 11 tumors, genomic PCR and direct sequencing of FHIT exons 5-9 was performed. This analysis revealed that none of these 11 primary esophageal tumors contained any alterations in the FHIT open reading frame or adjacent intron sequences. Finally, among 17 UCANs, the in vitro synthesized protein (IVSP) assay detected no truncated protein products, nor were there any abnormalities in size or DNA sequence of FHIT RT-PCR products. However, in six of nine esophageal carcinoma cell lines, no FHIT RT-PCR product was detectable using either of the overlapping primer sets. Genomic PCR and direct sequencing of exons 5-9, also performed in these nine cell lines, revealed wild-type sequence in eight cell lines; however, one cell line contained no exon 5 PCR product. This cell line also lacked detectable FHIT transcript. These data suggest that the open reading frame of FHIT is not important in the development or progression of most primary esophageal carcinomas or UCANs, although lack of expression of the FHIT transcript may be common in esophageal cancer-derived cell lines. The possibility of an additional tumor suppressor gene at chromosome 3p14.2 remains to be evaluated.