Surgical wound morbidity in an austere surgical environment.

Surgical wound morbidity was analyzed for a U.S. military field hospital deployed to the Republic of Haiti in support of Operation New Horizons 1998. The purpose of the analysis was to determine if procedures performed in the field hospital had greater infectious risks as a result of the environment compared with historical reports for traditional hospital or clinic settings. Acceptable historical infection rates of 1.5% for clean surgical cases, 7.7% for clean contaminated cases, 15.2% for contaminated cases, and 40% for dirty cases have been noted. There were 827 operations performed during a 6-month period, with the majority of patients assigned American Society of Anesthesiologists Physical Status Classification class I or II. The distribution of these cases was: 72% clean cases, 5% clean contaminated cases, 4% contaminated cases, and 19% dirty cases. The overall wound complication rate was 3.6%, which included 5 wound infections, 11 wound hematomas, 8 superficial wound separations, and 6 seromas. The infectious morbidity for clean cases, the index for evaluation of infectious complications, was 0.8%, well within the accepted standards. There were two major complications that required a return to the operating room: a wound dehiscence with infection in an orchiectomy, and a postoperative hematoma with airway compromise in a subtotal thyroidectomy. There were no surgical mortalities. The infectious wound morbidity for operations performed in the field hospital environment was found to be equivalent to that described for the fixed hospital or clinic settings. No special precautions were necessary to ensure a low infection rate. The safety for patients undergoing elective surgical procedures has been established. Further training using these types of facilities should not be limited based on concerns for surgical wound morbidity.

Repression of somatostatin gene transcription mediated by two promoter silencer elements.

We report that expression of the somatostatin gene in pancreatic islets and in non-islet cells is negatively regulated by two proximal silencer elements, PS1 and PS2. Transient transfection assays showed that PS1 decreases somatostatin gene promoter activity stimulated by an upstream enhancer in the islet D-cell line RIN-1027-B2, but not in the islet B-cell line RIN-1046-38, whereas PS2 inhibits gene transcription both B- and D-cell lines. In BHK fibroblasts, both PS1 and PS2 independently inhibit somatostatin gene in non-islet cells. DNA-binding studies revealed that both PS1 and PS2 bind similar nuclear protein complexes in islet and non-islet cells (120 and 130 kDa). PS1 also binds a 100-kDa protein present in islet B- and D-cell lines. In addition, both PS1 and PS2 bind three D-cell-specific proteins (40, 43 and 45 kDa). These observations support a direct involvement of both positive and negative transcriptional control mechanisms in the regulation of the islet cell-specific expression of the somatostatin gene.

Impaired cyclic AMP-dependent phosphorylation renders CREB a repressor of C/EBP-induced transcription of the somatostatin gene in an insulinoma cell line.

Transcription factor CREB regulates cyclic AMP (cAMP)-dependent gene expression by binding to and activating transcription from cAMP response elements (CREs) in the promoters of target genes. The transcriptional transactivation functions of CREB are activated by its phosphorylation by cAMP-dependent protein kinase A (PKA). In studies of many different phenotypically distinct cells, the CRE of the somatostatin gene promoter is a prototype of a highly cAMP-responsive element regulated by CREB. We now report on a somatostatin-producing rat insulinoma cell line, RIN-1027-B2, in which transcription from the somatostatin gene promoter is paradoxically repressed by CREB. We find that CREB fails to transactivate a CRE-containing somatostatin-chloramphenicol acetyltransferase reporter even when coexpressed with the catalytic subunit of PKA. CAAT box/enhancer-binding protein beta (C/EBP beta) and C/EBP-related activating transcription factor bind to the CRE in the promoter of the somatostatin gene and transactivate transcription. CREB binds competitively with C/EBP beta to the somatostatin CRE in vitro and represses C/EBP beta-induced transcription of the CRE-containing somatostatin-chloramphenicol acetyltransferase reporter. The lack of CREB-mediated transcriptional stimulation is due to the presence of a heat-stable inhibitor of PKA that prevents activation of PKA and subsequent CREB phosphorylation in the nucleus. These findings indicate that dephosphorylated CREB is a negative regulator of C/EBP-activated transcription of the somatostatin gene promoter in RIN-1027-B2 cells.

The use of generalized cell-survival data in a physiologically based objective function for hyperthermia treatment planning: a sensitivity study with a simple tissue model implanted with an array of ferromagnetic thermoseeds.

PURPOSE: A physiologically based objective function for identifying a combination of ferromagnetic seed temperatures and locations that maximizes the fraction of tumor cells killed in pretreatment planning of local hyperthermia. METHODS AND MATERIALS: An objective-function is developed and coupled to finite element software that solves the bioheat transfer equation. The sensitivity of the objective function is studied in the optimization of a ferromagnetic hyperthermia treatment. The objective function has several salient features including (a) a physiological basis that considers increasing the fraction of cells killed with increasing temperatures above a minimum therapeutic temperature (Tmin,thera), (b) a term to penalize for heating of normal tissues above Tmin,thera, and (c) a scalar weighting factor (gamma) that has treatment implications. Reasonable estimates for gamma are provided and their influence on the objective function is demonstrated. The cell-kill algorithm formulated in the objective function is based empirically upon the behavior of published hyperthermic cell-survival data. The objective function is shown to be independent of normal tissue size and shape when subjected to a known outer-surface, thermal boundary condition. Therefore, fractions of cells killed in tumors of different shapes and sizes can be compared to determine the relative performance of thermoseed arrays to heat different tumors. RESULTS: In simulations with an idealized tissue model perfused by blood at various rates, maxima of the objective function are unique and identify seed spacings and Curie-point temperatures that maximize the fraction of tumor cells killed. In ferromagnetic hyperthermia treatment planning, seed spacing can be based on maximizing the minimum tumor temperature and minimizing the maximum normal tissue temperature. It is shown that this treatment plan is less effective than a plan based on seed spacings that maximize the objective function. CONCLUSIONS: It is shown that under the assumptions of the model and based on a desired therapeutic goal, the objective function identifies a combination of thermoseed temperatures and locations that maximizes the fraction of tumor cells killed.

Effect of interseed spacing, tissue perfusion, thermoseed temperatures and catheters in ferromagnetic hyperthermia: results from simulations using finite element models of thermoseeds and catheters.

Finite element heat-transfer models of ferromagnetic thermoseeds and catheters are developed for simulating ferromagnetic hyperthermia. These models are implemented into a general purpose, finite element computer program to solve the bioheat transfer equation. The seed and catheter models are unique in that they have fewer modeling constraints than other previously developed thermal models. Simulations are conducted with a 4 x 4 array of seeds in a multicompartment tissue model. The heat transfer model predicts that fractions of tumor greater than 43 degrees C are between 8 and 40% lower when seed temperatures depend on power versus models which assume a constant seed temperature. Fractions of tumor greater than 42 degrees C, in simulations using seed and catheter models, are between 3.3 and 25% lower than in simulations with bare seeds. It is demonstrated that an array of seeds with Curie points of 62.6 degrees C heats the tumor very well over nearly all blood perfusion cases studied. In summary, results herein suggest that thermal models simulating ferromagnetic hyperthermia should consider the power-temperature dependence of seeds and include explicit models of catheters.

Temperature-dependent versus constant-rate blood perfusion modelling in ferromagnetic thermoseed hyperthermia: results with a model of the human prostate.

Finite-element solutions to the Pennes bioheat equation are obtained with a model of a tumour-containing, human prostate and surrounding normal tissues. Simulations of ferromagnetic hyperthermia treatments are conducted on the tissue model in which the prostate is implanted with an irregularly spaced array of thermoseeds. Several combinations of thermoseed temperatures with different Curie points are investigated. Non-uniform, constant-rate blood perfusion models are studied and compared with temperature-dependent descriptions of blood perfusion. Blood perfusions in the temperature-dependent models initially increase with tissue temperature and then decrease at higher temperatures. Simulations with temperature-dependent versus constant-rate blood perfusion models reveal significant differences in temperature distributions in and surrounding the tumour-containing prostate. Results from the simulations include differences (between temperature-dependent and constant-rate models) in (1) the percentage of normal tissue volume and tumour volume at temperatures > 42 degrees C, and (2) temperature descriptors in the tumour (subscript t) and normal (subscript n) tissues including Tmax.t, Tmin.t and Tmax.n. Isotherms and grey-scale contours in the tumour and surrounding normal tissues are presented for four simulations that model a combination of high-temperature thermoseeds. Several simulations show that Tmin.t is between 1.7 and 2.6 degrees C higher and Tmax.n is between 2.1 and 3.3 degrees C higher with a temperature-dependent versus a comparable constant-rate blood perfusion model. The same simulations reveal that the percentages of tumour volume at temperatures > 42 degrees C are between 0 and 68% higher with the temperature-dependent versus the constant-rate perfusion model over all seed combinations studied. In summary, a numerical method is presented which makes it possible to investigate temperature-dependent, continuous functions of blood perfusion in simulations of hyperthermia treatments. Simulations with this numerical method reveal that the use of constant-rate instead of temperature-dependent blood perfusion models can be a conservative approach in treatment planning of ferromagnetic hyperthermia.

Molecular feminization of mouse seminal vesicle by prenatal exposure to diethylstilbestrol: altered expression of messenger RNA.

Exposure to estrogens during critical stages of development has been reported to cause irreversible changes in estrogen target tissues such as the reproductive tract. In fact, recent studies using mice describe prenatal estrogen exposure resulting in the expression of the major estrogen-inducible uterine secretory protein, lactoferrin (LF), by the seminal vesicles of the male offspring. Thus, we have studied the role of estrogens in abnormal and normal gene expression in the developing male reproductive tract using LF and seminal vesicle secretory protein IV (SVS IV), an androgen-regulated murine seminal vesicle secretory protein, as markers. Lactoferrin and SVS IV protein and mRNA expression were studied in histological samples by using the techniques of in situ hybridization (ISH) and immunohistochemistry (IHC). Seminal vesicle secretory protein IV was expressed in all (100%) epithelial cells of the control seminal vesicle, but this protein was decreased by castration. However, LF expression was undetectable by ISH or IHC in control seminal vesicle epithelium. Lactoferrin was inducible in 2% of the seminal vesicle epithelial cells from adult castrated mice treated with estradiol 17 beta (E2; 20 micrograms/kg/day for 3 days), indicating that a small percentage of the seminal vesicle cells could be induced to secrete LF after modification of the endocrine environment. Prenatal DES treatment (100 micrograms./kg. maternal body weight on days 9 through 16 of gestation) resulted in the male offspring exhibiting constitutive expression of LF in 5% of the seminal vesicle epithelial cells, while expression of the androgen-regulated protein SVS IV was slightly decreased. The maximal contrast between LF and SVS IV expression was observed in prenatally DES-treated mice that were subsequently castrated as adults and further treated with E2; LF was detected in 40% of the epithelial cells in these mice. Double immunostaining techniques revealed that epithelial cells which were making LF had ceased production of SVS IV. Since a large percentage of the epithelial cells in the intact prenatal DES exposed male was capable of expressing the normal gene product, SVS IV, it was concluded that DES treatment during prenatal development appears to imprint or induce estrogenic sensitivity in the adult seminal vesicle, causing increased production of LF. The results suggest that this altered protein response may be an example of atypical gene expression in male reproductive tract tissues following hormonal manipulation early in development.

Fluctuations of lactoferrin protein and messenger ribonucleic acid in the reproductive tract of the mouse during the estrous cycle.

The physiological role of lactoferrin (LF), the major estrogen-inducible protein in the murine uterus, is unclear; however, LF may be a useful marker for the study of estrogen action in the uterus. Thus, the expression of LF mRNA and the localization of the protein in genital tract tissues and secretions of female mice (6-8 wk old) at different stages of the estrous cycle were investigated. Uterine luminal fluid (ULF) was analyzed for LF by means of gel electrophoresis and Western blot techniques; LF mRNA and protein were identified in reproductive tract tissues through in situ hybridization and immunocytochemistry. At diestrus, the level of LF mRNA was low, and staining for the protein was very light in uterine epithelial cells; LF was undetectable in ULF. At proestrus, LF mRNA and protein increased in the uterine epithelium and LF was readily detectable in ULF. LF mRNA and protein reached the highest levels at estrus. At early metestrus as compared to estrus, LF mRNA and protein were detected in decreasing amounts in uterine epithelial cells; the protein was undetected in ULF. By late metestrus and diestrus, LF mRNA and protein returned to a low level, and the protein was undetectable in ULF. LF protein was also demonstrated by immunocytochemistry in the epithelium of the oviduct, cervix, and vagina. LF protein fluctuation similar to that observed in the uterus was seen in these tissues; however, the uterus demonstrated the most dramatic changes in the number of epithelial cells involved in LF production during the estrous cycle. In summary, LF mRNA and its expression in uterine epithelial cells of the mouse varied with the stage of the estrous cycle. These results, combined with previously reported findings that LF is a major constituent of mouse ULF under the influence of estrogen, suggest that LF may play an important role in normal reproductive processes.

Evaluation of a fluorinated 2-nitroimidazole binding to hypoxic cells in tumor-bearing rats by 19F magnetic resonance spectroscopy and immunohistochemistry.

We have examined a hexafluorinated 2-nitroimidazole, CCI-103F, as a probe for hypoxic tumor cells by in vivo 19F magnetic resonance spectroscopy (MRS). Following initial intraperitoneal injections of the drug in tumor-bearing (Dunning R3327-AT1-Matlylu) rats, 19F spectra were obtained on an Otsuka 2.0T Vivospec spectrometer using a 1.5-cm surface coil. Signal at 1- and 2-h time points indicated initial biodistribution of drug in the tumor. At 4 and 8 h, a progressive increase in signal intensity was observed, indicating retention of drug within the tumor. Tumor signal remained detectable in 4 of 10 rats at 24 h, indicating possible nitroreductive bioactivation by hypoxic cells. Immunohistochemistry of these tumors revealed a staining pattern consistent with labeling of hypoxic cells. No detectable 19F signal was found at 24 h for the other rats, indicating complete washout of unbound drug. Immunohistochemical assessment of these tumors revealed some staining for bound drug at the periphery of necrotic zones. 31P-MRS of the tumors showed good correlation with the presence or absence of hypoxia as evaluated by 19F-MRS, T1- and T2-weighted images, and immunohistochemistry. These results provide the groundwork for further studies using this misonidazole analog for noninvasive identification of hypoxic tumor cells in vivo by MRS.

The mechanism of ICI 164,384 antiestrogenicity involves rapid loss of estrogen receptor in uterine tissue.

The antiestrogen ICI 164,384 (ICI) binds the estrogen receptor (ER) with approximately 20% the affinity of estradiol, but without the partial agonistic effects caused by tamoxifen. Investigations into the mechanism of ICI action have used ER molecules expressed in vitro to examine the binding of ER to ICI and the capacity of ICI-ER complexes to dimerize and bind to the estrogen response element (ERE). Our objectives were to study the biological effects, cellular distribution, and ERE-binding capacity of native uterine ICI-ER complexes after ip injection of 1 mg/kg ICI into 10-day castrate adult female mice. Synthesis of DNA and progesterone receptor were measured as end points of agonistic activity. ICI failed to stimulate either DNA or progesterone receptor synthesis above control levels, and pretreatment with ICI for 0.5 h reduced the stimulatory effect of estradiol by 75%. Measurement of uterine nuclear ER and cytosolic levels by exchange binding assay indicated a reduction in total ER levels within 0.5 h after ICI treatment, which remained below 20% for 24 h. Cycloheximide treatment did not block the ICI effect. Western blot analysis, immunohistochemistry, and steroid autoradiography confirmed the loss of ER protein. The ICI effect on ER was also demonstrable in vitro in the mouse TM4 estrogen-responsive cell line. ICI dramatically reduced ER levels to 5% of the control value by 4 h. Northern analysis indicated that ICI did not affect ER message levels, suggesting that the observed reduction in ER did not occur at the level of transcription. Gel shift assays indicated a low, but detectable, amount of ICI-ER binding to the vitellogenin A2 (VitA2) ERE. These results suggest that, although the ICI-ER complex binds weakly to DNA, ICI may cause its antagonistic effect by producing a rapid disappearance of the ER from the target tissue, resulting in an insufficient amount of ER to bind the native ligand and elicit agonist responses.

Expression and localization of androgen receptor in the R-3327 Dunning rat prostatic adenocarcinoma.

The Dunning R-3327 rat prostatic adenocarcinoma and its sublines have been developed as a model system to study prostate tumor progression. We have used this system to study the changes in androgen receptor (AR) and AR mRNA expression which occur during tumor progression from androgen dependent to androgen independent growth. Dorsal prostate and all tumor sublines contained a 10-kilobase AR mRNA on Northern blot analysis. The levels of AR mRNA in each subline compared to dorsal prostate (100%) were: H (75%) greater than G (48%) greater than HI (25%) greater than HI-F = AT-1 = AT-3 = MAT-Lu = MAT-Ly-Lu = less than 5%. Immunocytochemistry showed AR predominantly in acinar epithelial cells of dorsal prostate and the androgen sensitive H subline. In the H subline, both acinar epithelial cells and locally invasive adenocarcinoma cells within the stroma showed positive immunostaining. The androgen responsive, anaplastic G subline also showed strong positive immunostaining. The androgen resistant AT-1 and MAT-Lu sublines lacked immunostaining for the AR. Steroid autoradiography revealed a similar cellular distribution of AR. These data suggest that in the Dunning system the loss of androgen binding and responsiveness is primarily due to selective changes in gene expression and not to gene rearrangements or posttranscriptional or translational modification of the AR mRNA or protein.

Bimodal nuclear estrogen receptor binding: synchrony in athymic mouse uterus and human breast tumor xenografts.

Human MCF-7 tumors were transplanted into ovariectomized female athymic nude mice supplemented with estradiol pellets. Ten days after hormone pellet removal, the animals were treated with 10 micrograms/kg estradiol, and the nuclear estrogen receptor (ERn) profile was assessed by the exchange assay. The pattern in the tumors was qualitatively similar to that in the uterus. A bimodal pattern of ERn was seen, with peaks at 1 and 8 h. Further biochemical analysis of uterine samples showed that both peaks were comprised of similar levels of salt-resistant ERn forms. Scatchard plot analysis of estradiol binding demonstrated high affinity receptors (Kd = 0.73-0.86 nM) as components of both peaks. In the ovariectomized adult rat there was also a bimodal pattern of ERn 1 and 13-14 h after the injection of 20 micrograms/kg estradiol. Direct hormone stimulation of the uterus was achieved with intraluminal (IL) injection of estradiol. IL injections of estradiol (100-800 pg/horn) stimulated uterine DNA synthesis compared to IL saline injections in the contralateral horn. IL injection of 200 pg/horn estradiol resulted in a bimodal pattern of ERn at 3 and 9 h. These data indicate that a bimodal pattern of ERn is present in estrogen target tissues exhibiting a growth response.

Structure and regulation of the immediate-early frog virus 3 gene that encodes ICR489.

To test whether the promoters of two immediate-early genes from frog virus 3 were similar in nucleotide sequence, we have cloned and sequenced an immediate-early gene encoding an infected-cell mRNA of 489 kilodaltons (ICR489) and have shown that the protein product of this gene is approximately 46 kilodaltons. The 5' and 3' ends of the transcripts from this gene, as determined by mung bean nuclease analysis, were microheterogeneous. The promoter region was subcloned upstream from a promoterless chloramphenicol acetyltransferase gene, forming the recombinant plasmid pBS489CAT. As with the previously sequenced frog virus 3 immediate-early gene encoding ICR169, expression of chloramphenicol acetyltransferase in transfected cells required activation by a virion-associated protein. Although the promoter region of the gene encoding ICR489 contained TATA, CAAT, and GC motifs similar to those of typical eucaryotic promoters, it showed no significant homology to the ICR169 promoter, indicating that the concomitant temporal expression of these two genes is not due to similar promoter sequences.

Androgen regulation of c-myc messenger ribonucleic acid levels in rat ventral prostate.

Androgens regulate growth of the rat ventral prostate gland. In a search for possible mediators of androgen stimulated growth we have studied c-myc proto-oncogene expression in ventral prostate after androgen withdrawal and replacement. Steady state levels of c-myc mRNA were determined by Northern hybridization and compared with mRNA levels for prostatein, the major androgen dependent protein of ventral prostate. C-myc mRNA in ventral prostate increased nearly 4-fold within 1 day and 6- to 7-fold within 2 days after castration. Administration of androgen at the time of castration prevented this increase in c-myc mRNA levels. Androgen treatment of 4-day castrate rats caused c-myc mRNA levels to decrease within 4 h. Cycloheximide increased c-myc mRNA severalfold within 2 h. The net increase in c-myc mRNA after cycloheximide treatment was greater in the castrate than in the noncastrate or in androgen-treated castrate rats. These results suggest that androgen may influence both transcription and turnover of c-myc mRNA. Prostatein C3 mRNA decreased rapidly after castration and increased after androgen treatment of the castrate but was only slightly influenced by cycloheximide. Steady state levels of c-myc mRNA were higher in the 10-day-old rat and decreased with age while prostatein C3 mRNA increased with age. In situ hybridization demonstrated that both c-myc and prostatein mRNAs are expressed in the epithelial cells of ventral prostate acinar glands. These data indicate that androgens regulate the expression of c-myc in the ventral prostate.

Interstitial laser photochemotherapy of rhodamine-123-sensitized rat glioma.

The effect of interstitial laser photochemotherapy with the mitochondrial-specific intravital dye rhodamine-123 (Rh-123) was studied using a malignant rat glioma model system (RT2). Tumors were transplanted subcutaneously into the flank of athymic mice and into the cerebrum of adult rats. The Rh-123 photosensitization was produced by direct intratumoral injection of Rh-123 into the mouse RT2 flank tumors and by intravenous Rh-123 administration to adult rats with implanted RT2 intracerebral tumors. Intratumoral irradiation with 150 mW of argon laser light for an exposure time of 15 minutes was performed using a conical sapphire-tipped quartz optical fiber. Control groups of animals received either no treatment, Rh-123 injections, or administration of 150 mW of argon laser light for 15 minutes. Both flank and intracerebral tumors showed progressive diminution in size after treatment with Rh-123 photochemotherapy. There was no evidence of tumor recurrence in 60% of Rh-123 photochemotherapy-treated tumors. Recurrences in tumors treated with Rh-123 photochemotherapy usually appeared at the periphery of the original tumor at 10 days after treatment. Histologically, photochemotherapy-treated intracerebral tumors showed progressive shrinkage with increasing tumor necrosis over time. The finding of residual or recurrent tumor at the periphery of the original tumor mass suggests that the lack of penetration of the blue-green (argon) light was responsible for preventing complete tumor ablation. Our results suggest that Rh-123 photochemotherapy can destroy malignant gliomas in vivo; however, the poor penetrability of the photoactivating blue-green light may limit the effectiveness of this treatment for large or extensively invasive tumors.

The epithelial origin of a stromal cell population in adenocarcinoma of the rat prostate.

Dunning R3327-H rat prostate adenocarcinoma cells, when grown in syngeneic (Copenhagen) rats or nude mice, produce tumors with prominent hypercellular stroma. The authors have previously demonstrated the presence of anomalous steroid-sensitive cells in both the epithelium and stromal compartments of this model system. In order to better understand the histogenesis of these cells, the authors studied samples of the tumor which were radiolabeled overnight with tritiated dihydrotestosterone (3H-DHT). Frozen sections of the tissues were thaw-mounted onto autoradiographic emulsion-coated slides to permit silver grain identification in association with nuclei of androgen-sensitive cells. Surprisingly, numerous silver grains were found to be associated with nuclei of large cells within the stroma. Therefore, these cells were termed "epithelioid" pending confirmation of their origin. To further define these cells and their relationship to the surrounding matrix, autoradiograms have now been examined immunohistochemically with antibodies directed against the basement membrane glycoprotein, laminin, as well as antibodies specific for intermediate cytoskeletal filaments. Following identification of acinar basement membranes, epithelioid cells were identifiable both in the stroma and in the acinar epithelial cell layer. Histochemical staining with acid phosphatase, a marker for prostatic epithelium, was performed and shown to be present in acinar epithelial cells as well as in epithelioid cells. Additionally, fluorescence-activated cell sorting was employed to characterize the DNA content of cell types within the H tumor. Epithelioid cells were found to be in highest concentration in an aneuploid peak with a ploidy of approximately 6N. The autoradiographic, immunohistochemical, cytometric, and ultramicroscopic studies suggest that 1) epithelioid cells are epithelial derived stromal cells; 2) these epithelioid cells arise by pathologic division of aneuploid neoplastic precursor cells of approximately 3N ploidy, which are found within the prostatic epithelium; and 3) the resulting 6N cells degrade the basement membrane locally, invade the stroma, and populate it. Here, they can be distinguished from fibroblasts by their size, acid phosphatase activity, and hormone receptor content. Thus, the term "epithelioid" is inappropriate; and these cells should be regarded simply as large neoplastic epithelial (LNE) cells. The presence of this cell type suggests that this tumor subline represents a useful naturally occurring model for the study of the initial stages of neoplastic transformation.

Analysis of changes in rat prostate carcinoma following hormone deprivation.

The R3327-H model of prostatic adenocarcinoma was employed for the study of the cellular changes that occur during induction, regression, and recurrence of prostate cancer after endocrine therapy. The present study was designed to compare the glandular and stromal elements of the relapse phase with the histologically distinct early and intermediate phases of tumor progression. Morphometric analysis revealed significant differences between all three groups in the percentages of total tumor occupied by the epithelial component. At all three time periods, high-power inspection of autoradiograms prepared after incubation of the tissues with radioactive dihydrotestosterone revealed large cells in the stroma, especially in the intermediate phase. Immunohistochemistry further revealed evidence of invasion across the prostatic acinar basement membranes by similar cells. These studies lead the authors to postulate a mechanism by which hormone-independent cells in the epithelium repopulate the stroma, causing a recapitulation of the original morphology of the tumor in the postremission period. They propose that prostate tumor response to estrogen therapy can be operationally defined in three phases: involution, rebound, and relapse. They infer that further knowledge of the timing of these phases may permit early selective use of specific therapeutic strategies which will be able to balance the clinical risk with the known behavior of the neoplasm during progression of the disease.

Transfer of chromosomal genes and plasmids in Bacillus thuringiensis.

A low frequency of chromosomal gene transfer from Bacillus thuringiensis to Bacillus cereus was detected by cell mating, with a tryptophan marker being the most frequently transferred gene among four that were tested. The process was resistant to DNase and was not mediated by cell filtrates. Among several B. thuringiensis subspecies tested, transfer was best with a derivative of B. thuringiensis subsp. kurstaki HD1, which lost several plasmids. All of the B. cereus recombinants contained at least one plasmid from the donor B. thuringiensis; frequently, it was a plasmid that encoded a protoxin gene. In matings with B. thuringiensis subsp. kurstaki HD1, a 29-megadalton plasmid that contained a ca. 2.5-kilobase region of homology with the chromosome was always transferred. No detectable transfer of chromosomal genes was found in B. thuringiensis subsp. kurstaki HD1 strains lacking this plasmid, suggesting that there may be chromosome mobilization.

Serum hormone levels among patients with prostatic carcinoma or benign prostatic hyperplasia and clinic controls.

This study sought to identify differences in serum hormone levels between prostatic cancer (CaP) patients, benign prostatic hyperplasia (BPH) patients, and clinic controls (CC). Serum testosterone, estradiol, and prolactin values were obtained from 35 CaP, 42 BPH, and 161 CC patients attending a single medical center between January 1984 and April 1985. Relative risk estimates adjusted for age and race were calculated to compare hormone values between each case group and the CC. The distributions of hormone values and the testosterone to estradiol (T/E) ratios were grouped into thirds with the lowest third forming the reference category. The relative risk estimates for BPH in the middle and high thirds of testosterone were greater than unity (1.26 and 2.10, respectively), whereas the relative risk estimates in the middle and high thirds of estradiol were less than unity (0.63 and 0.35, respectively). For the middle and high thirds of the T/E ratio, the relative risk estimates for BPH showed statistically significant three- to fourfold increases. Modest depression of serum testosterone and estradiol was noted for CaP patients compared to CC, although the differences were not statistically significant. This depression was interpreted to be a likely result of the malignant process rather than a cause of it, whereas the development of clinically evident BPH was felt to be a biologically plausible response to an elevated T/E ratio.

Androgen receptors detected by autoradiography in prostatic carcinoma and benign prostatic hyperplastic tissue.

Androgen receptor (AR) content in prostatic tissues from patients with either cancer or benign prostatic hyperplasia (BPH) is of interest from at least two standpoints: receptors may be a feature of the pathogenesis of these conditions, and they may be important to the management and prognosis of prostatic cancer patients. For these reasons, a quantitative autoradiographic assay for AR content in prostatic tissues has been developed. Application of autoradiography to rodent tissues yielded results that were highly correlated with those from biochemical assays. Thus, the autoradiographic analyses with human tissues reported in this paper were undertaken. Average AR content in 22 prostatic carcinomas was lower than that in tissues from 14 patients with BPH; the median values of the affinity index, the quantitative estimate of receptor content, were 7.0 and 12.0, respectively. For the cancer tissues, a trend of declining receptor content with advancing stage of disease appeared but was not statistically significant. No association between receptor content and degree of tumor aggressiveness as measured by Gleason score and MD Anderson score was evident. Patient age and race were not related to receptor content in either type of tissue.