Comparison of spherical equivalent refraction and astigmatism measured with three different models of autorefractors.

PURPOSE: The purpose of this study was to compare refractions measured with three different autorefractors. METHODS: The refractive error of each eye of 50 adults aged 17 to 59 years (mean, 30.5 years) was measured without cycloplegia using the Canon R-1 and two newer instruments, the Grand Seiko WR-5100K and the Nidek ARK 700-A. For the first two, an isolated line of 20/100 letters on an ETDRS chart at 4.0 m served as a target, whereas for the Nidek, the subject looked at a picture of a balloon in the instrument. Five readings were taken for each eye, and the data (sphere, negative cylinder power, and axis) were analyzed using Fourier decomposition of the power profile. Each reading was broken down into the spherical equivalent (M) and two Jackson crossed-cylinder vectors, J0 and J45. Right-eye results are reported. RESULTS: The mean spherical equivalent refraction measured by the Canon R-1 was -2.44 D. Measurements from the Grand Seiko were more hyperopic (mean M, -2.01 D), whereas those from the Nidek were more myopic (mean M, -2.66 D). Correlation of M for each pair of autorefractors was 0.99. For J0, the Canon was more minus than the other two instruments by 0.15 D compared with the Nidek and 0.13 D with the Grand Seiko, and on this component, the correlation of the Canon with each of the other two was 0.87. Mean J0 values for the Nidek and Grand Seiko were similar, 0.05 D and 0.03 D, respectively, and mean J45 values were 0.04 D for both instruments. Correlations were 0.97 between these two autorefractors for each of the two components. J45 measured by the Canon was more positive than the other two by 0.06 D. For J45, the correlation of the Canon with the Grand Seiko was 0.40 and with the Nidek was 0.38. In 92% of the eyes, the absolute difference in cylinder power between the Grand Seiko and the Nidek was < or =0.25 D. Only 42% of the differences between the Canon and the Grand Seiko and 40% of the differences between the Canon and the Nidek were this small. CONCLUSIONS: The Canon provided more myopic readings than the Grand Seiko and more hyperopic readings than the Nidek. The Canon measured more astigmatism that did not correlate well with the other instruments, whereas measurements of astigmatism taken by the Nidek and the Grand Seiko showed good agreement. If the Grand Seiko is used in place of the older Canon, the differences in spherical equivalent and astigmatism must be considered.     

Optic disc haemorrhages and vascular abnormalities in a glaucoma population

Purpose: To retrospectively examine the optic disc photographs of a glaucoma population for optic disc haemorrhages, vascular occlusions and vascular abnormalities. Methods: The optic disc photographs of 906 eyes of glaucoma and suspect glaucoma patients were examined. Optic disc photographs were taken annually, where possible, with the follow-up period varying between 1 and 14 years duration (mean, 2.89). Glaucoma patients are regularly reviewed every 4–6 months and glaucoma suspects every 1–2 years, depending on the ophthalmologist. Low-tension glaucoma patients were reviewed more frequently (mean, every 2.6 months). The results of the findings were compared to a control group of 39 subjects with a mean follow-up period of 7 years, using Fisher's exact test. Results: It was found that during the period under review, 7.4% (n= 67) of eyes had optic disc haemorrhages. The highest frequency of optic disc haemorrhages (37.5%) was found in the low tension glaucoma group (P= 0.0001) followed by 11.4% of primary open-angle glaucoma eyes (P= 0.03). In the normal group there were three eyes with optic disc haemorrhages and one with a disc collateral, which constitutes 5.1% vascular changes in this sub-group. Of the study eyes 2.8% had central retinal vein occlusions, 1.3% branch vein occlusion, 1.2% disc vessel abnormalities (loops) and 1.1% disc collaterals. Discrete nerve fibre layer haemorrhages and microaneurysms were found in 0.8% and 1.8% of eyes, respectively. Conclusions: A total of 16.8% of the eyes observed in this study had either disc haemorrhages or vascular changes. The underlying trend of vascular and haemorrhagic changes in glaucoma are demonstrated in this sample, which is in general agreement with previous studies. The high percentage of optic disc haemorrhages in low tension glaucoma is highlighted. The presence of microaneurysms and nerve fibre layer haemorrhages is interesting but of unknown significance.     

Dose-effect relationships between manganese exposure and neurological, neuropsychological and pulmonary function in confined space bridge welders

Background

Although adverse neuropsychological and neurological health effects are well known among workers with high manganese (Mn) exposures in mining, ore‐processing and ferroalloy production, the risks among welders with lower exposures are less well understood.

Methods

Confined space welding in construction of a new span of the San Francisco–Oakland Bay Bridge without adequate protection was studied using a multidisciplinary method to identify the dose–effect relationship between adverse health effects and Mn in air or whole blood. Bridge welders (n = 43) with little or no personal protection equipment and exposed to a welding fume containing Mn, were administered neurological, neuropsychological, neurophysiological and pulmonary tests. Outcome variables were analysed in relation to whole blood Mn (MnB) and a Cumulative Exposure Index (CEI) based on Mn‐air, duration and type of welding. Welders performed a mean of 16.5 months of welding on the bridge, were on average 43.8 years of age and had on average 12.6 years of education.

Results

The mean time weighted average of Mn‐air ranged from 0.11–0.46 mg/m³ (55% >0.20 mg/m³). MnB >10 µg/l was found in 43% of the workers, but the concentrations of Mn in urine, lead in blood and copper and iron in plasma were normal. Forced expiratory volume at 1s: forced vital capacity ratios (FEV₁/FVC) were found to be abnormal in 33.3% of the welders after about 1.5 years of welding at the bridge. Mean scores of bradykinesia and Unified Parkinson Disease Rating Scale exceeded 4 and 6, respectively. Computer assisted tremor analysis system hand tremor and body sway tests, and University of Pennsylvania Smell Identification Test showed impairment in 38.5/61.5, 51.4 and 88% of the welders, respectively. Significant inverse dose–effect relationships with CEI and/or MnB were found for IQ (p⩽0.05), executive function (p⩽0.03), sustaining concentration and sequencing (p⩽0.04), verbal learning (p⩽0.01), working (p⩽0.04) and immediate memory (p⩽0.02), even when adjusted for demographics and years of welding before Bay Bridge. Symptoms reported by the welders while working were: tremors (41.9%); numbness (60.5%); excessive fatigue (65.1%); sleep disturbance (79.1%); sexual dysfunction (58.1%); toxic hallucinations (18.6%); depression (53.5%); and anxiety (39.5%). Dose–effect associations between CEI and sexual function (p<0.05), fatigue (p<0.05), depression (p<0.01) and headache (p<0.05) were statistically significant.

Conclusions

Confined space welding was shown to be associated with neurological, neuropsychological and pulmonary adverse health effects. A careful enquiry of occupational histories is recommended for all welders presenting with neurological or pulmonary complaints, and a more stringent prevention strategy should be considered for Mn exposure due to inhalation of welding fume.Manganese (Mn) exposure through welding fume has been reported to cause parkinsonian syndrome, sometimes described as welding fume‐related parkinsonism and often misdiagnosed as Parkinson''s disease because of similarities in neurological features including tremor, masked facies and generalised bradykinesia.¹ However, important differences in movement disturbance between Mn‐induced parkinsonism (also called manganism) and idiopathic Parkinson''s disease (IPD) include an awkward high‐stepping dystonic gait in manganism, which is in stark contrast with the typical shuffling gait in patients with IPD, and the tendency to lose balance by falling backward in IPD and forward in manganism. Additionally, tremor characteristics are different, usually resting tremor in IPD and postural intention tremor in manganism.¹ Magnetic resonance imaging (MRI) may be used to differentiate IPD from Mn‐induced parkinsonism if a patient has had excess Mn exposure within the previous 6 months.² Positive MRIs can show cerebral Mn²⁺ deposition in both animals and humans, especially in the globus pallidus (possibly in the striatum), by exhibiting a T₁‐weighted signal hyperintensity.³ IPD, however, is associated with lesions in the substantia nigra pars compacta, and does not exhibit MRI abnormality in the globus pallidus. Two other key features differentiating between Mn‐induced parkinsonism and IPD are: (1) a younger age of onset for Mn‐exposed workers and (2) little or no response to l‐dopa among Mn‐induced parkinsonism cases.^4,5 Case reports of neurological findings in career welders exposed to Mn have shown dystonia bilaterally in the shoulders and four distal limbs, as well as other parkinsonian features—for example, tremor and postural instability.^5,6Welders have been reported to be exposed to “a wide variety of potential respiratory hazards”,^7,8 although earlier studies did not show increases in chronic bronchitis.⁹ However, shipyard welders have been reported to have a higher standardised mortality ratio for lung cancer, a finding which was also supported by the California Occupational Mortality Survey, after adjustment for smoking and asbestos exposure. Sjögren presented evidence of a causal relationship between exposure to stainless steel welding and lung cancer.¹⁰Diagnosis of Mn intoxication in workers actively exposed to excessive Mn in welding fumes can be further supported by biomarkers of exposure indicating increased internal Mn concentrations—for example, in whole blood and to a lesser extent in plasma/serum or urine. Sjögren et al¹¹ reported a mean concentration of 8.4 μg/l for whole blood Mn (MnB) in welders, whereas in other industrial settings the mean MnB ranged from 8.1 to 25.3 µg/l. No clear cutoff value of MnB is currently agreed upon, but HAR postulates that any values >10 µg/l is of concern.Mn air levels (Mn‐air) as reported in a few welder studies indicate that aerosols in welding operations (external exposure) usually contain <0.5 mg Mn/m³ (total dust), but sometimes they are >1 mg Mn/m³. A paramount feature of welding fume is that most of the airborne particles are in the respirable fraction (particle size <10 µm).¹² It is astonishing that reliable levels of respirable Mn particulate have rarely been reported, given the importance of the pulmonary uptake of Mn via the alveoli and its significance for Mn distribution to and effects on the central nervous system.¹³ It should be pointed out that inhalation exposure to Mn is for most of the jurisdictions regulated on the basis of total (or inhalable) dust: however, in the particular case of welding, a permissible exposure level established on the respirable fraction would enhance health prevention strategies.Neuropsychological testing methods used over the past two decades have successfully differentiated Mn‐exposed welders from unexposed controls.^4,6,11 There have been 13 reports on welders showing deficits for motor, tremor, memory and neurocognitive domains, as well as for sleep, sexual function and vision. Although not all reports dealt with all of these domains, 11 studies indicated slowing of motor speed/efficiency^{4,6,11,14,15,16,17,18,19,20,21} and tremor^{3,4,6,14,15,16,17,19,20,21,22}; eight found loss of neurocognitive functioning^{4,6,11,14,16,18,19,21}; and six reported diminished memory function.^{4,6,11,14,18,21} Six studies reported sleep disturbances^{4,6,11,14,15,17} and three sexual problems.^4,6,14 Vision was assessed in only two studies, and both found loss of colour vision associated with Mn exposure.^6,14Welders exposed to Mn‐containing welding fumes and dust have rarely been investigated by clinical neuropsychologists using an epidemiological study design in which actual measurements of internal and external exposure to Mn are studied in relation to outcome variables of a comprehensive test battery (including measures of IQ). Therefore, in the latter part of 2004, we decided to evaluate a welder group with health complaints, identified as employees on the reconstruction project of the San Francisco–Oakland Bay Bridge, which was damaged during the 1989 earthquake. The work on a vulnerable portion of the East span of the bridge began in 2003, requiring confined space welding of 28 anchoring foundations or piers, consisting of steel piles and footing boxes. The welding operations took place below the Bay''s surface in unpressurised cofferdams. During the first 1.5 years of welding on the support piers for the new bridge, welders began to express concerns of ill health feared to be the result of exposure to fumes due to confined space welding. During this period the welders were not required to wear personal protective equipment, and ventilation was minimal or ineffective. After receiving health complaints from almost 90% of the welders employed on the project, workers'' compensation evaluations were enacted, which supported their report of adverse health effects. A multidisciplinary study group took advantage of this “natural experiment” for undertaking additional clinical evaluations (1) to assess the extent of neurological, neuropsychological, neurophysiological and pulmonary effects, (2) to explore whether these effects were associated with internal and/or external measures of Mn exposure and (3) to define a tentative permissible exposure level for Mn in welding fume.     

Association of pupillary parasympathetic hyperreflexia and systemic inflammation in patients with systemic lupus erythematosus

In chronic inflammatory diseases, cytokines stimulate the hypothalamus pituitary adrenal axis and the hypothalamus autonomic nervous system (HANS) axis. The present study was performed to find autonomic nervous function parameters in patients with systemic lupus erythematosus (SLE) which are suitable to demonstrate the activation of the HANS axis during systemic inflammation. Thirty-four patients with SLE (age 35.3 +/- 1.9 yr) were investigated by seven standardized autonomic nervous function tests. The SLEDAI and laboratory parameters of systemic inflammation were assessed by standard techniques. Pupillary latency time hyperreflexia was found in 29.4%, whereas maximal pupillary area was hyperresponsive in only 2.9%. A total of 12% had overall cardiovascular autonomic nervous hyperreflexia. Patients with latency time hyperreflexia had more severe systemic inflammation [erythrocyte sedimentation rate (ESR): P < 0.001; C-reactive protein (CRP): P = 0.0094; fibrinogen: P < 0.001; albumin: P = 0.003; antinuclear antibodies: P = 0.020]. The longitudinal study of 13 patients during 4 yr demonstrated a parallel increase and decrease in latency time percentile and ESR. SLE patients with increased systemic inflammation had an activated HANS axis which can be measured by a parasympathetic pupillary reflex test.      

Elevation of serum cystathionine levels in patients with cobalamin and folate deficiency

Homocysteine can be methylated to form methionine by the cobalamin- (Cbl) and folate-dependent enzyme, methionine synthase; serum levels of total homocysteine are elevated in greater than 95% of patients with either Cbl or folate deficiency. Homocysteine can also condense with serine to form cystathionine in a pyridoxal phosphate-dependent reaction catalyzed by cystathionine beta-synthase. Cystathionine is subsequently cleaved to cysteine and alpha-ketobutyrate by the pyridoxal phosphate-dependent enzyme gamma-cystathionase. To assess levels of cystathionine in Cbl and folate deficiency, we developed a new capillary gas chromatographic-mass spectrometric assay and measured cystathionine in the serum of normal subjects and patients with clinically confirmed deficiencies of these vitamins. The normal range for serum cystathionine was 65 to 301 nmol/L (median = 126 nmol/L) for 50 normal blood donors. In 30 patients with clinically confirmed Cbl deficiency, values for cystathionine ranged from 208 nmol/L to 2,920 nmol/L (median = 816 nmol/L) and 26 (87%) had levels above the normal range. In 20 patients with clinically confirmed folate deficiency, cystathionine concentrations ranged from 138 nmol/L to 4,150 nmol/L (median = 1,560 nmol/L) and 19 (95%) had values above the normal range. Five homozygotes for cystathionine beta-synthase deficiency had high values for serum-total homocysteine and low or low-normal values for serum cystathionine that ranged from 30 nmol/L to 114 nmol/L even though they were on treatment with pyridoxine and had partially responded. One patient with a defect in the synthesis of 5-CH3- tetrahydrofolate and five patients with defects in the synthesis of CH3- Cbl had high values for serum-total homocysteine and high values for cystathionine that ranged from 311 nmol/L to 1,500 nmol/L even though they were on treatment with folic acid and Cbl, respectively, and had partially responded. We conclude that levels of cystathionine are evaluated in the serum of most patients with Cbl and folate deficiency and that they are useful in the differential diagnosis of an elevated serum-total homocysteine level.     

Comparison between published clinical success of direct resin composite restorations in vital posterior teeth in 1995–2005 and 2006–2016 periods

Composites are increasing in popularity as restorative materials. This growing role indicates the necessity of studies on their clinical outcome. In this study, clinical studies published on the performance of posterior composite restorations were included except those of less than a 24‐month assessment period. Results of non‐vital, anterior or primary teeth and cervical single‐surface restorations were also excluded. Records about composite type, number of final recall restorations, failure/survival rate, assessment period and failure reasons were analysed for each decade. Overall survival/failure rates for studies in 1995–2005 were 89.41%/10.59% and for 2006–2016 were 86.87%/13.13%, respectively. In 1995–2005, the reasons for failure were secondary caries (29.47%) and composite fracture (28.84%) with low tooth fracture (3.45%) compared with reasons of failure in 2006–2016, which were secondary caries (25.68%), composite fracture (39.07%), and tooth fracture (23.76%). An increase in incidence of composite fracture, tooth fracture and need for endodontic treatment as failure reasons was noted in the latter decade in addition to a decrease in secondary caries, postoperative sensitivity, unsatisfactory marginal adaptation and wear. The overall rates of failure showed little difference, but the causes showed a notable change. This is believed to be a reflection of increased use of composites for larger restorations and possibly changes of material characteristics.     

Treatment of progressive Hodgkin's disease with intensive chemoradiotherapy and autologous bone marrow transplantation

Twenty-six patients with progressive Hodgkin's disease after conventional chemotherapy received intensive chemoradiotherapy and autologous bone marrow transplantation (ABMT); 19 also received additional involved-field radiotherapy. Twenty-one patients [81%, 95% confidence intervals (CI) 61% to 94%] attained complete (n = 18) or partial responses. Ten patients (38%, 95% CI 20% to 59%) are disease- free a median of 4.5 years later (range 3.5 to 7.0 years), including seven patients with continuous complete responses. The likelihood of overall response was not significantly influenced by any clinical or treatment variable examined. However, there was a trend favoring patients with higher Karnofsky scores, and higher scores were associated with attainment of complete responses (P = .06 and P = .02, respectively, Mann-Whitney U test). Both higher Karnofsky scores and shorter durations of disease before transplantation were associated with improved survival in a stepwise Cox multivariate analysis. The chief cause of failure was progression at sites previously involved with Hodgkin's disease. No patient relapsed in the marrow, and two of three patients with a history of marrow involvement with Hodgkin's disease achieved durable complete responses after transplantation. These data suggest that inadequate pretransplant conditioning, and not the reinoculation of occult tumor cells in the autologous marrow, caused most relapses. Fatal treatment-related toxicity occurred in six patients. Three patients died of idiopathic interstitial pneumonitis; each had previously received local mediastinal irradiation before intensive chemoradiotherapy. Intensive chemoradiotherapy and ABMT produces durable responses in some patients with Hodgkin's disease incurable with conventional therapy. Use of such therapies at the first sign of failure with conventional chemotherapy and development of more effective conditioning regimens should further improve results.     

High-dose cytosine arabinoside and daunorubicin as consolidation therapy for acute nonlymphocytic leukemia in first remission: a pilot study

High-dose (HD) cytosine arabinoside (ARA-C) is more effective treatment than conventional-dose ARA-C regimens for patients with relapsed acute nonlymphocytic leukemia (ANLL). We report here that HD ARA-C given during the first remission of ANLL has resulted in long remission durations and a high proportion of patients who survive more than three years free of disease. From August 1979 to September 1983, 36 adult patients with ANLL in first remission received one to three courses of HD ARA-C (3 g/m2 by one-hour infusion every 12 hours for 12 doses on days 1 through 6) alone or with daunorubicin (30 mg/m2 for two or three doses on days 7 through 9). Three patients died of sepsis or hemorrhage during consolidation, and 14 patients have relapsed from five to 48 months after diagnosis. The remaining 19 patients are in continued complete remission (CCR) from 11 to 62 months. Denoting all deaths in remission as relapse, the actuarial probability of CCR is 42% at 62 months, with an apparent plateau in the survival curve. Of the first 22 patients treated, ten remain in CCR from 37 to 62 months with no therapy for at least three years. Due to its heightened anti-leukemic activity, HD ARA-C allows brief but effective consolidation of ANLL in first remission, with long-term disease-free survival comparable to other approaches.     

世界胃肠病学组织(WGO-OMGE)临床指南——发展中国家幽门螺杆菌感染

我非常高兴向大家推荐这份发展中国家幽门螺杆菌（H．priori）临床指南。该指南的编译是由数位在该领域具有丰富临床经验的世界知名专家共同完成的。