NASA SPRINT exercise program efficacy for vastus lateralis and soleus skeletal muscle health during 70 days of simulated microgravity

The efficacy of the NASA SPRINT exercise countermeasures program for quadriceps (vastus lateralis) and triceps surae (soleus) skeletal muscle health was investigated during 70 days of simulated microgravity. Individuals completed 6° head-down-tilt bedrest (BR, n = 9), bedrest with resistance and aerobic exercise (BRE, n = 9), or bedrest with resistance and aerobic exercise and low-dose testosterone (BRE + T, n = 8). All groups were periodically tested for muscle (n = 9 times) and aerobic (n = 4 times) power during bedrest. In BR, surprisingly, the typical bedrest-induced decrements in vastus lateralis myofiber size and power were either blunted (myosin heavy chain, MHC I) or eliminated (MHC IIa), along with no change (P > 0.05) in %MHC distribution and blunted quadriceps atrophy. In BRE, MHC I (vastus lateralis and soleus) and IIa (vastus lateralis) contractile performance was maintained (P > 0.05) or increased (P < 0.05). Vastus lateralis hybrid fiber percentage was reduced (P < 0.05) and energy metabolism enzymes and capillarization were generally maintained (P > 0.05), while not all of these positive responses were observed in the soleus. Exercise offsets 100% of quadriceps and approximately two-thirds of soleus whole muscle mass loss. Testosterone (BRE + T) did not provide any benefit over exercise alone for either muscle and for some myocellular parameters appeared detrimental. In summary, the periodic testing likely provided a partial exercise countermeasure for the quadriceps in the bedrest group, which is a novel finding given the extremely low exercise dose. The SPRINT exercise program appears to be viable for the quadriceps; however, refinement is needed to completely protect triceps surae myocellular and whole muscle health for astronauts on long-duration spaceflights.NEW & NOTEWORTHY This study provides unique exercise countermeasures development information for astronauts on long-duration spaceflights. The NASA SPRINT program was protective for quadriceps myocellular and whole muscle health, whereas the triceps surae (soleus) was only partially protected as has been shown with other programs. The bedrest control group data may provide beneficial information for overall exercise dose and targeting fast-twitch muscle fibers. Other unique approaches for the triceps surae are needed to supplement existing exercise programs.

Exercise microdosing for skeletal muscle health applications to spaceflight

Findings from a recent 70-day bedrest investigation suggested intermittent exercise testing in the control group may have served as a partial countermeasure for skeletal muscle size, function, and fiber-type shifts. The purpose of the current study was to investigate the metabolic and skeletal muscle molecular responses to the testing protocols. Eight males (29 ± 2 yr) completed muscle power (6 × 4 s; peak muscle power: 1,369 ± 86 W) and V̇o2max (13 ± 1 min; 3.2 ± 0.2 L/min) tests on specially designed supine cycle ergometers during two separate trials. Blood catecholamines and lactate were measured pre-, immediately post-, and 4-h postexercise. Muscle homogenate and muscle fiber-type-specific [myosin heavy chain (MHC) I and MHC IIa] mRNA levels of exercise markers (myostatin, IκBα, myogenin, MuRF-1, ABRA, RRAD, Fn14, PDK4) and MHC I, IIa, and IIx were measured from vastus lateralis muscle biopsies obtained pre- and 4-h postexercise. The muscle power test altered (P ≤ 0.05) norepinephrine (+124%), epinephrine (+145%), lactate (+300%), and muscle homogenate mRNA (IκBα, myogenin, MuRF-1, RRAD, Fn14). The V̇o2max test altered (P ≤ 0.05) norepinephrine (+1,394%), epinephrine (+1,412%), lactate (+736%), and muscle homogenate mRNA (myostatin, IκBα, myogenin, MuRF-1, ABRA, RRAD, Fn14, PDK4). In general, both tests influenced MHC IIa muscle fibers more than MHC I with respect to the number of genes that responded and the magnitude of response. Both tests also influenced MHC mRNA expression in a muscle fiber-type-specific manner. These findings provide unique insights into the adaptive response of skeletal muscle to small doses of exercise and could help shape exercise dosing for astronauts and Earth-based individuals.NEW & NOTEWORTHY Declines in skeletal muscle health are a concern for astronauts on long-duration spaceflights. The current findings add to the growing body of exercise countermeasures data, suggesting that small doses of specific exercise can be beneficial for certain aspects of skeletal muscle health. This information can be used in conjunction with other components of existing exercise programs for astronauts and might translate to other areas focused on skeletal muscle health (e.g., sports medicine, rehabilitation, aging).

Multitissue responses to exercise: a MoTrPAC feasibility study

We assessed the feasibility of the Molecular Transducers of Physical Activity Consortium (MoTrPAC) human adult clinical exercise protocols, while also documenting select cardiovascular, metabolic, and molecular responses to these protocols. After phenotyping and familiarization sessions, 20 subjects (25 ± 2 yr, 12 M, 8 W) completed an endurance exercise bout (n = 8, 40 min cycling at 70% V̇o2max), a resistance exercise bout (n = 6, ∼45 min, 3 sets of ∼10 repetition maximum, 8 exercises), or a resting control period (n = 6, 40 min rest). Blood samples were taken before, during, and after (10 min, 2 h, and 3.5 h) exercise or rest for levels of catecholamines, cortisol, glucagon, insulin, glucose, free fatty acids, and lactate. Heart rate was recorded throughout exercise (or rest). Skeletal muscle (vastus lateralis) and adipose (periumbilical) biopsies were taken before and ∼4 h following exercise or rest for mRNA levels of genes related to energy metabolism, growth, angiogenesis, and circadian processes. Coordination of the timing of procedural components (e.g., local anesthetic delivery, biopsy incisions, tumescent delivery, intravenous line flushes, sample collection and processing, exercise transitions, and team dynamics) was reasonable to orchestrate while considering subject burden and scientific objectives. The cardiovascular and metabolic alterations reflected a dynamic and unique response to endurance and resistance exercise, whereas skeletal muscle was transcriptionally more responsive than adipose 4 h postexercise. In summary, the current report provides the first evidence of protocol execution and feasibility of key components of the MoTrPAC human adult clinical exercise protocols. Scientists should consider designing exercise studies in various populations to interface with the MoTrPAC protocols and DataHub.NEW & NOTEWORTHY This study highlights the feasibility of key aspects of the MoTrPAC adult human clinical protocols. This initial preview of what can be expected from acute exercise trial data from MoTrPAC provides an impetus for scientists to design exercise studies to interlace with the rich phenotypic and -omics data that will populate the MoTrPAC DataHub at the completion of the parent protocol.

European Society of Cardiology quality indicators for the prevention and management of cancer therapy-related cardiovascular toxicity in cancer treatment

AIMS

To develop quality indicators (QIs) for the evaluation of the prevention and management of cancer therapy-related cardiovascular toxicity.

METHODS AND RESULTS

We followed the European Society of Cardiology (ESC) methodology for QI development which comprises (i) identifying the key domains of care for the prevention and management of cancer therapy-related cardiovascular toxicity in patients on cancer treatment, (ii) performing a systematic review of the literature to develop candidate QIs, and (iii) selecting of the final set of QIs using a modified Delphi process. Work was undertaken in parallel with the writing of the 2022 ESC Guidelines on Cardio-Oncology and in collaboration with the European Haematology Association, the European Society for Therapeutic Radiology and Oncology and the International Cardio-Oncology Society. In total, 5 main and 9 secondary QIs were selected across five domains of care: (i) Structural framework, (ii) Baseline cardiovascular risk assessment, (iii) Cancer therapy related cardiovascular toxicity, (iv) Predictors of outcomes, and (v) Monitoring of cardiovascular complications during cancer therapy.

CONCLUSION

We present the ESC Cardio-Oncology QIs with their development process and provide an overview of the scientific rationale for their selection. These indicators are aimed at quantifying and improving the adherence to guideline-recommended clinical practice and improving patient outcomes.

Skeletal muscle size, function, and adiposity with lifelong aerobic exercise

We examined the influence of lifelong aerobic exercise on skeletal muscle size, function, and adiposity. Young exercisers [YE; n = 20, 10 women (W), 25 ± 1 yr], lifelong exercisers (LLE; n = 28, 7 W, 74 ± 2 yr), and old healthy nonexercisers (OH; n = 20, 10 W, 75 ± 1 yr) were studied. On average, LLE exercised 5 days/wk for 7 h/wk over the past 52 ± 1 yr. The LLE men were subdivided by exercise intensity [Performance (LLE-P), n = 14; Fitness (LLE-F), n = 7]. Upper and lower leg muscle size and adiposity [intermuscular adipose tissue (IMAT)] were determined via MRI, and quadriceps isotonic and isometric function was assessed. For the quadriceps, aging decreased muscle size, isotonic and isometric strength, contraction velocity (men only), and power (P < 0.05). In women, LLE did not influence muscle size or function. In men, LLE attenuated the decline in muscle size and isometric strength by ~50% (P < 0.05). LLE did not influence other aspects of muscle function, nor did training intensity influence muscle size or function. For the triceps surae, aging decreased muscle size only in the women, whereas LLE (both sexes) and training intensity (LLE men) did not influence muscle size. In both sexes, aging increased thigh and calf IMAT by ~130% (P < 0.05), whereas LLE attenuated the thigh increase by ~50% (P < 0.05). In the LLE men, higher training intensity decreased thigh and calf IMAT by ~30% (P < 0.05). In summary, aging and lifelong aerobic exercise influenced muscle size, function, and adipose tissue infiltration in a sex- and muscle-specific fashion. Higher training intensity throughout the life span provided greater protection against adipose tissue infiltration into muscle.NEW & NOTEWORTHY This is the first study to examine skeletal muscle size, function, and adiposity in women and men in their eighth decade of life that have engaged in lifelong aerobic exercise. The findings reveal sex and upper and lower leg muscle group-specific benefits related to skeletal muscle size, function, and adiposity and that exercise intensity influences intermuscular adiposity. This emerging cohort will further our understanding of the health implications of maintaining exercise throughout the life span.

Effectiveness and core components of infection prevention and control programmes in long-term care facilities: a systematic review

BACKGROUND

Infection prevention and control (IPC) is a measure to prevent healthcare-associated infections in healthcare settings. There is limited evidence of the effectiveness of IPC programmes in long-term care facilities (LTCFs).

AIM

To review and analyse the effectiveness and the components of IPC programmes in LTCFs for older adults.

METHODS

Electronic databases (PubMed, EMBASE, CINAHL and Cochrane CENTRAL) were searched systematically for English-language articles assessing IPC interventions in LTCFs, published over the last decade (2007-2016). The components of IPC programmes were analysed based on the World Health Organization (WHO) manuals for improving IPC activities. Two reviewers independently assessed the quality of studies using the Cochrane risk-of-bias tool and the risk-of-bias assessment tool for non-randomized studies.

FINDINGS

Seventeen studies met the eligibility criteria; 10 studies were randomized trials (58.8%) and the others were non-randomized trials to examine the impact of IPC programmes on infection and/or performance outcomes of healthcare workers. None of the included studies implemented all of the WHO core components. Behavioural change strategies using education, monitoring and feedback were reported to be successful interventions for reducing the threat of healthcare-associated infections. Generally, studies using four or more elements of the WHO multi-modal strategy reported significant reductions in infection rates.

CONCLUSIONS

There is some evidence for the effectiveness of IPC interventions using education, monitoring, feedback and four or more elements of the WHO multi-modal strategy to control healthcare-associated infections in LTCFs.

[Total broncho-alveolar lavage in respiratory diseases among coal mining workers]

To prevent progressive lung ventilation disorders, to lower inflammatory activity in respiratory diseases, to prevent pneumoconiosis in coal miners, total broncho-alveolar lavage was included into therapeutic and prophylactic measures system. Results are reduction of lung ventilation disorders progression over 5-year observation, lower intensity of tracheo- bronchial inflammation in miners with chronic respiratory diseases.

Impact of warm ischemia time on survival after heart transplantation

BACKGROUND

There is little data available on the specific effects of warm ischemia time (WIT) as opposed to cold ischemia or storage time. With current research endeavors focusing on warm continuous perfusion, storage of donor hearts, and utilization of hearts from non-heart-beating donors, the impact of WIT on outcomes is increasingly relevant. The aim of this study was to analyze our results in cardiac transplantation with specific focus on the impact of WIT.

METHODS

A retrospective review of 206 patients who underwent orthotopic heart transplantation at our institution between June 2001 and November 2010 was performed. Donor, recipient, and operative factors were analyzed. The main outcome variables were all cause mortality, survival, and primary graft failure.

RESULTS

WIT of >80 minutes was associated with reduced survival compared with a shorter WIT of <60 minutes. Multivariate analysis showed increasing donor age to be the most significant variable associated with increased risk of mortality (hazard ratio 1.04; P = .004) per year of increasing donor age.

CONCLUSIONS

This study has demonstrated a reduced survival in heart transplant recipients with increased WIT. This finding may be of particular relevance to potential future heart transplantation using organs procured from non-heart-beating donors.

Surgical revision of dysfunctional filtration blebs with bleb preservation, sliding conjunctival flap and fibrin glue

PURPOSE

The introduction of anti-metabolite regimens to glaucoma filtration surgery has improved post-operative intraocular pressure (IOP) control; however, it has also increased the frequency of dysfunctional blebs. In this study, we report a surgical technique for the repair of trabeculectomy blebs using bleb preservation, a sliding conjunctival flap, and fibrin glue.

METHODS

This study is a retrospective, non-comparative, consecutive case series involving 10 eye samples collected from 10 patients (6 M : 4 F) with one or a combination of bleb overfiltration, dysesthesia, thinning, leak, or blebitis, in which a conjunctival flap was advanced over the failing bleb and secured in place using fibrin glue and sutures.

RESULTS

All patient eyes had symptom resolution post-operatively. There were no bleb leaks or hypotonous eyes after an average follow-up of 15.2 months (range: 6-31 months). Three patients required needling augmented with 5-fluorouracil needling to maintain IOP control. IOP decreased from a mean of 13.6+/-1.8 mm Hg (with a mean of 0.7 glaucoma medications) pre-operatively to 11.7+/-0.9 mm Hg (with a mean of 0.9 glaucoma medications).

CONCLUSION

Conjunctival flap advancement with bleb preservation and adjunctive fibrin glue is a successful technique used for the treatment of bleb dysfunction. The major advantages compared with other techniques are preservation of IOP control and reduced post-operative complications, such as wound leak and the need for re-suturing.

Influence of aging on the in vivo properties of human patellar tendon

Tendons are important for optimal muscle force transfer to bone and play a key role in functional ability. Changes in tendon properties with aging could contribute to declines in physical function commonly associated with aging. We investigated the in vivo mechanical properties of the patellar tendon in 37 men and women [11 young (27 +/- 1 yr) and 26 old (65 +/- 1 yr)] using ultrasonography and magnetic resonance imaging (MRI). Patella displacement relative to the tibia was monitored with ultrasonography during ramped isometric contractions of the knee extensors, and MRI was used to determine tendon cross-sectional area (CSA) and signal intensity. At peak force, patellar tendon deformation, stress, and strain were 13 (P = 0.05), 19, and 12% less in old compared with young (P < 0.05). Additionally, deformation, stiffness, stress, CSA, and length were 18, 35, 41, 28, and 11% greater (P < 0.05), respectively, in men compared with women. After normalization of mechanical properties to a common force, no age differences were apparent; however, stress and strain were 26 and 22% higher, respectively, in women compared with men (P < 0.05). CSA and signal intensity decreased 12 and 24%, respectively, with aging (P < 0.05) in the midregion of the tendon. These data suggest that differences in patellar tendon in vivo mechanical properties with aging are more related to force output rather than an age effect. In contrast, the decrease in signal intensity indirectly suggests that the internal milieu of the tendon is altered with aging; however, the physiological and functional consequence of this finding requires further study.

Patient and spouse perceived quality of life five years after coronary artery bypass graft surgery

Health-related quality of life (HRQoL) was examined in patients’ and their respective spouses’ perspectives five years after cardiac bypass surgery. Participants completed the Short-Form 36 (SF-36) which consists of eight domains and two component summary scores measuring physical and mental HRQoL (PCS and MCS respectively). Paired t tests were used to compare couples responses (n=56 pairs) with spouses recording higher (i.e. better scores) in the physical-related domains although differences were not significant. Statistically significant results were found between patients and spouses in emotional role, mental health, social functioning, energy/vitality and general health perceptions (p< 0.001). The PCS were very similar for both the patient and spouses sample (45.9 v. 45.8 respectively, p = .829) and the MCS was significantly higher in the patients compared to the spouses (54.8 v. 47.7, p < .001). The results demonstrated that spouses could accurately report the physical aspects of HRQoL but not the mental health of their partner.

Influence of concurrent exercise or nutrition countermeasures on thigh and calf muscle size and function during 60 days of bed rest in women

AIM

The goal of this investigation was to test specific exercise and nutrition countermeasures to lower limb skeletal muscle volume and strength losses during 60 days of simulated weightlessness (6 degrees head-down-tilt bed rest).

METHODS

Twenty-four women underwent bed rest only (BR, n = 8), bed rest and a concurrent exercise training countermeasure (thigh and calf resistance training and aerobic treadmill training; BRE, n = 8), or bed rest and a nutrition countermeasure (a leucine-enriched high protein diet; BRN, n = 8).

RESULTS

Thigh (quadriceps femoris) muscle volume was decreased (P < 0.05) in BR (-21 +/- 1%) and BRN (-24 +/- 2%), with BRN losing more (P < 0.05) than BR. BRE maintained (P > 0.05) thigh muscle volume. Calf (triceps surae) muscle volume was decreased (P < 0.05) to a similar extent (P > 0.05) in BR (-29 +/- 1%) and BRN (-28 +/- 1%), and this decrease was attenuated (P < 0.05) in BRE (-8 +/- 2%). BR and BRN experienced large (P < 0.05) and similar (P > 0.05) decreases in isometric and dynamic (concentric force, eccentric force, power and work) muscle strength for supine squat (-19 to -33%) and calf press (-26 to -46%). BRE maintained (P > 0.05) or increased (P < 0.05) all measures of muscle strength.

CONCLUSION

The nutrition countermeasure was not effective in offsetting lower limb muscle volume or strength loss, and actually promoted thigh muscle volume loss. The concurrent aerobic and resistance exercise protocol was effective at preventing thigh muscle volume loss, and thigh and calf muscle strength loss. While the exercise protocol offset approximately 75% of the calf muscle volume loss, modification of this regimen is needed.

Trabeculectomy: a training dilemma

AIM/PURPOSE

The incidence of trabeculectomy is falling due to more effective medical therapies, resulting in fewer trabeculectomy operations carried out by Ophthalmology trainees. This study audits all primary trabeculectomy procedures performed publicly at the two major teaching hospitals in Brisbane, Australia.

METHOD

A retrospective consecutive case review analysing the rates and outcomes of Ophthalmology trainee versus consultant trabeculectomies that were performed during the period May 1996-May 2002.

RESULTS

In all, 290 primary trabeculectomies were undertaken during the study period. Ophthalmology trainees performed 95 (33%) of the procedures. This represents a rate of 1.6 trabeculectomy procedures per year per trainee (10 trainees train at the two hospitals per year). Rates of complications postoperatively were similar between the trainee and consultant groups. The percentage of patients achieving an IOP < or =15 mmHg on no medication at their last follow-up was low at 30%.

CONCLUSIONS

The results of this study suggests that improvement in trabeculectomy technique is required. In order to acquire skills, wetlab training on artificial or animal eyes may become mandatory within the training programmes, otherwise trabeculectomy will become the realm of sub-specialists with glaucoma fellowship training.

Pig eye trabeculectomy—a wet-lab teaching model

PURPOSE

A teaching model for trabeculectomy is described using pig eyes prepared in formalin.

METHOD

The model enables trainee surgeons to practice various aspects of tissue handling required for successful trabeculectomy including the construction of a fornix-based conjunctival flap, scleral flap with buried releasable sutures, and water-tight conjunctival closure.

RESULTS

Exposure to the necessary skills required to perform trabeculectomy surgery can be improved by the use of wet laboratory practice.

CONCLUSIONS

Trabeculectomy surgery experience is becoming more limited as fewer procedures are being performed due to the efficacy of recent medications. Wet laboratories will become an increasingly important aspect of a comprehensive ophthalmology training programme.

Effects of lamellar keratotomy on postkeratoplasty astigmatism

AIM

To determine the changes in postkeratoplasty astigmatism induced by lamellar keratotomy.

METHODS

A prospective, non-randomised comparative trial of patients undergoing a hinged lamellar corneal flap for treatment of significant astigmatism after penetrating keratoplasty. Uncorrected visual acuity, best corrected visual acuity, refraction, and corneal topography were assessed at 1 and 3 months after the lamellar keratotomy.

RESULTS

17 eyes in 16 patients (13 M, 3F) were included in the study (mean age 48.2 years; range 20-86 years). Six of 17 eyes (35.3%) changed more than 1 dioptre (D) in spherical equivalent by 3 months. Nine of 17 eyes (52.9%) changed more than 1 D in sphere by 3 months. 12 of 17 eyes (70.6%) changed more than 1 D in refractive cylinder. Seven patients of 15 (46.7%) changed more than 1 D in corneal power as measured topographically. Five of 17 eyes (29.4%) changed in refractive cylinder axis more than 15 degrees and this was similar to the change measured topographically of four of 15 eyes (26.7%). Vector analysis showed 60% of eyes had a surgically induced astigmatism (SIA) vector of more than 1 D, including a net corneal astigmatism decrease of more than 1 D in four eyes and increase of more than 1 D in two eyes at 3 months after surgery. Complications of the lamellar keratotomy included two partial buttonholes and one partial wound dehiscence.

CONCLUSIONS

The creation of a lamellar flap alone can have significant effects on the astigmatism following penetrating keratoplasty. LASIK for correction of postkeratoplasty astigmatism may be more accurately performed as a two stage procedure rather than a single stage, after the corneal effects of the lamellar keratotomy have stabilised.

Cyclodiode photocoagulation for refractory glaucoma after penetrating keratoplasty

OBJECTIVE

This study analyzes the results of intraocular pressure (IOP) reduction by contact diode cycloablation (cyclodiode) in cases of refractory glaucoma after penetrating keratoplasty.

DESIGN

Retrospective noncomparative, interventional case series.

PARTICIPANTS

Twenty-eight eyes in 28 patients attending the Moorfields Eye Hospital.

INTERVENTION

Cyclodiode (40 applications x 1.5 W x 1.5 seconds over 270-300 degrees ) was used to control the IOP in refractory glaucoma after penetrating keratoplasty.

MAIN OUTCOME MEASURES

Postoperative IOP, graft status, visual acuity, and number of antiglaucoma medications were recorded after cyclodiode treatment.

RESULTS

Cyclodiode resulted in a reduction of IOP from a median of 33 mmHg (interquartile range [28, 40.5]) to a median of 15 mmHg (interquartile range [12, 20.5]). Most patients had a significant lowering in IOP with a median reduction of 16 mmHg (interquartile range [12, 25]; P < 0.0001). IOPs of 6 to 21 mmHg were achieved in 22 patients (79%). Sixteen patients (57%) required more than one treatment with cyclodiode to control the IOP, with three patients (11%) requiring three treatments and two patients (7%) requiring four treatments. Visual acuity improved (> two Snellen lines of acuity) in three patients (11%) and remained the same (+/- one Snellen line) in 17 patients (61%). The mean number of antiglaucoma medications before cycloablation was 2.6 and was 1.8 after treatment (P < 0.001). Of the 19 patients (68%) with originally clear grafts, three grafts (16%) developed opacification. One patient (4%), with a history of nanophthalmos and recurrent uveal effusion, had delayed hypotony (IOP < 6 mmHg) occurring 46 months after the diode treatment. All patients had at least 6 months follow-up.

CONCLUSIONS

These patients have often undergone multiple previous complicated ocular interventions and are often not suitable for filtration surgery. Reduction of IOP with maintenance of visual acuity and a good safety profile was achieved in most patients in this study but may require multiple treatments. We propose cyclodiode as an effective treatment for many patients in the management of refractory glaucoma after penetrating keratoplasty.

Calf muscle strength in humans

In an effort to measure strength characteristics of the calf muscles, 18 subjects (14 male, 4 female, age =34.3+/-2.4yrs) were tested using a specially designed torque velocity device (TVD). This TVD is a hardware interface with the subject's lower leg which stabilizes the leg for calf muscle strength measurements. Calf muscle strength measurements consisted of 1) isometric force production at ankle angles of 80, 90, and 100 degrees of plantar flexion, 2) peak torque at six isokinetic angular velocities 0.52, 1.05, 2.09, 3.14, 4.19, and 5.24 rad x s(-1), and 3) a fatigue test consisting of 30 maximal contractions at 3.14 rad x s(-1). The greatest force production occurred at 80 degrees of ankle plantar flexion (148.5 +/- 40.2 Nm). Isokinetic force production ranged from 114.1 +/- 24.7 Nm at 0.52 rad x s(-1) to 16.8 +/- 6.5 Nm at 5.24 rad x s(-1). A fatigue test consisting of 30 maximal repetitions at 3.14 rad x s(-1) resulted in a 61 +/- 15% decline in force production. To assess reproducibility and day to day variation, measurements at 1.05 and 2.09 rad x s(-1) were made during five different trials in a single day and one trial per day for three days, respectively. The within subject coefficient of variation was 2.6 to 6.5% for reproducibility and 1.9 to 7.4% for day to day variation. Magnetic resonance imaging (MRI) of the lower limb and muscle biopsy specimens from the gastrocnemius (lateral head) and soleus muscles were obtained to examine the relationship between strength and morphological characteristics of the calf muscles. Cross-sectional area of the primary plantar flexors (gastrocnemius and soleus) was 47.9 +/- 1.3 cm2 while muscle volume was 642 +/- 16 cm3. Muscle fiber composition of the gastrocnemius and soleus averaged 57 +/- 2 and 85 +/- 3% type I fibers, respectively. A poor correlation was found between fiber type and maximal isometric force production (r =0.38; p>0.05). However, calf muscle strength and muscle size was positively correlated (r = 0.76; p < 0.05). These data indicate that using the TVD interface to stabilize the lower leg is a reliable and reproducible procedure for the measurement of calf muscle strength.

Penetrating keratoplasty for silicone oil keratopathy

PURPOSE

Penetrating keratoplasty for silicone oil keratopathy is associated with high risks and limited visual prognosis. This study examined the outcomes and factors influencing graft failure.

METHODS

A retrospective, non-comparative, interventional case series of patients attending Moorfields Eye Hospital, London.

RESULTS

A total of 24 penetrating keratoplasties were performed in 17 patients (13 men and four women) from 1991 to 2000. The mean age of patients undergoing surgery was 43.6 years (range 17-84 years, SD +/- 21.0). Silicone oil was removed before or during the time of initial penetrating keratoplasty in nine patients (52.9%) and left in situ in eight patients (47.1%). Ten out of 24 grafts survived (41.7%). The median duration of graft survival was 21 months (range 2 weeks-98 months) with median duration of follow up 33 months (range 2-100 months). At final follow up, the number of patients with a clear graft who had oil removed before or during the time of penetrating keratoplasty was seven out of 10 (70.0%). Risk factors for graft failure included hypotony, multiple keratoplasty, corneal neovascularization, rejection episode, silicone oil left in situ and postoperative glaucoma.

CONCLUSIONS

Management of these complex patients requires a combined approach from anterior segment and vitreoretinal subspecialties. The long-term success of the graft can be improved if silicone oil is removed prior or during the time of penetrating keratoplasty.

Comparison of a space shuttle flight (STS-78) and bed rest on human muscle function

The purpose of this investigation was to assess muscle fiber size, composition, and in vivo contractile characteristics of the calf muscle of four male crew members during a 17-day spaceflight (SF; Life and Microgravity Sciences Spacelab Shuttle Transport System-78 mission) and eight men during a 17-day bed rest (BR). The protocols and timelines of these two investigations were identical, therefore allowing for direct comparisons between SF and the BR. The subjects' age, height, and weight were 43 +/- 2 yr, 183 +/- 4 cm, and 86 +/- 3 kg for SF and 43 +/- 2 yr, 182 +/- 3 cm, and 82 +/- 4 kg for BR, respectively. Calf muscle strength was examined before SF and BR; on days 2, 8, and 12 during SF and BR; and on days 2 and 8 of recovery. Muscle biopsies were obtained before and within 3 h after SF (gastrocnemius and soleus) and BR (soleus) before reloading. Maximal isometric calf strength and the force-velocity characteristics were unchanged with SF or BR. Additionally, neither SF nor BR had any effect on fiber composition or fiber size of the calf muscles studied. In summary, no changes in calf muscle strength and morphology were observed after the 17-day SF and BR. Because muscle strength is lost during unloading, both during spaceflight and on the ground, these data suggest that the testing sequence employed during the SF and BR may have served as a resistance training countermeasure to attenuate whole muscle strength loss.

Biomechanical comparison of five different atlantoaxial posterior fixation techniques

STUDY DESIGN

Five different reconstructions of the atlantoaxial complex were biomechanically compared in vitro in a nondestructive test.

OBJECTIVES

To determine whether non-bone graft-dependent one-point fixation affords stability levels equivalent to three-point reconstructions.

SUMMARY OF BACKGROUND DATA

Previous investigations have demonstrated that three-point fixation, using bilateral transarticular screws in combination with posterior wiring, provide the most effective resistance to minimize motion around C1-C2. However, placement of transarticular screws is technically demanding. Posterior wiring techniques affording one-point fixation have failure rates of approximately 15%, with failure considered to be secondary to structural bone graft failures. One-point, non-bone graft-dependent fixations have not been tested.

METHODS

Eight human cervical specimens, C0-C3 were loaded nondestructively. Unconstrained three-dimensional segmental motion was measured. The reconstructions tested were two one-point fixations, one two-point fixation, and two three-point fixations.

RESULTS

Under axial rotation two and three-point reconstructions provided better stiffness than the one-point reconstructions (P < 0.05). During flexion-extension, higher stiffness levels were observed in one- and three-point fixations when compared with the intact spine (P < 0.05). In lateral bending no significant differences were observed among the six groups, although the trend was that reconstructions including transarticular screws provided greater stability than one-point fixations.

CONCLUSION

The current findings substantiate the use of three-point fixation as the treatment of choice for C1-C2 instability. [l: atlantoaxial fixation, biomechanics, cervical spine, instability, spinal instrumentation, transarticular screws]

Biomechanical properties of anterior thoracolumbar multisegmental fixation: an analysis of construct stiffness and screw-rod strain

STUDY DESIGN

Three types of anterior thoracolumbar multisegmental fixation were biomechanically compared in construct stiffness and rod-screw strain.

OBJECTIVES

To investigate the effects of rod diameter and rod number on construct stiffness and rod-screw strain in anterior thoracolumbar multisegmental instrumentation.

SUMMARY OF BACKGROUND DATA

No studies have been undertaken to investigate the biomechanical effects of rod diameter and rod number in thoracolumbar anterior instrumentation.

METHODS

Ten fresh-frozen calf spines (T13-L5) were used. After intact analysis, a total discectomy and transection of the ALL and PLL were performed at L1-L2, L2-L3, and L3-L4 with intervertebral reconstruction using carbon fiber cages. Three types of anterior fixation were then performed at L1-L4: 1) 4.75-mm diameter single-rod, 2) 4.75-mm dual-rod, and 3) 6.35-mm single-rod systems. Single screws at each vertebra were used for single-rod and two screws for dual-rod fixation. These systems share the same basic design except rod diameter. Nondestructive biomechanical testing was performed and included compression, torsion, flexion-extension, and lateral bending. Construct stiffness and rod-screw strain of the three reconstructions were compared.

RESULTS

The 6.35-mm single-rod fixation significantly improved construct stiffness compared with the 4.75-mm single rod fixation only under torsion (P < 0.05). The 4. 75-mm dual rod construct resulted in significantly higher stiffness than did both single-rod fixations (P < 0.05), except under compression. No statistical differences were observed in rod-screw strain between the two types of single rods, whereas dual-rod reconstruction exhibited less rod-screw strain (P < 0.05).

CONCLUSIONS

For single-rod fixation, increased rod diameter neither markedly improved construct stiffness nor affected rod-screw strain, indicating the limitations of a single-rod system. In thoracolumbar anterior multisegmental instrumentation, the dual-rod fixation provides higher construct stiffness and less rod-screw strain compared with single-rod fixation.

Revision strategies for salvaging or improving failed cylindrical cages

STUDY DESIGN

This is a review of 20 patients who experienced failure of threaded interbody fusion cages and underwent surgical correction.

OBJECTIVE

To review the causes and possible treatment strategies for failed cylindrical cages.

SUMMARY OF BACKGROUND DATA

Intraoperative complications have been described in the past; however, management of the postoperative patient with failure of interbody fusion devices has not been described.

METHODS

In 20 patients with failed threaded titanium fusion cages (18 Bagby and Kuslich Devices [BAK; Sulzer-Spine Tech, Minneapolis, MN], 2 Ray Threaded Fusion Cages [Ray TFC; Surgical Dynamics, Norwalk, CT) who underwent revision surgery, all had failure before successful arthrodesis was achieved. Eight of the original titanium cages had been inserted anteriorly (7 laparoscopically), and 12 had been inserted for posterior interbody lumbar fusion. Before the revision surgery, five of the implants were thought to be solid by the referring surgeon, but pseudarthrosis was clearly present in all. In addition, 14 other explanted BAK devices were subjected to undecalcified histologic preparation, quantitative histomorphometry, and histopathologic analysis.

RESULTS

The average length of time before revision surgery (implant duration) was 31.8 weeks (range, 1-156 weeks). The most common revision procedure was posterior exploration of the symptomatic nerve root with foraminotomy for unrecognized lateral recess stenosis (11 cases) or excision of iatrogenically herniated intervertebral disc fragments (4 cases). However, four cages inserted through posterior exposure during an interbody lumbar fusion procedure had to be removed because of migration into the spinal canal. In nine cases posterior pedicle screw instrumentation was necessary in addition to posterolateral fusion using iliac crest bone grafting.

CONCLUSIONS

All 20 cages failed because of surgical technique rather than an intrinsic defect in fusion cage technology. The factors associated with failure of the original insertion procedure were failure to achieve adequate distraction of the anulus fibrosis; undersized cages, especially when placed through the posterior interbody lumbar fusion approach; cerebrospinal fluid leakage or pseudomeningocele; Type 2 diabetes mellitus; the use of local bone graft rather than iliac crest inside the cage; anterior insertion in an excessively lateral position resulting in symptoms of a far lateral disc herniation; and failure to identify the spinal midline during an anterior approach.

Knowledge of sunlight effects on the eyes and protective behaviors in adolescents

The knowledge of the effects of sunlight on the eyes and protective behaviors were studied in an adolescent population. A group of 652 systematically sampled students aged between 13 and 17 years was surveyed with a standardized questionnaire in Brisbane, Australia in October-November, 1995. Survey data on the knowledge of sunlight effects on the eyes, ultraviolet light, eye and body protection as well as risk factors for ultraviolet (UV) exposure were relatively ranked and totalled to give overall scores. Of the 652 subjects, 330 (51%) were female. Most subjects (568 or 88%) were aged between 15 and 16 years. Overall, this group of subjects demonstrated a moderate level of knowledge with respect to UV, sunlight and the eyes. The knowledge of the effects of sunlight and body protection was higher than the knowledge of the effects of sunlight and eye protection. Almost three-quarters (462 or 71%) of the subjects owned a pair of sunglasses. The mean age at which subjects started to wear sunglasses was 10.4 years. However, most subjects (528 or 81%) only wore sunglasses occasionally or not at all. The reported frequency of wearing sunglasses was significantly related to personal, family and peer attitudes to such use, but not to media advertizing. Assessment of adolescent knowledge is important in the formulation of health promotion strategies designed to prevent excessive UV exposure at this young age.

Proximal kyphosis after posterior spinal fusion in patients with idiopathic scoliosis

STUDY DESIGN

For this retrospective study, preoperative and postoperative radiographs of posterior spinal fusions for idiopathic scoliosis were reviewed.

OBJECTIVES

To determine the prevalence and possible causes of proximal kyphosis after posterior spinal fusion for idiopathic scoliosis.

SUMMARY OF BACKGROUND DATA

Proximal kyphosis has been anecdotally noted after the insertion of Harrington rods and after use of the new posterior multisegmented hook/rod systems. In this study no attempt was made to determine whether this condition is painful or an adverse outcome for the patient or just a radiographic abnormality; however, it is suspected that this may be a problem in the long term, and it may be worthwhile to try to avoid it if predictive values can be ascertained.

METHODS

Patients with adolescent idiopathic scoliosis who had undergone posterior spinal fusion not extending above T3 with good-quality radiographs of the proximal thoracic spine and a minimum 2-year follow-up were studied. Of the 106 patients who underwent posterior spinal fusion from 1990 through 1994, 69 met the inclusion criteria. Abnormal kyphosis from T2 to the proximal level of the instrumented fusion was defined as kyphosis of more than 5 degrees above the summed normal angular segments.

RESULTS

Of 69 patients, 37 (54%) had normal proximal kyphosis, and 32 (46%) of the 69 were defined as having abnormal proximal kyphosis. In the 32 patients with abnormal proximal kyphosis, the measurement from T2 to the fusion was 10.3 degrees before surgery and 21.2 degrees after surgery. The normal group had kyphosis measuring 2.7 degrees from T2 to fusion before surgery and 5.3 degrees after surgery (P < 0.00001). Junctional kyphosis in the kyphosis group measured 6.5 degrees before surgery and 12.6 degrees after surgery, compared with normal kyphosis of 1.7 degrees and 2.6 degrees, respectively (P < 0.00001). When analyzing who would develop proximal kyphosis, preoperative one-level junctional kyphosis of more than 5 degrees above the proposed proximal instrumented vertebrae was shown to have the highest sensitivity (78%) and specificity (84%).

CONCLUSIONS

In this study, 32 (46%) of 69 patients had abnormal proximal kyphosis after undergoing posterior spinal fusion. A preoperative junctional kyphosis of more than 5 degrees above the proposed proximal instrumented vertebrae indicates that extending the fusion to a higher level in the thoracic spine would be beneficial in avoiding this problem.

Improving calf muscle strength in patients with spastic equinovarus deformity by transfer of the long toe flexors to the Os calcis

The split tibialis anterior tendon transfer (SPLATT), Achilles tendon lengthening, and toe flexor release are proven and effective procedures for correcting a spastic equinovarus deformity of the foot. Paresis is a prominent feature of upper motoneuron syndrome. Lengthening the Achilles tendon, although necessary to correct the equinus, further weakens the gastrocnemius-soleus muscle group. The calf paresis commonly results in the need for an ankle-foot orthosis (AFO) during ambulation. Previous studies have shown that despite the correction of the equinovarus deformity, only one third of patients were able to ambulate without an AFO. The need for continued use of an AFO was because of insufficient calf strength to stabilize the tibia during late stance when the body mass is anterior to the ankle joint. This study prospectively evaluated the results of transfer of the flexor hallucis longus (FHL) and flexor digitorum longus (FDL) to the os calcis in 30 patients. The transfer was done in an effort to augment the strength of the gastrocnemius-soleus muscle complex. Twenty-five patients in group I (the control group) underwent SPLATT, Achilles tendon lengthening, and toe flexor release. Thirty patients in group II (the study group) underwent the identical procedures plus the additional FHL and FDL transfer to the os calcis. Postoperatively, the varus and toe flexion deformities were corrected in all feet. In group II, two feet had a mild residual equinus that did not interfere with ambulation. Of the 11 patients who were not independent community ambulators in group I, 7 (64%) improved ambulatory status by at least one level after surgery. Of the 15 patients who were not independent community ambulators in group II, 14 (93%) improved ambulatory status by at least one level after surgery. In group I, 10 of 25 (40%) of the patients were brace free at follow-up. In group II, 21 of 30 (70%) were brace free at follow-up (c2, P =.025). These results indicate that the addition of an FHL and FDL transfer to the os calcis at the time of SPLATT, Achilles tendon lengthening, and toe flexor release improves calf strength and allows greater increase in function and less reliance on orthotics.

Clinicopathological report: mucinous carcinoma of the eyelid

BACKGROUND

Mucinous carcinoma of the skin is a rare tumour that may involve the peri-ocular region.

METHODS/RESULTS

A case report is presented of a 73-year-old woman with a right upper lid tumour, initially diagnosed as a basal cell carcinoma. Excisional biopsy of the residual tumour revealed mucinous carcinoma. Re-examination of the original pathology proved to be mucinous carcinoma, originating in the eyelid skin. Further treatment involved wide local resection and reconstruction. Systemic investigations were undertaken to exclude the possibility of metastatic mucinous carcinoma.

CONCLUSION

This case is presented to alert ophthalmologists to the occurrence of this tumour in the periocular region, to highlight the importance of surgical excision with wide margins and the need for systemic investigation to exclude a primary malignancy in other sites, in particular the gastrointestinal system and breast.

Angle-closure glaucoma after laser treatment for retinopathy of prematurity

Laser photocoagulation has become the standard for treatment of retinopathy of prematurity. In general, it has been found to be a safe and effective means of retinal ablation. We report a case of angle-closure glaucoma in an infant after diode laser treatment for retinopathy of prematurity, which required bilateral surgical peripheral iridectomies.

Corneoscleral transplantation for end stage corneal disease

AIM

To describe the prognosis and complications of corneoscleral transplantation in the management of end stage eye disease.

METHODS

A case series is presented of 23 patients who have undergone corneoscleral transplantation (> or = 11 mm). Patients were examined for visual acuity, intraocular pressure, recurrence of disease process, epithelialisation of the graft, signs of rejection, and other potential complications.

RESULTS

14 patients retained their eye, with six maintaining a clear graft. Vision ranged from 6/30 to no perception of light. 13 patients developed glaucoma (range 25-69 mm Hg), with six patients requiring surgical intervention. 12 patients required tarsorrhaphy to promote epithelialisation. Only two grafts resulted in typical rejection.

CONCLUSIONS

The technique of corneoscleral transplantation can salvage otherwise end stage eye disease, but the results are poor with respect to maintenance of vision. These patients need careful follow up because of potential complications of glaucoma, epithelial defects, rejection, and recurrence of disease.

Elbow valgus stress radiography in an uninjured population

Valgus instability of the elbow joint is a clinical diagnosis. However, many authors describe valgus stress radiographs as an aid in making this diagnosis. We studied valgus stress radiographs of 20 men (40 elbows) and 20 women (40 elbows), none with a history of elbow trauma or instability. The medial ulnohumeral distance was measured with no stress, valgus stress by gravity, and an applied valgus stress of 25 N (approximately 5 pounds). Measurements were made with the elbow positioned in extension and in 30 degrees of flexion. The increase in medial ulnohumeral gapping with either gravity or 5 pounds of stress was statistically significant at both extension and 30 degrees of flexion compared with the unstressed condition. The difference in ulnohumeral gapping between gravity stress and 5 pounds of valgus stress in extension and in 30 degrees of flexion was also significant. We found no differences with regard to hand dominance or sex. We conclude that uninjured elbows have significant medial ulnohumeral gapping on valgus stress radiography. Although this is an important tool in diagnosing valgus instability of the elbow, it may yield a false-positive assessment of valgus instability. Valgus stress radiographs comparing contralateral elbows may reduce the false-positive rate since there appears to be no significant difference in medial ulnohumeral gapping between the two elbows.

Subretinal perfluorodecalin toxicity

BACKGROUND

Subretinal injection of perfluorocarbon liquids (PFCL) can occur during vitreoretinal surgery. The long-term effects of this complication are not well established.

METHODS

A case report is presented of a patient with retained subretinal perfluorodecalin following retinal detachment repair for a giant retinal tear.

RESULTS

In the early postoperative period, the macular retinal pigment epithelium (RPE) became opalescent in appearance and by 2 months postoperatively the patient developed macular RPE atrophy with resulting poor central vision.

CONCLUSIONS

Toxicity of subretinal perfluorodecalin causing RPE atrophy is proposed. We recommend all traces of PFCL should be removed if possible.

Retrospective study of ocular surface squamous neoplasia

BACKGROUND

Ocular surface squamous neoplasia (OSSN) encompasses the conditions of simple dysplasia to carcinoma in situ to invasive squamous cell carcinoma. It has a high rate of recurrence after treatment and the potential to metastasize. The present retrospective study was aimed at further defining the characteristics and clinical course of OSSN.

METHODS

With ethical approval, the records of all major pathology laboratories in Queensland were surveyed. Two hundred and eighty-eight cases were identified: 155 dysplasia, 71 carcinomas in situ and 62 invasive squamous cell carcinoma. The records were analysed and an attempt was made to contact and re-examine the patients.

RESULTS

Ocular surface squamous neoplasia occurs mainly in males (78.5%) with a mean age of 60.1 years (range 20-88 years). They present as irritation (40.1%) and are located usually at the limbus (87.8%). The majority of OSSN are treated by simple excision (87.5%), after which there is a high rate of recurrence (23.3%). The main predictors for recurrence include histological grade of the lesion, corneal location and larger size (> 2 mm).

CONCLUSIONS

Management of OSSN requires adequate excision and careful follow up to monitor any recurrence. As with other ultraviolet light-related conditions, preventative measures must remain the key to disease control.

Congenital orbital teratoma

BACKGROUND

The occurrence of proptosis at birth is unusual and may be associated with a variety of tumours and structural abnormalities. Congenital orbital teratoma is a rare cause of congenital proptosis.

METHODS

A case report is presented of a female infant with gross right proptosis.

RESULTS

Computed tomography demonstrated a characteristic multicystic structure with no intracranial involvement. Histological examination found tissues derived from all three germ cell layers, consistent with a congenita orbital teratoma. The tumour was successfully removed preserving the globe and vision.

CONCLUSIONS

This report is an example of how early surgical intervention may allow preservation of the globe and vision in some patients with congenital orbital teratoma.

Cracked acrylic intraocular lens requiring explantation

BACKGROUND

Intraoperative cracking of foldable acrylic posterior chamber intraocular lenses has previously been documented. However, most cracks have resulted in no significant visual impairment.

METHODS

A case report of an acrylic posterior chamber intraocular lens that cracked during folding.

RESULTS

The crack in the lens resulted in significant optical disturbance and required explanation and insertion of another lens.

CONCLUSIONS

Acrylic intraocular lenses must be folded carefully with appropriate forceps to prevent cracking of the optic.

Ocular surface squamous neoplasia

Ocular surface squamous neoplasia presents as a spectrum from simple dysplasia to carcinoma in situ to invasive squamous cell carcinoma involving the conjunctiva as well as the cornea. It is a distinct clinical entity, although it has been known by a variety of different names throughout the literature. Most commonly it arises in the limbal region, occurring particularly in elderly males who have lived in geographic areas exposed to high levels of ultraviolet-B radiation. Symptoms range from none to severe pain and visual loss. The development of preoperative diagnostic techniques, such as impression cytology, are of value in clinical decision making and follow-up management. Simple excision with adequate margins is currently the best established form of treatment despite trials of other modalities. The course of this disease may be evanescent, but is more frequently slowly progressive and may require exenteration and occasionally may lead to death.

Knowledge of sunlight effects on the eyes and protective behaviors in the general community

The knowledge of sunlight effects on the eyes and protective behaviors was assessed in the general community of Brisbane, Australia. Five hundred people were systematically sampled and surveyed via a telephone questionnaire. Of the participants, 279 (56%) were female and 258 (52%) were aged 40 years or less. Levels of knowledge were found to be lower in the older subjects, those with dark complexions and outdoor workers. Most were unaware of specific ultraviolet light related eye diseases such as cataract, pterygium and eye cancer. Three hundred and ninety (78%) wore sunglasses > 10% of the time while outdoors during the day; the most common reasons for wearing included protection from glare in 254 (65%) and driving in 60 (15%). Ninety-six (19%) never wore sunglasses, the most common reasons being inconvenience in 16 (17%), thought unnecessary in 16 (17%) and uncomfortable in 13 (14%). Promotion of sun protection to prevent ultraviolet light related diseases should include information on the eye. This information is important for establishing preventative behaviors and the selection of optimal eye protective measures.

Nicotine patch therapy for smoking cessation combined with physician advice and nurse follow-up. One-year outcome and percentage of nicotine replacement

OBJECTIVE

To determine the efficacy of a 22-mg nicotine patch combined with the National Cancer Institute program for physician advice and nurse follow-up in providing withdrawal symptom relief, 1-year smoking cessation outcome, and percentage of nicotine replacement.

DESIGN

Randomized, double-blind, placebo-controlled trial.

SUBJECTS

Two-hundred forty healthy volunteers who were smoking at least 20 cigarettes per day.

INTERVENTIONS

Based on the National Cancer Institute program, subjects received smoking cessation advice from a physician. Follow-up and relapse prevention were provided by a study nurse during individual counseling sessions. Subjects were randomly assigned to 8 weeks of a 22-mg nicotine or placebo patch.

MAIN OUTCOME MEASURES

Abstinence from smoking was verified by expired air carbon monoxide levels. Withdrawal symptoms were recorded during patch therapy, and the percentage of nicotine replacement was calculated by dividing serum nicotine and cotinine levels at week 8 of patch therapy by levels obtained while smoking.

RESULTS

Higher smoking cessation rates were observed in the active nicotine patch group at 8 weeks (46.7% vs 20%) (P < .001) and at 1 year (27.5% vs 14.2%) (P = .011). Higher smoking cessation rates were also observed in subjects assigned to the active patch who had lower serum levels of nicotine and cotinine at baseline, and withdrawal symptom relief was better in the active patch group compared with placebo.

CONCLUSIONS

Clinically significant smoking cessation can be achieved using nicotine patch therapy combined with physician intervention, nurse counseling, follow-up, and relapse prevention. Smokers with lower baseline nicotine and cotinine levels had better cessation rates, which provides indirect evidence that they had more adequate nicotine replacement with this fixed dose of transdermal nicotine than those smokers with higher baseline levels.

Risk factors in the development of ocular surface epithelial dysplasia

BACKGROUND

Ocular surface epithelial dysplasia involves a spectrum of diseases ranging from only minor eye irritation to blindness and potentially death.

METHODS

A case-control study involving 60 patients with ocular surface epithelial dysplasia treated between 1972 and 1991 and 60 age- and sex-matched individuals was conducted to compare relative ultraviolet light exposures over their lifetimes. A standardized self-administered ultraviolet exposure questionnaire was used for assessment.

RESULTS

Risk factors identified include phenotypic features such as fair skin (odds ratio [OR], 5.4; 95% confidence interval [CI], 1.1, 25.6), pale iris (OR, 1.8; 95%; CI, 0.9, 3.8), and propensity to sunburn (OR, 3.8; 95% CI, 0.7, 19.7), history of previous skin cancers removed (OR, 15; 95% CI, 2.0, 113.6), and being outdoors more than 50% of time in the first 6 years of life while living 30 degrees or less from the equator (OR, 7.5; 95% CI, 1.8, 30.6).

CONCLUSION

These risk factors suggest that ocular surface epithelial dysplasia is an ultraviolet light-related disease.

Incidence of ocular surface epithelial dysplasia in metropolitan Brisbane. A 10-year survey

The ocular histologic records of all hospital and private pathologic laboratories in metropolitan Brisbane, Australia, were surveyed from 1980 through 1989. One hundred thirty-nine cases of histologically proven dysplasia, carcinoma in situ, and invasive carcinoma of the cornea and conjunctiva were identified. The incidence of these conditions in the area surveyed is estimated to be 1.9 per 100,000 per year averaged for 10 years.

Mesenteric occlusive lesion and ileal carcinoids

Occlusion of mesenteric vessels due to fibrosis and adventitial elastosis complicated ileal carcinoids and resulted in infarction of bowel in two patients. Synovial sarcoma antedated the carcinoid syndrome in one patient who died; carcinoma of the breast was discovered one year after hemicolectomy in the other. This rare mesenteric occlusive lesion is associated exclusively with ileal carcinoids; it is poorly recognized and the mortality is high.

Mesenteric occlusive lesion and ileal carcinoids

Occlusion of mesenteric vessels due to fibrosis and adventitial elastosis complicated ileal carcinoids and resulted in infarction of bowel in two patients. Synovial sarcoma antedated the carcinoid syndrome in one patient who died; carcinoma of the breast was discovered one year after hemicolectomy in the other. This rare mesenteric occlusive lesion is associated exclusively with ileal carcinoids; it is poorly recognized and the mortality is high.