An unusual testicular metastasis from transitional cell carcinoma of the ureter: a case report

Testicular tumor metastasis from transitional cell carcinoma (TCC) of the ureter is very rare. Herein, we report a case who presented with a palpable mass of left testis, after he underwent radical nephroureterectomy and bladder cuff excision and adjuvant radiotherapy and chemotherapy for the TCC of left ureter tumor for 5 months. We performed left radical orchiectomy and histology revealed a TCC identical to the original ureteral tumor. In a review of the literature, we found this case was the second case of metastatic testicular tumor from the ureteral TCC. In patients presenting the symptom of a palpable testicular mass, if they are known to have a ureteral TCC, metastatic neoplasm should be considered in the differential diagnosis, even if in the absence of other systemic metastasis.

Sequence diversification and exon inactivation in the glycophorin A gene family from chimpanzee to human

In humans, the allelic diversity of MNSs glycophorins (GP) occurs mainly through the recombinational modulation of silent exons (pseudoexons) in duplicated genes. To address the origin of such a mechanism, structures of GPA, GPB, and GPE were determined in chimpanzee, the only higher primate known to have achieved a three-gene framework as in humans. Pairwise comparison of the chimpanzee and human genes revealed a high degree of sequence identity and similar exon-intron organization. However, the chimpanzee GPA gene lacks a completely formed M- or N-defining sequence as well as a consensus sequence for the Asn-linked glycosylation. In the case of the GPB gene, exon III is expressed in the chimpanzee but silenced, as a pseudoexon, in the human. Therefore, the protein product in the chimpanzee bears a larger extracellular domain than in the human. For the GPE genes, exon III and exon IV have been inactivated by identical donor splice-site mutations in the two species. Nevertheless, the chimpanzee GPE-like mRNA appeared to be transcribed from a GPB/E composite gene containing no 24-bp insertion sequence in exon V for the transmembrane domain. These results suggest a divergent processing of exonic units from chimpanzee to human in which the inactivation of GPB exon III preserved a limited sequence repertoire for diversification of human glycophorins.

Difference between in vivo and in vitro effects of propofol on defluorination and metabolic activities of hamster hepatic cytochrome P450-dependent mono-oxygenases

We have compared the in vivo and in vitro effects of propofol on cytochrome P450-dependent monooxygenase activities in hamster liver microsomes. Propofol (Diprivan) 10 mg/100 g body weight was injected i.p. twice a day for 2 weeks to induce cytochrome P450 enzymes. Liver microsomes were prepared by differential centrifugation. Metabolism of the cytochrome P450-dependent mono-oxygenase system was evaluated by measuring aniline hydroxylation, benzphetamine demethylation and benzo(a)pyrene hydroxylation. Defluorination of enflurane was assayed by detecting free fluoride metabolites. At similar concentrations as in the in vivo group, propofol in vitro exhibited concentration-dependent inhibition of metabolism of benzphetamine and benzo(a)pyrene. Aniline hydroxylation and defluorination of enflurane were inhibited to 78% of control with propofol 0.25 mmol litre-1. In propofol-treated hamsters, there was only minimal inhibitory or inductive effects on either mono-oxygenase activities or capacity for defluorination. This difference between the in vitro and in vivo effects of propofol on cytochrome P450 mono-oxygenase activities emphasizes the need for care when comparing in vitro and clinical data.

Phosphatidylcholines with sn-1 saturated and sn-2 cis-monounsaturated acyl chains. Their melting behavior and structures

Recently, we have shown by high resolution differential scanning calorimetry that the position of a cis double bond (delta-bond) in a series of 1-stearoyl-2-octadecenoyl- phosphatidylcholines can affect the phase transition temperature (Tm) or enthalpy (delta H) of the gel-to-liquid crystalline phase transition of this series of lipids in the following manner. The value of Tm (or delta H) is minimal when the delta-bond is positioned at C(11) in the sn-2 acyl chain; in addition, this value increases steadily as the delta-bond migrates toward either end of the acyl chain, resulting in a symmetrical, inverted bell-shaped profile (Wang, Z.-q., Lin, H.-n., Li, S., and Huang, C. (1995) J. Biol. Chem. 270, 2014-2023). In this communication, we have further demonstrated the inverted bell-shaped profile of Tm using 1-arachidoyl-2-eicosenoyl-phosphatidylcholines. In addition, we have extended the lipid series of 1-stearoyl-2-octadecenoyl-phosphatidylcholines to include 1-arachidoyl-2-octadecenoyl- phosphatidylcholines and 1-behenoyl-2-octadecenoyl-phosphatidylcholine, each series with a delta-bond at varying carbon position of 6, 7, 9, 11, 12, and 13. Calorimetric results obtained with these three series of lipids indicate that the inverted bell-shaped curve shifts toward higher temperatures in a nonuniform manner as the saturated sn-1 acyl chain length increases from 17 to 19 and then to 21 C-C bond lengths. Specifically, the Tm (or delta H) values are nearly identical for these cis-monoenoic lipids when their delta-bonds are positioned at C(13). Based on the height of the rotational energy barrier obtained with molecular mechanics calculations, it is evident that the rotational flexibility of the single C-C bond adjacent to the delta-bond in 1-stearoyl-2-octadecenoyl-phosphatidylcholine increases as the delta-bond migrates from C(9) to C(13). The differential scanning calorimetry results obtained with the three series of lipids can thus be attributed to an increase in the rotational flexibility of the short chain segment succeeding the C(14) atom in the sn-2 octadecenoyl chain. In this communication, we also propose that in the gel-state bilayer of sn-1 saturated/sn-2 cis-monounsaturated phosphatidylcholine the entire length of the shorter segment of the sn-2 acyl chain acts as a structural perturbing element; hence, it is mainly responsible for the large lower Tm of the monoenoic lipid relative to the saturated counterpart. Finally, two general equations relating Tm with the structural parameters of cis-monoenoic phosphatidylcholines are presented.(ABSTRACT TRUNCATED AT 400 WORDS)

The temporal relationship between the severity of hydroureter and the dynamic changes of obstructed ureters in a rat model

OBJECTIVE

To investigate dynamic changes in the obstructed rat ureter and to evaluate the usefulness of the rat model in the study of obstructive uropathy.

MATERIALS AND METHODS

Unilateral ligation of the ureter was performed in 26 rats. After ureteric ligation, four to seven rats were killed and examined after 1, 3, 7, 10, and 14 days. The severity of hydroureter and hydronephrosis was assessed by pyelography and the hydroureter-hydronephrosis index. The middle portion of the ureter was prepared for light and electron microscopic observation. Five rats which received a sham operation were also examined as controls.

RESULTS

The severity of hydroureter and hydronephrosis in the ligated ureters progressively increased during the period of obstruction (P < 0.005) and reached a maximum 10-14 days after ligation. Hypertrophy of the smooth muscle layer developed on the third day after ligation and proliferation of submucosal connective tissue occurred on the 10th day after ligation. The changes in smooth muscle and connective tissue layers also progressed consistently during ureteric obstruction (P < 0.001 and < 0.005, respectively). The number and size of granular endoplasmic reticulum and Golgi apparatus in the smooth muscle cells increased after ureteric ligation and then caveolae exocytosis developed. Deposition of collagen fibres between muscle cells became apparent later.

CONCLUSION

The rat model of hydrouropathy demonstrated a clear temporal relationship between the severity of hydroureter and the dynamic changes in the obstructed ureter and could be used as a conventional method for the study of obstructive ureter.

Protein kinase C-and ras-dependent activation of c-jun gene by human papillomavirus type 11 E5a oncoprotein

E5a of HPV-11 is a transforming oncogene. Previously, we have shown that E5a constitutively activates the expression of protooncogene c-jun by transcriptional regulation through the AP-1 binding site in the c-jun promoter. In the present study, we used two different types of cells: the E5a transfected NIH 3T3 cells and human epidermal keratinocytes, and selectively inhibited different signal transduction pathways to investigate effects of E5a on c-jun expression. We find that protein kinase C and ras-dependent pathways are important for the c-jun induction by E5a, but not the cAMP-dependent pathway.

Allelic frequency of p53 gene codon 72 polymorphism in urologic cancers

Alterations in the p53 tumor suppressor gene appear to be important in the development of many human tumors. The wild-type p53 gene has a polymorphism at codon 72 that presents the arginine (CGC) or proline (CCC) genotype, which recently has been reported to be associated with genetically determined susceptibility to smoking-related lung cancers. To determine whether this p53 genotype influences individual risk of urologic cancer and/or its progression, we used polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis to assay the allelic frequencies of this polymorphism in 85 renal cell carcinoma patients, 151 urothelial cancer patients, 33 testicular cancer patients, 28 prostatic cancer patients and 56 patients without neoplastic disease. The allelic distributions of the three genotypes (Arg/Arg, Arg/Pro, Pro/Pro) in patients with renal cell carcinoma (29.4%, 55.3%, 15.3%), urothelial cancers (45.7%, 39.7%, 14.6%), testicular cancer (45.4%, 48.5%, 6.1%) or prostate cancer (42.9%, 50.0%, 7.1%) did not differ significantly from those in the normal controls. However, Pro/Pro genotype in renal cell carcinoma and urothelial cancer (smoking-related cancers) was more frequent than that in prostate cancer and testicular cancer (smoking-unrelated cancers) with borderline significance (P = 0.0881). There was no particular correlation between frequency of the three genotypes and grade or stage of each type of tumor. The association of genetic predisposition to urologic cancers with p53 gene codon 72 polymorphism is not so clear as the previous study of Japanese lung cancer patients, but this polymorphism may play some role in urothelial cancers and renal cell carcinoma, in which smoking is an epidemiological risk factor.

Identification of a partial internal deletion in the RH locus causing the human erythrocyte D--phenotype

The D--phenotype of the human erythrocyte is a genetic variant of the Rh blood group system associated with the expression of D but not C, c, E, and e (designated non-D) antigens. In this report, we characterize the structure and expression of Rh polypeptide genes in two D--homozygotes of Italian origin. Southern blot analysis detected a gross deletion in their genomic DNA that correlated with the alteration of CcEe rather than the D polypeptide gene. With detailed exon mapping, the deletion was found to be partial and internal, encompassing exons 2 through 8 of the non-D gene. Analysis of Rh cDNAs showed that no functional mRNA was produced from the truncated non-D gene, whereas the D gene gave rise to one major and two minor mature transcripts. The full-length RhD cDNA sequence contained four nucleotide changes resulting in four amino acid substitutions on the polypeptide backbone. The shortened RhD cDNAs occurred as alternatively spliced isoforms lacking sequences corresponding to exons 7 and/or 8. The identification of a partial and internal deletion in the non-D gene shows that the molecular basis for the D--phenotype is heterogenous and that its alterations have occurred on different genetic backgrounds.

A calorimetric study of binary mixtures of 1-octadecanoyl-2-decanoyl-sn-glycero-3-phosphoethanolamine and dimyristoyl phosphatidylethanolamine

Model membranes composed of 1-octadecanoyl-2-decanoyl-sn-glycero-3- phosphoethanolamine and dimyristoyl phosphatidylethanolamine have been studied calorimetrically. 1-Octadecanoyl-2-decanoyl-sn-glycero-3- phosphoethanolamine is a highly asymmetric mixed-chain lipid, whereas dimyristoyl phosphatidylethanolamine is an identical-chain lipid with the same molecular weight. Calorimetric results indicate that these two lipids with a common molecular weight are completely miscible in the two-dimensional plane of the lipid bilayer in the liquid-crystalline state and that they are only partially miscible in the gel-state bilayer. Specifically, binary mixtures of these two lipids form eutectic phase diagrams at pH 7.4 and 10.0.

Glycophorin SAT of the human erythrocyte membrane is specified by a hybrid gene reciprocal to glycophorin Dantu gene

Previous studies of two unrelated Japanese families showed that two isoforms of glycophorin were associated with the expression of SAT antigen on the erythrocyte membrane. Here we report the molecular basis for one form of this MNSs-related surface marker that displayed an altered immunoblotting pattern. Evidence is presented that glycophorin SAT (GPSAT) is encoded by a hybrid gene resulting from unequal homologous recombination between GPA and GPB genes. Analysis of SAT genomic DNAs by Southern blots showed gross alterations in the glycophorin gene cluster. Those restriction fragments characteristic of the GPA 3' and GPB 5' ends were absent from the SAT homozygote and showed reduced intensity in SAT heterozygotes. Reticulocyte RNA polymerase chain reaction showed the presence in the SAT homozygote of GPSAT and GPE transcripts but no GPA and GPB transcripts. Direct sequencing of the amplified SAT cDNA showed that its sequence from exon I to exon IV was identical with the N allele of GPA, whereas its 3' portion, including exon V and exon VI, was derived from the GPB gene. The GPSAT protein in its mature form should contain 104 amino acid residues and bear a novel sequence, Ser-Glu-Pro-Ala-Pro-Val, encoded by the junction of GPA exon IV and GPB exon V. This sequence interfaces the extracellular and transmembrane domains and could be the epitope site of the SAT antigen. The formation of such a hybrid junction not only explains why SAT homozygous erythrocytes lack S, s, and U antigens but also shows a reciprocal arrangement with respect to the B-A hybrid GPDantu gene.

Incidence of internal cancers and ingested inorganic arsenic: a seven-year follow-up study in Taiwan

In order to elucidate the dose-response relationship between ingested inorganic arsenic and internal cancers, a total of 263 patients with blackfoot disease and 2293 healthy residents in the endemic area of arseniasis were recruited and followed up for 7 years. The information on consumption of high-arsenic artesian well water, sociodemographic characteristics, life-style and dietary habits, and personal and family history of cancers was obtained through standardized interviews. The occurrence of internal cancers among study subjects was determined through annual health examinations, home visit personal interviews, household registration data checks, and national death certification and cancer registry profile linkages. A dose-response relationship was observed between the long-term arsenic exposure from drinking artesian well water and the incidence of lung cancer, bladder cancer, and cancers of all sites combined after adjustment for age, sex, and cigarette smoking through Cox's proportional hazards regression analysis. Blackfoot disease patients had a significantly increased cancer incidence after adjustment for cumulative arsenic exposure.

Phase transition behavior and molecular structures of monounsaturated phosphatidylcholines. Calorimetric studies and molecular mechanics simulations

High resolution differential scanning calorimetric studies were performed to investigate the thermotropic phase behavior of 26 molecular species of sn-1 saturated/sn-2 monounsaturated phosphatidylcholines. In parallel with calorimetric studies, the energy-minimized structures and steric energies of the diglyceride moieties of these monoenoic lipids were determined using a molecular mechanics approach. The combined calorimetric and computational studies led to the following results and conclusions. (i) When a single cis-carbon-carbon double bond (delta) is incorporated into a saturated diacylphosphatidylcholine molecule at any position within the central segment of the long sn-2 acyl chain, the resulting monoenoic lipid molecules will, in excess water, exhibit reduced phase transition temperature (Tm) and transition enthalpy (delta H) as they undergo the gel to liquid-crystalline phase transition. The Tm and delta H-lowering effects of the delta bond can be attributed to a decrease in the chain length of the sn-2 acyl chain, a change in the chain length difference between the sn-1 and sn-2 acyl chains, and a local perturbation of the chain-chain van der Waals interaction in the vicinity of the delta bond. (ii) For a series of positional isomers of 1-stearoyl-2-cis-octadecenoylphosphatidylcholine, C(18):C(18:1 delta n)PC, with a delta bond at different positions along the sn-2 acyl chain, the Tm value depends critically on the position of the delta bond. Specifically, the Tm value is minimal as the delta bond is located at the geometric center of the linear segment of the sn-2 acyl chain, and the Tm value is progressively increased as the delta bond migrates toward either end of the sn-2 acyl chain. (iii) The various monoenoic phosphatidylcholines under study can be divided into two groups. The Tm values of most lipids in each group can be correlated in an identical manner with their structural parameters, yielding a common Tm-structure relationship.

Molecular genetics of the glycophorin gene family, the antigens for MNSs blood groups: multiple gene rearrangements and modulation of splice site usage result in extensive diversification

The purpose of the review is to describe a system of human erythrocyte membrane glycoproteins exhibiting extensive diversity. Glycophorins A and B (GPA and GPB) are the antigens of the MNSs blood groups; thus individuals bearing variant glycophorins can be readily identified by serological typing. Examination of the wide array of variants of these antigens showed that they include many forms, possibly made evident by lack of constraints due to the apparent dispensability of the parent molecules. This article reviews the molecular genetics of 25 variants of the glycophorin gene family, whose common denominator is that they arise from unequal gene recombinations or gene conversions coupled to splice-site mutations. Most rearrangements occurred within a 2-kb region mainly within GPA and GPB of the gene family and only rarely within the third member, GPE. The key feature is the shuffling of sequences within two specific exons (one of which is silent), homologous in the two parent genes. This has resulted in expression of a mosaic of sequences within this region, leading to polymorphism. The common pattern of recombinations coupled to pre-mRNA splicing was the predominant mechanism of the origin of glycophorin diversity. Thus far this mechanism appears to be unique among human gene families. It could have occurred by chance rearrangements among closely linked genes and been driven by a biological advantage, not as yet identified. This remains to be established. Nevertheless, gene rearrangements observed here are akin to those reported for the major histocompatibility complex (MHC). In the glycophorin family the small size of the region within which gene interactions have occurred and the participation of essentially only two alleles makes this relatively simpler system more focused and easier to dissect and describe molecularly.

High-performance liquid chromatography with light-scattering detection and desorption chemical-ionization tandem mass spectrometry of milk fat triacylglycerols

The utility of reverse-phase high-performance liquid chromatography (HPLC), desorption chemical-ionization mass spectrometry (DCI-MS) and tandem mass spectrometry (MS/MS) for the characterization of triacylglycerols in complex mixtures has been further explored. Triacylglycerols of anhydrous bovine milk fat were separated by using two reverse-phase C18 HPLC columns, and eluents were monitored with an evaporative light-scattering detector. Fifty-eight fractions were resolved and analyzed by positive ion isobutane DCI-MS. The formation of protonated molecules and of major fragments corresponding to the random loss of any one of the constituent fatty acids readily identified acyl carbon numbers and the number of double bonds within each fatty acid. MS/MS was only required when the original mass spectra indicated the presence of more than one triacylglycerol or of impurities in a fraction. Protonated molecules produced by DCI were fragmented using high energy collisional activation, and the resulting ions were detected by MS/MS. Odd-chain triacylglycerols were also readily distinguished using this methodology. The positive ion DCI and MS/MS techniques described here demonstrate the usefulness of this approach for the characterization of triacylglycerols in complex mixtures.

[Epidermoid cyst of testis: benign testicular tumor]

Epidermoid cyst of the testis is very rare and accounts for approximately 1% of all testicular tumors. In the clinical examination, the testis has a palpable mass. Pathological findings usually reveal a squamous cell lined cyst, containing keratin, and the absence of appendages and teratoma element. If scrotum ultrasonography reveals a target sign suggestive of epidermoid cyst, the testis should be explored through an inguinal incision. Clamp the spermatic cord gently, and perform tumor enucleation. The frozen section is available at the time to check for any malignant cells. If no malignant cells exist, it is important to perform testis-preserving surgery, especially for young adults and children. We report two cases of epidermoid cyst. Serum beta-HCG and alpha-fetoprotein were within normal limits. We review our experience with scrotum ultrasonography and testis-preserving surgery in 2 men with epidermoid cyst to indicate when the clinical and intraoperative characteristics justify testis-preserving management.

Xanthogranulomatous cystitis: a case report and review of the literature

Xanthogranulomatous cystitis is a rare benign chronic inflammatory disease of unknown aetiology. We report a case of xanthogranulomatous cystitis. The patient is well more than 15 years after partial cystectomy. The relevant literature is reviewed.

Adenosine modulation of neurotransmission in penile erection

1. Adenosine inhibited the noradrenaline-induced contraction of rabbit corpus cavernosum in a dose-dependent manner. The effect of adenosine was greater in intact corpus cavernosa than in endothelium-denuded preparations. This finding indicates that the relaxing effect of adenosine is partially endothelium-dependent and involved in the release of endothelium-derived relaxing factors. 2. Adenosine and its analogues relaxed the noradrenaline-induced contractile response as well as inhibited the transmural nerve induced contraction with the potency order: NECA > R-PIA > adenosine. These data indicate that adenosine can modulate both the non-adrenergic non-cholinergic and adrenergic neurotransmission. DMPX, an adenosine antagonist selective for the A2 receptors, abolished the electrically elicited relaxation. However, CGS 21680, selective for A2a receptor, had no effect on relaxation. Therefore, adenosine receptors involved in the modulation of neurotransmission in rabbit corpus cavernosum appear to be A2b subtype. 3. Adenosine also induced an increase in human cavernosal arterial velocity and resistive index measured by colour duplex sonography. The combination of adenosine and 10 micrograms prostaglandin E1 was more effective in resistive index and erection grade than 20 micrograms prostaglandin E1 alone. Our results suggest that adenosine seems to be an important neuromodulator for penile erection and can be an effective and alternative combination in the treatment of impotence.

Calorimetric studies and molecular mechanics simulations of monounsaturated phosphatidylethanolamine bilayers

This investigation was designed to determine how information about the lipid chain melting and structural characteristics of sn-1 saturated/sn-2 monounsaturated phosphatidylethanolamines, a subclass of naturally occurring phospholipids, can be generalized among these lipid molecules. Specifically, 30 molecular species of sn-1 saturated/sn-2 unsaturated monoenoic phosphatidylethanolamines were semi-synthesized. The phase transition behavior of these monoenoic lipids in excess water was studied calorimetrically. The computer-based molecular mechanics approach was used to simulate the energy-minimized structures and to calculate steric energies for the diglyceride moieties of some of the 30 monoenoic lipid molecules, at T < Tm, in various aggregated states. These combined calorimetric and computational studies led to the following results and conclusions. 1) For a homologous series of monoenoic lipids with a common molecular weight and with a cis-double bond at various positions along the sn-2 acyl chain, the characteristic reduction of the main phase transition temperature (Tm) is proposed to be a result of an entropy-driven phenomenon. 2) The maximal decrease in the Tm for bilayers prepared from four series of monoenoic phosphatidylethanolamines containing a sn-2 octadecenoyl chain is shown by interpolation of calorimetric data to occur uniquely when the cis double bond is located commonly between C(10) and C(11) positions from the carboxyl end. 3) Monoenoic phosphatidylethanolamines can be divided into two groups. The Tm values obtained with bilayers of monoenoic lipids within each group can be systematically correlated with their structural parameters, leading to the derivation of two general Tm-structure relationships.

Hyperbilirubinemia after cardiac operation. Incidence, risk factors, and clinical significance

Three hundred and two consecutive patients who had undergone cardiac operation for various cardiac lesions were studied prospectively to evaluate the incidence, risk factors, and the associated mortality of postoperative hyperbilirubinemia after cardiopulmonary bypass. Concentrations of the serum total (conjugated and unconjugated) bilirubin, alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, alkaline phosphatase, albumin, globulin, and serum haptoglobin were measured before the operation and again on the first, second, and seventh postoperative days. Postoperative hyperbilirubinemia was defined as occurrence of a serum total bilirubin concentration of more than 3 mg/dl in any measurement during the postoperative period. Logistic regression was done to identify possible risk factors for postoperative hyperbilirubinemia. Overall incidence of postoperative hyperbilirubinemia was 35.1%; the incidence of postoperative hyperbilirubinemia was higher in patients whose valves were replaced with mechanical prostheses than in those without prostheses (p < 0.00001). In patients with postoperative hyperbilirubinemia, 70% of the increase of total bilirubin on the first postoperative day came about from an increase in unconjugated bilirubin. Serum haptoglobin decreased significantly at the same time (p < 0.01). Development of the postoperative hyperbilirubinemia was associated with a higher mortality (5.6% versus 0.5%, p < 0.01) and higher frequency of use of intraaortic balloon counterpulsation, especially for patients in whom the highest postoperative total bilirubin occurred after the first 2 days. The numbers of valves replaced, preoperative right atrial pressure, and preoperative total bilirubin concentration are the significant risk factors that, in combination, correctly predict the occurrence of postoperative hyperbilirubinemia in 80% of the patients. We concluded that postoperative hyperbilirubinemia results mainly from an increase in unconjugated bilirubin and is associated with higher mortality, especially for patients in whom highest postoperative total bilirubin occurred late after operation. Patients with the higher preoperative right atrial pressure and total bilirubin level who then underwent multiple valve replacement procedures are at greater risk for development of postoperative hyperbilirubinemia.

Bilayer packing characteristics of mixed chain phospholipid derivatives: Raman spectroscopic and differential scanning calorimetric studies of 1-stearoyl-2-capryl-sn-glycero-3-phosphocholine (C(18):C(10)PC) and 1-stearoyl-2-capryl-sn-glycero-3-phospho-N-trimethylpropanolamine (C(18):C(10)TMPC)

Raman spectroscopy and high-sensitivity differential scanning calorimetry (DSC) were used to compare the effects of headgroup conformation on the acyl chain packing arrangements in two highly asymmetric phosphatidylcholine (PC) analogues, 1-stearoyl-2-capryl-sn-glycero-3-phosphocholine (C(18):C(10)PC) and a polar headgroup derivative of C(18):C(10)PC, 1-stearoyl-2-capryl-sn-glycero-3-phospho-N-trimethylpropanolami ne (C(18):C(10)TMPC), which contains an additional methylene group within the choline moiety; namely, -P-O-(CH2)3-N(CH3)3. The C(18):C(10)TMPC headgroup exhibits an extended trans conformation which is independent of bilayer phase. A comparison of gel phase spectral order parameters of the two lipid species indicates a mixed interdigitated state characteristic of three chains per headgroup for C(18): C(10)TMPC. A more intermolecularly ordered liquid crystalline phase is observed, however, for the C(18):C(10)TMPC bilayers. The phase transition cooperative unit size estimated for the C(18):C(10)PC bilayers (approximately 140 molecules per unit) is about 7-fold greater than that for the C(18):C(10)TMPC dispersions (approximately 20 molecules per unit). We suggest that the extended headgroup for C(18):C(10)TMPC induces a slight tilt in the gel phase packing arrangements for the acyl chains, which may persist in the partially interdigitated liquid crystalline phase bilayer. Macroscopically, tighter packed multilamellar dispersions of C(18):C(10)TMPC occur for systems prepared first in the presence of a higher ionic strength medium. The stacked bilayers may then be transferred to a lower ionic strength environment without loss of their more closely packed adjacent lamellae.

Glycophorin He(Sta) of the human red blood cell membrane is encoded by a complex hybrid gene resulting from two recombinational events

A complex glycophorin (GP) variant of the human red blood cell membrane exhibiting both He and Sta antigens was characterized at the molecular level. Restriction mapping identified two novel Msp I fragments derived from the 5' and 3' portions of the GPHe(Sta) gene, respectively. Genomic DNA, including exons II-V and their splice junctions, was amplified by polymerase chain reaction, and the nucleotide sequences were determined. Comparison with the GPA and GPB sequences showed the presence in GPHe(Sta) of multiple recombinational breakpoints. In the 5' region of the variant gene, a sequence covering a portion of exon II to intron 2 had been transferred from GPA to GPB, resulting in a B-A-B hybrid structure. Such a gene conversion-like event introduced a number of templated and untemplated nucleotide replacements and was the direct cause for the expression of the He antigen. In the 3' region of the variant gene, an unequal crossover from GPB to GPA took place in the third intron at a recombination site apparently identical to that observed in the B-A hybrid GPSta type A gene. These results indicated that GPHe(Sta) occurs as a B-A-B-A hybrid gene, most likely originating from a two-step mechanism of homologous recombination. Transcript analysis showed the maturation from the GPHe(Sta) pre-mRNA of two shortened mRNAs of which the exon III-deleted species encodes both the He and Sta antigens.

Recovery from propofol anesthesia: a quantitative electroencephalographic analysis

Four numerical descriptors (median frequency, spectral edge frequency-95%, total power, and delta-ratio) derived from the computer-processed electroencephalogram (Neurometrics Lifescan) were analyzed for their ability to predict imminent arousal from total intravenous anesthesia with propofol. Fifteen patients undergoing minor surgical procedures without intubation were enrolled in the study. Arousal was defined as eye opening in response to verbal stimuli. During emergence from propofol, there were no significant changes among the descriptors except the delta-ratio. Significant change of delta-ratio occurred 210 seconds before patients' arousal and thereafter. An increase of delta-ratio value indicates that patients shifted from anesthetic to arousal state. It is concluded that the degree of delta-ratio change may be used for predicting patients' arousal from propofol anesthesia.

Remodeling of the transmembrane segment in human glycophorin by aberrant RNA splicing

This paper describes the identification in S-s-U-erythrocytes of a novel glycophorin (GP), He(P2), with structural variations in both its extracellular and transmembrane domains. In the exon II-intron 2 region, a sequence transfer from GPA to GPB, probably via the mechanism of gene conversion, was associated with the induction of multiple untemplated nucleotide replacements. These changes defined the sequence for the He epitope while concomitantly abolishing GPB-associated N antigenicity. Moreover, the GPHe(P2) gene carries two splice site mutations that coordinately affect the processing of exon V coding for the transmembrane segment. The C-->G transversion at the 3' end of exon V created a cryptic acceptor splice site, whereas the G-->T transversion at the +5 position of intron 5 altered the consensus of the donor splice site. Transcript sequencing revealed that neither site was utilized in the splicing of GPHe(P2) pre-mRNA. Rather, complete skipping of exon V and subsequent joining of exon IV to exon VI caused a shift in the open reading frame, which remodeled GPHe(P2) with an elongated new hydrophobic sequence for membrane anchoring. As a result, GPHe(P2) does not display the S and U epitopes although it still contains an intact linear sequence for the two antigens. These findings illustrate how exon and intron sequences concertedly determine the specificity of in vivo splice site selection. In addition, they pinpoint the conformational dependence of the S, s, and U antigens and the importance of the hinge region for their presentation.

Magnetic resonance imaging and computed tomography of transitional cell carcinoma of renal pelvis and ureter

Fourteen patients with clinically suspicious transitional cell carcinoma of renal pelvis or ureter were preoperatively examined with magnetic resonance imaging (MRI) and computed tomography (CT). All of the cases had surgical approval. In eleven of these patients, the tumor was correctly detected by MRI. Two cases were falsely positive including one squamous cell carcinoma (SCC) and one Wilms' tumor of the kidney. The final case was falsely negative. The positive predictive value of MRI was 92.9%. The sensitivity was 91.7%. In seven of the fourteen patients, the CT findings were truly positive. There were five falsely negative findings and two falsely positive cases. The positive predictive value by CT was 64.3%. The sensitivity was 59.3%. Tumor stagings were done for all patients. The accuracy rate of staging was 7/7 by CT and 10/11 by MRI. MRI showed better identification of distant metastasis in the liver, vertebrae and vascular structure because of its high tissue contrast and larger field of view. MRI had a higher positive predictive rate and sensitivity for identification of uroepithelial tumor than CT.

Difference in efficacy of the Cell Saver in coronary bypass grafting surgery and cardiac valvular reoperations

The efficacy of the Cell Saver in reducing transfusion requirements in patients who underwent either coronary artery bypass grafting (CABG) or reoperation for valvular replacement (Redo) were prospectively studied in 112 patients. In 41 patients, the Cell Saver was used from the beginning of the surgery (group 1), and in the other patients, no blood conservation techniques were undertaken (group 2). Perioperative hematological profile, postoperative chest tube drainage and transfusion requirements were examined in all patients. More red cells could be retrieved from the Redo patients than from the CABG patients (p < 0.05) during operation. The use of the Cell Saver in CABG patients reduced the total amount of blood transfusion required (p < 0.001). However, in the Redo patients, the use of the Cell Saver did not reduce the transfusion requirements during hospitalization. Furthermore, the amount of platelet concentrates transfused in the group 1 Redo patients was greater than the group 2 Redo patients. The use of the Cell Saver did not increase the postoperative chest tube drainage in either the CABG or the Redo patients. We conclude that the Cell Saver is useful in CABG patients, as far as the reduction of transfusion requirements is concerned; however, its efficacy in reducing transfusion requirements for Redo patients is questionable.