Augmented intestinal trefoil factor (TFF3) and loss of pS2 (TFF1) expression precedes metaplastic differentiation of gastric epithelium

The trefoil peptides spasmolytic polypeptide (SP), intestinal trefoil factor (ITF), and pS2 show lineage-specific expression in the normal gut and are strongly induced after mucosal injury. We assessed the relationship between this induction and the development of the regenerative epithelial lineage over time in the rat stomach and verified these observations in the metaplastic and dysplastic human stomach. Antral or colonic ulcers were induced in Wistar rats by application of serosal acetic acid and tissues harvested 2 hours to 125 days later. Human endoscopic biopsies or gastric resection specimens were also assessed. Tissues were examined by radioimmunoassay, immunoblotting, or immunohistochemistry for ITF, SP, and transforming growth factor alpha (rat) or ITF and pS2 (human) expression. ITF and SP mRNA in antral ulcer margins was localized by in situ hybridization. ITF and SP peptide expression rose steadily in ulcer margins after 4 days, with the rise in ITF being more pronounced. By 40 days, several hundred-fold elevations in ITF levels were present, with a field effect in uninvolved mucosa. Hyperproliferative, elongated glands of undifferentiated cells expressing abundant trefoil peptides and acid sulfomucins were present after day 12 and persisted after ulcer healing. ITF mRNA was aberrantly expressed in basal and mid-regions of these regenerative glands. In contrast, transforming growth factor alpha peptide expression rose promptly after injury then fell to baseline levels with healing. Seven months after injury, gastric atrophy, intestinal metaplasia, and severe dysplasia with conserved ITF expression were seen. ITF was also induced in human intestinal metaplasia and conserved in all gastric cancers, whereas expression of the gastric peptide pS2 was progressively reduced in the progression from metaplasia to dysplasia. Persistent, selective overexpression of ITF, possibly acting in an autocrine fashion, is a feature of regeneration after antral ulceration, and may provide insight into the nature of metaplastic phenotypes arising from chronic gastric injury. The loss of pS2 expression in metaplasia and cancer supports a role for this protein in gastric tumor suppression.

Human recombinant pro-dipeptidyl peptidase I (cathepsin C) can be activated by cathepsins L and S but not by autocatalytic processing

Human dipeptidyl peptidase I was expressed in the insect cell/baculovirus system and purified in its active (rhDPPI) and precursor (pro-rhDPPI) forms. RhDPPI was very similar to the purified enzyme (hDPPI) with respect to glycosylation, enzymatic processing, oligomeric structure, CD spectra, and catalytic activity. The precursor, which was a dimer, could be activated approximately 2000-fold with papain. Cathepsin L efficiently activated pro-rhDPPI in vitro at pH 4.5 (k(app) approximately 2 x 10(3) min(-)(1) M(-)(1)), and two cleavage pathways were characterized. The initial cleavage was within the pro region between the residual pro part and the activation peptide. Subsequently, the activation peptide was cleaved from the catalytic region, and the latter was cleaved into the heavy and light chains. Alternatively, the pro region was first separated from the catalytic region. Cathepsin S was a less efficient activating enzyme. Cathepsin B and rhDPPI did not activate pro-rhDPPI, and the proenzyme was incapable of autoactivation. Incubation of both pro-rhDPPI and rhDPPI with cathepsin D resulted in degradation. Cystatin C and stefins A and B inhibited rhDPPI with K(i) values in the nanomolar range (K(i) = 0.5-1.1 nM). The results suggest that cathepsin L could be an important activator of DPPI in vivo and that cathepsin D and possibly the cystatins may contribute to DPPI downregulation.

A 20-year study of an adolescent psychiatric clientele, with special reference to the age of onset

During a period of 20 years (1968-1988) all inpatients admitted for the first time to the adolescent psychiatric unit in Copenhagen (n = 841) were classified in accordance with social and psychiatric variables, to describe the clientele as a group and, furthermore, to investigate changes occurring during that period. The total clientele had a broad age range (12-21 years), with as many as 36% less than 15 years old. Eleven percent of the patients had attempted suicide before admission. Fifty-six percent of the total group were diagnosed as psychotic or as borderline cases. The patients came predominantly from lower social levels, and almost half the group had a child debut defined as symptoms that had resulted in referral for further investigation during childhood. Moreover, among the schizophrenic patients 35% had an early onset. The age of onset may have some clinical significance, as this item was related to several sociodemographic variables. Finally, an increase in the rate of psychoses and lower social class was recorded during the period.

Increased platelet reactivity and significant changes in coagulation markers after cavopulmonary connection

OBJECTIVE

To evaluate platelet reactivity and coagulation markers after surgical palliation of univentricular hearts.

DESIGN AND PATIENTS

Cross sectional survey of 24 patients, median age 11 (range 4-22) years, at 2 (range 0.5-6) years after a total cavopulmonary connection (TCPC; n = 14) or a bidirectional Glenn anastomosis (Glenn; n = 10).

MAIN OUTCOME MEASURES

Platelet reactivity and/or coagulation markers were measured in 20 patients (four excluded because of anticoagulant treatment) and compared with 33 healthy controls, median age 12 (range 6-16) years.

RESULTS

None of the patients had clinically apparent thromboembolic events. However, increased platelet reactivity was observed ex vivo both after collagen induced platelet aggregation (median 73% (interquartile range 61-84%) in patients, and 61% (47-69%) in controls; p < 0.01), and after ADP induced platelet aggregation (69% (53-77%) in patients, and 56% (40-66%) in controls; p < 0.05). Concentrations of protein S antigen, antithrombin III, and protein C activity were reduced after both TCPC and Glenn. A concomitant decrease was seen in coagulation factor II, VII, X, and factor VII clot activity.

CONCLUSIONS

Several abnormalities in the coagulation system were observed after bidirectional Glenn anastomosis, similar to alterations previously described in Fontan operated and TCPC patients. Antithrombotic treatment in these patients is still an unresolved issue, but aspirin is often recommended. This study shows that such a strategy is rational and the results suggest that antiplatelet treatment may be advantageous, either alone or in combination with oral anticoagulant treatment.

A 10-year follow-up study of an adolescent psychiatric clientele and early predictors of readmission

Over a period of 20 years (from 1968 to 1988) all inpatients (n = 839) who were admitted for the first time to the adolescent psychiatric unit in Copenhagen were registered, and 40 social and psychiatric variables were recorded, to investigate early predictors of later readmission. Overall, 44.8% of the patients were readmitted within a certain observation period (range, 1.5-21.5 years). Among a subsample of 488 patients (58%) who could be followed up for more than 10 years after their first admission 26% became heavy users of psychiatric services, defined as long-term inpatients or revolving-door patients. Severe early diagnoses (schizophrenia and affective psychoses) were strongly associated with rapid relapses and frequent readmissions. A statistical estimate of the risk of later heavy use based on 12 independent variables is presented.

Localization of activin beta(A)-, beta(B)-, and beta(C)-subunits in humanprostate and evidence for formation of new activin heterodimers of beta(C)-subunit

Activin ligands are formed by dimerization of activin ss(A)- and/or ss(B)-subunits to produce activins A, AB, or B. These ligands are members of the transforming growth factor-ss superfamily and act as growth and differentiation factors in many cells and tissues. New additions to this family include activin ss(C)-, ss(D)-, and ss(E)-subunits. The aim of this investigation was to examine the localization of and dimerization among activin subunits; the results demonstrate that activin ss(C) can form dimers with activin ss(A) and ss(B) in vitro, but not with the inhibin alpha-subunit. Using a specific antibody, activin ss(C) protein was localized to human liver and prostate and colocalized with ss(A)- and ss(B)-subunits to specific cell types in benign and malignant prostate tissues. Activin C did not alter DNA synthesis of the prostate tumor cell line, LNCaP, or the liver tumor cell line, HepG2, in vitro when added alone or with activin A. Therefore, the capacity to form novel activin heterodimers (but not inhibin C) resides in the human liver and prostate. Activin A, AB, and B have diverse actions in many tissues, including liver and prostate, but there is no known biological activity for activin C. Thus, the evidence of formation of activin AC or BC heterodimers may have significant implications in the regulation of levels and/or biological activity of other activins in these tissues.

Mapping of the locus for cholestasis-lymphedema syndrome (Aagenaes syndrome) to a 6.6-cM interval on chromosome 15q

Patients with cholestasis-lymphedema syndrome (CLS) suffer severe neonatal cholestasis that usually lessens during early childhood and becomes episodic; they also develop chronic severe lymphedema. The genetic cause of CLS is unknown. We performed a genome screen, using DNA from eight Norwegian patients with CLS and from seven unaffected relatives, all from an extended pedigree. Regions potentially shared identical by descent in patients were further characterized in a larger set of Norwegian patients. The patients manifest extensive allele and haplotype sharing over the 6.6-cM D15S979-D15S652 region: 30 (83.3%) of 36 chromosomes of affected individuals carry a six-marker haplotype not found on any of the 32 nontransmitted parental chromosomes. All Norwegian patients with CLS are likely homozygous for the same disease mutation, inherited from a shared ancestor.

Carica papaya glutamine cyclotransferase belongs to a novel plant enzyme subfamily: cloning and characterization of the recombinant enzyme

A full-length cDNA encoding Carica papaya glutamine cyclotransferase was cloned by RT-PCR on the basis of results from amino acid sequencing of tryptic fragments of the native enzyme. The cDNA of 1036 nucleotides encodes a typical 22-residue signal peptide and a mature protein of 266 residues with a calculated molecular mass of 30,923 Da. Five plant ESTs encoding putative QCs highly homologous to PQC were identified and the numbers and locations of cysteines and N-glycosylation sites are conserved. The plant QC amino acid sequences are very different from the known mammalian QC sequences and no clear homology was observed. The PQC cDNA was expressed in Escherichia coli as either His-tagged PQC, with three different signal peptides and in fusions with thioredoxin, glutathione S-transferase, and (pre-) maltose-binding protein. In all cases, the expressed protein was either undetectable or insoluble. Expression in Pichia pastoris of PQC fused to the alpha-factor leader resulted in low levels of PQC activity. Extracellular expression of PQC in the insect cell/baculovirus system was successful and 15-50 mg/liter of active PQCs with three different secretion signals was expressed and purified. Further, PQC N-terminally fused to a combined secretion signal/His-tag peptide was correctly processed by the host signal peptidase and the His-tag could subsequently be removed with dipeptidyl peptidase I. The expressed products were characterized by activity assays, SDS-PAGE, N-terminal amino acid sequencing, MALDI-TOF mass spectroscopy, and peptide mass fingerprint analysis.

Elevated intramuscular concentration of bradykinin in jaw muscle increases the fusimotor drive to neck muscles in the cat

Patients suffering from temporomandibular dysfunction exhibit clinical findings such as fatigue, painful muscles, and muscles that are tender to palpation, not only in the temporomandibular area, but also in the neck/shoulder region. The mechanisms behind this are not known, although previous studies of similar spreading phenomena have revealed a possible involvement of the fusimotor system. In the present study, we evaluated the activity of this system by recording the activity of muscle spindle afferents from dorsal neck muscles after intramuscular injections of 6 microg to 25 microg bradykinin in the ipsilateral masseter muscle. A total of 23 muscle spindle afferents from the trapezius and splenius muscles was recorded at the C3-C4 level in 7 adult cats anesthetized with alpha-chloralose. Of these 23 afferents, 17 (74%) showed significantly different responses to bradykinin injections compared with control injections (dissolving agent, Tyrode), and the majority of the effects were compatible with an increased static fusimotor drive to the muscle spindle system. Thus, the results demonstrate potent reflex connections from groups III and IV masseter muscle afferents to fusimotor neurones on the C3-C4 level. It is concluded that the fusimotor system might play a significant role in the mechanisms behind the spread of muscle pain and tension from the temporomandibular region to the neck.

Determinants of infant and child mortality in the West Bank and Gaza Strip

Infant and child mortality in the West Bank and Gaza Strip has steadily reduced since 1967, even though fertility has remained extremely high. In this paper the determinants of infant and child mortality are discussed, with particular emphasis on the role of consanguineous marriages, short birth spacing and maternal education. It is shown that short birth spacings and type of marriage are more important determinants of infant mortality than maternal education. Moreover, the relative role of consanguineous marriages appears to increase with time.

Application of PCR to the identification of dermatophyte fungi

Infection of the keratinised tissues (skin, hair and nails) in man and animals by keratinophilic fungi (dermatophytes) results in dermatophytosis (also known as tinea or ringworm). As conventional laboratory procedures for the identification of dermatophytes are either slow or lack specificity, improved diagnostic methods are required. The application of nucleic acid amplification technology has made rapid and precise identification of dermatophytes possible. Recent studies have shown that when one of the four random primers (OPAA11, OPD18, OPAA17 and OPU15) was used in arbitrarily primed PCR (AP-PCR), up to 20 of the 25 dermatophyte species or subspecies under investigation could be distinguished on the basis of characteristic band patterns detected in agarose gel electrophoresis. A combination of two random primers (OPD18 and OPAA17) used in separate reaction tubes identified 23 of the 25 dermatophyte species or subspecies examined. AP-PCR provides a rapid and practical tool for identification of dermatophyte isolates that is independent of morphological and biochemical characteristics and thus enhances laboratory diagnosis of dermatophytosis.

Position sense testing: influence of starting position and type of displacement

OBJECTIVE

To assess the effect of starting position, target position, and various types of limb displacement on repositioning tests commonly used for clinical evaluation of rehabilitation.

SETTING

Controlled laboratory environment.

PARTICIPANTS

Sixteen healthy volunteer subjects.

MAIN OUTCOME MEASURE

Absolute error, ie, the absolute difference between target and replicate positions.

DESIGN

Each subject performed four testing procedures consisting of different types of limb displacement (active, passive, and passive during antagonist muscle contraction). For each procedure, horizontal movements were performed ipsilaterally about the right glenohumeral joint from one intermediate starting position (40 degrees ) and two extreme starting positions (0 degrees and 80 degrees ). Four fixed target positions (16 degrees , 32 degrees, 48 degrees , 64 degrees ) were presented for each starting position. The subjects were required to replicate target position after returning to the respective starting position.

RESULTS

Lower repositioning errors occurred with active displacement procedures compared with passive, and with the intermediate starting position compared with the extreme. Target position, however, had no effect on repositioning errors.

CONCLUSIONS

Starting position and type of displacement should be considered in interpretations and comparisons of data from clinical studies.

Inhibition of nitric oxide synthesis improves left ventricular contractility in neonatal pigs late after cardiopulmonary bypass

BACKGROUND

Following neonatal open heart surgery a nadir occurs in left ventricular function six to 12 hours after cardiopulmonary bypass. Although initiated by intraoperative events, little is known about the mechanisms involved.

OBJECTIVE

To evaluate the involvement of nitric oxide in this late phase dysfunction in piglets.

DESIGN

Piglets aged 2 to 3 weeks (4-5 kg) underwent cardiopulmonary bypass (1 h) and cardioplegic arrest (0.5 h) and then remained ventilated with inotropic support. Twelve hours after bypass, while receiving dobutamine (5 microg/kg/min), the left ventricular response to non-selective nitric oxide synthase inhibition (l-N(G)-monomethylarginine (l-NMMA)) was evaluated using load dependent and load independent indices (E(es), the slope of the end systolic pressure-volume relation; M(w), the slope of the stroke work-end diastolic volume relation; [dP/dt(max)](edv), the slope of the dP/dt(max)-end diastolic volume relation), derived from left ventricular pressure-volume loops generated by conductance and microtip pressure catheters.

RESULTS

10 pigs received 7.5 mg l-NMMA intravenously and six of these received two additional doses (37.5 mg and 75 mg). E(es) (mean (SD)) increased with all three doses, from 54.9 (40.1) mm Hg/ml (control) to 86.3 (69.5) at 7.5 mg, 117.9 (65.1) at 37.5 mg, and 119 (80.4) at 75 mg (p < 0.05). At the two highest doses, [dP/dt(max)](edv) increased from 260.8 (209.3) (control) to 470.5 (22.8) at 37.5 mg and 474.1 (296.6) at 75 mg (p < 0.05); and end diastolic pressure decreased from 16.5 (5.6) mm Hg (control) to 11.3 (5.0) at 37.5 mg and 11.4 (4.9) at 75 mg (p < 0. 05).

CONCLUSIONS

In neonatal pigs 12 hours after cardiopulmonary bypass with ischaemic arrest, low dose l-NMMA improved left ventricular function, implying that there is a net deleterious cardiac action of nitric oxide at this time.

Fin-flicking behaviour: a visual antipredator alarm signal in a characin fish, Hemigrammus erythrozonus

Glowlight tetras, Hemigrammus erythrozonus, show a conspicuous visual display ('fin flicking') upon detecting a conspecific chemical alarm signal (alarm pheromone). We conducted laboratory studies to test two, nonmutually exclusive hypotheses regarding the function of this behaviour. To test the hypothesis that fin flicking acts as a visual alarm signal to conspecifics, we paired shoals of tetras with a stimulus tetra in an adjacent tank (separated by a one-way mirror) and exposed the stimulus tetras to conspecific skin extract (with alarm pheromone) or swordtail skin extract (which lacks ostariophysan alarm pheromone). Stimulus tetras significantly increased their frequency of fin flicking when exposed to conspecific skin extract, but not to the swordtail skin extract control. The test shoals showed a significant increase in antipredator behaviour in response to fin-flicking stimulus tetras, but not to stimulus tetras that did not fin-flick. To test the hypothesis that fin flicking serves as a predator deterrent, we paired predatory Jack Dempsey cichlids, Cichlasoma octofaciatum, with tetras in adjacent tanks and exposed the tetras to either conspecific or swordtail skin extract. Predators remained further away from the stimulus tetra, took longer to initiate a bite and displayed fewer bites towards tetras that fin-flicked compared with tetras that did not fin-flick. These results support our hypothesis that fin flicking in tetras serves as both a visual alarm signal to conspecifics and a deterring signal to predators, and suggest that individual tetras may reduce their risk of predation by fin flicking upon detecting a predation threat. Copyright 1999 The Association for the Study of Animal Behaviour.

Localized muscle fatigue decreases the acuity of the movement sense in the human shoulder

PURPOSE

The purpose of this study was to investigate alterations in the movement sense acuity during localized muscle fatigue in the human dominant shoulder.

METHODS

Fourteen healthy volunteers (8 males and 6 females) with a mean age 23 +/- 2 yr participated in the study. The subjects' ability to discriminate movement velocity relative to a reference velocity imposed over the dominant shoulder was tested following two experimental conditions: 1) Light exercise (LE), repetitive isokinetic horizontal flexion/extensions at the shoulder, ranging from 85 degrees to 20 degrees relative to the frontal plane, at 10% of maximal voluntary contraction (MVC) and 2) Hard exercise (HE), same movements as in LE, but performing MVC to fatigue.

RESULTS

The results showed that subjects had a lower probability of distinguishing between different movement velocities following HE as compared with those during the LE condition (P < 0.001). When genders were compared, female subjects had a lower probability of distinguishing correctly than male subjects (P < 0.001).

CONCLUSIONS

The acuity of the movement sense in the dominant shoulder is reduced in the presence of shoulder muscle fatigue. The possible influence of muscle fatigue via peripheral muscle receptors on movement sense is discussed.

Molecular modeling and preclinical evaluation of the humanized NR-LU-13 antibody

A mouse-human chimeric monoclonal antibody (chNR-LU-13), specific for the EGP40 pancarcinoma antigen, was humanized through three-dimensional molecular modeling. Humanization of the chNR-LU-13 antibody is expected to enhance its use for patients undergoing immunotherapy. On the basis of the observed amino acid sequence identity, chNR-LU-13 complementary determining regions (CDRs) of the V(L) and V(H) regions were grafted onto the human anti-DNA-associated idiotype immunoglobulin clone, R3.5H5G'CL. Ten amino acids residues within the humanized framework were back-mutated to their corresponding chNR-LU-13 sequence, because they were predicted to disrupt the canonical classification of the CDRs or were within 5 A of a CDR. Synthesis of the V(L) and V(H) regions was accomplished by recursive PCR, and the dual-chain expression vector p451.C4 was positioned under control of the CMV(P+E). We observed by competitive ELISA that the recombinant humanized NR-LU-13 (huNR-LU-13) IgG1 antibody exhibited an indistinguishable immunoreactivity profile when compared with the murine monoclonal antibody (muNR-LU-10). The huNR-LU-13 antibody was effective in mediating both antibody-dependent cellular cytotoxicity and complement-mediated cytotoxicity when assayed against either the breast carcinoma cell line, MCF-7, or the colon adenocarcinoma cell line, SW1222. Biodistribution studies using i.v. coinjected 131I-muNR-LU-10 and 125I-huNR-LU-13 confirmed that the huNR-LU-13 specifically targets to the tumor in athymic BALB/c mice bearing the SW1222 human tumor xenograft. Humanization of the chNR-LU-13 antibody is expected to eliminate an undesired human antimouse antibody response, allowing for repeated i.v. administration into humans.

Removal of N-terminal polyhistidine tags from recombinant proteins using engineered aminopeptidases

We have developed a specific and efficient method for complete removal of polyhistidine purification tags (HisTags) from the N-termini of target proteins. The method is based on the use of the aminopeptidase dipeptidyl peptidase I (DPPI), either alone or in combination with glutamine cyclotransferase (GCT) and pyroglutamyl aminopeptidase (PGAP). In both cases, the HisTag is cleaved off by DPPI, which catalyzes a stepwise excision of a wide range of dipeptides from the N-terminus of a peptide chain. Some sequences, however, are resistant to DPPI cleavage and a number of mature proteins have nonsubstrate N-termini which protects them against digestion. For such proteins, HisTags composed of an even number of residues can be cleaved off by treatment with DPPI alone. When the target protein is unprotected against DPPI, a blocking group is generated enzymatically from a glutamine residue inserted between the HisTag and the target protein. A protein with a HisTag-Gln extension is incubated with both DPPI and GCT. As above, the polyhistidine sequence is cleaved off by DPPI, but when the glutamine residue appears in the N-terminus, it is immediately converted into a pyroglutamyl residue by an excess of GCT and further DPPI digestion is prevented. The desired sequence is finally obtained by excision of the pyroglutamyl residue with PGAP. All the enzymes employed can bind to immobilized metal affinity chromatography (IMAC) matrices, and in this paper we demonstrate a simple and highly effective process combining IMAC purification of His-tagged proteins, our aminopeptidase-based method for specific excision of HisTags and use of subtractive IMAC for removing processing enzymes. Typical recoveries were 75-90% for the enzymatic processing and subtractive IMAC. The integrated process holds promises for use in large-scale production of pharmaceutical proteins because of a simple overall design, use of robust and inexpensive matrices, and use of enzymes of either recombinant or plant origin.

Active recombinant rat dipeptidyl aminopeptidase I (cathepsin C) produced using the baculovirus expression system

An active form of rat dipeptidyl aminopeptidase I (DPPI, cathepsin C) was obtained by heterologous expression in insect cells. Baculoviruses carrying a cDNA sequence encoding the entire rat DPPI precursor was used to infect High Five cells in a serum-free medium. Recombinant DPPI (rDPPI) was secreted into the medium from which it was purified by a combination of ammonium sulfate fractionation, hydrophobic interaction chromatography (HIC), and ion-exchange chromatography. A polyhistidine-tagged form of the enzyme (HT-rDPPI) was purified from the medium by immobilized metal affinity chromatography (IMAC). In vivo activation of native rat DPPI involves at least three chain cleavages per subunit and the ability of the expression system to imitate this processing was investigated. Both rDPPI and HT-rDPPI were secreted into the medium as unprocessed and inactive proenzymes and gradually converted into their active forms in the medium. This process was not completed at the time of harvest but mature enzyme processed similarly to native rat and human DPPI could be obtained by incubating the eluates from the HIC and IMAC columns at pH 4.5 and 5 degrees C for 18-40 h. The yield of purified and matured enzyme was approximately 50 mg/liter, and it was shown that rDPPI and HT-rDPPI were active against both a dipeptide-p-nitroanilide substrate and human growth hormone N-terminally extended with an Ala-Glu dipeptide.

Bradykinin and muscle stretch alter contralateral cat neck muscle spindle output

The objective of this study was to investigate the activity of primary and secondary muscle spindle afferents (MSAs) in neck muscles, when the contralateral splenius or trapezius muscles were (1) exposed to i.m. injection of bradykinin (BK) (6-86 microg/ml), (2) stretched, (3) stretched during exposure to BK or (4) stretched after exposure to BK. It was found that injection of BK, muscle stretch and the combination of the two stimuli significantly excited primary and secondary MSAs via reflex effects onto static fusimotor neurones. BK, alone, and in combination with muscle stretch, induced more frequent, potent and long lasting effects as compared to muscle stretch. The effects of muscle stretch was significantly increased after exposure of BK, indicating that stretch-sensitive nerve-endings within neck muscles are sensitised by BK. The results are discussed in relation to the disturbances in motor co-ordination and proprioception found in patients suffering from chronic muscle pain in the cervical region.

Convective warming blankets improve peroperative heat preservation in congenital heart surgery

Peroperative heat preservation, following hypothermic cardiopulmonary bypass (CPB) in children, has always been a challenge to the anaesthetist. We studied the efficiency of a convective heating system on peroperative heat preservation in 50 children undergoing congenital heart surgery. Twenty-five children, rewarmed by CPB and heating mattress, were randomly selected (Group 1). Another 25 children, rewarmed by CPB, heating mattress and convective warming blankets in addition (Group 2), were selected so the two groups were comparable regarding age, weight and anaesthetic management. The central and peripheral temperatures were measured during bypass, at the end of bypass and at the end of operation. A retrospective evaluation showed that during bypass the peripheral temperature was significantly lower in Group 2 than in Group 1, with no significant difference in central temperature. At the end of bypass there was no significant difference between the two groups. At the end of operation the central and peripheral temperatures were significantly higher in Group 2. In conclusion convective warming blankets are effective in keeping or even raising the temperature following congenital heart surgery.

Alterations in information transmission in ensembles of primary muscle spindle afferents after muscle fatigue in heteronymous muscle

This study showed that fatigue of the ipsilateral medial gastrocnemius muscle caused a clear-cut reduction in the ability of ensembles of primary muscle spindle afferents from the lateral gastrocnemius muscle to discriminate between muscle stretches of varying amplitude. The results were probably caused by reflex-mediated effects from chemosensitive group III and IV afferents onto the gamma-motoneurons projecting to lateral gastrocnemius muscle spindles. The experiments were conducted on seven cats anaesthetized with alpha-chloralose and a total of 41 primary muscle spindle afferents from the lateral gastrocnemius were registered. Afferents were simultaneously recorded in ensembles of three to 10 afferents. A method based on principal component analysis and algorithms for quantification of stimulus discrimination in ensembles of muscle afferents was used prior to, immediately following and five or more minutes after muscle fatigue had been induced to the ipsilateral medial gastrocnemius muscle. It is well established that the primary muscle spindle afferents play an important role in proprioception and kinaesthesia. Therefore the decrease in the accuracy of the information transmitted by ensembles of primary muscle spindle afferents caused by fatigue in an ipsilateral muscle implies concomitant effects on proprioception and kinaesthesia.