Deoxyribonucleic Acid Analysis Research Articles

Validation Studies for the Genetic Typing of the D1S80 Locus for Implementation into Forensic Casework

A series of validation experiments were designed to evaluate, according to the Technical Working Group on DNA Analysis Methods (TWGDAM) guidelines, the analysis of the D1S80 locus for casework implementation. Approximately 400 samples from three different populations (Minnesota Caucasian, Minnesota African Americans, and Minnesota Native Americans) were typed to determine allele frequencies. Simulated forensic type specimens (blood, saliva, hair and semen, or vaginal secretions) were typed to demonstrate that deoxyribonucleic acid (DNA) extracted from various tissues of an individual yield the same D1S80 type. Dilution studies were performed and it was determined that a wide range of input DNA (0.5 ng to 40.0 ng) will consistently yield typeable results. The evaluation of DNA from various animals showed that the D1S80 locus is specific to human DNA within the limits of the parameters tested. The reproducibility of the system was tested by duplicate analysis of approximately 200 population samples. Duplicate samples were analyzed on both horizontal and vertical gel systems. In addition, simulated forensic specimens were analyzed by two independent laboratories: the Minnesota Forensic Science Laboratory (MFSL) and the Roche Biomedical Laboratories (RBL). All analyses, including extraction, quantitation, amplification and typing, were performed independently. All typing results for both laboratories were in agreement. By the analysis of mixtures from various simulated casework type mixtures, it was demonstrated that the D1S80 typing system is suitable for analyzing mixtures. In addition to the simulated casework, evidentiary samples from several adjudicated cases previously analyzed by restriction fragment length polymorphism (RFLP) analysis and/or DQA1 were typed at the D1S80 locus. The D1S80 results were consistent with previous RFLP and/or DQA1 results regarding inclusions/exclusions.

Molecular methods for diagnosis and epidemiological studies of parasitic infections

Direct microscopy is widely used for the diagnosis of parasitic infections although it often requires an experienced microscopist for accurate diagnosis, is labour intensive and not very sensitive. In order to overcome some of these shortcomings, molecular or nucleic acid-based diagnostic methods for parasitic infections have been developed over the past 12 years. The parasites which have been studied with these techniques include the human Plasmodia, Leishmania, the trypanosomes, Toxoplasma gondii, Entamoeba histolytica, Giardia, Trichomonas vaginalis, Cryptosporidium parvum, Taenia, Echinococcus, Brugia malayi, Wuchereria bancrofti, Loa loa and Onchocerca volvulus. Early methods, which involved hybridisation of specific probes (radiolabelled and non-radiolabelled) to target deoxyribonucleic acid (DNA), have been replaced by more sensitive polymerase chain reaction (PCR)-based assays. Other methods, such as PCR-hybridisation assays, PCR-restriction fragment length polymorphism (PCR-RFLP) assays and random amplified polymorphic DNA (RAPD) analysis have also proved valuable for epidemiological studies of parasites. The general principles and development of DNA-based methods for diagnosis and epidemiological studies will be described, with particular reference to malaria. These methods will probably not replace current methods for routine diagnosis of parasitic infections in developing countries where parasitic diseases are endemic, due to high costs. However, they will be extremely useful for genotyping parasite strains and vectors, and for accurate parasite detection in both humans and vectors during epidemiological studies.

Nasal potential difference in cystic fibrosis patients presenting borderline sweat test.

The diagnosis of cystic fibrosis (CF) can be difficult if the sweat test and routine deoxyribonucleic acid (DNA) analysis are inconclusive. Under these circumstances, measurement of nasal potential difference (NPD) was proposed as a complementary diagnostic tool, as demonstrated in subjects bearing the G551S or 3849+10KbC-->T mutations. The purpose of the present study was to verify the diagnostic value of this technique in CF patients with a borderline sweat test. NPD was measured in 18 patients with a borderline sweat test, in whom CF diagnosis was based on the presence of one CF gene mutation in each chromosome (CF borderline). These patients were compared both to non-CF controls and CF patients with an abnormal sweat test (CF controls). Basal NPD values of CF borderline patients (mean value -39+/-6 mV, range -29 to -52 mV; n=18) were in the pathological range of CF controls (-39+/-8 mV, range -28 to -57 mV; n=37), and both were statistically different from values obtained in non-CF controls (-15+/-4 mV, range -6 to -23 mV; n=24; p<0.0001). Mutation analysis confirmed a high frequency of the 3849+10KbC-->T mutation in this group of CF borderline patients (positive in 14 out of 18 subjects), whereas other mutations, such as AF508, Q552X, N1303K and R1162X, were also found to be associated with this atypical CF phenotype. These results confirm the presence of pathological values of basal NPD in CF patients with borderline sweat test, and also extend this finding to subjects bearing genotypes other than the G551S and 3849+10KbC-->T mutations. The present findings, therefore, confirm the usefulness of measurement of basal nasal potential difference in all those patients in whom diagnosis of cystic fibrosis can be suspected but the sweat test remains inconclusive.

Epidemiological and genetic observations on human schistosomiasis in Kinshasa, Zaire

A survey for Schistosoma intercalatum conducted in Kinshasa, Zaire, in September 1994 revealed a prevalence of 3·6% ( n = 167). Three isolates of schistosomes were made by exposing Bulinus wrighti to miracidia hatched from eggs collected from 2 infected children. Characterization of the isolates by biochemical (isoenzymes of phosphoglucomutase), molecular (restriction fragment length polymorphism and randomly amplified polymorphic deoxyribonucleic acid analysis) and morphological (egg measurements) techniques confirmed the existence of an autochthonous transmission focus of S. intercalatum in Kinshasa. The study also provided evidence of the occurrence of natural hybridization between S. intercalatum and S. haematobium. No potential snail host for either species was found in the 2 rivers examined. Apart from Bu. globosus from Zambia and Bu. wrighti, snail infection experiments showed an incompatible relationship between the parasite isolates and snails belonging to the Bu. forskalii group, the Bu. truncatus/Bu. tropicus complex, and the Bu. africanus group.

Cloning and Characterization of the Promoter Regions of the Human Parathyroid Hormone (PTH)/PTH-Related Peptide Receptor Gene: Analysis of Deoxyribonucleic Acid from Normal Subjects and Patients with Pseudohypoparathyroidism Type 1b

Cloning and Characterization of the Promoter Regions of the Human Parathyroid Hormone (PTH)/PTH-Related Peptide Receptor Gene: Analysis of Deoxyribonucleic Acid from Normal Subjects and Patients with Pseudohypoparathyroidism Type 1b

Cloning and characterization of the promoter regions of the human parathyroid hormone (PTH)/PTH-related peptide receptor gene: analysis of deoxyribonucleic acid from normal subjects and patients with pseudohypoparathyroidism type 1b.

Expression of the PTH/PTH-related peptide (PTHrP) receptor (PTHR) in the mouse is controlled by at least two promoters. The downstream promoter (P2) is ubiquitously expressed, whereas expression of the upstream promoter (P1) is largely restricted to kidney. These observations may provide a genetic basis for a human PTH resistance syndrome, pseudohypoparathyroidism type 1b (PHP1b), in which renal, but not osseous, signaling by PTH is defective. We, therefore, cloned and characterized the 5'-end of the human PTHR gene and found that its organization is very similar to that of the mouse. Transcription initiation sites of human P1 and P2 promoters are in similar, but not identical, positions to those of the mouse gene. The identification of a human P2 promoter is significant because no P2-specific human PTHR complementary DNAs have been isolated to date. Southern analysis of genomic DNA from seven PHP1b patients did not reveal any rearrangements in proximal promoter regions or exons encoding 5'-untranslated region sequences. No significant sequence differences were found in clones of normal and patient DNAs encompassing proximal promoter sequences, and untranslated region and signal sequence exons. Thus, in the seven PHP1b patients analyzed, no defects were identified that would influence initiation site selection, stability, or splicing of renal PTHR transcripts. These data indicate that the genetic defect(s) in PHP1b in these patients lies in distal enhancer elements of the gene, in an essential transcriptional regulator, or in some as yet unidentified cofactor required for renal PTH signaling.

Paternal somatic and germ-line mosaicism for a sex-determining region on Y (SRY) missense mutation leading to recurrent 46,XY sex reversal

Objective: To determine the etiology for recurrent 46,XY sex reversal in a family with two Swyer siblings. Design: Deoxyribonucleic acid (DNA) from peripheral lymphocytes and sperm were analyzed for duplication of the dosage sensitive sex locus (DSS) and for mutations in sex-determining region on Y (SRY). Setting: An academic teaching hospital. Patients: A family consisting of mother, father, and five phenotypic daughters, of which two were 46,XY sex-reversed females. Intervention: Deoxyribonucleic acid (DNA) extraction, polymerase chain reaction (PCR), Southern blotting, dosage densitometry, single-strand conformation polymorphism (SSCP), and sequencing. Main Outcome Measure: Comparison of control and subject DNA. Results: Deoxyribonucleic acid (DNA) analysis of SRY in genomic DNA from the 46,XY sexreversed siblings revealed identical missense mutations (T → G) in both sisters. Analysis of the SRY gene in paternal lymphocyte and sperm DNA revealed mosaicism for wild and mutant (T→ G) SRY sequences. SRY analysis of sperm DNA also demonstrated the same mosaicism for the T → G missense mutation. Conclusion: A postembryonic SRY mutation gave rise to paternal mosaicism for two distinct cell populations (SRY+/SRY-). The presence of a wild type SRY in the somatic cell line may account for a normal pattern of male sexual differentiation, whereas the presence of a mutated SRY in the germ line resulted in two 46,XY sex-reversed offspring. These results confirm a proposed mechanism for the condition of recurrent 46,XY sex-reversed females.

Deoxyribonucleic Acid Ploidy and the Clinical Pattern of Grade 2 Superficial Bladder Cancer

We attempted to find an objective and quantitative parameter that would enable us to differentiate between aggressive and nonaggressive grade 2 superficial transitional cell carcinoma of the bladder. This type of tumor belongs to a heterogeneous group, 30% of which behave aggressively by invading lamina propria and muscle tissue in the course of the evolution. The remaining 70% of tumors have less aggressive qualities, are nonprogressive and have a low recurrence rate. To date to our knowledge there is no way to differentiate between these 2 subpopulations of tumors. We performed a retrospective flow cytometric analysis of deoxyribonucleic acid (DNA) ploidy and cell cycle phases on primary and solitary formalin fixed and paraffin embedded tumor tissue. Of the 41 specimens studied 16 were aneuploid and 25 were diploid. Aneuploidy was associated with progressive disease and high mortality rates, particularly in patients who did not receive postoperative adjuvant intravesical instillation. DNA diploidy was equated with lack of mortality and a low progression rate. The use of intravesical bacillus Calmette-Guerin as an adjuvant postoperative treatment was associated with low recurrence rates. In this group elevated G2M percent and S phase fractions correlated with higher recurrence rates. DNA ploidy was a prognostic factor in stage Ta grade 2 bladder transitional cell carcinoma and should be considered as a complementary test to histopathological analysis. Adjuvant instillation with bacillus Calmette-Guerin is advised after transurethral resection of primary solitary aneuploid stage Ta grade 2 bladder transitional cell carcinomas and of primary solitary diploid tumors with elevated G2M percent and S phase fraction.

Inflammatory polyarthropathy and bone remodeling in HTLV-I Tax-transgenic mice.

Transgenic mice carrying the tax gene of human T-cell lymphotropic virus type I displayed a high prevalence of arthropathy. The percentage of affected animals increased with age, reaching a peak of 43% at 20 months. Southern analysis of deoxyribonucleic acid (DNA) from tissue samples indicated that disease development was related to tax copy number. Histopathologic evaluation of the ankle joints disclosed deep erosion of the synovial lining, fibrous tissue proliferation together with angiogenesis, mononuclear cell infiltration, and activation of osteoclasts. Radiologic examination confirmed joint involvement and revealed bone architecture modifications. The phenotype exhibited by the affected animals closely resembles that of seronegative arthritis in humans, and may indicate tax protein as a causal agent of arthropathy observed in HTLV-I infected individuals.

Molecular Cloning and Expression Analysis of the Human Rab7 GTP-ase Complementary Deoxyribonucleic Acid

Rab7 is a small GTP-ase localized on late endosomes, which regulates late endocytic membrane traffic in mammalian cells. Moreover it has been shown that this protein has a fundamental role in the cellular vacuolation induced by the cytotoxin VacA ofHelicobacter pylori.We report here for the first time the isolation of a cDNA encoding human Rab7 from a placenta cDNA library. The open reading frame for human Rab7 encodes a protein of 207 amino acids which exhibits high homology with the mouse, rat, and dog counterparts. Northern blot analysis of total RNAs isolated from different cell lines with a cDNA probe containing the entire open reading frame revealed two mRNA transcripts of 2.5 and 1.8 kilobases. The isolation of human Rab7 cDNA will allow further characterization of its function in normal and pathological states.

Azoospermia in a 46,xx/47,xxx phenotypic male

We report the unique case of a 34-year-old 46,XX/47,XXX man with complete masculinization and azoospermia. Analysis of the patient's deoxyribonucleic acid failed to detect the azoospermia factor (AZF) region. Lack of germ cell elements on subsequent testicular biopsy illustrates the importance of the AZF region for spermatogenesis. Discussion concerning the genetics of testicular and germ cell formation is undertaken in the context of the patient presented.

Flow-cytometric analysis of deoxyribonucleic acid content in advanced ovarian carcinoma: Its importance in long-term survival

OBJECTIVE: Our purpose was to evaluate the importance of deoxyribonucleic acid content to long-term survival from advanced epithelial ovarian carcinoma. STUDY DESIGN: Clinical and pathologic prognostic factors, including deoxyribonucleic acid content measured by means of flow cytometry, were analyzed for 282 patients. RESULTS: In 80% of the patients, the deoxyribonucleic acid patterns were nondiploid. In univariate analysis stage ( p < 0.0001), residual disease ( p < 0.0001), deoxyribonucleic acid index ( p = 0.01), and deoxyribonucleic acid ploidy ( p = 0.02) significantly predicted progression-free survival. In multivariate analysis stage ( p < 0.001), residual tumor ( p = 0.001), deoxyribonucleic acid ploidy ( p = 0.02), and deoxyribonucleic acid index ( p = 0.02) retained independent prognostic value. Residual disease and deoxyribonucleic acid content retained independent prognostic value for stage III tumors but not for stage IV tumors. CONCLUSION: Deoxyribonucleic acid analysis with flow cytometry provides prognostic information about long-term progression-free survival from advanced ovarian carcinoma and should be considered in the stratification processes of patients in future clinical trials. This prognostic information appears to be inversely related to tumor burden. (Am J Obstet Gynecol 1996;175:1217-25.)

Molecular typing of multi-drug resistant Shigella dysenteriae type 1 by plasmid analysis and pulsed-field gel electrophoresis

Recently, an outbreak of dysentery due to multi-drug resistant Shigella dysenteriae type 1 strains was reported along the coastal area of Kenya and shortly thereafter another outbreak appeared in the outskirts of Nairobi. We analysed 22 multi-drug resistant S. dysenteriae type 1 strains isolated from cases in the latter oubreak using plasmid deoxyribonucleic acid (DNA) profiles and pulsed-field gel electrophoresis of genomic DNA. All isolates were resistant to commonly available drugs including ampicillin, trimethoprim, sulphamethoxazole, chloramphenicol, tetracycline and streptomycin with minimum inhibitory concentrations >64 μg/mL, but were fully sensitive to gentamicin. Only 2 strains were resistant to nalidixic acid. Analysis of plasmid DNA and genomic DNA revealed that all 22 strains were clonally related. It is likely that the present outbreak was related to that on the coast, as suggested by the similarity in drug susceptibility data. The drug susceptibility and molecular epidemiological data provide a useful baseline for future monitoring of epidemic and endemic S. dysenteriae activity in East Africa.

Injectable cartilage using polyethylene oxide polymer substrates.

This study demonstrates that polyethylene oxide gels, which are biocompatible and biodegradable synthetic polymers, can be utilized for the encapsulation of isolated chondrocytes and maintenance of three-dimensional spatial support for new tissue development. Chondrocytes isolated from the glenohumeral and humeroradioulnar joints of a calf were added to a 20% polyethylene oxide solution in Ham's F-12 medium to generate a final cellular density of 10 x 10(6)/mL. The polymer-chondrocyte constructs were injected through a 22-gauge needle in 500-microliters aliquots subcutaneously in 12 nude mice and incubated for 6 and 12 weeks in vivo. Histologic and biochemical analyses including deoxyribonucleic acid and glycosaminoglycan quantitative analyses confirmed the presence of actively proliferating chondrocytes with production of a well-formed cartilaginous matrix in the transplanted samples. Control specimens from eight implantation sites consisting of chondrocytes alone or polyethylene oxide substrates did not demonstrate any gross or histologic evidence of neocartilage formation. These findings demonstrate the potential use of an injectable and moldable polymer substrate that can support cell proliferation and matrix synthesis after subcutaneous transplantation for neocartilage generation. The use of functional biologic tissue substitutes may serve as an alternative solution to current methods of augmentation or reconstruction of structural craniofacial contour deformities.

The factor V Leiden mutation may predispose women to severe preeclampsia

OBJECTIVE: A recent study showed that resistance to activated protein C may underlie some cases of severe preeclampsia. A common missense mutation in the factor V gene, the Leiden mutation, is the most frequent genetic cause of resistance to activated protein C. Our objective was to determine whether this mutation is more prevalent in patients with severe preeclampsia than in normotensive controls. STUDY DESIGN: Deoxyribonucleic acid was extracted from whole blood of 158 gravid women meeting criteria of The American College of Obstetricians and Gynecologists for severe preeclampsia and 403 normotensive gravid women. The polymerase chain reaction was used to amplify exon 10 of the factor V gene, followed by allele-specific restriction with Mnl 1 for mutation detection. Results were analyzed with a χ2 contingency table. RESULTS: No patients were homozygous for the Leiden mutation. Fourteen of 158 women with severe preeclampsia (8.9%) were heterozygous for the Leiden mutation compared with 17 of 403 normotensive gravid controls (4.2%). The difference in frequency between women with severe preeclampsia and normotensive controls was statistically significant, χ2 4.686, p = 0.03. CONCLUSIONS: Our data suggest that carriers of the factor V Leiden mutation are at increased risk for severe preeclampsia. Deoxyribonucleic acid analysis for the factor V Leiden mutation could serve as one component of a genetic screening profile for preeclampsia and other adverse pregnancy outcomes. Women who carry this mutation are at increased risk for deep venous thrombosis. Carriers of this common thrombophilic mutation may be identified so that adequate counseling regarding future contraceptive usage and effective thromboembolic prophylaxis during pregnancy and surgical procedures may be offered. (Am J Obstet Gynecol 1996;175:902-5.)

Relationship between protein kinase C and adenylyl cyclase activity in the regulation of growth hormone secretion by human pituitary somatotrophinomas.

To determine the potential role of protein kinase C (PKC) and its relationship to adenylyl cyclase activity in controlling growth hormone (GH) secretion by human pituitary somatotrophinomas. Twenty-eight somatotrophinomas were placed into cell culture, and the in vitro effects of the PKC activator 12-O-tetradecanoylphorbol 13-acetate (TPA) and the PKC inhibitor staurosporine on basal and GH-releasing hormone (GHRH)-stimulated GH secretion were examined. In addition, the influence of chronic exposure of cultured somatotrophinoma cells to TPA on the rate of inositol 1,4,5-trisphosphate production was determined. Each tumor was assessed for the presence of gsp oncogenes, and thus constitutive adenylyl cyclase activity, by direct sequence analysis of polymerase chain reaction-generated deoxyribonucleic acid. GH secretory responses of tumors with and without these oncogenes were compared. TPA consistently stimulated GH secretion by cultured somatotrophinoma cells. There was no difference in response between somatotrophinomas with and without gsp oncogenes, and the effects did not correlate with the variable stimulation exerted by GHRH. Tumors in which GHRH had no significant effect nevertheless responded to TPA. In combination, TPA and GHRH exerted additive stimulation. TPA treatment of cultured somatotrophinoma cells eventually resulted in suppression of inositol 1,4,5-trisphosphate production, probably reflecting down-regulation of membrane phosphatidylinositol hydrolysis, a second messenger system that also generates the endogenous PKC activator diacylglycerol. GHRH had no effect on phosphatidylinositol hydrolysis. In contrast to the effects of TPA, the PKC inhibitor staurosporine tended to reduce GH secretion, although this effect was not observed in all tumors examined. As with TPA, the effects of staurosporine did not correlate with presence or absence of gsp oncogenes. Furthermore, staurosporine did not reduce the stimulatory effects exerted by GHRH on GH secretion. These results demonstrate a role for the phosphatidylinositol-PKC second messenger cascade in controlling GH secretion by human pituitary somatotrophinomas. The results also show that the system operates relatively independent of intracellular adenylyl cyclase and, thus, protein kinase A.

Carcinoid tumor of the rectum

This study was designed to evaluate the clinical characteristics, surgical treatment, and outcome of carcinoid tumors of the rectum and to assess flow cytometry deoxyribonucleic acid (DNA) analysis as a potential prognostic factor for management of these tumors. Medical records, tumor registry database, and pathology slides were retrospectively reviewed. Flow cytometry DNA analysis was performed on archived specimens. One hundred nine patients with rectal carcinoid tumors underwent surgery between 1962 and 1987. Follow-up was available in 86 patients for a mean period of 12 years. Of 100 patients with tumors less than 2 cm, only one with a 1.5 cm ulcerated tumor developed liver metastases. Of nine patients with a tumor more than or equal to 2 cm, three with known liver metastases underwent rectal biopsy only, and three had rectal biopsy and laparotomy with biopsy of liver metastases. Three patients underwent radical resection. Following abdominoperineal resection, one patient died with local recurrence after 5 years, and one developed hepatic recurrence after 5.5 years and died at 9 years. One patient with coloanal anastomosis developed local and hepatic metastases seven years after surgery and died at ten years. No patients developed carcinoid syndrome. DNA ploidy did not correlate with metastases at presentation or recurrence of carcinoid tumor. Radical resection of rectal carcinoids with ulceration or size greater than or equal to 2 cm is associated with a poor prognosis; however, survival may be long term, even in the presence of metastatic disease. DNA ploidy does not appear to be a useful prognostic factor for rectal carcinoid tumors.

Development of a deoxyribonucleic acid (DNA) restriction fragment length polymorphism (RFLP) database for Punjabis in East Punjab, India

In response to continuing interest in obtaining reference deoxyribonucleic acid (DNA) analysis data for previously unstudied population groups, blood samples were collected from Punjabi individuals living in East Punjab, India. This first segment of our research is focused on restriction fragment length polymorphism (RFLP) analysis, with future segments anticipated for various polymerase chain reaction (PCR) based techniques. In this study, the samples were subjected to RFLP analysis using HaeIII, followed by hybridization with variable number tandem repeat (VNTR) probes for loci D2S44, D1S7, D10S28, D4S139, D17S79 and D5S110. The band sizes of the resulting patterns were estimated using an FBI imaging system. The resulting data were subjected to statistical analysis for conformity with Hardy-Weinberg expectations, first for the total population of Punjabis, and additionally for the subgroups of Sikhs and Hindus. The loci are highly polymorphic in all sample populations studied. Except for D5S110, there is no evidence for departure from Hardy-Weinberg equilibrium (HWE) for the VNTR loci in the population groups. In addition, there is little evidence of correlation between the alleles at any of the pairs of loci and no evidence of association across the six loci. Finally, the data suggest that a multiple locus VNTR profile would be rare in the Punjabi or either of its subgroups.

Molecular genetic differentiation between primary lung cancers and lung metastases of other tumors

When solitary pulmonary tumors are observed in patients with a history of cancer, differentiation between metastasis and primary lung cancer is crucial for appropriate therapy. Assuming that p53 mutations are conserved in metastases, mutation analysis of the p53 gene would be a valuable tool in differentiating metastases from primary carcinomas of the lung. In nine of 267 resected lung tumors, the origin of the lung tumor could not be defined histologically. Five patients had a history of colorectal carcinoma, one had a history of breast carcinoma, one had a history of soft-tissue carcinoma, and one had a history of head and neck carcinoma. One patient with a clear cell carcinoma of the lung had been surgically treated for both renal and thyroid cancer. Material from one patient with adenocarcinoma of the lung, histologically defined regional lymph nodes, and distant brain metastasis served as a control. We extracted deoxyribonucleic acid from the snap-frozen tissue of the unclassified lung tumors, from paraffin-embedded tissue of the previously removed primary cancers, and also from peripheral blood of the patients. Exons 2 to 11 of the p53 gene were amplified in separated polymerase chain reactions and directly sequenced. In all cases, the presence of germline mutations was excluded by analysis of peripheral blood deoxyribonucleic acid. The p53 mutation detected in the deoxyribonucleic acid of the lung tumor of the control patient proved to be conserved in the lymph nodes as well as in the brain metastasis. In two cases, the lung tumors exhibited a p53 mutation not present in the previously removed primary tumor and were therefore classified as new primary lung cancers. In five cases, the lung tumors proved to be metastases of the first tumor, exhibiting the identical p53 mutation. One of these lung tumor samples could be identified as a metastasis from the renal cancer, but the corresponding thyroid cancer material was different. For two cases, molecular analysis remained inconclusive. In one case, no p53 mutation could be found in the compared samples; in the other, no deoxyribonucleic acid could be extracted. Analysis of p53 mutations allowed exact classification in tumors for which standard methods failed to distinguish between metastasis or primary tumor. More than two thirds of lung tumors in patients with previous gastrointestinal carcinoma were revealed to be metastases, but second primary lung cancer could also be diagnosed. This diagnosis allowed correct surgical and adjuvant treatment of these patients. (J T HORAC C ARDIOVASC S URG 1996;111:827-32)

Tumor Proliferative Activity is Predictive of Pathological Stage in Clinical Stage a Nonseminomatous Testicular Germ Cell Tumors

Purpose Traditional histopathological features have failed to predict accurately the pathological stage of clinical stage A nonseminomatous germ cell tumors of the testis. Based on pilot studies in nonconsecutive patients at our university, we evaluated nontraditional risk factors (cell cycle analysis by flow cytometry, deoxyribonucleic acid analysis by single cell cytophotometry [image analysis] and assessment of proliferative activity by immunohistochemistry) combined with histopathological features in consecutive patients with clinical stage A nonseminomatous testis cancer. Materials and Methods Orchiectomy specimens from 105 consecutive patients with clinical stage A nonseminomatous germ cell tumors who underwent retroperitoneal lymph node dissection (76 with pathological stage A disease and 29 with proved metastasis) were recut, histopathologically reviewed, immunohistochemically stained with proliferation markers (for example Ki-67/MIB-1), and examined by flow cytometry and image analysis. Results After multiple logistic regression analysis, the G 2 M + S cell cycle fraction of the aneuploid tumor stemline was the most predictive parameter of pathological stage (p = 0.0004). Using a cutoff of 41 percent, patients with metastasis were predicted with a sensitivity of 71 percent. Of 61 patients with a G 2 M + S value of less than 41 percent, 53 had pathological stage A cancer (negative predictive value 87 percent). A low volume of embryonal carcinoma was predominant in patients at low risk for metastasis and MIB-1 immunohistochemical staining identified 23 percent of patients with pathological stage A tumor who were at extremely low risk for metastatic disease. Conclusions Assessment of tumor cell proliferation cannot classify accurately high risk patients at a clinically applicable level. However, identification of patients at low risk for metastasis by flow cytometry, immunohistochemical proliferation markers and volume of embryonal carcinoma may be possible at the 90 percent level. MIB-1 staining is able to classify patients at extremely low risk for metastasis. These parameters deserve further study, since identification of patients at extremely low risk for metastasis could potentially decrease overall morbidity in the management of clinical stage A nonseminomatous testis cancer.