Reduced tumorigenicity of metastatic human lung cancer cell subline (PGCL3) transfected with hRAR beta gene

The recombinant PSG5-RAR beta plasmid and the G418-resistant PSV2 neo plasmid (10.1) were cotransfected into PGCL3 cells by coprecipitation with calcium phosphate. The transfectants CR3 and CR4, which expressed the RAR beta gene, were identified by Northern blot hybridization. The results showed that the in vitro growth and invasion of CR3 and CR4 were dramatically reduced compared to the control-transfected cell (CSV1). Furthermore, the colony-forming abilities in soft agar and the tumorigenicity in nude mice of CR3 and CR4 were abrogated. Our results suggests that RAR beta functions not only as a receptor mediating the RA action, but also as a suppressor in lung tumorigenesis.

Two new loci for hybrid sterility in cultivated rice (Oryza sativa L.)

Female gamete abortion in Indica-Japonica crosses of rice was earlier identified to be due to an allelic interaction at the S-5 locus on chromosome 6. Recently, in other crosses of rice, similar allelic interactions were found at loci designated as S-7 and S-8, located on chromosomes 7 and 6 respectively. All of them are independent of each other. At the S-5 locus, Indica and Japonica rice have S-5 (i) and S-5 (j) alleles respectively and Javanicas, such as Ketan Nangka, have a neutral allele S-5 (n) .The S-5 (i) /S-5 (j) genotype is semi-sterile due to partial abortion of female gametes carrying S-5 (j) , but both the S-5 (n) /S-5 (i) and S-5 (n) /S-5 (j) genotypes are fertile. The S-5 (n) allele is thus a "wide-compatibility gene" (WCG), and parents homozygous for this allele are called wide-compatible varieties (WCV). Such parents when crossed with Indica or Japonica varieties do not show F1 hybrid sterility. Wide-compatible parents have been used to overcome sterility barriers in crosses between Indica and Japonica rice. However, a Javanica variety, Ketan Nangka (WCV), showed typical hybrid sterility when crossed to the Indian varieties N22 and Jaya. Further, Dular, another WCV from India, showed typical hybrid sterility when crossed to an IRRI line, IR2061-628-1-6-4-3(IR2061-628). By genetic analyses using isozyme markers, a new locus causing hybrid sterility in crosses between Ketan Nangka and the Indicas was located near isozyme loci Est-1 and Mal-1 on chromosome 4, and was designated as S-9. Another new locus for hybrid sterility in the crosses between Dular and the IR2061-628 was identified and was found linked to four isozyme loci, Sdh-1, Pox-2, Acp-1 and Acp-2, on chromosome 12. It was designated as S-15. On the basis of allelic interactions causing female-gamete abortion, two alleles were found at S-9, S-9 (kn) in Ketan Nangka and S-9 (i) in N22 and Jaya. In the heterozygote, S-9 (kn) /S-9 (i) , which was semisterile, female gametes carrying S-9 (kn) were aborted. The hybrid of Dular and IR2061-628, with a genetic constitution of S-15 (Du) /S-15 (i) , was semi-sterile and the female gametes carrying S-15 (Du) were aborted. A Japonica tester variety, Akihikari, and an Indica variety, IR36, were found to have neutral alleles, S-9 nand S-15 n, at these loci, in addition to S-7 nand at S-7. The accumulation of three neutral alleles into a breeding line should help solve the hybrid sterility problem in wide crosses of rice.

Production of brevicin 286 by Lactobacillus brevis VB286 and partial characterization

Brevicin 286 was produced by Lactobacillus brevis VB286 isolated from vacuum-packaged meat and was partially purified by ammonium sulphate precipitation, gel filtration and dialysis. The bacteriocin was susceptible to proteolytic enzymes, stable to heating at 100 degrees C particularly under acidic against Listeria sp. Production of brevicin 286 was optimal during exponential growth at 20 degrees C. Higher rates of cell growth occurred between 30 and 37 degrees C but with little or no expression of brevicin 286. A food-grade formulation consisting of 4% yeast extract and 1% glucose was found to be adequate for optimal brevicin 286 production and the bacteriocin-containing culture supernate was successfully spray dried with full recovery of antibacterial activity in the resultant powder.

Toilet habits of children evaluated for urinary tract infection

The toilet habits of 77 girls and 24 boys who were evaluated after having a urinary tract infection were examined prospectively. Children with known urological conditions that can predispose to urinary tract infections were excluded. A voiding cystourethrogram and renal ultrasound were performed, and a diary of toilet habits was obtained for all patients. Six children were lost to followup. Of the remaining 95 children imaging studies were negative in 60 (negative imaging group) and positive in 35 (positive imaging group). Only 10% of the negative imaging group were without constipation or abnormal voiding compared to 60% of the positive imaging group (p = 0.0001). Toilet habits can affect the development of urinary tract infections. Our data suggest that the evaluation of urinary tract infection should include an inquiry into these habits. Among children with negative imaging studies there may be functional problems that promote the development of urinary tract infections.

Regional renal blood flow measurements using radioactive microspheres in a chronic porcine model with unilateral vesicoureteral reflux

95Niobium labeled radioactive microspheres were used to determine regional renal blood flows in a porcine model of chronic sterile vesicoureteral reflux. Unilateral vesicoureteral reflux was surgically created in 5 mini-pigs and regional renal blood flows were determined by microsphere injection 6 months later. The contralateral nonrefluxing kidney acted as a control. There was a significant reduction of flow in the inner cortical regions of the middle (78% of control, p < or = 0.0437) and lower poles (69% of control, p < or = 0.0274), and the juxta-medullary cortical region of the lower pole (67% of control, p < or = 0.0124). There was no difference in flow in the other regions or when comparing whole kidneys. There were no differences between refluxing and nonrefluxing kidneys when comparing ratios of inner to outer cortical flow level by level. These observations are in contrast to those in acutely created vesicoureteral reflux in a porcine model, which had no significant differences in flow in any region using the microsphere technique. Decreases of blood flow in certain cortical regions may help explain some of the physiological changes in vesicoureteral reflux in children and experimental models of reflux.

Import characteristics of a leucoplast pyruvate kinase are influenced by a 19-amino-acid domain within the protein

Two cDNA clones encoding distinct forms of plastid pyruvate kinase (designated Pka and Pkg) have recently been characterized. Pkg is found in both leucoplasts and chloroplasts, whereas Pka is present only in leucoplasts. The precursors of these proteins have different in vitro import characteristics. The Pkg precursor behaves like a typical stromal protein precusor with both types of plastid. In contrast, Pka precursors accumulate on the outer envelope membrane of leucoplasts under the same assay conditions and require a higher level of ATP for import into the organelle. Interestingly, the binding of Pka precursors to chloroplasts cannot be detected at any tested level of ATP even though the precursors are imported into the organelle at higher concentrations of ATP. Various N-terminal deletions and chimeric fusions were used to examine the translocation signaling mechanism of the Pka precursor. The N-terminal 83-amino-acid segment of Pka contains a transit peptide that is capable of directing dihydrofolate reductase and the mature body of Pkg into both types of plastid. Unlike the complete Pka precursor, these fusion proteins behave like typical stromal protein precursors. The behavior of the Pka transit peptide is influenced by a 19-amino-acid domain (-P-S-S-I-E-V-D-A-V-T-E-T-E-L-K-E-N-G-F-) located immediately downstream of the N-terminal 83-residue segment. Deletion of this domain from Pka alters its import properties such that it resembles a typical stromal protein precursor. Re-introduction of the 19-residue domain into the Dhfr fusion protein alters its import characteristics to resemble that of the complete Pka precursor. This 19-amino-acid domain can also influence the function of transit sequences from other precursors when it is placed immediately behind the transit peptide. These results suggest that this 19-amino-acid domain plays an important role in governing the import characteristics of the Pka precursor. We have named this 19-residue segment the "import modifying domain."

Intrascrotal epidermoid cyst with extension into the pelvis

An 8-year-old boy presented with an asymptomatic extratesticular, scrotal epidermoid cyst with extension across the urogenital diaphragm into the pelvis. While routine contrast studies and ultrasound were performed, magnetic resonance imaging was most useful in depicting the anatomical boundaries of the lesion, including the intrapelvic extension. Complete excision was performed transcrotally. The lesion is histologically indistinguishable from epidermoid cysts found elsewhere in the external genitalia, that is the penis, scrotum or testis. The etiology is unknown but it may represent a monolayer teratoma of germ cell origin or abnormal embryological closure of the median raphe.

The regulation of euchromatin and heterochromatin by histones in yeast

Yeast chromosomes may lack the linker histone H1 (normally required to compact 10 nm beads-on-a-string fiber into the 30 nm fiber) and there is no cytological evidence for higher order fiber structure but they do contain regions which correspond to euchromatin and heterochromatin of higher eukaryotes. Both euchromatin and heterochromatin contain nucleosomal particles (composed of two molecules each of H2A, H2B, H3 and H4), however histones have been shown to regulate genes in these regions in quite different ways. The mechanisms by which such regulation occurs are the topic of this paper.

Fish oil and cell proliferation kinetics in a mammary carcinoma tumor model

In vivo bromodeoxyuridine (BrdUrd) labelling and bivariate BrdUrd/DNA analysis was used to evaluate cell cycle kinetics in a rat tumor model known to be sensitive to dietary fatty acid manipulation. Fish oil supplementation significantly reduced the rate of BrdUrd movement relative to DNA content, indicating prolongation of the DNA replication time. This finding, which accounted for most of the decrease in tumor growth rate in the fish oil-fed group, represents the first description of an alteration in S phase duration by an extrinsic factor. The significance of this finding is discussed in relation to current understanding of cell cycle regulation. Fish oil feeding is associated with slower growth rate in certain tumors (1,2). According to current concepts of cellular proliferation (3), regulation of growth by extrinsic factors is thought to precede the S phase. This statement is based on the notion that, within a given cell type, DNA replication time (S phase duration) is constant (4-6). Extensive evidence also supports an on/off mechanism of cell cycle regulation at the level of entry into the S phase (3). In this report, we present evidence showing, for the first time, that the S phase duration of fat-responsive tumor cells can be altered by dietary manipulation of fatty acids. Furthermore, these differences in S phase duration appear to account for all the in vivo variation in tumor growth resulting from fish oil feeding. Although the mechanism of this phenomenon remains unclear, our observations support increasing evidence for a regulatory step at the level of the nucleus. They are also important for understanding the relationship between dietary fat and tumor growth.

Molecular characterization of plastid pyruvate kinase from castor and tobacco

Clones encoding two different forms of plastid pyruvate kinase (PKp; EC 2.7.1.40) have been isolated from both castor and tobacco seed cDNA libraries. One form, designated PKpA, from castor was described in a previous report, and the tobacco homologue of PKpA has now been isolated. In addition, a second cDNA, designated PKpG, has been identified and sequenced in both species. Western blot analysis, using antibodies raised against protein overexpressed from these clones, indicates that they encode the two predominant polypeptides of plastid pyruvate kinase from developing castor endosperm. In castor, both PKpA and PKpG are encoded by single genes. In the allotetraploid Nicotiana tabacum, there are two copies of each, one derived from each of the progenitors of this species. The expression of the genes for PKpA and PKpG was examined in various tissues from both castor and tobacco. In castor, both forms are expressed in developing and germinating endosperm and in the root but neither is expressed in the leaf. In tobacco, both forms are expressed in developing seeds but in mature tissues, PKpA is most abundant in roots and PKpG in leaves.

Transepithelial transport of tyramine across filter-grown MDCK cells via a poly(D-lysine) carrier

In order to investigate the advantage of using membrane-adsorptive carriers to mediate drug transport across epithelial tissue, we have prepared disulfide- and thioether-linked conjugates of tyramine (tyn) as a model drug to a cationic, nondegradable carrier, poly(D-lysine) (PDL). The transport properties were evaluated using microporous filter-grown Madin-Darby canine kidney (MDCK, strain I) epithelial cells, and we have determined that: (a) the [125I]tyn-SS-PDL conjugate predominantly transported [125I]tyn in the apical-to-basal direction (20-fold greater transport vs. basal-to-apical); (b) [125I]tyn-SS-PDL elicits a 10-fold greater degree of [125I]tyn transport than [125I]tyn-S-PDL, thus demonstrating the importance of the reducible disulfide linkage for [125I]tyn transport to occur; (c) 125I-radioactivity recovered in the basal media was determined to be 95% [125I]tyn-containing small molecules, thus demonstrating the release of [125I]tyn from its PDL carrier; (d) the apical addition of an anionic species, heparin, completely blocks apical-to-basal transport of [125I]tyn, indicating the importance of PDL-mediated binding to the apical membrane for transport to occur; (e) apical-to-basal transport proceeds via non-lysosomal pathways, as lysosomal inactivation by NH4Cl exposure does not inhibit transport, and (f) the addition of a membrane-impermeable inhibitor of disulfide reduction, bisdithionitrobenzoic acid (DTNB), to the apical media inhibits transport by approximately 70%, indicating the importance of apically-localized disulfide reducing reactions for transport of [125I]tyn. Pulse-chase studies indicate that there is no paracellular leakage of conjugate, and the ratio of recycled:membrane-associated:transported [125I]tyn fragment following chase is 4:2:1.

Two-stage repair for severe hypospadias

In 39 patients a 2-stage modified Belt-Fuqua repair was performed for severe hypospadias and chordee. Patient age at initial surgery averaged 2 years and stage 2 was done 7 months later. Testosterone was given before stage 1 to 22 patients (56%) and before both stages to 13 (33%). Of 5 patients with intersex 2 had mixed gonadal dysgenesis, 1 was a true hermaphrodite and 2 were 46 XX male subjects. The preoperative meatal location was subglanular in 9 cases, mid shaft in 8, proximal shaft in 2, penoscrotal in 15 and perineal in 5. Those with subglanular meatus had hypoplastic distal urethras and severe chordee. A dorsal Nesbit procedure for chordee correction was done in 24 cases (62%). Neourethral length ranged from 3 to 7 cm. (average 4 cm.) and average followup was 16 months. Neourethral diverticula developed in 8 cases (21%) and they were repaired uneventfully an average of 7 months (range 2 to 24) after stage 2. Minor urethral strictures (3 distal and 4 proximal) were treated with a single visual internal urethrotomy and there was 1 (2.5%) urethrocutaneous fistula. All children had excellent cosmetic and functional outcomes. A staged approach allows for cosmetic reconstruction of the glans and mucosal collar during stage 1 and offers 2 opportunities to augment penile size with testosterone. Bladder or buccal mucosal grafts are avoided since the prepuce is always adequate. There are no hypospadias deformities, penile shaft torsion or asymmetry. Fistula formation is minimal and strictures are minor. The 2-stage repair remains a safe, reliable alternative for boys with severe hypospadias.

Intravesical instillation of gentamicin sulfate: in vitro, rat, canine, and human studies

OBJECTIVE

Intravesical instillation of gentamicin sulfate has been used empirically as prophylaxis and to treat bacilluria in spinal-cord-injured patients undergoing clean intermittent catheterization. To assess the risks of absorption and the effects of storage conditions on antimicrobial potency, a series of studies were conducted.

METHODS

Four studies were carried out: (1) An infected fulgurated rat bladder model was created to determine the effects of inflammation and infection on absorption. (2) A canine model with bilateral vesicoureteral reflux and elevated bladder pressures (> 40 cmH2O) assessed the effects of reflux and storage pressure. (3) The effects in patients with associated conditions including renal transplantation, myelomeningocele, vesicoureteral reflux, and bladder augmentation, were analyzed. (4) To determine the effects of storage conditions, solutions of gentamicin sulfate (480 mg gentamicin sulfate in 1 L 0.9% NaCl) were made that controlled for pH, storage temperature, and duration.

RESULTS

(1) Increased absorption was found in 43 percent of rat serum samples. (2) None of the dogs demonstrated measurable absorption. (3) None of the patients likewise had measurable absorption. (4) All solutions were equally potent when tested against a panel of common urinary pathogens. Storage up to two months at room temperature without alkalinization had no effect on potency.

CONCLUSIONS

Instilled intravesical gentamicin sulfate has a low risk of absorption and is highly effective. Severe bladder inflammation can increase transvesical absorption. It has prolonged stability without special storage conditions and should be considered as a route of prophylaxis in patients who perform intermittent catheterization.

The effect of terazosin on bladder function in the spinal cord injured patient

We prospectively studied the effect of terazosin on bladder compliance in 12 spinal cord injured patients. All study patients had demonstrated previously poor compliance despite clean intermittent catheterization and maximum anticholinergic therapy. Patients were started on 5 mg. terazosin nightly for 4 weeks. They were evaluated with a history, physical examination, symptom score, and synchronous cystoscopy and cystometry before, during and after terazosin therapy. Detrusor compliance improved in all patients during the treatment phase. The change in bladder pressure and the safe bladder volume were statistically and clinically significant. Patients also reported fewer episodes of incontinence and dysreflexia. The improvement in compliance and continence suggests that in the spinal cord injured patient terazosin may have an effect on alpha receptors in the detrusor muscle or central effects and that improved compliance is not due to decreased outlet resistance.

Influence of the Gas-Water Interface on Transport of Microorganisms through Unsaturated Porous Media

In this article, a new mechanism influencing the transport of microorganisms through unsaturated porous media is examined, and a new method for directly visualizing bacterial behavior within a porous medium under controlled chemical and flow conditions is introduced. Resting cells of hydrophilic and relatively hydrophobic bacterial strains isolated from groundwater were used as model microorganisms. The degree of hydrophobicity was determined by contact-angle measurements. Glass micromodels allowed the direct observation of bacterial behavior on a pore scale, and three types of sand columns with different gas saturations provided quantitative measurements of the observed phenomena on a porous medium scale. The reproducibility of each break-through curve was established in three to five repeated experiments. The data collected from the column experiments can be explained by phenomena directly observed in the micromodel experiments. The retention rate of bacteria is proportional to the gas saturation in porous media because of the preferential sorption of bacteria onto the gas-water interface over the solid-water interface. The degree of sorption is controlled mainly by cell surface hydrophobicity under the simulated groundwater conditions because of hydrophobic forces between the organisms and the interfaces. The sorption onto the gas-water interface is essentially irreversible because of capillary forces. This preferential and irreversible sorption at the gas-water interface strongly influences the movement and spatial distribution of microorganisms.

Ureteral reimplantation in infants

Between 1984 and 1990, 30 infants (46 ureters) 8 weeks to 6 months old (mean age 4 months) underwent ureteral reimplantation. Weight at operation ranged from 4.9 to 9.5 kg. (mean 6.9). Underlying abnormalities were primary vesicoureteral reflux (28 ureters), primary ureterovesical junction obstruction (11), ectopic ureterocele (4) and ectopic ureter (3). Patients with reflux underwent surgery because of high grade reflux (grade IV or V) or breakthrough infection. Infants with primary ureterovesical junction obstruction underwent obstructive diethylenetriaminepentaacetic acid diuretic renograms. Reimplantations performed included 44 Glenn-Anderson advancements, 1 Cohen cross-trigonal advancement and 1 Politano-Leadbetter procedure. Of the ureters 30 (65%) were tapered intravesically. Ureteral stents were used in all instances. Transient ureteral obstruction developed in 2 children following stent removal and 1 required temporary percutaneous nephrostomy drainage. No permanent ureterovesical obstruction was noted in any patient. Followup at 18 months revealed no postoperative reflux in 43 of 46 ureters (93%). One infant required repeat reimplantation to correct a vesicoureteral fistula and the remaining 2 patients (2 ureters) with low grade reflux (grade I and II) are being observed. Surgery was successful in 27 of 30 tapered ureters (90%) and in all 16 of the nontapered ureters (100%). While the majority of infants with ureterovesical junction abnormalities may be observed, some may require surgery. Reimplantation, when necessary in this age group, can be performed with a high degree of success and diverting procedures such as vesicostomy or ureterostomy can be avoided.

Clinical assessment of urethral sphincter function

Measurements of urethral pressures, such as maximum urethral pressure, are widely believed to have relevance in the management of urinary incontinence despite evidence to the contrary. In this study maximum urethral pressure and the abdominal pressure required to cause stress incontinence were measured in 125 women with stress incontinence. In women the abdominal pressure required to cause stress incontinence was unrelated to maximum urethral pressure. These findings indicate that maximum urethral pressure has little relationship to urethral resistance to abdominal pressure. In the 9 children with myelodysplasia we compared the detrusor pressure with the abdominal pressure required to induce urethral leakage. These values also were quite different, indicating that as far as the urethra is concerned abdominal pressure and detrusor pressure are not equivalent forces.

Stress leak point pressure: a diagnostic tool for incontinent children

The stress leak point pressure is the lowest bladder pressure at which leakage occurs during prompted increases in intra-abdominal pressure. The stress leak point pressure is distinct from the simple bladder leak point pressure and can be determined using simple urodynamic equipment without fluoroscopy. In 15 incontinent girls and boys 2.5 to 15 years old the mean stress leak point pressure was 54.7 cm. water (range 11 to 100), whereas the mean leak point pressure was 19.9 cm. water (range 5 to 50, paired t test p < 0.0001). The stress leak point pressure is a useful diagnostic tool that provides specific data on bladder neck and proximal urethral function.

Distal intussusception of processus vaginalis: a cause of acute hydrocele

Acute obstruction of a patent processus vaginalis occurred in two boys, mimicking incarceration of an inguinal hernia. In fact, obstruction was caused by an intussusception of the processus vaginalis forming an intussuscipiens that occluded the hernia sac. This lesion, described previously in 1896 and in 1974, is one of the mechanisms by which an asymptomatic hernia or hydrocele becomes acutely symptomatic.

The management of meatal obstruction due to Kaposi's sarcoma of the glans penis

Kaposi's sarcoma involving the glans penis was first described in 1902, with a subsequent report of meatal disease in 1943. With the recognition of the acquired immunodeficiency syndrome, genital lesions are becoming more frequently reported, with 51 cases cited in the literature. To date only 4 additional cases of meatal or fossa navicularis involvement have appeared in the literature, 3 of which described difficulty with micturition. We report a case of Kaposi's sarcoma involving the urethral meatus resulting in documented outflow obstruction, relieved with simple urethral serial dilation performed on an outpatient basis followed by intermittent obturation. We believe that this therapy represents a low risk, cost-effective treatment modality aimed at resolution of symptoms and alleviation of a potential source of infection in the patient with the acquired immunodeficiency syndrome.

Primary mucinous adenocarcinoma of renal pelvis in solitary pelvic kidney

Mucinous adenocarcinoma of the renal pelvis is a rare tumor. We report the case of a fifty-three-year-old man with this unusual cancer and review the literature. Usual features of this tumor include long duration of symptoms, an association with calculi and hydronephrosis, and a preoperative appearance of an inflammatory condition.

Detection of non-palpable prostate cancer. A mathematical and laboratory model

Prostate cancer is currently the most commonly diagnosed cancer among males in the United States. As technology improves and the search for this enigmatic condition intensifies, we are detecting greater numbers of non-palpable tumours. These tumours are generally treated aggressively, given the uncertainty of their behaviour, but this approach may be over-zealous for small volume disease. The likelihood of detecting any cancer volume can be derived from Bayes' theorem of conditional probability. A laboratory model using coloured clay was created to contrast tumour volumes of 2.5, 5 and 20% (n = 75). Six random systematic biopsies were taken from each model in a blind fashion; 36% of the 2.5%, 44% of the 5% and all of the 20% models had at least 1 positive biopsy. Twenty-two of the 25 models representing 20% tumour had 3 or more biopsy cores positive. These data suggest that low volume disease with low biological potential will be found by random biopsy as the mathematical probability predicts. The high incidence of occult prostate cancer in the older population makes this a worrying observation. Also, and perhaps more important, there is a direct correlation between the volume of disease and the number of positive biopsies. This correlation is easily seen in both models and may allow for an estimation of tumour volume. This ability to estimate tumour volume may be a useful clinical tool that helps to guide therapy and assess prognosis.

Retroperitoneal neurogenous choristoma

A 6-year-old girl with urinary complaints underwent ultrasonography, which revealed a retroperitoneal cystic mass adjacent to the left kidney. Computerized tomography did not demonstrate whether the mass was an adrenal cyst or a duplicated upper pole segment. Exploration revealed a neurogenous choristoma, which is a collection of histologically normal tissue that is ectopically situated. We believe that this is the first report of this rare entity occurring in the retroperitoneum.