SEARCH · PubMed Health

Results for “Protocol”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,099 records · Page 61Linked to original sources

PubMed2006

Differences between the effects of three plasticity inducing protocols on the organization of the human motor cortex.

Several experimental protocols induce lasting changes in the excitability of motor cortex. Some involve direct cortical stimulation, others activate the somatosensory system and some combine motor and sensory stimulation. The effects usually are measured as changes in amplitude of the motor-evoked-potential (MEP) or short-interval intracortical inhibition (SICI) elicited by a single or paired pulses of transcranial magnetic stimulation (TMS). Recent work has also tested sensorimotor organization within the motor cortex by recording MEPs and SICI during short periods of vibration applied to single intrinsic hand muscles. Here sensorimotor organization is focal: MEPs increase and SICI decreases in the vibrated muscle, whilst the opposite occurs in neighbouring muscles. In six volunteers we compared the after effects of three protocols that lead to lasting changes in cortical excitability: (i) paired associative stimulation (PAS) between a TMS pulse and an electrical stimulus to the median nerve; (ii) motor practice of rapid thumb abduction; and (iii) sensory input produced by semicontinuous muscle vibration, on MEPs and SICI at rest and on the sensorimotor organization. PAS increased MEP amplitudes, whereas vibration changed sensorimotor organization. Motor practice had a dual effect and increased MEPs as well as affecting sensorimotor organization. The implication is that different protocols target different sets of cortical circuits. We speculate that protocols that involve repeated activation of motor cortical output lead to lasting changes in efficacy of synaptic connections in output circuits, whereas protocols that emphasize sensory inputs affect the strength of sensory inputs to motor circuits.

Adult↗

PubMed2006

Isolation and enumeration of circulating endothelial cells by immunomagnetic isolation: proposal of a definition and a consensus protocol.

BACKGROUND: Circulating endothelial cells (CECs) have been identified as markers of vascular damage in a variety of disorders, such as myocardial infarction, vasculitis, and transplantation. CD146-driven immunomagnetic isolation has gained widespread use, but the technique is hampered by the lack of a definition of CECs and the absence of a consensus for their enumeration. AIM: To evaluate several variables influencing immunomagnetic isolation of CECs, formulate a definition for CECs and propose a consensus protocol for their enumeration. METHODS: We devised a protocol based on CD146-driven immunomagnetic isolation and a subsequent confirmatory step with Ulex-Europaeus-Lectin-1 staining. In a multi-center effort, we evaluated the preanalytical and analytical phases of this protocol. We evaluated the effects of storage, anticoagulation and density centrifugation, and compiled previous experience with this technique. RESULTS: Our protocol permitted unequivocal identification of CECs with acceptable reproducibility. There was an effect of storage time in that median cell numbers declined to only 87.5% of their baseline values during 24 h of storage at 4 degrees C. Recovery was lower with citrate than with ethylene-diamine tetra-acetic acid after 4 h of storage; density centrifugation was also associated with lower recovery. We provide a comprehensive list of technical recommendations and potential pitfalls. Finally, based on our experience with this protocol and a recent consensus workshop, we formulated a working definition for CECs. CONCLUSION: Our work represents an important step toward consensus regarding the CECs. Our recommendations represent the experience of three major centers and should now be scrutinized by others in the field.

CD146 Antigen↗

PubMed2006

Subclinical rejection associated with chronic allograft nephropathy in protocol biopsies as a risk factor for late graft loss.

Chronic allograft nephropathy (CAN) in protocol biopsies is associated with graft loss while the association between subclinical rejection (SCR) and outcome has yielded contradictory results. We analyze the predictive value of SCR and/or CAN in protocol biopsies on death-censored graft survival. Since 1988, a protocol biopsy was done during the first 6 months in stable grafts with serum creatinine <300 micromol/L and proteinuria <1 g/day. Biopsies were evaluated according to Banff criteria. Borderline changes and acute rejection were grouped as SCR. CAN was defined as presence of interstitial fibrosis and tubular atrophy. Mean follow-up was 91 +/- 46 months. Sufficient tissue was obtained in 435 transplants. Biopsies were classified as normal (n = 186), SCR (n = 74), CAN (n = 110) and SCR with CAN (n = 65). Presence of SCR with CAN was associated with old donors, percentage of panel reactive antibodies and presence of acute rejection before protocol biopsy. Cox regression analysis showed that SCR with CAN (relative risk [RR]: 1.86, 95% confidence interval [CI]: 1.11-3.12; p = 0.02) and hepatitis C virus (RR: 2.27, 95% CI: 1.38-3.75; p = 0.01) were independent predictors of graft survival. In protocol biopsies, the detrimental effect of interstitial fibrosis/tubular atrophy on long-term graft survival is modulated by SCR.

Adolescent↗

PubMed2004

A cleaning protocol for rotary nickel-titanium endodontic instruments.

BACKGROUND: The cleaning of endodontic and all dental instruments prior to sterilization is a prerequisite for their processing for re-use. This study aimed to develop a clinically practical cleaning protocol for rotary nickel-titanium (NiTi) endodontic files prior to sterilization. METHODS: Cleaning experiments were conducted on six different types of files that had been used on human teeth. The experiments involved three components of mechanical and chemical removal of root canal debris from the files: the use of sponges soaked with chlorhexidine to remove gross debris, pre-soaking, and ultrasonication. After cleaning, the files were immersed in Van Gieson's solution and examined under magnification for stained debris. New unused files were also examined. RESULTS: Macroscopically, there were no instances of visible debris and all files appeared clean after all cleaning sequences. Microscopically, new files showed both stained and unstained debris, and several experimental cleaning regimens produced files that were free of stained debris. Combining elements of the most effective cleaning sequences resulted in a cleaning protocol that predictably produced clean files. CONCLUSIONS: The results do not support the recommendation for the single use of endodontic files based on inability to clean files between uses. Under experimental conditions the cleaning protocol developed rendered rotary NiTi files 100 per cent free of stained debris. The protocol comprises 10 vigorous strokes in a scouring sponge soaked in 0.2 per cent chlorhexidine solution, a 30 minute pre-soak in an enzymatic cleaning solution, 15 minutes ultrasonication in the same solution, and a 20 second rinse in running tap water. The protocol can be applied to all endodontic files.

Chlorhexidine↗

PubMedDate not supplied

The implementation of the AAPM Task Group 21 protocol by the Radiological Physics Center and its implications.

The Radiation Therapy Committee of the American Association of Physicists in Medicine appointed Task Group 21 to write a new protocol for the calibration of high-energy photon and electron therapy beams. This protocol updates the physical parameters used in the calculations and is intended to account for differences in ionization chamber design and some differences between phantom materials that were not considered in previous protocols. This paper discusses how the Radiological Physics Center (RPC) intends to implement the new protocol, the changes required in the RPC calibration techniques, and the magnitude of the change in the RPC calculations of absorbed dose resulting from the implementation of the new protocol. Although the change in the RPC absorbed-dose calculations will be only 0%-2% over the range of photon and electron energies of interest, some institutions using specific dosimetry systems may find their absorbed-dose calculations changing by 4% or more.

Calibration↗

PubMedDate not supplied

Calibration of high-energy photon and electron beams for radiotherapy using AAPM 1983 and IAEA 1987 dosimetry protocols.

To follow up on the theoretical comparison of the IAEA 1987 and AAPM 1983 protocols for dosimetry calibration of high-energy photons and electrons [Med Phys. 18, 26-35 (1991)], results of a set of dosimetric measurements made with a Farmer type PTW and Capintec ionization chambers in solid water, PMMA, and polystyrene phantoms and exposed to a 4 MV photon beam from a Varian Clinac 4S at Yale, a 10 MV photon beam and 6 and 15 MeV electron beams from a Varian Clinac 1800 at Phelps Radiation Center, University of Connecticut, and a 25 MV photon beam from a Sagittaire at Yale, are presented. Because different methods are used for the determination of electron beam energies, the values of mean electron energy determined by the two protocols are different by up to 8%. However, for dose inter-comparison, the overall agreement between the two protocols is within 1% in most cases, with a maximum discrepancy of 3.3% in one case. For photons, the IAEA results are smaller than the AAPM results by 0.7% on the average, while maximum discrepancies are in the range of -0.4%-(-1%). In the case of 15 MeV electrons, the discrepancies between the two protocols are found to be in the range of -0.1%-1% and have an average value of 0.5%. In contrast to the above, a large discrepancy is observed between the two protocols for 6 MeV electrons. Depending upon the choice of phantom and ion chamber, this discrepancy is found to be in the range of -0.1%-(-3.3%).(ABSTRACT TRUNCATED AT 250 WORDS)

Calibration↗

PubMed2004

Protocol for specific isolation of virulent strains of Vibrio vulnificus serovar E (biotype 2) from environmental samples.

The eel pathogen Vibrio vulnificus biotype 2 comprises at least three serovars, with serovar E being the only one involved in both epizootics of eel vibriosis and sporadic cases of human infections. The virulent strains of this serovar (VSE) have only been recovered from clinical (mainly eel tissue) sources. The main objective of this work was to design and validate a new protocol for VSE-specific isolation from environmental samples. The key element of the new protocol is the broth used for the first step (saline eel serum broth [SEB]), which contains eel serum as a nutritive and selective component. This approach takes advantage of the ability of VSE cells to grow in eel serum and thus to separate themselves from the pool of competitors. The growth yield in SEB after 8 h of incubation was 1,000 times higher for VSE strains than for their putative competitors (including biotype 1 strains of the species). The selective and differential agar Vibrio vulnificus medium (VVM) was selected from five selective media for the second step because it gave the highest plating efficiency not only for the VSE group but also for other V. vulnificus groups, including biotype 3. The entire protocol was validated by field studies, with alkaline peptone water plus VVM as a control. V. vulnificus was isolated by both protocols, but serovar E was only recovered by the new method described here. All selected serovar E isolates were identified as VSE since they were virulent for both eels and iron-overloaded mice and resisted the bactericidal action of eel and iron-overloaded human sera. In conclusion, this new protocol is a suitable method for the isolation of VSE strains from environmental samples and is recommended for epidemiological studies of the pathogenic serovar E.

Animals↗

PubMed1993

Preventing false positives: quantitative evaluation of three protocols for inactivation of polymerase chain reaction amplification products.

False-positive results because of carryover contamination by previously amplified nucleic acids are currently the greatest impediment to routine implementation of nucleic acid amplification protocols. We evaluated three methods for inactivation of a 156-bp Borrelia burgdorferi polymerase chain reaction (PCR) product: (i) post-PCR cross-linking with isopsoralen (IP), (ii) pre-PCR treatment of a dU-containing PCR product with uracil N-glycosylase (UNG), and (iii) post-PCR alkaline hydrolysis (primer hydrolysis) of PCR products synthesized by using primers containing 3' ribose residues. The sensitivities of the PCR performed under the conditions of each protocol were comparable. Inactivation of amplified DNA was highly efficient for all three protocols; the IP and UNG protocols eliminated at least to 3 x 10(9) copies of the product. The primer hydrolysis protocol varied in efficiency depending on the number and position of the 3' ribose residues, but inactivation ranged from 10(4) to 10(9) copies. We conclude that with some modifications, all three systems are effective for eliminating amplified DNA products. Routine implementation of at least one method should help to avoid false-positive results because of carryover contamination.

Base Sequence↗

PubMed1996

New laboratory guidelines for serologic diagnosis of Lyme disease: evaluation of the two-test protocol.

Recent guidelines established by the Association of State and Territorial Public Health Laboratory Directors (ASTPHLD) and the U.S. Centers for Disease Control and Prevention (CDC) recommend the use of a two-test protocol for the serologic diagnosis of Lyme disease (LD). The two-test protocol relies on a sensitive screening test, which is followed by specific immunoglobulin M (IgM) and/or IgG immunoblotting (IB), depending on the date of disease onset, of all samples with equivocal and positive screening test results. We evaluated a commercially available IgM-IgG enzyme-linked immunosorbent assay (ELISA) and separate IB tests for IgM and IgG antibodies to Borrelia burgdorferi as candidate assays for the two-test protocol. Serum samples obtained from healthy controls (n = 29), from patients with diagnoses or laboratory findings associated with serologic cross-reactivity to LD (n = 24), and from patients with well-documented early- and late-stage LD provided by the CDC and the College of American Pathologists (n = 53) were examined to determine each assay's individual sensitivity and specificity. No false-positive results were detected among the healthy controls by either ELISA or IB, whereas four false-positive ELISA results were recorded within the cross-reactive group. None of these sera, however, were positive for either IgM or IgG reactivity according to IB band criteria. With regard to the patients with LD, we determined the sensitivity and specificity of the ELISA to be 96 and 100%, respectively, compared with the reference data provided for these specimens. When we compared our IB results with data from CDC, the assay sensitivity and specificity were 80 and 96.2%, respectively, for IgM and 81.8 and 95.8%, respectively, for IgG. Pursuant to this evaluation we assessed the suitability of the two-test protocol by performing a retrospective analysis using clinical history to define samples as positive or negative for LD. We determined clinical sensitivity and specificity for all study subjects (n = 112) to be 50 and 100%, respectively. A reduction in the clinical sensitivity of the two-test protocol was associated with a lack of antibody response or seroconversion in LD patients treated with antibiotics. We conclude that the CDC-ASTPHLD guidelines provide useful criteria for test performance and interpretation aimed at standardizing the serologic diagnosis of LD.

Borrelia burgdorferi Group↗

PubMed2000

Simplified protocol for pulsed-field gel electrophoresis analysis of Streptococcus pneumoniae.

A variety of pulsed-field gel electrophoresis (PFGE) protocols for the molecular subtyping of Streptococcus pneumoniae have been reported; most are time-consuming and complex. We sought to modify reference PFGE protocols to reduce the time required while creating high-quality gels. Only protocol modifications that resulted in high-quality banding patterns were considered. The following protocol components were modified. Lysis enzymes (lysozyme, mutanolysin, and RNase A) were deleted in a stepwise fashion, and then the lysis buffer was deleted. Lysis and digestion were accomplished in a single step with EDTA and N-lauroyl sarcosine (ES; pH 8.5 to 9.3) incubation at 50 degrees C in the absence of proteinase K. All enzymes except the restriction enzyme were omitted. A minimum incubation time of 6 h was required to achieve high-quality gels. All of the reactions were performed within 9 h, and the total protocol time from lysis to gel completion was reduced from 3 days to only 36 h. Combining lysis and digestion into a single step resulted in a substantial reduction in the time required to perform PFGE for S. pneumoniae. The ES solution may have caused cell lysis by activating N-acetylmuramyl-L-alanine amidase, the pneumococcal autolysin.

Bacterial Typing Techniques↗

PubMed2001

Development of a Canadian standardized protocol for subtyping methicillin-resistant Staphylococcus aureus using pulsed-field gel electrophoresis.

A panel of 24 methicillin-resistant Staphylococcus aureus strains was distributed to 15 laboratories in Canada to evaluate their in-house pulsed-field gel electrophoresis (PFGE) protocols and interpretation criteria. Attempts to compare fingerprint images using computer-aided analysis were not successful due to variability in individual laboratory PFGE protocols. In addition, individual site interpretation of the fingerprint patterns was inadequate, as 7 of 13 sites (54%) made at least one error in interpreting the fingerprints from the panel. A 2-day standardized PFGE protocol (culture to gel image) was developed and distributed to all of the sites. Each site was requested to use the standardized protocol on five strains from the original panel. Thirteen sites submitted gel images for comparisons. The protocol demonstrated excellent reproducibility and allowed interlaboratory comparisons with Molecular Analyst DST software (Bio-Rad) and 1.5% band tolerance.

Bacterial Typing Techniques↗

PubMed1984

Maximum oxygen uptake utilising different treadmill protocols.

The study compared five treadmill protocols (four utilising a motorised, and one a non-motorised, treadmill) on maximum oxygen uptake. The five male and five female subjects, all actively engaged in training, were assigned the tests in random order. Statistical analysis revealed no significant differences between the five protocols for maximal oxygen uptake, maximum ventilation, maximum heart rate and blood lactate inflection point, relative to maximal oxygen uptake. Significant differences were observed between the 3' protocol with incline increments of 1.5% and all other protocols on time to exhaustion (p = less than 0.01) and maximum blood lactate levels (HLA, p = less than 0.05). The results indicate that the protocols used in this study did not significantly influence the maximum oxygen uptake attained.

Exercise Test↗

PubMed2004

A survey of flexibility training protocols and hamstring strains in professional football clubs in England.

OBJECTIVES: To investigate the relation between current flexibility training protocols, including stretching, and hamstring strain rates (HSRs) in English professional football clubs. METHOD: Questionnaire based data on flexibility training methods and HSRs were collected from 30 English professional football clubs in the four divisions during the 1998/99 season. Data were coded and analysed using cross tabulation, correlation, and multiple regression. RESULTS: Flexibility training protocols were characterised by wide variability, with static stretching the most popular stretching technique used. Hamstring strains represented 11% of all injuries and one third of all muscle strains. About 14% of hamstring strains were reinjuries. HSRs were highest in the Premiership (13.3 (9.4)/1000 hours) with the lowest rates in Division 2 (7.8 (2.9)/1000 hours); values are mean (SD). Most (97%) hamstring strains were grade I and II, two thirds of which occurred late during training/matches. Forwards were injured most often. Use of the standard stretching protocol (SSP) was the only factor significantly related to HSR (r = -0.45, p = 0.031) in the correlation analysis, suggesting that the more SSP is used, the lower the HSR. About 80% of HSR variability was accounted for by stretching holding time (SHT), SSP, and stretching technique (STE) in the multiple regression equation: HSR = 37.79 - (0.33SHT + [corrected] 10.05SSP + 2.24STE) +/- 2.34. SHT (negatively correlated with HSR) was the single highest predictor, and accounted for 30% of HSR variability, and an additional 40% in combination with SSP. CONCLUSIONS: Flexibility training protocols in the professional clubs were variable and appeared to depend on staffing expertise. Hamstring stretching was the most important training factor associated with HSR. The use of SSP, STE, and SHT are probably involved in a complex synergism which may reduce hamstring strains. Modification of current training patterns, especially stretching protocols, may reduce HSRs in professional footballers.

England↗

PubMed1999

Performance of research ethics committees in Spain. A prospective study of 100 applications for clinical trial protocols on medicines.

OBJECTIVES: To review the characteristics and performance of research ethics committees in Spain in the evaluation of multicentre clinical trial drug protocols. DESIGN: A prospective study of 100 applications. SETTING: Forty-one committees reviewing clinical trial protocols, involving 50 hospitals in 25 cities. MAIN MEASURES: Protocol-related features, characteristics of research ethics committees and evaluation dynamics. RESULTS: The 100 applications involved 15 protocols (of which 12 were multinational) with 12 drugs. Committees met monthly (except one). They had a mean number of 12 members, requested a mean of six complete dossiers and nine additional copies of the protocol with a mean deadline of 14 days before the meeting. All applications were approved except three (two of the three were open-label long-term safety trials rejected by the same committee), which were approved by the other committees involved. The mean time from submission to approval was 64 days. The mean time from submission to arrival of the approval document at our offices was 85 days. Twenty-five committees raised queries for 38 of the 97 finally approved applications. Impact of evaluation fee, number of members, queries raised and experience of committees on timings were not statistically significant. CONCLUSION: Obtaining ethical approval is time-consuming. There is much diversity in the research ethics committees' performance. A remarkable delay (> 20 days) exists between the decision and the arrival of the written approval, suggesting administrative or organisational problems.

Analysis of Variance↗

PubMed2006

Which electroencephalography (EEG) for epilepsy? The relative usefulness of different EEG protocols in patients with possible epilepsy.

BACKGROUND AND AIMS: Electroencephalography (EEG) is an essential investigative tool for use in young people with epilepsy. This study assesses the effects of different EEG protocols on the yield of EEG abnormalities in young people with possible new epilepsy. METHODS: 85 patients presenting to the unit underwent three EEGs with differing protocols: routine EEG (r-EEG), sleep-deprived EEG (SD-EEG), EEG carried out during drug-induced sleep (DI-EEG). The yield of EEG abnormalities was compared using each EEG protocol. RESULTS: 98 patients were recruited to the study. Of the 85 patients who completed the study, 33 (39%) showed no discernible abnormality on any of their EEG recordings. 36 patients (43%) showed generalised spike and wave during at least one EEG recording, whereas 15 (18%) had a focal discharge evident at some stage. SD-EEG had a sensitivity of 92% among these patients, whereas the sensitivity of DI-EEG and r-EEG was 58% and 44%, respectively. The difference between the yield from SD-EEG was significantly higher than that from other protocols (p < 0.001). Among the 15 patients showing focal discharges, SD-EEG provoked abnormalities in 11 (73%). r-EEG and DI-EEG each produced abnormalities in 40% and 27%, respectively. 7 patients (47%) had changes seen only after sleep deprivation. In 2 (13%), the only abnormalities were seen on r-EEG. In only 1 patient with focal discharges (7%) was the focal change noted solely after drug-induced sleep. These differences did not reach significance. CONCLUSION: EEG has an important role in the classification of epilepsies. SD-EEG is an easy and inexpensive way of increasing the yield of EEG abnormalities. Using this as the preferred protocol may help reduce the numbers of EEGs carried out in young patients presenting with epilepsy.

Adolescent↗

PubMed2002

Evolution of a protocol for ketamine-induced sedation as an alternative to general anesthesia for interventional radiologic procedures in pediatric patients.

PURPOSE: To establish a protocol for credentialed pediatric radiology nurses, with radiologist supervision, to administer ketamine to induce sedation and analgesia during interventional radiologic procedures. MATERIALS AND METHODS: This study was conducted in two phases. The goal of the first phase was to develop a sedation protocol to replace that of using general anesthesia for specified pediatric interventional procedures. Ketamine was administered intravenously (with intermittent bolus or continuous infusion) or intramuscularly. Sedation induction times, adverse events, doses, and sedation and recovery durations were recorded. In phase 2, the results of phase 1 were reviewed and a formal ketamine protocol was developed. RESULTS: Neither sedation failures nor substantial adverse events occurred in phase 1. Mean duration of all sedations was 52 minutes, and median recovery room time was 0 minutes. In phase 2, the results of phase 1 were reviewed and a sedation protocol was proposed to a hierarchy of hospital committees before final approval from the medical staff executive committee. Subsequently, standard order forms for radiology nurse administration of ketamine with radiologist supervision were prepared for exclusive use by the pediatric interventional radiology department. CONCLUSION: Ketamine-induced sedation may be a safe and effective alternative to general anesthesia for some interventional radiologic procedures in pediatric patients. Collaboration between anesthesia and radiology departments is important for development of a safe and successful ketamine sedation program. To the authors' knowledge, this is the first report describing the intravenous infusion of ketamine for sedation in pediatric patients and the only report describing the establishment of a protocol for ketamine administration by credentialed radiology nurses with radiologist supervision.

Adolescent↗

PubMed1990

Search and nonsearch protocols for radiographic consultation.

Six radiologists, acting as radiograph reviewers, used two different consultation protocols to differentiate among 292 ambiguous chest radiographic findings: 120 simulated nodules and 172 normal findings (previous readers' false-positive reports of nodules). The nonsearch protocol identified each finding (by film location), and reviewers rated the likelihood of each finding's being a pulmonary nodule. The search protocol asked reviewers to report and rate all locations regarded as possible nodules on each radiograph and assigned a default negative rating to any unreported finding (nodule or normal structure). Receiver operating characteristic analyses demonstrated a significantly higher accuracy for each reviewer's search-protocol discriminations between these nodules and ambiguous normal findings. This superiority-of-search result suggests that radiologists' second opinions about suspected lesions might be more accurate when consultants follow a search protocol, independently reviewing radiographs without prior knowledge of the specific findings that concerned the primary radiograph readers.

False Positive Reactions↗

PubMed2006

"Clock-scan" protocol for image analysis.

Comparative analysis of extra- and intracellular distributions of protein markers in immunohistochemical and immunofluorescent studies relies on techniques of image analysis. Line or region of interest pixel intensity scans are methods routinely used. However, although having good spatial resolution, linear pixel intensity scans fail to produce integral image of the cellular distribution of the label. On the other hand, the regions of interest scans have good integrative capacity but low spatial resolution. In this work, we describe a "clock-scan" protocol that, when applied to convex objects (such as neuronal cell bodies and the majority of cells in culture), combines advantages and circumnavigates limitations of the above-mentioned techniques. The protocol 1) collects multiple radial pixel intensity profiles scanned from the cell center to the periphery, 2) scales these profiles according to the cell radius measured in the direction of the scan, and finally, 3) averages these individual profiles into one integral radial pixel intensity profile. Because of scaling, the mean pixel intensity profiles produced by the clock-scan protocol depend on neither the cell size nor, within reasonable limits, the cell shape. This allows direct comparison or, if required, averaging or subtraction of profiles of different cells. We have successfully tested the clock-scan protocol in experiments with immunostained dorsal root ganglion neurons. In addition, the protocol seems to be equally applicable for studies in a variety of other preparations.

Animals↗