Lack of germline CDK6 mutations in familial melanoma

Germline mutations in genes encoding several components of the retinoblastoma pathway have been linked with inherited predisposition to melanoma. Most commonly, such mutations involve CDKN2A, a cyclin-dependent kinase inhibitor of two kinases, CDK4 and CDK6, which phosphorylate the retinoblastoma protein (pRB) and thereby promote passage through the G1/S cell-cycle restriction point. Less frequently, germline mutations in the CDK4 gene have also been linked with an increased risk of melanoma. Despite the sequence and functional homology between CDK4 and CDK6, the role of germline mutations in CDK6 in melanoma predisposition is unknown. We detected no CDK6 mutations within the p16 (CDKN2A) binding domain in index cases from 60 melanoma-prone kindreds that lacked germline mutations in the coding regions of either CDKN2A or within the entire CDK4 coding region. We conclude that germline mutations in CDK6 do not make a significant contribution to melanoma predisposition.

Tracking and follow-up of marginalized populations: a review

Maintaining study cohorts is a key element of longitudinal research. Participant attrition introduces the possibility of bias and limits the generalizability of a study's findings, but with appropriate planning it is possible to sustain contact with even the most transient participants. This paper reviews the essential elements of tracking and follow-up of marginalized populations, which are (1) collection of contact information, (2) thorough organization of tracking efforts, (3) attention to staff training and support, (4) use of phone and mail follow-up, (5) use of incentives, (6) establishing rapport with participants, (7) assurance of confidentiality, (8) use of agency tracking, (9) use of field tracking, and (10) attention to safety concerns. Diligent application of these tracking strategies allows researchers to achieve follow-up rates of 75 percent to 97 percent with vulnerable populations such as homeless, mentally ill adults, injection drug users, and runaway youth.

Cross-Canada spread of methicillin-resistant Staphylococcus aureus via transplant organs

We report our investigation of the transmission of methicillin-resistant Staphylococcus aureus (MRSA) through transplantation. The kidneys, liver, and corneas were harvested from a child who died in Nova Scotia. Several days postmortem it was learned that culture of a premortem endotracheal tube aspirate from the donor yielded MRSA. Both kidneys were transplanted into a child in Nova Scotia and the liver into a child in Alberta. Both recipients subsequently became blood culture-positive for MRSA. One corneal ring from the donor was MRSA-positive. All four MRSA isolates were mecA-positive by polymerase chain reaction (PCR). The relatedness of the MRSA isolates was examined by restriction fragment length polymorphism (RFLP) analysis, a 16S-23S ribosomal PCR typing method, and comparison of antibiograms. Results were identical for all four MRSA isolates. These findings indicate that MRSA from the donor was transferred to recipients during implantation of harvested organs in Alberta and Nova Scotia, a cross-Canada spread.

Needle exchange program participation by anabolic steroid injectors, United States 1998

A significant number of people are currently misusing and abusing anabolic steroids. Hepatitis B, C, and HIV have all been documented to occur among anabolic steroid injectors (ASIs), most likely from the sharing of injection equipment. A survey was administered to 42 needle exchange programs (NEPs) from 17 states in the US to determine ASI participation. Sixty percent of the NEPs surveyed reported having at least some ASIs as participants, however, only 512 ASIs were identified among the 36,000 total monthly participants (1.4%). With the expanding number of NEPs in the US, it is possible to reach a higher proportion of ASIs with clean syringes and education, thus offering the means to prevent the spread of infection in this population.

Obstacles to needle exchange participation in Rhode Island

OBJECTIVE

This study explores obstacles to participation in needle exchange programs (NEPs) among injection drug users (IDUs) in the state of Rhode Island, U.S.A.

METHODS

A written questionnaire was administered at two Rhode Island drug detoxification sites in 1998.

RESULTS

488 self-administered surveys were completed, 226 (46.3%) respondents had injected drugs in the past 6 months. 62.1% reported sharing syringes in the past 6 months, and each syringe was used a mean of 10.7 times. Major obstacles to NEP participation were a lack of awareness of the program (25.6%), inconvenient location or hours (15.9%), and fear of identification and/or police harassment (12.2%). Non-white race was a significant predictor of being unaware of the NEP (p = .01) and not participating in the NEP (p = .03). 13.1% of IDUs who used the NEP were referred to the detoxification program by the NEP. Among all IDUs surveyed, 51.0% had participated in a NEP.

CONCLUSIONS

NEPs are important in reducing the spread of bloodborne pathogens among IDUs and are effective referral sources for drug treatment. Surveys of IDUs at sites other than NEPs, such as detoxification facilities, can identify obstacles to the use of NEPs.

Mutation detection using fluorescent enzyme mismatch cleavage with T4 endonuclease VII

Mutation detection techniques are often limited by sensitivity, ease of use and short fragment lengths. Enzyme mismatch cleavage (EMC) is a technique capable of rapidly scanning 1 kbp fragments of DNA for mutations. It relies on the ability of a bacteriophage resolvase enzyme, T4 endonuclease VII, to cleave DNA at single base pair mismatches and small heteroduplex loops. Originally the process was performed using radioactively labeled DNA and the results analysed after denaturing polyacrylamide gel electrophoresis and autoradiography. However, access to systems capable of detecting fluorescent species migrating through a gel and the widespread availability of fluorescently tagged primers have greatly improved upon the original technique. A number of mutations were detected using fluorescent EMC and the results compared to performing the technique using radiolabeled DNA. Fluorescent EMC detected the presence, position and number of mutations in DNA fragments as large as 1 kbp. The fluorescent method was found to have advantages over the original method in its ease of use, increase in signal-to-noise ratio and the ability to multiplex samples by labeling DNA fragments with different fluorophores. This improvement on an already established method provides a sensitive, robust technique for mutation detection.

Postirradiation sarcoma after external beam radiation therapy for localized adenocarcinoma of the prostate: report of three cases

We report 3 cases of postirradiation sarcoma that arose in the pelvis 8, 15, and 16 years after completion of external beam radiation therapy (RT) for localized adenocarcinoma of the prostate. Although such cases must be regarded as extremely rare, postirradiation sarcoma should be considered as a potential cause of pelvic pain developing after RT.

Peritonitis due to Stenotrophomonas maltophilia in patients undergoing chronic peritoneal dialysis

The occurrence of cases of Stenotrophomonas maltophilia peritonitis in chronic peritoneal dialysis (PD) patients prompted a review of our experience with this condition. A search of microbiology records revealed seven episodes of S. maltophilia peritonitis in 7 patients in 1996 - 3.8% of all PD patients - compared to no cases in 1994 and 1995 (p = 0.01). Patients ranged in age from 16 to 64 years; there were 3 males and 4 females. Six of seven episodes of peritonitis were community acquired and one was hospital acquired. No temporal clustering of cases was seen. Patients were from different urban and rural communities. Patients used the same commercially supplied dialysate fluid, different dialysis techniques, and were taught a no-touch technique for connection. Treatment of peritonitis required removal of the Tenckhoff catheter in 4 of 7 cases. Fingerprinting of six available isolates by polymerase chain reaction using primers derived from the conserved region of the 16/23Sr RNA gene sequence and pulsed field gel electrophoresis revealed all to be unique strains. A case-control study comparing 7 S. maltophilia cases to 21 PD controls showed case patients to be younger and more likely to be on immunosuppressive therapy. We conclude that S. maltophilia has emerged as an important cause of peritonitis in our continuous ambulatory PD population. Evidence to date suggests community acquisition with no evidence of a common source.

Pion conformal radiation of prostate cancer: results of a randomized study

PURPOSE

To compare the efficacy of pion radiation therapy with conventional external beam photon therapy, for the treatment of locally advanced stage T3/4, N0, M0 adenocarcinoma of the prostate.

METHODS AND MATERIALS

Two hundred seventeen eligible patients were randomly allocated to either photon or pion therapy. No adjuvant hormone therapy was used.

RESULTS

Median follow-up was 42 months (range 2-90). Acute bladder toxicity was worse in the pion arm, p = 0.2, but other acute toxicity did not differ. Late grade 2 toxicity was significantly less in the pion arm (29% at 5 years versus 48%, p = 0.002), but late grade 3 or 4 toxicity did not differ. Clinical local control was not significantly different between treatment arms (64% after 5 years with photons, 56% with pions, p = 0.6). Cause-specific and overall survival also did not differ (p = 0.7). There was a significant delay in time to first failure in the photon arm, largely as a result of decreased biochemical relapse, p = 0.01. A multivariate analysis is presented.

CONCLUSION

Pion therapy was well tolerated, with increased acute toxicity and significantly decreased late tissue injury. This contrasts with the late toxicity observed with higher LET particle therapy such as neutron therapy. No improvement in local control with pion therapy was observed.

Central venous catheters as a source of hemodialysis-related bacteremia

OBJECTIVE

To describe investigations into an increase in hemodialysis-related bacteremia that occurred in our hospital in the first 6 months of 1996.

SETTING

Hemodialysis unit in a tertiary-care medical center.

METHODS

Prospective surveillance for hemodialysis bacteremia has been performed for several years. Cases that occurred in 1995 were compared to cases in the first 6 months of 1996. Unit data on dialysis runs and method of dialysis access were used to calculate rates. Nested polymerase chain reaction (PCR) was used to type 18 Staphylococcus aureus isolates from 1996. A case-control study comparing 80 randomly selected hemodialysis patients from 1995 and 1996 was performed to examine infection risk factors.

RESULTS

The hemodialysis bacteremia rate was 1.2 per 1,000 runs in 1995 and 2.8 per 1,000 in the first 6 months of 1996 (P=.0009). The 25 cases in 1995 and 32 in the first half of 1996 were similar in age, gender, means of vascular access, and microbial etiology. Central venous catheter (CVC) access accounted for >90% of cases in both time periods. S aureus was the most common microbial etiology (53% of the 1996 cases). PCR typing of S aureus isolates from 1996 demonstrated five different strains, the most common having six isolates. The use of CVCs as a means of vascular access abruptly increased in the unit in January 1996, from <30% of dialysis runs in 1995 to >40% in 1996 (P<.001), associated with structural changes in healthcare delivery in the region resulting in delays in performing surgical procedures, such as creation of vascular grafts and fistulae.

CONCLUSION

A marked increase in hemodialysis bacteremia occurred in 1996, associated with increased reliance on CVCs for vascular access in hemodialysis patients during a period of healthcare restructuring.

New combination of the old drugs for elderly patients with small-cell lung cancer: a phase II study of the PAVE regimen

PURPOSE

A regimen of cisplatin, doxorubicin, vincristine, and etoposide (PAVE) was designed for patients with small-cell lung cancer (SCLC) who were older than 65 years, with the following objectives compared with standard chemotherapy regimens: maintain efficacy, diminish toxicity, enhance compliance, and improve chemotherapy administration convenience at an acceptable cost.

PATIENTS AND METHODS

The PAVE regimen consisted of cisplatin 30 mg/m2 intravenously (i.v.) day 1; doxorubicin 40 mg/m2 i.v. day 1; vincristine 1.0 mg/m2 i.v. day 1; and etoposide 100 mg/m2 i.v. day 1 and orally days 3 and 5. Cycles were repeated every 3 weeks for four cycles. Patients with limited-stage disease and selected patients with extensive-stage disease received thoracic irradiation delivered concurrently with etoposide-cisplatin (EP) at the time of the second chemotherapy cycle.

RESULTS

Sixty-six eligible patients were treated, which included 25 patients with limited-stage disease and 41 patients with extensive-stage disease. Median survival was 70 weeks and 5-year survival was 25% for limited-stage disease. Median survival was 46 weeks for extensive-stage disease. Only one treatment-related death occurred and severe toxicity was infrequent. The median delivered dose-intensity was according to protocol and the mean delivered total dose was 80% of intended.

CONCLUSION

The treatment outcome achieved with PAVE in a phase II study of elderly patients compared favorably with published results of standard regimens in patient populations with better prognostic factors. Because the PAVE regimen can be delivered with good compliance, has acceptable toxicity, and is associated with logistic advantages compared with standard regimens, this protocol is suitable for further investigative trials in elderly patients with SCLC.

Cooperative health care clinics: a group approach to individual care

In cooperative health care clinics (CHCC), health care is provided to older patients in a group setting. The CHCC concept, which was developed under a research grant by Kaiser Permanente in Colorado in 1991, showed improvement in patient and provider satisfaction, as well as improved quality of care and cost effectiveness. CHCC are being replicated in other sites under a research grant from the Robert Wood Johnson Foundation. In addition to formal findings from research studies, much has been learned about factors that have promoted the success of the program.

Watchful waiting or watchful progression?: Prostate specific antigen doubling times and clinical behavior in patients with early untreated prostate carcinoma

BACKGROUND

Prostate specific antigen doubling time (PSAdt) is a dynamic model of prostate tumor biology. It predicts aggressive disease and subsequent clinical recurrence after radical treatment. However, as yet there is only limited evidence for its validity in the watchful waiting population.

METHODS

One hundred and thirteen previously untreated patients with adenocarcinoma of the prostate who were referred to the British Columbia Cancer Agency for a management opinion subsequently were placed into a prospective watchful waiting program. The reasons for watchful waiting, previous medical history, serial PSA, and histopathologic data were recorded.

RESULTS

The median age of patients was 75 years (range, 49-85 years). The median follow-up from the time of the first appointment was 14 months (range, 0-58 months). The reasons for watchful waiting were correlated highly with T classification (P = 0.003) and past medical history (P = 0.002). Approximately 40% of T1 patients and 51% of T2 patients had clinical progression by 2 years, increasing to 60% at 3 years. On multivariate analysis PSAdt strongly correlated with clinical progression (P < 0.0001), stage progression (P = 0.01), and time to treatment (P = 0.0001); tumor grade and initial stage were not found to be predictive for any of the endpoints studied. Initial PSA only was significant in predicting for time to treatment (P = 0.03). Approximately 50% of patients with a PSAdt of <18 months progressed within 6 months. At last follow-up, no deaths from prostate carcinoma had been recorded. Overall survival at 2 and 5 years was 92% and 68%, respectively.

CONCLUSIONS

Using digital rectal examination, the findings of this study demonstrated high rates of clinical tumor progression within the watchful waiting population. PSAdt rather than standard histopathologic criteria was found to be the most powerful indicator of disease activity.

Family grief therapy: a preliminary account of a new model to promote healthy family functioning during palliative care and bereavement

The family is usually the primary provider of care for the terminally ill patient with cancer or other serious progressive illness. The way in which such a family functions is a major determinant of psychological well-being for its members. Through screening with the Family Relationships Index (FRI) (Moos and Moos, 1981), dysfunctional families and those at risk can be identified, and then helped to achieve better family functioning, thus improving psychosocial outcome of their grief. In this paper, we describe the techniques and themes involved in the application of our empirically developed model of family grief therapy, designed as a preventive intervention for use in the setting of palliative care and bereavement.

Increasing the availability of vasectomy in public-sector clinics

A program designed to improve the availability of vasectomy in public-sector clinics trained physicians at 43 facilities in no-scalpel vasectomy between 1993 and 1995. Among the 38 clinics that responded to a follow-up survey in 1996, the number of clinics providing vasectomies rose from 23 to 32, an increase of almost 40%, while the number of vasectomies performed rose by 18%. Seventeen of the 32 clinics performed more vasectomies after the training; 10 of the 17 had not previously provided the procedure. In-depth interviews with staff from seven sites that experienced large caseload increases and from seven that experienced decreases identified three elements for the successful establishment or expansion of vasectomy services-sufficient numbers of trained providers, funds to subsidize vasectomies for men who cannot afford them and activities to raise awareness about the availability of low-cost or free vasectomy.

Postradiation osteonecrosis of the mandible: a long-term follow-up study

OBJECTIVES

The objective of this study was to assess the long-term progress of 26 patients who experienced postradiation osteonecrosis of the jaw between 1975 and 1989.

STUDY DESIGN

Of 26 patients who had been previously managed with hyperbaric oxygen therapy as a part of their treatment for postradiation osteonecrosis of the jaw, 20 were evaluated to determine their current status of the condition: resolved, chronic persisting (unresolved), or active progressive (symptomatic).

RESULTS

Two of 20 patients experienced recurrences of the condition. In one of these patients, surgical treatment was identified as the stimulus of postradiation osteonecrosis. In the other patient, the recurrence appeared to be related to periodontal disease activity. In 60% (12 of 20) of the patients, the condition remained resolved, improvement in clinical staging occurred in 10% (2 of 20) (from symptomatic to unresolved or resolved), and 20% (5 of 20) of the patients continued to demonstrate chronic persisting postradiation osteonecrosis at the end of the long-term follow-up period.

CONCLUSION

This study supports the contention that postradiation osteonecrosis can occur at any time after radiation therapy, and that patients remain at risk up to 231 months after treatment of the cancer and probably indefinitely after radiation therapy. Our findings also suggest that risk of second episodes of the condition after management of an initial episode is low. In addition, our follow-up study revealed that chronic nonprogressive postradiation osteonecrosis can remain stable without extensive intervention including combined hyperbaric oxygen therapy and surgery.

Phase I and pharmacologic study of paclitaxel administered weekly in patients with relapsed ovarian cancer

PURPOSE

Paclitaxel has shown significant activity in advanced ovarian cancer. In vitro studies with paclitaxel have suggested that fractionated brief infusion schedules may be more effective than the standard 24-hour infusion. We commenced a phase I evaluation of escalating-dose paclitaxel (40, 50, 60, 80, 100 mg/m2) administered weekly as a 1-hour infusion in patients with recurrent ovarian cancer. All patients had received prior paclitaxel and cisplatin therapy. All patients received standard premedication.

PATIENTS AND METHODS

Eighteen patients are assessable on this phase I study. The mean age was 54 years (range, 48 to 74). The median number of prior chemotherapy regimens was three (range, two to five). The mean paclitaxel-free interval was 10.1 months (range, 1 to 24).

RESULTS

A total of 194 cycles of therapy were administered, with a mean of 10 (range, one to 12) per patient. No mucositis or grade III neuropathy was seen. Alopecia occurred in one out of 18 assessable patients. The mean neutrophil nadir was 4.0 x 10(9)/L. At the top dose level (100 mg/m2) delivered, dose-intensity was 90.75% of that planned and greater than two fold the standard dose-intensity. Partial responses were seen in four of 13 assessable patients (30%). Two patients with progression of disease on standard three-week paclitaxel schedules switched to a weekly schedule with demonstrated response. Increasing paclitaxel dose correlated with measured area under the curve (AUC) (R2 = .614). Dose-limiting toxicity was reached at 100 mg/m2 with two of three patients experiencing a treatment delay, thus defining a maximum-tolerated dose of 80 mg/m2 in this group of heavily pretreated patients on this weekly schedule.

CONCLUSION

(1) Paclitaxel administered as a 1-hour infusion is well tolerated; (2) this schedule of administration does not result in cumulative myelosuppression; and (3) this schedule of administration results in dose-intensive paclitaxel delivery with a favorable toxicity profile.

Bacteremic nosocomial pneumonia. A 7-year experience in one institution

STUDY OBJECT

To describe the epidemiology, microbiology, and outcome of nosocomial pneumonia with secondary bloodstream infection.

DESIGN

Prospective cohort study.

SETTING

Tertiary care Canadian teaching hospital.

PATIENTS

Inpatients.

MEASUREMENT

All inpatient blood cultures were concurrently monitored over an 89 month period. Following chart review, patients experiencing nosocomial bloodstream infection due to pneumonia were identified. A standardized definition of pneumonia was used.

RESULTS

One hundred forty-nine episodes occurred in 145 patients, 0.66/1,000 hospital admissions, 8.4% of all nosocomial bloodstream infections. No change in rate occurred in the study period. Fifty-four percent of episodes developed in one of seven ICUs. Staphylococcus aureus was the most frequently identified etiologic organism (27%). The ICU and non-ICU cases did not differ in etiology. No organism became more prevalent during the study period. Twenty percent of patients died within 1 week of first positive culture; episodes associated with Pseudomonas species had a much higher mortality rate (45%) than other infections (14%) (p = 0.002). The ICU and non-ICU infections had a similar mortality rate.

CONCLUSION

Pneumonia is an important cause of nosocomial bloodstream infection, but it is not increasing in frequency or changing in etiology in our institution. The ICUs are a major contributor to this problem but have the same case short-term mortality rate and microbial etiology as non-ICU cases. Cases associated with Pseudomonas have a much higher mortality rate.