bluuebunny/crossref_metadata_2025 huggingface dataset:
Radiographic evaluation of the prevalence and technical quality of root canal treatment in a French subpopulation
Authors: Boucher Y. , Matossian L. , Rilliard F. , Machtou P.
Published: March 2003

Aim This study was undertaken to examine the prevalence and technical quality of root fillings and the periapical status of endodontically treated teeth in a French subpopulation.

Methodology Full‐mouth periapical radiographs were obtained from 208 consecutive adult patients seeking care within the dental service provided by the Hôtel‐Dieu in Paris. The occurrence and technical quality of root fillings were assessed for each root according to the position and the density of the obturation. The periapical status was evaluated using the Periapical Index Scoring System. The type of coronal restoration and the presence of posts were also noted.

Results Of the 8743 roots included in the survey, 23% were root‐filled. An acceptable standard of treatment was found in 21% of roots with 16% of these cases associated with signs of periapical disease. In roots with unacceptable root‐fillings, 27% had periapical pathology. A post was seen in 26% of the root‐filled canals, with 29% of these cases associated with periapical pathology. An intracoronal restoration existed in 30% of the filled roots, of which 22% exhibited a periapical lesion. An extra‐coronal restoration was present in 60% of the filled roots, of which 24% had radiographic signs of periapical pathology. The remaining 10% of filled roots that had no coronal restoration were associated with periapical pathology in 33% of cases. At least one periapical lesion was seen in 63% of the patients.

Conclusion The results demonstrate a high prevalence of root‐filled teeth and poor technical quality of treatment. Roots presenting with acceptable root fillings were associated with a lower prevalence of periapical pathology (P < 0.001). Posts in roots were associated with periapical pathology significantly more than in roots without posts (P < 0.001).
Direct amplification of rRNA gene sequences for identification of selected oral pathogens in root canal infections
Authors: Siqueira J. F. , Rôças I. N. , Moraes S. R. , Santos K. R. N.
Published: March 2003

Aim The purpose of this study was to assess the prevalence of selected oral pathogens in root canal infections and their relationship with symptoms using a highly sensitive technique, the polymerase chain reaction.

Methodology Samples were obtained from 91 infected teeth associated with periradicular lesions, including cases of acute periradicular abscesses. DNA was extracted from the samples and analysed for the presence of target microbial species using a PCR‐based identification assay.

Results All samples were positive for the presence of bacteria. Streptococcus anginosus group was detected in 16.7%, Fusobacterium nucleatum in 14.3%, and Bacteroides forsythus in 7.1% of the abscess samples. No pus sample yielded Actinomyces israelii, Actinobacillus actinomycetemcomitans or fungal species. In general, B. forsythus was found in 20% of the cases (16 of 80), S. anginosus in 12% (6 of 50), F. nucleatum in 10% (6 of 60) and A. israelii in 5% (two of 40). A. actinomycetemcomitans was not detected in any case. Fungi were present in only one of 50 cases (2%). There was no correlation between the species and symptoms.

Conclusions Direct molecular approaches appear to be a valuable tool for the rapid and reliable diagnosis of infectious diseases, as well as for research purposes. There was no correlation between target microbial species and symptoms.
Gossypol as a male antifertility agent – why studies should have been continued
Authors: YU ZONG‐HAN , CHAN HSIAO CHANG
Published: March 2003

It has been nearly three decades since the beginning of nationwide research into gossypol as a male antifertility agent in China. Several lines of data implicating some side effects of gossypol were published which led to the termination of this area of research in China. The present review re‐examines these data and points out the confusion surrounding issues such as hypokalaemia, irreversible azoospermia and other side effects. The prospects and related difficulties for gossypol as a potential male contraceptive are also discussed.
Progesterone in mare follicular fluid induces the acrosome reaction in stallion spermatozoa and enhances in vitro binding to the zona pellucida
Authors: CHENG  , FAZELI  , VOORHOUT  , TREMOLEDA  , BEVERS  , COLENBRANDER
Published: March 2003

The aim of this study was to investigate whether mare follicular fluid (FF) induces the acrosome reaction (AR) in stallion spermatozoa and, if so, to identify the component in FF responsible for it. Furthermore, the effect of this component on sperm–zona binding and the subsequent AR was studied. Pooled FF, aspirated from the preovulatory follicles of mares in oestrous, was used and aliquots of the fluid were treated with charcoal to remove steroids (CFF). Charcoal treatment reduced the progesterone concentration in FF from 153 to <2 ng/mL. Spermatozoa from fertile stallions collected by a swim‐up procedure were preincubated in modified Tyrode's medium for 5 h and then incubated for 30 min at 37 °C with either (1) 50% FF + 50% CFF, (2) 50% FF + 50% CFF + 150 ng/mL progesterone, (3) 50% CFF + 150 ng/mL progesterone, (4)150 ng/mL progesterone or (5) modified Tyrode's medium alone. The sperm–hemizona assay was applied: (a) to compare the number of spermatozoa bound to a hemizona in the presence and absence of 1.5, 15 or 150 ng/mL progesterone after 1 h co‐incubation of spermatozoa and hemizonae, (b) to compare the incidence of the AR in sperm–hemizona complexes incubated for 1 h in the presence and absence of 1 μg/mL progesterone. Both spermatozoa in suspension and bound to a hemizona were treated with the supravital dye Ethidium homodimer and fixed. Their plasma membranes were permeabilized, and the outer acrosomal membranes were labelled with FITC‐PNA. Viable spermatozoa without the outer acrosomal membrane were considered as physiologically acrosome‐reacted. Results showed that (1) FF induced a higher percentage of AR than did CFF or modified Tyrode's medium, (2) addition of 150 ng/mL progesterone to CFF restored 77% of the AR‐inducing activity and (3) CFF and modified Tyrode's medium both induced the AR to a similar extent when supplemented with 150 ng/mL progesterone. Neither FF nor progesterone treatment affected sperm viability severely. The number of spermatozoa bound to a hemizona in the presence of 15 and 150 ng/mL progesterone was significantly higher ( p < 0.05) than the number of spermatozoa bound in the absence of progesterone. A higher incidence of the AR was found in sperm–hemizona complexes incubated in the presence of progesterone (55.6 ± 3.4% vs. 27.1 ± 4.3%, in the presence and absence of progesterone, respectively) (n = 15,p < 0.05). It is concluded that mare FF can induce the AR in stallion spermatozoa. Progesterone is the physiological component responsible for this AR‐inducing capacity. Progesterone enhances sperm–zona binding activity and exerts an additive effect on the zona‐induced AR.
Hormonal regulation and germ cell‐specific expression of heat shock protein 60 (hsp60) in the testis of macaque monkeys (Macaca mulatta and M. fascicularis)
Authors: MEINHARDT  , SEITZ  , ARSLAN  , AUMÜLLER  , WEINBAUER
Published: March 2003

Decrease of heat shock protein 60 (hsp60), a mitochondrial chaperonin, in germ cells of men has been shown to be associated with low spermatogenic efficiency. In the present study, we have investigated the hormonal regulation of hsp60 in a pre‐clinical primate animal model. Hsp60 production in the testes of the intact cynomolgus monkey (Macaca fascicularis) and animals that had been treated with the GnRH antagonist Cetrorelix for 25 days was studied by immunohistochemistry. In addition, testes of untreated adult rhesus monkeys (Macacamulatta) and immature animals either exposed to human chorionic gonadotrophin (hCG), human follicle stimulating hormone (FSH) or hCG and FSH in combination, as well as vehicle‐treated controls were analysed. In adult monkeys, specific hsp60 staining was observed in Leydig cells, spermatogonia and early primary spermatocytes. The labelling in Sertoli cells was not stage dependent. The hsp60 staining pattern was unaffected by gonadotrophin releasing hormone (GnRH) antagonist treatment. Western blot analysis confirmed the presence of a single band of 60 kDa in␣testicular homogenates of the cynomolgus monkey. In the testis of immature rhesus monkeys, hsp60 immunoreactivity was visible in gonocytes, spermatogonia and in Sertoli cells, whereas interstitial cells were negative. In the experimental study, hCG alone or in combination with FSH caused a substantial and marked upregulation of the chaperonin in Leydig cells. Human FSH alone did not affect hsp60 expression. We conclude that hCG is an important regulator of Leydig cell hsp60 expression during development, whereas FSH in immature animals and GnRH in adult monkeys is of less importance.
Papanicolaou and Kruger assessment of sperm morphology: thresholds and agreement
Authors: VAZQUEZ‐LEVIN  , GOLDBERG  , FRIEDMANN  , JARLAIS D. C. DES , NAGLER
Published: March 2003

The current World Health Organization guidelines (1992) suggest that the presence of ≥30% normal sperm forms (i.e. PAP criteria) is consistent with normal semen quality. Critical evaluation of sperm morphology (CE; Kruger classification) has shown an excellent correlation with human in vitro fertilization. Utilizing Kruger criteria, >14% normal sperm forms has been proposed as indicative of normal semen quality. We have performed a retrospective analysis on 261 individuals to assess the agreement between PAP and Kruger criteria for normal sperm morphology (NSM). When the threshold for NSM by PAP was set at 30%, a significant agreement was found between the percentage normal forms of both criteria (Kappa coefficient = 0.37; p < 0.001). Sixty‐seven (92%) of the 73 men found to have abnormal sperm morphology by PAP had abnormal semen by Kruger classification. When the threshold for NSM by PAP was established at 50%, the Kappa coefficient was 0.48 ( p < 0.001). Sixty of the 72 samples (83%) classified as normal by PAP staining were normal by Kruger criteria. Interestingly, when NSM by PAP was between 30 and 50%, the specimen was just as likely to have normal or abnormal sperm morphology by Kruger (40 vs. 60%, respectively). These results strongly suggest that a high or low percentage of NSM by PAP is in agreement with the Kruger classification. The excellent agreement of Kruger and WHO criteria at the extremes (< 30% and >50%) may obviate the need for Kruger assessment. However, when WHO morphology is between 30 and 50%, the addition of Kruger evaluation may provide meaningful information to help better diagnose a patient and plan his treatment.
Immunohistochemical expression of monoclonal antibody 43‐9F in testicular germ cell tumours
Authors: HEIDENREICH  , SESTERHENN  , MOSTOFI  , MOUL
Published: March 2003

The aim of this study was to evaluate the clinical utility of immunohistochemical staining of human testicular germ cell tumours with the monoclonal antibody 43‐9F to distinguish embryonal carcinoma (EC) from other malignant germ cell components in order to facilitate pathohistological assessment of prognostic risk factors for metastatic disease in clinical stage I NSGCT. Archival, formalin‐fixed, paraffin‐embedded tissue blocks of 24 classical seminomas, 7 spermatocytic seminomas, and 20 non‐seminomatous germ cell tumours were stained for 43‐9F, AFP, hCG and PLAP expression. Immunohistochemical expression was graded using a semi‐quantitative scoring system: 1+=0–25%, 2+=26–50%, 3+=51–75% and 4+=76–100%.

Positive immunohistochemical staining for 43‐9F was found in all embryonal carcinomas and yolk sac tumours (YST); staining intensity was not statistically different between the two tumours (3.8 ± 1.2 vs. 3.1 ± 0.9). Classical seminomas and seminomatous components of NSGCT stained positive in 13/24 cases (54%); staining intensity was weak to moderate (1.1 ± 0.7) in all but two cases (4+). Spermatocytic seminomas demonstrated weak positive immunostaining in 2/7 cases (29%). Adjacent CIS was found in 33/54 (61.1%) of tumours and 24/33 (72.7%) of CIS cells exhibited a weak to moderate staining intensity (1.4 ± 0.7). AFP expression was found in 93% of YST and in only 10% of EC; however, based on the focal staining pattern, adequate differentiation of YST and EC was not possible. Positive PLAP staining was observed in 75% of EC, 79% of seminomas and in 88% of CIS cells. We did not find 43‐9F staining clinically useful to distinguish embryonal carcinoma from other germ cell tumour components such as yolk sac tumour. The detection rate of CIS by 43‐9F immunohistochemical staining was low and combination of PLAP staining with light microscopy was even superior. Additionally, our study confirms the link between pre‐invasive CIS and embryonal carcinoma and suggests the possible direct development of embryonal carcinoma from CIS.
Effects of male accessory sex glands on sperm decondensation and oocyte activation during in vivo fertilization in golden hamsters
Authors: Ying  , Cheung  , Chow  , O
Published: March 2003

Removal of paternal male accessory sex glands (ASG) could cause a delay in DNA synthesis in hamster zygotes fertilized in vivo. In view of the fact that this process is closely related to pronuclear development which, in part, depends on sperm nuclear decondensation and oocyte activation during fertilization, we carried out a series of experiments were undertaken to determine whether ASG also has an effect on these early events. (1) Oocytes were collected from females mated with SH (sham‐operated control), AGX (bilateral excision of ampullary glands), VPX (bilateral excision of ventral prostates) or TX (excision of all ASG) males (n = 8 per group) at 4, 5 and 6 h post coitus. (2) Epididymal spermatozoa were incubated with total ventral prostate (VP) secretion to study its effect on dithiothreitol‐induced sperm decondensation. (3) Histone H1 kinase activity in oocytes collected as described in (1) was determined. (4) Exocytosed cortical granules on oocytes were labelled with FITC‐LCA and quantified by a Metamorph Imaging System. Results showed that sperm decondensation and resumption of meiosis in oocytes in VPX and TX groups were significantly slower compared with SH. VP secretion augmented sperm decondensation in vitro. At 4 h post coitus, the relative activity of histone H1 kinase in the TX and VPX groups was significantly higher than that in the SH group (p < 0.01). Cortical granule exocytosis in the AGX group was consistently weaker at all time points studied and was significantly lower than that of the control at 4 h post coitus (p < 0.05), while the percentage of polyspermic fertilization in the AGX group was significantly higher compared with that in the SH group (p < 0.05). Taken together, these results show that the lack of exposure of spermatozoa to secretions of the ASG does not jeopardize their ability to penetrate ova, although other aspects of their function in the early stages of gamete interaction and subsequent initiation of embryonic development are affected.
The relationship between critical evaluation of sperm morphology and the TYB‐optimized zona free hamster oocyte sperm penetration assay
Authors: Vazquez‐Levin Mónica H. , Chue Jason , Goldberg Svetlana , Medley Nadine E. , Nagler Harris M.
Published: March 2003

The objective of this study was to analyse the relationship between the percentage of spermatozoa in semen with normal morphology, assessed using the Tygerberg criteria, and sperm fertilizing ability assessed using the TYB‐optimized zona free hamster oocyte sperm penetration assay (TYB‐optimized SPA), to evaluate the predictive value of strict morphology on outcome of the SPA. In a retrospective study, 56 samples were analysed. In addition to routine semen parameters, the percentage of spermatozoa with normal morphology (A forms) and the average number of penetrations per oocyte (Sperm Capacitation Index) was evaluated in all cases. Using a multiple linear regression analysis with all semen parameters, sperm morphology was the best predictor (p=0.001) of the SPA score. The agreement between the percentage of A forms and the Sperm Capacitation Index beyond chance (kappa coefficient) was 0.5842. Twenty‐two specimens had abnormal SPA scores, with 21 exhibiting abnormal sperm morphology (Sensitivity=96%). The remaining 34 samples had normal Sperm Capacitation Index values; of these, 23 had normal sperm morphology in semen (Specificity=68%). The positive predictive value was 96%, and the negative predictive value was 66%. All semen samples from control donors had normal semen parameters and Sperm Capacitation Index values. In conclusion, the percentage of spermatozoa with normal morphology assessed using Tygerberg criteria (>14% A forms) are predictive of the results in the TYB‐optimized SPA. However, sperm morphology appears to be a better predictor when it is normal than when it is abnormal.
Clinical characteristics of prostate cancer in Gunma Prefecture
Authors: Kurokawa  , Fukabori  , Ito  , Suzuki  , Nakata  , Suzuki  , Imai  , Suzuki  , Namiki  , Yamanaka
Published: March 2003

Prostate cancer clinical data from patients registered at Gunma University Urologic Oncology Study Group were compared between pre‐PSA and PSA eras, dividing them between those patients diagnosed at clinical practice and those diagnosed on the Gunma mass‐screening programme.

In the MS, the number of incidents of prostate cancer increased from 126 out of 16750 screened cases in the pre‐PSA era (0.75%) to 227 out of 19782 screened cases in the PSA era (1.15%). The average age was lower in the PSA era. As for clinical stage, stage B and C cases increased while stage D cases decreased.

For the clinical practice cases at the Gunma University Urologic Oncology Study Group, the number of registered incidents of prostate cancer increased from 1164 in the pre‐PSA era to 2098 in the PSA era. The average age was similar between the pre‐PSA and PSA eras. The percentage of cases who were stage D declined from 46.1 during the pre‐PSA era to 37.7 in the PSA era.

In the PSA era, earlier and more cases of prostate cancer are diagnosed both in clinical practice and in the mass screening program in Gunma Prefecture.
Up‐regulation of cytokines in glomerulonephritis associated with murine malaria infection
Authors: Sinniah Raja , Rui‐Mei Li , Kara Au
Published: March 2003

Malaria infections often cause glomerulonephritis (GN), and multiple factors have been implicated in the pathogenesis of glomerular injury. The role of cytokines in malaria associated glomerulonephritis has not been clearly defined. To study the importance of cytokines in malarial nephritis, we investigated the expression of tumour necrosis factor‐alpha (TNF‐α), interleukin‐1alpha (IL‐1α), IL‐6, IL‐10 and granulocyte macrophage‐colony stimulating factor (GM‐CSF) in kidneys acutely infected with murine malaria parasite Plasmodium berghei ANKA in C57BL/6 J mice. Groups of six mice sacrificed on days 5, 8–10, 15, and 20 postinfection, and normal controls were used for cytokine analysis. Elevated levels of messenger RNA (mRNA) specific for these cytokines in infected kidneys after day 5 postinfection were demonstrated by reverse transcription‐polymerase chain reaction (RT‐PCR) analysis. Kidney sections stained with specific antibodies against TNF‐α, IL‐1α, IL‐6, IL‐10 and GM‐CSF by immunohistochemistry showed that the staining for these cytokines on the glomeruli was positive from day 10 postinfection, and increased progressively, mainly in the infiltrating macrophages and the glomerular mesangium. Strong correlation was found between the expression of TNF‐α with IL‐6, and IL‐1α with IL‐6. The expression of TNF‐α, IL‐1α, IL‐6, and IL‐10 also strongly correlated with the severity of proteinuria. Our findings show that there is up‐regulation of cytokines in the pathogenesis of glomerulonephritis associated with murine malaria infection.
Synergistic action of endothelin (ET)‐1 on the activation of bronchial fibroblast isolated from normal and asthmatic subjects
Authors: Dubé Jean , Chakir Jamila , Dubé Carl , Grimard Yan , Laviolette Michel , Boulet Louis‐Philippe
Published: March 2003

Bronchial subepithelial fibrosis is an histological characteristic of asthma. Cytokines and other mediators, such as PDGF‐BB, TGF‐β1 and ET‐1 found in the asthmatic submucosa can potentially activate a repair process that leads to fibroblast proliferation and collagen synthesis. The mechanisms of modulation of the repair process leading to extracellular matrix deposition are still to be documented. In this study, we assessed thein vitroproliferation and collagen synthesis of bronchial fibroblasts isolated from normal and asthmatic subjects in response to ET‐1, platelet‐derived growth factor (PDGF)‐BB and transforming growth factor (TGF)‐β1 alone or in combination, in the presence or absence of dexamethasone. The combination of ET‐1 with one of the other two growth factors, or the triple combination, significantly increased DNA synthesis and collagen production of bronchial fibroblasts isolated from both normal and asthmatic subjects, but the same growth factors used separately had no significant effect on the same parameters. These results suggest that the simultaneous presence of ET‐1, PDGF‐BB and TGF‐β1 in both normal and asthmatic subjects is necessary to activate bronchial fibroblast proliferation and collagen synthesis. As these mediators are present in the submucosa of the asthmatic bronchi, they could be responsible, at least in part, for the accumulation of collagen in the mucosa.
Viral escape mechanisms – escapology taught by viruses
Authors: Lucas Michaela , Karrer URS , Lucas Andrew , Klenerman Paul
Published: March 2003

Viruses have ‘studied’ immunology over millions of years of coevolution with their hosts. During this ongoing education they have developed countless mechanisms to escape from the host's immune system.To illustrate the most common strategies of viral immune escape we have focused on two murine models of persistent infection, lymphocytic choriomeningitis virus (LCMV) and murine cytomegalovirus (MCMV).LCMV is a fast replicating small RNA virus with a genome prone to mutations. Therefore, LCMV escapes from the immune system mainly by two strategies: ‘speed’ and ‘shape change’. At the opposite extreme, MCMV is a large, complex DNA virus with a more rigid genome and thus the strategies used by LCMV are no option. However, MCMV has the coding capacity for additional genes which interfere specifically with the immune response of the host. These escape strategies have been described as ‘camouflage’ and ‘sabotage’. Using these simple concepts we describe the spectrum of viral escapology, giving credit not only to the researchers who uncovered this fascinating area of immunology but also to the viruses themselves, who still have a few lessons to teach.
Modelling the change in colour of potassium sorbate powder during heating
Authors: Han Jung H. , Floros John D.
Published: March 2003

Colour change of potassium sorbate caused by heating was statistically modelled to examine its potential as a time–temperature process indicator. A full factorial design with five levels of heating time (t) and temperature (T) was used. L, a and b values were measured by a HunterLab colorimeter, and second‐order polynomial models were developed. Heating significantly reduced L and increased b values, causing the potassium sorbate powder to turn dark yellow, possibly because of non‐enzymatic browning reactions. Statistically significant models with good fit were developed for L and b, and their response surfaces were generated. This potassium sorbate‐based system may be a suitable indicator for high‐temperature heating processes such as dry heat sterilizers or baking ovens.
The characteristics of percolation olive oils produced with a new processing enzyme aid
Authors: Ranalli Alfonso , De Mattia Gabriella , Ferrante Maria L.
Published: March 2003

Theee olive varieties (Leccino, Coratina and Dritta) were processed using the percolation–centrifugation system with a new olive enzyme processing aid, ‘Cytolase 0’. The enzyme adjuvant led to oils characterized (with respect to reference oils) mostly by: (i) higher contents of total phenols, o‐diphenols, tyrosol‐ and hydroxytyrosol‐aglycones, tocopherols, trans‐2‐hexenal and other pleasant aromatic volatile compounds, and triterpene alcohols; (ii) higher values of oxidative stability and carotenoid colour index; (iii) higher ratios of 1,2‐diglycerides/1,3‐diglycerides, campesterol/stigmasterol, trans‐2‐hexenal/hexanal, and trans‐2‐hexenal/total aroma; (iv) lower values of turbidity; (v) similar values of acidity, peroxide index, carbonyl index, UV (ultraviolet) spectrophotometric indices and alcoholic index; (vi) similar contents of saturated fatty acids, unsaturated fatty acids, triglycerides, diglycerides, sterols, and green lipochromes; and (vii) similar sensory score. Stigmastadienes, trans‐oleic, trans‐linoleic, and trans‐linolenic acid isomers were not detected. Hence, the enzyme adjuvant produced better qualitative characteristics and higher extraction outputs.
The use of response surface methodology to optimize the Maillard reaction to produce melanoidins with high antioxidative and antimutagenic activities
Authors: Lee Gee‐Dong , Kwon Joong‐Ho
Published: March 2003

Response surface methodology was applied to determine the optimum conditions for the Maillard reaction so that high levels of antioxidative and antimutagenic substances could be produced from defatted soybean and corn starch hydrolysates. The optimum reaction conditions predicted to produce the greatest levels of active antioxidative and antimutagenic melanoidins were 155.0 °C for 6.3 h at a pH of 12.1 and 155.5–160.4 °C for 4.60–9.70 h at pH 10.4–12.5 respectively. The range of optimum reaction conditions to maximize melanoidin production were 148–170 °C for 3.0–7.5 h at pH values between 10.2 and 13.5. These predicted values for optimum reaction conditions were in good agreement with experimental values.
Normalized particle residence times as affected by process parameters in a vertical scraped surface heat exchanger
Authors: Lee Jun H. , Singh Rakesh K.
Published: March 2003

The effects of process parameters and their two‐way interactions on the normalized particle residence times (NPRTs) of 1.0–2.0 cm potato cubes in 0.4–1.2% aqueous solutions of sodium carboxymethylcellulose (CMC), flowing at 453–599 mL s−1 in a vertical scraped surface heat exchanger, rotating at 60–160 rpm were investigated. Minimum and maximum NPRTs and the standard deviations of the mean values were not significantly affected by the conditions studied (P < 0.05). Mean NPRTs were significantly influenced by process parameters, including the concentration of the carrier, mutator speed and particle size, as well as two‐way interactions between flow rate, mutator speed and particle size (P < 0.001). The orientation of the heat exchanger was an important factor influencing the forces acting on the particles.
Effects of storage atmosphere on Listeria monocytogenes and competing microflora using a surface model system
Authors: Francis Gillian A. , O'Beirne David
Published: March 2003

A solid‐surface model system was used to study the effects of gas atmospheres encountered in modified atmosphere packaging of vegetables on the survival and growth of Listeria monocytogenes and competing micro‐organisms. The effects of increasing CO2 levels (from 5% to 20%), 100% N2 and 3% O2 were determined. The model system allowed for estimation of the growth of L. monocytogenes alone or in the presence of competing microflora. CO2 concentrations of 5–10% (with 5% O2 in N2) had no inhibitory effect, by comparison with air, on the growth and survival of pure cultures of L. monocytogenes. At 20% CO2 population densities were reduced up to day 8, but the final population densities reached were not. An atmosphere of 100% N2 allowed survival of pure cultures of L. monocytogenes, but populations did not significantly change (P > 0.05) during storage, whereas a low O2 (3%, balance N2) atmosphere allowed significant growth (P < 0.05) of L. monocytogenes. Growth and inhibitory activities of Enterobacter cloacae and E. agglomerans were inversely related to the concentration of CO2. By contrast, the growth and anti‐listerial activities of Leuconostoc citreum increased with elevated CO2 concentrations. In the low O2 atmosphere, L. monocytogenes grew considerably better in the presence of populations from the indigenous microflora of lettuce than when in pure culture. The results indicate that the gas atmospheres present within modified atmosphere packages of minimally processed vegetables may affect the interactions between the pathogen and the natural competitive microflora sufficiently to indirectly enhance L. monocytogenes growth.
A modified colorimetric method for the estimation of β‐cyclodextrin using phenolphthalein
Authors: Basappa Channa , Rao Pramila , Rao D. Narasimha , Divakar
Published: March 2003

The binding equilibrium between β‐cyclodextrin and phenolphthalein has been used to develop a method for the estimation of β‐cyclodextrin in solution. From logarithmic plots of amounts of β‐cyclodextrin against absorbance at 554 nm, a relation log X = (log A − log Y)/B was found, which gave an estimate of β‐cyclodextrin in the concentration range 0.0045 mg mL−1 (3.96 μm) to 4.7 mg mL−1 (4.14 mm), where X = intercept and B = slope. This method was found to be highly reproducible and reliable.
Application of competitive indirect enzyme‐linked immunosorbent assay (Ci‐ELISA) for monitoring the degree of frozen denaturation of bovine myosin
Authors: Lee Ju‐Woon , Park Jong‐Heum , Kim Seong‐Bae , Kim Cheon‐Jei , Hyun Chang‐Kee , Shin Heuyn‐Kil
Published: March 2003

The denaturation of myosin on freezing and frozen storage was monitored using competitive indirect enzyme‐linked immunosorbent assay (Ci‐ELISA) formatted with polyclonal antibodies anti‐MWM IgG, anti‐S‐1 IgG and anti‐LMM IgG raised against the antigens (Ags) bovine myosin whole molecules (MWMs), heavy meromyosin S‐1 (myosin head part, S‐1) and light meromyosin (myosin tail part, LMM) respectively. Beef slices and cuts stored at −20 °C or −50 °C lost immune affinity with all antibodies, in particular anti‐LMM IgG. Repeated thawing–refreezing treatment caused more myosin denaturation than simple freezing. Myosin from beef stored at −20 °C was denatured more than that stored at −50 °C. The immune affinities between anti‐LMM IgG and thawed samples were similar to those from anti‐MWM IgG. We were unable to differentiate reliably between fresh and thawed beef using anti‐S‐1 IgG. Myosin was denatured by freezing, in particular its tail part (LMM).
Water changes in canned dry peas and beans during heat processing
Authors: Thanos Apostolos J.
Published: March 2003

The amount of water absorbed by dry peas (Pissum sativum L. cv. ‘Marrowfat’) and dry beans (Phaseolus vulgaris L. cv. ‘Haricot’) during soaking, blanching and canning was studied. The temperature during soaking significantly affected the water absorption rate up to 40 °C, but not beyond this temperature. The final water content of the product was significantly increased by blanching after soaking as opposed to blanching before soaking. Water uptake was also significantly affected by the water used. Total water uptake was about 150% greater in peas when soft water was used (60 °C). High soaking temperatures with correspondingly short soaking time (4 h at 60 °C) would be advantageous to a food manufacturer. Under these conditions, water absorption is increased in the finished product and the amount of product ‘in process’ is reduced, allowing a greater flexibility and control of the process.
The effects of pH, salt, heating and freezing on the physical properties of bacterial cellulose—nata
Authors: Chung Yunchung , Shyu Yuantay
Published: March 2003

Summary The effects of pH (2, 7 and 10), NaCl concentrations (0, 1, 3 and 5% w/w), and temperatures (−20, 25 and 100 °C) on the physical properties of nata, a bacteria cellulose produced by Acetobacter aceti ssp. xylinum, were evaluated in this study. The addition of NaCl was found to increase the hardness of nata but to decrease the water‐holding capacity; however, no effect of NaCl on the hardness of nata was found when nata was acidified or alkalized. Compared to the texture properties of nata at 25 °C, freezing at −20 °C for 24 h gave a more elastic texture, but heating at 100 °C for 3 h had no significant effect on the textural properties. The results of this study indicated that acidification or alkalization was necessary to prepare salted nata products without increasing their hardness.
Non‐thermal inactivation of Lactobacillus plantarum as influenced by pressure and temperature of pressurized carbon dioxide
Authors: Hong Seok‐In , Park Wan‐Soo , Pyun Yu‐Ryang
Published: March 2003

Summary Non‐thermal inactivation of Lactobacillus plantarum cells as influenced by pressure and temperature of pressurized carbon dioxide was investigated to evaluate its potential use for preservation of foods and biological substances. Microbial inactivation by the pressurized CO2 was dependent principally on the transfer rate of CO2 into cells and effectiveness could be improved by increasing pressure and temperature. Microbial reduction of more than 6 logs occurred within 30 min under CO2 pressure of 2000 psi at 30 °C. The results showed that the pressurized CO2 treatment could be used as a potential non‐thermal preservation technology for foods.
High moisture food extrusion
Authors: Akdogan Hülya
Published: March 2003

Summary Extrusion at higher moisture contents (> 40%), also known as wet extrusion, is relatively less investigated compared to low and intermediate moisture extrusion. Literature on high moisture food extrusion has been reviewed. Wet extrusion applications utilise twin screw extruders due to their efficient conveying capabilities. Extruders can be used as bioreactors for starch hydrolysis using thermally stable enzymes. This process is usually followed by saccharification inside or outside an extruder to produce a high DE (dextrose equivalent) syrup. Starch‐based high moisture extrusion research also reports a few modelling studies. The rheological properties, torque and energy requirements of high moisture extrusion systems are different from those of low and intermediate systems. Other research reviewed includes the extrusion of low‐cost plant and animal proteins to manufacture nutritious food products that imitate the texture, flavour, and mouthfeel of meat.
Changes in phenolic content of olive during maturation
Authors: Ryan Danielle , Robards Kevin , Lavee Shimon
Published: March 2003

Summary Qualitative and quantitative data are presented for the phenolic content of cvs Manzanillo and Cucco based on separation by high performance liquid chromatography, HPLC, with ultraviolet, fluorescence and mass spectrometric detection. Oleuropein is the principal phenolic compound in olive and its concentration changed significantly during fruit development. Changes in the content of tyrosol, ligstroside and verbascoside were also observed but these were relatively smaller.
Application of native and phosphorylated tapioca starches in potato starch noodle
Authors: Muhammad Kharidah , Kusnandar Feri , Mat Hashim Dzulkifly , Rahman Russly AbD.
Published: March 2003

Summary Characteristics of potato starch noodles substituted with native, phosphorylated and commercial phosphorylated (MTS283) tapioca starches were evaluated. Substitution of up to 17% with phosphorylated tapioca starch or up to 35% with MTS283 improved the quality of potato starch noodles. The resulting noodles were transparent and less brittle when uncooked, and were moderately elastic, less sticky and experienced lower cooking loss and less swelling when cooked. Substitution with native tapioca starch of up to 17% was also possible, but the uncooked noodles were less transparent and the cooked noodles swelled more and were less elastic.
Rheological properties of some starch‐water‐sugar systems
Authors: Sikora Marek , Pielichowski Krzysztof
Published: March 2003

Summary When certain amounts of starch were blended with saturated, aqueous solutions of d‐fructose, d‐glucose or sucrose, shear thickening, easily pourable semi‐solids were formed. The amount of starch necessary to cause this rheological effect depended, at least in part, on the starch variety. The conditions necessary to observe this effect using potato and corn starch blends with d‐fructose, d‐glucose and sucrose are presented. This method may be useful in studies of starch granule morphology. Gelation characteristics and differential scanning calorimetry (DSC) of potato and corn starch in saturated aqueous d‐fructose, d‐glucose, and sucrose solutions showed that both starch varieties interacted differently with the environment. Starch more readily gelatinised in sucrose solutions than in solutions of d‐fructose and d‐glucose.
A comparison of the quality of whole corn tortillas made from instant corn flours by traditional or extrusion processing
Authors: Gómez‐Aldapa C. , Martínez‐Bustos F. , Figueroa C. J. D. , Ordorica F. C. A.
Published: March 2003

Summary The nutritional quality (chemical and biological assays) was evaluated for tortillas made with two samples of instant corn flour prepared with 0.15 and 0.25% calcium hydroxide and processed either by extrusion or by the traditional process (nixtamalization). Both raw corn and the tortillas made from instant whole corn flours prepared by extrusion (TEP) had higher Protein Efficiency Ratio (PER), and Net Protein Utilization (NPU) values (p < 0.05) than tortillas prepared from traditional nixtamalization process. The Ca assimilation in the femurs bones of rats fed with raw corn, TEP (with 0.25% lime), and tortillas prepared from the nixtamal process, yielded lower values (p < 0.05) as compared with those shown by the rats fed with the other treatments of TEP (with 0.15% lime). The Ca, Mg, and P contents and protein quality of the treatments used in the feed affected some physical characteristics rat femurs (length, diameter, weight, breaking force, volume and density). The force required to break the femurs of rats fed diets of raw corn, tortillas prepared using the traditional process and without added protein, was measured and compared with the force required to break the femurs of rats fed with diets contain casein and TEP with either 0.15 and 0 0.25% lime. Those animals assimilating the lowest content of lime had the weakest femurs.
Heat‐induced denaturation and aggregation of β‐Lactoglobulin: kinetics of formation of hydrophobic and disulphide‐linked aggregates
Authors: Galani Despina , Owusu Apenten* Richard K.
Published: March 2003

Summary Solutions of a whey protein mixture were subjected to various time/temperature treatments, at pH 6.7. Kinetic and thermodynamic activation parameters for the rates of irreversible denaturation/aggregation of the principal whey protein component—β‐lactoglobulin (β‐lg) were followed by gel permeation. Fast Protein Liquid Chromatography (non‐dissociating, non‐reducing conditions) and by SDS‐PAGE (dissociating, non‐reducing conditions). The rate of loss of native β‐lg owing to the formation of disulphide linked protein aggregates (ksds‐page) and the rate of formation of aggregates via both covalent and non‐covalent bonds (kgp‐fplc) showed similar biphasic Arrhenius plots. However, the break of the plot occurred at different points. The kgp‐fplc values were higher than values of ksds‐page for all the temperatures examined. There was a similar trend for the thermodynamic activation parameters implying that not all of the β‐lg aggregates through thiol–disulphide interactions. Hydrophobically driven associations occur within the aggregates.
Some physico‐chemical properties of nine commercial or semi‐commercial whey protein concentrates, isolates and fractions
Authors: Holt Carl , McPhail Deborah , Nylander Tommy , Otte Jeanette , Ipsen Richard H. , Bauer Rogert , Øgendal Lars , Olieman Kees , de Kruif Kees G. , Léonil Joëlle , Mollé Daniel , Henry Gwénaële , Maubois Jean Louis , Pérez M. Dolores , Puyol Pilar , Calvo Miguel , Bury Stella M. , Kontopidis George , McNae Iain , Sawyer Lindsay , Ragona Laura , Zetta Lucia , Molinari Henriette , Klarenbeek Bert , Jonkman Margrethe J. , Moulin Jacques , Chatterton Dereck
Published: March 2003

Summary The physico‐chemical properties are reported for a group of whey protein powders prepared on a commercial or semi‐commercial scale by three companies and chemically characterized as described elsewhere (Holt et al., 1999). The dependence of the apparent β‐lactoglobulin % on the recovered % showed that the nine samples could be placed in three distinct groups with β‐lactoglobulin weight % of 70.9 ± 1.1 (Group 1), 62.0 ± 3.4 (Group 2) and 39.5 ± 4.9 (Group 3). Measurements by 1H‐NMR spectroscopy, on 3 of the samples confirmed that the native fold still predominated in the β‐lactoglobulin. β‐lactoglobulin could be crystallized from all the powders and the normal space group and cell dimensions were determined for the 8 samples that gave crystals of good enough quality for X‐ray studies. Differential scanning microcalorimetry of samples dispersed in a phosphate buffer showed a clear difference between Goups 1 and 2 with a more prominent peak due to α‐lactalbumin in the Group 2 samples. Light scattering and size exclusion chromatography showed that two types of aggregates were present to a variable extent in all the samples and after a heat treatment, the larger aggregates tended to predominate in Group 2. The rheology measurements, also made in the phosphate buffer, showed a difference of gel stiffness during heat treatment between the Group 1 and Group 2 samples with the exception of the BORCwpc+ sample. Within each group, gel stiffness increased with the degree of lactoslylation of the β‐lactoglobulin. Interfacial measurements on samples dispersed in water presented a more complex pattern of behaviour although surface tension measurements at the air water interface of the Group 2 samples showed a two‐step pattern of surface tension decrease with time, compared to a single step pattern in the Group 1 samples.
Xanthylium salts formation involved in wine colour changes
Authors: Es‐Safi Nour‐Eddine , Le Guernevé Christine , Fulcrand Hélène , Cheynier Véronique , Moutounet Michel
Published: March 2003

Summary The reaction of (+)‐catechin in wine‐like model solution was investigated. First appearance of colourless dimeric compounds consisting of two flavanol units linked by carboxy‐methine bridge was observed. Their isolation and further incubation was found to yield two types of yellowish pigments showing visible absorption maxima at 440 and 460 nm, respectively. Mass spectroscopy (MS) spectral analysis showed that the first type were xanthylium salt pigments formed by dehydration of the colourless compounds followed by an oxidation process. The loss of a water molecule was shown to take place between two A ring hydroxyl groups of the colourless dimers. The second type were shown to be ester derivatives of the first ones. Thus ethylester of xanthylium salt was obtained and fully characterized by mass and nuclear magnetic resonance (NMR) spectroscopy. Esterification was found to involve the colourless compound before dehydration and thus a general scheme for xanthylium salt formation was postulated. The proposed scheme constitutes a new xanthylium formation pathway as up to now only anthocyanin‐flavanol reactions were supposed to form xanthylium salt derivatives during wine ageing. This work also provides new support to the contribution of xanthylium salt in colour evolution observed during wine ageing which is generally expressed in an increase of absorption in the 400–500 nm, region of xanthylium salt absorption maxima.
An overview of formation and roles of acetaldehyde in winemaking with emphasis on microbiological implications
Authors: Liu Shao‐Quan , Pilone Gordon J.
Published: March 2003

Summary Acetaldehyde is an important aroma compound in wine. This article first reviews the microbial and chemical formation of acetaldehyde, then the effects of sulphur dioxide on acetaldehyde and effects of acetaldehyde on wine colour and physical stability are described briefly. Finally, the microbiological implications of acetaldehyde are emphasized with respect to practical significance in wine fermentation.
The effects of freezing and freeze‐drying of Oenococcus oeni upon induction of malolactic fermentation in red wine
Authors: Maicas Sergi , Pardo Isabel , Ferrer Sergi
Published: March 2003

Summary The use of Oenococcus oeni starter cultures for the induction of malolactic fermentation (MLF) in wine permits control over the timing of the process and the quality of the wine. Successful inoculation of bacterial starter cultures into wine depends on the selection of suitable strains and on the preparation and conservation of those cultures. Medium for Leuconostoc oenos (MLO) is the best medium for easy and rapid growth of O. oeni cultures under laboratory controlled conditions for isolation and identification. However, this study showed that O. oeni cells inoculated in MLO failed to induce MLF in wine while cells grown in Medium of Preculture (MP) or wine, stored at −20 °C or freeze‐dried retained the ability to induce MLF when inoculated in wine. Our results suggest that the use of freeze‐dried cultures of O. oeni previously grown in MP is the best choice for industrial application.
Textural properties of a model aqueous phase in low fat products. Part 1: Alginate, caseinate and starch in isolation, and in starch containing binary mixtures
Authors: Roberts Simon A. , Kasapis Stefan , De Santos López Inés
Published: March 2003

Summary The effect of increasing additions of calcium on the textural properties of alginate, caseinate and starch dispersions was investigated to provide a baseline for further work on mixtures of these biopolymers. Increasing concentrations of calcium transformed the alginate solutions into gels having a maximum rigidity at 1000 and 300 p.p.m. Ca2+ for 2.0 and 0.5% of the polysaccharide, respectively. Gelation was achieved by cooling which unveiled a two stage process of network formation. Caseinate solutions (12%) showed an increased viscosity with a rising Ca2+ concentration up to 2250 p.p.m., above which viscosity decreased. Starch (2.5%) exhibited a slight loss in storage modulus (G′) with increasing levels of calcium. The texture of the alginate starch mixture was determined by the alginate component (two stage gelation process), but inverted to that of starch at high levels of added Ca2+. In the absence of the counterion, casein had an adverse effect on the strength and cohesion of starch networks. At 400 p.p.m. Ca2+, the protein forms a continuous liquid like phase which suspends the starch inclusions thus dictating the textural properties of the mixture. Caseinate continues to dominate up to 1200 p.p.m. Ca2+, at which point the starchy matrix influences the system once more. Finally at higher levels of the counterion the sample phase inverts back to a starch continuous gel. Part 2 of this work examines the effect of calcium on the remaining preparations in order to facilitate the formulation of improved low fat products.