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Biomedical subjects

J Eng

Publications and source records attributed to J Eng.

At least 145 records · Page 8Linked to original sources
PubMed1987

Cholecystokinin octapeptides purified from chinchilla and chicken brains.

Cholecystokinin octapeptides (CCK8's) have been purified from methanol extracts of 30 chinchilla and 50 chicken brains containing 9.3 nmol and 8.5 nmol of the peptides respectively. Immunoreactive CCK was concentrated on a DEAE trisacryl column and purification effected by two successive HPLC steps. The peptides were each shown to have a sulfated tyrosine. The sequences of the two peptides are compared with the corresponding CCK8's of pig and guinea pig (GP). Chinchilla & GP: D Y V G W M D F; Chicken & pig: D Y M G W M D F. Since chinchilla insulin resembles other mammalian insulins more than does GP insulin, it is of particular interest that the CCK8's of these two species are identical and raises the question as to whether other brain-gut peptides of the chinchilla, which is a New World mammal as is the GP, would resemble those of the GP or the corresponding peptides of Old World mammals.

Amino Acid Sequence↗
PubMed1987

Chicken glucagon: sequence and potency in receptor assay.

Glucagon is a 29 amino acid peptide that is generally highly conserved. Among mammalian glucagons the only one that has been shown to differ significantly is that of the guinea pig which differs from the others in 5 of the 9 COOH-terminus amino acids. The amino acid content and partial sequencing of chicken glucagon had been reported earlier. This report describes the purification and complete amino acid sequencing of chicken glucagon and demonstrates that it differs from the usual mammalian glucagon by the replacement of asparagine at position 28 with serine. Chicken glucagon is indistinguishable from porcine glucagon in the rat liver receptor assay system.

Amino Acid Sequence↗
PubMed1987

Brain/gut peptides in fed and fasted rats.

The concentrations and contents of vasoactive intestinal peptide (VIP) and cholecystokinin (CCK) in the brain and of these peptides along with secretin and glucagon-like immunoreactivity (GLI) in the gut were compared in a group of 16 5-day fasted adult Sprague-Dawley rats with the corresponding peptides in a group of 16 nonfasted littermates. The mean weight of the fasted rats at the beginning of the study was 263 +/- 10 g (+/- SEM) and was 177 +/- 7 g before killing, for a net loss of 33% of initial body weight; the 16 fed rats increased their mean weight from 225 +/- 11 to 284 +/- 12 g, for a net gain of 12%. During the 5-day fast there was no change in the weight of the cortex, hypothalamus, or brain stem. However, the weight of tissues from the gut decreased to about half the weight of the corresponding tissues in the fed animals. There was no significant change in brain VIP or CCK. VIP content in the gut was unchanged. However, because of the decrease in organ weight, its concentration almost doubled. Secretin concentrations in the gut of fasted rats did not change significantly, but organ contents fell to about half. The gut content of GLI also fell by half or more. The concentrations of CCK in methanol extracts of the duodenum and jejunum remained relatively constant, but those in acid extracts fell by 40% in the fasted animals. This represents an approximately 70% decrease in organ content of CCK. These findings are interpretable as demonstrating that during a prolonged fast neuronal CCK and VIP are well conserved, but endocrine CCK, secretin, and GLI are markedly decreased because of loss of intestinal mucosa.

Animals↗
PubMed1987

Monoarthritis due to Mycobacterium chelonei.

A 48-year-old woman with infection of the tendon sheaths and proximal interphalangeal joint by Mycobacterium chelonei is described. Antibiotic therapy was not administered, and the patient recovered spontaneously.

Arthritis, Infectious↗
PubMed1986

Guinea pig 33-amino acid gastrin.

Only two 34 amino acid gastrin precursors have previously been purified and sequenced, those of pig and of human. The larger molecular form generally accounts for only about 5% of antral gastrin in most species. This report describes the purification of "big gastrin" from guinea pig (GP) antra. Two hundred grams of antra were defatted with acetone and the acetone cakes were extracted with 0.1M NH4HCO3. The extract was concentrated by adsorption onto and batch elution from QA-52 anion exchange cellulose. Fractionation on a mu Bondapak C18 cartridge resolved 3.6 nmol of the larger peptide from 61 nmol of immunoreactive gastrin in the original extract. Two additional HPLC steps brought the peptide to final purity. GP big gastrin is a 33 amino acid peptide with the following sequence: less than ELGPQVPAHLRTDLSKKQGPWAEEEAAYGWMDF# The GP peptide is different from pig G34 in 6 of the 17 NH2-terminal amino acids as well as in the previously reported deletion of a glutamic acid in the COOH-terminus.

Amino Acid Sequence↗
PubMed1986

Radiological findings in children with respiratory syncytial virus infection: relationship to clinical and bacteriological findings.

Respiratory syncytial virus (RSV) is a frequent cause of bronchiolitis leading to acute admission to hospital in the winter months. A wide range of findings accompanies this disease and the appearances are seldom completely diagnostic. Associated bacterial co-infections are common and we have shown an association with atelectasis among patients with pathogenic bacteria in the nasopharynx.

Bacteria↗
PubMed1986

Comparison of mammalian VIP bioactivities in dispersed acini from guinea pig pancreas.

Mammalian VIP is identical in pig, cow, human, rat, dog and goat but differs in the guinea pig (GP) in positions 5, 9, 19, and 26. We now demonstrate that GP, goat, rat and synthetic mammalian VIP are indistinguishable in their inhibition of binding of 125I-labelled synthetic VIP to dispersed acini from GP pancreas and that GP, pig, dog, goat and synthetic VIP are also similar in their efficacy and potency in stimulating amylase release from these acini. Thus in spite of the differences in amino acid sequence, GP VIP appears to have full biologic potency in its action on dispersed acini from GP pancreas.

Animals↗
PubMed1986

Purification and amino acid sequences of dog, goat and guinea pig VIPs.

VIP has been reported to be identical in pig, cow, human and rat but to differ in four amino acids in chicken. We report now on the purification and sequences of VIP from three other mammalian species, dog, goat and guinea pig (GP). The general method of purification of the three peptides was similar. The frozen intestines were extracted in five volumes of an organic solvent and the residual cakes re-extracted with acid or acid-ethanol. The VIPs were brought to final purity through a series of HPLC steps. Overall recovery using this methodology is in the range of 20-30%. The VIP sequences obtained were: Dog and Goat: (sequence in text) Dog and goat VIP are identical to, but GP VIP differs from, that of other mammalian species. Substitution of the four amino acids in positions 5, 9, 19 and 26 appears not to affect its biological activity. That GP VIP differs from other mammalian VIP's is further evidence that the GP gastroenteropancreatic axis has a unique evolutionary separation from other mammals.

Amino Acid Sequence↗
PubMed1986

A high prevalence of diabetes in a rural village in Papua New Guinea.

The prevalence of glucose intolerance was determined in a sample of 192 adults (34% of the adult population) from Wanigela in rural Central Province, Papua New Guinea. This centre was chosen to compare the high prevalence rates previously found in residents from this village who had become urbanized in Port Moresby. The age- and sex-standardised rates for abnormal glucose tolerance in Wanigela were significantly lower than those recorded in the urban community. However, the crude rates of 8.9% for diabetes and 5.7% for impaired glucose tolerance are among the highest reported for rural populations in the Pacific. These results strongly suggest that a genetic predisposition to glucose intolerance is present in this ethnic group, and argue for the early adoption of primary prevention programmes as the process of development encroaches rapidly upon the traditional lifestyles of previously isolated communities in Papua New Guinea.

Adolescent↗
PubMed1986

Cholecystokinin-associated COOH-terminal peptides are fully sulfated in pig brain.

A radioimmunoassay was developed to detect the cholecystokinin (CCK)-associated nonapeptide (CAP-9) that forms the COOH terminus of pig preproCCK. This peptide (Ser-Ala-Glu-Glu-Tyr-Glu-Tyr-Thr-Ser) is presumably produced at the time that the tyrosine-sulfated octapeptide CCK8(s) is cleaved from preproCCK. Radioimmunoassay of a dried methanol extract of pig brain revealed no detectable CAP-9 immunoreactivity, whereas acid desulfation of the dried methanol extract prior to radioimmunoassay resulted in easily measurable concentrations of CAP-9 immunoreactivity. Two peptides, CAP-9 and des-Ser9-CAP-9, were purified from a methanol extract of 8 kg of commercially obtained whole pig brains. Amino acid analysis showed that each peptide has both tyrosines sulfated. Thus, the likely sequence of CCK post-translational processing events is sulfation of the three tyrosines in the COOH terminus of preproCCK followed by peptide cleavage and appearance of CCK8(s) and CAP-9(s,s).

Amino Acid Sequence↗
PubMed1986

Ontogeny of immunoreactive cholecystokinin, vasoactive intestinal peptide, and secretin in guinea pig brain and gut.

The ontogeny of cholecystokinin (CCK), vasoactive intestinal peptide (VIP), and secretin (SEC) as well as other brain and gut peptides has been extensively studied in the rat. However, since the guinea pig (GP) appears to be functionally more mature at birth than the rat, we hypothesized that the concentrations of brain peptides, but not necessarily of gut peptides, in GP neonates would be closer to adult concentrations than those in the rat. The concentration and organ content of these three peptides were determined at birth, at 7, 14, 21, and 28 days of age, and in the adult in various portions of the gastrointestinal tract and brain. VIP and CCK in the brain at birth are 75% of adult levels compared to less than 10% in the rat. VIP concentrations in the stomach, duodenum, and jejunum are relatively constant from birth through adult life, whereas in the rat, the intestinal VIP concentration increased 3- to 4-fold from birth to adulthood. SEC, which in the gut is found only in mucosal tissues, peaked at birth, remained low from 7-28 days of age, and rose again in the adult. CCK, which in the gut is found in both the mucosa and muscle wall, like SEC peaks at birth, then remains low from 7-28 days of age, and rises in the adult. It is concluded that the GP neuronal tissues are much more mature at birth than are those in the rat.

Age Factors↗
PubMed1986

Guinea pig glucagon differs from other mammalian glucagons.

Mammalian glucagon is thought to be highly conserved. Glucagons from pig, cow, human, rat, and hamster have identical amino acid sequences, whereas the amino acid contents of rabbit and camel glucagons are consistent with this 29-amino acid sequence. It had earlier been reported that guinea pig (GP) glucagon contains 40 amino acids. In the current study, glucagon was purified from two GP pancreata by a series of three HPLC steps after acid-alcohol extraction and acetone precipitation. GP glucagon is a 29-amino acid peptide that differs from other mammalian glucagons by substitution of Gln for Asp in position 21, Leu for Val in position 23, Lys for Gln in position 24, Leu for Met in position 27, and Val for Thr in position 29. In view of the marked changes in the COOH-terminal of GP glucagon, receptor binding studies were performed using both rat and GP liver membranes. Labeled synthetic porcine glucagon has similar binding in the two systems and its binding is inhibited to a similar degree by synthetic porcine glucagon, whereas GP glucagon is 10-fold less potent at inhibiting binding in both systems. This suggests that glucagon receptor binding sites in the GP are evolutionarily more conserved than is GP glucagon.

Amino Acid Sequence↗
PubMed1986

Methods for concentration of urinary immunoreactive insulin.

Insulin is readily concentrated from 10 to 50 ml of urine with better than 75% recovery using octadecylsilyl (ODS) silica columns (C18Sep-Pak cartridge) and can then be measured by radioimmunoassay. Fractionation on Sephadex G50 gel filtration reveals that the apparent immunoreactivity corresponds for the most part to 6000 dalton insulin. Renal clearance of insulin in 5 normal subjects does not appear to differ in the fasted or fed state and ranged from 0.34 to 0.58 ml/min with an average of 0.44 +/- 0.10 (S.D.) ml/min. Increased urinary insulin output was observed following feeding and fell during prolonged fasting. Insulin output in urine from 7 non-diabetic subjects ranged from 11 to 39 mU/24 hr, averaging 25 +/- 10 mU/24 hr. In normal subjects without renal disease a single determination of renal insulin clearance and a timed urinary insulin output appear to be sufficient for determination of mean plasma insulin during that time period. Concentration of urine using this methodology could provide the material for HPLC screening for abnormal insulins and for their subsequent purification to determine the site of change in amino acid sequence.

Adult↗
PubMed1985

Guinea pig "little" gastrin is a hexadecapeptide.

Gastrin heptadecapeptides (gastrins I and II which differ in the presence of sulfate on the tyrosine of the latter) have been purified and sequenced from several mammalian species including pig, dog, cat, sheep, cow, human and, more recently, rat. This report describes the purification of "little" gastrin from guinea pig (GP) antra. GP antra were defatted with acetone and the acetone cakes were extracted with 0.1M NH4HCO3. The extract was concentrated by adsorption to DE53 anion exchange cellulose and the peak eluates were fractionated on a Sephadex G50F column. The peptides were brought to final purity by 3 successive HPLC steps. The GP sequence compared to other species is shown: (formula: see text) Thus GP "little" gastrins I and II are hexadecapeptides due to a deletion of a glutamic acid in the region 6-9 from the N-terminus.

Amino Acid Sequence↗
PubMed1985

Purification of dog VIP from a single animal.

VIP, a potent vasodilator peptide, is reported to be identical in pig, cow, human and rat but to differ in four amino acids in chicken. This report describes the purification of dog VIP from the small intestine of a single animal. The purification method is based on tissue extraction with a sequence of organic solvents. The extracted VIP is concentrated onto cation-exchange cellulose and brought to purity by three HPLC steps. A 30% final yield of pure VIP was obtained from the original extract. Dog VIP was found to have the following sequence: His-Ser-Asp-Ala-Val-Phe-Thr-Asp-Asn-Tyr-Thr-Arg-Leu-Arg-Lys-Gln-Met-Ala -Val-Lys-Lys-Tyr-Leu-Asn-Ser-Ile-Leu-Asn. Thus the amino acid sequence of dog VIP is identical with all the mammalian VIP's which have been reported. This suggests that a high degree of conservation throughout the molecule may be required for VIP bioactivity.

Amino Acid Sequence↗
PubMed1985

Guinea pig has a unique mammalian VIP.

Mammalian vasoactive intestinal peptide (VIP) has been reported to be identical in four species. This report describes the extraction of guinea pig (GP) intestinal VIP, its purification and sequence. Frozen intestines were extracted in five volumes of methanol and the methanol cakes reextracted with acid. VIP in the acid extract was concentrated onto ion-exchange cellulose and was brought to final purity through a series of HPLC steps. GP VIP differs from other mammalian VIP's by four amino acid substitutions: (sequence in text) This is further evidence that the GP gastroenteropancreatic axis has a unique evolutionary separation from other mammals.

Amino Acid Sequence↗
PubMed1985

Invasiveness of Salmonella typhimurium in HEp-2 cell cultures pre-infected with Mycoplasma hominis and Mycoplasma orale.

The influence of mycoplasma infection on the in vitro invasiveness of S. typhimurium in HEp-2 cell cultures has been tested. Two strains of arginine-utilizing mycoplasma species Mycoplasma hominis and M. orale both seemed to inhibit the bacterial in vitro invasiveness. Both the ratio of infected cells and the number of intracellular bacteria per cell were reduced in the mycoplasma-infected cultures.

Cells, Cultured↗