Tools for assessing health research partnership outcomes and impacts: a systematic review.

OBJECTIVE: To identify and assess the globally available valid, reliable and acceptable tools for assessing health research partnership outcomes and impacts. METHODS: We searched Ovid MEDLINE, Embase, CINAHL Plus and PsycINFO from origin to 2 June 2021, without limits, using an a priori strategy and registered protocol. We screened citations independently and in duplicate, resolving discrepancies by consensus and retaining studies involving health research partnerships, the development, use and/or assessment of tools to evaluate partnership outcomes and impacts, and reporting empirical psychometric evidence. Study, tool, psychometric and pragmatic characteristics were abstracted using a hybrid approach, then synthesized using descriptive statistics and thematic analysis. Study quality was assessed using the quality of survey studies in psychology (Q-SSP) checklist. RESULTS: From 56 123 total citations, we screened 36 027 citations, assessed 2784 full-text papers, abstracted data from 48 studies and one companion report, and identified 58 tools. Most tools comprised surveys, questionnaires and scales. Studies used cross-sectional or mixed-method/embedded survey designs and employed quantitative and mixed methods. Both studies and tools were conceptually well grounded, focusing mainly on outcomes, then process, and less frequently on impact measurement. Multiple forms of empirical validity and reliability evidence was present for most tools; however, psychometric characteristics were inconsistently assessed and reported. We identified a subset of studies (22) and accompanying tools distinguished by their empirical psychometric, pragmatic and study quality characteristics. While our review demonstrated psychometric and pragmatic improvements over previous reviews, challenges related to health research partnership assessment and the nascency of partnership science persist. CONCLUSION: This systematic review identified multiple tools demonstrating empirical psychometric evidence, pragmatic strength and moderate study quality. Increased attention to psychometric and pragmatic requirements in tool development, testing and reporting is key to advancing health research partnership assessment and partnership science. PROSPERO CRD42021137932.

Circadian rhythm dysfunction: a novel environmental risk factor for Parkinson's disease.

Parkinson's disease (PD) is a chronic and progressive neurodegenerative disorder. Although rare genetically linked cases of PD have been reported, most incidences are sporadic in nature. Late-onset, sporadic PD is thought to result from the combined effects of genetic and environmental risk factors exposure. Sleep and circadian rhythm disorders are recurrent among PD patients and appear early in the disease. Although some evidence supports a relationship between circadian disruption (CD) and PD, whether this is secondary to the motor symptoms or, indeed, is a factor that contributes to the pathogenesis of the disease remains to be investigated. In the present paper, we studied the direct consequence of chronic CD on the development of the phenotype in the MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridinen) model of PD. Pre-exposure to CD to mice treated with MPTP resulted in an exacerbation of motor deficit and a significant reduction in the capability of acquiring motor skills. These changes were associated with a greater loss of tyrosine hydroxylase cell content and intense neuroinflammation. Taken together, our findings demonstrate that CD by triggering a robust neuroinflammatory reaction and degeneration of the nigral-dopaminergic neuronal system exacerbates motor deficit. They support the novel hypothesis that circadian rhythm disorder is an environmental risk factor for developing PD.

Chronic behavioral stress exaggerates motor deficit and neuroinflammation in the MPTP mouse model of Parkinson's disease.

Environmental stressor exposure is associated with a variety of age-related diseases including neurodegeneration. Although the initial events of sporadic Parkinson's disease (PD) are not known, consistent evidence supports the hypothesis that the disease results from the combined effect of genetic and environmental risk factors. Among them, behavioral stress has been shown to cause damage and neuronal loss in different areas of the brain, however, its effect on the dopaminergic system and PD pathogenesis remains to be characterized. The C57BL/6 mice underwent chronic restraint/isolation (RI) stress and were then treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), whereas the control mice were treated only with MPTP and the effect on the PD-like phenotype was evaluated. The mice that underwent RI before the administration of MPTP manifested an exaggerated motor deficit and impairment in the acquisition of motor skills, which were associated with a greater loss of neuronal tyrosine hydroxylase and astrocytes activation. By showing that RI influences the onset and progression of the PD-like phenotype, our study underlines the novel pathogenetic role that chronic behavioral stressor has in the disease process by triggering neuroinflammation and degeneration of the nigral dopaminergic system.

p-Aminobenzoic acid transport by normal and Plasmodium falciparum-infected erythrocytes.

De novo folate biosynthesis is required for the growth of malarial parasites and is inhibited by several important antimalarial agents. We show here that exogenous p-aminobenzoic acid (pABA) can be utilized by malaria parasites to synthesize folates. The transport of pABA into parasite infected red cells was therefore characterized. Normal red cells transport pABA in a saturable and energy-dependent manner, with a dissociation constant of 83 nM. pABA transport in parasite-infected red cells may use the same mechanism, as demonstrated by similarities in time course, concentration-response, and dissociation constant (111 nM). The transport capacity of red cells is temperature-, energy- and pH-dependent. It is inhibited by the proton ionophore, carbonylcyanide m-chlorophenylhydrazone (CCCP), but not by the sodium ionophores nigericin and monensin. p-Aminosalicylic acid (PAS) inhibits pABA transport competitively, with a inhibition constant of 378 nM. Phloritin, flufanamic acid, and 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DITS), which are inhibitors of the anion transporter (band 3), and oxalic acid, a substrate of this transporter, partially inhibit pABA transport into both normal and infected red cells. Interestingly, in both normal and infected red cells, the inhibitory effects of PAS and the anion transport inhibitors are additive, suggesting the involvement of 2 independent mechanisms.

Pneumocystis carinii polyamine catabolism.

DL-alpha-Difluoromethylornithine (DFMO) causes polyamines of the AIDS-associated opportunistic pathogen Pneumocystis carinii to diminish 15 times more rapidly than mammalian host cells. The proposed mechanism was that, unlike mammalian cells, P. carinii is unable to regulate polyamine catabolism when synthesis is blocked. To test this, the responses of the polyamine catabolic enzymes spermidine/spermine acetyltransferase (SSAT) and polyamine oxidase (PAO) were determined using a new high-performance liquid chromatography assay to measure the products of these enzymes. The specific activities in untreated Pneumocystis carinii were 1.78 +/- 0.5 pmol min(-1) mg protein(-1) for SSAT, similar to mammalian cells, and 6.42 +/- 0.8 pmol min(-1) mg protein(-1) for PAO, 19% of that of mammalian cells. DFMO treatment for 12 h caused reductions of only 11 and 4% in SSAT and PAO, respectively, despite polyamine reductions of 94, 96, and 90% for putrescine, spermidine, and spermine, respectively. The P. carinii SSAT K(m) value of 25 microM spermidine is 20% of that of mammalian cells, and the PAO K(m) value of 14 nM N(1)-acetylspermidine is 0.01% of that of mammalian cells. Acetylated polyamines continue to be lost from P. carinii even when exposed to DFMO. Collectively, these results support the hypothesis that P. carinii is unable to regulate polyamine catabolism.

Susceptibility of Pneumocystis carinii to artemisinin in vitro.

The susceptibility of Pneumocystis carinii to artemisinin (qinghaosu) was determined in short-term primary culture. In untreated cultures, trophozoites increased an average of fivefold over 4 days. Inhibition of parasite growth in cultures treated with artemisinin at concentrations as low as 0.5 microM was seen. In contrast, artemisinin concentrations up to 100 microM had no effect on feeder layer cells.

Polyamine analysis using N-hydroxysuccinimidyl-6-aminoquinoyl carbamate for pre-column derivatization.

N-Hydroxysuccinimidyl-6-aminoquinoyl carbamate (AccQ.Fluor) was used as a polyamine pre-column derivatization reagent prior to HPLC analysis using a 5-micron C8 reversed-phase column. The fluorescence detector excitation wavelength was set at 250 nm and emission at 395 nm. Quantitation, reproducibility, linearity, recovery and stability were demonstrated. The lower limit of detection was 660 fmol. This method is 45 and 61 times more sensitive than those using the pre-column derivatizing agents dansyl chloride and orthophthalaldehyde, respectively. Applicability to biological samples was demonstrated by analyses of polyamines in extracts of mouse erythrocytes and Trypanosoma brucei brucei.

Polyamine content of Pneumocystis carinii and response to the ornithine decarboxylase inhibitor DL-alpha-difluoromethylornithine.

Difluoromethylornithine (DFMO; eflornithine hydrochloride [Ornidyl]), a suicide inhibitor of the key polyamine biosynthesis enzyme ornithine decarboxylase (ODC), is effective in treating Pneumocystis carinii pneumonia, a common opportunistic infection associated with AIDS. Despite DFMO's specificity for ODC, the reason for its selective toxicity against P. carinii is unknown since both host and parasite are dependent on the same enzyme for polyamine biosynthesis. A new high-performance liquid chromatography method was used with P. carinii cells isolated from infected rat lungs to measure polyamine content, to confirm the presence of ODC, and to examine the effect of DFMO on polyamine concentrations. Putrescine, spermidine, and spermine were found to be present at 2.00 +/- 0.54, 1.26 +/- 0.51, and 1.59 +/- 0.91 nmol (mg of protein)-1, respectively, neither unusually high nor low values. ODC's specific activity was 79 +/- 11 pmol (mg of protein)-1 h-1, again not a remarkable value. However, the rates of both DFMO-induced polyamine depletion and subsequent repletion upon DFMO removal were unusually high. A 3-h exposure to 1 mM DFMO in vitro caused the depletion of putrescine, spermidine, and spermine to levels 12, 29, and 16%, respectively, of that of control cells. After DFMO removal and incubation for 1 h in serum-free media, polyamine levels returned to 78, 88, and 64%, respectively, of that of the control cells not exposed to DFMO. Since such depletions and repletions usually occur over periods of days rather than hours, these rapid changes may provide a clue to the selective action of DFMO against P. carinii and may guide the development of new compounds and an optimal drug administration schedule for DFMO.

Inhibition of Pneumocystis carinii dihydropteroate synthetase by sulfa drugs.

A new reversed-phase high-pressure liquid chromatography assay procedure for dihydropteroate synthetase (DHPS) that involves the elution of the enzyme incubation solution with a series of three solvents of decreasing polarity (ammonium phosphate buffer, 10% methanol, and 50% methanol) was designed. By this procedure DHPS was detected in Escherichia coli and Pneumocystis carinii with specific activities of 450 and 14 U/mg, respectively. A comparison of the effects of five sulfa drugs on P. carinii DHPS activity revealed that dapsone is the most potent of these drugs.

Continuous infusion of DL-alpha-difluoromethylornithine and improved efficacy against a rat model of Pneumocystis carinii pneumonia.

The rapid depletion of Pneumocystis carinii polyamines caused by in vitro exposure to DL-alpha-difluoromethylornithine (DFMO; also called eflornithine or Ornidyl) and the rapid repletion following removal of this drug suggested that the in vivo efficacy of DFMO against P. carinii pneumonia (PCP) may be limited by troughs in drug concentration resulting from the schedule of administration. This led to the prediction that, compared with the response to the standard animal protocol of administering DFMO in drinking water, the response of a rat model of PCP to DFMO would be lessened by bolus administration and improved by continuous infusion. These predictions were confirmed. Intraperitoneal bolus administration of up to 3 g of DFMO kg of body weight-1 was completely ineffective, although this dose has been shown to be effective when given in the drinking water. Conversely, continuous infusion improved the response against PCP seven- to ninefold over the response to drinking water administration. These findings suggest that, compared with the standard clinical investigational protocol for treatment of PCP with DFMO given in four divided daily doses, continuous infusion combined with monitoring of drug concentrations in plasma may improve efficacy and/or reduce the already low rate of adverse effects.

S-adenosylmethionine and Pneumocystis carinii.

We previously reported that S-adenosylmethionine (AdoMet), a key molecule in methylation reactions and polyamine biosynthesis, enhances axenic culture of the AIDS-associated opportunistic fungal pathogen Pneumocystis carinii. Here we report that AdoMet is absolutely required for continuous growth. Two transporters are present, one high affinity, K(m) = 4.5 microm, and one low affinity, K(m) = 333 microm. The physiologically relevant high affinity transporter has a pH optimum of 7.5 and no related natural compounds compete for uptake. Transport is 98% inhibited at 4 degrees C, 24% inhibited by 20 mm sodium azide, and 95% inhibited by the combination of 20 mm sodium azide and 1 mm salicylhydroxamic acid; thus transport is active and dependent on both a cytochrome chain and an alternative oxidase. In vitro, AdoMet is used at a rate of 1. 40 x 10(7) molecules cell(-1) min(-1). AdoMet synthetase activity was not detected by a sensitive radiolabel incorporation assay capable of detecting 0.1% of the activity in rat liver. In addition, the AdoMet plasma concentration of rats is inversely correlated with the number of P. carinii in the lungs. These findings demonstrate that P. carinii is an AdoMet auxotroph. The uptake and metabolism of this compound are rational chemotherapeutic targets.

Effect of a bis-benzyl polyamine analogue on Pneumocystis carinii.

Pneumocystis carinii is the causative agent of P. carinii pneumonia (PCP), an opportunistic infection associated with AIDS and other immunosuppressed conditions. Although polyamine metabolism of this fungus has been shown to be a chemotherapeutic target, this metabolism has not been thoroughly investigated. Reported here is the effect of one polyamine analogue, N, N'-bis[3-[(phenylmethyl)amino]propyl]-1,7-diaminoheptane (BBS), on P. carinii. BBS inhibits the growth of P. carinii in culture, but at concentrations higher than those required to inhibit the growth of other pathogens. However, BBS is at least as active in an animal model of PCP as in other models of diseases studied. BBS causes some reduction in P. carinii polyamine content and polyamine biosynthetic enzyme activities, but the effect is less than that observed with other pathogens and very much less than the effect of the polyamine biosynthesis inhibitor DL-alpha-difluoromethylornithine. BBS enters P. carinii cells via a polyamine transporter, unlike all other cells that have been studied. P. carinii cells do not remove the benzyl groups of BBS, as is reported for mammalian cells. The most likely mode of action is displacement of natural polyamines. Overall, the activity of BBS provides further evidence that polyamines and polyamine metabolism are rational targets for the development of drugs to treat PCP. Because the details of BBS-P. carinii interaction differ from those of other cells studied, polyamine analogues may provide a highly specific treatment for PCP.

Pneumocystis carinii infection presenting as an intra-abdominal cystic mass in a child with acquired immunodeficiency syndrome.

We describe the case of a pediatric patient with acquired immunodeficiency syndrome (AIDS) with an unusual large, fluid-filled intra-abdominal cystic lesion in which Pneumocystis carinii trophozoites were identified. Extrapulmonary P. carinii infection should be considered in the differential diagnosis of an intra-abdominal cystic mass in a child with AIDS.

Trophozoite elimination in a rat model of Pneumocystis carinii pneumonia by clinically achievable plasma deferoxamine concentrations.

In a rat model of Pneumocystis carinii pneumonia, a 3-week infusion of deferoxamine producing concentrations in plasma of > or = 1.5 micrograms m-1 eliminated the trophozoite life cycle stage. Since this concentration is well below that routinely achieved in patients treated for iron overload, deferoxamine has promise as a therapy for AIDS-associated P.carinii pneumonia.

Antiviral activity of characterized extracts from echinacea spp. (Heliantheae: Asteraceae) against herpes simplex virus (HSV-I).

Extracts of 8 taxa of the genus Echinacea were found to have antiviral activity against Herpes simplex (HSV) virus Type I in vitro when exposed to visible and UV-A light. n-Hexane extracts of roots containing alkenes and amides were more active in general than ethyl acetate extracts containing caffeic acids. The most potent inhibitors of HSV were E. pallida var. sanguinea crude (70 % ethanol) inflorescence extract (MIC = 0.026 mg/mL), cichoric acid (MIC = 0.045 mg/mL) and Echinacea purpurea n-hexane root extract (MIC = 0.12 mg/mL).

Response of rat model of Pneumocystis carinii pneumonia to continuous infusion of deferoxamine.

The iron-chelating drug deferoxamine mesylate (DFO) is active against Pneumocystis carinii in vitro and in rat and mouse models of P. carinii pneumonia. Because DFO has a short half-life, daily divided or continuous dosage was expected to improve the dose response, as is the case with DFO treatment of malaria. Therefore, results of single daily intraperitoneal injections were compared with results of an evenly divided four-times-daily dosage and the efficacy of delivery with implanted infusion pumps. The highest bolus dosage (1,000 mg kg-1 of body weight day-1) was as effective as the standard combination of trimethoprim with sulfamethoxazole. Unexpectedly, very little improvement was observed with the divided or continuous dosage, and several mechanisms that could account for this are discussed.

Continuous axenic cultivation of Pneumocystis carinii.

Continuous axenic culture of Pneumocystis carinii has been achieved. A culture vessel is used that allows for frequent medium exchange without disturbance of organisms that grow attached to a collagen-coated porous membrane. The growth medium is based on Minimal Essential Medium with Earle's salt supplemented with S-adenosyl-L-methionine, putrescine, ferric pyrophosphate, N-acetyl glucosamine, putrescine, p-aminobenzoic acid, L-cysteine and L-glutamine, and horse serum. Incubation is in room air at 31 degrees C. The pH of the medium begins at 8.8 and rises to approximately 9 as the cells grow. Doubling times calculated from growth curves obtained from cultures inoculated at moderate densities ranged from 35 to 65 hours. With a low-density inoculum, the doubling time is reduced to 19 hours. The morphology of cultured organisms in stained smears and in transmission electron micrographs is that of P. carinii, and P. carinii-specific mAbs label the cultured material. Cultured organisms are infective for immunosuppressed rats and can be stored frozen and used to reinitiate culture.

Action of deferoxamine against Pneumocystis carinii.

We found earlier that deferoxamine (DFO), a drug used for treatment of iron overload, is active against a rat model of Pneumocystis carinii pneumonia (PCP). We had assumed a mode of action by deprivation of nutritional iron; however, data here show that DFO penetrates P. carinii, causing irreversible damage, thus indicating a different mode of action. Penetration was demonstrated by showing DFO uptake by high-pressure liquid chromatography analysis. By using calcein-AM as an indicator, exposure to DFO was shown to cause a reduction in P. carinii cytoplasmic free iron. Exposure to >or=100 microM DFO for >or=8 h in vitro caused growth to cease and cell numbers to decline over several days. This direct and irreversible damage to P. carinii led to the prediction that infrequent delivery of DFO to the lungs via an aerosol would be an effective treatment in the animal model of PCP. This prediction was confirmed by demonstrating that a once-a-week aerosol treatment of rats was 100% effective both as a prophylactic and as a curative treatment in a rat model of PCP.

Clinically achievable plasma deferoxamine concentrations are therapeutic in a rat model of Pneumocystis carinii pneumonia.

The iron-chelating drug deferoxamine (DFO) has been shown to be active in animal models of Pneumocystis carinii pneumonia (PCP), with effective daily intraperitoneal bolus dosages being 400 and 1,000 mg of DFO mesylate kg of body weight-1 in mouse and rat models, respectively. Continuous infusion produced a moderately improved response in a rat model. The data reported here demonstrate that the response achieved by continuous infusion of 195 and 335 mg of DFO mesylate kg-1 day-1 in the rat model is associated with mean concentrations in plasma of 1.3 and 2.5 micrograms of DFO ml-1 and mean concentrations in lung tissue of 4.9 and 6.0 micrograms of DFO g of lung tissue-1, respectively. Since current clinical use of DFO mesylate for the treatment of iron overload produces higher concentrations in the plasma of patients, DFO may prove to be a useful anti-PCP treatment. The 2.4- to 3.8-fold higher DFO concentration observed in lung tissue compared with that observed in plasma may be important in the response of PCP to DFO.