Isolation and characterization of 26- and 30-kDa rat liver proteins immunoreactive to anti-sterol carrier protein-2 antibodies

Although the existing literature suggests that the sterol carrier protein-2 (SCP-2) gene has only two initiation sites encoding for a 58- and a 15-kDa protein, respectively, this does not explain the profusion of other putative SCP-2-related proteins detectable on Western blotting. Two of these additional anti-SCP-2 immunoreactive proteins, 13.2 and 46 kDa, appear due to proteolytic processing of the two gene transcripts. However, the origin of additional immunoreactive rat liver proteins near 26 and 30 kDa is unclear. The latter proteins were consistently detected on Western blotting by three independent types of polyclonal antisera: anti-13.2-kDa SCP-2, anti-synthetic peptide from the amino-terminus of the 13.2-kDa SCP-2, and Protein A affinity-purified anti-synthetic peptide to the amino-terminus of 13.2-kDa SCP-2. To resolve whether the 26- and 30-kDa proteins are SCP-2 gene products, each protein was isolated from rat liver and purified to homogeneity as indicated by Tricine-SDS polyacrylamide gel electrophoresis, isoelectric focusing, and/or mass spectroscopy. Their masses, determined by MALDI-TOF mass spectroscopy, were 25.7 and 29.8 kDa, respectively. However, the mass spectral data were not consistent with either protein being an SCP-2 gene product. Peptide mass mapping of the 25.7-kDa protein revealed identity to the rat 25,784.79-Da glutathione-S-transferase. Furthermore, neither the mass nor the amino acid composition of the 29.8-kDa protein correlated with any SCP-2 gene product or dimerized SCP-2 gene product. A database search of the amino acid composition identified the protein as rat carbonic anhydrase. In summary, although the 26- and 29.8-kDa proteins may share some common epitopes with the 13.2-kDa SCP-2, they were not SCP-2 gene products.

The role of incision design and location in the healing processes of alveolar ridges and implant host sites

This research examined the nature and role of a linea alba, found consistently at the crest of edentulous ridges in dogs. Angiovist dye was used to outline the microvasculature in these regions. The findings demonstrated a zone of avascularity directly beneath each linea alba. When novel incision designs were used in the gingivae and the outlined mucoperisteal flaps were elevated and then replaced, alterations in underlying bone morphology were noted. In a subsequent study during which implants were placed, a direct relationship was noted between incision design and level of pericervical bone support.

Extracellular levels of dopamine and its metabolite 3,4-dihydroxy-phenylacetic acid measured by microdialysis in the corpus striatum of conscious AS/AGU mutant rats

The AS/AGU rat is a mutant derived from the Albino Swiss (AS) strain. It is characterized by an ungainly, staggering gait, hind limb rigidity, whole body tremor and, in older animals, difficulty in initiating movement. As and AS/AGU males aged three, six and nine months (n=6 per group) were used to estimate the levels of dopamine and its metabolites in the extracellular fluid of the caudate-putamen. The results indicate a profound loss of dopamine in the extracellular fluid at all age points examined, together with an increase in the concentration of the metabolite 3,4-dihydroxyphenylacetic acid. It is suggested that these changes reflect a defect of dopaminergic neuron function which may underlie the motor disorder seen in these animals.

Intravenous anaesthesia: manual infusion schemes versus TCI systems

Propofol was first used to induce and maintain anaesthesia in the early 1980s. Several infusion regimens were described, some based on pharmacokinetic predictions. Advances in computing technology subsequently have allowed the development of portable target controlled infusion devices, with drugs delivered to achieve specific predicted target blood propofol concentrations. Assessments of propofol target controlled infusion systems in clinical practice and comparisons of 'Diprifusor' target controlled infusion systems with manual infusion are reviewed here.

[Cerebral microembolism detected by transcranial Doppler ultrasonography]

The clinical diagnosis of brain embolism has traditionally been based on evidence suggesting a potential embolic source. However, it is now possible to detect circulating cerebral microemboli by means of transcranial Doppler ultrasound. We explain the theory behind microembolus detection, and discuss initial clinical experience of this method. During invasive cardiovascular investigations and surgery this method can warn the physician that microemboli are entering the cerebral circulation, and preventive measures can be taken. Cerebral microemboli are quite often detected in stroke prone patients, and their presence probably indicates increased risk of stroke. In the acute phase of ischemic stroke, microembolus detection may help to decide the etiology and the source of the emboli. When microemboli are detected in cases of acute embolic stroke, serial detections can be performed which, in future studies, might be of help when evaluating the effect of the treatment.

Consensus on microembolus detection by TCD. International Consensus Group on Microembolus Detection

Transcranial Doppler ultrasound is capable of detecting microembolic material, both gaseous and solid, within the intracranial cerebral arteries. To avoid discrediting this promising and exciting new technique, experts in this field met in January 1997 in Frankfurt, Germany, to discuss the limitations and problems of embolus detection and to determine guidelines for its proper use in clinical practice, as well as in scientific investigations. In particular, the authors suggest that studies report the following parameters: (1) ultrasound device, (2) transducer type and size, (3) insonated artery, (4) insonation depth, (5) algorithms for signal intensity measurement, (6) scale settings, (7) detection threshold, (8) axial extension of sample volume, (9) fast Fourier transform (FFT) size (number of points used), (10) FFT length (time), (11) FFT overlap, (12) transmitted ultrasound frequency, (13) high-pass filter settings, and (14) recording time. There was agreement that no current system of automatic embolus detection has the required sensitivity and specificity for clinical use.

Air-filled ultrasound contrast agents do not damage the cerebral microvasculature or brain tissue in rats

RATIONALE AND OBJECTIVES

Air microemboli may damage the cerebral microvasculature. The aim of this study was to evaluate the safety of ultrasound contrast agents composed of air microspheres with regard to cerebral damage when administered into the arterial system (ie, when not filtered by the capillary system of the lungs).

METHODS

Three experimental methods were used in 75 rats after injection of either Albunex, Echovist, or Levovist into the left heart ventricle. The alkaline phosphatase (ALP) method to demonstrate small segmental brain capillary and arteriolar dilatations (SCADs), intravenous injections of Evans blue and fluorescence microscopy to detect increased vascular permeability (blood-brain barrier damage), and histologic examination of the brain to detect microinfarction. Intracardiac injections of saline, air, and corn oil were used as controls.

RESULTS

Brain microinfarcts and SCADs formation of the brain microvasculature occurred only after control injections with corn oil. None of the brains from animals that received ultrasound contrast agent showed gross discoloration, as an indication of increased vascular permeability, with the Evans blue/fluorescence microscopy method. Definite leakage of Evans blue occurred only after large doses (150 microL) of air.

CONCLUSIONS

This study indicates that ultrasound contrast media composed of air microspheres do not cause lesions of the brain microvasculature or parenchyma.

Safety and tolerability of cyclosporine and cyclosporine microemulsion during 18 months of follow-up in stable renal transplant recipients: a report of the Canadian Neoral Renal Study Group

BACKGROUND

There has been concern that the increased drug exposure associated with treatment with cyclosporine microemulsion (CsA-ME) would lead to an increase in adverse events.

METHODS

The long-term safety and tolerability of conventional cyclosporine (CsA) and CsA-ME were compared in a randomized, multicenter, pharmacoepidemiologic study involving 1097 stable renal transplant patients after 18 months of follow-up.

RESULTS

No significant difference was seen in change in serum creatinine or calculated creatinine clearance between the two groups. Episodes of deterioration in renal function (change in serum creatinine > or = 20%) were categorized with the following results for CsA-ME versus CsA, respectively: acute rejection, 4.5% vs. 4.5%; chronic rejection, 8% vs. 11%; CsA nephrotoxicity, 12% vs. 7% (P=0.008); transient changes, 17% vs. 12%; other causes, 4% vs. 6%. During the first 6 months of the study, a transient increase in the incidence of gastrointestinal and neurological adverse events was seen in the CsA-ME group compared with the CsA group. Up to 18 months, patients in the CsA group reported significantly fewer hearing and vestibular disorders, but more cardiovascular problems than those in the CsA-ME group (P=0.035).

CONCLUSIONS

Tolerance to CsA and CsA-ME was similar. Renal function over 18 months was not adversely affected by the increased drug exposure with CsA-ME, although there was a transient increase in nephrotoxicity. The frequency of acute and chronic rejection did not change.

Age changes in dopamine levels in the corpus striatum of Albino Swiss (AS) and AS/AGU mutant rats

The AS/AGU rat is characterised by an ungainly, staggering gait, hind-limb rigidity, whole body tremor and (in older animals) difficulty in initiating movement. Brains of AS and AS/AGU males aged between 3 and 12 months (n = 10 per group) were sectioned transversely on a cryostat (-20 degrees C) to produce two successive cut faces (corresponding approximately to Bregma +1.2 and -0.5 mm) and 1 mm diameter x 1 mm deep micropunches were taken from four areas of the caudate-putamen. Levels of dopamine in all four areas (measured by HPLC-ECD followed by protein estimation) peaked at around 6 months and then declined in AS and AS/AGU rats. In the dorsal and lateral caudate-putamen, dopamine levels were significantly reduced in AS/AGU rats compared to AS controls from 6 months onwards. This provides further evidence that the AS/AGU mutant has impairment of its striatal dopaminergic systems.

Subcellular distribution of SERCA and calcium-activated ATPase in rabbit and human urinary bladder smooth muscle

Previous studies have demonstrated that calcium storage and release from IP3-dependent sites in the sarcoplasmic reticulum play an important role in the contractile response of the rabbit urinary bladder to both field stimulation (mediated via neurotransmitter release) and bethanechol (direct muscarinic stimulation). In view of the importance of SERCA (see text) in urinary bladder smooth muscle function, we studied the distribution of SERCA by two methods; using Western blotting to quantitate the protein concentration and by enzyme analysis using thapsigargin to specifically inhibit SERCA. Rabbit and human samples of urinary bladder smooth muscle were homogenized and the homogenate separate into three particulate fractions by different centrifugation: the cell wall-nuclear, mitochondrial, and microsomal. The protein concentration of these three particulate fractions was determined and the SERCA protein level quantitated by Western blotting using SERCA-2 antibodies. The calcium ATPase activity was quantitated using standard enzymatic analysis and the thapsigargin sensitivity determined. The results demonstrated that (1) the concentration of SERCA was significantly greater in the microsomal fraction than in either of the other fractions for both rabbit and human bladder smooth muscle; (2) the enzymatic activities of both total calcium-activated ATPase and thapsigargin-sensitive calcium ATPase were evenly divided among the three fractions, and (3) the enzymatic activity of both total calcium-activated ATPase and thapsigargin-sensitive calcium ATPase of the rabbit exceeded that of the human. In conclusion, the distribution of SERCA and calcium ATPase of the rabbit bladder smooth muscle was similar to that in the human bladder smooth muscle, although activities in rabbit were significantly greater than those of human tissue.

Enforced Bcl-2 expression inhibits antigen-mediated clonal elimination of peripheral B cells in an antigen dose-dependent manner and promotes receptor editing in autoreactive, immature B cells

The mechanisms that establish immune tolerance in immature and mature B cells appear to be distinct. Membrane-bound autoantigen is thought to induce developmental arrest and receptor editing in immature B cells, whereas mature B cells have shortened lifespans when exposed to the same stimulus. In this study, we used Emu-bcl-2-22 transgenic (Tg) mice to test the prediction that enforced expression of the Bcl-2 apoptotic inhibitor in B cells would rescue mature, but not immature, B cells from tolerance induction. To monitor tolerance to the natural membrane autoantigen H-2Kb, we bred 3-83mudelta (anti-Kk,b) Ig Tg mice to H-2(b) mice or to mice expressing transgene-driven Kb in the periphery. In 3-83mudelta/bcl-2 Tg mice, deletion of autoreactive B cells induced by peripheral Kb antigen expression in the liver (MT-Kb Tg) or epithelia (KerIV-Kb Tg), was partly or completely inhibited, respectively. Furthermore, Bcl-2 protected peritoneal B-2 B cells from deletion mediated by acute antigen exposure, but this protection could be overcome by higher antigen dose. In contrast to its ability to block peripheral self-tolerance, Bcl-2 overexpression failed to inhibit central tolerance induced by bone marrow antigen expression, but instead, enhanced the receptor editing process. These studies indicate that apoptosis plays distinct roles in central and peripheral B cell tolerance.

Cerebral microembolic signals during cardiopulmonary bypass surgery. Frequency, time of occurrence, and association with patient and surgical characteristics

BACKGROUND AND PURPOSE

We sought to determine the number of cerebral microembolic signals (MES) and their time of occurrence during the two most frequent types of cardiopulmonary bypass (CPB) surgery: coronary artery bypass grafting (CABG) and cardiac valve replacement (VR). Furthermore, we sought to examine the association between MES, patient characteristics, and intraoperative parameters.

METHODS

Forty-two patients were studied, 15 of whom had CABG and 27 VR. Cerebral MES were detected with the use of transcranial Doppler monitoring of the right middle cerebral artery.

RESULTS

Cerebral MES were detected in all patients. The number was significantly higher during VR (median, 1048) than during CABG (median, 82) (P < .001). In VR patients, 85% of the MES were detected when the heart regained effective ejection. During CABG, the highest number was detected when the aorta was cross-clamped (18%) and on release of the side clamp (13%). The numbers of MES during the period when the aorta was cross-clamped and in association with surgical procedures were not significantly different in the two patient groups. The total number of MES was inversely correlated to nasopharyngeal temperature (P < .01).

CONCLUSIONS

A significantly higher number of cerebral MES were detected during VR than during CABG. The highest number occurred in VR patients when effective heart ejection was regained and in CABG patients when the aorta was cross-clamped and on release of the side clamp. The total number of MES increased at lower nasopharyngeal temperatures. Transcranial Doppler monitoring may alert the surgical team when emboli enter the cerebral circulation during CPB surgery, thus allowing preventive measures to be taken.

Effect of temperature and cardiopulmonary bypass on the pharmacokinetics of remifentanil

Sixteen patients undergoing coronary revascularization requiring cardiopulmonary bypass received remifentanil 2 micrograms kg-1 or 5 micrograms kg-1 by infusion over 1 min after sternotomy but before commencing cardiopulmonary bypass, during hypothermic cardiopulmonary bypass and during cardiopulmonary bypass after rewarming. Hypothermic cardiopulmonary bypass reduced the clearance of remifentanil by an average of 20%, and this was attributed to the effect of temperature on blood and tissue esterase activity. Reductions in arterial pressure occurred with administration of both doses during normothermia only.

A comparison of intensive neurodevelopmental therapy plus casting and a regular occupational therapy program for children with cerebral palsy

The purpose of this research was to evaluate the combined effect of intensive neurodevelopmental therapy (NDT) and casting in improving hand function, quality of upper-extremity movement and range of motion in children aged between 18 months and 4 years with cerebral palsy (CP). A randomized crossover design was used to evaluate the difference between intensive NDT plus casting and a less intensive regular occupational therapy (OT) program. Blinded assessments of hand function, quality of upper-extremity movement, and parents' perception of hand-function performance were carried out at baseline, 4 months (end of first intervention period), 6 months (after a 2-month 'washout' period), and 10 months (end of second intervention period). Analysis of the outcomes revealed no significant differences in hand function, quality of upper-extremity movement, or parents' perception of hand-function performance between the two treatment groups-intensive NDT plus casting or regular OT programs. There does not appear to be any beneficial effect of an increased amount of therapy for the children in this study.

Expression and characterization of bryodin 1 and a bryodin 1-based single-chain immunotoxin from tobacco cell culture

Bryodin 1 (BD1) is a potent ribosome-inactivating protein (RIP) isolated from the plant Bryonia dioica. It is relatively nontoxic in rodents (LD50 > 40 mg/kg) and represents a potential improvement over other RIPs and bacterial toxins that have been used in immunotoxins. Recombinant BD1, expressed in Escherichia coli, localizes to insoluble inclusion bodies necessitating denaturation and refolding steps to generate active protein. In this report, BD1 was expressed as a soluble recombinant protein in tobacco cell culture (ntBD1) and purified to near homogeneity with yields of up to 30 mg/(L of culture). The protein synthesis inhibition activity of ntBD1 was identical to that of both native BD1 isolated from the roots of B. dioica and recombinant BD1 expressed in E. coli. Toxicology analysis showed that ntBD1 was well tolerated in rats at doses that cannot be achieved with most other toxin components of immunotoxins. Additionally, a single-chain immunotoxin composed of BD1 fused to the single-chain Fv region of the anti-CD40 antibody G28-5 (ntBD1-G28-5 sFv) was expressed in tobacco tissue culture as a soluble protein and was specifically cytotoxic toward CD40 expressing non-Hodgkin's lymphoma cells in vitro. These data indicate that tobacco tissue culture is a viable system for soluble expression of BD1 and BD1-containing immunotoxins.

Subcellular distribution of SERCA and calcium-activated ATPase in rabbit and human urinary bladder smooth muscle

Previous studies have demonstrated that calcium storage and release from IP-3-dependent sites in the sarcoplasmic reticulum play an important role in the contractile response of the rabbit urinary bladder to both field stimulation (mediated via neurotransmitter release) and bethanechol (direct muscarinic stimulation). In view of the importance of SERCA in urinary bladder smooth muscle function, we studied the distribution of SERCA by two methods: using Western blotting to quantitate the protein concentration and by enzyme analysis using thapsigargin to specifically inhibit SERCA. Rabbit and human samples of urinary bladder smooth muscle were homogenized and the homogenate separated into three particulate fractions by differential centrifugation: nuclear-cell wall, mitochondrial, and microsomal. The protein concentration of these three particulate fractions was determined and the SERCA protein level quantitated by Western blotting using SERCA-2 antibodies. The calcium-ATPase activity was quantitated using standard enzymatic analysis and the thapsigargin sensitivity determined. The results demonstrated that: (1) the concentration of SERCA was significantly greater in the microsomal fraction than in either of the other fractions for both rabbit and human bladder smooth muscle; (2) the enzymatic activities of both total calcium-activated ATPase and thapsigargin-sensitive calcium ATPase were evenly divided among the three fractions, and (3) the enzymatic activity of both total calcium-activated ATPase and thapsigargin-sensitive calcium ATPase of the rabbit exceeded that of the human. In conclusion, the distribution of SERCA and calcium-ATPase of the rabbit bladder smooth muscle was similar to that in the human bladder smooth muscle, although activities in rabbit were significantly greater than those of human tissue.

An oral history project in mental health nursing

The main aim of this study was to produce material which would support, or alternatively challenge the content of a piece of historical writing, based largely on primary archival sources. The method chosen was to replicate and develop an earlier oral history project, which was carried out to discover and report on trained nurses who could offer their impressions of both the practical and theoretical frameworks of psychiatric care. The work described here took that project a stage further by focusing on a single organization, and developing the line of inquiry by adding topics of contemporary interest, such as gender issues, ethnicity, the management of violence and nurses' roles in treatment. Apart from comparisons and contrasts with the previous study, subsidiary interest was to reflect on the intrinsic value and continuing relevance of the material, or the lack of it. The process section considers the problems and dynamics of the interview situation, and how this may have affected the material produced and what this implied for the interpretation. The study confirms an assumption of the usefulness of oral history, as a record, additional to the written documents, which enriches the descriptions of historical processes.

Hospital infant formula discharge packages. Do they affect the duration of breast-feeding?

OBJECTIVE

To determine whether the duration of breast-feeding is affected by the contents of the hospital discharge package.

DESIGN

A randomized clinical trial with 2 experimental interventions (a discharge package containing a manual breast pump only and a discharge package containing a commercially prepared infant formula and a manual breast pump) and a control group who received a commercially prepared infant formula discharge package only. Sociodemographic characteristics and information concerning prior births (including feeding methods) were obtained from each mother within 48 hours of her infant's birth. Sources of influence on the mother's feeding decision, maternal attitudes concerning breast-feeding, and maternal feeding preferences were also assessed.

PARTICIPANTS

The sample consisted of 763 women who had given birth who were admitted to the maternal-fetal unit of a midwestern community hospital.

MAIN OUTCOME MEASURES

Information concerning current method of infant feeding was obtained from telephone interviews conducted at 2-week intervals until the infant was 16 weeks old. The data were analyzed using descriptive statistics, multivariate analysis of variance, logistic regression analysis, and survival analysis.

RESULTS

The content of the hospital discharge package did not affect whether the mother engaged in exclusive or partial breast-feeding during the 16-week follow-up interval. However, there was some evidence that providing formula samples at discharge from the hospital increased the duration of exclusive breast-feeding compared with providing a manual breast pump.

CONCLUSION

This study does not support the assumption that inclusion of infant formula in hospital discharge packages decreases the duration of breast-feeding.

Intercenter agreement in reading Doppler embolic signals. A multicenter international study

BACKGROUND AND PURPOSE

Different frequencies of asymptomatic Doppler embolic signals have been reported in studies. There has been concern that different criteria for identification may account for some of this variation. A previous reproducibility study between two centers found good agreement, but no studies among large numbers of centers have been performed. We performed an international reproducibility study among nine centers, each of which had published recent studies of embolic signal detection in peer-reviewed journals.

METHODS

Each center performed blinded analysis of a taped audio Doppler signal composed of transcranial Doppler middle cerebral artery recordings from 6 patients with symptomatic carotid artery stenosis. The exact time of any embolic signal was recorded. Six centers also measured the intensity increase of any embolic signals detected. Interobserver agreement was determined by a method based on the proportion of specific agreement.

RESULTS

Seven centers reported between 39 and 55 signals, but one center reported 142 embolic signals. The probability of agreement between observers was .678, which rose to .791 when the data from the highest reporting center were excluded. Introducing a decibel threshold resulted in a significant increase in the probability of agreement; a decibel threshold of > 7 dB resulted in a probability of agreement of .902. Intensity measurements made by different centers were usually highly correlated, but this was not always the case, and 3 of the 15 correlations were not significant. The absolute values of the intensities measured varied between centers by as much as 40%.

CONCLUSIONS

Although most centers report similar numbers of embolic signals, some use less specific criteria and report more events. The use of a decibel threshold improves reproducibility. However, intensity thresholds developed by one center cannot be directly transferred without validation to another center; differing methods of measurement are being used, and this results in different intensity values for the same embolic signals, even when the same equipment is used.

Development and reliability of a system to classify gross motor function in children with cerebral palsy

To address the need for a standardized system to classify the gross motor function of children with cerebral palsy, the authors developed a five-level classification system analogous to the staging and grading systems used in medicine. Nominal group process and Delphi survey consensus methods were used to examine content validity and revise the classification system until consensus among 48 experts (physical therapists, occupational therapists, and developmental pediatricians with expertise in cerebral palsy) was achieved. Interrater reliability (kappa) was 0.55 for children less than 2 years of age and 0.75 for children 2 to 12 years of age. The classification system has application for clinical practice, research, teaching, and administration.