Absence of p53 in a mouse mammary tumor model promotes tumor cell proliferation without affecting apoptosis

Loss or mutation of p53 may have multiple biological and genetic effects that result in accelerated tumor progression. Loss of p53 in some tumors has been correlated with a marked decrease in tumor cell apoptosis. p53 loss may also accelerate tumor growth through an increase in cell proliferation rates. To examine the effects of p53 loss on tumor progression in a controlled experimental context, we previously crossed p53-deficient mice to mammary tumor-susceptible Wnt-1 transgenic (TG) mice. The resulting female Wnt-1 TG offspring of this cross all developed mammary tumors, regardless of p53 status (p53+/+, p53+/-, or p53-/-). However, female p53-/- Wnt-1 TG mice developed tumors much sooner than their p53+/+ counterparts. In this report, we demonstrate that the average growth rates of tumors missing (p53-/-) or losing p53 (p53+/- with loss of heterozygosity) are accelerated compared to tumors with both wild-type p53 alleles (p53+/+). This accelerated growth rate appears to be due primarily to increases in rates of tumor cell proliferation. Tumor cell apoptotic levels were modest and were not measurably different in the presence or absence of wild-type p53. These results differ substantially from other mouse tumor models in which p53 loss was closely correlated with accelerated growth rates through attenuated apoptosis. Thus, the mechanisms by which p53 loss influences tumor progression may differ, depending on the tissue type and/or the oncogenic pathways involved.

Direct measurement of flow from the posterior lymph hearts of hydrated and dehydrated toads (Bufo marinus)

Flow from the posterior lymph hearts of Bufo marinus was measured using Doppler flow probes. These probes were placed on the posterior vertebral vein and recorded flow as lymph was ejected from the heart. In resting, hydrated toads, mean lymph flow from one of the paired posterior lymph hearts was 25.9 +/- 4.9 ml kg-1 h-1, stroke volume was 8.9 +/- 1.4 microL kg-1 and lymph heart rate was 47.5 +/- 3.7 beats min-1. We estimate that, together, the paired posterior lymph hearts are capable of generating flows that are approximately one-sixtieth of the resting cardiac output. Mean peak systolic pressure developed by the posterior lymph hearts was 1.62 +/- 0.08 kPa. Simultaneous measurements of lymph heart pressure development and flow revealed that the outflow pore of the heart opened at a pressure of 0.71 +/- 0.04 kPa, approximately 113 +/- 5 ms into systole. When toads were moderately disturbed, stroke volume increased by as much as fourfold with little change in lymph heart rate (< 5 beats min-1). When toads were dehydrated, lymph flow decreased by 70% at 12h and by 80% and 24h. Since there was only a modest non-significant decrease in lymph heart rate (30%), this reduction in flow was attributed to decreases in stroke volume (approximately 80%). Lymph heart flow and stroke volume returned to control values 30 min after adding water back into the experimental chamber. Stroke volume was clearly more important in regulating lymph flow than lymph heart rate under these conditions in Bufo marinus.

Mutation of the Ca2+ channel beta subunit gene Cchb4 is associated with ataxia and seizures in the lethargic (lh) mouse

Ca2+ channel beta subunits regulate voltage-dependent calcium currents through direct interaction with alpha 1 subunits. The beta- and alpha 1-binding motifs are conserved, and all beta subunits can stimulate current amplitude, voltage dependence, and kinetics when coexpressed with various alpha 1 subunits. We used a positional candidate approach to determine that the ataxia and seizures in the lethargic (lh) mouse arise from mutation of the beta-subunit gene Cchb4 on mouse chromosome 2. A four-nucleotide insertion into a splice donor site results in exon skipping, translational frameshift, and protein truncation with loss of the alpha 1-binding site. The lethargic phenotype is the first example of a mammalian neurological disease caused by an inherited defect in a non-pore-forming subunit of a voltage-gated ion channel.

Toward standardization of health information

NCVHS has made recommendations to the DHHS to standardize 42 core health data elements, a number of which relate to medical conditions and services. The committee has asked the DHHS Data Council to actively promote, both within the department and externally, standardization of data elements and definitions where substantial consensus already exists. For those elements that have been recognized as significant core data elements, but for which there is not consensus on approach or definition, the NCVHS is recommending that the Data Council support the formation of a public-private working group to conduct further study and evaluation. This group, or a separate group, could also be the focus for evaluating additions to the list of core data elements and for setting up methods for testing and promulgating the final products. The coming 12-18 months will be exceedingly important for health data standardization efforts in the US as the DHHS responds to both the NCVHS recommendations and the legislation recently enacted by Congress.

Cardiopulmonary arrest in general wards: a retrospective study of referral patterns to an intensive care facility and their influence on outcome

OBJECTIVE

To analyse the effect on outcome of referral to specialist facilities after cardiopulmonary arrest in a general ward.

METHODS

A retrospective analysis of resuscitation records of 743 patients in whom cardiopulmonary resuscitation was performed in a general ward between 1988 and 1992. After successful initial cardiopulmonary resuscitation, patients were identified as transferred to coronary care unit (CCU) or intensive care unit (ITU), or as staying in a general ward.

MAIN OUTCOME MEASURE

Survival to discharge home.

RESULTS

There were 322 initial survivors, of whom 148 (20% of the overall total) survived to be discharged from hospital; 63% of those transferred to CCU and 48% of those transferred to ITU survived to discharge, compared with 28% of those who stayed on the ward (P < 0.001). Of those aged less than 65 years, 75% survived to discharge after transfer to CCU and 54% after transfer to ITU, compared with 44% of those who stayed on the ward (P = 0.023); the respective figures for those over 65 years were: CCU 25%, ITU 34%, ward 25% (P = 0.014). Only half of those aged more than 65 years were transferred to a specialist facility, compared with 90% of those aged less than 65.

CONCLUSIONS

Transfer to a specialist care facility after resuscitation from cardiopulmonary arrest has an influence on outcome. Age as an independent factor is not an appropriate criterion to use in deciding on transfer. The decision to arrange transfer must always be taken by the most experienced person available, and in line with peer reviewed guidelines.

Appropriateness of acute medical admissions and length of stay

OBJECTIVE

To use the Appropriateness Evaluation Protocol (AEP) to assess the extent of inappropriate utilisation of hospital beds by acute medical patients. To determine whether clinicians viewed the AEP decisions as valid.

DESIGN

Retrospective review of the medical records of a 10% random sample of 8,210 patients admitted as medical emergencies. An objective independent review instrument (AEP) was used to assess the medical necessity for hospitalisation at admission and on each subsequent day. To test the validity of the screening instrument, a subsample of the reviewed records was further assessed by a panel of physicians.

SETTING

A district general hospital in the West Midlands region of England.

SUBJECTS

Eight hundred and twenty-one adult patients admitted to general medicine during one calendar year.

MAIN OUTCOME MEASURES

Proportions of admissions and days of care for which inpatient medical care was judged appropriate. Reasons for inappropriate utilisation and potential bed-days that could be saved by the development and use of alternative services were also considered. Validity of the AEP was tested by assessing agreement between the majority decision of an expert panel and the criterion-based AEP decision.

RESULTS

AEP identified 51/821 (6%) admissions and 2,195/4,885 (45%) days of care as inappropriate. Over half the patients had a hospital stay in which at least half the days were judged inappropriate. The commonest reason for inappropriate days was remaining in hospital after the medical purpose for admission had been accomplished. This accounted for 38% of inappropriate days reviewed. In validity testing there was a high level of agreement between the physicians and the AEP, with kappa values greater than 0.80 for admissions and days of care.

CONCLUSIONS

The AEP is a valid and useful instrument for assessing the utilisation of acute medical beds in a NHS hospital. In this study acute medical admissions were largely appropriate at the time of admission but a substantial proportion of subsequent days of care was considered inappropriate by AEP criteria. Most inappropriate utilisation was due to organisational issues within the hospital. As a result of this study, several service and policy developments were identified that should improve the efficiency of bed utilisation at the hospital.

Trophectoderm projections: a potential means for locomotion, attachment and implantation of bovine, equine and human blastocysts

The behaviour of bovine, equine and human blastocysts was studied in vitro by time-lapse videomicrography and computer imaging. This study revealed that cytoplasmic extensions of the trophectoderm ['trophectoderm projections' (TEP)] were expressed by embryos of all three species, prior to or during zona escape. Bovine and human blastocysts escaped their zonae with a combination of blastocoele expansion, collapse and re-expansion coupled with the penetration of the zona pellucida by TEP. In equine embryos, after several cycles of blastocoele expansion and collapse, trophectoderm ruptured the zona with the concomitant appearance of TEP. This study provides documentation that TEP are expressed by a diverse range of mammalian species, bringing the total number of species in which this phenomenon is found to six, since TEP are also known to be expressed by guinea-pig, hamster and rhesus monkey blastocysts, representing rodents, ungulates and primates. In all species studied, the dynamic nature (extension, retraction, and angular movement) of the TEP was similar, moving in an undulating manner with rapid cycles of extension and retraction. Because TEP appear to be a general feature of mammalian blastocysts, they are implicated in one or more key events in early development, namely zona escape, attachment and/or implantation.

The successful use of hyperstimulated washed therapeutic donor insemination after standard therapeutic donor insemination has failed

OBJECTIVE

To investigate whether an aggressive therapeutic donor insemination regimen (stimulated folliculogenesis and ovulation plus intrauterine insemination) can produce a better fecundability rate than a more traditional insemination regimen (non-stimulated folliculogenesis plus LH-timed intracervical insemination) in women who have failed to become pregnant during an initial series of six traditional insemination cycles.

DESIGN

A retrospective comparison of fecundability rates was undertaken between women undergoing the traditional insemination protocol and those who voluntarily switched to ovarian hyperstimulation coupled with intrauterine insemination.

PARTICIPANTS

Eight-two women who failed to become pregnant during an initial series of six intracervical insemination cycles.

RESULTS

Fecundability was 5.6% in cycles of continued urinary LH-timed intracervical insemination and 19.4% when the more aggressive regimen was applied. The difference in fecundability between protocols was significant (P < .005).

CONCLUSION

After an initial series of donor inseminations has failed, a more aggressive insemination regimen involving ovarian hyperstimulation followed by washed intrauterine insemination provides a higher fecundability rate than continued intracervical insemination.

Latex allergen levels of injectable collagen stored in syringes with rubber plungers

OBJECTIVES

To assess the latex allergen content of glutaraldehyde cross-linked injectable bovine collagen stored in rubber plunger syringes.

METHODS

Extracts of syringe plungers and collagen solutions before and after storage in syringes with natural rubber latex plungers were tested for latex protein allergens. Thirty-nine patients known to be allergic to latex underwent skin prick testing with extracts of the latex plungers, collagen solutions before and after storage in syringes, standard latex skin test reagents, four extracts from commercially available gloves, and positive (histamine) and negative (diluent) control solutions. Thirty-one control patients not known to be latex allergic were similarly tested.

RESULTS

No latex proteins were detected using in vitro immunochemical techniques. Only 1 of 39 (2.5%) latex allergic patients reacted to the syringe extract and the collagen stored in the syringe. No reactions were recorded to collagen that no contact with latex.

CONCLUSIONS

The level of latex antigens in injectable collagen is very low. The low prevalence of skin test reactivity in these highly latex allergic individuals suggests that type 1 hypersensitivity reactions as a result of latex contamination would be unlikely.

Twin transfusion syndrome: reassessment of ultrasound diagnosis

OBJECTIVE

To assess the antenatal ultrasonic diagnosis of the twin transfusion syndrome, an enigmatic disorder that results in an imbalance in the blood flow between monochorionic twins.

STUDY DESIGN

Retrospective review of 16 cases of twin transfusion syndrome confirmed by placental pathology and neonatal data.

RESULTS

A disparity in antenatal fetal weights, size difference between the two amniotic sacs and a single placenta were present in 81% (13/16) of confirmed cases. The finding of two separate umbilical cords with a disparity in the size or number of vessels was rare. Evidence of hydrops in either fetus or findings of congestive cardiac failure in the recipient twin were uncommon.

CONCLUSION

Our data strongly suggest that the twin transfusion syndrome can be diagnosed in a significant number (81%) of cases. The syndrome is variable, and it is rare to observe all the diagnostic criteria in one case.

Treatment and survival of lymphoid malignancy in the north-west of England: a population-based study

Classification of lymphoid malignancy has changed markedly in recent years and advances have been made in therapy. This study investigated the variations in treatment and survival of 1622 patients in a population-based registry. A total of 1009 cases of malignant lymphoma (ML) were classified according to the Kiel classification. Pathology review resulted in major diagnostic changes for 24% of cases. Of the ML cases, 39% had not had full staging procedures. Younger patients were more likely to have been treated with multiagent chemotherapy regimens, as were patients with B symptoms. Median survival for ML patients was 12 months for high-grade patients and more than 60 months for low-grade patients. Significant factors affecting the survival of ML patients were performance status, whether treatment had followed a recognised protocol, whether treatment had been carried out at a specialist oncology centre (SOC), grade of disease, stage, gender and age. The same factors had a significant effect on survival of the leukaemia patients, except for treatment at an SOC, which had a significant favourable effect on survival of acute lymphoblastic leukaemia (ALL) patients only. Median survival for patients with chronic lymphocytic leukaemia was 43 months and 7 months for ALL patients.

A comparison of symptoms experienced following minor head injury and acute neck strain (whiplash injury)

The symptoms reported by patients who have experienced minor head or minor neck injury are compared. Symptoms were identified using a questionnaire-based out-patients interview. Rank order correlation analyses were carried out on data obtained at 2 and 6-12 weeks post-injury. Data on 24 head-injured and 29 neck-injured patients are presented. There was a significant rank order correlation at both assessments but neck injured patients reported more phobia (fear of travelling in car) and depression, and head-injured more dizziness. It is likely that neck-injury contributes to the symptomatology experienced after minor head injury, and vice-versa.

Functional status and the use of formal home care in the year before death

A national sample of persons who died in 1986 was analyzed to obtain a valid estimate of the relationship between functional status and the provision of formal home care during the last year of life. Community-based care has become increasingly important as the size of the elderly population increases and the cost for institutional care rises. When people need help in caring for themselves because of illness, frailty, or disability, community-based care may be more appropriate than acute or institutional care. The year before death is often a time of dependence and a high intensity of health service consumption. Although care at home is provided primarily by families, formal home care is also a critical component in any continuum of care.

Mutation of a new sodium channel gene, Scn8a, in the mouse mutant 'motor endplate disease'

The mouse neurological mutant 'motor endplate disease' (med) is characterized by early onset progressive paralysis of the hind limbs, severe muscle atrophy, degeneration of Purkinje cells and juvenile lethality. We have isolated a voltage-gated sodium channel gene, Scn8a, from the flanking region of a transgene-induced allele of med. Scn8a is expressed in brain and spinal cord but not in skeletal muscle or heart, and encodes a predicted protein of 1,732 amino acids. An intragenic deletion at the transgene insertion site results in loss of expression. Scn8a is closely related to other sodium channel alpha subunits, with greatest similarity to a brain transcript from the pufferfish Fugu rubripes. The human homologue, SCN8A, maps to chromosome 12q13 and is a candidate gene for inherited neurodegenerative disease.

Supplemental protein sources for steers fed corn-based diets: II. Growth and estimated metabolizable amino acid supply

Seventy Simmental-cross steers (average initial weight 301 +/- 24 kg) were individually fed in a 175-d completely randomized design experiment to evaluate the effects of source and level of protein in the diet on gain and feed efficiency. Steers were allotted to 1 of 10 treatments (seven steers per treatment) in a 3 x 3 factorial arrangement of treatments plus a urea-supplemented control diet. Main factors were source of supplemental protein (soybean meal [SBM], a high ruminal escape soybean meal [SP; SoyPLUS], or a combination of corn gluten meal and blood meal [CB; 50:50 on a nitrogen basis]) and level of each protein source (20, 30, or 40% of total dietary CP). Based on 18-h in situ ruminal incubation, escape N content of the protein sources was 66.0, 82.5, and 90.8% of total N and metabolizable amino acid (MAA) content was 29.1, 33.4, and 67.8 g/100 g of DM for SBM, SP, and CB respectively. The steers were fed 12.5% CP diets based on cracked corn (70%) on d 0 through 70 and were switched to a common 11.5% CP urea-supplemented cracked corn diet (80%) on d 71. The steers were housed in individual confinement stalls and had ad libitum access to feed. Replacing urea with SBM or SP increased (P < .05) 28- and 70-d ADG and DMI and increased (P < .05) 28-d efficiency (kg of gain/100 kg of feed). Replacing urea with CB did not improve (P > .05) 28- or 70-d ADG or DMI but did increase (P < .05) 28-d efficiency. The growth rate of steers at 28 and 70 d was correlated to a greater degree with ME intake (r2 = .83 and .85, respectively) rather than MAA supply, suggesting that the MAA supply was not first-limiting for growth. The source of supplemental protein fed during d 0 through 70 had no effect (P > .05) on 175-d DMI or efficiency; however, feeding SBM increased (P < .05) 175-d ADG compared with feeding urea, SP, or CB. Increasing supplemental true protein tended to linearly increase ADG and DMI at 28 and 70 d, but overall, ADG, DMI, and efficiency were not affected (P > .05) by treatment. Replacing urea with SBM or CB in the first 70 d decreased (P < .05) carcass quality grade, dressing percentage, and longissimus muscle area.(ABSTRACT TRUNCATED AT 400 WORDS)

Expression of the cell cycle control protein cdc25 in cleavage stage bovine embryos

We have examined the synthesis and expression of a homologue of the cell cycle control protein cdc25 by early cleavage stage bovine embryos. cdc25 is the protein phosphatase responsible for activating p34cdc2 by dephosphorylating the threonine 14 (Thr 14) and tyrosine 15 (Tyr 15) residues of p34cdc2. Human cdc25 antibody was utilised in western blots and immunoprecipitations to examine the presence and synthesis of cdc25 in bovine embryos. cdc25 is present as a 52 kDa non-phosphorylated and a 66 kDa presumably phosphorylated form in bovine 1-, 2-, 4- and 8-cell embryos. However, cdc25 is actively synthesised only in 8-cell embryos, indicating that the cdc25 present prior to this stage is inherited from the oocyte. In addition, the synthesis of cdc25 was induced in 2-cell embryos in which cleavage was blocked with the DNA synthesis inhibitor aphidicolin.

Insertional mutation of the motor endplate disease (med) locus on mouse chromosome 15

Homozygous transgenic mice from line A4 have an early-onset progressive neuromuscular disorder characterized by paralysis of the rear limbs, muscle atrophy, and lethality by 4 weeks of age. The transgene insertion site was mapped to distal chromosome 15 close to the locus motor endplate disease (med). The sequence of mouse DNA flanking the insertion site junctions was determined. A small (< 20 kb) deletion was detected at the insertion site, with no evidence of additional rearrangement of the chromosomal DNA. Noncomplementation of the transgene-induced mutation and med was demonstrated in a cross with medJ/+mice. The new allele is designated medTgNA4Bs (medtg). The homologous human locus MED was assigned to chromosome 12. Synaptotagmin 1 and contactin 1 were eliminated as candidate genes for the med mutation. The transgene-induced allele provides molecular access to the med gene, whose function is required for synaptic transmission at the neuromuscular junction and long-term survival of cerebellar Purkinje cells.

Measurement of intracellular pH in mammalian sperm cells under physiological conditions

The goal of this study was to develop a technique for the measurement of intracellular pH (pHi) in living mammalian (bovine) sperm cells under physiological conditions. Like many other biochemical measurements, pHi measurements have typically been made under non-physiological conditions on cells whose immediate functional status is not readily assessed and may even be non-viable. Additionally, many pHi measurement techniques may themselves alter the pHi of the cells being measured. Such measurements could yield misinformation. The sperm cell is unique in that its functional status can be easily and continuously monitored by means of its motility, which is directly affected by pHi. In this respect, the sperm cell provides an ideal model system for evaluating pHi measurement techniques. In this article we summarize the validation of a ratiometric absorbance technique for the measurement of pHi of mammalian (bovine) sperm cells under physiological conditions which does not affect their functional status. The pHi of ejaculated bovine sperm cells was calculated to be 6.9 +/- 0.05 (11 replicates). This approach may also be suitable for pHi measurements in other cell types.

Nerve sheath tumours in the dog and cat

Schwannomas were diagnosed in twelve dogs and five cats at Massey University Small Animal Clinic and Hospital over a 15-year period (1977-92). A further two feline cases were reported at the Batchelar Animal Health Laboratory. In six dogs, the tumour involved nerves of the brachial plexus. Clinical signs observed in these dogs were forelimb lameness, muscle wasting and pain on movement of the affected limb or neck. Hindlimb paresis was observed in two dogs. Surgical excision of the brachial plexus tumour was attempted in one dog, leading to an 8-month remission of signs. In one dog, the tumour involved the sacral nerves, and in two dogs the cranial nerves were affected. Three dogs had skin nodules. Seven of the twelve affected dogs were destroyed. In five cats, the tumours developed on the carpus, tarsus or interdigital area of a forelimb or hindlimb as a slowly developing nodular lesion. In the other two cats, the site of the tumour was the flank and the lateral thigh respectively. Surgical excision of the tumour was successful in three cats.

An approach to the analysis of trauma data having a response variable of death or survival

OBJECTIVE

To present an analysis for identifying important factors related to the mortality of trauma patients.

METHODS

Practical aspects of univariate and multivariate techniques are discussed, particularly with the nonstatistician in mind. The derivation and application of the linear logistic regression model are considered, and a checklist of information is suggested for reporting results from such an analysis. A brief comparison of the logistic model is made with other relevant types of statistical models.

Mapping of the taurine transporter gene to mouse chromosome 6 and to the short arm of human chromosome 3

Transport proteins have essential functions in the uptake of neurotransmitters and neuromodulators. We have mapped the gene encoding the taurine transporter, Taut, to the central region of mouse chromosome 6. Analysis of a cross segregating the neurological mutant mnd2 excluded Taut as a candidate gene for this closely linked mutation. To map the human taurine transporter gene, TAUT, a sequence-tagged site (STS) corresponding to the 3' untranslated region of the human cDNA was developed. TAUT was assigned to human chromosome 3 by typing this STS on a panel of somatic cell hybrids. Further analysis of a hybrid panel containing defined deletions of chromosome 3 suggested that TAUT maps to 3p21-p25. These data extend a conserved linkage group on mouse chromosome 6 and human chromosome 3p. Deletion of TAUT might contribute to some phenotypic features of the 3p- syndrome.

A multivariate analysis of factors related to the mortality of blunt trauma admissions to the North Staffordshire Hospital Centre

OBJECTIVE

To identify characteristics of blunt trauma admissions associated with mortality and to derive a linear logistic model for predicting the probability of mortality.

DESIGN

A prospective observational study.

MATERIALS AND METHODS

Data were collected on blunt trauma patients admitted via the Accident and Emergency Department, North Staffordshire Hospital Centre. Univariate and multivariate analyses were performed of potential risk factors associated with mortality.

MEASUREMENTS AND MAIN RESULTS

The main outcome variable was survival or death occurring in hospital within 30 days of admission. Injury Severity Score, age, Revised Trauma Score, and place of injury (road traffic, home, or elsewhere) were independently related to mortality. The effect of age on mortality was best described using three categories: 0-64 excluding 15-24, 15-24, 65+. The survival probability model suggests that a person whose injury occurs in the home has a lower probability of survival than a patient with similar age and trauma scores who is involved in a road traffic accident. A model validation check indicated good agreement between model predictions and patient outcomes.

CONCLUSIONS

The authors propose that use of this model may provide a more accurate evaluation of the mortality of British trauma admissions than would be obtained using models based on data from American trauma cases.

Uses and abuses of statistical models for evaluating trauma care

OBJECTIVE

A statistical model is a powerful tool for evaluating trauma care. With accident and emergency clinicians becoming more aware of the importance of monitoring their department's performance, there is a danger that such models may be inappropriately applied to new sets of trauma cases, resulting in misleading evaluations. The primary objective is to present a method for assessing whether an existing survival probability model can be correctly applied to a different data set.

METHODS

Correct and incorrect utilization of statistical models for evaluating the mortality of trauma patients are presented. Circumstances that may lead to the modification of an existing model, and the use of statistical models for evaluating different aspects of trauma care, are suggested.

Soft tissue calcification in children with terminal transverse defects of the upper limb--is it tumoral calcinosis?

We report five children with transverse defects of the upper limb who developed calcified deposits at the distal end of the limb. The lesions were excised from two children and had the typical histological appearance of tumoral calcinosis but on clinical grounds it is unlikely that this is the same condition as that previously described as tumoral calcinosis.

Kidney and retinal defects (Krd), a transgene-induced mutation with a deletion of mouse chromosome 19 that includes the Pax2 locus

The semidominant mutation Krd (kidney and retinal defects) was identified in transgenic line Tg8052. Krd/+ mice have a high incidence of kidney defects including aplastic, hypoplastic, and cystic kidneys. Retinal defects in Krd/+ mice include abnormal electroretinograms and a reduction of cell numbers that is most extreme in the inner cell and ganglion layers. Viability of Krd/+ mice is strongly influenced by genetic background, and growth retardation is observed in young animals. Homozygosity results in early embryonic lethality. Fluorescence in situ hybridization of a transgene-specific probe localized the insertion site to the distal region of mouse Chromosome 19. The sequence of the insertion site revealed transgene insertion into a LINE element with deletion of a single nucleotide from the 3' terminus of the transgene. A polymorphic microsatellite, D19Umi1, was identified in a junction clone and mapped in several large crosses. D19Umi1 is located 1.7 +/- 1.0 cM distal to Pax2, which encodes a paired type transcription factor expressed in embryonic kidney and eye. Deletion of Pax2 from the transgenic chromosome was demonstrated by Southern analysis of genomic DNA from (Krd/+ x SPRET/Ei)F1 mice. Additional genetic and molecular data are consistent with an approximately 7-cM deletion that includes the loci stearoyl CoA desaturase (Scd1), pale ear (ep), D19Mit17, D19Mit24, D19Mit27, D19Mit11, and Pax2. This deletion, Del(19)TgN8052Mm, will be useful for genetic and functional studies of this region of mouse Chromosome 19.

Purification and characterization of the major antigen WI-1 from Blastomyces dermatitidis yeasts and immunological comparison with A antigen

The lack of well-defined antigens from Blastomyces dermatitidis has hampered the ability to reliably diagnose human infection and study the immunobiology of blastomycosis. We recently discovered a novel surface protein on B. dermatitidis yeasts, designated WI-1, and demonstrated it to be a key antigenic target of humoral and cellular responses during infection. In the present article, we purified and characterized WI-1 and compared it immunologically with the only Blastomyces antigen commercially available, A antigen. WI-1 was purified by high-performance liquid chromatography over a DEAE-cellulose column. It eluted from the column at a point on the salt gradient corresponding to 460 to 490 mM NaCl, reflecting its acidic pI of approximately equal to 5.2. Purified WI-1 had a molecular mass of 120 kDa and contained a large amount of cysteine (85 residues) and aromatic amino acids but undetectable carbohydrate. In contrast, A antigen had a molecular mass of 135 kDa and contained 37% carbohydrate. Immunological comparison of the two antigens showed that, when radiolabeled, WI-1 was more reactive with anti-Blastomyces antisera than A antigen but did not cross-react with anti-Histoplasma antisera. Proteinase digestion of WI-1 eliminated its recognition by anti-WI-1 and anti-Blastomyces antisera. Proteinase treatment of A antigen had no effect on its recognition by anti-Blastomyces or anti-Histoplasma antisera, but periodate treatment abolished recognition by anti-Histoplasma antisera, indicating that the cross-reactive determinant(s) of A antigen is displayed on the accompanying carbohydrate. In further studies, anti-WI-1 antiserum reacted with A antigen and, conversely, anti-A antiserum and monoclonal antibodies (MAbs) reacted with WI-1, indicating a shared determinant on the two antigens. A recombinant 25-amino-acid repeat, recently cloned from WI-1 and found to be the major target of antibody recognition of WI-1, reacted strongly with anti-A antiserum and MAbs. In MAb competition tests, MAbs specific for the 25-residue repeat abolished binding of anti-A antiserum to A antigen. In antigen inhibition tests, the recombinant repeat abolished binding of anti-A antiserum to A antigen. These results demonstrate that the repeat is the major site of antibody recognition of both WI-1 and A antigen and that the recombinant, nonglycosylated peptide could replace either native antigen in formatting better diagnostic tests for blastomycosis. Moreover, they suggest that producing fungal protein antigens as nonglycosylated peptides in a procaryotic expression system may circumvent problems of antigen cross-reactivity that are due to posttranslational modification.

Altered expression of surface protein WI-1 in genetically related strains of Blastomyces dermatitidis that differ in virulence regulates recognition of yeasts by human macrophages

The molecular basis for pathogenicity and virulence of the dimorphic fungus Blastomyces dermatitidis remains unknown. WI-1 is a major cell wall protein of B. dermatitidis yeasts and is a recognition target of both humoral and cell-mediated immunity. As an initial study to determine if WI-1 might be linked to virulence of B. dermatitidis, we quantified WI-1 expression on three genetically related strains that differ in their virulence for mice: wild-type virulent ATCC strain 26199, mutant ATCC strain 60915 (which is 10,000-fold reduced in virulence), and mutant ATCC strain 60916 (which is avirulent). Two principal alterations in WI-1 expression were observed in the mutants. First, the mutants express more WI-1 on their surface, as quantified by flow cytometry with monoclonal antibody to WI-1 and by radioimmunoassay, but the WI-1 on their cell wall is less extractable than that on the wild-type strain. Second, the mutants shed less WI-1 during culture and demonstrate impaired processing of shed WI-1. Surface alterations in WI-1 were accompanied by significant differences in the binding of the virulent and mutant strains to human monocyte-derived macrophages. Attachment of yeasts to macrophages paralleled and was proportional to the expression of WI-1. Compared with wild-type yeasts, both mutants bound to macrophages more rapidly and in two- to threefold-greater magnitude. Furthermore, about 75% of yeast binding to macrophages was inhibited by a Fab anti-WI-1 monoclonal antibody. These results suggest that altered WI-1 expression on attenuated and avirulent mutant B. dermatitidis yeasts greatly facilitates macrophage recognition and binding of yeasts and, in turn, may contribute to more rapid ingestion and killing in the host.

Utility of anti-WI-1 serological testing in the diagnosis of blastomycosis in Wisconsin residents

WI-1, a 120-kD protein found in the outer cell wall of Blastomyces dermatitidis, has been purified, labeled with 125I, and used as a target in a radioimmunoassay (RIA). In an assessment of the usefulness of anti-WI-1 serology in the diagnosis of blastomycosis, the RIA was used to test four panels of sera from residents of Wisconsin, a state in which blastomycosis is endemic. Twenty-four (75%) of 32 patients whose blastomycosis had been reported to the Wisconsin Division of Health had at least one serum sample positive for antibody to WI-1; 25 (93%) of 27 serum samples obtained from these patients within 60 days of diagnosis were positive. In an effort to simulate clinical practice, 132 serum samples were assayed from another 107 patients in whom blastomycosis was being considered as a cause of illness. The result was positive for at least one sample from 83% of the 23 patients with confirmed blastomycosis and from 5% of the 84 patients from whom the fungus was not documented. Serum samples from another five patients with blastomycosis identified during investigation of a 1990 outbreak in Oconto Falls, Wisconsin, also gave a positive result, whereas none of the serum specimens from 57 healthy family members or neighbors did so. Only three (0.56%) of 535 serum samples from random blood donors residing in two counties with a high annual incidence of blastomycosis were positive for antibody to WI-1. Modification of the RIA so that IgM rather than IgG antibody was detected did not enhance diagnostic sensitivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Radiation and taxol effects on synchronized human cervical carcinoma cells

PURPOSE

To evaluate the effectiveness of the plant derived chemotherapeutic agent taxol alone and in combination with ionizing radiation on synchronous and asynchronous human cervical carcinoma cells and to define the mechanistic basis for this cytotoxic response.

METHODS AND MATERIALS

Asynchronous and synchronous cells (obtained by modified mitotic shake-off) derived from carcinomas of the human uterine cervix were treated with a range of concentrations of taxol (0, 1.0, 2.5, 5.0, 10.0 and 20.0 nM) for either 8, 24 or 48 h. Synchronized cell cycling was evaluated by counting mitotic indices and by uptake of bromodeoxyuridine (BrdUrd). Cells were irradiated (137Cs gamma rays at 1.12 Gy/min) alone and after taxol treatment and plating efficiencies and radiosensitivity determined.

RESULTS

Taxol treatment resulted in a dose time dependent loss of colony forming ability with 10 nM for 24 h producing about 10% cell survival. Irradiating taxol treated cells resulted in a strictly additive response in contrast to previous supra-additive results with astrocytoma and melanoma cells. Mitotically synchronized cells rapidly moved into G1 phase with a second mitotic peak at 28 h (total cycle time). Taxol treatment resulted in a continued accumulation of mitoses, and a failure and/or delay of entry of a fraction of cells into S phase after a G1 phase of at least 10 h. That is, taxol effects cell cycling at a stage other than G2/M. Irradiating (3 Gy) synchronized cells showed a 10-fold variation in sensitivity, with mitosis as the most sensitive phase with taxol alone resulting in some cytotoxicity and combined effects additive or less than additive.

CONCLUSION

Taxol effects these cervical carcinoma cells at other stages of the cell cycle than G2/M. This may explain the failure to obtain taxol radiosensitization with these cells and it may indicate that taxol has a multiplicity of actions with differences in effectiveness likely between cells of different origins.

The significance of patient appearance in predicting severity of injury

The observations of pallor, sweating, agitation and restlessness, at the time of an injured patient's admission to the resuscitation room, were compared with other more complex indices of injury severity and the ability of each observation to predict mortality was observed. The number of positive observations was significantly related to the Revised Trauma Score and the Injury Severity Score, and pallor was significantly related to mortality. The observation that an injured patient is pale is an important index of severity.

Comparison of percutaneous anaesthesia for venous cannulation after topical application of either amethocaine or EMLA cream

We have compared, in a double-blind study, the efficacy of topical amethocaine cream 1 g (5% w/w) in alleviating the pain of venous cannulation with that of 5% EMLA cream 2.5 g. One hundred and twenty unpremedicated female patients undergoing minor gynaecological surgery, were allocated randomly to one of four groups: 5% EMLA cream 2.5 g for 30 min: 5% EMLA cream 2.5 g for 60 min; amethocaine cream 1 g (5% w/w) for 30 min; amethocaine cream 1 g (5% w/w) for 60 min. After removal of the cream, venous cannulation was performed with an 18-gauge cannula. Patients assessed the pain experienced using a 100-mm visual analogue score and four-point rank score. In addition, a blinded observer assessed the patient's response to venous cannulation using a four-point rank score. Good analgesia was obtained in all groups and there was no statistically significant difference in pain scores between the groups.

Conserved linkage of early growth response 4, annexin 4, and transforming growth factor alpha on mouse chromosome 6

The mouse genes encoding early growth response 4 (Egr4), annexin IV (Anx4), and transforming growth factor alpha (Tgfa) have been mapped to a linkage group on mouse chromosome 6 that is conserved on human chromosome 2p11-p13. The genes are closely linked, with 0/215 recombinants between Anx4 and Tgfa and 1/215 recombinants between these genes and Egr4. The genes are located approximately 2 cM distal to mnd2, a mouse mutation causing neuromuscular disease. The results demonstrate that mnd2 is located at an internal position within this conserved linkage group.

Candida albicans exocellular antigens released into a synthetic culture medium: characterization and serological response in rabbits

Different exocellular extracts were isolated by concentrating the supernatants of yeast- and mycelial-phase Candida albicans cultures incubated in a synthetic medium. The only difference between the extracts obtained from the two phases was the presence in those obtained from mycelial cultures of a polysaccharide-rich, high-molecular-mass component, migrating in SDS-polyacrylamide gels at a position that would correspond to proteins with molecular masses of 245-265 kDa. The electrophoretic band patterns obtained before and after concanavalin A-Sepharose 4B affinity column treatments confirmed that the 245-265 kDa band was the only one of mannoprotein nature. The extract obtained from 24 h mycelial-phase culture (EA) was selected as the exocellular antigen for this work. The dry weight of EA obtained from 1 litre of culture medium was 30 mg; it contained 53% carbohydrate (18.3% glucose and 21.7% mannose measured by gas-liquid chromatography) and 10% protein. Rabbit antisera against EA were absorbed with yeast-phase organisms and used to stain Western blots of gels loaded with EAs. These antisera clearly recognized bands in the 21, 33 and 44 kDa areas. The antiserum obtained was employed to develop a double-antibody enzyme-linked immunosorbent assay for measuring EA concentrations in a culture medium. Most of the EA was released during the exponential phase of growth.

Insertional mutation of the hairless locus on mouse chromosome 14

Crosses between heterozygous transgenic mice from line 5053 produced offspring with progressive irreversible hair loss beginning at day 19. With increasing age, the skin of these animals became thicker and plicated in appearance. Histological analysis revealed the complete absence of normal hair follicles and numerous intradermic cystic structures, which enlarged with time and became filled with keratinaceous material. Test crosses demonstrated that the affected animals are homozygous for the transgene insertion. The clinical and histological phenotype of the new mutant closely resembles that of the rhino allele at the hairless locus on Chromosome (Chr) 14. Complementation tests and linkage analysis indicate that the transgene has interrupted the hairless locus. It has been demonstrated previously that mutation at the hr locus is accompanied by a variety of immune deficiencies. Many of the older affected transgenic mice developed an impetigo-like skin eruption which responded to antibiotic ointment and which may reflect impaired immune function. The transgenic allele, hrTgN5053Mm, will be useful for identification of the transcription unit of the hairless locus.

The spectrum of disease associated with a positive ANCA

This is a retrospective analysis of all patients with a raised titre of ANCA in a single centre over a two-year period. Sixty-five patients were identified and clinical data is presented for 58 of these-34 male and 24 female. The median age is 56 years (13-83). Fourteen patients had Wegener's granulomatosis, 14 microscopic polyarteritis nodosa and 30 had other diagnoses. The patients with unexpectedly positive results are discussed in detail. This study confirms the sensitivity of ANCA in Wegener's granulomatosis and microscopic polyarteritis nodosa but suggests that the test is not as specific as initially claimed.

Ombrotrophic peat as a medium for historical monitoring of heavy metal pollution

Knowledge of historical trends in heavy metal deposition can aid the study and impact prediction of contemporary pollution. For this purpose, analysis of ombrotrophic peat cores has proved a valuable complement to other sedimentary analyses. However, doubts still remain concerning the mobility of heavy metals in peat. The debate cannot be resolved until the behaviour of these elements in peat is better understood.Peat cores were collected from hollows and hummocks on Ringinglow Bog in the southern Pennines. The cores were sliced into contiguous 1-cm slices. Samples were analysed for total concentrations of major elements (Al, Ca, K, Mg, Na) and trace metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn) using atomic absorption spectrophotometry. Multivariate statistical analysis was conducted on the data.Preliminary results indicate relatively high concentrations of Cd, Cu, Fe, Pb and Zn reflecting the influence of industrial activities in Sheffield and Manchester. As aluminium, cadmium, copper, lead and zinc exhibit similar profiles they may be suitable surrogates for monitoring historical pollution. However, other elements (e.g. Fe, K, Mn, Na) are clearly influenced by bog hydrology or plant translocation and would be inappropriate monitors.

Immunologic recognition of a 25-amino acid repeat arrayed in tandem on a major antigen of Blastomyces dermatitidis

A 120-kD glycoprotein antigen abundantly expressed on Blastomyces dermatitidis yeasts is a target of cellular and humoral immune responses in human infection. To investigate the antigen and immune response more carefully at the molecular level, we screened an expression library from B. dermatitidis to identify clones that encode this antigen, designated WI-1. A 942-bp cDNA was isolated by immunologic screening with polyclonal, rabbit anti-WI-1 antiserum. Northern hybridization analysis showed that the cDNA hybridized to yeast message approximately equal to 3.9 kb. DNA and deduced protein sequence analysis of the clone demonstrated a 25-amino acid repeat arrayed in tandem, present in 4.5 copies near the 5' end, and rich in predicted antigenic epitopes. Further analysis showed strong homology in these tandem repeats with invasin, an adhesin of Yersiniae. Cloned cDNA was used to express a 30-kD fusion protein strongly recognized in western blots by rabbit anti-WI-1 antiserum, and by sera from all 35 blastomycosis patients studied. The fusion protein product of subcloned cDNA encoding only the tandem repeat also was strongly recognized in western blots by sera from the 35 blastomycosis patients, but not by sera from 10 histoplasmosis and 5 coccidioidomycosis patients. An antigen-inhibition radioimmunoassay showed that the tandem repeat alone completely eliminated rabbit and human anti-WI-1 antibody binding to radiolabeled native WI-1. From these results, we conclude that the 25-amino acid repeat of WI-1 displays an immunodominant B cell epitope, and that the carboxyl-terminus of the molecule exhibits an architecture that may promote adhesion of Blastomyces yeasts to host cells or extracellular matrix proteins and ultimately provide a clearer picture of the molecular pathogenesis of blastomycosis.

mnd2: a new mouse model of inherited motor neuron disease

The autosomal recessive mutation mnd2 results in early onset motor neuron disease with rapidly progressive paralysis, severe muscle wasting, regression of thymus and spleen, and death before 40 days of age. mnd2 has been mapped to mouse chromosome 6 with the gene order: centromere-Tcrb-Ly-2-Sftp-3-D6Mit4-mnd2-D6Mit 6, D6Mit9-D6Rck132-Raf-1, D6Mit11-D6Mit12-D6Mit14, mnd2 is located within a conserved linkage group with homologs on human chromosome 2p12-p13. Spinal motor neurons of homozygous affected animals are swollen and stain weakly, and electromyography revealed spontaneous activity characteristic of muscle denervation. Myelin staining was normal throughout the neuraxis. The clinical observations are consistent with a primary abnormality of lower motor neuron function. This new animal model will be of value for identification of a genetic defect responsible for motor neuron disease and for evaluation of new therapies.

An audit of outcome of treatment in acromegaly

In order to determine whether acromegaly is still associated with increased mortality, a hospital case note review of all patients with acromegaly followed up in Stoke-on-Trent since 1967 was carried out. Of 79 subjects identified, 51 are alive and being monitored and 28 have died. Mortality was compared to the general population by life table analysis. Secretion of growth hormone was assessed and compared in dead and alive patients. The effect of diabetes, hypertension, and growth hormone secretion on long-term outcome was assessed. Acromegaly is still associated with increased mortality, with an overall ratio of observed to expected deaths equal to 2.68 (95% C.I. 1.8-3.9; p < 0.001), but the survival of 31 (39%) patients whose growth hormone level had been reduced to below 5 mU/l was equal to that of the general population (O/E = 1.42; 95% C.I. 0.46-3.31: p > 0.05). The dead patients had had significantly higher growth hormone levels than those still alive, but mortality did not appear to be influenced by diabetes or hypertension. The cause of death was vascular in 57% of cases. Growth hormone hypersecretion is still associated with excess mortality in acromegaly. The present study suggests that the therapeutic objective should be to lower average daytime growth hormone levels to less than 5 mU/l. There is need for a large study to compare different modes of treatment in terms of their effect on growth hormone secretion and on long-term outcome.