Feminist perspectives on environmental justice and health in Jamaica.

Jamaica is an island nation with a history that is informed by Taino settlement, European colonisation, chattel slavery, disinvestment, and continued extractivism. This perspective paper leverages a historical analysis to explore environmental injustices affecting the health and quality of life of Jamaicans living in Jamaica. This article hopes to contribute to a growing but limited body of scholarly research that contends with environmental and climate justice in the context of the Caribbean. In discussing a lack of critical environmental infrastructure, such as reliable solid waste management, and the impacts of extractive industries, such as bauxite mining, the paper intends to highlight the environmental, public health, and social harms that are produced. Employing an intersectional approach grounded in Black feminist epistemology put forward by Patricia Hill Collins, the authors use their lived experiences as a source of knowledge. The paper analyses how these environmental injustices harm Jamaican communities at large but underscores the compounded challenges faced by Jamaican women who experience marginalisation on the basis of gender, urban/rural residency, and class. The paper concludes by urging researchers, policymakers, regulatory bodies, and other stakeholders to conduct further research and create sustainable and equitable environmental standards that have considerations for environmental injustice in Jamaica.

Principles for increasing equity in WASH research: understanding barriers faced by LMIC WASH researchers.

INTRODUCTION: There have long been critiques of colonial legacies influencing global health. With growing public awareness of unjust systems in recent years, a new wave of calls for antiracist and decolonisation initiatives has emerged within the sector. This study examined research inequities in the water, sanitation and hygiene (WASH) sector, centring the perspectives of researchers from low-income and middle-income countries (LMICs), to identify barriers faced by WASH researchers in order to support more equitable changes in this subsector of global health. METHODS: Nineteen semistructured interviews were conducted with researchers of different backgrounds regarding nationality, gender and research experience. Researchers from eight countries were asked about their experiences and direct observations of discrimination across various stages of the research process. Five interviews were conducted with key WASH research funders to assess perceptions of obstacles faced by LMIC researchers, successes achieved and challenges faced by these organisations when working towards more equitable research processes within the WASH sector. RESULTS: The results were analysed using an emergent framework that categorised experiences based on power differentials and abuse of power; structural barriers due to organisational policies; institutional and individual indifference; othering speech, action and practices; and context-specific discrimination. The social-ecological model was combined with this framework to identify the types of actors and the level of co-ordination needed to address these issues. Researchers who worked in both LMICs and high-income countries at different career stages were particularly aware of discrimination. Ensuring pro-equity authorship and funding practices were identified as two significant actions to catalyse change within the sector. CONCLUSION: Sector-wide efforts must centre LMIC voices when identifying research questions, conducting research, and in dissemination. Individuals, organisations and the entire WASH sector must examine how they participate in upholding inequitable systems of power to begin to dismantle the system through the intentional yielding of power and resources.

Carfilzomib for the treatment of multiple myeloma.

Carfilzomib is a second-generation selective proteasome inhibitor that has been recently approved in the use for refractory multiple myeloma. It has been shown to be beneficial in both bortezomib-resistant and bortezomib-naive patients, with a tolerable side effect profile. Peripheral neuropathy is less common in patients receiving carfilzomib compared to bortezomib. Recent and ongoing clinical trials are establishing the role of carfilzomib in the treatment of refractory multiple myeloma.

Dielectric constants of multiwall carbon nanotubes from direct current to microwave frequencies.

A cylindrical rod constructed from a uniform mixture of multiwall carbon nanotubes and alumina powders dissolved in paraffin was inserted in the center of a radio frequency cavity. The real and imaginary dielectric constants of carbon tubes at various frequencies were measured, respectively, from the resonant frequencies and the quality factors, by a resistance-inductance-cacitance (RLC) meter and a microwave network analyzer. The dielectric rod benefits the protection of the sample from adsorbing moisture and preventing the rod from filling with air, thus making accurate measurments. A tunable probe specifically designed for the field pattern of a TM010 mode is delineated to improve the microwave coupling of the dielectric microwave resonator. This refined design is expected to facilitate the measurement yielding a significant manner. The real and imaginary parts of the dielectric constant of carbon nanotubes increase and decrease, respectively as frequencies increase satisfactorily in complying with the description from the free electron Drude model.

Pain relief in ventilated preterms during endotracheal suctioning: a randomized controlled trial.

BACKGROUND: In Switzerland approximately 8% of infants are born prematurely. Some of them undergo mechanical ventilation including endotracheal suctioning (ETS). ETS is one of the most frequently performed interventions and is linked to stress and pain, but its treatment is controversial. In Switzerland there is a lack of standardisation in pain relief for ETS. AIMS: To test the hypothesis that an intermittent dose of morphine reduces pain during ETS and that subsequent multisensorial stimulation (MSS), as a non pharmacological comforting intervention, helps infants to recover from experienced pain. METHOD: A randomized placebo controlled trial in two tertiary neonatal intensive care units (NICU) with a sample of 30 mechanically ventilated preterm infants was conducted. Pain was measured by three pain assessment tools (Bernese Pain Scale for Neonates, Premature Infant Pain Profile and Visual Analogue Scale) RESULTS: Morphine did not lead to any pain relief from ETS as measured by three pain scales. Nor did the comforting intervention of MSS show any effect. Repeated-measure analysis of variance for the within and between groups comparison showed no statistical significance. CONCLUSIONS: The administration of morphine for pain relief in ventilated preterm neonates during ETS remains questionable and the use of MSS as a comforting intervention after painful stimulus cannot be recommended. The validity testing of the instruments for this patient population should undergo a systematic validation trajectory. Future research should focus on options among non pharmacological interventions for relieving pain during ETS.

High molecular weight polyethylene nanospheres: synthesis, physical and mechanical properties--second harmonic generation.

The weak second harmonic light generating from carbon nanotubes are detected. The signal intensity closely related to the density of pi-bonds attributed to the defects in the rolled graphene sheets, which is stimulated to have anharmonic oscillation as strongly affected by the environment. The intensities of SHG are diminished in order of well-aligned multi-wall carbon nanotubes (MWCNTs), randomly-aligned MWCNTs, and then to single-wall CNTs.

Surface modification by electric discharge implemented with electrodes composed of carbon nanotubes.

In this work the electric discharge machining (EDM) implementing with multi-wall carbon nanotubes (MWCNT) as a miniscule electrode for pursuing precise surface modification was studied. The excellent upright growth of carbon nanotubes on copper based alloy substrates by a radio frequency (RF) assisted hot filament chemical vapor deposition (HFCVD) method suggests us to exploit MWCNTs as the miniature electrodes for discharge machining. The results reveal that the electrodes are much endurable to be distorted even when the spoiling rates for the polishing of n-type Si wafer (of 10 to approximately 100 omega-cm) are up to 30 nm/min with. It is expected that MWCNTs can be applied to non-conventional material processing especially in miniature discharge machining.

Regional differences in the dynamics of refractoriness in intact and hypertrophied in situ canine hearts.

OBJECTIVES: Functional re-entry is thought to represent the predominant mechanism underlying ventricular arrhythmias. Functional conduction block may be caused by regional dispersion of refractoriness (ERP). Dispersion of ERP may not be evident at baseline, but may occur with sudden changes in heart rate, as ventricular arrhythmias are commonly induced by short-long-short cycles. METHODS: We examined the dynamics of local ERPs at two left ventricular (LV) sites in dogs with either no structural heart disease or biventricular hypertrophy (BVH). ERPs were determined at each of four bipoles of two adjacent needle electrodes in the LV apex and the lateral wall. The stimulation protocol included two different basic cycle lengths, one or two longer cycles after a train of 6 or 5 shorter cycles, and one shorter cycle after a train of 6 longer cycles. RESULTS: In normal dogs, a significant apicolateral ERP gradient was only evident with the longer basic cycle length. One shorter cycle was sufficient to dissolve that gradient. One longer cycle was enough to create a regional ERP gradient. Dynamic regional gradients occurred because the apex responded more markedly and more readily to abrupt changes in cycle length. BVH led to an increase in ERP at both LV sites and to an aggravation of regional ERP gradients. CONCLUSIONS: Dynamic ERP behavior seems to depend on topography and underlying pathology. Abrupt changes in heart rate might induce dynamic refractory gradients between various regions of the normal heart, but also between adjacent regions inhomogenously affected by hypertrophy.

Comparison of finasteride and alpha-blockers as independent risk factors for erectile dysfunction.

There are insufficient data on the effects of alpha-blockers and finasteride on erectile function in men who have other risk factors for erectile dysfunction (ED). This study was conducted to compare the relative effects of these medications on ED in men who may be on other medications or have other risk factors for ED. Patients attending urology and primary care clinics were asked to complete an IRB-approved questionnaire that combined the validated Sexual Health Inventory for Men (SHIM) and a detailed medical history. A total of 123 patients completed the questionnaire. The age range was 28-88 years (mean: 68 years). Eighty-one per cent of patients had SHIM scores <21, indicating some degree of ED. The average SHIM scores in a population of patients with similar age and risk factors who had been on finasteride or alpha-blockers indicated the presence of ED but did not reveal a significant difference between the two groups. The scores were no different from an age-matched group of patients who were not on either medication, demonstrating the relatively greater importance of various other risk factors for ED. There was an inverse linear relationship between the number of ED risk factors and SHIM scores. There does not appear to be a significant difference between alpha-blockers and finasteride as independent risk factors for ED. Age and other risk factors (heart disease, diabetes, hypertension, smoking, and hypercholesterolaemia) tend to have a much stronger influence on the severity of ED as assessed by SHIM scores.

Axotomy along with hypoxia enhances the neuronal NADPH-d/NOS expression in lower brain stem motor neurons of adult rats.

This study was aimed to determine whether axotomy coupled with hypoxia would exert a more profound effect on injury-induced neuronal nitric oxide synthase (NOS) expression. In this connection, the vagus and the hypoglossal nerves of adult rats were transected unilaterally in the same animal, and half of the operated animals were subjected to hypoxia treatment. Both the neuronal NOS immunohistochemistry and the nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry were used to assess the neuronal NOS expression. The present results have shown that the number of NADPH-d/NOS-positive [NADPH-d/NOS(1)] neurons in the hypoglossal nucleus (HN) peaked at 14 days after axotomy, while that in dorsal motor nucleus of vagus (DMN) and nucleus ambiguus (NA) was progressively increased up to 60 days. The up-regulation of NADPH-d/NOS in HN and DMN was more pronounced in hypoxic than in normoxic animals, a feature that was not evident in the NA. Quantitative analysis showed that the number of surviving motoneurons in normoxic animals was significantly higher than those subjected to hypoxia at 14 days postaxotomy in HN and at all postaxotomy time points in DMN. The difference may be attributed to their different functional components. Since O2 deprivation leads to poor cellular function, the stronger expression of NADPH-d/NOS and the more drastic neuronal loss following nerve transection in the hypoxic animals compared with the controls suggest that hypoxia plays an important role in peripheral neuropathies in which NO is implicated.

The distribution and characterization of NADPH-d/NOS-IR neurons in the rat cuneate nucleus.

Nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry and nitric oxide synthase (NOS) immunohistochemistry have been used to characterize the nitric oxide (NO)-containing neurons in the rat cuneate nucleus. The present results showed that NADPH-d-positive/NOS-immunoreactive (-IR) neurons were distributed in the entire rostrocaudal extent of the nucleus. In the caudal region (approximately 1-2 mm caudal to the obex), NADPH-d/NOS-IR neurons were aggregated along the dorsal area of the nucleus notably in the lateral aspect. When traced rostrally, labeled neurons were progressively reduced and the cells were randomly distributed. The labeled neurons varied from round, ovoid to spindle-shaped with a mean profile area of about 140.1+/-1.7 microm(2) (n=720). They made up 7-10% of the neuronal population in the cuneate nucleus. By immunoelectron microscopy, the immunoreaction product was deposited throughout the cytoplasm extending from the soma to the proximal and distal dendrites. Results of NADPH-d staining paralleled that of NOS immunohistochemistry. Furthermore, NADPH-d reactivity and NOS-IR were colocalized in the same neurons following double labeling. Using NADPH-d histochemistry along with anti-gamma-aminobutyric acid (GABA) and -glycine postembedding immunolabeling for identification of GABA- and glycine-IR neurons, respectively, about 33% of the NADPH-d-positive neurons contained both GABA and glycine, 26% of them contained only glycine, while 41% of them showed neither GABA nor glycine labeling. Cuneothalamic neurons (CTNs) were identified by injecting the retrograde tracer Fluorogold (FG) into the ventrobasal complex of the thalamus. Numerous FG-labeled neurons were present in the contralateral cuneate nucleus, but none were reactive for NADPH-d. The present results suggest that approximately 60% of the NADPH-d/NOS-IR neurons in the cuneate nucleus are interneurons containing GABA and/or glycine.

Somatic noxious mechanical stimulation induces Fos expression in the postsynaptic dorsal column neurons in laminae III and IV of the rat spinal dorsal horn.

This study was conducted to ascertain the possible expression of Fos-like immunoreactivity (Fos-LI) in the postsynaptic dorsal column (PSDC) neurons in response to noxious mechanical stimulation of the forepaw glabrous area of normal rats. For this purpose, Fos immunohistochemistry along with Fluoro-Gold (FG) retrograde tracing was utilized. After repeated noxious pinching of the forepaw glabrous area, there was a marked increase in number of Fos-LI neurons in the dorsal horn, including Rexed's laminae III and IV, at C5-T1 spinal cord segments ipsilateral to the stimulation. Between segments C5 and T1, about 40% of the Fos-LI neurons in laminae III and IV were distributed at segment C7. In the rats subjected to the noxious pinch coupled with FG injection into the right cuneate nucleus, PSDC neurons double labeled with Fos and FG were localized in the ipsilateral laminae III and IV extending from segment C5 to T1, with about 70% of them distributed at segments C6 and C7. At segment C6 or C7, double-labeled neurons made up about 10% of the PSDC neurons that projected their axons to the cuneate nucleus. Most of the double-labeled neurons appeared fusiform with their primary dendrites projected dorso-ventrally. The present results suggest that the morphologically distinct, subclasses of PSDC neurons in spinal laminae III and IV may contribute to the central transmission of mechanical nociceptive information through the dorsal column into the cuneate nucleus.

Afferent synaptic contacts on glycine-immunoreactive neurons in the rat cuneate nucleus.

This study was aimed to clarify whether the primary afferent terminals (PATs), GABAergic terminals, and glutamatergic terminals made direct synaptic contacts with glycine-IR neurons in the cuneate nucleus of rats. In this connection, injection of the anterograde tracer WGA-HRP into brachial plexus, antiglycine preembedding immunoperoxidase, and anti-GABA, along with antiglutamate postembedding immunogold labeling, were used to identify the PATs, glycine-IR neurons, GABA-IR terminals, and glutamate-IR terminals, respectively. The present results showed that HRP-labeled PATs, immunoperoxidase-labeled glycine-IR terminals, immunogold-labeled GABA-IR, and glutamate-IR terminals made axodendritic synaptic contacts with immunoperoxidase-labeled glycine-IR neurons. The latter three presynaptic elements also formed axosomatic synapses with glycine-IR neurons. Statistical analysis has shown that the minimum diameter of the glycine-IR dendrites postsynaptic to the above-mentioned four presynaptic elements did not differ significantly. In addition, the synaptic ratio of the glutamate-IR terminals on the glycine-IR dendrites was higher than that of GABA-IR terminals. The synaptic ratio of the GABA-IR terminals on glycine-IR dendrite was in turn higher than that of the PATs and glycine-IR terminals. It is suggested that the PATs and glutamate-IR terminals on the glycine-IR neurons may be involved in subsequent postsynaptic inhibition for spatial precision of lateral inhibition. On the other hand, the GABA-IR and glycine-IR terminals which make synaptic contacts with the dendrites of glycine-IR neurons may provide a putative means for disinhibition or facilitation to maintain the baseline neuronal activity in the rat cuneate nucleus. The results of quantitative analysis suggest that glutamate act as the primary excitatory neurotransmitter, while GABA, when compared with glycine, may serve as a more powerful inhibitory neurotransmitter on glycine-IR neurons in the rat cuneate nucleus.

Evidence of neuroanatomical connection between the superior cervical ganglion and hypoglossal nerve in the hamster as revealed by tract-tracing and degeneration methods.

Previous studies have shown the existence of a sympathetic component in some cranial nerves including the hypoglossal nerve. In this study, the horseradish peroxidase (HRP) tract-tracing retrograde technique and experimental degeneration method were used to elucidate the possible neuroanatomical relationship between the superior cervical ganglion (SCG) and the hypoglossal nerve of hamsters. About 10% of the SCG principal neurons were HRP positive following the tracer application to the trunk of hypoglossal nerve. Most of the HRP-labelled neurons were multipolar and were randomly distributed in the ganglion. When HRP was injected into the medial branch of the hypoglossal nerve, some of the SCG neurons were labelled, but they were not detected when HRP was injected into the lateral branch. The present findings suggest that postganglionic sympathetic fibres from the SCG may travel along the hypoglossal nerve trunk via its medial branch to terminate in visceral targets such as the intralingual glands. By electron microscopy, the HRP reaction product was localised in the neuronal somata and numerous unmyelinated fibres in the SCG. In addition, HRP-labelled axon profiles considered to be the collateral branches of the principal neurons contained numerous clear round and a few dense core vesicles. Besides the above, some HRP-labelled small myelinated fibres, considered to be visceral afferents, were also present. Results of experimental degeneration following the severance of the hypoglossal nerve showed the presence of degenerating neuronal elements both in the hypoglossal nucleus and the SCG. This confirms that the hypoglossal nerve contains sympathetic component from the SCG which may be involved in regulation of the autonomic function of the tongue.

A beta-fiber intensity stimulation of chronically constricted median nerve induces c-fos expression in thalamic projection neurons of the cuneate nucleus in rats with behavioral signs of neuropathic pain.

This study was aimed to investigate the possible involvement of neurons in the cuneate nucleus (CN) in the processing of A beta afferent inputs evoked by electrical stimulation of constricted median nerve in rats with behavioral signs of neuropathic pain. Immunohistochemical localization of Fos protein was used to examine the neuronal activation, and the combination of Fos immunohistochemistry with the retrograde labeling of Fluoro-Gold (FG) injected into the ventrobasal complex of the thalamus was used to characterize the activated neurons. Two weeks after unilateral median nerve constriction injury, the rats exhibited behavioral signs of neuropathic pain in the affected forepaws. In rats after nerve injury but without electrical stimulation, some Fos-like immunoreactive (Fos-LI) neurons were detected in the dorsal horn of the seventh cervical segment (C7) but none was found in the CN. Similar features were also noted when the stimulation of the intact median nerve served as an additional control. After A beta-fiber intensity stimulation of the previously constricted median nerve, an increase in number of Fos-LI neurons occurred in the medial half of the ipsilateral C7 dorsal horn as well as in the ipsilateral CN. In the latter, the Fos-LI neurons were located in the median nerve projection territory throughout the nucleus. Most of the Fos-LI neurons were distributed in the middle region of the CN, with about 78% of them emitting FG fluorescence indicating that they were cuneothalamic projection neurons. The results of this study suggest that the dorsal column-medial lemniscal system may contribute to the transmission and modulation of A beta-fiber mediated neuropathic pain signals.

Ultrastructural localisation of NADPH-d/nNOS expression in the superior cervical ganglion of the hamster.

This study examined NADPH-d and nNOS expression in the SCG of hamsters. By light microscopy, numerous NADPH-d/NOS positive processes were widely distributed in the ganglion. Ultrastructurally, the NADPH-d reaction product was associated with the membranous organelles of neuronal soma, dendrites, myelinated fibres, small granular cells, and axon profiles bearing agranular vesicles. The NOS immunoreaction product, on the other hand, was localised in the cytoplasm of principal neurons and dendrites. Some of the NADPH-d/NOS labelled processes formed junctional contacts including synapses or zonulae adherentia. Compared with the neurons, the nonneuronal cells in the ganglion, namely, macrophages, satellite cells and endothelial cells were labelled by NADPH-d but devoid of nNOS immunoreaction product. The results suggest that the NADPH-d/NOS positive fibres in the SCG originate not only from the projecting fibres of the lateral horns of thoracic spinal cord, but also from the principal neurons and small granular cells; some may represent visceral afferent fibres. Electron microscopic morphometry has shown that about 67% of the principal neurons contain NADPH-d reaction product, and that the majority were small to medium sized neurons based on cross-sectional areas in image analysis. On the basis of the present morphological study, it is concluded NO is produced by some local neurons and possibly some nonneuronal cells in the SCG as well as some fibres of extrinsic origin. In this connection, NO may serve either as a neurotransmitter or neuromodulator.

Tazarotene plus UVB phototherapy in the treatment of psoriasis.

BACKGROUND: The addition of oral retinoids to phototherapy may accelerate and enhance antipsoriatic efficacy, but can result in systemic adverse events and additional laboratory monitoring costs. OBJECTIVE: Our purpose was to determine whether the topical addition of tazarotene to UVB phototherapy improves efficacy without problems related to photosensitivity. METHODS: Bilateral target plaques were randomized to receive two of the following, one on each plaque once daily for 14 days: tazarotene 0.1% gel, vehicle gel, or no treatment. Thereafter, the same treatments were continued 3 times per week, plus UVB phototherapy 3 times per week, for an additional 67 days. RESULTS: Tazarotene plus UVB phototherapy achieved faster and significantly greater reductions in plaque elevation and scaling throughout treatment and achieved at least 50% improvement from the pretreatment baseline with a significantly lower median cumulative UVB exposure than vehicle gel plus UVB light or UVB phototherapy alone. No case of unusual photosensitivity was noted in the tazarotene plus UVB treatment group. CONCLUSION: The addition of tazarotene to UVB phototherapy improves and accelerates efficacy and maintains acceptable safety and tolerability.

Somatostatin-IR neurons are a major subpopulation of the cuneothalamic neurons in the rat cuneate nucleus.

This study was aimed to localize and characterize the somatostatin-immunoreactive (SOM-IR) neurons in the rat cuneate nucleus (CN). By immuno-histochemistry, the SOM-IR neurons, which were widely distributed in the nucleus, were round, spindle or multiangular in shape (mean area = 226.1 +/ -3.1 microm(2), n = 1016). By electron microscopy, the neurons shared all the ultrastructural features of the cuneothalamic neurons (CTNs) which showed a slightly indented nucleus and a fairly rich cytoplasm containing well-developed Golgi apparatuses and rough endoplasmic reticulum (rER). The SOM immunoreaction product filled the cytoplasm of the neurons extending from the soma to the proximal and distal dendrites, which were postsynaptic to unlabeled boutons. In addition to soma and dendrites, SOM-IR boutons were also identified which made axodendritic synaptic contacts with SOM-IR dendrites. The SOM-IR neurons were characterized by using anti-SOM pre-embedding immunolabeling coupled with horseradish peroxidase (HRP) retrograde method, or SOM immunolabeling along with anti-glutamate, gamma-aminobutyric acid (GABA) or glycine post-embedding immunolabeling for identification of CTNs, glutamate-IR, GABA-IR and glycine-IR neurons, respectively. It was shown that more then 80% of the CTNs contained SOM and, furthermore, they contained glutamate but not GABA or glycine. On the basis of present findings, it is suggested the majority of the SOM-IR neurons in the rat CN are CTNs and that they may be involved in modulation of somatosensory synaptic transmission.

Photodamage pilot study: a double-blind, vehicle-controlled study to assess the efficacy and safety of tazarotene 0.1% gel.

BACKGROUND: Tazarotene, a potent acetylenic retinoid for topical use, might be expected to benefit photodamaged skin, including improving the classical signs of fine wrinkles, mottled hyperpigmentation, and roughness. OBJECTIVE: Our purpose was to determine the efficacy and safety of tazarotene 0.1% gel in the treatment of photodamaged dorsal forearm skin. METHODS: Ten healthy female volunteers, aged 45 to 65 years, with moderately photodamaged forearm skin applied tazarotene 0.1% gel to one arm and vehicle gel to the other once daily for 12 weeks. The study was a double-blind, randomized, paired-comparison evaluation conducted at a single site. RESULTS: Tazarotene showed beneficial effects for several efficacy variables. It was more efficacious than vehicle in reducing skin roughness and fine wrinkling based on objective measurements. Tazarotene also corrected epidermal atrophy and atypia and improved skin hydration properties. CONCLUSION: In this 12-week pilot study tazarotene redressed abnormalities associated with photo-damaged skin.

Melatonin attenuates neuronal NADPH-d/NOS expression in the hypoglossal nucleus of adult rats following peripheral nerve injury.

Oxidative stress and massive production of nitric oxide (NO) have been implicated in the neuropathogenesis following peripheral nerve injury. This study was aimed to ascertain whether melatonin would exert its neuroprotective effect on the lesioned hypoglossal neurons after peripheral axotomy, since it is known to reduce the oxidative damage in a variety of experimental neuropathologies in which NO is involved. Right-sided hypoglossal nerve transection was performed in adult rats following which the animals were given two different doses of melatonin administered intraperitoneally for 3, 7, 14, 21 and 30 successive days. Nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry and neuronal nitric oxide synthase (nNOS) immunohistochemistry were carried out to detect the neuronal NADPH-d/NOS expression in the hypoglossal nucleus (HN). At various time intervals following axotomy, the neurons in the affected HN were induced to express NADPH-d/NOS reactivity on the lesioned side peaking at 14 days. However, the enzyme expression was markedly depressed by melatonin treatment in a dose-dependent manner in terms of frequency of labelled neurons and staining intensity. It is suggested that the suppressive effect of melatonin on NADPH-d/NOS expression may be attributed to its antioxidant properties. Hence, in consideration of therapeutic strategies for reducing the oxidative stress following peripheral nerve injury, melatonin may prove to be beneficial.