Gabapentin use in the neonatal intensive care unit and beyond: Single center report of 104 cases

BACKGROUND

We aimed to describe our experience with gabapentin use in infants admitted to our neonatal intensive care unit (NICU), including neurodevelopmental follow-up after discharge.

METHODS

We performed a retrospective medical record review of infants prescribed gabapentin during admission to the University of Virginia NICU from 01/01/2015 to 04/30/2021. We report clinical characteristics including gabapentin indication, dosing and side-effects while in the NICU, discharge data, and assessments in outpatient developmental follow-up clinic.

RESULTS

Gabapentin was prescribed to 104 infants (median gestational age 29 weeks, median postmenstrual age at initiation 41 weeks). Sixty-one percent of infants were male. The primary indication was irritability in 86%, and 67% were receiving at least one other neurosedative medication. Median maximum dose was 25 mg/kg/day (IQR 15-35 mg/kg/day) and 84% were discharged home on gabapentin. The majority required equipment at discharge (64% gastrostomy or nasogastric tube feeds, 54% supplemental oxygen or mechanical ventilation, and 40% both). At the first neurodevelopmental follow-up appointment, at least one area of delay was identified in 93% of infants and by 2 years corrected age 66% had a diagnosis of global developmental delay.

CONCLUSIONS

NICU patients treated with gabapentin often require complex post-discharge care and require close neurodevelopmental follow up.

Differential Uptake of Antisense Oligonucleotides in Mouse Hepatocytes and Macrophages Revealed by Simultaneous Two-Photon Excited Fluorescence and Coherent Raman Imaging

Antisense oligonucleotides (ASOs), a novel paradigm in modern therapeutics, modulate cellular gene expression by binding to complementary messenger RNA (mRNA) sequences. While advances in ASO medicinal chemistry have greatly improved the efficiency of cellular uptake, selective uptake by specific cell types has been difficult to achieve. For more efficient and selective uptake, ASOs are often conjugated with molecules with high binding affinity for transmembrane receptors. Triantennary N-acetyl-galactosamine conjugated phosphorothioate ASOs (GalNAc-PS-ASOs) were developed to enhance targeted ASO delivery into liver through the hepatocyte-specific asialoglycoprotein receptor (ASGR). We assessed the kinetics of uptake and subsequent intracellular distribution of AlexaFluor 488 (AF488)-labeled PS-ASOs and GalNAc-PS-ASOs in J774A.1 mouse macrophages and primary mouse or rat hepatocytes using simultaneous coherent anti-Stokes Raman scattering (CARS) and two-photon fluorescence (2PF) imaging. The CARS modality captured the dynamic lipid distributions and overall morphology of the cells; two-photon fluorescence (2PF) measured the time- and dose-dependent localization of ASOs delivered by a modified treatment of suspension cells. Our results show that in macrophages, the uptake rate of PS-ASOs did not significantly differ from that of GalNAc-PS-ASOs. However, in hepatocytes, GalNAc-PS-ASOs exhibited a peripheral uptake distribution compared to a polar uptake distribution observed in macrophages. The peripheral distribution correlated with a significantly larger amount of internalized GalNAc-PS-ASOs compared to the PS-ASOs. This work demonstrates the relevance of multimodal imaging for elucidating the uptake mechanism, accumulation, and fate of different ASOs in liver cells that can be used further in complex in vitro models and liver tissues to evaluate ASO distribution and activity.

Congenital Unilateral Renal Aplasia in a Cynomolgus Monkey (Macaca fascicularis) With Investigation Into Potential Pathogenesis

We describe and characterize unilateral renal aplasia in a cynomolgus monkey (Macaca fascicularis) from a chronic toxicology study adding to the limited histopathology reports of congenital renal anomalies in macaques. In the current case, the affected kidney was macroscopically small and characterized microscopically by a thin cortex with an underdeveloped medulla and an absent papilla. The remnant medulla lacked a corticomedullary junction and contained only a few irregular collecting duct-like structures. The cortex had extensive interstitial mature collagen deposition with fibromuscular collar formation around Bowman's capsules. Due to parenchymal collapse, mature glomeruli were condensed together with occasional atrophic and sclerotic glomeruli. The majority of the cortical tubules were poorly differentiated with only small islands of fully developed cortical tubules present. Histochemical and immunohistochemical stains were utilized to demonstrate key diagnostic features of this congenital defect, to assist with differentiating it from renal dysplasia, and to provide potential mechanistic pathways. Immunostaining (S100, paired box gene 2 [PAX2], aquaporins) of the medulla was compatible with incomplete maturation associated with aplasia, while the immunostaining profile for the cortex (vimentin, calbindin, PAX2-positive cortical tubules, and smooth muscle actin-positive fibromuscular collars) was most compatible with dedifferentiation secondary to degenerative changes.

Scientific Regulatory Policy Committee Points to Consider*: Nuisance Factors, Block Effects, and Batch Effects in Nonclinical Safety Assessment Studies

Detection of test article-related effects and the determination of the adversity of those changes are the primary goals of nonclinical safety assessment studies for drugs and chemicals in development. During these studies, variables that are not of primary interest to investigators may change and influence data interpretation. These variables, often referred to as "nuisance factors," may influence other groups of data and result in "block or batch effects" that complicate data interpretation. Definitions of the terms "nuisance factors," "block effects," and "batch effects," as they apply to nonclinical safety assessment studies, are reviewed. Multiple case examples of block and batch effects in safety assessment studies are provided, and the challenges these bring to pathology data interpretation are discussed. Methods to mitigate the occurrence of block and batch effects in safety assessment studies, including statistical blocking and utilization of study designs that minimize potential confounding variables, incorporation of adequate randomization, and use of an appropriate number of animals or repeated measurement of specific parameters for increased precision, are reviewed. [Box: see text].

Evaluation of a Dental Diagnostic Terminology Subset

The objective of this study was to determine how well a subset of SNODENT, specifically designed for general dentistry, meets the needs of dental practitioners. Participants were asked to locate their written diagnosis for tooth conditions among the SNODENT terminology uploaded into an electronic dental record. Investigators found that 65% of providers’ original written diagnoses were in “agreement” with their selected SNODENT dental diagnostic subset concept(s).

Immunolesion of melanopsin neurons causes gonadal regression in Pekin drakes (Anas platyrhynchos domesticus)

Several light sensitive receptors have been described in the avian brain that are thought to regulate the reproductive axis independently from the eyes and pineal gland. Recently, our lab has described the presence of three of these photoneuroendocrine systems in the Pekin duck: opsin, opsin 5, & melanopsin. We set out to test the hypothesis that melanopsin receptive neurons are necessary to maintain seasonal reproductive status along with growth and development in the Pekin drake. To accomplish these goals we first investigated 50-week-old Pekin drakes that were housed in the aviary at Hope College under long day length (18h lights on) conditions in floor pens. To specifically lesion melanopsin-receptive neurons, 3μl of an anti-melanopsin-saporin conjugate (MSAP, 100ng/ul) was injected into the lateral ventricle (n=10). Control drakes were injected with 3μl of equimolar unconjugated anti-melanopsin and saporin (SAP, n=10). Reproductive behaviors were analyzed weekly in a test pen with adult hens and MSAP drakes showed a significant (p<0.01) reduction in reproductive behaviors after week 2. After 5weeks, drakes were euthanized and body weights were measured, and brains, pituitaries, and testes collected and stored for analyses. Mature MSAP-treated drakes had significantly (p<0.001) reduced relative teste weights compared to SAP controls. qRT-PCR analyses of hypothalamus showed a significant reduction (p<0.001) in GnRH and melanopsin mRNA levels, but not opsin 5, vertebrate ancient opsin, or opsin 2 (rhodopsin). Immunocytochemical analyses showed a significant reduction (p<0.01) in tyrosine hydroxylase-immunoreactivity in the PMM. These data suggest that although blue light alone is not able to maintain testicular function, the blue-light sensitive melanopsin activity is critical to maintain gonadal function.

Inhibition of ALK5 Signaling Induces Physeal Dysplasia in Rats

TGF-|β|, and its type 1 (ALK5) receptor, are critical to the pathogenesis of fibrosis. In toxicologic studies of 4 or more days in 10-week-old Sprague–Dawley rats, using an ALK5 inhibitor (GW788388), expansion of hypertrophic and proliferation zones of femoral physes were noted. Subphyseal hyperostosis, chondrocyte hypertrophy/hyperplasia, and increased matrix were present. Physeal zones were laser microdissected from ALK5 inhibitor-treated and control rats sacrificed after 3 days of treatment. Transcripts for TGF-|β|1, TGF-|β|2, ALK5, IHH, VEGF, BMP-7, IGF-1, bFGF, and PTHrP were amplified by real-time PCR. IGF and IHH increased in all physis zones with treatment, but were most prominent in prehypertrophic zones. TGF-|β|2, bFGF and BMP7 expression increased in proliferative, pre- and hypertrophic zones. PTHrP expression was elevated in proliferative zones but decreased in hypertrophic zones. VEGF expression was increased after treatment in pre- and hypertrophic zones. ALK5 expression was elevated in prehypertrophic zones. Zymography demonstrated gelatinolytic activity was reduced after treatment. Apoptotic markers (TUNEL and caspase-3) were decreased in hypertrophic zones. Proliferation assessed by Topoisomerase II and Ki67 was increased in multiple zones. Movat stains demonstrated that proteoglycan deposition was altered. Physeal changes occurred at doses well above those resulting in fibrosis. Interactions of factors is important in producing the physeal dysplasia phenotype.

Abstract PD2-04: ERα phosphorylation at pS294: A biomarker of ligand or mutational (Y537S, D538G) activation, and a receptor target for CDK2 inhibition

Background: Certain ERα phosphorylation (p) sites are essential for ERα transcriptional activity; and with development of ERα p-specific antibodies, some of these sites predict endocrine responsiveness. Unlike other ERα p-sites, pS294 has been shown to be induced by ligand activation and not by cross-talking growth factor signals. With development of a new rabbit monoclonal, pS294 induction was found to be dependent on a cyclin-dependent kinase (CDK). This study aimed to identify the specific CDK mediating induction of pS294, determine if ligand-independent ERα activating mutations (Y537S, D538G) also induce pS294, and learn if specific CDK inhibitors might enhance endocrine therapeutic efficacy by suppressing pS294.

Methods: MCF7 cells, untreated (stripped media) or stimulated by estradiol (E2, 10nM) or growth factor (EGF, 5nM), were treated with either CDK-specific knockdown siRNAs or small molecule CDK inhibitors (with indicated specificities): Roscovitine (pan-CDKs); Dinaciclib (CDK1, CDK2, CDK5, CDK9); Palbociclib (CDK4, CDK6); JNJ7706621 (CDK1, CDK2); BMS265246 (CDK1, CDK2); and SNS032 (CDK2, CDK7, CDK9). Whole cell, nuclear or cytosolic lysates were either Western blotted (for ERα or specific CDKs) or first immunoprecipitated (total ERα, pS294-ERα) and then immunoblotted. RT-PCR of cellular RNA quantified pS294-ERα induced transcripts (EGF3, AREG, CXCL12 vs. GAPDH) potentially inhibited by CDK inhibitors. MCF7 overexpressing ERα activating mutations (Y537S, D538G) were produced by either transient transfection or knock-in; knock-in clones were innoculated into immunocompromised mice to assess ligand-independent xenograft tumor growth in vivo, while transfected cells and tumors were assessed for ligand-independent ERα phosphorylation.

Results: CDK2 was determined to be the primary kinase mediating ligand-dependent induction of pS294-ERα, with co-precipitation of cyclins A/E confirming the expected mechanism of CDK2 recruitment to chromatin-bound pS294-ERα. Knock-in MCF7 cells expressing either Y537S or D538G ERα rapidly formed tumors in vivo without E2 supplementation; tumors and transiently transfected cells overexpressing mutated ERα showed pS294 &gt;&gt; pS118 expression, with constitutive pS294 suppressed by Dinaciclib but not by Palbociclib. CDK1/2 inhibitors (Dinaciclib, BMS265246) but not a CDK4/6 inhibitor (Palbociclib) cooperated with tamoxifen (4-HT) to induce apoptosis in wildtype MCF7.

Conclusion: CDK2 is the primary mediator of pS294 induced by either ligand stimulation or ligand-independent mutational activation of ERα. While the CDK4/6 inhibitor Palbociclib is a recently approved adjunct to endocrine therapy, it enhances cytostatic growth arrest without affecting ERα phosphorylation or receptor induced gene expression. In contrast, CDK2 inhibitors like Dinaciclib should be explored for their ability to enhance ER-positive breast cancer cell death in combination with antiestrogens and for their ability to prevent the emergence of constitutively active ERα mutations by suppressing pS294 induction, essential for ERα mediated gene transactivation and breast tumor growth.

Citation Format: Benz CC, Scott GK, Chu D, Kaur R, Muthurajah M, Rothschild D, Frazier K, Park BH. ERα phosphorylation at pS294: A biomarker of ligand or mutational (Y537S, D538G) activation, and a receptor target for CDK2 inhibition. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr PD2-04.

Increased water contamination and grow-out Pekin duck mortality when raised with water troughs compared to pin-metered water lines using a United States management system

Controversy has developed as to whether or not pin-metered water lines or water troughs are more appropriate for Pekin ducks. We hypothesized that water troughs would show improved duck body conditions and environmental quality compared to pin-metered water lines. To test this hypothesis, we housed ducks in 2 barns, one with water lines and one with water troughs. Water troughs were constructed to meet RSPCA guidelines for number and density of ducks and with recently described verandas. Ducks were divided into 4 pens per barn (n=1,000 ducks/pen). The study was then repeated (n=8 pens per water source) in a cross-over design so the barns each contained the opposite water source to the first experiment. We scored the ducks' body condition using an established scoring rubric and analyzed using SAS Proc GLM-Mix as binomial data. Ducks housed with water troughs showed higher (thus worse condition; P<0.001) scores for eyes, nostrils, feather quality, feather cleanliness, and foot pads. We also compared water condition, water quality, and duck mortality using a Student t test for both water sources each week. We found that the water troughs showed higher iron (P<0.001), nitrites (P<0.001), pH (P<0.01), and bacterial growth (P<0.001). The bacterial growth was shown to have higher (P<0.001)E. coli, coliforms, and Staphylococcusin the water troughs. Water lines typically showed no bacterial growth in culture-based assays. Ducks housed with water troughs used greater (P=0.001) volumes of water compared to ducks housed with water lines. Ducks with water troughs also showed a greater percent (P=0.008) mortality at all ages compared to ducks with water lines. These data suggest that water troughs may not be beneficial for duck welfare and could adversely impact both environment and duck or human health.

Characterization of a piscirickettsiosis-like disease in Hawaiian tilapia

In 1994, tilapia (Oreochromis mossambicus and Sarotherodon melanotheron) in wild and farmed populations on Oahu, Hawaii, USA, began to die of an unknown disease that was similar but not identical to piscirickettsiosis in salmonids. Only tilapia were affected. Diseased tilapia often swam erratically and had trouble staying at depth. Scattered cutaneous haemorrhage and exophthalmia were often noted. In many cases, fish were found dead with no clinical signs. Gills exhibited epithelial hyperplasia with severe multifocal consolidation of secondary lamellae. Multiple granulomas were observed in the gills, spleen, kidney, choroid gland and testes, but not in the liver. Tilapia mortalities occurred only during the cooler months (October to April) of the year and were not recorded during the warmer months (May to September). The mortalities declined with each successive year, after the 1994 outbreak, and currently losses are sporadic. Oxytetracycline-medicated feed reduced mortality. Cytologic examination of blood smears revealed moderate to large numbers of Gram-negative, pleomorphic, intracellular bacteria in rare circulating monocytes. Histologically, some predilection for nervous tissue and brain was observed. When viewed with transmission electron microscopy, pleomorphic coccoid bacteria, measuring 0.56 +/- 0.14 x 0.7 +/- 0.20 microm, occurred free in the cytoplasm and within phagolysosomes. The organisms had a double cell wall, no defined nucleus and variable electron-dense and -lucent areas. Unlike Piscirickettsia salmonis, the agent of piscirickettsiosis, the Hawaiian tilapia Piscirickettsia-like organism (HTPLO) does not form craterform lesions in the liver and is active above 20 degrees C. HTPLO can be transmitted horizontally by cohabitation, and cold stress induces the syndrome in juvenile tilapia from farms where the disease is endemic.

Endometritis in postparturient cattle associated with bovine herpesvirus-4 infection: 15 cases

Suppurative, ulcerative endometritis associated with bovine herpesvirus-4 (BHV-4) infection was identified in 15 postparturient dairy cows from 5 separate dairies. Characteristic eosinophilic to amphophilic intranuclear viral inclusion bodies were identified within degenerate endometrial lining epithelium and endothelial cells. Bovine herpesvirus-4 was confirmed as the etiology by a combination of fluorescent antibody assays, viral isolation, heminested PCR, ultrastructural examination of the uterus and inoculated tissue culture cells, and negative-stain electron microscopy of tissue culture supernatant. Viral particles measuring 70-95 nm were demonstrated in uterine epithelial and endothelial cells by electron microscopy. Bacteria including Arcanobacterium pyogenes, Escherichia coli, and an alpha-Streptococcus isolate were isolated from all uteri. Bovine herpesvirus-4-associated endometritis has been previously reported in sporadic cases in Europe but has not been previously reported in the United States. Endometritis associated with BHV-4 appears to be an emerging syndrome in Georgia dairy herds.

Mushroom toxicity in a horse with meningioangiomatosis

We describe a fatal case of mushroom intoxication in an 18-y-o horse presumably due to Amanita verna. Horses are normally regarded as too fastidious to eat the ill-flavored toadstools. In this case, the horse had a rare benign brain tumor, meningioangiomatosis, which may have altered the horse's normal eating behavior resulting in consumption of the mushrooms.

162 cases of aldicarb intoxication in Georgia domestic animals from 1988-1998

A 10-y retrospective study of aldicarb intoxication in domestic animals from 1988 to 1998 is provided from animals submitted to the University of Georgia Veterinary Diagnostic and Investigational Laboratory. Within the period examined, 162 separate cases were confirmed and 18 additional cases were suspected based on bioassay but could not be confirmed. Some cases involving as many as 15 affected animals. Dogs were most often involved, but cats, horses, cattle and goats were also poisoned. Most intoxications appeared intentional or malicious. "Baits" including frankfurters, ham or ground beef were consistently found in stomach contents. The restriction of aldicarb to an agricultural soil application limits accidental exposure to domestic animals. Its use is regulated through license in Georgia as a systemic insecticide for pecan trees, peanuts and cotton. Unfortunately, aldicarb seems favored as a malicious poison, possibly due to its quick lethality.

Postmortem diagnosis of accidental cocaine intoxication in a dog

Despite an abundance of data on the experimental effects of cocaine in dogs, no detailed reports documenting accidental cocaine exposure in domestic pets have been reported in the veterinary literature. A case of cocaine intoxication is described in a 19-mo-old male catahoula hound in which the diagnosis was confirmed using histopathology, thin-layer chromatography and mass spectrometry. The case was presented as a possible intoxication of unknown etiology. Routine toxicologic screens and characteristic histologic lesions provided evidence for the diagnosis without prior suspicion of cocaine involvement.

Bovine arsenic toxicosis from ingestion of ashed copper-chrome-arsenate treated timber

Arsenic toxicosis is reported in a variety of animal species. It occurs most commonly in cattle and ranks second only to lead as a cause of heavy metal poisoning. We describe a case of arsenic toxicosis attributable to ingestion of ashes from burned posts treated with an arsenic-containing preservative. Burning of the posts concentrated the arsenic and rendered lethal a product normally used around livestock. Lack of normal salt supplementation to the herd was conducive to pica-like behavior and ingestion of toxic ashes. Rapid diagnosis led to removal of the arsenic source and limited losses to 4 cows.

Microcystin toxicosis in cattle due to overgrowth of blue-green algae

Toxicosis due to microcystin-containing blue-green algae has been sporadically reported in a variety of animal species. Most reports of intoxication involve algal blooms during periods of warm temperatures and abundant sunshine in the spring or early summer. A case of blue-green algae toxicosis with lesions attributable to toxins from Microcystis aeruginosa is described in 4 cattle from southern Georgia during November. The case was unusual in that characteristic hepatic necrosis was accompanied by severe mesenteric edema and peritoneal effusion. In addition, weather conditions and location were not expected to be conducive to algal blooms. Rapid diagnosis and identification of the probable source of intoxication allowed the owner to move the herd away from the affected pond. This action limited losses to only the 4 cattle.

Stimulation of fibroblast cell growth, matrix production, and granulation tissue formation by connective tissue growth factor

Connective tissue growth factor (CTGF) is a 36-to 38-kDa peptide that is selectively induced by transforming growth factor-beta (TGF-beta) in fibroblastic cell types. We compared the biologic activities of CTGF with TGF-beta on fibroblasts in culture and in animal models of fibroplasia. CTGF was active as a mitogen in monolayer cultures of normal rat kidney fibroblasts. CTGF did not stimulate anchorage-independent growth of NRK fibroblasts, however, or inhibit the growth of mink lung epithelial cells, distinguishing CTGF's growth-regulatory activities from those of TGF-beta. In NRK fibroblasts, both TGF-beta and CTGF significantly increased the transcripts encoding alpha 1 type I collagen, alpha 5 integrin, and fibronectin. Stimulation of type I collagen and fibronectin protein synthesis by TGF-beta and CTGF was confirmed by pulse labeling of cells with [35S]methionine. Subcutaneous injection of TGF-beta and CTGF into neonatal NIH Swiss mice resulted in a large stimulation of granulation tissue and fibrosis at the site of injection. In situ hybridization studies revealed that TGF-beta injection induced high levels of CTGF mRNA in the dermal fibroblasts at the injection site, demonstrating that TGF-beta can induce the expression of CTGF in connective tissue cells in vivo. No CTGF transcripts were detected in the epidermal cells in either control or TGF-beta-injected skin or in fibroblasts in control (saline-injected) skin. These results demonstrate that, like TGF-beta, CTGF can induce connective tissue cell proliferation and extracellular matrix synthesis.

Development of small-cell osteogenic sarcoma after ulnar ostectomy in a dog

A 5-year-old male Saint Bernard was evaluated for vague forelimb lameness. Four and a half years earlier, the dog had undergone left ulnar ostectomy to correct a valgus deformity. Focal bone lysis was evident radiographically at the ostectomy site. Four months later, marked bony swelling was apparent and the dog was bearing partial weight. The dog was euthanatized, and at necropsy, a bone tumor with lung metastasis was found. Microscopically, features of the tumor were compatible with those of small-cell osteogenic sarcoma.