Increased ciliary neurotrophic factor expression in reactive astrocytes following spinal cord injury in the rat

Expression of ciliary neurotrophic factor (CNTF) was observed in reactive astrocytes in injured spinal cord of the adult rat. After unilateral incision of the dorsal funiculus at a midthoracic level, the rats were sacrificed on the day of postoperation (DPO) 3, 7, 14 or 28. Western blot analysis of spinal cord extracts showed that the intensity of the CNTF-immunoreactive band of 24 kDa was increased on DPO 3 and 7 and decreased on DPO 14. CNTF- or glial fibrillary acidic protein (GFAP)-like immunoreactivity was also increased progressively in the injured dorsal funiculus and adjacent gray matter. Double immunofluorescence histochemistry revealed that all CNTF-like immunoreactive cells showed GFAP-like immunoreactivity. The CNTF upregulation in the reactive astrocytes may play important roles in repair process after spinal cord injury.

Functional dissociation between local and systemic immune response during anti-melanoma peptide vaccination

Peptide vaccination against tumor Ags can induce powerful systemic CTL responses. However, in the majority of patients, no tumor regression is noted. To study this discrepancy, we analyzed CTL reactivity in a melanoma patient (F001) vaccinated with g209-2M peptide, a single residue variant of gp100(209-217). G209/g209-2M-reactive CTL were identified in post- but not prevaccination PBL. Limiting dilution analysis identified one predominant CTL clone (C1-35), with TCR Vbeta6s2, recognizing g209/HLA-A*0201-expressing targets. Additionally, two autologous melanoma lines (F001TU-3 and -4) and 20 separate tumor-infiltrating lymphocyte cultures were generated from a fine needle aspirate of a metastatic lesion progressing after initial response to vaccination. Both F001TU did not express gp100 and were not recognized by C1-35. Loss of gp100 by F001TU correlated with a marked reduction of gp100 expression in the same metastatic lesion compared with prevaccination. Thus, ineffectiveness of C1-35 and tumor progression could be best explained by loss of target Ag expression. Interestingly, 12 of 20 tumor-infiltrating lymphocyte cultures recognized F001TU, but none demonstrated g209/g209-2M reactivity, suggesting a functional dissociation between systemic and local immune response. This study suggests that vaccination effects must be analyzed in the target tissue, rather than in the systemic circulation alone.

Gamma knife treatment of acoustic neurinoma

The results of treatment of acoustic neurinomas using Gamma Knife radiosurgery (GKR) during a 6-year period in our center were reviewed. Since May 7, 1990, we treated 88 cases of acoustic neurinoma with GKR. During a 52-month mean follow-up period, MRI was obtained in 63 patients. Reduction in tumor size occurred in 34 (54%) cases, and another 27 (42.8%) tumors showed no change. The tumor control rate was thus 95%. Tumor size increased in 3 (4.8%) cases, but one case is still in early follow-up. Two cases were operated after GKR. Histological examination of the tumors removed at surgery 8 months after GKR were obtained. The examinations showed enlargement of nucleoli and cytoplasm and proliferation of endothelial cells due to delayed radiation changes. Post-GKR facial neuropathy was noted in 7 (8.8%) patients, of which 4 recovered during the follow-up period. The tumor volume, margin dose, number of isocenters and marginal isodose did not have any statistically significant relationship with the development of facial neuropathy. Transient trigeminal neuropathy were noted in 3 patients. Hearing was preserved in 2 of 3 hearing patients. In conclusion, our GKR results for acoustic neurinomas were very similar to the previously reported series, which makes GKR for acoustic tumors an excellent treatment modality for small- to medium-sized tumors with or without microsurgical tumor removal.

[Tuberous sclerosis associated with renal angiomyolipoma, pulmonary lymphangioleiomyomatosis and subungual fibroma: report of a case]

We report a case of tuberous sclerosis associated with bilateral renal angiomyolipomas (AMLs), pulmonary lymphangioleiomyomatosis (LAM) and subungual fibroma of hands and feet. A 42-year-old woman who was diagnosed as tuberous sclerosis at the age of 18 complained of left flank pain and abdominal fullness. Bilateral renal AMLs were pointed out when complete examinations were performed for hypertension at the age of 32. She suffered from severe left flank pain and abdominal distension due to the left renal tumor. Left nephrectomy and excision of the renal hilar tumor were performed. The left renal tumor weighed 1120 g, the perirenal space was filled with the tumor. histopathological diagnosis of the left renal tumor and renal hilar tumor was AML. In our case, bilateral pneumothorax appeared, and chest CT scan revealed bilateral multiple pulmonary cysts. Histopathological diagnosis of pulmonary cysts was LAM. Other complications of our case are intracranial calcification and adenoma sebaceum.

Histotopographic distribution of placental inflammation: analysis of 22 cases

Twenty-two placentas were investigated for the presence and patterns of inflammation by extensive examination, and divided into four groups: 1) term vaginal delivery [group I; n=6]; 2) term cesarean section delivery [group II; n=5]; 3) preterm vaginal delivery [group III; n=4], and 4) preterm cesarean section delivery [group IV; n=7]. In group I, all had deciduitis, and choriodeciduitis/ chorionitis was present in two cases (33.3%). In group II, four cases (80%) showed deciduitis and/or choriodeciduitis/chorionitis; three of these had intact membranes. In group III, three cases (75%) showed deciduitis, and two had chorionitis. In group IV, three cases (42.9%) showed no evidence of inflammation, three had deciduitis and one had deciduitis/chorioamnionitis. In all groups, membranitis was more severe, confined to the inner and mid segments in general, and deciduitis, choriodeciduitis/chorionitis and chorioamnionitis tended to overlap. The study newly demonstrates major characteristics of placental inflammation: higher prevalence and severity of inflammation in the inner segments of membrane and at the periphery of the placenta. Taking this histotopography into account, it is desirable to take sections from the placental margin, and the current concept of placental inflammation as a surrogate marker of intrauterine infection should be reevaluated.

Expression of uroplakin Ib and uroplakin III genes in tissues and peripheral blood of patients with transitional cell carcinoma

Uroplakins (UPs), urothelium-specific transmembrane proteins, are present only in urothelial cells. We have determined the nucleotide sequences of human UP-Ib and UP-III and synthesized specific primer pairs. The two UP genes were expressed in both cancerous and noncancerous urothelial taken from all patients examined by reverse transcription-polymerase chain reaction (RT-PCR). These genes were also detected in the peripheral blood of 3 patients with metastatic transitional cell carcinoma (TCC), but not in that from 9 patients with non-metastatic TCC or 3 healthy volunteers. The sensitivity of our assay was sufficient to detect one cancer cell in 5 ml of peripheral blood. Detection of UP gene-expression in blood by RT-PCR may provide helpful information for the diagnosis and management of TCC.

Role of tyrosine kinase in erythrocyte lysate-induced contraction in rabbit cerebral arteries

OBJECT

This study was undertaken to explore whether erythrocyte lysate, a proposed cause of vasospasm, produces vasoconstriction by activation of tyrosine kinase in rabbit cerebral arteries.

METHODS

Isometric tension was used to monitor contractions in rabbit basilar arteries induced by erythrocyte lysate, 5-hydroxytryptamine (5-HT), or KCl in the absence or presence of tyrosine kinase inhibitors. Erythrocyte lysate, 5-HT, or KCl produced concentration-dependent contractions in rabbit basilar arteries. Preincubation with the tyrosine kinase inhibitors tyrphostin A23 and genistein (30 and 100 microM), but not diadzein, an inactive analog of genistein, attenuated significantly the contraction induced by erythrocyte lysate (p < 0.05). Tyrphostin A23, genistein, and diadzein (30 microM) failed to reduce the contraction caused by 5-HT. Genistein, but not tyrphostin A23 or diadzein (30 microM), attenuated significantly the contraction induced by KCl (p < 0.05). In another series, arterial rings were initially contracted with erythrocyte lysate, 5-HT, or KCl and the relaxant effect of genistein was then tested. Genistein relaxed rabbit basilar arteries that had been contracted by exposure to erythrocyte lysate, 5-HT, or KCl (30-100 microM; p < 0.05).

CONCLUSIONS

These data indicate that tyrosine kinase may play a role in the regulation of cerebral arterial contraction and tyrosine kinase inhibitors may be useful in the management of cerebral vasospasm.

Stringent allele/epitope requirements for MART-1/Melan A immunodominance: implications for peptide-based immunotherapy

The exclusiveness of the relationship between peptide and HLA alleles, combined with their extensive polymorphism, emphasizes the need for immunization strategies based on endogenous processing of full length proteins (containing multiple epitopic determinants) for presentation to T cells. This could allow vaccination regardless of the patient's HLA phenotype, assuming that individual molecules can be efficient T cell Ags in association with various HLA alleles. An endogenous system of Ag presentation was developed using dendritic cells infected with recombinant viral vectors expressing the melanoma-associated Ag MART-1/Melan A. CD8+ T cells from melanoma patients were activated in vitro by coincubation with infected dendritic cells and tested for recognition of HLA-A-matched melanoma targets. This allowed the analysis of T cell induction in association with any HLA-A allele of a given patient's phenotype. In this system, MART-1/Melan A could not efficiently immunize in association with HLA-A alleles other than A*0201, including the one residue variant from A*0201: HLA-A*0226. Clonal analysis of MART-1/Melan A-specific CTL confirmed that MART-1/Melan A immunodominance is strongly restricted to the AAGIGILTV/HLA-A*0201 combination. The stringent epitope/allele requirements for MART-1/Melan A/TCR interactions were not associated with limitations in the TCR repertoire. In conclusion, autologous induction of MART-1/Melan A CTL by whole Ag processing and presentation is restricted to a unique allele/ligand combination and is excluded by minimal changes in HLA structure. Thus, whole protein vaccination for small m.w. Ags may provide no further advantage over a peptide-based approach.

Effects of drug solubility, drug loading, and polymer molecular weight on drug release from Polyox tablets

This study investigated the effects of polymer molecular weight, drug solubility, addition of a water-soluble excipient, and drug loading on zero-order release kinetics and elucidated the release mechanism of a drug from directly compressed tablets. Directly compressed tablets consisting of polyethylene oxides (PEO) (MW = 0.9, 2.0 and 4.0 x 10(6)) and drugs (solubility ranging from 290 to 25,000 mg/l) were formulated with or without a water-soluble excipient (lactose). For PEO tablets (MW = 0.9 x 10(6)), drug release is primarily swelling/erosion controlled for drugs for which solubility is below 1%, resulting in zero-order release kinetics. For PEO tablets (MW = 4.0 x 10(6)), drug release is controlled at a zero-order rate by the dissolution rate of the drug at high loading (39%). At low loading (20%), drug diffusion through the swollen gel layer becomes the governing release mechanism. For a highly water-soluble drug (e.g., diclofenac Na), drug diffusion is the controlling mechanism regardless of the molecular weight of the PEOs. Zero-order release kinetics can be achieved with PEO tablets (MW = 0.9 x 10(6)) for drugs for which solubility is below 1%. PEO tablets (MW = 2.0 x 10(6)) provided zero-order release for poorly water-soluble drugs (below 0.2%) at 39% drug loading. It is possible to attain zero-order release kinetics with PEO tablets (MW = 4.0 x 10(6)) using a drug which has a solubility of less than 0.1%.

The involvement of protein kinase C and tyrosine kinase in vanadate-induced contraction

Gastric smooth muscle of cats was used to investigate the involvement of protein kinase in vanadate-induced contraction. Vanadate caused a contraction of cat gastric smooth muscle in a dose-dependent manner. Vanadate-induced contraction was totally inhibited by 2 mM EGTA and 1.5 mM LaCl3 and significantly inhibited by 10 microM verapamil and 1 microM nifedipine, suggesting that vanadate-induced contraction is dependent on the extracellular Ca2+ concentration. and the influx of extracellular Ca2+ was mediated through voltage-dependent Ca2+ channel. Both protein kinase C inhibitor and tyrosine kinase inhibitor significantly inhibited the vanadate-induced contraction and the combined inhibitory effect of two protein kinase inhibitors was greater than that of each one. But calmodulin antagonists did not have any influence on the vanadate-induced contraction. On the other hand, both forskolin (1 microM) and sodium nitroprusside (1 microM) significantly inhibited vanadate-induced contraction. Therefore, these results suggest that both protein kinase C and tyrosine kinase are involved in the vanadate-induced contraction which required the influx of extracellular Ca2+ in cat gastric smooth muscle, and that the contractile mechanism of vanadate may be different from that of agonist binding to its specific receptor.

Antitumor killer lymphocytes in the peripheral blood of a patient with transitional cell carcinoma of the bladder

BACKGROUND

Peripheral blood lymphocytes (PBL) from patients with bladder cancer also contain cells possessing cytotoxic activity against autologous tumor cells. These cells are phenotypically heterogenous and include natural killer (NK) and cytotoxic T cells. This study investigated the role of cytotoxic lymphocytes directed against autologous bladder cancer cells.

METHODS

PBL were obtained at intervals before and after surgery and analyzed for cytotoxic activity against autologous bladder cancer cells in 4-hour 51Cr release assay. PBL stimulated with autologous tumor cells were also transformed with human T-lymphotropic virus type-1, establishing a cell line (KB31) which was analyzed for phenotype and cytotoxic activity against the autologous tumor cells.

RESULTS

PBL preoperative cytotoxic activity was low, but increased after surgery. Cytotoxic activity was found not only against autologous bladder cancer cells, but also against heterologous bladder cancer (KK-47) and myeloid leukemia (K562) cells, with the highest activity against the heterologous cell lines. The cytotoxic activity of KB31 was 40% against autologous tumor cells 6 weeks after initiation of the cell line, but decreased to 5% by 6 months. This activity was lower than that against the other cell lines, and was similar to that of PBL in short-term culture. Fluorescence-activated cell sorter (FACS) analysis demonstrated that in KB31 cells at 6 weeks, CD8+ cells were dominant, but CD56+ cells predominated at 6 months.

CONCLUSION

These results suggest that the presence of cytotoxic activity in the peripheral blood of the patient was due to both cytotoxic T cells and NK cells. The cytotoxic activity was lowest prior to surgery and increased postoperatively.

HPV-16-related proteins as the serologic markers in cervical neoplasia

OBJECTIVE

Recently, a variety of HPV-related proteins have been synthesized and their utility as diagnostic and prognostic markers in cervical cancers needs to be assessed. The ability to generate preparative amounts of HPV-16 L1/L2 VLPs and E6, E7 proteins may have implications for the development of a serologic assay to detect anti-HPV-16 virion immune responses. The purpose of the study is to improve the way of proper management of the cervical cancer by investigating the utility of the recently developed HPV-16 L1/L2 VLPs, HPV-16 E6, E7 proteins as the clinical serologic markers through antibody reactions by comparison with those of SCCA and CEA which have been used as tumor markers for cervical cancer.

METHODS

The serologic responses in Korean women with cervical neoplasia by ELISA using HPV-16 L1/L2 VLPs and radioimmunoprecipitation assay (RIPA) using in vitro translated HPV-16 E6, E7 proteins were investigated. PCR using E6 type-specific primers for HPV-16/18 was used to determine the presence and type of HPV infection (normal controls, 15 cases; preinvasive lesions, 28 cases; invasive cervical cancers, 124 cases).

RESULTS

The sera of 34% (42/124) of cervical cancers were positive for SCCA and the sera of 18% (22/124) of cervical cancers were positive for CEA. The positivity of SCCA was increased with advancing clinical stages, but the antibody levels were not correlated with clinical stage of disease. The sera of 7% (1/15) of normal controls, 39% (11/28) of preinvasive lesions, and 56% (70/124) of patients with cervical cancer were ELISA positive for HPV-16 L1/L2 VLPs (P < 0.05). The sera of 7% (2/28) of preinvasive lesions and 51% (63/124) of cervical cancers were positive for in vitro translated HPV-16 E6 protein (P < 0.05) and the sera of 11% (3/28) of preinvasive lesions and 33% (41/124) of cervical cancers were positive for in vitro translated HPV-16 E7 protein (P < 0.05). The antibody levels to HPV-16 E7 protein were correlated to clinical stage and tumor burden in a significant number of cervical cancers.

CONCLUSIONS

These data suggest that a considerable number of patients with cervical neoplasia generated positive antibody response to L1/L2 VLPs and in vitro translated E6, E7 proteins of HPV-16. These HPV-16-associated proteins might be disease-specific markers which could be useful in an adjunctive diagnostic assay and a seroepidemiologic study of HPV-related cervical neoplasia. In particular, the monitoring of antibody to HPV-16 E7 protein seems to be valuable in the proper management of cervical cancers for specific tumor markers.

Epidemiology and time trends of gestational trophoblastic disease in Korea

OBJECTIVES

For the purpose of determining the annual incidence and time trends of gestational trophoblastic disease (GTD), the medical records from 24 university hospitals, 13 private general hospitals and the Korean Research Institute of Gestational Trophoblastic Disease (KRI-TRD) were analyzed from 1971 to 1995.

MATERIALS & RESULTS

From a total of 7198 GTD cases (H-mole=3831, Invasive mole=2163, Choriocarcinoma=1177, PSTr=27) among 838659 deliveries between 1971 and 1995, the hospital-based incidence of H-mole per 1000 deliveries declined from 40.2 during 1971-975, to 2.3 during 1991-995. The population-based incidence of H-mole, however, revealed an average of 2.05 per 1000 deliveries during 1991-995. Old age and gravidities as factors in GTD patients both decreased significantly during the study period. Time trends for the incidence of GTD in Korea revealed significant changes, not only a decrease in the incidence of GTD, but also an improvement in the annual remission rate. Korea's socio-eonomic improvement in recent decades also contributed to the decreased incidence of GTD and the increased survival rates.

Immunodominance across HLA polymorphism: implications for cancer immunotherapy

Recent advances in the understanding of the mechanisms leading to tumor recognition by the immune system have shown that, at least in the case of human melanoma, the majority of cytotoxic T lymphocytes (CTL) identified in association with in vivo tumor regression after interleukin-2 therapy recognize nonmutated molecules expressed by most melanoma cells. For this reason, peptide-based or whole protein vaccination protocols against melanoma-associated antigens (MAA) are ongoing in several institutions, with the goal of inducing tumor regression by enhancing in vivo specific antitumor CTL reactivity. The rationale for the use of such vaccines is supported by: (a) preclinical evidence that vaccination with major histocompatibility complex class I restricted epitopes can enhance effectively cellular immunity, (b) evidence that potent antimelanoma CTL reactivity can be generated by repetitive in vitro stimulation of peripheral blood monocytes with MAA, and (c) evidence that the systemic administration of the same MAA can elicit antitumor CTL reactivity in vivo. As strategies are being developed for the development of sound vaccines, two basic approaches are investigated: one vaccination strategy is based on the administration of the specific amino acid sequence recognized by the CTL in association with a particular human leukocyte antigen (HLA) restriction element, and the other is based on the administration of the whole antigenic molecule, which relies on the organism's antigen-processing capabilities to render suitable the antigen for induction of HLA class I restricted CTL reactivity in vivo. Among the various factors complicating T-cell-based vaccination approaches stands the polymorphism of the HLA molecules. HLA are the most polymorphic of human genes, and because such polymorphism is clustered in the functional peptide-binding region, the binding of antigenic peptides is necessarily restricted to specific HLA alleles. This limits the interactions between CTL and antigen to specific sequences for each HLA allele. For this reason, the ability of an individual antigen to function as a T-cell immunogen in the context of different HLA allele restriction elements is an open question. It seems logical that whole-molecule vaccines have the potential advantage of broader use across patient populations. In particular, large antigenic molecules may contain multiple peptide sequences with putative binding properties for different HLA alleles, which in turn may elicit T-cell reactivity across the polymorphism of HLA. Such a concept, however, relies on the assumption that the same antigen may function with similar efficiency as an immunogen in association with different HLA alleles, independently from the epitopic sequence recognized in the various situations. This concept has been challenged recently by several practical observations and remains, in our opinion, an open question. This review will address the practical question of immunogenicity of molecules across the HLA polymorphism. We postulate that the complexity and success of the development of peptide-based vaccination strategies depend on the severity of this restriction, which is currently only incompletely studied and understood. Although no solutions are offered to the problem, emphasis is placed on the importance of this question, hopefully to stimulate the interest of other researchers, particularly in clinical settings, toward the investigation of this type of problem.

p53 mutation and overexpression in hepatocellular carcinoma and dysplastic nodules in the liver

In hepatocarcinogenesis, both de novo and multistep pathways have been suggested and in the latter a dysplastic nodule is the proposed precancerous lesion. In this study, we tried to ascertain whether or not the p53 gene is altered in low-grade/high-grade dysplastic nodules (LDN/HDN) and to determine the role of p53 alteration in multistep hepatocarcinogenesis. Eight hepatocellular carcinomas (HCCs), 9 HDNs, 17 LDNs and 25 cirrhotic nodules (LCs) were examined by polymerase chain reaction-single strand conformation polymorphism/direct sequencing and immunohistochemical staining for p53. Four of the 8 HCCs (50%) revealed p53 overexpression and 2 (25%) had missense mutations. Four of the 9 HDNs (44%) showed weak and/or focal p53 overexpression but none had mutation in the exons examined. Neither p53 overexpression nor mutation was found in 17 LDNs and 25 LCs. These results suggest that p53 mutation might be an unusual event in precancerous lesions of multistep hepatocarcinogenesis (DN-HCC sequence) and may play a less crucial part than in colorectal carcinogenesis.

[Adenocarcinoma of the bladder 19 years after the augmentation ileocystoplasty: report of a case]

We report a case of adenocarcinoma of the augmented bladder 19 years after ileocystolasty. The patient was a 53-year-old man who underwent right nephrectomy and ileocystoplasty (Pyrah's method) for contracted bladder due to tuberculosis in 1965. In another hospital, transurethral resection (TUR) was performed against a tumor in the anastomotic site between the bladder and the ileal segment in 1996. Histopathological examination of the specimen obtained by TUR revealed poorly-differentiated mucinous adenocarcinoma. In our hospital, partial cystectomy with total resection of ileal segment and ileocystoplasty were performed. The tumors located in the anastomotic site between the bladder and ileal segment as well as in the ileal segment. Histopathological examination revealed poorly-differentiated mucinous adenocarcinoma. The patient has survived 12 months without any evidence of tumor recurrence. To our knowledge, this is the eighth case report in Japan.

Azathioprine-induced megaloblastic anemia with pancytopenia 22 years after living-related renal transplantation

Macrocytosis and megaloblastic changes in the bone marrow are frequently seen in renal transplant recipients treated with azathioprine (Az). However, severe anemia is a rare side effect of Az. We recently observed a case of severe megaloblastic anemia with pancytopenia in a renal transplant recipient who had been receiving Az therapy for 22 years. The patient was a 46-year-old woman who had been administered Az and prednisolone at a dose of approximately 1.7 mg/kg and 0.17 mg/kg daily, respectively. A bone marrow aspiration revealed megaloblastic anemia with the depletion of myeloid cells and megakaryocytes. She did not have vitamin B12 or folate deficiency. Therefore, FK506 (tacrolimus), a macrolide produced by Streptomyces tsukubaensis, which acts directly on T cells and is known to have less myelosuppression than Az, was substituted for Az. Although the leukopenia improved, the anemia and thrombocytopenia did not improve in the short term. She developed dyspnea and severe subcutaneous bleeding of the right lower extremity due to knee contusions. Hemodialysis was started to treat her uremic state. Although it was impossible to evaluate the long-term effects of FK506 therapy for the pancytopenia in our case, the conversion from Az to a less myelosuppressive drug, such as FK506, should be considered in renal transplant recipients with severe myelosuppression caused by long-term Az treatment.

Use of recombinant poxviruses to stimulate anti-melanoma T cell reactivity

BACKGROUND

Dendritic cells (DC) are potent professional antigen-presenting cells that can activate naive T lymphocytes and initiate cellular immune responses. As adjuvants, DC may be useful for enhancing immunogenicity and mediating tumor regression. Endogenous expression of antigen by DC could offer the potential advantage of allowing prolonged constitutive presentation of endogenously processed epitopes and exploitation of multiple restriction elements for the presentation of the same antigen.

METHODS

DC were prepared from the peripheral blood of HLA A*0201 patients with metastatic melanoma in the presence of IL-4 (1000 IU/mL) and GMCSF (1000 IU/mL). Recombinant vaccinia and fowlpox viruses encoding the hMART-1 gene were constructed and used to infect DC. The efficiency of infection and expression of the MART-1 antigen were assessed by immunohistochemistry and intracellular FACS analyses. Cytotoxic lymphocytes (CTL) were generated by the stimulation of CD8+ T cells, with DC expressing the recombinant gene. Reactivity of the CTL was determined at weeks 1 and 2 by the amount of IFN-gamma released.

RESULTS

DC were infected with recombinant poxviruses and demonstrated specific melanoma antigen expression by immunohistochemistry, immunofluorescence, and intracellular FACS analysis. The expression by DC of MART-1 MAA after viral infection was sufficient to generate CD8+ T lymphocytes that recognized naturally processed epitopes on tumor cells in 10 of 11 patients.

CONCLUSIONS

Human DC are receptive to infection by recombinant poxviruses encoding MAA genes and are capable of efficiently processing and presenting these MAA to cytotoxic T cells. The potential advantage of this approach is the ability to present specific antigen independent of the identification of the epitope or the MHC restriction element. This strategy may be useful for the identification of relevant epitopes for a diverse number of HLA alleles and for active immunization in patients.

Erythrocyte lysate releases Ca2+ from IP3-sensitive stores and activates Ca(2+)-dependent K+ channels in rat basilar smooth muscle cells

Erythrocyte lysate increases intracellular Ca2+ ([Ca2+]i), contracts cerebral arteries and has been suggested to be the causative agent for cerebral vasospasm. However, the mechanism of erythrocyte lysate-induced [Ca2+]i mobilization is not clear. This study was undertaken to investigate the action of erythrocyte lysate on [Ca2+]i mobilization by monitoring [Ca2+]i and the Ca(2+)-dependent K+ channels (KCa) in freshly isolated rat basilar artery smooth muscle cells. In a [Ca2+]i imaging study, erythrocyte lysate produced a biphasic response, a transient peak and a prolonged plateau [Ca2+]i elevation. In the absence of external Ca2+, erythrocyte lysate induced only a transient peak [Ca2+]i response without a marked plateau phase, indicating the [Ca2+]i was Ca2+ released from internal stores. Erythrocyte lysate-induced plateau [Ca2+]i response was resistant to nicardipine, a voltage-dependent Ca2+ channel blocker, but was abolished by EGTA. Elevation of [Ca2+]i induced by erythrocyte lysate contracted smooth muscle cells. In the electrophysiological study, elevation of [Ca2+]i by erythrocyte lysate increased KCa currents in whole-cell patch-clamp configuration. This effect of erythrocyte lysate on KCa was blocked by heparin, an antagonist of IP3 receptors. We conclude that erythrocyte lysate releases Ca2+ from IP3-sensitive intracellular stores and produces Ca2+ entry from voltage-independent Ca2+ pathways.

Nephron sparing surgery for de novo renal cell carcinoma in an allograft kidney: a case report

De novo renal cell carcinoma in a renal allograft is rare and has special implications in renal transplant recipients. We describe a patient with a renal allograft who developed a de novo renal cell carcinoma in the functioning renal allograft 258 months after transplantation. The patient underwent enucleation of the tumor because preoperative MRI showed it was well-encapsulated. A DNA banding study showed that the tumor originated from the donor. Indications for conservative renal surgery in renal cell carcinoma have been increasing. Accordingly, 1 option in the treatment of de novo renal cell carcinoma in a functioning renal allograft is enucleation as a method of nephron sparing surgery.

Experimentally induced intrauterine infection causes fetal brain white matter lesions in rabbits

OBJECTIVE

Periventricular leukomalacia, a common brain white matter lesion in preterm neonates, is a major risk factor for cerebral palsy. Epidemiologic studies have demonstrated an association between infection and periventricular leukomalacia. The purpose of this study was to determine whether ascending intrauterine infection could cause brain white matter lesions in the fetal rabbit.

STUDY DESIGN

Rabbits with timed pregnancies underwent hysteroscopy at 20 to 21 days of gestation (70%). Animals were allocated in a ratio of 2:1 for inoculation with either Escherichia coli (0.2 ml containing 10(3) to 10(4) colony-forming units) or sterile saline solution. Both groups were treated with ampicillin-sulbactam (Unasyn, 100 mg/kg per day; Pfizer, Seoul) every 8 hours until they were killed 5 to 6 days after hysteroscopy. Histologic examination of the placentas and fetal brains was conducted.

RESULTS

Forty-five animals underwent hysteroscopy; 31 were inoculated with E. coli and 14 with sterile saline solution. At the time the animals were killed, the rate of intrauterine infection was higher and there were fewer live fetuses in the E. coli-inoculated animals than in the saline solution group. Histologic evidence of brain white matter damage was identified in 12 fetuses born to 10 E. coli-inoculated rabbits but none in the saline solution group (p < 0.05). All rabbits with brain white matter lesions had evidence of intrauterine infection. Evidence of white matter damage included increased karyorrhexis, rarefaction, and disorganization of white matter. Apoptosis was demonstrated in areas of white matter damage by immunohistochemical studies.

CONCLUSION

Experimental ascending intrauterine infection can cause fetal brain white matter lesions.

High expression of tumor necrosis factor-alpha and interleukin-6 in periventricular leukomalacia

OBJECTIVE

Periventricular leukomalacia, a common neonatal brain white matter lesion, is a major risk factor for cerebral palsy. Subclinical chorioamnionitis is a risk factor for the development of periventricular leukomalacia, and inflammatory cytokines have been implicated as central mediators of brain injury in this disorder. To elucidate the relationship between the local expression of cytokines and periventricular leukomalacia, we studied neonatal brains to determine whether high expression of tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6 was observed in these lesions.

STUDY DESIGN

Immunohistochemical staining for cytokines (tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6) was performed in 10% formalin-fixed, paraffin-embedded brain sections of 17 cases with periventricular leukomalacia. Specimens were obtained from autopsies performed between 1987 and 1994. Brain sections from 17 cases of neonatal deaths without periventricular leukomalacia lesions matched for gestational age at birth, duration of postnatal survival, and presence or absence of infection-related morbidity were used as controls.

RESULTS

The expression of tumor necrosis factor-alpha, interleukin-1 beta, or interleukin-6 was demonstrated in 88% (15/17) of cases with and in 18% (3/17) of cases without periventricular leukomalacia (p < 0.001). Cytokines were expressed mainly in hypertrophic astrocytes and microglial cells. The expression of tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6 was identified in 82% (14/17), 29% (5/17), and 71% (12/17) of cases of periventricular leukomalacia, respectively. However, a significantly lower proportion of cases without periventricular leukomalacia expressed tumor necrosis factor-alpha (18%, 3/17) and interleukin-6 (6%, 1/17) than those with the disorder (p < 0.005 for each).

CONCLUSIONS

Expression of tumor necrosis factor-alpha and interleukin-6 was observed more frequently in brain lesions with periventricular leukomalacia than in those without periventricular leukomalacia. These findings provide strong support for the hypothesis that proinflammatory cytokines play a role in the genesis of periventricular leukomalacia.

Cerebral leiomyoma in a child

A case of primary cerebral leiomyoma in a 12 year-old boy with unique clinical features is described. He presented with fever, and the magnetic resonance imaging demonstrated a well demarcated mass in the subcortical white matter of the right temporal lobe. The mass showed low signal intensity on T1-weighted images and high signal intensity on T2-weighted images with a strong homogeneous gadolinium-DTPA enhancement. The mass was removed in toto and was composed of fasciculating, monotonous oval to spindle cells which had both immunohistochemical and ultrastructural features of primitive smooth muscle differentiation. The patient is free of recurrence during the follow-up period of 56 months. Detailed clinicopathologic findings are discussed.

Dissolution of thrombotic arterial occlusion by high intensity, low frequency ultrasound and dodecafluoropentane emulsion: an in vitro and in vivo study

OBJECTIVES

We examined the effectiveness of the microbubbles of an echo contrast agent, dodecafluoropentane (DDFP) emulsion, to enhance low frequency ultrasound clot disruption in vitro and in vivo.

BACKGROUND

Ultrasound is reported to facilitate clot dissolution, and microbubbles could theoretically enhance ultrasound clot dissolution by augmenting cavitational effects.

METHODS

IN VITRO STUDIES

The disruption rate of fresh human clots by ultrasound (24 kHz, 2.9 W/cm2) was examined in saline and DDFP emulsion. In vivo studies: Using a rabbit iliofemoral thrombotic occlusion model, recanalization rate and histopathologic findings were compared among groups treated with DDFP emulsion alone, transcutaneous ultrasound (20 kHz, 1.5 W/cm2) alone and with DDFP emulsion and ultrasound combined.

RESULTS

The ultrasound clot disruption rate was significantly (p < 0.01) increased, from 72 +/- 18% (mean +/- SD) in saline to 98 +/- 4% in DDFP emulsion in 3 min in vitro. No vessel was recanalized by DDFP emulsion alone (0%), and only a single artery was patent after ultrasound treatment alone (9%). In contrast, 82% of iliofemoral arteries were angiographically recanalized after ultrasound treatment with DDFP emulsion. Histologically, the patent arteries had only minimal focal mural thrombus, with no evidence of vessel wall damage. However, substantial damage was observed in rabbit dermis and subcutaneous tissue.

CONCLUSIONS

1) DDFP emulsion, an echo contrast agent, significantly enhances the clot-disrupting effect of low frequency ultrasound in vitro and in an in vivo rabbit iliofemoral occlusion model. 2) This simple combination therapy has potential for clinical application in patients with thrombotic arterial occlusions.

Dendritic cells infected with poxviruses encoding MART-1/Melan A sensitize T lymphocytes in vitro

Dendritic cells (DC) are potent professional antigen-presenting cells that can activate naive T lymphocytes and initiate cellular immune responses. As adjuvants, DC may be useful in enhancing the immunogenicity of tumor antigens and mediating tumor regression. Endogenous expression of antigen by DC offers the potential advantage of allowing prolonged constitutive presentation of endogenously processed epitopes and exploitation of multiple restriction elements for the presentation of the same antigen. In this report, we show that human DC are (a) capable of infection by recombinant poxviruses encoding melanoma-associated antigen (MAA) genes and (b) capable of efficiently processing and presenting these MAA to cytotoxic T cells. In 6/6 HLA A*0201-expressing melanoma patients tested, the virally driven expression of MART-1/Melan A MAA by DC was sufficient to generate CD8+ T lymphocytes that could recognize naturally processed epitopes on tumor cells. In most cases, specific anti-MART-1 reactivity could be detected after a single stimulation. Analysis of epitope dominance revealed that the amino acid sequence recognized by these cytotoxic T lymphocytes (CTL) corresponded to the MART-1(27-35) residues previously shown to be most commonly recognized by cytotoxic T lymphocytes expanded from metastatic melanoma lesions. These data show that the virally driven expression of MAA by DC can be exploited for the efficient induction of clinically relevant cytotoxic T-cell responses. This has clinical implications for active immunization therapy, and currently vaccine trials have been proposed for patients with metastatic melanoma.

A prospective randomized evaluation of the prophylactic use of low-dose dopamine in cancer patients receiving interleukin-2

The administration of high-dose interleukin-2 (IL-2) causes tumor regression in 17-25% of patients with metastatic melanoma or renal cell carcinoma. Renal dysfunction is a common dose-limiting toxicity of IL-2 administration, limiting 26% of treatment cycles. We have conducted a prospective randomized trial to evaluate whether the prophylactic administration of low-dose dopamine (2 mg/kg/min) can minimize renal toxicity and thus affect the amount of IL-2 administered. Forty-two patients were randomly assigned to receive systemic high-dose IL-2 with standard supportive measures (group A = 21 patients) or with the addition of prophylactic dopamine (group B = 21 patients) at 2 mg/kg/min. For patients in group B, dopamine was instituted 1 h before the initiation of IL-2 administration and was discontinued 6-12 h after the maximum number of doses of IL-2 were given. There was no difference in the amount of IL-2 administered for each course of therapy for groups A and B. Despite differences in urine flow (milliliters per kilogram per day), fluid balance (liters per day), and overall weight gain, prophylactic low-dose dopamine did not significantly alter maximum plasma urea or creatinine levels in group B when compared with the control group (group A). The overall toxicity profile considering all grade 3 and 4 toxicities for patients in groups A and B was comparable. Thus, there is no evidence to support the routine use of prophylactic low-dose dopamine in patients receiving high-dose IL-2.

Comparison of intravascular ultrasound measurements at the sites of balloon dilatations of femoral arteries with measurements of postmortem gross arterial segments at the same sites

Intravascular ultrasound measurements of arterial cross-sectional area at the site of balloon dilatation are quantitatively accurate and consistent with measurements by digital planimetry. Lumen cross-sectional area determinations are virtually the same and the minor differences in total arterial cross-sectional area are probably related to the dehydration of each specimen, which occurred during the interval between studies. Thus, arterial disruption by balloon angioplasty does not interfere with the quantitative accuracy of intravascular ultrasound measurements.

Physical status and expression of HPV genes in cervical cancers

It is known that E2 protein of oncogenic human papillomavirus (HPV) inhibits the expression of E6 and E7 genes from their major promoters in vitro and suppresses the proliferation of cervical cancer cells. This suggests that the loss of functional E2 gene may provide selective advantages in the development of cervical cancer. Investigation of the relationship between the disruption of HPV-16/18 E2 genes by DNA integration and clinical outcome of cervical cancer may not only help to understand the mechanism of HPV-related cervical carcinogenesis, but may also provide novel management of cervical cancer. It was noted that integrated HPV-16/18 DNA was predominant in most patients with cervical cancers, marking 51 of a total of 68 cases (75%); episomal HPV DNAs were found in 5 cases (7.4%), and finally mixed forms of HPV DNAs with episome and integration were found in 12 cases (17.6%). Whole portions of E2 DNA of HPV-16 could be amplified by PCR in 19 (36.5%) of 52 cases of cervical intraepithelial neoplasia. It was shown that there was not statistically significant association with the different stages, but integrated HPV DNAs were detectable only in the patients with far-advanced stage of cervical cancers, which also means no episomal forms were detected. Episomal forms of HPV DNA were detectable in 14 (25.9%) of 54 squamous cell carcinomas (4 pure episomal forms and 10 mixed forms), whereas only 1 (8.3%) of 12 adenocarcinomas and adenosquamous cell carcinomas contained episomal viral DNA. When HPV DNA forms were compared with initial tumor size, lymphovascular space involvement, and frequency of nodal metastasis, statistically significant relationships were not found. The association of DNA integration with invasive cervical cancers was seen regardless of HPV type; however, there were differences between the integration profiles of HPV-16 and HPV-18 DNA. Of the 51 HPV-16-containing cancers, 36 (70.6%) revealed purely integrated HPV DNA, and another 10 cases (19.6%) displayed both integrated and episomal HPV DNAs. However, 5 (9.8%) cases showed only episomal copies of the HPV-16 genome. In contrast, all 17 HPV-18-containing cancers (5 cases positive for HPV-18 and 12 cases positive for both HPV-16 and -18) revealed only the integrated form of HPV-18 DNA. The expression of E6 and E7 transcripts of HPV-16/18 is uniformly correlated with the physical status of HPV DNAs. HPV E2 mRNAs were constantly expressed in the presence of the intact virus in cases with episome and mixed forms of HPV DNA. In general, amplified signals from HPV E2 RT-PCR are more intensive than those from DNA-PCR in the same patients. It is suggested that RT-PCR is a valuable method to evaluate dynamic expression of the specific gene and seems to be more sensitive than the DNA-PCR method in detecting intact E2 gene because of the gene copy numbers.

Genetic evidence for the multicentric origin of synchronous multiple gastric carcinoma

Multiple gastric cancers, which constitute 4% to 10% of all gastric cancers, occur in older people and are associated with more extensive intestinal metaplasia. With regard to the genesis of multiple gastric cancers, multicentricity (independent origin) rather than multifocality (local or lateral spread of one cancer) has been the favored theory. Conventional morphologic study, however, has not been able to provide convincing evidence in support of multicentricity. The purpose of this study was to verify the multicentric origin of multiple gastric cancers at a genetic level. For this purpose, immunohistochemical and molecular techniques were used to define the mutation pattern of APC, MCC and p53 in multiple lesions of synchronous multiple gastric cancers. The study was based on a total of 30 gastric tumors from 13 patients, including 10 double tumors, 2 triple tumors, and 1 quadruple tumor. Single-strand conformation polymorphism and polymerase chain reaction direct sequencing were carried out for exons 5 to 8 of p53, and loss of heterozygosity was detected on the basis of polymerase chain reaction amplification of polymorphism in exon 10 of MCC and in exon 11 of APC. Twelve of 13 cases showed alteration in one or more genetic markers. Of these, three demonstrated a discordant mutation pattern of p53 in individual lesions, and another two revealed allelic loss of MCC in one lesion and p53 mutation in the other. In six other cases, only one lesion showed alteration of APC, MCC, or p53, and in the remaining case, one lesion carried p53 and MCC mutations and the other carried MCC loss of heterozygosity only. The results of this study showed discordance of the mutation pattern of APC, MCC, and p53 in individual lesions of multiple gastric cancers, providing genetic evidence for a multicentric origin of synchronous multiple gastric carcinomas. Collectively, these findings supported the theory of field cancerization in gastric carcinogenesis.

Modulation of high-voltage activated Ca2+ channels in the rat periaqueductal gray neurons by mu-type opioid agonist

The effect of mu-type opioid receptor agonist, D-Ala2,N-MePhe4,Gly5-ol-enkephalin (DAMGO), on high-voltage-activated (HVA) Ca2+ channels in the dissociated rat periaqueductal gray (PAG) neurons was investigated by the use of nystatin-perforated patch recording mode under voltage-clamp condition. Among 188 PAG neurons tested, the HVA Ca2+ channels of 38 neurons (32%) were inhibited by DAMGO (DAMGO-sensitive cells), and the other 80 neurons (68%) were not affected by DAMGO (DAMGO-insensitive cells). The N-, P-, L-, Q-, and R-type Ca2+ channel components in DAMGO-insensitive cells shared 26.9, 37.1, 22.3, 7.9, and 5.8%, respectively, of the total Ca2+ channel current. The channel components of DAMGO-sensitive cells were 45.6, 25.7, 21.7, 4.6, and 2.4%, respectively. The HVA Ca2+ current of DAMGO-sensitive neurons was inhibited by DAMGO in a concentration-, time-, and voltage-dependent manner. Application of omega-conotoxin-GVIA occluded the inhibitory effect of DAMGO approximately 70%. So, HVA Ca2+ channels inhibited by DAMGO were mainly the N-type Ca2+ channels. The inhibitory effect of DAMGO on HVA Ca2+ channels was prevented almost completely by the pretreatment of pertussis toxin (PTX) for 8-10 h, suggesting that DAMGO modulation on N-type Ca2+ channels in rat PAG neurons is mediated by PTX-sensitive G proteins. These results indicate that mu-type opioid receptor modulates N-type HVA Ca2+ channels via PTX-sensitive G proteins in PAG neurons of rats.

Prognostic significance of pretreatment squamous cell carcinoma antigen and carcinoembryonic antigen in squamous cell carcinoma of the uterine cervix

Sixty-seven patients with squamous cell carcinoma of the uterine cervix (FIGO Stages IB2, IIA, and IIB) were reviewed to evaluate the pretreatment level of squamous cell carcinoma antigen (SCC) and carcinoembryonic antigen (CEA) which may be used to predict a subset of patients with poor prognosis. The rate of pathologic pretreatment serum level of SCC increased significantly in cases with Stage IIB compared to that of Stages IB2 and IIA (50% versus 16.3%). The rate of pathologic pretreatment serum level of CEA did not show any difference between these two groups (29.2% versus 30.2%). The 48-month disease-free survival for patients with pathologic pretreatment serum levels for one or both tumor-associated antigens (TAAs) was 40.0% versus 91.7% for patients with normal levels (log-rank test, P < 0.005) in Stages IB2 and IIA. Patients who had a pathologic pretreatment serum level for one or both TAAs showed higher incidence of lymph node metastasis than patients with normal levels (36.7% versus 10.8%). The patients who had pathologic pretreatment serum levels for both TAAs and lymph node metastasis have the poorest prognosis. The pretreatment serum levels for one or both TAAs make it possible to predict the clinical response to neoadjuvant chemotherapy consisting of cis-platinum (DDP) and 5-fluorouracil (5-FU). Our findings suggest that pretreatment of SCC in conjunction with CEA is a valuable tumor marker to predict the prognosis of squamous cell carcinoma of the uterine cervix and to foresee a clinical response to subsequent neoadjuvant chemotherapy.

Preserved vasodilatory response to nitroglycerin in saphenous vein bypass grafts

BACKGROUND

Uncertainty exists regarding the effects of nitroglycerin on atherosclerotic segments of coronary arteries, and information on vasoreactivity of saphenous vein bypass grafts is sparse. Intravascular ultrasound enables identification of atherosclerosis in angiographically normal segments and allows continuous determination of alterations in cross-sectional lumen areas.

METHODS AND RESULTS

Patients with documented coronary atherosclerosis were studied. Vessel morphology and lumen area at baseline and after 100 to 200 micrograms nitroglycerin were assessed at 10-second intervals for 60 seconds in vessel segments without angiographically apparent lesions. Coronary artery saphenous vein bypass grafts from 11 patients were compared with native coronary arteries in 16 different patients. Atherosclerosis was present in all vessel segments studied. There was a rapid increase in lumen area compared with baseline after intravascular nitroglycerin in both native coronary arteries and saphenous vein bypass grafts. Maximum lumen area dilatation was 19.6 +/- 12.2% in saphenous vein bypass grafts and 19.7 +/- 13.1% in native coronary arteries. An earlier peak response in saphenous vein bypass grafts (34.5 +/- 6.9 seconds) compared with native coronary arteries (44.7 +/- 8.5 seconds; P = .003) was found. Vessel wall area remained constant during vasodilation, but there was a significant reduction in measured wall thickness (P = .034).

CONCLUSIONS

In patients with documented coronary artery disease, intravascular ultrasound reveals substantial atherosclerosis in angiographically normal vessel segments. In these vessel segments, both native coronary arteries and saphenous vein bypass grafts exhibit prompt vasodilation with the intravascular administration of nitroglycerin. The vasodilatory capacity in response to nitroglycerin seems to be preserved in transposed, denervated, and devascularized saphenous veins.

Correspondence of aortic valve area determination from transesophageal echocardiography, transthoracic echocardiography, and cardiac catheterization

The correspondence of aortic valve area measurements from transesophageal echocardiography, transthoracic echocardiography, and cardiac catheterization was determined in 100 patients with severe aortic stenosis (aortic valve area < or = 0.75 cm2), moderate aortic stenosis (aortic valve area > 0.75 to < or = 1.2 cm2), mild aortic stenosis (aortic valve area > 1.2 to < or = 2.0 cm2), and nonstenotic aortic valves (aortic valve area > 2.0 cm2). Because high correlation does not require high agreement, data were assessed by analysis of agreement. Aortic valve areas determined by transthoracic echocardiography (1.43 +/- 0.76 cm2), transesophageal echocardiography (1.40 +/- 0.79 cm2), and cardiac catheterization (1.47 +/- 0.82 cm2) were similar. Correlations between methods were excellent (r values = 0.96). "Limits of agreement" between the three comparisons did not differ significantly. Similar levels of agreement when comparing these independent methods for determining the aortic valve area indicate that direct planimetry by transesophageal echocardiography, the continuity equation with transthoracic echocardiography, and the Gorlin formula are equally accurate and may be used interchangeably. Clinically important discrepancies between methods are uncommon and are readily settled by adding a third method.

Primary intramedullary spinal cord primitive neuroectodermal tumor with intracranial seeding in an infant

Primary spinal cord primitive neuroectodermal tumor (PNET) is a rare entity. In all 13 cases have been reported in the literature, including 3 with intracranial seeding. A 3-month-old girl with involvement of the spinal cord below the mid-thoracic level is described. The brain MRI revealed findings indicative of seeding along the intracranial subarachnoid space. Biopsy, duraplasty and removal of laminotomy flap were done. In spite of a good response to the first cycle of postoperative "8-drugs-in-a-day' chemotherapy, further treatment was refused. She died 21 days after the onset of leg weakness, which reveals the rapid progression of untreated cases. To our knowledge, this is the first case of spinal cord PNET with parenchymal involvement that has been described in an infant.

A designer's polymer as an oral drug carrier (tablet) with pseudo-zero-order release kinetics

A new synthetic polymeric material has been investigated as an oral controlled-release system. The water soluble polymer consists of a non-cross-linked, ionic polymer possessing sulfonate functional groups: poly(sulfopropyl methacrylate potassium-co- methyl methacrylate) (PSPMK/MMA). Drug-resin complexes were obtained by preparing an aqueous solution of the polymer to which propranolol HCl as a model drug was added. Using either dextrose or microcrystalline cellulose as a tablet binder did not cause any problems in fabricating a compact drug-resinate tablet. The release of propranolol HCl from drug-resinate tablets (2.5 mm x 9.0 mm, 10% dextrose) was pseudo-zero-order kinetics from the beginning to the end for over 21 h. This was due to the greater contribution of drug release from the edge of the tablets. However, zero-order release tablets were obtained by increasing the radius to thickness ratio of the tablet to greater than 3.13. A mathematical model describing release kinetics from drug-resinate tablets predicted the effects of drug loading and the physical dimensions of the tablets by a heterogeneous dissociation/erosion-controlled mechanism. As the content of dextrose in the tablets increased, the dissociation/erosion rate constant (K0) increased due to the greater influx of water into the tablets along with counterions. As expected, the release rate was decreased as the stirring rate decreased from 100 to 50 rpm, resulting in the dissociation/erosion rate constant of 2.62-2.04 mg/cm2h, respectively. Therefore, this system has been proven to release drugs independent of the pH of simulated gastric/intestinal fluids (1.2 and 7.5) as well as the compression force of the tablet, which ranged from 1500 to 4400 lbs.

Modulation of glycine-induced chloride current in acutely dissociated rat periaqueductal gray neurons by mu-opioid agonist DAGO

Effect of a mu-opioid agonist (D-Ala2,N-MePhe4,Gly5-ol-enkephalin, DAGO), on glycine (Gly)-induced chloride current (IGly) was investigated in the periaqueductal gray (PAG) neurons acutely dissociated 1-2-week-old Wistar rats by the use of nystatin-perforated patch recording configuration under voltage-clamp condition. At a holding potential (VH) of -40 mV, DAGO caused a sustained potentiation of IGly at the low concentrations (10(-6)-10(-5) M) but reduced slightly the Gly response at the high concentration (10(-4) M). The reversal potential of IGly was equal to the Cl- equilibrium potential (ECl) and was not changed in the presence of 10(-6) M DAGO. The 10(-5) M Gly response was inhibited by the simultaneous treatment of forskolin and 3-isobutyl-1-methylxanthine (IBMX). H-89, a protein kinase A (PKA) inhibitor, increased the 10(-5) M Gly response but had little effect on the 10(-4) M Gly response. DAGO increased 10(-5) M Gly response in the presence of forskolin and IBMX but, not more than in the absence of forskolin and IBMX. The 10(-5) M Gly response augumented by DAGO was not affected by adding H-89. The present results suggest that the glycine-induced chloride current is cAMP dependent and is inhibited by PKA, and that the potentiation of the glycine response by DAGO is also cAMP dependent and is due to the inhibition of PKA as that of H-89. We conclude that the potentiation of glycine response by DAGO is mediated by an inhibition of cAMP-dependent PKA in the PAG neurons.

Effect of BQ-123 and tissue plasminogen activator on vasospasm after subarachnoid hemorrhage in monkeys

BACKGROUND AND PURPOSE

We aimed to determine the effect of intracisternal administration of an endothelin-A receptor antagonist (BQ-123) against vasospasm in a monkey model and to determine whether this drug would have adverse interactions with intracisternal tissue plasminogen activator (TPA).

METHODS

Thirty-three monkeys were randomly allocated to undergo baseline cerebral angiography, creation of right subarachnoid hemorrhage (SAH), and intracisternal delivery of (1) placebo (n = 10); (2) low-dose BQ-123 (5 mg/kg per day, n = 7); (3) high-dose BQ-123 (10 mg/kg per day, n = 9); or (4) BQ-123 10 mg/kg per day plus TPA 1 mg every 12 hours for three doses (n = 7). Angiography was repeated after 7 days, and animals were killed. Vasospasm was assessed by comparisons of angiograms within groups across time by paired t test and by comparisons across groups at each time by ANOVA.

RESULTS

Significant clot remained in the basal cisterns in all groups except those receiving TPA, in whom complete clot clearance was noted. Comparisons of angiograms at baseline and after 7 days showed significant vasospasm of the right middle cerebral artery in animals receiving placebo (mean +/- SEM reduction in diameter, 36 +/- 7%; P < .05) and low- and high-dose BQ-123 (16 +/- 4% and 18 +/- 7%, respectively). Animals that received TPA did not develop significant right cerebral artery vasospasm. Comparisons of arterial diameters at day 7 revealed significant variance in right middle cerebral artery diameter, with animals in the placebo group having significantly more and animals in the TPA group having significantly less vasospasm than the BQ-123 groups. Histopathological examination of the brains did not show inflammation or pathological change in animals that received BQ-123 or BQ-123 plus TPA.

CONCLUSIONS

Intracisternal TPA was efficacious against vasospasm in monkeys. Combination therapy with TPA and BQ-123 was not associated with reduction in efficacy of either drug or with evidence of toxicity.

Transcutaneous ultrasound augments lysis of arterial thrombi in vivo

BACKGROUND

External ultrasound has a synergistic effect on thrombus disruption with thrombolytic agents in vitro. We hypothesized that transcutaneous ultrasound could augment thrombolysis in vivo.

METHOD AND RESULTS

Thrombus formation was induced electrically in 48 pairs of iliofemoral arteries of 24 rabbits; arterial occlusions were documented angiographically. In 17 of 24 rabbits, 25000 units/kg streptokinase was then administered intravenously. The pairs of iliofemoral arteries were randomized to receive ultrasound treatment or no ultrasound treatment. Low-frequency (26 kHz) ultrasound (continuous wave, 18 W/cm2) was applied transcutaneously over the area of occlusion. In 7 of 24 rabbits, 14 thrombotically occluded iliofemoral arteries were exposed to ultrasound alone without streptokinase. The results were evaluated through the use of angiography (TIMI grade flow) and histopathology. After 30 +/- 10 minutes of activated sonication combined with intravenous streptokinase, 10 of 17 iliofemoral arteries (59%) treated with transcutaneous ultrasound were widely patent angiographically, with TIMI grade 3 flow. Histologically, the patent arteries had only minimal focal moral thrombus. The angiographic patency rate was significantly lower in the control groups: 1 of 17 arteries (6%) treated with streptokinase alone (P = .0012) and 1 of 14 arteries (7%) treated with ultrasound alone (P = .0036).

CONCLUSIONS

In vivo transcutaneous ultrasound significantly augments lysis of thrombi with streptokinase in rabbit iliofemoral arteries.

Effect of hormone replacement therapy on lipoprotein(a) and lipid levels in postmenopausal women. Influence of various progestogens and duration of therapy

BACKGROUND

Estrogen replacement therapy in postmenopausal women reduces the risk of coronary artery disease. One of the possible mechanisms of this effect is the modification of lipid profiles. However, there is controversy concerning the effects on lipoprotein(a) [Lp (a)] and lipid levels of progestogens administered with estrogen.

METHODS

Five hundred fifty-one postmenopausal women were divided into 5 groups: group 1, 0.625 mg of conjugated equine estrogen (CEE) (n = 140); group 2, 0.625 mg of CEE plus 5 mg of medroxyprogesterone acetate (MPA) (n = 97); group 3, 0.625 mg of CEE plus 10 mg of MPA (n = 109); group 4, 2 mg of estradiol valerate plus 0.5 mg of norgestrel (n = 134); and group 5, control (n = 71). The Lp(a) and lipid levels were measured before and 2, 6, and 12 months after hormone replacement therapy.

RESULTS

Estrogen replacement therapy for 12 months lowered the Lp(a) level by 37.1%. The addition of progestogen attenuated the Lp(a)-lowering effect of estrogen. The high-density lipoprotein cholesterol (HDL-C) level was markedly increased in group 1 (16.5%), was moderately increased in groups 2 (10.8%) and 3 (11.3%), and was not changed in group 4. The low-density lipoprotein cholesterol level was decreased by 10.9% to 17.6% in all the treatment groups. Estrogen replacement therapy for 2, 6, and 12 months raised the HDL-C level by 7.2%, 17.4%, and 17.8%, respectively. In the group with combined estradiol plus norgestrel therapy, the HDL-C level was decreased after 2 months and was not changed after 6 and 12 months. The groups that received CEE plus MPA showed intermediate effects between the group that received CEE only and the group that received estradiol plus norgestrel.

CONCLUSIONS

Combined estrogen and progestogen therapy may have effects on the heart different from those of estrogen therapy alone because of adverse impact of progestogens on Lp(a) and HDL-C levels. The effects of progesterones were dependent on the androgenic potency of progestogen and the duration of therapy.

Contribution of inadequate compensatory enlargement to development of human coronary artery stenosis: an in vivo intravascular ultrasound study

OBJECTIVES

This intravascular ultrasound study sought to examine to what extent native coronary artery stenosis is accompanied by vessel wall thickening or inadequate compensatory enlargement (relative vessel constriction), or both.

BACKGROUND

In human femoral arteries, inadequate compensatory enlargement is reported to be a paradoxic mechanism for the development of severe arterial lumen narrowing. However, it is unclear in human coronary arteries whether inadequate compensatory enlargement contributes to the development of critical arterial stenosis.

METHODS

Thirty-five primary coronary artery lesions from 30 patients (19 men, 11 women; mean [+/- SD] age 65 +/- 13 years) were imaged by intravascular ultrasound. The vessel cross-sectional area and lumen area were measured, and the wall area (vessel cross-sectional area minus lumen area) was calculated at the lesion site and at the proximal and distal reference sites. We defined compensatory enlargement to be present when the vessel cross-sectional area at the lesion site was larger than that at the proximal reference site, inadequate compensatory enlargement when the vessel cross-sectional area at the lesion site was smaller than that at the distal reference site and intermediate remodeling when the vessel cross-sectional area at the lesion site was intermediate between the two reference sites.

RESULTS

Compensatory enlargement was observed in 19 (54%) of 35 lesions, inadequate compensatory enlargement in 9 (26%) of 35 and intermediate remodeling in 7 (20%) of 35. In the inadequate compensatory enlargement group, reduction of the vessel cross-sectional area contributed to 39% of lumen reduction.

CONCLUSIONS

Compensatory enlargement commonly (54%) occurs at stenotic coronary lesions. However inadequate compensatory enlargement results in a substantial amount (39%) of the lumen area reduction in 26% of primary coronary artery lesions.

Hemolysate inhibits L-type Ca2+ channels in rat basilar smooth muscle cells

Erythrocyte lysate increases intracellular Ca2+ ([Ca2+]i) and contracts cerebral arteries in vitro and has been suggested to be the cause for cerebral vasospasm. We investigated the effect of hemolysate on L-type Ca2+ channels directly by using patch clamp techniques in freshly isolated single smooth muscle cells from rat basilar artery. Patch clamp studies revealed a whole-cell current which resembles the L-type Ca2+ current reported by others. Hemolysate reduced the amplitude of the L-type Ca2+ channel current. The effect of hemolysate was reversible by washout and repeatable. Hemolysate was separated into two fractions by using filter membranes. The fraction > 1 kDa which contains oxyhemoglobin and other proteins mimicked the effect of hemolysate, while the fraction < 1 kDa and ATP were without effect. We conclude that hemolysate does not increase [Ca2+]i by activation of L-type Ca2+ channel.

Changes in Lp(a) lipoprotein and lipid levels after cessation of female sex hormone production and estrogen replacement therapy

OBJECTIVE

To investigate the serial changes in Lp(a) lipoprotein levels with the loss of female sex hormones by surgical menopause and with estrogen replacement therapy in the same woman.

PATIENTS AND METHODS

Forty-four premenopausal women who underwent a transabdominal hysterectomy (TAH) because of benign gynecological disorders were divided into two groups: women who underwent a TAH and unilateral salpingo-oophorectomy (n=31) and women who underwent a TAH and bilateral salpingo-oophorectomy (n=13). In the group of women who underwent a TAH and bilateral salpingo-oophorectomy, 0.625 mg of conjugated equine estrogen was given daily 2 months after the operation. The levels of Lp(a) lipoprotein and lipids were measured before and at 2 and 4 months after the operation.

RESULTS

In the group of women who underwent a TAH and bilateral salpingo-oophorectomy, the mean (+/-SD) concentration of Lp(a) lipoprotein was increased by 24.5% from 0.48+/-0.47 mmol/L (18.4+/-18.3 mg/dL) to 0.59+/-0.54 mmol/L (22.9+/-21.0 mg/dL) after 2 months (P<.05), and it was reduced by 30.6% to 0.41+/-0.51 mmol/L (15.9+/-20.1 mg/dL)(P<.005) with therapy with conjugated equine estrogen (Premarin). The Lp(a) lipoprotein levels were not changed in the group of women who underwent a TAH and unilateral salpingo-oophorectomy. In the group of women who underwent a TAH and bilateral salpingo-oophorectomy, the high density lipoprotein cholesterol level showed a trend of increase after 2 months from 1.45+/-0.48 mmol/L (56.1+/-18.5 mg/dL) to 1.58+/-0.309 mmol/L (61.2+/-15.1 mg/dL) without statistical significance, and it revealed a significant elevation to 1.76+/-0.43 mmol/L (68.2+/-16.8 mg/dL) with therapy with conjugated equine estrogen (Premarin) compared with that of the basal level (P<.05).

CONCLUSIONS

tHE Lp(a) lipoprotein levels appear to be closely associated with female sex hormones. This association might play a pivotal role in postmenopausal increases of atherosclerotic diseases and cardioprotective effect of estrogen in postmenopausal women.

Presence of oncogenic HPV DNAs in cervical carcinoma tissues and pelvic lymph nodes associating with proliferating cell nuclear antigen expression

The presence of oncogenic HPV DNAs (HPV-16/18) in cervical carcinomas and their normal and metastatic pelvic lymph nodes and the expression patterns of proliferating cell nuclear antigen (PCNA) in cervical carcinomas were retrospectively studied to elucidate the possible roles of them in malignant transformation and progression of the disease. HPV-16/18 DNAs were detected by polymerase chain reaction using HPV E6 type-specific primers in 79 patients with cervical cancer. 31 patients who had pelvic lymph node metastasis (group I) and 48 patients without pelvic lymph node metastasis (group II) who were proven by pathologic examination of surgical specimens. HPV-16 or -18 DNAs were detectable in cervical carcinoma tissues in 60 patients from 79 cervical cancer patients (75.9%; HPV-16 was 67.1% and HPV-18 was 8.9%). HPV DNAs were amplified from metastatic pelvic lymph nodes in 13 patients of group I (42%) and from nonmetastatic lymph nodes in 7 group I patients (22.5%). Recurrence was identified in 9 group I patients (29.0%) in 3 years of follow-up. HPV DNAs were amplified from nonmetastatic lymph nodes in 11 group II patients (22.9%). Two group II patients, who had HPV-16 DNA by PCR in nonmetastatic nodes, were recurrent. PCNA was overexpressed in 66.7% of HPV-16- or -18-positive cervical cancers and 16.7% of HPV-16- or -18-negative cervical cancers. However, the expression levels of PCNA in cervical cancers were not influenced by the presence of oncogenic HPV DNA or pathologic metastasis in the pelvic lymph nodes. In conclusion, HPV DNA could be amplified from some metastatic and nonmetastatic pelvic lymph nodes and the detectability of oncogenic HPV DNA in pelvic lymph nodes may represent the poor outcome in the treatment of disease. The expression of PCNA protein which was associated with presence of oncogenic HPV DNAs in cervical cancers, suggesting activation of S phase of cell cycle, may contribute to the malignant progression by HPV-16 or -18.

Absence of focal compensatory enlargement or constriction in diseased human coronary saphenous vein bypass grafts. An intravascular ultrasound study

BACKGROUND

No in vivo data are available on the occurrence of compensatory enlargement or vessel constriction in diseased human coronary saphenous vein bypass grafts (SVBGs). The aim of this intravascular ultrasound (IVUS) study was to examine to what extent lumen reduction is accompanied by (1) vessel wall thickening and (2) arterial wall constriction in SVBGs.

METHODS AND RESULTS

We used IVUS to examine 43 SVBGs from 42 patients (32 men, 10 women; mean age, 72 +/- 5 years) 8 to 23 (11 +/- 4) years after SVBG. IVUS images were obtained with a 3.5F monorail ultrasound catheter with a 30-MHz frequency and were analyzed at the lesion site, the reference site, and an intermediate site. The lumen area was significantly (P < .01) decreased; the vessel wall area (SVBG cross-sectional area minus lumen area) and the plaque area (area within the external elastic lamina minus lumen area) were significantly (P < .01) increased from the reference site through the lesion site. However, SVBG cross-sectional area was the same at these three sites (24.0 +/- 8.1 versus 24.4 +/- 8.6 versus 24.5 +/- 8.6 mm2, P = NS), and the external elastic lamina area was also quite constant in each vessel (17.8 +/- 6.0 versus 17.7 +/- 6.4 versus 17.6 +/- 6.2 mm2, P = NS).

CONCLUSIONS

These in vivo IVUS data from human coronary SVBGs demonstrate that (1) no focal compensatory enlargement or vessel constriction occurred in stenotic segments compared with the reference segments and that (2) the absence of focal compensatory enlargement appears to be a potentially important factor in the progression of stenoses in coronary SVBGs.

Maternal blood C-reactive protein, white blood cell count, and temperature in preterm labor: a comparison with amniotic fluid white blood cell count

OBJECTIVE

To compare the diagnostic and prognostic performance of maternal blood C-reactive protein, white blood cell count (WBC), and temperature with that of amniotic fluid (AF) WBC in preterm labor.

METHODS

One hundred two women with preterm labor and intact membranes were studied. Maternal blood was collected to measure C-reactive protein concentration and WBC, and maternal temperature was also measured. Amniotic fluid obtained by amniocentesis was cultured and WBC determined. Receiver operating characteristic curve, logistic regression, and survival techniques were used for analysis.

RESULTS

Patients with acute histologic chorioamnionitis had significantly higher median C-reactive protein concentration, WBC, temperature, and AF WBC than patients without this lesion (P < .05). Receiver operating characteristic curve and survival analysis demonstrated that an elevated C-reactive protein, WBC, or AF WBC was strongly associated with the likelihood of histologic chorioamnionitis, shorter interval to delivery, clinical chorioamnionitis, and neonatal morbidity (P < .05 for each). Of all the tests, AF WBC was the best independent predictor of a positive AF culture (odds ratio [OR] 16.8), interval to delivery (hazard ratio 5.7), clinical chorioamnionitis (OR 15.2), neonatal sepsis (OR 16.8), and significant neonatal complications (OR 7.4), after other confounding variables were adjusted (P < .05 for each).

CONCLUSION

An elevated C-reactive protein, WBC, or AF WBC identified patients with intrauterine infection and adverse perinatal outcomes. Amniotic fluid WBC was a better independent predictor of these outcomes than C-reactive protein, WBC, or temperature.

Effects of prolonged glucose infusion on insulin secretion, clearance, and action in normal subjects

It was the aim of this study to determine whether prolonged hyperglycemia can produce "glucose toxicity" in normal human subjects. To this end, plasma glucose was clamped at approximately 5, approximately 8.8, and approximately 12.6 mM for 68 h in healthy volunteers. Rates of insulin secretion (by deconvolution of plasma C-peptide) and rates of insulin clearance [area under curve (AUC) 24 h insulin secretion/AUC 24 h insulin] were determined. Pre- and posthyperglycemia glucose turnover was measured (with [6,6-2H2]glucose) during euglycemic-hyperinsulinemic clamping to assess peripheral (muscle) and hepatic insulin action. Hyperglycemia (approximately 12.6 mM) for 68 h was associated with significant reductions in rates of insulin secretion (-35%, P < 0.05), insulin clearance (-57%, P < 0.05), glucose infusion rates needed to maintain hyperglycemia (-36%, P < 0.05), and insulin-stimulated glucose uptake (-55%, P < 0.01). No significant changes were seen during approximately 8.8 mM hyperglycemia or during euglycemia. These data showed that 12.6 mM hyperglycemia, but not 8.8 mM hyperglycemia or euglycemia, was associated with reduced insulin secretion, insulin clearance, and peripheral (muscle) insulin action. We concluded that 1) in normal subjects, desensitization to glucose involving beta-cells and muscle developed at plasma glucose concentrations between approximately 9 and approximately 12 mM, and 2) these effects were partially compensated for by a decrease in insulin clearance.

A partially purified beta-glucosidase from Bifidobacterium adolescentis converts cycasin to a mutagenic compound

beta-Glucosidase was extracted from sonicated Bifidobacterium adolescentis Int-57 and partially purified by Sepharose CL-6B gel-filtration and DEAE-cellulose ion-exchange chromatography. The partially purified enzyme was confirmed to convert cycasin to a mutagen in the Ames and SOS chromotests. beta-Glucosidase negative strains were unable to activate cycasin mutagenically.