[Application value of arousal threshold in obstructive sleep apnea]

The pathogenesis of obstructive sleep apnea (OSA) includes anatomical and non-anatomical factors, and the arousal threshold (ArTH) is one of the important non-anatomical factors. At present, the main method is to assess the increased respiratory effort due to arousal to determine the arousal threshold, and invasive epiglottic or esophageal manometry is the gold standard, while the non-invasive continuous positive airway pressure (CPAP) method and polysomnography (PSG) ventilation signal conversion method are also widely used. Arousal threshold is expected to serve as an important evaluation index and potential target for drug therapy in OSA, which is of great importance for realization of precise treatment of OSA. This article focused on the method and clinical significance of OSA arousal threshold.

[Clinical effects of expanded frontal flap and flip scar flap in repairing partial nasal defect]

Objective: To investigate the clinical effects of expanded frontal flap and flip scar flap in repairing partial nasal defect. Methods: A retrospective observational study was conducted. From January 2012 to January 2022, 26 patients with partial nasal defects who met the inclusion criteria were admitted to the First Affiliated Hospital of Air Force Medical University, including 19 males and 7 females, aged 5 to 61 years. The surgery was performed in 4 stages. In the first stage, a rectangular skin and soft tissue expander (hereinafter referred to as expander) with suitable rated capacity was planted in frontal region and expanded by injecting water regularly. In the second stage, flip scar flap was grafted to reconstruct nasal inner lining, whose area was about 10% larger than the area of defect. The expanded frontal flap with pedicle was transferred to repair the nasal defect, whose pedicle was supraorbital vessel or supratrochlear vessel on the contralateral side of the defect, and the area of expanded flap was 20% larger than the nasal defect area after resection and flipping of scar flap. The donor site of expanded flap was sutured directly. After 3 weeks of flap transferring, the flap was delayed in the third stage. After 1 week of delaying operation, the pedicle of flap was cut off in the fourth stage. The number, rated capacity, injection volume, and expansion time of embedded expanders were recorded. The occurrences of complications including infection, hematoma, ulceration of expanded flap after the first stage operation, and blood supply disorder or necrosis of flap after operation in the second and fourth stages were observed. All the patients were followed up for 1 year at least, and the color of flap, scar of frontal donor site, symmetry of bilateral eyebrows, and the nasal appearance and ventilated function of external nasal tract were observed. Results: A total of 26 expanders were embedded in 26 patients. The rated capacity of expanders ranged from 100 to 300 mL. The injection volume was 1.0 to 1.5 times of the rated capacity of expanders. The expansion time ranged from 2.5 to 4.0 months, with an average time of 3 months. There were no complications occurred after each operation. The follow-up showed that the color of flap was similar to the normal nasal skin, the scar of frontal region was not obvious, the bilateral eyebrows were basically symmetrical, the nose had excellent appearance, ventilation function of external nasal tract was not affected, while some of the patients had downward rotation or unapparent tip-defining point of nose. Conclusions: Using the flip scar flap to reconstruct the nasal inner lining and pre-expanded frontal flap to reconstruct the nasal skin, without free cartilage transplantation to repair the partial nasal defects can achieve satisfied nasal appearance post operation, without abnormal external nasal ventilation function.

POS0779 STANDARDIZED MORTALITY RATIO AND RISK FACTORS FOR DEATH IN SOUTHERN CHINESE PATIENTS WITH THE ANTIPHOSPHOLIPID SYNDROME (APS)

Objectives

To report the mortality rate and risk factors for death in southern Chinese patients with the antiphospholipid syndrome (APS)

Methods

The HKAPS registry was established in early 2020 by the Hong Kong Society of Rheumatology to study the outcomes of Chinese patients with APS treated in public hospitals in Hong Kong. Patients aged ≥18 years were identified by the Hospital Authority Clinical Data retrieval system using the ICD-10 diagnostic code of APS. The medical history and APS diagnosis was verified by sub-investigators in different hospitals using the 2006 modified consensus criteria for the APS. Eligible patients were classified into definite APS or probable APS, which was further categorized into primary (without underlying rheumatic diseases) and secondary types. The treatment and outcome (recurrence and mortality) of the patients was studied by Kaplan-Meier analysis and risk factors for recurrence of thrombosis and mortality were studied by Cox regression.

Results

428 APS patients were studied - 282 fulfilled the 2006 criteria for APS while 146 patients had probable APS (anti-phospholipid [aPL] antibodies positive once or with non-criteria manifestations). All were ethnic Chinese. The mean age at diagnosis was 44.1±15.6 years and the female to male ratio was 3.4:1. APS was primary in 211 patients and secondary to concomitant rheumatic diseases in 217 patients (SLE in 89.9%). 369(86.4%) patients had thromboembolic manifestations, 85(19.9%) had obstetric morbidities and 20(4.7%) had both. In patients with secondary APS, 23% thrombotic or obstetric manifestations occurred before diagnosis of the rheumatic diseases. Lupus anticoagulant (LAC), moderate/high titers of IgG anticardiolipin and anti-β2glycoprotein-1 antibodies was present in 326(76.1%), 242(56.5%) and 29(6.7%) patients, respectively. 137(32%) patients were double positive while 19(4.4%) patient was triple positive for these aPL antibodies. Among the thromboembolic manifestations, arterial thrombosis (n=201) was more common than venous thrombosis (n=186). The following treatment regimens were used: warfarin (63.6%), aspirin plus subcutaneous heparin (6.8%), aspirin plus warfarin (3%), aspirin alone (17.8%) and direct oral anticoagulant (DOAC) (2.8%). Bleeding complications developed in 77(18%) patients.

After a mean follow-up of 8.0±14.1 years, recurrence of thromboembolic or obstetric complications occurred in 83(19.4%) and 14(3.3%) patients, respectively (1 patient had recurrence of both thrombosis and obstetric complications). Cox regression did not reveal any factors significantly associated with recurrence of thrombosis. A total of 67(15.7%) patients succumbed (median time to death 7.3 years). The causes of death were vascular in 29.9% (intracranial haemorrhage [35%], myocardial infarction [30%], limb ischemia [10%], ischemic stroke[10%], bowel ischemia[5%]) and non-vascular in 70.1% of patients (infection [59.6%], malignancy [10.6%], SLE activity [6.4%], pulmonary arterial hypertension [2.1%], organ failure [6.4%] and others). The cumulative risk of mortality over time was 6.4% at 5 years and 11.9% at 10 years. The age and sex adjusted standardized mortality ratio (SMR) of our APS patients relative to the general population was 18.2(14.2-23.0). In patients with thrombotic APS, mortality was associated with older age (≥60 years) (HR 2.57[1.34-4.95]) and the presence of LAC (HR 2.01[1.07-3.75]), adjusted for age, sex and vascular risk factors that included hypertension, diabetes mellitus, dyslipidaemia, smoking and atrial fibrillation.

Conclusion

APS in southern Chinese is relatively uncommon and most cases were associated with SLE. In contrast to the Caucasians, venous thrombosis related to APS is less frequent. Over 8 years, recurrence of thrombotic events is uncommon. The mortality of APS in our Chinese patients was increased, with older age and the presence of LAC being independent risk factors.

Disclosure of Interests

None declared

[Establishment and validation of a clinical prediction model for infection risk at the placement sites of skin and soft tissue expanders]

Objective: To establish a clinical prediction model for infection risk at the placement sites of skin and soft tissue expanders (hereinafter termed as expanders) and to validate the predictive value of the model. Methods: A retrospective observational study was conducted. Totally 2 934 patients who underwent skin and soft tissue dilatation surgery in the Department of Plastic Surgery of the First Affiliated Hospital of Air Force Medical University from January 2009 to December 2018 and met the selection criteria were included. There were 1 867 males and 1 067 females, with a median age of 18 years. Totally 3 053 skin and soft tissue expansion procedures were performed with 4 266 expanders implanted. The following indexes were selected as predictor variables, including patients' age, gender, marital status, ethnicity, hospital admission, surgical indication, disease duration, with/without history of smoking, history of drinking, history of blood transfusion, history of underlying diseases, and inability to use cephalosporin antibiotics due to allergy, number of expander in a single placement, rated volume of expander, water injection rate of expander in the first time, placement site of expander, anesthesia method, duration of operation, and with/without postoperative hematoma evacuation, and infection at the placement site of expander as the outcome variable. Univariate analysis of the data was performed using least absolute shrinkage and selection operator (LASSO) regression to screen the potential risk factors affecting infection at the placement sites of expanders, the factors selected by the univariate analysis were subjected to binary multivariate logistic regression analysis to screen the independent risk factors affecting infection at the placement sites of expanders, and a nomogram prediction model for the occurrence of infection at the placement sites of expanders was established. The C index and Hosmer-Lemeshow goodness of fit test were used to evaluate the discrimination and accuracy of the model, respectively, and the bootstrap resampling was used for internal verification. Results: The results of LASSO regression showed that age, gender, hospital admission, surgical indication, disease duration, history of drinking, history of heart disease, history of viral hepatitis, history of hypertension, inability to use cephalosporin antibiotics due to allergy, number of expander in a single placement, rated volume of expander, placement site of expander, postoperative hematoma evacuation were the potential risk factors for infection at the placement sites of expanders (regression coefficient=-0.005, 0.170, 0.999, 0.054, 0.510, -0.003, 0.395, -0.218, 0.029, 0.848, -0.116, 0.175, 0.085, 0.202). Binary multivariate logistic regression analysis showed that male, emergency admission, disease duration ≤1 year, inability to use cephalosporin antibiotics due to allergy, rated volumes of expanders ≥200 mL and <400 mL or ≥400 mL, and expanders placed in the trunk or the limbs were the independent risks factors for infection at the placement sites of expanders (odds ratio=1.37, 3.21, 2.00, 2.47, 1.70, 1.73, 1.67, 2.16, 95% confidence interval=1.04-1.82, 1.09-8.34, 1.38-2.86, 1.29-4.41, 1.07-2.73, 1.02-2.94, 1.09-2.58, 1.07-4.10, P<0.05 or P<0.01). The C index for evaluating the discriminative degree of the model was 0.63, the Hosmer-Lemeshow goodness of fit test for evaluating the accuracy of the model showed P=0.685, and the C index for internal validation by the bootstrap resampling was 0.60. Conclusions: Male, emergency admission, disease duration ≤1 year, inability to use cephalosporin antibiotics due to allergy, rated volume of expander ≥200 mL, and expanders placed in the trunk or the limbs are the independent risk factors for infection at the placement sites of expanders. The clinical prediction model for infection risk at the placement sites of expanders was successfully established based on these factors and showed a certain predictive effect.

POS0865 REDUCED BONE MINERAL DENSITY IN PATIENTS WITH IDIOPATHIC INFLAMMATORY MYOPATHIES: A CASE CONTROL STUDY

Background:

Idiopathic Inflammatory Myopathies (IIMs) patients are at risk of bone mineral density (BMD) loss due to systemic inflammation, use of glucocorticoids (GCs) and disability. Cross sectional study showed 70% of IIMs patients had reduced BMD but whether they were at excessive risk compared to controls were unknown.

Objectives:

To compare the prevalence of reduced BMD between IIMs patients, non-rheumatological controls, rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) patients and to determine the clinical determinants of BMD in IIMs patients.

Methods:

This was a single centre retrospective case control study. BMD at lumbar spine L1-L4 and neck of femur (NOF) were assessed by dual-energy X-ray absorptiometry (DXA) scans. The prevalence of reduced BMD and osteoporosis in Chinese IIMs patients and age-and-sex-matched non-rheumatological controls were compared. The BMD of female IIMs were then compared to age matched female RA and SLE patients in the secondary analysis. Binary logistic regression was used for adjustment of confounders. The demographics and clinical variables independently associated with BMD were determined by linear regression.

Results:

A total of 230 patients were recruited including 65 IIMs, 65 non-rheumatological controls, 50 RA and 50 SLE patients. The mean age was 58.6±10.96 years and 76.9% were female. There was no significant difference on demographics between the two groups. Almost all IIMs patients (98%) and 52% of controls had exposed to GCs (p<0.001). Significantly more IIMs patients had used immunosuppressants (92.3% vs 38.5%, p<0.001) and biologics (13.8% vs 1.5%, p=0.01). The prevalence of reduced BMD and osteoporosis were significantly higher in IIMs patients than non-rheumatological control (Reduced BMD: 73.8% vs 43.1%, p=0.043; Osteoporosis: 29.2% vs 13.8%, p=0.033) (Table 1). The mean lumbar spine and hip BMD were 0.886±0.181 g/cm2 and 0.651±0.144 g/cm2 in IIMs patients, which were significantly lower than that of the control group (0.960±0.143g/cm2, p=0.011 and 0.751±0.127g/cm2, p<0.001) (Figure 1). Multivariate analysis confirmed IIMs were associated with increased risk of reduced BMD (Odds ratio:2.118, p=0.048, 95% CI 1.005-4.461). The prevalence of reduced BMD and osteoporosis were not significantly different between IIMs, RA and SLE patients but the mean hip BMD was the lowest in the IIM group (0.641±0.152g/cm2 vs 0.663±0.102g/cm2 in the RA group vs 0.708±0.132 g/cm2 in the SLE group, p=0.035). Lower BMI (p=0.035) and more advanced age (p<0.001) were associated with lower BMD in the IIM patients.

Conclusion:

Reduced BMD was more prevalent in IIM patients than non-rheumatological controls. Lower BMI and more advanced age were associated with lower BMD. Vigilant monitoring of BMD and use of antiresorptive treatment should be considered in IIM patients.

References:

[1]Briot K, Geusens P, Em Bultink I et al. Inflammatory diseases and bone fragility. Osteoporos Int. 2017;28:3301-14.

[2]So H, Yip ML, Wong AKM. Prevalence and associated factors of reduced bone mineral density in patients with idiopathic inflammatory myopathies. Int J Rheum Dis. 2016;19:521-8.

Table 1.

Prevalence of reduced BMD in IIM patients and non-rheumatologcial controls

Myositis (n=65)Non-rheumatological controls (n=65)SignificanceOsteopenia at LS25 (38.5%)20 (30.8%)0.357Osteoporosis at LS13 (20%)6 (9.2%)0.082Osteopenia at NOF29(44.6%)26 (40%)0.542Osteoporosis at NOF12(18.5%)6 (9.2%)0.119Osteopenia overall29(44.6%)28 (43.1%)0.860Osteoporosis overall19(29.2%)9(13.8%%)0.033Reduced BMD overall48 (73.8%)37 (56.9%)0.043Occurrence of fragility fractureNone=52None=540.651Vertebral =5Vertebral=4Femoral=1Femoral=1Femoral=0Wrist=4Wrist=3Other sites=3Other sites=3

Disclosure of Interests:

None declared

POS0773 CLINICAL PRESENTATION AND OUTCOMES OF THE ANTIPHOSPHOLIPID SYNDROME (APS) IN SOUTHERN CHINESE PATIENTS: THE HONG KONG APS REGISTRY

Objectives:

To report the clinical presentation and outcomes of the APS in Hong Kong Chinese patients.

Methods:

The HKAPS registry was established in early 2020 by the Hong Kong Society of Rheumatology to study the outcomes of Chinese patients with APS treated in public hospitals in Hong Kong. Patients aged ≥18 years were identified by the Hospital Authority Clinical Data retrieval system using the ICD-10 diagnostic code of APS. The medical history and APS diagnosis was verified by sub-investigators in different hospitals using the 2006 modified consensus criteria for the APS. Eligible patients were classified into definite APS or probable APS, which was further categorized into primary (without underlying rheumatic diseases) and secondary types. The presentation, treatment and outcomes of these patients were summarized.

Results:

232 APS patients (76.3% women) were identified. All were ethnic Chinese. A total of 160 patients fulfilled the 2006 criteria for APS (definite APS) while 72 patients had probable APS (anti-phospholipid [aPL] antibodies positive once or with non-criteria manifestations). In those with definite APS, the mean age at diagnosis was 44.9±15.8 years and the female to male ratio was 3.1:1. APS was primary in 82 patients while 78 patients had concomitant rheumatic diseases (SLE in 95% of patients). 130(81%) patients had thromboembolic manifestations, 20(13%) had obstetric morbidities and 10(6%) had both. In patients with secondary APS, 23% thrombotic or obstetric manifestations occurred before diagnosis of the rheumatic diseases (ie. evolved from primary APS). Lupus anticoagulant was present in 81(51%) patients, moderate/high titers of anti-cardiolipin were present in 90(56%) patients and anti-β2glycoprotein-1 was present in 6(4%) patients. Sixteen (10%) patients were double positive while 1 patient was triple positive for these aPL antibodies. Among the thromboembolic manifestations, arterial thrombosis (n=84) (ischemic stroke 77%, myocardial infarction 4.8%, peripheral vascular disease with limb/digital gangrene 2.4%, retinal artery 2.4%, splenic artery 1.2%, bowel infarct 1.2%) was more common than venous thrombosis (n=73) (calf vein thrombosis ± pulmonary embolism 86%, cerebral veins 2.7%, inferior vena cava/iliac veins 6.8%, retinal vein 2.7%, splenic vein 1.4%). The following treatment regimens were used in our APS patients: warfarin (71%), aspirin plus subcutaneous heparin (4%), aspirin + warfarin (3.1%), aspirin alone (17%) and the direct oral anticoagulant (DOAC) (5%). Bleeding complications developed in 35(22%) patients. Over a mean follow-up of 9.9±7.0years, recurrence of thromboembolic or obstetric manifestations recurred in 39(24%) and 6(4%) patients, respectively. A total of 29(18%) patients succumbed (median time to death: 6.4 years) and the causes of death were: pneumonia (24%), septicemia (17%), intracranial hemorrhage (14%), myocardial infarction (10%), ischemic stroke (3%), bowel infarct (3%), pulmonary hypertension (6.9%) and sudden death with unknown causes (14%).

Conclusion:

APS in southern Chinese is relatively uncommon and most cases were associated with SLE. In contrast with the Caucasians, venous thrombosis related to APS is less frequent than arterial thrombosis in Chinese patients. With long-term anticoagulation treatment, the outcome is satisfactory with relatively low rates of recurrence and mortality. Expansion of the sample size to study factors associated with recurrence and mortality by involving more hospitals is in progress.

Disclosure of Interests:

None declared

AB0616 REDUCED BONE MINERAL DENSITY IN PATIENTS WITH IDIOPATHIC INFLAMMATORY MYOPATHIES: A LONGITUDINAL STUDY

Background:

Reduced bone mineral density (BMD) leads to fragility fracture which is associated with a significant morbidity and excess mortality [1,2]. Patients with idiopathic inflammatory myopathies (IIM) should be at a heightened risk of reduced BMD as a result of the systemic inflammation, reduced mobility and corticosteroid use [3]. A previous cross-sectional study demonstrated a high prevalence of osteoporosis (23.7%) and osteopenia (47.4%) in a cohort of IIM patients [4]. However, longitudinal data are lacking.

Objectives:

To assess the BMD of IIM patients longitudinally and to investigate the factors associated with accelerated bone loss.

Methods:

This is a single centered observational study. Existing adult Chinese patients with IIMs who had serial BMD measurements done were recruited. The diagnosis of IIMs was based on the Bohan and Peter’s criteria with definite or probable cases being included [5]. Patients with clinically amyopathic disease must have the typical Gottron’s papules or heliotrope rash as determined by rheumatologists or dermatologists, and with no symptoms or signs of muscle involvement according to Sontheimer [6]. BMD was measured by dual energy X-ray absorptiometry (DEXA). Clinical variables thought to be associated with bone health were documented.

Results:

All together 28 patients were studied. The mean age of the patients at disease onset was 46.1 years (S.D. 12.2). There was a female predominance (92.9%). The subgroups of IIMs were: dermatomyositis (39.3%), polymyositis (25.3%), clinically amyopathic dermatomyositis (21.4%) and immune mediated necrotising myopathy (14.3%). Only a minority of the patients smoked (7.1%) and none of them drinks regularly. About one fifth of the patients were underweight. All patients have been exposed to systemic corticosteroid, while 82.1% of them were still on it between the two scans with 32.1% even on high dose (>0.5mg prednisolone/kg/day). Three out of the 28 patients (10.7%) was found to be osteoporotic at baseline and 17 patients (60.7%) were osteopenic. Follow-up DEXAs were performed mostly 5 to 10 years after the initial scan. Despite 8 patients (28.6%) were given active anti-osteoporotic medications, the bone health deteriorated significantly. The mean baseline neck of femor BMD dropped from 0.711 to 0.657 g/cm2 (p=0.042) on follow-up, while the total lumbar BMD from 0.951 to 0.905 g/cm2 (p=0.036). The T-score in 11 patients (39.3) reached osteoporotic range at the second DEXA. Together with the patients with osteopenia, 78.6% of the IMM patients had reduced BMD at the follow-up scan. Actually, 5 patients (17.9%) already had one episode of fragility fracture. The use of high dose corticosteroid in between the 2 scans was found to be associated with a greater degree of mean BMD loss in the hip (-0.171 vs -0.007 g/cm2, p=0.007).

Conclusion:

Reduced BMD is prevalent in patients with IIM. Follow-up study revealed significant worsening of bone health. High dose corticosteroid use might be especially detrimental. Liberal assessment of BMD and use of anti-osteoporotic drugs in IIM patients are advisable. Prompt use of steroid-sparing agents to minimize steroid exposure may also be helpful.

References:

[1]Falch J, Aho H, Berglund K, et al. Hip fractures in Nordic Cities: difference in incidence. Ann Chir Gynaecol 1995;84:286-90.

[2]Dennison E, Mohammed MA, Cooper C. Epidemiology of osteoporosis. Rheum Dis Clin North Am 2006;32:617-29.

[3]Luigi S, Massimo V, Giuseppe G. Epidemiology of osteoporosis in rheumatic disease. Clin Exp Rheumatol 2006;32:631-58.

[4]So H, Yip ML, Wong KM. Prevalence and associated factors of reduced bone mineral density in patients with idiopathic inflammatory myopathies. Int J Rheum Dis 2016;19:521-8.

[5]Bohan A, Peter JB. Polymyositis and dermatomyositis. N Engl J Med 1975;292:344-7.

[6]6. Sontheimer RD. Clinically myopathic dermatomyositis: what can we now tell our patients? Arch Dermatol 2010;146:76-80.

Disclosure of Interests:

None declared

[The study of locating facial nerve precisely in middle ear surgery based on clinical anatomy]

Objective:To investigate the methods of locating facial nerve precisely in middle ear surgery through the observation and measurement of the facial nerve and surrounding anatomical structures and to provide reference for the middle ear surgery.Method:Combined surgical approach on 15 cases (30 sides) fresh adult cadaveric specimens were dissected, observed the characteristics of facial nerve and its shape and spatial relationship of the surrounding structures, and measured the distance between the facial nerve and its surrounding structures.Result:The shortest distance from the midpoint of the posterior wall of external auditory canal (annulus level) to the vertical segment of the facial nerve was (3.37±0.34)mm, the shortest distance from the leading edge of the sigmoid sinus to the vertical segment of facial nerve was (7.40±0.71)mm, the shortest distance from the lateral margin of jugular bulb to the facial nerve was (5.58±0.79)mm, the shortest distance from Henle crest to the pyramidal segment of facial nerve was (12.76±1.24)mm, the shortest distance between the pyramidal segment of facial nerve and the posterior short limb of incus was (1.56±0.35)mm, the shortest distance between the pyramidal segment of facial nerve and the lower edge of posterior semicircular canal was (2.56±0.41) mm, the shortest distance between the lower edge of horizontal semicircular canal and the horizontal segment of facial nerve was (1.28±0.32) mm, the shortest distance between the upper edge of vestibular window and the horizontal segment of facial nerve was (0.67±0.15)mm.Conclusion:A good command of the anatomy of temporal bone as well as the methods of locating facial nerve will provide the key to reduce the probability of iatrogenic facial nerve injury in middle ear surgery.

Sealing the intramedullary femoral canal with autologous bone plug in total knee arthroplasty

In a prospective study of 262 consecutive patients with total knee arthroplasty, we compared the postoperative suction drainage and transfusion requirement in cases in which the defect made by the femoral intramedullary rod was either unplugged (n = 134) or plugged (n = 128). All operations were performed with a single surgical approach and technique. Inflammatory arthritis and lateral releases were excluded. Blood loss was recorded at 24, 48, and 72 hours. The difference in postoperative suction drainage was not statistically significant. The hemoglobin decrease in the unplugged group (3.5 g/dL) was different from that in the plugged group (2.3 g/dL) (P<.05). Of patients, 64.4% (n = 85) in the unplugged group and 35.9% (n = 46) in the plugged group required transfusion (P<.05). Sealing the femoral canal is effective in reducing hemoglobin decrease and blood transfusion in total knee arthroplasty.

Determination of chemical composition of commercial honey by near-infrared spectroscopy

The feasibility of using near-infrared spectroscopy to determine chemical composition of commercial honey was examined. The influences of various sample presentation methods and regression models on the performance of calibration equations were also studied. Transmittance spectra with 1 mm optical path length produced the best calibration for all constituents examined. The regression model of modified partial least squares (mPLS) was selected for the calibration of all honey constituents except moisture, for which the optimal calibration was developed with PLS. Validation of the established calibration equations with independent samples showed that the spectroscopic technique could accurately determine the contents of moisture, fructose, glucose, sucrose, and maltose with squared correlation coefficients (R(2)) of 1.0, 0.97, 0.91, 0.86, and 0.93 between the predicted values and the reference values. The prediction accuracy for free acid, lactone, and hydroxymethylfurfural (HMF) contents in honey was poor and unreliable. The study indicates that near-infrared spectroscopy can be used for rapid determination of major components in commercial honey.

Changes in refractive trends and optical components of Hong Kong Chinese aged over 40 years

The age trends of refractive errors, astigmatism and optical components were studied in 220 Chinese subjects aged over 40 years. Myopia did not dominate in this age group. With increasing age, the prevalence of hyperopia increases from 2% at age 40-45 years to 66% at age > 65 years. Against-the-rule astigmatism was more prevalent than the other types. Significant correlations were found between age and spherical equivalent power, age and vitreous depth and axial length. Sex differences were found among the optical components but not in the refractive error. Myopia appears to be more prevalent among the younger age groups than the older age groups of the Hong Kong Chinese population, and the importance of genetics in determination of refractive error is called into question by these findings.

[A field study on the post-inoculation reaction and immunological effects in vaccinated population immunized with "Zhejiang type-D" leptospiral vaccine]

A comparative study on the post-inoculation and antibody responses after inoculation with two different dosage (1ml, 2ml) of "zhejiang type-D" leptospiral vaccine was carried out. There was no general reaction in all of the vaccinated people after immunization. The GMT values of antibody against leptospire were 3.08-7.91 times in 1ml dose group and 3.48-9.57 times in 2ml dose group more than pre-vaccination respectively. 3 months after immunization the levels of specific antibody still were high in most vaccinated people, whatever in 1ml dose or 2ml dose of immunization. However the antibody couldn't be detected in part of vaccinated people at that time, but there was no difference between the two different dosages. During the epidemic season, there was no leptospirosis case (0/3260) in the 1ml group, 1 case (1/625) in the 2 ml group while there was 9/3970 in the control group.

Olfactory bulbectomy prevents the gonadal regression associated with short photoperiod in male golden hamsters

In male rats, pre-pubertal olfactory bulbectomy (BX) unmasks photoperiodic responsiveness so that maintenance of BX animals on short photoperiod results in a pineal gland mediated gonadal regression (Nelson and Zucker, Neuroendocrinology, 32 (1981) 266). The objective of the present study was to determine the effect of BX in Syrian hamsters, a species where short photoperiod alone induces a pineal gland induced testicular regression. Pre-pubertal (25-days old) Syrian hamsters underwent either sham BX, BX, or pinealectomy (PX) plus BX. One half of each group was then placed on an LD 14:10 photoperiod and the other half on LD 6:18. Thirteen weeks later all animals were decapitated. In the animals on LD 14:10, BX resulted in a slight but highly significant increase in testes weight but had no effect on other parameters examined. Sham BX hamsters on LD 6:18 had regressed testes and reduced serum testosterone levels, but these effects of short photoperiod were reversed in BX hamsters, so that the testes and seminal vesicles remained large. In addition, serum LH and testosterone levels were elevated following BX of the animals on LD 6:18. These results indicate that the olfactory bulbs tonically inhibit the reproductive system even in male hamsters maintained on long photoperiod and that olfactory bulbectomy prevents gonadal regression in male Syrian hamsters on short photoperiod, an effect which is the opposite of results obtained in rats on short photoperiod. Elucidation of the neural pathways involved and the nature of the relationship between the olfactory bulb and the pineal gland or photoperiodism remains for further investigation.