John B. Crowe
Food and Drug Administration
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by John B. Crowe.
American Journal of Veterinary Research | 2008
Renate Reimschuessel; Charles M. Gieseker; Ron A. Miller; Jeffrey L. Ward; Jamie L. Boehmer; Nathan Rummel; David N. Heller; Cristina B. Nochetto; G. K. Hemakanthi de Alwis; Neal Bataller; Wendy C. Andersen; Sherri B. Turnipseed; R. Duane Satzger; John B. Crowe; Nancy R. Wilber; Mary K. Reinhard; John F. Roberts; Mark R. Witkowski
OBJECTIVE To determine whether renal crystals can be experimentally induced in animals fed melamine or the related triazine compound cyanuric acid, separately or in combination, and to compare experimentally induced crystals with those from a cat with triazine-related renal failure. ANIMALS 75 fish (21 tilapia, 24 rainbow trout, 15 channel catfish, and 15 Atlantic salmon), 4 pigs, and 1 cat that was euthanatized because of renal failure. PROCEDURES Fish and pigs were fed a target dosage of melamine (400 mg/kg), cyanuric acid (400 mg/kg), or melamine and cyanuric acid (400 mg of each compound/kg) daily for 3 days and were euthanatized 1, 3, 6, 10, or 14 days after administration ceased. Fresh, frozen, and formalin-fixed kidneys were examined for crystals. Edible tissues were collected for residue analysis. Crystals were examined for composition via Raman spectroscopy and hydrophilic-interaction liquid chromatography-tandem mass spectrometry. RESULTS All animals fed the combination of melamine and cyanuric acid developed goldbrown renal crystals arranged in radial spheres (spherulites), similar to those detected in the cat. Spectral analyses of crystals from the cat, pigs, and fish were consistent with melamine-cyanurate complex crystals. Melamine and cyanuric acid residues were identified in edible tissues of fish. CONCLUSIONS AND CLINICAL RELEVANCE Although melamine and cyanuric acid appeared to have low toxicity when administered separately, they induced extensive renal crystal formation when administered together. The subsequent renal failure may be similar to acute uric acid nephropathy in humans, in which crystal spherulites obstruct renal tubules.
Journal of Pharmaceutical and Biomedical Analysis | 2012
Adam Lanzarotta; John B. Crowe; Mark R. Witkowski; Bryan M. Gamble
Fourier transform infrared (FT-IR) microspectroscopic imaging, Raman microspectroscopy, optical microscopy and high performance liquid chromatography with mass spectrometric (LC/MS) detection were employed to examine a dietary supplement adulterated with an undeclared active pharmaceutical ingredient (API). While a trace level of the API was detected in the capsule contents, a higher concentration of API was found in the capsule shell, which indicated the use of an unconventional manufacturing process to hide the API and thus avoid detection. This study demonstrates the need for a multidisciplinary approach to provide a complete assessment of a suspect adulterated dietary supplement.
Food Additives and Contaminants Part A-chemistry Analysis Control Exposure & Risk Assessment | 2000
Cheryl L. Flurer; John B. Crowe; Karen A. Wolnik
Capillary electrophoresis (CE) and polarized light microscopy (PLM) were utilized in the detection of the adulteration of locust bean gum with guar gum. For CE analyses, standards of locust bean and guar gums were extracted with 30% CH3CN, removing the residual proteins from the gum matrix. A 8.75 mM NaH2PO4-20.6 mm Na2b4O7 buffer, pH 9, was used to separate these proteins and to identify marker proteins that were present in the guar gum. These markers did not co-migrate with components in the extracts of mechanically processed locust bean gum, and are used as indicators of adulteration. Using PLM with toluidine blue and iodine staining techniques, unadulterated locust bean gum samples were distinguished from mixed samples through the differential staining of components in locust bean versus guar and tara gums. These experiments in the use of CE and PLM provide orthogonal and complementary methods for the verification of ‘true’ positives and the elimination of ‘false’ positives.
Journal of Chromatography A | 1992
Lisa A. Kaine; John B. Crowe; Karen A. Wolnik
Abstract Non-suppressed ion-exchange chromatography coupled with ion-exclusion chromatography separates carboxylic acids and inorganic anions in one isocratic run. The sample is injected into an ion-exclusion column, which provides separation of weak acid anions. The void volume of the ion-exclusion column is collected on-line and injected into an anion-exchange column, which separates the strong acid anions found there. Samples are described in which inorganic anion as well as carboxylic acid interferences were removed by coupled ion chromatography. Additionally, the practicality of the coupled system for forensic sample screening is discussed.
Clinical Toxicology | 2005
John T. Watson; Roderick C. Jones; Alicia Siston; Pamela S. Diaz; Susan I. Gerber; John B. Crowe; R. Duane Satzger
Background. Many botanicals, particularly ornamental houseplants, contain crystals of calcium oxalate called raphides. Raphides have known toxic effects when chewed, including painful edema, vesicle formation, and dysphagia. We report a food-borne illness outbreak associated with ingestion of raphides. Methods. On February 24, 2003, the Chicago Department of Public Health was notified of multiple cases of oral burning and facial edema associated with lunch in an office cafeteria on February 21. The investigation included a case-control study, interviews with kitchen staff, an environmental inspection, and laboratory analysis of leftover foods. Results. Ten cases were identified, including one admitted to the Intensive Care Unit for potential airway obstruction secondary to severe edema, and another seen by Emergency Department staff for oral edema and pain. Ten of 10 case-patients reported oral stinging and burning, and 8 of 10 reported dysphagia. Four of 10 case-patients continued to have symptoms 2 weeks later. Food from the cafeterias international buffet was consumed by 10 of 10 case-patients and by 1 of 22 control subjects (odds ratio = undefined); each of the 10 case-patients reported consumption of a Chinese vegetable entrée from the international buffet and had no other foods in common. Plant material from the Chinese vegetable entrée contained raphides. Conclusion. This outbreak was associated with consumption of raphides resembling those from common botanicals. Clinicians and public health practitioners should be aware of raphide-containing plants as a potential cause of food-borne illness.
Journal of Analytical Atomic Spectrometry | 1995
Karen A. Wolnik; Douglas T. Heitkemper; John B. Crowe; Barbara S. Barnes; Thomas W. Brueggemeyer
The identity and relative amounts of various elements in samples of two compounds, sodium gamma hydroxy butyrate (GHB) and ephedrine hydrochloride (ephedrine), have been used to compare items of evidence. GHB, unapproved for use in the United States, and ephedrine, used in the illicit manufacture of methamphetamine, are currently of interest to law enforcement authorities. In this paper, the analysis of the elemental impurities in GHB by inductively coupled plasma atomic emission spectrometry (ICP-AES) has been used to further the investigation of clandestine manufacturing sources. The following elements were detected in samples of GHB: Ba, Ca, Cd, Fe, K, Mg, Ni, P, Pb, Si, Sr, and Zn. Results were used to demonstrate an association between samples of unknown origin. Analysis of samples of ephedrine of known origin from legitimate manufacturers by ICP-mass spectrometry showed that Al, Ba, Mn, Pt, Rb, and Sr were the most useful for discriminating between sources and making direct comparisons. Interpretation of results with respect to the intended use of conclusions derived from those results is discussed.
Journal of Forensic Sciences | 2001
Sf Platek; John B. Crowe; Nicola Ranieri; Karen A. Wolnik
As part of a suspected homicide investigation, a sampling of the gastric contents from the victim was forwarded to the U.S. Food and Drug Administrations Forensic Chemistry Center (FCC) for analysis of specific, selected components. The victim was known to have consumed string mozzarella cheese, as a snack, less than 24 h before his disappearance and the subsequent discovery of the body. The investigation sought to confirm or dismiss speculation the victim may have been fed a meal or eaten additional food prior to his death. Analysis of the stomach contents involved examination by stereoscopic light microscopy (SLM) and isolation, processing, and analysis of suspect materials by scanning electron microscopy (SEM). Several wax-like, off-white to cream-colored objects were noted by SLM examination and removed from the gastric contents. Through a series of fixation, sectioning, drying, and coating steps, these objects were prepared for analysis by SEM. Comparison of the suspect material with laboratory control string mozzarella cheese showed excellent correlation between the analyzed samples, confirming the suspect material from the stomach contents as string mozzarella cheese.
Journal of Forensic Sciences | 2015
John B. Crowe; Adam Lanzarotta; Mark R. Witkowski; Sara Andria
Suspect hypodermic needles and syringes were seized from an unlicensed individual who was allegedly injecting patients with silicone (polydimethylsiloxane [PDMS]) for cosmetic enhancement. Since control syringe barrels and needles often contain an interfering PDMS lubricant, a risk for false positives of foreign PDMS exists. The focus of this report was to minimize this risk and determine a quick and reliable test for the presence of blood in PDMS matrices. Using ATR‐FT‐IR spectroscopy, the risk for false‐positive identification of foreign PDMS was reduced by (i) overfilling the sampling aperture to prevent spectral distortions and (ii) sampling a region of the suspect syringe/needle assembly where manufacturer‐applied PDMS is not typically located. Analysis for blood indicated that the Teichman microchemical test was effective for detecting blood in the presence of PDMS. Overall, detecting PDMS established intent and detecting blood established that the needle containing the PDMS had been used for injection.
Journal of Forensic Sciences | 2002
Sf Platek; Ma Keisler; Nicola Ranieri; Tw Reynolds; John B. Crowe
The ability to accurately determine the number of syringe needle penetration holes through the rubber stoppers in pharmaceutical vials and rubber septa in intravenous (i.v.) line and bag ports has been a critical factor in a number of forensic cases involving the thefts of controlled substances or suspected homicide by lethal injection. In the early 1990s, the microscopy and microanalysis group of the U.S. Food and Drug Administrations Forensic Chemistry Center (FCC) developed and implemented a method (unpublished) to locate needle punctures in rubber pharmaceutical vial stoppers. In 1996, as part of a multiple homicide investigation, the Indiana State Police Laboratory (ISPL) contacted the FCC for information on a method to identify and count syringe needle punctures through rubber stoppers in pharmaceutical vials. In a joint project and investigation using the FCCs needle hole location method and applying a method of puncture site mapping developed by the ISPL, a systematic method was developed to locate, identify, count, and map syringe punctures in rubber bottle stoppers or i.v. bag ports using microscopic analysis. The method requires documentation of punctures on both sides of the rubber stoppers and microscopic analysis of each suspect puncture site. The final result of an analysis using the method is a detailed diagram of puncture holes on both sides of a questioned stopper and a record of the minimum number of puncture holes through a stopper.
Journal of Forensic Sciences | 2001
Ja Tomlinson; John B. Crowe; Nicola Ranieri; Jp Kindig; Sf Platek
Product tampering, as detailed by the Federal Anti-Tampering Act of 1983 (1), is a felony punishable by both fine and imprisonment. The rationale for product tampering ranges from pranks and attention seeking acts to extortion, terrorism, and homicide. One such case submitted for analysis involved four medical syringes found in a supermarket and suspected of being used to tamper with various products. One of the syringes was found piercing a pear while the other three syringes were found with needles exposed in other parts of the supermarket. Microscopic analysis was used to collect residue from the syringe barrels and the pear. A multidiscipline approach involving SLM, PLM, including microchemical analysis, FTIR, and GC/MS analyses, performed on the residual liquid found in the syringe barrels and in the suspect pear, confirmed the presence of cocaine. This multidisciplinary approach is often necessary when there is a possible health risk to the public and rapid response is important. With this approach, it was quickly determined which drugs or poisons were used in this tampering.