Does wild-type p53 play a role in normal cell differentiation?

Inactivation of the p53 tumor suppressor gene plays a major role in malignant transformation. The central question in this issue is concerned with the understanding of the function of p53 in normal cells and its deregulation in cancer cells. Several in vitro and in vivo experimental models have indicated that induction of cells to undergo differentiation involve up-regulation in the expression of the p53. In the case of B cell differentiation, p53 was found to be involved in several steps of the differentiation pathway. The conclusion that p53 plays a role in normal development and differentiation in vivo is substantiated by the observation that p53 is expressed during embryonic development and is detected at low levels in a number of organs of adult mice. Accentuated levels of p53 in testes of adult mice, suggests that p53 plays a role in the meiotic process of spermatogenesis. B cell differentiation and spermatogenesis are biological pathways which normally involve DNA reshuffling and rearrangements. In accordance with the notion that p53 is associated with DNA repair it is tempting to speculate that at least in these physiological pathways p53 functions as a master gene that controls genome integrity.

Comparison of the immune response to recombinant gp120 in humans and chimpanzees

OBJECTIVE

To assess similarities and differences in antibody responses to recombinant (r) HIV-1IIIB gp120 in chimpanzees, previously protected from HIV-1 infection, and human volunteers immunized in connection with a Phase I clinical trial.

METHODS

Frozen sera from humans immunized with rgp120 from HIV-1IIIB and chimpanzees immunized with the same antigen or recombinant soluble gp160 were compared in a variety of serologic assays.

RESULTS

The magnitude of the antibody response to gp120 was similar in both species; however, the half-life of the antibody response to rgp120 was approximately 4.5 times longer in humans (9 weeks) than in chimpanzees (2 weeks). Antibodies to gp120 in both species were broadly cross-reactive with gp120 from diverse isolates of HIV-1 and were effective in blocking the binding of gp120 to CD4. Antibody binding to native gp120 was greater than to denatured gp120 in both species. Antibody responses to the principal neutralizing determinant (V3 domain) and virus neutralization titers were approximately 10-fold lower in humans than chimpanzees. The relative avidity of antibody binding to gp120 was higher in the sera from the immunized chimpanzees than in the immunized humans.

CONCLUSIONS

While the antibody responses to rgp120 elicited in man and chimpanzees were in many ways similar, significant differences did occur. Predictions made on the basis of chimpanzee immunogenicity studies over-estimated the potency of the virus neutralizing titers and under-estimated the duration of the antibody response achieved in humans.

Outcome of the treatment for sarcoidosis

The clinical characteristics and pathology of sarcoidosis are well defined; however, the optimal therapy for this disorder remains unclear. Although patients respond, acutely, to corticosteroid therapy, it is not clear that these agents ultimately alter the natural history of this disease. These observations and that corticosteroids have significant side effects suggest that only patients who will clearly benefit from corticosteroid therapy should be treated. In a prospective study of patients' with sarcoidosis (n = 98), we limited our use of corticosteroids to those patients who had objective evidence of recent deterioration in lung function or serious extrapulmonary disease. All patients with sarcoidosis fulfilling these criteria were treated with corticosteroids. Patients were tapered off corticosteroids after they were treated for 1 yr. Of the 98 study subjects, 91 had not received therapy for the disease and 7 were on therapy before entry into the study. Of the 91 previously untreated patients, 55 were observed without therapy and 36 were treated with corticosteroids. Of those who were observed off therapy, only eight deteriorated. Of these latter patients, six responded and stabilized with the administration of corticosteroids for treatment of the underlying disease, to antibiotics for an associated bronchiectasis, or to diuretics for treatment for congestive heart failure; two were lost to follow-up. None of these six patients deteriorated while receiving corticosteroids. Of the 36 patients who deteriorated and were treated with corticosteroids, 20 remained stable and 16 improved clinically. Of the 37 patients who were eventually tapered off corticosteroids, five deteriorated and required reinitiation of corticosteroid therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Transplantation of hepatocytes: an in-vitro and in-vivo study in canines

We isolated and transplanted hepatocytes in the canine, large animal model to evaluate hepatocyte yield and purity as well as the optimal site for hepatocyte engraftment (i.e., the spleen or the portal bed). We obtained viable, pure, single hepatocyte suspensions that were readily preserved at 4 degrees C in University of Wisconsin (UW) solution for up to 3 days. Both intrasplenic and portal vein injection were well tolerated, with minimal recipient morbidity and mortality when 1-2 x 10(9) hepatocytes were injected into immunosuppressed allogeneic hosts. We noted the embolization of hepatocytes into the parenchyma of the native liver within 7 days of intrasplenic transplantation that produced a mild reversible derangement of liver function and histology. These results warrant consideration prior to clinical trials of hepatocyte transplantation in man.

Selective chemical modification of Cys264 with diiodofluorescein iodacetamide as a tool to study the membrane topology of cytochrome P450scc (CYP11A1)

Cys264 of cytochrome P450scc (CYP11A1) was selectively labelled with diiodofluorescein iodacetamide in solution and in proteoliposomes. The labelling affected the interaction of P450scc with adrenodoxin and significantly inhibited the side-chain cleavage activity of the soluble and membrane-bound hemeprotein in the reconstituted system. In proteoliposomes both the labelled and unlabelled hemeproteins were susceptible to trypsin and split into F1 and F2, two fragments corresponding to the two main domains of P450scc. These results suggest that the hinge connecting the two domains in the region Arg250-Asn257 is exposed to the surface of the membrane and involved in the interaction of P450scc with adrenodoxin.

Iron-regulated proteins in outer membranes of Campylobacter jejuni diarrhoea isolates and immune response to the proteins in patients

The outer membrane protein (OMP) profiles from 8 Campylobacter jejuni and 5 Campylobacter coli fecal isolates grown under various conditions were compared by SDS-PAGE. The bacteria were grown under usual conditions, in iron-deficient medium (Dip) and on iron-supplemented medium (Fe). The OMP profiles of most bacterial strains grown under usual conditions, or in the Fe-supplemented medium, contained four major bands of approximately 31, 45, 63-66 and 97 kDa, and in addition, a number of minor bands. It was found that OMP from 10 of 13 strains tested and grown on iron deficient medium contained an intensive band of a protein in the molecular weight region of 76 kDa which was lacking in the OMP of bacteria grown in the presence of iron (iron-regulated protein). Sera from 11 children with C. jejuni infection analyzed by Western blot recognized the 76 kDa bands, in contrast to only one out of 10 control sera from healthy children. The Western-blot experiments demonstrated also various bands of other OMP components, both in OMP-Dip and OMP-Fe. The 45 kDa (porin protein) was recognized by all 11 serum samples from C. jejuni-infected patients and in 8 out of 10 control sera. The data suggested that the 76 kDa iron-regulated protein was expressed by bacteria during infection and it stimulated the immune response in children infected with C. jejuni.

Safety and immunogenicity of a fully glycosylated recombinant gp160 human immunodeficiency virus type 1 vaccine in subjects at low risk of infection. National Institute of Allergy and Infectious Diseases AIDS Vaccine Evaluation Group Network

Recombinant gp160 derived from human immunodeficiency virus type 1 (HIV-1)IIIB and produced in mammalian tissue culture cells using a vaccinia virus expression system (rgp160-mam) was evaluated as a vaccine in combination with alum and deoxycholate adjuvant. Sixty low-risk, uninfected subjects received 12.5 micrograms, 50.0 micrograms, or adjuvant control at 0, 1, 6, and 12 months in a randomized, double-blind dose-escalation study. A single injection of 200 micrograms of vaccine was given at 18 months in an open study to 9 vaccines who had received 50 micrograms. The vaccine was safe. Six of 16 subjects receiving 50 micrograms developed neutralizing antibody to HIV-1IIIB. Seven of the 9 boosted with 200 micrograms of vaccine at 18 months developed neutralizing antibodies. Lymphocyte proliferation to rgp160-mam and baculovirus-derived rgp160 and rgp120 was induced in both groups (12.5 and 50.0 micrograms) and appeared after the first dose. Further studies with higher doses of rgp160-mam and vaccines derived from other strains of HIV-1 are warranted.

The emergence of chronic peer victimization in boys' play groups

This investigation utilized a contrived play group procedure to examine the behavioral patterns leading to chronic victimization by peers in middle childhood. 30 play groups, each of which consisted of 6 unacquainted African-American 6-year-old or 8-year-old boys, met for 45-min sessions on 5 consecutive days. Play group interactions were videotaped and then examined. 13 boys who came to be chronically victimized by their play group peers were identified, along with matched nonvictim contrasts. Victims demonstrated lower rates of assertive behaviors, such as persuasion attempts and social conversation initiatives, and higher rates of nonassertive behaviors, such as submissions to peers' social initiatives, than contrasts. This nonassertive behavior pattern appears to have preceded the development of chronic victimization. Children who eventually emerged as victims were pervasively submissive, beginning in the initial 2 sessions. However, marked individual differences in victimization by peers did not become apparent until the final 3 sessions. These data provide evidence of strong linkages between submissive social behavior and the emergence of chronic victimization by peers.

Self- and spouse ratings of anger and hostility as predictors of coronary heart disease

Self- and spouse ratings of anger and hostility were examined as predictors of coronary heart disease (CHD) in 185 cardiac patients. Patients completed the Multidimensional Anger Inventory (MAI) and the Marlowe-Crowne Social Desirability (MCSD) Scale; the MAI (rewritten to 3rd person) was completed by patients' spouses or by a peer. Thallium scans were used to measure CHD status. Results showed that patient-rated MAI scores were inversely correlated with MCSD. There were no gender differences for patient-rated MAI scores, but spouse ratings showed gender effects for Anger-Arousal and Hostile Outlook: Women rated their husband higher than men rated their wife. Patients with positive thallium scans were no different from those without CHD on patient-rated MAI scores; however, spouse ratings indicated that those with CHD had higher Hostile Outlook and Anger-In scores. After accounting for the effects of traditional CHD risk factors, only spouse-rated hostility contributed significant incremental variance to the prediction of CHD status.

Mice with reduced levels of p53 protein exhibit the testicular giant-cell degenerative syndrome

Transgenic mice which carry hybrid p53 promoter-chloramphenicol acetyltransferase (CAT) transgenes were found to express CAT enzymatic activity predominantly in the testes. Endogenous levels of p53 mRNA and protein were lower than in the nontransgenic control mice. The various p53 promoter-CAT transgenic mice exhibited in their testes multinucleated giant cells, a degenerative syndrome resulting presumably from the inability of the tetraploid primary spermatocytes to complete meiotic division. The giant-cell degenerative syndrome was also observed in some genetic strains of homozygous p53 null mice. In view of the hypothesis that p53 plays a role in DNA repair mechanisms, it is tempting to speculate that the physiological function of p53 that is specifically expressed in the meiotic pachytene phase of spermatogenesis is to allow adequate time for the DNA reshuffling and repair events which occur at this phase to be properly completed. Primary spermatocytes which have reduced p53 levels are probably impaired with respect to DNA repair, thus leading to the development of genetically defective giant cells that do not mature.

Poor survival of black patients in carcinoma of the endometrium

PURPOSE

To compare the prognostic factors and survivals of black and white patients with endometrial carcinoma.

METHODS AND MATERIALS

A retrospective study was undertaken of a total of 290 patients with endometrial carcinoma who were treated similarly at the Health Science Center at Brooklyn and Kings County Hospital Center from 1975 and 1990. One hundred and thirty-six of 290 (47.2%) were black and 135/290 (46.9%) were white. Well-known prognostic factors affecting endometrial carcinoma were studied in black and white group of patients. Their overall survival and comparison of survival in each prognostic group were also estimated using multi-variate analysis.

RESULTS

Fifty-four percent of white patients had Stage I disease, compared to 45.9% in black patients. In Stage II, 51.6% were white and 48.4% were black, and in Stage III, 88.89% were black and 11.1% were white patients (p = 0.034). Fifty six percent Grade 1 patients were white and 44% were black. In Grade 2, 53.3% were white and 46.7% were black and in Grade 3 disease, 70.5% were black and 29.5% were white (p = 0.008). Up to the inner third of myometrial invasion had occurred in 60.6% of white patients and 39.4% in black patients. The middle third of the myometrium was invaded in 60.7% of white patients, and 39.3% of black patients. Thirty-seven percent of outer third of myometrial invasion was found in white patients and 63% in black patients (p = 0.038). Seventy-two percent of positive lymph nodes were found in black patients and 28.0% in white patients (p = 0.01). Sixty-one percent of patients with positive peritoneal cytology were black as compared to 38.7% in white patients (p = 0.017). The overall ten-year corrected survival for white and black patients was 72% and 40%, respectively (p = 0.0003). Survivals comparisons, when stratified by race and each prognostic group, showed statistically significant overall survival differences in favor of white patients.

CONCLUSION

Black patients with endometrial carcinoma have poor survival. Low socio-economic status (SES) would not explain these findings. More research is required to determine the cause of poor survival in black patients with endometrial carcinoma.

Plasmid profiles and antimicrobial susceptibility of Campylobacter jejuni isolated from Israeli children with diarrhea

Thirty Campylobacter jejuni (C. jejuni) strains isolated from stools of Israeli children with enteritis were tested for sensitivity to eight antimicrobial agents (MIC) and the presence of plasmids. It was found that all the isolates were sensitive to ciprofloxacin, ofloxacin, furazolidone and erythromycin. Of the 30 strains tested, 21 (70%) were found to be tetracycline-resistant, a relatively high resistance rate as compared with data from other countries and previous reports from Israel. Plasmids were detected in 17 out of 30 C. jejuni isolates (55.6%). A total of nine different plasmid profiles could be distinguished; six profiles were represented by one strain each. Of the 21 tetracycline-resistant strains, plasmids were found in 17 isolates (80%) carrying from 1-2 to 5 plasmids of various sizes. No plasmids were found in tetracycline-sensitive strains, with the exception of one isolate which contained a 24.4 MDa plasmid and was co-trimoxazole-resistant. Our studies indicate a relatively high percentage of tetracycline-resistant C. jejuni isolates in the Tel Aviv area. In 80% of these strains, various plasmid profiles were detected.

Anaerobic bacteremia: a retrospective four-year analysis in general medicine and cancer patients

Anaerobic bacteremia was studied in 32 medical patients (mean age 72 years) in a four-year retrospective analysis. Malignancy was the most common underlying disease and probable portal of entry. The gastrointestinal tract was affected most often, followed by the respiratory and urinary tracts. Bacteremia occurred either following invasive (non surgical) procedures or spontaneously. The clinical course ranged from asymptomatic bacteremia, to mild febrile illness, to sepsis and septic shock (two, 12, 16 and two patients, respectively). The case fatality rate was 25%. The causative organisms were Clostridium and Bacteroides species. All organisms isolated were susceptible to chloramphenicol. Early diagnosis and prompt treatment may reduce mortality in cases of anaerobic sepsis.

Self- and spouse ratings of anger and hostility as predictors of coronary heart disease

Self- and spouse ratings of anger and hostility were examined as predictors of coronary heart disease (CHD) in 185 cardiac patients. Patients completed the Multidimensional Anger Inventory (MAI) and the Marlowe-Crowne Social Desirability (MCSD) Scale; the MAI (rewritten to 3rd person) was completed by patients' spouses or by a peer. Thallium scans were used to measure CHD status. Results showed that patient-rated MAI scores were inversely correlated with MCSD. There were no gender differences for patient-rated MAI scores, but spouse ratings showed gender effects for Anger-Arousal and Hostile Outlook: Women rated their husband higher than men rated their wife. Patients with positive thallium scans were no different from those without CHD on patient-rated MAI scores; however, spouse ratings indicated that those with CHD had higher Hostile Outlook and Anger-In scores. After accounting for the effects of traditional CHD risk factors, only spouse-rated hostility contributed significant incremental variance to the prediction of CHD status.

Expression of p53 protein in spermatogenesis is confined to the tetraploid pachytene primary spermatocytes

The various steps of differentiation and maturation in spermatogenesis are well characterized and offer a convenient system to explore the possibility that p53 plays a role in cell differentiation in vivo. In situ hybridization experiments indicate that the p53 gene is expressed in tetraploid primary spermatocytes at the meiotic pachytene stage of the first round of spermatogenesis in young mice. An analysis of spermatogenic cells treated with anti-p53 antibodies reveals that the p53 protein is expressed in a discrete tetraploid cell population, with size and cellular structure parameters characteristic of midpachytene spermatocytes. The specific kinetics of p53 expression in the first round of spermatogenesis and its localization in adult testicular sections, coupled with the fact that the protein is expressed in the largest cells with lower DNA density, suggest that p53 expression is confined to the tetraploid primary spermatocytes of the meiotic pachytene phase. These observations identify p53 protein as a potential member of the meiosis control protein family.

Immunoglobulin secretion by the normal and the infected newborn infant

The development of quantitative single-cell immunoassays has provided a novel opportunity to demonstrate the isotype-specific immunoglobulin responses in normal and infected neonates. The reverse enzyme-linked immunospot assay was used to determine the number of immunoglobulin-secreting cells (IgSCs) in peripheral blood. Baseline numbers of IgSCs were established in 69 uninfected term and preterm infants within 5 days of birth; values above the 99th percentile were considered elevated. The IgSCs were also measured in 266 infants with proved or suspected infections or congenital anomalies. A subset of newborn infants was retested weekly. Few IgSCs (mostly IgMSCs) were detected within 5 days of birth in uninfected neonates, but by 1 month 77% had increased numbers of IgSCs, primarily IgASCs. Sixty-three (24%) of 266 study infants had increased IgSCs on initial sampling (predominantly IgMSCs); these included infants as immature as 25 to 27 weeks of gestational age; elevations in IgSCs were most frequent in infants with intrauterine infections. Increased numbers of IgSCs were uncommon in infants with early-onset sepsis in the first 5 days but were frequent by the second week, consistent with acquisition of infection near the time of delivery. We conclude that the presence of elevated numbers of IgSCs soon after birth may be a useful surrogate marker of untreated intrauterine infection. The development of predominantly IgASCs in the first month of life suggests postnatal exposure to common mucosal antigens.

Clinical and serologic evaluation of neonates for congenital syphilis: a continuing diagnostic dilemma

Neonates born to women with reactive serologic tests for syphilis were studied; the total of 116 included 18 who were symptomatic, 60 asymptomatic but possibly infected, and 38 asymptomatic and probably uninfected. The fluorescent treponemal antibody-absorption (FTA-ABS) 19S IgM test and an IgM capture ELISA for Treponema pallidum, both treponema-specific assays, and the reverse enzyme-linked immunospot (RELISPOT), which detects immunoglobulin-secreting cells and is a nonspecific indicator of infection, were evaluated. Sensitivities among symptomatic neonates were 88% (IgM ELISA), 73% (FTA-ABS), and 78% (RELISPOT). Specificities ranged from 97% to 100%. A major problem has been the inability to identify which asymptomatic but possibly infected neonate is really uninfected. Among 41 such babies who had all three tests done, 93% were negative by all assays, suggesting they were uninfected or recently infected. Strategies to accurately identify the truly uninfected asymptomatic newborn would prevent the unnecessary hospitalization of all at-risk infants, resulting in improved quality of care and reduced costs.

Quantitative determination of pentane in exhaled air correlates with colonic inflammation in the rat colitis model

Oxygen radicals play a key role in inflammation and inflammatory tissue damage. Quantitative determination of pentane, a hydrocarbon generated by membrane lipid peroxidation initiated by oxygen radicals, in expired air has been used as a noninvasive determinant or index of inflammation in various conditions. Herein we report the first examination of the relationship between exhaled pentane and colonic inflammation in a rodent model of colitis. Colitis was induced in rats (n = 33) using the trinitrobenzene-sulfonic acid (TNB) model of colitis. Exhaled air was collected in a closed chamber on randomly selected animals on days 1, 2, 4, 7, 11, 13, 15, 20, and 25 post-TNB treatment, and pentane was assayed by means of gas chromatography. Gross and microscopic evidence of inflammation was compared with exhaled pentane levels. Pentane levels varied from 0.0 to 14.6 nmol/l of air and were significantly increased in TNB-treated rats compared with control rats only on days 7 to 15 after treatment (P < 0.05). Gross inspection showed severe colonic inflammation through the first week (mean score = 4.7 out of a possible 5), persistent inflammation on days 7 to 15 (3.2), and healing and fibrosis from the end of week two until day 25 (1.9 to 0). Histologic evaluation confirmed a progression of inflammation from acute ulceration to chronic inflammation to fibrosis and scarring. We have demonstrated that pentane exhalation is increased after the induction of colonic inflammation, with a seven-day lag time, and returns rapidly to normal as acute inflammation resolves. This suggests that pentane exhalation can be used as a noninvasive measure of colonic inflammation in rodent models of colitis and perhaps clinically in humans.

Testicular tissue-specific expression of the p53 suppressor gene

The hybrid transgene approach was adapted to study the physiological pathway(s) in which the p53 suppressor gene is involved. p53 promoter-CAT transgenic mice were found to express enzymatic CAT activity predominantly in the testes. In situ hybridization indicated that expression of the transgene as well as the endogenous p53 agreed with the typical wave and cycle patterns of spermatogenesis. p53 promoter-CAT transgenic mice expressed in the testes reduced levels of endogenous p53 mRNA that correlated with the copy number of the mouse or human transgene. The spatial and cyclical expression of the p53 gene which is confined to the primary spermatocytes in the seminiferous tubuli suggested that p53 may play a role in the meiotic process of spermatogenesis in vivo.

Endometrial carcinoma. Influence of prognostic factors on radiation management

The earliest intracavitary radium treatment for uterine cancer was reported in 1908. Refinements reported during the next 20 years, using an intrauterine tube and colpostats or radium capsules, established a treatment philosophy of preoperatively irradiating uterine and parauterine tissues. Thus, preoperative intracavitary irradiation became entrenched as therapy for all endometrial cancers for the better part of four decades. In the 1950s and 1960s, the ability of external irradiation to eradicate cancer in regional lymphatic vessels prompted the use of pelvic field irradiation in Stage II and III and recurrent disease. The results of surgical exploratory studies in the 1970s established more refined criteria for preoperative or postoperative external pelvic irradiation in high-grade infiltrating Stage I cancers. In the 1980s, it became apparent that, for tumors with lymphovascular invasion, clear cell, and serous papillary histologic types, the disease spread to the upper abdomen and the paraaortic nodes might benefit from extended field and/or whole abdominal irradiation, with or without systemic bolus or concomitant continuous-infusion chemotherapy. In the 1980s, a subset of patients was identified with high-grade lymphovascular invasion clear cell and papillary serous histologic types or with positive peritoneal cytologic findings who were at high risk of failing in the paraaortic nodes and/or the upper abdomen for whom extended field or whole abdominal irradiation have been advocated. Given the fraction and dose limitation for a large abdominal field, the addition of systemic concomitant bolus or continuous infusion of chemotherapy currently is proposed to improve the control of intraabdominal failure in these high-risk patients.