Multidisciplinary perspectives on roles of hospital pharmacists in tertiary settings: a qualitative study.

In today's complex healthcare landscape, exacerbated by resource constraints at various levels, optimization of health professionals' roles is becoming increasingly paramount. Interprofessional collaboration, underpinned by role recognition and teamwork, leads to improved patient and organizational outcomes. Hospital pharmacists play a pivotal role in multidisciplinary teams, and it is imperative to understand multidisciplinary viewpoints on hospital pharmacists' roles to guide role prioritization and organizational efficiency. However, no study extensively investigated multidisciplinary views on values of diverse pharmacist roles in tertiary settings. This study aims to address this gap by examining non-pharmacist health professionals' views on hospital pharmacists' roles, recognizing their specialized niches as a crucial step towards optimizing their roles and services in Australia and internationally. Multiple focus group discussions and interviews were held via a virtual conferencing platform. Study participants were recruited using the study investigators' professional networks who were non-pharmacist health professionals with experience working with pharmacists in hospital settings. Data were collected from transcripts of the focus group recordings, which were later summarized using descriptive statistics and thematic analysis. Overarching themes were categorized and mapped against work system models to conceptualize organizational implications of multidisciplinary feedback, linking them to patient and organizational outcomes. Twenty-seven health professionals participated across focus groups and interviews, with the majority of professions being doctors and nurses. Three major themes were identified as follows: (i) overarching perceptions regarding hospital pharmacists; (ii) professional niches of hospital pharmacists; and (iii) future opportunities to optimize hospital pharmacy services. Valued professional niches included patient and health professional educators, transition-of-care facilitators, and quality use of medicines analysts. The study highlights critical insights into hospital pharmacists' roles in Australia, identifying their niche expertise as vital to healthcare efficiency and success. Based on multidisciplinary feedback, the study advocates for strategic role optimization and targeted research for enhanced clinical, economic, and organizational outcomes.

Heterozygous GBA D409V and ATP13a2 mutations do not exacerbate pathological α-synuclein spread in the prodromal preformed fibrils model in young mice.

Autophagic dysregulation and lysosomal impairment have been implicated in the pathogenesis of Parkinson's disease, partly due to the identification of mutations in multiple genes involved in these pathways such as GBA, SNCA, ATP13a2 (also known as PARK9), TMEM175 and LRRK2. Mutations resulting in lysosomal dysfunction are proposed to contribute to Parkinson's disease by increasing α-synuclein levels, that in turn may promote aggregation of this protein. Here, we used two different genetic models-one heterozygous for a mutated form of the GBA protein (D409V), and the other heterozygous for an ATP13a2 loss-of-function mutation, to test whether these mutations exacerbate the spread of α-synuclein pathology following injection of α-synuclein preformed fibrils in the olfactory bulb of 12-week-old mice. Contrary to our hypothesis, we found that mice harboring GBA D409V+/- and ATP13a2+/- mutations did not have exacerbated behavioral impairments or histopathology (α-synuclein, LAMP2, and Iba1) when compared to their wildtype littermates. This indicates that in the young mouse brain, neither the GBA D409V mutation or ATP13a2 loss-of-function mutation accelerate the spread of α-synuclein pathology. As a consequence, we postulate that these mutations increase Parkinson's disease risk only by acting in one of the initial, upstream events in the Parkinson's disease pathogenic process. Further, the mutations, and the molecular pathways they impact, appear to play a less important role once the pathogenic process has been triggered and therefore do not specifically influence α-synuclein pathology spread.

The Effects of Insulin-Induced Hypoglycaemia on Tyrosine Hydroxylase Phosphorylation in Rat Brain and Adrenal Gland.

In this study we investigated the effects of insulin-induced hypoglycaemia on tyrosine hydroxylase (TH) protein and TH phosphorylation in the adrenal gland, C1 cell group, locus coeruleus (LC) and midbrain dopaminergic cell groups that are thought to play a role in response to hypoglycaemia and compared the effects of different concentrations of insulin in rats. Insulin (1 and 10 U/kg) treatment caused similar reductions in blood glucose concentration (from 7.5-9 to 2-3 mmol/L); however, plasma adrenaline concentration was increased 20-30 fold in response to 10 U/kg insulin and only 14 fold following 1 U/kg. Time course studies (at 10 U/kg insulin) revealed that in the adrenal gland, Ser31 phosphorylation was increased between 30 and 90 min (4-5 fold), implying that TH was activated to increase catecholamine synthesis in adrenal medulla to replenish the stores. In the brain, Ser19 phosphorylation was limited to certain dopaminergic groups in the midbrain, while Ser31 phosphorylation was increased in most catecholaminergic regions at 60 min (1.3-2 fold), suggesting that Ser31 phosphorylation may be an important mechanism to maintain catecholamine synthesis in the brain. Comparing the effects of 1 and 10 U/kg insulin revealed that Ser31 phosphorylation was increased to similar extent in the adrenal gland and C1 cell group in response to both doses whereas Ser31 and Ser19 phosphorylation were only increased in response to 1 U/kg insulin in LC and in response to 10 U/kg insulin in most midbrain regions. Thus, the adrenal gland and some catecholaminergic brain regions become activated in response to insulin administration and brain catecholamines may be important for initiation of physiological defences against insulin-induced hypoglycaemia.

Identifying rates and risk factors for medication errors during hospitalization in the Australian Parkinson's disease population: A 3-year, multi-center study.

BACKGROUND: Admission to hospital introduces risks for people with Parkinson's disease in maintaining continuity of their highly individualized medication regimens, which increases their risk of medication errors. This is of particular concern as omitted medications and irregular dosing can cause an immediate increase in an individual's symptoms as well as other adverse outcomes such as swallowing difficulties, aspiration pneumonia, frozen gait and even potentially fatal neuroleptic malignant type syndrome. OBJECTIVE: To determine the occurrence and identify factors that contribute to Parkinson's medication errors in Australian hospitals. METHODS: A retrospective discharge diagnosis code search identified all admissions for people with Parkinson's disease to three tertiary metropolitan hospitals in South Australia, Australia over a 3-year period. Of the 405 case notes reviewed 351 admissions met our inclusion criteria. RESULTS: Medication prescribing (30.5%) and administration (85%) errors during admission were extremely common, with the most frequent errors related to administration of levodopa preparations (83%). A higher levodopa equivalent dosage, patients with a modified swallowing status or nil by mouth order during admission, and patients who did not have a pharmacist led medication history within 24 hours of admission had significantly higher rates of medication errors. CONCLUSIONS: This study identified 3 major independent factors that increased the risk of errors during medication management for people with Parkinson's disease during hospitalization. Thus, targeting these areas for preventative interventions have the greatest chance of producing a clinically meaningful impact on the number of hospital medication errors occurring in the Parkinson's population.

Characterisation of parasympathetic ascending nerves in human colon.

Background: In the human large bowel, sacral parasympathetic nerves arise from S2 to S4, project to the pelvic plexus ("hypogastric plexus") and have post-ganglionic axons entering the large bowel near the rectosigmoid junction. They then run long distances orally or aborally within the bowel wall forming "ascending nerves" or "shunt fascicles" running in the plane of the myenteric plexus. They form bundles of nerve fibres that can be distinguished from the myenteric plexus by their straight orientation, tendency not to merge with myenteric ganglia and greater width. Aim: To identify reliable marker(s) to distinguish these bundles of ascending nerves from other extrinsic and intrinsic nerves in human colon. Methods: Human colonic segments were obtained with informed consent, from adult patients undergoing elective surgery (n = 21). Multi-layer immunohistochemical labelling with neurofilament-H (NF200), myelin basic protein (MBP), von Willebrand factor (vWF), and glucose transporter 1 (GLUT1), and rapid anterograde tracing with biotinamide, were used to compare ascending nerves and lumbar colonic nerves. Results: The rectosigmoid and rectal specimens had 6-11 ascending nerves spaced around their circumference. Distal colon specimens typically had 1-3 ascending nerves, with one located near the mesenteric taenia coli. No ascending nerves were observed in ascending colon specimens. GLUT1 antisera labelled both sympathetic lumbar colonic nerves and ascending nerves in the gut wall. Lumbar colonic nerves joined the myenteric plexus and quickly lost GLUT1 labelling, whereas GLUT1 staining labelled parasympathetic ascending nerves over many centimetres. Conclusion: Ascending nerves can be distinguished in the colorectum of humans using GLUT1 labelling combined with NF200.

Direct targeting of wild-type glucocerebrosidase by antipsychotic quetiapine improves pathogenic phenotypes in Parkinson's disease models.

Current treatments for Parkinson's disease (PD) provide only symptomatic relief, with no disease-modifying therapies identified to date. Repurposing FDA-approved drugs to treat PD could significantly shorten the time needed for and reduce the costs of drug development compared with conventional approaches. We developed an efficient strategy to screen for modulators of ß-glucocerebrosidase (GCase), a lysosomal enzyme that exhibits decreased activity in patients with PD, leading to accumulation of the substrate glucosylceramide and oxidized dopamine and α-synuclein, which contribute to PD pathogenesis. Using a GCase fluorescent probe and affinity-based fluorescence polarization assay, we screened 1280 structurally diverse, bioactive, and cell-permeable FDA-approved drugs and found that the antipsychotic quetiapine bound GCase with high affinity. Moreover, quetiapine treatment of induced pluripotent stem cell-derived (iPSC-derived) dopaminergic neurons from patients carrying mutations in GBA1 or LRRK2 led to increased wild-type GCase protein levels and activity and partially lowered accumulation of oxidized dopamine, glucosylceramide, and α-synuclein. Similarly, quetiapine led to activation of wild-type GCase and reduction of α-synuclein in a GBA mutant mouse model (Gba1D409V/+ mice). Together, these results suggest that repurposing quetiapine as a modulator of GCase may be beneficial for patients with PD exhibiting decreased GCase activity.

An extended release GLP-1 analogue increases α-synuclein accumulation in a mouse model of prodromal Parkinson's disease.

The repurposing of drugs developed to treat type 2 diabetes for the treatment of Parkinson's disease (PD) was encouraged by the beneficial effect exerted by the glucagon-like peptide 1 (GLP-1) analogue exenatide in a phase 2 clinical trial. The effects of GLP-1 analogues have been investigated extensively using rodent toxin models of PD. However, many of the toxin-based models used lack robust α-synuclein (α-syn) pathology, akin to the Lewy bodies and neurites seen in PD. One prior study has reported a protective effect of a GLP-1 analogue on midbrain dopamine neurons following injection of α-syn preformed fibrils (PFF) into the striatum. Here, we used olfactory bulb injections of PFF as a model of prodromal PD and monitored the effect of a long-acting GLP-1 analogue on the propagation of α-syn pathology in the olfactory system. Thirteen weeks after PFF injection, mice treated with long-acting the GLP-1 analogue had a significant increase in pathological α-syn in brain regions connected to the olfactory bulb, accompanied by signs of microglia activation. Our results suggest that the nature of the neuronal insult and intrinsic properties of the targeted neuronal population markedly influence the effect of GLP-1 analogues.

Deficits in olfactory sensitivity in a mouse model of Parkinson's disease revealed by plethysmography of odor-evoked sniffing.

Hyposmia is evident in over 90% of Parkinson's disease (PD) patients. A characteristic of PD is intraneuronal deposits composed in part of α-synuclein fibrils. Based on the analysis of post-mortem PD patients, Braak and colleagues suggested that early in the disease α-synuclein pathology is present in the dorsal motor nucleus of the vagus, as well as the olfactory bulb and anterior olfactory nucleus, and then later affects other interconnected brain regions. Here, we bilaterally injected α-synuclein preformed fibrils into the olfactory bulbs of wild type male and female mice. Six months after injection, the anterior olfactory nucleus and piriform cortex displayed a high α-synuclein pathology load. We evaluated olfactory perceptual function by monitoring odor-evoked sniffing behavior in a plethysmograph at one-, three- and six-months after injection. No overt impairments in the ability to engage in sniffing were evident in any group, suggesting preservation of the ability to coordinate respiration. At all-time points, females injected with fibrils exhibited reduced odor detection sensitivity, which was observed with the semi-automated plethysmography apparatus, but not a buried pellet test. In future studies, this sensitive methodology for assessing olfactory detection deficits could be used to define how α-synuclein pathology affects other aspects of olfactory perception and to clarify the neuropathological underpinnings of these deficits.

The effects of rotenone on TH, BDNF and BDNF-related proteins in the brain and periphery: Relevance to early Parkinson's disease.

Loss of dopaminergic neurons in the substantia nigra (SN) is one of the pathological hallmarks in Parkinson's disease (PD). This neuron loss is accompanied by reduced protein and activity levels of tyrosine hydroxylase (TH), the rate-limiting enzyme of catecholamine synthesis. Reduced nigral brain-derived neurotrophic factor (BDNF) has been postulated to contribute to the loss of nigral dopaminergic neurons in PD by causing a lack of trophic support. Prior to this nigral cell loss many patients develop non-motor symptoms such as hyposmia, constipation and orthostatic hypotension. We investigated how TH, BDNF and BDNF related receptors are altered in the SN, olfactory bulb, adrenal glands and colon (which are known to be affected in PD) using rotenone-treated rats. Rotenone was administered to Sprague-Dawley rats at a dose of 2.75 mg/kg, 5 days/week for 4 weeks, via intraperitoneal injections. Rats underwent behavioural testing, and tissues were collected for western blot and ELISA analysis. This rotenone treatment induced reduced rears and distance travelled in the rearing and open field test, respectively but caused no impairments in forced movement (rotarod test). The SN had changes consistent with a pro-apoptotic state, such as increased proBDNF but no change in TH; whereas, the colon had significantly reduced TH and increased sortilin. Thus, our results indicate further investigation is warranted for this rotenone-dosing paradigm's capacity for reproducing the early stage of PD, as we observed impairments in voluntary movement and pathology in the colon without overt motor symptoms or nigral dopaminergic loss.

Triggers, Facilitators, and Aggravators: Redefining Parkinson's Disease Pathogenesis.

We hypothesize that Parkinson's disease (PD) pathogenesis can be divided into three temporal phases. During the first phase, 'triggers', such as viral infections or environmental toxins, spark the disease process in the brain and/or peripheral tissues. Triggers alone, however, may be insufficient, requiring 'facilitators' like peripheral inflammation for PD pathology to develop. Once the disease manifests, 'aggravators' spur further neurodegeneration and exacerbate symptoms. Aggravators are proposed to include impaired autophagy and cell-to-cell propagation of α-synuclein pathology. We believe clinical trials need to consider these three phases and target potential therapies at the appropriate stage of the disease process in order to be effective.

Rotenone induces gastrointestinal pathology and microbiota alterations in a rat model of Parkinson's disease.

While people are often aware of the motor symptoms in Parkinson's disease (PD), few know of the many non-motor symptoms, which patients report have a greater impact on their quality of life. Gastrointestinal (GI) dysfunction is one of the most common non-motor symptoms, which can occur at any stage of PD, even years prior to diagnosis, and can affect all sections along the GI tract causing a range of symptoms including drooling, gastroparesis and constipation. We have investigated whether a neurotoxin model of PD induced by rotenone, a mitochondrial complex I inhibitor, is capable of reproducing the GI dysfunction seen clinically. Sprague-Dawley rats were administered 2.75 mg/kg rotenone, 5 days/week for 4 weeks, via intraperitoneal injection. Rats underwent behavioural testing, including the one-hour stool and gastric emptying tests before GI contents and tissues were collected for microbiota and histological analysis. Rats exposed to rotenone had more days with evidence of diarrhoea and significantly delayed gastric emptying, reproducing the clinical symptom of gastroparesis. Microbiota analysis revealed alterations in the small intestine and colon of rotenone-treated rats, relatively consistent with changes described in PD patients. Histological analysis demonstrated mucosal thickening and goblet cell hyperplasia in the colon of rotenone rats, which may be an adaptive response to the toxin or changes in GI microbiota. Our results indicate that rotenone may be a good model for investigating the mechanisms involved with Parkinson's GI symptoms and for screening potential therapeutic options as it is capable of recapitulating some key GI changes that occur during PD progression.

An update on the rotenone models of Parkinson's disease: their ability to reproduce the features of clinical disease and model gene-environment interactions.

Parkinson's disease (PD) is the second most common neurodegenerative disorder that is characterized by two major neuropathological hallmarks: the degeneration of dopaminergic neurons in the substantia nigra (SN) and the presence of Lewy bodies in the surviving SN neurons, as well as other regions of the central and peripheral nervous system. Animal models have been invaluable tools for investigating the underlying mechanisms of the pathogenesis of PD and testing new potential symptomatic, neuroprotective and neurorestorative therapies. However, the usefulness of these models is dependent on how precisely they replicate the features of clinical PD with some studies now employing combined gene-environment models to replicate more of the affected pathways. The rotenone model of PD has become of great interest following the seminal paper by the Greenamyre group in 2000 (Betarbet et al., 2000). This paper reported for the first time that systemic rotenone was able to reproduce the two pathological hallmarks of PD as well as certain parkinsonian motor deficits. Since 2000, many research groups have actively used the rotenone model worldwide. This paper will review rotenone models, focusing upon their ability to reproduce the two pathological hallmarks of PD, motor deficits, extranigral pathology and non-motor symptoms. We will also summarize the recent advances in neuroprotective therapies, focusing on those that investigated non-motor symptoms and review rotenone models used in combination with PD genetic models to investigate gene-environment interactions.

Investigation of tyrosine hydroxylase and BDNF in a low-dose rotenone model of Parkinson's disease.

Tyrosine hydroxylase (TH, the rate limiting-enzyme in catecholamine synthesis) is regulated acutely via phosphorylation of 3 serine residues--Ser19, 31 and 40, and chronically via changes in TH protein levels. In this study, we aimed to investigate how TH is regulated in the brain, gut and adrenal gland as well as changes in mature brain-derived neurotrophic factor (mBDNF) and proBDNF levels in a low-dose (2 mg/kg, 5 days/week for 4 weeks) rotenone model of Parkinson's disease (PD). Rearing behaviour decreased by week 3 in the rotenone group (p<0.01), with further decreases in rearing by week 4 (p<0.001); however, TH remained unchanged in the substantia nigra (SN) and striatum; TH levels were also unaltered in other catecholaminergic cell groups of the brainstem such as A1C1 neurons or locus coeruleus. In the olfactory bulb, TH protein decreased (2.5-fold, p<0.01) while Ser31 phosphorylation increased (1.4-fold, p<0.05) in the rotenone group. In contrast, TH protein was increased in the adrenal gland (2-fold, p<0.05) and colon (5-fold, p<0.05) of rotenone rats. mBDNF levels were not changed in the SN but were significantly reduced in plasma and significantly increased in the colon (2-fold, p<0.01) of rotenone-treated rats. This is the first study to assess TH and BDNF in the brain and periphery in the rotenone model before SN/striatum degeneration is evident. Together these results suggest that low-dose rotenone may have some potential to model the early stages of PD.