Immunofluorescence signal amplification by the enzyme-catalyzed deposition of a fluorescent reporter substrate (CARD)

Progress has been made in improving the immunohistochemical detection of antigens for imaging and flow cytometry. We report the synthesis of a novel fluorescent horseradish peroxidase substrate, Cy3.29-tyramide, and its application in an enzyme-based signal amplification system, catalyzed reporter deposition (CARD). The catalyzed deposition of Cy3.29-tyramide was used to detect cell surface markers such as CD8 and CD25 on tonsil tissue and human lymphocytes. We compared the fluorescence CARD method to standard indirect immunofluorescence detection methods and found that an amplification of up to 15-fold was possible with CARD. The detection of the intracellular protein myosin II in fibroblastic cells and rabbit serum proteins blotted onto nitrocellulose was also improved. Thus, fluorescent CARD is a simple modification that can be made to standard immunofluorescence staining protocols to enhance significantly the detection of antigens.

Crystallization and preliminary X-ray diffraction studies of haemorrhagin I from the snake venom of Agkistrodon acutus

Haemorrhagin I from the snake venom of Agkistrodon acutus (AaHI) has been crystallized using the hanging-drop vapour diffusion method. The crystals belong to space group P4(1)2(1)2 or P4(3)2(1)2 with unit-cell dimensions a = b = 63.61 and c = 95.69 A. There is one molecule in the asymmetric unit. Data to 2.35 A resolution have been collected using a single-crystal.

Toxic metal-responsive gene transcription

Metals play a dual role in biological systems, serving as essential co-factors for a wide range of biochemical reactions yet these same metals may be extremely toxic to cells. To cope with the stress of increases in environmental metal concentrations, eukaryotic cells have developed sophisticated toxic metal sensing proteins which respond to elevations in metal concentrations. This signal is transmitted to stimulate the cellular transcriptional machinery to activate expression of metal detoxification and homeostasis genes. This review summarizes our current understanding of the biochemical and genetic mechanisms which underlie cellular responses to toxic metals via metalloregulatory transcription factors.

[The effect of antiseptic agents on the growth of mouse skin]

Using new born mouse skin slice culture, we studied the effects on certain antiseptic agents on the growth of epidermis, 0.015% approximately 1% chloromycin, 0.125 approximately 1% zinc sulfadiazine, 0.125% approximately 1.0% silver sulfadiazine markedly inhibited the expending rate of mouse skin. The higher the concentration of drugs, the higher is the inhibition rate. 10,000 U% gentamycin and 25,000U% polymyxin showed no adverse effects on skin expending rate. We conclude that during topical use of antiseptic agents (antibiotics or chemical compounds) in treatment of patients, the inhibitability of those agents on epidermis growth should be seriously considered.

Envelopment of varicella-zoster virus: targeting of viral glycoproteins to the trans-Golgi network

Previous studies suggested that varicella-zoster virus derives its final envelope from the trans-Golgi network (TGN) and that envelope glycoproteins (gps) are transported to the TGN independently of nucleocapsids. We tested the hypothesis that gpI is targeted to the TGN as a result of a signal sequence or patch encoded in its cytosolic domain. cDNAs encoding gpI wild type (wt) and a truncated mutant gpI(trc) lacking transmembrane and cytosolic domains were cloned by using the PCR. Cells transfected with cDNA encoding gpI(wt) or gpI(trc) synthesized and N glycosylated the proteins. gpI(wt) accumulated in the TGN, some reached the plasmalemma, but none was secreted. In contrast, gpI(trc) was retained and probably degraded in the endoplasmic reticulum; none was found on cell surfaces, but some was secreted. The distribution of gpI(trc) was not affected by deletion of potential glycosylation sites. To locate a potential gpI-targeting sequence, cells were transfected with cDNA encoding chimeric proteins in which the ectodomain of a plasmalemmal marker, the interleukin-2 receptor (tac), was fused to different domains of gpI. A chimeric protein in which tac was fused with the transmembrane and cytoplasmic domains of gpI was targeted to the TGN. In contrast, a chimeric protein in which tac was fused only with the gpI transmembrane domain passed through the TGN and concentrated in endosomes. We conclude that gpI is targeted to the TGN as a result of a targeting sequence or patch in its cytosolic domain.

[Viability and antigenic changes in the skin after preservation under different temperatures]

Oxygen consumption and succinate dehydrogenase contents were determined to compare mean viabilities (%) of human cadaver and guinea pig skin stored under different temperature: 4 C, -20 C, -80 C, and -196 C. The results showed that the mean viability (%) of skin cryopreserved under -196 C was superior to those under 4 C, -20 C, and -80 C (70.8%, 61% respectively for -196 C, P < 0.05 or 0.01). Microimmunoelectrophoresis and rocket immunoelectrophoresis were performed for related antigens and antibodies. The results of microimmunoelectrophoresis showed that the antigenicities were different for four groups. Antigenicity of fresh skin was highest. The higher the storage temperature, the lower the antigenicity of skin was.

Toward the production of bispecific antibody fragments for clinical applications

The clinical potential of bispecific antibodies (BsAb) has been hindered by the difficulty of obtaining clinical grade material, together with the immunogenicity of rodent-derived BsAb in patients. The supply issue is being directly addressed by recombinant methods for BsAb fragment production reviewed here. The immunogenicity issue will likely be overcome by the use of humanized or human antibodies. Currently, three technologies appear suitable for the production of BsAb fragments for clinical applications: BsF(ab')2 assembled from Fab' fragments expressed in Escherichia coli, BsF(ab')2 assembled using leucine zippers, and diabodies.

[Quantitative analysis of gamma-schizandrin in manganbao granules, a complex prescription of Chinese medicine]

This paper deals with a HPLC method for determining the content of gamma-schizandrin in Manganbao granules. Samples are extracted with haxane, re-dissolved in MeOH, chromatographed on HPLC (Column, Spheri-5 RP-18, 220 mm x 4. 6mm, mobile phase, 75% MeOH) and the main components can be easily isolated. Six samples were analyzed by calibration curve method. The results have shown that the quantitative analysis of gamma-schizandrin conducted in this way is convenient, fast and highly reproducible.

Absorption of ciprofloxacin in patients with diabetic gastroparesis

The purpose of this study was to assess the pharmacokinetic profile of ciprofloxacin in 12 patients with diabetic gastroparesis. Patients received both a single 500-mg oral (p.o.) dose and a single 400-mg intravenous (i.v.) dose of ciprofloxacin separated by a 1-week washout period. Pharmacokinetic parameters (means +/- standard deviations) for the p.o. and i.v. doses were as follows: areas under the concentration-time curve from 0 h to infinity, 9.74 +/- 2.59 and 11.78 +/- 3.18 micrograms.h/ml, respectively; maximum concentrations of drug in serum, 2.13 +/- 0.67 and 4.21 +/- 1.07 micrograms/ml, respectively; and half-lives, 4.03 +/- 0.58 and 4.20 +/- 0.58 h, respectively. The ratio of the areas under the concentration-time curves from 0 h to infinity for the p.o. and i.v. doses was 0.84, with a 90% confidence interval of 0.68 to 0.98; the mean absolute bioavailability was calculated to be 67% (range, 43 to 82%). From these data it appears that ciprofloxacin is adequately absorbed in patients with diabetic gastroparesis.

[Localization of insulin-like growth factor I in the upper end of human fetal femur]

The localization of insulin-like growth factor I in the upper end of the human fetal femur was studied by immunohistochemistry on the undecalcified bone sections. Certain numbers of chondrocytes in germinal, proliferating and hypertrophic zones of the epiphysial growth plates, some osteoblasts and a few osteoclasts were immunoreactive to the antibody to IGF-I. The end-product of the DAB reaction was deposited in the osteoid and bone matrix of metaphysis. Also presented is a discussion on the local effects of IGF-I on the chondrocytes, osteoblasts and osteoclasts.

Use of skin-cancer prevention strategies among farmers and their spouses

Epidemiologic studies show that farmers are at increased risk of skin cancer, presumed to be secondary to the increased time they spend outdoors with exposure to the sun. We surveyed a random sample of farmers and their spouses 40 years of age or older from four rural counties in Michigan on their knowledge, attitudes, and behavior regarding protection of their skin from the sun and screening medical exams for skin cancer. Questionnaires were completed by 1,342 farmers and their spouses. This was a response rate of 63.5%. Eighty to ninety percent knew the changes in the skin that could indicate cancer and required medical follow-up. Only 40% of the men and 65% of the women were likely to protect their skin when they went outdoors. Increasing age and personal history of skin cancer increased the likelihood of both men and women protecting their skin when they went outside. Additionally, higher-income women were likely to use sun protection. Despite the fact that 90% of the respondents had had a physical examination in the last three years, less than one third reported ever having had their skin examined for cancer. Increasing age, income, and education increased the likelihood of having had such an exam. The majority of those who had had a skin exam had the exam for a particular skin problem, and not as part of a routine physical examination. Farmers and their spouses need to increase their use of sun protection when going outside. Additionally, health care providers need to routinely include examination of the skin for skin cancer and alert their patients that it is being performed.

POU-domain sequences from the flatworm Dugesia tigrina

Redundant primers matching well-conserved sequences within vertebrate and invertebrate POU genes were used in the PRC (polymerase chain reaction) to detect three different POU-domain-containing genes within the genome of the flatworm, Dugesia tigrina. Two of these genes appear to be close homologues of class-III POU genes previously identified in Dugesia japonica, while the third represents a new class-III POU gene. Nucleotide sequences encoding highly related POU domains within the two species of planaria exhibited a surprisingly poor degree of shared identity. Since only class-III POU genes have been observed to date in flatworms, these genes may represent ancestral versions of the multiple classes of POU genes that exist in vertebrates, and may play important roles in the development of metazoan nervous tissue.

Identification of heavy chain residues in a humanized anti-CD3 antibody important for efficient antigen binding and T cell activation

A previously identified humanized anti-CD3 Ab variant, v9, binds T cells with > 100-fold higher efficiency than the original variant, v1, and almost as efficiently as a chimeric molecule containing corresponding murine variable domains. Variants v1 and v9 differ at six positions in the H chain second CDR. Here a mutational analysis was used to identify which of these six replacements are primarily responsible for the difference in binding efficiency. These anti-CD3 variants were used to probe the relationship between Ag binding efficiency and potency in stimulating T cell proliferation. The human to mouse mutations T57S and V63F increase the binding efficiency of variant v1 for T cells by 8- and 12-fold, respectively, and together in variant M18 enhance binding by 26-fold to within 4-fold of variant v9. A framework mutation, 169L, was identified that enhances the binding of variants v1 and M18 by 14- and 3-fold, respectively. The Ag binding efficiencies of anti-CD3 variants correlate directly with their potencies in stimulating the proliferative activity of both resting human PBMC and IL-2-activated human T lymphocytes. Humanized variant v9 is equipotent to the murine parent Ab in stimulating ATL activity. PBMC activated by variants v1 and v9 IgG in a short term culture are equally cytotoxic against human breast carcinoma cells. Thus, high efficiency Ag binding by anti-CD3 variants is important for stimulating efficient T cell proliferation, but not cytotoxicity, in vitro.

Identification of heavy chain residues in a humanized anti-CD3 antibody important for efficient antigen binding and T cell activation

A previously identified humanized anti-CD3 Ab variant, v9, binds T cells with &gt; 100-fold higher efficiency than the original variant, v1, and almost as efficiently as a chimeric molecule containing corresponding murine variable domains. Variants v1 and v9 differ at six positions in the H chain second CDR. Here a mutational analysis was used to identify which of these six replacements are primarily responsible for the difference in binding efficiency. These anti-CD3 variants were used to probe the relationship between Ag binding efficiency and potency in stimulating T cell proliferation. The human to mouse mutations T57S and V63F increase the binding efficiency of variant v1 for T cells by 8- and 12-fold, respectively, and together in variant M18 enhance binding by 26-fold to within 4-fold of variant v9. A framework mutation, 169L, was identified that enhances the binding of variants v1 and M18 by 14- and 3-fold, respectively. The Ag binding efficiencies of anti-CD3 variants correlate directly with their potencies in stimulating the proliferative activity of both resting human PBMC and IL-2-activated human T lymphocytes. Humanized variant v9 is equipotent to the murine parent Ab in stimulating ATL activity. PBMC activated by variants v1 and v9 IgG in a short term culture are equally cytotoxic against human breast carcinoma cells. Thus, high efficiency Ag binding by anti-CD3 variants is important for stimulating efficient T cell proliferation, but not cytotoxicity, in vitro.

[Study on skin storage at -20 degrees C]

Small pieces of fresh guinea pig or cadaveric skin, 0.3mm in thickness, were soaked in cryoprotective solution for 30 min, then were put into plastic bags and kept in -20 degrees C refrigerator. Before and after 14, 30, 45, 60, 75 days storage, the skin were sent for succinae dehydrogenase assay (modified Hershey's method) and oxygen consumption determination (microelectrolyte method). The average viabilities measured by succinated dehydrogenase and oxygen consumption were nearly 50% after 60 days storage and 30% after 75 days storage in both guinea pig and cadaveric skin. 37 times of autologous skin stored at -20 degrees C for 1-26 days were grafted on the granulation wounds with good results. Skin can be preserved viably at -20 degrees C for 45 days but not longer than 60 days. This method may be helpful for hospital which has no -80 degrees C deep freezer or liquid nitrogen container.

[Clinicopathological features and surgical treatment of early gastric cancer]

We analyzed retrospectively the clinicopathological data obtained from 126 patients with early gastric cancer (EGC) to elucidate the relationship between pathological patterns and lymphatic metastasis and the criteria of selecting appropriate surgery. Lymph node metastasis was 3.1% (2/65) in mucosal and 16.4% (10/61) in submucosal tumors respectively (P < 0.05). 26 patients with tumors smaller than 10 mm had no lymphatic metastasis, and 100 patients with tumors larger than 10mm in size had 8% (8/100) n1 positive, 4% (4/100) n2 positive and 7% (7/100) lymphatic duct invasion (P < 0.05). The 5-year survival rate in patients with lymphatic metastasis (79%, 15/19) was significantly lower than that in patients without lymphatic metastasis (97.2%, 104/107) (P < 0.01). It seemed that the most important prognostic factor is whether the presence of lymphatic metastasis or not. Lymphadenectomy is expected to improve the survival rate in EGC. D2 procedure is generally recommended as a standard operation for EGC, especially for the submucosal or larger lesion. Anyhow, D1 operation is sufficient for mucosal or smaller cancer, and D3 is suitable only for EGC patients with multifoci, superficially spreading type and group 3 lymph node metastasis.

Engineering high affinity humanized anti-p185HER2/anti-CD3 bispecific F(ab')2 for efficient lysis of p185HER2 overexpressing tumor cells

We previously constructed a humanized anti-p185HER2/anti-CD3 bispecific antibody variant, BsF(ab')2 v1 which retargets the cytotoxic activity of human T cells in vitro against human breast tumor cells which overexpress the p185HER2 product of the HER2/neu (c-erbB-2) protooncogene. Subsequently we identified an improved anti-CD3 variant, v9, which binds to T cells with approx. 100-fold higher affinity than the original variant, v1. Here we demonstrate that BsF(ab')2 v9 is more potent than BsF(ab')2 v1 in stimulating the proliferation of both resting peripheral blood lymphocytes (PBL) and IL-2-activated, long-term cultured T lymphocytes (ATL). In addition, at low concentrations (0.01-1 ng/ml) BsF(ab')2 v9 is much more efficient than BsF(ab')2 v1 in directing lysis of p185HER2-overexpressing tumor cells by IL-2 activated PBL. In contrast, at higher concentration BsF(ab')2 v9 and BsF(ab')2 v1 have similar potency in retargeted cytotoxicity. At BsF(ab')2 v9 concentrations of > or = 1 ng/ml the susceptibility of p185HER2-expressing tumor cells to lysis is apparently independent of the level of p185HER2 expression. At lower concentrations of BsF(ab')2 v9 and/or lower ratios of effector to target cells the extent of lysis is reduced, in some cases improving the selectivity of lysis of high p185HER2 expressors over low expressors. Thus selection of a high affinity anti-CD3 arm is likely important in the design of BsF(ab')2 for retargeting the cytotoxicity of T cells to tumors. The dose of BsF(ab')2 v9 in any future clinical evaluation will require optimization to maximize anti-tumor efficacy whilst minimizing potential toxicity against normal tissue expressing p185HER2.

MacMARCKS mutation blocks macrophage phagocytosis of zymosan

A major protein kinase C substrate, MacMARCKS (F52, MPR), was examined for its role in phagocytosis. In macrophage-phagocytosing zymosan particles, MacMARCKS was concentrated around nascent phagosomes as detected by immunofluorescent microscopy. The effector domain of MacMARCKS contains the phosphorylation sites, a calmodulin binding site, as well as a putative actin binding site. Stable J774 macrophage cell lines constitutively expressing effector domain deletion mutants of MacMARCKS were generated. When given zymosan particles, these transfectants showed approximately a 90% reduction in their phagocytic capacity. The receptor-mediated endocytosis of acetylated low density lipoproteins, however, was not affected by the mutant. These results strongly suggest the involvement of MacMARCKS in macrophage phagocytosis.

Effect of selenium on malignant tumor cells of brain

Some reports have demonstrated that selenium can inhibit tumorigenesis in some tissues of animal. However, little is known about the inhibitory effect on malignant tumor cells of brain. The purpose of our study was to determine the biological effect of selenium on growth of rat glioma and human glioblastoma cell lines. Cell lines C6 and A172 were obtained from Japanese Cancer Research Resources Bank, Tokyo, Japan (JCRB). Cells were cultured in Dulbecco's Modified Eagle's Medium (DMEM) supplemented with 10% fetal calf serum at 37 degrees C in a humidified atmosphere of air and 5% CO2. Antiproliferative effects of selenium were evaluated using growth rate assay quantifying cell number by MTT assay. An antiproliferative effect of selenium was found in two cell lines, which was more effective on human A172 glioblastoma and less effective on rat C6 glioma.

[Determination of modulus of elasticity of human periodontal membrane]

The modulus of elasticity of periodontal membrane, as an essential parameter indicating the mechanical character of periodontal membrane, is very important in biomechanical studies (e.g. finite element stress analysis and photoelastic analysis) of dental restoration. However, determination of modulus of elasticity of human periodontal membrane has not been reported in China, and there are differences among the foreign reports. In this study, 135 periodontal samples were collected from fresh teeth and alveoli of 6 healthy adults. Drawing and compressing test were performed. The results showed that the tensile modulus of elasticity of human periodontal membrane is between 3.35 and 4.59MPa and the compress modulus of elasticity 0.5402(+/- 0.348) MPa.

The determination of strong mutagen MX [3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone] in drinking water in China

The strong mutagen, [3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone] (MX) was found to occur in chlorinated drinking water in China. Some tap water samples from Jiangsu province, which contained MX of 3-60ng/L, were analyzed. Quantitation is based on gas chromatography-mass spectrometry, using peak area of selective ion monitoring of the methyl derivative of MX.

Ocular effects of exposure to triethylamine in the sand core cold box of a foundry

OBJECTIVES

To assess the acute and chronic ophthalmological effects of triethylamine exposure among foundry workers.

METHODS

Ocular effects on people currently, previously, and never exposed to triethylamine in a foundry cold box were studied at two points in time. The initial phase included an ocular examination with a slit lamp to assess corneal health, a visual acuity test, and a questionnaire to assess vision symptoms. The follow up included measurements of corneal thickness with an ultrasonic pachymeter and the vision symptoms questionnaire before and after the shift and at the beginning and end of the week. Personal air measurements for triethylamine were also obtained during the follow up.

RESULTS

The vision symptoms of blurriness, halos around lights, and blue hazy vision occurred more often in currently exposed workers than those previously or never exposed to triethylamine. Air concentrations of triethylamine ranged from < 0.33 mg/m3 to 20.3 mg/m3. Among currently exposed workers, symptoms were more common among those with exposure to > 10 mg/m3 of triethylamine (odds ratio (OR) = 3.0, 95% confidence interval (95% CI) 0.35-25.6). No differences in corneal thickness were found in currently or previously exposed workers and those never exposed. No increase in corneal thickness was found after v before the shift.

CONCLUSION

Despite low concentrations of triethylamine and no corneal oedema, workers exposed to triethylamine reported vision symptoms. Possible explanations for these symptoms without corneal oedema are that triethylamine affects ciliary muscle function or that the corneal oedema was transient and not present when corneal thickness measurements were taken. No chronic effects were found in previously exposed workers. Further research is needed to elucidate the mechanism for the reported vision symptoms, which occurred below the current United States eight hour time weighted standard of 100 mg/m3 and the American Conference of Governmental Industrial Hygienists (ACGIH) recommended value at the time of our study of 40 mg/m3. We recommend that air concentrations be maintained to meet the current recommended ACGIH threshold of 4.1 mg/m3.

Iodothyronine deiodinase activity in methionine-deficient rats fed selenium-deficient or selenium-sufficient diets

We examined the effect of methionine deficiency on iodothyronine 5'-deiodinase activity in selenium-deficient rats or selenium-sufficient rats fed sodium selenate or selenomethionine. Forty-two weanling male Wistar rats were divided into six groups and pair fed the respective purified L-amino acid-based diets for 4 wk. L-methionine concentrations in the diet were 8.0 g/kg for sufficient rats, and 2.0 g/kg for deficient rats. Selenium concentrations in the diet were 0.5 mg/kg (as sodium selenate or selenomethionine) for selenium-sufficient rats and less than 0.005 mg/kg for selenium-deficient rats. Type I 5'-deiodinase activities were significantly lower in liver and higher in kidney of methionine-deficient rats than in those of methionine-sufficient rats fed either the selenium-sufficient or the selenium-deficient diets. The type I 5'-deiodinase activity in brain was significantly lower in the methionine-deficient rats than in the methionine-sufficient rats fed the selenium-deficient diet. Type II 5'-deiodinase activity in brain was significantly higher in the methionine-deficient rats than in the methionine-sufficient rats fed selenium-sufficient diet as sodium selenate. Both thyroxine and 3,3',5-triiodothyronine concentrations in plasma were significantly higher in the methionine-deficient rats than in the methionine-sufficient rats. It is suggested that the methionine deficiency affects the 5'-deiodinase activity and thyroid hormones level in the rats.