Incidence of Nephrogenic Systemic Fibrosis Using Gadobenate Dimeglumine in 1423 Patients With Renal Insufficiency Compared With Gadodiamide

OBJECTIVE

The purpose of this study was to assess the incidence of nephrogenic systemic fibrosis (NSF) before and after educational interventions, implementation of a clinical screening process, and change to gadobenate dimeglumine in patients who had an estimated glomerular filtration rate (eGFR) of 30 mL/min per 1.72 m or less.

METHODS

This is a Health Insurance Portability and Accountability Act compliant, institutional review board exempt study. Two periods were studied-July 2005 to June 2006, during which gadodiamide was utilized as our magnetic resonance (MR) contrast agent, and November 2006 to August 2014, during which gadobenate dimeglumine was used as our MR contrast agent in patients who had an eGFR 30 mL/min per 1.72 m or less. In addition to a change in the MR contrast agent, education of our staff physician to the risks of NSF with MR contrast agents and the implementation of a clinical screening process occurred. The rate of NSF before and after the interventions was compared using the χ test.

RESULTS

There was a statistically significant difference in the incidence of NSF in patients with an eGFR 30 mL/min per 1.72 m or less between the 2 periods: July 2005 to June 2006, 6 of 246 patients were diagnosed with NSF (P < 0.001), versus November 2006 to August 2014, 0 of 1423 patients were diagnosed with NSF.

CONCLUSIONS

Our data demonstrates a marked decrease in the incidence of NSF after education of our referring physicians, implementation of clinical screening process, and change to gadobenate dimeglumine from gadodiamide in patients with renal insufficiency. This approach potentially provides an acceptable risk-benefit profile for patients with renal insufficiency that required MR imaging for clinical care.

Anticonvulsant Use in Treating Dementia-Related Agitation

Dementia is often accompanied by disturbances in behavior which require treatment with medications. Traditionally, antipsychotics and benzodiazepines have been used. Their modest beneficial effects must be balanced against toxicities such as drug-induced parkinsonism which leads to falls, and worsened cognitive function. Anticonvulsant medications have been used in the past to treat agitated and aggressive behaviors from various conditions. Recent reports attest to their usefulness in treating behavioral problems secondary to dementia. Carbamazepine and divalproex sodium have proven effective in treatment while newer agents like gabapentin may be useful as well. These agents may be preferable because they target a broad variety of symptoms and diseases, are less likely to induce extrapyramidal reactions and some have a low drug interaction profile.

Frequency and Significance of Abnormal Pancreatic Imaging in Patients with BRCA1 and BRCA2 Genetic Mutations

Objective. Pancreatic adenocarcinoma is typically diagnosed in advanced stages resulting in a significant reduction in the number of patients who are candidates for surgical resection. Although the majority of cases are believed to occur sporadically, about 10% show familial clustering and studies have identified an increased frequency of BRCA germline mutations. The role of screening for pancreatic adenocarcinoma in these populations is unclear. Our study aims to identify the abnormal pancreatic imaging findings in BRCA1 and BRCA2 mutation carriers. Methods. A retrospective review of patient medical records with known BRCA1 and BRCA2 mutations was conducted. Data was collected and all available abdominal imaging studies were reviewed. Results. A total of 66 patients were identified, 36 with BRCA1 and 30 with BRCA2 mutations. Only 20/66 (30%) had abdominal imaging (14 BRCA1 and 6 BRCA2 patients). Of those patients with abdominal imaging, abnormal pancreatic imaging findings were detected in 7/20 (35%) cases. Conclusion. Our study shows a high incidence of abnormal pancreatic imaging findings in patients with BRCA genetic mutations (35%). Larger studies are needed to further define the role of pancreatic cancer screening and the significance of abnormal imaging findings in BRCA1 and BRCA2 mutation carriers.

A unique case of a patient with rectal cancer who developed benign esophageal stenosis after localized rectal radiation and systemic chemotherapy

Acute esophagitis and esophageal strictures typically occur after local radiation therapy to the thoracic field. Toxicity is usually limited to the field of radiation and potentially augmented by concomitant use of chemotherapy, however esophageal stricturing due to chemotherapy alone is exceedingly rare. Gastrointestinal toxicity has been previously reported in the setting of 5-fluorouracil (5-FU)-based chemotherapy with abnormal thymidylate synthase or dihydropyrimidine dehydrogenase activities. We present a unique case of isolated chemotherapy-induced esophageal stricture in the setting of stage IIIa rectal adenocarcinoma which presented shortly after initiation of treatment with 5-FU-based chemotherapy in a patient with normal thymidylate synthase and dihydropyrimidine dehydrogenase assays. These findings prompt further investigation of pathways and potential risk factors leading to esophageal toxicity in patients treated with 5-FU-based chemotherapy.

Gastroduodenal Intussusception, Intermittent Biliary Obstruction and Biochemical Pancreatitis due to a Gastric Hyperplastic Polyp

We present the case of a 76-year-old man with gastroduodenal intussusception secondary to a gastric hyperplastic polyp. Intussusception in the adult population occurs infrequently. Our patient presented with gastroduodenal intussusception, which is very uncommon and accounts for <10% of all types of intussusception. This case is unique in that partial endoscopic resection of the gastric hyperplastic polyp resolved the patient's gastroduodenal intussusception, biliary obstruction and biochemical pancreatitis without the need for surgical intervention.

The role of parathyroid hormone and insulin-like growth factors in hematopoietic niches: physiology and pharmacology

Hematopoietic stem cells (HSC) capable of both self-renewal and differentiation into all blood lineages reside within the bone marrow in specialized microenvironmental niches. While the precise location and composition of these niches largely remains unknown, it is now believed that osteoblasts at the endosteal surface play critical roles. Among the molecules demonstrated to influence the function of these niches are parathyroid hormone (PTH) and the insulin-like growth factors (IGF). Administration of PTH to both mice and men expands the number of bone marrow HSC, and an increase in the number of those cells in peripheral blood following treatment with mobilizing agents. Several molecules downstream of PTH are capable of signaling to HSC, including IGF that appear to regulate both the survival and expansion of hematopoietic stem and progenitor cells. As our current understanding of the role for PTH and IGF in hematopoietic niches is limited, we believe it is important that both their physiological importance and pharmacological potential be more fully investigated.

Nephrogenic systemic fibrosis: risk factors and incidence estimation

PURPOSE

To retrospectively review data in 13 patients with biopsy-confirmed nephrogenic systemic fibrosis (NSF), assess the associated risk factors, and report the incidence of NSF at the authors' institution.

MATERIALS AND METHODS

This HIPAA-compliant study had institutional review board approval; informed consent was waived. Statistical analysis was performed for all available clinical and laboratory data in patients with biopsy-confirmed NSF. The data from the patients with NSF were compared with data from a control population of patients with renal insufficiency but who did not develop NSF.

RESULTS

There were eight male and five female patients, aged 17-69 years, with a diagnosis of NSF. Within 6 months of diagnosis, all 13 patients had been exposed to gadodiamide and one had been exposed to gadobenate dimeglumine in addition to gadodiamide. At the time of contrast material-enhanced magnetic resonance (MR) imaging, all 13 patients had renal insufficiency (estimated glomerular filtration rate [eGFR] < 60 mL/min/1.73 m(2)) and were hospitalized for a proinflammatory event (major surgery, infection, or vascular event). The group with NSF had significantly decreased eGFR (P = .01), more proinflammatory events (P < .001), and more contrast-enhanced MR examinations per patient (P = .002) than did the control group.

CONCLUSION

A combination of factors, including altered kidney function, inflammatory burden, and exposure to gadolinium-based contrast agents may all play a role in development of NSF. Alternative imaging should be considered in patients with these factors. If use of a gadolinium-based agent is clinically indicated, the referring physician and patient should be informed of the potential risk of developing NSF.

Hydrogel lens monomer constituents modulate protein sorption

PURPOSE

To examine the effect of hydrogel lens monomer constituents on protein sorption.

METHODS

A series of hydroxyethylmethacrylate (HEMA)-based hydrogels with various amounts of methacrylic acid (MAA) or N-vinyl pyrrolidone (NVP) were synthesized. A radiolabel tracer technique was used to measure the amount of protein adsorbed on or penetrating into the hydrogels. Penetration of fluorescence-labeled proteins in the hydrogels was studied by laser scanning confocal microscopy. Single-protein solutions of human serum albumin (HSA) and hen egg lysozyme were studied.

RESULTS

Inclusion of the comonomers MAA or NVP in hydrogels resulted in an increase in water content and also had a strong impact on protein sorption. An increase in the amount of MAA in the poly(HEMA-co-MAA) hydrogels increased lysozyme adsorption and penetration but reduced HSA adsorption. However, the amount of protein adsorbed for both HSA and lysozyme increased with the amount of NVP in the poly(HEMA-co-NVP) hydrogels. In contrast to the marked effect of MAA on protein sorption, in particular, on lysozyme sorption, NVP had little influence on protein sorption. When a hydrogel contains both MAA and NVP, MAA has the dominant effect on protein sorption-in particular, on lysozyme sorption. Furthermore, a large difference was observed in the amount of lysozyme adsorbed on the hydrogels that had similar water contents but little variation in adsorption of HSA.

CONCLUSIONS

Negatively charged carboxyl groups of the MAA constituent may influence lysozyme sorption in two ways: by electrostatic attraction and by increasing the possibility for the small lysozyme molecule to penetrate the hydrogels. Interactions of the surface lactam groups of NVP with proteins may be attributable to the attraction of proteins to NVP. Water content is not a primary factor in determining protein adsorption. It appears that the monomer constituents, such as MAA or NVP, control protein adsorption.

Irreversible adsorption of human serum albumin to hydrogel contact lenses: a study using electron spin resonance spectroscopy

Human serum albumin (HSA) was specifically spin labelled with 4-maleimido-tempo (MSL) at its cysteine 34 residue (HSA-MSL). The irreversible adsorption of HSA-MSL to hydrogel contact lenses (etafilcon A, tefilcon and vifilcon A) was investigated using electron spin resonance (ESR) spectroscopy. Changes in ESR spectral characteristics of adsorbed HSA-MSL as compared to HSA-MSL in solution displayed an additional immobilisation of the spin label due to the adsorption. This immobilisation of MSL corresponds to a large conformational alteration of the HSA-MSL near the modified Cys 34 residue. For both etafilcon A and tefilcon, the rate of irreversible adsorption was relatively slow compared with that of vifilcon A where the maximum state of immobilisation and hence conformational change occurred within the first hour of adsorption. Furthermore, tefilcon produced markedly different ESR spectra where a strong conformational change to a less mobile protein was apparent. This supported a model where the direct irreversible adsorption of HSA from solution dominated on tefilcon as opposed to conversion of the adsorbed protein from the reversible to the irreversible state on both etafilcon A and vifilcon A. HSA-MSL adsorption onto hydrophobic poly(methylmethacrylate) (PMMA) and hydrophilic poly(N-ter-butylacrylamide) (PTBAM) latex beads was also investigated. The spin label MSL was found to be less mobile when HSA was adsorbed onto PMMA compared with PTBAM beads. It was also found that the rate of irreversible adsorption of HSA is far higher onto PMMA surfaces than onto PTBAM surfaces.

Lysozyme sorption in hydrogel contact lenses

PURPOSE

To examine the processes involved in formation of protein deposits on hydrogel contact lenses.

METHODS

The adsorption and/or penetration of lysozyme on or into three types of contact lenses, etafilcon A, vifilcon A, and tefilcon, were investigated in vitro using a radiolabel-tracer technique, x-ray photoelectron spectroscopy, and laser scanning confocal microscopy.

RESULTS

Binding of lysozyme to high-water-content, ionic contact lenses (etafilcon A and vifilcon A) was dominated by a penetration process. The extent of this penetration was a function of charge density of the lenses, so that there was a higher degree of penetration of lysozyme in etafilcon A than in vifilcon A lenses. In contrast, the binding of lysozyme to tefilcon lenses was a surface adsorption process. The adsorption and desorption kinetics showed similar trends to those found in human serum albumin (HSA) adsorption on lens surfaces. However, the extent of lysozyme adsorption on tefilcon is much higher than HSA adsorption, probably because of the self-association of lysozyme on the tefilcon lens surface. Furthermore, either penetration or adsorption of lysozyme involved reversible and irreversible processes and were both time dependent.

CONCLUSIONS

Binding of lysozyme to hydrogel lenses involves surface adsorption or matrix penetration. These processes may be reversible or irreversible. The properties of the lens materials, such as charge density (ionicity) and porosity (water content) of the lenses, determine the type and rates of these processes.

Borderline personality disorder

The lives of patients with borderline personality disorder are characterized by turmoil, and their interpersonal relationships by conflict. As a result, these patients can be very difficult to treat. However, an accurate diagnosis and an understanding of the psychodynamics and emotional development of borderline patients can lead to improved management.