Evaluation and characterisation of A and B fragments of Corynebacterium diphtheriae toxin towards recombinant diphtheria vaccine

BACKGROUND

Diphtheria is a highly communicable disease caused by toxin-producing strains of Corynebacterium diphtheriae.

OBJECTIVES

To evaluate the efficacy of A and B subunits of diphtheria toxin (DT-A, DT-B) as potential vaccines against C. diphtheriae. A culture of C. diphtheriae (strain PW 8) was grown on Loeffler plates while Lingood medium was used for production of diphtheria toxin (DT).

MATERIALS AND METHODS

DT was purified and digested to obtain pure DT-A and DT-B and detoxified to obtain diphtheria toxin. Four groups of mice were immunised with different antigens (Ag) of C. diphtheriae.

RESULTS

The antibody (Ab) titres were significantly increased with immunised groups subsequent to three injections. On the other hand, Ab titres were estimated after the three immunisations and the levels of different Ab isotypes were comparatively measured. The levels of various isotypes immune responses showed variation between immunised groups where the IgG subclasses were significantly increased mainly with DPT immunised group. The IgM and IgA were significantly increased with DT-A more than others. Additionally, the evaluation of the cellular immune responses demonstrated that spleen cells from DPT and DT-A groups gave highly significant proliferative response with production of high levels of IL-2 and IFN-γ (Th1/Th2). Separation and purification of DT gene were performed using polymerase chain reaction (PCR) and sub-cloned in pGEM-T vector, for further studying of recombinant vaccine.

CONCLUSION

Our results showed the possibility to prepare a potent recombinant vaccine containing whole DT gene or DT-A against C. diphtheriae or could be used in treatment of cancer as it give high levels of IL-2 and IFN-γ.

Diabetic retinopathy in native and non-native Sarawakians--findings from the Diabetic Eye Registry

This study aims to determine the risk factors associated with diabetic retinopathy (DR) among natives and non-natives Sarawakians who were seen at 3 public hospitals and one health clinic in Sarawak. It is a cross sectional study where data on patients with DM were collected by staff at these healthcare facilities and entered into the web-based Diabetic Eye Registry. Univariate and multivariate analysis was used to determine the association factors for DR. DR was significantly less associated with natives (24.4%) compared to non-native Sarawakians (34.1%) (p < 0.001). The odds of getting DR was higher in patients whose duration of DM was more than 20 years (OR = 2.6), who have renal impairment (OR = 1.7) and non-natives (OR = 1.4).

Severe diabetic papillopathy mimicking non-arteritic anterior ischemic optic neuropathy (NAION) in a young patient

With the pathophysiology not clearly understood and fewer than 130 cases having been reported in the literature, diabetic papillopathy presents a special challenge to the ophthalmologist. We report a case of a young patient with more than 12 years of type 1 diabetes mellitus (T1DM) on insulin with poor compliance to treatment who presented with sudden bilateral loss of vision. Ocular examination, fluorescence angiography (FA) and systemic signs were conclusive of diabetic papillopathy. His fasting blood sugar level was high and serum glycosylated haemoglobin (HbA1c) indicated a long term fluctuating blood glucose control. His vision initially improved with treatment, but later deteriorated with tight glycemic control.

Spatial pattern of 2009 dengue distribution in Kuala Lumpur using GIS application

In the last few years in Malaysia, dengue fever has increased dramatically and has caused huge public health concerns. The present study aimed to establish a spatial distribution of dengue cases in the city of Kuala Lumpur using a combination of Geographic Information System (GIS) and spatial statistical tools. Collation of data from 1,618 dengue cases in 2009 was obtained from Kuala Lumpur City Hall (DBKL). These data were processed and then converted into GIS format. Information on the average monthly rainfall was also used to correlate with the distribution pattern of dengue cases. To asses the spatial distribution of dengue cases, Average Nearest Neighbor (ANN) Analysis was applied together with spatial analysis with the ESRI ArcGIS V9.3 programme. Results indicated that the distribution of dengue cases in Kuala Lumpur for the year 2009 was spatially clustered with R value less than 1 (R = 0.42; z-scores = - 4.47; p < 0.001). Nevertheless, when this pattern was further analyzed according to month by each zone within Kuala Lumpur, two distinct patterns were observed which include a clustered pattern (R value < 1) between April to June and a dispersed pattern (R value > 1) between August and November. In addition, the mean monthly rainfall has not influenced the distribution pattern of the dengue cases. Implementation of control measures is more difficult for dispersed pattern compared to clustered pattern. From this study, it was found that distribution pattern of dengue cases in Kuala Lumpur in 2009 was spatially distributed (dispersed or clustered) rather than cases occurring randomly. It was proven that by using GIS and spatial statistic tools, we can determine the spatial distribution between dengue and population. Utilization of GIS tools is vital in assisting health agencies, epidemiologist, public health officer, town planner and relevant authorities in developing efficient control measures and contingency programmes to effectively combat dengue fever.

An unusual entry site of an intraorbital foreign body in a child

Intraorbital foreign bodies (IOrbFB) are associated with both sight and life threatening injuries. We report a case of an IOrbFB associated with retrobulbar hemorrhage and injury of the frontal sinus in an 11 year-old boy, after history of fall from the tree. Imaging studies revealed a metallic foreign body (FB) in the orbit and fracture of the walls of the frontal sinus. The usual entry route of an IOrbFB is either through the eye or orbital walls and extremely rare through the paranasal sinuses. This is the first reported case of a FB entering the orbit through the frontal sinus.

Pseudophacocoele following blunt ocular trauma

Blunt ocular trauma may result in expulsion of the intraocular lens in a patient who has undergone cataract surgery. This case report describes a patient who presented with an extrusion of intraocular lens following blunt ocular trauma post-operatively. The authors emphasise the importance of patient counselling and protection of the operated eye after surgery.

Comparison between the panoptic ophthalmoscope and the conventional direct ophthalmoscope in the detection of sight threatening diabetic retinopathy: the kuching diabetic eye study

OBJECTIVE

To determine the sensitivity and specificity of the conventional direct ophthalmoscope and the PanOptic ophthalmoscope in the detection of sight threatening retinopathy, as well as the "Ease of Use" of these equipments.

METHODS

200 diabetics, newly referred from primary health physicians were examined. Fundus examinations were performed with pupil dilatation in a dark room. The examinations were performed by a single investigator using the PanOptic ophthalmoscope, the conventional direct ophthalmoscope and slit lamp biomicroscopy.

RESULTS

The overall sensitivity in detecting sight threatening retinopathy using the conventional direct ophthalmoscope was 73.2% (95% CI: 57.1-85.8%), specificity 93.7% (95% CI: 88.7-96.9%). For PanOptic ophthalmoscope, the overall sensitivity in detecting sight threatening retinopathy was 58.5% (95% CI: 42.1-73.7%), specificity 93.7% (95% CI: 88.7-96.9%). The conventional direct ophthalmoscope was 1.38 times (95% CI: 1.17-1.61 times) as easy to use compared to the PanOptic ophthalmoscope.

CONCLUSION

The PanOptic ophthalmoscope is not superior to the conventional direct ophthalmoscope for the screening of Sight Threatening Retinopathy.

Central retinal artery occlusion and ophthalmoplegia following spinal surgery in the prone position

A 14 year old boy underwent a 7 hour long spinal surgery for scoliosis in the prone position. In the immediate postoperative period, he developed right proptosis, periorbital swelling, chemosis and total ophthalmoplegia. The vision in his right eye was only counting fingers and the intraocular pressure was 68 mmHg. Fundus examination revealed occlusion of the right central retinal artery. A rare manifestation of both vein and artery occlusion was possible in this patient as a result of external ocular compression due to a prolonged period in the prone position. This report highlights the importance of being aware of the possible complications of external ocular compression in non-ocular surgery.

Penetrating ocular injury by durian fruit

Durian may inflict severe body injury when it drops from the tree. This case report describes a patient who presented with facial and penetrating eye injury when a ripe durian fruit dropped onto her face while harvesting the fruits under the tree. The authors emphasized the importance of facial and eye protective devices during durian fruit harvesting season.

Are Orthoptic Exercises an Effective Treatment for Convergence and Fusion Deficiencies?

PURPOSE

To investigate whether orthoptic exercises are an effective way to influence the near point of convergence, fusion range and asthenopic symptoms.

METHODS

Seventy-eight patients met the inclusion criteria of visual acuity 6/9 or better, no history of orthoptic treatment, squint surgery or Meares Irlen syndrome/dyslexia. Information was collected from case records related to diagnosis, near point of convergence, fusion range, prism and cover test measurements and symptoms. Type, duration and frequency of exercises were also recorded. Non-parametric statistics were applied.

RESULTS

Patients ranged in age from 5 to 73 years (mean 11.9). Females outnumbered males (46:32). The diagnoses were: decompensating heterophoria (n = 50) or convergence insufficiency (n = 28: primary 27; secondary 1). Exophoria was more common (n = 65), than esophoria (n = 11) or orthophoria (n = 1). Treatments were aimed at improving near point of convergence and/or reduced fusional reserves. The mean treatment period was 8.2 months. Reduced near point of convergence normalized following treatment in 47/55 cases, and mean near point of convergence improved from 16.6 to 8.4 cm (p = 0.0001). Fusional reserves normalized in 29/50. Fusional convergence improved significantly for those with exodeviation (p > 0.0006). Asthenopic symptoms improved in 65 patients. A reduction in deviation of 5 pd or more occurred in 20 patients.

CONCLUSIONS

Orthoptic exercises are an effective means of reducing symptoms in patients with convergence insufficiency and decompensating exophoria, and appear to target the proximal and fusional components of convergence. Their role in esophoria is unclear and needs further study.

The Importance of Ophthalmic Signs in the Diagnosis of Suprasellar Meningioma - a case report

A forty-two year old lady presented with gradual, painless, progressive blurring of vision of her left eye for four months. There were no other associated ocular or systemic complaints. Examination showed decreased visual acuity in both eyes and a pale optic disc on the left side. Visual field examination revealed a temporal field defect of the right eye which aroused the suspicion of an intracranial mass lesion. MRI of her brain revealed a suprasellar meningioma. We would like to emphasize the importance of visual field examination of both eyes in patients presenting with unilateral loss of vision.

Thyroid associated ophthalmopathy - a review

Thyroid associated ophthalmopathy is an autoimmune disorder affecting the orbital and periorbital tissues. Hyperthyroidism is commonly associated with thyroid associated ophthalmopathy, however in 5% to 10% of cases it is euthyroid. Genetic, environmental and endogenous factors play a role in the initiation of the thyroid ophthalmopathy. Smoking has been identified as the strongest risk factor for the development of the disorder. The pathogenesis involves activation of both humoral and cell mediated immunity with subsequent production of gycoaminoglycans, hyaluronic acid resulting in oedema formation, increase extraocular mass and adipogenesis in the orbit. The natural history of the disease progresses from active to inactive fibrotic stage over a period of years. Diagnosis is mainly clinical and almost all patients with ophthalmopathy exhibit some form of thyroid abnormality on further testing. Treatment is based on the clinical severity of the disease. Non-severe cases are managed by supportive measures to reduce the symptomatology and severe cases are treated by either medical or surgical decompression. Rehabilitative surgery is done for quiescent disease to reduce diplopia and improve cosmesis.

Pattern of ocular trauma in kuching, malaysia

OBJECTIVES

To analyze the causes and characteristics of ocular injuries presenting to Sarawak General Hospital (SGH), Kuching.

DESIGN

It is a prospective hospital-based study done for a period of 1 year.

SETTING

Department of Ophthalmology, Sarawak General Hospital, Malaysia.

PARTICIPANTS

All ocular injury patients seen for the first time in the Eye Department during the period January 2006 to December 2006 were included in the study. Eye injury patients on follow-up and treated elsewhere were excluded.

RESULTS

A total of 233 patients, and 257 eyes, were studied. Men had six-fold higher rates of injury than women. The average age of presentation was 30 years. The predominant age group was between 21-30 years, 26.2 % (n=61). Eye injuries related to work were seen in 36.9% of patients. There was a gross negligence in the use of personal protective devices in the work-related group. The common settings in which the injuries occurred included home 34.3% (n=80) and industrial premises 31.8% (n=74). Assault-related injuries 7.7% (n=18) were seen mostly among young men in the age between 20-30 years. The initial presenting visual acuity of the patients with blunt ocular trauma was better than penetrating injury.

CONCLUSION

Ocular injuries were common in young males. Work related eye injuries were noted in a significant number of cases. Health education and preventive strategies both in the working place and at home will help to decrease the occurrence of ocular injuries.

Neonatal conjunctivitis - a review

Ophthalmia neonatorum remains a significant cause of ocular morbidity, blindness and even death in underdeveloped countries. The organisms causing ophthalmia neonatorum are acquired mainly from the mother's birth canal during delivery and a small percentage of cases are acquired by other ways. Chlamydia and Neisseria are the most common pathogens responsible for the perinatal infection. Fortunately in most cases, laboratory studies can identify the causative organism and unlike other form of conjunctivitis, this perinatal ocular infection has to be treated with systemic antibiotics to prevent systemic colonization of the organism. Routine prophylaxis with 1% silver nitrate solution (crédés method) has been discontinued in many developed nations for the fear of development of chemical conjunctivitis.

Ethambutol ocular toxicity in a patient with pulmonary tuberculosis - a case report

Purpose. To highlight the importance of using the Farnsworth Panel D-15 Hue test in colour vision testing in patients on ethambutol treatment. Case Report. A 70 year-old lady received ethambutol as part of her anti-tuberculous regime. She developed blue-yellow colour defect detectable with the Farnsworth Panel D-15 Hue test, but not with the Isihara Pseudoisochromatic Plates. Ethambutol was immediately discontinued from her anti-tuberculous regime. Two months later, her colour vision returned to normal. Conclusion. This case report illustrates the importance of regular monitoring of patients receiving ethambutol for blue-yellow colour defect using the Farnsworth Panel D-15 Hue Test.

Single instillation of mitomycin C reduces 1st year recurrence following transurethral resection of non-muscle invasive bladder cancer

OBJECTIVE

To study the impact of single instillation of 40 mg Mitomycin C (MMC-40) within first hour of transurethral resection (TUR), on first year recurrence of non-muscle invasive bladder cancer.

METHODS

In this study of two groups of patients with similar demographics and tumour profile were compared to assess first year tumour recurrence pattern. Group A received MMC-40 within 30 minutes of TUR. Group B patients only had TUR of bladder tumour. Patients' charts were reviewed for demographic profile, preoperative diagnosis and imaging used, cytological work up, tumour profile both during cystoscopy and imaging used, patients records were also reviewed for all subsequent check cystoscopies for recurrence. Any adjuvant treatments like intravesical chemo/immunotherapy etc. were also noted. The results were analysed using a commercially available statistical package, SPSS. The level of significance was < or = 0.05.

RESULTS

There were 29 and 46 patients in group A and B respectively. The demographic profile in terms of age, gender distribution, tumour characteristics (size, site, multiplicity) and pathological evaluation including, tumour grade and presence of carcinoma in situ were similar (p < 0.4 and p < 0.5) respectively. The first year recurrence rate in group A was 15% whereas it was 37.4% in group B (p < 0.04).

CONCLUSIONS

The first year recurrence rate is significantly decreased if MMC-40 is instilled following TUR. MMC-40 is safe and cost effective. Most low grade, low volume tumours would not require any further treatment if MMC-40 is given immediately following TUR.