[Research on pediatric hereditary kidney disease: from now to the future]

Hereditary kidney disease is an important cause of chronic kidney disease in children. With the progress of genome sequencing, single-cell technology, and organoid cultures, the research on hereditary kidney disease has entered a new era. How to integrate big data resources, discover new disease-causing genes, and develop effective treatment methods will be the focus of future research. This article discusses the classification, research progress, challenges and prospects of pediatric hereditary kidney disease, so as to provide valuable insights into the research of hereditary kidney disease in children.

[Genotype-phenotype analysis of Fabry disease caused by GLA gene variation in a pedigree]

Objective: To investigate the clinical phenotype and genetic characteristics of patients with Fabry disease caused by a GLA variant, IVS4+919G>A. Methods: It was a prospective study. Fabry disease screening was conducted among high-risk population in Ninghai from October 2021 to August 2023. Those children with decreased α-galactosidase enzyme activity<2.40 μmol/(L·h) or elavated Lyso-GL-3 level>1.10 μg/L in dried blood spot (DBS) method underwent GLA genetic testing for diagnosis confirmation. Meanwhile, family screening was carried out. A proband and his family members diagnosed with Fabry disease were research subjects. The clinical and genetic characteristics of patients with Fabry disease caused by the GLA variant (IVS4+919G>A) were analyzed. Results: The female proband aged 9.8 years with pain in both lower limbs as the initial symptom was found to have a heterozygous GLA variant IVS4+919G>A among 102 patients. In family screening, there were 4 family members (proband's father, elder sister, elder male cousin and elder female cousin) with Fabry disease and a family member (proband's fifth aunt) with a GLA variant. Among these 4 diagnosed family members, the elder male cousin of the proband, a boy aged 13.2 years had a heterozygous GLA variant, IVS4+919G>A with intermittent pain in both lower limbs as the initial symptom. The proband's father had knee joint pain. The proband's elder sister had decreased vision and his elder female cousin had no obvious symptoms. The proband's fifth aunt with a GLA variant had decreased vision. Conclusions: High-risk screening in children and family screening are helpful for early diagnosis and treatment of Fabry disease. Neuropathic pain may be a early symptom in children with Fabry disease caused by the GLA variant, IVS4+919G>A.

[Nutritional status of 15 children with progeria]

Objective: To analyze the nutritional status of progeria, and to provide reference for scientific nutritional management of progeria. Methods: This cross-sectional study included 15 children with progeria who were treated at Children's Hospital, Zhejiang University School of Medicine, between April 2022 and May 2023. Data of medical history, physical examination, laboratory tests, dietary survey and body composition were collected and analyzed. Results: Among 15 patients there were 7 males and 8 females, aged 7.8 (2.3, 10.8) years. Twelve of the 15 patients exhibited signs of malnutrition. A 24-hour dietary survey was carried out in 14 of them. The daily energy intake of 11 cases was below recommended levels. Carbohydrate intake was insufficient in 10 cases, protein intake was insufficient in 7 cases, and fat intake was insufficient in 12 cases. Deficiencies in calcium, magnesium, iron and zinc were noted in 13, 13, 9 and 10 cases, respectively. Body composition was determined by dual-energy X-ray absorptiometry in 8 cases, and the bone mineral density was below average in 5 of them. Conclusions: Malnutrition, characterized by reduced energy intake, micronutrient deficiencies, and alteration in body composition, is prevalent in children with progeria. Regular routine nutritional assessment and proper interventions may benefit their long-term health status.

[Efficacy of adrenocorticotropic hormone in children with frequently relapsing or steroid-dependent nephrotic syndrome]

Objective: To investigate the efficacy and safety of adrenocorticotropic hormone (ACTH) in children with frequently relapsing or steroid-dependent nephrotic syndrome. Methods: The clinical data of 38 children with frequently relapsing or steroid-dependent nephrotic syndrome who were admitted to the Department of Nephrology, the Children Hospital, Zhejiang University School of Medicine from January 2015 to December 2020 were retrospectively analyzed. The general information, clinical manifestations, laboratory data of the children and follow-up (till 12 months after treatment) were collected. The patients were divided into ACTH group and Glucocorticoid (GC) group according to treatment plan. Cumulative remission, average recurrence rate, GC dosage, height and weight change and peripheral blood CD19⁺B lymphocyte count were compared between the two groups to evaluate the efficacy and adverse reactions of ACTH. Fisher's exact test, t test or rank sum test was used for comparison between groups. Results: Among the 38 patients, 28 were male and 10 were female, aged 84 (24, 180) months; 19 were in ACTH group and 19 were in GC group. The cumulative remission rate of 12 months in ACTH group was higher than that in GC group (9/19 vs. 2/19,χ²=6.81,P=0.009), the average recurrence rate was lower than that in GC group ((0.7±0.8) vs. (1.7±1.1) times, t=-3.27, P=0.011), and the average dosage of GC was lower than that in GC group ((0.27±0.16) vs. (0.51±0.27) mg/(kg·d), t=-3.21, P=0.014). The increase in height was higher than that in the GC group (4 (3,5) vs. 3 (2, 3) cm/year, Z=2.58, P=0.010), and the peripheral blood CD19⁺B lymphocyte count was lower than that in the GC group ((223±149)×10⁶ vs. (410±213)×10⁶/L,t=-3.35, P=0.009). In safety, 19 cases had transient decreased urine volume, 7 cases had hyperglycemia, and 3 cases had hypertension during the infusion of ACTH, which could be relieved after drug withdrawal. Conclusion: ACTH has a better effect on children with frequently relapsing or steroid-dependent nephrotic syndrome, which can improve cumulative sustained remission rate, lower relapses rate and decrease the dosage of GC, with good safety.

Identification of a novel cancer microbiome signature for predicting prognosis of human breast cancer patients

BACKGROUND

Prognosis of breast cancer (BC) patients differs considerably and identifying reliable prognostic biomarker(s) is imperative. With evidence that the microbiome plays a critical role in the response to cancer therapies, we aimed to identify a cancer microbiome signature for predicting the prognosis of BC patients.

METHODS

The TCGA BC microbiome data (TCGA-BRCA-microbiome) was downloaded from cBioPortal. Univariate and multivariate Cox regression analyses were used to examine association of microbial abundance with overall survival (OS) and to identify a microbial signature for creating a prognostic scoring model. The performance of the scoring model was assessed by the area under the ROC curve (AUC). Nomograms using the microbial signature, clinical factors, and molecular subtypes were established to predict OS and progression-free survival (PFS).

RESULTS

Among 1406 genera, the abundances of 94 genera were significantly associated with BC patient OS in TCGA-BRCA-microbiome dataset. From that set we identified a 15-microbe prognostic signature and developed a 15-microbial abundance prognostic scoring (MAPS) model. Patients in low-risk group significantly prolong OS and PFS as compared to those in high-risk group. The time-dependent ROC curves with MAPS showed good predictive efficacy both in OS and PFS. Moreover, MAPS is an independent prognostic factor for OS and PFS over clinical factors and PAM50-based molecular subtypes and superior to the previously published 12-gene signature. The integration of MAPS into nomograms significantly improved prognosis prediction.

CONCLUSION

MAPS was successfully established to have independent prognostic value, and our study provides a new avenue for developing prognostic biomarkers by microbiome profiling.

[Clinical features and enzyme replacement therapy in 4 children with Fabry disease]

Objective: To analyze the clinical features and efficacy of enzyme replacement therapy in 4 children with Fabry disease. Methods: A retrospective analysis of the clinical manifestations, laboratory findings, genetic variations and treatment were conducted in 4 children with Fabry disease in Children's Hospital of Zhejiang University School of Medicine from January 2014 to July 2020. Results: All four children (2 males, 2 females) with onset age of 12.4 (6.0-16.8) years were diagnosed based on clinical features, α-Gal A enzyme activity, genetic analysis and family history. The clinical manifestations varied in 4 children. All patients had left ventricular hypertrophy and abnormal urinalysis results, 1 case of neuropathic pain, 2 cases of hypohidrosis, 1 case of insipidus, but no angiokeratomas or hearing abnormalities were found. Three missense mutations of GLA gene were identified: c.424T>C (p.C142R), C.335G>A (p.R112H) and c.644A>G (p.N215S). The first two gene mutations were classical phenotypes, and the last one had also been reported in a classic case. In Case 1, no severe adverse events were reported in the first two months of agalsidase beta treatment. The dosage was 1 mg/kg once every 2 weeks. Symptoms of pain intensity and hypohidrosis were improved. Transiently elevated proteinuria was observed but it returned to normal after a week without any treatment. Conclusions: Clinical manifestations of Fabry disease varied in childhood. Multidisciplinary collaboration is required for its early diagnosis and treatment. Severe adverse events are rare in children with short-term therapy of agalsidase beta.

[A multicenter study of reference intervals for 15 laboratory parameters in Chinese children]

Objective: To establish comprehensive laboratory reference intervals for Chinese children. Methods: This was a cross-sectional multicenter study. From June 2013 to December 2014, eligible healthy children aged from 6-month to 17-year were enrolled from 20 medical centers with informed consent. They were assessed by physical examination, questionnaire survey and abdominal ultrasound for eligibility. Fasting blood samples were collected and delivered to central laboratory. Measurements of 15 clinical laboratory parameters were performed, including estradiol (E2), testosterone(T), luteinizing hormone(LH), follicle-stimulating hormone(FSH), alanine transaminase(ALT), serum creatinine(Scr), cystatin C, immunoglobulin A(IgA), immunoglobulin G(IgG), immunoglobulin M(IgM), complement (C3, C4), alkaline phosphatase(ALP), uric acid(UA) and creatine kinase(CK). Reference intervals were established according to central 95% confidence intervals for reference population, stratified by age and sex. Results: In total, 2 259 children were enrolled. Finally, 1 648 children were eligible for this study, including 830 boys and 818 girls, at a mean age of 7.4 years. Age- and sex- specific reference intervals have been established for the parameters. Reference intervals of sex hormones increased gradually with age. Concentrations of ALT, cystatin C, ALP and CK were higher in children under 2 years old. Serum levels of sex hormones, creatinine, immunoglobin, CK, ALP and urea increased rapidly in adolescence, with significant sex difference. In addition, reference intervals were variable depending on assay methods. Concentrations of ALT detected by reagents with pyridoxal 5'-phosphate(PLP) were higher than those detected by reagents without PLP. Compared with enzymatic method, Jaffe assay always got higher results of serum creatinine, especially in children younger than 9 years old. Conclusion: This study established age- and sex- specific reference intervals, for 15 clinical laboratory parameters based on defined healthy children.

MicroRNA (miR)-203 and miR-205 expression patterns identify subgroups of prognosis in cutaneous squamous cell carcinoma

BACKGROUND

Cutaneous squamous cell carcinoma (CSCC) is the second most widespread cancer in humans and its incidence is rising. These tumours can evolve as diseases of poor prognosis, and therefore it is important to identify new markers to better predict its clinical evolution.

OBJECTIVES

We aimed to identify the expression pattern of microRNAs (miRNAs or miRs) at different stages of skin cancer progression in a panel of murine skin cancer cell lines. Owing to the increasing importance of miRNAs in the pathogenesis of cancer, we considered the possibility that miRNAs could help to define the prognosis of CSCC and aimed to evaluate the potential use of miR-203 and miR-205 as biomarkers of prognosis in human tumours.

METHODS

Seventy-nine human primary CSCCs were collected at the University Hospital of Salamanca in Spain. We identified differential miRNA expression patterns at different stages of CSCC progression in a well-established panel of murine skin cancer cell lines, and then selected miR-205 and miR-203 to evaluate their association with the clinical prognosis and evolution of human CSCC.

RESULTS

miR-205 was expressed in tumours with pathological features recognized as indicators of poor prognosis such as desmoplasia, perineural invasion and infiltrative growth pattern. miR-205 was mainly expressed in undifferentiated areas and in the invasion front, and was associated with both local recurrence and the development of general clinical events of poor evolution. miR-205 expression was an independent variable selected to predict events of poor clinical evolution using the multinomial logistic regression model described in this study. In contrast, miR-203 was mainly expressed in tumours exhibiting the characteristics associated with a good prognosis, was mainly present in well-differentiated zones, and rarely expressed in the invasion front. Therefore, the expression and associations of miR-205 and miR-203 were mostly mutually exclusive. Finally, using a logistic biplot we identified three clusters of patients with differential prognosis based on miR-203 and miR-205 expression, and pathological tumour features.

CONCLUSIONS

miR-205 and miR-203 tended to exhibit mutually exclusive expression patterns in human CSCC. This work highlights the utility of miR-205 and miR-203 as prognostic markers in CSCC.

Graphene based quantum dots

Laterally localized electronic states are identified on a single layer of graphene on ruthenium by low temperature scanning tunneling spectroscopy (STS). The individual states are separated by 3 nm and comprise regions of about 90 carbon atoms. This constitutes a highly regular quantum dot-array with molecular precision. It is evidenced by quantum well resonances (QWRs) with energies that relate to the corrugation of the graphene layer. The dI/dV conductance spectra are modeled by a layer height dependent potential-well with a delta-function potential that describes the barrier for electron penetration into graphene. The resulting QWRs are strongest and lowest in energy on the isolated 'hill' regions with a diameter of 2 nm, where the graphene is decoupled from the surface.

Kimura disease: a case report and review of the Chinese literature

BACKGROUND

Kimura disease, often accompanied by nephrotic syndrome, is a rare, chronic inflammatory disorder of unknown cause. In this report, the clinical and histopathological characteristics of 20 Chinese patients with Kimura disease-associated nephrotic syndrome were retrospectively evaluated.

METHODS

We report a case of Kimura disease that was diagnosed recently in our ward, with steroid-responsive but recurrent minimal-change nephrotic syndrome. Meanwhile, we also used three powerful Chinese journal search engines (Cqvip.com, Wanfang.data and ScienceChina) to search the cases reported in Chinese from 1984 to 2007.

RESULTS

The nephrotic syndrome of our patient occurred 20 months after the onset of Kimura disease. Renal biopsy revealed minimal-change lesions. The patient was responsive to the steroid, but proteinuria recurred. In most of the 19 other cases, the onset of nephrotic syndrome occurred after subcutaneous masses. Renal biopsy in 13 cases showed mesangial proliferative glomerulonephritis in 9, minimal change disease in 2 and membrane nephropathy in 2 cases. Serum creatinine levels were elevated in 5 patients.

CONCLUSION

Normally, Kimura disease-associated nephrotic syndrome patients are sensitive to prednisone therapy but are likely to relapse. In patients with recurrent nephrotic syndrome, renal insufficiency is not uncommon.

Characterization of breast cancer by array comparative genomic hybridization

Cancer progression is due to the accumulation of recurrent genomic alterations that induce growth advantage and clonal expansion. Most of these genomic changes can be detected using the array comparative genomic hybridization (CGH) technique. The accurate classification of these genomic alterations is expected to have an important impact on translational and basic research. Here we review recent advances in CGH technology used in the characterization of different features of breast cancer. First, we present bioinformatics methods that have been developed for the analysis of CGH arrays; next, we discuss the use of array CGH technology to classify tumor stages and to identify and stratify subgroups of patients with different prognoses and clinical behaviors. We finish our review with a discussion of how CGH arrays are being used to identify oncogenes, tumor suppressor genes, and breast cancer susceptibility genes.

Association of cytokine responses with disease severity in infants with respiratory syncytial virus infection

AIM

To explore the relationship between cytokine responses and severity of respiratory syncytial virus (RSV) infection in infants.

METHODS

Intracellular interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) expression in peripheral blood CD3+ and CD8+ lymphocytes was measured by four-colour flow cytometry. Serum IL-12, IL-4 and IFN-gamma levels were also determined by enzyme-linked immunosorbent assay.

RESULTS

The frequency of IL-4 and IFN-gamma expression in CD3+CD8- cells was the same in RSV-infected, non-RSV-infected and control infants and in those with RSV bronchiolitis or RSV pneumonia, indicating that no Th2 predominance exists in the acute phase of RSV infection and RSV bronchiolitis. Furthermore, RSV-infected infants had a more frequent IFN-gamma expression in CD3+CD8+ cells than controls, and they also showed a much lower serum IL-4/ IFN-gamma ratio because of decreased IL-4 and elevated IFN-gamma, the latter being most prominent in RSV bronchiolitis. The serum IL-12 level in RSV-infected infants was the same as in control infants, while those with non-RSV infections had a much higher level. Serum IL-12, IFN-gamma and frequency of IFN-gamma expression in CD3+CD8+ cells in mild RSV infection were much higher than in controls, while no difference existed between severe cases and controls.

CONCLUSION

Type 2 cytokine predominance was not found in the acute phase of RSV infection and RSV bronchiolitis, but both were accompanied by enhanced production of IFN-gamma and a much higher serum IFN-gamma level than in healthy controls, especially in those with RSV bronchiolitis, suggesting a role in causing airway obstruction. IFN-gamma and IL-12 may also play a protective role in RSV infections by diminishing viral replication, and high levels of IL-12 and IFN-gamma may be associated with lessening of the severity of infection.

The effect of tissue-specific growth patterns of target stem cells on the spectrum of tumours resulting from multistage tumorigenesis

A multistage mathematical model of tumorigenesis has been developed to explore the effects of target cell growth pattern on the proportions of tumours deriving from different tissues (the tumour spectrum). Analytical modelling techniques have shown that the effect of the target cell growth pattern on the tumour spectrum also depends on the number of stages (gene mutations) necessary for malignant change in cells of each tissue type. This suggests the existence of temporal "windows of opportunity" for tumours of different types in relation to stage number and growth kinetics. Models of this kind are applicable to cancer-prone transgenic (e.g. p53 deficient) mice, where homozygotes and heterozygotes differ in one carcinogenic stage, and differ also in the spectrum of tumours observed. Generally, tumours deriving from target stem cells which are developmentally short-lived will arise more frequently in homozygotes than heterozygotes. Such models may also be applicable to human syndromes (e.g. Li-Fraumeni) in which susceptibility to cancer is inherited.

Epistatic interactions between skin tumor modifier loci in interspecific (spretus/musculus) backcross mice

The development of cancer is influenced both by exposure to environmental carcinogens and by the host genetic background. Epistatic interactions between genes are important in determining phenotype in plant and animal systems and are likely to be major contributors to cancer susceptibility in humans. Several tumor modifier loci have been identified from studies of mouse models of human cancer, and genetic interactions between modifier loci have been detected by genome scanning using recombinant congenic strains of mice (R. Fijneman et al., Nat. Genet., 14: 465-467, 1996; T. van Wezel et al., Nat. Genet., 14: 468-470, 1996; W. N. Frankel et al., Nat. Genet., 14, 371-373, 1996). We demonstrate here that strong genetic interactions between skin tumor modifier loci can be detected by hierarchical whole genome scanning of a complete interspecific backcross [outbred Mus spretus X Mus musculus (NIH/Ola)]. A locus on chromosome 7 (Skts1) showed a highly significant interaction with Skts5 on chromosome 12 (P < 10(-16)), whereas additional significant interactions were detected between loci on chromosomes 4 and 5, and 16 and 15. Some of these quantitative trait loci and their interactions, in particular the Skts1-Skts5 interaction, were confirmed in two completely independent backcrosses using inbred spretus strains (SEG/Pas and SPRET/Ei) and NIH/Ola. These results, therefore, illustrate the general use of interspecific crosses between Mus musculus and Mus spretus for the detection of strong genetic interactions between tumor modifier genes.

Advanced-stage cervix cancer: rapid tumour growth rather than late diagnosis

Either diagnostic delay or tumour biology are possible factors governing the degree of spread at diagnosis of cervical cancer. To try to identify the most important parameter contributing to advanced stage, the duration of symptoms were recorded from patients scheduled for radiotherapy (n = 141) or radical hysterectomy (n = 36). In 146 cases tumour proliferation rates were evaluated following in vivo labelling with the DNA precursor BrdUrd. For symptomatic patients there was no association between duration of symptoms and stage at presentation. There was a significant trend for patients with increasing tumour stage to have more rapidly proliferating tumours with higher mean labelling index (LI) measurements (P = 0.001) and a shorter mean potential doubling time (Tpot) (P = 0.023). Socio economic deprivation may be associated with shorter Tpot values. The conclusion from this data is that stage at diagnosis is more dependent on the biological behaviour of the tumour, as expressed by proliferation rates, than delay in presentation.

Factors affecting fetal weight distribution in women with type I diabetes

OBJECTIVE

To identify factors independently affecting fetal weight in women with type I diabetes.

DESIGN

Prospectively recorded data in consecutive women with type I diabetes, between 1975-1992.

SETTING

Simpson Memorial Maternity Hospital, Edinburgh. Population Three hundred and two pregnancies with type I diabetes identified before pregnancy, with antenatal care and delivery in the Simpson Memorial Maternity Hospital, a singleton pregnancy, and the same diabetic physician.

METHODS

Normal ranges for birthweight were established for the total hospital population. All cases and the total population had pregnancy dating by ultrasound. The relation between standardised birthweight and explanatory variables was investigated using correlation analysis, t tests and chi2 tests as appropriate, and subsequently using multiple linear regression.

RESULTS

Standardised birthweight in cases, compared with the reference population, showed a unimodal, approximately normal distribution, markedly shifted to the right (mean + 1.26 SD). The most predictive variable was glycated haemoglobin concentration at 27-33 weeks, which explained 6.3% of the birthweight variance, while smoking explained 2.7% and maternal weight 2.0%. There was a trend towards a negative relationship with glycated haemoglobin concentration at 6-12 weeks. Smoking and glycated haemoglobin concentration were strongly intercorrelated.

CONCLUSIONS

Most of the variance in standardised birthweight remains unexplained, but glycated haemoglobin concentration at 27-33 weeks is the most powerful explanatory variable. Possible reasons why there is not a stronger relationship between markers of maternal glycaemia and birthweight are discussed.

Apoptosis in cervical squamous carcinoma: predictive value for survival following radiotherapy

BACKGROUND

Apoptosis, or programmed cell death, can be induced by radiotherapy. The extent of apoptosis in a tumour before treatment may have important implications for response to radiotherapy and long term survival.

AIM

To examine the extent of apoptosis in tumour tissue from patients with squamous carcinoma of the cervix before radiotherapy, and to correlate this with response to treatment and prognosis.

METHODS

The percentage of apoptotic cells was assessed in 146 carcinomas of the cervix from patients scheduled to receive radiotherapy. The CAS 200 static image analysis system was used to count the number of tumour nuclei per high power field, while the numbers of apoptotic cells in the same field were visualised simultaneously on the image analyser and recorded manually.

RESULTS

The median apoptotic level was 0.73%. Patients were divided into two groups around the median. There was no statistically significant difference in outcome between the two groups as determined by long term survival following radiotherapy.

CONCLUSIONS

The CAS 200 static image analyser system can be used to assist in the rapid semiautomated assessment of apoptosis in conventionally prepared tissue. The results suggest that the apoptotic state of a tumour before treatment is of no value in predicting response to radiotherapy and subsequent prognosis. Tumour stage, size, and BrdU labelling index, as a measure of proliferation rate, remain the most important prognostic factors in terms of predicting local tumour control.

A subset of skin tumor modifier loci determines survival time of tumor-bearing mice

Studies of mouse models of human cancer have established the existence of multiple tumor modifiers that influence parameters of cancer susceptibility such as tumor multiplicity, tumor size, or the probability of malignant progression. We have carried out an analysis of skin tumor susceptibility in interspecific Mus musculus/Mus spretus hybrid mice and have identified another seven loci showing either significant (six loci) or suggestive (one locus) linkage to tumor susceptibility or resistance. A specific search was carried out for skin tumor modifier loci associated with time of survival after development of a malignant tumor. A combination of resistance alleles at three markers [D6Mit15 (Skts12), D7Mit12 (Skts2), and D17Mit7 (Skts10)], all of which are close to or the same as loci associated with carcinoma incidence and/or papilloma multiplicity, is significantly associated with increased survival of mice with carcinomas, whereas the reverse combination of susceptibility alleles is significantly linked to early mortality caused by rapid carcinoma growth (chi(2) = 25.22; P = 5.1 x 10(-8)). These data indicate that host genetic factors may be used to predict carcinoma growth rate and/or survival of individual backcross mice exposed to the same carcinogenic stimulus and suggest that mouse models may provide an approach to the identification of genetic modifiers of cancer survival in humans.

LD78beta, a non-allelic variant of human MIP-1alpha (LD78alpha), has enhanced receptor interactions and potent HIV suppressive activity

Chemokines play diverse roles in inflammatory and non-inflammatory situations via activation of heptahelical G-protein-coupled receptors. Also, many chemokine receptors can act as cofactors for cellular entry of human immunodeficiency virus (HIV) in vitro. CCR5, a receptor for chemokines MIP-1alpha (LD78alpha), MIP-1beta, RANTES, and MCP2, is of particular importance in vivo as polymorphisms in this gene affect HIV infection and rate of progression to AIDS. Moreover, the CCR5 ligands can prevent HIV entry through this receptor and likely contribute to the control of HIV infection. Here we show that a non-allelic isoform of human MIP-1alpha (LD78alpha), termed LD78beta or MIP-1alphaP, has enhanced receptor binding affinities to CCR5 (approximately 6-fold) and the promiscuous beta-chemokine receptor, D6 (approximately 15-20-fold). We demonstrate that a proline residue at position 2 of MIP-1alphaP is responsible for this enhanced activity. Moreover, MIP-1alphaP is by far the most potent natural CCR5 agonist described to date, and importantly, displays markedly higher HIV1 suppressive activity than all other human MIP-1alpha isoforms examined. In addition, while RANTES has been described as the most potent inhibitor of CCR5-mediated HIV entry, MIP-1alphaP was as potent as, if not more potent than, RANTES in HIV-1 suppressive assays. This property suggests that MIP-1alphaP may be of importance in controlling viral spread in HIV-infected individuals.

Stochastic modelling of tumorigenesis in p53 deficient mice

Stochastic models of tumorigenesis have been developed to investigate the implications of experimental data on tumour induction in wild-type and p53-deficient mice for tumorigenesis mechanisms. Conventional multistage models in which inactivation of each p53 allele represents a distinct stage predict excessively large numbers of tumours in p53-deficient genotypes, allowing this category of model to be rejected. Multistage multipath models, in which a p53-mediated pathway co-exists with one or more p53-independent pathways, are consistent with the data, although these models require unknown pathways and do not enable age-specific curves of tumour appearance to be computed. An alternative model that fits the data is the 'multigate' model in which tumorigenesis results from a small number of gate-pass (enabling) events independently of p53 status. The role of p53 inactivation is as a rate modifier that accelerates the gate-pass events. This model implies that wild-type p53 acts as a 'caretaker' to maintain genetic uniformity in cell populations, and that p53 inactivation increases the probability of occurrence of a viable cellular mutant by a factor of about ten. The multigate model predicts a relationship between the time pattern of tumour occurrence and tumour genotype that should be experimentally testable. Stochastic modelling may help to distinguish 'gatekeeper' and 'caretaker' genes in other tumorigenic pathays.

A two-stage model for childhood acute lymphoblastic leukemia: application to hereditary and nonhereditary leukemogenesis

A differential equation model is developed to represent a two-stage mutational process leading to childhood acute lymphoblastic leukemia (ALL). Leukemogenesis is modeled as transformation of target stem cells that initially grow rapidly in the embryo but plateau and then decline in postnatal childhood. Inheritance of the first of two leukemogenic mutations is allowed as a possibility in a small minority of leukemic patients who would characteristically develop leukemia at an early age. The model is shown to be capable of providing good fits to incidence data for childhood ALL; these fits allow estimation of some parameters of the model. The analysis shows that individuals inheriting one of the two mutations necessary for ALL would be likely to experience "multiclonal leukemogenesis"; that is, the parallel development of several leukemic clones arising from multiple independent leukemic events. The model suggests that between two and ten such clones would typically have developed in such individuals by the time of diagnosis. The main conclusions of the deterministic investigation were confirmed by stochastic modeling. The existence of multiclonal leukemogenesis is in principle testable by molecular biological methods (clonality analysis) that rely on the random inactivation of one of two X-chromosomes in normal female subjects. It is expected that the mathematical methods developed here will also be useful for more general (N-stage) models of malignant transformation of stem cell populations undergoing growth or decline.

Clinical and ultrasound prediction of macrosomia in diabetic pregnancy

OBJECTIVE

To study prospectively the prediction power, at different gestations, of clinical and ultrasound measurements for fetal size in diabetic pregnancy.

SETTING

A large combined obstetric diabetic clinic in a teaching hospital.

PARTICIPANTS

One hundred and eighty-one pregnancies in which women had scans at least two of three specific time points and who were delivered of singletons after 34 weeks: 73% were pre-gestational insulin-dependent diabetics, the others were pre-gestational White class A or gestational diabetics.

INTERVENTIONS

Clinical estimates of fundal height and fetal size and ultrasound estimates of abdominal circumference and head circumference were routinely carried out at gestational ages of 28, 34 and 38 weeks or before delivery.

MAIN OUTCOME MEASURES

Standardised birthweight, corrected for gestation and parity. The relation with clinical and ultrasound measurements was investigated using multiple linear regression and the capability of the measurements to predict macrosomic births (> 95th centile of normals) using receiver-operator characteristic curves.

RESULTS

All measurements are poor predictors of eventual standardised birthweight. Prediction improves with closeness to delivery. Prediction is significantly improved by adding ultrasound to clinical information, but at 34 weeks or later this only contributes 8% of the variance. There is no difference in the prediction power for macrosomia between clinical and ultrasound measurements.

CONCLUSIONS

Even regular serial scanning and clinical examination will not always diagnose the macrosomic fetus in diabetic pregnancy. In our hands, clinical examination is as predictive as ultrasound measurements. Ultrasound does add to clinical prediction power but only to a small extent. Ultrasound should be used in a selected way, as defined by clinical findings, and with recognition and understanding of the errors and biases involved.

A stochastic model for multistage tumorigenesis in developing and adult mice

A stochastic process model for one-, two-, and three-stage malignant transformation has been developed for embryonic and adult mice. The model has been used to study the influence of mutation rate, number of stages required for transformation, and number of stem cells at risk on the kinetics of spontaneous appearance of malignant tumors. As expected, tumors appeared earlier with fewer required mutational stages, higher mutation rate, and greater number of stem cells at risk. However, a notable observation was that tumor latency was more strongly influenced by number of stages and by stem cell number at lower mutation rates than at higher rates. This implies that tumor latency may be a less useful observation when the spontaneous mutation rate is high. In the future, the model will be applied to analysis of tumorigenesis experiments in transgenic mice with p53 genetic abnormalities, subjected to irradiation or chemical tumorigenesis at different stages of development.

An open, prospective comparison of beta 2 agonists given via nebuliser, Nebuhaler, or pressurised inhaler by ambulance crew as emergency treatment

BACKGROUND

The merits of the use of beta 2 agonists by ambulance crew and best methods of delivery have not been fully explored.

METHODS

A prospective comparison has been made of treatments applied in three districts in South Wales (200 micrograms salbutamol by pressurised inhaler, 5 mg salbutamol via nebuliser, and 5 mg terbutaline via Nebuhaler) by emergency ambulance personnel to acutely wheezy patients en route to hospital. Pulse rate, respiratory rate, peak expiratory flow rate (PEFR), and breathlessness scored on a visual analogue scale were compared before and after treatment. Data were collected on diagnosis, artificial ventilation, cardiorespiratory arrest, and death.

RESULTS

Thirty eight patients received salbutamol inhaler, 51 salbutamol via nebuliser, and 41 terbutaline via Nebuhaler. There were greater reductions in respiratory rate and breathlessness score and more improvement in PEFR in the group receiving nebulised salbutamol than in the other two groups. No patient was ventilated and of the five deaths none was caused by asthma.

CONCLUSIONS

For wheezy, breathless patients treated en route to hospital by emergency ambulance personnel, 5 mg salbutamol given by an oxygen-driven nebuliser was more effective than either 5 mg terbutaline via a Nebuhaler or 200 micrograms salbutamol via a pressurised inhaler.

Urethral stricture and urethritis in men in Scotland

OBJECTIVES

To examine the incidence of urethral stricture in men in Scotland during the years 1982-1991 in relation to the changing incidence of gonococcal and non-gonococcal urethritis (NGU) over the past 20 years.

DESIGN

Retrospective study of incidence of urethral stricture in Scotland.

METHOD

The number of new men in whom a diagnosis of urethral stricture was made for the years 1982-1991 was obtained using the new Scottish Record Linkage system, and the number of cases of gonorrhoea and NGU was obtained from Communicable Diseases (Scotland) Unit. Age-specific rates of urethral stricture were calculated and the Poisson regression model was used to test if there was a trend of rate with age or time change.

RESULTS

There was a highly significant increase in the incidence of urethral stricture with age but only a slight increase in incidence over the study period within each age group.

CONCLUSION

As the interaction between age and time was not significant, it is concluded that urethritis associated with sexually transmitted organisms is an uncommon cause of urethral stricture in Scotland.

Insulin requirements during pregnancy in women with type I diabetes

OBJECTIVES

To document individual variations in the rise in insulin requirements during type I diabetic pregnancies, to relate the degree of increase to maternal characteristics and fetal outcome, and to examine these factors in a subgroup of patients experiencing a large fall in insulin requirement in the third trimester.

METHODS

Insulin dose was documented in 237 pregnancies in women with type I diabetes. Multiple regression analysis was performed to identify significant associations with maternal and fetal characteristics. Eighteen pregnancies with a fall in insulin requirement of 30% or more in the third trimester were considered in detail.

RESULTS

The mean absolute increase in insulin requirement was 52 units. The degree of rise was significantly related to maternal weight gain between 20-29 weeks and maternal weight at booking, and was inversely related to duration of diabetes. It was not related to the degree of diabetes control, complications of pregnancy, White class, or outcome of pregnancy. In the 18 women experiencing a large fall in insulin requirement, there was no relation with maternal characteristics or fetal outcome.

CONCLUSION

There is a wide individual variation in the change in insulin requirements in type I diabetic pregnancy. The degree of increase is related only to maternal weight gain during weeks 20-29 and maternal weight at booking, and is inversely related to duration of diabetes. Large falls in insulin requirement remain unexplained and may not be associated with placental failure.

Successful application of a previously derived prognostic index in the analysis of a randomised trial of 281 patients with high grade non-Hodgkin's lymphoma (HIGNHL)

BACKGROUND

The selection of patients for experimental therapies for high grade non-Hodgkin's lymphoma (NHL) is now recognised to be very influential in affecting results. We showed previously that simple clinical indices could be used to create an index of risk of death in a series of 972 patients. We wished to test this prognostic index in a subsequent randomised treatment trial of CHOP-based chemotherapy.

PATIENTS AND METHODS

281 patients with high grade NHL randomised between two chemotherapy designs were followed up from 1-6 years and survival analysed to develop a Cox model which was then compared against the previously described prognostic index.

RESULTS

The previous index based on age, sex, performance status, stage and symptoms was similar to the data-derived model. Three year survivals for the best (109), intermediate (93) and worst (79) cohorts were 69%, 50% and 24% respectively, similar to the survivals in the previous series.

CONCLUSIONS

CHOP-based chemotherapy is probably adequate for around 40% of cases of high grade NHL. The prospective test of a prognostic index shows that we can be confident about selecting poor-risk patients for trials of novel therapies, including dose intensification.

Macrophage prostaglandin E2 and oxidative responses to endotoxin during immunosuppression associated with anaesthesia and transfusion

The widespread use of blood transfusion in major surgical procedures has led to concern about the immunosuppressive effect of transfusion on patients with underlying malignancy. Transfusion may also suppress the host response to infection. The cellular mechanisms of transfusion-associated immunosuppression may involve macrophage prostaglandin E2 (PGE2) in modulating the host response to cancer and infection. We previously observed that the transfusion of blood increased PGE2 production by unstimulated macrophages. To investigate this PGE2 associated immunosuppression, we studied the effect of transfusion of rats using a physiological stimulus of macrophage PGE2 production, bacterial endotoxin. In the same macrophages, we analysed intracellular oxidative activity. Both allogeneic and syngeneic blood transfusion were associated with increased PGE2 release by macrophages. This stimulation of PGE2 increased with duration of storage of blood. A similar effect of serum indicated that a humoral factor was involved. Endotoxin (50 ng/ml-500 micrograms/ml) stimulated PGE2 production in all transfused subjects. The lowest endotoxin concentration gave proportionately the greatest stimulation. Oxidative activity was down-regulated in macrophages of transfused rats, supporting an immunosuppressive role of PGE2 within the macrophage. An effect of surgery on the oxidative response was also detected.

Identification of prognostic groups in follicular lymphoma. The Scotland and Newcastle Lymphoma Group Therapy Working Party

Follicular lymphoma is often seen as an indolent disease with a reasonable medium-term survival. We have used the information in the Scotland and Newcastle Lymphoma Group database to devise an index which is easily calculated and differentiates patients into poor, intermediate and good prognostic groups with 5 years survivals of 24%, 61% and 86% respectively. The key factors at presentation are age, ECOG performance status, stage and the presence or absence of B symptoms or gastro-intestinal tract involvement. The use of such an index permits early identification of patients with a poor prognosis for whom more intensive treatment could be offered.