[Application of acellular dermal matrix in periodontal soft tissue augmentation surgery].

The substitute materials of autologous tissue graft for periodontal soft tissue augmentation surgery develop rapidly. The use of substitute material can avoid the second operation area, shorten the operation time, reduce the postoperative reaction and pain, and is not limited by the quantity, suitable for a wide range of cases. In this paper, the characteristics, histological study, clinical application and therapeutic effect of acellular dermal matrix as a substitute material for autologous tissue transplantation were introduced to provide reference for clinical work.

[Evaluation of the effects of plaque and inflammation control on treatment of gingival enlargement].

Gingival enlargement or hypertrophy is one of the common clinical symptoms in patients with periodontitis. Plaque stimulation, hormones and drug use could be the promoting factors for the occurrence of gingival enlargements. This paper reviews the literature on the pathogenesis, treatment methods and the effect of plaque and inflammation control in the treatment of various types of gingival hypertrophy. The therapeutic effect of controlling plaque and inflammation on various types of gingival hypertrophy is also discussed and the treatment scheme of gingival hypertrophy is proposed, which may provide reference for clinical work.

Specific oxidative cleavage of carotenoids by VP14 of maize.

The plant growth regulator abscisic acid (ABA) is formed by the oxidative cleavage of an epoxy-carotenoid. The synthesis of other apocarotenoids, such as vitamin A in animals, may occur by a similar mechanism. In ABA biosynthesis, oxidative cleavage is the first committed reaction and is believed to be the key regulatory step. A new ABA-deficient mutant of maize has been identified and the corresponding gene, Vp14, has been cloned. The recombinant VP14 protein catalyzes the cleavage of 9-cis-epoxy-carotenoids to form C25 apo-aldehydes and xanthoxin, a precursor of ABA in higher plants.

The lateral "backdoor" approach to open thyroid surgery: A comparative study.

INTRODUCTION: The traditionally taught technique for conventional open thyroidectomy is via a midline splitting of the strap muscles following a skin crease neck incision - midline approach (MA). The lateral "backdoor" approach (LA) uses the same central neck incision but approaches the thyroid gland between the anterior border of sternocleidomastoid (SCM) and strap muscles. This technique is usually reserved for re-do thyroid surgery. We compared the results of the two approaches in patients undergoing conventional thyroidectomy for the first time. METHODS: A case-control study was performed on 90 patients undergoing conventional open thyroidectomy from 2012 to 2014. The first 45 patients underwent MA and subsequent 45 patients underwent LA. All patients were given 10 ml of 1% Marcaine infiltration into the neck incision before closure. Basic demographic data, operative time, incision length, weight of gland, need for transection of strap muscles and complications were recorded. Revision thyroid surgery and minimally invasive thyroid operations were excluded. RESULTS: The demographics, operative timing, gland weight and incisional length showed no significant difference. Post-operative pain was significantly lower in the LA group. 5 patients (11%) in MA group needed horizontal transection of strap muscles to extract large goitres compared to 1 patient (2.2%) in the LA group. No major complications occurred in either group. CONCLUSION: The LA method is as safe as the midline technique with comparable operative time and significantly lower pain scores. It avoids midline separation and suturing of strap muscles and reduces the need for strap muscle transection to removal large goitres.

Marjolin's ulcer--a near forgotten entity.

We report a case of a 55-year-old man who presented with a 6-month history of a fungating ulcer on the right hand at the site of a previously healed ulcer that had been present for 40 years. Histopathological examination of four-quadrant biopsy specimens showed a moderately differentiated squamous cell carcinoma (SCC). A transradiocarpal amputation with stump closure using radial flap was performed as it was not possible to achieve a functionally and cosmetically acceptable hand after a wide excision with 2 cm tumour-free margin. It is our intention to highlight this rare condition as reminder to consider this entity as a differential diagnosis of chronic non-healing skin ulcer.

Dual-faced SH3BGRL: oncogenic in mice, tumor suppressive in humans.

Despite abundant data supporting c-Src as a metastasis-promoting oncogene, activating mutations of c-Src are rare. This suggests that trans-interacting proteins may have a critical role in regulating c-Src activation. Here, we first report the discovery of Src homology 3 (SH3) domain-binding glutamic acid-rich-like protein (SH3BGRL), a novel c-Src activator in mice. Ectopic expression of murine SH3BGRL (mSH3BGRL) strongly promoted both tumor cell invasion and lung metastasis. Molecularly, mSH3BGRL specifically bound the inactive form of c-Src phosphorylated at Tyr527, promoting Tyr416 phosphorylation of c-Src and subsequent FAK-mediated activation of ERK and AKT signaling pathways. Targeting endogenous c-Src alone was sufficient to abolish mSH3BGRL-induced cancer metastasis in vivo. Unexpectedly, human SH3BGRL (hSH3BGRL) in turn suppressed tumorigenesis and metastasis in nature. We attempted site-specific reversion of hSH3BGRL amino-acid sequence to mSH3BGRL and found V108A substitution sufficient to restore SH3BGRL function as a c-Src activator and metastasis promoter. Notably, the somatic mutation R76C of hSH3BGRL can similarly act as hSH3BGRL-V108A and mSH3BGRL in tumorigenesis and metastasis. Our results uncover an evolutionarily controversial role of SH3BGRL in driving tumor metastasis through c-Src activation, and suggests that hSH3BGRL mutation status could be relevant to cancer diagnosis and therapy.

Radiotherapy of carcinoma of the uterine cervix in Singapore, 1973-1975.

The results of 322 patients with uterine cervix carcinoma treated by radiotherapy at the Singapore General Hospital in the 3-year period from 1973 to 75 are presented. Two hundred seventy-nine patients were treated with a combination of intracavitary radium, using Fletcher-Suit applicators and cobalt teletherapy; the remaining 43 patients received only cobalt teletherapy. One hundred thirty-four patients (41.6%) presented with FIGO Stage III disease. Only 46 patients (14.3%) presented with Stage I disease, showing that patients tended to present late in the disease course. Five-year actuarial (uncorrected) survival rates of 86.7% for Stage I, 65.0% for Stage II, 41.4% for Stage III and 4.9% for Stage IV were obtained with corresponding 10 year rates of 79.6%, 60.2%, 35.2% and 0%. The overall 5 and 10 year survival rates were 54.0% and 48.2%, respectively. The survival rates "flattened off" at about 7-8 years, reflecting late deaths after the fifth anniversary of treatment. Non-severe complications consisted mainly of chronic proctitis (41.3%) and vaginal stenosis (20.8%). Major complications were intestinal stricture (1.2%) and fistula formation (1.6%).

Lung cancer metastases--management.

Distant metastases from lung cancer is a common occurrence in a common malignancy. Almost every organ may be involved but the extra-thoracic sites posing common clinical problems are brain metastases, cord compression, painful bone metastases or pathological fractures, nodal spread and liver involvement. A review of the records of 225 lung cancer patients referred to the Therapeutic Radiology Department, Singapore General Hospital, during the calender year 1985 showed a metastatic rate of 13.8% at referral. On subsequent follow up, an additional 49 patients (21.7%) developed metastases clinically. The organs involved were bone (21 patients), spinal cord (21 patients), brain (18 patients), liver (13 patients), other lung (7 patients) and other sites (17 patients). The management of metastases to the brain, bone and liver, and spinal cord compression will be discussed.

Conservation breast treatment: a viable option locally.

Conservation treatment in carcinoma of the breast is a viable option in the West but is still an uncommon practice locally. Many reasons have been put forth, including the late stage of the tumour we see and the small breast size. This paper presents 25 cases treated by lumpectomy and irradiation with satisfactory cosmetic results, although the follow-up period is short. The introduction of this technique may encourage women to seek treatment earlier, without the fear of losing their breasts.

Radiation induced cancer: a report of 10 cases.

Ionizing radiations have been shown to be carcinogenic to man as well as experimental animals. Malignancies following therapeutic radiation occur rarely. Over the past 10 years the authors recorded 10 cases of tumours in irradiated tissues. 3 occurred in patients irradiated for nasopharyngeal carcinoma, 3 were irradiated for tuberculosis adenitis, 2 for carcinoma of the cervix, 1 for carcinoma of the breast and 1 for basal cell carcinoma. The latent period for tumour induction following the irradiation varied from 5 years to 31 years. All these cases showed no evidence of recurrence or metastases of the original primary lesion; and the histology of the second primary differed from the first. Evidence of radiation damage was seen in all cases except for 2 patients who were treated for tuberculosis adenitis. The doses received varied from 900r to about, 9000r. Among the tumours produced, there were 3 cases of squamous cell carcinoma of the oral & postcricoid region, 2 cases of papillary carcinoma of the thyroid, 2 cases of adenocarcinoma of the rectum, 1 case of adenocarcinoma of the ethmoid, 1 case of osteosarcoma of the mandible and 1 case of extraskeletal osteosarcoma. The clinical features of these cases are discussed and other cases reported in the literature are reviewed.

The development of radiation therapy in Singapore--its present status & future prospects.

X-rays were introduced into Singapore soon after their discovery but their use in therapy did not take place until 1914. Radiation therapy was widely used only after 1949 when the first deep X-ray machine was installed. Since then the number of patients given this treatment has progressively increased, keeping pace with the rising cancer incidence. In 1981, 2533 cases were referred for treatment, out of which 1889 were given radiation treatment. The value of radiotherapy in malignant disease has been established both as a palliative as well as a radical method of treatment. Through improved techniques, better therapy equipment, and greater understanding of malignant disease, results of radical radiotherapy have shown progressive improvement. Further advances can be expected with newer techniques which have been put to clinical trials recently. These are planning with CT Scan, conformation radiotherapy, radiation sensitizers and protectors, hyperfractionation, hyperthermia, intraoperative radiotherapy, heavy particle radiotherapy and isotopic immunoglobulin therapy.

Thyroid scanning & the significance of the solitary cold nodule.

Since thyroid scanning was introduced in Singapore in 1968 there has been progressive increase in the demand for these scans. 215 patients comprising 153 females and 62 males were scanned in 1976 using 131I. The solitary nodule was the commonest condition referred for scans (60%) and next was the multinodular goitre 919%). Other indications for scan included postthyroidectomy cases, aberrant thyroids, retrosternal goitres, thyrotoxicosis and metastases from thyroid carcinoma. 73 cases of solitary cold nodules were discovered and 43 of these were operated on. 7 of these were found to be malignant, giving an incidence of 16%. The incidence of malignancy in the cold nodule varies in the reported literature. By itself the 131I scan cannot diagnose malignancy but is it a useful supplementary test in addition to the clinical and other investigations.

Hyperthermia with radiotherapy.

The use of hyperthermia together with radiotherapy in the treatment of relatively radioresistant tumours has been widely studied. In this preliminary non control study we used a 8MHz RF capacitive heating machine together with temperature probes inserted into the tumours under local anaesthesia. 27 patients with advanced post-radiation tumour recurrences as well as known radioresistant tumours were selected for treatment with hyperthermia and radiation. 7 patients withdrew from the study because of their intolerance to heat. 3 patients received superficial skin burns. Of the 20 patients studied, we were able to obtain moderate hyperthermia in most cases. 2 patients showed complete responses and 13 partial responses, giving rise to a total response rate of 75%. Some of the technical difficulties in achieving satisfactory hyperthermia are discussed. These include insertion of multiple probes into the body and the problem of achieving uniform heating of the tumour. Advances in hyperthermia can be expected with the development of improved methods of heat delivery and temperature measurements. However, presently methods of heat delivery can be improved by careful adjustment of the heating applicators and manipulation of cooling pads to avoid areas of excessive heating. Further clinical trials should be carried out to establish the optimum technique of hyperthermia.

Radiotherapy in treatment of nasopharyngeal carcinoma.

Nasopharyngeal Carcinoma is one of the most prevalent malignancies treated by radiotherapy in Singapore. Planning of the radiation fields for this condition is difficult because of the proximity of anatomical structures that are vulnerable to irradiation, such as the eyes, brain stem and cervical cord. However, the treatment results have shown progressive improvement. The treatment technique currently used utilized cobalt as well as caesium teletherapy units. Of the 104 cases treated in 1970 using this technique, the overall absolute 5 years survival rate with no evidence of disease is 30.8%. For Stage I cases, the rate is 62.5%. The prognosis is significantly better for the female than the male and is also related to age.

A report of 21 cases of malignant lymphoma treated by radiotherapy.

In 1971, 21 new patients with malignant lymphoma were treated at the Therapeutic Radiology Department, Singapore General Hospital. 17 patients completed their courses of radiotherapy. Of the 17 patients given radical treatment, 5 were of Hodgkin's disease and 12 of Non-Hodgkin's disease. The 5-year survival for the group with Hodgkin's disease is 80% (4/5). The 5-year survival for the group with Non-Hodgkin's disease in 41.6% (5/12).

Radiotherapy of early glottic cancer Singapore, 1978-1981.

This study analyses the results of primary radiotherapy for 44 patients with early glottic cancer (Tis, T1 stage) given at the Therapeutic Radiology Department, Singapore General Hospital during the 4-year period from 1978 to 1981. Irradiation was delivered using cobalt teletherapy with free set-ups, and without "air-gap" compensation. Total doses of 55Gy to 64Gy were given in daily fractions of 1.8Gy, treating five times a week. The crude 5-year survival rate for Tis/T1a tumours was 88.9% and for T1b lesions, 81%. On correcting for deaths from intercurrent disease, the survival rates improved to 95.5% and 92.6% respectively. In 33 cases where the quality of voice after radiation was assessed, 15 patients (45.4%) retained good voice quality with an additional 11 patients (33.3%) having acceptable voice quality. In seven cases the voice after radiation was rated as poor. Nine patients had local recurrence, giving a rate of 20.4%. One other patient had cervical node metastasis and subsequently developed lung secondaries. Surgery, solely or with re-irradiation, was an effective treatment for local recurrence. Re-irradiation alone failed to control any case with recurrence.

Advanced colorectal carcinoma--5 year survival of 76 cases treated at the Department of Therapeutic Radiology, Singapore General Hospital.

The results of 76 cases of advanced colorectal carcinoma treated at the Department of Therapeutic Radiology, Singapore General Hospital, from 1977 to 1978, are presented. All cases had "Curative" Surgery and were given adjuvant radiotherapy or chemotherapy or both. All were adenocarcinoma and had lymph node involvement as well as tumour infiltration through the bowel wall. 44 cases of rectal carcinoma were given radiotherapy to the pelvis followed by I/V 5-fluorouracil for at least one year. 32 cases of colon cancer were given I/V 5-fluorouracil for at least one year. 20 of these cases had cancer of the sigmoid colon and were given pelvic irradiation as well. The five year actuarial survival rates were 27.8% for rectal cancer and 24.3% for colon cancer.

Patient profile and survival in 270 computer tomography-staged patients with nasopharyngeal cancer treated at the Singapore General Hospital.

This is a report analysing the patient profile and survival results in 270 patients with nasopharyngeal carcinoma treated with radiation therapy between July 1987 and December 1988. The patients had a median age of 52.6 months, and a male-female ratio of 2.5:1. Ninety-four percent of patients were Chinese. The commonest presentation was that of a neck mass (found in approximately 65% of patients). Approximately two-thirds presented with disease more advanced than Ho's stage II. At a median follow-up of 52.6 months, the 5-year actuarial survival rate was 53% and the freedom from relapse rate was 57%. One hundred and seven patients died within the observation period. Of these, 46 patients had disease in the post nasal space, 41 in the neck and 60 in sites outside the head and neck.

ADAR1 deaminase contributes to scheduled skeletal myogenesis progression via stage-specific functions.

Adenosine deaminases acting on RNA 1 (ADAR1) catalyzes cellular RNA adenosine-to-inosine editing events on structured RNA molecules. In line with this critical role, ADAR1 exhibits ubiquitous expression and is essential for embryonic development. However, regulation and developmental significance of this RNA editor in a spatiotemporal context are largely elusive. Here we unveil a novel tissue-specific role of ADAR1 in skeletal myogenesis. ADAR1 expression displayed programmed alteration that is coordinated with differentiation cues, and mediated negatively by miRNA-1/206. Coincidently, ADAR1 exerts stage-dependent functions-suppression of apoptosis at the onset of differentiation and preservation of timely myotube formation through later phase. Furthermore, the post-transcriptional aspect of its myogenic role was illustrated by the spectrum of binding RNAs, as revealed by high-throughput approach, as well as by direct regulation of myogenesis-associated targets such as dynamin 1/2 (Dnm1/2) and annexin A4. Consequently, maintenance of target gene expression profiles likely contributes to a state of cytoskeleton and membrane dynamics that is amenable to myoblast morphogenesis. Collectively, these findings uncover a critical link of ADAR1 to myogenesis, and further highlight an epigenetic mechanism by which ADAR1 and miR-1/206 interplay to control scheduled myoblast-myotube transition.

Population genetic structure of the tropical moss Acanthorrhynchium papillatum as measured with microsatellite markers.

Mosses and other bryophytes are vital components of forests, because they sustain a tremendous diversity of invertebrates and influence significant ecological functions. There have been few studies on moss population diversity in Southeast Asia, despite the escalating deforestation in this region of rich biodiversity. The genetic diversity of the tropical moss Acanthorrhynchium papillatum (Harv.) Fleisch., collected from forested areas in Singapore and Peninsular Malaysia, was elucidated using eight microsatellite markers developed for this species. Significant levels of allelic and haplotypic diversity were observed among clumps of the moss. Differences in allelic richness and genotypic diversity among the populations were higher in less disturbed forests compared to the more disturbed areas, suggesting that genetic diversity is affected by habitat quality. Genetic diversity levels within the clumps studied were low, indicating that vegetative reproduction was more important within clumps than sexual reproduction. However, multilocus genotypes of samples within the clumps studied were not all alike, providing evidence of microsatellite mutation or of occasional sexuality. Despite the isolation of populations, A. papillatum can introduce genetic variability by mutation among vegetatively propagated individuals. This study provides baseline information on the genetic diversity of A. papillatum tropical rain forests.