Comprehensive analysis of NiFe2O4/MWCNTs nanocomposite to degrade a healthcare waste - tetracycline.

Tetracycline (TC), a commonly used antibiotic for studying bacterial illnesses in living organisms, poses a significant risk to the aquatic environment. Despite various conventional methods having been attempted to remove TC antibiotics from water solutions, they have not proven effective. Consequently, the focus of the research is on the photocatalytic degradation of TC. According to the research, MWCNTs were successfully incorporated into NiFe2O4 nanoparticles, which reduced the pace at which charge carriers recombined after joining with MWCNTs. Subsequently, the catalyst's efficacy was assessed in a batch reactor by analyzing the weight percentage change of the nanocomposite, the initial concentration of TC antibiotics, the effects of pH and contact time. The identical operational parameters were employed to investigate the degradation of TC using NiFe2O4 and MWCNTs as individual pure materials. The findings indicated that the photocatalytic process using NiFe2O4/MWCNTs achieved a degradation efficiency of 95.8% for TC at a pH value of 9. This result was obtained after a reaction time of 120 minutes, the concentration of TC solution was 10 mg L-1, with a nanocomposite dose of 0.6 g L-1 of TN 04 and 120 W m-2. The pseudo-first-order approach was used to estimate the rate at which TC degrades. After four consecutive uses, it was observed that the photocatalysts maintained their original properties, with only a slight decrease of approximately 2.4% in the removal efficiency. The study demonstrated that the NiFe2O4/MWCNTs nanocomposite exhibited considerable efficiency in degrading TC. Due to its simple manufacture and useful recovery, it has the potential to function well as a catalyst for the removal and degradation of pharmaceutical organic contaminants.

Impact of dysprosium doped (Dy) zinc ferrite (ZnFe2o4) nanocrystals in photo- fenton exclusion of recalcitrant organic pollutant.

The issue of effluent, especially organic colorants from several manufacturing units overlays an immense delinquent of the current epoch owing to its effect on oncogenic health hazards. Thus, Rare Earth Metal dysprosium (Dy) doped Zinc Ferrite (ZnFe2O4) were as-synthesized by a facile co-precipitation technique as an effectual nano photocatalyst intended to the amputation of these noxious dyes. The structural, functional, optical, magnetic, and degradation properties of this RE (Dy3+) doped ions were investigated using various characterizations, such as crystallite size (D) and several parameters (cation distribution, oxygen positional parameters, and bond length) were determined using XRD (X-ray diffraction) and it was found that as the dy3+ ion concentration increases the speck size decreased and the grain size remained within nano regime, which intern affects the surface area. From BET analysis it was found that on increasing the doping concentration, the surface area increases which pave a substantial role in the photo-Fenton activity. By using FT-IR (Fourier-transform infrared spectroscopy) various functional parameters (elastic, interionic bonds, ion distribution, etc.) were determined. Raman spectra had no extra peak formation which is seen to have pure phase formation of the as-synthesized samples. HR-TEM (High-Resolution Transmission Electron Microscopy analysis were done to determine the nature of the sample, the as-synthesized magnetic samples exhibit a polycrystalline formation with cubical agglomeration. The magnetic property was very significant for x = 0.10 concentration. As-synthesized (Fe0.9064Zn0.0936) [Fe1.0936Dy0.1Zn0.8064] O4) exhibits a momentous photo - Fenton activity against MB (Methylene blue), its removal efficiency was found to be 97.3% after 45 min. Also, this spinel ferrite acts as a magnetic recyclable catalyst even after 5 cycles with an insignificant lessening of elements and photo-Fenton activity.

Exploring the influence of varying pH on structural, electro-optical, magnetic and photo-Fenton properties of mesoporous ZnFe2O4 nanocrystals.

An economically viable and superficial technique was indorsed to yield ZnFe2O4 nanocrystals in the system to investigate the impact of pH variation on the optical, structural, electrical, and magnetic properties of as-prepared nanocrystals. The as-synthesized ZnFe2O4 nanocrystals were premeditated with the application protracted to degradation of Methylene blue organic dye. The results specify that the pH plays the utmost decisive facet in photo-Fenton recital. From XRD (X-Ray diffraction) analyses, it was confirmed that as-synthesized nanocrystals belong to a cubic Fd3m crystal phase. The crystallite size was also determined by the Scherrer formula and it was noticed that as the pH rises the crystallite size also increased. FT-IR (Fourier Transform Infrared) analysis depicts two absorption peaks âˆ¼ 500 and ∼600 cm-1 that represents tetrahedral (Td) and octahedral (Oh) sites. Using TEM (Transmission Electron Microscopy), the morphology was observed to be spherical particles with some agglomeration. Photoluminescence and UV-visible spectral studies were performed to investigate the optical properties. The bandgap energy was seen to decrease as the pH increased. Using BET analysis, the surface area for the as-synthesized samples was found to decrease on increasing the pH. The reaction results showed that the ZnFe2O4 has good photocatalytic activity, which can be attributed to high surface area and pore volume, and large pore size. The ZnFe2O4 produced by the co-precipitation route exhibited promising photocatalytic activity for the removal of textile dye, reaching nearly 99.2% of decolorization at 100 min. Therefore, ZnFe2O4 particles rapidly prepared by the co-precipitation route have the potential for use in treatment of textile wastewater by the heterogeneous photo-Fenton process. With the help of VSM analysis, the coercivity and other magnetic properties were determined for the as-synthesized nanocrystal with plays a significant role in photocatalytic recyclability, which intends to premediate that the prepared nanocrystals can be used in industrial persistence.

Synthesis of titanium oxide nanoparticles using Aloe barbadensis mill and evaluation of its antibiofilm potential against Pseudomonas aeruginosa PAO1.

Titanium dioxide nanoparticles (TiO2-NPs) were synthesized using the aqueous leaf extract of Aloe barbadensis as a reducing and fabricating agent. The biosynthesis of the TiO2-NPs was initially confirmed by UV-vis spectroscopy. Based on the HRTEM and FESEM analysis, the biosynthesized NPs were found to be polydispersed and predominantly spherical in shape, with an average size of ~20 nm. A sharp and strong characteristic peaks of titanium (Ti) and oxygen (O) observed in the EDS pattern confirmed the synthesis of the TiO2-NPs. The FTIR spectroscopy suggested the presence of terpenoids, flavonoids and proteins which might be responsible for the biosynthesis and fabrication of the TiO2-NPs. The crystalline nature of the synthesized TiO2-NPs constituting of a mixture of brookite, anatase, and rutile phases was indicated by the XRD pattern. The spectral window around 180-1000 cm-1 covered the high-frequency Raman spectra of the TiO2-NPs. The Raman vibrational spectrum showed four Eg modes centered at 197.84, 399.24, 514.50, and 641.58 cm-1 representing the anatase phase of TiO2-NPs. The strongest and broadened peak of anatase was observed at the frequency of 641.58 cm-1. The metabolic activity of P. aeruginosa exposed to the MIC of TiO2-NPs was measured based on the reduction of tetrazolium salt by the dehydrogenase enzyme, produced by the metabolically active bacterial cells. The reduction in TTC was evident from the appearance of a red colored formazan in the solution. A noticeable suppression in the cell viability by 30.76 ±â€¯3.96% of P. aeruginosa in the biofilm mode was found in presence of TiO2-NPs. Furthermore, the Minimum Inhibitory Concentration (MIC) of TiO2-NPs exhibited profound antibiofilm activity against P. aeruginosa by effectively preventing the adherence of the planktonic cells to the substratum. Thus, these NPs may be employed in controlling bacterial infections associated with biofilm.

A low cost additive-free facile synthesis of BiFeWO6/BiVO4 nanocomposite with enhanced visible-light induced photocatalytic activity.

In this study, visible light driven BiFeWO6/BiVO4 nanocomposite was synthesized via simple additive-free wet-chemical process. Various physicochemical characterization methods such as X-ray diffraction (XRD), fourier transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electrons microscopy (TEM), energy dispersive spectroscopy (EDS) spectra, UV visible diffuse reflectance spectroscopy (DRS), photoluminescence (PL) and photoelectrochemical measurements were performed to examine the structure, surface morphology, electrochemical and optical behavior of the synthesized material. The photocatalytic performances of the as-synthesized materials were assessed by the photodegradation of methylene blue (MB) in visible-light illumination. The optimum BiFeWO6/BiVO4-2 nanocomposite has shown 95% degradation efficiency of (MB) after 90min. This is about 10-folds higher than that of pristine bismuth vanadate (BiVO4). This enhancement of photocatalytic performances is credited to the photogenerated electrons transfer from BiVO4 to BiFeWO6 catalyst surface and thereby reduced the recombination process. The higher photocatalytic activity, long-term stability and recyclability results have revealed that the BiFeWO6/BiVO4 nanocomposite could be an auspicious material for the elimination of organic contaminants present in the ecosystem. Moreover, a probable mechanism for the catalytic degradation of MB dye over BiFeWO6/BiVO4 system is also proposed based on experimental results.

Growth, thermal, dielectric and mechanical properties of L-phenylalanine-benzoic acid: a nonlinear optical single crystal.

An efficient amino acid family nonlinear optical single crystal L-phenylalanine-benzoic acid (LPB) was conveniently grown by slow evaporation technique at room temperature. The crystal system and the lattice parameters were analyzed by single crystal X-ray diffraction studies. The grown crystal has excellent transmission in the entire visible region and its lower cut-off wavelength was found to be 248 nm. The SHG efficiency of the grown crystal was found to be 1.6 times higher than that of KDP crystal. The Laser damage threshold value of LPB has been found to be 6.5 GW/cm(2). The sample was thermally stable up to 134°C. Microhardness, dielectric and AC/DC conductivity measurements were made along (001) plane and reported for the first time. Microhardness studies revealed that the sample belongs to hard nature. Frequency dependent dielectric constant was measured for different temperatures and found maximum dielectric constant of 14 for 363 K. Photoconductivity studies of LPB divulged its negative photoconducting nature.

Complete neurological recovery after delayed onset resuscitation in a normothermic witnessed arrest.

Cardiac arrest following aortic dissection carries high morbidity and mortality, primarily due to poor neurological outcomes. Most efforts are directed towards perfusing vital organs and replenishing oxygen and adenosine triphosphate (ATP) stores during and immediately after arrest. Methods of reperfusion (including external cardiopulmonary resuscitation (CPR), open CPR, extracorporeal life support and ventricular assist devices) and other ATP preservation methods, such as pharmaceutical agents and hypothermia, are maximally beneficial only if started early during cardiac arrest. We describe a case of aortic rupture with arrest on the table which was re-perfused after 20 minutes, using cardiopulmonary bypass (CPB), but still managed to recover without neurological sequelae.

Bi-spectral index, entropy and predicted plasma propofol concentrations with target controlled infusions in Indian patients.

OBJECTIVE: Many processed electroencephalographic signals are used now to help the anaesthesiologist titrate the depth of sedation. We investigated the relationship between target plasma propofol concentration and objective end-points of sedation- Bispectral Index (BIS), State Entropy (SE) and Response Entropy (RE)-at clinical end-points as assessed by Modified Observer Assessment of Alertness/sedation Scale (MOAAS) in Indian patients. METHODS: Eighteen ASA 1 and 2 Indian adult patients scheduled to undergo elective surgery were included. The target control infusion (TCI) of propofol was administered using 'Diprifusor'. The level of sedation was assessed using MOAAS by the anaesthesiologist. BIS, SE, RE were recorded throughout. TCI was started at 0.5 µg/ml and increased by 0.5 µg/ml every 6 min till MOAAS scores reached 0 or there was sustained BIS value less than 30. RESULTS: The EC(50) and EC(95) of predicted plasma propofol concentration for loss of consciousness (assessed by loss of response to verbal command), were 2.3 and 2.8 µg/ml respectively and for loss of response to painful stimuli (trapezius squeeze) were 4.0 and 5.0 µg/ml respectively. The BIS and entropy values (EC(50) and EC(95)) for loss of consciousness and response to painful stimuli in Indian patients were estimated. The preliminary relation of target plasma propofol concentration with BIS was found to be BIS = 100.5-16.4 × (Target concentration). CONCLUSIONS: The target plasma propofol concentrations required to produce unconsciousness and loss of response to painful stimuli in Indian patients have been estimated. Also, the relations between target plasma concentration and objective measures of different levels of anaesthesia have been established.

Closed-loop isoflurane administration with bispectral index in open heart surgery: randomized controlled trial with manual control.

OBJECTIVE: Improved anesthetic agent delivery system (IAADS), a modification of closed-loop anesthesia delivery system (CLADS), is designed to deliver inhalational anesthetics and propofol through closed-loop control with bispectral index (BIS) as target. We compared the performance of IAADS with the manual control isoflurane administration during cardiac surgery. METHODS: Forty patients of ASA (American Society of Anesthesiologists) physical status class II-III, undergoing elective cardiac surgery with cardiopulmonary bypass (CPB) in a tertiary care hospital in India were randomized to receive isoflurane through a closed-loop system (IAADS group) or through a Tech 7 vaporizer adjusted manually (manual group) to achieve a target BIS of 50. Patients were induced with a propofol infusion and isoflurane was started after intubation. During CPB, patients received propofol; isoflurane was restarted after separation from CPB. The efficacy of IAADS in controlling depth of anesthesia and hemodynamic variations was compared with that of manual control. RESULTS: IAADS was able to maintain BIS within ± 10 of target for significantly longer period (84.6 ± 7.2% in IAADS group vs. 75.9 ± 11.2 in manual group, p < 0.01). Both overall performance, as assessed by global score (p < 0.01), and precision, as judged by median absolute performance error (MDAPE) (p < 0.04), were significantly better in the IAADS group. The IAADS group required significantly less propofol for induction (1.3 ± 0.4 mg/kg in IAADS vs. 1.6 ± 0.5 mg/kg in manual, p < 0.05) and less isoflurane during maintenance of anesthesia (3.3 ± 0.8 ml/h vs. 3.4 ± 0.9 ml/h, p < 0.01). CONCLUSION: The present study proves the feasibility and efficacy of inhalation anesthetic administration through closed-loop control. This is the first system that has been developed to control intravenous and inhalational anesthetic agents in a closed-loop model using BIS.

A study on the resting preference of mosquito species in wells in Vellore in Tamilnadu, South India.

The resting preferences of mosquito species was investigated in domestic wells. In addition to the routine adult surveys in human dwellings, adult collections were also made in domestic wells using an innovated equipment operating on the principles of spray sheet collections. Above the water surface, wells provide humid and dark microclimate along the inner walls. It has been observed that this microclimate provides very congenial resting place for few mosquito species; specially for the males and for the females between their gonotropic cycles. Larval collections in the wells did not reveal breeding of majority of the mosquito species collected by this technique. Investigations were conducted in 87 wells in 11 localities during 2005. A total of 4969 mosquitos were collected of which 69.1% (3441) were males and 30.9% (1528) were females. From among the mosquitos collected 96.5% were Cu. quinquifasciatus, 0.26% All stephensi, 3.0% Aedes agypti and 0.24% Armegeres sp. The results of the analysis of the physical and chemical parameter of water samples of the study wells before and after the surveys endorsed the utility of this technique for entomological investigations in outbreak situations, for monitoring the liquidation of outbreak foci and for other research purposes.

CYP1A1m2 polymorphisms regulate estrogen and interleukin-6 in lung cancer.

Lung cancer, the most common cause of cancer-related death in men and women, is responsible for 1.3 million deaths worldwide annually. Women are diagnosed to a greater extent than men with adenocarcinoma and small cell carcinoma, both of which are secretory-type tumors. Never smokers diagnosed with lung cancer are also predominantly female, demonstrating the association of genetic factors with lung carcinogenesis. Several epidemiologic studies have associates certain CYP1A1 genotypes, alone or in combination, with an increased risk of estrogen-related cancer. The aim of this study was to investigate the impact of the CYP and GST polymorphisms along with estrogen and interleukin-6 (IL-6) levels on the risk of lung cancer. Eighty-six lung cancer patients and 60 controls were included in the study. A significantly higher frequency of polymorphisms in the genes was observed in lung cancer patients compared to controls. Mean estradiol concentration was reduced and IL-6 levels were elevated in patients compared to controls. In conclusion, increased polymorphisms in metabolic genes may be the reason for the reduced estradiol and, thereby, the increased expression of IL-6 in the serum of lung cancer patients.

Synthesis, growth and characterization of new borate-mixed crystals of type (NH4)1-xKxB5O8.

New borate-mixed crystals of type (NH4)1-x KxB5O8 were grown from aqueous solution by slow solvent evaporation method. The mixed crystals were confirmed by atomic absorption studies (AAS) and characterized by X-ray diffractometry (XRD), Fourier transform infrared (FT-IR), Fourier transform Raman (FT-Raman), optical absorption and solubility studies. The second harmonic generation efficiencies of the parent and mixed crystals were studied and compared with that of KDP.

Oral cancer detection using diffuse reflectance spectral ratio R540/R575 of oxygenated hemoglobin bands.

A low-cost, fast, and noninvasive method for early diagnosis of malignant lesions of oral mucosa based on diffuse reflectance spectral signatures is presented. In this technique, output of a tungsten halogen lamp is guided to the tissue through the central fiber of a reflection probe whose surrounding six fibers collects tissue reflectance. Ex vivo diffuse reflectance spectra in the 400 to 600-nm region is measured from surgically removed oral cavity lesions using a miniature fiber optic spectrometer connected to a computer. Reflectance spectral intensity is higher in malignant tissues and shows dips at 542 and 577 nm owing to absorption from oxygenated hemoglobin (HbO2). Measurements carried out, within an hour of surgical excision, on malignant lesion and adjoining uninvolved mucosa show that these absorption features are more prominent in neoplastic tissues owing to increased microvasculature and blood content. It is observed that reflectance intensity ratio of hemoglobin bands, R540/R575, from malignant sites are always lower than that from normal sites and vary according to the histological grade of malignancy. The diffuse reflectance intensity ratio R540/R575 of the hemoglobin bands appears to be a useful tool to discriminate between malignant lesions and normal mucosa of the oral cavity in a clinical setting.

Late scar recurrence in mucoepidermoid carcinoma of base of tongue.

Recurrence in mucoepidermoid carcinoma of the salivary gland after 15 years is rare and present difficult therapeutic decisions. A rare case of mucoepidermoid cancer of the base of the tongue that recurred loco-regionally after 20 years and was managed judiciously by a planned combined modality approach is presented.

Altered expression of jack fruit lectin specific glycoconjugates in benign and malignant human colorectum.

Lectins bind to terminal non reducing sugars of glycoconjugates in cell membranes and secretions. These glycoproteins can be very characteristic, both for the differentiation state of a tissue and for its grade of malignancy. The carbohydrate structures of cellular glycoconjugates in normal, adenoma, and carcinoma of human colorectum were analysed using HRP conjugated Jack Fruit Lectin (JFL). Fifty two rectal carcinomas, 18 adenomas and 25 normal rectal tissues were used for the study. Diaminobenzidine (DAB) was used as the visualant. Normal rectal tissues showed positive reaction with intense staining in more than 60% of the cells. Adenomas were seen to have moderate to intense staining with a range of 30 to 60% positive cells. The lowest levels of JFL staining were observed in invasive tumours. JFL binding was found to decrease with carcinomatous cells compared to adenomas and normal cells. A significant negative association was found between JFL binding and histologic abnormality (r = -0.85, P <0.0000). These results suggest that there are alterations in the carbohydrate structures of cellular glycoconjugates, which can be related to goblet cell differentiation, in normal, benign and malignant human colorectal tissue.

Deficient DNA repair capacity: a predisposing factor and high risk predictive marker in familial colorectal cancer.

Even though colorectal cancer tends to aggregate in families, there is paucity of information on the genetic determinism for familial colorectal cancer (FCRC) predisposition. Therefore, we investigated constitutional chromosome abnormalities and bleomycin induced chromosome sensitivity of 26 familial and 30 sporadic colorectal cancer (SCRC) patients, 60 unaffected family members (first/second degree relatives) and 30 normal healthy controls to determine whether these parameters could give any clues on genetic predisposing factors by which high risk members in CRC families could be identified. The test assay used bleomycin-induced chromatid breaks in short term microcultures of peripheral blood lymphocytes of the subjects. The CRC patients, the unaffected family members and the controls did not show any constitutional chromosomal abnormalities. However, with regard to bleomycin sensitivity, there was significant difference between the CRC patients, unaffected relatives and controls. The mean b/c values of 1.64+/-0.42 for the FCRC patients and 1.08+/-0.34 for the SCRC patients were significantly higher than the mean b/c values of 0.62+/-0.18 for the unaffected relatives and 0.52+/-0.12 for the controls (P<0.001). A noteworthy observation was that 6 unaffected members from 6 CRC families also showed bleomycin hypersensitivity, at the initiation of the study. Since they expressed mean b/c values greater than 1.0, which was as high a value as those of the patients, they were regularly followed up. Out of these 6 members, 2 developed CRC later. This clearly demonstrates that mutagen hypersensitivity among unaffected relatives in CRC families may be related to cancer predisposition. Hence, this cytogenetic assay could be utilised to identify the genetically high risk individuals in CRC families.

Spontaneous programmed cell death in infiltrating duct carcinoma: association with p53, BCL-2, hormone receptors and tumor proliferation.

Recent evidence has emphasized the importance of programmed cell death or apoptosis in the maintenance of tissue homeostasis and pathogenesis of tumors. This study, analyzed in breast cancer, investigates the significance of apoptosis in relation to the expression of p53 and bcl-2 proteins, tissue proliferation defined by Ki-67 expression, hormone receptors and tumor grade. The extent of apoptosis was defined by morphological criteria and the TUNEL (Tdt-mediated dUTP biotin nick end labelling) assay. Immunocytochemistry was performed for p53, bcl-2, estrogen receptor, progesterone receptor and Ki-67 expression. Mutant p53 protein was detected using a mutant specific ELISA. Immunoreactivity of p53 significantly correlated with the presence of mutant p53 protein detected by ELISA (r = 0.654, p = 0.00001). An inverse correlation was observed between bcl-2 expression and the extent of apoptosis (r = -0.33369, p = 0.01912). The extent of apoptosis directly correlated with p53 protein accumulation (r = 0.485, p = 0.00041), Ki-67 immunoreactivity (r = 0.435, p = 0.001), histopathological grade (r = 0.492, p = 0.0003), tumor size (r = 0.326, p = 0.023) and lymph node status (r = 0.287, p = 0.047). A direct correlation was also observed between p53 expression and Ki-67 immunoreactivity (r = 0.623, p = 0.0002). There was no statistically significant association between estrogen and progesterone receptor status and apoptosis. In addition, the TNM stage of the disease correlated with immunoreactivity of p53 (r = 0.572, p = 0.00012) and Ki-67 (r = 0.3744, p = 0.00818). Bcl-2, by inhibiting apoptosis, may cause a shift in tissue kinetics towards the preservation of genetically aberrant cells, thereby facilitating tumor progression. These results imply that rapidly proliferating tumors appear to have a high "cell turnover state" in which there may be an increased chance of apoptosis amongst the proliferating cells. The ability of apoptosis to also occur in the presence of mutant p53 protein suggests the existence of at least two p53-dependent apoptotic pathways, one requiring activation of specific target genes and the other independent of it.

DNA repair proficiency: a potential marker for identification of high risk members in breast cancer families.

Breast cancer is the single largest cancer and causes the high rate of cancer mortality among women. A positive family history of breast cancer is recognized as one of the major risk factors for this disease. The present study evaluates bleomycin (BLM)-induced chromosome sensitivity analysis in breast cancer families which provides indirectly a measure of the DNA repair defect of each person. BLM sensitivity assay on cultured lymphocytes of 36 familial breast cancer patients, their 85 first or second degree female relatives, 36 sporadic breast cancer patients and 40 age- and sex-matched controls (without any family history of cancer) were carried out to measure interindividual variation in their DNA repair capacity through mutagen-induced chromosome sensitivity analysis. Fifty percent of familial breast cancer patients and seven unaffected relatives showed hypersensitivity. Compared to hyposensitive relatives these seven subjects may be considered as high risk individuals.

p53 tumor suppressor protein and tissue proliferative fraction in infiltrating duct carcinoma.

BACKGROUND AND OBJECTIVES: Breast cancer continues to frustrate oncologists worldwide. In India, it is the second most common neoplasm among women and is increasing in incidence. Several molecular markers have been associated with a poor prognosis in patients with breast cancer, and the presence of these markers is often thought to provide information on the biological behavior of the malignant breast tumor. Much attention has recently been focused on the tumor suppressor gene p53. Mutation or alteration in this gene leads to the loss of negative growth regulation and hence to rapid cell proliferation. The present study was designed to evaluate the connection between expression of the p53 protein and its relation to the tissue proliferative compartment as measured by expression of the proliferating cell nuclear antigen (PCNA). METHODS: Expression of p53 and PCNA were detected by immunocytochemistry in paraffin-embedded sections of infiltrating duct carcinoma and control breast tissue (normal tissue and adenoma). RESULTS: A significant correlation was observed between expression of p53 and PCNA. A significant correlation was also observed between expression of p53 and grade of tumor and stage of disease. CONCLUSIONS: Our results support the hypothesis that accumulation of p53 is associated with a high tumor proliferation rate an association that might be expected in view of the role of wild p53 as a negative regulator of cell proliferation.

Conservative surgery and radiotherapy in the treatment of spinal cord astrocytoma.

Spinal cord astrocytomas are rare neoplasms, and optimal treatment guidelines are undefined, 23 patients with spinal cord astrocytomas were treated between 1984 and 1993 with conservative surgery and postoperative radiotherapy. The mean age was 31 years. Twelve patients were male and eleven female. All patients presented with neurologic deficit. Cervical cord was involved in five patients, cervicothoracic in four, thoracic in eight and thoracolumbar in six. Five patients had intramedullary cysts. Fifteen patients had low grade tumors and six high grade. Surgery was near total excision in three patients, partial excision in ten and biopsy in ten patients. All patients received postoperative radiotherapy to a median dose of 45 Gy in 25 fractions over 5 weeks. The median followup was 51 months (range 7-143 months). At 6 months post radiotherapy, twelve patients had improvement of neurologic status, nine had stable status, and two deteriorated. The actuarial overall survival was 55% at 5 years and 39% at 10 years. The actuarial progression free survival probability was 75% at 5 years and 55% at 10 years. Five patients had local failure and two failed at distant sites. Twelve patients died, six due to progressive disease, five due to complications of paraplegia and one patient of unrelated causes. Tumor grade was a significant prognostic factor for overall survival. 5 year overall survival was 79% for low grade tumors. No patient with high grade tumor survived more than 2 years and the median survival was 10 months. Low grade, female sex and presence of intramedullary cysts were associated with significantly improved progression free survival. Conservative surgery followed by radiotherapy appears to have a role in achieving tumor control and neurologic recovery in patients with low grade astrocytomas of the spinal cord. Treatment results of high grade tumors remain poor and new therapeutic strategies need to be studied.