Stability of neuronal and glial marker enzymes in post-mortem rat brain

The enzymatic activities in post-mortem rat brain kept at 4°C and at 25°C were determined for a number of enzymes localized in specific cell types in the central nervous system. Choline acetyltransferase (CAT), glycerol-3-phosphate dehydrogenase (GPDH), glutamine synthetase (GS), lactate dehydrogenase (LDH) and 2,3-cyclic nucleotide phosphohydrolase (CNPase) were found to be very stable at both 4°C and 25°C with only slight, if any, losses of activity being seen even at periods as long as 72 hr. Glutamic acid decarboxylase (GAD) activity was less stable than that of the other enzymes. In brains kept at 4°C GAD activity was stable out to 24 hr after which it began to decline rapidly to 65% of control at 72 hr. In brains kept at 25°C, GAD activity was stable for 6–8 hr and then began to steadily decline to 58% of control at 24 hr and 29% of control at 72 hr. Assuming that these enzymes have similar stabilities in post-mortem human brain, the effect of post-mortem delay in processing tissues may be of lesser significance than other factors with regard to the measured enzyme activities in human brain samples.     

Influence of malnutrition and alterations in dietary protein on murine rotaviral disease

The possible correlation between malnutrition and degree of severity of rotavirus-associated infantile diarrhea which appears to occur in human populations was studied using a mouse model. To determine the effects of general malnutrition or altered levels of dietary protein, female mice were fed throughout pregnancy and infection periods with diets diluted with 0, 300, or 600 g glucose/kg, designated as normal nutrient to calorie ratio (N/C) diet, 70% N/C diet, or 40% N/C diet or with diets containing 75, 150, or 300 g casein/kg, as low-, normal-, or high-protein diets. Murine rotavirus was given by gavage to the 2-day-old offspring of these dams, and the extent of infection determined. Marked increases in severity of diarrheal disease were seen in the infants from dams receiving the 40 and 70% N/C diets and the low-protein diet. Severity of infection was seen as increased deaths, reduced weight gain, and increased passage of diarrheic feces. Intestinal viral levels and intestinal diarrhea scores did not vary appreciably. Serum interferon remained below detectable limits throughout the studies, but serum antibody was determined in dams 30 days post-virus exposure. The latter titers were lower in the infected mice from dams fed the 40 and 70% N/C diets, but were essentially the same in all the protein diet groups. Cross-fostering was done using the 40 and 100% N/C diets, wherein mice from dams fed either diet were placed on mothers fed the opposite diet. Increased severity of infection was again seen when the virus was given 2 days after the exchange, although the greatest infection occurred in animals from dams fed 40% N/C diet which were then fostered by other similarly fed dams. The increased host sensitivity to the rotaviral infection appeared to be a result of both pre- and postnatal dietary effects.     

Furanosesquiterpenes from the essential oil of myrrh

An examination of the essential oil of myrrh from Commiphora molmol has permitted the identification of 1(10)Z,4Z-furanodiene-6-one, 2-meth     

Australia Antigen and Liver Function Tests Following Infectious Hepatitis—A Study of 111 Patients in Quest of Aids in Blood Donor Screening

An epidemic of infectious hepatitis involving 99 patients and employees of a state mental hospital revealed Australia antigen Au(1) to be absent from the blood of all but one of the subjects when tested at six weeks, three months, nine months and 12 to 18 months after onset of jaundice. The single patient with Au(1) at 12 months had no enzyme abnormality to indicate residual liver disease.If Au(1) is the virus of hepatitis these data would support the concept that persistent or long standing viremia is not a feature of epidemic hepatitis. Moreover, results of this study suggest that the Au(1) test should not be used to establish the absence of a past history of hepatitis in blood donors. These data do not establish the value of the Au(1) test in blood donors with active viremia, but do suggest that of 111 patients with recent hepatitis 1 percent had persistent antigenemia and 4 percent probably had circulating antigen antibody complexes and constituted a potential risk to recipients of their blood. The degree of risk to recipients from transfused blood of post-hepatitis patients without demonstrable Au(1) cannot be assessed.     

Excitatory amino acids inhibit stimulated phosphoinositide hydrolysis in the rat prefrontal cortex

In rat prefrontal cortical slices, the excitatory amino acids N-methyl-D-aspartate (NMDA), ibotenate, L-aspartate, quisqualate, kainate and L-glutamate inhibit carbachol-induced phosphoinositide hydrolysis as measured by the accumulation of [3H]inositol-1-phosphate ([3H]IP1). NMDA dose-dependently inhibited the carbachol response (IC50 = 14.4 microM), and this inhibition was blocked by the NMDA receptor antagonist D,L-aminophosphonovaleric acid. Lowering medium Na+ concentration to 10 mM or exposing slices to pertussis toxin alleviated the inhibitory effect of NMDA on carbachol-induced [3H]IP1 formation. Serotonin-induced stimulation of [3H]IP1 was also inhibited by NMDA; in contrast, stimulation by norepinephrine, epinephrine or dopamine was unaffected. The results suggest that excitatory amino acids, besides their traditional role as stimulatory substances, can also act to inhibit the production of 2nd messengers activated by certain neurotransmitters in the brain.     

Sequencing of peptides and proteins from the carboxy terminus.

A new chemical method for carboxy-terminal (C-terminal) protein sequencing has been developed. This approach has been successfully used to sequence 5 residues of standard proteins and 5 to 10 residues of synthetic peptides at low nanomole levels. The sequencing procedure consists of converting the C-terminal amino acid into a thiohydantoin (TH) derivative, followed by transformation of the TH into a good leaving group by alkylation. Next, the alkylated TH is cleaved mildly and efficiently with (N = C V S)- anion, which simultaneously forms a TH on the newly truncated protein or peptide. Thus, after the initial TH derivatization, there is no return to a free carboxyl group at the C-terminus. An additional benefit of this method is that the alkylating moiety can be chosen with a variety of properties allowing for variation in the detection method. This chemistry has been adapted to automated protein sequencers with a cycle time of about 1 h.     

Association of enkephalin catabolism inhibitors and CCKB antagonists: A potential use in the management of pain and opioid addiction

The overlapping distribution of opioid and cholecystokinin (CCK) peptides and their receptors (μ and δ opioid receptors; CCK-A and CCK-B receptors) in the central nervous system have led to a large number of studies aimed at clarifying the functional relationships between these two neuropeptides. Most of the pharmacological studies devoted to the role of CCK and enkephalins have been focused on the control of pain. Recently the existence of regulatory mechanisms between both systems have been proposed, and the physiological antagonism between CCK and endogenous opioid systems has been definitely demonstrated by coadministration of CCK-B selective antagonists with RB 101, a systemically active inhibitor, which fully protects enkephalins from their degradation. Several studies have also been done to investigate the functional relationships between both systems in development of opioid side-effects and in behavioral responses. This article will review the experimental pharmacology of association of enkephalin-degrading enzyme inhibitors and CCK-B antagonists to demonstrate the interest of these molecules in the management of both pain and opioid addiction. Special issue dedicated to Dr. Eric J. Simon.     

Production of live offspring with predicted genotypes using PCR-RFLP analysis of polar bodies from mouse oocytes

Accurate identification of genotypes in gametes and early embryos could facilitate the efficient production of offspring with desirable traits. This study demonstrates the feasibility of producing offspring with predictable genotypes from micromanipulated mouse oocytes. The Polymerase Chain Reaction (PCR) was used to amplify genes in the IA subregion of the major histocompatibility complex of the mouse. The validity of the approach was demonstrated in experiment 1 with IA haplo-types of unfertilized mouse ova amplified via PCR and distinguished by restriction fragment length polymorphism (RFLP) analysis. In experiment 2, fertilized oocytes were micromanipulated to remove the first and second polar bodies, which were then genotyped by validated PCR-RFLP procedures. Primary oocytes of heterozygous females contain two copies of each of the different alleles. Following meiosis I and II, the genotype of the ovum was predicted by subtracting the alleles observed in micromanipulated polar body samples. Sixty-two fertilized ova were micromanipulated and transferred to recipient females resulting in 27 live offspring (44%). The correct maternal contribution to the embryonic genotype was predicted in 19 of 27 (71%) offspring as confirmed by PCR-RFLP analysis of DNA from pup tails. Predicted genotypes of two pups were not confirmed (7%), whereas no prediction could be made in six cases (22%). © 1995 Wiley-Liss, Inc.     

Structure and putative origin of a plasmid from Staphylococcus hyicus that mediates chloramphenicol and streptomycin resistance

The structure and functional organization of Staphylococcus hyicus plasmid pSCGp3EB that mediates chloramphenicol and streptomycin resistance (Cm^rSm^r) is described and compared with another Cm^rSm^r plasmid, pSCS12, from Staphylococcus sciuri. Both plasmids appeared to be formed by co-integrate formation between plasmids that very closely resemble the chloramphenicol resistance (Cm^r) plasmid pC221 and the streptomycin resistance (Sm^r) plasmid pS194. In addition to the established recombination site B (RS_B) in pC221 and pS194, another area suitable for recombination immediately downstream of the cat gene in pC221 and upstream of the str gene in pS194 has been identified. Co-integration at these sites would lead to the structures we have observed in the wild-type Cm^rSm^r plasmids pSCGp3EB and pSCS12.     

Design justification of manufacturing systems—a review

The development of design systems which ensure economic feasibility has been the focus of recent research in the manufacturing area. Traditional design and justification approaches have been cited as having shortcomings; thus, there have been a variety of modifications and enhancements developed. An approach that is conceptually different from the traditional approaches seeks the integration of the economic analysis within the design process. We denote this approach as thedesign justification method. This paper reviews literature related to the explicit and implicit integration of economic factors in the manufacturing system design process, followed by supporting issues for the implementation of the design justification concept.