Automated identification of diabetes type-2 subjects with and without neuropathy using eigenvalues.

Diabetes is a disorder of metabolism and has been a leading healthcare burden throughout the world. The most typical form of diabetes is type-2 diabetes. It is commonly developed in adults of age 40 and older. The purpose of this study is to identify the plantar pressure distribution in normal subjects, diabetic type-2 subjects with neuropathy, and diabetic type-2 subjects without neuropathy. Foot scan images were obtained using the F-Scan (Tekscan USA) in-shoe measurement system. The eigenvalues were evaluated from principal-component analysis after performing continuous wavelets transformation (CWT). The eigenvalues of CWT in regions 5 and 7 had shown excellent p values of more than 95 per cent confidence level when subjected to an analysis-of-variance test. These parameters were then presented to an artificial neural network (ANN) and a Gaussian mixture model (GMM) for automatic classification. The results show that the ANN classifier performs better than the GMM and is able to identify the unknown class with a sensitivity of 100 per cent and a specificity of 72 per cent.

Non-linear analysis of body responses to functional electrical stimulation on hemiplegic subjects.

Functional electrical stimulation (FES) is a method of applying low-level electrical currents to restore or improve body functions lost through nervous system impairment. FES is applied to peripheral nerves that control specific muscles or muscle groups. Application of advanced signal computing techniques to the medical field has helped to achieve practical solutions to the health care problems accurately. The physiological signals are essentially non-stationary and may contain indicators of current disease, or even warnings about impending diseases. These indicators may be present at all times or may occur at random on the timescale. However, to study and pinpoint these subtle changes in the voluminous data collected over several hours is tedious. These signals, e.g. walking-related accelerometer signals, are not simply linear and involve non-linear contributions. Hence, non-linear signal-processing methods may be useful to extract the hidden complexities of the signal and to aid physicians in their diagnosis. In this work, a young female subject with major neuromuscular dysfunction of the left lower limb, which resulted in an asymmetric hemiplegic gait, participated in a series of FES-assisted walking experiments. Two three-axis accelerometers were attached to her left and right ankles and their corresponding signals were recorded during FES-assisted walking. The accelerometer signals were studied in three directions using the Hurst exponent H, the fractal dimension (FD), the phase space plot, and recurrence plots (RPs). The results showed that the H and FD values increase with increasing FES, indicating more synchronized variability due to FES for the left leg (paralysed leg). However, the variation in the normal right leg is more chaotic on FES.

A comparative analysis of scaffold material modifications for load-bearing applications in bone tissue engineering.

To facilitate optimal application of appropriate scaffold architectures for clinical trials, there is a need to compare different scaffold modifications under similar experimental conditions. In this study was assessed the effectiveness of poly-e-caprolactone (PCL) scaffolds fabricated by fused deposition modelling (FDM), with varying material modifications, for the purposes of bone tissue engineering. The incorporation of hydroxyapatite (HA) in PCL scaffolds, as well as precalcification through immersion in a simulated body fluid (SBF) to produce a biomimetic apatite coating on the scaffolds, was assessed. A series of in vitro studies spanning 3 weeks as well as in vivo studies utilizing a subcutaneous nude mouse model were carried out. PCL and HA-PCL scaffolds demonstrated increasing tissue growth extending throughout the implants, as well as superior mechanical strength and mineralization, as evidenced by X-ray imaging after 14 weeks in vivo. No significant difference was found between PCL and HA-PCL scaffolds. Precalcification with SBF did not result in increased osteoconductivity and cell proliferation as previously reported. Conversely, tensile forces exerted by tissue sheets bridging adjacent struts of the PCL scaffold caused flaking of the apatite coating that resulted in impaired cell attachment, growth and mineralization. The results suggest that scaffolds fabricated by FDM may have load-bearing applications.

Evaluation of ultra-thin poly(epsilon-caprolactone) films for tissue-engineered skin.

Various natural and synthetic polymeric materials have been used as scaffold matrices for tissue-engineered skin. However, the commercially available skin replacement products pose problems of poor mechanical properties and immunological rejection. We have thus developed a film of 5 microm thickness, via biaxial stretching of poly(epsilon-caprolactone) (PCL), as a potential matrix for living skin replacements. The aim of this study was to evaluate the feasibility of using biaxially stretched PCL films as matrices for culturing human dermal fibroblasts. For this purpose, we cultured human dermal fibroblasts for 7 days on the films. Glass cover slips and polyurethane (PU) sheets were used as controls. The data from phase contrast light, confocal laser, and scanning electron microscopy suggested that biaxially stretched PCL films support the attachment and proliferation of human dermal fibroblasts. Thymidine-labeling results showed quantitatively that cell proliferation on the PCL films was superior to that on the PU samples. These results indicated that biaxially stretched PCL films supported the growth of human dermal fibroblasts and might have potential to be applied in tissue engineering a dermal equivalent or skin graft.

Necrospermia and chronic spinal cord injury.

OBJECTIVE: To determine whether improvement in quality of semen over 4 consecutive days of electroejaculation in men with chronic spinal cord injury (SCI) was consistent with epididymal necrospermia. DESIGN: Prospective study of a random sample of men with SCI. SETTING: A southeastern Australian SCI management center in collaboration with the specialist andrology service of a university-based department of obstetrics and gynecology in a tertiary referral hospital. PATIENT(S): Nine men with chronic spinal cord injury. INTERVENTION(S): Semen samples were obtained by using electroejaculation, and testicular biopsy samples were obtained by using fine-needle tissue aspiration. MAIN OUTCOME MEASURE(S): Semen analysis was performed according to World Health Organization criteria. Testicular biopsy and electron microscopy were done by using standard techniques. RESULT(S): During up to 4 days of consecutive-day electroejaculation, sperm motility and viability in semen obtained from men with chronic SCI increased by an average of 23% on days 2 and 3. The severity of the degenerative changes and the numbers of spermatozoa affected on day 1 became less marked by day 4. The changes were not present in late spermatids obtained from testicular biopsies. CONCLUSION(S): The asthenospermia of chronic SCI is similar to epididymal necrospermia and can be improved by consecutive-day electroejaculation.

Transareolar dye-injection microdochectomy.

Single-duct microdochectomy is described for use in patients with bloody or serosanguinous nipple discharge arising from a single duct in the breast. Because most such cases are caused by benign, intraductal papillomata, the technique used in removing the offending ductal system should be fully diagnostic, adequately therapeutic, and cosmetically acceptable. A technique is described that is used in 40 consecutive patients with good diagnostic, therapeutic, and cosmetic result. The procedure itself combines techniques and principles of plastic and reconstructive surgery such as minimal tissue trauma, use of anatomical tissue planes, bloodless-field surgery, and microdissection.

Ophthalmic involvement in cranio-facial trauma.

OBJECTIVES: This is a retrospective descriptive case study which will look into the spectrum of ophthalmic involvement in cases with orbital and eye injuries after cranio-facial trauma and to analyse the visual and motility outcome. MATERIAL: One hundred and four cases with ophthalmic involvement after cranio-facial trauma that were referred to and seen in the eye department of a tertiary teaching hospital in Singapore between 1991-97 were included in the study. METHODS: The case records of 104 such patients were traced. The demographic data, the mode of injury, the type of fracture sustained and presence of serious eye injury were noted. The details about visual acuity, significant diplopia and enophthalmos at the first and last visits were charted. Presence of traumatic optic neuropathy including the type of treatment given was recorded. RESULTS: There was a male preponderance (82%). The industrial accidents were 21%, only next to road traffic accidents, which constituted approximately 36.5%. The predominant types of fractures seen were blow-out orbital fractures, complex fractures comprising of Le-Fort II, III, panfacial and fronto-basilar skull fractures. Diplopia was the most common presenting feature (40%) with visual acuity disturbance (23% having <6/60) as the next most common finding. Traumatic optic neuropathy was seen in 20% of patients and serious eye injury was present in 9% of patients. The incidence of traumatic optic neuropathy was significantly higher (p<0.001) in patients with complex fractures and fronto-basilar fractures, as compared to the blow-out and zygomatico-maxillary fractures. Analysis of final results indicated 15% as having significant diplopia in one or more gazes and 12.5% as having a vision of <6/60. CONCLUSION: Diplopia and visual acuity disturbances seem to be the most common ophthalmic presentations in cranio-facial trauma. A significant number of patients suffer from poor vision and significant diplopia despite treatment.

The superior gluteal artery perforator flap for the closure of sacral sores.

The purpose of this paper is to report the use of the superior gluteal artery perforator (SGAP) flap in the closure of sacral pressure sores here in Singapore. This fasciocutaneous flap is a refinement of the musculocutaneous flap which is popularly used for the closure of sacral sores. There were minimal complications. This is a reliable flap and gives the option of further reconstructive possibilities should a recurrence occur.

Aetiology and distribution of mandibular fractures in the National University Hospital, Singapore.

Sixty-seven consecutive mandibular fractures treated mainly in 1998 were surveyed retrospectively. Treatment was performed at the National University Hospital, Singapore. Males outnumbered females by 5:1, with Chinese the commonest racial group involved (56.7%). Most patients were between 20 and 29 years of age. Road traffic accidents formed the largest proportion (61.2%) followed by industrial accidents and assaults. The symphyseal and parasymphyseal regions were most commonly fractured (46.5%). Almost a third of the patients sustained other facial fractures. Treatment was commonly administered within one to two days of discovery of the fracture and open reduction was the treatment plan of choice in 79.1% of the time. Discussion on how aetiology affects the fracture pattern in Singapore is carried out.

Management of concomitant maxillofacial, cervical spine and laryngeal trauma--case reports.

Three cases are presented to stress important points in the diagnosis and management of concomitant maxillofacial, cervical spine and laryngeal trauma. Emergency tracheostomy to control airway, immediate rigid fixation of maxillofacial fractures, early computed tomographic (CT) scans to evaluate the extent of laryngeal and cervical spine injury and the early repair of laryngeal injury will provide better aesthetic and functional results.

A case of ductal carcinoma in situ of breast with Poland syndrome.

INTRODUCTION: A 51-year-old woman was diagnosed with a rare case of multi-focal ductal carcinoma in situ (DCIS) of the breast associated with Poland syndrome. CLINICAL PICTURE: Physical examination showed mild hypoplasia of the left breast with microcalcifications on mammogram. Intraoperatively, there was complete absence of the pectoralis major, which precluded the insertion of a breast implant. TREATMENT AND OUTCOME: She underwent a skin-sparing mastectomy and autologous microsurgical free flap reconstruction with deep inferior epigastric perforator (DIEP) flap. Postoperative recovery was uneventful with no evidence of recurrence at 6 months. CONCLUSION: This is the first reported case of DCIS of the breast with Poland syndrome. We performed a skin-sparing mastectomy with immediate DIEP flap recontruction. Patient recovered well postoperatively with no evidence of recurrence at 6 months.

Phyllodes tumour: an update of 40 cases.

This is a retrospective study of 40 cases of phyllodes tumour treated at the National University Hospital since 1985. The mean age of presentation was 37.8 years, with a range of 15 to 58 years [standard deviation (SD) 11.22 years]. Ninety per cent of the patients were premenopausal. The mean size of tumours was 52 mm, with a range of 10 to 220 mm. Preoperative diagnosis was correct in only five patients, the lesion most commonly being mistaken as a fibroadenoma. Initial surgical treatment was by simple excision in 80% of cases. Histologically, the ratio of benign, intermediate and malignant tumours was 82.5%, 12.5% and 5% respectively. Recurrences occurred in only four patients (10%), all of whom were initially treated by simple excision. The diagnosis of phyllodes tumour continues to be difficult even with newer modalities of preoperative investigations, resulting in simple excision as initial treatment of these tumours. Expectant follow-up should be continued for these patients, with wide excision of future recurrences.

Radionuclide measurement of liquid and solid gastric emptying in normal subjects in Singapore.

Scintigraphic methods for liquid and solid gastric emptying were utilised to study normal patterns in 21 volunteers. Of these, 19 had solid emptying studies and 14 had liquid emptying studies. The liquid study lasted 1/2 hour, while the solid study was for 1 hour. The gastric emptying half-time (T 1/2), as well as percentage retention at 15 minutes (liquids), and at 60 minutes (for solids) were noted. The time-activity curves were also corrected for tissue attenuation. Results indicated normal average liquid emptying T 1/2 to be 14.2 minutes, while that for solids was 116 minutes.

Hepatocellular carcinoma--a clinical study.

Hepatocellular carcinoma afflicts mainly Chinese Singaporeans 75/77 (97.4%), of which 71/77 (92.2%) of the patients are males. It is rare below the 3rd decade of life (1.3%), with the peak incidence occurring in the 5th to 7th decade of life (68.5%). Common presenting features are hepatomegaly (85.7%), jaundice (63.6%), and right hypochondrial pain (51.9%). Liver function tests were abnormal in 98.7%. Alpha-foetoprotein were positive in 61/77 (79.2%) of patients. Hepatitis B surface Antigen were positive in 43.75 (57.3%) of patients. Radiology and ultrasound studies demonstrated that 70.1% had lesions involving both lobes at diagnosis. Only 4/77 (5.1%) had surgical resections of the tumour. 50/65 (76.9%) died within six months of diagnosis, 11/65 (16.9%) survived for one year, 1/65 (1.5%) for 1 1/2 years, 1.65 (1.5%) for 2 years and 2/65 (3.0%) for more than 2 1/2 years; the longest survivor is still alive, at 4 1/2 years after diagnosis.

Ulcerative colitis in Singapore: a clinical study of sixty-one patients.

Sixty-one consecutive cases of ulcerative colitis from the Department of Medicine, Singapore General Hospital, over a 16-year period (1971 to 1986) were reviewed. Mean duration of follow-up was 35.9 months (range 2 months to 16 years). Fifty-one (83.6%) cases were diagnosed in the last 8 years. Sex ratio was almost equal (males 30, females 31) and mean age was 38.2 years. All racial groups were affected but a predilection among Indians (21.3%) was observed. At presentation, the disease was mild in 36 (59.0%), moderate in 14 (22.9%) and severe in 11 (18.1%) patients. Fifty-two (85.2%) patients had symptoms of at least one month's duration before presentation. The 3 commonest symptoms were haematochezia (95.1%), diarrhoea (95.1%) and mucoid stools (83.6%). Extraintestinal manifestations of disease such as backache (8.2%), peripheral arthritis (6.5%), iritis (6.5%) and liver disease (1.6%) were uncommon. Severe intestinal complications include toxic megacolon (1.6%), colonic perforation (1.6%) and massive gastrointestinal haemorrhage (1.6%). Haematological and biochemical indices at presentation generally reflected the activity and severity of disease. The disease was limited to the rectum and sigmoid colon in 12 (19.7%) patients, extended up to the splenic flexure in 16 (26.2%), up to the hepatic flexure in another 16 (26.2%) and involved the whole colon in 17 (27.9%). Pseudopolyposis was present in 13 (21.3%) patients. Of 49 patients: (a) 18 (36.7%) had remission and were relapse free subsequently (b) 14 (28.6%) had infrequent relapses (less than 3 x/year) (c) 3 (6.1%) had frequent relapses (greater than 3 x/year) (d) 10 (20.4%) had chronically active disease (e) 4 (8.2%) had a short fulminant course terminating in death.(ABSTRACT TRUNCATED AT 250 WORDS)

Changing patterns in the treatment of early breast cancer: a historical perspective and a review of changing local trends.

Over the past 50 years, a variety of surgical procedures have been advocated for the treatment of operable breast cancer, ranging from local excision to supraradical mastectomy. Today, the surgical treatment of breast cancer remains highly contentious. We review the historical development of breast cancer surgery and analyse the available evidence supporting conservative procedures. We also express our opinions on the treatment of early breast cancer and illustrate the changing patterns of surgery with our experience at National University Hospital.

The role of DRE in the diagnosis of prostate carcinoma.

DRE has been used as a diagnostic and screening tool for prostate cancer for decades. However these are based on Western data and its local applicability has yet to be verified. We held a Prostate Health Awareness Week in August 1998 and a total of 2086 men were screened. All men aged 50 years old and above were included for the study. The subjects were evaluated on DRE findings, PSA levels and if indicated a TRUS-guided biopsy results. We concluded that DRE per se might have limited role in the screening of prostate cancer in Malaysia. Screening using DRE and PSA combined are still recognized as the most cost-effective means. Neither DRE nor PSA alone has high enough specificity for diagnosis of prostate cancer cases. Combining DRE and PSA will definitely increase the specificity significantly.

Prevalence of symptomatic BPE among Malaysian men aged 50 and above attending screening during prostate health awareness campaign.

OBJECTIVE: To study the prevalence of symptomatic BPE among Malaysian men age 50 and above attending prostate health awareness campaign and to identify differences in prevalence between different ethnic groups residing within metropolitan Kuala Lumpur. MATERIALS AND METHODS: Demographic data and the completed International Prostate Symptom Score (IPSS), maximal uroflow rate (Qmax) and prostate size of volunteers, aged 50 and above, who attended the prostate health awareness campaign were analyzed. Subjects with known prostate diseases or prostate surgery, bladder disorders and neurological disorders were excluded. RESULTS: 2086 volunteers attended the campaign. 575 men fulfilled the inclusion criteria and their demographic data, IPSS; peak flow rate and prostate volume were analysed. Overall, 18.9% and 39.6% of the men were severely and moderately symptomatic, respectively. The prevalence of moderate to severe lower urinary tract symptoms (LUTS) in Malays, Chinese and Indians were 70%, 59% and 50% respectively (p = 0.004). The commonest bothersome symptoms were nocturia (56%), frequency (50.4%) and sense of incomplete voiding (43.5%). The mean peak flow rate of the subjects was 15.4 ml/s. 20.9% and 55.2% of the subjects had peak flow less than 10 ml/sec and 15 ml/sec respectively. The mean prostate size was 25.1 cc. There is no significant difference in term of maximal flow rate and prostate size among Malays, Chinese and Indians in Malaysia. A good correlation was found between the total symptom score and the single disease-specific quality of life question (r = 0.69, p < 0.001). The correlation between IPSS and peak flow rate (r = -0.22, p < 0.001) and prostate volume (r = 0.11, p = 0.009) was weak. There was no correlation between IPSS and age (r = 0.06, p = 0.17). The prevalence of symptomatic benign prostate enlargement (BPE) was 39.3%. The prevalence increased 8% per decade from 41.7% for men aged 50 to 59 to 65.4% for men aged 70 or more. There is no significant difference in prevalence of symptomatic BPE among the three ethnic groups. The Prevalence of BPO was 15.8%. CONCLUSION: The correlation between symptom score, maximal flow rate and prostate size was poor and one cannot predict the value of one parameter by knowing one or more of the other parameters. There is a high prevalence of LUTS suggestive of benign prostatic obstruction in the apparently healthy Malaysian aged 50 and above attending the prostate health awareness campaign.

Assessment of tumor blood flow distribution by dynamic contrast-enhanced CT.

A distinct feature of the tumor vasculature is its tortuosity and irregular branching of vessels, which can translate to a wider dispersion and higher variability of blood flow in the tumor. To enable tumor blood flow variability to be assessed in vivo by imaging, a tracer kinetic model that accounts for flow dispersion is developed for use with dynamic contrast-enhanced (DCE) CT. The proposed model adopts a multiple-pathway approach and allows for the quantification of relative dispersion in the blood flow distribution, which reflects flow variability in the tumor vasculature. Monte Carlo simulation experiments were performed to study the possibility of reducing the number of model parameters based on the Akaike information criterion approach and to explore possible noise and tissue conditions in which the model might be applicable. The model was used for region-of-interest analysis and to generate perfusion parameter maps for three patient DCE CT cases with cerebral tumors, to illustrate clinical applicability.