An in silico comparative dosimetric study of postmastectomy locoregional irradiation using intensity-modulated vs 3-dimensional conventional radiotherapy

An in silico dosimetric evaluation of intensity-modulated radiation therapy (IMRT) vs 3-dimensional conventional radiation therapy (3D-CRT) treatment plans in postmastectomy radiation therapy (PMRT) to the chest wall and regional lymphatics was conducted. Twenty-five consecutive patients with breast cancer referred for locoregional PMRT, stages T_2-4 with N_1-3, were planned to receive 50 Gy in 25 fractions with IMRT. Additionally, a 3D-CRT plan was generated using identical contours for the clinical target volumes (CTV), planning target volumes (PTV), and organs at risk (OAR). Treatment plans were assessed using dose-volume histogram (DVH) parameters of D₉₈, D₉₅, D₅₀, D₂, and homogeneity index for individual CTVs and PTVs. OARs evaluated were ipsilateral and contralateral lungs, heart, spinal cord, and opposite breast. Most DVH parameters pertaining to CTVs and PTVs significantly favored IMRT. V₂₀ for ipsilateral and contralateral lungs, D₃₃ of heart and maximum dose to spinal cord favored IMRT (all p < 0.001). The mean dose to the opposite breast was significantly lesser with 3D-CRT (5.8 ± 1.8 Gy vs 2.0 ± 1.0 Gy, p < 0.001). Thus, except for the mean dose to the opposite breast, the compliance to DVH constraints applied to PTV and OARs were significantly better with IMRT. At a median follow-up of 76 months (7-91), none had locoregional failure or pulmonary or cardiac morbidity. For PMRT, requiring comprehensive irradiation to both chest wall and regional lymphatics, IMRT offers superior dosimetric advantages over 3D-CRT. This was also corroborated by long-term outcomes in these patients treated with IMRT.

Respiratory gated radiotherapy-pretreatment patient specific quality assurance

Organ motions during inter-fraction and intra-fraction radiotherapy introduce errors in dose delivery, irradiating excess of normal tissue, and missing target volume. Lung and heart involuntary motions cause above inaccuracies and gated dose delivery try to overcome above effects. Present work attempts a novel method to verify dynamic dose delivery using a four-dimensional (4D) phantom. Three patients with mobile target are coached to maintain regular and reproducible breathing pattern. Appropriate intensity projection image set generated from 4D-computed tomography (4D-CT) is used for target delineation. Intensity modulated radiotherapy plans were generated on selected phase using CT simulator (Siemens AG, Germany) in conjunction with “Real-time position management” (Varian, USA) to acquire 4D-CT images. Verification plans were generated for both ion chamber and Gafchromic (EBT) film image sets. Gated verification plans were delivered on the phantom moving with patient respiratory pattern. We developed a MATLAB-based software to generate maximum intensity projection, minimum intensity projections, and average intensity projections, also a program to convert patient breathing pattern to phantom compatible format. Dynamic thorax quality assurance (QA) phantom (Computerized Imaging Reference Systems type) is used to perform the patient specific QA, which holds an ion chamber and film to measure delivered radiation intensity. Exposed EBT films are analyzed and compared with treatment planning system calculated dose. The ion chamber measured dose shows good agreement with planned dose within ± 0.5% (0.203 ± 0.57%). Gamma value evaluated from EBT film shows passing rates 92–99% (96.63 ± 3.84%) for 3% dose and 3 mm distance criteria. Respiratory gated treatment delivery accuracy is found to be within clinically acceptable level.

Analyzing the performance of ArcCHECK diode array detector for VMAT plan

AIM

The aim of this study is to evaluate performance of ArcCHECK diode array detector for the volumetric modulated arc therapy (VMAT) patient specific quality assurance (QA). VMAT patient specific QA results were correlated with ion chamber measurement. Dose response of the ArcCHECK detector was studied.

BACKGROUND

VMAT delivery technique improves the dose distribution. It is complex in nature and requires proper QA before its clinical implementation. ArcCHECK is a novel three dimensional dosimetry system.

MATERIALS AND METHODS

Twelve retrospective VMAT plans were calculated on ArcCHECK phantom. Point dose and dose map were measured simultaneously with ion chamber (IC-15) and ArcCHECK diode array detector, respectively. These measurements were compared with their respective TPS calculated values.

RESULTS

The ion chamber measurements are in good agreement with TPS calculated doses. Mean difference between them is 0.50% with standard deviation of 0.51%. Concordance correlation coefficient (CCC) obtained for ion chamber measurements is 0.9996. These results demonstrate a strong correlation between the absolute dose predicted by our TPS and the measured dose. The CCC between ArcCHECK doses and TPS predictions on the CAX was found to be 0.9978. In gamma analysis of dose map, the mean passing rate was 98.53% for 3% dose difference and 3 mm distance to agreement.

CONCLUSIONS

The VMAT patient specific QA with an ion chamber and ArcCHECK phantom are consistent with the TPS calculated dose. Statistically good agreement was observed between ArcCHECK measured and TPS calculated. Hence, it can be used for routine VMAT QA.

Measurement and comparison of head scatter factor for 7 MV unflattened (FFF) and 6 MV flattened photon beam using indigenously designed columnar mini phantom

AIM

To measure and compare the head scatter factor for 7 MV unflattened and 6 MV flattened photon beam using a home-made designed mini phantom.

BACKGROUND

The head scatter factor (Sc) is one of the important parameters for MU calculation. There are multiple factors that influence the Sc values, like accelerator head, flattening filter, primary and secondary collimators.

MATERIALS AND METHODS

A columnar mini phantom was designed as recommended by AAPM Task Group 74 with high and low atomic number material for measurement of head scatter factors at 10 cm and d max dose water equivalent thickness.

RESULTS

The Sc values measured with high-Z are higher than the low-Z mini phantoms observed for both 6MV-FB and 7MV-UFB photon energies. Sc values of 7MV-UFB photon beams were smaller than those of the 6MV-FB photon beams (0.6-2.2% (Primus), 0.2-1.4% (Artiste) and 0.6-3.7% (Clinac iX (2300CD))) for field sizes ranging from 10 cm × 10 cm to 40 cm × 40 cm. The SSD had no influence on head scatter for both flattened and unflattened beams. The presence of wedge filters influences the Sc values. The collimator exchange effects showed that the opening of the upper jaw increases Sc irrespective of FF and FFF.

CONCLUSIONS

There were significant differences in Sc values measured for 6MV-FB and unflattened 7MV-UFB photon beams over the range of field sizes from 10 cm × 10 cm to 40 cm × 04 cm. Different results were obtained for measurements performed with low-Z and high-Z mini phantoms.

Comparison of Head Scatter Factor for 6MV and 10MV flattened (FB) and Unflattened (FFF) Photon Beam using indigenously Designed Columnar Mini Phantom

To measure and compare the head scatter factor for flattened (FB) and unflattened (FFF) of 6MV and 10MV photon beam using indigenously designed mini phantom. A columnar mini phantom was designed as recommended by AAPM Task Group 74 with low and high atomic number materials at 10 cm (mini phantom) and at approximately twice the depth of maximum dose water equivalent thickness (brass build-up cap). Scatter in the accelerator (Sc) values of 6MV-FFF photon beams are lesser than that of the 6MV-FB photon beams (0.66-2.8%; Clinac iX, 2300CD) and (0.47-1.74%; True beam) for field sizes ranging from 10 × 10 cm² to 40 × 40 cm². Sc values of 10MV-FFF photon beams are lesser (0.61-2.19%; True beam) than that of the 10MV-FB photons beams for field sizes ranging from 10 × 10 cm² to 40 × 40 cm². The SSD had no influence on head scatter for both flattened and unflattened beams and irrespective of head design of the different linear accelerators. The presence of field shaping device influences the Sc values. The collimator exchange effect reveals that the opening of the upper jaw increases Sc irrespective of FB or FFF photon beams and different linear accelerators, and it is less significant in FFF beams. Sc values of 6MV-FB square field were in good agreement with that of AAPM, TG-74 published data for Varian (Clinac iX, 2300CD) accelerator. Our results confirm that the removal of flattening filter decreases in the head scatter factor compared to flattened beam. This could reduce the out-of-field dose in advanced treatment delivery techniques.

Impact of 6MV photon beam attenuation by carbon fiber couch and immobilization devices in IMRT planning and dose delivery

Multiple fields in IMRT and optimization allow conformal dose to the target and reduced dose to the surroundings and the regions of interest. Thus we can escalate the dose to the target to achieve better tumor control with low morbidity. Orientation of multiple beams can be achieved by i) different gantry angles, ii) rotating patient's couch isocentrically. In doing so, one or more beam may pass through different materials like the treatment couch, immobilization cast fixation plate, head and neck rest or any other supportive device. Our observations for 6MV photon beam on PRIMUS-KXE2 with MED-TEC carbon fiber tabletop and 10 × 10 cm² field size reveals that the maximum dose attenuation by the couch was of the order of 2.96% from gantry angle 120-160°. Attenuation due to cast fixation base plate of PMMA alone was of the order of 5.8-10.55% at gantry angle between 0 and 90°. Attenuation due to carbon fiber base plate alone was 3.8-7.98%. Attenuation coefficient of carbon fiber and PMMA was evaluated and was of the order of 0.082 cm⁻¹ and 0.064 cm⁻¹ respectively. Most of the TPS are configured for direct beam incidence attenuation correction factors only. Whereas when the beam is obliquely incident on the couch, base plate, headrest and any other immobilization device get attenuated more than the direct beam incidence. The correction factors for oblique incidence beam attenuation are not configured in most of the commercially available treatment planning systems. Therefore, such high variations in dose delivery could lead to under-dosage to the target volume for treatments requiring multiple fields in IMRT and 3D-CRT and need to be corrected for monitor unit calculations.

An analysis of the persistence and potency of film-coated seed protectant as influenced by various storage parameters

BACKGROUND

An efficient delivery system for seed-protectant chemicals is needed in light of several disadvantages of conventional seed treatment methods. This study evaluates the efficacy of film-coat application in maintaining the persistence and potency of imidacloprid on Lycopersicon esculentum (L.) Mill. seeds after simultaneous storage under ambient and regulated environment in paper and aluminium packages.

RESULTS

High-performance liquid chromatography (HPLC) revealed 0.135 mg kg(-1) of herbage material to be the threshold value beyond which absolute control was obtained, and with film coating the latter was achieved even with half-dosage seed treatment, irrespective of the storage condition. The technique provided early protection to the crop and also nullified the deleterious effects of ambient storage on the persistence and potency of the pesticide.

CONCLUSION

Film coating enabled superior pesticide dosage as well as higher biological efficacy to be achieved. Hence, in addition to being an ecofriendly alternative, the technique would be a more economically viable option for storage of treated seeds.

Favourable impact of intensity-modulated radiation therapy on chronic dysphagia in patients with head and neck cancer

The aim of this study was to evaluate the impact of intensity-modulated radiation therapy (IMRT) on the incidence and severity of chronic dysphagia in patients with head and neck cancer. 62 evaluable patients with head and neck cancer who were treated with IMRT with or without concurrent chemotherapy were analysed. The majority of the patients (77.4%) had advanced locoregional disease. 45 patients underwent definitive IMRT and 17 received post-operative IMRT. Concurrent chemotherapy was given to 29 of the 45 patients treated with definitive IMRT. The average prescribed dose to clinical target volume (CTV)1 was 66-70 Gy (definitive IMRT) and 56-62 Gy (post-operative IMRT); 60 Gy to CTV2; 54 Gy to CTV3; and 50-52 Gy to the supraclavicular area. At a median follow-up of 19 months, 2-year actuarial locoregional control and survival was 77% and 74%, respectively. At 6 months after IMRT, chronic dysphagia was Grade 0 in 77.1% of patients, Grade 1 in 10.5% and Grade 2 in 12.3%. Acute mucositis showed no correlation with long-term dysphagia. The percutaneous endoscopic gastrostomy or nasogastric tube was removed in all of the patients within 8 weeks of completion of treatment. Xerostomia was Grade 0 in 61.4% of patients, Grade 1 in 31.5% and Grade 2 in 7% of patients. In conclusion, IMRT conferred a major favourable impact on chronic dysphagia in patients with locally advanced head and neck cancers, with satisfactory locoregional control.

Intensity modulated radiotherapy in abdominal malignancies: our experience in reducing the dose to normal structures as compared to the gross tumor

BACKGROUND AND PURPOSE

A better understanding of appropriate sequencing and use of multimodality approach in the management and subsequent improvement in overall survival mandates a vigil on quality of life issues. Intensity modulated radiotherapy (IMRT) is a powerful tool, which might go a long way in reducing radiation doses to critical structures and thereby reduce long term morbidities. The purpose of this paper is to evaluate the impact of IMRT in reducing the dose to the critical normal tissues while maintaining the desired dose to the volume of interest for abdominal malignancies.

MATERIALS AND METHODS

During the period January 2002 to March 2004, 11 patients of various sites of malignancies in the abdominal region were treated using physical intensity modulator based IMRT. Plans of these patients treated with IMRT were analyzed using dose volume histograms.

RESULTS

An average dose reduction of the mean values by 50% to the liver, 57% to the right kidney, 56% to the left kidney, 66% to the cord and 27% to the bowel, with respect to the GTV could be achieved with IMRT. The two-year disease free survival was 79% and two-year overall survival was 88%. The average number of IMRT fields used was six.

CONCLUSION

IMRT with inverse planning enabled us to achieve desired dose distribution, due to its ability to provide sharp dose gradients at the junction of tumor and the adjacent critical organs.

Can dose reduction to one parotid gland prevent xerostomia?--A feasibility study for locally advanced head and neck cancer patients treated with intensity-modulated radiotherapy

AIMS

Dryness of the mouth is one of the most distressing chronic toxicities of radiation therapy in head and neck cancers. In this study, parotid function was assessed in patients with locally advanced head and neck cancers undergoing intensity-modulated radiotherapy (IMRT) with or without chemotherapy. Parotid function was assessed with the help of a questionnaire and parotid scintigraphy, especially with regards to unilateral sparing of the parotid gland.

MATERIALS AND METHODS

In total, 19 patients were treated with compensator-based IMRT between February 2003 and March 2004. The dose to the clinical target volume ranged between 66 and 70 Gy in 30-35 fractions to 95% of the isodose volume. Ipsilateral high-risk neck nodes received an average dose of 60 Gy and the contralateral low-risk neck received a dose of 54-56 Gy. Eight of 19 patients also received concomitant chemotherapy.

RESULTS

Subjective toxicity to the parotid glands was assessed with the help of a questionnaire at 0, 3 and 6 months and objective toxicity was assessed with parotid scintigraphy at 0 and 3 months. The mean dose to the ipsilateral parotid gland ranged from 19.5 to 52.8 Gy (mean 33.14 Gy) and the mean dose to the contralateral gland was 11.1-46.6 Gy (mean 26.85 Gy). At a median follow-up of 13 months, 9/19 patients had no symptoms of dryness of the mouth (grade I), 8/19 had mild dryness of the mouth (grade II) and only 2/19 had grade III xerostomia, although the parotid gland could only be spared on one side in most of the patients.

CONCLUSIONS

Minimising the radiation dose to one of the parotid glands with the help of IMRT in patients with advanced head and neck cancers can prevent xerostomia in most patients and parotid scintigraphy is a useful method of documenting xerostomia.

Dose reduction to normal tissues as compared to the gross tumor by using intensity modulated radiotherapy in thoracic malignancies

BACKGROUND AND PURPOSE

Intensity modulated radiotherapy (IMRT) is a powerful tool, which might go a long way in reducing radiation doses to critical structures and thereby reduce long term morbidities.The purpose of this paper is to evaluate the impact of IMRT in reducing the dose to the critical normal tissues while maintaining the desired dose to the volume of interest for thoracic malignancies.

MATERIALS AND METHODS

During the period January 2002 to March 2004, 12 patients of various sites of malignancies in the thoracic region were treated using physical intensity modulator based IMRT. Plans of these patients treated with IMRT were analyzed using dose volume histograms.

RESULTS

An average dose reduction of the mean values by 73% to the heart, 69% to the right lung and 74% to the left lung, with respect to the GTV could be achieved with IMRT.The 2 year disease free survival was 59% and 2 year overall survival was 59%. The average number of IMRT fields used was 6.

CONCLUSION

IMRT with inverse planning enabled us to achieve desired dose distribution, due to its ability to provide sharp dose gradients at the junction of tumor and the adjacent critical organs.

Upregulation of inducible nitric oxide synthase (iNOS) expression in faster-healing leg ulcers

OBJECTIVE

Chronic leg ulcers represent a growing clinical problem in the light of today's ageing population. Nitric oxide (NO), which is mostly produced by inducible nitric oxide synthase (iNOS) in healing wounds, exerts beneficial effects on many processes of healing, including bactericidal effects, angiogenesis, epithelialisation and ECM formation. This study sought to investigate whether iNOS expression in chronic leg ulcers can be correlated with the healing process.

METHOD

Sixteen patients with chronic leg ulcers were recruited and attempts were made to take punch biopsies at two separate time points (however, a second biopsy could not be obtained on seven patients). A linear healing rate was derived using the obtained ulcer area and perimeter. The iNOS levels in the biopsy samples were assessed using immunoblotting.

RESULTS

The mean linear healing rate of patients with high iNOS levels was significantly higher (p < 0.01) than that of patients with low iNOS levels. An incidental finding was that the linear healing rate was significantly higher (p < 0.05) post-biopsy than before biopsy in the same patients.

CONCLUSION

This study therefore shows for the first time that high iNOS levels are associated with higher healing rates and have the potential to be used in prognostication. This also opens the possibility of augmentation of ulcer healing through the manipulation of wound NO levels.

A correlation of secondary aerosol (nitrate and sulfate) with respirable particulate matter (RPM) in ambient air at different traffic junctions of Vadodara city

The correlation study of secondary aerosol (nitrate and sulfate) with RPM in ambient air at different traffic junctions of Vadodara city is reported. RPM was analyzed using Ion Chromatography technique and measured the level of nitrate and sulfate in ambient air. The correlation studies of these particulates with RPM have been established. The average concentration of sulfate and nitrate in ambient air was found 35.74 microg/m3 and 24.22 microg/m3, which ranged of 5.33-84.69 and 1.93-77.86 microg/m3 respectively. The correlation of RPM and SO4 (r = 0.813, P<0.01), RPM-NO3 (r = 0.5549, P<0.01) and SO4-NO3 (r = 0.6133, P<0.01) were found significant. The presence of sulfate and nitrate in RPM is 8.25% and 5.60% . The pH of water extract of RPM averaged 6.81, which ranged 6.17-7.28. Regression analysis result showed that the relationship between RPM-SO4 was significantly (R2=0.66215) correlated. This indicate that probably the secondary aerosols such as nitrate and sulfate in excess may cause irritation and increasing lung disease.

Erosion of nails following thallium poisoning: a case report

This case report describes a patient with thallium poisoning caused by repeated exposure to low doses of thallium. Alopecia and nail changes were the most prominent features of this case. There was dystrophy of nails in the form of whitish lunular stripes. This is the first report of complete erosion of proximal parts of nails following thallium poisoning. This case is the first report of thallium poisoning from India occurring from repeated low dose exposure.

Mesh plug repair for paraumbilical hernia

BACKGROUND

The standard method of repair of paraumbilical hernia (PUH) is by the Mayo technique, using a double-breasted flap of the rectus sheath. The reproducibility of this technique in the hands of others is highly variable. The present study describes and evaluates the application of a Prolene mesh plug in the repair of PUH. The use of a mesh plug in hernia repair is not a new concept with previous investigators yielding consistently excellent results in the repair of femoral and inguinal hernias.

METHODS

The study is a retrospective analysis of hospital records and telephone interviews of 34 patients having undergone PUH repair using the mesh plug technique in the period March 1998- May 2002. There were 20 males and 14 females with a median age of 53 years (range 34-86 years). Seventy-six percent (26) of the patient sample was obese (median BMI 33). Whenever possible local anaesthetic was used. Principal outcome measures studied were post-operative complications, recurrences, length of stay in hospital, post-operative analgesia, duration of drain, return to normal activities and patient satisfaction.

RESULTS

Post-operative complications encountered included one case of seroma and a single wound infection with recurrence. Ninety-seven percent (32) of patients were satisfied with the procedure.

CONCLUSION

Mesh plug repair can be performed with minimal postoperative complications, low recurrence rate, minimal post-operative pain and achieving excellent patient satisfaction. Prosthetic mesh plug repair under local anaesthetic could become the standard treatment for PUH in adults.

Do leg ulcer clinics improve patients' quality of life?

The aim of this prospective study was to measure quality of life in patients with chronic leg ulcers. All eligible, consenting patients who attended the leg ulcer clinic at the Repatriation General Hospital (Tasmania, Australia) during the 16-month study period were included. Patients completed questionnaires on their first visit and at follow-up which occurred, on average, eight weeks later. This study found an improvement in three quality-of-life indicators--pain, sleep and mobility--over an average of eight weeks' treatment involving one to three visits to the clinic and home visits by primary care nurses. Of the 57 patients, 53 (93%) indicated that their wound had improved following attendance at the clinic. The cost-effectiveness of providing treatment in a dedicated leg ulcer clinic has been the focus of many previous studies. This study emphasises the additional benefits a dedicated clinic may have in improving quality of life in patients with chronic leg ulcers. Such benefits ought to be considered when allocating resources to leg ulcer services.

Refractory amiodarone-associated thyrotoxicosis: an indication for thyroidectomy

BACKGROUND

Tasmania is an area of endemic iodine deficiency. Amiodarone is a class III anti-arrhythmic drug that is widely used for the management of ventricular and supraventricular tachydysrhythmias. Individuals from areas of endemic iodine deficiency appear more likely to manifest hyperthyroidism following amiodarone therapy, whereas hypothyroidism is a more frequent complication in iodine-replete communities.

METHODS

Cases series. The clinical and biochemical response to medical and surgical management of five consecutive Tasmanian patients presenting with severe type-II amiodarone-associated thyrotoxicosis was reviewed.

RESULTS

Five patients were identified. Combinations of antithyroid therapy including propylthiouracil, lithium carbonate, dexamethasone and cholestyramine were used. Thyroidectomy was required in two cases (40%) due to severe unremitting thyrotoxicosis despite combined drug regimens. Anaesthesia and total thyroidectomy were undertaken without complication despite the presence of severe hyperthyroidism at the time of surgery. In both cases thyroid histopathology demonstrated degenerative and destructive follicular lesions with multinuclear cell infiltrate and focal fibrosis.

CONCLUSION

Amiodarone-associated thyrotoxicosis may be severe and refractory to medical therapy. Despite the potential risks of anaesthesia associated with uncontrolled thyrotoxicosis, thyroidectomy should be considered in the setting of life-threatening thyrotoxicosis.

Chromatographic studies on the isolation of peroxydisulphate oxidation products of primaquine

Eight compounds from peroxydisulphate oxidation of primaquine were fractionated on Bio-Gel P-2 column using water as an eluent. A HPLC method employing acetonitrile-methanol-1 M perchloric acid-water (30:7:1:95, v/v) as a mobile phase at 1.0 ml/min on microBondapak reversed-phase column and UV detection at 254 nm was developed for the separation and identification of different oxidation products of primaquine. A combination of Bio-Gel chromatography with reversed-phase HPLC was found to be the most suitable analytical technique for the semipreparative isolation of various products formed from the oxidation. Two oxidation products that were isolated had three or four times higher gametocytocidal activity as compared to primaquine.

Burns admissions to Port Moresby General Hospital 1978-1984

A retrospective survey of 169 burns cases admitted to Port Moresby General Hospital was conducted for the period 1978 to 1984. A third of the patients were young children. Hot-water burns were the commonest type of injury, accounting for 43%. This was followed by accidental falls into a fire and suicidal kerosene burns, which accounted for 28% and 13% respectively. Post-burn contractures were the commonest long-term complications. Prevention of burns is theoretically very attractive but hard to achieve in rural and squatter populations who rely almost entirely on open fires for cooking and heating. Burns awareness campaigns by all government and community groups stressing the dangers of open fires and leaving children unattended would no doubt take a long time but might ultimately produce tangible results.

Initial parathyroid exploration: current trends in Australia

BACKGROUND

An Australia-wide multicentre prospective study was undertaken to audit cases of initial parathyroid exploration between 1 January and 31 December 1992. One hundred and sixty-two cases were audited. The audit was designed to study pre-operative biochemical assessment, localization techniques and the technique of exploration.

METHOD

A pro forma audit form was circulated to all Australian surgeons known to perform parathyroid surgery. Eleven responded.

RESULTS

Free serum ionized calcium (iCa) was measured in 30% of cases, with the majority of pre-operative calcium assays being performed using total serum calcium (tCa). In 40 cases (29%) pre-operative localization techniques were used. These proved inaccurate in 10 cases. The intra-operative technique of localization with methylene blue infusion was used in 11% of cases. All four glands were biopsied in 11% of cases. No deaths were reported and a postoperative morbidity rate of 3.1% was noted. Eighty-eight per cent of patients were discharged within 5 days of surgery with a third going home within 48 h of neck exploration surgery. Only one patient (0.6%) required re-exploration for persistent hypercalcaemia due to a second adenoma.

CONCLUSIONS

The surgical treatment of hyperparathyroidism can be regarded as safe, with minimum morbidity in experienced hands. Pre-operative localization studies in initial parathyroid exploration are not indicated.

Review of liver trauma management in Tasmania: an analysis of risk factors for mortality and morbidity

A review of liver trauma treated by the major trauma care facilities of Tasmania in the 5 year period between 1989 and 1993 is presented. The aim of this retrospective review was to provide an audit of the management of liver trauma in the island of Tasmania and to analyse the risk factors contributing to mortality and major morbidity. Thirty-seven patients were treated with a median Injury Severity Score (ISS) of 14 (range 9-34). The overall mortality rate of this series was 5.8%. Age, mechanism of injury (blunt or penetrating), delay prior to hospital presentation and modality of treatment (operative or non-operative) were not significant risk factors for mortality and morbidity; however, transfusion requirement of over 10 units of blood (P < 0.005), ISS score of over 20 (P < 0.0005), haemodynamic instability at presentation (P < 0.05) and a Hepatic Injury Score (HIS) grade of 3 or more (P < 0.05) were statistically significant risk factors.

Immunohistochemical detection of p53 and the recurrence of rectal adenocarcinoma

The relationship between immunohistochemical detection of the p53 tumour-suppressor gene and recurrence of disease in 66 cases of rectal adenocarcinoma treated at the Royal Hobart Hospital, Hobart, Tasmania, between 1984 and 1992 was investigated. Fifty-five per cent (n = 36) of patients demonstrated p53 nuclear immunoreactivity consistent with the presence of the stabilized protein derivative of a mutation at the p53 gene locus. No correlation between p53 immunoreactivity and tumour site, differentiation and stage was noted. An overall recurrence rate of 64% (n = 42) was noted. Multivariate analysis confirmed the absence of p53 immunoreactivity and anatomical site of tumour below 7 cm from the anal verge to be significant predictors of tumour recurrence (P < 0.001). A review of the current literature on p53 suggests caution in using the immunohistochemical detection of p53 to predict the clinical outcome in cases of rectal adenocarcinoma because of discordant results between studies.

Intramural haematoma of the duodenum

Intramural duodenal haematoma secondary to blunt abdominal trauma is a rare injury. One case is reported, and the clinical features, diagnosis and management are discussed.

Surgical thyroid disease in Papua New Guinea

A clinical and histopathological analysis was carried out on 376 thyroid specimens removed under various diagnoses from the surgical clinics of Papua New Guinea over a period of 11 years (1980-90). Solitary nodular goitre (solid and cystic) was the most common clinical diagnosis. Nineteen per cent of the solid and 35% of the cystic solitary nodular goitres were found to be malignant. Malignant goitres were confirmed histologically in 73.3% of the clinically diagnosed cases of malignancy. The presence of amyloid goitre (1.9%) posed a significant diagnostic and therapeutic problem due to its clinical features resembling that of malignant goitre. Hemithyroidectomy (lobectomy) was the most common surgical procedure employed for all unilateral thyroid lesions and partial or subtotal thyroidectomy was performed for benign and most malignant lesions.

Binding pattern of eight different lectins in healthy subjects and patients with dysplastic and malignant lesions of the oral cavity

The present investigation was undertaken to assess the binding characteristics of eight different lectins to normal oral mucosa (11 cases), leukoplakia with varying degrees of dysplasia (five cases), and oral mucosal squamous cell carcinoma (12 cases) by the use of biotinylated lectins and avidin biotin peroxidase complexes. The lectins employed were soybean (SBA), peanut (PNA), Dolichos biflorus (DBA), concanavalin A (Con A), wheat germ (WGA), Ulex europaeus (UEA), Ricinus communis (RCA), and Lotus tetragonolobus (LTA). It was observed that SBA, DBA, WGA, UEA, RCA, and LTA showed very strong to strong binding in healthy oral mucosa but no or very weak binding in squamous cell carcinoma. On the contrary, PNA showed weak binding to normal mucosal epithelial cells but showed strong binding to malignant cells. The dysplastic mucosa had an intermediate binding pattern. The lectin Con A was not bound at all or seen in very low concentration in the malignant cells and dysplastic epithelium, but it showed weak binding in the normal mucosa. Hence, we conclude that lectins may be utilized as probes to determine the dysplastic and malignant status of the oral mucosal epithelium.

Early childhood mortality--a rural study

The present study was conducted in 9 villages of Rural Health Training Centre, Jawan, Aligarh, India, having 1792 registered families. The infant mortality rate was 79.3 per 1000 live births. Higher mortality in children between 1-2 years (29.6/1000) in comparison to 2-5 years (16.2/1000) reflected the higher vulnerability of children below 2 years. Diarrhoea (21.2%) and neonatal factors (21.2%) were the major cause of infant mortality followed by pneumonia (18.2%) and tetanus (15.1%). Diarrhoea (32.2%), pneumonia (22.6%) and malnutrition (12.9%) were the major killers in children between 1-5 years. Mortality in females was higher than males in infancy. Risk factors associated with infant mortality included extremes of maternal age (< 20+ > 35 years) primipara or multipara and illiterate mothers.

Peptide alpha-amidation activity in human plasma: relationship to gastrin processing

OBJECTIVE AND DESIGN

C-terminal amidation is an essential processing step towards bioactivation of many peptides including gastrin. This reaction is catalysed by peptidylglycine alpha-amidating mono-oxygenase (PAM, EC 1.14.17.3) which converts the glycine extended precursors on their carboxyl termini to the des-glycine amidated peptide products. In the case of gastrin, most of the amidation is thought to occur in the antrum. However substantial quantities of glycine extended gastrin and PAM are present in plasma. It is unclear whether circulating PAM reflects the secretory activity of the gastrin secreting cell or whether PAM is involved in the postsecretory processing of gastrin. The aim of the present study was to relate the circulating amidation activity to the plasma concentrations of glycine extended and amidated gastrins.

PATIENTS AND MEASUREMENTS

Plasma PAM, gastrin-amide and gastrin-gly were measured in subjects with different gastrin secretory status: healthy subjects basally and following a meal, members of families with multiple endocrine neoplasia type 1 (MEN-1) with normal and high plasma gastrin, and patients with hypergastrinaemic atrophic gastritis.

RESULTS

Patients with MEN-1 and hypergastrinaemia tended to have a higher plasma PAM activity than MEN-1 subjects with normal circulating G-NH2 indicating a cosecretion of hormone and PAM. However in contradistinction to patients with medullary thyroid carcinoma, PAM activity does not appear to be a useful tumour marker of gastrinoma. Hypergastrinaemia from a non-tumour source (hypergastrinaemic non-atrophic gastritis) was associated with a lower plasma PAM activity than in normal subjects and may reflect the secretion of a greater proportion of already amidated gastrin. In general, there was no relationship between plasma PAM activity and the ratio of amidated to non-amidated gastrin suggesting that circulating PAM was not involved in the amidation of gastrin. Feeding increased circulating gastrin but had no effect on plasma PAM activity.

CONCLUSION

The results support the view that gastrin is amidated at the site of its synthesis and that hypergastrinaemia is associated with elevated plasma amidating enzyme activity only when the gastrin originates from tumour sources.

Susceptibility status of Culex quinquefasciatus in Patna to insecticides

To obtain the base line data, a study conducted in district Patna, Bihar to note the susceptibility status of adult Culex quinquefasciatus against organochlorine, organophosphorous and synthetic pyrethroids. It was found that adult of Cx.quinquefasciatus developed double resistance to DDT and dieldrin but susceptible to O.P. compounds and pyrethroids. Cx.quinquefasciatus larvae are also found susceptible to O.P compounds like malathion, temophos, fenthion and fenitrothion.

Deliberate self-harm by means of kerosene fire by women in Papua New Guinea

This paper reports the results of an investigation into the psychosocial and sociodemographic factors relating to 10 females admitted to the Burns Unit of the Port Moresby General Hospital with a common diagnosis of deliberate self-inflicted burns by kerosene fire. All 10 patients were admitted during the first six months of 1990 and all originated from Gulf Province. 6 of the 10 patients died despite intensive, standard surgical management. Discussion of the results centres around the possible causes of the sudden increase in the number of patients presenting with burns caused by self-inflicted kerosene fire. Recommendations are made for some preventive measures.

Clinicopathological features of primary gastrointestinal lymphomas: a study of 42 cases

The clinicopathological features of 42 patients with gastrointestinal lymphoma during the period 1982-88 are described. Ten cases (23.8%) were seen in the stomach, 23 cases (54.8%) in the small intestine and 9 cases (21.4%) in the large intestine. In 4 cases multiple sites were involved. The tumours occurred most frequently in the 2nd to 4th decade. Histologically, using the working formulation for non-Hodgkin's lymphoma, all were found to be diffuse and mostly of the high grade type (45%). Seven lymphomas were seen in children. Three were of the Burkitt's type. Patients presented quite late in a large number of cases (43%). Compared with most other published series small intestinal involvement was common. There was a high incidence in males. Predominant small intestinal involvement did not result in malabsorption syndrome and primary lymphomas constituted 3.5% of all malignancies of the gastrointestinal tract.

Anthropometric measurements in rural school children

Anthropometric measurements of 1012 rural school-going children, selected randomly, were performed. There were 776 males and 236 females in the age group of 5-15 years. The values of weight and height were recorded for every child in the study sample. Age and sex break-up was studied and compared with the ICMR (Indian Council of Medical Research) standard. The comparison made separately for boys and girls showed that the values for both sexes and in all age groups were less than the ICMR standard. The majority (83.6%) of the children belonged to the middle and low social class according to the modified Prasad's classification. An inference is, therefore, drawn that rural school children of middle and low socio-economic status are shorter and lighter as compared with even their own counterparts on whom the ICMR values are based. The state of health of school-going children in India is far from satisfactory despite the fact that school health programmes along with other nutritional programmes have been in operation for several decades. School-going children constitute a sizeable section of India's population, i.e. about 27%, which is easily accessible and also receptive. An early and convenient method of assessing nutritional and socio-economic status of growing children is anthropometry. Physical growth, in terms of weight and height, is considered an important parameter reflecting the pattern of growth and development in a community. In the developing countries, the growing children by and large are deprived of good nutrition on account of their poor socio-economic status, ignorance and lack of health promotional facilities. This nutritional deprivation results in relative stunting of growth.

Trauma patients in an Indian hospital

The study was carried out at the Emergency Department of Jawaharlal Nehru Medical College Hospital, Aligarh Muslim University, Aligarh, India, to ascertain the pattern of trauma in the patients. A total of 2446 trauma cases were recorded in the year 1987. Accidental falls were the commonest cause of injury, i.e 35.7%, followed by motor-vehicle collisions (23.5%), pedal cyclists (8%), occupational injuries (5.2%) and sports injuries (5.2%). The commonest age group involved was 5-15 years which accounted for 32.8% of all trauma. Fractures (44%) were the most frequently observed nature of injury. Death due to trauma was highest in motor-vehicle collisions (31%) followed by accidental falls (16%), and occupational injuries (12%).

Responses of small intrapulmonary arteries to vasoactive compounds in the fetal and neonatal lamb: norepinephrine, epinephrine, serotonin, and potassium chloride

Despite considerable study, the mechanisms responsible for the transition of the pulmonary circulation from the fetal to newborn life remain obscure. We compared the responses of third and fourth generation pulmonary arteries to norepinephrine, epinephrine, serotonin, and KCl from lambs 7 d preterm and 1, 7, and 21 d of age to assess differences between age and third and fourth generations of the pulmonary arterial tree during the transitional period. Preterm vessels were significantly smaller in internal diameter than all other aged vessels for both generations. Fourth generation vessel response to KCl increased with age (94 +/- 15 mg/mm2, preterm; 259 +/- 31 mg/mm2, 21 d). Third generation vessel response to KCl did not change with age (135 +/- 15 mg/mm2, preterm; 158 +/- 18 mg/mm2, 21 d). There were no differences in maximum response to norepinephrine and epinephrine between ages; however, third generation vessel response to these compounds was significantly greater (30-60% of maximum KCl response) than fourth generation vessel response (0-10%). Third and fourth generation vessels had the same maximum response to serotonin regardless of age or generation. Third generation vessels were significantly reduced in sensitivity (log molar concentration which produced 50% of the maximum response--EC50) to norepinephrine at d 1 (5.89 +/- 0.12 log molar) and 7 (5.90 +/- 0.21) compared to preterm (6.48 +/- 0.10) and 21 d of age (6.50 +/- .03).(ABSTRACT TRUNCATED AT 250 WORDS)