Conjunctival vessel morphology in patients with type 2 diabetes mellitus: findings of a case-control study

OBJECTIVE

Diabetic retinopathy is a serious complication of diabetes mellitus that may lead to vision loss. Retinal problems are more likely to occur as the illness advances. Micro- and macro-vascular angiopathy is both linked to diabetes mellitus. Examining the impact of diabetes on blood vessels is one approach to understanding the disease's outward symptoms. The purpose of this research is to evaluate the morphology and breadth of conjunctival vessels in people with type 2 diabetes mellitus and to establish a correlation between these alterations and clinical retinal changes.

PATIENTS AND METHODS

A case-control study was conducted in the Department of Ophthalmology, KIMS, Koppal, Karnataka. The study included diabetic patients who voluntarily participated and were assessed at the Ophthalmology Outpatient Department (OPD). The general and ophthalmic history was taken for both cases and control. The best corrected visual acuity was estimated. Each subject, including cases and controls, had a general and ophthalmic history recorded. The anterior segment was evaluated with a slit lamp. After completing the clinical examination, the subjects underwent a conjunctival vessel imaging study using the slit lamp. The imaging included the study of conjunctival vessel morphology using ImageNet.

RESULTS

Both the test and control groups are comparable in terms of age and gender. The severity of diabetic retinopathy was shown to correlate with the conjunctival width range. Mild diabetic retinopathy is characterized by a conjunctival width of 30-34 microns (mean: 34.9), moderate diabetic retinopathy by 35-39 microns (mean: 37.3), severe diabetic retinopathy by 40-44 microns (mean: 42.4), and proliferative diabetic retinopathy by 50-54 microns (mean: 45.6).

CONCLUSIONS

Diabetes mellitus patients have larger conjunctival arteries as the disease becomes more severe. Dilated and tortuous conjunctival arteries are visible indicators that correlate with worsening diabetic retinopathy. This could be used for screening to ensure timely referral.

Fabrication of Thermal Insulation Bricks Using Pleurotus florida Spent Mushroom

This study explores the potential for making lightweight bricks via the use of dry, pulverized spent mushroom materials (SMM) as a thermal insulator. There are five distinct replacement proportions of SMM that are used, and they range from 0% to 15% of the weight of the clay. The firing of the fabricated bricks at temperatures of 700, 800, and 900 °C led to the development of pores on the interior surface of the bricks as a consequence of the decomposition of SMM. The impact of SMM on the physicomechanical characteristics of fabricated bricks is assessed based on standard codes. Compressive strength, bulk density, and thermal conductivity decreased as the SMM content increased, reaching up to 8.7 MPa, 1420 kg/m³, and 0.29 W/mK at 900 °C and 15% substitution percentage. However, cold water absorption, boiling water absorption, linear drying shrinkage, linear firing shrinkage, and apparent porosity increased with the increase in SMM, reaching 23.6%, 25.3%, and 36.6% at 900 °C and 15% substitution percentage. In the study simulation model, there was a significant improvement in energy consumption, which reached an overall reduction of 29.23% and 21.49% in Cario and Jazan cities, respectively.

Impact of core stability exercises vs. interferential therapy on pelvic floor muscle strength in women with pelvic organ prolapse

OBJECTIVE

Pelvic organ prolapse (POP) is the descent of the pelvic organs into or through the vaginal walls. Females who have prolapse have symptoms that interfere with their daily lives, sexual function, and exercise. POP can have a negative effect on one's sexuality and body image. This study attempted to assess the significance of core stability exercises vs. interferential therapy on the power of the pelvic floor muscles in females with prolapsed pelvic organs.

PATIENTS AND METHODS

A randomized control trial was conducted on forty participants (aged between 40-60 years, diagnosed with mild degree pelvic organ prolapse participated in the research. Participants were randomly divided into two groups: (group A; n = 20) and (group B; n = 20). The participants were tested twice, before and after 12 weeks, during which group (A) performed core stability exercises while group (B) received interferential therapy. A modified Oxford grading scale and the perineometer were used to assess how the vaginal squeeze pressure changed.

RESULTS

The study's findings demonstrated that the modified Oxford grading scale values and vaginal squeeze pressure had a non-statistically significant difference (p-value ≥ 0.05) between both groups pre-treatment while had a statistically significant difference (p-value ≤ 0.05) between both groups post-treatment in favor of group A.

CONCLUSIONS

It was concluded that both training programs are efficient at strengthening the pelvic floor muscles, but the core stability exercises were more effective.

Emamectin Benzoate-Induced Hepatotoxicity in Rats with Special Reference to Protective Potential of Nigella sativa Oil

This study was designed to explore the hepatotoxicity of emamectin in male rats and the possible effect of Nigella sativa oil (NSO) in ameliorating this. Twenty-eight male rats were used in this study. They were divided into four groups, Control group: rats orally administered distilled water; NSO group: rats administered NSO orally; EMB group: rats administered emamectin benzoate orally; and EMB+NSO group: rats orally co-administered NSO with EMB, with the administrations being performed every other day for 6 weeks. Body weight was measured, liver alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) activities were determined, and total protein and albumin levels were recorded. Histopathological examination of the liver was also performed, along with caspase-3 and TNF-α immunostaining of liver tissue. EMB treatment resulted in decreased body weight, while the co-administration of NSO modulated the EMB-induced alterations in body weight. There were also increases in the activities of serum ALT, AST, and ALP and decreases in total protein and albumin levels in the EMB group. Co-treatment with NSO significantly reduced serum ALT, AST, and ALP and improved total protein and albumin levels. Histopathological examination of the liver in the EMB group revealed the presence of different histopathological alterations that were improved by the co-administration of NSO. Immunostaining of caspase-3 and TNF-α in the liver revealed strong expression in the EMB-treated group. Meanwhile, the EMB+NSO group showed weak positivity for immunoreactive cells.

Knowledge and awareness levels of diabetes mellitus risk factors among nondiabetic visitors of primary health care centers: a multicenter study

OBJECTIVE

People with a high risk of developing Type 2 Diabetes Mellitus are primarily due to lifestyle factors and can be reduced by implementing awareness programs. Therefore, this study evaluates the diabetic awareness level, risk factors, and lifestyle behaviors among nondiabetic participants.

PATIENTS AND METHODS

This is a cross-sectional study conducted among 538 nondiabetic participants based on American Diabetic Association (ADA) parameters via face-to-face interview. The sample was collected from five different primary health care centers from November 2019 to February 2020. The target population was nondiabetic with age ≥18 years and participants with other serious chronic illnesses, pregnant women, or unable to communicate effectively were excluded.

RESULTS

A total of 538 participants without diabetes data were analyzed, of which 363 (67.5%) were males. Good, moderate, and insufficient knowledge of Type 2 Diabetes Mellitus awareness was 34.6%, 52.4%, and 13.0%, respectively. The knowledge level in females' participants was significantly less than the males (OR=2.4; p=0.0005). About 44% had diabetic risk, and the prevalence of diabetes risk was significantly high in males (OR=1.7), obesity (OR=2.9), overweight (OR=2.3), and high blood pressure (OR= 2.2) (all p < 0.05). The risk of diabetes was increased in those participants who consumed more bakery items (p < 0.05). The diabetes risk score was negatively associated with diabetes awareness levels (r= -0.29, p= 0.063).

CONCLUSIONS

The risk of diabetes in the general population can be prevented by proactive public health awareness campaigns, particularly among elderly age group, with lower educational level, physically inactive, and obese.

Hepatoprotective effects of Tagetes lucida root extract in carbon tetrachloride-induced hepatotoxicity in Wistar albino rats through amelioration of oxidative stress

CONTEXT

The roots of Tagetes lucida Cav. (Asteraceae) have antioxidant and antimicrobial properties.

OBJECTIVE

This study aimed to examine the hepatoprotective effects of T. lucida roots ethanol extract (TLRE) using carbon tetrachloride (CCl₄)-induced hepatotoxicity in rats.

MATERIALS AND METHODS

The active ingredients of TLRE were identified by high-performance liquid chromatography, infra-red spectrum, and mass spectrometric procedures. Ninety rats were distributed into four main groups: positive, therapeutic, protective, and negative group. The therapeutic group was implemented using CCl₄ (a single dose of 2 mL/kg) before TLRE or silymarin administration. Meanwhile, the protective group was implemented by administering CCl₄ (a single dose of 2 mL/kg) after force-feeding TLRE or silymarin. Each therapeutic and protective group was divided into three subgroups: force-fed with saline, TLRE (500 mg/kg), and silymarin (25 mg/kg). The positive group was split into two subgroups that were force-fed TLRE and silymarin. Positive, therapeutic, and protective groups were compared to the negative group (untreated rats). CCl_4, TLRE, and silymarin were orally administrated using a gastric tube.

RESULTS

In the therapeutic and protective groups, TLRE significantly reduced liver enzymes, i.e., aspartate aminotransferase (12.47 and 6.29%), alanine aminotransferase (30.48 and 11.39%), alkaline phosphatase (17.28 and 15.90%), and cytochrome P450-2E1 (39.04 and 48.24%), and tumour necrosis factor-α (53.72 and 53.72%) in comparison with CCl₄-induced hepatotoxicity controls.

CONCLUSIONS

TLRE has a potent hepatoprotective effect with a good safety margin. After a repeated study on another type of small experimental animal, their offspring, and an experiment with a large animal, this study may lead to clinical trials.

Diagnostic accuracy of magnetic resonance imaging in detecting depth of invasion of tongue cancers

The recent eighth edition of the American Joint Committee on Cancer (AJCC) staging system has introduced depth of invasion (DOI) as one of its important components. DOI is also important for deciding neck management in superficial tongue cancers. Magnetic resonance imaging (MRI) is mainly used to assess DOI, and in this study we have evaluated the efficacy of MRI to detect it. This is a retrospective study consisting of 60 treatment-naïve tongue cancer patients operated on between July 2017 and June 2019. Patients underwent MR imaging on an Optima MR450W 1.5T unit, and MRI was reported by two experienced ead and eck adiologistss. Postoperative histological DOI was considered the gold standard. The correlation coefficient was derived for postoperative DOI and MRI-detected DOI. A subgroup analysis of superficial tongue cancer was also done. The mean MRI DOI was 13.7 mm and the mean histological DOI 12.45 mm. The shrinkage factor was 0.6 mm. Pearson's correlation coefficient was 0.80 (p=<0.001) for Radiologist 1 and 0.85 (p=<0.001) for Radiologist 2. The interobserver variation was low, with a correlation coefficient between the two radiologists of 0.965 (p=<0.001). For superficial tongue cancers there was moderate correlation for MRI and histologically-detected DOI with a kappa value of 0.681 (p=0.03). As per the ROC curve, the cut-off value for MRI DOI to predict nodal metastasis was 4.6 mm. MRI has high reliability to predict the DOI of tongue cancers. The interobserver variation was low. The diagnostic accuracy in cases of superficial tongue cancer was moderate.

Study of Chronic Obstructive Pulmonary Disease patients in Gamal Abd El-Nasser Hospital in 2017

Background

COPD is characterized by non-remitting airflow limitation and persistent respiratory symptoms which is an enhanced inflammatory response to prolonged exposure to smoking or noxious gases or particles and manifested through chronic cough, effort dyspnea, expectoration and wheezing, symptoms that appears in context of airways hyper-responsiveness and may be partially reversible.

Objective

Assessment of COPD patients in Gamal Abd El Nasser Hospital during period from January 2017 to June 2017.

Subjects and Methods

This study was a cross sectional study that included 290 COPD patients recommended for spirometric assessment. The patients were classified into 2 groups: Outpatients and inpatients in the period from January 2017 to June 2017, they were subjected to full medical history, general and local examination, Pre and post bronchodilator spirometric study according to (GOLD,2017) and each patient will be subjected to the following questionnaire [Serial number, Name, Age, Sex, Occupation, Residence, Level of education, Smoking, Smoking index, Family history of COPD, Symptoms, Number and severity of exacerbation attacks in the last year, Number of Hospitalization during the last year, Vaccination status, Spirometry, Treatment prescribed by, Treatment, Inhalation therapy, Regulation of treatment, Non pharmacological therapy, Satisfaction of treatment, co morbidities, Complications, Outcome for inpatient]

Results

The study included 290 patients, 259 males and 31 females with age range of 29 _ 83 years, the majority of the studied cases were Current smoking but only 22.5% was ex-smoker. Mean FEV1% pred. Post-bronchodilator was 75.9± 16.9 in outpatients and mean FEV1% pred. Post – bronchodilator was 52.9 ± 13.4 in inpatient. The most common co morbidities in COPD patients were hypertension in 25% of cases. More than half of all studied cases had complications and the most frequent complication was Cor-pulmonale and respiratory Failure. In this study, Severity of COPD according to GOLD 2017 was 27.8% in mild stage, 34.2% in moderate stage, 35.8% in severe stage and 2.5% in very severe stage.

Conclusion

Spirometry had a great role in diagnosis of COPD and its differential diagnosis from asthma. Smoking is the major risk factors in developing COPD and this reflects on the disease occurrence and severity. Some of COPD patients refuse to use inhalers due to fear of addiction and incorrect method in using it. Inhaler steroids were preferred due to fear of systemic complications of steroids. There is great defect in vaccination and trials of quitting smoking as a non-pharmacological treatment for COPD patients.

Evaluation of a human in vitro skin test for predicting drug hypersensitivity reactions

The occurrence of drug hypersensitivity reactions (DHRs) following administration of low molecular weight (LMW) drugs is an important health concern. However, in vivo animal models which could be used as tools for the prediction of DHRs are lacking. As a result, research has focused on development of in vitro tools for predicting DHRs. In this study a novel human in vitro pre-clinical skin explant test was used to predict T cell-mediated hypersensitivity responses induced by LMW drugs. Responses in the skin explant test for 12 LMW drugs associated with T cell-mediated hypersensitivity in the clinic (abacavir, amoxicillin, carbamazepine, diclofenac, lamotrigine, lapatinib, lumiracoxib, nevirapine, ofloxacin, phenytoin, propranolol, sulfamethoxazole) were compared with responses for 5 drugs with few/no reports of T cell-mediated hypersensitivity reactions (acetaminophen, cimetidine, flecainide, metformin, verapamil). Changes in skin histology following in vitro exposure to the drugs as well as T cell proliferation and interferon gamma (IFNγ) production were studied. The results of the skin explant assays showed a good positive correlation (r = 0.77, p < .001) between the test outcome (prediction of positive or negative) and the clinical classification of the tested drugs. The T cell proliferation assay showed a correlation of r = 0.60 (p < .01) and the IFNγ assay r = 0.51 (p < .04). The data suggest that the skin explant model could be a useful tool to predict the potential of LMW drugs to induce DHRs.

Aging changes in the retina of male albino rat: a histological, ultrastructural and immunohistochemical study

BACKGROUND

Degenerative changes caused by aging may affect the eye, especially the retina. Such changes occur as a part of normal physiological process and may be irreversible. The aim of the study was to demonstrate the influence of aging on the morphology of the retina to provide a basis to explain the pathogenesis of age-associated decline in visual acuity, scotopic and photopic sensitivity.

MATERIALS AND METHODS

Forty male albino rats were used and divided into four age groups (group I: age of cortical maturity, group II: middle-aged, group III: aged group and group IV: senile group). The rats were sacrificed, the eye balls were enucleated. Intra-vitreal injections of formalin for haematoxylin and eosin and immunohistochemical sections, glutaraldehyde for toluidine blue semithin and E/M ultra-thin sections were performed. Measurements and quantitative histomorphometric estimation of the layers of the retina were done.

RESULTS

Light microscopic examination revealed age-dependent attenuation of photoreceptor striations. Aged and senile groups presented pyknotic, widely- -spaced nuclei of the outer nuclear layer. The inner nuclear layer was thinned out to 2 or 3 cellular rows. Retinal capillaries showed progressive dilatation and congestion. Statistical analysis proved significant thinning of the retina with variable degrees of thinning of the constituting layers. Decreased arborisation with age was confirmed with quantification of synaptophysin-immunostained sections. Glial fibrillary acidic protein immunostaining revealed the picture of reactive gliosis. On the ultrastructural level, the retinal pigment epithelium exhibited major alterations with aging. Numerous phagosomes, lipofuscin and melanolipofusin granules appeared within the cells, together with exaggerated basal infoldings. The pho- toreceptor nuclei became degenerated and the perinuclear space was widened.

CONCLUSIONS

Rat retinae clearly undergo age-related morphological changes. Such changes provide a cellular base for explanation of decreased vision in humans with aging other than reflection errors. Effect of aging was not only qualitative, but also quantitative.

Hyperthermic Potentiation of Cisplatin Cytotoxicity on Solid Ehrlich Carcinoma

Background

Hyperthermia produces marked effects on many biochemical parameters of tumor cells and has been reported to potentiate the effect of many drugs. We therefore evaluated the possible synergistic effect between hyperthermia and cisplatin against solid Ehrlich carcinoma. The study was based on the measurement of some biologic characteristics in tumor tissues, namely: DNA, RNA, and protein content and their rate of synthesis as parameters for nuclear damage; total lipids and cholesterol as parameters for membrane damage; acid-phosphatase and acid-ribonuclease as parameters for lysosomal damage; and tumor volume as a direct parameter for tumor growth.

Methods

Treatment of solid Ehrlich carcinoma by hyperthermia at 43 °C for 30 min for 3 successive days produced a 41.5 % decrease in tumor volume, as well as a significant decrease in nucleic acids, protein contents and their rate of synthesis, in total lipids and cholesterol, and in acid-phosphatase and acid-ribonuclease. Chemotherapeutic management of the tumor by 5 mg/kg × 3 of cisplatin alone showed a continuous increase in tumor volume but at a lower rate than that of the untreated control. However, when cisplatin was given 1 h prior to hyperthermia, the tumor volume was significantly decreased by 82.6 %.

Results

The effects observed on all the investigated parameters were intensified when cisplatin was combined with hyperthermia. The results obtained suggest that hyperthermia may enhance the penetration of cisplatin to its target site inside the tumor cells due to a membrane-damaging effect. The enhanced lethality of cisplatin on tumor cells may also be due to the inhibition of DNA repair processes by hyperthermia.

Do protons and X-rays induce cell-killing in human peripheral blood lymphocytes by different mechanisms?

Purpose

Significant progress has been made in the technological and physical aspects of dose delivery and distribution in proton therapy. However, mode of cell killing induced by protons is less understood in comparison with X-rays. The purpose of this study is to see if there is any difference in the mode of cell-killing, induced by protons and X-rays in an ex vivo human peripheral blood lymphocyte (HPBL) model.

Materials and methods

HPBL were irradiated with 60 MeV proton beam or 250-kVp X-rays in the dose range of 0.3–4.0 Gy. Frequency of apoptotic and necrotic cells was determined by the Fluorescein (FITC)-Annexin V labelling procedure, 1 and 4 h after irradiation. Chip-based DNA Ladder Assay was used to confirm radiation-induced apoptosis and necrosis. Chip-based DNA Ladder Assay was used to confirm radiation-induced apoptosis.

Results

Ex vivo irradiation of HPBL with proton beams of 60 MeV or 250 kVp X-rays resulted in apoptotic as well as necrotic modes of cell-killing, which were evident at both 1 and 4 h after irradiation in the whole dose and time range. Generally, our results indicated that protons cause relatively higher yields of cell death that appears to be necrosis compared to X-rays. The analysis also demonstrates that radiation type and dose play a critical role in mode of cell-killing.

Conclusion

Obtained results suggest that X-rays and protons induce cell-killing by different modes. Such differences in cell-killing modes may have implications on the potential of a given therapeutic modality to cause immune modulation via programmed cell death (X-rays) or necrotic cell death (proton therapy). These studies point towards exploring for gene expression biomarkers related necrosis or apoptosis to predict immune response after proton therapy.

Species-specific control of hepatocyte growth factor expression and production in adipocytes in a differentiation-dependent manner

Hepatocyte growth factor (HGF) is a mesenchymal cell-derived factor that regulates cell growth, cell motility, and morphogenesis. Since there are conflicting reports on HGF-producing cells, we herein examined HGF activity in conditioned medium (CM) of bovine and mouse preadipocytes before and after adipogenic differentiation. CM of bovine adipocytes and mouse preadipocytes induced the morphogenesis of mammary epithelial cells that was inhibited by an NK4 HGF antagonist, whereas CM of bovine preadipocytes and mouse adipocytes did not. HGF mRNA expression was increased by a treatment with dexamethasone and isobutylmethylxanthine in bovine as well as human cells, whereas it was decreased in rodent cells. It was unfortunate that HGF gene promoter activity failed to reflect HGF mRNA expression in these cells. After actinomycin D treatment, expression of HGF mRNA remained stable in pre- and differentiated bovine adipocytes and mouse preadipocytes, whereas rapidly decreased in mouse-differentiated adipocytes. These results indicate that expression and production of HGF are regulated in a species-specific adipogenic differentiation-dependent manner and suggest that the decrease in HGF mRNA in mouse differentiated adipocytes is, at least in part, mediated by differentiation-dependent loss of its stability.

Neuroprotective effects of quercetin in diabetic rat retina

Diabetic retinopathy (DR) is a severe complication of diabetes and the leading cause of blindness among working adults worldwide. DR is being widely recognized as a neurodegenerative disease of the retina, since, retinal neurons are damaged soon after diabetes onset. Diabetes-induced oxidative stress is considered as central factor that dysregulates neurotrophic factors and activates apoptosis, thereby damages neurons in the diabetic retina. Flavonoids being a powerful antioxidant have been considered to protect neurons in diabetic retina. The purpose of this study was to analyze the beneficial effects of flavonoid, quercetin to protect neurons in the diabetic rat retina. We quantitated the expression levels of BDNF, NGF, TrkB, synaptophysin, Akt, Bcl-2, cytochrome c and caspase-3 using Western blotting techniques in the diabetic retina with and without quercetin treatments and compared with non-diabetic rats. In addition, we employed ELISA techniques to determine the level of BDNF. Caspase-3 activity and the level of glutathione were analyzed by biochemical methods. Our results indicate that quercetin treatment to diabetic rats caused a significant increase in the level of neurotrophic factors and inhibited the level of cytochrome c and caspase-3 activity in the diabetic retina. Furthermore, the level of an anti-apoptotic protein Bcl-2 was augmented in quercetin treated diabetic retina. Thus, quercetin, may protect the neuronal damage in diabetic retina by ameliorating the levels of neurotrophic factors and also by inhibiting the apoptosis of neurons. Therefore, this study suggests that quercetin can be a suitable therapeutic agent to prevent neurodegeneration in diabetic retinopathy.

Verification of high efficient broad beam cold cathode ion source

An improved form of cold cathode ion source has been designed and constructed. It consists of stainless steel hollow cylinder anode and stainless steel cathode disc, which are separated by a Teflon flange. The electrical discharge and output characteristics have been measured at different pressures using argon, nitrogen, and oxygen gases. The ion exit aperture shape and optimum distance between ion collector plate and cathode disc are studied. The stable discharge current and maximum output ion beam current have been obtained using grid exit aperture. It was found that the optimum distance between ion collector plate and ion exit aperture is equal to 6.25 cm. The cold cathode ion source is used to deposit aluminum coating layer on AZ31 magnesium alloy using argon ion beam current which equals 600 μA. Scanning electron microscope and X-ray diffraction techniques used for characterizing samples before and after aluminum deposition.

Epidemiology of autistic disorder in Bahrain: prevalence and obstetric and familial characteristics

European and North American studies show that the prevalence of autistic disorder is inccreasing. This study was performed to identify the prevalence of autistic disorder in Bahrain, and determine some of the demographic and family characteristics. Using a case-control design, 100 children who received a diagnosis of autistic disorder according to DSM-IV-TR during the period 2000-2010 were selected. An equal numberofcontrols who had received a diagnosis of nocturnal enuresis and no psychopathology were selected, matched for sex and age group. The prevalence of autistic disorder was estimated as 4.3 per 10,000 population, with a male:female sex ratio of 4:1. Significantly more cases than controls were delivered by caesarean section and had mothers who suffered prenatal complications. The prevalence estimate in Bahrain is comparable to previous reports using similar methods. Obstetric complications and caesarean section delivery may be associated with autistic disorder.

Improvement of four anode rods ion source

In this work, an improved form of a saddle field ion source has been designed and constructed. It consists of four anode rods made from copper and two copper cathode discs. The two cathode discs are placed symmetrically on both sides of the four anode rods. The electrical discharge and output ion beam characteristics were measured at different pressures using argon gas. The optimum distance between each two anode rods was determined. Also the optimum distance between the four anode rods and any cathode disc was obtained. It was found that the optimum distance between each two anode rods equal to 6 mm, while the optimum distance between the four anode rods and any cathode disc equal to 16 mm, where a stable discharge current and maximum output ion beam current can be obtained. The effect of negative extraction voltage applied to both the extractor electrode and Faraday cup on the output ion beam current was studied. The sputter yield of copper and aluminum targets using argon ions of different energies was determined.

Short communication: Graph for calculating maximum local analgesic dose in millilitres for the paediatric population

AIM

Determination of the maximum local analgesic dosage in millilitres can be confusing. This article presents a new graph that easily allows the dental practitioner to determine a child's maximum local analgesic dosage in millilitres based on their weight.

BACKGROUND

Local analgesia is used daily in dentistry to manage pain, and different kinds of agents are available in the market that may be selected depending on the strength and duration of analgesia required. Each analgesic agent has a maximum recommended dose, and it is very important to calculate that dose, especially in children, to avoid the risk of toxicity that could lead to death. Currently a series of calculations are used to calculate the maximum recommended dose for local analgesic agents that could be taxing. This paper presents a newly-developed graph that makes it easier for dental practitioners to quickly identify the maximum recommended dose of the different local analgesic agents used in dentistry based on a patient's weight.

CONCLUSION

Dentists can utilize this graph to obtain the maximum local analgesic dose in millilitres based on the child's weight. This will save time and encourage dentists to routinely identify the maximum allowed dose and most importantly, decrease or eliminate the risks of toxicity and overdose especially when treating small children.

Quantitative assessment of posture stability using computerised dynamic posturography in type 2 diabetic patients with neuropathy and its relation to glycaemic control

INTRODUCTION

Patients with diabetic neuropathy have an imbalance, which comes with a higher risk of falls. The aim of this study was to assess posture stability using computerised dynamic posturography in type 2 diabetics mellitus patients with neuropathy as well as its relation to glycaemic control.

METHODS

54 type 2 diabetics mellitus patients with peripheral neuropathy were recruited, together with 18 type 2 diabetics mellitus patients without peripheral neuropathy acting as the control group. The first group was divided into two subgroups according to glycaemic control assessed by HbA1c (A1c), the first subgroup comprising 24 patients had good glycaemic control with A1c less than or equal to seven percent and the second subgroup with 30 patients had poor glycaemic control with A1c more than 7 percent. The postural stability was evaluated using dynamic posturography.

RESULTS

The composite equilibrium score, sensory organisation test 1, 2 and 3 conditions were significantly lower in the neuropathic group as compared to the non-neuropathic group (p-value is less than 0.001). A1c was significantly correlated with the composite equilibrium score in the neuropathic group with poor glycaemic control (r-value equal to -0.395) but not correlated in the neuropathic group with good glycaemic control (r-value equal to 0.151).

CONCLUSION

Posture instability in type 2 diabetic patients with peripheral neuropathy reflects an impairment of the somatosensory system; also, poor glycaemic control resulted in more posture instability. The early detection of imbalance using dynamic posturography and achieving good glycaemic control may be of great help in the prevention of falls in such patients.

Sickle cell-haemoglobin E (HbSE) compound heterozygosity: a clinical and haematological study

The paucity of clinical reports in the world literature suggests that, as a disease entity, haemoglobin SE compound heterozygosity is of negligible importance. In view of the significant community prevalence of this haemoglobinopathy in the Sultanate of Oman where it is the second most prevalent sickling disorder, a hospital study of 12 SE compound heterozygotes from six unrelated Arab families was undertaken to determine their clinico-haematological features. Our findings were compared with those reviewed in the literature. Clinical and haematological evaluation was carried out by conventional methods including chromatographic haemoglobin analysis. At least 50% of those studied were asymptomatic throughout the study period but sickling-related complications occurred in the rest and included the acute chest syndrome (1/12), severe vaso-occlusive skeletal pain (2/12), frontal bossing (1/12) possibly indicative of significant chronic haemolysis and recurrent infections of the urinary tract (1/12). Steady-state haemoglobin levels fell within the reference range while MCV and MCH values were, as expected, reduced in most cases; nevertheless, concomitant inheritance of alpha-thalassaemia trait was also likely. Red cell morphology was striking by the absence or rarity of pseudo-sickled cells in the blood films of many patients during the steady state and in crises. Bearing in mind the prevalence of 0.05% of SE compound heterozygosity in Oman, the findings in this single study of the largest number of SE patients and their relatives confirm the predominantly asymptomatic nature of this sickling disorder in individuals in the community at large. HbF levels do not appear to explain the heterogeneous nature of this haemoglobinopathy. Correlation of the variable clinical and haematological features of SE cases with their alpha-globin gene status and beta-cluster haplotypes (linked to the beta(s)- and beta(e)-genes) merits a separate investigation, which is being currently organized.

Summative assessment of under graduate medical student's performance in physiology by structured oral examination

To evaluate the importance and efficiency of structured oral examination (SOE). This is a retrospective study, has been designed to compare the newly adopted structured oral examination (SOE) with that of the traditional oral examination (TOE). This study was conducted at the department of physiology during the year 2006, on 607 2nd year medical students of Mymensingh Medical College and 106 students from some other medical colleges who appeared in the first professional examination under Dhaka University from 2003-2006. For this purpose, scores achieved by the students in physiology in first professional examination for 4 successive years (2003-2006) were analyzed. The examinations in (2003-2004) and (2005-2006) were conducted under TOE and SOE respectively. Mean score achieved in SOE and TOE was 67+/-.02 and 57+/-.003 respectively. The difference is statistically significant. The pass percentage in SOE is 94.70% and 90.3% in TOE and the difference is significant. Maximum number of students in SOE attained score in the range of 60-69 but in TOE scores attained by maximum frequency fall in the range of 50-59. This observation indicates improvement in student's performance by quality and success rate in SOE. Therefore SOE is a more effective, skill full technique and superior to TOE in assessing student's competency and cognitive ability. The need and skill of SOE over the TOE in assessing oral part of examination has been proved.

Nephrogenic Fibrosing Dermopathy/Nephrogenic Systemic Fibrosis in 2 Patients With End-Stage Renal Disease on Hemodialysis

Nephrogenic fibrosing dermopathy/nephrogenic systemic fibrosis (NFD/NSF) is a newly recognized disorder occurring in patients with renal failure. It is manifested by progressive cutaneous and systemic fibrosis involving the extremities and the trunk with usual sparing of the face and internal organs. NFD/NSF can lead to joint contractures and painful disability. The etiology is unknown and there are no proven effective treatments. NFD/NSF must be distinguished from other clinically similar disorders such as scleroderma, scleromyxedema, and eosinophilic fasciitis among a myriad of others. NFD/NSF can pose many diagnostic challenges to physicians; however, a team of experienced rheumatologists, nephrologists, dermatologists, and dermatopathologists is essential in identifying this disorder. We report 2 new cases of NFD/NSF in patients on hemodialysis.

Thyroid dysfunction and thyroid autoimmunity in Saudi type 2 diabetics

Diabetes mellitus and thyroid disease are common endocrine disorders in the general population. To investigate the association between thyroid dysfunction, thyroid autoimmunity and Saudi type 2 diabetics, a random sample of 100 Saudi type 2 diabetics and 100 age- and sex-matched controls were studied. The mean age was 54 years for diabetics and 55 years for controls while the male:female ratios were 1:1.6 and 1:14 respectively. GAD65ab were found in 26% diabetics and 2% controls (p=0.001). Thyroid autoimmunity were detected in 10% diabetics vs. 5% controls (p=0.05), while thyroid dysfunction was found in 16% and 7% respectively (p=0.03). In GAD65ab-positive diabetics, thyroid autoimmunity was observed in 27% vs. 4% GAD65ab-negative diabetics (p=0.02) and thyroid dysfunction was reported in 42% and 7% respectively. We conclude that thyroid dysfunction and autoimmunity are common in Saudi type 2 diabetics. Further studies are needed on the cost effectiveness of thyroid screening in diabetics.

Genetic haemochromatosis presenting as porphyria cutanea tarda

Porphyria cutanea tarda (PCT) is the commonest form of porphyria. It can be inherited or acquired. We present a case of genetic haemochromatosis with associated PCT. Venesection led to improvement in both conditions. We highlight the need for the awareness of PCT and its associated conditions.

Metallic stents in large bowel obstruction: experience in a District General Hospital

INTRODUCTION

Metallic stents are used increasingly in the palliation of malignant large bowel obstruction. Stenting has also been used in the setting of acute obstruction, allowing appropriate patient preparation for an elective colectomy.

METHODS

Uncovered metallic stents were inserted using a combined endoscopic/radiological technique in patients presenting with large bowel obstruction.

RESULTS

Seventeen patients (10 female, mean age 75.2 years) presented with large bowel obstruction, 14 due to malignancy and 3 secondary to diverticular stricture. Technical success was achieved in 13/17 with clinical success in 12 of these 13. There were no perforations or procedure related deaths. One stented patient had elective surgery. The five patients with clinical/technical failure required emergency surgery.

CONCLUSION

The result of our preliminary experience in the use of metallic stents is encouraging. Metallic stents should be available in all hospitals as part of a multimodality approach in treating large bowel obstruction.

Effect of memantine on the levels of glial cells, neuropeptides, and peptide-degrading enzymes in rat brain regions of ibotenic acid-treated alzheimer's disease model

It has been implicated that glia activation plays a critical role in the progression of Alzheimer's disease (AD). However, the precise mechanism of glia activation is not clearly understood yet. In our present studies, we confirmed our previous results where change the levels of neuropeptides and peptidases in ibotenic acid (IBO) infusion into the rat nucleus basalis magnocellularis, an animal model of AD. Furthermore, we extended our study to investigate a possible protection effect of co-administration on the changes of neuropeptides, and neuronal and glial cells in IBO-infused rat brain by memantine treatment. The levels of substance P and somatostatin were decreased in the striatum and frontal cortex 1 week after IBO infusion, and recovered to the control level by memantine treatment, indicating the involvement of neuropeptides in AD pathology. Furthermore, the immunohistochemical and enzymatic studies of GFAP and CD 11b, and peptidylarginine deiminase, markers of glia, in the striatum and frontal cortex showed the increase in IBO-treated rat brain as compared with controls, while co-administration of memantine and IBO no increase of astrocytes and microglia activation was observed. The present biochemical and immunohistochemical results suggest that glia activation might play an important role to the pathology of AD, and correlate with the changes of neuropeptide levels in AD brain that is recovered by memantine treatment.

Esophageal involvement in cicatricial pemphigoid: a rare cause of dysphagia

Cicatricial pemphigoid is a rare, autoimmune, blistering disorder affecting the mucous membranes and skin. Esophageal involvement affects a small proportion of affected individuals and may present up to 10 years after the initial onset of the disease. We present a case of esophageal cicatricial pemphigoid that presented initially as linear IgA disease. We describe the successful treatment of dysphagia by graded esophageal dilatations.

Cardiovascular risk factors in Saudi Arabian and non-Saudi Arabian diabetic patients in Saudi Arabia

To determine frequency of cardiovascular risk factors in Saudi and non-Saudi diabetics, we studied patients attending King Abdulaziz University Hospital for follow-up in the period January 1997 to December 2001. Cardiovascular risk factors, including hypertension, hyperlipidaemia, obesity and smoking, were studied as well as degree of blood glucose control. Of 1122 patients in the study, 48% were Saudis and 52% non-Saudis. No statistically significant difference was found for prevalence of cardiovascular risk factors between the two groups. Correlation of each of the risk factors to patient's age showed significant correlation to hypertension and smoking.

Early growth response-1 gene: potential radiation response gene marker in prostate cancer

This study was undertaken to determine whether the transcription factor EGR-1 expression: (1) in the primary tumor, correlates with radiation response in terms of complete local tumor control with no evidence of disease or recurrence and no evidence of metastasis; (2) in the postirradiated biopsies correlates with residual tumor; and (3) correlates with the expression of Egr-1 target genes such as TP53, pRB, and Bax. The authors analyzed: (1) 25 pretreated surgically resected paraffin-embedded primary adenocarcinomas of the prostate for the presence of EGR-1 expression and mutation, and correlated this with clinical endpoints such as serum prostate-specific antigen levels and current clinical status; (2) 27 postirradiated biopsies of prostate for the presence of EGR-1 expression, and correlated these findings to the residual tumor status; and (3) 12 prospective prostate tumor specimens for EGR-1 expression and its target genes. EGR-1 expression was determined by immunohistochemistry and mutations were screened in two regions of the Egr-1 gene (trinucleotide AGC repeats in transactivation domain [TD] and poly A tract in 3'UTR) by polymerase chain reaction-single strand conformational polymorphism analysis. Of 25 patients, 18 patients showed expression of EGR-1. EGR-1 overexpression correlated with treatment failure. No correlation with EGR-1 overexpression and its target genes was found, which may indirectly suggest that overexpressed EGR-1 may lack transactivation function. In summary, EGR-1 overexpression in the mutant form may provide an indication of clinical failure (local recurrence or metastasis).

Effects of Taxol plus radiation on the apoptotic and mitotic indices of mouse intestinal crypt cells

PURPOSE

In this study we investigated the effect of Taxol, radiation, or Taxol plus radiation on highly proliferative normal tissue--the intestinal crypt cells of Swiss albino mice.

MATERIALS AND METHODS

Swiss-albino mice, 3-4 months old, were used in this study. Taxol was administered by bolus intravenously through the tail vein. Radiation was given using a linear accelerator. There were four treatment categories, which comprised a total of 34 groups. Each group consisted of five animals. The first category was a control category which comprised one group (n = 5). The second treatment category was Taxol alone which comprised three groups (n = 15). The third treatment category was radiation alone which comprised three groups (n = 15). The fourth treatment category was Taxol plus radiation which comprised 27 groups (n = 135). Mice were killed 24 h after Taxol or radiation or combined administration using ether anesthesia. Using a light microscope, apoptotic and mitotic indices were counted on jejunal crypt cells of mice that were stained with hematoxylin-eosin. Differences between groups were statistically evaluated with Student's t-test.

RESULTS

Taxol caused a dose-dependent increase in apoptosis (P = 0.045) and decreased the mitotic index (P = 0.006) at high doses. Similarly, radiation caused a dose-dependent increase in apoptosis (P = 0.046) and decreased the mitotic index (P = 0.299) at higher radiation doses. Compared to radiation alone, Taxol caused a significant induction of apoptosis (P = 0.010). In combination, no significant radiosensitizing effect of Taxol was observed (enhancement ratio < 1), when compared to radiation alone. However, an increase in apoptosis was observed after 24 h of Taxol exposure when compared to 12 or 48 h of Taxol exposure (P = 0.0001 and P = 0.0001).

CONCLUSION

These findings suggest that Taxol did not cause a radiosensitizing effect in intestinal crypt cells. However, a 24-hour pretreatment of Taxol exposure followed by radiation caused significant induction of apoptosis and reduction of the mitotic index when compared to other Taxol timing sequences. Thus, the lack of a radiosensitizing effect of Taxol in these proliferative cells may be due to enhanced mitotic death rather than apoptotic death.

Adsorptive stripping voltammetric determination of antihypertensive agent: diltiazem

Adsorptive stripping voltammetry was used to determine the antihypertensive agent diltiazem in phosphate buffer (pH 7.0). The adsorptive cathodic peak was observed at -1.72 V vs. Ag/AgCl. The peak response was characterized with respect to pH, preconcentration time, possible interferences, accumulation potential and supporting electrolytes. The obtained results were analyzed and the statistical parameters were calculated. The proposed method was applied to determine the mentioned drug in pharmaceutical formulation (capsule) and urine. The detection limit is 1x10(-8) M (4.5 ng ml(-1)) using 180 s preconcentration time, whereas the lower limit of detection is 6x10(-9) M (2.7 ng ml(-1)).

Fate of postharvest-applied dichlorvos in stored and processed dates

The fate of dichlorvos (DDVP) on dates after storage and processing of postharvest-treated fruits has been investigated. Residues were determined using GC-ECD after extraction of the fruits. A postharvest application was made to fruits at different stages of maturity: khalal fruits (mature full colored stage), rutab fruits (soft brown stage), and the mature tamer fruits (hard raisin-like stage). The fate of the residues was followed during the storage at refrigerated, room, and summer average temperatures (3, 22, and 43 degrees C). The amount of residues absorbed varied with the level of maturity. The rate of the loss of the residues was found to follow first-order kinetics. First-order rate constants were calculated for the different levels of maturity. The rate of the loss of DDVP increased as the temperature of storage increased. Also, it decreased with increasing maturation of the dates, which was characterized by a decrease in moisture content as well as water activity and an increase in sugar content. The period of storage study was limited by the time of maturation to the next stage. Most common home-cooking methods, including dehydration, jam-making, and syrup-making, resulted in significant decreases in residue levels. Only 0-13% of initial DDVP residues was detected in final products.

Ionizing radiation down-regulates p53 protein in primary Egr-1-/- mouse embryonic fibroblast cells causing enhanced resistance to apoptosis

In this study, we sought to investigate the mechanism of the proapoptotic function of Egr-1 in relation to p53 status in normal isogenic cell backgrounds by using primary MEF cells established from homozygous (Egr-1(-/-)) and heterozygous (Egr-1(+/-)) Egr-1 knock-out mice. Ionizing radiation caused significantly enhanced apoptosis in Egr-1(+/-) cells (22.8%; p < 0.0001) when compared with Egr-1(-/-) cells (3.5%). Radiation elevated p53 protein in Egr-1(+/-) cells in 3-6 h. However, in Egr-1(-/-) cells, the p53 protein was down-regulated 1 h after radiation and was completely degraded at the later time points. Radiation elevated the p53-CAT activity in Egr-1(+/-) cells but not in Egr-1(-/-) cells. Interestingly, transient overexpression of EGR-1 in p53(-/-) MEF cells caused marginal induction of radiation-induced apoptosis when compared with p53(+/+) MEF cells. Together, these results indicate that Egr-1 may transregulate p53, and both EGR-1 and p53 functions are essential to mediate radiation-induced apoptosis. Rb, an Egr-1 target gene, forms a trimeric complex with p53 and MDM2 to prevent MDM2-mediated p53 degradation. Low levels of Rb including hypophosphorylated forms were observed in Egr-1(-/-) MEF cells before and after radiation when compared with the levels observed in Egr-1(+/-) cells. Elevated amounts of the p53-MDM2 complex and low amounts of Rb-MDM-2 complex were observed in Egr-1(-/-) cells after radiation. Because of a reduction in Rb binding to MDM2 and an increase in MDM2 binding with p53, p53 is directly degraded by MDM2, and this leads to inactivation of the p53-mediated apoptotic pathway in Egr-1(-/-) MEF cells. Thus, the proapoptotic function of Egr-1 may involve the mediation of Rb protein that is essential to overcome the antiapoptotic function of MDM2 on p53.

Low dose fractionated radiation enhances the radiosensitization effect of paclitaxel in colorectal tumor cells with mutant p53

BACKGROUND

The current study was undertaken to investigate the influence of wild-type or mutant p53 status on the radiosensitizing effect of paclitaxel in colorectal tumor cell lines.

METHODS

HCT-116 (contains wild-type p53) and HT-29 (contains mutant p53) established from moderately differentiated colorectal carcinomas were used in this study. Colony-forming assay was performed after exposure to either different radiation doses (0.5-6 gray [Gy]) or paclitaxel (1-10 nM) or in combination. Induction of p53 and p21(waf1/cip1) by these treatments were determined by immunocytochemistry and Western blot analysis.

RESULTS

Radiation caused an increase in nuclear p53 and p21(waf1/cip1) proteins in HCT-116 cells, indicating that p53 functionally induced p21(waf1/cip1). However, induction of nuclear p53 and p21(waf1/cip1) protein was not evident in HT-29 cells, suggesting that p53 was not functional in these cells. Survival data showed that the HCT-116 cells (survival fraction of exponentially growing cells that were irradiated at the clinically relevant dose of 2 Gy [SF(2)] = 0.383; dose required to reduce the fraction of cells to 37% [D(0)] = 223 centigray [cGy]) were significantly sensitive to ionizing radiation (P < 0.008) when compared with the HT-29 cells (SF(2) = 0.614; D(0) = 351 cGy). Paclitaxel caused a higher degree of clonogenic inhibition in HCT-116 (D(0) = 0.7 nM) than HT-29 (D(0) = 1.11 nM) cells (P < 0.06). When paclitaxel and radiation were combined, an enhanced radiosensitizing effect (P < 0.05) was observed in HCT-116 cells (SF(2) = 0.138; D(0) = 103 cGy), whereas in HT-29 cells no significant radiosensitization of paclitaxel was observed (SF(2) = 0.608; D(0) = 306 cGy). However, pretreatment with paclitaxel followed by multifractionated low dose radiation (0.5- or 1-Gy fractions for a total dose of 2 Gy) significantly enhanced the radiosensitizing effect in both HCT-116 and HT-29 cells.

CONCLUSIONS

The results of the current study suggested that multifractionated radiation given at very low doses after exposure of cells to paclitaxel conferred a potent radiation sensitizing effect irrespective of p53 status.

Deep vein thrombosis at King Abdul Aziz University Hospital

OBJECTIVE

To study the incidence of deep vein thrombosis and pulmonary embolism at King Abdul Aziz University Hospital. To determine the risk factors, use of different diagnostic modalities, treatment given and to compare our findings with those reported in the literature.

METHODS

Retrospective study which included all cases of deep vein thrombosis and pulmonary embolism admitted to the medical ward of King Abdul Aziz University Hospital during the period between January 1994 till March 1999 were analyzed.

RESULTS

Total of 75 patients were diagnosed to have deep vein thrombosis with mean age of 44.16 +/- 14.5 years and male:female ratio of 1:2. Doppler ultrasound was used for the diagnosis in 56 of 75 patients (75%). Pulmonary embolism as a complication of deep vein thrombosis developed in 24 of 75 patients (32%). Prolonged immobilization was found to be the most common risk factor 17 of 75 (23%). All the patients were treated with conventional heparin followed by warfarin.

CONCLUSION

As discussed, our results are comparable with those reported in the literature. Post operative patients who are anticipated to have prolonged immobilization should receive prophylactic anti coagulation with subcutaneous heparin. Thrombophillia screening should be reserved for those with recurrent deep vein thrombosis or patients with positive family history.

Long-term stability of anterior segmental maxillary osteotomy

The long-term stability of anterior segmental maxillary osteotomy was evaluated in 11 patients. Both the Wunderer and down-fracture procedures were used. The patients were examined periodically until 18 months after surgery. Operative and postoperative cephalograms were compared; a more reliable method was utilized to assess the displacement of the osteotomy segment. Linear and angular measurements were used for evaluation of relapse. No major complications were recorded, and no correlation was found between the magnitude of segment repositioning and degree of relapse. Positional changes at the end of the study, though statistically significant, were clinically acceptable and subjectively undetectable. Results emphasized the merits and potential of the surgical osteotomy. Satisfactory correction of anterior maxillary excess was achieved, with absolute improvement in esthetics and occlusion.

Characterization of a newly established human pancreatic carcinoma cell line, UK Pan-1

BACKGROUND

A highly tumorigenic cell line designated as UK Pan-1 was established in a surgically removed human pancreatic adenocarcinoma and characterized as having many of the genotypic and phenotypic alterations commonly found in pancreatic tumors.

METHODS

The cell line was characterized by its morphology, growth rate in monolayer culture and soft agar, tumorigenicity in nude mice, and chromosomal analysis. Furthermore, the status of p53, Ki-ras mutation and transforming growth factor (TGF)-/receptor expression were determined. The characteristics of UK Pan-1 were compared with those of other commonly used pancreatic carcinoma cell lines.

RESULTS

Quiescent UK Pan-1 cells could be stimulated to proliferate in growth factor free nutrient media, indicating a growth factor independent phenotype. UK Pan- 1 cells grew in soft agar and rapidly formed tumors in nude mice. This cell line possesses a mutation at codon 12 of the c-Ki-ras-2 gene that is commonly found in pancreatic carcinoma. Fluorescence in situ hybridization showed that two alleles of p53 tumor suppressor gene were present in UK Pan-1. However, sequencing analysis revealed a mutation in one allele at exon 8, codon 273 (G to A; Arg to His). Additional growth assays indicated that the cell line was insensitive to negative growth regulation induced by exogenous TGF-beta. Molecular analysis of the TGF-beta signaling pathway showed that UK Pan-1 did not express appreciable levels of the TGF-beta receptor type I, II, or III mRNAs, but did express DPC4 mRNA. Karyotype analysis revealed an 18q21 deletion indicating a possible loss of heterozygosity for DPC4, as well as other chromosomal deletions and rearrangements.

CONCLUSIONS

This study indicates that UK Pan-1 is a highly tumorigenic cell line possessing a molecularly complex pattern of mutations that may be used as a model to further the understanding of the mechanisms responsible for the development of pancreatic carcinoma.

Differential expression of transforming growth factor beta receptors in human pancreatic adenocarcinoma

BACKGROUND

Many cancer cells show resistance to transforming growth factor beta (TGF-beta)-mediated growth inhibition. This resistance to TGF-beta is associated with an increased tumorigenic phenotype.

OBJECTIVE

In this study, we determined whether a loss in expression of TGF-beta receptors or DPC4, an important down stream target of TGF-beta signaling, might account for this lack of TGF-beta sensitivity in pancreatic adenocarcinoma.

MATERIALS AND METHODS

To accomplish this, six established pancreatic cancer cell lines, twenty-six surgically resected tumor specimens of pancreatic adenocarcinoma and ten non-tumor pancreas tissues were analyzed for the mRNA expression of the three TGF-beta receptors (RI, RII, and RIII) and DPC4.

RESULTS

We report here that five of six pancreatic cancer cell lines were not sensitive to TGF-beta. All the ten non-tumor specimens of pancreas showed expression of RI, and DPC4; while nine of ten showed expression of RIII and eight of ten showed expression of RII. Five of six pancreatic cancer cell lines and 23 of 26 tumor specimens showed expression of RI. Two cell lines and about half (46%) of the tumor specimens did not express RII. Only two cell lines showed appreciable levels of RIII expression; while ten of 26 (38%) tumor specimens did not show expression of RIII. DPC4 expression was observed in three of the six (50%) cell lines and 19 of 24 (79%) tumor specimens.

CONCLUSION

This study indicates that apart from the functional loss of DPC4 due to mutations or homozygous deletion, a lack of the TGF-beta receptors, particularly RII and RIII, may contribute to a loss of TGF-beta signaling in a population of pancreatic cancers.

High-dose spatially-fractionated radiation (GRID): a new paradigm in the management of advanced cancers

PURPOSE

With the advent of megavoltage radiation, the concept of spatially-fractionated (SFR) radiation has been abandoned for the last several decades; yet, historically, it has been proven to be safe and effective in delivering large cumulative doses (> 100 Gy) of radiation in the treatment of cancer. SFR radiation has been adapted to megavoltage beams using a specially constructed grid. This study evaluates the toxicity and effectiveness of this approach in treatment of advanced and bulky cancers.

METHODS AND MATERIALS

From January 1995 through March 1998, 71 patients with advanced bulky tumors (tumor sizes > 8 cm) were treated with SFR high-dose external beam megavoltage radiation using a GRID technique. Sixteen patients received GRID treatments to multiple sites and a total of 87 sites were irradiated. A 50:50 GRID (open to closed area) was utilized, and a single dose of 1,000-2,000 cGy (median 1,500 cGy) to Dmax was delivered utilizing 6 MV photons. Sixty-three patients received high-dose GRID therapy for palliation (pain, mass, bleeding, or dyspnea). In 8 patients, GRID therapy was given as part of a definitive treatment combined with conventionally-fractionated external beam irradiation (dose range 5,000-7,000 cGy) followed by subsequent surgery. Forty-seven patients were treated with GRID radiation followed by additional fractionated external beam irradiation, and 14 patients were treated with GRID alone. Thirty-one treatments were delivered to the abdomen and pelvis, 30 to the head and neck region, 15 to the thorax, and 11 to the extremities.

RESULTS

For palliative treatments, a 78% response rate was observed for pain, including a complete response (CR) of 19.5%, and a partial response (PR) of 58.5% in these large bulky tumors. A 72.5% response rate was observed for mass effect (CR 14.6%, PR 52.9%). The response rate observed for bleeding was 100% (50% CR, 50% PR) and for dyspnea, a 60% PR rate only. A relatively higher response rate (CR 23.3%, PR 60%) was observed in patients who received GRID treatment in the head and neck area. No grade 3 late skin, subcutaneous, mucosal, GI, or CNS complications were observed in any patient in spite of these high doses. In the 8 patients who received GRID treatment for definitive treatment, a clinical CR was observed in 5 patients (62.5%) and a pathological complete response was confirmed in the operative specimen in 4 patients (50%).

CONCLUSION

The efficacy and safety of using a large fraction of SFR radiation was confirmed by this study and substantiates our earlier results. In selected patients with bulky tumors (> 8 cm), SFR radiation can be combined with fractionated external beam irradiation to yield improved local control of disease, both for palliation and selective definitive treatment, especially where conventional treatment alone has a limited chance of success.

Hepatitis C viral load, genotype and histological severity in patients with bleeding disorders

We report the relationship between hepatitis C virus (HCV) titre, liver histology and HCV genotype in patients with bleeding disorders. One hundred and thirty-two RIBA-2-positive patients, including 56 who were also HIV positive, were identified at our centre. Fifty of these patients, including nine who were HIV infected, underwent percutaneous liver biopsy. Liver histology was assessed using a modified histological activity index (HAI). Qualitative serum HCV PCR was positive in 87 (87%) of the 101 patients tested including 43 of 50 biopsied patients. HCV RNA titres, measured by quantitative PCR, were significantly higher in HIV-positive patients compared with HIV-negative patients (P < 0.05) but were not related to HAI, mean factor concentrate usage, duration of HCV infection or HCV genotype. There was no relationship between HCV genotype and HAI. Qualitative HCV PCR was positive in 30 of 43 liver biopsies tested. Biopsy PCR-positive and -negative cohorts were not distinguished by HAI or serum HCV titre. We conclude that although serum HCV PCR is useful in confirming the presence of HCV infection in patients with bleeding disorders, little meaningful information concerning the severity of the disease can be obtained from serum HCV quantification.

Novel mutations in the polyadenine tract of the transforming growth factor beta type II receptor gene are found in a subpopulation of human pancreatic adenocarcinomas

In this study, we determined the incidence of microsatellite instability (MIN) in pancreatic adenocarcinoma and determined whether MIN might target, for mutations, the simple nucleotide repeats of the transforming growth factor beta type II receptor (TGFBR2) gene. Forty-eight surgically resected pancreatic tumor tissue samples and two normal pancreas tissue samples were analyzed in this study. Microsatellite analysis was performed for six loci in 14 of the 48 tumor specimens for which we had matching normal genomic DNA. Only four of the 14 tumors (29%) were MIN-positive as determined by the presence of microsatellite variations in more than one locus. Interestingly, eight of the 14 specimens (57%) showed microsatellite variations or loss of heterozygosity at D18S34, suggesting that this locus may be a critical region of genetic instability in pancreatic tumorigenesis. Of the 48 tumors, only two (4%) showed mutations in the polyA region, one of the MIN-targeted sites of the TGFBR2 gene. DNA sequence analysis of these two specimens showed the presence of a two-base deletion in one tumor specimen and the other tumor specimen showed a base substitution in the polyA tract at codon 128 of the TGFBR2 gene. The fact that these mutations occurred in the polyA tract of some pancreatic tumors suggests that a subpopulation of these tumors may be susceptible to MIN-targeted mutations. The incidence of these mutations are low and similar to that reported for nonhereditary, sporadic colon cancers.

Ionizing radiation-inducible apoptosis in the absence of p53 linked to transcription factor EGR-1

The tumor suppressor protein p53 is a pivotal regulator of apoptosis, and prostate cancer cells that lack p53 protein are moderately resistant to apoptotic death by ionizing radiation. Genes encoding the transcription factor early growth response-1 (EGR-1) and cytokine tumor necrosis factor-alpha (TNF-alpha) were induced upon irradiation of prostate cancer cells, and inhibition of EGR-1 function resulted in abrogation of both TNF-alpha induction and apoptosis. Induction of the TNF-alpha gene by ionizing radiation and EGR-1 was mediated via a GC-rich EGR-1-binding motif in the TNF-alpha promoter. Because TNF-alpha induces apoptosis in prostate cancer cells, these findings suggest that, in the absence of p53, ionizing radiation-inducible apoptosis is mediated by EGR-1 via TNF-alpha transactivation.