Biomedical subjects

J Ling

Publications and source records attributed to J Ling.

At least 55 records · Page 3Linked to original sources

PubMed1999

The orthodontic treatment need and demand of Hong Kong Chinese children.

OBJECTIVE: To investigate the need and demand for orthodontic treatment of Chinese school children in Hong Kong. METHODS: The material consisted of study casts and questionnaires collected from 765 randomly selected 12-year-old school children in Hong Kong. The need for orthodontic treatment was assessed by the Index of Orthodontic Treatment Need, and questionnaires were used in assessing demand for orthodontic treatment. RESULTS: The results indicate that 12% of the 12-year-old school children had no need of orthodontic treatment, 18% had little need (Grade 2), 33% moderate need (Grade 3), 33% great need (Grade 4), and 4% of children had very great need for orthodontic treatment (Grade 5). About two thirds of the children were not satisfied with their dental appearance, but only 40% of these would like to have orthodontic treatment. A definite relationship was found between negative self-appraisal of dental appearance and demand for orthodontic treatment. CONCLUSION: The study demonstrates that the need of orthodontic treatment among Chinese children is similar to that of Caucasian children; the attitude and demand toward treatment are also similar.

Chi-Square Distribution↗

PubMed1999

[Recombinant Salmonella typhimurium anticaries vaccine. I. Sequence of Streptococcus mutans surface protein pac gene's upstream].

OBJECTIVE: To sequence the Streptococcus mutans surface protein pac gene's upstream. METHODS: The PCR autosequence kit and autosequence instrument ABI310 were used for sequence. RESULTS: The 517 base pairs sequence of the pac gene's upstream is sequenced. CONCLUSION: The sequence of pac gene's upstream will provide useful information to construct the recombinant Salmonella typhimurium anticaries vaccine.

Antigens, Surface↗

PubMed1999

Differentiation of embryonic stem cells into neurons and retina-like structure in nude mice.

PURPOSE: To investigate the intraocular growth and biological characteristics of mice embryonic stem cells in nude mice. METHODS: Murine embryonic stem cells (D3 cell line) were cultured and maintained in an undifferentiated state in vitro, then transplanted into the anterior chamber of nude mice. Mophological and immunohistochemical examinations were implemented. RESULTS: Two to three days after transplantation, yellow-white floating granules, sheets and masses were seen inside the anterior chamber and vitreous cavity, and enlarged gradually. 14-20 days later, the mice were executed. Morphological examination showed that there were undifferentiated cells and some round or polygonal differentiated cells in anterior chamber and vitreous cavity. The morphology of these differentiated cells were similar to that of the retina. The cells were highly positive in NSE staining. CONCLUSION: The transplanted embryonic stem cells could grow in the eyes of nude mice with tendency to differentiate into neurons and retina-like structure.

Animals↗

PubMed1998

DNA-cleaving activity of superoxide dismutase specific for circular supercoiled double-stranded DNA in vitro.

Several superoxide dismutases (SODs), N. tabacum Mn-SOD, porcine erythrocyte Cu/Zn-SOD and bovine erythrocyte Cu/Zn-SOD, have been found to exhibit the activity to cleave the circular supercoiled double-stranded DNA into nicked and further linear form in vitro. The fact that porcine erythrocyte Cu/Zn-SOD did not cleave the linear double-stranded DNA excluded the possibility that nuclease contaminated the SOD preparations and showing the cleaving activity was dependent on the supercoiled form of DNA. Porcine erythrocyte Cu/Zn-SOD inactivated by H2O2 or guanidine still remained its supercoiled DNA-cleaving activity. However, when the SOD was digested with proteases, its activity to cleave supercoiled DNA was completely abolished. These results suggested that the supercoiled DNA-cleaving activity was relative to the apoenzyme moiety, less relevant to the O2- dismutation site of SOD. The enzymatic mechanism of cleaving activity of SOD to supercoiled DNA was discussed.

Animals↗

PubMed1998

Systematic analysis of hMSH2 and hMLH1 in young colon cancer patients and controls.

Germ-line mutations in DNA mismatch-repair genes impart a markedly elevated cancer risk, often presenting as autosomal dominant hereditary nonpolyposis colorectal cancer (HNPCC). However, there are no pathognomonic features of HNPCC, not all gene carriers have a family history of the disease, and families fulfilling the Amsterdam criteria are relatively uncommon. Genetic testing of probands with early-onset colorectal cancer, irrespective of family history, is one approach that would allow predictive genetic testing of at-risk relatives. We cloned and sequenced hMSH2 and hMLH1 introns, to optimize genomic sequencing. We then systematically analyzed the entire hMSH2 and hMLH1 genes, by genomic sequencing and in vitro synthesized-protein-truncation assay (IVSP), in 50 colorectal cancer patients <30 years of age at diagnosis. To determine polymorphic variants, 26 anonymous donors also were sequenced. All subjects analyzed had at least 1 of 37 different polymorphic or pathogenic variants. IVSP complemented genomic sequencing, by detection of mutations not identified by genomic analysis. Fourteen cancer patients (28%) had pathogenic mutations, and a number of other variants also may have had a pathogenic significance that remains to be elucidated. Tumor replication-error status was useful in targeting sequencing efforts for this cohort of young patients: sensitivity was 86%, specificity 73%, and positive and negative predictive values 63% and 90%, respectively. These data indicate that an appreciable proportion of young colon cancer probands carry a germ-line mutation in a DNA mismatch-repair gene.

Adaptor Proteins, Signal Transducing↗

PubMed1998

Impact of femoro-distal bypass on major lower limb amputation rate.

BACKGROUND: Limb salvage is one of the cardinal aims of vascular surgery, but the influence of distal bypasses on amputation rates has been difficult to demonstrate. METHODS: The incidence and indications for major limb amputations and infrapopliteal bypass during two consecutive 16-month periods were analysed. RESULTS: There was a decrease in the number of major amputations from 34 during the first period to 13 in the second, while the number of bypasses to the infrapopliteal arteries increased from four in the first period to 21 in the second. CONCLUSIONS: An increase in the incidence of bypasses to the infrapopliteal arteries was matched by a decrease in the number of major amputations. Factors that may have contributed to the increase in the incidence of distal bypass and the decrease in the number of amputations include the availability of digital subtraction angiography, and a change in referral patterns within the hospital so that, except for trauma, all patients who were considered to be candidates for major amputation were assessed by a vascular surgeon.

Aged↗

PubMed1998

Predicting hemodialysis access failure with color flow Doppler ultrasound.

Color flow doppler ultrasound examination of the hemodialysis access was conducted in 2,792 hemodialysis patients to evaluate its value in predicting hemodialysis access failure. After baseline assessment of vascular access function with clinical and laboratory tests including color flow doppler evaluation these patients were followed for a minimal of 6 months or until graft failure occurred (defined as surgery or angioplasty intervention, or graft loss). The patient demographics and vascular accesses were typical of a standard hemodialysis patient population. On the day of the color flow doppler examination systolic and diastolic blood pressure, hematocrit, urea reduction ratio, dialysis blood flow, venous line pressure at a dialysis blood flow of 250 ml/min, and access recirculation rate were measured. At the conclusion of the study 23.5% of the patients had access failure. Case mix predictors for access failure were determined using the Cox Model. Case mix predictors of access failure were race, non-white was higher than white (p < 0.005), younger accesses had a higher risk than older accesses (p < 0.025), accesses with prior thrombosis had a higher risk of failure (p=0.042), polytetrafluoroethylene (PTFE) grafts had a higher risk than native vein fistulae (p < 0.05), loop PTFE grafts had a higher risk than straight PTFE grafts (p < 0.025), and upper arm accesses had a higher risk than forearm accesses (p=0.033). Most significant, however, was decreased access blood flow as measured by color flow doppler (p < 0.0001). The relative risk of graft failure increased 40% when the blood flow in the graft decreased to less than 500 ml/min and the relative risk doubled when the blood flow was less than 300 ml/min. This study has shown that color flow doppler evaluation, quantifying blood flow in a prosthetic graft, can identify those grafts at risk for failure. In contrast, color doppler volume flow in native AV fistulae could not predict fistula survival. This technique is noninvasive, painless, portable, and reproducible. We believe that preemptory repair of an anatomical abnormality in vascular access grafts with decreased blood flow may decrease patient inconvenience, associated morbidity, and associated costs.

Arteriovenous Shunt, Surgical↗

PubMed1998

Pitfalls in placebo-controlled trials in palliative care: dexamethasone for the palliation of malignant bowel obstruction.

To determine the effect of dexamethasone when treating malignant bowel obstruction, 35 patients were randomized to receive intravenous dexamethasone or a placebo, crossing over to the alternate treatment arm if there had been no resolution of obstruction by day 5. This was done in two consecutive studies. Patients were stratified according to whether or not they had received specific anticancer therapy within 28 days of study. In trial 1, 15 out of 22 patients 'responded' (resolution of obstruction by day 5; 10 on dexamethasone, five on placebo). Eleven out of 15 patients were 'on treatment'. In trial 2, six out of 13 responded (three on dexamethasone, three on placebo); three out of six were 'on treatment'. When both studies are combined, 60% (21/35) patients responded (13 on dexamethasone, eight on placebo). Poor patient accrual terminated both studies. Numbers are too small to allow a combination of studies or formal statistical analysis. We are unable to make any conclusion as to the effectiveness of dexamethasone in the palliation of malignant bowel disease.

Adult↗

PubMed1998

The use of the Edmonton Symptom Assessment Scale (ESAS) within a palliative care unit in the UK.

The Edmonton Symptom Assessment scale (ESAS) was used on 1004 occasions to assess 71 patients with advanced malignant disease admitted to a palliative care unit in the UK over a six-week period. The median length of inpatient stay was eight days (range 1-36) and the median survival from start of ESAS to death was 16 days (range 2-202). Across all patients there was a trend towards worsening symptom scores over the first five days from admission with a significant deterioration in appetite scores. When scores were analysed retrospectively over five days according to outcome (death--group 1, or discharge--group 2) there was a significant improvement in pain scores in group 2 but no change in overall score, and a significant deterioration in activity, drowsiness and appetite in group 1 with no change in overall score. ESAS did not seem an appropriate tool in this group of patients as the total symptom scores were so often biased by the inevitable increase in individual symptom scores immediately prior to death.

Adult↗

PubMed1998

[Coexisting pheochromocytoma and renal artery stenosis].

OBJECTIVE: To improve the diagnosis of coexisting pheochromocytoma and renal artery stenosis. METHOD: Four patients with coexisting pheochromocytoma and renal artery stenosis were treated. RESULT: After removal of the pheochromocytoma, the blood pressure became normal in two patients combined with resection of kidney with renal artery stenosis, and one patient with local adhesion loosened. The hypertension, however, persisted in another patient after the resection of pheochromocytoma even though the long segment of renal artery stenosis was relieved. CONCLUSION: After pheochromocytoma was diagnosed with its known position, coexisting renal artery stenosis should be suspected according to one of the following conditions: (1) Vascular murmurs are noted at the area of the upper abdomen or back; (2) One of the kidneys becomes less sized; (3) Using the inhibitor of receptor alpha only has no effect lowering blood pressure and it is necessary to add the inhibitor of angiotension; (4) Postoperative hypertension does not resolve when no remaining pheochromocytoma is present. the renal artery stenosis can be reversed after both removal of pheochromocytoma and loosening of adhesion in case of stenosis due to the pressure of the tumor and adhesion caused renal artery angling and local stricture. Extensive stenosis or closure, however, can not be corrected with severe atrophy of renal parenchyma due to pheochromocytoma, and the resection of kidney should be indicated.

Adolescent↗

PubMed1998

[Studies on voice identification].

The spectrographic method of voice identification was investigated and its application in forensic sciences was discussed.

Forensic Medicine↗

PubMed1998

[A study on anti-caries activity of genetic recombinant vaccine of Streptococcus lactis. II. Immunization in vein with recombinant S. lactis in pregnant rabbits].

The effects of immunization in vein with recombinant S. lactis HL107 carring the S. mutans surface protein PAc gene in pregnant rabbits were studied. The results indicated that specific anti-PAc IgG in serum and milk were obviously induced 1 week after immunization and retained at high level for several weeks. It suggests that the recombinant S. lactis HL107 possessing immunogenicity of S. mutans surface protein PAc is able to stimulate specific systemic immune response against PAc.

Animals↗

PubMed1998

[Approach to recognition of ECG P waves based on approximating functions].

A new method of recognizing ECG P waves based on approximating function is presented in this paper. The result of experiment demonstrates that the method based on the second order approximating functions to recognize P waves in useful and easy to do. The rate of correctness for recognizing P waves is higher than 99% according to MIT/BIH ECG Datebase.

Algorithms↗

PubMed1997

ABO blood group incompatibility in liver transplantation: a single-centre experience.

BACKGROUND: For most organ transplantation (Tx), ABO blood group incompatibility (ABOI) is an absolute contraindication because of the high incidence of hyperacute rejection (HAR). While HAR occurs in ABOI liver Tx (LTx), it is known that some liver grafts can be accepted. METHODS: ABO-incompatible (ABOI) liver allografts were used in seven of 355 orthotopic LTx operations performed at our institution over a 10-year period. All seven recipients were in fulminant hepatic failure (FHF) prior to Tx. RESULTS: Following Tx, all grafts functioned immediately. One patient died without recovering consciousness. Six patients recovered consciousness following Tx but three patients subsequently required re-transplantation (with ABO-compatible grafts (ABOC)) because of severe acute rejection (2) and chronic rejection (1). Hyper-acute rejection did not occur. All six patients are now well, with a mean survival of 61.5 months. When compared to 36 other FHF patients who received ABOC grafts, graft survivals were 3/7 (43%) for ABOI versus 23/36 (64%) for ABOC (P = not significant (NS)). Patient survivals were 6/7 (85.7%) for ABOI patients and 23/36 (64%) for ABOC (P = NS). The re-transplantation rate was significantly higher in the ABOI group (P = 0.001). CONCLUSIONS: The results confirm that ABOI liver grafts should be used in urgent circumstances when compatible grafts are not available. Some grafts function indefinitely, while those that fail may function for sufficient time to allow successful retransplantation with ABOC grafts.

ABO Blood-Group System↗

PubMed1997

Characteristics and outcomes of self inflicted pediatric injuries: the role of method of suicide attempt.

OBJECTIVE: To examine the epidemiologic characteristics and clinical outcomes of self inflicted pediatric injuries in relation to the method of suicide attempt. METHODS: Using data from the National Pediatric Trauma Registry Phase II, a comparative analysis was conducted for children under 15 years of age who were admitted from 1 October 1988 through 30 April 1996 because of self inflicted injury by firearm (n = 28), hanging (n = 38), or jumping from heights (n = 21). RESULTS: Of the 87 cases under study, 90% occurred at home, and 86% occurred between noon and midnight, with a peak in early evening (between 6 pm and 7 pm)-More than one quarter (29%) had preexisting mental disorders, such as disturbance of conduct and depression. Toxicological tests were conducted on admission on 40 (46%) of the patients; 20% tested positive for alcohol or other illicit drugs. The method of suicide attempt was associated with gender and age of the patients: 75% of the firearm cases and 82% of the hanging cases were boys compared with 29% of the jumping cases (p < 0.01); 79% of the hanging cases were aged 13 years or younger compared with 39% of the firearm cases and 48% of the jumping cases (p < 0.01). The mean injury severity score was 18.6 for the firearm cases and 16.3 for the hanging cases, significantly greater than 8.5 for the jumping cases (p < 0.02). Reflecting the differences in injury severity, firearm cases and hanging cases were more likely than jumping cases to be sent to intensive care units or operating rooms from emergency departments, and to develop complications during hospitalization. The case fatality rate was 50% for the firearm cases, 32% for the hanging cases, and 5% for the jumping cases (p < 0.01). On average, these patients stayed in hospitals for 11 days and 52% of those who were alive at discharge had at least one impairment in communication, cognition, or self care functions. CONCLUSION: Boys and older children tend to use more lethal methods in suicide attempts. Even in this age group, suicide attempts often involve psychiatric disorders and acute abuse of alcohol or other illicit drugs. Firearms are associated with significantly increased risk of inhospital fatality. The clinical outcomes of self inflicted injuries appear to be worse than other injuries treated in the same trauma centers.

Adolescent↗

PubMed1997

[Painful mild scoliosis in the elderly].

We followed up and analysised 25 patients with slight painful scoliosis including symptoms, signs, images, as well as treatment and effects. The results showed that the mild scoliosis with rotation in lumbar and thoracic-lumbar region will develop and aggraviate with age. In the elderly, it may cause severe low-back pain intermittent claudication and neurological defect of lower extremities due to stenosis and spondylolethesis. We think this kind of patients should be treated with the anterior Zielke operation in early stage in order to correct rotation and prevent the later stage problems. If the symptoms and signs as described above have occured, surgical decompression and internal fixation should be recommended, the operative treatment is more effective than the non-operative treatment.

Aged↗

PubMed1997

[The effect of chlorhexidine varnish system on Streptococcus mutans in fissure plaques].

A chlorhexidine varnish system and a controlled releasing varnish were prepared by the authors. The release rate of chlorhexidine in vitro and the effects on S. mutans and S. sanguis in vivo were determined. The results showed that the system could selectively inhibit the growth of S. mutans in fissure plaque and had no effect on S. sanguis. The period of interaction between the layer of varnish and plaque was prolonged by the control-releasing reagent. The study suggests that the chlorhexidine varnish system is effective of anticaries and can maintain microflora balance in oral bacteria.

Adolescent↗

PubMed1997

[Study on the vaccine against dental caries of recombinant Streptococcus lactis and artificial active immunization. V. Extraction, purification and dot blot analysis of RNA in the recombinant S. lactis].

To investigate the transcription level of the pac gene in the recombinant S. lactis, the amount of PAc-specific mRNA was measured by RNA dot blot analysis with the biotin-labeled 1.5 kb PstI fragment of the pac gene. RNA were extracted with guanidinium thiocyanate followed by centrifugation in cesium chloride solutions. These results indicated the sequence of PAc-mRNA in S. lactis HL107 or HL45 was the same as that in S. mutans Ingbritt and showed similar density photograph. The PAc-specific mRNA plated an intermediary role of protein synthesis in recombinant S. lactis and made it complete the expression of cloned pac gene.

Blotting, Northern↗