A systematic review of N-of-1 trials and single case experimental designs in physiotherapy for musculoskeletal conditions

BACKGROUND

Single Case Experimental Designs (SCEDs) are especially useful for small heterogeneous samples. Their role in evaluation of physiotherapy interventions for musculoskeletal conditions has not been systematically reviewed.

OBJECTIVES

Systematically review use, purpose, and outcomes of SCEDs for physiotherapy interventions for musculoskeletal conditions.

DATA SOURCES

Electronic databases and grey literature, searched using pre-defined terms.

STUDY SELECTION OR ELIGIBILITY CRITERIA

Studies of human participants enrolled in eligible SCEDs (individual or a series).

STUDY APPRAISAL AND SYNTHESIS METHODS

We extracted study characteristics, analytic methods and results, synthesising these descriptively. We used RoBiN-T scale to assess risk of bias.

RESULTS

We included 19 SCEDs comprising 92 participants, with wide variability in design, methodology, analysis and in conditions and interventions evaluated. 95% of participants responded favourably to the tested intervention. Overall risk of bias was high, due to poor internal validity, especially regarding randomisation, blinding, inter-rater agreement and measurement of treatment adherence. Visual analysis alone was performed in 55% of studies. Assessment of provider and participant satisfaction was limited.

CONCLUSIONS AND IMPLICATIONS

of key findings: SCEDs may be well-suited to evaluation of physiotherapy interventions for musculoskeletal conditions, but the risk of bias in studies to date is high. Following SCED guidelines to minimize the risk of bias and maximise clinical usefulness is recommended.

A Consistent Lack of Consistency in Defining the Acute and Chronic Phases of Peyronie's Disease: A Review of the Contemporary Literature

INTRODUCTION

Treatment recommendations for Peyronie's Disease (PD) differ based on whether a patient is in the acute/active versus chronic/stable phase of the disease, yet there are no agreed upon criteria for defining these clinical entities.

OBJECTIVES

To review the criteria used to define acute and chronic phase PD in modern PD intervention studies.

METHODS

We performed a search engine review to identify indexed publications for PD intervention studies and review articles / meta-analyses from the year 2011-2020. Outcomes results were catalogued and summarized across articles. As a result of the substantial heterogeneity of outcome measures and follow-up intervals, meta-analytic techniques were not applied to the data analysis.

RESULTS

We identified a total of 104 studies that met inclusion criteria and had available information for review (n = 79 primary intervention studies; n = 25 review articles/meta-analyses/guidelines). Among the queried studies, we were unable to identify a consensus with respect to the criteria used to define acute and chronic phases of PD. 33% of primary intervention studies did not specifically define their criteria for acute and chronic phase PD, despite referencing these populations as part of the inclusion criteria in many instances. Studies used heterogenous criteria including total symptom duration, duration of "stable" symptoms, and presence/absence of pain.

CONCLUSION

Due to varying definitions across the literature, we were unable to create a standardized definition of acute and chronic phase Peyronie's in terms of time. Our findings emphasize the need for greater consensus in defining the treatment cohorts with future studies that assess treatment for men with PD.

Chronic lymphocytic leukemia/small lymphocytic lymphoma presenting as acute renal failure

Lymphoma of the urinary bladder is quite rare, accounting for a small percentage of all bladder neoplasms. Here we discuss the case of a 68-year-old male patient who initially presented with acute renal failure and severe bilateral hydronephrosis on ultrasound. Cross-sectional imaging further revealed a diffusely thickened bladder wall with extensive retroperitoneal and mesenteric lymphadenopathy. Bladder biopsies ultimately led to a diagnosis of stage IV chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). This is a rare instance of upper tract dilatation being the first sign of a widely disseminated hematologic malignancy.

Personalised treatments for acute whiplash injuries: A pilot study of nested N-of-1 trials in a multiple baseline single-case experimental design

BACKGROUND

Whiplash associated disorder (WAD), a common and disabling condition, incurs huge burden and costs to Australia. Yet, current treatments for whiplash are not very effective; improved outcomes are urgently needed. Clinical guidelines recommend simple analgesia (paracetamol and non-steroidal anti-inflammatory drugs) but there have been no trials of guideline-recommended drugs. This study will investigate the effectiveness of evidence-based advice (EBA), paracetamol, naproxen, and both paracetamol and naproxen, in reducing daily neck pain and preventing chronic neck pain after whiplash injury.

METHODS

This study is a pilot series of multi-cycle, double-blinded, randomised N-of-1 trials, nested in a multiple baseline design. The design will comprise three baselines of 5, 8 or 11 days duration. Post enrolment, participants will be randomly assigned to one of the baselines. Fifteen participants with acute (<2 weeks) Grade II WAD, experiencing at least moderate pain (NRS: ≥ 5/10), and at risk of poor recovery will be recruited from hospitals in Queensland, Australia, and through local physiotherapists. Patients will receive EBA plus a randomised sequence of three cycles of ten day treatment triplets (paracetamol designated as a C phase, naproxen, designated as a D phase, and both paracetamol and naproxen, designated as an E phase).

DISCUSSION

We will test the effects of different treatments on the primary outcome of average neck pain intensity collected daily and at 4 and 7 months post-injury. Secondary outcomes, including disability, depression, post-traumatic stress symptoms, pain catastrophizing, and feasibility of study procedures, will also be evaluated. The results of this study will inform a larger trial aiming to strengthen the evidence on EBA and simple analgesics for WAD.

TRIAL REGISTRATION

Clinical Trials Primary Registry: Australian and New Zealand Clinical Trials Registry.

CLINICAL TRIAL REGISTRATION NUMBER

ACTRN12618001291279.

DATE OF REGISTRATION

31/07/2018.

PRIMARY TRIAL SPONSOR

The University of Queensland, Brisbane QLD 4072 Australia.

FUNDING

The University of Queensland.

Pregabalin versus placebo in targeting pro-nociceptive mechanisms to prevent chronic pain after whiplash injury in at-risk individuals - a feasibility study for a randomised controlled trial

BACKGROUND

Whiplash-associated disorders (WAD) are an enormous and costly burden to Australian society. Up to 50% of people who experience a whiplash injury will never fully recover. Whiplash is resistant to treatment and no early management approach has yet been shown to prevent chronic pain. The early presence of central sensitization is associated with poor recovery. Pregabalin's effects on central sensitization indicate the potential to prevent or modulate these processes after whiplash injury and to improve health outcomes, but this has not been investigated. This paper describes the protocol for a feasibility study for a randomised controlled trial of pregabalin plus evidence-based advice compared to placebo plus evidence-based advice for individuals with acute whiplash injury who are at risk of poor recovery.

METHODS

This double blind, placebo-controlled randomised feasibility study will examine the feasibility and potential effectiveness of pregabalin and evidence-based advice (intervention) compared to placebo and evidence-based advice (control) for individuals with acute whiplash injury at risk of poor recovery. Thirty participants (15 per group) aged 18-65 years with Grade II WAD, within 48 hours of injury and currently experiencing at least moderate pain (NRS: ≥ 5/10) will be recruited from Emergency Departments of public hospitals in Queensland, Australia. Pregabalin will be commenced at 75 mg bd and titrated up to 300 mg bd as tolerated for 4 weeks followed by 1 week of weaning.

RESULTS

The feasibility of trial procedures will be tested, as well as the potential effect of the intervention on the outcomes. The primary outcome of neck pain intensity at 3 months from randomisation will be compared between the treatment groups using standard analysis of variance techniques.

DISCUSSION

Feasibility and potential effectiveness data will inform an appropriately powered full trial, which if successful, will provide an effective and cost-effective intervention for a costly and treatment resistant condition. It will also have implications for the early management of other traumatic conditions beyond whiplash.

TRIAL REGISTRATION

Clinical Trials Primary Registry: Australian and New Zealand Clinical Trials Registry.

CLINICAL TRIAL REGISTRATION NUMBER

ACTRN12617000059369 . Date of Registration: 11/01/2017. Primary Trial Sponsor: The University of Queensland, Brisbane QLD 4072 Australia.

Structural analysis of IPC zeolites and related materials using positron annihilation spectroscopy and high-resolution argon adsorption

Precise pore size analysis of isoreticular series of UTL related zeolites is performed using high-resolution argon adsorption and positron annihilation spectroscopy.

Effect of different aerodynamic time trial cycling positions on muscle activation and crank torque

To reduce air resistance, time trial cyclists and triathletes lower their torso angle. The aim of this study was to investigate the effect of lowering time trial torso angle positions on muscle activation patterns and crank torque coordination. It was hypothesized that small torso angles yield a forward shift of the muscle activation timing and crank torque. Twenty-one trained cyclists performed three exercise bouts at 70% maximal aerobic power in a time trial position at three different torso angles (0°, 8°, and 16°) at a fixed cadence of 85 rpm. Measurements included surface electromyography, crank torques and gas exchange. A significant increase in crank torque range and forward shift in peak torque timing was found at smaller torso angles. This relates closely with the later onset and duration of the muscle activation found in the gluteus maximus muscle. Torso angle effects were only observed in proximal monoarticular muscles. Moreover, all measured physiological variables (oxygen consumption, breathing frequency, minute ventilation) were significantly increased with lowering torso angle and hence decreased the gross efficiency. The findings provide support for the notion that at a cycling intensity of 70% maximal aerobic power, the aerodynamic gains outweigh the physiological/biomechanical disadvantages in trained cyclists.

The effect of time trial cycling position on physiological and aerodynamic variables

To reduce aerodynamic resistance cyclists lower their torso angle, concurrently reducing Peak Power Output (PPO). However, realistic torso angle changes in the range used by time trial cyclists have not yet been examined. Therefore the aim of this study was to investigate the effect of torso angle on physiological parameters and frontal area in different commonly used time trial positions. Nineteen well-trained male cyclists performed incremental tests on a cycle ergometer at five different torso angles: their preferred torso angle and at 0, 8, 16 and 24°. Oxygen uptake, carbon dioxide expiration, minute ventilation, gross efficiency, PPO, heart rate, cadence and frontal area were recorded. The frontal area provides an estimate of the aerodynamic drag. Overall, results showed that lower torso angles attenuated performance. Maximal values of all variables, attained in the incremental test, decreased with lower torso angles (P < 0.001). The 0° torso angle position significantly affected the metabolic and physiological variables compared to all other investigated positions. At constant submaximal intensities of 60, 70 and 80% PPO, all variables significantly increased with increasing intensity (P < 0.0001) and decreasing torso angle (P < 0.005). This study shows that for trained cyclists there should be a trade-off between the aerodynamic drag and physiological functioning.

Acute management of symptomatic nephrolithiasis

Over half a million patients present to emergency departments and nearly 3 million patients visit healthcare providers annually due to problems associated with urolithiasis. Despite updated guidelines from the American Urological Association and European Association of Urology for the evaluation and management of nephrolithiasis, considerable variability still exists regarding treatment for acute symptomatic upper urinary tract stones. Therefore, this article will review the current evaluation and management of acute symptomatic nephrolithiasis. Initial management includes analgesia and antiemetics. Additionally, a urinalysis and creatinine are required laboratory evaluations. Acute imaging with a non-contrast computed tomography (CT) scan is the diagnostic imaging modality of choice. However, concerns over radiation exposure have led towards low-dose and even ultra-low-dose protocols for the detection of urinary calculi. Low-dose non-contrast CT scans are now standard of care for the initial diagnosis of renal colic in patients with a body mass index ≤ 30. Medical expulsive therapy is recommended for patients with a ureteral calculus < 10 mm and no signs of infection. Emergency urinary decompression is mandatory for a specific subset of patients, especially those with infection. Although limited data exists, emergency ureteroscopy or even shock wave lithotripsy may also be therapeutic options.

Optimal cycling time trial position models: aerodynamics versus power output and metabolic energy

The aerodynamic drag of a cyclist in time trial (TT) position is strongly influenced by the torso angle. While decreasing the torso angle reduces the drag, it limits the physiological functioning of the cyclist. Therefore the aims of this study were to predict the optimal TT cycling position as function of the cycling speed and to determine at which speed the aerodynamic power losses start to dominate. Two models were developed to determine the optimal torso angle: a 'Metabolic Energy Model' and a 'Power Output Model'. The Metabolic Energy Model minimised the required cycling energy expenditure, while the Power Output Model maximised the cyclists׳ power output. The input parameters were experimentally collected from 19 TT cyclists at different torso angle positions (0-24°). The results showed that for both models, the optimal torso angle depends strongly on the cycling speed, with decreasing torso angles at increasing speeds. The aerodynamic losses outweigh the power losses at cycling speeds above 46km/h. However, a fully horizontal torso is not optimal. For speeds below 30km/h, it is beneficial to ride in a more upright TT position. The two model outputs were not completely similar, due to the different model approaches. The Metabolic Energy Model could be applied for endurance events, while the Power Output Model is more suitable in sprinting or in variable conditions (wind, undulating course, etc.). It is suggested that despite some limitations, the models give valuable information about improving the cycling performance by optimising the TT cycling position.

The relationship between temperament, gender, and childhood dysfunctional voiding

OBJECTIVE

Dysfunctional voiding (DV) is an extremely common pediatric complaint. The goal of this study was to examine the relationship between DV and childhood temperament.

METHODS

Information about the voiding behaviors and temperaments of 50 children was examined using a case-control model. Caregivers were asked to fill out the Children's Behavior Questionnaire in order to rate their child on the dimensions of surgency, negative affect, and effortful control. The relationship between DV and these dimensions was then evaluated.

RESULTS

Males with DV were found to have lower effortful control than males with normal voiding habits. Females with DV did not demonstrate a difference in effortful control, but did demonstrate a higher rate of surgency.

CONCLUSIONS

The results suggest that temperament does have an association with DV. These findings are in line with temperamental associations with other externalizing trouble behaviors and may inform potential treatment strategies for DV.

Laypersons' expectations of recovery and beliefs about whiplash injury: a cross-cultural comparison between Australians and Singaporeans

BACKGROUND

Beliefs and expectations are thought to influence outcome following whiplash injury. Studies have proposed a link between rates of chronic whiplash and laypersons' expectations about outcome following a motor vehicle accident. The prevalence of chronic whiplash is relatively high in Australia and apparently low in Singapore. This study's objectives were to compare laypersons' beliefs and expectations of recovery of whiplash injury in Brisbane and Singapore and to assess the effect of demographic factors on whiplash beliefs.

METHODS

A cross-sectional study using online surveys was conducted on adult Internet users in Brisbane (Australia) and Singapore. The 14-item whiplash beliefs questionnaire (WBQ) was used to evaluate whiplash beliefs. Two additional items assessed expectations of recovery. Individual items of WBQ, WBQ score and expectations of recovery were analysed. Stratified analysis was performed to adjust for sampling bias due to quota sampling.

RESULTS

A total of 402 participants from Singapore and 411 participants from Brisbane, Australia, completed the survey. While participants from Singapore demonstrated slightly more negative whiplash beliefs than participants from Brisbane [t(811)  = -5.72; p < 0.0001], participants from both samples were similar in their expectations of quick recovery and return to normal activities following whiplash injury. Only gender had a significant effect on whiplash beliefs [estimated marginal means of WBQ score for men = 21.5; standard error (SE) = 0.20; women = 22.5; SE = 0.20; F(1,810)  = 11.2; p = 0.001].

CONCLUSIONS

Laypersons' expectations of recovery and beliefs about whiplash injury in Brisbane and Singapore were generally similar and mostly positive. Our results demonstrate that cultural differences reflected by laypersons' beliefs may not reflect the differences in prevalence of chronic whiplash between countries.

Recombinant MG53 protein modulates therapeutic cell membrane repair in treatment of muscular dystrophy

Mitsugumin 53 (MG53), a muscle-specific TRIM family protein, is an essential component of the cell membrane repair machinery. Here, we examined the translational value of targeting MG53 function in tissue repair and regenerative medicine. Although native MG53 protein is principally restricted to skeletal and cardiac muscle tissues, beneficial effects that protect against cellular injuries are present in nonmuscle cells with overexpression of MG53. In addition to the intracellular action of MG53, injury to the cell membrane exposes a signal that can be detected by MG53, allowing recombinant MG53 protein to repair membrane damage when provided in the extracellular space. Recombinant human MG53 (rhMG53) protein purified from Escherichia coli fermentation provided dose-dependent protection against chemical, mechanical, or ultraviolet-induced damage to both muscle and nonmuscle cells. Injection of rhMG53 through multiple routes decreased muscle pathology in the mdx dystrophic mouse model. Our data support the concept of targeted cell membrane repair in regenerative medicine, and present MG53 protein as an attractive biological reagent for restoration of membrane repair defects in human diseases.

Laparoendoscopic single-site varicocele repair in adolescents-initial experience at a single institution

BACKGROUND AND PURPOSE

Laparoendoscopic single-site (LESS) varicocele repair is a modification of standard laparoscopic varicocele repair that uses a single port. We describe our initial experience with LESS varicocele repair.

PATIENTS AND METHODS

During a 1-year period, all patients who presented for varicocele repair underwent LESS repair. We evaluated our initial experience by determining operative time, operative and postoperative complications, and overall cost of the procedure.

RESULTS

A total of 11 adolescents underwent LESS varicocele repair. There were no intraoperative complications, and there were no conversions to open surgery or traditional laparoscopy. Estimated blood loss was minimal, and mean operative time was 66.9 minutes (range 48-91 min). The varicocele was corrected in all cases. During the 4 to 14 month follow-up, there was no recurrence, testis atrophy, or hernia in any patient. One subclinical hydrocele developed postoperatively that has not been repaired.

CONCLUSION

Our experience with LESS varicocele repair in adolescents suggests it to be a safe and effective method for varicocele repair in adolescents.

Does the presence of sensory hypersensitivity influence outcomes of physical rehabilitation for chronic whiplash? – A preliminary RCT

Patients with chronic whiplash associated disorders present with varied sensory, motor and psychological features. In this first instance it was questioned whether a multimodal program of physical therapies was an appropriate management to be broadly prescribed for these patients when it was known that some would have sensory features suggestive of a notable pain syndrome. A randomised controlled trial was conducted with 71 participants with persistent neck pain following a motor vehicle crash to explore this question. Participants were randomly allocated to receive either a multimodal physiotherapy program (MPT) or a self-management program (SMP) (advice and exercise). In the randomisation process, participants were stratified according to the presence or not of widespread mechanical or cold hyperalgesia. The intervention period was 10 weeks and outcomes were assessed immediately following treatment. Even with the presence of sensory hypersensitivity in 72.5% of subjects, both groups reported some relief of neck pain and disability (Neck Disability Index) and it was superior in the group receiving multimodal physiotherapy (p=0.04). Post-hoc observations however suggested that relief was marginal in the subgroup with both widespread mechanical and cold hyperalgesia. Further research is required to test the validity of this sub-group observation and to test the effect of the intervention in the long term.

Analysis of air contrast barium enema, computed tomographic colonography, and colonoscopy: prospective comparison

BACKGROUND

The usefulness of currently available colon imaging tests, including air contrast barium enema (ACBE), computed tomographic colonography (CTC), and colonoscopy, to detect colon polyps and cancers is uncertain. We aimed to assess the sensitivity of these three imaging tests.

METHODS

Patients with faecal occult blood, haematochezia, iron-deficiency anaemia, or a family history of colon cancer underwent three separate colon-imaging studies--ACBE, followed 7-14 days later by CTC and colonoscopy on the same day. The primary outcome was detection of colonic polyps and cancers. Outcomes were assessed by building an aggregate view of the colon, taking into account results of all three tests.

FINDINGS

614 patients completed all three imaging tests. When analysed on a per-patient basis, for lesions 10 mm or larger in size (n=63), the sensitivity of ACBE was 48% (95% CI 35-61), CTC 59% (46-71, p=0.1083 for CTC vs ACBE), and colonoscopy 98% (91-100, p<0.0001 for colonoscopy vs CTC). For lesions 6-9 mm in size (n=116), sensitivity was 35% for ACBE (27-45), 51% for CTC (41-60, p=0.0080 for CTC vs ACBE), and 99% for colonoscopy (95-100, p<0.0001 for colonoscopy vs CTC). For lesions of 10 mm or larger in size, the specificity was greater for colonoscopy (0.996) than for either ACBE (0.90) or CTC (0.96) and declined for ACBE and CTC when smaller lesions were considered.

INTERPRETATION

Colonoscopy was more sensitive than other tests, as currently undertaken, for detection of colonic polyps and cancers. These data have important implications for diagnostic use of colon imaging tests.

Responses to a clinical test of mechanical provocation of nerve tissue in whiplash associated disorder

Involvement of nerve tissue may contribute to the persistence of pain following a whiplash injury. This study aimed to investigate responses to the brachial plexus provocation test (BPPT) in 156 subjects with chronic whiplash associated disorder (WAD) with and without associated arm pain and 95 asymptomatic control subjects. The range of elbow extension (ROM) and visual analogue scale (VAS) pain scores were measured. Subjects with chronic WAD demonstrated significantly less ROM and higher VAS scores with the BPPT than the asymptomatic subjects (P<0.001). These effects occurred bilaterally. Within the whiplash population, subjects whose arm pain was reproduced by the BPPT demonstrated significantly less ROM on both the symptomatic and asymptomatic sides when compared to the whiplash subjects whose arm pain was not reproduced by the BPPT (P=0.003) and significantly less ROM and higher VAS scores than those whiplash subjects with no arm pain (P=0.003, 0.01). Only the whiplash subjects whose arm pain was reproduced by the BPPT demonstrated differences between the symptomatic and asymptomatic sides. These generalized hyperalgesic responses to the BPPT support the hypothesis of central nervous system hypersensitivity as contributing to persistent pain experienced by WAD patients.

The effect of musculoskeletal pain on motor activity and control

Aberrant movement patterns and postures are obvious to clinicians managing patients with musculoskeletal pain. However, some changes in motor function that occur in the presence of pain are less apparent. Clinical and basic science investigations have provided evidence of the effects of nociception on aspects of motor function. Both increases and decreases in muscle activity have been shown, along with alterations in neuronal control mechanisms, proprioception, and local muscle morphology. Various models have been proposed in an attempt to provide an explanation for some of these changes. These include the vicious cycle and pain adaptation models. Recent research has seen the emergence of a new model in which patterns of muscle activation and recruitment are altered in the presence of pain (neuromuscular activation model). These changes seem to particularly affect the ability of muscles to perform synergistic functions related to maintaining joint stability and control. These changes are believed to persist into the period of chronicity. This review shows current knowledge of the effect of musculoskeletal pain on the motor system and presents the various proposed models, in addition to other shown effects not covered by these models. The relevance of these models to both acute and chronic pain is considered. It is apparent that people experiencing musculoskeletal pain exhibit complex motor responses that may show some variation with the time course of the disorder.

Cervical mobilisation: concurrent effects on pain, sympathetic nervous system activity and motor activity

Recent findings that spinal manual therapy (SMT) produces concurrent hypoalgesic and sympathoexcitatory effects have led to the proposal that SMT may exert its initial effects by activating descending inhibitory pathways from the dorsal periaqueductal gray area of the midbrain (dPAG). In addition to hypoalgesic and sympathoexcitatory effects, stimulation of the dPAG in animals has been shown to have a facilitatory effect on motor activity. This study sought to further investigate the proposal regarding SMT and the PAG by including a test of motor function in addition to the variables previously investigated. Using a condition randomised, placebo-controlled, double blind, repeated measures design, 30 subjects with mid to lower cervical spine pain of insidious onset participated in the study. The results indicated that the cervical mobilisation technique produced a hypoalgesic effect as revealed by increased pressure pain thresholds on the side of treatment (P=0.0001) and decreased resting visual analogue scale scores (P=0.049). The treatment technique also produced a sympathoexcitatory effect with an increase in skin conductance (P<0.002) and a decrease in skin temperature (P=<0.02). There was a decrease in superficial neck flexor muscle activity (P<0.0002) at the lower levels of a staged cranio-cervical flexion test. This could imply facilitation of the deep neck flexor muscles with a decreased need for co-activation of the superficial neck flexors. The combination of all findings would support the proposal that SMT may, at least initially, exert part of its influence via activation of the PAG.

Pressure pain thresholds of upper limb peripheral nerve trunks in asymptomatic subjects

BACKGROUND AND PURPOSE

Palpation of peripheral nerve trunks has been advocated as a method of assessing the presence of hyperalgesic nerve tissue as a contributing factor to pain syndromes in musculoskeletal disorders of the upper quadrant. This study investigated, in the first instance, the pressure pain thresholds of the median, radial and ulnar nerve trunks of the upper limb in healthy, asymptomatic subjects.

METHOD

Forty-five male and 50 female healthy volunteer subjects participated in this study which involved measurement of pressure pain thresholds by use of pressure algometry bilaterally over the three peripheral nerve trunks in the upper limbs.

RESULTS

Pressure pain thresholds were shown to be lowest in the median nerve (p = 0.001) and lower in female subjects (p = 0.001). Laterality (p = 0.077) or the age of the subject (p = 0.254) did not significantly influence results.

CONCLUSIONS

The study demonstrated differences in pressure pain thresholds in the three nerve trunks of the upper limb. These findings should be taken into account when interpreting the findings of nerve palpation in musculoskeletal upper quadrant disorders.

Leukocystatin, a new Class II cystatin expressed selectively by hematopoietic cells

We describe a new cystatin in both mice and humans, which we termed leukocystatin. This protein has all the features of a Class II secreted inhibitory cystatin but contains lysine residues in the normally hydrophobic binding regions. As determined by cDNA library Southern blots, this cystatin is expressed selectively in hematopoietic cells, although fine details of the distribution among these cell types differ between the human and mouse mRNAs. In addition, we have determined the genomic organization of mouse leukocystatin, and we found that in contrast to most cystatins, the leukocystatin gene contains three introns. The recombinant proteins corresponding to these cystatins were expressed in Escherichia coli as N-terminal glutathione S-transferase or FLAGTM fusions, and studies showed that they inhibited papain and cathepsin L but with affinities lower than other cystatins. The unique features of leukocystatin suggests that this cystatin plays a role in immune regulation through inhibition of a unique target in the hematopoietic system.

The effect of corticosteroids and other antineoplastic agents on the generation of leukocyte migration inhibition factor

We have shown that hydrocortisone in physiological concentrations can inhibit the production of leukocyte migration inhibition factor (LMIF), but does not diminish the action of this lymphokine. Other agents tested failed to influence LMIF production. Inhibition of LMIF production by corticosteroids was influenced by the nature of the stimulus used for the production as an effect could be seen with PHA or Con A, but not Staphylococcal enterotoxin A (SEA). Production of LMIF was promptly restored after removal of the steroids. Furthermore, addition of a calcium ionophore to PHA restored the production of LMIF even in the presence of corticosteroids. In contrast, addition of exogenous IL-2 did not correct the defect in lymphokine secretion. We believe that inhibition of the production of LMIF by steroid may lead to defective granulocytic function and thus, predispose to infection.

Toxicity with intravenous injection of crude marijuana extract

Intravenous injection of crude marijuana extract led to development of an acute illness with multisystem involvement. Gastrointestinal manifestations consisted of severe vomiting, diarrhea, and crampy abdominal pain. Hypotension, tachycardia, and peripheral vasodilation constituted the main cardiovascular manifestations of the disease. Moderate azotemia and oliguria, presumed to be of prerenal origin, were present and rapidly resolved with administration of intravenous fluids. Hematologic manifestations consisted of leukocytosis with a left shift, thrombocytopenia, prolonged partial thromboplastin time, increased fibrin degradation products, and positive protamine sulfate test. The observed coagulation abnormalities may suggest intravascular coagulation. C3, C4, and total hemolytic complement were reduced, suggesting possible activation of the complement system. Hyperventilation, hypoxemia, pulmonary edema, obstructive, and restrictive pulmonary function abnormalities and bilateral pleural effusions highlighted the pulmonary manifestations of the disease. Rhadbomyolysis and mild hepatic function abnormalities were also present. All observed abnormalities reversed in a few days with no significant sequelae.