Biomedical subjects
M Thomas
Publications and source records attributed to M Thomas.
Biological control of locusts and grasshoppers.
Control of grasshoppers and locusts has traditionally relied on synthetic insecticides, and for emergency situations this is unlikely to change. However, a growing awareness of the environmental issues associated with acridid control as well as the high costs of emergency control are expanding the demand for biological control. In particular, preventive, integrated control strategies with early interventions will reduce the financial and environmental costs associated with large-scale plague treatments. The recent development of effective oil formulations of Metarhizium anisopliae spores in Africa, Australia, and Brazil opens new possibilities for environmentally safe control operations. Metarhizium biopesticide kills 70%-90% of treated locusts within 14-20 days, with no measurable impact on nontarget organisms. An integrated pest management strategy, with an emphasis on the use of Metarhizium, that incorporates rational use of chemical pesticides with biological options such as the microsporidian Nosema locustae and the hymenopteran egg parasitoids Scelio spp., has become a realistic option.
Final height in children with idiopathic growth hormone deficiency treated with recombinant human growth hormone: the Belgian experience.
BACKGROUND: The growth response to recombinant hGH (rhGH) treatment and final height of 61 Belgian children (32 boys) with idiopathic growth hormone deficiency (GHD) were studied. PATIENTS/METHODS: Two patient groups were compared: Group 1 with spontaneous puberty (n = 49), Group 2 with induced puberty (n = 12). The patients were treated with daily subcutaneous injections of rhGH in a dose of 0.5-0.7 IU/kg/week (0.17-0.23 mg/kg/week) from the mean +/- SD age of 11.9 +/- 3.1 years during 5.1 +/- 2.1 years. RESULTS: rhGH treatment induced a doubling of the height velocity during the first year and resulted in a normalisation of height in 53 (87%) patients. Final height was -0.7 +/- 1.1 SDS, being 170.4 +/- 7.2 cm in boys and 158.0 +/- 6.4 cm in girls. Corrected for mid-parental height, final height was 0.0 +/- 1.1 SDS. Ninety-two percent of the patients attained an adult height within the genetically determined target height range. Although height gain during puberty was smaller in the patients with induced puberty (boys: 17.1 +/- 7.0 cm vs. 27.5 +/- 6.6 cm (p < 0.005); girls: 9.6 +/- 7.4 cm vs. 22.2 +/- 6.1 cm (p < 0.005)), no differences in final height after adjustment for mid-parental height were found between patients with spontaneous or induced puberty. CONCLUSIONS: We conclude that patients with idiopathic GHD treated with rhGH administered as daily subcutaneous injections in a dose of 0.5-0.7 IU/kg/week reach their genetic growth potential, resulting in a normalisation of height in the majority of them, irrespective of spontaneous or induced puberty.
Mucinous and nonmucinous bronchioloalveolar adenocarcinomas have distinct staining patterns with thyroid transcription factor and cytokeratin 20 antibodies.
We studied 14 mucinous and 26 nonmucinous bronchioloalveolar adenocarcinomas (BACs) with thyroid transcription factor (TTF), cytokeratin (CK) 7, CK20, and villin to characterize their staining patterns with these antibodies and identify staining differences between the neoplasms. We also stained 11 mucinous colon adenocarcinomas with the same antibodies to compare their reaction patterns with mucinous BACs. All pulmonary neoplasms were confirmed pulmonary primary BACs. Three (21%) of 14 mucinous neoplasms had weak TTF reactivity in fewer than 25% of neoplastic cell nuclei, and the other 11 (79%) were nonreactive. In contrast, 24 (92%) of 26 nonmucinonus BACs were strongly TTF reactive. Eleven mucinous BACs (79%) had CK20 reactivity in more than 25% of neoplastic cells, whereas only 1 nonmucinous BAC (4%) had reactivity in fewer than 50% of the cells. One mucinous BAC (7%) had villin reactivity in approximately 10% of the neoplastic cells. All mucinous colon adenocarcinomas were diffusely reactive with CK20 and villin. Mucinous and nonmucinous BACs have disparate staining patterns with TTF and CK20. Mucinous BACs are usually TTF nonreactive and CK20 reactive, but nonreactive with villin, which distinguishes them from mucinous colon adenocarcinomas.
Grading of tumor regression in non-small cell lung cancer : morphology and prognosis.
OBJECTIVE: Different types of multimodality therapy, including chemoradiotherapy and surgery, increasingly are being used for the treatment of patients with locally advanced non-small cell lung cancer (NSCLC; stages IIIA and IIIB). In this context, the applicability of a morphologic regression grading and its prognostic value were investigated. PATIENTS AND METHODS: In a multicenter phase II trial, 54 patients with locally advanced NSCLC received neoadjuvant bimodality treatment (ie, two cycles of ifosfamide, carboplatin, and etoposide, followed by twice-daily radiation up to 45 Gy with simultaneous administration of carboplatin and vindesine). Forty patients underwent resections. Using the corresponding resection specimens of the primary and regional lymph nodes, the following regression grading was established: grade I, no regression or only spontaneous tumor regression; grade II, morphologic evidence of therapy-induced tumor regression with at least 10% (grade IIa) or < 10% (grade IIb) vital tumor tissue; and grade III, complete tumor regression with no evidence of vital tumor tissue. Regression grading then was correlated with the survival time. RESULTS: Three tumors were classified as regression grade I, 10 were classified as regression grade IIa, 20 were classified as regression grade IIb, and 7 were classified as regression grade III. Patients with tumors of regression grades IIb or III showed significantly longer survival times than those with tumors of regression grades I or IIa (median survival time, 36 vs 14 months, respectively; 3-year survival rate, 52% vs 9%, respectively; p = 0.02). These survival times were also compared for patients who had undergone complete resection (median survival time, not reached vs 23 months, respectively; 3-year survival rate, 56% vs 11%, respectively; p = 0.03). The presurgical clinical response after patients had received neoadjuvant multimodality therapy had no predictive value in assessing the extent of therapy-induced tumor regression in the resection specimen. CONCLUSIONS: After neoadjuvant therapy of patients with NSCLC, the proposed tumor regression grading was of predictive value for long-term survival. Beyond the achievement of complete tumor resection (R0), a therapy-induced tumor regression of < 10% of vital tumor tissue is pivotal for superior long-term outcomes.
Natural history of lower respiratory tract illness.
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Performance of the full-scale biological nutrient removal plant at Noosa in Queensland, Australia: nutrient removal and disinfection.
Stringent effluent quality guidelines are progressively implemented in coastal and sensitive areas in Australia. Biological Nutrient Removal (BNR) plants are becoming a standard often including a tertiary treatment for disinfection. The BNR plant in Noosa - Queensland is designed to produce a treated effluent with less than 5 mg/l of BOD5, 5 mg/l of total nitrogen, 1 mg/l of total phosphorus, 5 mg/l of suspended solids and total coliforms of less than 10/100 ml. A flexible multi-stage biological process with a prefermentation stage, followed by sand filtration and UV disinfection was implemented to achieve this level of treatment. Acetic acid is added for phosphorus removal because: i) the volatile fatty acids (VFA) concentration in raw wastewater varies a lot, and ii) the prefermenter had to be turned off due to odor problems on the primary sedimentation tanks. An endogenous anoxic zone was added to the process to further reduce the nitrate concentration. This resulted in some secondary P-release events, a situation that happens when low nitrate and low phosphorus objectives are targeted. Long-term performance data and specific results on nitrogen removal and disinfection are presented in this paper.
Late presentation of congenital factor V deficiency--a case report.
Congenital factor deficiency is a rare coagulation disorder, which is inherited in an autosomal recessive manner. The severity of bleeding symptoms in general is only partially related to the degree of factor V deficiency in plasma. In this report, a boy presenting with hemarthrosis in his late adolescence due to congenital factor V deficiency is reported.
MEFV mutations and phenotype-genotype correlations in North African Jews and Armenians with familial Mediterranean fever.
BACKGROUND: Familial Mediterranean fever is a genetic disease in which some characteristic gene mutations have been found. OBJECTIVES: To analyze the phenotype-genotype correlations in North African Jews and Armenians with FMF. METHODS: We studied MEFV gene mutations and phenotype-genotype correlations in North African Jews and Armenians with Familial Mediterranean Fever living in France. RESULTS: M694V mutation was the most common mutation in Jews and in Armenians. Patients with M680I homozygosity or M680I/M694V compound heterozygosity had a phenotype as severe as patients with M694V homozygosity. CONCLUSIONS: This study characterizes the phenotype-genotype in specific ethnic groups of patients with FMF.
Superstition and fatal diabetic foot.
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Myostatin, a negative regulator of muscle growth, functions by inhibiting myoblast proliferation.
Myostatin, a member of the transforming growth factor-beta (TGF-beta) superfamily, has been shown to be a negative regulator of myogenesis. Here we show that myostatin functions by controlling the proliferation of muscle precursor cells. When C(2)C(12) myoblasts were incubated with myostatin, proliferation of myoblasts decreased with increasing levels of myostatin. Fluorescence-activated cell sorting analysis revealed that myostatin prevented the progression of myoblasts from the G(1)- to S-phase of the cell cycle. Western analysis indicated that myostatin specifically up-regulated p21(Waf1, Cip1), a cyclin-dependent kinase inhibitor, and decreased the levels and activity of Cdk2 protein in myoblasts. Furthermore, we also observed that in myoblasts treated with myostatin protein, Rb was predominately present in the hypophosphorylated form. These results suggests that, in response to myostatin signaling, there is an increase in p21 expression and a decrease in Cdk2 protein and activity thus resulting in an accumulation of hypophosphorylated Rb protein. This, in turn, leads to the arrest of myoblasts in G(1)-phase of cell cycle. Thus, we propose that the generalized muscular hyperplasia phenotype observed in animals that lack functional myostatin could be as a result of deregulated myoblast proliferation.
Screening for asymptomatic early bronchogenic carcinoma with low dose CT of the chest.
BACKGROUND: Survival of patients with lung carcinoma is very poor, particularly for patients with advanced disease. There are no early clinical symptoms, and screening with chest radiography has not been recommended. Computed tomography (CT) is superior to radiography for detection of pulmonary nodules but usually is associated with relatively high radiation exposure. Recently, accuracy of low dose CT has been shown to be similar to conventional dose CT. The goal of the current study was to assess the findings of low dose CT of the chest in heavy smokers. METHODS: More than 700 heavy smokers (> 20 pack years; age: > 40 years) underwent unenhanced low dose CT of the chest. Detected nodules were classified according to their density (soft tissue, calcified, fat) and size (< 6 mm, 6-10 mm, > 10 mm). In nodules larger than 10 mm with no CT features to suggest a benign lesion, histology was obtained. RESULTS: In approximately 40% of smokers, nodules smaller than or equal to 10 mm were detected. None was resected. In less than 3% of individuals, lesions larger than 10 mm were detected; 8 were bronchogenic carcinoma. All eight carcinomas were resectable. Lesions for which no histology was obtained were followed with low dose CT. CONCLUSIONS: Low dose CT detected 8 bronchogenic carcinomas in more than 700 heavy smokers. All eight were resectable. Pulmonary nodules measuring up to 10 mm were found in 40% of smokers. The significance of these small lesions has remained unclear.
Role of Bak in UV-induced apoptosis in skin cancer and abrogation by HPV E6 proteins.
Ultraviolet B (UVB) damage is recognized as the most important etiological factor in the development of skin cancer. Human papillomaviruses (HPV) have also been implicated in the disease, although the mechanism of action of these viruses remains unknown. We present evidence here that Bak protein is involved in signaling apoptosis in the skin in response to UVB damage, and that cutaneous HPV E6 proteins target and abrogate Bak function by promoting its proteolytic degradation both in vitro and in regenerated epithelium. Additionally, HPV positive skin cancers had undetectable levels of Bak in contrast to HPV negative cancers, which expressed Bak. This study supports a link between the virus and UVB in the induction of HPV-associated skin cancer and reveals a survival mechanism of virally infected cells.
Interactions of the PDZ-protein MAGI-1 with adenovirus E4-ORF1 and high-risk papillomavirus E6 oncoproteins.
The oncoproteins of small DNA tumor viruses promote tumorigenesis by complexing with cellular factors intimately involved in the control of cell proliferation. The major oncogenic determinants for human adenovirus type 9 (Ad9) and high-risk human papillomaviruses (HPV) are the E4-ORF1 and E6 proteins, respectively. These seemingly unrelated viral oncoproteins are similar in that their transforming activities in cells depend, in part, on a carboxyl-terminal PDZ domain-binding motif which mediates interactions with the cellular PDZ-protein DLG. Here we demonstrated that both Ad9 E4-ORF1 and high-risk HPV E6 proteins also bind to the DLG-related PDZ-protein MAGI-1. These interactions resulted in MAGI-1 being aberrantly sequestered in the cytoplasm by the Ad9 E4-ORF1 protein or being targeted for degradation by high-risk HPV E6 proteins. Transformation-defective mutant viral proteins, however, were deficient for these activities. Our findings indicate that MAGI-1 is a member of a select group of cellular PDZ proteins targeted by both adenovirus E4-ORF1 and high-risk HPV E6 proteins and, in addition, suggest that the tumorigenic potentials of these viral oncoproteins depend, in part, on an ability to inhibit the function of MAGI-1 in cells.
Tracing European founder lineages in the Near Eastern mtDNA pool.
Founder analysis is a method for analysis of nonrecombining DNA sequence data, with the aim of identification and dating of migrations into new territory. The method picks out founder sequence types in potential source populations and dates lineage clusters deriving from them in the settlement zone of interest. Here, using mtDNA, we apply the approach to the colonization of Europe, to estimate the proportion of modern lineages whose ancestors arrived during each major phase of settlement. To estimate the Palaeolithic and Neolithic contributions to European mtDNA diversity more accurately than was previously achievable, we have now extended the Near Eastern, European, and northern-Caucasus databases to 1,234, 2, 804, and 208 samples, respectively. Both back-migration into the source population and recurrent mutation in the source and derived populations represent major obstacles to this approach. We have developed phylogenetic criteria to take account of both these factors, and we suggest a way to account for multiple dispersals of common sequence types. We conclude that (i) there has been substantial back-migration into the Near East, (ii) the majority of extant mtDNA lineages entered Europe in several waves during the Upper Palaeolithic, (iii) there was a founder effect or bottleneck associated with the Last Glacial Maximum, 20,000 years ago, from which derives the largest fraction of surviving lineages, and (iv) the immigrant Neolithic component is likely to comprise less than one-quarter of the mtDNA pool of modern Europeans.
Differences in the pathologic features of ductal carcinoma in situ of the breast based on patient age.
BACKGROUND: Young patient age at diagnosis has been reported as a risk factor for recurrence in patients with ductal carcinoma in situ (DCIS) of the breast treated with breast-conserving therapy (BCT). The authors examined pathologic features of DCIS in three different age groups of patients to identify differences that might explain why young patient age at the time of diagnosis is a risk factor for recurrence. METHODS: Excised specimens from 177 breasts of 172 patients with DCIS treated with BCT were studied. All slides from all specimens were reviewed. Patients were divided into 3 age groups: those age < 45 years, those ages 45-59 years, and those age >/= 60 years. The histologic features that were quantified included most common and highest nuclear grades, DCIS architectural pattern, amount of central necrosis (quartiles), calcifications, amount of DCIS, and number of terminal duct lobular units (TDLUs) with cancerization of lobules (COL) within 0.42 cm of the margin, margin status, and size and volume of excision specimens. RESULTS: Patients age < 45 years at the time of diagnosis more frequently had higher nuclear grade DCIS (highest nuclear Grade 3: 69%, 60%, and 39%; P = 0.003), respectively and central necrosis (72%, 62%, and 44%; P = 0. 01), respectively. Although not statistically significant, younger patients tended to have comedo subtype DCIS more often (31%, 23%, and 19%; P = 0.35), respectively. Younger patients also more often had smaller initial biopsy specimen maximum dimensions (4.3 cm, 5.2 cm, and 5.7 cm; P = 0.004), respectively, with close or positive margins (89%, 61%, and 64%; P = 0.03), and more TDLUs with COL in the 0.42-cm rim of tissue adjacent to the margin (5.2, 3.6, and 1.9; P = 0.23), respectively. No other features including the amount of DCIS when classified as > 50% or > 75% of ducts, calcifications within DCIS ducts, pattern of DCIS involvement, number of slides examined, number of slides with DCIS, and mean number of DCIS ducts near the margin were found to occur more frequently in younger patients. CONCLUSIONS: Younger patients with DCIS may have an increased risk of local recurrence when treated with BCT due to smaller initial excision volumes, a greater proportion of high nuclear grade DCIS, and central necrosis.