Low-tension Group Research Articles

Effects of Initial Graft Tension and Patient Sex on Knee Osteoarthritis Outcomes After ACL Reconstruction: A Randomized Controlled Clinical Trial With 10- to 12-Year Follow-up

Background: The initial graft tension applied during anterior cruciate ligament (ACL) graft fixation may promote posttraumatic osteoarthritis (PTOA). Purpose/Hypothesis: This study sought to assess the effect of initial graft tension and patient sex on PTOA outcomes at 10 to 12 years after ACL reconstruction (ACLR). The hypothesis was that there would be no group- or sex-based differences in outcomes. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: Patients were randomized to receive ACLR with a low or high initial graft tension. Outcomes were evaluated at 10 to 12 years postoperatively and compared with a matched, uninjured control group. Outcomes included clinical assessments (anteroposterior [AP] knee laxity measurement, International Knee Documentation Committee [IKDC] examination score), a functional assessment (single-leg hop for distance), patient-reported outcomes (Knee injury and Osteoarthritis Outcome Score [KOOS], 36-Item Short Form Health Survey, Tegner activity level, patient satisfaction), and PTOA imaging (Osteoarthritis Research Society International [OARSI] radiographic score and Whole-Organ Magnetic Resonance Imaging Score [WORMS]). Two-way mixed-model analyses of variance were used to evaluate differences in outcomes between tension groups and the control group and between female and male patients. Results: Both tension groups scored worse than the control group for the IKDC examination (P≤ .021), KOOS (Pain, Activities of Daily Living, Sport/Recreation, and Quality of Life subscales) (P≤ .049), and WORMS difference score (P≤ .042). The low-tension group scored worse than the control group for KOOS Symptoms (P = .016) and the OARSI difference score (P = .015). The index limb had worse scores than the contralateral limb within the high-tension group for AP laxity (P = .030) and hop deficit (P = .011). This result was also observed within both tension groups for the WORMS (P≤ .050) and within the low-tension group for the OARSI score (P = .001). Male patients had higher Tegner scores (mean ± SE) relative to female patients (male, 5.49 ± 1.88; female, 4.45 ± 1.65) and worse OARSI difference scores (male, 1.89 ± 5.38; female, 0.244 ± 0.668) (P = .007 and .034, respectively). However, no significant differences were detected between tension groups for any of the outcomes measured. Conclusion: Overall, ACLR failed to prevent PTOA regardless of initial graft tension. However, male patients treated with a low initial graft tension may be at greater risk for PTOA. These results do not support the hypothesis of no sex differences in outcomes at 10 to 12 years after ACLR.

The effects of stress reduction strategies of breathing technique relaxation programme and positive psychology on biochemical variable response among schoolteachers

We aimed to investigate the effects of job stress on the biochemical variables of schoolteachers before and after stress reduction strategies. In 2019, 200 schoolteachers (98 males, 102 females) in the private and fully aided higher secondary schools of urban and rural areas in Vellore, India were enrolled in the study based on the principle of consecutive sampling. Questionnaires were used to investigate demographic characteristics and occupational stress-related factors. Fasting blood glucose was detected by venous plasma and a biochemical analyser with the cut-off thresholds method. Salivary cortisol was determined by the specific enzyme-linked immunosorbent assay kit method. Total cholesterol in serum was determined by the CHOD-PAP method. Serumalbumin was detected by the bromocresol green dye-binding method on a Roche Modular DP analyser (Roche Diagnostics). Blood pressure was measured by aneroid sphygmomanometers. Levels of fasting blood glucose, salivary cortisol, albumin and cholesterol were lower in the high-tension group than those in the low-tension group. Those of the high-coping strategy group were higher than those of the low-coping strategy group. Systolic blood pressure and diastolic blood pressure significantly reduced among the intervention groups after administering the relaxation response programme for three and six weeks, respectively, to urban and rural school teachers. Occupational stress can lead to increased salivary cortisol, cholesterol, albumin, blood glucose and blood pressure levels. The relaxation response programme resulted in quantifiable improvements in physiological markers of stress in rural and urban schoolteachers.

Effects of Occupational Stress on Blood Lipids, Blood Sugar and Immune Function of Doctors

We aimed to investigate the effects of occupational stress on blood lipids, blood glucose and immune function of doctors. In 2017, 1291 doctors (565 males, 726 females) in The First Hospital Affiliated with Harbin Medical University (Harbin, China) were enrolled based on the principle of convenience of sampling and cluster sampling. Questionnaires were used to investigate demographic characteristics and occupational stress related factors. Level of glycated hemoglobin was detected by immunoturbidimetric method. Concentration of triglyceride was determined by glycerol phosphate oxidase end point method. Total cholesterol concentration in serum was determined by total cholesterol oxidase end point method. Concentration of serum immunoglobulin was detected by immunoturbidimetry. Levels of glycated hemoglobin and triglyceride in high tension group were higher than those in the low tension group. Levels of IgG and IgM in high tension group were lower than those in low tension group. The risk of elevated glycated hemoglobin levels in > 50-yr-old age group was higher than that of the =<35-yr-old age group. Those in the high coping strategy group was higher in the low coping strategy group. The risk of elevated total cholesterol levels in drinkers is 1.158 times that of non-drinkers. The risk of IgG concentration reduction in smokers was 0.428 times that of non-smokers. The risk of a decrease in IgA concentration in doctors with good sleep quality is 1.527 times that of those with poor sleep quality. Occupational stress can lead to increased blood lipids and sugar levels as well suppression of immune function in doctors.

Melatonin Levels in Patients With Primary Open-angle Glaucoma With High or Low Intraocular Pressure.

To evaluate circulatory melatonin levels by assessing nocturnal urinary excretion of 6-sulfatoxymelatonin (aMT6s) in patients with primary open-angle glaucoma (POAG) and to compare the high-tension group and the low-tension group. This study included 80 eyes of 41 POAG patients and 87 eyes of 44 control subjects. POAG group was further classified into high-tension group and low-tension group according to the pretreatment intraocular pressure (IOP). The first urine in the morning was collected and aMT6s were measured using a commercial ELISA kit. Urinary aMT6s levels were expressed as ng aMT6s/mg creatinine. Differences in melatonin levels among the control and POAG subgroups were evaluated by generalized estimating equation adjusting age, sex, sleep duration, and intereye correlation. Urinary aMT6s/creatinine ratio did not differ between POAG and control group (P=0.097). The difference in the aMT6s/creatinine ratio between the 3 groups-high-tension group with baseline IOP≥21 mm Hg (19.74±3.12 ng/mg), low-tension glaucoma group with baseline IOP<21 mm Hg (26.71±3.47 ng/mg), and control group (30.35±3.05 ng/mg)-was statistically significant (P=0.046). Post hoc analysis revealed that the difference between the control and high-tension glaucoma groups was significant (P=0.014), whereas the difference between the control and low-tension glaucoma groups was not (P=0.436). This study found low melatonin levels in high-tension glaucoma compared with the control.

Effect of Matching or Overconstraining Knee Laxity During Anterior Cruciate Ligament Reconstruction on Knee Osteoarthritis and Clinical Outcomes

Background: The “initial graft tension” applied at the time of graft fixation during anterior cruciate ligament (ACL) reconstruction surgery modulates joint contact mechanics, which in turn may promote posttraumatic osteoarthritis (OA). Purpose/Hypotheses: The study objectives were to compare clinical, functional, patient-reported, and OA imaging outcomes between 2 different initial laxity-based graft tension cohorts and a matched uninjured control group as well as to evaluate the effects of laxity-based graft tension on OA development at 84-month follow-up. The 2 laxity-based tension protocols were (1) to restore normal anteroposterior (AP) laxity at the time of surgery relative to the contralateral uninjured knee (low-tension group) or (2) to overconstrain AP laxity by 2 mm relative to the contralateral uninjured knee (high-tension group). The hypotheses were that (1) the high-tension group would have improved outcomes and decreased OA compared with the low-tension group after 84 months, and (2) the outcomes for the high-tension group would be equivalent to those for an age-, sex-, race-, and activity-matched group of control participants with uninjured knees. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: Patients had their ACLs reconstructed with either a bone–patellar tendon–bone or 4-stranded hamstring autograft, and outcomes were compared with a matched control group. Outcomes were evaluated preoperatively and at 60 and 84 months postoperatively and included clinical (KT-1000 arthrometer AP laxity measurement and International Knee Documentation Committee [IKDC] examination score), functional (1-legged hop for distance and knee extensor torque), patient-reported (Knee injury and Osteoarthritis Outcome Score [KOOS], Short Form–36 [SF-36], and patient satisfaction survey), and OA imaging (measurement of joint space width [JSW], Osteoarthritis Research Society International [OARSI] radiographic score, and Whole-Organ Magnetic Resonance Imaging Score [WORMS]) components. Repeated-measures analyses of variance were used to evaluate differences in outcomes between the treatment groups and the control group. Results: There were significant differences between the 2 tension groups in 1 of 5 KOOS subscales (sports and recreation; P = .04) and 2 of 8 SF-36 subscales (vitality, mental health; P < .04) at 84 and 60 months, respectively. Both tension groups scored significantly worse than the control group in the IKDC examination (P < .001), 1-legged hop (P ≤ .017), KOOS quality of life and symptoms subscales (P < .03), and OARSI radiographic score (P ≤ .02) at 84 months. The low-tension group performed significantly worse than the control group on the KOOS pain subscale (P = .03), SF-36 general health and social functioning (P < .04), OARSI radiographic score (P < .001), and WORMS (P = .001), while the high-tension group had statistically different results than the control group in AP knee laxity (P < .001), radiographic JSW (P = .003), and OARSI radiographic score (P = .02) as well as significantly more subsequent knee injuries (P = .02) at 84 months. Conclusion: The results do not support the hypotheses that the high-tension group would have improved outcomes when compared with the low-tension group after 84 months of healing or that the outcomes for the high-tension group would be equivalent to those for the matched control group. While there were minor differences in patient-reported outcomes between the 2 laxity-based tension groups, all other outcomes were similar. Registration: NCT00434837

Epidemiology of electrical injury: Differences between low- and high-voltage electrical injuries during a 7-year study period in South Korea.

Electrical burns are uncommon, but they result in high morbidity and mortality due to severe tissue damage. The purpose of this study is to analyze epidemiological variables of electrical injuries and identify preventable measures through them. We retrospectively analyzed the clinical records of 625 patients admitted to Hangang Sacred Heart Hospital's Department of Plastic Surgery from January 2005 to December 2011. We divided the patients into two groups: (1) low-voltage injury (under 1000 V) and (2) high-voltage injury (over 1000 V). We reviewed the following variables: age, sex, total burn surface area, injury type and mode, and surgical modalities. The mean age of all patients was 33.4 ± 18.2 years. The ratio of males to females was 13.5 in the whole group. The mean total body surface are burned was 14.0% ± 13.8% in total. The majority of electrical burns in the low-tension group and high-tension group occurred in patients under 20 years and in patients aged 40-59 years, respectively. Steel chopstick insertions and high-voltage electrical work/repair were the most common injury modes in the low-tension group and the high-tension group, respectively. Groin and abdominal distant flap surgeries were commonly performed in both groups. It is recommended that these risks be prevented through education and safety measures to reduce the incidence of electrical injuries.

Effect of occupational stress and effort-reward imbalance on sleep quality of people's policeman

To explore the effect of occupational stress and effort-reward imbalance on sleep quality of people's police. A cluster sampling survey of sleep quality and occupational stress correlated factors was conducted on 287 police from a city public security bureau by questionnaires in May, 2011; the relationship between sleep quality and occupational stress correlated factors was analyzed by one-way ANOVA and multivariate non-conditional logistic regression using effort-reward imbalance model (ERI) and demand-control-support model (DCS). And the subjects were divided into high tension group and low tension group using the 1.0 of ERI and DCS coefficients as the boundary. The sleep quality score of shift work police was higher than day work police (11.95 ± 6.54 vs 9.52 ± 6.43, t = 2.77, P < 0.05).In ERI model, the sleep quality score in high tension group was higher than low tension group (14.50 ± 6.41 vs 8.60 ± 5.53, t = -5.32, P < 0.01), and in DCS model, the sleep quality score in high tension group was also higher than low tension group (13.71 ± 6.62 vs 9.46 ± 6.04, t = -3.71, P < 0.01).For the regression analysis of ERI model as an argument, sex (OR = 3.0, 95%CI:1.16-7.73) , age for 30-39 years (OR = 3.48, 95%CI:1.32-9.16) , intrinsic effort (OR = 2.30, 95%CI:1.10-4.81) and daily hassles (OR = 2.15, 95%CI:1.06-4.33) were risk factors of low sleep quality, and reward (OR = 0.26, 95%CI:0.12-0.52) was the protective factor.For the regression analysis of DCS model as an argument , age for 30-39 years (OR = 2.55, 95%CI:1.02-6.37) , depressive symptom (OR = 2.10, 95%CI:1.14-3.89) and daily hassles (OR = 3.25, 95%CI:1.70-6.19) were risk factors of low sleep quality.While the ERI model and the DCS model were analyzed simultaneously, sex (OR = 3.03, 95%CI:1.15-7.98) , age for 30-39 years (OR = 3.71, 95%CI:1.38-9.98) and daily hassles (OR = 2.09, 95%CI:1.01-4.30) were the risk factors of low sleep quality, and reward (OR = 0.22, 95%CI:0.10-0.48) was the protective factor. Occupational stress and effort-reward imbalance affected the sleep quality to people's policeman.

The Effect of Initial Graft Tension After Anterior Cruciate Ligament Reconstruction

Background: The initial graft tension applied at the time of anterior cruciate ligament (ACL) reconstruction alters joint contact and may influence cartilage health. The objective was to compare outcomes between 2 commonly used “laxity-based” initial graft tension protocols. Hypotheses: (1) The high-tension group would have less knee laxity, improved clinical and patient-oriented outcomes, and less cartilage damage than would the low-tension group after 36 months of healing. (2) The outcomes of the high-tension group would be equivalent to those of a matched control group. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: Ninety patients with isolated unilateral ACL injuries were randomized to undergo ACL reconstruction using 1 of 2 initial graft tension protocols: (1) autografts tensioned to restore normal anterior-posterior (AP) laxity at the time of surgery (ie, low tension; n = 46) and (2) autografts tensioned to overconstrain AP laxity by 2 mm (ie, high tension; n = 44). Sixty matched healthy patients formed the control group. Outcomes were assessed preoperatively, intraoperatively, and at 6, 12, and 36 months after surgery. Results: No significant differences were found between the 2 initial graft tension protocols for any of the outcome measures at 36 months. However, there were differences when comparing the 2 treatment groups to the control group. On average, AP laxity was 2 mm greater in the ACL-reconstructed groups than in the control group (P < .007). International Knee Documentation Committee (IKDC) knee evaluation scores, peak isokinetic knee extension torques, and 4 of 5 Knee Osteoarthritis Outcome Scores (KOOS) were significantly worse than the control group (P < .001, P < .027, and P < .05, respectively). Short Form–36 Health Survey (SF-36) scores and reinjury rates were similar between groups at 36 months. Although there were significant changes in radiography and magnetic resonance imaging present in the ACL-reconstructed knees of both treatment groups, the magnitude was relatively small and likely clinically insignificant at 36 months. Conclusion: Both laxity-based initial graft tension protocols produced similar outcomes without fully restoring joint function or patient-oriented outcomes (KOOS) when compared with the control group. There was minimal evidence of cartilage damage 36 months after surgery.

Intraocular Pressure (IOP) Reduction by Latanoprost in Japanese Normal Tension Glaucoma Patients Over a Five-Year Period Stratified by Presenting IOP

We examined the effectiveness of latanoprost for reducing intraocular pressure (IOP) in Japanese patients with normal tension glaucoma (NTG) over a 5-year period. Prospective interventional case series. The patients were classified into 2 groups based on mean IOP. A total of 38 patients with NTG were studied after being classified into the high-tension (mean IOP 16 mmHg or greater, n = 27) and low-tension (mean IOP lower than 15 mmHg, n = 11) groups. IOP was measured and Humphrey Field Analyzer (HFA) examinations were conducted at 6, 12, 24, 36, 48, and 60 months after beginning a daily administration of latanoprost. Mean IOP before administration was 17.6 mmHg in the high-tension group, which was reduced to 13.9, 14.6, 14.4, 14.1, 13.6, and 14.6 mmHg at 6, 12, 24, 36, 48, and 60 months, respectively, after beginning administration. That in the low-tension group was 13.6 mmHg before administration, and then was reduced to 12.2, 11.4, 11.5, 12.5, 10.5, and 11.5 mmHg, respectively, after beginning administration was noted. Mean deviation (MD) values in the HFA examinations were reduced by -4.27 and -1.49 dB after 5 years in the high- and low-tension groups, respectively. Latanoprost administration was effective in reducing IOP over a 5-year period in a range of 3.1-4.1 and 1.3-3.6 mmHg in NTG patients with high- and low-tension levels, respectively. In addition, our results indicate that latanoprost helped to prevent a decrease in MD values in both groups, as shown by the results of HFA examinations.

Oxygen saturation levels in the juxta-papillary retina in eyes with glaucoma

Oxygen saturation (OS) levels in the juxta-papillary retina particularly inferotemporal retina were investigated in open-angle glaucoma (OAG) patients as well as normal subjects. Fifty-six eyes of 56 OAG Japanese patients and 20 eyes of 20 age-matched normal subjects were recruited for the study. OAG eyes (56) were subdivided into two groups: 15 eyes of low-tension (LT) subgroup and 41 eyes of high-tension (HT) subgroup. The average of age of the LT, HT subgroup and normal group were 60.5, 55.9 and 52.6 years, respectively. OS levels in the retina were measured using a Fourier transform-based spectral retinal imaging (SRI) system (Retinal Cube; ASI Co. Migdal Hemak, Israel), with which OS levels in the fundus could be computed at every pixel point of a 35 degrees fundus image. We calculated OS levels at five points in the retina near the optic disc and retinal arteries and veins in all eyes. The OS levels were also compared with the results analyzed using Humphrey visual field Analyzer with the program 30-2 SITA. At the superior and nasal juxta-papillary retinal points, OS level of the LT subgroup showed significant decrease as compared with the HT subgroup and the normal group (p=0.048–0.009). The LT and the HT subgroups were significantly lower than the normal group at the inferotemporal and the average of the retinal points (p=0.047–0.001). There were no statistically significant differences among the three groups in regards to the OS in the retinal artery. There was a statistical significant correlation between the mean of total deviation of the 17 points in the upper arcuate area and OS of the inferotemporal point (p=0.018), and between mean deviation and the average of OS of the inferotemporal and the superotemporal point (p=0.037) in the HT subgroup. However, there was no significant correlation in the LT subgroup. OS levels in the retina were especially decreased in the low-tension glaucoma subtype. There was a correlation between the visual field defect and OS in the HT eyes in the inferotemporal region. OS measurement may be a novel adjunct to study glaucoma patients.

Effects of Suture Tension During Unilateral Cricoarytenoid Lateralization on Canine Laryngeal Resistance In Vitro

To evaluate the effect of abduction suture tension for unilateral arytenoid lateralization on laryngeal resistance. Experimental study. Canine cadaver larynges (n=16). Laryngeal resistance was calculated in all specimens with the epiglottis in open and closed positions. Left cricoarytenoid lateralization was performed under low or high suture tension, and laryngeal resistance was re-calculated. The effects of suture tension on laryngeal resistance were evaluated by repeated measures ANOVA. Cricoarytenoid lateralization under low or high suture tension significantly reduced laryngeal resistance with the epiglottis in an open or closed position. There was no difference in laryngeal resistance with an open epiglottis between the low-tension (1.00+/-0.0001 cm H(2)O/L/s) and high-tension (1.10+/-0.35 cm H(2)O/L/s) groups (P=.33). The low-tension group (22.80+/-14.20 cm H(2)O/L/s) had significantly greater laryngeal resistance than the high-tension group (8.45+/-4.00 cm H(2)O/L/s) with a closed epiglottis (P=.016). There was no difference in laryngeal resistance with a closed epiglottis for the low-tension group before (34.30+/-36.50 cm H(2)O/L/s) and after (22.80+/-14.20 cm H(2)O/L/s; P=.42) arytenoid lateralization. Cricoarytenoid lateralization under low suture tension significantly reduced laryngeal resistance with an open epiglottis, but resulted in a significantly greater resistance with a closed epiglottis than cricoarytenoid lateralization under high suture tension. Clinically, use of a low-tension suture for cricoarytenoid lateralization may provide an adequate decrease in open-epiglottis laryngeal resistance to alleviate clinical signs, while maintaining enough closed-epiglottis laryngeal resistance to reduce the risk of postoperative aspiration pneumonia.

A Prospectively Randomized Double-Blind Study on the Effect of Initial Graft Tension on Knee Stability after Anterior Cruciate Ligament Reconstruction

Background No consensus exists on the amount of tension that should be applied to anterior cruciate ligament grafts to best facilitate graft incorporation and re-create normal knee mechanics. Hypothesis Differences in initial graft tension will affect postoperative knee stability. Study Design Prospective, randomized, double-blind clinical trial. Methods Forty-nine patients undergoing bone-patellar tendon-bone autograft anterior cruciate ligament reconstruction by a single surgeon were randomized into high-tension (n = 27) and low-tension (n = 22) groups. Grafts were set at 90 N or 45 N. Arthrometric measurements (KT-1000 arthrometer manual maximum) of anterior tibial displacement and knee range of motion were made before surgery and at 1 week and an average of 20 months after surgery. Knee outcome scores were collected before and after surgery, and a single-leg hop test was also performed at final follow-up. Results After anterior cruciate ligament reconstruction, anterior tibial displacement was significantly greater in the patients in the low-tension group (P < .05). The side-to-side difference in anterior tibial displacement in the high-tension and low-tension groups was 1.1 ± 1.7 mm versus 2.4 ± 2.4 mm 1 week after surgery and 2.2 ± 1.6 mm versus 3.0 ± 2.2 mm at follow-up. Five patients had abnormal anterior tibial displacement (>5 mm side-to-side difference), and all were in the low-tension group (P <.05). Knee outcome scores improved with surgery (P < .01), with similar results for low-tension and high-tension groups. Hop test deficits were not different between groups. Conclusions Initial graft tension affects the restoration of knee stability. A graft tension of 45 N was not sufficient for restoring knee stability.

Sectorization of central 10-deg visual field in open-angle glaucoma

• Purpose: To obtain an optimal clustering of the test points of the Humphrey 10-2 program in glaucoma for brief evaluation of the visual field characteristics in the central 10-deg field and to examine its clinical usefulness. • Methods: We applied VARCLUS, a new clustering algorithm, to 379 visual fields obtained with the 10-2 program of the Humphey perimeter from 211 eyes of 140 normal-tension glaucoma (NTG) patients and 168 eyes of 111 primary open-angle glaucoma (POAG) patients with the mean deviation (Statpac 2) ⩾−15 dB. Based on the interpoint correlation of deviation of the measured threshold value from age-corrected normal reference (total deviation), the 68 2-deg grid points were mathematically clustered, i.e., the central 10-deg visual field was divided into sectors. Between 76 eyes of 76 POAG patients with the peak intraocular pressure (IOP) ⩾25 mmHg (high-tension group) and 85 eyes of 85 NTG patients with the peak IOP ⩽ 18 mmHg (low-tension group) which had similar mean deviation and age, the mean of total deviation in each obtained sector was compared. • Results: The central 10-deg visual field in glaucoma was divided into 10 sectors. The sector pattern obtained was compatible with the projection of nerve fiber layers, with no sectors extending over the horizontal meridian, and it was not completely symmetrical around the horizontal meridian. A group of sectors in the superior arcuate area was significantly more depressed in the low-tension group, while a group of sectors in the inferior centrocecal area was significantly more depressed in the high-tension group. • Conclusion: We suggest that the sector pattern obtained here is useful to provide brief evaluation of the result of the 10-2 program and that it may be used in the study of the central visual field in glaucoma.

Experimental study on the influence of tension, immobilisation and denervation on muscle transplantation

To observe the effects of tension and immobilisation on denervated muscle, rats' denervated soleus muscles were transplanted orthotopically at different tensions: high, neutral, moderate and low tension with immobilisation. Results were evaluated by measuring muscle mass, twitch and tetanic tension, and histologically by HE staining. The results showed better preservation of muscle weight in the high tension group. Atrophy and loss of function were rapid during the first 4 weeks and were greatest in the low tension group. Rate of atrophy was slowed and relatively stabilised at the eighth postoperative week. We conclude that increased tension with immobilisation produced slower initial atrophy and loss of function in denervated muscle flaps. Although slower, the atrophy continued during the prolonged immobilisation and there was no significant difference compared with neutral tension at a later period. Moreover, immobilisation produced atrophy and affected function regardless of the amount of tension. Increased tension decelerates and decreased tension accelerates denervation atrophy of muscle. Thus denervation, immobilisation and reduced tension are all detrimental in muscle transplantation.

Comparison of Visual Field Defects in the Low-Tension Glaucomas with Those in the High-Tension Glaucomas

We compared the visual fields of 79 eyes (48 patients) with low-tension glaucoma (intraocular pressure less than 21 mm Hg) to the visual fields of 106 eyes (74 patients) with high-tension glaucoma (intraocular pressure greater than 30 mm Hg). Both groups had similar amounts of total field loss as determined by computerized threshold perimetry. Scotomas in the low-tension group had a steeper slope (P less than .001), were significantly closer to fixation (P less than .001), and had greater depth (P less than .001) than those in the high-tension group. These findings suggested that more than one causative factor is important in the production of optic nerve damage in glaucoma.

The T-Group Trainer: Group Facilitator or Prisoner of Circumstance?

In this study of 31 English T Groups, trainers were reported to be more influential, more trusted and more likely to create tension than were members. An index of group outcome was found to correlate significantly with high trainer influence and high trust in the trainer. However, effective trainer behavior also showed substantial variation between different types of T Group. In low tension groups, trainers whose behavior made others tense were more effective, whereas in high tension groups the reverse was true. Seven trainers within the sample conducted more than one group. When these groups were compared, there was no evidence that particular trainers tend to create in their groups a climate of a consistent type. It was concluded that the culture of a group depended primarily on the group's composition. Some trainer behaviors, such as supportive ones, were effective across a wide range of group types. Others, such as confronting behavior, were effective only where the trainer correctly diagnosed its appropriateness to the group culture.

Circulating lipoprotein and blood glucose levels in association with low-tension and chronic simple glaucoma.

Circulating lipoprotein and blood glucose levels were determined for 53 patients with low-tension glaucoma and 39 patients with chronic simple glaucoma. The incidence of hypercholesterolaemia was significantly higher in the low-tension group than in the chronic simple glaucoma group and control data obtained elsewhere. Preliminary follow-up results of the effects of treatment are also reported. The incidence of raised fasting blood glucose levels was not significantly increased in either group.

Degree of structural balance and group effectiveness

The degree of structural balance, β( S), of groups was experimentally manipulated; β( S) = 1.00 and β( S) = .62. Groups in each β( S) condition solved 10 problems in a totally connected communication network. The data showed, as expected by the theory of balance, that group tension was inversely related to β( S), and, as predicted, group effectiveness was directly related to β( S) ( p = .07, 1-tail test). The weak relationship between β( S) and group effectiveness may be due to the small, but significant differences in tension. Since the predicted relationship between β( S) and group effectiveness is predicted on differences in tension, the groups were divided into high- and low-tension groups, irrespective of β( S), to determine if group tension is inversely related to group effectiveness. This analysis produced the expected inverse relationship between group tension and effectiveness p < .005). These results suggest that the failure to obtain strong differences in group effectiveness as a function of β( S) was not a failure in theory, but a failure in method.