A prospective observational study of needle-handling practices at a University Veterinary Teaching Hospital

AIM

To determine the period prevalence of needlestick injury (NSI) at the Massey University Veterinary Teaching Hospital (VTH) and to identify handling and disposal practices that may contribute to the risk of NSI.

METHODS

Observations of personnel were conducted in the equine (EVH) and companion animal (CAH) clinics of the VTH during scheduled clinical activities over 9- and 10-day periods, respectively. The number and type of NSI incidents, needle uncapping, capping and disposal events were recorded for veterinarians, nurses and other personnel (visitors and students). The number of needle-related practices, as a proportion of observations, were compared between CAH and EVH, and veterinarians, nurses and others using χ(2) tests.

RESULTS

Needlestick injury was not observed during 190 and 163 needle handling and disposal observations in the CAH and EVH, respectively. Uncapping of needles by mouth was observed and was practised more by veterinarians (15/119; 13%) than nurses (2/42; 5%) and others (6/193; 3%) (p=0.001). Two-handed needle recapping after use was observed 265/354 times, and the one handed scooping technique was rarely observed (8/352). In the case of needle disposal, EVH workers used a container that was not purpose built for disposal more than CAH staff (p=0.02), or placed them in a pocket more frequently (p=0.003). Needle disposal containers were available on adjacent bench tops for 65/190 (34%) CAH observations, but no EVH observations. For 51/163 (31%) EVH observations the needle disposal containers were located on the ground, whereas none were observed there in the CAH. No approved sharps containers were observed in the immediate EVH and CAH work areas for 47/163 (28.8%) and 1/191 (0.5%) needle-handling activities, respectively.

CONCLUSIONS

Unsafe needle-handling practices must be reduced by policies and training programmes to encourage safe needle-related practices, and ensuring that approved sharps containers are available in close proximity to where needles are used.

ERK and p38MAPK pathways regulate myosin light chain phosphatase and contribute to Ca2+ sensitization of intestinal smooth muscle contraction

BACKGROUND

Mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated protein kinase (ERK) and p38MAPK, are known regulators of smooth muscle contractility. The contraction of smooth muscle is mainly regulated by the phosphorylation of regulatory light chains of myosin II (LC20), which is driven by the balance between myosin light chain kinase (MLCK) and myosin light chain phosphatase (MLCP). We hypothesized that one possible mechanism for MAPK-dependent modulation of intestinal smooth muscle contractility is via the regulation of MLCP activity.

METHODS

Contractile responses to carbachol (CCh) and effects of MAPK inhibitors on CCh-induced contractions were assessed with isolated rat ileal longitudinal smooth muscle strips. Biochemical assessments of MLCP activity and myosin phosphatse targeting subunit (MYPT1) and CPI-17 phosphorylations were completed.

KEY RESULTS

Treatment of ileal smooth muscle with PD98059 (10 μM; MEK inhibitor) or SB203580 (10 μM; p38MAPK inhibitor) significantly inhibited CCh-induced contractile force. Decreased MLCP activity was observed during sustained contractions induced by CCh; the MLCP activity was recovered by treatment with PD98059 and SB203580. However, MYPT1 (Thr697 and Thr855) and CPI-17 (Thr38) phosphorylations were not affected. Application of ML-7 (MLCK inhibitor) during CCh-induced sustained contraction elicited an MLCP-dependent relaxation, the rate of which was accelerated by application of PD98059 and SB203580 with proportional changes in LC20 phosphorylation levels but not MYPT1 phosphorylation (Thr697 or Thr855).

CONCLUSIONS & INFERENCES

ERK and p38MAPK contribute to CCh-induced sustained contraction in a LC20 phosphorylation dependent manner. Moreover, both kinases inhibit MLCP activity possibly by a novel mechanism.

Attenuation of Clostridium difficile toxin-induced damage to epithelial barrier by ecto-5'-nucleotidase (CD73) and adenosine receptor signaling

BACKGROUND

Clostridium difficile (Cdf) releases toxins (TcdA and TcdB) that damage the intestinal epithelial barrier. Ecto-5'-nucleotidase (CD73) is expressed on intestinal epithelial cells, and it is hypothesized to protect against toxin-induced epithelial damage through the cleavage of 5'-AMP to adenosine (Ado) and subsequent activation of adenosine receptors (AdoRs). Herein, we sought to assess the potential protective effects of CD73 and AdoR signaling on the injurious effects of Cdf toxins.

METHODS

Barrier function was assessed with T84 colonocytes. Transepithelial electrical resistance (TEER), paracellular fluorescein isothiocyanate (FITC)-dextran flux, and tight junction protein (ZO-1) integrity were monitored. Intrarectal installation of Cdf toxin was used to assess epithelial damage in vivo.

KEY RESULTS

TcdA/B caused reduced TEER and increased paracellular flux in vitro. Concurrent treatment with 5'-AMP attenuated these responses to Cdf toxin; an effect that was blocked with ZM241385 (AdoRA2 antagonist). APCP, a CD73 inhibitor, also suppressed the protective effects of 5'-AMP on paracellular flux. 5'-AMP reduced toxin-induced disruption of ZO-1, an effect that was abolished by APCP and ZM241385. Inhibition of CD73 with APCP during Cdf toxin exposure led to increased intestinal barrier permeability and epithelial damage in vivo. Intrarectal instillation of 5'-AMP had no effect on toxin-induced intestinal injury.

CONCLUSIONS & INFERENCES

Our data suggest that CD73 has a protective role against TcdA/B-induced damage. 5'-AMP treatment attenuated the damaging effects of Cdf toxin in vitro, and inhibitors of CD73 (APCP) and AdoRs (ZM241385) revealed that the cleavage of 5'-AMP to Ado was necessary for the protective effects. Inhibition of CD73 in vivo increases colonic tissue damage and epithelial permeability during Cdf toxin exposure.

The contribution of protein kinase C and CPI-17 signaling pathways to hypercontractility in murine experimental colitis

BACKGROUND

Colonic smooth muscle contractility is altered in colitis, and several protein kinase pathways can mediate colonic smooth muscle contraction. In the present study, we investigated whether protein kinase C (PKC) pathways also play a role in colonic hypercontractility observed during T(H) 2 colitis in BALB/c mice.

METHODS

Colitis was induced in BALB/c mice by provision of 5% dextran sodium sulfate (DSS) for 7 days. Changes in smooth muscle contractility were examined using dissected circular smooth muscle preparations from the distal colon. The contribution of conventional and novel PKC isozymes to the hypercontractile response was examined with pharmacological PKC inhibitors. Western blot analyses were used to examine protein expression and phosphorylation changes.

KEY RESULTS

Colonic smooth muscle was associated with inflammation-induced hypercontractility and altered PKC expression. Carbachol-induced peak (phasic) and sustained (tonic) contractions were increased. Chelerythrine was the most effective PKC inhibitor of both phasic and tonic contractions. There was no general difference in the percent contribution of conventional and novel PKC isozymes toward the DSS-induced hypercontractility, but inhibition of sustained force with GF109203x was higher for inflamed muscle. The CPI-17 phosphorylation was equally suppressed in both normal and DSS conditions by Gö6976 and chelerythrine, but only for the phasic component of contraction.

CONCLUSIONS & INFERENCES

The outcomes suggest that both conventional and novel PKC isozymes contribute to the phasic and tonic contractile components of BALB/c colonic circular smooth muscle under normal conditions, with novel PKC isozymes having a greater contribution to the tonic contraction. However, no effect of inflammation was observed on the relative contribution of PKC and CPI-17 toward the observed hypercontractility.

Exploring the interplay of barrier function and leukocyte recruitment in intestinal inflammation by targeting fucosyltransferase VII and trefoil factor 3

Intestinal mucosal integrity is dependent on epithelial function and a regulated immune response to injury. Fucosyltransferase VII (Fuc-TVII) is an essential enzyme required for the expression of the functional ligand for E- and P-selectin. Trefoil factor 3 (TFF3) is involved in both protecting the intestinal epithelium against injury as well as aiding in wound repair following injury. The aim of the present study was to assess the interplay between barrier function and leukocyte recruitment in intestinal inflammation. More specifically, we aimed to examine how targeted disruption of Fuc-TVII either in wild-type or TFF3(-/-) mice would alter their susceptibility to colonic injury. TFF3 and Fuc-TVII double-knockout mice (TFF3/Fuc-TVII(-/-) mice) were generated by mating TFF3(-/-) and Fuc-TVII(-/-) mice. Colitis was induced by administration of dextran sodium sulfate (DSS) (2.5% wt/vol) in the drinking water. Changes in baseline body weight, diarrhea, and fecal blood were assessed daily. Upon euthanasia, extents of colonic inflammation were assessed macroscopically, microscopically, and through quantification of myeloperoxidase (MPO) activity. Colonic lymphocyte subpopulations were assessed at 6 days after administration of DSS by flow cytometry and immunohistochemistry. No baseline intestinal inflammation was found in TFF3/Fuc-TVII(-/-), TFF3(-/-), Fuc-TVII(-/-), or wild-type mice. Loss of Fuc-TVII resulted in a reduction in disease severity whereas TFF3(-/-) mice were markedly more susceptible to DSS-induced colitis. Remarkably, the loss of Fuc-TVII in TFF3(-/-) mice markedly decreased the severity of DSS-induced colitis as evidenced by reduced weight loss, diarrhea, decreased colonic MPO levels and improved survival. Furthermore, the loss of TFF3 resulted in increased severity of spontaneous colitis in IL-2/beta-microglobulin-deficient mice. These studies highlight the importance of the interplay between factors involved in the innate immune response, mucosal barrier function, and genes involved in regulating leukocyte recruitment and other aspects of the immune response.

Smooth muscle phenotypic plasticity in mechanical obstruction of the small intestine

Chronic, partial obstruction of the small intestine can dramatically alter peristaltic contractile properties. Morphological studies have revealed hypertrophy of the circular smooth muscle cells in the constricted part of the intestine. In this issue of Neurogastroenterology and Motility, Chen et al. show that hyperplasia and hypertrophy of intestinal smooth muscle cells occur at distinct times in response to partial obstruction of the ileum. Furthermore, the first evidence is provided to link intestinal smooth muscle remodelling during mechanical obstruction with changes in serum response factor and two of its co-regulating factors, myocardin and Elk-1.

Haematological and biochemical measurements in a population of wild Eurasian badgers (Meles meles)

Blood samples were collected from a high density population of wild badgers in Woodchester Park, Gloucestershire, England, where animals were routinely captured and examined as part of a long-term ecological study, and a selection of haematological and biochemical variables were measured. The badger cubs had lower red blood cell counts and haemoglobin concentrations than the adults, consistent with physiological anaemia, and lower serum protein concentrations. Growth of muscle and active bone formation in the cubs probably accounted for their higher serum concentrations of creatinine and calcium, and higher activities of alkaline phosphatase. Only triglyceride concentrations varied between the sexes. The serum concentration of urea was higher than observed in other mustelids, consistent with a protein-rich diet and possibly related to the consumption of earthworms.

Evaluation of a DNA probe test kit for detection of Salmonellae in biosolids

AIMS

Current US regulations (40 CFR 503) for 'Class A' biosolids (treated sewage sludge) requires use of multiple-tube fermentation techniques for fecal coliform or multiple tube enrichment techniques for Salmonella spp. followed by isolation and biochemical and serologic confirmation. The technical difficulties and the time required to complete the procedure for enumeration of Salmonellae in biosolids and sludges has limited the use of this assay. This study was conducted to determine if a commercially available molecular probe system could be used to isolate and enumerate Salmonella spp. in biosolids or sludges in less time than cultural techniques with biochemical confirmation.

METHODS AND RESULTS

Several types of treated and untreated municipal sludges were assayed for Salmonellae using a cultural technique with biochemical and serologic confirmation and a DNA probe diagnostic test kit. The results indicate that the molecular probe and the conventional fermentation tube technique yielded equivalent results. Interestingly, the probe technique yielded results within 52 h following initiation of sample analysis compared with the conventional fermentation tube technique with confirmation which required approx. 120 h.

CONCLUSIONS

These results suggest that the molecular probe system used for this work may be used to determine the presence or absence of Salmonella spp. in biosolids within a relatively short time frame.

SIGNIFICANCE AND IMPACT OF THE STUDY

The ease of using the DNA probe test kit, along with its ability to produce results in less than half the time of conventional culture techniques, suggests that this assay is useful for determining the presence or absence of Salmonellae in biosolids samples.

Reassessment of the cold-labile nature of phosphofructokinase from a hibernating ground squirrel

This study reassesses the proposal that cellular conditions of low temperature and relative acidosis during hibernation contribute to a suppression of phosphofructokinase (PFK) activity which, in turn, contributes to glycolytic rate suppression during torpor. To test the proposal that a dilution effect during in vitro assay of PFK was the main reason for activity loss (tetramer dissociation) at lower pH values, the influence of the macromolecular crowding agent, polyethylene glycol 8000 (PEG), on purified skeletal muscle PFK from Spermophilus lateralis was evaluated at different pH values (6.5, 7.2 and 7.5) and assay temperatures (5, 25 and 37degrees C). A 78 +/- 2.5% loss of PFK activity during 1 h incubation at 5 degrees C and pH 6.5 was virtually eliminated when 10% PEG was present (only 7.0 +/- 1.5% activity lost). The presence of PEG also largely reversed PFK inactivation at pH 6.5 at warmer assay temperatures and reversed inhibitory effects by high urea (50 or 400 mM). Analysis of pH curves at 5 degrees C also indicated that approximately 70% of activity would remain at intracellular pH values in hibernator muscle. The data suggest that under high protein concentrations in intact cells that the conditions of relative acidosis, low temperature or elevated urea during hibernation would not have substantial regulatory effects on PFK.

Site-specific phosphorylation and point mutations of telokin modulate its Ca2+-desensitizing effect in smooth muscle

Forskolin and 8-bromoguanosine 3'-5'-cyclic monophosphate (8-Br-cGMP) induce phosphorylation of Ser-13 of telokin and relaxation of smooth muscle at constant calcium. Comparison with the effect of wild type with aspartate (D; to mimic phosphorylation) and alanine (A; non-phosphorylatable) mutants of telokin showed that the S13D mutant was more effective than wild type in relaxing smooth muscle at constant calcium. The efficacy of the Ser-13A, S12A, and S12D mutants was not significantly different from that of wild-type telokin. The effect of neither S13D nor Ser-13A was affected by 8-Br-cGMP, whereas the effect of wild type, S12A, and S12D was enhanced by 8-Br-cGMP, indicating the specificity of Ser-13 charge modification. Mutation of Ser-19 (a mitogen-activated protein kinase site) showed the S19A to be more effective than, and S19D to be not different from, wild-type telokin. The effect of both mutants was slightly enhanced by 8-Br-cGMP. A truncated (residues 1-142) form lacking the acidic C terminus had the same relaxant effect as wild-type telokin, whereas the C-terminal peptide (residues 142-155) had no effect. We conclude that site-specific modification of the N terminus modulates the Ca2+ -desensitizing effect of telokin on force.

Dual Ser and Thr phosphorylation of CPI-17, an inhibitor of myosin phosphatase, by MYPT-associated kinase

Phosphorylation of CPI-17 and PHI-1 by the MYPT1-associated kinase (M110 kinase) was investigated. M110 kinase is a recently identified serine/threonine kinase with a catalytic domain that is homologous to that of ZIP kinase (ZIPK. GST-rN-ZIPK, a constitutively active GST fusion fragment, phosphorylates CPI-17 (but not PHI-1) to a stoichiometry of 1.7 mol/mol. Phosphoamino acid analysis revealed phosphorylation of both Ser and Thr residues. Phosphorylation sites in CPI-17 were identified as Thr 38 and Ser 12 using Edman sequencing with (32)P release and a point mutant of Thr 38.

Identification of the endogenous smooth muscle myosin phosphatase-associated kinase

Ca(2+) sensitization of smooth muscle contraction involves inhibition of myosin light chain phosphatase (SMPP-1M) and enhanced myosin light chain phosphorylation. Inhibition of SMPP-1M is modulated through phosphorylation of the myosin targeting subunit (MYPT1) by either Rho-associated kinase (ROK) or an unknown SMPP-1M-associated kinase. Activated ROK is predominantly membrane-associated and its putative substrate, SMPP-1M, is mainly myofibrillar-associated. This raises a conundrum about the mechanism of interaction between these enzymes. We present ZIP-like kinase, identified by "mixed-peptide" Edman sequencing after affinity purification, as the previously unidentified SMPP-1M-associated kinase. ZIP-like kinase was shown to associate with MYPT1 and phosphorylate the inhibitory site in intact smooth muscle. Phosphorylation of ZIP-like kinase was associated with an increase in kinase activity during carbachol stimulation, suggesting that the enzyme may be a terminal member of a Ca(2+) sensitizing kinase cascade.

Phosphorylation of telokin by cyclic nucleotide kinases and the identification of in vivo phosphorylation sites in smooth muscle

The Ca(2+)-independent acceleration of dephosphorylation of the regulatory light chain of smooth muscle myosin and relaxation of smooth muscle by telokin are enhanced by cyclic nucleotide-activated protein kinase(s) [Wu et al. (1998) J. Biol. Chem. 273, 11362-113691. The purpose of this study was to determine the in vivo site(s) and in vitro rates of telokin phosphorylation and to evaluate the possible effects of sequential phosphorylation by different kinases. The in vivo site(s) of phosphorylation of telokin were determined in rabbit smooth muscles of longitudinal ileum and portal vein. Following stimulation of ileum with forskolin (20 microM) the serine at position 13 was the only amino acid to exhibit increased phosphorylation. Rabbit portal vein telokin was phosphorylated on both Ser-13 and -19 as a result of forskolin and GTPgammaS stimulation in vivo. Point mutation of Ser-13 (to Ala or Asp) abolished in vitro phosphorylation by cyclic nucleotide-dependent protein kinases.

Structure-activity relationships for selected sulfur-rich antithrombotic compounds

We assessed the antithrombotic activity of some simple organosulfur compounds which have some of the functionality found in the disulfide ajoene, a pharmacologically active compound isolated from garlic. The results establish that antithrombotic activity is associated with disulfides directly attached to a phenyl ring and is further enhanced by an alpha-sulfonyl group. CH(3)SO(2)CH(2)SSPh proved to be a potent inhibitor of platelet aggregation with an IC(50) of 5 microM.

The muscle fatty acid binding protein of spadefoot toad (Scaphiopus couchii)

Fatty acid binding protein was purified from skeletal muscle of the spadefoot toad (Scaphiopus couchii), an estivating species. While estivating, this animal relies on the fatty acid oxidation for energy. Hence we were interested in the behaviour of fatty acid binding protein under conditions of elevated urea (up to 200 mM) and potassium chloride such as exist during estivation. Also we examined whether there were interactions between glycolytic intermediates and the binding ability of the protein. The amount of bound fatty acid (a fluorescence assay using cis-parinarate) was not affected (P < 0.05) by glucose, fructose 6-phosphate or phosphoenolpyruvate at physiological concentrations. By contrast, glucose 6-phosphate increased the amount of bound cis-parinarate but the apparent dissociation constant was not different from the control. Fructose 1,6-bisphosphate but not fructose 2,6-phosphate decreased cis-parinarate binding by 40%, commensurate with doubling the apparent dissociation constant (1.15-2.62 microM). Urea, guanidinium and trimethylamine N-oxide at 200 mM increased cis-parinarate binding 60% over controls. Urea (1 M) and KCl (200 mM) did not affect cis-parinarate binding compared to controls. The interaction of this fatty acid transporter with fructose 1,6-bisphosphate is discussed in terms of reciprocal interaction with phosphofructokinase since fatty acid is also an inhibitor of phosphofructokinase.

Interferons, serotonin and neurotoxicity

BACKGROUND

Interferons are a class of cytokines profoundly affecting immune function. Several interferons are now synthesized and used clinically, notably for viral diseases and cancer. In addition to their desired immune effects, interferons cause a number of toxicities, including prominent effects on the nervous system.

METHODS

This literature review focused on the incidence of depression associated with interferon treatment. Possible neurochemical mechanisms and remedial strategies were also considered.

RESULTS

Interferon treatment, particularly with the alpha subtype, is unquestionably linked with depression, but the strength of association is uncertain because of erratic ascertainment and pretreatment co-morbidity. A likely pathogenic mechanism has been described, involving interferon suppression of serotonin synthesis. Controlled treatment trials of interferon-induced depression are not yet available.

CONCLUSIONS

Neurotoxicity substantially limits the use of interferons. At least some of the risk of depression appears to derive from their anti-serotonergic effects, consistent with the large body of evidence pointing to a general link between serotonin and affective illness. Vigilant detection and aggressive treatment of depression is necessary to optimize interferon treatment of many patients.

Termite assemblages, forest disturbance and greenhouse gas fluxes in Sabah, East Malaysia

A synthesis is presented of sampling work conducted under a UK government-funded Darwin Initiative grant undertaken predominantly within the Danum Valley Conservation Area (DVCA), Sabah, East Malaysia. The project concerned the assemblage structure, gas physiology and landscape gas fluxes of termites in pristine and two ages of secondary, dipterocarp forest. The DVCA termite fauna is typical of the Sunda region, dominated by Termes-group soil-feeders and Nasutitermitinae. Selective logging appears to have relatively little effect on termite assemblages, although soil-feeding termites may be moderately affected by this level of disturbance. Species composition changes, but to a small extent when considered against the background level of compositional differences within the Sunda region. Physiologically the assemblage is very like others that have been studied, although there are some species that do not fit on the expected body size-metabolic rate curve. As elsewhere, soil-feeders and soil-wood interface-feeders tend to produce more methane. As with the termite assemblage characteristics, gross gas and energy fluxes do not differ significantly between logged and unlogged sites. Although gross methane fluxes are high, all the soils at DVCA were methane sinks, suggesting that methane oxidation by methanotrophic bacteria was a more important process than methane production by gut archaea. This implies that methane production by termites in South-East Asia is not contributing significantly to the observed increase in levels of methane production worldwide. Biomass density, species richness, clade complement and energy flow were much lower at DVCA than at a directly comparable site in southern Cameroon. This is probably due to the different biogeographical histories of the areas.

Regulation of ground squirrel Na+K+-ATPase activity by reversible phosphorylation during hibernation

Maintenance of skeletal muscle energy status during hibernation in ground squirrels, Spermophilus lateralis, was accompanied by a decrease in Na+K+-ATPase pump activity. Energy charge was maintained (0.89) during hibernation at the expense of total adenylates (decreased by 41%). Muscle Na+K+-ATPase activity was 9.1 U/mg protein in euthermic controls but decreased by 60% during hibernation. Enzyme activity was similarly suppressed in vitro when extracts of control muscle were incubated with ATP plus second messengers of protein kinases A, G or C whereas stimulation of protein phosphatases in muscle extracts from hibernators increased Na+K+-ATPase activity. Additional studies confirmed that suppression and reactivation of the enzyme in euthermic muscle extracts can be achieved with protein kinase A and alkaline phosphatase treatments, respectively, and indicated that phosphorylation changes the ATP dependency of the enzyme. Thus, hibernation-induced suppression of Na+K+-ATPase activity in muscle and other organs of ground squirrels, which is a key part of the overall suppression of metabolic rate that constitutes torpor, appears to be regulated via reversible protein phosphorylation.

cAMP-dependent protein kinase from brown adipose tissue: temperature effects on kinetic properties and enzyme role in hibernating ground squirrels

Arousal from hibernation requires thermogenesis in brown adipose tissue, a process that is stimulated by beta-adrenergic signals, leading to a rise in intracellular 3',5'-cyclic adenosine monophosphate AMP (cAMP) and activating cAMP-dependent protein kinase A (PKA) to phosphorylate a suite of target proteins and activate lipolysis and uncoupled respiration. To determine whether specific adaptations (perhaps temperature-dependent) facilitate PKA kinetic properties or protein-phosphorylating ability, the catalytic subunit of PKA (PKAc) from interscapular brown adipose of the ground squirrel Spermophilus richardsonii, was purified (final specific activity = 279 nmol phosphate transferred per min per mg protein) and characterized. Physical properties of PKAc included a molecular weight of 41 kDa and an isoelectric point of 7.8 +/- 0.08. A change in assay temperature from a euthermic value (37 degrees C) to one typical of hibernating body temperature (5 degrees C) had numerous significant effects on ground squirrel PKAc including: (a) pH optimum rose from 6.8 at 37 degrees C to 8.7 at 5 degrees C, (b) K(m) values at 37 degrees C for Mg.ATP (49.2 +/- 3.4 microM) and for two phosphate acceptors, Kemptide (50.0 +/- 5.5 microM) and Histone IIA (0.41 +/- 0.05 mg/ml) decreased by 53%, 80% and 51%, respectively, at 5 degrees C, and (c) inhibition by KCl, NaCl and NH4Cl was reduced. However, temperature change had little or no effect on K(m) values of rabbit PKAc, suggesting a specific positive thermal modulation of the hibernator enzyme. Arrhenius plots also differed for the two enzymes; ground squirrel PKAc showed a break in the Arrhenius relationship at 9 degrees C and activation energies that were 29.1 +/- 1.0 kJ/mol for temperatures > 9 degrees C and 2.3-fold higher at 68.1 +/- 2.1 kJ/mol for temperatures < 9 degrees C, whereas the rabbit enzyme showed a breakpoint at 17 degrees C with a 13-fold higher activation energy over the lower temperature range. However, fluorescence analysis of PKAc in the absence of substrates, showed a linear change in fluorescence intensity and wavelength of maximal fluorescence over the entire temperature range; this suggested that the protein conformational change indicated by the break in the Arrhenius plot was substrate-related. Temperature change also affected the Hill coefficient for cAMP dissociation of the ground squirrel PKA holoenzyme which rose from 1.12 +/- 0.18 at 37 degrees C to 2.19 +/- 0.07 at 5 degrees C, making the release of catalytic subunits at low temperature much more responsive to small changes in cAMP levels. Analysis of PKAc function via in vitro incubations of extracts of ground squirrel brown adipose with 32P-ATP + cAMP in the presence versus absence of a PKA inhibitor, also revealed major differences in the patterns of phosphoproteins, both between euthermic and hibernating animals as well as between 37 and 5 degrees C incubation temperatures; this suggests that there are both different targets of PKAc phosphorylation in the hibernating animal and that temperature affects the capacity of PKAc to phosphorylate different targets. Both of these observations, plus the species-specific and temperature-dependent changes in ground squirrel PKAc kinetic properties, suggest differential control of the enzyme in vivo at euthermic versus hibernating body temperatures in a manner that would facilitate a rapid and large activation of the enzyme during arousal from torpor.

Coexpression of the HER-2 gene product, p185HER-2, and epidermal growth factor receptor, p170EGF-R, on epithelial ovarian cancers and normal tissues

Monoclonal antibodies (MAbs) and immunoconjugates reactive with different antigens expressed by neoplastic cells can inhibit tumor growth. Use of these agents in combination with one another or with chemotherapy can exert additive or synergistic cytotoxicity against tumor cells. An augmented therapeutic activity with favorable therapeutic index might be attained when coexpression is observed on tumor cells, but not in normal tissues. In this study frozen sections of 19 ovarian cancers (2 stage I, 10 stage III, 2 stage IV, and 5 recurrent), as well as 29 normal tissues, were evaluated by immunohistochemistry using 11 distinct MAbs against HER-2/p185 and 2 antibodies against EGF-R/p170 to assess coexpression of these receptors. HER-2/p185 expression was detected in 5 to 100% of ovarian cancers and 0 to 50% of normal ovarian epithelia, depending on the antibody used. EGF-R/p170 expression was detected in approximately 70% of cancers and 40% of normal ovaries by both antibodies. Coexpression of p185 and p170 was observed in 47-68% of ovarian cancers and 9-18% of normal ovarian epithelial specimens depending upon the combination of antibodies used. Staining of 273 specimens from 29 normal tissues indicated that coexpression of HER-2 and EGF-R is rare. Normal tissues that coexpressed both receptors in > or =50% of the cases included cervix, endometrium, esophagus, skin, and prostate. These data confirm that HER-2 and EGF-R are more frequently expressed in advanced ovarian cancers than in normal ovarian epithelium and a significant fraction of these tumors coexpress both HER-2 and EGF-R.

Plasmid transfer for enhancing degradation capabilities

The kinetics of plasmid conjugation for the TOL and RP4 plasmids depend strongly on the donor cells' specific growth rate and substrate concentration, both of which determine the cells' energy availability. Although transfer rates can be large when energy availability is high, normal biological processes have low energy availability. Therefore, we propose and evaluate preliminarily a simple scheme to create a small zone of high energy availability.

Differential immunoreactivity of epidermal growth factor receptor in benign, dysplastic and malignant prostatic tissues

To investigate epidermal growth factor receptor (EGFr) presence in the prostate, monoclonal antibody (clone EGFR1) immunohistochemical examination of radical prostatectomy specimens was performed (n = 37). All prostatic specimens contained benign prostatic hyperplasia (BPH) and/or dysplasia (prostatic intraepithelial neoplasia or PIN), as well as prostatic carcinoma (CaP). Areas of dysplasia were further categorized as to the basal cell layer and the luminal cell area. BPH, PIN, and CaP tissues in each specimen were analyzed by a single observer and graded on a scale from 0-4+. Fifteen samples were also analyzed for EGFr content utilizing a Cell Analysis Systems (CAS 200) image cytometer. EGFr immunoreactivity of BPH basal cells was significantly higher than EGFr immunoreactivity in areas of CaP (p < 0.001). EGFr staining of BPH basal cells was also significantly higher than that seen in PIN luminal cells (p < 0.001). Immunoreactivity of EGFr in PIN basal cells was significantly higher than in PIN luminal cells (p < 0.001). EGFr staining of basal cells in BPH tissues was higher than that seen in the PIN basal cell layer but the difference was not statistically significant (p = 0.06). The amount of staining present in PIN luminal cells was also significantly greater than in CaP tissues (p = 0.002). Quantitative image analysis utilizing the CAS 200 image cytometer was performed on BPH and CaP areas exclusively. EGFr immunoreactivity in basal cells of the BPH tissues was significantly greater than that seen in CaP tissues (p < 0.001). The decreased EGFr immunoreactivity in CaP may reflect a differentiating role for EGFr in normal tissues. Loss of EGFr influence may be associated with an increased proliferative state in PIN and CaP. Destruction or alteration of the epidermal grwoth factor receptor by a protease, such as prostatic specific antigen, may also explain our findings. At the present time the meaning of the different amounts of EGFr in the various types of prostate tissues is unknown.

Morphology of single vestibulospinal collaterals in the upper cervical spinal cord of the cat. II. Collaterals originating from axons outside the ventral funiculi

Recent studies have shown that vestibulospinal axons reach the upper cervical spinal cord of the cat via several different funicular routes. The purpose of this study was to describe the projections of those axons travelling outside the well-recognized pathways in the ventral funiculi. These axons are located in the dorsal columns, dorsolateral funiculi, and lateral funiculi. Collaterals of these axons were stained following extracellular injections of Phaseolus vulgaris leucoagglutinin in the medial and descending vestibular nuclei. The trajectories of individual collaterals were reconstructed from serial histological sections. Collaterals arising from axons in the same funiculus usually had the same characteristic appearance. Axons in the lateral funiculi, ipsilateral or contralateral to their cells of origin, gave rise to collaterals that had a simple structure and usually followed a horizontal trajectory across laminae VII and VIII. The boutons of these collaterals were distributed throughout the mediolateral extent of laminae VI and VII and the dorsal half of lamina VIII. In contrast, axons in the dorsolateral funiculi, ipsilateral or contralateral to their cells of origin, terminated primarily in laminae IV and V. Many collaterals of these axons projected either rostrally or caudally and had a narrow mediolateral distribution. The combined distribution of boutons from collaterals originating from axons in the dorsal columns included the dorsal horn and intermediate zone. Although these collaterals were less common and formed a heterogeneous group, they were easily distinguished from collaterals originating from axons travelling in other funiculi. These results indicate that vestibulospinal axons travelling outside the ventral funiculi comprise several distinct systems. Each system travels by a different funicular route and is distinguished by differences in collateral morphology and termination zones.(ABSTRACT TRUNCATED AT 250 WORDS)

Differential immunoreactivity of her-2/neu oncoprotein in prostatic tissues

To investigate HER-2/neu oncoprotein immunoreactivity, monoclonal antibody TA1 immunohistochemical examination of flash-frozen radical prostatectomy specimens was performed (n = 35). All prostatic specimens contained benign prostatic hyperplasia (BPH) and/or prostatic intraepithelial neoplasia (PIN), as well as prostatic carcinoma (CaP). HER-2/neu oncoprotein immunoreactivity in BPH tissues was not significantly different than that for the PIN basal cell layer (P = 0.10) or for the PIN luminal cells (P = 0.17). There was significantly more HER-2/neu oncoprotein immunoreactivity in BPH than in areas of CaP (P < 0.001). There was no significant difference in the amount of immunoreactivity present in PIN basal cells when compared to the PIN luminal cells (P = 0.49). Both the PIN basal cells and luminal cells stained for the HER-2/neu oncoprotein to a higher degree than cells in the CaP areas (P < 0.001 in both cases). HER-2/neu oncoprotein immunoreactivity is present at a significantly higher degree in BPH and PIN than in malignant prostatic epithelium.

Primary leiomyoma of the liver

A 30-yr-old woman with right upper quadrant abdominal pain was found to have a hepatic leiomyoma. This is the youngest patient in whom this rare tumor has been found. The diagnostic approach toward gastrointestinal leiomyomata is emphasized, including the role of immunohistochemistry.

The wax-secreting glands of Eriocampa ovata L. (Hymenoptera: Tenthredinidae): ultrastructural observations and chemical composition of the wax

Larvae of the red-backed alder sawfly, Eriocampa ovata, in all instars except the last, exhibit external accumulations of wax. Approximately 93% of the hexane-extractable wax consists of primary alcohols ranging in chain length from 20 to 32 carbons. The major component is hexacosan-1-ol. Wax is secreted from specialized cuticular modifications found only on tergites and distinguishable from surrounding cuticle by the presence of cupular papillae. A single thread of wax exudes from the apical crater of each papilla. One feature peculiar to cuticle lining the craters is the presence of vast numbers of epicuticular filaments. These may represent channels for the transport of wax. The underlying glandular cells are modified columnar, ductless epidermal cells which, during wax secretion, exhibit organelles characteristic of lipid-producing cells. There are no wax secreting areas or similarly modified epidermal cells in the last larval instar.

Ultrastructure of scent glands in larvae of Apateticus bracteatus (Hemiptera: Pentatomidae) and chemical composition of the secretion

The three dorsal abdominal glands in larvae of Apateticus bracteatus (Pentatomidae) secrete a mixture of compounds. Major volatile constituents of the secretion are identified, herein, as tridecane and 2-octenal. There are also trace amounts of 2-hexenal and two other unidentified compounds.Each of the glands has paired orifices that are located between tergites 3/4, 4/5, and 5/6, but only the most anterior gland is paired. In anterior glands of midinstar larvae, glandular cells associated with ducts, and interstitial glandular cells are distributed along the ventral walls of the reservoirs. In posterior glands, columnar glandular cells are located in the anterior dorsal wall of the reservoirs; secretory cells associated with ducts, and nonglandular interstitial cells are distributed throughout the ventral and posterior walls of the reservoirs. The interstitial glandular cells of the anterior gland and the columnar glandular cells of the middle and posterior glands contain cytoplasmic organelles characteristic of lipid-producing cells. In all glands the secretory cells associated with ducts secrete lipids. Evidence indicating the importance of Golgi and ER in secretion synthesis is presented. The reservoirs and ducts have a thin cuticular lining.The bearing of the results on present ideas of gland function in Heteroptera is discussed.

Modulation of alcohol dehydrogenase and ethanol metabolism by sex hormones in the spontaneously hypertensive rat. Effect of chronic ethanol administration

In young (4-week-old) male and female spontaneously hypertensive (SH) rats, ethanol metabolic rate in vivo and hepatic alcohol dehydrogenase activity in vitro are high and not different in the two sexes. In males, ethanol metabolic rate falls markedly between 4 and 10 weeks of age, which coincides with the time of development of sexual maturity in the rat. Alcohol dehydrogenase activity is also markedly diminished in the male SH rat and correlates well with the changes in ethanol metabolism. There is virtually no influence of age on ethanol metabolic rate and alcohol dehydrogenase activity in the female SH rat. Castration of male SH rats prevents the marked decrease in ethanol metabolic rate and alcohol dehydrogenase activity, whereas ovariectomy has no effect on these parameters in female SH rats. Chronic administration of testosterone to castrated male SH rats and to female SH rats decreases ethanol metabolic rate and alcohol dehydrogenase activity to values similar to those found in mature males. Chronic administration of oestradiol-17beta to male SH rats results in marked stimulation of ethanol metabolic rate and alcohol dehydrogenase activity to values similar to those found in female SH rats. Chronic administration of ethanol to male SH rats from 4 to 11 weeks of age prevents the marked age-dependent decreases in ethanol metabolic rate and alcohol dehydrogenase activity, but has virtually no effect in castrated rats. In the intoxicated chronically ethanol-fed male SH rats, serum testosterone concentrations are significantly depressed. In vitro, testosterone has no effect on hepatic alcohol dehydrogenase activity of young male and female SH rats. In conclusion, in the male SH rat, ethanol metabolic rate appears to be limited by alcohol dehydrogenase activity and is modulated by testosterone. Testosterone has an inhibitory effect and oestradiol has a testosterone-dependent stimulatory effect on alcohol dehydrogenase activity and ethanol metabolic rate in these animals.

Cells of the thoracic defensive gland of the red-humped caterpillar, Schizura concinna (J. E. Smith) (Lepidoptera: Notodontidae): ultrastructural observations

The thoracic defensive gland in larvae of Schizura concinna J. E. Smith consists of an anterior and posterior gland joined by an interglandular neck. Ultrastructural observations indicated that there are no cuticular ductules associated with gland cells and that there are three, or possibly four, types of cells within the gland. Two types, as suggested by their location, probably function to maintain the form of the orifice and the interglandular neck. The remaining cells, located in the anterior gland, the anterior lateral longitudinal folds, and the posterior gland exhibit no appreciable ultrastructural differences from each other. Only the cells of the lateral longitudinal folds contain deposits of a lipid-like material. The apical plasma membranes of these cells have a peculiar array of folds surrounding cylinders of endocuticle. Within the apical folds these cylinders are encircled longitudinally by tubules which presumably arise from smooth tubular endoplasmic reticulum. Within the cuticle overlying the cells are filaments which are similar in appearance to the secretion contained within the lumen of the glands.

Measurement of chloroprocaine and procaine in plasma by flame ionization gas-liquid chromatography

We describe an isothermal gas-liquid chromatographic procedure developed for measuring procaine and chloroprocaine in plasma. The unchanged drug is extracted into toluene from alkalinized plasma, together with an internal standard. The solvent is removed, the residue redissolved in methanol, and aliquots are injected into a 91.5-cm gas-liquid chromatographic column containing 3% OV-210. Sensitivity of detection is in the nanogram range.

Measurement of chloroprocaine and procaine in plasma by flame ionization gas-liquid chromatography

We describe an isothermal gas-liquid chromatographic procedure developed for measuring procaine and chloroprocaine in plasma. The unchanged drug is extracted into toluene from alkalinized plasma, together with an internal standard. The solvent is removed, the residue redissolved in methanol, and aliquots are injected into a 91.5-cm gas-liquid chromatographic column containing 3% OV-210. Sensitivity of detection is in the nanogram range.

Measurement of thiamylal and thiopental in plasma by electron capture and flame photometric gas-liquid chromatography

We describe an isothermal gas-liquid chromatographic procedure developed for measuring thiamylal and thiopental in plasma. The unchanged drug is extracted into ethyl acetate from acidified plasma, together with an internal standard. The solvent is removed, the residue methylated, aliquots, diluted with benzene, are injected into a 183-cm gas-liquid chromatographic column containing 3% OV-17. Sensitivity of detection is in the nanogram to picogram range.

Measurement of thiamylal and thiopental in plasma by electron capture and flame photometric gas-liquid chromatography

We describe an isothermal gas-liquid chromatographic procedure developed for measuring thiamylal and thiopental in plasma. The unchanged drug is extracted into ethyl acetate from acidified plasma, together with an internal standard. The solvent is removed, the residue methylated, aliquots, diluted with benzene, are injected into a 183-cm gas-liquid chromatographic column containing 3% OV-17. Sensitivity of detection is in the nanogram to picogram range.

Ultrastructure of sex pheromone gland cells in Lobesia botrana Den &Schiff. (Lepidoptera: Olethreutidae)

In newly emerged and 48-h-old female adults of Lobesia botrana the sex pheromone gland cells are columnar. Organelles characteristic of lipid-producing cells are very prominent. Smooth tubular endoplasmic reticulum is extensively developed but few lipid droplets are observed. Numerous microbodies are present and are located, along with the Golgi complexes, primarily in the vicinity of the nucleus. The apical plasma membrane is folded. The cuticle overlying the gland cells differs from unmodified cuticle in the number and location of epicuticular filaments. They originate near the bases of the furrows between the apical folds.

Ventricular function in experimental hemorrhagic shock

Hemorrhagic shock was induced in 20 spontaneously breathing adult greyhounds by lowering the mean arterial pressure to 40 millimeters of mercury. In the first group of six dogs, reinfusion was carried out without delay; in a second group of six dogs, hypovolemia was continued for two hours, during which time the arterial pressure was permitted to rise in response to intact cardiovascular reflexes; in a third group of eight dogs, the mean arterial pressure was artificially maintained at 40 millimeters of mercury for two hours, initially by further bleeding. In all dogs in the latter group, take-up of blood from the reservoir was required during the second hour to maintain the arterial pressure, this being indicative of irreversible shock. In two of this group, fatal arrhythmias developed during reinfusion. All three groups showed evidence of ventricular dysfunction during and immediately after reinfusion, as indicated by disproportion between left ventricular stroke work and left ventricular end diastolic pressure, these data being used to construct ventricular function curves. Measurement of dP/dt maximum suggested that this dysfunction was due to impairment of myocardial contractility. The first two groups recovered normal function within one hour; the third group failed to have such a recovery. Evidence indicates that generalized tissue hypoxia, in addition to myocardial hypoxia, is important in the cause of cardiac dysfunction in irreversible shock.

A comparison of methods for the measurement of cardiac output and blood oxygen content

A comparison has been made between the recently introduced thermal dilution method for measurement of cardiac output and the standard dye dilution technique. Two relatively new methods of measurement of blood oxygen content, one involving the measurement of oxygen tension after release of oxygen by carbon monoxide, and the other the measurement of current flow upon reduction of oxygen in a galvanic cell, have been compared with a standard indirect method of measurement of blood oxygen content. All three new methods fulfilled the criteria of accuracy and simplicity and compared favourably with the standard methods. Of the two new methods for measurement of oxygen content, that involving reduction of oxygen in a galvanic cell was superior by virtue of compactness and speed of operation.

Early cholecystectomy for acute cholecystitis

A series of 65 cases of acute cholecystitis from among 500 patients on whom cholecystectomy was performed by the author is presented. Early cholecystectomy was the operation of choice in 63 and cholecystostomy in two. The operative mortality for cholecystectomy was 1.6%; the postoperative morbidity was low and there were no serious complications such as common bile duct injury or biliary fistula. Operation for acute cholecystectomy is recommended within 48 hours of diagnosis to avoid serious complications such as perforation and suppurative cholangitis.