Differentially expressed snoRNAs in Bungarus multicinctus (Taiwan banded krait)

Twenty novel snoRNAs forming extensive sequence complementarities to mature 5S rRNA were identified from Bungarus multicinctus by reverse transcription-polymerase chain reaction. It was found that the snoRNA species were differentially transcribed in different tissues as evidenced by single stranded conformational polymorphism analysis and direct nucleotide sequence analysis. Although the diversity in the sequences of snoRNAs is observed, comparison of these snoRNA genes reveals that the regions involved in binding to 5S rRNA are highly conserved and form two 12-nt-15-nt tracts of complementarity to phylogenetically invariant sequences in eukaryotic 5S rRNAs. Nevertheless, the lower conservation of box C/D or box H/ACA in these snoRNAs was observed. Likewise, the sequences in several fish and human genes forming perfect duplexes with 5S rRNA also did not highly retain these box elements. These results may infer that the box elements are dispensable for the function of snoRNA species identified in the present study. Moreover, the novel finding of the differentially expressed snoRNA variants in B. multicinctus suggests that the snoRNA genes are selectively processed in different tissues and are likely associated with tissue-specific regulation of their host gene transcripts.

Structural factors affect the interactions of anticardiotoxin antibodies and cobra venom cardiotoxins

Two antibody preparations against cardiotoxins were raised by immunizing rabbits with cardiotoxin 1 and cardiotoxin 3, respectively. The two antibody preparations showed precipitin reactions with cardiotoxins 1, 2, 3 and 5, respectively. However, the results of competitive enzyme-linked immunoassay revealed that the respective cardiotoxin molecules exhibited different reactivity toward anticardiotoxin antibodies. Moreover, the order of reactivity with antibodies was not in line with the degree of their sequence identity. This suggest that the anticardiotoxin antibodies may recognize conformational epitopes rather than sequential ones in the toxin molecules. Alternatively, the four cardiotoxins reacted well with the antibodies in the absence of competitor, suggesting that sequence variations with cardiotoxin molecules may not exclusively influence the potential use of the anticardiotoxin antibodies for the neutralization of the activity of cardiotoxin variants.

Developmental expression of mouse erythrocyte protein 4.2 mRNA: evidence for specific expression in erythroid cells

Erythrocyte protein 4.2 (P4.2) is an important component of the erythrocyte membrane skeletal network with an undefined biologic function. Presently, very little is known about the expression of the P4.2 gene during mouse embryonic development and in adult animals. By using the Northern blot and in situ hybridization techniques, we have examined the spatial and temporal expression of the P4.2 gene during mouse development. We show that expression of the mouse P4.2 gene is temporally regulated during embryogenesis and that the P4.2 mRNA expression pattern coincides with the timing of erythropoietic activity in hematopoietic organs. P4.2 transcripts are first detected in embryos on day 7.5 of gestation and are localized exclusively in primitive erythroid cells of yolk sac origin. These erythroid cells remain to be the only source for P4.2 expression until the switch of the hematopoietic producing site to fetal liver. In mid- and late-gestation periods, P4.2 mRNA expression is restricted to the erythroid cells in fetal liver and to circulating erythrocytes. Around and after birth, the site for P4.2 expression is switched from liver to spleen and bone marrow, and P4.2 transcripts are only detected in cells of the erythroid lineage. These results provide the evidence for specific P4.2 expression in erythroid cells. In addition, the timing and pattern of expression of the P4.2 gene suggest the specific regulation of the P4.2 gene.

Is renal function at the tumor side a prognostic factor in ureteral transitional cell carcinoma?

OBJECTIVES

To evaluate whether the ipsilateral renal function on the tumor side is a prognostic factor in transitional cell carcinoma (TCC) of the ureter.

PATIENTS AND METHODS

We retrospectively reviewed 129 consecutive patients with ureteral TCC between September 1973 and July 1993 at our hospital. There were 98 males and 31 females aged from 31 to 84 years (mean 64.9). Of them, 126 patients who received intravenous pyelography (IVP) were divided into 3 groups according to their radiological findings (group 1: nonvisualization of kidney at tumor side; group 2: hydronephrosis or hydroureter; group 3: no obstruction). Eighty patients receiving radionuclide (131I-hippuran) renal function test (RRFT) with available effective renal plasma flow (ERPF) were divided into 2 groups using ipsilateral ERPF 50 ml/min as a cutoff value (group 1: < 50 ml/min; group 2: > or = 50 ml/min). The mean survival of each group was estimated by the Kaplan-Meier method.

RESULTS

For patients receiving IVP, the mean survivals were 61.7, 99.7 and 83.8 months for groups 1, 2, and 3, respectively, and the differences between each 2 of the 3 groups were statistically significant (p < 0.05). For patients having RRFT, the mean survivals were 65.8 months for group 1 and 89.2 months for group 2 patients, and the difference between them was statistically significant (p < 0.05). When renal function, tumor number, grade, stage and type of treatment were analyzed using a multivariate method, only tumor stage was statistically significant as a prognostic factor.

CONCLUSION

Ipsilateral renal function at the tumor side is not a good prognostic factor for patients with ureteral TCC. However, when the stage of tumor is not available, renal function at the tumor side may provide an implication of the patient's prognosis.

Immunoreactivity of nm23-H1 protein in renal cell carcinoma

Formalin-fixed, paraffin-embedded tissue blocks from 25 surgical specimens of renal cell carcinoma (RCC) including 13 adjacent normal renal tissues were investigated. The specimens were examined by immunohistochemistry using the monoclonal antibody, nm23-H1. The positive immunostaining of nm23-H1 protein was confined primarily to the cytoplasm of both normal renal tubular epithelial cells and renal tumor cells. Immunostaining of nm23-H1 protein was reduced significantly in RCC as compared to the normal renal tissues (P = 0.003). The positive immunostaining of nm23-H1 protein was seen in 92% (12/13) of normal renal tissues and in 60% (15/25) of RCC. No relationship was found between immunostaining of nm23-H1 protein and the patient's clinicopathological factors including age, tumor size, tumor location, tumor grade and tumor stage. Furthermore, immunostaining of nm23-H1 protein was not correlated with patient survival. Although immunoreactivity of nm23-H1 protein in patients with RCC was not correlated with survival, nm23-H1 protein may play a role in human renal tubular tumorigenesis.

A novel neurotoxin, cobrotoxin b, from Naja naja atra (Taiwan cobra) venom: purification, characterization, and gene organization

A novel neurotoxin, cobrotoxin b, was isolated from Naja naja atra (Taiwan cobra) venom by successive chromatographies on gel filtration and SP-Sephadex C-25 columns. The yield of this novel toxin was 5% of that of cobrotoxin from the same venom. Its neurotoxicity determined as the inhibition of acetylcholine-induced muscle contractions was approximately 50% of that of cobrotoxin. Cobrotoxin b consists of 61 amino acid residues including 8 cysteine residues. Moreover, there are 12 amino acid substitutions between cobrotoxin b and cobrotoxin. The genomic DNA, with a size of 2,386bp, encoding the precursor of cobrotoxin b was isolated from the liver of N. naja atra. The gene consists of three exons separated by two introns. This exon/intron structure is essentially the same as that reported for the cobrotoxin gene. Moreover, the nucleotide sequences of the two neurotoxin genes exhibit 92% identity. These results highly suggest that the cobrotoxin b and cobrotoxin genes are derived from a common ancestor. Comparative analyses of cobrotoxin b and cobrotoxin precursors showed that the protein-coding regions of the exons are more diverse than introns, except for in the signal peptide domain. This indicates that the protein-coding regions may have arised via accelerated evolution. BLAST searches for sequence similarity in the GeneBank databases showed that intron 1 of the cobrotoxin b and cobrotoxin genes encodes a small nucleolar RNA (snoRNA). However, the snoRNA gene is absent from the gene encoding the Laticauda semifasciata erabutoxin c precursor (L. semifasciata and N. naja atra are sea and land snakes, respectively). Since previous studies suggested the potential mobility of snoRNA genes during evolution, we propose that intron insertions or deletions of snoRNA genes occurred with the evolutionary divergence between the sea snake and land snake neurotoxins.

Paraneoplastic elevation of serum alkaline phosphatase in renal cell carcinoma: incidence and implication on prognosis

PURPOSE

We investigated the incidence and prognostic significance of paraneoplastic elevation of serum alkaline phosphatase in patients with renal cell carcinoma.

MATERIALS AND METHODS

Clinical data of 365 pathologically proved renal cell carcinoma cases were reviewed. Serum alkaline phosphatase level greater than 100 units per 1., but without obvious conditions that may cause phosphatase elevation, including metastasis to or disease of liver or bone and pregnancy, was regarded as paraneoplastic serum alkaline phosphatase elevation. Survival was evaluated using the Kaplan-Meier method.

RESULTS

Of 365 patients 77 (21.1%) had paraneoplastic serum alkaline phosphatase elevation. The respective incidence from stage I to IV cases was 9.9% (16 of 161), 31.9% (15 of 47), 34.3% (23 of 67) and 25.6% (23 of 90). Patients with stage I disease had the lowest incidence but there were no statistically significant differences among stages II, III and IV disease. Of 77 patients with elevated serum alkaline phosphatase 48 had additional paraneoplastic manifestations. The disease specific 5-year survival rate in patients with normal serum alkaline phosphatase was significantly better than in patients with isolated phosphatase elevation, which in turn was better than in patients with multiple paraneoplastic syndromes (70.7 versus 50.5 versus 30.8%). Patients with persistent or recurrent elevation of serum alkaline phosphatase after radical nephrectomy had metastatic lesion or local recurrence. In some patients serum alkaline phosphatase returned to normal after nephrectomy but metastasis developed later without recurrent phosphatase elevation.

CONCLUSIONS

Paraneoplastic serum alkaline phosphatase elevation in renal cell carcinoma patients implies an unfavorable prognosis, and additional paraneoplastic syndromes further worsen the prognosis. Recurrent or persistent serum alkaline phosphatase elevation after radical nephrectomy suggests distant metastasis or residual tumor. However, the return of serum alkaline phosphatase to normal does not guarantee cure of the disease. Identification of paraneoplastic serum alkaline phosphatase elevation is valuable in the prediction of outcome and postoperative followup of renal cell carcinoma patients.

Genomic structures of cardiotoxin 4 and cobrotoxin from Naja naja atra (Taiwan cobra)

Two genomic DNAs with the size of 2.3 kb and 2.4 kb, which were isolated from the liver of Naja naja atra (Taiwan cobra), encoded the precursors of cardiotoxin 4 and cobrotoxin, respectively. Both genes shared virtually identical overall organization with three exons separated by two introns, which were inserted in the similar positions of the gene's coding regions. Moreover, their nucleotide sequences shared approximately 84.2% identity. This result reveals the evolutionary relationship between cardiotoxin and cobrotoxin. The exon/intron structures of cardiotoxin 4 and cobrotoxin genes were similar to that reported for erabutoxin c gene, a neurotoxin genomic DNA from a sea snake (Laticauda semifasciata). However, in contrast to the finding that the intron 2 of these genes had a similar size, a notable variation with the size of intron 1 was observed (1233 bp, 1269 bp and 197 bp for cardiotoxin 4, cobrotoxin and erabutoxin c genes, respectively). The different size with intron 1 is due to the middle region at the first intron of cardiotoxin 4 and cobrotoxin genes, which encoded small nucleolar RNA (snoRNA), being absent in that of erabutoxin c gene. These results, together with the finding of the potential mobility of snoRNA genes during evolution, suggest that intron insertions or deletions of snoRNA genes occur with the evolutionary divergence of snake neurotoxins and cardiotoxins.

cDNA sequence analysis of a novel neurotoxin homolog from Taiwan banded krait

The cDNA encoding a novel protein was constructed from the cellular RNA isolated from the venom glands of Bungarus multicinctus (Taiwan banded krait) by reverse transcription-polymerase chain reaction. The deduced amino acid sequence of this novel protein contains 68 amino acid residues with 10 cysteine residues. Comparative sequence analyses show that it is structurally related to alpha-bungarotoxin and kappa-bungarotoxins from Bungarus multicinctus venom. Eight out of the ten cysteine residues in this protein are located at the homologous positions as those in the neurotoxins. However, instead of the fifth disulfide linkage appearing in loop II of alpha-bungarotoxin and kappa-bungarotoxins, the other two cysteine residues in this novel toxin are situated at the N-terminal region. Phylogenetic analyses suggest that it probably represents a small evolutionary divergence between the long and short neurotoxins.

Clinical outcome at 3 months after transurethral vaporization of prostate for benign prostatic hyperplasia

OBJECTIVES

To evaluate the clinical outcome of transurethral vaporization of the prostate (TUVP) for the management of benign prostatic hyperplasia (BPH).

METHODS

Between March and June 1995, 30 patients with symptomatic BPH treated by TUVP were enrolled in this study. Transrectal ultrasonography (TRUS) was done preoperatively. American Urological Association (AUA) symptom score determination, pressure flow study, and questionnaire (for evaluating potency) were done preoperatively and 3 months postoperatively.

RESULTS

The average age was 70.5 years (range 60 to 83) and estimated prostate size by TRUS before surgery was 33.8 +/- 14.0 g. The average AUA symptom score decreased significantly 3 months after TUVP (6.2 +/- 7.8 versus 18.2 +/- 9.0; P < 0.01). The maximum urine flow rate (Qmax) was 11.1 +/- 3.7 mL/min before TUVP (mean +/- SD) and 17.0 +/- 6.5 mL/min 3 months after TUVP, whereas the detrusor pressure at maximum urine flow (Pdes at Qmax) was 61.0 +/- 23.9 and 41.2 +/- 15.2 cm H2O, respectively. Qmax increased and Pdes at Qmax decreased significantly 3 months after TUVP. Of the 30 patients, 3 (10%) developed bladder neck contracture. Of the 24 patients who were potent sexually before operation, 3 (12.5%) developed impotence 3 months after surgery.

CONCLUSIONS

TUVP is an effective alternative surgical procedure to relieve obstruction for patients with symptomatic BPH. However, cautious attitude on its usage is advocated based on our preliminary results indicating the occurrence of late complication such as impotence and bladder neck contracture.

Inhibition of mouse thymidylate synthase promoter activity by the wild-type p53 tumor suppressor protein

The p53 tumor suppressor protein is an important negative regulator of the G1 to S transition in mammalian cells. We have investigated the effect of p53 on the expression of the mouse thymidylate synthase (TS) gene, which normally increases as cells enter S phase. A luciferase indicator gene that was driven by the wild-type or various modified forms of the TATA-less mouse TS promoter was transiently cotransfected with a p53 expression plasmid into TS-deficient hamster V79 cells and the level of luciferase activity was determined. We found that wild-type p53 inhibited TS promoter activity by greater than 95% but had a strong stimulatory effect on an artificial promoter that contained multiple p53-binding sites. In contrast, an expression plasmid that encodes a mutant form of p53 or a wild-type retinoblastoma tumor suppressor protein had little effect on TS promoter activity. Deletion of sequences upstream or downstream of the TS essential promoter region, or inactivation of each of the known elements within the essential promoter region, had no effect on the ability of wild-type p53 to inhibit TS promoter activity. Our observations indicate that the inhibition of TS promoter activity by p53 is not due to the presence of a specific p53 negative response element in the TS promoter. Rather, it appears that p53 inhibits the TS promoter by sequestering ("squelching") one or more general transcription factors.

Participation of paraventricular nucleus of hypothalamus in central regulation of penile erection in the rat

PURPOSE

To investigate the possible participation of the paraventricular nucleus of hypothalamus in central regulation of penile erection.

MATERIALS AND METHODS

Male adult Sprague-Dawley rats were anesthetized and maintained with pentobarbital sodium. The intracavernous pressure (ICP) was used as an experimental index for penile erection, and was recorded alongside systemic arterial pressure and heart rate. The effect on ICP of electrical (30-s train of 30-120 microA, 40-160 Hz, 1-ms rectangular pulses) or chemical (L-glutamate, 0.5 nmol/50 nl.) activation of the paraventricular nucleus of hypothalamus (PVN) or hippocampal formation was evaluated.

RESULTS

Electrical activation of the PVN elicited both multiple and single episodes of elevation in ICP, along with visible erection and ejaculation. The former pattern exhibited an increase in ICP that was more sustained, with higher peak amplitude and longer latency. Chemical stimulation of neuronal perikarya in the PVN also resulted in similar patterns of rise in ICP and visible erection. These effects were, nonetheless, not accompanied by significant alterations in systemic arterial pressure and heart rate. Activation of the hippocampal formation, as we reported previously, similarly elicited multiple and single episodes of increase in ICP. These erectile responses, however, were substantially reduced or eliminated upon electrolytic lesion of the ipsilateral PVN.

CONCLUSION

These observations suggest that the PVN may be an important nucleus that participates in central neural regulation of penile erection in the rat. Furthermore, an efferent pathway(s) from the hippocampal formation to PVN may constitute part of the neural circuitry in the forebrain in the regulation of erectile functions.

cDNA sequence analysis of cardiotoxin variants from Taiwan cobra

Five cDNAs encoding cardiotoxin variants were constructed from the cellular RNA isolated from the venom glands of Naja naja atra by reverse transcription-polymerase chain reaction. A high degree of nucleotide sequence homology was observed between these variants and other determined ones. Among them, a novel cardiotoxin 6 had 61 amino acid residues rather than 60 ones that usually observed with Naja naja atra cardiotoxins. The other cardiotoxin variants were the homologues of cardiotoxins 1, V or N with one or two amino acid substitutions, respectively. These results probably reflect the involvement of RNA editing in the production of cardiotoxin variants in the venom of Taiwan cobra.

The structural and functional essentiality of the N-terminal alpha-helix in the phospholipase A2 of the Taiwan banded krait

In order to identify the structural and functional essentiality of the N-terminal alpha-helix of Bungarus multicinctus PLA2 for its enzymatic activity, comparative studies of the biochemical properties of native and recombinant PLA2 were made. It was found that the appearance of a Met residue preceding the N-terminus Asn-1 of the recombinant protein appreciably affected PLA2 activity and the hydrophobic character of the ANS-binding site. Additionally, the charged state and the hydrophobicity of the molecular surface changed as well. However, removal of the N-terminal Met-1 from the recombinant PLA2 resulted in the production of a fully active PLA2, whose biochemical properties were indistinguishable from those of the native enzyme. These observations, together with the findings that the helical wheel plot of the N-terminal alpha-helix showed distinct hydrophobic and hydrophilic faces and that the ANS-binding site was the active site of PLA2 enzymes, suggest that the hydrophobic face of the N-terminal alpha-helix in native PLA2 should be in the interior of the enzyme molecule for binding with ANS and the phospholipid/substrate.

Impact of aging on rat urinary bladder fatigue

PURPOSE

Little is known about the fatigability of the urinary bladder. In these experiments, we characterized contractile and bioenergetic changes in bladder fatigue and investigated the impact of aging on these changes.

MATERIALS AND METHODS

Whole urinary bladders from 3-month-old (n = 17) and 24-month-old (n = 12) SD rats were isolated and individually mounted in organ baths. The bladders were electrostimulated repeatedly (50 volts, 32 Hz, 1 MS; every 2.5 minutes). The pressure generation, rate of pressure generation and the emptying ability (% volume emptied) of the isolated bladders were measured with each stimulation. After the 20th electrostimulation, the bladders were immediately stimulated with 500 microM bethanechol. Upon completion of their series of stimulations, some of the bladders were quickly frozen in liquid nitrogen. Tissue phosphocreatine and ATP content of the frozen bladders and a group (six 3-month-old and six 24-month-old rats) of fresh bladder tissues was determined using high performance liquid chromatography (HPLC).

RESULTS

The results can be summarized as follows: (1) Pressure generation, rate of pressure generation and emptying ability were gradually reduced in both young and aged bladders as repeated stimulation proceeded. (2) The final bethanechol stimulation emptied the same intravesical volume as the 20th electrostimulation emptied (in both groups), indicating that bladder fatigue is due to a post-synaptic mechanism. (3) As compared to their own first responses, aged rats exhibited significantly greater rates of reduction in both pressure generation and emptying ability than did young rats. (4) Analysing fresh bladder tissues, the phosphocreatine and ATP concentration of the aged bladders were significantly less than those of the young bladders-13.2 +/- 2.0 and 1.2 +/- 0.3 nmol/mg. protein respectively in the aged bladders vs. 21.2 +/- 1.8 and 7.5 +/- 1.0 nmol/mg. protein respectively in the young bladders. After repeated stimulation, phosphocreatine and ATP concentration were reduced in both groups (1.4 +/- 0.3 and 0.43 +/- 0.1 nmol./mg. protein in the aged bladders, 7.5 +/- 1.4 and 4.1 +/- 0.5 nmol./mg. protein in the young bladders), with a greater degree of reduction in the aged bladders.

CONCLUSION

These observations indicate that, in response to repeated electrostimulation, aged rat bladders became fatigued faster than young bladders. Decreased capability in energy production might be one contributing factor for faster fatiguability of the aged urinary bladders.

Amino acid sequence and chemical modification of a novel alpha-neurotoxin (Oh-5) from king cobra (Ophiophagus hannah) venom

A novel alpha-neurotoxin, Oh-5, was isolated from king cobra (Ophiophagus hannah) venom and purified by successive SP-Sephadex C-25 column chromatography and reversed-phase HPLC. The complete sequence of Oh-5 was determined by Edman degradation of peptide fragments generated by endopeptidases, i.e., trypsin, Saccharomyces aureus V8 protease and lysyl endopeptidase. This novel toxin comprises 72 amino acid residues with 10 cysteines. The sequence shows 89% sequence homology with Oh-4, and 60% with Toxins a and b from the same venom. The tyrosine, tryptophan, lysine and arginine residues in Oh-5 were modified with tetranitromethane (TNM), 2-nitrophenylsulfenyl (NPS) chloride, trinitrobenzene sulfonate (TNBS), and p-hydroxyphenylglyoxal (HPG), respectively. Modification of Tyr-4 or Trp-27 did not affect the lethal toxicity at all, while the Tyr-4 and 23 nitrated derivative retained about 50% of the lethality of native toxin. Selective trinitrophenylation of Lys-51 or 69 resulted in a decrease in lethality by 29%, and 50% lethality was retained after modification of Lys-2, 51, and 69. A drastic decrease in lethality to 26% was observed when both Arg-35 and 37 were modified. The neurotoxicity was further decreased when Arg-9 was additionally modified. These results suggest that the aromatic residues, Tyr-4 and Trp-27, are not crucial for the neurotoxicity, whereas the cationic residues are involved in multipoint contact between the toxin molecule and the nicotinic acetylcholine receptor (nAChR). The residues Tyr-23 and Arg-35 and 37 in the central loop of Oh-5 seem to contribute greatly to the neurotoxicity.

The human POLD1 gene. Identification of an upstream activator sequence, activation by Sp1 and Sp3, and cell cycle regulation

The promoter of the human POLD1 gene encoding the catalytic subunit of DNA polymerase delta is G/C-rich and does not contain a TATA box. Transient transfection analysis in HeLa cells employing POLD1-luciferase chimeric plasmids revealed a core promoter region extending 328 base pairs (bp) from the major transcription initiation site. Multiple elements in this region including two 11-bp direct repeats located between nucleotide positions -92 and -22, play an important role in POLD1 promoter activity. Deletion or linker-replacement mutations of the repeats drastically reduced the promoter activity. A 70-bp DNA fragment containing the two repeats could stimulate the expression of the POLD1 or a heterologous promoter in an orientation-independent manner. DNase I footprinting and band-shift assays showed that HeLa nuclear extracts contained proteins specifically binding to the repeat sequences. Southwestern blot and UV cross-linking analyses identified Sp1 and two 85-kDa proteins that bound to the repeats. Additionally, screening of HeLa cDNA expression libraries for the sequence-specific DNA-binding protein using the 11-bp repeat sequences as the probe, identified a cDNA that corresponds to Sp3, a member of the Sp1 family. Cotransfection studies in Drosophila SL2 cells showed that both Sp1 and Sp3, but not Sp2, could activate the POLD1 promoter through the repeat sequences. The POLD1 promoter activity was induced about 4-fold at the late G1/S boundary in serum-stimulated cells. The 11-bp repeats together with an E2F-like sequence, located adjacent to the major transcription initiation site, were important for the stimulation. Taken together, this study provides a direct evidence for transcriptional regulation of the human POLD1 gene.

The route of seminal vesicle involvement in adenocarcinoma of prostate: lymphaticovascular or local extension?

BACKGROUND

Adenocarcinoma of the prostate with seminal vesicle involvement indicates a rather poor prognosis. The aim of this study is to evaluate the route of seminal vesicle involvement via lymphaticovascular or local extension, as a possible way which may determine the extent of disease as systemic or local.

METHODS

In a retrospective study of 32 patients who underwent radical prostatectomy for localized cancer of the prostate, medical records and imaging studies were reviewed, and the histopathological slides of the resected specimens were rechecked.

RESULTS

Of 32 patients, 12 (37.5%) had seminal vesicle involvement. Seven patients had involvement of bilateral seminal vesicles and five had unilateral involvement. Tumor cells invaded the muscle portion of seminal vesicle from the adjacent prostatic tissues in all 12 patients. Four of the seven patients with involvement of bilateral seminal vesicles developed bony metastasis 7 to 12 months after operation. No patient with unilateral involvement of seminal vesicle was found to have disease progression to bony metastasis during follow-up for as long as 39 months.

CONCLUSIONS

The route of seminal vesicle involvement in prostate cancer was through local extension in all of our patients. Involvement of bilateral seminal vesicles may have more chances to develop bony metastasis than unilateral involvement. Further study with a large number of patients is necessary to clarify the issue regarding the route of seminal vesicle involvement in adenocarcinoma of prostate.

The significance of serum alkaline phosphatase bone isoenzyme in prostatic carcinoma with bony metastasis

OBJECTIVE

To evaluate the clinical significance of serum alkaline phosphatase (ALP). ALP bone isoenzyme (ALPb) and prostate specific antigen (PSA) levels in predicting bony metastasis in prostatic carcinoma.

PATIENTS AND METHODS

The levels of serum ALP, ALPb and PSA were assessed in 32 patients with prostatic carcinoma and bony metastasis (group 1), 31 with prostatic carcinoma without bony metastasis (group 2), and 31 with benign prostatic hyperplasia (group 3). Bony metastases were detected using whole-body bone scintigraphy and ALPb was estimated electrophoretically before surgical or medical treatment. The levels of the three markers were compared for their ability to predict bony metastasis.

RESULTS

In groups 1, 2 and 3, respectively, the mean (SD) serum levels of ALP were 304 (322.2), 76.6 (47.5) and 63.8 (14.7) IU/L, of ALPb were 79.9 (76.9), 23.6 (9.9) and 25.3 (9.0) IU/L and of PSA were 478.1 (352.2), 46.9 (32.1) and 8.1 (1.8) ng/mL. The differences in serum ALP and ALPb between groups 1 and 2, and between groups 1 and 3 were significant (P < 0.05), but not those between groups 2 and 3. The positive predictive value (PPV) for bony metastasis in patients with prostatic carcinoma was 91.3% (21/23) and 100% (18/18) and the negative predictive value (NPV) was 71.8% (28/39) and 68.9% (31/45) for ALP and ALPb, respectively.

CONCLUSION

Both serum ALP and ALPb were increased significantly in patients with prostatic carcinoma with bony metastasis. The level of ALPb had a higher PPV and specificity for bony metastasis than had the level of ALP, but a lower NPV and sensitivity than ALP or PSA (at PSA levels > 20 ng/mL).

The structural variations of epsilon-amino groups in phospholipase A2 enzymes from Naja naja atra and Bungarus multicinctus venoms

Comparative studies on Naja naja atra phospholipase A2 (NNA-PLA2), Bungarus multicinctus phospholipase A2 (BM-PLA2), and their Lys-modified derivatives were made to assess the differences in the fine structures around the conserved Lys residues of PLA2 enzymes. It has found that the accessibility of Lys residues of PLA2 enzymes toward modified reagent, trinitrobenzene sulfonate, were not the same. Moreover, the extent of decrease in pI values of PLA2 enzymes that resulted from trinitrophenylation of lysine residues was different between NNA-PLA2 and BM-PLA2. The Lys-6 of BM-PLA2 mostly contributed to the positively charged character of the enzyme molecule, whereas the contribution of Lys-6 of NNA-PLA2 to its molecular charge was not notably different from other Lys residues. A linear relationship was observed by plotting the mobilities of PLA2 enzymes and their TNP derivatives against their pI values. However, native and Lys-modified NNA-PLA2 were not aligned with those of BM-PLA2 in the same line. Apparently the gross conformation of PLA2 enzymes was not notably perturbed by the modification of Lys residues, but the fine structure of NNA-PLA2 was not the same as that of BM-PLA2. These results indicate that the positioning of side chains of the conserved Lys residues in the two PLA2 enzymes is essentially different, and suggest that the variations in the fine structures of homologous proteins could be effectively explored by chemical modification studies and electrophoretic analysis.

Renal angiomyolipoma--experience of 20 years in Taiwan

OBJECTIVE

32 cases of renal angiomyolipoma were presented. Diagnosis, treatment and prognosis of the 32 cases were discussed.

MATERIAL AND METHODS

A total of 32 cases of renal angiomyolipoma treated at the Veterans General Hospital-Taipei between 1974 and 1994 were retrospectively reviewed. Follow-up periods ranged from 2 to 108 months (mean 43.4).

RESULTS

Of the 32 cases, 26 were female, 28 were unilateral lesions and 2 were associated with tuberous sclerosis. The tumor size averaged 6.73 cm (range 2-25). The mean age was 48.3 years. There was a typical image finding in 87.5% of the 28 unilateral tumors. Tumors larger than 4 cm had a greater incidence of symptoms (90%) and a higher nephrectomy rate (18/22). 30 cases underwent surgery including 22 nephrectomy, 1 partial nephrectomy and 7 enucleation. The nephrectomy rate decreased from 90% (9/10) to 59.1% (13/22) after 1985. Only 1 patient had a contralateral recurrence 26 months after surgery. Two cases had unusual presentations, which were perirenal capsule invasion and renal vein extension, respectively.

CONCLUSIONS

Our experience with angiomyolipoma in the past 20 years showed that the advancement of imaging technology has much improved the diagnosis of this tumor. A correct diagnosis is possible in most cases before surgery. The nephrectomy rate has markedly decreased in recent years. Every effort should be made to preserve renal tissue in the treatment of this benign tumor.

Probing calcium ion-induced conformational changes of Taiwan cobra phospholipase A2 by trinitrophenylation of lysine residues

Phospholipase A2 (PLA2) from Naja naja atra (Taiwan cobra) snake venom was subjected to lysine modification with trinitrobenzene sulfonate (TNBS). Three major derivatives, TNP-1, TNP-2, and TNP-3, were separated by high-performance liquid chromatography (HPLC) from the reaction mixtures in the absence of Ca2+. However, only TNP-2 and TNP-3 were isolated when trinitrophenylated reaction was carried out in the presence of Ca2+. TNP-1 and TNP-2 contained only one TNP group, on Lys-65 and Lys-6, respectively; and both Lys-6 and Lys-65 were modified in TNP-3. The extent of modification on Lys-6 and Lys-65 was calculated from the peak areas of TNP proteins in the HPLC profile. It was found that the susceptibility of Lys-6 toward TNBS markedly increased by the addition of Ca2+ when Ca2+ concentration was higher than 5 mM. With regard to the involvement of Lys-6 in the binding of substrate, the increase in the reactivity of Lys-6 may arise from a conformational change around Lys-6 for binding with substrate in the presence of Ca2+. Alternatively, the nonessentiality of Lys-65 for PLA2 activity was revealed by the finding that TNP-1 still retained 95% activity of native enzyme. Moreover, the reactivity of Lys-65 toward TNBS did not greatly change in either the absence or presence of Ca2+, suggesting that Ca2+ binding did not cause an appreciable change in the microenvironment around Lys-65. These results indicate that the differential reactivities of Lys-6 and Lys-65 toward TNBS as affected by the binding of Ca2+ are well consistent with their functional roles in the catalytic mechanism of PLA2, and suggest that the occurrence of conformational changes with PLA2 could be explored by chemical modification studies.

Alterations in pulmonary function after retroperitoneoscopic surgery

OBJECTIVE

To evaluate and compare changes in pulmonary function after retroperitoneoscopic and open surgery.

PATIENTS AND METHODS

From June 1994 to October 1995. 11 patients (five men and six women, mean age 44.7 years, range 29-69) underwent retroperitoneoscopic procedures (Group 1) and 11 patients (eight men and three women, mean age 57.5 years, range 22-73) underwent flank-incision procedures (Group 2). The surgery comprised eight adrenalectomies and one each of nephroureterectomy, nephrectomy and pyelolithotomy in Group 1, and five adrenalectomies, four nephroureterectomies, one ureterolithotomy and one excision of a retroperitoneal tumour in Group 2. Pulmonary function tests (PFTs) were performed before and 3 days after surgery; the forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), forced expiratory volume at 25% (FEV25%), FEV1/FVC, vital capacity (VC), total lung capacity (TLC), residual lung volume (RV) and functional residual capacity (FRC) were compared between the groups. The post-operative changes in the PFTs were assessed using a paired t-test and the degree of change in both groups compared using the Mann-Whitney U-test. Other factors possibly influencing PFT were analysed using multiple regression.

RESULTS

Pulmonary function was impaired in both groups on the third day after surgery. In Group 2, the FVC, FEV1, FEV25%, VC and TLC had declined significantly (all P < 0.05) from the pre-operative value. In Group 1, only the FVC and VC decreased significantly (P < 0.05). Post-operative pulmonary complications occurred in two patients in Group 2 but in none of those in Group 1, showing that pulmonary function was generally less affected in Group 1 than in Group 2.

CONCLUSION

Although pulmonary function was impaired 3 days after surgery in both groups, retroperitoneoscopic surgery, by eliminating a large flank incision, caused less post-operative pulmonary dysfunction than open surgery.

Changes in urinary output and electrolytes during gaseous and gasless laparoscopy

Urological laparoscopy has gained increasing acceptance recently. Alterations in renal water and electrolyte homeostasis by carbon dioxide peritoneal insufflation, retroperitoneal insufflation and abdominal wall lifting were measured in 30 well-hydrated pigs over a 2-h period. Oliguria was observed after gaseous insufflation but not alter lifting the abdominal wall. Return to normal urinary output was observed at 30 min after release of pneumoretroperitoneum, and 60 min after pneumoperitoneum. Creatinine clearance declined, while the clearance rates of potassium, sodium and urea remained unchanged during peritoneal and retroperitoneal insufflation. An elevated serum aldosterone concentration was found which may mediate the increased urinary excretion of potassium and decreased urinary excretion of sodium found during peritoneal insufflation. Renal function remained stable, despite an elevation of serum creatine kinase being elicited after lifting the abdominal wall. In conclusion, significant changes in water and electrolyte homeostasis occurred gaseous, not gasless, laparoscopy in pigs.