bluuebunny/crossref_metadata_2025 huggingface dataset:
An in vitro comparison of pH changes in root dentine following canal dressing with calcium hydroxide points and a conventional calcium hydroxide paste
Authors: Ardeshna S. M. , Qualtrough A. J. E. , Worthington H. V.
Published: March 2003

Aim This study aimed to measure and compare pH changes at apical and cervical sites on the external root surface of extracted teeth dressed with calcium hydroxide in two different formulations.

Methodology Root canals of 45 single‐rooted extracted human teeth were accessed and shaped using a step‐down technique with rotary instrumentation. Standard cavities were prepared on the external root surface at specific apical and cervical sites. The teeth were randomly allocated to three groups. Teeth in group A were dressed with calcium hydroxide points, those in group B were dressed with an aqueous calcium hydroxide paste and teeth in group C were left unfilled. Following storage in humid conditions, the pH of the dentine at apical and cervical sites was measured at baseline and then at 24 h, 72 h, 1 week, 10 days, 2 weeks and 3 weeks.

Results The pH of the root dentine at both apical and cervical sites was significantly greater (P < 0.001) in teeth dressed with aqueous calcium hydroxide paste compared with those dressed with calcium hydroxide points, when averaged out across all time periods. For all groups, there was a significant difference between the mean apical and cervical pH values for each tooth with lower values for the apical sites (P < 0.001).

Conclusion The results of this study indicate that an aqueous calcium hydroxide paste was more effective than calcium hydroxide points at raising the pH on the external root surface of extracted teeth.
A protocol for polymerase chain reaction detection of Enterococcus faecalis and Enterococcus faecium from the root canal
Authors: Molander A. , Lundquist P. , Papapanou P. N. , Dahlén G. , Reit C.
Published: March 2003

Aim The present study was set up to develop a protocol for detection of Enterococcus faecalis and Enterococcus faecium from the root canal.

Methodology A collection of type strains and clinical isolates of E. faecalis and E. faecium was used. Specific polymerase chain reaction (PCR) primers targeted against the 16S/23S rDNA intergenic region were used and PCR reactions were set up. PCR products were run on TBE‐agarose gel and analysed. The sensitivity of the PCR system was studied using serial dilutions of (i) bacterial DNA and (ii) bacterial cells from E. faecalis. The specificity of the identification was tested against closely related species.

Results All strains of E. faecalis and E. faecium produced identical amplicon profiles composed of two major bands corresponding to sizes of 320 and 420 bp. When amplifying DNA of higher purity, a third band of 600 bp became evident as well. Closely related species demonstrated single bands of various sizes and were easily distinguished from enterococci. The detection level of DNA from serial dilutions of DNA was 10−13 g. The DNA extraction protocol from bacterial cell suspensions resulted in a detection level of 10 bacterial cells per sample.

Conclusions The present study demonstrated a good potential for using PCR technology in the detection of E. faecalis and E. faecium from root canal samples. With a high specificity the methodology was able to detect 10 cells of E. faecalis.
An in vitro comparison of the bactericidal efficacy of lethal photosensitization or sodium hyphochlorite irrigation on Streptococcus intermedius biofilms in root canals
Authors: Seal G. J. , Ng Y.‐L. , Spratt D. , Bhatti M. , Gulabivala K.
Published: March 2003

Aim To compare the bacterial killing of Streptococcus intermedius biofilms in root canals using lethal photosensitization with various combinations of photosensitizer concentration and laser light dose or 3% sodium hypochlorite (NaOCl) irrigation.

Methodology Extracted teeth (n = 35) with single canals were selected and the canals prepared to apical size 25 with a 10% taper. The teeth were autoclaved and the canals inoculated with Streptococcus intermedius in brain heart infusion broth and were incubated for 48 h to allow a biofilm to form. The teeth were then subjected to 3% NaOCl irrigation (n = 4) or lethal photosensitization using combinations of a range of toluidine blue O (TBO) photosensitizer concentrations (12.5, 25, 50, 100 µgmL−1) and light doses (60, 90, 120, 300, 600 s equivalent to energy doses of 2.1–21 J) using a 35‐mW helium–neon low power laser targeted at the access cavity (n = 4 for each combination). Controls consisted of laser light only (TBO = 0 µgmL−1) (n = 4), TBO only (light dose = 0 s) (n = 4), and no treatment (positive control n = 17). Following treatment the canal contents were sampled with sterile paper points, the sample was dispersed in transport medium, serially diluted and cultured on blood agar to determine the number of colony forming units (CFU).

Results The combination of 100 µgmL−1 TBO and 600 s (21 J) of laser energy achieved maximum reduction in recovered viable bacteria (5 log10 CFU). TBO at low concentrations (≤50 µgmL−1) was not bactericidal but treatment with 100 µgmL−1 TBO alone reduced recovered viable bacteria by 3 log10 CFU. Laser light alone had limited bactericidal effect. No viable bacteria were recovered following treatment with 3% NaOCl.

Conclusions The combined use of a photosensitizing agent and a low power laser directed at the access cavity was bactericidal to S. intermedius biofilms in root canals but was unable to achieve total kill, unlike 3% NaOCl.
The perceived benefit of endodontic retreatment
Authors: Kvist T. , Reit C.
Published: March 2003

Kvist T, Reit C. The perceived benefit of endodontic retreatment. International Endodontic Journal, 35, 359–365, 2002.

Aim There is substantial variation amongst dentists in the management of symptom‐free periapical lesions in root‐filled teeth. It has been suggested that this variation can be understood as clinicians’ choice of different cut‐off points on a continuous periapical health scale (the ‘Praxis Concept (PC) theory’). Based on this suggestion, an individual’s inclination to propose retreatment can be expressed in the Retreatment Preference Score (RPS). In the present study it was hypothesized that: (i) the PC theory is valid amongst experienced endodontists; and that (ii) interindividual variation in RPS can be explained by a corresponding variation in the perceived benefit of endodontic retreatment.

Methodology The RPS was determined for 16 experienced Swedish endodontists. The retreatment benefit (RTB) was defined as the gain in utility when a root‐filled tooth with a persistent periapical lesion (‘health state B’) moved to a state where the lesion had healed (‘health state A’). For each individual the utility values of the two health states were measured by means of the standard gamble technique.

Results The RPS and RTB were found to be subjected to substantial inter‐ and intrarater variation. The decision makers acted in accordance with the PC theory. No significant correlation between RPS and RTB was detected.

Conclusions Findings suggest that the PC theory is valid amongst endodontic experts. The study did not support the notion that the more potential utility that could be produced, the more the individual dentist should tend to perform retreatment. However, alternative consequentialist strategies focusing low risk taking may be involved.
Reduction in intracanal bacteria during root canal preparation with and without apical enlargement
Authors: Coldero L. G. , McHugh S. , MacKenzie D. , Saunders W. P.
Published: March 2003

Aim To compare in vitro intracanal bacterial reduction using nickel–titanium rotary instruments with and without apical enlargement.

Methodology Thirty‐eight palatal roots of maxillary molar teeth, with mature apices were subdivided according to lengths and then randomly assigned to two experimental and one control groups. The roots were sterilized and then reinfected with Enterococcus faecalis, which served as a bacteriological marker. All roots in the experimental groups were prepared in a step‐down sequence with engine‐driven GT rotary files at 350 rpm. In experimental group A (n = 16) additional apical enlargement to ISO size 35 was performed. In group B (n = 16) a serial step‐back technique was followed with no apical enlargement. This was combined in groups A and B with irrigation with NaOCl and EDTA. In the control group (group C, n= 6) irrigation only was carried out, with no mechanical preparation. Samples were then taken from the root canals to determine the numbers of remaining bacteria.

Results In groups A and B, 15 (94%) and 13 (81%) specimens were rendered bacteria‐free, respectively. In the control group C none of the specimens were bacteria‐free. There was a significant difference (P < 0.001) in the antibacterial effects of experimental and control regimens. There was, however, no significant difference (P = 0.276) between the preparation methods used in the experimental groups.

Conclusions There was no significant difference in intracanal bacterial reduction when Ni–Ti GT rotary preparation with NaOCl and EDTA irrigation was used with or without apical enlargement preparation technique. It may therefore not be necessary to remove dentine in the apical part of the root canal when a suitable coronal taper is achieved to allow satisfactory irrigation of the root canal system with antimicrobial agents.
Supplementary routes to local anaesthesia
Authors: Meechan J. G.
Published: March 2003

Meechan JG. Supplementary routes to local anaesthesia. International Endodontic Journal, 35, 885–896, 2002.

The satisfactory provision of many dental treatments, particularly endodontics, relies on achieving excellent pain control. Unfortunately, the administration of a local anaesthetic solution does not always produce satisfactory anaesthesia of the dental pulp. This may be distressing for both patient and operator. Fortunately, failure of local anaesthetic injections can be overcome. This is often achieved by using alternative routes of approach for subsequent injections. Nerves such as the inferior alveolar nerve can be anaesthetized by a variety of block methods. However, techniques of anaesthesia other than the standard infiltration and regional block injections may be employed successfully when these former methods have failed to produce adequate pain control. This paper describes some supplementary local anaesthetic techniques that may be used to achieve pulpal anaesthesia for endodontic procedures when conventional approaches have failed. Although some of these techniques can be used as the primary form of anaesthesia, these are normally employed as ‘back‐up’. The methods described are intraligamentary (periodontal ligament) injections, intraosseous anaesthesia and the intrapulpal approach. The factors that influence the success of these methods and the advantages and disadvantages of each technique are discussed. The advent of new instrumentation, which permits the slow delivery of local anaesthetic solution has led to the development of novel methods of anaesthesia in dentistry. These new approaches are discussed.
Improvement of sperm count and motility after ligation of varicoceles detected with colour Doppler ultrasonography
Authors: PIERIK  , VREEBURG  , STIJNEN  , ROIJEN J. H. VAN , DOHLE  , LAMÉRIS  , TIMMERS  , WEBER
Published: March 2003

The debate regarding the efficacy of varicocele ligation for improvement of semen parameters and pregnancy rates is ongoing. In addition, no consensus exists as to the benefit of treatment of subclinical varicoceles. The aim of this study was to investigate, retrospectively, the effect of high ligation of both subclinical and clinical varicoceles on sperm count and motility. The value of several factors from history‐taking and physical examination for the prediction of successful varicocelectomy was analysed. A total of 139 patients, operated on for a unilateral varicocele on the left side, were studied. Varicoceles were subclinical in 73 patients, based on colour Doppler ultrasonography, and 66 varicoceles were clinical, based on palpation in addition to ultrasonography. Comparison of semen parameters before and after surgery revealed a significant improvement. The median sperm count increased from 10.0 to 14.7, and from 18.2 to 28.6 million/ejaculate, in patients with subclinical and clinical varicoceles, respectively ( p < 0.001). The percentage improvement in median sperm count in subclinical varicoceles was not statistically different from the improvement in clinical varicoceles. Mean progressive motility improved significantly after ligation ( p < 0.001). The improvement in motility in subclinical varicoceles, from 16 to 23%, was significantly larger than the 24 to 27% improvement in clinical varicoceles. The increase in sperm count was related positively to testicular volume before surgery ( p < 0.05). The increase in sperm motility was significantly lower in patients with a history of cryptorchidism (n = 22, p < 0.05). The present data show that ligation of varicoceles detected using Doppler ultrasonography, whether palpable or not, results in an increase in sperm concentration and motility.
Testosterone replacement therapy in older adult men
Authors: Tenover J. Lisa
Published: March 2003

Serum testosterone levels decline slowly with normal ageing in men and, although all men are not destined to become hypogonadal as they age, the prevalence of androgen deficiency in the older male is not insignificant. Over the past several decades, there has been an increasing interest in evaluating whether testosterone therapy (male HRT) might be beneficial for certain older men in preventing or reversing some aspects of ageing. The major androgen target organs of interest with regard to beneficial effects of male HRT include bone, muscle, adipose tissue, the cardiovascular system and the central nervous system (libido and aspects of mood). At the same time, potential adverse effects of male HRT on target organs such as the prostate continue to be evaluated. It is the purpose of this review to summarize the information to date with regard to testosterone replacement therapy in the older man and to discuss areas where more research and clinical information need to be forthcoming.

Hormonal replacement therapy (HRT) for post‐menopausal women has been studied and discussed for many years. The idea of male HRT, however, is a relatively recent development, with increasing interest in this area occurring only over the past two decades. Reasons for this nascent enthusiasm include burgeoning evidence that testosterone levels decline with normal male ageing (and with age‐associated diseases) and an interest in preventing age‐related dysfunction and prolonging quality life among an ever increasing population of older adults. The decline in testosterone with age often parallels unfavourable changes in organs upon which androgens act and the goal of male HRT would be to prevent, stabilize or even reverse some of these detrimental target‐organ changes.
Inter‐observer variation in the results of the clinical andrological examination including estimation of testicular size
Authors: Carlsen Elisabeth , Andersen Anne‐Grethe , Buchreitz Louise , JØrgensen Niels , Magnus Øystein , Matulevicuus Valentinas , Nermoen Ingrid , Petersen JØrgen Holm , Punab Margus , Suominen Jyrki , Zilaitiene Birute , Giwercman Aleksander
Published: March 2003

Inter‐observer variation in andrological examination by 10 clinical investigators from five Nordic and Baltic countries was investigated. In addition, information on intra‐observer variation was obtained for six of the 10 investigators. Testicular size was measured using Prader’s orchidometer and one of the investigators also performed an ultrasound estimate of testicular size. A highly significant difference (p < 0.001) between observers was found with an inter‐observer error of 16% in estimating testicular size in 23 young men. The difference in the estimate tended to increase with increasing testicular size. There was no significant intra‐observer difference in two measurements performed on consecutive days. Only differences in median testis size, which were greater than 31% between measurements by two investigators, were found to be significant at the 5% level. The ultrasound estimate of testicular size was significantly lower than the orchidometer estimate, with a mean difference of 3.6 mL for the left testis and 4.3 mL for the right testis. Tanner staging of genitalia and diagnosis of a varicocele was subject to great inter‐observer variation, and for the diagnosis of varicocele only one‐third of the investigators was able to reproduce their results on a second examination.

In conclusion, it was found that the clinical andrological examination of young men is subject to great inter‐observer variation. This should be kept in mind when results from different studies are compared as well as in daily clinical practice.
Diurnal scrotal skin temperature and semen quality
Authors: Hjollund Niels Henrik I. , Bonde Jens Peter E. , Jensen Tina Kold , Olsen Jørn ,   The Danish First Pregnancy Planner Study Team
Published: March 2003

It is well established that heat is associated with reduced sperm production, but the role of physiological variation in temperature has never been scrutinized in humans. We studied diurnal scrotal temperature and markers of male fertility in a population of couples planning their first pregnancy. Sixty men from a cohort of couples who were planning their first pregnancy were included and scrotal skin temperature was monitored during 3 days using a portable data recorder. Working hours and working postures were recorded daily in a questionnaire. Each man provided a fresh semen sample and the couples were followed for six menstrual cycles or until a clinical pregnancy was recognized. The median value of scrotal skin temperature was 33.3 °C in the daytime and 34.8 °C at night. In periods of sedentary work, the median temperature was on average 0.7 °C higher (SE=0.2 °C). In addition, scrotal temperature was higher in the daytime, in summer, and in leisure time compared with working hours. Median sperm concentration among men with more than 75% of their daytime readings above 35 °C was 33.4 × 106/mL, compared with 91.8 × 106/mL for men with less than half of their readings above 35 °C (difference 58.4; 95% CI: 25.9–77.8 × 106/mL). It is concluded that a sedentary position is a significant source of increased scrotal skin temperature, and even moderate and physiological elevation in scrotal skin temperature is associated with a substantially reduced sperm concentration. Sedentary work should be considered as an important potential confounder for reduced sperm count in epidemiological research.
Specificity of a new lipid mediator produced by testicular and peritoneal macrophages on steroidogenesis
Authors: Lukyanenko  , Carpenter  , Boone  , Baker  , McGunegle  , Hutson
Published: March 2003

Macrophage‐derived factor (MDF) is a lipophilic factor produced by rat testicular and peritoneal macrophages that maximally stimulates testosterone production by rat Leydig cells through a steroidogenic acute regulatory protein independent mechanism. The purpose of the present study was to determine whether MDF is also produced by human macrophages, and/or if it acts on human steroidogenic cells. We also studied the tissue‐specific functions of MDF by determining if it also acts on steroidogenic cells of the ovary and adrenal glands and, if so, does it require new protein synthesis. It was found that MDF was produced by human peritoneal macrophages, and was capable of stimulating human steroidogenic cells. In terms of tissue specificity, it was found that primary cultures of rat adrenocortical cells respond to MDF with increased secretion of aldosterone and corticosterone, as did rat granulosa cells by producing progesterone. MDF acted in the presence of cycloheximide, indicating that it does not require new protein synthesis. These results indicate that MDF may have significant therapeutic potential and provide a basis for future studies concerning its physiological role in humans. These results further suggest that MDF is not only involved in paracrine regulation of Leydig cells, but also has the potential for the local regulation of steroidogenesis in both granulosa and adrenal cortical cells.
Seminal plasma androgen/oestrogen balance in infertile men
Authors: LUBOSHITZKY R. , KAPLAN‐ZVERLING M. , SHEN‐ORR Z. , NAVE R. , HERER P.
Published: March 2003

The hypothesis that the balance between oestrogen and androgen in seminal plasma is important for normal fertility was investigated. We determined the concentrations of oestradiol and testosterone in blood and seminal plasma from 62 infertile men and 32 normozoospermic men. Infertile men were classified according to semen analysis (concentration, motility and morphology): asthenozoospermia, oligozoospermia and oligoteratoasthenozoospermia. Serum luteinizing hormone (LH) and follicle‐stimulating hormone (FSH) were determined in all participants. For all subjects, mean testosterone levels were lower and mean oestradiol were higher in seminal plasma than in blood. Seminal plasma testosterone levels were lower in the infertile groups vs. control men ( p < 0.0002). Oligpzoospermic and oligoteratoasthenozoospermic men had significantly higher seminal plasma oestradiol levels compared with controls ( p < 0.03). The three infertile groups had significantly lower seminal plasma testosterone/oestradiol ratio than control men ( p < 0.001). Sperm analysis data (concentration, motility and morphology) significantly correlated with seminal plasma testosterone/oestradiol ratio. The findings of elevated seminal plasma oestradiol, decreased testosterone and testosterone/oestradiol ratio in infertile men, and the significant correlation between hormone levels and sperm analysis data suggest that the local balance between androgen and oestrogen is important for spermatogenesis.
Glycated plasma proteins in experimentally induced acute toxic renal failure by dichromate injection: evidence for loss with urine and decreased plasma levels.
Authors: DE TATA VINCENZO , BOMBARA MARIA , NOVELLI MICHELA , PINGITORE RAFFAELE , BERGAMINI ETTORE
Published: March 2003

In the rat, a single subcutaneous injection of sodium dichromate (20 mg/kg) causes acute renal injury and significant polyuria, proteinuria, and glycosuria (peaking 2–3 days after treatment, and returning to normal by day 5) without any changes in the plasma levels of protein, glucose, and glycated haemoglobin. Surprisingly, the percentage levels of glycated plasma total proteins and albumin (assayed by boronate affinity chromatography) transiently and significantly decrease during recovery from proteinuria (days 4 and 10 after treatment) and were found in the normal range of values by day 18. These changes are concomitant with a significant increase in the percentage level of glycated albumin in urine. Constancy of total plasma protein and the temporal pattern of levels of glycation suggest that changes in the percentage values of glycated proteins are secondary to a transient selective loss of glycated plasma proteins in urine.
Quantitative analysis of the development of experimentally induced post surgical adhesions: a microstereological study
Authors: Ricketts Sally‐Ann , Sibbons Paul D. , Green Colin J.
Published: March 2003

The aim of this study was to quantitatively define the development of post surgical adhesions (PSAs) in a well characterized experimental model and identify possible windows of pathogenesis where pharmaceutical intervention may be most effective.

PSAs were induced, in an established rabbit uterine horn model, using standardized reproducible injury, in 17 experimental groups, each with 8 experimental sites and these PSAs were sampled from 30 seconds to 42 days post surgery. Using design based, unbiased stereology, mean volumes of PSAs and associated tissue damage and reaction per experimental site were calculated for each sample time point.

PSA development followed the normal pattern of wound healing with surrounding adjacent tissue having a profound influence and interaction. There was a direct relationship between volume of damage (initial and subsequent) and the volume of injury tissue generated.

In vivo weak fibrinous PSAs were present from 10 min following injury, with tenacious fibrinous PSAs present from 1 h and onwards. PSA development can be classified into two distinct stages: (i) PSA modelling — occurring during the first 16 h, in which maximum rate of PSA construction is achieved; and (ii) PSA remodelling — from 16 h onwards. Considering this, PSA prevention should ideally be initiated immediately post injury to prevent PSA modelling or, alternatively, during PSA modelling.
Demyelination and axonal dystrophy in alpha A‐crystallin transgenic mice
Authors: De Rijk  , Van Rijk  , Van Esch  , De Jong  , Wesseling  , Bloemendal
Published: March 2003

Homozygous mice transgenic for αA‐crystallin, one of the structural eye lens proteins, developed hindlimb paralysis after 8 weeks of age. To unravel the pathogenesis of this unexpected finding and the possible role of αA‐crystallin in this pathological process, mice were subjected to a histopathological and immunohistochemical investigation. Immunohistochemistry showed large deposits of αA‐crystallin in the astrocytes of the spinal cord, and in the Schwann cells of dorsal roots and sciatic nerves. Additionally, microscopy showed dystrophic axons in the spinal cord and digestion chambers as a sign of ongoing demyelination in dorsal roots and sciatic nerves. Apart from a few areas with slight αA‐crystallin‐immunopositive structures, the brain was normal. Because the αA‐crystallin protein expression appeared in specific cells of the nervous system (astrocytes and Schwann cells), the most plausible explanation for the paralysis is a disturbance of cell function caused by the excessive intracytoplasmic accumulation of the αA‐crystallin protein. This is followed by a sequence of secondary changes (demyelination, axonal dystrophy) and finally arthrosis. In conclusion, αA‐crystallin transgenic mice develop a peripheral and central neuropathy primarily affecting spinal cord areas at the dorsal side, dorsal root and sciatic nerve.
TNF‐α is expressed at sites of parasite and tissue destruction in the spleen of mice acutely infected with Trypanosoma cruzi
Authors: Lima Elianita Suzart , Andrade Zilton A. , Andrade Sonia G.
Published: March 2003

Mice infected with a macrophagotropic strain of Trypanosoma cruzi develop progressive splenomegaly due to reactive hyperplasia with increased number of lymphocytes and macrophages, culminating in parasite disintegration and necrosis of parasitized cells. Necrotic changes have been attributed to the liberation of toxic cytokines, including TNF‐α, from parasitized macrophages. In the present study, the presence of TNF‐α was investigated in situ. In addition the participation of destroyed parasites in inducing the liberation of TNF‐α was examined in two highly susceptible mice strains (C3H and Swiss) and a more resistant strain (DBA). Swiss (90) C3H/He (83) and DBA (30) mice were infected with the Peruvian strain of T. cruzi. Nineteen infected Swiss mice, and 22 infected C3H/He were treated with Benznidazole (one or two doses, 100 mg/kg bw/day), on the 8th and 9th days after infection. Necrotic splenic lesions occurred in both susceptible and resistant strains of mice. Although differing in degree, lesions were more intense in C3H and Swiss than in DBA mice. Comparing untreated and treated susceptible mice, necrotic lesions were significantly less intense in the latter. By specific monoclonal antibody immunolabelling, TNF‐α was demonstrated in the cytoplasm of macrophages and within necrotic areas, from Swiss, C3H/He and DBA mouse spleens. In conclusion, TNF‐α, probably synthesized by macrophages, was strongly expressed at the sites of parasite and cell destruction, thus appearing to play a pivotal role in splenic necrotic changes associated with severe experimental T. cruzi infection.
The biology of the combretastatins as tumour vascular targeting agents
Authors: TOZER GILLIAN M. , KANTHOU CHRYSO , PARKINS CHARLES S. , HILL SALLY A.
Published: March 2003

The tumour vasculature is an attractive target for therapy. Combretastatin A‐4 (CA‐4) and A‐1 (CA‐1) are tubulin binding agents, structurally related to colchicine, which induce vascular‐mediated tumour necrosis in animal models. CA‐1 and CA‐4 were isolated from the African bush willow, Combretum caffrum, and several synthetic analogues are also now available, such as the Aventis Pharma compound, AVE8062. More soluble, phosphated, forms of CA‐4 (CA‐4‐P) and CA‐1 (CA‐1‐P) are commonly used for in vitro and in vivo studies. These are cleaved to the natural forms by endogenous phosphatases and are taken up into cells. The lead compound, CA‐4‐P, is currently in clinical trial as a tumour vascular targeting agent. In animal models, CA‐4‐P causes a prolonged and extensive shut‐down of blood flow in established tumour blood vessels, with much less effect in normal tissues. This paper reviews the current understanding of the mechanism of action of the combretastatins and their therapeutic potential.
Functional properties of chemically modified proteins of sardine meal defatted with 1‐propanol
Authors: Kawai Yuji , Fujimura Satoshi , Takahashi Koretaro
Published: March 2003

After extracting oil from sardines using 1‐propanol, the proteins of the residual defatted meal were chemically modified using either succinylation, acetylation, maleylation or phosphorylation, and their functional properties were investigated. The solubility and viscosity of defatted meal protein was improved by succinylation and maleylation. The modified proteins had higher emulsifying activity. Succinylated and maleylated proteins had superior emulsifying capacity and emulsion stability. The nutritional qualities of the modified proteins, based on their amino acid compositions, were somewhat decreased. Modification of the electrostatic and hydration characteristics of protein molecules to a more highly charged state by succinylation and maleylation could be effective in improving the functional properties of defatted meal proteins.
Some factors affecting Norway lobster (Nephrops norvegicus) cuticle polyphenol oxidase activity and blackspot development
Authors: Bartolo Ivan , Birk Else O.
Published: March 2003

Polyphenol oxidase (PPO) activity was measured in the cuticles of Norway lobsters caught over a period of 7 months. Increased PPO activity was observed between early August and early October 1995, coinciding with one of the reported annual periods of peak moulting activity, although a high PPO activity detected in May may have marked the spring moulting period. A relationship was found between the number of claws remaining on the Norway lobsters and the PPO activity, suggesting that exposing Norway lobsters to damage and stress is associated with an increase in PPO activity. No correlation was observed between initial PPO activity and blackspot development during storage of the Norway lobsters. This indicates that biochemical events occurring during storage are more important to blackspot development than the initial PPO level.
Isolation and characterization of a ‘quinone‐trapping’ substance from a crude Carica papaya protein preparation
Authors: Richard‐Forget Florence , Cerny Muriel , Fayad Nina , Saunier Thierry , Varoquaux Patrick
Published: March 2003

The oxidation of different phenols [4‐methylcatechol, chlorogenic acid, (−)‐epicatechin and (+)‐catechin] by endive polyphenoloxidase (PPO) was investigated in the presence of an extract from Carica papaya. The occurrence of cysteine and another ‘quinone‐trapping’ substance in the extract was demonstrated. The unknown substance was purified, as a 4‐methylcatechol conjugate form, by a combination of Bio‐gel Pz chromatography and semipreparative high‐performance liquid chromatography (HPLC). Use of liquid chromatography/tandem mass spectroscopy (LC–MS/MS) equipment and an amino acid analyser allowed us to identify this agent as a dipeptide cysteine‐glutamic acid, commercially available as γ‐Glu‐Cys. γ‐Glu‐Cys formed one adduct compound with 4‐methylcatechol and chlorogenic acid, and two with the flavan‐3‐ols. The thiol adducts were not substrates for endive PPO but, in the case of the 4‐methylcatechol conjugate, they acted as competitive PPO inhibitors.
High‐performance liquid chromatography analysis of nutmeg and mace oils produced by supercritical CO2 extraction – comparison with steam‐distilled oils – comparison of East Indian, West Indian and Papuan oils
Authors: Ehlers Dorothea , Kirchhoff Jolanta , Gerard Dieter , Quirin Karl‐Werner
Published: March 2003

Nutmeg and mace oils, produced by supercritical CO2 extraction, are now increasingly traded. Unlike the steam‐distilled oils, no information about their composition is published. Supercritical CO2 nutmeg and mace extracts from the East Indies, West Indies and Papua were analysed by high‐performance liquid chromatography (HPLC) for myristicin, safrole, elemicin, eugenol, methyleugenol, isoeugenol, methylisoeugenol, methoxyeugenol and isoelemicin, and were very similar to steam‐distilled oils from the same batch. East Indian, West Indian and Papuan oils displayed clear differences in their composition and could be clearly characterized by HPLC. The dominating aromatic ether in the East Indian oils was myristicin, in West Indian elemicin and in Papuan safrole.
Incidents of food poisoning and food‐borne diseases from ‘new’ or ‘unexpected’ causes: can they be prevented?
Authors: Harrigan Wilkie F.
Published: March 2003

This paper presents a survey of selected incidents of food poisoning and food‐borne disease and examines the lessons that can be learned about the extent of the success of food hygiene and quality assurance approches.
Application of microfiltration to egg white depleted in ovomucin
Authors: Ferreira Maria , Oliveira Fernanda A. R. , Jost Rolf
Published: March 2003

Summary An attempt was made to reduce the microbial load of unpasteurized fresh egg white by using cross‐flow microfiltration and a Tetra‐Laval bactocatch installation. Cross‐flow tangential microfiltration of liquid fresh egg white was not feasible as there was irreversible membrane clogging within a few minutes of operation. As membrane clogging could have been caused by ovomucin, this protein was removed from whole fresh egg white by increasing the salt strength and lowering the pH. Ovomucin‐depleted egg white (ODEW) was successfully microfiltered on the same membrane. Compared to fresh egg white, ODEW had lower foaming and viscous properties, and these properties remained unchanged after bactofiltration. The reduction of microbial load was, however, relatively low.
Glass formation and dormancy in bacterial spores
Authors: Ablett Steve , Darke Arthur H. , Lillford Peter J. , Martin David R.
Published: March 2003

Summary Differential scanning calorimetry (DSC) and nuclear magnetic resonance (NMR) techniques were used to obtain evidence whether a glassy state exists within fully hydrated dormant Bacillus subtilis spores. DSC thermograms of hydrated dormant spores contained two major transitions; one at ∼60 °C assigned to be associated with the initial ‘activation’ stage for germination, and the other at ∼120 °C assigned to be associated with the ‘inactivation’ process (i.e. killing of the spores). The peak at ∼60 °C had characteristics which were all consistent with at least some region of the compartmentalised structure of fully hydrated dormant spores being in a glassy state. Solid (CPMAS) and liquid state (SPMAS) mobility resolved 13C NMR spectroscopy studies on the calcium dipicolinic acid (CaDPA) resonances, which are only present in the central protoplast of bacterial spores, showed it to be present in an amorphous solid‐like environment. The DSC and NMR results were both found to be consistent with the hypothesis that the dormancy of bacterial spores is due to at least the central protoplast region being maintained in a low moisture content glassy state.
Composition and functional properties of raw and heat processed velvet bean (Mucuna pruriens (L.) DC. var utilis) flours
Authors: Ahenkora Kwaku , Dadzie Martin , Osei‐Bonsu Patterson
Published: March 2003

Summary The proximate composition and functional properties of raw and heat‐processed velvet bean (Mucuna pruriens (L.) DC. var utilis) flours were studied. The flours were prepared by soaking raw beans for 14 h, boiling for 30 min (heat‐processed), manual dehulling, oven‐drying (65 °C) and milling. The heat‐processed flour contained 6.8% moisture, 24.3% protein, 4.9% fat, 1.3% crude fibre, 3.5% ash and 61.2% carbohydrate. The flour was rich in potassium (125 mg/100 g), zinc (9.8 mg/100 g) and phosphorus (361 mg/100 g). Differences in proximate and mineral composition of raw and heat‐processed flours were not significant. The flours showed minimum protein solubility at pH 4.5 and formed reasonably stable emulsions and foams. Compared to raw flour, heat‐processed flour had better water and fat absorption capacities, but lower protein solubility, emulsion and foam capacities. The flours have potential for food product development.
Verification of a formula for estimating average quality factor degradation in thermally processed foods in cylindrical containers
Authors: Garrote Raúl L. , Ré Roberto
Published: March 2003

Summary A formula suggested by Jen et al. (1971) may be suitable for estimating the average retention of quality factors in conduction heated foods. This hypothesis was tested by comparing the results obtained for thiamine retention with calculations based on analytical and finite difference solutions of transient heat conduction in cylindrical containers. For a high Biot number, agreement was within 10.8% over a wide range of processing conditions (can size, retort temperature, initial temperature, etc).
Study on cholesteryl ester fatty acids in camel and cow milk lipid
Authors: Gorban Ali M. S. , Izzeldin Omar M.
Published: March 2003

Summary The average lipid content of mature camel milk (3.48 g100g−1), was found to be less than cow's milk (3.69g 100g−1), but the total cholesterol content of camel milk was high (31.32 mg100g−1) when compared to the total cholesterol content of cow's milk (25.63mg100g−1). The average free cholesterol content of mature milk from 54 lactating camels was 21.34 mg100g−1, while the average free cholesterol of mature milk of 24 lactating cows was 17.25 mg100g−1. In the esterified fraction of camel's milk the percentage of saturated fatty acids was 52% with a content of palmitic acid of 18.4%. In cow's milk saturated fatty acids accounted for 58% of the total with a content of palmitic acid of 23.6%. The unsaturated fatty acids fraction in both groups was mainly contributed by oleic acid and palmitoleic acid. Pelargonic acid (C9:0) and decanoic acid (C10:1) were found in significant amounts in mature camel milk, but were only just detectable in cow's milk. The higher content of medium chain fatty acids in camel milk is useful from a nutritional point of view as they are more easily absorbed and metabolized than long chain fatty acids.
Water sorption isotherm of solution containing hydrogels at high water activity
Authors: Tesch Ralf , Ramon Ory , Ladyzhinski Ilya , Cohen Yachin , Mizrahi Shimon
Published: March 2003

Summary The water vapour sorption isotherm, in the water activity range of 0.9–1.0, was determined for hydrogels containing glucose or sodium chloride solutions, as a model of food systems. Due to their high osmotic pressure, these solutes play the major role in determining the osmotic pressure of the gel, thus its driving force for moisture uptake. As long as the gel's network pressure is relatively low, the sorption isotherm of the gel is similar to that of the solutions. At high water activity, the swollen gel develops a relatively large network pressure that not only counteracts the osmotic pressure and reduces moisture uptake, but also may induce syneresis. That is likely to take place if the network pressure exceeds the osmotic pressure of the polymeric matrix in the gel's internal solution. The onset of syneresis, which changes the gel composition, marks the end point of the sorption isotherm for the original gel.
Selection of starters and a starter‐mediated novel procedure for production of wara, a West African soft cheese
Authors: Sanni Abiodun I. , Onilude Anthony A. , Momoh Margaret O.
Published: March 2003

Summary Wara serves as an important protein source for people in West Africa. The ten most frequently isolated lactic acid bacteria from abomasum‐soured milk samples were screened singly or in combinations as starter organisms for the production of wara. The screening was based on the bacteria's ability to produce lactic acid, diacetyl, β‐galactosidase and an average weighted firm curd at 30 °C (6 h, 72 h). With lactic acid concentration of 10.0 g l−1, β‐galactosidase of 25.2 U mL−1 and a firm curd weight of 16.0 g l−1 milk at 30 °C, pH 5.1 after 6 h, a single‐organism starter culture of Lactococcus lactis was chosen as the best suited. Compared with the commercial market samples, wara produced by this starter culture showed a 54% increase in percentage protein, 17.9% increase in ash, 23.6% increase in iron and a 150% increase in vitamin A content. Statistical analysis of sensory evaluation results showed a preference for the market sample only in terms of appearance and texture, while the starter‐produced wara matched the market sample in terms of flavour and palatability. Treatment with 3% brine reduced microbial counts although dipping in 5% NaCl‐in‐whey gave better results in terms of the total viable count of mesophiles, psychrotrophs and coliforms compared with the untreated sample.
Physicochemical and sensory properties of restructured beef steaks containing beef heart surimi
Authors: Wang Baowu , Xiong Youling L. , Moody William G.
Published: March 2003

Summary Restructured beef steaks containing beef heart surimi were prepared. Changes in flavour, texture, thiobarbituric acid‐reactive substances (TBARS), and compression force of the restructured steaks were evaluated after frozen storage (−29 °C) for 1, 30, and 90 days. Incorporation of propyl gallate‐washed beef heart surimi improved the steak flavour score by 7%, texture score by 30%, and cooking yield by 4%, compared to non‐surimi control steaks. Addition of water‐washed surimi (without propyl gallate) also improved physical properties of restructured steaks, but it induced off‐flavour and rancidity development.
Chemical changes in β‐Lactoglobulin structure during ageing of protein‐stabilized emulsions
Authors: Leaver Jeffrey , Law Andrew J. R. , Brechany Elizabeth Y. , McCrae Catharina H.
Published: March 2003

Summary Commercial protein‐stabilized emulsions are often stored for many months. Reversed phase high performance liquid chromatography (HPLC) analysis of protein displaced from β‐lactoglobulin‐stabilized oil‐in‐water emulsions by the competitive adsorption of Tween 20, showed that whereas the retention time of protein displaced from a tetradecane–water interface did not change greatly upon ageing, that of the protein displaced from a soya oil–water interface did. The changes in the retention time of the displaced protein were accompanied by an increase in the mass of the protein. When 2‐mercaptoethanol was added prior to emulsification, the rate of modification was significantly slower than in its absence. Tryptic digests of the displaced, modified protein showed that the changes were specific. Analysis of volatile components present in the emulsions showed that emulsification induced the autoxidation of the polyunsaturated fatty acyl chains of the soya oil resulting in the time‐dependent formation of low molecular weight compounds. 2‐Mercaptoethanol inhibits the process probably by reacting with hydroperoxides and terminating the chain reaction. Aldehydes, particularly enals, are known to react with nucleophilic amino acid residues such as lysine via addition and/or condensation reactions, leading to the observed increase in the mass of the protein.
Degradation of anthocyanins from blood orange juices
Authors: Krifi, Boubaker , Metche Maurice
Published: March 2003

Summary The degradation of anthocyanic pigments of fresh and industrial juices from blood oranges were studied during storage periods of a few days at −18 °C and 12 months at 4 °C in nitrogen. The change of anthocyanin pigments was followed by HPLC at 520 nm while the coloured polymeric pigments were fractionated by chromatography and characterized by their transformation indices and their reactivity with NaHSO3. The results show that the process of polymerization is accompanied by production of chemical indicators of sugar and ascorbic acid degradation (furfural and hydroxymethylfurfural). It seems that the resulting polymeric compounds have structures different from those of the compounds formed during wine processing. Reactions between anthocyanic pigments and the intermediates of degradation of sugar and ascorbic acid in an acidic environment are the main causes of formation of these polymers.
Textural properties of a model aqueous phase in low fat products. Part 2: Alginate/caseinate blends and three‐component systems
Authors: Roberts Simon A. , Kasapis Stefan , De Santos López Inés
Published: March 2003

Summary The second paper in this series completes the investigation of the textural properties of alginate, starch and caseinate preparations. Thus mixtures of alginate and caseinate show liquid‐like properties up to 200 p.p.m. Ca2+. At higher levels of the counterion, alginate gels form a continuous matrix which supports the liquid‐like caseinate inclusions. Caseinate acts mainly as a sequestrant for calcium ions. In the absence of added counterions, the ternary system is characterized by a weak starchy network which supports the liquid alginate and caseinate phases. Addition of Ca2+ produces a plethora of textures governed mainly by the alginate phase and the sequestering influence of caseinate. Intelligent manipulation of polymeric composition and levels of calcium resulted in binary systems of caseinate/starch, alginate/starch and caseinate/alginate capable of reproducing the texture of ternary mixtures, thus offering attractive alternatives to the commercial aqueous phases. In conclusion, it is demonstrated that basic understanding of ingredients and their properties in mixtures leads to purposeful formulation of products.
Storage conditions affect quality of noodles with added soy flour and sweet potato
Authors: Pangloli Philipus , Collins James L. , Penfield Marjorie P.
Published: March 2003

Summary Noodles were prepared from a formulation in which a portion of the flour was replaced with 10% defatted soy flour and sweet potato as 10% flour or 15% puree. Dried noodles were packaged in plastic bags under partial vacuum or air and stored at 4.4 °C or 22–30 °C for 6 months. Colour, β‐carotene and sensory characteristics were analyzed at 2‐month intervals. Packaging atmosphere had minor effects on colour. Stored noodles became lighter and yellower, and β‐carotene decreased, with all changes being greater at 22–30 °C. Storage conditions influenced acceptability scores minimally. Noodles were stored successfully under air with greater quality retention with 4.4 °C storage.