Physical principles and application of magnetic resonance angiography.

This paper reviews the physical principles of magnetic resonance angiography (MRA) acquisition methods, explains image presentation strategies for MRA, and discusses the advantages and disadvantages of various MRA methods. These methods include the time-of-flight, phase contrast, and black blood techniques. The essential goal of each of these flow imaging methods is to maximize signal differences between flowing and stationary tissues in order to provide morphological and physiological information.


Approaches to diagnostic magnetic resonance carotid angiography.

MR angiography (MRA) by the time-of-flight technique has been very successful in the carotid arteries as a result of relatively rapid flow velocities and the availability of high sensitivity neck coils. Two-dimensional or three-dimensional acquisition through the carotid bifurcation is an effective screening technique whose accuracy is very competitive with Doppler ultrasound and whose anatomic detail rivals that of conventional contrast angiography. As methods are perfected for visualizing the entire carotid from the aortic arch to the circle of Willis, MRA will replace contrast angiography for many diagnostic applications.


Magnetic resonance angiography in intracranial vascular disease.

Magnetic resonance angiography (MRA) offers a noninvasive alternative for studying normal and pathological blood vessels within the brain. Insights from important clinical aspects of intracranial vascular disease enable the effective application of MRA. Several MRA techniques have demonstrated clinical utility for the detection and characterization of intracranial vascular pathology. Clinical protocols should comprise combinations of time-of-flight and phase-contrast acquisitions to achieve diagnostic sensitivity.


Cardiothoracic magnetic resonance angiography.

At the current state of the art, cardiothoracic MR angiography offers the clinician information that is supplemental to that provided by other noninvasive imaging techniques. Indeed, in some areas MR angiography will likely surpass currently used methods as the technique of choice. Specifically, measurement of cardiac output, pulmonary blood flow, and lung perfusion can be performed relatively accurately and simply during a brief MR examination. Both standard spin-echo and angiographic evaluation of the thoracic aorta provide qualitative images with superior resolution. Additionally, development of pulmonary artery angiography is progressing rapidly and may soon be clinically useful. Phase incoherence caused by complex flow and resulting in a signal void is useful for location and qualitative assessment of abnormal flow jets induced by stenoses. However, this phenomenon represents the major limitation to quantitative assessment of flow abnormalities. Methods to increase signal to noise and/or reduce phase incoherence must be developed before MR angiography can be used effectively to assess abnormal flow conditions.


Magnetic resonance angiography of the lower extremity and renal arteries.

Magnetic resonance angiography (MRA) has been used to image the arteries to the lower extremities and to the kidneys, with promising initial results. In the case of the lower extremity arterial system, MRA provides a first opportunity to obtain anatomic images in a completely noninvasive fashion, including evaluation of the iliac and tibial vessels, to supplement the hemodynamic measurements that are a routine part of the preoperative evaluation. In the case of renal artery stenosis, MRA may soon become the initial screening modality of choice, especially in patients with renal insufficiency, in whom contrast scintigraphy may have limited accuracy and in whom contrast angiography is relatively contraindicated.


Prospects for the future: magnetic resonance fast scanning and flow quantitation.

High-speed scanning techniques are quickly emerging to provide new applications in the MRI domain. These potential applications range from the reduction of patient examination time to the functional imaging of human cognition. Additionally, flow quantitation is rapidly developing into a clinical diagnostic tool available for routine use. This article provides the concepts to acquire a rudimentary understanding of both topics.


The contribution of nutrition research to the control of undernutrition: the Indian experience.

Since diseases directly related to undernutrition are the major public health problems of India, nutrition research in the country has been largely directed towards elucidating their causes and identifying the most feasible methods for their prevention and control. This effort is an interdisciplinary exercise carried out in the laboratory, the clinic, and the field, with close interaction among biochemists, clinicians, and epidemiologists. Some of the identified solutions have found practical application; but, as in other areas of scientific endeavor, a gap exists between the acquisition of knowledge in the laboratories and its application in the field. Today, thanks to research efforts of the last few decades, we have the knowledge with which most diseases related to undernutrition can be prevented. Unfortunately, however, we do not always have the means of applying this knowledge under real-life conditions in the field. Even so, nutrition research during the last few decades has contributed significantly to the amelioration of undernutrition among poor communities in India.


Retinoids and cancer prevention.

As indicated above, in some cases the effects of retinoids appear to be species-specific. Although retinyl acetate and 4-HPR are ineffective in preventing mammary cancer induced by DMBA or occurring spontaneously in mice, these retinoids prevent carcinogen-induced mammary cancer in rats. In contrast, retinoids have modest chemopreventive activity for bladder cancer in various strains of both mice and rats and may have some therapeutic and preventive effects in human bladder. Retinyl palmitate is reported to reduce the incidence of esophageal lesions in hamsters; however, retinyl acetate may increase the incidence of esophageal tumors in rats. Although 13-cis-RA reduces the incidence of spontaneous thymic lymphomas in AKR mice and C57Bl/10W mice exposed to X rays and has some therapeutic effect on myelodysplastic syndromes in humans, 4-HPR may enhance leukemic progression in patients with this syndrome. For treatment of this syndrome, selection of the proper retinoid appears to be important. Topically applied retinyl palmitate reduces the incidence of cervical cancer in hamsters, and topically applied RA has a therapeutic effect on cervical dysplasia in humans. Retinamides have a modest chemopreventive effect against pancreatic cancer in rats dosed with azaserine; these compounds are reported both to increase and to decrease the incidence of pancreatic cancer in hamsters. Retinoids may, or may not, be carcinogen-specific in different species. Some are effective in preventing mammary cancer in rats, regardless of which carcinogen is used. Applied to mouse skin, retinoids are active with either DMBA or BP as the carcinogen and 12-tetradecanoyl phorbol-13-acetate (TPA) as the promoter. Nevertheless, retinoids are not effective in preventing skin papillomas and carcinomas caused by UV light. There is no comparable system for humans, although retinoids demonstrate activity against basal cell carcinomas, squamous cell carcinomas, and actinic keratoses on the skin of humans. Fewer bladder tumors develop in rats dosed with HO-BBN when they are put on diets containing certain retinoids, but those dosed with FANFT are not affected. Similarly, retinyl acetate is reported to be active against liver tumors induced by 3'-MeDAB but not against those induced by aflatoxin B1. In contrast, forestomach carcinomas induced in hamsters by either DMBA or BP are prevented by retinyl palmitate. The route of administration of retinoids may also be important.(ABSTRACT TRUNCATED AT 400 WORDS)


Cellular and molecular aspects of adipose tissue development.

Both in animals and humans, before or after birth, angiogenesis appears to be closely coordinated in time and space with the formation of fat cell clusters. Monobutyrin, a novel fat-specific angiogenesis factor, may play a role in this process. The potential to acquire new fat cells appears to be permanent throughout life in both animals and humans, as revealed by in vitro experiments. Considerable evidence now supports the view that BAT and WAT are distinct organs; in addition, the existence of distinct BAT precursor cells is demonstrated by their unique ability to express the UCP gene. In bovine and ovine, the transformation of BAT into WAT is strongly suggested by the rapid disappearance after birth of UCP from the various BAT depots. Despite the initial cell heterogeneity of the stromal-vascular fraction, cultured stromal-vascular cells of adipose tissue are adipose precursor cells that show varying capacities for replication and differentiation, according to age and fat depot. Studies of adipose cell differentiation in vitro correspond to the sequence: adipoblast (unipotential cells)----commitment preadipose cell (preadipocyte)----terminal differentiation immature adipose cell----terminal differentiation mature adipose cell (adipocyte). Cell commitment is triggered by growth arrest and characterized by the expression of early markers (A2COL6/pOb24; clone 5; LPL), whereas only terminal differentiation of preadipocytes requires the presence of various hormones. Multiple signaling pathways have been characterized and shown to cooperate in the process of terminal differentiation. The concept that adipose cells behave as secretory cells is now emerging from in vitro data, since secretion of various proteins (LPL, adipsin, CETP) and important metabolites (fatty acids, monobutyrin, androgens, estrogens, prostaglandins) takes place both constitutively and upon hormonal stimulation. This suggests that adipose tissue participates more directly than previously thought in metabolic activities and energy balance.


Dietary impact on biliary lipids and gallstones.

Although dietary factors influence bile lithogenicity and gallstone formation, the main dietary effect appears to be indirect, depending on an interaction between caloric consumption and gender-specific aspects of lipoprotein metabolism. Excessive energy intake elicits its detrimental effect by altering lipoprotein and hepatic cholesterol metabolism in association with hyperinsulinemia. Factors, dietary and genetic, that favor elevated hepatic cholesterol synthesis and production of a bile acid profile in which chenodeoxycholic acid predominates appear to be associated with lithogenic bile. An inconsistent effect of dietary fat saturation on gallstones is that polyunsaturates possibly increase risk in men and decrease risk in women. Vegetable protein may reduce the risk of cholelithiasis. Whereas both the amount and type of dietary fiber influence cholesterol and bile lipid metabolism, specific associations between fiber and gallstones in humans remain elusive.


Serum cholesterol and cancer risk: an epidemiologic perspective.

This review has examined the evidence surrounding two questions: (a) Is having low serum cholesterol associated with increased risk of cancer? (b) Does reducing serum cholesterol increase the occurrence of cancer? Some elevated risk of cancer for males with low serum cholesterol levels has been noted: the median of the studies examined is consistent with a 30% increased risk. The answer for females is less clear. The median of the studies examined suggests no more than a 5-10% increased risk associated with having low serum cholesterol. However, the risk seems to depend strongly on whether females have a central or peripheral body fat pattern (54). The cancers most consistently associated with low serum cholesterol levels are those of the colon and lung in males, the cervix and breast (but only for females under 50 years of age) in females, and leukemia in both sexes. In contrast, high cholesterol levels have been linked with an increase in brain cancer. While immunologic, genetic, and dietary explanations have been offered to explain the association, it is difficult to support the idea that low serum cholesterol causes cancer in any direct manner. First, the findings themselves tend to be generally weak and somewhat inconsistent. Second, the strong influence of fat distribution in women suggests that a metabolic/hormonal basis underlies the association. One would not expect the results to differ by body fat pattern if the relationship were a causal one. Finally, if there were a direct causal role, one would expect populations with low serum cholesterol levels to have higher cancer rates. In China, counties with the lowest average plasma cholesterol levels have the lowest cancer rates (78). While this observation is open to a number of interpretations, it does not support the idea that low serum cholesterol is a tumor initiator. In aggregate, the trials of lipid-lowering interventions reviewed here show an increase in cancer occurrence (primarily mortality) of approximately 24% in the cholesterol-lowered groups. However, the post-trial experience has shown a comparative deficit of cancer occurrence in the experimental groups. Recent evidence indicates that products in the cholesterol biosynthetic pathway affect DNA replication and cell proliferation. These findings suggests a mechanism by which cholesterol lowering might accelerate the development of tumors already initiated. The data that have been reviewed in no way suggest that treatment of hypercholesterolemia should not be pursued. They do suggest the presence of a relatively small subpopulation in whom reduction of plasma cholesterol may lead to increased occurrence of cancer.(ABSTRACT TRUNCATED AT 400 WORDS)


Lipids in human milk and infant formulas.

About 50 metabolically important fatty acids can be identified in human milk. The extent of absorption of milk fatty acids varies considerably from infant to infant, particularly in pre-term infants, and requires more study. Human milk provides sufficient vitamins A and E for the term infant, but supplementation with vitamins D and K may be necessary. More research is needed on the amounts of the fat-soluble vitamins in human milk, the efficiency of transfer from mother to infant, the reasons for variation in different women, and the consequences to breast-fed infants of inadequate intake of vitamins D and K. Breast milk contains the PUFA needed by term infants who are able to synthesize the long-chain PUFA soon after birth. Pre-term infants fed formulae need supplementation with n3 and n6 long-chain PUFA, since formulas currently do not contain these acids. More work is needed to determine the requirements for n3 and n6 fatty acids, expressed as weights per kilogram. A larger data base using improved analytical procedures to study the nature and content of lipids in human milk is needed. The impact of maternal genetics and diet on fatty acids in milk should be studied, as well as the effect of maternal diet on eicosanoids secreted by the mammary gland. Information on the structure and function of the milk fat globule and its membrane is needed. Little is known about the effect of milk banking on milk lipids. The reader of this review will no doubt find other gaps in our knowledge of the lipid composition and nutritional value of milk that require additional investigation.


Fat substitutes: a regulatory perspective.

Fat substitutes, in theory, may provide special health benefits to certain population segments. The most probable benefits are a reduction in total fat intake and a subsequent reduction in intake of calories from fat. Whether individuals who consume high intakes of fat substitutes that are partially or totally nondigestible also benefit from lower calorie intake on a long-term basis is unknown. It is likely that many individuals will compensate by increasing total food intake to maintain calorie intake. Consumption of fat substitutes presents nutrition problems. Those fat substitutes that are partially or totally nondigested may reduce the bioavailability of other nutrients. Similarly, fat substitutes may have adverse effects on normal gastrointestinal tract function or intestinal tract flora. Unlike other functional food additives, fat substitutes can make up a significant portion of the total diet. For this reason, traditional safety factors cannot be applied. Consequently, more reliance on data from clinical studies involving human subjects and requirements for postmarket surveillance will be necessary as part of the approval process.


The immunology of HIV infection: implications for therapy.

It is known that antiretroviral drugs can induce immunologic improvement in patients with acquired immunodeficiency syndrome (AIDS) and other manifestations of HIV infection. However, the improvements so attained are often partial and transient. This may result from a number of factors, including incomplete inhibition of human immunodeficiency virus (HIV) replication by available agents, the development of viral drug resistance, the effect of cytokines, or thymic damage. An understanding of this problem may be important in further development of AIDS therapies. It will also be important to learn how to best assess the response to various therapies. In this regard, the CD4 count is evolving as a mortality risk indicator in AIDS and as such may find utility in assessing new therapeutic approaches. We have observed that in a cohort of gay men receiving antiretroviral therapy in a research environment, nearly all deaths occurred in individuals with fewer than 50 CD4 cells/mm3. However, the relationship between the CD4 count and the hazard of dying may be influenced by a number of factors (e.g., active intravenous drug use, extreme poverty, etc.), and further studies are needed to define the relationship between CD4 and clinical endpoints under a variety of conditions.


Potential use of immunoconjugates for AIDS therapy.

More than a dozen of hybrid proteins possessing reactivity with human immunodeficiency virus-type 1-(HIV-1) infected cells and cytotoxicity have been produced and studied by several groups. These proteins are prepared either by chemical cross-linking of a toxin and a carrier molecule or by expressing fused genes of the two moieties. These cytotoxic agents have been investigated to eliminate HIV-1-infected cells in vitro. The ID50 of these agents range from pM to nM. This article compares the results of the various approaches and discusses the limits and potential of immunoconjugates for AIDS therapy.


Localized conformational changes in the N-terminal domain of CD4 identified in competitive binding assay of monoclonal antibodies and HIV-1 envelope glycoprotein.

The CD4 antigen is established as a major cellular receptor for the human immunodeficiency virus (HIV). Previous studies have suggested that certain anti-CD4 monoclonal antibodies (MAbs) can inhibit or enhance the binding of the viral envelope glycoprotein gp120 to CD4 by allosteric effects. In the study reported here, 17 anti-CD4 MAbs were tested for their ability to influence the binding of each other to recombinant soluble CD4 in a solid-phase radioimmunoassay. Marked enhancement of binding between specific pairs of MAbs was seen, as well as inhibition or lack of interaction. Enhancement was seen less often when CD4+ cells were used as the target antigen. Information on patterns of enhancement and inhibition permitted grouping of MAbs on the basis of epitope specificity, and this grouping was in agreement with published findings based on X-ray crystallographic studies. These results demonstrate connectivity between epitopes in the first domain of recombinant CD4 and suggest a high degree of flexibility of surface structure. These findings may be of physiological significance both in the normal function of CD4 and in the interaction of CD4 with HIV. The data have implications for research or therapeutic strategies based on recombinant CD4 or CD4 mutants and highlight the problems of interpreting experimental findings based on abrogation of MAb binding.


Anti-CD4 anti-idiotype antibodies in volunteers immunized with rgp160 of HIV-1 or infected with HIV-1.

We examined the sera of volunteers vaccinated with recombinant gp160 of human immunodeficiency virus type 1 (HIV-1) and control volunteers for the presence of anti-(anti-gp160 idiotype) antibodies which antigenically mimic gp160 and, therefore, bind to CD4 on human cells. Anti-CD4 antibodies were detected in the sera of 3 of 5 rgp160 recipients and 1 of 5 controls by indirect immunofluorescence using CD4-transfected HeLa cells or enzyme-linked immunosorbent assay (ELISA) using recombinant soluble CD4 as the solid phase. The control volunteer who was positive subsequently developed antibodies to HIV-1 by Western blot analysis. The anti-CD4 antibodies detected in the sera of the rgp160 vaccinees and the control volunteer appeared to be anti-idiotypic in nature, reacting with a paratope expressed on goat anti-gp160 antibodies but not on antibodies from normal goat serum. Binding to either transfected CD4+ HeLa cells or blotted anti-gp160 serum could be inhibited by preincubating the anti-CD4 serum with soluble CD4, or preincubating the cells or blotted anti-gp160 serum with recombinant gp160. Anti-CD4 antibodies were initially detectable only after the antibody response to gp160 began to decrease in the vaccinees, and the HIV-1-infected volunteer mounted a detectable anti-HIV-1 antibody response only after a decline in the anti-CD4 antibodies in his serum. These data strongly suggest that anti-CD4 antibodies which are anti-idiotypic to a paratope expressed on anti-gp160 antibodies are generated in response to both vaccination with rgp160 and infection with HIV-1.(ABSTRACT TRUNCATED AT 250 WORDS)


High-titer HIV-1 neutralizing antibody response of rhesus macaques to gp160 and env peptides.

Three groups of four rhesus macaques were immunized twice, one month apart with purified recombinant HIV-1LAI gp160 in the presence of either alum, incomplete Freund's adjuvant (IFA), or SAF-1. Two months later, the animals were injected twice again with a synthetic peptide with the sequence of the principal neutralization determinant (PND) of the HIV-1LAI isolate mixed with the same adjuvants. All animals received a booster injection of gp160 and PND peptide at 6 months. This regimen of immunization induced in the SAF-1 and IFA groups a high-titer neutralizing antibody response that declined progressively over the course of the following 6 months. In contrast, only a weak response was observed in the alum group. Neutralizing antibody titers varied as anti-PND titers, suggesting that they were principally targeted to the PND. A shortened immunization protocol comprising two injections of gp160 at 0 and 1 month followed by one injection of PND peptide at 3 months is suggested as optimal for the induction of high titers of HIV-1 neutralizing antibodies in primates.


Lack of autologous neutralizing antibodies in the cerebrospinal fluid of HIV-1 infected individuals.

The cerebrospinal fluids (CSF) and sera from HIV-1-infected individuals at different clinical stages were monitored for neutralizing activity against CSF-derived HIV-1 isolates. None of the CSF samples and only one of seven serum samples could neutralize the autologous CSF isolate. CSF samples collected one to two years later from the same patients also lacked autologous neutralizing antibodies against these isolates. However, some CSF samples were able to neutralize heterologous CSF isolates albeit in low titers. HIV antibody positive control sera could readily neutralize all of the CSF isolates demonstrating that these isolates were not resistant to neutralization per se. IgG antibodies against the HIV-1 envelope protein and, specifically, against the V3 loop of HIV-1 gp120 (MN) were present in some CSF samples, although the samples lacked neutralizing activity. In summary, this study demonstrates a lack of autologous neutralizing antibodies in CSF samples when assayed against CSF-derived HIV-1 isolates.


Molecular clones from a non-acutely pathogenic derivative of SIVsmmPBj14: characterization and comparison to acutely pathogenic clones.

Molecularly cloned simian immunodeficiency viruses capable of inducing acute, fatal disease in pig-tailed macaques had been derived previously from a biological clone (bcl-3) of the PBj14 isolate of SIV from sooty mangabey monkeys (SIVsmmPBj14). The present study was undertaken in order to characterize virus from a second biological clone of SIVsmmPBj14, bcl-1, which fails to induce acute or fatal disease. Polymerase chain reaction was used to amplify 5' and 3' viral genome halves. The DNA sequence of two 3' halves was determined, and an infectious recombinant generated using a bcl-3-derived 5' half and a bcl-1-derived 3' half. Overall, bcl-1- and bcl-3-derived viruses displayed close homology, differing by a total of 2% at the DNA level and 1-6% at the amino acid level within the 8 open reading frames examined. In contrast to the bcl-3-derived viruses, the bcl-1-derived viruses encode a truncated transmembrane envelope glycoprotein. Another consistent difference was the presence of a 22 bp duplication in the U3 portion of the long terminal repeat (LTR) of bcl-3-derived viruses that includes the NF-kappa B transcriptional enhancer binding site. To assess the importance of this duplication, virus chimeras were generated which removed the duplication from the 3'-LTR or from both LTRs of a bcl-3 clone. The former virus was unstable, reacquiring the duplication through recombination with the 5' LTR. No consistent difference were observed, however, between viruses with or without the duplication in the in vitro studies conducted to date.(ABSTRACT TRUNCATED AT 250 WORDS)


Differences in neutralization of simian lentivirus (SIVMAC) in lymphocyte and macrophage cultures.

Comparison of neutralization of SIVmac251 in primary macrophage cultures with neutralization in lymphocytes (CEM174 cells) showed that neutralizing antibodies induced by SIV251 in infected rhesus macaques protected both macrophages and T lymphocytes against infection when the virus was preincubated with the antibodies. In macrophages, the neutralizing antibodies also protected against infection when added 1 hour after the virus. Addition of antisera to macrophages between 24 and 48 hours after virus inoculation resulted in infection with continuous release of small amounts of p24 into the supernatant fluids but these antibody-treated cultures failed to exhibit cytopathic virus replication. In contrast, the same neutralizing antisera did not protect lymphocytes against infection and subsequent cytopathic replication of the virus when added only 1 hour after virus inoculation. This distinction in the effect that neutralizing antibodies had on the development of cytopathic infection in lymphocytes and macrophages when added after virus inoculation, suggests that they could alter the dynamics of virus replication and therefore the pathogenesis of disease.


Application of latent HIV-1 infected cellular models to therapeutic intervention.

The 10-year period of clinical latency following infection with the human immunodeficiency virus type-1 remains as a tremendous opportunity for therapeutic intervention. To decipher the viral and cellular mechanisms involved in controlling active and nonproductive viral expression, chronically infected cell lines have been developed which mimic in vivo latency at a cellular level. This review compares these models of chronic infection, emphasizing the advantages and limitations of this approach to the understanding of AIDS progression. In addition, it accentuates the utility of these models of chronic infection in the development and testing of novel drugs aimed at altering the efferent component of the HIV--1 life cycle. It is this component of the viral life cycle that has remained largely unexplored and open to novel therapeutic strategies for the prevention of lethal immunosuppression.


Alternative management of a crown root fractured tooth in a child.

A crown root fracture of a tooth in a young person may necessitate the removal of the root and the placement of a space-maintaining partial denture followed by provision of a bridge. A case is reported of an alternative approach to treatment, in which the root fragment is retained in situ until the end of the pubertal growth spurt, in order to preserve alveolar bone, following which it is removed and replaced by an implant.


An iatrogenic foreign body (dental bur) in the maxillary antrum: a report of two cases.

Two cases of foreign bodies of the antrum are reported. One was a turbine bur which presumably entered through an oro-antral fistula after a tooth extraction. The other was also a turbine bur where the mode of entry was not clear (lack of oro-antral fistula), but it presumably entered through the socket of the extracted tooth. The mucosa of the antrum appeared normal in spite of the lengthy presence of the foreign body.


The clinical use of ITI transmucosal implants.

The ITI implant system has a background of research and development of over 15 years. It is distinctive in that the implant fixtures are transmucosal from the time of placement, requiring only a single stage in surgical treatment. In a relatively simplified approach to prosthetic management, standard overdenture components and conventional fixed partial denture techniques are used. In this report the assessment, surgical treatment and post-operative management of patients using ITI Bonefit implants are described and early results from 168 consecutive fixtures placed over a period of 3 years indicated.


Arterial embolisation of a facial haemangioma.

Non-invasive investigations in the diagnosis of highly vascular lesions are without doubt a sound principle. A case is presented however, in which the clinical diagnosis of a haemangioma was confirmed by ultrasound and magnetic resonance imaging (MRI) but required further investigation by angiography to facilitate treatment. Embolisation is a well established technique available in most large radiology departments, but may not be well known by general dental practitioners.


The check record in NHS practice.

Incorrect occlusion is a major cause of complete denture failure. Any technique which has the potential to solve this problem and consequently limit the number of review appointments must be worthy of consideration. The pre-occlusal or precentric check record is an accurate method of verifying the occlusion of complete dentures. Although the check record is taught in many teaching hospitals, it is not widely used in general practice. This is primarily due to the time-consuming nature of the conventional method. A variation on the standard technique is described, which is designed specifically for NHS complete denture practice. The materials used are inexpensive and the procedure takes approximately 10 minutes.


The cost of keeping one's hands clean.

After reading 'A Practical Gloving and Handwashing Regimen for Dental Practice' (Field E A, Jedynakiewicz N M, King C M. A Practical Gloving and Handwashing Regimen for Dental Practice. Br Dent J 1992; 172: 111-113), I undertook to do some simple research into the economics of glove wearing for the general dental practitioner based on the regimens mentioned in the article. The conclusion which I reached is that one not only needs to take into account the cost of the gloves but also the valuable surgery time taken in the washing of one's hands and gloves. The most cost-effective method of hand and glove washing was found to be the use of a single non-sterile glove with Hibisol.


Application of antibody-mediated extraction for the stereoselective determination of the active metabolite of loxoprofen in human and rat plasma.

Antibody-mediated extraction followed by chiral high-performance liquid chromatography (HPLC) was applied to stereoselective determination in human and rat plasma of the active metabolite [(2S,1'R,2'S)-trans-alcohol] with three chiral centers of Loxoprofen, a 2-arylpropionic acid antiinflammatory agent after oral administration. Antiserum against the (1'R,2'S)-cyclopentanol moiety was obtained from a rabbit immunized with bovine serum albumin conjugate linked to the propionic acid moiety, in which another chiral center is located. Then, the immunoglobulin G purified by a protein A column was coupled to BrCN-activated Sepharose 4B. Plasma samples were applied to the immobilized antibody column. After washing the column to remove unrequired stereoisomers, a mixture of two diastereomers whose configurations were 1'R,2'S in the cyclopentanol moiety was extracted with 95% methanol. The solvent was evaporated and the residue was derivatized with (+)-(R)-1-(1-naphthyl)ethylamine as a chiral reagent to separate the diastereomers by HPLC. This combined analytical method showed the stereoselective metabolism of Loxoprofen in human, that is, 64% of the total amount of four trans-alcohol stereoisomers was in the 2S,1'R,2'S form, which is the active metabolite. This phenomenon was also observed in rats given Loxoprofen and its (2S)- and (2R)-isomers, and is explained by stereoselective ketone reduction of Loxoprofen to the (1'R,2'S)-trans-alcohol and inversion from 2R to 2S in the propionic acid moiety. Antibody-mediated extraction should be a selective and simple clean-up method for determining haptens with complicated structures, combined with an appropriate analytical method.


[Cantrell's pentalogy: complete treatment, step by step].

Since MAYOR and CANTRELL described in 1953 and in 1958 the ectopia cordis associated to other four anomalies, few cases have been reported, and only a small part of them have survived. We report the case of a neonate who presented with the features of the pentalogy. On the 3rd day we found at operation the heart laying over the left hepatic lobe, no pericardium could be identified and diaphragm was absent at its anterior edge. We made an "isolating sac" with duramadre fixed to the anterior thoracic wall, to both sides and to the posterior diaphragmatic defect. The initial management of the ventral defect is described. At the age of two years we initiated the definitive treatment aiming to: 1. To protect the heart. 2. To correct the huge abdominal eventration following the closure of the omphalocele. We described in details the technic employed to cover the precordial defect, to reconstruct the diaphragm, and finally as we treated in three consecutives stages the huge abdominal eventration.


A preliminary report on the effect of storage in water on the properties of commercial light-cured glass-ionomer cements.

Two commercially available light-curable glass-ionomer cements, Vitrebond and XR-Ionomer, have been studied and their compressive strengths measured following storage under wet and dry conditions for varying lengths of time up to 3 months. The strongest cements were those stored in air and allowed to age. On the other hand, cements that were stored in water were found to become progressively weaker with time. Their failure mode was different from that of cements stored in air in that specimens became barrel-shaped as they were loaded and exhibited considerable plastic deformation prior to fracturing. By contrast, air-stored specimens behaved as predominantly brittle materials, the specimens essentially maintaining their integrity up to the point of catastrophic failure. Both of these findings indicate that the properties of these particular light-cured cements change markedly on exposure to moisture, a fact which is of clinical significance.


[Pyknodysostosis: extreme cause of sleep apnea].

We describe a twentieth month old infant who had a pycnodysostosis syndrome. This malformation shows a loss of the normal mandible angle with generalized bone hyperdensification. The first produced and airway obstruction, with special relevance during sleeping hours. A polysomnography revealed an obstructive sleep apnea syndrome. The respiratory picture deteriorated with worsening of the airway obstruction, hypoxemia and finally pulmonary hypertension and cor pulmonale. A tracheostomy was performed, with resolution of the sleep apnea and pulmonary hypertension. The etiology, pathophysiologic consequences and surgical treatment of obstructive sleep apnea syndrome is reviewed.


[Superficial cutaneous nevus lipomatosus of Hoffmann-Zurhelle. Report of a case].

Nevus lipomatosus cutaneous superficialis is a rare idiopathic abnormality characterized by ectopic adipose tissue in the dermis. We present a typical case, making reference to the main clinical characteristics, histological peculiarities, pathogenical hypothesis and treatment of this tumor.


[Intestinal neuronal dysplasia].

Neuronal intestinal dysplasia and hypogenesis of the submucous plexus, frequent cause of constipation in infancy and childhood.


[Manometric study in the newborn].

Hirschsprung's disease in the newborn period has a bad prognosis due to the high mortality rate caused mainly by enterocolitis. It has been shown that the incidence of enterocolitis diminishes with the precocity with which diagnosis is made. All diagnostic methods have problems in the neonate. We intent to investigate the anorrectal manometry in the neonate using a probe devised and built by us. The hypothesis we try to prove is that the rectoanal reflex is present in all newborn, having no relation with age, length of gestation period, nor weight. The characteristics of the probes used allowed long recording sessions without any sedation of patients. The validity of this technique is unquestionable from the view of the reliability of the recordings independently of the weight, gestational age and birth age of the infants.


[Total colonic aganglionosis].

Between 1966 and 1990, 171 cases of Hirschsprung's disease, of which 21 were total colonic aganglionosis, were surgically treated at our centre. In the first period up to 1978, in which total parenteral nutrition (TPN) was not used, six of 11 patients died. From 1979 to 1990, ten further cases were treated with the support of TPN and only one death occurred, in a child with aganglionosis up to one-half of the yeyunum. The 14 surviving patients were treated, ten with the Duhamel technique, two with Rehbein and one with Boley procedure. The Lester Martin technique was not used. Follow-up of ten of then patients showed their good general condition. The number of daily bowel movements, on the average three, was higher than normal. Studies of serum iron, vitamin B12 and folic acid absorption showed slightly low values, which require close monitoring. Hydrogen and fecal test were normal.


[Mechanical ventilation in rats].

In order to create an experimental model of mechanical ventilation that allows functional respiratory studies and different studies related to thorax surgery in small animals, young adult Sprague-Dawley male rats were anesthetised with sodium thiopental and a tracheostomy with a tephlonated catheter was performed. The carotid artery was canulated for arterial blood gas samples, and the cardiovascular system was controlled permanently. A continuous flow time cicled neonatal ventilator, Loosco Amsterdan Infant Ventilator M.K.2, was used for mechanical ventilation. Conventional ventilation with different volumes and pressures were tested. Good adaptation and tolerance and normal blood gases were found with a rate of 60/min; flow rate 0.2 l/min; I:E 1:2; PEED 0 cm H2O; PIP 6.7 +/- 0.5 (mean +/- SD) cm H2O and sharp waves. We conclude that with these very old neonatal ventilators it is possible to ventilate very small experimental animals easily, and allow to small laboratories to do respiratory functional studies or experimental surgery of the thorax.


[Intestinal dysmotility-pseudo-obstruction].

Chronic intestinal pseudo-obstruction is defined as a syndrome related to any process which affects intestinal regulation and propulsion. Its origin may be muscular, neurogenic or hormonal, excluding Hirschsprung's disease or any known mechanical obstruction. Between 1989 and 1991, 11 patients with intestinal pseudo-obstruction were studied at our centre, and included nine hyperganglionisms B, and two hypoganglionisms) and two visceral myopathies (Berdon's syndrome). Diagnosis was established in all cases by histologic study. The techniques of haematoxylin-eosin, acetylcholinesterase, enolase, protein S-100 and Smith were used in neuropathies and haematoxylin-eosin and Masson's trichromic in myopathies. Intestinal motility was studied by ano-rectal and gastrointestinal manometry in seven and three cases respectively. Gastrointestinal manometry and radiology permitted differentiation of localized and diffuse forms of involvement. Medical treatment consisted of total parenteral nutrition when oral feeding was impossible, and in five cases, cisapride was given, with good results in four. Derivative surgery was performed in cases of diffuse involvement, and resection with anastomosis in those of localized forms. We conclude that: 1. Diagnosis is established according to histologic criteria. 2. Complementary examinations should be directed towards distinguishing localized from diffuse involvement. 3. Cisapride was effective in the treatment of neuropathies in the majority of cases.


[Cholelithiasis in childhood. Proposals based on a multicentric study].

Fifty six cases of cholelithiasis in patients aged two months to 15 years (mean age 7.65 years) concerning to 11 hospitals are reviewed. The study protocol followed was the same in all medical records, although own criterions were considered on management performed in each center. From the cases, it follows: 1. Male/female rate is 1/1.5. 2. Symptomatology in infancy is relatively poor and pain localization is not orientative. 3. It was an incidentally finding in 41 per 100 of the cases. 4. Ultrasonography is the best examination procedure rendering diagnosis in the 51 cases it was underwent. 5. Hematologic study was abnormal in six of 46 cases. 6. Medical treatment was not performed in any hospital. 7. Existence of "lithogenic families" seems to be demonstrated. 8. The presence of four patients with Down syndrome in this series must be pointed out. 9. Among total 56 cases, 21 underwent surgical treatment, 29 were conservatively treated, two have died and four patients had spontaneous stone resolution. 10. In the face of these, we propose: A) Surgical treatment in symptomatic cases, porcelain gallbladder and nonfunctionating gallbladder. B) Expectant management and sonographic monitoring in asymptomatic cases. C) Carefully evaluation in patients with predisposing factors and patients with recurrent abdominal pain.


New clinical and radiographic features of ankylosing spondylitis.

This article reviews new classification criteria for spondyloarthropathies and describes ankylosing spondylitis-like features in nonhuman primates. It describes the literature in general and analyzes specific papers on clinical assessment, outcome measurements, and standardization procedures. The extra-articular manifestations of ankylosing spondylitis and recent papers dealing with the clinical associations and differential diagnosis of ankylosing spondylitis are reviewed. The normal appearance of sacroiliac joints with magnetic resonance imaging and the value of different imaging techniques in the diagnosis of sacroiliitis, are discussed.


Psoriatic arthritis.

Psoriatic arthritis is an inflammatory arthropathy associated with psoriasis and is classified as a seronegative spondyloarthropathy. It occurs in approximately 5% to 7% of patients with psoriasis. The etiopathogenesis of psoriatic arthritis is not well known, but interaction among genetic, immunologic, and environmental factors is believed to play a key role in the development and clinical expression of the disease. Studies on intercellular interactions, particularly concerning the role of cytokines, growth factors, and intercellular adhesion molecules, have provided new insights into the pathogenesis. A new clinical classification has been introduced based on the experience of a British group. New concepts in the topography (chest, lower limbs, temporomandibular joint) and extra-articular manifestations of the disease have been reported. The usefulness of the erythrocyte sedimentation rate and of bone scintigraphy in the evaluation and follow-up of patients with psoriatic arthritis has also been reported.


Immunogenetic basis of the seronegative spondyloarthropathies.

This review discusses recent data relevant to better understanding the HLA-B27 association with seronegative spondyloarthropathies. Although much is known about the B27 molecule, its contribution to the pathogenesis of disease is unclear. It is still unknown whether the B27 molecule is involved directly, and whether this is due to the basic function of the molecule, ie, presentation of allele-specific antigenic peptides to the T-cell receptor. Experiments performed with B27 transgenic mice and rats strongly support the view that some unique or special property of the B27 molecule is involved in pathogenesis. However, the data are of a preliminary nature.


Infections and the immunopathogenesis of seronegative spondyloarthropathies.

Evidence is accumulating for invasion of joints by bacterial antigens in the seronegative spondyloarthropathies. In spite of the inability to isolate bacteria directly from joint material, indirect evidence, provided by antibody and cellular immune studies, points to a local response to local antigen within the joint. Using monoclonal or polyclonal antibodies, several groups have reported detection of bacterial antigens in synovial fluid cells and synovium itself both in reactive arthritis and in undifferentiated forms of seronegative arthritis. There appear to be direct parallels with animal models insofar as bacterial persistence and arthritogenicity are concerned. To date, however, attempts to detect bacterial DNA in joint material, with the possibility of viability that such findings might imply, have been negative.


Therapy for the seronegative spondyloarthropathies.

Rheumatologists have recently become more circumspect and have begun to demand biologic as well as statistical meaning from the data obtained in therapeutic trials. The same may be applied to therapy for the seronegative spondyloarthropathies. In some respects, the spondyloarthropathies present an even greater problem, because the axial skeleton is even more difficult to evaluate. The studies reviewed here represent the current state of the art, and with the exception of those examining the effects of antimicrobial treatment in reactive arthritis occurring after specific infections, are subject to the same uncertainties. Nonetheless, they represent our immediate point of departure.


Bacterial arthritis.

The 1991 literature on septic arthritis included a concise review of adult septic arthritis, examples of pseudoseptic arthritis, and two interesting animal studies. One animal study examined the induction of acute synovitis by the intra-articular injection of bacterial endotoxin and the cytokines tumor necrosis factor-alpha, and interleukin-1 beta; and the other studied the effects of early and delayed synovectomy in the management of septic arthritis. The predispositions to septic arthritis can be divided into local joint abnormalities, systemic factors, or both. Examples of the local joint abnormalities include osteoarthritis of the hip and apatite-associated arthropathy. Septic arthritis in a patient with rheumatoid arthritis, in a patient with diabetes mellitus and hip arthropathy associated with hemochromatosis, or in a patient with acquired immunodeficiency syndrome and hemophilic arthropathy are examples of how systemic predisposition is coupled with local joint pathology to increase the vulnerability of the host to joint infection. Other examples of systemic disease that predispose to septic arthritis are systemic lupus erythematosus, hypogammaglobulinemia, and human immunodeficiency virus infection, as well as intravenous drug abuse. Unusual microorganisms causing septic arthritis in the adult include Achromobacter xylosoxidans, Moraxella catarrhalis, meningococci, and diphtheroids. Uncommon pathogenesis is represented by a case of intra-articular inoculation of Mycobacterium gastri into the small joint of the hand and a case of mixed bacterial infection of the hip resulting from an extension of a contiguous pelvic infection associated with trauma. Two cases of immune complex glomerulonephritis illustrate the extra-articular complications of septic arthritis: one due to group G streptococcus and the other due to pneumococcus. Finally, septic bursitis is reviewed from the community practice perspective.


Arthritis due to tuberculosis, fungal infections, and parasites.

A significant proportion of the world's population is afflicted with tuberculosis, fungal infections, or parasitic diseases. The epidemic of acquired immunodeficiency syndrome in developing and developed countries is partially responsible for the increased number of cases. These conditions can cause infectious arthritis and localized bone infection. In addition, reactive arthritis, manifestations that resemble connective tissue disorders, and vasculitis continue to be reported. Prompt diagnosis and adequate treatment of these infections continue to be emphasized in the current literature.


Epidemiology, clinical features, and diagnosis of Lyme disease.

Lyme disease is the most common vector-borne disease in the United States. Epidemiologic research has contributed to a better understanding of the factors involved in the geographic spread and increased incidence of the disease. Clinical features of Lyme disease, including skin, joint, cardiac, and neurologic involvement, are discussed here, along with recent studies that better characterize these clinical manifestations and more clearly define their immunopathogenesis. The diagnosis of Lyme disease is based on the clinical presentation. Laboratory testing may be helpful but has significant limitations, which we discuss in our review.


Viral infections, acquired immunodeficiency syndrome, and rheumatic diseases.

There is increasing evidence of a role for viruses in the pathogenesis and etiology of rheumatic diseases. Although definitive evidence of any involvement in diseases such as rheumatic arthritis and systemic lupus erythematosus is currently lacking, there is increasing evidence that viruses may be involved in the pathogenesis of related diseases. In particular, the recent world-wide epidemic of human immunodeficiency virus infection has been associated with the identification of a wide variety of rheumatic manifestations, most notably oligoarthropathies, psoriatic arthropathies, and Reiter's-like syndromes. The spectrum of rheumatic diseases associated with human immunodeficiency virus infection appears to be expanding at a considerable rate. Other viruses have also been shown to be associated with rheumatic disorders, most notably hepatitis viruses, human T lymphotropic virus type I, and parvoviruses. In the latter case, acute arthropathies and those resembling rheumatoid arthritis and Lyme arthritis have recently been identified. This review presents some of the evidence in the recently published literature on the role of different viruses and their implications in the pathogenesis of various rheumatic diseases.


Infection as a cause of reactive arthritis, ankylosing spondylitis, and rheumatic fever.

Recent advances in understanding the role of infectious agents in the etiology of reactive arthritis (Reiter's syndrome), ankylosing spondylitis, and rheumatic fever are reviewed. The reader is referred to other reviews in this section for discussions of septic, spirochetal, mycobacterial, and fungal arthritis, and human immunodeficiency virus-related connective tissue diseases.


The epidemiology of osteoarthritis of the knee.

Estimates of the prevalence and incidence of knee osteoarthritis increase with age and are higher for women. Other differences in such estimates arise due to methodologic variables, including radiographic techniques. The risk for knee osteoarthritis increases with increasing body weight, long-term occupational joint stresses, joint trauma, and probably higher bone mass. Weight restriction and cigarette smoking are associated with reduced risk of knee osteoarthritis. The relationships among these risk factors (eg, bone mass, physical activity, weight, and smoking) and other influences (eg, genetics) remain to be classified.


Cartilage research and treatment of osteoarthritis.

Research in the past year involving the cartilage structural components, especially the collagens and proteoglycans, has helped to increase our understanding of their complex macromolecular interactions in both normal and osteoarthritic cartilage. The number of factors that regulate the synthesis, deposition in tissue, and catabolism of cartilage, and the complexity of their interactions, continually grows. One of the most significant advances is that the powerful techniques of molecular biology are beginning to be applied to the study of articular cartilage, improving our understanding of chondrogenesis, gene expression in both normal and diseased cartilage, and genetic disorders affecting cartilage. Studies of cartilage in culture suggest the possibility of therapeutic intervention that would have a meaningful impact on disease outcome, the so-called chondroprotective therapy, but none has been demonstrated conclusively. Nonsteroidal anti-inflammatory drugs continue to be the most common mode of therapy for osteoarthritis, but recent studies have called this form of treatment into question, suggesting that analgesic therapy may produce equivalent results.


Imaging, arthroscopy, and markers in osteoarthritis.

Osteoarthritis is the most common form of arthritis occurring in humans, but its diagnosis in early stages continues to be elusive. Early diagnosis is of great potential importance because it would allow identification of individuals at risk for progressive disease and permit early intervention. At present, perhaps even more important, the ability to recognize patients with early, often asymptomatic, disease and the ability to monitor disease progression over time would be most useful for the evaluation of new forms of therapy to prevent, halt, or even reverse osteoarthritis. Thus, 1991 has witnessed the continued search for the ideal indicator of early osteoarthritis.


Gout and hyperuricemia.

A number of investigators have applied the tools of molecular biology to characterize genes responsible for the control of urate homeostasis and clarify the roles of uric acid precursors in inflammation. Some, using the tools of clinical medicine, continue to provide novel descriptions of gout and to explore better ways for evaluating hyperuricemia and for understanding the pathophysiology of disorders such as familial urate nephropathy. Others link the disciplines of basic research and clinical medicine in approaching the perplexing questions of crystal-induced inflammation.


Calcium pyrophosphate crystal deposition disease and other crystal deposition diseases.

A number of cells, chemotactic factors, and inflammatory mediators are implicated in the complex mechanisms underlying crystal-mediated inflammation. Interleukin-8, released from mononuclear cells that have been exposed to urate and other crystals, is a potent chemotaxin and activator of neutrophils. Experimental and clinical observations suggest that joint movements, local biomechanical factors, and previous joint damage may play a role in influencing the intensity of microcrystalline synovitis and the distribution of articular and periarticular crystal deposits in both calcium pyrophosphate dihydrate crystal deposition disease and gout. There are rare reports of extra-articular calcium pyrophosphate dihydrate crystal deposition in tendons, bursae, dura mater, and ligamentum flavum (with radiculomyelopathy) and of massive "tumoral," tophuslike, periarticular calcium pyrophosphate dihydrate crystal deposits. Synovial fluid levels of ATP, the main substrate for nucleoside triphosphate pyrophosphohydrolase ectoenzyme, which cleaves ATP-releasing inorganic pyrophosphate, are higher in patients with calcium pyrophosphate dihydrate crystal deposition disease than in those with other arthritides, and the levels correlate with inorganic pyrophosphate concentrations. Further reports of acute calcific periarthritis of the first metatarsophalangeal joint (hydroxyapatite pseudopodagra) in young women have been described. The mitogenic response of fibroblasts to stimulation with basic calcium phosphate crystals is accompanied by induction and secretion of collagenase and neutral proteases, implicating a role for the crystals in the pathogenesis of both synovial proliferation and joint damage in chronic basic calcium phosphate crystal-associated arthropathy. Subcutaneous cholesterol crystal deposition with tophus formation is extremely rare and has been described in a patient with scleroderma and calcinosis cutis.


Functional abnormalities in the intestine associated with mucosal mast cell activation.

Mast cells are a significant component of the mucosa in the gastrointestinal tract. There is increasing evidence that these cells are involved in the pathophysiology of various intestinal disorders ranging from food allergy to inflammatory bowel disease. When activated, mast cells release a host of potent mediators and cytokines which are capable of inducing pathophysiology. The bulk of the evidence has come from hypersensitivity studies in experimental animals sensitized either by parasitic infection or by active immunization to an antigen using adjuvants which stimulate IgE production. Subsequent antigen challenge of the gut results in mast cell activation associated with alterations in intestinal functions including ion transport and epithelial permeability. Intestinal secretory transport responses are inhibited by antagonists of mast cell mediators and neurotoxins, implicating mast cell-nerve interactions with the epithelium. In genetically mast cell-deficient mice, antigen-induced secretion is reduced approximately 70% and this component is not affected by neural or mast cell inhibitors; adoptive transfer of bone marrow containing mast cell precursors derived from congenic normal mice restores the complete antigen response. These results provide more direct proof that mast cell activation causes abnormal gut function. Recently, we have begun studies which indicate that activation of mast cells induces ion secretion in surgically resected human intestine. Reduced secretory responses in specimens from patients with IBD suggest that mast cells may play a role in the pathophysiology of inflammatory bowel disease.


Cholera toxin conjugates for intragastric vaccination against herpes simplex virus type 2.

In this study, we tested the hypothesis that enteric immunization with cholera toxin (CTX) conjugated to glycoprotein D (gD) of herpes simplex virus type 2 (HSV-2) or a peptide corresponding to residues (1-23) of gD (gD(1-23)) would induce relevant antiviral immunity. Intraperitoneal (IP) immunization of mice with CTX-gD(1-23) conjugate induced anti-HSV-2 sera antibody responses which correlated with protection from a lethal IP challenge with HSV-2. Intragastric (IG) immunization of mice with the same conjugate or a CTX-gD conjugate did not result in measurable anti-HSV-2 responses in sera or vaginal washings and only small numbers of anti-HSV-2 antibody-secreting cells (ASC) were found in intestinal lamina propria cell and splenocyte preparations. In comparison, anti-CTX responses were detected in sera and vaginal washings after IG immunization with CTX and anti-CTX ASC in lamina propria cell preparations accounted for 5-10% of total ASC detected at this site. No significant differences in the survival of mice immunized with the conjugates were noted after a lethal intravaginal (IVAG) challenge with HSV-2. The poor enteric immunogenicity of gD(1-23) and gD conjugated to CTX was attributable to proteolysis in the gastrointestinal tract. These results indicate that although peptide-CTX conjugates can induce protective immune responses when administered parenterally, it may not be feasible to use peptides as the basis of an oral vaccine unless methods are developed to protect these antigens from degradation in the gastrointestinal tract.


The use of the hu-PBL-SCID mouse model to study lymphocyte homing and responsiveness to recall antigens.

SCID mice were injected intraperitoneally with human peripheral blood lymphocytes (PBL) that had been previously stimulated with pokeweed mitogen (PWM) for two days to generate activated B cells. After two weeks, serum and gut washes obtained from SCID mice reconstituted with human PBL (hu-PBL-SCID mice) contained human IgA, IgG, and IgM indicating the successful survival of human lymphoid cell grafts in both mucosal and nonmucosal tissues of the SCID mice. Human IgA plasma cells could be detected by immunofluorescence microscopy in the lamina propria of the small intestine, while IgM plasma cells predominated in the spleen. The results suggested that PWM-activated plasma cell precursors homed to the spleen and the lamina propria of the SCID mouse where they differentiated into plasma cells. In vivo stimulation of hu-PBL-SCID mice with diphtheria and tetanus toxoids (DT/TT) elicited a primary (IgM) immune response pattern rather than a secondary (IgG) response. Antigen-specific antibody-secreting cells were found in the spleen and lamina propria after immunization. The microenvironment of the hu-PBL-SCID mice may select virgin B cells subsets over memory B cell clones.


Modulation of cis-diamminedichloroplatinum(II) resistance: a review.

In this review an inventory is made of agents used to circumvent cis-diamminedichloroplatinum(II) (CDDP) resistance in vitro and in vivo. Agents that affect CDDP accumulation and membrane related systems, cytoplasmic defense mechanisms, as well as DNA accessibility and repair are reviewed. In resistant cell lines that have decreased accumulation, this can be restored by hyperthermic treatment. With or without effects on accumulation compounds that affect cell signal transduction often increase CDDP cytotoxicity. Calcium channel blockers and calmodulin inhibitors do not seem to be uniformly good modulators of CDDP resistance. For transduction modulators as well as cellular calcium affecting agents mechanisms are mainly unclear or controversial. Glutathione appears, with the now available agents, to be the most promising target for modulation of cytoplasmic defense mechanisms. At the nuclear level the inhibition of DNA repair related enzymes as well as the use of modified nucleosides to interfere with repair is studied in various cell lines. Results with these agents suggest opportunities for clinically feasible cytotoxicity modulation. DNA accessibility could in vitro be affected, but seems to be an unreliable target for modulation. Whenever possible the resistance mechanism affected and the mode of action of the modulator are discussed. As an alternative for modulation another method of overcoming CDDP resistance namely the application of CDDP analogues is considered.


The Walter Herbert Lecture. Control of cell motility and tumour invasion by extracellular matrix interactions.

Integrins are heterodimeric transmembrane proteins with large ectodomains and a short cytoplasmic tail inside the cell. They mediate cell adhesion to extracellular matrix proteins and to the surfaces of other cells. In many cases the sequence recognised by the integrins in the extracellular matrix proteins is the tripeptide Arg-Gly-Asp (RGD). Short synthetic peptides containing this sequence can inhibit invasion in vitro and tumour dissemination in vivo. Thus, the alpha 5 beta 1 fibronectin binding integrin appears to be the key integrin in the invasion of at least melanoma, osteosarcoma and glioblastoma cells. Modulation of the level and activities of this integrin can suppress invasion, whereas the alpha v beta 3 vitronectin binding integrin appears to be associated with increased invasiveness. There is increasing evidence that some of these effects are mediated through signals elicited by the binding of integrins to their target proteins. This possibility has generated a great deal of interest in the cytoplasmic molecules that might mediate the integrin-associated signalling.


Growth control by epidermal growth factor and transforming growth factor-alpha in human lung squamous carcinoma cells.

Although EGF receptor expression is generally elevated in human lung squamous carcinoma, the biological significance of this phenomenon and the role of EGF and TGF-alpha in this disease are poorly understood. We have investigated three human lung squamous carcinoma cell lines (NX002, CX140 and CX143) and have shown, using an antibody (EGFR1) directed against the EGF receptor, that the majority of cells in all three lines express the EGF receptor. Using a ligand binding assay, Scatchard analysis indicated high concentrations (1,300-2,700 fmol mg-1 protein) of a single low affinity binding site (Kd = 3-5 nM) within these lines. Addition of EGF or TGF-alpha at concentrations greater than 0.1 nM resulted in growth inhibition of all three lines and this was associated with an accumulation of cells in the G2/M phase of the cell cycle. Growth inhibitory effects were not explained by an enhancement of cellular differentiation as monitored by involucrin expression and the ability to form cornified envelopes. While the presence of EGF could not be detected in medium conditioned by the NX002 cell line, mRNA for TGF-alpha was detected in all three lines suggesting the possibility of an autocrine loop. These results together with reports of growth inhibition by EGF and TGF-alpha in other systems suggest that EGF and similar molecules might have a growth regulatory role in lung cancer cells and modulation of such may have therapeutic potential.


The binding of cis-dichlorodiammineplatinum(II) to extracellular and intracellular compounds in relation to drug uptake and cytotoxicity in vitro.

The biological consequence of the binding of cis-dichlorodiammineplatinum(II) (cis-DDP) to serum protein as well as to cellular components in general, was studied on human NHIK 3025 cells in vitro. As expected, we found that the cytotoxicity of cis-DDP was lost by binding to serum protein, and that protein-bound platinum was impermeable to the cells. As we have previously shown that electropermeabilisation may transiently increase the influx of cis-DDP, we applied this technique in an attempt to increase the efflux of cis-DDP or any other cytotoxic intermediates. Our data demonstrate that if cells are electropermeabilised shortly after treatment with cis-DDP, cell survival increased. This indicates that cis-DDP in an active form is released from the cells; furthermore, the plasma membrane represents a barrier against efflux, as it has also been shown to be against influx of active cis-DDP. Thus, our data are consistent with the idea that there must be an intracellular pool of either cis-DDP, or some biologically active intermediates, in cells treated with this drug. Additionally, our data indicate that the binding rate of cis-DDP to biological molecules is much quicker intracellularly than in the extracellular environment: We found the biological half-life at 37 degrees C to be about 2.1 h in human serum and about 11 min inside our cells.


The effects of ICRF-154 in combination with other anticancer agents in vitro.

We studied the effects of ICRF-154 in combination with 11 anticancer agents on four human leukaemia cell lines. Cells were incubated for 3 days in the presence of two drugs (ICRF-154 and one other), and cell growth inhibition was determined by MTT assay. Effects of drug combinations at the ID50 level were analysed using the isobologram method (Steel). In the lymphoblastic leukaemia cell lines, MOLT-3, HSB, and B-ALL, supra-additive effects were observed for ICRF-154 in combination with amsacrine, bleomycin, doxorubicin, and etoposide. Additive effects were observed for its combinations with cisplatin, CPT-11, cytosine arabinoside, 5-fluorouracil, mitomycin C, and vincristine. Sub-additive to protective effects were observed in combination with methotrexate. In an erythroleukaemia cell line, K-562, no drug showed supra-additive effects with ICRF-154, while sub-additive to protective effects were observed for ICRF-154 in combination with cisplatin and methotrexate. The other drugs showed additive effects with ICRF-154. These results indicate that the combined effects of ICRF-154 with other agents vary, depending on the cell line. Against lymphoid malignancies, ICRF-154 would be advantageous when administered simultaneously with many anticancer agents. Of such agents, amsacrine, bleomycin, doxorubicin, and etoposide are the most suitable, while methotrexate is least suitable for such combined treatment.


Is there a relationship between regional microsphere distribution and hepatic arterial blood flow?

The relationship between hepatic arterial albumin microsphere distribution and hepatic arterial blood flow and the effects of regional angiotensin II were studied in a rat liver metastases model. Hooded-Lister rats were inoculated subcapsularly with 2 x 10(6) HSN sarcoma cells. At 20 days, hepatic arterial blood flow was measured using the reference microsphere technique. Animals then randomly received 50 microliters hepatic arterial saline or albumin microspheres (40 microns, 20 mg ml-1). Hepatic arterial blood flow measurements were then repeated at 5 min. After 5 min, animals were killed and tissues were weighed and counted in a gamma well counter. There were no significant differences between the hepatic blood flow measurements recorded before and after the control hepatic arterial saline infusion. However, regional albumin microspheres produced a significant reduction in tumour and normal liver blood flow and an 80% reduction in mean T/N blood flow ratio. Regional albumin microspheres were delivered to tumour in greater proportions (mean T/N ratio 3.89, SE 0.49) than would be expected from baseline hepatic arterial blood flow (mean T/N ratio 1.28, SE 0.22. P = 0.006). There was no correlation between T/N for baseline blood flow and albumin microsphere distribution.


Uptake of plasma lipids by tissue-isolated hepatomas 7288CTC and 7777 in vivo.

The uptake of myristic (C14:0), palmitic (C16:0), palmitoleic (C:16,N-7), stearic (C18:0), oleic (C18:1,N-9), linoleic (C18:2,N-6) and arachidonic (C20:4,N-6) acids from plasma free fatty acids (FFA), triglycerides (TGA), phospholipids (PL) and cholesterol esters (CE) was measured in tissue-isolated hepatomas 7288CTC and 7777 in vivo. Adult tumour-bearing Buffalo rats were fed a normal chow diet ad libitum and were subjected to darkness from 1800 to 0600 h. Arterial plasma levels of FFA, TGA, PL and CE were increased during the dark period without change in fatty acid compositions. Arteriovenous difference measurements of tumour lipid uptake were performed between 0600 and 0900 h and included both high (dark) and low (light) arterial blood lipid concentrations. The rate of lipid uptake from each lipid class was directly dependent on the rate of supply of the lipid to the tumour. The efficiency of uptake, however, depended on the type of plasma lipid and the tumour. During one pass of arterial blood, hepatoma 7288CTC (n = 5 to 13) removed 46, 33, 36 and 31%, and hepatoma 7777 (n = 7 to 9) removed 48, 50, 52 and 49% of the fatty acids supplied in FFA, TGA, PL and CE, respectively. Perfusion of tissue-isolated tumours in situ with donor blood containing plasma free (1-14C)palmitic acid showed that 14C-palmitic acid was removed from the arterial blood and was incorporated into tumour lipids and that 14CO2 was released into the tumour venous blood. Uptake of the seven fatty acids over a 24 h period was greatest from PL greater than TGA greater than FFA greater than CE and was estimated to total 18.1 +/- 3.5 mg fatty acids g-1 for hepatoma 7288CTC and 25.9 +/- 3.5 mg fatty acids g-1 for hepatoma 7777. Both hepatoma 7288CTC and 7777 grew at a rate of about 1 g day-1 and contained 13.4 +/- 2.5 and 10.6 +/- 3.9 mg of these 7 fatty acids g-1 tumour wet weight, respectively. We conclude that these two tumours obtain all of the fatty acids needed for daily growth from host arterial blood.


The effect of omega-6 and omega-3 fatty acids on 3H-thymidine incorporation in hepatoma 7288CTC perfused in situ.

Ingestion of diets containing corn oil or marine fish oils is known to increase or decrease, respectively, the growth of transplantable rodent tumours. The active agents in these oils have been identified as linoleic acid (in corn oil) and omega-3 fatty acids (in marine oils), but it is still not known how they influence the tumour growth processes. In these experiments we examined the effects of plasma free omega-6 and omega-3 fatty acids on the rate of 3H-thymidine incorporation in tissue-isolated hepatoma 7288CTC perfused in situ. Host Buffalo rats were fed an essential fatty acid-deficient diet. Plasma and tumours in these animals contained low endogenous levels of both omega-6 and omega-3 fatty acids. Perfusion of these tumours for 2 h with donor whole blood containing added omega-6 free fatty acids, including 0.5 mM linoleic (C18:2,N-6), gamma-linolenic (C18:3,N-6), dihomo-gamma-linolenic (C20:3,N-6) or arachidonic acids (C20:4,N-6), increased the rate of 3H-thymidine incorporation. Linoleic acid was about three times more effective than the other omega-6 fatty acids. Typical hyperbolic substrate-saturation curves were observed as the plasma free linoleate or arachidonate concentration was increased. When perfused alone plasma free omega-3 fatty acids had no effect on tumour 3H-thymidine incorporation, but in the presence of linoleic acid the omega-3 fatty acids, alpha-linolenic (C18:3,N-3) and eicosapentaenoic (C20:5,N-3), competitively inhibited both tumour linoleate uptake and the stimulative effect on 3H-thymidine incorporation. The results suggest that the ambient plasma free linoleic and arachidonic acid concentrations in host arterial blood directly influence the rate of tumour DNA synthesis. Plasma free omega-3 fatty acids appear to modulate the effect of linoleic acid by competitively inhibiting its uptake. These relationships could explain the actions of dietary linoleic and omega-3 fatty acids on tumour growth in vivo.


Synergism between a novel amphibian oocyte ribonuclease and lovastatin in inducing cytostatic and cytotoxic effects in human lung and pancreatic carcinoma cell lines.

A novel anti-tumour amphibian oocyte RNase, ONCONASER (ONC), previously known as P-30 Protein, is in the clinical trials. The effect of ONC alone and in combination with lovastatin (LVT), an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, a rate-limiting enzyme of mevalonate (MVA) and cholesterol synthesis pathway, in three human tumour cell lines ASPC-1 pancreatic, A-549 lung, and HT-520 lung carcinomas, has been presently studied. A synergism between ONC and LVT in inducing the cytostatic and cytotoxic effects was observed. The cytostatic effect, seen during the early phase of the treatment with this combination of drugs was manifested as prolongation of the cell cycle duration, especially of the G1 phase; cell death was apparent after 72 h of treatment. The synergistic effect of ONC and LVT was also evident in the clonogenicity assays. Both LVT lactone and its in vitro activated beta-hydroxy acid form, alone and in respective combinations with ONC, exerted similar degree of growth suppression. The effects of both forms of LVT (used alone or in combination with ONC) were reversed by MVA, which suggests that HMG-CoA reductase inhibition is a primary mechanism of LVT action. The data indicate that the LVT lactone can be activated intracellularly by tumour cells studied, and that the combination of ONC with LVT can produce significantly enhanced anti-tumour activities.


Effects of agents which inhibit the regulation of intracellular pH on murine solid tumours.

Cell killing can be achieved in an acidic environment in tissue culture (medium pH less than 7.0) by agents (nigericin, carbonylcyanide-3-chlorophenylhydrazone (CCCP)) which transport protons from the extracellular space into the cytoplasm. Cell killing is enhanced when these agents are used in combination with compounds (amiloride, 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS)) which inhibit the membrane-based exchangers responsible for the regulation of intracellular pH (pHi). We describe experiments which assess the ability of these agents to kill tumour cells in spheroids and in vivo. Both nigericin and CCCP were observed to penetrate tissue based on their ability to kill tumour cells in spheroids. The mean extracellular pH (pHe) of the KHT fibrosarcoma and the EMT-6 sarcoma were observed to be 0.21 and 0.32 pH units more acidic than the mean pHe in muscle tissue. Intraperitoneal (i.p.) administration of the vasodilator hydralazine (10 mg kg-1) caused a reduction of the mean pHe of the KHT but not the EMT-6 tumour. Nigericin (2.5 mg kg-1, i.p.) plus amiloride (10 mg kg-1, i.p.) followed 30 min later by hydralazine (10 mg kg-1, i.p.) reduced the surviving fraction of cells in the KHT and EMT-6 tumours, but had minimal effects on growth delay. When KHT tumours were treated with 15 Gy X-rays followed immediately by nigericin plus amiloride and hydralazine a reduced surviving fraction as well as an increase in tumour growth delay was observed compared to radiation alone. The administration of nigericin (2.5 mg kg-1, i.p.) or the combination of nigericin (2.5 mg kg-1, i.p.) followed by hydralazine (10 mg kg-1, intravenous (i.v.)) resulted in reductions of tumour pHi of 0.27 and 0.29 pH units respectively as determined by 31P magnetic resonance spectroscopy (MRS). Our results show that the combination of nigericin and hydralazine (with or without amiloride) can kill cells in rodent solid tumours and that cell killing is associated with a reduction in the mean pHi of tumour cells.


Changes in expression of alpha 6/beta 4 integrin heterodimer in primary and metastatic breast cancer.

The alpha 6/beta 4 integrin complex has been shown to be expressed in murine tissues at the basolateral aspect of most epithelial cells including the mammary epithelium, thus suggesting that this heterodimer may interact with components of the basement membrane. Because transformation of mammary epithelium frequently results in disappearance of basement membranes and loss of cell polarisation we have analysed in the present study whether expression of the alpha 6/beta 4 complex is altered in human breast tumours. The results of the present study confirm that in human mammary gland alpha 6 and beta 4 subunits colocalise at the basolateral aspect of the epithelium. While in benign breast lesions this distribution pattern remains mostly unchanged, in primary carcinomas the expression of both chains is either redistributed over the cells surface or significantly reduced. This altered pattern of expression is paralleled by the lack of detection of basement membrane laminin and collagen type IV. In metastatic lesions the expression of the heterodimer is maintained in most of the lymphnodal foci, but less frequently detected in metastasis localised in the pleural cavity and in parenchymal tissues. These findings indicate that in breast epithelium expression of the alpha 6/beta 4 heterodimer is modulated by the presence of basement membrane and is possibly influenced by microenvironmental factors as suggested by the different pattern of alpha 6/beta 4 expression in nodal and extranodal metastatic foci.


The influence of hydralazine on the vasculature, blood perfusion and chemosensitivity of MAC tumours.

We have studied the influence of the peripheral vasodilator hydralazine (HDZ) on the vasculature and blood perfusion of two members of a series of subcutaneous murine adenocarcinomata of the colon (MAC tumours), and the influence of HDZ on the efficacy and/or toxicity of TCNU and melphalan. The fluorescent DNA stain Hoechst 33342, showed that HDZ caused a shutdown of tumour vasculature, related in magnitude to both dose and tumour differentiation state; 10 mg kg-1 caused an 80% vascular shutdown of well differentiated MAC 26 tumours, but only a 50% shutdown of the poorly differentiated MAC 15A tumours. 2.5 mg kg-1 was ineffective. The blood perfusion marker 99mTc-HMPAO showed that the normal perfusion of MAC tumours was consistently markedly less than that of lung, liver or kidneys (4-5% of lung perfusion). HDZ (10 mg kg-1) decreased MAC 26 perfusion by 63%, and that of MAC 15A by 20%. Again, 2.5 mg kg-1) was ineffective. Use of in vivo to in vitro clonogenic assays showed that HDZ (10 mg kg-1) potentiated the efficacy of melphalan (1-10 mg kg-1 i.p.) by a factor of 2.1, and increased the efficacy of TCNU (1-10 mg kg-1 i.v., factor = 1.7) when given 10 or 15 min respectively after dosing. However, the addition of HDZ increased the acute bone marrow toxicity of melphalan, but not that of TCNU. The clinical relevance of these results is discussed.


Serum concentration of the cross-linked carboxyterminal telopeptide of type I collagen (ICTP) is a useful prognostic indicator in multiple myeloma.

Type I collagen is the main collagen type found in mineralised bone. Specific immunoassays for PICP (carboxyterminal propeptide of type I procollagen) and ICTP (cross-linked carboxyterminal telopeptide region of type I collagen) allow simultaneous assessment of the synthesis and degradation of type I collagen in serum samples, respectively. Our aim was to find out whether these metabolites of type I collagen are useful markers for following bone turnover and evaluating treatment response in multiple myeloma, which is a good model disease of excessive osteolysis. Fifteen consecutive patients were studied before and throughout their treatment. Samples for serum PICP and ICTP were collected before starting each treatment course of melphalan and prednisolon. Response to treatment was evaluated by following the changes in M protein and bone roentgenograms. The disease was progressing in four and regressive in 11 patients, but in four of these a recurrence occurred. In nonresponders the ICTP concentration was permanently elevated despite treatment. In responders both increased or normal levels of ICTP were initially observed, but they returned to or remained in the reference interval during treatment. The ICTP concentration increased upon recurring disease. There was a strong correlation between the extent of bone lesions and ICTP. There was no correlation between ICTP and PICP, the latter mainly remaining within the reference range, a finding that suggests no change in bone formation. ICTP was a significant predictor for survival in this patient group (P less than 0.05). We conclude that ICTP is a specific and sensitive marker for bone resorption. Simultaneous use of serum ICTP and PICP offers an additional and easy means to follow bone turnover and evaluate the response to therapy in multiple myeloma.


Antigenic modulation of metastatic breast and ovary carcinoma cells by intracavitary injection of IFN-alpha.

Antigenic modulation of major histocompatibility and tumour associated antigens was observed in neoplastic cells obtained from patients with pleural and abdominal effusions of breast and ovary carcinomas following a single intracavitary dose of 18 x 10(6) U recombinant IFN-alpha. This regimen resulted in antigenic modulation in seven out of 11 tested cases, suggesting a potential, although limited, responsiveness of at least a fraction of breast and ovary carcinoma cells to in situ biomodification with IFN-alpha.


Modification of the volumetric growth responses and steady-state hypoxic fractions of xenografted DLD-2 human colon carcinomas by administration of basic fibroblast growth factor or suramin.

We studied the growth characteristics and hypoxic fractions of DLD-2 human colon tumours xenografted into male nude mice either in the unperturbed state or after i.p. injection (q.i.d. x 7) of basic fibroblast growth factor (0.25 mg kg-1) or suramin (50 mg kg-1). Hypoxic fractions were measured by clonogenic excision assay 1 day after administration b FGF or suramin was stopped. As compared to controls, the growth of tumours in b FGF treated mice was increased by a factor of 1.5 as indicated by the relative volumes of tumours on the day of excision. Similarly, suramin decreased the growth of DLD-2 tumours by a factor of 1.6. The percentage of hypoxic cells in control neoplasms was 42.9% (95% confidence limits 34.2-52.1%). In mice that received basic fibroblast growth factor injections, hypoxic fractions decreased to 19.1% (95% confidence limits 13.5-26.9%). In contrast, in mice treated with suramin, the percentage of hypoxic cells increased to 74.0% (95% confidence limits 65.3-83.9%). These data indicate that the biology of solid tumours can be significantly modified by alteration of growth factor status.


Separable growth and migration factors for large-cell lymphoma cells secreted by microvascular endothelial cells derived from target organs for metastasis.

Metastatic variant sublines of the murine large-cell lymphoma cell line RAW117 were tested for their growth and migration properties in vitro in medium conditioned by soluble factors released from syngeneic mouse liver-, lung-, and brain-derived microvessel endothelial cells. Medium conditioned with hepatic sinusoidal endothelial cells stimulated the growth of highly liver-colonising (RAW117-H10) and highly liver- and lung-colonising (RAW117-L17) sublines at higher rates than the poorly metastatic parental line (RAW117-P) (H10 greater than L17 greater than P). Medium conditioned with lung microvessel endothelial cells selectively stimulated the growth of the lung-colonising RAW117-L17 subline. Medium conditioned with brain microvessel endothelial cells showed no growth selectivity, and equivalently stimulated the growth of various RAW117 cell sublines. Medium conditioned with hepatic sinusoidal endothelial cells preferentially promoted the migration of the liver-colonising H10 and L17 sublines, and medium conditioned with lung endothelial cells differentially stimulated the migration of the lung-colonising L17 subline; whereas medium conditioned with brain endothelial cells only slightly stimulated the migration of L17, but not H10 or P cells. Fractionation of medium conditioned with hepatic sinusoidal endothelial cells by DEAE Sephacel anion exchange chromatography revealed that the growth-stimulating activities were clearly separable from migration-stimulating activities. The growth- and migration-stimulating activities released from organ microvessel endothelial cells may be important in determining the ability of RAW117 cells to selectively form metastatic colonies in particular organs.


Immunohistological examination of the inter- and intracellular distribution of O6-alkylguanine DNA-alkyltransferase in human liver and melanoma.

The tissue and cellular distribution of the DNA repair protein O6-alkylguanine-DNA-alkyltransferase (ATase) is an important question in relation to the response of tumour and normal tissues to chemotherapeutic regimes employing alkylating agents such as methyltriazenes and nitrosoureas. In order to examine this issue by immunostaining, we have raised a rabbit antiserum to apparently pure recombinant human enzyme. The antiserum is highly specific and sensitive, detecting a band at 24 kDa on western blots of crude extracts of ATase-expressing human lymphoblastoid cells, liver and melanoma. Adjacent sections of acetone or formalin fixed normal human liver and subcutaneous malignant melanoma were reacted with preimmune serum or antiserum and an immunoperoxidase detection system with silver enhancement was used to locate binding of the primary antibody to the antigen. In sections reacted with preimmune serum or with antigen-preadsorbed antiserum, only faint cytoplasmic and little or no nuclear staining was seen. In contrast, using antiserum, the reaction in positively staining cells was very intense and predominantly nuclear. In the liver, there was interindividual variation in the cellular distribution of reaction with staining present in all discernable cell types in most samples but confined to the hepatocytes and bile duct epithelial cells in others. In the melanoma sections, all discernable cell types showed mainly nuclear staining: the intensity of staining varied between tissue samples and there was evidence of a range of intermediate staining intensities with some melanoma cells showing no detectable reaction.


Prognostic implications of p53 protein, epidermal growth factor receptor, and Ki-67 labelling in brain tumours.

The expression of p53 protein, epidermal growth factor receptor (EGFR), and Ki-67 nuclear antigen was examined by immunohistochemistry in biopsies of 16 types of human brain tumours, including 43 astrocytomas. P53 protein, almost certainly its mutant form, was expressed in seven of the 16, and EGFR in 11 of the 16 types of tumours. In astrocytomas both the proportion of tumours which expressed p53 or EGFR increased with grade of malignancy as did the mean Ki-67 labelling index (LI): p53-0% in grade 1, 17% in grade 2, 38% in grade 3, 65% in grade 4; EGFR-0% in grade 1, 33% in grade 2, 85% in grade 3, 95% in grade 4; mean Ki-67 L1-1.1% in grades 1 and 2, 8.3% in grade 3, and 13.4% in grade 4. Astrocytomas which expressed p53 or EGFR had a significantly higher Ki-67 LI at P less than 0.05 (11.8% and 10.7%, resp.) than those that did not (6.2% or 4.1%, resp.). Patients with astrocytomas expressing p53 or EGFR had a significantly reduced survival (P = 0.035 and P = 0.007, resp.): only 11% of the p53 + ve and 13% of the EGFR + ve patients were alive at 100 weeks following diagnosis compared to 36% of p53-ve or 60% of EGFR-ve patients. Patients with Ki-67 LI greater than 5% had a reduced survival (P less than 0.0001)--none survived beyond 86 weeks following diagnosis, whilst 63% of patients with less than 5% positive cells were still alive at 100 weeks. The univariate analysis showed that in astrocytomas expression of p53 mutants, EGFR protein, and Ki-67 greater than 5% are associated with malignant progression and poor prognosis. The multivariate analysis revealed that only tumour grade and Ki-67LI were independent prognostic factors for survival.


Reduced risk of colorectal cancer among recent generations in New Zealand.

Male and female age standardised mortality and incidence rates of colorectal cancer have increased over the most recent 30 years in New Zealand. Among men and women aged 40 to 74, age standardised mortality and incidence rates increased 18 to 105%. However, age standardised mortality and incidence rates among younger men and women have declined from 14 to 69%. Analysis of trends in age specific mortality and incidence rates indicates that the occurrence of colorectal cancer has been declining equally for men and women in successive cohorts born about 1943 to 1953 in New Zealand. This decline in the frequency of colorectal cancer among recent generations was apparent for both the right and left sides of the colon and the rectum. Age-specific trends in coronary heart disease and breast cancer differed from those apparent for colorectal cancer, suggesting that the factors producing the reduction in colorectal cancer risk may affect these diseases among different age groups or may not be of major aetiological importance in these diseases. These trends provide empirical evidence that the occurrence of colorectal cancer can be reduced by at least 50% with a substantial component of the risk being determined before the age of 30. Further study is needed to establish whether changes in risk factors at older ages contribute to the prevention of the disease.


Time trends in accuracy of classification of testicular tumours, with clinical and epidemiological implications.

Initial classifications of 1009 testicular tumours were reviewed as part of a population based survey of all testicular neoplasms in Victoria, Australia, between 1950 and 1978. All reviews were made by one of two pathologists at the Peter MacCallum Cancer Institute, using the system of the British Testicular Tumour Panel. Accuracy of diagnosis varied markedly over the time period and with pathological category. Seven cases were initially designated malignancies but were determined to be non-malignant conditions upon review. In each decade, review reduced the proportion of seminomas and increased the proportion of non-seminoma germ cell tumours (NSGCT) and non germ cell tumours. Reclassification resulted in changed age specific incidences of seminoma and NSGCT, most noticeably in 1950-59. Trends in age standardised incidence of seminoma and NSGCT were not affected by reclassification although the values were. The trend in age standardised incidence of non germ cell tumours was affected by reclassification. The implications of the changes in classification for epidemiological studies and clinical management are discussed.


A randomised trial of second-line hormone vs single agent chemotherapy in tamoxifen resistant advanced breast cancer.

Sixty patients with advanced breast cancer unresponsive to tamoxifen have been randomised to receive four course of mitozantrone, 14 mg m-2 (n = 30) intravenously every 3 weeks (9 weeks total) or megesterol acetate, 160 mg bd (n = 30). One in three patients (11 from each group) had substantial disease control for a minimum period of 6 months i.e., lack of progression; seven patients (23%) showed objective response to mitozantrone compared to four (13%) receiving megesterol. Non-progressive disease occurred in all sites, including visceral metastases and receptor negative patients. There were no significant differences between treatment groups in the median time (5 months each) to disease progression response duration or survival (13 months megesterol, 11 months mitozantrone) from commencing second-line therapy. Toxicity was considerably higher in the mitozantrone group. Second-line hormonal therapies can produce similar therapeutic results as those achieved from a short course of a 'short option' single agent cytotoxic in patients who were previously thought hormone insensitive. Provided that the patient does not have life threatening disease a trial of megesterol acetate is worth consideration in that it does not prejudice subsequent response to combination cytotoxic chemotherapy.


Completeness of cancer and death follow-up obtained through the National Health Service Central Register for England and Wales.

For the last 20 years the National Health Service Central Register (NHSCR) has been used as the principal source of follow-up for mortality, and often for cancer incidence, in many cohort and clinical follow-up studies in England and Wales. Completeness of notification of childhood cancer registrations and deaths from the NHSCR was investigated by comparison between cancers and deaths notified to the Childhood Cancer Research Group (CCRG) from this source and notifications received directly from regional cancer registries and the national death registry. Six thousand, seven hundred and seventy-six (91.8%) of 7,379 cancers incident 1971-84, and 588 (95.8%) of 614 deaths occurring 1953-88, were successfully notified. Failures in cancer notification occurred mainly between the regional cancer registries and the National Cancer Register (3.3%), and between the National Cancer Register and the NHSCR (3.0%). An additional 1.9% of cancer notifications failed between the NHSCR and the CCRG. Incompleteness of registration of childhood cancers by regional cancer registries was estimated to be 4.7%. A total of 12.5% of incident childhood cancers were not notified by NHSCR. Incompleteness of notification may be greater for adults, for whom registration and record linkage may be more difficult. Failures in death notifications occurred mostly because deaths entered on the NHSCR were not notified to the CCRG (3.3%). This incompleteness of notification needs to be taken into account in the interpretation of published studies and in the analysis of studies using NHSCR flagging. It also implies similar incompleteness in published national cancer survival data, which use the same system of flagging. Nevertheless it is a notable achievement that NHSCR has successfully monitored such a high proportion of a population of 50 million people, by entirely clerical procedures, for 40 years.


Neuroblastoma in the very young child: biological considerations.

Neuroblastoma is one of the childhood malignancies that frustrates both the clinical and scientist. Clearly, some forms of the disease are relatively benign and the patient can expect to be cured. However, even today, Stage 4 neuroblastoma is one of the childhood malignancies where the overall prognosis remains very poor. Despite extensive investigations into the biology of the disease, little has been gleaned about the underlying causes of the tumour and what truly separates good and poor risk disease. Fortunately, patients under the age of one with neuroblastoma often fall into the good risk group. Many people now believe that neuroblastoma is not just one disease, but several. Some forms of the tumours may, in fact, not be truly malignant. The data that has led to this conclusion and the biological characteristics that are associated with the different forms of the neuroblastoma will be reviewed. In addition, a brief outline of new studies which may identify some of the factors associated with the neuroblasts ability to metastasise will be discussed.