Germline diversity of the expressed BALB/c VhJ558 gene family.

Although the mouse immunoglobulin heavy chain (Igh) locus contains 15 heavy chain V (Vh) gene families, at least half of the Vh gene segments are members of the VhJ558 family. This large Vh gene family represents the least characterized germline coding regions of any of the mouse antigen receptor loci and the contribution of individual VhJ558 genes to the preimmune repertoire is poorly understood. In fact, relatively few germline VhJ558 sequences have been reported for BALB/c, the foundation strain for mouse immunoglobulin genetics and the prototypic strain of the Igh(a) haplotype. Here we present a database consisting of 66 sequences estimated to represent one-half of the total number of functional BALB/c VhJ558 genes. Our results indicate that a subset of the VhJ558 genes is highly expressed in the preimmune repertoire, with just nine Vh sequences accounting for nearly 50% of the VhJ558 heavy chains expressed by splenic B cells. We show that this disparity in the expressed Vh gene repertoire is not due to the position of the Vh genes relative to the Dh cluster or to multiple germline copies of the highly expressed VhJ558 genes. Together, these data constitute the first detailed analysis of functional BALB/c VhJ558 genes, demonstrate a striking bias in the use of particular VhJ558 genes in the preimmune repertoire, and provide sufficient information to study the regulation of the Dh-distal region of the Igh-V locus at the level of individual genes.

B cell antigen receptor-evoked calcium influx is enhanced in CD22-deficient B cell lines.

CD22 is a B cell membrane glycoprotein that, upon Ag receptor engagement, becomes rapidly tyrosyl phosphorylated and associates with several signaling molecules including Lyn, Syk, PLCgamma1, and the protein-tyrosine phosphatase, SHP-1. Two allelic forms of murine CD22 exist: CD22.1 is expressed in strains such as NZB and DBA/2, whereas CD22.2 is expressed in BALB/c and most other strains. WEHI-231 cells, which derive from a (BALB/c x NZB)F1 mouse, express one copy of each allele. Previous studies have proposed both positive and negative functions for CD22. We explored the role of CD22 in surface IgM Ag receptor signal transduction by examining signaling in three clonally independent WEHI-231 variants that have lost expression of the CD22.2 allele. This experimental design allowed us to assess the signaling functions of CD22 independent of its developmental role. These variants, which exhibit a 50% reduction of total surface CD22, are hyper-responsive to Ag receptor stimulation: several cellular proteins are hyperphosphorylated on tyrosyl residues and surface IgM-mediated calcium flux is markedly increased. Interestingly, the increased calcium response observed in CD22-deficient cells is due largely to enhanced calcium influx. Reconstitution of CD22 expression reduces these changes. The SHP-1/CD22 association is reduced in CD22-deficient cell lines and is restored by re-expression of CD22. Our results demonstrate that CD22 is a cell autonomous negative regulator of B cell Ag receptor signaling, and suggest that it regulates calcium entry via a mechanism downstream from or independent of calcium release from intracellular stores.

Evaluation of p53 protein expression in renal cell carcinoma: comparison of two antibodies.

The aims of this study were to establish a profile for the expression of p53 in primary renal cell carcinoma using the polyclonal antibody NCL-CB1 and the monoclonal antibody D07, and to compare the results of staining with both antibodies. Ninety-six cases were studied using formalin-fixed paraffin-embedded tissue. Positive nuclear staining ranged from 5% (D07) to 12% (NCL-CM1). Positive cytoplasmic staining ranged from 7% (D07) to 25% (NCL-CM1) of cases. Interobserver agreement was excellent. The findings suggest that such a low level of immunohistochemical positivity reduces any potential prognostic value for p53 in this tumour type.

The effects of acute and chronic JJ stent placement on upper urinary tract motility and calculus transit.

OBJECTIVE: To determine the pathophysiological changes in upper urinary tract motility and calculus transit which may occur following JJ stent insertion. MATERIALS AND METHODS: The acute and chronic effects of JJ stent placement were studied in 24 canine renal units. Intrarenal and intraureteric pressures and motility were measured, in addition to transit times for complete passage of synthetic calculi from the upper ureter into the bladder. RESULTS: Acute effects included raised renal intrapelvic pressure, reduced pelvic and ureteric motility and delayed calculus transit time. Prolonged JJ stent placement was associated with return of intrapelvic pressure to normal but persistent changes in both renal and ureteric motility and also calculus transit time. CONCLUSION: In situ JJ stents impair upper urinary tract motility and experimental calculus transit time and may delay passage of ureteric calculi or calculus fragments following extracorporeal shock wave lithotripsy.

Lawsuits and nurses.

As a health care professional, you are legally accountable for the nursing services you provide. This means you could be sued if a patient suffers harm while in your care, whether or not you were to blame.

c-myc expression in renal carcinoma: correlation with clinical parameters.

There is evidence that c-myc is expressed in renal carcinomas and that it is associated with histological grade. This study reports on the clinical correlations of oncogene expression and clinical features of the disease. Tissue sections from 97 patients (95 primary and 12 secondary cancers) were immunostained with a c-myc oncoprotein antibody. The tumours were scored for extent and intensity of nuclear and cytoplasmic staining. Ninety patients were suitable for follow-up study. High levels of expression correlated significantly with increasing T category and nuclear grade, as well as with venous invasion. No correlation with nodal involvement, the presence of metastases, tumour architecture or cell type was found. The extent of nuclear staining was related to survival (although not to recurrence), but in a multivariate analysis did not provide independent prognostic information. It was concluded that semiquantitative assessment of levels of c-myc oncoprotein does not provide clinically useful prognostic information.

Comparison of flow and static image cytometry in the determination of ploidy.

AIMS: To compare the efficiency of flow cytometry and computed image cytometry; and to see if a reliable set of guidelines regarding interpretation of histograms could be drawn up. METHODS: The two methods were applied to a series of 111 formalin fixed renal cell carcinomas. Data generated by both methods were compared. RESULTS: The methods agreed in 85 cases. Hypodiploidy was detected by computed image cytometry in seven cases in which flow cytometry had shown only an aneuploid peak. Aneuploidy in seven in which the corresponding flow cytometry histogram was diploid. There was an overlap in the second peak proportions on flow cytometry histograms between those classed as diploid or tetraploid by computed image cytometry. In six cases the flow cytometry histograms had unacceptably high coefficients of variation and in all of these cases computed image cytometry demonstrated aneuploidy. CONCLUSIONS: Computed image cytometry is particularly useful for clarifying difficult areas in flow histograms--specifically, high coefficients of variation, high G2M phase, as well as possible near diploid aneuploidy and hypodiploidy.

Older donors and kidney transplantation.

Reluctance to use kidneys from older donors (> 50 years of age) is based on reports of inferior results. We reviewed our experience with 45 kidneys transplanted from older donors. Primary nonfunction, immediate graft function, and 1-, 2- and 3-year graft survival rates were similar to those obtained with kidneys transplanted from donors aged between 20 and 40 years. Renal function at 1 year (as measured by serum creatinine) was poorer in kidneys from older donors. No beneficial effect with respect to graft survival was noted with cyclosporin therapy compared to conventional immunosuppression; however, the numbers are small. We conclude that kidneys from older donors are a valuable source for transplantation.

Ploidy and prognosis in renal carcinoma.

The value of tumour ploidy status as a prognostic indicator in renal carcinoma is disputed. In this retrospective study the DNA content of 90 primary and 10 secondary renal cell carcinomas was measured using flow cytometry. Data on recurrence and survival were available in all cases. Tumours were staged according to the TNM system and histological grade was based on nuclear morphology. Formalin-fixed, paraffin-embedded material was processed using standard techniques. Multiple samples were examined in 19 cases. Of the primary tumours, 52 were diploid, 24 were aneuploid and 6 were tetraploid; 8 patients had uninterpretable histograms. Ploidy of the secondary tumours was similar to that of their respective primaries. Aneuploidy correlated with higher grade but not with TNM category and, although associated with an increased risk of death, did not provide independent prognostic information. Heterogeneity of ploidy was found in 6 of the 19 cases where more than 1 sample was assessed. It was concluded that tumour DNA content in renal carcinoma is weakly linked to outcome, is subject to sample error and does not provide accurate prognostic information as a single independent variable.

A novel method of induced renal hypothermia.

When the kidney is removed from cold storage for implantation into the recipient it gradually rewarms (second warm ischaemic time) and a prolonged second warm ischaemic time is a risk factor for delayed graft function. A cooling jacket has been designed to prevent this rewarming during transplantation. This study evaluates the efficacy of this device. Surface and core temperatures of less than 15 degrees Centigrade were maintained for 120 minutes. Renal function was significantly better in cooled than in uncooled kidneys in a single kidney canine model. Induced renal hypothermia, using a device such as this, should be a routine manoeuvre in renal transplantation.

Image analysis in the determination of ploidy and prognosis in renal cell carcinoma.

The usefulness of ploidy determination by flow cytometry in renal cell carcinoma is disputed. An alternative technique for DNA quantitation, computerised static image analysis, has several advantages over flow methods. Tissue from 90 cases of primary renal cell carcinoma was analysed by image analysis. Cases were assigned a histological grade and staged and stratified by the TNM system. Fifty-two cases were diploid, 28 were aneuploid and 9 were tetraploid (1 was unanalyzable). Heterogeneity of ploidy was noted in 4 cases. The degree to which nuclear DNA content exceeded that of normal nuclei from the same block was also calculated (5C exceeding rate). Stage and grade provided independent prognostic information. Aneuploidy was associated with higher mortality but neither ploidy nor 5C exceeding rate were prognostic indicators. Image analysis is a useful and accurate method for ploidy determination and provides additional data on DNA quantitation but this information is not predictive of the clinical outcome.

A canine model of cyclosporine enhanced ischemic renal injury.

Clinical reports of increased graft primary non function in patients receiving cyclosporine in whom the anastomosis time is prolonged (greater than 30 minutes) suggest a synergism between the nephrotoxic effects of cyclosporine and the ischaemia occurring during transplantation. Using unilaterally nephrectomised greyhound dogs, sixty minutes ischaemia and cyclosporine 10 mg./kg./day we have produced an animal model of cyclosporine enhanced ischaemia renal failure. Structural and functional data suggests the proximal tubule is the main site of injury.

Prevention of cyclosporine enhanced ischaemic renal injury using induced hypothermia.

Cyclosporine is associated with an increased incidence of graft primary non function and poorer long term graft function in patients with prolonged ischaemia times. We evaluated the role of hypothermia in preventing this synergism between the nephrotoxic effects of cyclosporine and ischaemia in a canine model. Induced renal hypothermia prevented this synergism.

Pararectus retroperitoneal radical nephrectomy.

We describe a new pararectus retroperitoneal approach to the kidney, which allows easy identification and occlusion of the renal vessels before mobilization of the kidney. This approach potentially reduces morbidity, hospital stay and cost. The technique has been used in 4 cases of radical nephrectomy for tumor and in 1 for pyonephrosis.

Transplantation of kidneys from pediatric cadaver donors to adult recipients.

Pediatric donors (less than 12 years old) are a potentially important source of kidneys for adult recipients. Previous reports of decreased graft survival and increased complication rates have made surgeons wary of using such kidneys. In 64 kidneys from younger donors transplanted to adult recipients the delayed graft function rate (41 versus 42%), and 2 and 3-year graft survival rates (67 versus 72% and 61 versus 65%, respectively) were similar to those seen with kidneys from adult donors. Kidneys from donors 24 months old or less experienced an 80% rate of graft loss at 1 year. When these kidneys are excluded the 1-year graft survival rate was similar to kidneys from older and younger donors (70 versus 77%). Mean serum creatinine at 1 year was similar in both groups (155 +/- 21 versus 151 +/- 10). Pediatric kidneys except those obtained from donors 2 years old or less are suitable for adult recipients. However, kidneys from very young donors may be more appropriate to pediatric recipients.