The Use of Data Mining for Obtaining Deeper Insights into the Fabrication of Prednisolone-Loaded Chitosan Nanoparticles

The present work explores a data mining approach to study the fabrication of prednisolone-loaded chitosan nanoparticles and their properties. Eight PLC formulations were prepared using an automated adaptation of the antisolvent precipitation method. The PLCs were characterized using dynamic light scattering, infrared spectroscopy, and drug release studies. Results showed that that the effective diameter, loading capacity, encapsulation efficiency, zeta potential, and polydispersity of the PLCs were influenced by the concentration and molecular weight of chitosan. The drug release studies showed that PLCs exhibited significant dissolution enhancement compared to pure prednisolone crystals. Principal components analysis and partial least squares regression were applied to the infrared spectra and the DLS data to extract higher-order interactions and correlations between the critical quality attributes and the diameter of the PLCs. Principal components revealed that the spectra clustered according to the type of material, with PLCs forming a separate cluster from the raw materials and the physical mix. PLS was successful in predicting the ED of the PLCs from the FTIR spectra with R2 = 0.98 and RMSE = 27.18. The present work demonstrates that data mining techniques can be useful tools for obtaining deeper insights into the fabrication and properties of PLCs, and for optimizing their quality and performance. It also suggests that FTIR spectroscopy can be a rapid and non-destructive method for predicting the ED of PLCs.

Efficiency of natural oils as alternative adjuvants to mineral oils in inactivated avian influenza vaccine formulation

1. The effectiveness of inactivated vaccines depends on selecting the suitable adjuvant for vaccine formulation. The potency of vaccines with low antigen content can be improved with the appropriate adjuvant. This could allow production of more doses and lower the production cost.2. This study evaluated the efficiency of vaccines prepared using oil extracted from natural sources including argan oil, almond oil, sesame seed oil, pumpkin oil, cactus oil and black seed oil as alternative adjuvants for improving the protection capacity of inactivated influenza virus vaccine as compared to commonly used mineral oils.3. Each vaccine formulation was evaluated for stability, safety and immunogenicity in chickens, as well as for reducing the viral shedding after challenge infection.4. The cactus, sesame and pumpkin seed oil-based vaccines were found to be potent and successfully induced the production of humoral immunity in vaccinated chickens.

Outcome of conventional radiotherapy in small centrally located tumours or lymph nodes: minimal toxicity, remarkable survival but challenging loco-regional control

BACKGROUND

In peripheral lung tumours, stereotactic body radiotherapy (SBRT) is superior to conventional RT. SBRT has also shown high loco-regional control (LC) in centrally located tumours, but there is a high risk of severe toxicity. The STRICTSTARLung trial (NCT05354596) examines if risk-adapted SBRT for central tumours is feasible. In this study, we examined overall survival (OS), Disease-free survival (DSF), LC, and toxicity in patients with central tumours that could have been candidates for SBRT but received conventional RT.

MATERIAL AND METHODS

Retrospectively, we evaluated 49 lung cancer patients that between 2008 and 2021 received RT (60-70Gy in 2 Gy fractions) for a solitary tumour or lymph node with a diameter <5cm located <2cm from the bronchial tree, oesophagus, aorta or heart. All tumours were pathologically verified; 30 were primary lung tumours (T1b-T4) and 19 were solitary lymph nodes (T0N1-N2). Chemotherapy was administered as concomitant (29) or sequential (4). OS and LC were analysed using Kaplan Meier. Cox proportional hazards model for OS and disease-free survival (DFS) was performed including tumour volume, histology, sex, T- vs N-site and chemotherapy. Toxicity was scored.

RESULTS

In 42 patients, the tumour was located <1 cm to mediastinum. Median follow-up time was 44 months (range: 7-123). The median OS was 51 months. OS at 1-, 3- and 5-year was 88% (SE:5), 59% (SE:7) and 50% (SE:8). Loco-regional recurrences occurred in 16 patients resulting in 1-, and 3-year LC rates of 77% (SE:6) and 64% (SE:8). The majority occurred within 3 years after RT. Only stage showed significant impact on OS and DFS. No patients experienced grade 4-5 toxicity. Seven patients developed grade 3 toxicity (5 oesophageal stenosis, 2 pneumonitis).

CONCLUSION

Conventional RT for patients with small central lung tumours or solitary lymph nodes is feasible. Median OS was 51 months, and toxicity was low with no grade 4-5 events.

Detecting Lung Cancer Stages Earlier By Appropriate Markers Rather Than Biopsy And Other Techniques

Introduction/Objective

Early detection of lung cancer stages is deeply under consideration of scientists. By day, high rate of mortality might be caused by cancer of lung over the world. The biopsy is still the golden standard as a histological predictor to determine lung cancer worldwide. However, a biopsy has various complications and hardness especially in collecting tissue samples. Therefore, detecting appropriate tools to determine the early stages of lung cancer is urgently needed. Some biomarkers levels have been determined in patient’s serum. The correlation between studied biomarkers and lung cancer has been studied by current research to avoid biopsy and other techniques.

Methods

The various biomarkers such as (CEA, SCCA, CYFRA21-1, ProGRP, Prolactin and CKAP4) were measured and calculated in 379 infected cases with lung cancer. Also, the same parameters were determined in 113 healthy persons as controls. Alternative markers’ levels were determined by using ELISA technique. Noninvasive markers were approved by comparison with CT chest scan and Biopsy techniques.

Results

Our research has indicated that Some of the studied biomarkers such as cytoskeleton-associated protein 4 (CKAP4), pro-gastrin-releasing peptide (ProGRP) and Prolactin (PRL) have high sensitivity from 77.05% to 96.72% and accuracy from 89.71% to 97.79% as well as their cut off which approved the aim of this study. However, other indicators (CEA, SCCA and CYFRA21-1) have low sensitivity from 62.49 % to 87.31% and accuracy between 71.27 % and 88.43 %. Meanwhile, CT scan has high sensitivity around 83% with specificity about 71%.

Conclusion

Alternative biomarkers (CEA, SCCA, CYFRA21-1, ProGRP, Prolactin and CKAP4) are considered as prospective markers to differentiate healthy individuals from lung cancer disease by their significant results in early stages detection. Thence, if serum CEA, SCCA, CYFRA21-1, ProGRP, Prolactin and CKAP4 are measured together, it would be the precise criterion of early levels of lung cancer rather than the lung biopsy definitely. However, further researches are needed to prove more reliable noninvasive markers of lung cancer.

Sodium Orthovanadate Inhibits Proliferation and Triggers Apoptosis in Oral Squamous Cell Carcinoma in vitro

Sodium orthovanadate (SOV) is a general inhibitor of tyrosine phosphatases, a large family of enzymes that catalyze the removal of phosphate groups from tyrosine residues. SOV is commonly used in the laboratory to preserve the protein tyrosyl phosphorylation state of proteins under study. It has shown promising antineoplastic activity in some human cancer cell lines; this effect has not been fully investigated in head and neck squamous cell carcinoma. In this study, the effect of SOV on cell growth, proliferation, viability, and apoptosis was assessed in Cal27 cells, an oral squamous cell carcinoma (OSCC) cell line. SOV exhibited dose-dependent inhibition of cell growth and decrease in cell viability and colony formation. The IC₅₀ values for treatment lasting 72 h and 7 days were 25 and 10 µM, respectively. The cytotoxic effect of the drug was associated with poly(ADP-ribose)polymerase cleavage detected by immunoblot. Flow cytometry of Cal27 cells stained with annexin V-FITC and propidium iodide showed a dose-dependent increase in apoptosis that reached approximately 40% at 25 µM SOV. These findings demonstrate that SOV has in vitro antiproliferative and proapoptotic effect on OSCC cells.

Design, synthesis and evaluation of some novel pyrazoline derivatives as potential anti-inflammatory and antitumor agents

A new series of pyrazoline derivatives was designed and synthesized with the objective of developing agents with anti-inflammatory activity together with chemoprevention of hepatobiliary malignancies. The prepared compounds were evaluated for their anti-inflammatory activity using carrageenan-induced granuloma bioassay, using celecoxib as a reference drug. Ulcerogenic effect and acute toxicity profiles (ALD50) for the most active compounds were also determined. Compound 5c was proved to display anti-inflammatory activity better than celecoxib. Compounds 4b, 5d, 5c and 8 were found to be safer than indomethacin with respect to ulcerogenic effect and were well tolerated by the experimental animals with high safety margin (ALD50 >300 mg/Kg). Moreover, histopathological examination was carried out to detect the anti-inflammatory effect of the tested compounds on the livers of carrageenan-injected rats. On the other hand, compounds 4b, 4c, 4d, 5b, 5c, 5d, 6a, 6b, 6c, 6d, 8 and 9 were selected by the NCI to be evaluated for their anticancer activities but none has passed to the 5-dose assay. In addition, the ligand-receptor interactions of the most active compounds with COX-2 were investigated by performing docking studies using Molecular Operating Environment (MOE) version 2008.10.

Synthesis, characterization and antibacterial activity of biodegradable films prepared from Schiff bases of zein

Pure zein is known to be very hydrophobic, but is still inappropriate for coating and film applications because of their brittle nature. In an attempt to improve the flexibility and the antimicrobial activity of these coatings and films, Chemical modification of zein through forming Schiff bases with different phenolic aldhydes was tried. Influence of this modifications on mechanical, topographical, wetting properties and antimicrobial activity of zein films were evaluated. The chemical structure of the Schiff bases films were characterized by ATR-FTIR spectroscopy. The results indicate an improvement in mechanical properties with chemically modification of zein to form Schiff bases leading to a reduction in the elastic modulus. An increase in the elongation at break has been observed, but with slight influence on tensile strength. Plasticized zein films have similar initial contact angle (∼40°). An increase in reaction temperature and time increases film's affinity towards water. As shown by contact angle measurements, a noticeable relation was found between film composition and the hydrophilicity. Surface topography also varied by forming Schiff bases, becoming rougher than zein-based films. The antibacterial activities of zein and Schiff bases of zein-based films were investigated against gram-positive bacteria (Listeria innocua, Listeria monocytogenes, Bacillus cereus and Clostridium sporogenes) and gram-negative bacteria (Escherichia coli, Yersinia enterocolitica and Salmonella enterica). It was found that the antibacterial activity of the Schiff bases-based films was more effective than that of zein-based films.

Pulse wave analysis: a preliminary study of a novel technique for the prediction of pre-eclampsia

OBJECTIVE

To investigate whether first-trimester arterial pulse wave analysis (PWA) can predict pre-eclampsia.

DESIGN

This was a prospective screening study.

SETTING

The Homerton University Hospital, a London teaching hospital.

POPULATION

Two hundred and ten low-risk women with a singleton pregnancy were analysed.

METHODS

Radial artery pulse waveforms were measured between the 11(+0) and 13(+6) weeks of gestation and the aortic waveform derived by applying a generalised transfer function. Augmentation pressure (AP) and augmentation index at heart rate of 75 beats per minute (AIx-75), measures of arterial stiffness, were calculated. The multiple of the gestation-specific median in controls for AP and AIx-75 were calculated. Logistic regression models were developed and their predictive ability assessed using the area under the receiver operator curve.

MAIN OUTCOME MEASURES

Prediction of pre-eclampsia by AIx-75.

RESULTS

Fourteen (6.7%) women developed pre-eclampsia, and 196 remained normotensive. Eight of the 14 women developed pre-eclampsia before 34 weeks of gestation (early-onset pre-eclampsia). For a false-positive rate of 11%, AIx-75 had a detection rate of 79% for all cases of pre-eclampsia and 88% for early-onset pre-eclampsia.

CONCLUSION

First-trimester arterial PWA can play a significant role in understanding the pathophysiology of pre-eclampsia and may play a role in early screening.

Studies on the liver fluke Fasciola in Egypt: I--Morphological and morphometrical studies

A comparative scanning electron microscopy and morphometrical study of the two geographically isolated species of Fasciola (F. heptica European isolate and F. gigantica from Egypt) were studied in order to clarify their genetic relationships and specific identification. Although the present study has revealed that most of the diagnostic morphological and morphometrical criteria in the two species are highly variable, the position of the ventral sucker relative to the whole body length produced the most significant differentiating criterion, in addition to the presence of markedly larger tegumental papillae on the ventral surface of F. gigiantica.

Production of intracellular milk-clotting enzyme in submerged cultures of Fusarium subglutinans

Fusarium subglutinans (Wollenweber and Reinking) Nelson et al. was found to produce intracellular milk-clotting enzyme (MCE) with good milk-clotting activity (MCA). The crude activity of the produced enzyme was recorded as optimum at 55 degrees C and pH 4.5. The highest yield i.e. 78.43 SU/mg dry biomass was obtained after 4 days of rotary shaking at 30 degrees C when the fermentation medium containes wheat flour 2%, glucose 1% and (NH4)2SO4 0.1% with an initial pH value 6.0. Under these conditions, the maximum ratio of MCA to proteolytic activity (PA) amounting to 603.31 SU/PU mg(-1) was also achieved. Production of intracellular MCE by F. subglutinans was assumed to be active growth-associated type. This enzyme preparation was less active than the calf rennet, but was superior to those of Meito's and Pfizer's rennets.

Charge transfer complexes of some oxazolones with iodine

Molecular charge-transfer (CT) complexes of some oxazolone derivatives with sigma-electron acceptor iodine have been investigated spectrophotometrically in CH2Cl2 at 20 degrees C. Stability constants of the CT complexes formed were computed and discussed in terms of the donor molecular structure and solvent polarity. The thermodynamic parameters of complex formation were determined and discussed. The solid CT complexes have been synthesized and characterized. It was deduced that the complexes formed are of strong n-sigma kind.

The magnitude of osteoporosis in middle aged women

OBJECTIVE

This study aims to increase the body of knowledge regarding osteoporosis in the Jordanian context by investigating the magnitude of osteoporosis amongst perimenopausal women, as well as the risk factors associated with the disease.

METHODS

Two hundred and fifty one women between the ages of 40 to 60 years were randomly selected from the Orthopedics and Rheumatology out patient clinics at the Major Teaching Hospital in Amman, Jordan. A structured questionnaire, which focused upon risk factors and preventive measures for osteoporosis, was administered by a trained staff nurse to all women. Index women were then referred to a private hospital, also in Amman, for a dual energy x-ray absorptiometry of the lumbar spine (Lumbar 1-4) and hip.

RESULTS

Results show the magnitude of osteoporosis was 13% according to the bone mineral density of the lumbar spine. Women with osteoporosis were older (p< 0.00) and smaller in build (p<0.00) than women with low or normal bone density. Osteoporotic women were also more likely to be menopausal (p<0.00) and to have taken corticosteroids for a prolonged period of time (p<0.00). Logistic regression showed being menopausal (p<0.00), taking corticosteroids (p<0.05), and having a relatively lower body mass index (p<0.00) were significantly related to being osteoporotic in this group of women.

CONCLUSION

The authors conclude that this study was not only able to report upon the magnitude of osteoporosis among women sampled, and the risk factors for low bone density, but also raised issues related to inconsistencies in how the health care system deals with women who are at risk for osteoporosis. Study findings are discussed in their socio-cultural context, and implications of the study findings are presented.

Isolation and characterization of a monoamine oxidase inhibitor from tobacco leaves

Recent positron emission tomography imaging studies have demonstrated a significant decrease in both monoamine oxidase A and B (MAO-A and MAO-B) activities in the brains of smokers. Normal levels of activity are observed in former smokers, suggesting the presence of one or more compounds in tobacco smoke that may inhibit these enzymes. In this paper, we report the results of efforts to identify compounds present in flue-cured tobacco leaves that inhibit MAO. The isolation procedure was guided by estimating the inhibitory properties of tobacco leaf extracts on the liver mitochondrial MAO-B-catalyzed oxidation of 1-methyl-4-(1-methylpyrrol-2-yl)-1,2,3, 6-tetrahydropyridine to the corresponding dihydropyridinium metabolite. Fractionation of extracts from flue-cured tobacco leaves led to the isolation of a competitive inhibitor of human MAO-A (K(i) = 3 microM) and MAO-B (K(i) = 6 microM), the structure of which could be assigned by classical spectroscopic analysis and confirmed by synthesis. This information may help to provide insights into some aspects of the pharmacology and toxicology of tobacco products.

Progressive deterioration of coronary flow reserve after heart transplantation

BACKGROUND

The purpose of this study was to determine coronary flow reserve in cardiac allograft recipients early (0 to 3 years) and late (3 to 7 years) after heart transplantation.

METHODS AND RESULTS

With the use of a Doppler tipped guide wire, coronary flow reserve (ratio of hyperemic to baseline coronary flow velocity) was measured in 82 patients before and after intracoronary adenosine. Forty-five patients were early (< or =3 years) after transplantation, 24 were late, and 13 were control patients with single-vessel coronary artery disease. Coronary flow reserve in the early transplantation patients was similar to that in the control group (2.9+/-0.2 vs 3.0 +/-0.6, p=not significant) but was reduced in the late transplantation group (2.2+/-0.5 vs 3.0+/-0.6, p < 0.001). There were differences in coronary flow reserve between the early and late transplantation patient groups (3.0+/-0.6 vs 2.2+/-0.5, p < 0.001 ) despite equally elevated mean arterial pressure, mean heart rate, mean pulmonary capillary wedge pressure, and mean left ventricular mass in the two groups. Coronary flow reserve in patients with angiographic allograft arteriopathy (n=19) was reduced when compared with coronary flow reserve of patients with normal vessels (n=50) (1.9+/-0.3 vs 3.1+/-0.6, p < 0.001).

CONCLUSIONS

There is progressive deterioration of coronary flow reserve over time after transplantation. Dysfunction of the coronary microcirculation rather than determinants of myocardial oxygen consumption contributes to this reduction.

Coronary flow reserve may predict myocardial recovery after myocardial infarction in patients with TIMI grade 3 flow

BACKGROUND

The aim of the study was to determine whether the recovery of global and regional left ventricular function after successful percutaneous transluminal angioplasty (PTCA) could be predicted by measuring coronary flow reserve before performing the intervention.

METHODS AND RESULTS

Thirty-two patients underwent PTCA 6.9 +/- 3.4 days after a recent myocardial infarction. Coronary flow reserve was determined in the infarct-related artery before PTCA by using an intracoronary Doppler tipped wire. Global and regional wall motion were determined by 2-dimensional echocardiography before the Flowire study and again 7 weeks after the angioplasty. Whereas the global and regional wall motion score indices improved in 20 patients (recovery group), they deteriorated or did not change in 9 patients (nonrecovery group). Coronary flow reserve distal to the lesion in the infarct-related artery was significantly higher in the recovery group (1.43 +/- 0.57 vs 0.98 +/- 0.70, P = .0001). Coronary flow reserve distal to the lesion in the infarct-related artery was < 1.1 in patients whose global or regional left ventricular function did not improve at follow-up, whereas flow reserve ranged between 1.1. and 1.8 while patients in whom left ventricular function improved.

CONCLUSIONS

These results suggest that the absence of inducible coronary flow reserve may predict failure of left ventricular systolic function to improve between the first and sixth week after infarction. Measurement of flow reserve with a Flowire at the time of diagnostic angiography after recent myocardial infarction may ultimately prove helpful in deciding whether to proceed with revascularization.

Steepness of the dose-response curve as a function of volume in an experimental tumor irradiated under ambient or hypoxic conditions

PURPOSE

Radiation dose-response curves play a fundamental role in the attempts to optimize radiotherapy, and it is a major task in clinical and experimental radiation research to characterize and quantify the factors that determine the position and shape of dose-response curves. A convenient measure of the steepness of radiation dose-response curves is the normalized dose-response gradient, gamma, which represents the increase in response, in percentage points, for a 1% increase in dose. Theoretically, the normalized dose-response gradient should increase with increasing clonogenic cell number or, assuming a constant clonogen density, with increasing tumor volume. The aim of this study was to test this hypothesis over a range of tumor volumes and to study how this relationship is affected by heterogeneity in tumor oxygenation.

METHODS AND MATERIALS

A C3H mouse mammary carcinoma implanted in the feet of female CDF1 mice was used. Groups of tumors with various volumes were irradiated with single graded radiation doses in air or after making them artificially hypoxic by clamping. The end point used was tumor control defined as complete absence of a macroscopic relapse within 90 days after irradiation. A Poisson dose-response model was assumed to describe tumor control probability in each volume group. The dose needed to control 37% of the tumors (D37) and the normalized dose-response gradient at this dose (gamma37) were estimated by the maximum likelihood method. In another group of animals with tumors in the same volume range, oxygenation status was assessed by a polarographic needle electrode. The percentage of pO2 values <3 mmHg was selected to represent the relative volume of the tumor with radiobiological hypoxia.

RESULTS

The D37 values increased as a function of tumor volume under both clamped and ambient conditions. For tumors irradiated under clamped conditions, gamma37 increased with increasing tumor volume throughout the range of volumes studied. However, for tumors irradiated under ambient conditions, there was an initial increase in gamma37 with tumor volume up to 100 mm3 with no further increase beyond that volume. As the tumor volume increased, both the level of hypoxia and the tumor-to-tumor heterogeneity in that level increased.

CONCLUSIONS

This study has confirmed the hypothesis that gamma37 increases with increasing tumor volume when tumors are irradiated under clamped condition. The increased heterogeneity of the hypoxic volume fraction with increasing tumor volume could explain why the steepness of the dose-response curve did not increase with increasing tumor volume when irradiation was done under ambient condition.

A new syndrome of Crohn's disease and pachydermoperiostosis in a family

Few syndromic associations with Crohn's disease are described. The aim of this study was to characterize a new syndrome of Crohn's disease associated with pachydermoperiostosis in 3 brothers. Three probands, 6 siblings, both parents, 20 of 21 third-generation relatives, and 9 spousal controls were evaluated. Serological evaluation for antineutrophil cytoplasmic antibodies and human leukocyte antigens as well as genetic testing for tumor necrosis factor microsatellites, intercellular adhesion molecule 1 polymorphisms, the interleukin 1 receptor antagonist gene, and the interleukin 1 beta gene were performed. Only the 3 probands were affected and developed pachydermoperiostosis between ages 14 and 17 years. Pachydermoperiostosis preceded Crohn's ileocolitis by 6 and 20 years in two probands, excluding secondary hypertrophic osteoarthropathy. Two probands were antineutrophil cytoplasmic antibody positive vs. 1 of 27 unaffected relatives (P < 0.001, chi 2). Haplotypes for human leukocyte antigen and tumor necrosis factor microsatellites were discordant. The probands' generation was homozygous for the common allele 1 of the interleukin 1 receptor antagonist and interleukin 1 beta genes. Two probands carried a rare polymorphism of the intercellular adhesion molecule 1 gene. A new syndrome of Crohn's disease and pachydermoperiostosis associated with antineutrophil cytoplasmic antibodies is described. Inheritance is most likely autosomal recessive by pedigree. No clear association was found between this syndrome and the gene regions evaluated.

A comparison of the physiological effects of RSU1069 and RB6145 in the SCCVII murine tumour

The physiological and therapeutic effects of the bioreductive agent RSU1069 (80 mg/kg i.p.) and its prodrug RB6145 (240 mg/kg i.p.) were investigated in the SCCVII tumour. Using laser Doppler flowmetry it was found that RSU1069 produced a significant 30% reduction in tumour blood flow 30 min after administration, while RB6145 had no effect. Tumour oxygenation, measured with an Eppendorf oxygen electrode, was unchanged by either agent except for a reduction in values less than 2.5 mmHg at 30 min after injection. Neither agent significantly altered tumour energy metabolism, assessed by 31P magnetic resonance spectroscopy. Both agents significantly increased tumour glucose content by a factor of 1.6-1.7 at 30 min after injection, but had no effect on glucose-6-phosphate or lactate levels. Tumour growth was significantly delayed by heating (42.5 degrees C, 60 min), and although neither RSU1069 nor RB6145 alone had any effect on tumour growth they produced a similar enhancement of the tumour response to heat. The therapeutic effects are consistent with the known conversion in vivo of one third of the pro-drug RB6145 to its active product RSU1069, however the physiological effects of the two agents in the SCCVII tumour are not identical.

The ability of nicotinamide to inhibit the growth of a C3H mouse mammary carcinoma

Experimental studies have suggested that nicotinamide and its analogs may inhibit the growth of murine tumours. We have now investigated this using a C3H mouse mammary carcinoma implanted into the right rear foot of female CDF1 mice. From days 1 to 30 after implantation mice were intraperitoneally (i.p.) injected with either 100, 200, 500 or 1,000 mg/kg nicotinamide. The tumour volume (+/- 1 S.E.) after 30 days in saline-treated mice had reached 1540 mm3 (+/- 260). No change in tumour growth was seen at that time with daily doses of up to 500 mg/kg nicotinamide, but at 1,000 mg/kg tumour volume was reduced to 904 mm3 (+/- 233). However, this large dose of nicotinamide was also toxic to the mice with some 16% of animals dying during the 30-day treatment period. A similar growth inhibition was seen with daily i.p. injections of 5 mg/kg fumagillin (tumour volume at 30 days = 821 +/- 191 mm3), a known inhibitor of angiogenesis, but whether this mechanism also explains the nicotinamide effect is not clear.

The importance of determining necrotic fraction when studying the effect of tumour volume on tissue oxygenation

The relationship between tumour tissue oxygenation and necrosis at different tumour sizes was investigated in a C3H mammary carcinoma implanted in the feet of female CDF1 mice. Experiments were performed using tumours that ranged in size from 80 to 800 mm3. Necrosis was estimated histologically. Tumour tissue oxygenation (pO2) was estimated with an Eppendorf electrode. Our results showed that as tumour volume increased there was a corresponding increase in necrotic fraction ranging from 1% in small tumours up to 51% in large tumours. The percentage of pO2 values < or = 5 mmHg increased from 2% up to 79%, in small and large tumours respectively. After correcting for necrosis, the apparent, significant increase in the % of pO2 values < or = 5 mmHg was lost. We conclude that correcting for necrotic fraction in this tumour model is necessary when attempting to measure tumour oxygenation using electrodes.

Cytotoxic effect of tumour necrosis factor -alpha on sarcoma F cells at tumour relevant oxygen tensions

We have investigated the response of a murine tumour cell line, the sarcoma F (SaF), to tumour necrosis factor-alpha (TNF) at oxygen tensions known to occur in vivo. Using the Eppendorf pO2 histograph, the oxygen status of SaF tumours grown in situ was assessed. The median pO2 of the SaF is less than 1% oxygen with over 90% of values at or below 15 mmHg (< 2% O2). SaF cells primed in vitro for 24 h at tumour relevant oxygen tensions required at least four times more TNF to reduce cell number to 50% of controls following a 24 h incubation period in 21% oxygen. Chronic exposure of SaF cells to hypoxia during several passages increased resistance to TNF more than 60-fold. The oxygen sensitizing effect is transient as the resistance of hypoxic cells to TNF was reversed after 24 h incubation in air. These data clearly show that oxygen tension is a key modulator of the cytotoxic action of this important cytokine.

Relationship between radiobiological hypoxia in tumors and electrode measurements of tumor oxygenation

PURPOSE

To determine whether electrode measurements of tumor oxygenation, made in a variety of murine tumor models, correlate with estimates of radiobiological hypoxia in the same tumor systems.

METHODS AND MATERIALS

The tumor models used were a C3H mammary carcinoma grown in the feet of CDF1 mice; the SCCVII, KHT and RIF-1 tumors grown in the feet or flanks of C3H/Km mice; and the CaNT and SaF tumors grown on the backs of CBA mice. All treatments were performed when tumors were about 200 mm3 in size. Radiobiological hypoxic fractions were determined using either a paired survival curve assay, with survival measured 0-24 h after irradiation, or using a clamped tumor control assay, with percent local tumor control estimated 90 days after treatment. Measurements of tumor oxygen partial pressure (pO2) distributions were performed using Eppendorf oxygen electrodes.

RESULTS

The hypoxic fractions determined from the radiation response data were about 1% in RIF-1 and SCCVII, 12% in C3H and KHT, 28% in CaNT and up to 38% in SaF tumors. When this data was compared with the tumor oxygenation measurements it was found that as hypoxic fraction increased the mean, median, and the percentage of pO2 values < or = 5 mmHg showed a trend towards poorer oxygenation status. However, none of these pO2 changes were significantly correlated with hypoxia. Moreover, the pO2 values < or = 2.5 mmHg indicated an improvement in oxygen status with increasing hypoxic fraction.

CONCLUSION

Electrode measurements of tumor oxygenation alone may, therefore, not be a good indicator of tumor hypoxia across different tumor cell lines.

Effect of carbon monoxide breathing on hypoxia and radiation response in the SCCVII tumor in vivo

PURPOSE

To study the influence of a clinically relevant concentration of carbon monoxide (CO) on tumor oxygenation and response to irradiation.

METHODS AND MATERIALS

The murine tumor model was the SCCVII squamous cell carcinoma transplanted to the feet of C3H/Km mice.

RESULTS

Sixty minutes of breathing CO at 200 ppm resulted in a carboxyhemoglobin level of 15%. This resulted in a reduction in p50 (the oxygen partial pressure at which hemoglobin is 50% saturated) to 78% of the control value, and a decrease in tumor blood perfusion to 73% of the control value. The combined effect of a decrease in effective hemoglobin and blood perfusion resulted in a reduction in tumor oxygen supply to 62% of the control value. In agreement with this, intratumoral pO2 measurements showed a significant increase in tumor hypoxia, such that the percentage of measurements with low pO2 (< or = 5 mmHg) increased from 33% to 62%. The fraction of clonogenic hypoxic cells, measured radiobiologically by paired cell survival curves, similarly increased from 0.2% to 3.8%. Radiation sensitivity, evaluated from in vivo-in vitro excision assay, was significantly decreased by CO breathing with both single dose and fractionated irradiation. The observed enhancement ratios for radiation given in 1, 4, 8, and 12 fractions were 0.71, 0.77, 0.83, and 0.71, respectively.

CONCLUSION

The present SCCVII tumor data confirm the general experimental observation that CO breathing significantly increases tumor hypoxia and reduces the effectiveness of ionizing irradiation.

The relationship between carbon monoxide breathing, tumour oxygenation and local tumour control in the C3H mammary carcinoma in vivo

The effect of acute carbon monoxide (CO) breathing on blood oxygenation and tumour hypoxia was related to the radiation response of the C3H/Tif mammary carcinoma. Blood gas analysis showed that CO breathing caused a time- and dose-dependent formation of carboxyhaemoglobin (HbCO), a significant left shift of the oxygen dissociation curve and a reduction in tumour blood perfusion. These factors all contributed to a marked drop in tumour oxygen supply. In agreement with this, tumour hypoxia was found to be significantly increased: Microelectrode PO2 measurements showed a clear relationship between CO concentration and the proportion of low PO2 measurements (< or = 5 mmHg). The fraction of clonogenic hypoxic cells increased from 8% in air-breathing animals to 13%, 18% and 54% with 75,220 and 660 p.p.m. CO respectively. The tumour hypoxia resulted in significant radiation modification. The local tumour control after single-dose and fractionated irradiation gave TCD50 enhancement ratios (relative to air-breathing controls) of 0.90, 0.85 and 0.89 for single dose and five or ten fractions given in 5 days (P < 0.005 for all values). For 15 fractions in 5 days with 6- 6- and 12 h intervals, the TCD50 was similar in CO- and air-breathing mice, presumably as a consequence of insufficient reoxygenation during the short inter-fraction intervals. It is concluded that elevated HbCO levels to increased tumour hypoxia and that the induced hypoxia has a significant impact on the local tumour control also after fractionated irradiation.

Reducing acute and chronic hypoxia in tumours by combining nicotinamide with carbogen breathing

The ability of nicotinamide and carbogen breathing to improve the radiation response of a C3H mammary carcinoma by reducing both acute and chronic hypoxia was investigated. Using a tumour growth delay assay the response of 200 mm3 foot tumours to local irradiation was found to be increased by either injecting nicotinamide (100-1,000 mg/kg) 20 min prior to irradiation, or by allowing mice to breathe carbogen for 10 min before and during the radiation treatment. The greatest radiosensitization occurred when nicotinamide and carbogen were combined. With a histological fluorescent staining technique nicotinamide was shown to prevent transient stoppages in microregional blood flow, and also appeared to improve tumour oxygenation as measured with an Eppendorf oxygen electrode, both effects being consistent with its ability to decrease perfusion limited acute hypoxia. Carbogen had no effect on vessel closure, but it significantly improved tumour oxygenation, which was indicative of it reducing diffusion limited chronic hypoxia.

Relationship between radiobiological hypoxia and direct estimates of tumour oxygenation in a mouse tumour model

CDF1 mice were allowed to breathe either oxygen, carbogen or different concentrations of carbon monoxide gas. These treatments significantly altered the percentage of clonogenic hypoxic cells in a C3H mouse mammary carcinoma and these changes were found to correlate with direct measurements of tumour oxygenation obtained using an Eppendorf pO2 electrode.

Cisplatin and hyperthermia treatment of a C3H mammary carcinoma in vivo. Importance of sequence, interval, drug dose, and temperature

The effect of combining cisplatin and hyperthermia was investigated in a C3H mammary carcinoma in vivo, using a regrowth delay assay. Cisplatin (6 mg/kg) was given i.p. at intervals ranging from 24 h before to 24 h after a 43.5 degrees C/60 min treatment. A supra-additive effect was obtained by giving cisplatin 15 min before heat, whereas an additive effect was obtained at all other intervals. The importance of cisplatin dose and heating temperature were investigated by giving variable cisplatin doses (2-8 mg/kg) 4 h or 15 min before a 60 min heating at temperatures in the range 40.5-43.5 degrees C. Linear relationships between length of regrowth delay and cisplatin dose were obtained both for cisplatin alone and for the combined treatment. The effect of the combined treatment could therefore be quantitated by a ratio (ER) between the slopes of dose-response curves. The ER values for cisplatin give 4 h before a 60 min heating at 42.5 or 43.5 degrees C were not significantly different from 1 (p greater than 0.5). In contrast, significant ER values were obtained above 40.5 degrees C (p less than 0.05) for cisplatin given 15 min before heat. The data demonstrates the possibility of achieving chemosensitization at clinically relevant temperatures.

Immunoglobulins in bilharzial patients with and without chronic hepatitis

The mean values of IgG and IgA were significantly higher in bilharzial patients than in the non bilharzial ones. The mean IgG level in patients with S. mansoni was significantly higher than that in patients with negative stool while the reverse was true as regards IgA. Among the bilharzial patients the mean values of IgG, IgM and IgA were significantly higher in C.A.H. and C.A.H. bilharziasis than in patients with pure bilharziasis, C.P.H. and C.P.H. with bilharziasis. It might be concluded that the altered immune response produced by schistosomiasis, the frequent exposure to the hepatitis B. virus and the bilharzial hepatitis lesions, all may pave the way for development of severe diseases e.g. chronic active hepatitis and liver cirrhosis.

Production of ethanol by alginate-entrapped Saccharomyces cerevisiae strain "14-12"

Cells of S. cerevisiae strain "14-12" of different ages were immobilized in sodium alginate and used for conversion of glucose to ethanol. Immobilized cells of 48 hr old were the most potential. Employment of high counts of alginate-entrapped cells shortened the period required for production of the maximal alcohol yield. However, the percentage surviving cells decreased with increasing initial cell counts. Maximal accumulation of ethanol (4.18 g/100 ml) was obtained after 4 days of static fermentation with 1.8 X 10(8) immobilized yeast cells. The residual viable cell count was found to represent 3-fold the surviving percentage in a control experiment using an inoculum of the free yeast cells. Immobilized yeast cells could convert about 85% of the available sugars to ethanol over 28 days of the repeated-batch fermentation. The immobilized cells retained 50% of their viability for 16 days. After 48 days of repeated fermentation only 6% of the yeast cells were viable, and on the 52nd day no viable cells could be detected.

Ethanol tolerance of Saccharomyces cerevisiae and its relationship to lipid content and composition

Saccharomyces cerevisiae strain 14-12 is a highly ethanol-tolerant organism. It can grow in the presence of 13% ethanol but growth is completely prevented at 14% ethanol. A relationship was detected between yeast lipids and ethanol tolerance. A gradual decrease of lipid content was recorded as the concentration of supplemented ethanol increased. Moreover, free fatty acids were comparatively decreased in these lipid extracts. When separately added to media with 14% ethanol different lipids produced varied stimulatory effects on yeast growth. Maximum yield of yeast growth was obtained at 14% ethanol in the presence of lecithin, palmitic acid and cholesterol. Yeast lipids produced in the presence of these fractions are characterized by a relatively high percentage of free fatty acids. The change in the percentage of free fatty acids was shown to be the controlling factor in ethanol tolerance.

Bullet injury to the pituitary gland: a rare cause of panhypopituitarism

An unusual case of head injury with a direct bullet injury to the pituitary gland is described. The hormonal profile one month after the injury showed severe panhypopituitatism which did not improve one month after surgical removal of the intrasellar bullet fragment.