Supersolidity in Two-Dimensional Trapped Dipolar Droplet Arrays

We theoretically investigate the ground states and the spectrum of elementary excitations across the superfluid to droplet crystallization transition of an oblate dipolar Bose-Einstein condensate. We systematically identify regimes where spontaneous rotational symmetry breaking leads to the emergence of a supersolid phase with characteristic collective excitations, such as the Higgs amplitude mode. Furthermore, we study the dynamics across the transition and show how these supersolids can be realized with standard protocols in state-of-the-art experiments.

Production of the Receptor-binding Domain of the Viral Spike Proteins from 2003 and 2019 SARS CoVs and the Four Common Human Coronaviruses for Serologic Assays and Inhibitor Screening

The recombinant receptor-binding domain (RBD) of the viral spike protein from SARS-CoV-1 and 2 are reliable antigens for detecting viral-specific antibodies in humans. We and others have shown that the levels of RBD-binding antibodies and SARS-CoV-2 neutralizing antibodies in patients are correlated. Here, we report the expression and purification of properly folded RBD proteins from SARS and common-cold HCoVs in mammalian cells. RBD proteins were produced with cleavable tags for affinity purification from the cell culture medium and to support multiple immunoassay platforms and drug discovery efforts. Graphic abstract: High-Yield Production of Viral Spike RBDs for Diagnostics and Drug Discovery.

Roton Excitations in an Oblate Dipolar Quantum Gas

We observe signatures of radial and angular roton excitations around a droplet crystallization transition in dipolar Bose-Einstein condensates. In situ measurements are used to characterize the density fluctuations near this transition. The static structure factor is extracted and used to identify the radial and angular roton excitations by their characteristic symmetries. These fluctuations peak as a function of the interaction strength indicating the crystallization transition of the system. We compare our observations to a theoretically calculated excitation spectrum allowing us to connect the crystallization mechanism with the softening of the angular roton modes.

Sex disparities and neutralizing antibody durability to SARS-CoV-2 infection in convalescent individuals

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) has now caused over 2 million deaths worldwide and continues to expand. Currently, much is unknown about functionally neutralizing human antibody responses and durability to SARS-CoV-2. Using convalescent sera collected from 101 COVID-19 recovered individuals 21-212 days after symptom onset with forty-eight additional longitudinal samples, we measured functionality and durability of serum antibodies. We also evaluated associations between individual demographic and clinical parameters with functional neutralizing antibody responses to COVID-19. We found robust antibody durability out to six months, as well as significant positive associations with the magnitude of the neutralizing antibody response and male sex. We also show that SARS-CoV-2 convalescent neutralizing antibodies are higher in individuals with cardio-metabolic comorbidities.

Longitudinal Spin Diffusion in a Nondegenerate Trapped ^{87}Rb Gas

Longitudinal spin diffusion of two pseudospin domains is studied in a trapped ^{87}Rb sample above quantum degeneracy, and the effect of coherence in the domain wall on the dynamics of the system is investigated. Coherence in a domain wall leads to transverse-spin-mediated longitudinal spin diffusion that is slower than classical predictions, as well as altering the domains' oscillation frequency. The system also shows an instability in the longitudinal spin dynamics as longitudinal and transverse spin components couple, and a conversion of longitudinal spin to transverse spin is observed, resulting in an increase in the total amount of coherence in the system.

The relationship between type of drug therapy and blood glucose self-monitoring test strips claimed by beneficiaries of the Seniors' Pharmacare Program in Nova Scotia, Canada

BACKGROUND

The healthcare expenditure on self-monitoring of blood glucose (SMBG) test strips under the Nova Scotia Seniors' Pharmacare Program (NSSPP) has increased significantly in recent years. The objective of this study was to identify the frequency and cost of claims for blood glucose monitoring test strips by NSSPP beneficiaries in the fiscal year 2005/06 and to explore the variation in the use of test strips by type of treatment, age and sex.

METHODS

Retrospective analysis was conducted using pharmacy administrative claims data for NSSPP beneficiaries. Study subjects were aged > or = 65 years on October 1, 2004, received SMBG test strips in the 110 days prior to April 1, 2005, and were alive throughout the twelve month study period. Subjects were categorized into four groups: insulin only, oral antihyperglycemic agents (OAA) only, both OAA and insulin; and no reimbursed diabetes medications. Statistical analysis was performed to identify differences in expenditure by medication group and in frequency of SMBG test strips claimed by medication group, age, and sex.

RESULTS

Of 13,564 included beneficiaries, 13.2% were categorized as insulin only, 53.5% OAA only, 7.2% both OAA and insulin, and 26.0% no reimbursed diabetes medications. Over half (58.7%) were femle. The insulin only category had the highest mean (+/- SD) number of SMBG test strips claimed per day (2.0 +/- 1.5) with a mean annual total cost of $615 +/- $441/beneficiary. Beneficiaries aged 80 years and above claimed fewer test strips than beneficiaries below 80 years.

CONCLUSION

This population based study shows that in Nova Scotia the SMBG test strips claimed by the majority of seniors were within Canadian guidelines. However, a small proportion of beneficiaries claimed for SMBG test strips infrequently or too frequently, which suggests areas for improvement. The provincial drug plan covers the majority of the costs of test strip utilization, suggesting that the majority of test strips claimed did not exceed the maximum allowable cost (MAC) established in the program's MAC policy. Drug insurance programs need to work with healthcare providers to determine if patients are using test strips optimally; and to determine their impact on patient outcomes. In addition, they need to determine the cost-effectiveness of their SMBG test strip reimbursement policies.

Effect of an academic detailing intervention on the utilization rate of cyclooxygenase-2 inhibitors in the elderly

BACKGROUND

Osteoarthritis is prevalent in the elderly. Nova Scotia general practitioners (GPs) identified the need for an academic detailing (AD) intervention aimed at optimizing the management of osteoarthritis. AD was provided by Dalhousie University Continuing Medical Education in a face-to-face encounter employing evidence-based information. GP participation was voluntary.

OBJECTIVE

To evaluate the effect of a GP-targeted osteoarthritis AD intervention on a reduction in the prescribing of cyclooxygenase-2 (COX-2) inhibitors, as well as examine the intervention effect on the utilization rates of gastroprotective agents and medical services.

METHODS

A retrospective cohort study design employing administrative data was used. Differences in utilization rates between intervention and control groups were evaluated using generalized estimating equations analysis for longitudinal data over four 90-day postintervention periods. Confounding was addressed using propensity scores to adjust for between-group bias on the measured covariates.

RESULTS

The between-group difference for change in COX-2 utilization rates was 0.76 defined daily doses/patient (p = 0.040; 95% CI 0.037 to 1.48) for the 3-month period following the intervention, with lower COX-2 utilization in the AD intervention group than in the control group. The intervention group showed a significant decrease in the within-group utilization rate between the pre- and postintervention periods (z =-2.34; p = 0.019). The between-group difference for change in GP office visit rates was 0.40 visits/patient (p = 0.028; 95% CI 0.046 to 0.79) with the intervention group, showing higher visit rates compared with the control group.

CONCLUSIONS

The osteoarthritis AD intervention was associated with a significant decrease (23%) in COX-2 utilization rates in the 3-month period immediately following the intervention. The only secondary outcome to show a significant between-group effect was the GP office visit rate, which was higher for the intervention group in the second 3-month postintervention period.

African horse sickness epidemiology: vector competence of south african Culicoides species for virus serotypes 3, 5 and 8

The oral susceptibilities of 17 Culicoides species to infection with African horse sickness virus (AHSV) serotypes 3, 5 and 8 were determined by feeding field-collected midges on AHSV infected horse blood. The mean titres of virus in the bloodmeals for the three serotypes of AHSV were between 5.7 and 6.5 log10 TCID50/ml. Virus was detected, after 10 days incubation at 23.5 degrees C, in the Culicoides imicola Kieffer (Diptera: Ceratopogonidae) that had fed on blood containing AHSV 5 (8.5%) and 8 (26.8%), and in the Culicoides bolitinos Meiswinkel that had fed on AHSV 3 (3.8%), 5 (20.6%) and 8 (1.7%). Although 44.4% of the C. imicola were shown to have ingested AHSV 3 immediately after feeding, no virus was detected in 96 C. imicola after incubation. The relatively high titres of virus recorded in individual midges of both species after 10 days incubation suggested a fully disseminated infection. Previously, C. imicola was considered to be the only field vector of AHSV in Africa. Identifying C. bolitinos as a potential vector for AHSV is an important finding, which if proven will have a significant impact on our understanding of the epidemiology of AHS. No AHSVs could be detected in the other 15 species of Culicoides assayed, which suggests that some of the southern African Culicoides species are refractory to AHSV infection. However, further work with larger numbers of each species will be necessary to confirm this observation.

Poor prognosis associated with thrombocytosis in patients with renal cell carcinoma

OBJECTIVES

To better define the relationship between platelet count and survival using a retrospective analysis in patients with thrombocytosis and metastatic renal cell carcinoma (RCC), some of whom had a shorter life expectancy than those with a normal platelet count.

PATIENTS AND METHODS

The records were reviewed of patients with stage IV RCC who had undergone a variety of adjuvant therapies after nephrectomy between 1972 and 1992. Entry criteria included a tissue diagnosis of RCC, at least one platelet count and a complete follow-up until the time of death. Of 350 patients available for review, 259 met the entry criteria. Patients were divided into two groups: group 1 included 112 patients whose platelet counts remained at < 4 x 105/microL between the time of nephrectomy and the time of death; group 2 included 147 patients with at least one platelet count of > 4 x 105/microL (mean age in each group 57 years).

RESULTS

The mean (SD) survival for group 1 was 151 (34) months, compared with 92 (18) months for those in group 2. Using the log-rank chi-square test the difference in survival between the groups was significant (P = 0.005). Controlling for established prognostic indicators of pathological stage, nuclear grade and cell type, using Cox's regression technique, the difference in survival between the groups remained significant (P = 0.015).

CONCLUSIONS

These results suggest that patients with metastatic RCC who receive adjuvant therapy and have a persistently normal platelet count have a 64% longer life expectancy than those with thrombocytosis. The difference is highly statistically significant when controlled for nuclear grade, cell type and pathological stage.

Ureteral rhabdomyosarcoma

Rhabdomyosarcoma is a malignant tumor well known to urologists. These tumors arise from the genitourinary system in 20% to 25% of cases, most commonly from the bladder, prostate, vagina, and paratesticular region. This is the first reported case of a rhabdomyosarcoma arising from the ureter. The radiographic findings and ureteroscopic appearance of this tumor suggested a benign fibroepithelial polyp; however, a ureteroscopic biopsy and subsequent nephroureterectomy revealed an embryonal rhabdomyosarcoma.

Donkeys as reservoirs of African horse sickness virus

Investigations have been carried out to elucidate the possible role of the donkey in the epidemiology of African horse sickness (AHS). These studies have shown that despite the absence of pyrexia or other observable clinical signs, donkeys become infected with virulent AHS virus serotype 4 (AHSV 4) and that they develop a viraemia which can persist for at least 12 days, albeit at a comparatively lower titre than that recorded for similarly infected ponies. AHSV 4 showed a similar tissue tropism in the pony and donkey but the virus appeared to replicate less efficiently in donkey tissues. The only gross pathological changes observed in the donkeys post mortem were increased fluid accumulation in the serosal lined compartments, particularly the peritoneal cavity, and petechial and ecchymotic haemorrhages on the left hepatic ligament. The absence of infectious virus or viral antigens in any of the tissues collected at 14 and 19 days post inoculation (dpi) from 6 experimental donkeys suggest that, though susceptible to infection, the donkey is unlikely to be a long term reservoir for AHSV. Although AHSV 4 was detected in all 6 donkeys following the primary inoculation, no virus could be isolated from blood collected from two donkeys subsequently challenged with a second virulent virus, AHSV 5. Data generated from virus neutralisation tests showed a second primary antibody response, against AHSV 5, in these donkeys at 12 dpi. In contrast, the boost in antibody levels detected from 5 dpi, as measured by ELISA, was probably due to an anamnestic response against the AHSV group-specific viral proteins. Homogenised spleen tissue, collected post mortem from a donkey 7 dpi with AHSV 4, caused a lethal, cardiac form of AHS when inoculated into a susceptible pony.

Evaluation of staging lymphadenectomy in prostate cancer

OBJECTIVES

To prospectively evaluate a clinical algorithm that predicts nodal status in patients with prostate cancer and to assess the impact on the outcome.

METHODS

Between September 1988 and December 1994, 192 patients with organ-confined prostate cancer and considered surgical candidates for radical perineal prostatectomy (RPP) were stratified using the algorithm: prostate-specific antigen (PSA) 20 ng/mL or less, Gleason score 7 or lower, and clinical Stage T2a or lower. Patients failing any of these criteria were placed in the high-risk group and underwent a pelvic lymphadenectomy. Patients who satisfied all the criteria were placed in the low-risk group and underwent RPP without evaluation of the pelvic lymph nodes. Another contemporaneous cohort of patients (n = 65) underwent pelvic lymphadenectomy and radical retropubic prostatectomy (RRP) without use of the algorithm and were used as a control group. Patients were monitored for at least 24 months.

RESULTS

In the RPP group, 177 patients were considered low risk according to the algorithm and were not offered staging lymphadenectomy before surgery, whereas 15 patients were categorized as high risk for metastasis and underwent staging lymphadenectomy. In the RRP and lymphadenectomy group, 41 patients were considered at low risk and 24 at high risk of disease spread according to the algorithm. In the RPP group, low-risk patients (no lymphadenectomy) had a PSA recurrence rate (27%) similar to that of low-risk patients in the RRP group with negative lymph nodes (29%), P = 0.8. Similarly, high-risk patients with negative lymph nodes in both groups had a similar recurrence rate (53% for RPP and 50% for RRP). Univariate logistic regression analysis showed that PSA was the most significant predictor for disease recurrence (P = 0.0004) followed by preoperative Gleason scores (P = 0.02) and clinical stages (P = 0.03). Multivariate stepwise analysis demonstrated that Gleason score and clinical stage did not add to the prediction of recurrence over PSA alone.

CONCLUSIONS

Staging lymphadenectomy can be omitted in low-risk patients without deleterious effects on the outcome as measured by PSA recurrence.

Bluetongue virus serotypes 1 and 3 infection in Poll Dorset sheep

OBJECTIVE

To study the clinical signs following bluetongue virus serotypes 1 and 3 infection in Poll Dorset sheep.

DESIGN

A clinical and pathological study.

PROCEDURE

Twenty Poll Dorset sheep were inoculated with bluetongue virus serotypes 1 or 3, each inoculum having a different passage history. The sheep were examined daily and their clinical appearance and rectal temperatures recorded. Heparinised and non-heparinised blood samples were taken at intervals for virological and serological study. Gross pathological findings were recorded for several sheep at necropsy and tissue samples were collected from three sheep for virological studies.

RESULTS

All inoculated sheep developed clinical disease. The clinical signs and gross pathological changes varied considerably but were consistent with damage to the vascular endothelial system. There was a decline in the titres of infectious bluetongue virus and of antigen in tissues collected between 7 and 12 days after infection.

CONCLUSIONS

The severity of disease was related to the speed of onset and duration of pyrexia and not the development or titre of viraemia. Generally, those animals with sensitive mouths, depression, coronitis, recumbency and reluctance to move were the most debilitated. Whole blood was the most reliable source of infectious virus from acutely and chronically infected and convalescent animals. However, tissue samples particularly spleen, collected from dead or killed animals suffering from either peracute or acute forms of disease were most appropriate for the rapid confirmation of a clinical diagnosis.

Camptothecin analogues/cisplatin: an effective treatment of advanced bladder cancer in a preclinical in vivo model system

OBJECTIVE

To evaluate the impact of the camptothecin analogs on human TCC xenograft, both as monotherapy and in combination with cisplatin (CDDP).

MATERIALS AND METHODS

Human transitional cell carcinoma (TCC) xenograft tumor line (DU4184) tested by subrenal capsule assay in 112 nude mice(NM-SRCA). CDDP and the camptothecin analogs irinotecan (CPT-11) and 9-aminocamptothecin(9-AC) were evaluated.

RESULTS

Both of the camptothecin analogs showed significant short term tumor inhibition which translated into enhanced survival. Maximal tumor inhibition (>95%) was achieved when either of the camptothecin analogs was combined with CDDP with minimal host toxicity. This translated into 400% increase in median survival. While all controls were dead 39 days following tumor implantation, none of the combination treated animals had died.

CONCLUSION

The combination of CDDP with these camptothecin analogs is an effective therapy against this model of advanced TCC. These observations suggest potential clinical value.

Comparison of four automated prostate-specific antigen assays for detection of recurrence after radical prostatectomy

OBJECTIVES

To compare four assays-the Abbott IMx, the Tosoh, the Chiron ACS PSA, and the Chiron ACS PSA2-in their ability to detect prostate-specific antigen (PSA) after radical prostatectomy.

METHODS

Serum samples were drawn on all men who had had a previous radical prostatectomy and who were seen in the urology clinic in March 1995. The results of each assay were compared using linear regression.

RESULTS

Twenty-two patients had an undetectable PSA by the IMx assay. The PSA was over the residual cancer detection limit (RCDL) of the Tosoh assay in 5 of these patients. The PSA was over the RCDL of the ACS PSA assay in 15 of these patients and over the RCDL of the PSA2 assay in 2 patients. There were no patients whose PSA was less than the RCDL of the ACS PSA assay who had a measurable PSA level by any of the other assays.

CONCLUSIONS

There is a difference among PSA assays in their ability to detect low levels of PSA after radical prostatectomy. The ACS PSA assay is the most sensitive, and the IMx assay is the least sensitive.

Incidence of granulomatous prostatitis and acid-fast bacilli after intravesical BCG therapy

OBJECTIVES

To determine the incidence of granulomatous prostatitis and acid-fast bacilli (AFB) after intravesical bacillus Calmette-Guerin (BCG) therapy for superficial bladder transitional cell carcinoma (TCC) or carcinoma in situ (CIS).

METHODS

One hundred nineteen men underwent radical cystoprostatectomy for invasive bladder cancer from January 1, 1980 through December 31, 1995. Twelve patients had received intravesical BCG therapy before undergoing cystoprostatectomy. Nine men who did not receive intravesical BCG therapy before undergoing cystoprostatectomy served as controls. The surgical specimens were examined with a Ziehl-Neelsen stain for the presence of granulomatous prostatitis and for the presence of AFB.

RESULTS

Granulomatous prostatitis was identified in 9 of 12 patients (75%) who had received intravesical BCG therapy. AFB were identified in 7 of 9 patients (77%) with granulomatous prostatitis.

CONCLUSIONS

Pathologic evidence of granulomatous prostatitis with AFB is a common occurrence after intravesical BCG therapy and its incidence is far greater than the reported incidence of symptomatic granulomatous prostatitis. AFB discovered during the evaluation of either an increased level of prostate-specific antigen or prostate nodule in otherwise asymptomatic men may require no specific therapy.

Bone fractures associated with luteinizing hormone-releasing hormone agonists used in the treatment of prostate carcinoma

BACKGROUND

Luteinizing hormone-releasing hormone agonists (LHRH-a) have become an established treatment for certain patients with prostate carcinoma. LHRH-a are known to decrease bone mineral density. The purpose of this study was to determine the risk of bone fracture in men receiving LHRH-a for prostate carcinoma.

METHODS

A retrospective chart review and phone interviews were conducted to determine the incidence of bone fractures occurring in patients receiving LHRH-a for the treatment of prostate carcinoma. Abstracted data included the number of monthly LHRH-a injections, age, clinical stage of disease, sites of metastases, and bone fracture history.

RESULTS

Twenty of the 224 patients (9%) treated with LHRH-a for prostate carcinoma between 1988 and 1995 at 3 teaching hospitals had at least 1 bone fracture during treatment with LHRH-a. The duration of treatment to the time of fracture ranged from 1 to 96 months (mean, 22.2 months). Seven fractures (32%) were osteoporotic in nature (i.e., vertebral compression fractures or hip fractures after a fall from standing), whereas 8 fractures (36%) were associated with a significant traumatic event (i.e., a motor vehicle accident, boxing, etc.) and 5 were of mixed etiology. Two of 22 fractures (9%) were pathologic.

CONCLUSIONS

This study demonstrated a 9% fracture incidence in a cohort of patients receiving LHRH-a for prostate carcinoma for up to 96 months. The incidence of osteoporotic fractures was 5%.

Adequacy of EMS data collection during pediatric cardiac arrest: are EMTs getting the whole story?

OBJECTIVE

To compare the initial emergency medical services (EMS) prehospital assessment of medical and traumatic cardiopulmonary arrest in the pediatric patient with that of the Office of the Medical Investigator (OMI) and assess differences and implications for EMS training and prevention.

DESIGN

Retrospective review of ambulance run forms with the OMI autopsy confirmations.

SETTING

An urban EMS system and the state Office of the Medical Investigator.

PARTICIPANTS

Patients 15 years of age or less who were treated by prehospital personnel from November 1, 1990, to October 31, 1991, for a medical or traumatic arrest.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

Ambulance runs were reported for 2,586 pediatric patients. Of these, 42 (1.6%) had suffered arrests, with 32 (76%) medical arrests and ten (24%) traumatic arrests. Children 1 year of age or less accounted for 75% of the medical arrests, while children more than 1 year of age accounted for 80% of the traumatic arrests (p = 0.003). Overall mortality was 81%. When EMS prehospital assessments of medical and traumatic arrests were compared with autopsy reports, there was good agreement for sudden infant death syndrome (SIDS) (kappa = 0.70), but poor agreement for child abuse (kappa = 0.37).

CONCLUSION

The authors found good agreement between EMS prehospital assessments and autopsy diagnoses for identifying pediatric SIDS, but child abuse was not well identified prior to autopsy.

Simplified sizing of low-density lipoprotein using polyacrylamide gradient gel electrophoresis of plasma

Low-density lipoprotein (LDL) particles can be separated into subfractions according to size by non-denaturing polyacrylamide gradient gel electrophoresis. Established research methods require specialised equipment and are frequently unsuited to the clinical laboratory. In this study, we utilised a colour flat bed scanner in conjunction with shareware image analysis software to compare LDL particle diameters of isolated LDL with LDL in whole plasma. LDL was isolated by ultracentrifugation and electrophoresed on 3-13% gels (Gradipore; Sydney, Australia) for 2400 Volt-hours in parallel with plasma and molecular size standards. Coomassie Blue-stained gels were scanned in reflexive mode using a colour flat-bed scanner and Adobe Photoshop 3.0 software. Density traces of each lane were obtained using NIH Image software (public domain, USA). LDL particle diameters were determined from calibration curves of the log of molecular diameter of standards against migration distance. There was a good correlation between LDL particle diameters obtained using isolated LDL and whole plasma (r = 0.87, P < 0.001; n = 22). However, the group means (+/- S.D.) (24.7 +/- 0.6 and 24.8 +/- 0.5 nm respectively) were statistically different on the paired t-test (P < 0.05). It is unclear whether this numerically small difference is due to alterations in LDL during the longer preparative procedures for LDL, or to matrix effects during electrophoresis of plasma samples. In conclusion, plasma samples stained with Coomassie Blue and scanned with a colour flat bed scanner can conveniently be used for LDL particle sizing by non-denaturing polyacrylamide gradient gel electrophoresis.

Leuprolide acetate 22.5 mg 12-week depot formulation in the treatment of patients with advanced prostate cancer

Two open-label, multicenter studies were conducted to evaluate the efficacy and safety of a long-acting depot formulation of leuprolide acetate (22.5 mg) administered intramuscularly every 12 weeks to patients with stage D2 prostate cancer. Clinical evaluations were performed every 12 weeks, and serum testosterone levels were monitored biweekly or weekly for 24 weeks. Onset of castrate levels (< or = 50 ng/dL) of testosterone was achieved within 30 days of the initial depot injection in 87 (95%) of the 92 assessable patients enrolled in the two studies. Mean testosterone levels remained well within the castrate range throughout each dosing interval. Two patients experienced a transient escape (testosterone levels > 50 ng/dL on two consecutive determinations). Delay of an injection of up to 2 weeks did not have an effect on testosterone suppression: in 16 patients in whom the depot injection was delayed by 3 to 14 days, testosterone values remained within the castrate range. A favorable objective tumor response (no progression) to treatment occurred in 85% of the patients. Prostate-specific antigen and prostatic acid phosphatase decreased by 50% or more in 96% and 84% of patients, respectively, with elevated pretreatment values and at least one treatment value. Assessment of local disease status and overall performance status showed improvement or stability in most patients. The most common adverse events were hot flashes (59%), pain (27%), and testicular atrophy (21%). The 22.5-mg depot formulation of leuprolide, which acts in a manner similar to the monthly 7.5-mg depot formulation, was shown to be effective and safe in treating patients with advanced prostate cancer.

Oral bropirimine immunotherapy of carcinoma in situ of the bladder: results of a phase II trial

OBJECTIVES

Bropirimine is an orally administered immunostimulant that has been shown to have activity against carcinoma in situ (CIS) of the bladder. To further assess this potential activity, bropirimine was administered to 42 patients for bladder CIS in a Phase II trial.

METHODS

Patients were treated with bropirimine 3.0 g/day by mouth for 3 consecutive days each week up to 1 year. Cystoscopy with biopsies and bladder wash cytology were performed quarterly.

RESULTS

Twenty (61%) of 33 evaluable patients converted malignant biopsies and bladder wash cytology to negative, including 6 (50%) of 12 who failed prior bacillus Calmette-Guérin (BCG) immunotherapy, 14 (67%) of 21 who had not received prior BCG therapy, and 12 (80%) of 15 with primary CIS. Median response duration exceeds 21 months. Four of the 20 responders did have a papillary tumor recurrence at 3 to 15 months, all Stage Ta or T1. Mild toxicity (grade I or II) suggestive to interferon induction or administration occurred in one third of patients. Headache, transient hepatic enzyme elevations, skin rash, and arthralgias each occurred in 5% to 14% of the patients, with nausea or emesis in 21%. Grade 1 tachycardia/palpitations or chest pain each were noted in 5%.

CONCLUSIONS

Oral bropirimine can induce remission of bladder CIS with acceptable toxicity at 3.0 g/day. Bropirimine may be a valuable alternative to cystectomy for some failures of BCG therapy and may have the potential to replace BCG as front-line therapy because of its ease of administration.

Microvascular invasion of the seminal vesicles in adenocarcinoma of the prostate

The objective of this article is to determine the relationship between microvascular invasion and seminal vesicle invasion in prostatic adenocarcinoma. Radical prostatectomies with seminal vesicle involvement were examined histologically and immunohistochemically with antibodies directed against S-100 protein and factor VIII. Microvascular invasion of the seminal vesicles showed a positive correlation with microvascular and capsular invasion of the prostate (P = 0.006 and 0.048, respectively) and lymph node metastases. Tumor progression was found in 8 of 14 (57%) patients with microvascular invasion of the seminal vesicles, compared with 3 of 22 (14%) without microvascular invasion (P = 0.001). Microvascular invasion of the seminal vesicles is predictive of tumor progression and lymph node metastases in prostatic adenocarcinoma.

Novel mitochondrial DNA deletion found in a renal cell carcinoma

Polymerase chain reaction (PCR) was used to analyze a rarely deleted region of mitochondrial DNA (mtDNA) from 39 human renal cell carcinomas (RCC) and matched normal kidney tissue removed during radical nephrectomy. One tumor specimen (E.R.) had a unique PCR product approximately 250 base pairs (bp) smaller than the PCR product found in the normal E.R. kidney. Sequence analysis of the tumor-specific PCR fragment revealed a 264 bp deletion in the first subunit (NDI) of NADH:ubiquinone oxidoreductase (complex I) of the electron transport chain. Southern analysis of the RCCs demonstrated that approximately 50% of the mtDNA molecules in the primary RCC contained a unique 3.2 kb EcoRV restriction fragment found only in E.R. tumor mtDNA. Northern analysis demonstrated preferential transcription of the truncated NDI mRNA. None of the five metastases or any normal tissue from E.R. contained levels of the NDI deletion detectable by PCR. This is the first reported case of an intragenic NDI mtDNA deletion.

Induction of autologous tumor-specific cytotoxic T-lymphocyte activity against a human renal carcinoma cell line by B7-1 (CD8O) costimulation

Recently mouse models have shown that expression of costimulatory molecules such as B7-1 on tumor cells can induce tumor-specific immunity, suggesting that tumor cells modified to express costimulatory molecules can be a potential tumor vaccine. To investigate the importance of B7-1 co-stimulation in induction of autologous tumor immunity in humans, we established a renal carcinoma cell line, RCC-1, from a tumor resection and studied the patient's antitumor immune responses in vitro. The RCC-1 cell line constitutively expressed major histocompatibility complex (MHC) class I, intercellular adhesion molecule (ICAM)-1, and leukocyte function-associated antigen (LFA)-3 molecules, and MHC class II molecules were induced by interferon-gamma (IFN-gamma) treatment in vitro. However, neither RCC-1- nor IFN-gamma-treated RCC-1 cells expressed B7-1, and both failed to induce T-cell proliferative responses in mixed lymphocyte and tumor cell reaction (MLTR) assays, suggesting that the costimulatory signals provided by cell adhesion molecules such as ICAM-1 and LFA-3 were not sufficient to elicit an antitumor immune response. However, on transfection of the human B7-1 into RCC-1, these cells were able to induce a significant T-cell proliferation in MLTR assays. This T-cell response could be blocked by anti-B7 mAb treatment of the tumor cells. RCC-1B7 cells also induced the generation of tumor-specific cytolytic T lymphocytes to the parent RCC-1 cells in vitro, with little nonspecific cytolysis of an unrelated RCC line, A498, or autologous phytohemagglutinin (PHA) blasts. This specific cytotoxicity could be abrogated by anti-CD8 mAb and complement treatment. In summary, our study indicates that B7-1-CD28 interaction plays a critical role in induction of autologous tumor-specific cytotoxic T lymphocytes (CTLs) in humans, suggesting that the costimulatory molecule transfected tumor cells could be useful in expanding tumor-specific autologous CTL in vitro for adoptive tumor immunotherapy.

Microvascular invasion in prostate cancer correlates with pathologic stage

OBJECTIVE

To determine the incidence of microvascular invasion in prostatic carcinoma and its correlation with other prognostic factors.

DESIGN

Evaluation of the frequency and extent of microvascular invasion by routine light microscopy in 210 whole-mounted radical prostatectomies with cancer.

RESULTS

Microvascular invasion was identified in 111 (53%) of 210 specimens. Focal microvascular invasion (involvement of fewer than three high-power fields) was present in 42 cases (20%); extensive microvascular invasion (involvement of three or more high-power fields) was present in 69 cases (33%). Capsular perforation was present in 43% and 62% of cases with focal and extensive microvascular invasion, respectively. Seminal vesical involvement was observed in 23% and 47% of cases with focal and extensive microvascular invasion, respectively. Lymph node metastases were only observed in cases with microvascular invasion and were present in 7% and 23% of cases with focal and extensive invasion, respectively. There was also a strong positive correlation of microvascular invasion with surgical margin status, Gleason score, and cancer volume. Tumors ranged in volume from 0.14 cc to 47.25 cc (mean, 9.09 cc), and the volume in cases without microvascular invasion was lower than in those with invasion (mean, 5.4 cc and 12.7 cc, respectively); also, the volume in cases with focal invasion was lower than in those with extensive invasion (mean, 9.4 cc and 16.1 cc, respectively).

CONCLUSIONS

Microvascular invasion in prostatic carcinoma correlates positively with virtually all measures of pathologic stage. Its presence should be reported in all prostate specimens according to the Cancer Committee of the College of Americans Pathologists.

Normal range prostate-specific antigen versus age-specific prostate-specific antigen in screening prostate adenocarcinoma

OBJECTIVES

Prostate-specific antigen (PSA) has become the most useful serum tumor marker in the diagnosis and screening of prostate adenocarcinoma. The currently cited reference range of normal (0 to 4.0 ng/mL monoclonal) lacks both the sensitivity and specificity to be universally accepted as a screening test, and alternatives to serum PSA have been proposed, such as PSA density, PSA velocity, and age-adjusted PSA. Age-adjusted PSA takes into account the facts that as men grow older the prostate enlarges and that screening should have maximum sensitivity in younger men and maximum specificity in older men.

METHODS

A population of 4,710 men with no known history of prostate adenocarcinoma underwent 5,629 examinations by transrectal ultrasound of the prostate (TRUS) from 1987 to 1994. This population consists of Mobile Urology Group, Mobile, Alabama, and Emory University, Atlanta, Georgia, patient databases. We have examined our data to determine the sensitivity, specificity, and positive predictive values for normal range PSA (0 to 4 ng/mL) versus age-specific PSA values.

RESULTS

A total of 2040 patients had an abnormal digital rectal examination (DRE) and 3581 procedures were performed for an elevated PSA and a normal DRE. Biopsies were performed in 2,657 patients with 945 (35.6%) positive for cancer. Criteria for biopsy included elevated PSA (more than 4 mg/mL), PSA density more than 0.15 abnormal DRE, or suspicious TRUS. Patients were grouped according to decade: group 1 (ages 40 to 49 years, n = 183), group 2 (ages 50 to 59 years, n = 1018), group 3 (ages 60 to 69 years, n = 2358), and group 4 (ages 70 to 79 years, n = 1687).

CONCLUSIONS

Use of the age-specific range for PSA increases the sensitivity in younger men more likely to benefit from treatment, and decreases the biopsy rate in older patients who may not be candidates for aggressive treatment. Age-adjusted PSA is the most valuable for patients over the age of 70 years of whom 22% would be spared TRUS with biopsy.

Conservative renal surgery. Has it a role in renal cell carcinoma?

Conservative renal surgery is a viable alternative for patients in whom preservation of renal function is important. The long-term survival is similar to that of radical nephrectomy, especially in low-grade malignancies. The technique is unproven in patients with a normally functioning contralateral renal unit, although it may be an option in small, peripheral, low-grade lesions.

Intravesical suramin in the prevention of transitional cell carcinoma

OBJECTIVES

To examine the effects of intravesical suramin on N-methyl-N-nitrosurea (MNU)-induced bladder tumors in Fischer 344 rats.

METHODS

Multiple cohorts of female rats received four biweekly intravesical instillations of MNU. A control group received no other treatment, the experimental group received 25 mg/kg intravesical suramin twice a week beginning at week 6.

RESULTS

After 18 weeks from the first instillation of MNU, 60% to 65% of control animals developed papillary transitional cell carcinoma, compared with only 0% to 10% of the suramin-treated animals (P = 0.01 to P = 0.0007). There was no local or systemic toxicity observed.

CONCLUSIONS

Intravesical suramin is an effective chemopreventative therapy for transitional cell carcinoma in vivo with minimal toxicity.

Methoxypsoralen phototherapy of transitional cell carcinoma

OBJECTIVES

The goal of this research was to assess whether methoxypsoralen compounds in combination with ultraviolet light were effective in preventing cellular proliferation in an in vitro model of human transitional cell carcinoma.

METHODS

Three methoxypsoralen compounds, 5-methoxypsoralen (5-MOP), 8-methoxypsoralen (8-MOP), and 4'-aminomethyl 4,5'-8'-trimethylpsoralen (AMT), were added in vitro to T-24 transitional cell carcinoma cells. Psoralens directly bind to DNA, cross-linking the strands when exposed to ultraviolet light and thereby prevent cellular division.

RESULTS

In vitro activity was demonstrated utilizing AMT and ultraviolet radiation at 320 to 340 nm, preventing cellular proliferation in T-24 transitional cell carcinoma.

CONCLUSIONS

Methoxypsoralen compounds in combination with ultraviolet light are effective in preventing proliferation of bladder carcinoma cells in vitro. This therapy may prove to be effective in clinical early stage transitional cell carcinoma and warrants further assessment.

Serum PSA adjusted for volume of transition zone (PSAT) is more accurate than PSA adjusted for total gland volume (PSAD) in detecting adenocarcinoma of the prostate

OBJECTIVE

This study evaluates the accuracy of comparing serum prostate-specific (PSA) levels in the range between 4.1 ng/mL and 10.0 ng/mL (monoclonal) to the volume of the transition zone (TZ) of the prostate and total gland volume as a predictor of a positive biopsy.

METHODS

Using sonographic voluming of the entire prostate and of the TZ, prostate-specific antigen density (PSAD) and prostate-specific antigen density of the TZ (PSAT) were calculated in 21 biopsy-positive patients and 38 biopsy-negative patients. Biopsy was directed at sonographically suspicious areas and did not include sextant biopsies.

RESULTS

A statistically significant association was determined between a positive biopsy and gland volume, TZ volume, and PSAT. The association of a positive biopsy with PSA and PSAD was not statistically significant.

CONCLUSIONS

PSAT is more accurate in predicting a positive biopsy than is PSAD for PSA levels between 4.1 ng/mL and 10.0 ng/mL.

Comparison of MGH-1 and TuMark antibody detection in transitional cell carcinoma

Two monoclonal antibodies, TuMark-BTA and MGH-1, were evaluated in patients with benign pathology, history of transitional cell carcinoma with no active disease and active transitional cell carcinoma. Both antibodies were accurate in predicting carcinoma in approximately two-thirds of patients. TuMark showed a 74% sensitivity and 50% specificity, while MGH-1 was more sensitive (86%) and less specific (38%). Positive predictive values for TuMark and MGH-1 were 79% and 78%, respectively.

Staging of early prostate cancer: a proposed tumor volume-based prognostic index

Current staging of early prostate cancer separates patients into two groups: those with palpable and non-palpable tumors. Such staging relies on digital rectal examination in making this separation, despite the low sensitivity, low specificity, and low positive predictive value of this method. As an alternative, tumor volume may be useful for staging because of its powerful prognostic ability and its potential to be assessed clinically due to recent advances in imaging techniques such as transrectal ultrasound. In this study, we evaluate the utility of tumor volume in predicting progression of early prostate cancer based on the composite published evidence from nine pathologic studies of serially-sectioned prostates. Logistic regression revealed that tumor volume was a good positive predictor of all measures of tumor progression. There was a 10 percent probability of capsular invasion in tumors measuring about 0.5 cm3; 10 percent probability of seminal vesicle invasion in tumors measuring about 4.0 cm3; and 10 percent probability of metastases in tumors measuring about 5.0 cm3. These composite results suggest that tumor volume is a significant predictor of cancer progression. A volume-based prognostic index is proposed as an adjunct to staging for early prostate cancer.

Suramin inhibits growth factor binding and proliferation by urothelial carcinoma cell cultures

Suramin is a polyanionic compound recently noted to inhibit growth factor action and proliferation of several types of neoplastic cells in vitro. Data from clinical trials show antineoplastic activity against some prostatic and adrenal cortical carcinomas. Suramin is excreted unmetabolized into the urine suggesting possible application in treatment of urothelial carcinoma and prompting us to examine the drug's effect on growth factor binding and cell proliferation by two urothelial carcinoma cell lines. Half-maximal inhibition of 125I-epidermal growth factor (EGF) binding to T24 and HT1376 cells was produced by suramin concentration of approximately 300 and 100 microM, respectively. The corresponding value for 125I-insulin-like growth factor 1 (IGF1) binding was 60 microM for both cell lines. Inhibition of T24 and HT1376 growth was virtually complete at suramin concentrations in the range achievable clinically.

Immunology of the bladder

Immunobiology techniques that once were the domain of research are increasingly being applied in the clinic. Transitional epithelium of the bladder undergoes some recognized immunologic changes as it becomes malignant, and their detection may have prognostic value. Examples of such changes are deletion of the ABO(H) blood group antigens, inappropriate expression of Lewis antigens, loss of beta-2 microglobulin and the MHC class 1 heavy chain, and alterations in the production of cellular adhesion molecules and integrins. Other possibly useful markers are ras oncogene products, Thomsen-Friedenreich antigen, epidermal growth factor receptor, and perhaps antigens unique to transitional-cell carcinoma.

Critical assessment of prostate cancer staging

Staging of prostatic adenocarcinoma is a systematic classification of the extent of disease based on clinical and pathologic criteria. This classification determines treatment and reflects ultimate expected clinical outcome. The technologic changes in diagnostic modalities need to be incorporated into the staging classification and a better assessment of biologic hazard of each individual tumor needs to be developed to further refine current treatment of prostate cancer.

The detection of African horse sickness virus antigens and antibodies in young Equidae

Four ponies were each inoculated with a different serotype of African horse sickness virus (AHSV) which had been passaged through cell culture in order to achieve attenuation. Three of the ponies died suddenly after showing mild clinical signs, the fourth pony remained clinically normal and was killed at day 38. Infectious AHSV was isolated from blood samples collected at intervals from all four ponies. Positive antigen ELISA reactions were only observed with blood samples from two of the ponies on the two days preceding death. Specific AHSV antibodies were detected by ELISA in serum samples from the other two ponies although one eventually died. African horse sickness viral antigens were detected by ELISA in post-mortem tissue samples collected from all four ponies. No infectious virus could be detected in tissue samples taken post-mortem from the pony which survived African horse sickness (AHS) infection. In the event of a suspected outbreak of AHS it is recommended that sera and heparinized blood should be tested for specific antibodies and AHSV antigen respectively. When available, post-mortem tissues, including spleen, heart, lung and liver, should also be tested for AHSV antigen. Although the ELISA used for the detection of AHSV antigen is highly sensitive and specific, negative ELISA results should be confirmed by virus isolation attempts.

Renal cell carcinoma with inferior vena caval involvement

Renal cell carcinoma extends into the lumen of the inferior vena cava in approximately 4% of patients at the time of diagnosis. Surgical removal of the intracaval tumor thrombus with radical nephrectomy is the preferred treatment for this malignancy. From January 1977 to June 1990, 31 such patients were examined for combined problems of renal carcinoma and intracaval tumor extension. Twenty-six of these patients underwent radical nephrectomy and vena caval thrombectomy. Ten patients had tumor thrombus confined to the infrahepatic vena cava, 11 had retrohepatic caval involvement, and 5 had extension to the level of the diaphragm or into the right atrium. Surgical approach was dictated by the level of caval involvement. Control of the suprahepatic vena cava plus temporary occlusion of hepatic arterial and portal venous inflow were necessary in some cases; cardiopulmonary bypass was required for transatrial removal of more extensive tumors. Five of the 26 patients had evidence before operation of distant metastatic disease; none of these survived beyond 12 months. The 5-year actuarial survival rate of the 21 patients without known preoperative metastatic disease was 57%. Complete surgical excision of all gross tumor appears to be critical for long-term survival in these patients.

Randomized study of interleukin 2 (IL-2) alone vs IL-2 plus lymphokine-activated killer cells for treatment of melanoma and renal cell cancer

The purpose of this study was to evaluate the efficacy and safety of a continuous-infusion interleukin 2 (IL-2) regimen for patients with metastatic melanoma and renal cell cancer. To investigate the contribution of adoptively transferred lymphokine-activated killer cells, patients were randomized to receive either IL-2 alone or IL-2 plus lymphokine-activated killer cells. Twenty-three patients with renal cell carcinoma and 20 with melanoma were entered into the protocol. There were no objective responses noted in the 38 assessable patients (20 with renal cell carcinoma, 18 with melanoma). Most patients demonstrated progressive disease following one 31-day cycle of weekly continuous-infusion IL-2. Grade I and II toxic reactions, including fever, rash, anorexia, and weight gain, were common and treated symptomatically. Significant in vivo stimulation of lymphokine-activated killer and natural killer cell activity was noted in most patients. This continuous-infusion IL-2 regimen with or without lymphokine-activated killer cells was ineffective in the treatment of melanoma and renal cell carcinoma.

ABO(H) antigens and beta-2 microglobulin in transitional cell carcinoma. Predictors of response to intravesical bacillus Calmette-Guerin

The response of patients with superficial transitional cell carcinoma of the bladder (STCB) to intravesical chemotherapy is variable; some patients enjoy a long period without recurrence, whereas others have recurrence of tumor within 2 years of removal of the primary lesion. Previously, others have demonstrated that the loss of normal cell surface antigens, such as ABO(H) blood group antigens or beta-2 microglobulin (B2M) has been correlated with more aggressive behavior by tumor. In this study, using immunohistochemical techniques, the authors evaluated the initial pretreatment biopsy specimen of bladder tumors for the presence of ABO(H) antigens and B2M. Data from this sample patient population, all with biopsy-proven STCB, indicate that expression of these two markers is predictive of a therapeutic response to prophylactic intravesical bacillus Calmette-Guerin (BCG) (Tice strain) after resection, and that expression of the two markers is of greater predictive value than expression of either antigen alone.

Antibodies in horses, mules and donkeys following monovalent vaccination against African horse sickness

A total of 256 sera collected from three species of domesticated equidae in four different Spanish provinces were examined 1-4 months after the administration of attenuated monovalent African horse sickness virus (AHSV) serotype 4 vaccine. Approximately 10% of the sera were negative by ELISA, virus neutralization, agar gel immuno-diffusion and complement fixation tests. Similar negative reactions were recorded with sera from two ponies after experimental primary vaccination. The rapid rise in antibodies in sera from these two ponies, after a second dose of vaccine, suggested they would probably have been immune to challenge. It is therefore suggested that the apparent absence of antibodies against AHSV in some animals after primary vaccination may not necessarily indicate a total lack of protection.

Changes in endocrine function after adrenal medullary transplantation to the central nervous system

Ten patients were studied before and after autologous adrenal medullary transplantation to the central nervous system for Parkinson's disease to determine if the presence of new catecholamine-producing tissue near the hypothalamus would alter hypothalamic or pituitary function, mineralocorticoid levels, or catecholamine production. No clinically apparent ill effects occurred. Changes in endocrine function were largely short-term and transient: at 7-10 days after surgery, urinary catecholamine levels were significantly increased, PRL levels were significantly elevated despite markedly increased serum dopamine levels, and gonadal steroid levels (estradiol and testosterone) were significantly lower despite unchanged basal and stimulated levels of gonadotropins. Dehydroepiandrosterone sulfate was significantly reduced at 7-10 days after surgery and remained low at 3-6 months. Other changes at 3-6 months after surgery included increased stimulated corticotropin levels and reduced serum aldosterone response to upright posture. The changes at 7-10 days were probably due to stress or unilateral adrenalectomy or both; the changes at 3-6 months were likely due to unilateral adrenalectomy. We conclude that unilateral adrenalectomy and autologous adrenal medullary transplantation to the central nervous system does not produce clinically important changes in endocrine function; however, possible adverse consequences of long-term reduction of dehydroepiandrosterone sulfate levels cannot be excluded.

Enucleation of tumor versus partial nephrectomy as conservative treatment of renal cell carcinoma

In patients with renal insufficiency, solitary kidney, or bilateral renal malignancies, conservative surgery for renal cell carcinoma has been suggested. The authors treated 17 such patients with either enucleation of tumor or partial nephrectomy. Overall survival from disease in this series was 58.8%. Seventy percent of patients undergoing enucleation and 42.9% undergoing partial nephrectomy survived with a mean follow-up period of 5 years. Survival or local recurrence rate after enucleative surgery is an effective treatment of renal carcinoma in selected patients, and despite concerns about tumor invasion of the pseudocapsule, the clinical data do not indicate any difference in survival. There was no significant difference between enucleation of tumor and partial nephrectomy regarding morbidity, mortality, or recurrence rate.

A competitive ELISA for the detection of group-specific antibodies to African horse sickness virus

A competition enzyme-linked immunosorbent assay (ELISA) has been developed for the rapid identification and quantification of antibodies against African horse sickness (AHS) in sera from solipeds. The data showed the ELISA to be sensitive, specific and reliable. More than 1600 sera from 37 different countries were examined and results compared with those obtained by agar gel immuno-diffusion (AGID) tests. In no case did any of 775 sera from countries where AHS has never been reported and where AHS vaccines are not used, record an ELISA titre greater than 4. A titre equal to or greater than 8 was considered positive. Using this criterion, 96.3% of sera tested in both assays were in agreement. Doubtful results by AGID (1.7%) were clearly defined in terms of positivity and negativity by ELISA. This ELISA is suited for the rapid laboratory confirmation of AHS and should be considered as a replacement for the traditional AGID test.

Preliminary report on adrenal-brain transplantation for parkinsonism in man

The attempt to restore lost neurological function through grafting of catecholaminergic tissue into the striatum is a dramatic new experimental treatment approach for parkinsonism. We have grafted autologous adrenal medullary tissue into the right caudate nucleus in 12 patients with advanced Parkinson's disease (10 males, 2 females, mean age 53 years, mean Hoehn and Yahr stage 'off' medications 4.2) applying a transcortical technique similar to that of Madrazo as modified by Allen using right adrenalectomy performed via a flank approach. There have been no deaths, surgical complications, or serious postoperative morbidity. Modified Columbia Parkinson's disease ratings of patients off all dopaminergic agents for 72 h revealed 22% improvement (p less than 0.01) 3-6 months postoperatively (n = 10) and 22% improvement (p less than 0.01) 7-12 months later (n = 9). Postoperative dyskinesias necessitated reduction of L-dopa by 11% and of carbidopa by 29%. Analysis of lumbar cerebrospinal fluid biogenic amine metabolites following a 4-day 'drug holiday' revealed that homovanillic acid increased to 159% of preoperative levels (p less than 0.01) 3-6 months (n = 9) and to 197% of preoperative levels (p less than 0.02) 7-12 months postoperatively (n = 5). We have observed a mild to moderate improvement persisting up to 1 year with this therapeutic approach, but further study is needed.

Immunotherapy of renal cell carcinoma

Metastatic renal cell carcinoma remains a frustrating disease to treat. Although there is significant evidence that this tumor is responsive to alterations in the immune system, a complete understanding of the antitumor immune response is still elusive. The early trials have been aimed primarily at nonspecific methods for stimulation of the immune system, with the equal possibility that aside from stimulation of the effector cells responsible for tumor containment, there may be stimulation of other mechanisms that will inhibit this response. The better responses in some cases appear to be in the treatments that produce the most toxicities, though even these treatments only have a 20% to 30% response in most trials. Although the prior trials of immunotherapy have yielded modest results, they have provided a better understanding of the immune system in the oncologic setting. Newer trials are now being directed at combinations of lymphokines, which is the beginning of the application of basic science in the clinical setting. With a better appreciation of the basic science behind the immune response, the current factors available will be put into better therapeutic perspective, and newer factors, including various growth factors, may play an important role in future therapy. Also, the addition of antisuppressor regimens to stimulation trials is a sign of recognition of the complexity of the immune response. Aside from suppressor cells, investigators are beginning to realize that there are circulating proteins probably generated either by the tumor or in response to the tumor that are immunosuppressive (eg, circulating IL-2 receptors). Inhibition of these proteins by pheresis or other methods may provide increased immunoreactivity to the tumors, as has already been shown in a small series. Monoclonal antibodies offer the promise of the most specificity; however, the technology is still far from making this therapy imminently available. Only through additional laboratory and clinical investigation, will significant advances be made.