Transcriptomes and metabolism define mouse and human MAIT cell populations

Mucosal-associated invariant T (MAIT) cells are a subset of T lymphocytes that respond to microbial metabolites. We defined MAIT cell populations in different organs and characterized the developmental pathway of mouse and human MAIT cells in the thymus using single-cell RNA sequencing and phenotypic and metabolic analyses. We showed that the predominant mouse subset, which produced IL-17 (MAIT17), and the subset that produced IFN-γ (MAIT1) had not only greatly different transcriptomes but also different metabolic states. MAIT17 cells in different organs exhibited increased lipid uptake, lipid storage, and mitochondrial potential compared with MAIT1 cells. All these properties were similar in the thymus and likely acquired there. Human MAIT cells in lung and blood were more homogeneous but still differed between tissues. Human MAIT cells had increased fatty acid uptake and lipid storage in blood and lung, similar to human CD8 T resident memory cells, but unlike mouse MAIT17 cells, they lacked increased mitochondrial potential. Although mouse and human MAIT cell transcriptomes showed similarities for immature cells in the thymus, they diverged more strikingly in the periphery. Analysis of pet store mice demonstrated decreased lung MAIT17 cells in these so-called "dirty" mice, indicative of an environmental influence on MAIT cell subsets and function.

Sentinel lymph node mapping for endometrial cancer improves the detection of metastatic disease to regional lymph nodes

OBJECTIVE

To compare the incidence of metastatic cancer cells in sentinel lymph nodes (SLN) vs. non-sentinel nodes in patients who had lymphatic mapping for endometrial cancer and to determine the contribution of metastases detected on ultrastaging to the overall nodal metastasis rate.

METHODS

All patients who underwent lymphatic mapping for endometrial cancer were reviewed. Cervical injection of blue dye was used in all cases. Sentinel nodes were examined by routine hematoxylin and eosin (H&E), and if negative, by standardized institutional pathology protocol that included additional sections and immunohistochemistry (IHC).

RESULTS

Between 09/2005 and 03/2010, 266 patients with endometrial cancer underwent lymphatic mapping. Sentinel node identification was successful in 223 (84%) cases. Positive nodes were diagnosed in 32/266 (12%) patients. Of those, 8/266 patients (3%) had the metastasis detected only by additional section or IHC as part of SLN ultrastaging. Excluding the 8 cases with positive SLN on ultrastaging only, 24/801 (2.99%) SLN and 30/2698 (1.11%) non-SLN were positive for metastatic disease (p=0.0003).

CONCLUSION

Using a cervical injection for mapping, metastatic cells from endometrial cancer are three times as likely to be detected in SLN than in the non-sentinel nodes. This finding strongly supports the concept of lymphatic mapping in endometrial cancer to fine tune the nodal dissection topography. By adding SLN mapping to our current surgical staging procedures we may increase the likelihood of detecting metastatic cancer cells in regional lymph nodes. An additional benefit of incorporating pathologic ultrastaging of SLN is the detection of micrometastasis, which may be the only evidence of extrauterine spread.

Sputum colour: a useful clinical tool in non-cystic fibrosis bronchiectasis

This study explored the utility of sputum colour in clinically stable patients with bronchiectasis. Interpretation of sputum colour between the doctor and the patient was reliable (intraclass correlation coefficient 0.83 (95% confidence interval 0.76-0.89). Sputum colour predicted bacterial colonisation (5% in mucoid sputum; 43.5% in mucopurulent sputum; 86.4% in purulent sputum; p<0.0001). On multivariate logistic regression analysis, independent factors associated with purulent sputum were bacterial colonisation, varicose or cystic bronchiectasis, forced expiratory volume in 1 s <80% predicted and diagnosis of bronchiectasis aged <45 yrs.

A randomised crossover trial of chest physiotherapy in non-cystic fibrosis bronchiectasis

Regular chest physiotherapy is advocated in non-cystic fibrosis bronchiectasis despite little evidence supporting its routine use. This study aimed to establish the efficacy of regular chest physiotherapy in non-cystic fibrosis bronchiectasis compared with no regular chest physiotherapy. 20 patients not practising regular chest physiotherapy were enrolled in a randomised crossover trial of 3 months of twice daily chest physiotherapy using an oscillatory positive expiratory pressure device compared with 3 months of no chest physiotherapy. The primary end-point was the Leicester Cough Questionnaire (LCQ). Additional outcomes included 24-h sputum volume, forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC), forced expiratory flow at 25-75% of FVC (FEF(25-75%)), maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), exercise capacity, sputum microbiology and St George's Respiratory Questionnaire (SGRQ). The treatment effect was estimated using the differences of the pairs of observations from each patient. There was a significant improvement in all domains and total LCQ score with regular chest physiotherapy (median (interquartile range) total score improvement 1.3 (-0.17-3.25) units; p = 0.002). 24-h sputum volume increased significantly with regular chest physiotherapy (2 (0-6) mL; p = 0.02), as did exercise capacity (40 (15-80) m; p = 0.001) and SGRQ total score (7.77 (-0.99-14.5) unit improvement; p = 0.004). No significant differences were seen in sputum bacteriology, FEV(1), FVC, FEF(25-75%), MIP or MEP. Regular chest physiotherapy in non-cystic fibrosis bronchiectasis has small, but significant benefits.

Validation of the Leicester Cough Questionnaire in non-cystic fibrosis bronchiectasis

Health-related quality of life is a potentially important marker for evaluating existing and new therapies in bronchiectasis. The Leicester Cough Questionnaire (LCQ) is a symptom specific questionnaire designed to assess the impact of cough severity, a major symptom of bronchiectasis. This study aimed to validate the LCQ in bronchiectasis. The validity, responsiveness and reliability of the LCQ were assessed as follows: ability to discriminate severe and mild disease; change in score following antibiotic treatment for exacerbations; repeatability over a 6-month period in stable disease; and comparison with the St George's Respiratory Questionnaire (SGRQ). In total, 120 patients (51 with severe disease, 29 with moderate disease and 40 with mild disease) completed the LCQ and SGRQ. The area under the receiver-operator curve was good for both severe and mild disease (0.84 and 0.80 respectively, p<0.0001). Following 2 weeks' antibiotic treatment, the median LCQ score (interquartile range) improved from 11.3 (9.3-13.7) to 17.8 (15-18.8) (p<0.0001). The LCQ score was repeatable over 6 months in stable disease (intraclass correlation coefficient of 0.96 (95%CI 0.93-0.97), p<0.0001). Correlation between the LCQ and SGRQ scores was -0.7 in both stable disease and exacerbations (p<0.0001). The LCQ can discriminate disease severity, is responsive to change and is reliable for use in non-cystic fibrosis bronchiectasis.

Risk factors for complicated parapneumonic effusion and empyema on presentation to hospital with community-acquired pneumonia

BACKGROUND

The aim of this study was to identify key factors on admission predicting the development of complicated parapneumonic effusion or empyema in patients admitted with community-acquired pneumonia.

METHODS

A prospective observational study of patients admitted with community-acquired pneumonia in NHS Lothian, UK, was conducted. Multivariate regression analyses were used to evaluate factors that could predict the development of complicated parapneumonic effusion or empyema, including admission demographics, clinical features, laboratory tests and pneumonia-specific (Pneumonia Severity Index (PSI), CURB65 (New onset confusion, urea >7 mmol/l, Respiratory rate > or = 30 breaths/min, Systolic blood pressure < 90 mm Hg and/or diastolic blood pressure < or = 60 mm Hg and age > or = 65 years) and CRB65 (New onset confusion, Respiratory rate > or = 30 breaths/min, Systolic blood pressure <90 mm Hg and/or diastolic blood pressure < or = 60 mm Hg and age > or = 65 years)) and generic sepsis scoring systems (APACHE II (Acute Physiology and Chronic Health Evaluation II), SEWS (standardised early warning score) and systemic inflammatory response syndrome (SIRS)).

RESULTS

1269 patients were included in the study and 92 patients (7.2%) developed complicated parapneumonic effusion or empyema. The pneumonia-specific and generic sepsis scoring systems had no value in predicting complicated parapneumonic effusion or empyema. Multivariate logistic regression identified albumin <30 g/l adjusted odds ratio (AOR) 4.55 (95% CI 2.45 to 8.45, p < 0.0001), sodium <130 mmol/l AOR 2.70 (1.55 to 4.70, p = 0.0005), platelet count >400 x 10(9)/l AOR 4.09 (2.21 to 7.54, p < 0.0001), C-reactive protein >100 mg/l AOR 15.7 (3.69 to 66.9, p < 0.0001) and a history of alcohol abuse AOR 4.28 (1.87 to 9.82, p = 0.0006) or intravenous drug use AOR 2.82 (1.09 to 7.30, p = 0.03) as independently associated with development of complicated parapneumonic effusion or empyema. A history of chronic obstructive pulmonary disease was associated with decreased risk, AOR 0.18 (0.06 to 0.53, p = 0.002). A 6-point scoring system using these combined variables had good discriminatory value: area under the receiver operator characteristic curve (AUC) 0.84 (95% CI 0.81 to 0.86, p < 0.0001).

CONCLUSION

This study has identified seven clinical factors predicting the development of complicated parapneumonic effusion or empyema. Independent validation is needed.

Incidence and cytological features of pulmonary hamartomas indeterminate on CT scan

OBJECTIVE

Pulmonary hamartomas have a characteristic heterogeneous radiological appearance. However, when composed predominantly of undifferentiated mesenchymal fibromyxoid component, their homogeneous appearance on computed tomography is indeterminate for malignancy. Rendering an accurate preoperative diagnosis in these cases can alter management. The aim of this study was to determine the incidence and accuracy of cytodiagnosis for hamartomas 'indeterminate' by imaging.

METHODS

We retrospectively reviewed records for hamartomas diagnosed by transthoracic fine needle aspiration (FNA) including immediate impressions and final diagnoses. Cytological features evaluated included the presence of fibromyxoid stroma, bronchioloalveolar cell hyperplasia, fibroadipose tissue, cartilage and smooth muscle.

RESULTS

Eighteen (1.3%) hamartomas were identified from 1355 transthoracic FNAs. The immediate impression was hamartoma in 13 (72%), carcinoid in one (6%), mucinous bronchioloalveolar carcinoma in two (11%) and non-diagnostic in two (11%). The final diagnosis of hamartoma in cases diagnosed as carcinoid, mucinous bronchioloalaveolar carcinoma and non-diagnostic on immediate impression was rendered following assessment of all cytological material.

CONCLUSION

Overall, FNAs are highly reliable for diagnosing hamartomas even when composed principally of undifferentiated mesenchymal fibromyxoid stroma, especially with the aid of all available preparations including Diff-Quik smears, Papanicolaou smears, ThinPreps and cell block material.

An evaluation of employee exposure to volatile organic compounds in three photocopy centers

Personal and area samples from three copy centres were collected in thermal desorption tubes and analyzed using gas chromatography-mass spectrometry. Real-time personal total volatile organic compounds (TVOC) were measured using a data-logging photoionization detector. Fifty-four different VOCs were detected in the area samples. The maximum concentration measured was 1132.0 ppb (toluene, copy center 3, day 1). Thirty-eight VOCs were detected in the personal samples and concentrations ranged from 0.1 ppb (1,1-biphenyl, p-dichlorobenzene, propylbenzene, styrene, and tetrachloroethylene) to 689.6 ppb (toluene). Real-time TVOC measurements indicated daily fluctuations in exposure, ranging from <71 to 21,300 ppb. The time-weighted average exposures for the photocopier operators on days 1 and 2 were 235 and 266 ppb and 6155 and 3683 ppb, in copy centers 2 and 3, respectively. Personal exposure measurements of individual VOCs were below accepted occupational standards and guidelines. For example, the maximum concentration was 0.3% of the permissible exposure limits (toluene, copy center 3). Exposures were highest in copy center 3; this is likely due to the presence of offset printing presses. It is concluded that photocopiers contribute a wide variety of VOCs to the indoor air of photocopy centers; however, exposures are at least 100 times below established standards.

Metastatic colorectal cancer cells induce matrix metalloproteinase release by human monocytes

Matrix metalloproteinases-2 (MMP-2) and -9 (MMP-9) facilitate tumor invasion and metastasis via basement membrane degradation. In colorectal cancer (CRC) specimens, MMP production is largely stromal in origin, implicating monocytes (M phi s) and fibroblasts. We hypothesize that CRC cells induce stromal cell MMP production. This study examines the differential effect of metastatic and non-metastatic CRC cells on M phi MMP production. The human M phi line THP-1 was co-cultured with either a non-metastatic human CRC cell line (SW620-P) or a metastatic clone (SW620-S5) established by serial cecal transplantation of SW620-P in nude mice. Conditioned medium MMP activity and cellular MMP mRNA expression were assessed by gelatinase zymography and Northern blot analysis, respectively. Neither CRC line released MMP-2 or MMP-9. Isolated THP-1 M phi s produced basal levels of both MMP-2 and MMP-9. The level of MMP-9 activity was increased moderately by co-culture of M phi s with the metastatic SW620-S5 clone, but decreased by the non-metastatic SW620-P cells. MMP-2 activity was greatly augmented by co-culturing M phi s with SW620-S5 cells, but was not affected by SW620-P cells. The stimulatory effect of SW620-S5 cells on MMP-2 secretion was confirmed by Western blot analysis. Both isolated and co-cultured M phi s expressed MMP-2 mRNA while SW620-S5 cells under similar conditions did not, implicating M phi s as the source of increased MMP-2 activity. Since the induction of MMP-2 activity was not associated with a parallel increase in M phi MMP-2 mRNA, the modulation of M phi MMP-2 release appears to be post-transcriptionally regulated. Metastatic CRC cells are distinct from non-metastatic cells in their ability to induce M phi MMP release. This observation emphasizes the role of M phi-derived MMPs in facilitating CRC invasion and metastasis and suggests modulation of stromal cell MMP production by CRC cells in a paracrine fashion.

Census adjustment and the distribution of federal spending

In 1989, programs that use population counts to determine the distribution of their funds transferred $236 per capita to state and local governments. If the 1990 census were adjusted to reflect undercounting, about 40% of state and local governments would receive increased grants averaging $56 per miscounted person; other jurisdictions would lose an almost equal amount of grant money. The surprisingly small reallocations arise because 1) total funds allocated by population are essentially fixed; 2) allocations depend on other factors in addition to population; and 3) programs vary as to whether they allocate funds in direct or inverse proportion to population.

Function following partial fibulectomy

The fibula is a valuable source of a bone graft, but because the fibula has a role in lower extremity function, it is important to determine whether partial removal results in dysfunction or other problems. Forty-one patients (48 +/- 10 years of age) had a portion of their fibula removed for a bone graft. At evaluation 27 +/- 8 months later, 24 had no pain, 11 mild pain, and six moderate or severe pain. Sixteen had no complaints of any kind, but four without pain had minor difficulties with vigorous activities, and three complained of ankle swelling. There were no differences in range of motion between the operated and nonoperated side. Average muscle torque was lower on the operated than on the nonoperated side, but this difference was statistically significant only for ankle evertors in men. This study demonstrates that most patients will have subjective complaints and mild muscular weakness after removal of a portion of the fibula.

Neck pain: a long-term follow-up of 205 patients

Two hundred five patients with neck pain were evaluated clinically and roentgenographically for a minimum of 10 years after onset of symptoms. Seventy-nine percent had a decrease in pain, and 43% were free of pain; however, 32% had moderate or severe residual pain. Patients who had been injured and initially had severe pain were the most likely to have an unsatisfactory outcome; however, no other clinical features were of value in predicting the final result. The presence or severity of pain was not related to the presence of degenerative changes, the sagittal diameter of the spinal canal, the degree of cervical lordosis, or to any changes in these measurements over the evaluation period.

Correlations between objective measures of function and a clinical knee rating scale following total knee replacement

Few objective measurements of function, other than range of motion, have been reported for patients with total condylar knee replacement. Moreover, to our knowledge, no studies have been reported which assess the degree of relationship between clinical ratings and measurements of function in these patients. Kinesiologic tests of function and the Hospital for Special Surgery (HSS) Knee Rating Form were used to evaluate 34 patients before and 2 years after 39 total condylar knee replacements. Prosthetic alignment was also evaluated postoperatively. The kinesiologic studies showed postoperative improvement in muscle strength, weight-bearing ability, and use of assistive devices, and in velocity, knee flexion-extension, and lateral head motion during walking. A moderate but significant degree of improvement was measured by the HSS score. Correlation coefficients showed that the postoperative knee rating score was significantly related to almost all of the postoperative objective measurements of function. Correlation coefficients between the prosthetic alignment scores and measurements of function were not statistically significant. The study strengthens the validity of use of the HSS Knee Rating Form as a tool for evaluating functional performance, particularly during the postoperative period.

Roentgenographic findings following anterior cervical fusion

We reviewed the pre- and postoperative lateral cervical roentgenograms in 90 patients who had anterior fusions and compared their findings with age and sex-matched people without neck problems. The average interval from surgery to review was 5 years. Preoperatively, all patients had a higher incidence of degenerative spondylosis at the levels to be fused than their asymptomatic counterparts. Postoperatively, there was no difference in the incidence of degenerative change between the operated and the control group at the levels above and below the fusion with the exception of anterior osteophyte formation which was more frequent in those with fusions.

Comparison of function two years after revision of failed total hip arthroplasty and primary hip arthroplasty

Because of the known high complication rate, it is important for both the patient and physician to know as much as possible about the outcome of revision operations for loosened total hip arthroplasties. This study evaluates the changes in subjective ratings and objective kinesiologic measurements from before revision operations through two years after revision operations. The object is to compare these measurements with the measurements of a group of patients with primary replacements. Both groups of patients showed significant improvement in most parameters from before to after surgery. These parameters included walking performance, hip muscle strength, range of motion, forces applied to canes, and the amount of weight borne on the operated limb during quiet standing. Compared to the control group with primary replacements, the group with revision used more assistive devices, had less pain relief, walked slower, had less hip motion, and had more lateral lurch. While results after revision surgery were not as gratifying as those after primary hip replacement, patients requiring revision can still anticipate substantial improvement.

Shoulder-muscle strength and range of motion following surgical repair of full-thickness rotator-cuff tears

Postoperative measurements of the range of motion and muscle strength of the shoulder and ratings of pain and the ability to perform daily activities were made in fifty-eight patients (sixty-three shoulders) who had a repair of a full-thickness rotator-cuff tear. Postoperatively, the patients had an average of 126 degrees of active flexion of the shoulder and an average of 130 degrees of active abduction. Passive motion averaged 21 degrees more than active motion. The strength of the abductor muscles of the shoulder averaged approximately 86 per cent of normal. Most patients reported marked relief of pain and rated themselves as having mild or no deficits in their ability to perform daily activities. The length of the cuff tear significantly affected the functional results. Short tears (less than 2.5 centimeters) were associated with greater strength and range of motion than were long tears. Fifteen of the nineteen patients who were unable to work preoperatively because of the shoulder returned to work after surgery, but not necessarily to the same type of work that they had done before the onset of the problem with the shoulder.

Antalgic maneuvers during walking in men with unilateral knee disability

The gait of men with unilateral knee disability has not been quantified previously. Interrupted-light photography was used to quantify the gait abnormalities of 35 men whose major disability was unilateral knee pain. The following antalgic maneuvers were found to be common to the gait of these patients: slow and uneven forward progression with lateral lurching toward the painful side, asymmetry in stride and temporal components, and abnormalities in the displacement patterns of most body segments. Subnormal knee motion was found during the stance and swing phases. Because treatment of patients with knee problems is usually directed toward pain relief, an understanding of how pain affects walking performance is important to the clinician when assessing a patient's problem.

Hip function after total vs. surface replacement

Kinesiologic measurements were made in two groups of 20 men before and 6 and 24 months after resurfacing or conventional replacement. Before surgery the group to have resurfacing was younger, had less pain, slightly more hip motion, greater muscle strength, walked faster, and used fewer assistive devices during walking than the group to have the conventional replacement. After surgery, the group with resurfacing maintained its advantage in muscle strength and walking velocity.

Treadmill vs. floor walking: kinematics, electromyogram, and heart rate

To identify the degree of difference between treadmill and floor walking, kinematic, electromyographic (EMG), and heart rate measurements were recorded in seven normal female subjects during walking at three speeds on the treadmill and on the floor. During treadmill walking, subjects tended to use a faster cadence and shorter stride length than during floor walking. In addition the displacements of the head, hip, and ankle in the sagittal plane showed statistically significant differences between floor and treadmill walking. Average EMG activity was usually greater on the treadmill than on the floor; however, this difference was only significant for the quadriceps. Heart rate was significantly higher during fast treadmill walking than floor walking. In general, treadmill walking was not found to differ markedly from floor walking in kinematic measurements or EMG patterns.

Age-related differences in knee muscle strength in normal women

This study provides normal baselines of knee muscle strength for women up to 86 years of age. Knee muscle strength (torque) was measured during maximum isometric and dynamic (isokinetic) contractions in 72 normal healthy women in three age groups between 20 and 86 years. Strength of the oldest group ranged from 56 to 78% of that in the youngest group, depending on knee joint position. Strength values were greater for isometric contractions than for isokinetic contractions (performed at 36 degrees per second) and were approximately twice as great for the extensor as for the flexor muscles. For both muscle groups, the torque generated with the knee in 30 degrees of flexion was usually lower than that generated with the knee at the 45- or 60-degree position. Despite the significant deficit found in the strength of the oldest group, it is likely that this relative weakness would not be detected on routine clinical examination using manual muscle testing.

Functional performance after tibial rotationplasty

We measured muscle strength, joint motion, and gait parameters and determined the electromyographic activities of the ankle and knee during walking, running, and stair-climbing in two children who had had a tibial rotationplasty for osteosarcoma of the distal end of the femur. Both had marked loss of strength in the plantar flexors on the side of the prosthesis compared with the sound side, although electromyographic recordings showed that the rotated calf muscles, to a substantial degree, had assumed the function of extensors of the prosthetic knee. Despite some abnormalities in gait, both children walked at speeds that were comparable to those of normal children. They could also run, climb stairs by stepping up with both limbs, and participate in many recreational activities. The functional abilities of these children suggested that rotationplasty, in patients with a similar lesion, is a worth-while alternative to above-the-knee amputation.

Shoulder motion and muscle strength of normal men and women in two age groups

Normal age- and sex-related standards for shoulder range of motion (ROM) and muscle strength are unavailable in the literature. Active range of shoulder motion and maximum isometric strength (torque) of several shoulder muscle groups were measured in normal healthy men and women between 25 and 36 and between 55 and 66 years of age. Values for joint motion were similar for the two age and sex groups. The strength of the women was 45% to 66% of that in men, and strength of the older subjects was 66% to 93% of that in younger subjects. Strength of the second attempt at contraction was greater than that of the first attempt. Arm dominance did not significantly affect strength values.

Function after revision of failed total hip arthroplasty

Measurements of functional performance were made before and 6 months after 31 primary total hip replacements and 31 total hip revisions for prosthetic loosening. After revision, functional performance returned to levels substantially the same as after primary hip replacement except for greater reliance on canes for patients in the revised group. Ratings of hip status and hip pain were slightly less satisfactory after revision as compared to after the primary operation.

Kinematic and EMG patterns during slow, free, and fast walking

Kinematics and electromyographic (EMG) activity were recorded in seven normal women during walking at slow, free, and fast speeds. Speed-related differences were found in the stride dimensions, temporal components, and most of the simultaneous displacement patterns of body segments measured. For most of the muscles tested, the amplitude of normalized EMG activity decreased as walking speed decreased. The findings emphasize the importance of accounting for the effect of speed itself on measurements of gait.

Gait patterns in above-knee amputee patients: hydraulic swing control vs constant-friction knee components

Multiple displacement patterns, stride dimensions, and temporal components during slow, free-speed, and fast walking were compared in the same seven above-knee amputees using prostheses with constant-friction knee components and using hydraulic swing-control knee components. During walking with the hydraulic-type prostheses, the amputees showed a wider range of walking speeds, improvement in the equality of the durations of successive swing and stance phases, and greater uniformity of forward progression. Improvements toward normal were also seen in several of the displacement patterns of the prosthetic limb during walking with the hydraulic knee. Several gait abnormalities persisted with both types of prostheses.

Kinematic and electromyographic patterns of Olympic race walkers

The performance of two Olympic race walkers was studied during free-speed, fast, and race walking. Measurements of the stride and temporal components of gait, as well as the simultaneous displacement patterns of the body segments, and the electromyographic activity of muscles of the trunk and upper and lower limbs were recorded during the three walking speeds. During the testing, the race walkers achieved an average speed of 12.5 km/hr as compared to the 8.7 km/hr average speed achieved by normal men of the same age during fast walking. Race walking was characterized by an increase in cadence and stride length beyond that of normal controls (in a prior study) during fast walking, with stride lengths averaging 125% of stature during race walking, and 115% during normal fast walking. In the two race walkers the amplitudes of most of the movement patterns of the trunk and upper and lower limbs were exaggerated during race walking as compared to normal controls' fast walking. Several mechanisms were used by the race walkers to minimize the vertical excursion of the center of gravity of the body during race walking. All of the muscles monitored in the race walkers showed an increase in the amplitude of electromyographic activity during race walking as compared to fast walking; duration of muscle activity was also usually increased during race walking. Several suggestions for prevention of injuries associated with race walking are made.

Anterolateral compared to posterior approach in total hip arthroplasty: differences in component positioning, hip strength, and hip motion

In order to identify the functional advantages or disadvantages between the anterolateral and the posterior approaches to total hip arthroplasty, measurements of prosthetic position, hip-muscle strength, and hip joint mobility were made after Müller total hip arthroplasty without osteotomy in 52 patents operated through a posterior approach and 41 patients operated through an anterolateral approach. Men and women who had the posterior approach had less prosthetic component anteversion and longer neck lengths, with resultant more lateral and distal placement of the greater trochanter than groups with the anterolateral approach. Groups with the posterior approach had more normal hip abductor-muscle strength and more inward rotation on the operated side than group with the anterolateral approach. Groups with the anterolateral approach had more outward rotation on the operated side than groups with the posterior approach. These differences in function were related to the surgical approach rather than to differences in component position. An understanding of these observations should be used for selection of the surgical approach for the patient on an individual basis.

Comparison of Müller total hip replacement with and without trochanteric osteotomy. Kinesiologic measurements of 82 cases 2 years after surgery

Function of 37 patients with osteotomy of the greater trochanter during total hip replacement (41 hips) is compared to function of 38 patients (41 hips) without osteotomy. Subjective assessments and cane force measurements were slightly more favorable in the group without osteotomy. Objective measurement of hip motion, hip abductor and adductor muscle strength, weight distribution during standing, and multiple components of free-speed and fast walking showed no statistically significant differences between performance of the groups with and without osteotomy before surgery or 6 months or 2 years after. This suggests that osteotomy provides no functional advantages to the patient beyond those obtained in total hip replacements without osteotomy.

Joint function after total hip arthroplasty: a four-year follow-up of 72 cases with Charnley and Müller replacements

To help determine the duration of benefits in functional performance resulting from total hip arthroplasty (THA), multiple kinesiologic measurements were made before surgery and two and four years after 32 Charnley and 40 Müller THA procedures were done in 58 patients. There were no complications of loosening or infection, nor was there additional disability in other joints of the lower extremities. Measurements of functional performance included range of hip motion, hip abductor and adductor muscle strength, weight distribution between the feet during standing, forces applied to canes or crutches, and multiple components of free-speed and fast-walking performance. The average measurements showed significant improvement in almost all components of function from the time preceding surgery to two years afterward. The two-year level of function was then maintained without significant improvement or decline in function four years postoperation.

Strength of isometric and isokinetic contractions: knee muscles of men aged 20 to 86

Maximum isometric and isokinetic torques of the knee flexor and extensor muscles were measured at three knee joint positions in 72 normal, health men in three age groups from 20 to 86 years. The isokinetic contractions were performed at a speed of 36 degrees per second. The isometric contractions were sustained for five seconds. Strength of the men in the older age groups was significantly less than that of the youngest group. The strength of the isokinetic contractions was significantly less than that of the isometric contractions for all joint positions. The men in the oldest age group generally took longer than the younger men to reach peak torque during the isometric contractions. The torque values provide base-lines for evaluating patients with knee joint disabilities.

A comparison of the funtional performance of patients with Charnley and Müller total hip replacement. A two-year follow-up of eighty-nine cases

Measurements of functional performance in 35 cases with Charnley total hip replacement were compared with those of 54 cases with Müller replacement before surgery and at 6- and 24-month follow-up intervals. The measurements included strength of the hip abductor and adductor muscles, hip motion, the amount of weight borne on the involved limb during standing posture, multiple components of free-speed and fast walking, and force applied to canes and crutches. Both replacement groups improved significantly in most components of function. In fact, both groups reached or nearly reached the lower limits of normal variability in weight-bearing ability, cadence, and some components which relate to smoothness of walking performance. The groups with Müller and Charnley replacement differed most in some components of range of hip motion, hip muscle strength, and lateral lurching during walking.

Mutagenic activity of epoxy embedding reagents employed in electron microscopy

Components of epoxy-based embedding media used in electron microscopy were examined for their mutagenicity in the Ames Salmonella system. The compounds, singly and in combination, were shown to be active with strain TA100 (base substitution indicator) but not with TA98 (frameshift indicator). When tested separately the epoxy resins Araldite, Epon, and vinyl cyclohexen dioxide (VCD) and the plasticizer diglycidyl ether of propylene glycol (DER-736) were found to be significantly mutagenic. These active compounds, in combination with liver mixed oxidase preparation (S9), showed increased mutagenicity over similar preparations in the absence of microsomal activation.

Walking patterns of men with parkinsonism

Interrupted-light photography was used to record the simultaneous displacement patterns of multiple body segments of 44 patients with parkinsonism during free-speed and fast walking to quantitatively characterize their gait peculiarities. The patients were categorized into three disability groups according to their independence in activities of daily living. Their measurements of walking performance were compared to those of normal men. The gait components of the patients, which related systematically to the degree of disability, were: step lengths, vertical excursions of the head, extension of the hip and knee of the backward-directed limb at the onset of contralateral weight bearing, toe-floor distance at the onset of weight bearing, and rotation of the thorax.

Function of the triceps surae during gait. Compensatory mechanisms for unilateral loss

We studied the gait of a woman who was normal except for surgical excision of the gastrocnemius and soleus muscles. She was able to compensate for nearly all of her abnormalites of gait by excessive lateral pelvic tilt and prolonged quadriceps activity. Her mild disability, as regards gait, consisted of inability to increase walking speeds beyond the normal pacing. However, despite uneven step lengths, she had uniform forward progression. She had excessive dorsiflexion of the ankle and diminished plantar flexion on the involved side even though the retained plantar flexors could provide 38 per cent of her normal plantar flexor strength.

Roentgenographic measurements after Müller total hip replacement. Correlations among roentgenographic measurements and hip strength and mobility

In fifty-two patients with Müller total hip replacement, roentgenographic measurements of prosthetic component positioning were correlated with hip-muscle strength and mobility measurements. Compared with the normal side, the average position of the center of the prosthetic head was more medial and superior in the pelvis, and the greater trochanter was more distal and lateral. Increasing neck length (distance from the center of the prosthetic head to the lesser trochanter) and a more distal position of the greater trochanter were among the measurements that related favorably to measurements of patient function. More superior placement of the center of the prosthetic head in the pelvis was associated with a more superior position of the lesser trochanter, which related adversely to function.

Kinesiologic measurements of functional performance before and after geometric total knee replacemtn: one-year follow-up of twenty cases

Kinesiologic measurements were made in patients with severe arthritis before and after geometric total knee replacements to evaluate the nature, rate and extent of change in their functional ability. Preoperatively, patients with rheumatoid arthritis functioned at lower levels than patients with osteoarthritis. Most patients with rheumatoid arthritis improved steadily after surgery, while progress of those with osteoarthritis was often irregular. The group with rheumatoid arthritis improved more than those with osteoarthritis, but they did not generally reach the functional level attained by the patients with osteoarthritis, and neither group reached the lower limits of normal variability 1 year postoperatively. On the average, both groups gained knee extensions, lost knee flexion, and gained isometric knee flexor muscle strength postoperatively. Every patient with osteoarthritis lost extensor muscle strength 1 year after surgery, while most with rheumatoid arthritis gained. During quiet standing, most patients had straighter knees postoperatively and bore a greater percent of body weight on the operated limb. Patients with rheumatoid arthritis improved more than patients with osteoarthritis in the type and amount of force applied to canes and crutches. Most patients walked faster postoperatively, took longer and more rapid steps, improved the pattern of knee motion used, and had smoother forward, lateral and vertical head motion.

Maximum isometric knee flexor and extensor muscle contractions: normal patterns of torque versus time

Isometric torque of the knee flexor and extensor muscles were recorded for 5 seconds at three knee joint positions. The subjects included healthy men in age groups from 20 to 35 and 45 to 65 years of age. The amplitudes and duration of peak torque and the time to peak torque were measured for each contraction. Peak torque was usually maintaned less than 0.1 second and never longer than 0.9 second. At each of the three angles, the mean extensor muscle torque was higher than the mean flexor muscle torque in both age groups, and the mean torque for both muscle group was higher among the younger than among the older man. The highest average torque was recorded at the knee angle of 60 degrees for the extensor muscles and 45 degrees for the flexor muscles, but this was not always a stereotyped response either for a given individual or among individuals.

Comparison of functional performance after McKee-Farrar, Charnley, and Muller total hip replacement. A six-month follow-up of one hundred sixty-five cases

Measurements of functional performance were compared before and at 6 months after 58 McKee-Farrar, 50 Charnley, and 57 Muller total hip replacements in 143 patients. The measurment included: range of motion of the hip, hip abductor and adductor-muscle torque, weight-bearing activity during standing, forces applied to canes or crutches, and multiple components of walking performance. Each group of patients improved significantly after surgery in all of the components measured. Early postoperative differences among the 3 groups were found with respect to pain ratings, impressions of hip status, hip motions, muscle torque, the number of patients using assistive devices, and certain components of walking performance. There is nothing to suggest that the performance of any 1 group is distinctly better or worse than that of any other group 6 months after surgery. On the basis of average values, each group improved in every component of function and it is gratifying that, except for a few patients who developed postoperative infection, each patient could be considered to have successful reconstruction.

A comparison of plantar flexion torque with and without the triceps surae

Torque generated about the ankle joints during maximum isometric contraction of the plantar flexor muscles was measured on a subject 4 months after unilateral excision of the entire triceps surae. Resulting torque output on the operated limb was 327 kg-cm, or 38 per cent of the 871 kg-cm total for the sound limb.

Walking patterns of men with unilateral surgical hip fusion

The gait of men with unilateral hip fusion is somewhat slow, asymmetrical, and arrhythmic as compared with that of normal men. Compensation for absent hip motion is accomplished by increased transverse and sagittal rotation of the pelvis, increased motion in the sound hip, and increased flexion of the knee throughout the stance phase on the fused side. Relationships between the fusion position, certain physical traits, and walking performance suggest that the best gait can be expected in young patients who have free motion of the lumbar spine, the sound hip, and the knee on the side of fusion, and who have equal limb lengths and a hip fused in a position that does not include excessive adduction.

A method of measuring the duration of foot-floor contact during walking

A new method for monitoring the durations of foot-floor contact during walking is described. The method uses a screen walkway and conducting paper on the soles of the shoes as parts of an electrical circuit. The materials used are identified and circuit diagrams are provided. Several clinical applications and advantages and disadvantages of the method are discussed.

Normal postural stability and steadiness: quantitative assessment

A force platform was utilized to provide a new and sensitive means to measure postural steadiness and stability. Normal standards are presented for the center of pressure of the vertical supportive force during standing and sustained weight-shifting of normal men in three age groups. Two distinguishing characteristics were seen for normal upright posture: (1) a large area of stability over which weight can be safely shifted and maintained, and (2) steadiness such that the center of pressure fluctuates incessantly, traversing large total excursions, while remaining remarkably close to the mean point. The youngest age group showed the greatest steadiness and stability and the oldest group showed the least.