Enzyme-linked synthetic oligonucleotide probes: non-radioactive detection of enterotoxigenic Escherichia coli in faecal specimens

Synthetic oligonucleotides, complementary to unique sequences in the heat stable enterotoxin gene of Escherichia coli specific for humans, were prepared with a 30-atom spacer arm and a 3' terminal sulfhydryl group which was coupled to bromoacetyl-derivatized alkaline phosphatase. The resulting direct enzyme-linked oligonucleotide probes, containing one enzyme molecule per oligonucleotide, successfully diagnosed enterotoxigenic Escherichia coli in clinical specimens by using a modified colony hybridization method and a colorimetric assay. The procedure is rapid, simple and reliable with a sensitivity equivalent to that using 5'-terminally labelled [32p]-oligonucleotide probes. The results indicate that the enzyme-labelled oligonucleotide probes should be applicable to the routine diagnosis of enterotoxigenic Escherichia coli and possess the potential for the detection of other microbial pathogens.

Caffeine enhances the slow-pressor response to angiotensin II in rats. Evidence for a caffeine-angiotensin II interaction with the sympathetic nervous system

The purpose of this study was to determine if caffeine augments the slow-pressor response to chronic low-dose infusions of angiotensin II (AII) or the rapid-pressor response to acute infusions of AII. AII was infused (125 ng/min i.p.) for 12 d via mini-osmotic pumps in four groups of rats: group I, intact rats not treated with caffeine (n = 9); group II, intact rats treated with caffeine (0.1% in drinking water, n = 9); group III, rats previously sympathectomized with 6-hydroxydopamine, but not treated with caffeine (n = 10); and group IV, rats previously sympathectomized with 6-hydroxydopamine and treated with caffeine (n = 10). Chronic low-dose AII infusions slowly elevated systolic blood pressure in all groups. Caffeine greatly augmented this slow-pressor response to AII in intact animals; however, caffeine failed to enhance AII-induced hypertension in sympathectomized rats. Caffeine pretreatment did not enhance the rapid-pressor response to acute intravenous infusions of AII. We conclude that caffeine augmented the slow-pressor effect of chronic low-dose infusions of AII via a mechanism that involved the sympathetic nervous system.

Cytogenetic studies of four human lung adenocarcinoma cell lines

G-banded karyotypes were analyzed on four human lung adenocarcinoma cell lines, AGZY83-a, LTEP-a1, LTEP-a2, and GLC-82. More than 50 cells were counted and 20-40 cells were karyotyped for each cell line at different passages. The chromosome numbers of cell line AGZY83-a, LTEP-a1, LTEP-a2, and GLC-82 were 53-69, 100-110, 51-56, and 61-63, respectively. Each cell line had a number of markers involving complex chromosome rearrangements. Chromosomal analysis at different passages showed the stability of these cell lines in vitro. It was revealed that the marker chromosomes involving deletions or rearrangements of the short arm of chromosome #1 were present in all the four cell lines with breakpoints at 1p12-1p22.

Extracorporeal enzyme reactors for depletion of phenylalanine in phenylketonuria

Multitubular enzyme reactors with immobilized enzymes were developed to achieve depletion of circulating substrate by extracorporeal means. To act as prototypes, reactors were prepared with immobilized L-phenylalanine ammonia-lyase, an enzyme that metabolizes phenylalanine to trans-cinnamic acid and ammonia without the need for a coenzyme. We report the first application of phenylalanine ammonia-lyase reactors in an extracorporeal circulation system in a patient with phenylketonuria. A phenylalanine level of 1.82 mmol/L (for the last 6 years) decreased to 1.24 mmol/L after 5.5. hours of treatment, without the enzyme entering the circulation. Total phenylalanine depletion from blood and tissue stores was estimated at 1800 mg. The hemodialysis-like procedure proved to be without side effects, specific for phenylalanine, and suitable in the management of pregnant women with phenylketonuria and late-onset hyperphenylalaninemia. The extracorporeal use of enzyme reactors for temporary enzyme replacement represents a new, safe, and effective therapeutic modality.

A pilot vitamin intervention trial in Linxian, People's Republic of China

A 24-week pilot study of daily or weekly multiple vitamin supplementation among 852 adults in Linxian, where the rate of esophageal cancer is exceptionally high, demonstrated the feasibility of an intervention trial in this population. Compliance, when judged by pill count, was high for both frequencies of pill use. Only 2% of the subjects refused to take any pills, and, among pill takers, over 95% were reported to be taking most of their pills at the end of the study. Biochemical confirmation of high compliance was demonstrated in urine and blood tests, which showed markedly improved vitamin levels after supplementation. Results of the pilot study indicated that a system in which barefoot doctors were used in pill distribution was effective and that established field operating procedures for a full-scale intervention trial in this area were acceptable.

Further observations on the role of IgE-mediated hypersensitivity in recurrent otitis media with effusion

One hundred young patients with recurrent otitis media with effusion (OME) were evaluated for IgE-mediated hypersensitivity by critical analysis of history, physical findings, skin testing for selected antigen, laboratory determination of total IgE, and radioallergosorbent testing (RAST) for six inhalant and two food allergens. The patients could be divided into allergic rhinitis and nonallergic groups. Allergic rhinitis patients had higher total IgE in their serum, and middle ear effusion (MEE). IgE was elevated in 16 of 35 allergic patients. In 8 of these 16 (23% of the allergic group), the IgE/mg protein was higher in the MEE than in the corresponding serum, suggesting local production of IgE. Nasal IgE was substantially increased in the allergic patients; however, in many patients there was no correlation between the corresponding MEE IgE and elevated nasal IgE, suggesting that local production of nasal and middle ear IgE is independent. We conclude that IgE-mediated allergic reactions may play a role in the pathogenesis of OME in about 23% of young allergic patients.

Control functions of adenovirus transformation region E1A gene products in rat and human cells

Altered control of the rat cell cycle induced by adenovirus requires expression of transformation region E1A, but not of E1B, E2A, E2B, or late genes. We show here that neither E3 nor E4 is required, so the effect results directly from an E1A product. Mutants with defects in the 289-amino-acid (aa) E1A product had little or no effect on the rat cell cycle even at 1,000 IU per cell. A mutant (pm975) lacking the 243-aa E1A product altered cell cycle progression, but less efficiently than did wild-type virus. The 289-aa E1A protein is therefore essential for cell cycle effects; the 243-aa protein is also necessary for the full effect but cannot act alone. Mutants with altered 289-aa E1A proteins showed different extents of leak expression of viral early region E2A as the multiplicity was increased; each leaked more in human than in rat cells. dl312, with no E1A products, failed to produce E2A mRNA or protein at 1,000 IU per cell in rat cells but did so in some experiments in human cells. There appears to be a very strict dependence of viral early gene expression on E1A in rat cells, whereas dependence on E1A is more relaxed in HeLa cells, perhaps due to a cellular E1A-like function. Altered cell cycle control is more dependent on E1A function than is early viral gene expression.

Inhibitory effect of analogous electro-acupuncture on experimental arrhythmia

Rabbits were used to study the inhibitory effect of analogous electro-acupuncture on the experimental arrhythmias, i.e. hypothalamic stimulation-induced ventricular extrasystole (HVE). The result revealed that HVE, which was due to an increased cardiac sympathetic activity, could be inhibited by deep peroneal nerve stimulation with an electrical current of low frequency and low intensity. Such effect is related to endogenous opioid peptides and serotonin in the arcuatus area, the periaqueductal gray and and the medial medulla. The acupuncture correction of arrhythmias may have the same mechanism.

The structural proteins of chick embryo lethal orphan virus (fowl adenovirus type 1)

Chick embryo lethal orphan (CELO) virus (fowl adenovirus type 1) contains at least 14 structural proteins with polypeptide molecular weights ranging from 100K to about 6K. A nomenclature of the CELO virion polypeptides is presented and the molar proportion of each polypeptide has been estimated. The CELO virus pentons were specifically released from the virion by dialysis against borate-based calcium-magnesium saline. The penton base (polypeptide III, mol. wt. 92K) and two fibres were separated, characterized and their polypeptides were correlated with their morphological positions in the virion. Peptide mapping suggested that the long fibre (polypeptide IV, mol. wt. 65K), and the short fibre (polypeptide VII, mol. wt. 44.5K) were not related in their primary sequences and are therefore probably encoded by separate genes. The time course of synthesis of the CELO virion polypeptides indicated that, like their mammalian adenovirus counterparts, they are synthesized late (after viral DNA replication).

Structural organization and polypeptide composition of the avian adenovirus core

CELO virus (fowl adenovirus 1) contained three core polypeptides of molecular weights 20,000, 12,000, and 9,500. The core was similar to that of human adenoviruses, with some evidence of compact subcore domains. Micrococcal nuclease digestion of CELO virus cores produced a smear of DNA fragments of gradually decreasing size, with no nucleosome subunit or repeat pattern. Moreover, when digested cores were analyzed without protease treatment, there was again no evidence of a nucleosome substructure; neither DNA fragments nor core proteins entered a 4% polyacrylamide gel. The organization of the core is thus quite unlike that of chromatin. Restriction endonuclease analysis of the DNA from digested cores showed that the right end was on the outside of the core. We suggest that adenovirus DNA is condensed into the core by cross-linking and neutralization by the core proteins, beginning with the packaging sequence at the center of the core and ending with the right end of the DNA on the outside.

The structural proteins of chick embryo lethal orphan virus (fowl adenovirus type 1)

Chick embryo lethal orphan (CELO) virus (fowl adenovirus type 1) contains at least 14 structural proteins with polypeptide molecular weights ranging from 100K to about 6K. A nomenclature of the CELO virion polypeptides is presented and the molar proportion of each polypeptide has been estimated. The CELO virus pentons were specifically released from the virion by dialysis against borate-based calcium-magnesium saline. The penton base (polypeptide III, mol. wt. 92K) and two fibres were separated, characterized and their polypeptides were correlated with their morphological positions in the virion. Peptide mapping suggested that the long fibre (polypeptide IV, mol. wt. 65K), and the short fibre (polypeptide VII, mol. wt. 44.5K) were not related in their primary sequences and are therefore probably encoded by separate genes. The time course of synthesis of the CELO virion polypeptides indicated that, like their mammalian adenovirus counterparts, they are synthesized late (after viral DNA replication).

DNA-binding proteins of chick embryo lethal orphan virus: lack of complementation between early proteins of avian and human adenoviruses

Chick cells infected by chick embryo lethal orphan (CELO) virus (fowl adenovirus type 1) contained four prominent virus-specific, structurally related DNA-binding proteins with mol. wt. of 74K, 64K, 56K, 52K, and two minor forms. The CELO virus DNA-binding proteins were phosphorylated, delayed-early nuclear proteins. CELO virus early proteins were expressed in BHK cells, but did not complement human adenovirus type 5 mutants with lesions E1A, E2A or E2B. Moreover, CELO virus DNA-binding proteins were not produced in 293 cells, which express human adenovirus E1 genes. These results suggest that activation of transcription by adenovirus E1A genes involves specific interactions between the E1A gene products and viral early promoters.

A comparison of the terminal protein and hexon polypeptides of avian and human adenoviruses

It was found that the virion terminal protein of chick embryo lethal orphan (CELO) virus had a molecular weight of 46,000, and the hexon a molecular weight of 100,000. 125I-labelled tryptic and chymotryptic peptide maps of the hexons and terminal proteins from CELO virus and human adenovirus type 5 (Ad5) differed. However, limited proteolysis of CELO virus and Ad5 terminal proteins by protease V8 showed similarities which were not detected in the case of the two hexons.

The effect of acupuncture on blood pressure: the interrelation of sympathetic activity and endogenous opioid peptides

Experimental hypertension was produced by intravenous infusion of norepinephrine in 13 conscious dogs. Electroacupuncture at the dogs' "Tsu San-Li" (St. 36) points showed a significant decrease in blood pressure, while the heart rate was not affected. The depressor effect was naloxone (0.2 mg/kg iv) reversible, and accompanied by an increased blood flow at the mesenteric artery, so it is suggested that the depressor effect was due to inhibition of the sympathetic vasoconstrictor tone. This inhibition was mediated by endogenous opioid peptides released by acupuncture. The location of this mediation was further analyzed. The central mechanism was evidenced by the ineffectiveness of acupuncture in reducing blood pressure in anesthetized dogs. On the other hand, the demonstration of opiate receptors in the blood vessels by radio-receptor assay provided evidence of peripheral mediation of blood pressure by opioids. The blood vessel might be a target organ for the plasma opioids, which can also be increased by acupuncture.

Adenovirus-induced alterations of the cell growth cycle: a requirement for expression of E1A but not of E1B

Mutants dl312, dl314, hr1, and hr3 with mutations in region E1A of adenovirus type 5 were defective for the induction of cell cycle abnormalities detectable by flow cytometry, cell DNA replication, thymidine kinase production, and chromosome aberrations and did not synthesize the viral DNA-binding protein (E2A) in rat cells. dl311, a leaky E1A mutant, induced cell cycle effects at high multiplicity in only one of three experiments, and synthesized the DNA-binding protein. hr7 (E1B) gave a wild-type response in all tests. dl313 was also positive in all tests, although it induced fewer polyploid cells than did wild-type virus, probably because of the leftward extension of the dl313 E1B deletion into E1A. sub315 and sub316, with mutations which also span the E1A-E1B border, synthesized DNA-binding protein, but caused no cell cycle alterations detectable by flow cytometry in rat or mouse cells. Although the participation of other viral early regions cannot be completely excluded, our results suggest that alteration of cell cycle progression is a direct effect of E1A unrelated to its control of other viral early regions, and may be the function of E1A in transformation.

A common sequence in the inverted terminal repetitions of human and avian adenoviruses

The termini of the avian chick embryo lethal orphan (CELO) virus DNA have been sequenced. The results revealed a 63-bp-long inverted terminal repetition (ITR) which shared the sequence ATAATA with all adenovirus termini, thus far analyzed. The CELO virus ITR differed from those of the mammalian adenoviruses in two major aspects: (i) it is not a perfect duplication; (ii) it begins with a 5'-guanylic acid residue instead of the cytidylic acid normally observed in adenoviruses.

Sequence homology between avian and human adenoviruses

Studies of hybridization between fowl adenovirus type 1 (chicken embryo lethal orphan virus) DNA and human adenovirus type 2 DNA revealed two short but distinct regions which cross-hybridized under stringent conditions. One of the homologous regions was located between map positions 18.1 and 19.3 and did not correspond to any gene recognized so far. The second region mapped in the hexon gene between position 57 and 58.

The role of IgE-mediated hypersensitivity in otitis media with effusion

Forty-one children with recurrent otitis media with effusion (OME) were evaluated for IgE mediated allergy by critical analysis of history, physical findings, skin testing for selected antigens, and laboratory determination of total IgE and radioallergosorbent testing (RAST) for six inhalant and two food allergens. The children were divided into an allergic and nonallergic group. The allergic group clearly had higher total IgE in their serum. There was an elevation of middle ear effusion (MEE) IgE in 5 of 20 allergic cases. In three of these five patients or 15% of the allergic group, the IgE/mg protein was higher in the MEE than in the corresponding serum, suggesting the possibility of local production of IgE. Specific IgE antibody as measured by RAST was noted in 9 of 20 MEE and 5 of 20 nasal washings in the allergic group and in only 2 of 21 MEE and in 10 nasal washings of the nonallergic group. Nasal IgE was substantially increased in three patients of the allergic group; however, the corresponding MEE IgE was not increased in proportion to the nasal IgE. The MEE RAST was positive in 22% of the allergic group and in less than 1% of the nonallergic group. Nasal RAST was positive in 20% of the allergic group and in none of the nonallergic group. We conclude that IgE-mediated allergic reactions may play a role in the pathogenesis of OME in only about 15% of children defined as allergic on the basis of clinical and laboratory evidence. Allergy investigation as a diagnostic procedure in children with recurrent OME, but without a history of allergy on the basis of history, family history, or laboratory testing is likely to be nonproductive.

Development of serum and intestinal antibody response to rotavirus after naturally acquired rotavirus infection in man

The temporal characteristics of the response of rotavirus specific IgM, IgG, IgA in serum and secretory antibody in feces to rotavirus were studied in 77 hospitalized patients with rotavirus induced gastroenteritis. The response in serum was characterized by the sequential appearance of rotavirus specific IgM, IgG, and IgA antibody. The IgM antibody appeared to be higher in the acute phase of the disease and was subsequently replaced by the IgG and IgA antibodies. However, the titers of IgG rotavirus antibody in convalescent specimens of serum were found to be statistically significantly lower in patients with severe or prolonged rotavirus infection than in specimens from subjects with mild or moderate disease. Most fecal specimens collected during both the acute and convalescent phase of illness contained virus specific secretory IgA. Higher concentrations of antibody were measured in convalescent samples from patients with prolonged diarrhea and virus shedding. These observations suggest a possible relationship between the severity of rotavirus infection and the nature of systemic and secretory antibody response.