Effect of surface treatment on fatigue life of postceramic soldered joints

PURPOSE

This research investigated the effect of surface treatment on the fatigue life of metal-ceramic postsoldering.

MATERIALS AND METHODS

Twenty cylindric specimens were cast in a metal-ceramic alloy. All specimens received appropriate heat treatment simulating ceramic application, although no porcelain was applied. Each specimen was cut in half to form two half specimens. The 40 half specimens were randomly assigned to one of the four treatment groups, which differed in the type of surface treatment performed on one end of each half specimen (joint surface) prior to soldering: (1) aluminous oxide pink stone; (2) 50-micron aluminum oxide sandblasting; (3) brown rubber point; and (4) gray silicone wheel followed by pink silicone wheel. All surface treatments were performed for 30 seconds. The half specimens were then steam cleaned, aligned, indexed, and oven soldered with #650 postceramic solder. The soldering of two half specimens formed a complete test specimen, and a total of 20 postceramic soldered specimens were prepared. Following soldering, a 241.1 MPa fatigue stress was applied to each solder joint during specimen testing. The test variable was the number of stress cycles required to fail each specimen.

RESULTS

All specimens failed adhesively at the joint interface between the solder and parent metal. There were significant differences in the number of stress cycles to failure between groups 1 and 2, groups 1 and 4, and between groups 2 and 3.

CONCLUSION

The load cycle to failure for postceramic soldered joints was affected by the metal surface treatment.

Combination carboplatin and radiotherapy in the management of stage II testicular seminoma: comparison with radiotherapy treatment alone

PURPOSE

To assess the results of treatment in 33 patients with stage IIA/B seminoma who were treated with carboplatin and radiotherapy (RT) between January 1989 and December 1996.

PATIENTS AND METHODS

Thirty patients received single course single agent carboplatin (400 mg/m2 or area under curve (AUC 7), two patients received two courses carboplatin, and one patient received single course carboplatin and etoposide, all 4-6 weeks prior to infra-diaphragmatic RT. Results were retrospectively compared with those obtained for 80 patients treated from 1970 to 1998 with radiotherapy alone.

RESULTS

There was minimal toxicity associated with the use of carboplatin prior to RT. With a median follow-up of 4 years (range 2-70 months) 2/33 patients treated with chemotherapy and RT have relapsed, 5-year relapse free survival (RFS) = 96.9% (95% confidence interval (CI) 72.9-99.4%), and one patient has died of progressive disease, 5-year overall survival (OS) = 96.7%. With a median follow-up of 11.2 years (range 6 months to 25.8 years) 15/80 patients treated with RT alone have relapsed, 5-year RFS = 80.7% (95% CI 70.1-87.9%), including 13/61 patients treated with infra-diaphragmatic RT, 5-year RFS = 77.9%, and 2/19 treated with additional supra-diaphragmatic RT, 5-year RFS = 89.5% (P = 0.277). Eleven out of 80 patients have died, 5-year OS = 94.7%. For stage IIA, 1/14 patients treated with chemotherapy and RT have relapsed, 5-year RFS = 92.3%, compared with 5/34 treated with infra-diaphragmatic RT alone 5-year, RFS = 84.9% (P = 0.527). For stage IIB, 1/19 patients relapsed (at 69 months) following chemotherapy and RT (5-year RFS = 100%), whereas 8/27 relapsed following infra-diaphragmatic RT alone, 5-year RFS = 69.4% (P = 0.0595).

CONCLUSION

Infradiaphragmatic RT alone cures the majority of patients with stage II seminoma, but the relapse rate remains high particularly for patients with stage IIB disease. As compared with historical controls, carboplatin with RT appears to reduce the relapse rate in stage II seminoma with minimal additional toxicity and the results approach statistical significance for stage IIB patients. Confirmation would require a phase III randomized comparison.

The LMP1 gene isolated from Russian nasopharyngeal carcinoma has no 30-bp deletion

The Epstein-Barr virus (EBV) is tightly linked to the induction of undifferentiated nasopharyngeal carcinoma (NPC), a tumour endemic in certain areas of southeast Asia. The LMP1 gene encoded by EBV is a classical oncogene due to its ability to transform rodent fibroblasts. LMP1 is absolutely essential for transformation of B cells by the virus and is one of the few EBV genes found to be expressed in NPC. It was originally shown that the LMP1 gene from NPC harbours a deletion of 30 bp in the 3' part of the gene. However, this deletion is also present in the virus spread in healthy people of the areas endemic for NPC and also in other EBV-positive tumours as well as in healthy carriers. We isolated and sequenced the LMP1 gene obtained from tissue of 7 Russian patients with NPC and 1 German patient with an NPC-like tumour of the parotid gland (PG) and compared them with the LMP1 gene isolated from peripheral blood lymphocytes (PBLs) of 6 Russian and 4 German healthy EBV-positive carriers. Neither the Russian NPC cases nor the German NPC-like tumour harboured an LMP1 gene with the 30-bp deletion, while 1 Russian and 2 German carriers contained the LMP1 gene with the 30-bp deletion. In addition, the LMP1 gene isolated from PBLs of the German patient was virtually identical to the gene isolated from the primary tumour. Functional analysis showed no correlation between the presence or absence of the 30-bp deletion and the level of induction of the transcription factors NFkappaB and jun/AP-1 caused by LMP1. These data indicate that the 30-bp deletion is not a factor predisposing for NPC. Comparison of the DNA sequences revealed that the LMP1 genes present in the NPCs most likely represent the "strain" persisting in the general population.

E1B-deleted adenovirus (dl1520) gene therapy for patients with primary and secondary liver tumors

Clinical studies were performed with a recombinant mutant adenovirus with an E1B 55-kDa deletion, dl1520, to assess its toxicity and efficacy in patients with irresectable primary and secondary liver tumors. A phase I study showed that dl1520 was well tolerated when administered directly intratumorally, intraarterially, or intravenously up to a dose of 3 x 10(11) PFU. Ultrastructural examination of tissue showed the presence of adenovirus in cell cytoplasm around the nucleus and revealed two dissimilar end points of cell death after virus infection: a preapoptotic sequence and necrosis. A phase II study showed that the combination of dl1520 and 5-fluorouracil (5-FU), when infused into the hepatic artery, was well tolerated. Further improvement in the recombinant vector design will be needed in order to achieve better clinical response.

Correlation of endoscopic and histologic findings before and after treatment for nasopharyngeal carcinoma

BACKGROUND

The endoscopic and histologic findings before and after radiotherapy (RT) for nasopharyngeal carcinoma (NPC) were correlated to study the sensitivity and specificity of endoscopic findings in predicting histologic results. The efficiacy of endoscopic examination and post-RT multiple site biopsies in detecting persistent disease was also evaluated.

METHODS

Seven hundred forty-six patients were evaluated. Pre-RT, biopsies were taken from both sides of the nasopharynx to assess the extent of tumor. Four to 16 weeks after RT, routine six-site biopsy specimens were taken from both roofs, lateral, and posterior walls of the nasopharynx and repeated 2 weeks later. Endoscopic findings of exophytic growth, nodule, ulcer, and submucosal bulge were considered "residual tumor," others were considered "no residual tumor." Persistent disease was defined as positive histologic findings 12 weeks after RT.

RESULTS

Before RT, sensitivity of endoscopic findings and biopsy specimens in detecting malignancy were 99.7% and 94.2%, respectively. After RT, sensitivity and specificity of endoscopic findings in predicting positive histologic findings were 29% and 85.8%, respectively, with a positive predictive value of 34.9% and a negative predictive value of 82.2%. Of positive histologic findings, 27.7% were missed in the first session of biopsies; 33.5% of those with positive histologic findings turned out to have persistent disease. For prediction of persistent disease, the sensitivity and specificity of endoscopic findings were 40.4% and 84.4%, with a positive predictive value of 16.3% and a negative predictive value of 95%, and that of histologic findings in the first session of biopsies were 59.6% and 88.3%, respectively, with a positive predictive value of 27.7% and a negative predictive value of 96.7%.

CONCLUSIONS

Endoscopic findings alone have low sensitivity in predicting persistent disease, multiple sites biopsy specimens are indicated. Because only 1.9% of patients with endoscopic findings of "no residual tumor" and negative histologic findings in first session of biopsies had persistent disease, this group can be spared second biopsies. Repeat biopsies are indicated for those with endoscopic findings of "residual tumor" or positive histologic findings in first session of biopsies to improve detection of persistent disease.

Abdominal relapse in stage 1 nonseminomatous germ cell tumours of the testis managed by surveillance or with adjuvant chemotherapy

OBJECTIVE

To assess the impact on patterns of recurrence of adjuvant chemotherapy in patients with stage 1 nonseminomatous germ cell tumours (NSGCT) of the testis, who have a high likelihood of relapse on surveillance if certain risk factors are identified in the orchidectomy specimen, and thus the theoretical need for retroperitoneal lymph node dissection (RPLND).

PATIENTS AND METHODS

The incidence of abdominal relapse was recorded in 417 men presenting with stage 1 NSGCT over the past 18 years. Up to 1986, 161 men were managed by surveillance alone, and abdominal relapse occurred in 26. From 1986 onwards, men with positive risk factors in the orchidectomy specimen were offered two courses of chemotherapy; 60 accepted and one relapsed in the abdomen, and 196 underwent surveillance and 19 relapsed in the abdomen.

RESULTS

Abdominal relapse was significantly reduced from 16% before 1986 to 8% afterward (P = 0.014). Mortality from testicular tumour or treatment toxicity remained low, at 0.6% before 1986 and 2.0% since then.

CONCLUSION

The need for RPLND in stage 1 NSGCT remains highly doubtful.

The changing role of the medical illustrator

The annual meeting of the Australian Institute of Medical and Biological Illustration in Melbourne in November 1998 included keynote addresses from Richard Morton and Robin Williams. Both speakers looked at the future of the medical illustration profession, and in particular the impact of new technology. This matter was also addressed by Joe Nicholls in a presentation given at the Institute of Medical Illustrators' Annual Symposium in Warwick, UK, in September 1998. This paper is a synthesis of the ideas presented by these three speakers and elaborates on common themes in their presentations.

Avascular necrosis in patients treated with BEP chemotherapy for testicular tumours

Avascular necrosis (AVN) is known to occur after combination chemotherapy for lymphomas and leukaemias that includes high dose corticosteroids, but it has been reported rarely in patients with solid tumours. We describe five recent cases in young men with testicular tumours (three of which were of good prognosis), who had been treated with chemotherapy using dexamethasone as an antiemetic. Dexamethasone is a low cost and effective antiemetic, but it may be responsible for inducing AVN in patients receiving chemotherapy for solid tumours. A prospective survey of the frequency of AVN is justified to quantify the extent of the problem.

The time course of histologic remission after treatment of patients with nasopharyngeal carcinoma

BACKGROUND

The objective of this study was to define the time course of histologic remission and to evaluate the prognostic significance of delayed histologic remission of patients with nasopharyngeal carcinoma (NPC).

METHODS

Between 1986-1994, 803 patients underwent serial postradiotherapy nasopharyngeal biopsies. Patients with positive histology underwent repeated biopsies every 2 weeks until the biopsies were found to be negative or, if remission did not occur by the 12th week after radiotherapy, treatment was initiated for persistent disease. Patients with positive histology found after the fifth week but who achieved spontaneous remission before the twelfth week were considered to have delayed histologic remission. Negative histology by the sixth week was considered early histologic remission. The outcome of patients with delayed histologic remission, early histologic remission, and persistent disease were compared.

RESULTS

Six hundred and seventeen patients (76.8%) had negative histology within 12 weeks of the completion of radiotherapy and 55 (6.9%) had persistent disease at Week 12. In 131 patients (16.3%) spontaneous remission was observed in repeat biopsies after initial positive histology. With increasing time after radiotherapy, the incidence of positive histology decreased but more patients were found to have persistent disease. Patients with early and delayed histologic remission had 5-year NPC control rates of 82.4% and 76.8%, respectively (P = 0.35) versus a 40% NPC control rate among patients with persistent disease (P < 0.001). The 5-year survival rates were 75.3%, 79.4%, and 54.2%, respectively, for the 3 groups (P < 0.001).

CONCLUSIONS

A high proportion of early positive histology remitted spontaneously. Delayed histologic remission in NPC patients is not a poor prognostic factor and additional treatment is not necessary. A confirmatory biopsy at 10 weeks is recommended before the initiation of salvage treatment.

Epstein-Barr virus expression within keratinizing nasopharyngeal carcinoma

Three stages of maturation can be seen in keratinizing nasopharyngeal carcinomas. These stages are similar morphologically to basal cells, intermediate and superficial squamous cells seen in normal squamous epithelium. Taking advantage of such a diverse tumour cell population, 10 keratinizing nasopharyngeal carcinoma (NPC) were examined by in situ hybridization for the presence of latent Epstein-Barr Virus (EBV) using EBV encoded RNAs (EBERs) and by immunohistology for the presence of EBV early antigen-diffuse (EA-D) and the 350/220 kd membrane glycoprotein of the EBV. The basal cell-like tumour cells are mainly infected latently with the virus; viral replication was found in isolated intermediate squamous cells, whilst superficial squamous cells are largely depleted of all the viral markers. We used a control series of nonkeratinizing nasopharyngeal carcinomas composed of undifferentiated and poorly differentiated tumour cells and EBV latency was present in these tumours. Viral replication was detected by RT-PCR, in the undifferentiated tumours but viral replication was not seen by immunohistology. The possible relationship between EBV life cycle in these tumours and tumour cell differentiation is discussed in the light of these findings.

Perinuclear anti-neutrophil cytoplasmic antibodies in ulcerative colitis after restorative proctocolectomy do not correlate with the presence of pouchitis

BACKGROUND

Although perinuclear anti-neutrophil cytoplasmic antibody (p-ANCA) expression is strongly associated with ulcerative colitis, its relationship with the occurrence of pouchitis after restorative proctocolectomy is uncertain.

METHODS

Serum p-ANCA was assayed using both indirect immunofluorescence and enzyme-linked immunosorbent assay (ELISA) in 49 patients, of whom 25 had, and 24 had not, developed pouchitis. Control sera were obtained from 15 healthy volunteers.

RESULTS

By means of indirect immunofluorescence, p-ANCA was detected in 45.8% of patients without and in 48% with pouchitis (NS). Twenty-three (46.9%) of the 49 colitis patients were p-ANCA-positive, compared with none of the 15 controls (P < 0.01). By means of ELISA, p-ANCA positivity was present in 50% of patients without and in 68% with pouchitis (NS).

CONCLUSION

Whereas p-ANCA was associated with ulcerative colitis as compared with normal individuals, it was not associated with pouchitis. Thus it is unlikely to be a suitable pre-operative marker to identify those patients who will develop pouchitis.

Identification of cytotoxic T cell epitopes within Epstein-Barr virus (EBV) oncogene latent membrane protein 1 (LMP1): evidence for HLA A2 supertype-restricted immune recognition of EBV-infected cells by LMP1-specific cytotoxic T lymphocytes

Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) and latent membrane proteins (LMP) are the only antigens consistently expressed in malignancies such as nasopharyngeal carcinoma (NPC) and Hodgkin's disease (HD). Since EBNA1 is not recognized by EBV-specific cytotoxic T lymphocytes (CTL), there is increasing interest in the identification of the potential target epitopes within LMP1. Although LMP1-specific CTL have been isolated from seropositive individuals, earlier attempts to identify the peptide epitopes recognized by these T cells have been unsuccessful. In the present report we used a novel protocol to identify CTL epitopes within LMP1 which can be recognized by both polyclonal and clonal CTL. Firstly, a computer-based program was employed to identify the potential HLA-binding peptides within LMP1. Polyclonal CD8+ CTL were then isolated from seropositive donors that recognized the peptide epitopes YLLEMLWRL and YLQQNWWTL from LMP1 in association with HLA A2. Limiting dilution analysis of the memory CTL response revealed that the LMP1-specific CTL response constitutes a minor component of the CTL response in healthy virus carriers. Interestingly, analysis of YLLEMLWRL-specific CTL revealed that these CTL were able to lyse EBV-infected B cells expressing different HLA A2 supertype alleles including A*0201, A*0202, A*0203, A*0204, A*0206, A*6802 and A*6901. These data strongly support the notion that HLA class I supertype-restricted CTL may be of significant use in the development of peptide-based immunotherapeutics against EBV-associated malignancies in different ethnic populations.

Combined hepatocellular-cholangiocarcinoma: a clinicopathological study

Combined hepatocellular-cholangiocarcinoma (HCC-CC) is an uncommon form of primary liver cancer having features of both hepatocellular and biliary epithelial differentiation. We reviewed 21 cases of this tumour diagnosed between 1972 and 1996 (patient age range 16-79 years; mean patient age 49.7 years; 18 male and three female patients). Histologically, the majority (n = 18) of tumours were 'mixed' tumours, in which areas of hepatocellular and biliary epithelial differentiation were intimately mixed within the same tumours. Two patients had separate tumours in which discrete nodules of HCC and CC occurred in the same livers. One patient had a 'fibrolamellar' tumour that histologically simulated the fibrolamellar variant of HCC, but some of the tumour cells were mucin-producing cells. Of the 21 cases, mucin was demonstrable in 16 and, in the few mucin-negative tumours, electron microscopic studies confirmed the presence of the dual differentiation. The tumours frequently exhibited an invasive character with frequent venous permeation, direct invasion into adjacent liver parenchyma and tumour microsatellite formation, similar to that of ordinary HCC. Histological evidence of cirrhosis or chronic hepatitis was present in 77.8% of patients and 75% of patients were hepatitis B surface antigen positive. Raised serum alpha-fetoprotein (AFP) levels (above 300 ng/mL) were present in 61.5% of patients and AFP was detected immunohistochemically in 55% of tumours. The overall survival times of patients with HCC-CC were short. In conclusion, HCC-CC showed clinical and pathological features more akin to those of ordinary HCC than to CC.

A randomized clinical trial of agents to reduce sensitivity after crown cementation

Three desensitizing agents were evaluated for the control of sensitivity after cementation of 77 crowns. Information was collected on pain in response to hot, cold, or bite preoperatively; and postoperatively with temporary crowns at one week and at one month after cementation of crowns. No medicament was clearly better than the placebo.

T-cell intravascular lymphomatosis (angiotropic large cell lymphoma): association with Epstein-Barr viral infection

AIMS

Intravascular lymphomatosis (IVL) is a very rare non-Hodgkin's lymphoma characterized by proliferation of lymphoma cells in the vascular lumina without involvement of adjacent parenchymal tissue. IVL is predominantly of B-cell lineage, but occasional cases of T lineage IVL involving almost exclusively the skin have been described. A case of IVL that occurred initially in the epididymis of a patient with an antecedent nasopharyngeal carcinoma was studied to define the clinicopathological features associated with this unique presentation.

METHODS AND RESULTS

This lymphoma was studied by standard histological and immunophenotyping methods. The results showed lymphoma cells confined within the blood vessels, which expressed leucocyte common antigen, and T-cell markers CD3 and UCHL-1. The T-cell origin of the IVL prompted investigations for an association with Epstein-Barr virus infection (EBV). In-situ hybridization with digoxigenin-labelled anti-sense RNA probes to EBV encoded RNA (EBER) showed strong signals in the nuclei of virtually all of the lymphoma cells.

CONCLUSIONS

EBV infection of the malignant cells was demonstrated by in-situ hybridization. This case suggests that T-cell IVL may be another EBV related human neoplasm. This observation will need to be validated by further studies.

Characterization of adenosine receptors on rat ileum, ileal longitudinal muscle and muscularis mucosae

Adenosine receptors were studied in isolated rat ileum, ileal longitudinal muscle and muscularis mucosae, using a range of agonists and an antagonist. In the rat ileal longitudinal muscle adenosine receptor agonists relaxed the tissues. N6-cyclopentyladenosine (CPA) was more potent than 5'-N-ethylcarboxamidoadenosine (NECA) or adenosine and 1,3-dipropyl-8-cyclopentylxanthine (DPCPX) (1 nM) gave a 5-fold parallel shift to the right of the concentration-response curves to both CPA and NECA corresponding to an apparent pA2 value of 9.6 suggesting that the agonists relax via adenosine A1 receptors. In the intact ileum adenosine receptor agonists also relaxed the tissue but NECA and CPA were equipotent. DPCPX (3 nM) however inhibited responses to both CPA and NECA with dose-ratios of 8 and 15.6, corresponding to pA2 values of 9.3 and 9.7, respectively. DPCPX (300 nM) gave a much greater shift to the right of the concentration-response curve to NECA with a dose-ratio of 769, corresponding to an apparent pA2 of 9.4. This suggests that the agonists are acting at adenosine A1 receptors to cause relaxation of the whole tissue. Adenosine receptor agonists contracted rat ileal muscularis mucosae with a potency order indicative of an A adenosine receptor. DPCPX (3-100 nM) antagonized responses to CPA giving a linear Schild plot with a slope close to unity and a pA2 of 8.4 suggesting an action on adenosine A1 receptors.

Nasopharyngeal carcinoma research in Hong Kong in the past decade

OBJECTIVE

To review the research carried out in Hong Kong on nasopharyngeal carcinoma (NPC) over the past 10 years.

METHODS

The literature published in Hong Kong over the past 10 years on nasopharyngeal carcinoma were reviewed in the light of other important international publications on the same subject.

RESULTS

The research carried out in Hong Kong covers etiology, natural behavior, treatment and prognosis of NPC. These studies not only elucidated the different aspects of NPC, many of these new findings will also guide future directions of research.

CONCLUSIONS

Major efforts have been made to research into the various aspects of NPC with important findings which will translate into better treatment results. As this tumor is uncommon in other parts of the world, continued efforts to improve the prevention, early diagnosis, treatment and care of this tumor are required in China.

Evolutionary dynamics of genetic variation in Epstein-Barr virus isolates of diverse geographical origins: evidence for immune pressure-independent genetic drift

The question whether immune pressure exerted by cytotoxic T lymphocytes (CTLs) can influence the long-term evolution of genetically stable viruses such as Epstein-Barr virus (EBV) has generated considerable scientific interest, primarily due to its important implications for the overall biology of the virus. While arguing for a role of CTLs in the evolution of viruses, it is important to differentiate between genetic variation in virus and immune recognition of these variant virus by CTLs. To assess the role of genetic selection in the long-term evolution of EBV, we have analyzed a large panel of type 1 EBV isolates from African, Southeast Asian, Papua-New Guinean (PNG), and Australian Caucasian individuals. Seven different regions of the EBV genome, which include nine CTL epitopes restricted through a range of HLA class I alleles, were sequenced and compared. Although numerous nucleotide changes were identified within these isolates, comparison of synonymous and nonsynonymous substitutions in the CTL epitope indicated that the genetic variation was generated mostly independently of immune selection pressure. Surprisingly, an inverse correlation between genetic variation within certain CTL epitopes and the frequency distribution of HLA alleles that present the CTL epitopes was seen, suggesting that the evolutionary pressures on the CTL epitopes of the virus may be toward their conservation rather than their inactivation. Furthermore, molecular evolutionary genetic analysis of nucleotide sequences revealed that viral isolates from PNG are evolving as a lineage distinct from isolates from African, Southeast Asian, and Australian Caucasian individuals.

Use of a newly developed technique to isolate rat pinealocytes and study the effects of adenosine agonists on melatonin production

Recent studies have suggested a role for adenosine in the regulation of rat pineal melatonin synthesis. The data, however, are conflicting and therefore the aim of this study was to characterize adenosine receptors more fully in vitro by using a range of selective adenosine agonists and the adenosine antagonist 8-sulphophenyltheophylline (8-SPT). A simple method for the mechanical separation of rat pinealocytes was developed. Pinealocytes were briefly (15 min) incubated with drugs followed by a 4 hr drug-free incubation period after which melatonin concentrations in the incubation medium were measured by radioimmunoassay. The beta-adrenoceptor agonist isoprenaline gave a dose-related increase in melatonin production, demonstrating that this pinealocyte preparation technique is suitable to evaluate the effect of drugs on pineal melatonin synthesis. Our results show that adenosine, N6-(phenylisopropyl)adenosine (R-PIA) and 2-p-(2-carboxethyl) phenethylamino-5'-N-ethylcarboxamidoadenosine (CGS21680) did not affect melatonin synthesis alone or in combination with isoprenaline. However 5'-N-ethylcarboxamidoadenosine (NECA) (100 microM) potentiated the stimulatory effect of isoprenaline (3 microM) on pineal melatonin production and this effect appeared to be antagonized by 8-SPT (50 microM). These results are consistent with activation by NECA of an A2b adenosine receptor.

Fertility after chemotherapy for testicular germ cell cancers

PURPOSE

To analyze the probability of recovery of spermatogenesis after orchidectomy and cisplatin-based chemotherapy (CT) for testicular germ cell cancer.

PATIENTS AND METHODS

One hundred seventy-eight patients treated between 1979 and 1991 were selected by the requirement of sperm count both pre-CT and post-CT. Counts were classified as normospermic (NS) if more than 10 x 10(6)/mL, oligospermic (OS) if 1 to 9 x 10(6)/mL, and azoospermic (AS) if less than 1 x 10(6)/mL. The median follow-up time after CT before sperm analysis was 30 months.

RESULTS

Analysis of 170 patients whose spermatogenesis was reassessed at least 1 year after CT showed that of 89 patients whose pre-CT counts were NS, the post-CT count was NS in 64%, OS in 16%, and AS in 20%. There was clear evidence for continued recovery beyond 1 year; the probability of spermatogenesis increased to 48% by 2 years and 80% by 5 years. There was a significantly higher probability of recovery to OS and NS count levels in the 54 patients treated with carboplatin-rather than cisplatin-based therapy. There was an independent and similar effect of normal pre-CT count. There was a reduced probability to recover to OS in the 26 patients treated with more than four cycles of CT. A prognostic model identified three groups with 25%, 45%, and 82% probabilities of recovering spermatogenesis by 2 years after CT.

CONCLUSION

Analysis of pre-CT sperm count together with details of planned treatment can be used to predict recovery of spermatogenesis following germ cell CT.

Residual mass following chemotherapy of seminoma

BACKGROUND

The residual mass so frequently found after chemotherapy of advanced seminoma may consist entirely of benign tissue or may contain residual disease amenable to adjuvant therapy.

PATIENTS AND METHODS

A detailed retrospective analysis was performed on 45 patients treated with cisplatin based chemotherapy for advanced seminoma between 1978 and 1994.

RESULTS

The probability of a residual mass after chemotherapy was higher if the pre-treatment mass diameter was > 5 cm (78% versus 15%, P = 0.0009). Of 33 patients with residual masses following cisplatin chemotherapy, 4 were explored surgically showing fibrosis only, 15 were treated by adjuvant radiotherapy and 14 were managed by observation alone. Recurrence occurred in 2 of 14 patients managed by observation and in 2 of 15 managed by radiotherapy. There was no evidence that risk of recurrence was related to diameter of residual mass.

CONCLUSION

Residual masses persisted following cisplatin based combination chemotherapy for seminoma in 73% of cases. In our study, recurrence was rare and there was no evidence that this was influenced by either the size of the residual mass or the use of adjuvant therapy.

Extensive alternative splicing within the amino-propeptide coding domain of alpha2(XI) procollagen mRNAs. Expression of transcripts encoding truncated pro-alpha chains

Heterogeneity in type XI procollagen structure is extensive because all three alpha(XI) collagen genes undergo complex alternative splicing within the amino-propeptide coding domain. Exon 7 of the human and exons 6-8 of the mouse alpha2(XI) collagen genes, encoding part of the amino-propeptide variable region, have recently been shown to be alternatively spliced. We show that exon 6-containing mRNAs for human alpha2(XI) procollagen are expressed at 28 weeks in fetal tendon and cartilage but not at 38-44 days or 11 weeks. In the mouse, exon 6 is expressed in chondrocytes from 13.5 days onward. We recently identified conserved sequences within intron 6 of the human and mouse alpha2(XI) collagen genes, containing additional consensus splice acceptor and donor sites that potentially increase the size of exon 7, dividing it into three parts, designated 7A, 7B, and 7C. We show by reverse transcription polymerase chain reaction and in situ hybridization that these potential splice sites are used to yield additional alpha2(XI) procollagen mRNA splice variants that are expressed in fetal tissues. In human, expression of exon 7B-containing transcripts may be developmental stage-specific. Interestingly, inclusion of exon 7A or exon 7B in human and mouse alpha2(XI) procollagen mRNAs, respectively, would result in the insertion of an in-frame termination codon, suggesting that some of the additional splice variants encode a truncated pro-alpha2(XI) chain.

An analysis of surveillance for stage I combined teratoma--seminoma of the testis

We analysed 973 patients with stage I testicular tumours presenting between 1983 and 1994. The median ages at presentation for non-seminomatous germ cell tumour (teratoma) were 27 years, seminoma 36 years and combined tumour 33 years. These differences were statistically significant (Mann-Whitney P < 0.05), suggesting that combined tumours may have a separate natural history. We, therefore, analysed all stage I patients managed with surveillance (530 in total) post orchidectomy. The actuarial 5 year relapse-free survival and anatomical patterns of relapse were identical for non-seminomatous germ cell tumour (NSGCT) and combined tumour and both were statistically distinct from seminoma (P = 0.01, log-rank test, chi-square test P = 0.001). The association of seminoma within a histologically confirmed NSGCT has no influence on the clinical outcome.

Regeneration of immature mammalian spinal cord after injury

In this review we describe the growth of regenerating fibres through lesions in immature mammalian spinal cord. In newborn opossums and foetal rats, repair occurs rapidly and reliably without antibodies, implants or bridges of undamaged spinal cord. In the neonatal opossum one can compare recovery from lesions made to the CNS at various stages of development in the animal and in culture. As the CNS matures, the capacity for regeneration ceases abruptly. In particular, the extracellular matrix and molecules associated with glia have been shown to play a role in promoting and inhibiting regeneration. Major problems concern the precision with which regenerating axons become reconnected to their targets, and the specificity needed for recovery of function.

Unusual endocrine presentations of nasopharyngeal carcinoma

BACKGROUND

Nasopharyngeal carcinoma is endemic in Southern China and the majority of patients present with local symptoms due to the tumor.

METHODS

This report describes two unusual cases of occult nasopharyngeal carcinoma in which the patients initially presented with endocrine manifestations.

RESULTS

The first patient presented with Cushing's syndrome secondary to ectopic adrenocorticotropic hormone (ACTH) production. Nasolaryngoscopy showed a growth in the left nasal fossa and biopsy revealed a poorly differentiated nasopharyngeal carcinoma that exhibited positive immunostaining for ACTH. The second patient presented with a 10-month history of bone pain over both lower limbs. She was normocalcemic but her serum alkaline phosphatase was markedly elevated. A bone biopsy showed both osteoclastic and osteoblastic activity with widespread fibrosis suggestive of Paget's disease. Three months later, she developed third cranial nerve palsy. Computed tomography investigation revealed a soft tissue mass filling the sphenoid and ethmoid sinuses. Biopsy showed a poorly differentiated nasopharyngeal carcinoma. The bone biopsy was reviewed and immunohistochemistry demonstrated the presence of cells positive for the epithelial marker AE1/3 within the fibrous stroma. Radio-labeled in situ hybridization showed that Epstein-Barr virus early RNA was present in these tumor cells and the bone lesions were in fact metastases.

CONCLUSIONS

Nasopharyngeal carcinoma can present with rather atypical symptoms that may lead to a delay in diagnosis. Therefore, in high risk populations, it is important to consider nasopharyngeal carcinoma as a possible primary tumor in patients with occult carcinomas.

Spermatocytic seminoma: a clinicopathological review of ten patients

Spermatocytic seminoma is an uncommon variety of testicular neoplasm, differing from its classical counterpart at both clinical and pathological levels and having a low propensity to metastasize. This is a retrospective review of ten patients with pathologically confirmed and reviewed disease who were seen at the Royal Marsden Hospital. All patients presented as Stage I. Five were treated with radiotherapy and five have undergone surveillance. The median age was 56.5 years. The median follow-up is 8 years and no patient has relapsed. Two have died of intercurrent disease. Our series supports others of a similar size in the literature with respect to both the rarity and the good prognosis of spermatocytic seminoma. With only one case of relapse confirmed in the literature, this is a subgroup of patients in whom radiotherapy can safely be omitted.

Characterization of P1-purinoceptors on rat isolated duodenum longitudinal muscle and muscularis mucosae

1. P1-purinoceptors mediating relaxation of the rat duodenum longitudinal muscle and contraction of the rat duodenum muscularis mucosae were characterized by the use of adenosine and its analogues, 5'-N-ethylcarboxamidoadenosine (NECA), N6-cyclopentyl-adenosine (CPA), N6-(phenylisopropyl)adenosine (R-PIA), 2-chloroadenosine (2-CADO) and 2-p-((carboxyethyl)phenethylamino)-5'-carboxamidoadenosine (CGS21680), as well as the P1-purinoceptor antagonist 8-phenyltheophylline (8-PT) and the A1-selective antagonist, 1,3-dipropyl-8-cyclopentylxanthine (DPCPX). 2. In the rat duodenum longitudinal muscle, the order of potency of the adenosine agonists was CPA > NECA > adenosine > CGS21680. DPCPX antagonized responses to CPA and NECA at a concentration of 1 nM suggesting that they are acting at A1 receptors. A Schild plot versus CPA gave a slope near to unity (slope = 0.955) and a pA2 of 9.8 confirming that CPA was acting via A1 receptors. Schild analysis for DPCPX versus NECA, however, gave a slope of 0.674 suggesting that NECA was acting on both A1 and A2 receptors. CGS21680, a selective A2a agonist, was much less potent than adenosine suggesting that the A2 receptors are of the A2b subtype. 3. In the rat duodenum muscularis mucosae, the order of potency of the adenosine agonists was NECA > or = R-PIA = CPA > 2-CADO > adenosine, and DPCPX antagonized responses to CPA and NECA at a concentration of 1 microM. CGS21680, at a concentration of 10 microM, had no effect on this tissue. This suggests the presence of A2 receptors in this tissue and that they are of the A2b subtype. 4. These results are in agreement with previous studies in the whole duodenum showing the presence of A1 and A2b receptors causing relaxation, and this shows that the longitudinal muscle dominates the response of the whole tissue. In addition, a contractile A2b receptor has been revealed on the muscularis mucosae, the first time this subtype has been reported to elicit an excitatory response in a smooth muscle preparation.

The mRNAs for the three chains of human collagen type XI are widely distributed but not necessarily co-expressed: implications for homotrimeric, heterotrimeric and heterotypic collagen molecules

In cartilage collagen type XI exists as heterotrimeric molecules composed of alpha 1(XI), alpha 2(XI) and alpha 3(XI) subunits. Messenger RNAs for some of the alpha chains of collagen type XI have also been found in non-chondrogenic tissues but the chain composition of the molecule in these sites is not known. Some non-chondrogenic tissues also contain heterotrimers containing collagen alpha 2(V) and alpha 1(XI) chains. We have explored the possibility that collagen type XI could exist in differing trimeric forms in non-chondrogenic tissues and aimed to predict the subunit composition of this collagen in those tissues. The distribution and relative levels of expression of collagen alpha 1(XI), alpha 2(XI) and alpha 3(XI)/alpha 1(II) mRNAs in different human fetal tissues were studied. Expression of mRNAs for all three genes of collagen type XI is not restricted to cartilage but is widespread. However, in some non-chondrogenic tissues, the mRNAs for all three alpha chains of collagen type XI were not co-expressed, but collagen alpha 1(XI) and alpha 2(XI) mRNAs were found either singly or without collagen alpha 3(XI) transcripts. Collagen type XI may therefore exist as homotrimers and/or heterotrimers composed of two collagen alpha(XI) chains in some tissues. The distribution of mRNAs for collagen alpha 2(V) and alpha 1(I) were also studied. Co-expression of collagen type XI, alpha 2(V) and alpha 1(I) mRNAs was found for many tissues. These findings have implications for the possibility of additional chain associations for collagen types XI and V in cross-type heterotrimers within heterotypic fibrils.

Expression of immune regulatory molecules in Epstein-Barr virus-associated nasopharyngeal carcinomas with prominent lymphoid stroma. Evidence for a functional interaction between epithelial tumor cells and infiltrating lymphoid cells

Undifferentiated nasopharyngeal carcinomas (UNPC) are characterized by an association with Epstein-Barr virus and an abundant lymphoid stroma. The role of this lymphoid stroma is uncertain but is mostly thought to represent an immune response against viral or tumor antigens. We have analyzed the expression of immune regulatory receptor/ligand pairs in snap-frozen biopsies of 20 UNPCs. All cases were Epstein-Barr virus positive and the virus-encoded latent membrane protein, LMP1, was expressed in 6 cases. By immunohistochemistry, we have demonstrated the expression of CD70 and CD40 in the tumor cells of 16 and 18 cases, respectively. Infiltrating lymphoid cells expressing CD27, the CD70 receptor, and the CD40 ligand were present in all cases. The Bcl-2 protein was detected in 17 cases. Unexpectedly, tumor cells of 5 cases expressed at least one member of the B7 family (CD80, CD86, and B7-3) and many lymphoid cells expressing the corresponding counter-receptor, CD28, were detected in all cases. Interestingly, 5 of 6 LMP1-positive cases also expressed B7, whereas all 14 LMP1-negative cases were also B7 negative. Our results indicate that T cells and carcinoma cells communicate in the microenvironment of UNPCs and suggest that the presence of a lymphoid stroma may be a requirement for UNPC growth at least in certain stages of tumor development.

Nine-month changes of maternal expressed emotion in conduct and emotional disorders of childhood: a follow-up study

In this follow-up study, mothers of 28 children with conduct disorders (CD) and 29 children with emotional disorders (ED) of 6-11 years of age, were interviewed and rated for expressed emotion 9 months after their first clinical assessment. Mothers of children with CD expressed significantly less criticism and higher warmth after 9 months. Initial externalizing scores in the CD group and initial internalizing scores in the ED group at the first assessment predicted symptomatic change, in contrast with EE scales. Initial externalizing scores and low levels of maternal warmth predicted presence of conduct disorder at the last contact with the clinician. The implications of the findings on the development of treatment techniques are discussed.

Tissue-specific and differential expression of alternatively spliced alpha 1(II) collagen mRNAs in early human embryos

Expression of the alpha 1(II) procollagen gene is not confined to chondrogenic tissues during vertebrate development. Transcripts of the human gene (COL2A1) are alternatively spliced to give mRNAs which either exclude (type IIB mRNA) or include (type IIA mRNA) an exon encoding a cysteine-rich domain in the amino-propeptide. The distribution of COL2A1 mRNAs in 27- to 44-day human embryos and 8- to 24-week fetuses was studied by in situ hybridization and RNase protection analyses. Type IIA mRNAs were expressed in prechondrogenic cells and were also preferentially expressed in chondrogenic tissues at regions of chondrocyte commitment and cartilage growth. During maturation of chondrocytes, there is a switch to expression of type IIB mRNAs. In non-chondrogenic tissues of early embryos, type IIA mRNA expression was associated with active tissue remodeling, epithelial organization, and sites of tissue interaction. Type IIA mRNAs were also expressed in some non-chondrogenic tissues where expression had previously been undetected, such as the tooth bud, liver, adrenal cortex, apical ectodermal ridge, and indifferent gonad. In older fetuses type IIA mRNAs were the sole or major transcript in most non-chondrogenic tissues except the choroid plexus and tendon. In the meninges there was a unique switch from type IIB to type IIA expression. The expression pattern of COL2A1 transcripts suggests that, in addition to contributing to the structural integrity of the cartilage extracellular matrix, type II procollagen may serve a morphogenetic role in embryonic development. Our findings clearly show that the pattern of expression of type II procollagen mRNAs is largely conserved between man and mouse. However, some differences exist, and these should be taken into consideration when animal models are used to study human diseases associated with COL2A1.

High-dose carboplatin and etoposide for salvage chemotherapy of germ cell tumours

We evaluated high-dose carboplatin and etoposide with autologous bone marrow stem cell support in the salvage treatment of patients with metastatic germ cell tumours who had failed previous chemotherapy. The treatment programme comprised initial conventional dose chemotherapy. 23 patients received a first cycle of high-dose treatment, and 12 who showed no evidence of progression had a second cycle 2-3 months later. 8 of the 23 patients treated with high-dose chemotherapy are alive in remission 4-29 months from the start of high-dose treatment. 3 of these 8 required further treatment for recurrence. In the initial part of the study, the dose of carboplatin was escalated in successive patients. Grade 3/4 treatment-related toxicity occurred in 4 of 18 patients (1 fatal) who received carboplatin doses to give a AUC (area under the serum concentration/time curve) of 30 mg.min/ml or less and 3 of 5 patients (2 fatal) who received higher doses. We, therefore, recommend 30 mg.min/ml for further evaluation in chemotherapy sensitive patients.

Detection of wild type and exon 5-deleted splice variant oestrogen receptor (ER) mRNA in ER-positive and -negative breast cancer cell lines by reverse transcription/polymerase chain reaction

Using reverse transcription (RT)/PCR we have shown that four breast cancer cell lines expressed oestrogen receptor (ER) mRNA, irrespective of whether they were assessed as ER-positive (MCF-7 and BT-474) or ER-negative (MDA-MB-231 and BT-20) by enzyme immunoassay (EIA). In addition to the wild type (WT) form, they were all found to express the exon 5-deleted variant (V) form of ER mRNA by RT/PCR; this is thought to code for a truncated constitutively active protein. By Northern blot analysis only the ER-positive cell lines (MCF-7 and BT-474) were found to express detectable levels of ER mRNA. Oestradiol-induced growth was found only in the ER-positive (by EIA) cell lines. These results confirm that the differences between ER-positive and ER-negative cell lines are quantitative rather than qualitative. As low levels of ER mRNA could be detected by RT/PCR, this may reflect the greater sensitivity of this approach. The presence of exon 5-deleted V form ER mRNA in addition to the WT form in all four breast cancer cell lines may allow these lines to be used to assess differential regulation of transcription and the impact of this on their oestrogen dependence.

Application of a composite faecal egg count procedure in diagnostic parasitology

Egg counts from a simple composite faecal counting procedure using equal amounts of sample from ten sheep were compared statistically against the arithmetic means of the same ten samples prepared by a conventional egg counting method. Forty separate data sets were analysed in an untransformed bivariate plot and after natural logarithmic transformation. A sign test analysis indicated a high degree of similarity between the two data sets. A confidence interval for the composite count (n = 10) was calculated to give a result between five eggs more and 15 eggs less than the arithmetic mean count of the ten samples. When multiple faecal samples are to be examined, the composite method has significant advantages in time saving and increased throughput whilst still providing an accurate result. This technique has been used to monitor gastrointestinal helminthosis and for faecal egg count reduction testing to assess anthelmintic efficacy.

Maternal expressed emotion in conduct and emotional disorders of childhood

Maternal expressed emotion (EE) scales were rated for children aged 6-11 with conduct disorders, emotional disorders and a group of non-referred children matched for sex and age (N = 30 in each of the three groups). Maternal warmth distinguished significantly between the three groups (CD < ED < Controls), while criticism distinguished the group of conduct disordered children. Maternal criticism was positively associated with child behaviour ratings even within the non-referred group. These observational ratings of warmth and criticism were found to be much more strongly associated with child behaviour than maternal ratings of their family environment.

Peripheral blood involvement in non-Hodgkin's lymphoma detected by clonal gene rearrangement as a biological prognostic marker

Peripheral blood from 67 patients with non-Hodgkin's lymphoma was examined at initial diagnosis for the presence of circulating lymphoma cells by DNA hybridisation using immunoglobulin and T-cell receptor gene probes. Clonal gene rearrangement was found in 31% (21/67) of patients and correlated with clinical stage, histological grade and bone marrow involvement. Clinical stage and the presence of lymphoma cells in peripheral blood were prognostic factors for progression-free survival in all patients on univariate analysis, but the detection of lymphoma cells was not independent of stage. It was also not a significant predictor for survival. In patients with intermediate- and high-grade lymphoma, the detection of lymphoma cells in peripheral blood was a significant prognostic factor for progression-free survival (PFS) and survival only on univariate analysis. The 3-year PFS was 17% in patients with circulating lymphoma cells compared with 75% if these were absent (P < 0.05). The presence of lymphoma cells in peripheral blood is associated with extensive disease and may be a biological marker of poor disease control. Sensitive techniques of detection should form part of large prospective studies in non-Hodgkin's lymphoma.