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Biomedical subjects

D Kaufman

Publications and source records attributed to D Kaufman.

At least 19 recordsLinked to original sources

A blinded, randomized, multicenter study of an intravenous Staphylococcus aureus immune globulin.

OBJECTIVES: Very low birth weight (VLBW) infants are vulnerable to nosocomial infections and subsequent morbidity; including infections caused by Staphylococcus aureus: 85% of nosocomial S. aureus infections are caused by capsular polysaccharide (CPS) types 5 and 8. Altastaph is a polyclonal investigational human immunoglobulin G (IgG) with high levels of opsonizing S. aureus CPS types 5 and 8 IgG. METHODS: A Phase 2 clinical trial to assess the safety and kinetics of Altastaph in VLBW infants. Neonates in this multicenter study were randomized to receive two identical 20 ml/kg i.v. infusions of either 0.45% NaCl placebo or 1000 mg Altastaph/kg. Each infant was followed for 28 days after the second infusion or until discharge. Serum S. aureus CPS types 5 and 8 IgG levels were measured preinfusion and at various times after each infusion. RESULTS: Of 206 neonates, 158 received both infusions. Adverse events were similar in the two treatment groups. Six subjects (3% in each group) discontinued owing to an adverse event. Geometric mean anti-type 5 IgG levels were 402 and 642 mcg/ml 1 day following infusion of the first (day 0) and Second (day 14) doses, respectively, in neonates < or =1000 g and slightly higher in neonates 1001 to 1500 g. Trough levels before second infusion were 188 mcg/ml. Type 8 IgG levels were similar. Geometric mean IgG levels among placebo recipients were consistently <2 and <5 mcg/ml for types 5 and 8 in both weight groups. Three episodes of S. aureus bacteremia occurred in each arm. CONCLUSIONS: Infusion of Altastaph in VLBW neonates resulted in high levels of specific S. aureus types 5 and 8 CPS IgG. The administration of this anti-staphylococcal hyperimmune globulin was well tolerated in this population.

Bacterial Capsules↗

Long-term renal allograft function on a tacrolimus-based, pred-free maintenance immunosuppression comparing sirolimus vs. MMF.

It is not known how different steroid-free immunosuppressive combinations affect renal graft survival and long-term kidney transplant function. Here we sought to compare the impact on graft survival and long-term graft function of two tacrolimus (Tac)-based, prednisone-free maintenance immunosuppressive protocols: Tac/Mycophenolate Mofetil (MMF) vs. Tac/Sirolimus (SRL). Renal transplant patients given induction therapy with IL2-RA and methylprednisolone on days 0, 1 and 2 post-transplant were prospectively randomized to two maintenance immunosuppressive regimens with Tac/MMF (n = 45) or Tac/SRL (n = 37). During the 3-year follow-up the following data were collected: patient survival, renal allograft survival, incidence of acute rejection and glomerular filtration rate (GFR) at different time-points post-transplant. Cumulative graft survival was significantly different in the two groups: one kidney loss in the Tac/MMF vs. six kidney losses in the Tac/SRL (log-rank test p = 0.04). GFR at different time-points post-transplant was consistently and statistically better in the Tac/MMF than in the Tac/SRL group. The slope of GFR decline per month was flatter in the Tac/MMF than in the Tac/SRL group. This study showed that renal graft survival and graft function were significantly lower in the combination of Tac/SRL than Tac/MMF.

Acute Disease↗

Single vs. dual vessel porcine extracorporeal liver perfusion.

BACKGROUND: The use of porcine extracorporeal liver perfusion (PECLP) to provide temporary hepatic support for patients in fulminant hepatic failure has been limited by the fact that individual perfusions can be sustained for only a few hours. Inadequate liver function and/or hemodynamic instability are the major contributing factors for early interruption of PECLP. Recent reports suggest that the choice of single (portal vein only) vs dual (portal vein and hepatic artery) vessel perfusion may influence the duration of perfusion. We hypothesize that PECLP with single vessel perfusion (SVP) is associated with worse liver function and greater hemodynamic instability than PECLP with dual vessel perfusion (DVP). MATERIALS AND METHODS: To eliminate the potentially confounding influences of liver failure and xenograft rejection, liver isografts procured from White-Landrace pig donors were perfused by either SVP or DVP via an extracorporeal circuit established with normal White-Landrace pig recipients. The function of perfused livers was evaluated by measuring production of bile and Factors V and VIII, clearance of ammonia and lactate, and extraction of O(2) at baseline and at 0, 1, 3, 6, 12, and 24 h after initiation of PECLP. The impact of PECLP on recipient hemodynamic status was assessed by monitoring BP, heart rate, urine output, O(2) saturation, etc. Among other parameters evaluated were serum albumin and total protein and hepatic release of IL-1beta and nitric oxide to assess their possible contributions to hemodynamic instability. RESULTS: DVP and SVP livers cleared ammonia and lactate similarly. Both approaches were associated with progressive hypoalbuminemia and hypoproteinemia. DVP livers produced more bile and Factor V and were associated with less recipient hypotension and IL-1beta and NO release than SVP livers. CONCLUSIONS: Livers with DVP function better than livers with SVP. The duration of PECLP can be limited by recipient hypotension, although this complication is less severe with DVP than with SVP.

Ammonia↗

Fluconazole prophylaxis against fungal colonization and infection in preterm infants.

BACKGROUND: Invasive fungal infection is associated with substantial morbidity and mortality in preterm infants. We evaluated the efficacy of prophylactic fluconazole in preventing fungal colonization and invasive infection in extremely-low-birth-weight infants. METHODS: We conducted a prospective, randomized, double-blind clinical trial over a 30-month period in 100 preterm infants with birth weights of less than 1000 g. The infants were randomly assigned during the first five days of life to receive either intravenous fluconazole or placebo for six weeks. We obtained weekly surveillance cultures from all patients. RESULTS: The 50 infants randomly assigned to fluconazole and the 50 control infants were similar in terms of birth weight, gestational age at birth, and base-line risk factors for fungal infection. During the six-week treatment period, fungal colonization was documented in 30 infants in the placebo group (60 percent) and 11 infants in the fluconazole group (22 percent; difference in risk, 0.38; 95 percent confidence interval, 0.18 to 0.56; P=0.002). Invasive fungal infection with positive growth of fungal isolates from the blood, urine, or cerebrospinal fluid developed in 10 infants in the placebo group (20 percent) and none of the infants in the fluconazole group (difference in risk, 0.20; 95 percent confidence interval, 0.04 to 0.36; P=0.008). The sensitivities of the fungal isolates to fluconazole did not change during the study, and no adverse effects of the fluconazole therapy were documented. CONCLUSIONS: Prophylactic administration of fluconazole during the first six weeks of life is effective in preventing fungal colonization and invasive fungal infection in infants with birth weights of less than 1000 g.

Antifungal Agents↗

Paclitaxel, estramustine phosphate, and carboplatin in patients with advanced prostate cancer.

PURPOSE: To determine the safety and activity of weekly paclitaxel in combination with estramustine and carboplatin (TEC) in patients with advanced prostate cancer. PATIENTS AND METHODS: In a dose-escalation study, patients with advanced prostate cancer were administered paclitaxel (weekly 1-hour infusions of 60 to 100 mg/m(2)), oral estramustine (10 mg/kg), and carboplatin (area under the curve, 6 mg/mL-min every 4 weeks). Paclitaxel levels were determined 0, 30, 60, 90, and 120 minutes and 18 hours after infusion, and a concentration-time curve was estimated. Once a safe dose was established, a multi-institutional phase II trial was conducted in patients with progressive androgen-independent disease. RESULTS: Fifty-six patients with progressive androgen-independent disease were treated for a median of four cycles. The dose of paclitaxel was escalated from 60 to 100 mg/m(2) without the occurrence of DLT. Posttherapy decreases in serum prostate-specific antigen levels of 50%, 80%, and 90% were seen in 67%, 48%, and 39% (95% confidence interval, 55% to 79%, 35% to 61%, 26% to 52%) of the patients, respectively. Of the 33 patients with measurable disease, two (6%) had a complete response and 13 (39%) had a partial response. The overall median time to progression was 21 weeks, and the median survival time for all patients was 19.9 months. Major grade 3 or 4 adverse effects were thromboembolic disease (in 25% of patients), hyperglycemia (in 38%), and hypophosphatemia (in 42%). Significant leukopenia, thrombocytopenia, and peripheral neuropathy were not observed. CONCLUSION: TEC has significant antitumor activity and is well tolerated in patients with progressive androgen-independent prostate cancer.

Aged↗

Alcohol withdrawal after open aortic surgery.

This study was designed to test the hypothesis that unexpected alcohol withdrawal-like syndrome (AWLS) is more common following aortic, but not other, vascular or nonvascular procedures. All patients undergoing open aortic surgery at our institution in 1997 who survived at least 48 hr were identified, as were those undergoing carotid endarterectomy, infrainguinal bypass, and total colectomy. AWLS was defined as prolonged confusion or agitation and response to conventional treatment for withdrawal, providing that all other sources had been ruled out or a significant history was present. Our results show that, for unknown reasons, AWLS is more common after aortic surgery than after other vascular and high-stress, nonaortic intraabdominal procedures at our institution, and is associated with increased length of stay and morbidity. Because prophylaxis may improve outcome, better efforts to identify patients at risk are required.

Aged↗

Diagnostic accuracy of simpson atherectomy catheter biopsy in detecting pancreaticobiliary malignancy.

OBJECTIVE: Impressive advances have been made in imaging the biliary tree by various modalities in the last few decades. However, the histological diagnosis of stenosing lesions in the biliary ductal system has remained difficult and unreliable. Application of Simpson atherectomy catheter biopsy in obtaining accurate histological diagnosis of bile duct lesions appears promising. The purpose of our study was to determine the clinical accuracy of the Simpson atherectomy catheter biopsy in the evaluation of bile duct strictures. METHODS: A retrospective study of medical records of patients who underwent bile duct biopsy by atherectomy catheter was conducted between 1991 and 1999. During this period, 53 patients underwent 56 endoluminal bile duct biopsies with an atherectomy catheter as part of an obstructive jaundice workup. Histological diagnosis on biopsy was confirmed by subsequent surgical biopsy and/or clinical follow-up. RESULTS: Fifty-four (96%) bile duct biopsies were technically successful in terms of yielding a histological diagnosis. Thirty-one of the 56 (55%) biopsy specimens were positive for malignancy (27 adenocarcinoma, two islet cell-carcinoids, one small cell carcinoma, and one malignant lymphoma). Four (7%) were read by the pathologist as highly suspicious for malignancy, and 19 (34%) specimens were considered negative for malignancy. Sensitivity of atherectomy catheter endoluminal biliary biopsy in this study was 97% with a specificity of 100%. In addition, the positive predictive and negative predictive values of this modality were 100% and 93%, respectively. CONCLUSIONS: Endoluminal bile duct biopsy by Simpson atherectomy catheter appears to be a highly sensitive and specific method for establishing histological diagnosis of stenosing lesions in the biliary ductal system.

Adult↗

Emergent patterns of feedback strategies in performing a closed motor skill.

This sturdy identified self-chosen patterns of feedback usage and how they influenced accuracy and consistency in performing a closed motor skill. Learners completed 100 practice trials with 25 opportunities to receive knowledge of results (KR), the timing of which was self-chosen, followed by 25 no KR retention trials. The study identified two patterns of self-chosen KR, namely, a faded frequency pattern and a reversed faded frequency pattern. Analyses of variance indicated a significant trial block effect for accuracy in acquisition and no significant main effects or interactions associated with self-chosen patterns of KR. Quantification of regularity of KR patterns yielded correlations indicating that less regularity was associated with greater accuracy in performing the task. These results were congruent with previous research on self chosen feedback.

Adult↗

High-dose methotrexate for isolated central nervous system relapse in patients with testicular non-Hodgkin's lymphoma.

Four consecutive patients with testicular non-Hodgkin's lymphoma who initially achieved a complete response to treatment with standard combination therapy later developed isolated central nervous system (CNS) relapses. At the time of CNS relapse, staging evaluations were negative for lymphoma outside the nervous system in all 4 patients. These patients were treated with high-dose intravenous methotrexate alone, and a complete remission was achieved in all 4 patients.

Aged↗

Malignant fibrous histiocytoma arising in the upper posterior triangle of the neck.

We describe the case of a 59-year-old man who came to us with a right neck mass of 4 to 5 months' duration. A histologic diagnosis of malignant fibrous histiocytoma was made, and the patient underwent wide local excision and neck dissection followed by postoperative radiation therapy. We briefly discuss the characteristics and treatment of this rare entity.

Head and Neck Neoplasms↗

Palliative care by family physicians in the 1990s. Resilience amid reform.

OBJECTIVE: To explore issues family physicians face in providing community-based palliative care to their patients in the context of a changing health care system. DESIGN: Focus groups. SETTING: Small (< 10,000 population), medium-sized (10,000 to 50,000), and large (> 50,000) communities in Nova Scotia. PARTICIPANTS: Twenty-five men and women physicians with varying years of practice experience in both solo and group practices. METHOD: A semistructured approach was used, asking physicians to reflect on recent palliative care experiences in order to explore issues of care. MAIN FINDINGS: Five themes emerged from the discussions: resources needed, availability of family support, time and money supporting physicians' activities, symptom control for patients, and physicians' emotional reactions to caring for dying patients. CONCLUSION: With downsizing of hospitals and greater emphasis on community-based care, the issues identified in this study will need attention, particularly in designing an integrated service delivery model for palliative care.

Adult↗

Vinorelbine and estramustine in androgen-independent metastatic prostate cancer: a phase II study.

BACKGROUND: The aim of this study was to determine the safety and activity of vinorelbine in combination with estramustine in men with androgen-independent metastatic prostate cancer. METHODS: Twenty-five men with androgen-independent metastatic prostate cancer were treated with the combination of vinorelbine and estramustine. Vinorelbine 25 mg/m(2) was administered by intravenous bolus on Days 1 and 8. Estramustine 140 mg was administered three times a day by mouth on Days 1 through 14. Treatment was repeated every 21 days. RESULTS: A total of 132 cycles of treatment were administered. The median number of cycles per patient was 5 (range: 1-16). Mild Grade 1 or 2 gastrointestinal toxicity and fatigue were the most common adverse effects. Hematologic toxicity was minimal. Treatment resulted in a sustained > 50% decrease in serum prostate-specific antigen (PSA) in 6 of 25 patients (24% of patients; 95% confidence interval (CI) 9-45%). The median duration of PSA response was 10 weeks (range: 3-39 weeks). Of the five men with bidimensionally measurable disease, none achieved a complete or partial response. There were no documented improvements in post-treatment bone scans. Median overall survival time was 14.1 months. CONCLUSIONS: The combination of vinorelbine and estramustine is a well-tolerated and modestly active regimen in men with androgen-independent metastatic prostate cancer.

Aged↗

Synthetic peptides which inhibit the interaction between C1q and immunoglobulin and prolong xenograft survival.

BACKGROUND: Acute vascular xenograft rejection (AVXR), also termed delayed xenograft rejection (DXR), occurs when hyperacute rejection (HAR) is prevented by strategies directed at xenoreactive natural antibodies and/or complement activation. We have hypothesized that AVXR/DXR is initiated in part by early components of the complement cascade, notably C1q. We have developed synthetic peptides (termed CBP2 and WY) that interfere with the interaction between C1q and antibody. METHODS: CBP2 and the WY-conjugates were used as inhibitors of immunoglobulin aggregate binding to solid phase C1q. Inhibition of complement activation by the peptides of the classical system was determined using lysis assays with sensitized sheep red blood cells or porcine aortic endothelial cells as targets and of the alternate complement pathway using guinea pig red blood cells as targets. Two transplant models were used to study the effects of administering peptides to recipients: rat heart transplant to presensitized mouse, and guinea heart transplant to PVG C6-deficient rats. RESULTS: CBP2 and WY-conjugates inhibited immunoglobulin aggregate binding to C1q. The peptides also inhibited human complement-mediated lysis of sensitized sheep red blood cells and porcine aortic endothelial cells in a dose-dependent manner and the WY-conjugates prevented activation of the alternate complement pathway as shown by inhibition of guinea pig red blood cells lysis with human serum. In addition, the use of the peptides and conjugates resulted in significant prolongation of xenograft survival. CONCLUSIONS: The CBP2 and WY peptides exhibit the functional activity of inhibition of complement activation. These peptides also prolong xenograft survival and thus provide reagents for the study of the importance of C1q and other complement components in transplant rejection mechanisms.

Animals↗

Laparoscopic live donor nephrectomy--is it safe?

BACKGROUND: Laparoscopic live donor nephrectomy (LDN) is a less invasive alternative to open nephrectomy (ODN) for living kidney donation. Concerns have been raised regarding the safety of LDN, the short and long term function of kidneys removed by LDN, and a potential higher incidence of urologic complications in LDN transplant recipients. METHODS: Between October 1997 and May 1999, 80 LDNs were performed at our center. All patients were followed longitudinally with office visits and telephone interviews. These LDNs were compared with 50 ODN performed from January 1996 to October 1997. RESULTS: LDN procedures took significantly longer than ODN (4.6 vs. 3.1 hr). However, LDN was associated with significant reduction in i.v. narcotic use, a rapid return to diet, and shorter hospital stay. Of the 80 LDN procedures, a total of 75 (94%) were completed laparoscopically. Five patients were converted to laparotomy: three for hemorrhage and two for complex vascular anatomy. ODN conversion was associated with large donor body habitus and/or obesity. Seven LDN patients had minor complications and 4 had major complications. All major complications consisted of vascular injuries (2 lumbar vein injuries, 1 renal artery, and 1 aortic injury). All patients made complete recoveries. All LDN kidneys functioned immediately posttransplant. We have observed 100% patient and 97% 1-year actuarial graft survival in LDN transplant recipients. There have been no short-or long-term urologic complications in this series. CONCLUSION: With increasing experience and standardization of technique, LDN is a safe and effective procedure. Patients undergoing LDN demonstrate clinically significant, more rapid postoperative recoveries and shorter hospital stays than ODN patients. Excellent initial graft function and long-term graft survival have been observed with LDN kidneys. Urologic complications can be avoided. LDN has become the preferred surgical approach for living kidney donation at our center.

Adult↗

Retinoic acid enhances the effect of collagen on bone union, following induced non-union defect in guinea pig ulna.

OBJECTIVE AND DESIGN: The aim of the present study is to evaluate the involvement of retinoic acid and collagen in wound healing, by combining them in a therapeutic modality for treating a non-union bone defect in a guinea-pig ulnar-bone model. METHODS: a 4-mm disc was excised from the guinea-pig's ulnar-bone, and the space formed between the two ulnar fragments was filled with either collagen solution, retinoic acid solution or a combination of both. The guinea-pigs were sacrificed 2 or 6 weeks later, and the defected ulnar bones were studied by X-ray, by histology and by computerized histomorphometry. RESULTS: After 6 weeks, the long bone area fraction within the histological sections of the bone, was increased after treatment with this mixture by 180%, as compared to the untreated controls. The cartilage area in those sections was decreased by 44% after the combined treatment, as compared to increases of 133% and 182% following treatments with collagen alone. CONCLUSION: These findings demonstrate that addition of 500 IU of retinoic acid to collagen at a site of a bone defect, is superior to either agent in enhancing regeneration of new bone, achieving union across the defect and leading to its complete repair.

Animals↗