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Dr. Matthew  Zapf  Md,Msc image

Dr. Matthew Zapf Md,Msc

444 S San Vicente Blvd Suite 603
Los Angeles CA 90048
310 239-9718
Medical School: Other - Unknown
Accepts Medicare: No
Participates In eRX: No
Participates In PQRS: No
Participates In EHR: No
License #: A129583
NPI: 1891115457
Taxonomy Codes:
207X00000X

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Publications

Inpatient Rehabilitation after Liver Transplantation Decreases Risk and Severity of 30-Day Readmissions. - Journal of the American College of Surgeons
Discharge location is associated with short-term readmission rates after hospitalization for several medical and surgical diagnoses. We hypothesized that discharge location: home, home health, skilled nursing facility (SNF), long-term acute care (LTAC), or inpatient rehabilitation, independently predicted the risk of 30-day readmission and severity of first readmission after orthotopic liver transplantation.We performed a retrospective cohort review using Healthcare Cost and Utilization Project (HCUP) State Inpatient Databases for Florida and California. Patients who underwent orthotopic liver transplantation from 2009 to 2011 were included and followed for 1 year. Mixed-effects logistic regression was used to model the effect of discharge location on 30-day readmission controlling for demographic, socioeconomic, and clinical factors. Total cost of first readmission was used as a surrogate measure for readmission severity and resource use.A total of 3,072 patients met our inclusion criteria. The overall 30-day readmission rate was 29.6%. Discharge to inpatient rehabilitation (adjusted odds ratio [aOR] 0.43, p = 0.013) or LTAC/SNF (aOR 0.63, p = 0.014) were associated with decreased odds of 30-day readmission when compared with home. The severity of 30-day readmissions for patients discharged to inpatient rehabilitation were the same as those discharged home or home with home health. Severity was increased for those discharged to LTAC/SNF. The time to first readmission was longest for patients discharged to inpatient rehabilitation (17 days vs 8 days, p < 0.001).When compared with other locations of discharge, inpatient rehabilitation reduces the risk of 30-day readmission and increases the time to first readmission. These benefits come without increasing the severity of readmission. Increased use of inpatient rehabilitation after orthotopic liver transplantation is a strategy to improve 30-day readmission rates.Copyright © 2016 American College of Surgeons. Published by Elsevier Inc. All rights reserved.
Early Intervention during Acute Stone Admissions: Revealing "The Weekend Effect" in Urological Practice. - The Journal of urology
Obstructing nephrolithiasis is a common condition that can require urgent intervention. In this study we analyze patient factors that contribute to delayed intervention during acute stone admission.We retrospectively reviewed the HCUP SID (Healthcare Cost and Utilization Project State Inpatient Database) for Florida and California from 2007 to 2011. Patients who were admitted urgently with nephrolithiasis and an indication for decompression (urinary tract infection, acute renal insufficiency and/or sepsis) were included in the study. Intervention was timely or delayed, defined as a procedure that occurred within or after 48 hours, respectively. Adjusted multivariate models were fit to assess factors that predicted a delayed procedure as well as mortality.Overall 10,301 patients were admitted urgently for nephrolithiasis with indications for decompression. Early intervention occurred in 6,689 patients (65%) and was associated with a decrease in mortality (11, 0.16%), compared to delayed intervention (17 of 3,612, 0.47%, p=0.002). On multivariate analysis timely intervention significantly decreased the odds of inpatient mortality (OR 0.43, p=0.044). Weekend day admission significantly influenced time to intervention, decreasing patient odds of timely intervention by 26% (p <0.001). Other factors decreasing patient odds of timely intervention included nonCaucasian race and nonprivate insurance. Presenting medical diagnoses of urinary tract infection, sepsis and acute renal failure did not appear to influence time to intervention.Delayed operative intervention for acute nephrolithiasis admissions with indications for decompression results in increased patient mortality. Nonmedical factors such as the "weekend effect," race and insurance provider exerted the greatest influence on the timing of intervention.Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.
Components of Hospital Perioperative Infrastructure Can Overcome the Weekend Effect in Urgent General Surgery Procedures. - Annals of surgery
We hypothesized that perioperative hospital resources could overcome the "weekend effect" (WE) in patients undergoing emergent/urgent surgeries.The WE is the observation that surgeon-independent patient outcomes are worse on the weekend compared with weekdays. The WE is often explained by differences in staffing and resources resulting in variation in care between the week and weekend.Emergent/urgent surgeries were identified using the Healthcare Cost and Utilization Project State Inpatient Database (Florida) from 2007 to 2011 and linked to the American Hospital Association (AHA) Annual Survey Database to determine hospital level characteristics. Extended median length of stay (LOS) on the weekend compared with the weekdays (after controlling for hospital, year, and procedure type) was selected as a surrogate for WE.Included were 126,666 patients at 166 hospitals. A total of 17 hospitals overcame the WE during the study period. Logistic regression, controlling for patient characteristics, identified full adoption of electronic medical records (OR 4.74), home health program (OR 2.37), pain management program [odds ratio (OR) 1.48)], increased registered nurse-to-bed ratio (OR 1.44), and inpatient physical rehabilitation (OR 1.03) as resources that were predictors for overcoming the WE. The prevalence of these factors in hospitals exhibiting the WE for all 5 years of the study period were compared with those hospitals that overcame the WE (P < 0.001).Specific hospital resources can overcome the WE seen in urgent general surgery procedures. Improved hospital perioperative infrastructure represents an important target for overcoming disparities in surgical care.
"Right place at the right time" impacts outcomes for acute intestinal obstruction. - Surgery
The purpose of this study was to measure how the duration of nonoperative intervention for intestinal obstruction impacted patient outcomes and whether hospital characteristics influenced the timing of operative intervention.The State Inpatient Database (Florida) of the Health Care Utilization Project and the Annual Survey database of the American Hospital Association were linked from 2006 to 2011. Included were patients ≥18 years of age with a primary diagnosis of intestinal obstruction. Patient factors included age, sex, socioeconomic factors, and comorbid conditions.A total of 116,195 patients met our inclusion criteria, and 43,079 underwent operative intervention (37.1%). Patients who required operative correction of the intestinal obstruction after the fifth day of hospitalization, compared with patients who underwent an operation on the day of admission, had increases in mortality (6.1% vs 1.8%, P < .001), complication rates (15.4% vs 4.0%, P < .001), and postoperative hospital stay (9 vs 5 days, P < .001). Patients cared for at a large teaching facility (with surgery residents) had increased odds of early operative intervention by 23% (odds ratio 1.23, [1.20-1.28]), whereas patients at low-volume hospitals had decreased odds of early intervention (odds ratio 0.88, [0.73-0.91]).Initial nonoperative treatment in patients with uncomplicated intestinal obstruction is an important strategy, but the odds of having an adverse event increase as intestinal obstruction is delayed. Importantly, the presence of surgery residents and increasing bed size are hospital characteristics associated with earlier operative intervention, suggesting a quality benefit for care at large teaching hospitals.Copyright © 2015 Elsevier Inc. All rights reserved.
Green tea component epigallocatechin-3-gallate decreases expression of osteopontin via a decrease in mRNA half-life in cell lines of metastatic hepatocellular carcinoma. - Surgery
Osteopontin (OPN) mediates metastasis and invasion of hepatocellular carcinoma (HCC). Epigallocatechin-3-gallate (EGCG), found in green tea, suppresses HCC tumor growth in vitro. We sought to investigate the role of EGCG in modulating OPN in cell lines of metastatic HCC.Experimental HCC cell lines included HepG2 and MHCC-97H HCC cells, which express high levels of OPN, and the Hep3B cells, which express lesser levels of OPN. Cells were treated with EGCG (0.02-20 μg/mL) before measurement of OPN with enzyme-linked immunosorbent assay and reverse transcriptase-polymerase chain reaction. Scratch assay measured cell migration. Binding of the OPN promoter to RNA pol II was evaluated by the use of Chromatin-IP assay after EGCG treatment. Transcriptional regulation of OPN was investigated with luciferase reporter plasmids containing various deletion fragments of the human OPN promoter. Measurement of the half-life of OPN mRNA was conducted using actinomycin D.Treatment of MHCC-97H and HepG2 cells with 2 μg/mL and 20 μg/mL EGCG caused a ∼6-fold and ∼90-fold decrease in secreted protein levels of OPN (All P < .001). OPN mRNA was decreased with EGCG concentrations of 0.2-20 μg/ml (All P < .001). The 3-(4, 5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (ie, MTT) assay revealed that differences in OPN expression were not due to viability of the HCC cell lines. Promoter assay and chromatin immunoprecipitation analysis revealed no effect of EGCG on the transcriptional regulation of OPN. Posttranscriptionally, EGCG decreased the half-life of OPN mRNA from 16.8 hours (95% confidence interval 9.0-125.1) to 2.5 hours (95% confidence interval 2.1-3.2) (P < .001). Migration was decreased in EGCG treated cells at 24 hours (8.0 ± 2.4% vs 21.2 ± 10.8%, P < .01) and at 48 hours (13.2 ± 3.6% vs 53.5 ± 19.8%, P < .001).We provide evidence that EGCG decreases OPN mRNA and secreted OPN protein levels by decreasing the half-life of OPN mRNA in MHCC-97H cells. The translatability of EGCG for patients with HCC is promising, because EGCG is an inexpensive, easily accessible chemical with an extensive history of safety.Copyright © 2015 Elsevier Inc. All rights reserved.
The "weekend effect" in urgent general operative procedures. - Surgery
There is growing concern that the quality of inpatient care may differ on weekends versus weekdays. We assessed the "weekend effect" in common urgent general operative procedures.The Healthcare Cost and Utilization Project Florida State Inpatient Database (2007-2010) was queried to identify inpatient stays with urgent or emergent admissions and surgery on the same day. Included were patients undergoing appendectomy, cholecystectomy for acute cholecystitis, and hernia repair for obstructed/gangrenous hernia. Outcomes included duration of stay, inpatient mortality, hospital-adjusted charges, and postoperative complications. Controlling for hospital and patient characteristics and type of surgery, we used multilevel mixed-effects regression modeling to examine associations between patient outcomes and admissions day (weekend vs weekday).A total of 80,861 same-day surgeries were identified, of which 19,078 (23.6%) occurred during the weekend. Patients operated on during the weekend had greater charges by $185 (P < .05), rates of wound complications (odds ratio [OR] 1.29, 95% confidence interval [95% CI] 1.05-1.58; P < .05), and urinary tract infection (OR 1.39, 95% CI 1.05-1.85; P < .05). Patients undergoing appendectomy had greater rates of transfusion (OR 1.43, 95% CI 1.09-1.87; P = .01), wound complications (OR 1.32, 95% CI 1.04-1.68; P < .05), urinary tract infection (OR 1.76, 95% CI 1.17-2.67; P < .01), and pneumonia (OR 1.41, 95% CI 1.05-1.88; P < .05). Patients undergoing cholecystectomy had a greater duration of stay (P = .001) and greater charges (P = .003).Patients undergoing weekend surgery for common, urgent general operations are at risk for increased postoperative complications, duration of stay, and hospital charges. Because the cause of the "weekend effect" is still unknown, future studies should focus on elucidating the characteristics that may overcome this disparity.Copyright © 2015 Elsevier Inc. All rights reserved.
Evaluation of Vessel Sealing Performance Among Ultrasonic Devices in a Porcine Model. - Surgical innovation
As new technologies emerge, it is imperative to define which new devices are most likely to provide a reproducible, effective result for the patient and surgeon. The purpose of our study was to analyze 3 commercially available ultrasonic energy devices; the Sonicision (SC), the Harmonic ACE (HA), and the THUNDERBEAT (TB).Eight female Yorkshire pigs were used for data collection and vessel harvest. Three devices were evaluated and compared with each other with respect to seal failure and cutting speed in vivo. After vessel harvest, one end of the fragment was sent for histological evaluation, and the other was used for burst pressure measurement testing in a blinded fashion. The coagulation and cut levels of all the generators were set up at a similar and constant level.Eighty-four vessels (47 arteries and 37 veins) were tested. Mean vessel diameter was equal among the groups. Cutting speed was significantly faster with TB (3.4 ± 0.7 seconds) than SC or HA (5.8 ± 2.4 and 6.1 ± 3.1 seconds; P < .0001). Burst pressure trended higher after ligation with TB (505.4 ± 349.4 mm Hg) than SC and HA (435.8 ± 403.0 and 437.6 ± 291.3 mm Hg). There were 2 seal failures in the SC group and HA group and none in the TB group. Histologically, the perpendicular width of tissue seal with TB (1.250 ± 0.55 mm) was significantly longer than that of the SC and the HA (0.772 ± 0.23 and 0.686 ± 0.23 mm; P < .0001).TB has proven to provide the most rapid and reliable seal. Therefore, TB may be safer and may decrease time during surgical procedures.© The Author(s) 2015.
Postoperative Atrial Fibrillation Predicts Long-Term Cardiovascular Events after Radical Cystectomy. - The Journal of urology
Postoperative atrial fibrillation after radical cystectomy occurs in 2% to 8% of cases. Recent evidence suggests that transient postoperative atrial fibrillation leads to future cardiovascular events. The long-term cardiovascular implications of postoperative atrial fibrillation in patients undergoing radical cystectomy are largely unknown.The Healthcare Cost and Utilization Project State Inpatient Databases for California and Florida were used to identify patients who underwent radical cystectomy between 2007 and 2010. After excluding patients with a history of atrial fibrillation, coronary artery disease and/or stroke, patients were matched using propensity scoring on age, race, insurance status and preexisting comorbidities. Adjusted Kaplan-Meier time-to-event analysis and Cox proportional hazards models were used to assess the effect of postoperative atrial fibrillation on cardiovascular events (acute myocardial infarction and stroke) during postoperative year 1.Radical cystectomy was performed in 4,345 patients who met the study inclusion criteria, of whom 210 (4.8%) had postoperative atrial fibrillation. There was a significantly higher cumulative incidence of cardiovascular events during the first postoperative year in patients in whom postoperative atrial fibrillation developed (24.8% vs 10.9%, adjusted log rank p=0.007). Cox proportional hazards regression demonstrated an increased risk of cardiovascular events in patients with postoperative atrial fibrillation (HR 10, p=0.02).Our results demonstrate that patients undergoing radical cystectomy in whom transient postoperative atrial fibrillation develops are at significantly increased risk for cardiovascular events in the first postoperative year. Physicians should be vigilant in assessing postoperative atrial fibrillation, even when transient, and establish appropriate followup given the increased risk of cardiovascular morbidity.Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.
Alcohol inhibits osteopontin-dependent transforming growth factor-β1 expression in human mesenchymal stem cells. - The Journal of biological chemistry
Alcohol (EtOH) intoxication is a risk factor for increased morbidity and mortality with traumatic injuries, in part through inhibition of bone fracture healing. Animal models have shown that EtOH decreases fracture callus volume, diameter, and biomechanical strength. Transforming growth factor β1 (TGF-β1) and osteopontin (OPN) play important roles in bone remodeling and fracture healing. Mesenchymal stem cells (MSC) reside in bone and are recruited to fracture sites for the healing process. Resident MSC are critical for fracture healing and function as a source of TGF-β1 induced by local OPN, which acts through the transcription factor myeloid zinc finger 1 (MZF1). The molecular mechanisms responsible for the effect of EtOH on fracture healing are still incompletely understood, and this study investigated the role of EtOH in affecting OPN-dependent TGF-β1 expression in MSC. We have demonstrated that EtOH inhibits OPN-induced TGF-β1 protein expression, decreases MZF1-dependent TGF-β1 transcription and MZF1 transcription, and blocks OPN-induced MZF1 phosphorylation. We also found that PKA signaling enhances OPN-induced TGF-β1 expression. Last, we showed that EtOH exposure reduces the TGF-β1 protein levels in mouse fracture callus. We conclude that EtOH acts in a novel mechanism by interfering directly with the OPN-MZF1-TGF-β1 signaling pathway in MSC.© 2015 by The American Society for Biochemistry and Molecular Biology, Inc.
Novel clinical therapeutics targeting the epithelial to mesenchymal transition. - Clinical and translational medicine
The epithelial to mesenchymal transition (EMT) is implicated in many processes, ranging from tissue and organogenesis to cancer and metastatic spread. Understanding the key regulatory mechanisms and mediators within this process offers the opportunity to develop novel therapeutics with broad clinical applicability. To date, several components of EMT already are targeted using pharmacologic agents in fibrosis and cancer. As our knowledge of EMT continues to grow, the potential for novel therapeutics will also increase. This review focuses on the role of EMT both as a necessary part of development and a key player in disease progression, specifically the similarity in pathways used during both processes as targets for drug development. Also, the key role of the tumor microenvironment with EMT is outlined, focusing on both co-factors and cell types with the ability to modulate the progression of EMT in cancer and metastatic disease. Lastly, we discuss the current status of clinical therapies both in development and those progressed to clinical trial specifically targeting pathologic EMTs including small molecule inhibitors, non-coding RNAs, exogenous co-factors, and adjunctive therapies to current chemotherapeutics.

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444 S San Vicente Blvd Suite 603 Los Angeles, CA 90048
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