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Biomedical subjects

A Ghezzi

Publications and source records attributed to A Ghezzi.

At least 37 records · Page 2Linked to original sources

Cord damage elicits brain functional reorganization after a single episode of myelitis.

OBJECTIVE: To assess, using fMRI, the brain pattern of movement-associated cortical activations in patients with a previous remitting episode of acute cervical myelitis of possible demyelinating origin and to investigate whether the extent of cortical reorganization is associated with the extent of cervical cord pathology measured using magnetization transfer (MT) MRI. METHODS: From 14 right-handed patients in a chronic and stable phase after an isolated myelitis (male/female = 7/7, mean age = 35.3 years, median disease duration = 21.2 months) involving the cervical cord and 15 sex- and age-matched healthy control subjects, we obtained 1) fMRI during repetitive flexion-extension of the last four fingers of the right hand, 2) brain diffusion tensor MRI, and 3) brain and cervical cord conventional and MT MRI. FMRI data were analyzed using Statistical Parametric Mapping software. Brain mean diffusivity, fractional anisotropy, and MT ratio (MTR) histograms of the normal-appearing white and gray matter and cervical cord MTR histograms were produced. RESULTS: Patients with myelitis had lower average cord MTR (p < 0.0001) and cord MTR histogram peak position (p = 0.002) than control subjects. Compared with healthy volunteers, patients with myelitis showed increased recruitment of the ipsilateral hemisphere in the primary sensorimotor cortex (p < 0.0001), supplementary motor area (p = 0.002), and middle frontal gyrus (MFG) (p < 0.0001). Average cervical cord MTR was inversely correlated with relative activations of the ipsilateral MFG (r = -0.80) and of the ipsilateral postcentral gyrus (r = -0.80). The relative activation of the ipsilateral MFG was also correlated with cervical cord MTR peak position (r = -0.92). CONCLUSIONS: An abnormal pattern of movement-associated cortical activations was found in patients with a previous episode of cervical myelitis. These functional cortical changes might have an adaptive role in limiting the clinical outcome of structural cord damage.

Acute Disease↗

Evidence of early cortical atrophy in MS: relevance to white matter changes and disability.

OBJECTIVE: To assess cortical gray matter (GM) changes in MS and establish their relevance to clinical disability and to inflammatory changes of white matter (WM) in patients with the relapsing-remitting (RR) and primary progressive (PP) forms of the disease. METHODS: Conventional MRI examinations were obtained in patients with definite MS who had either the RR or the PP form of the disease. An automated analysis tool was used with conventional T1-weighted MR images to obtain total and cortical brain volumes normalized for head size. Total brain lesion load was estimated on conventional proton density and T2-weighted MR images. The relationship between volumetric MR measures and scores of clinical disability was assessed. RESULTS: Normalized cortical volumes (NCV) were lower for both RR and PP MS patients than for normal control subjects (p < 0.001) but were similar between the two patient groups (p > 0.5). NCV decreases in both patients groups were detected even in those patients with short disease duration (<5 years; p < 0.001 in RR MS and p < 0.05 in PP MS) and minimal brain lesion volume (<5 mL; p < 0.0001 in RR MS and p < 0.005 in PP MS). Measures of NCV in individual patients were negatively correlated with T2-weighted lesion volume (r = -0.47, p < 0.001) and disease duration (r = -0.25, p < 0.05) only in the patients with RR MS. NCV correlated with Expanded Disability Status Scale scores across all of the patients, but the strength of the correlation was stronger (p < 0.05) for PP (r = -0.64, p < 0.0001) than for RR (r = -0.27, p = 0.04) MS patients. CONCLUSIONS: These data confirm substantial neocortical volume loss in MS patients and suggest that neocortical GM pathology may occur early in the course of the disease in both RR and PP MS patients and contribute significantly to neurologic impairment. Although a proportion of this neocortical pathology may be secondary to WM inflammation, the extent of the changes suggests that, especially in patients with PP MS, an independent neurodegenerative process also is active.

Adolescent↗

Evidence for widespread axonal damage at the earliest clinical stage of multiple sclerosis.

Although axonal pathology is recognized as one of the major pathological features of multiple sclerosis, it is less clear how early in its course it occurs and how it correlates with MRI-visible lesion loads. To assess this early axonal pathology, we quantified the concentration of whole-brain N-acetylaspartate (WBNAA) in a group of patients at the earliest clinical stage of the disease and compared the results with those from healthy controls. Conventional brain MRI and WBNAA using unlocalized proton magnetic resonance spectroscopy were obtained from 31 patients at presentation with clinically isolated syndromes suggestive of multiple sclerosis and paraclinical evidence of dissemination in space, and from 16 matched controls. An additional conventional MRI scan was obtained in all patients 4-6 months later to detect dissemination of lesions in time. The mean WBNAA concentration was significantly lower in patients compared with the controls (P < 0.0001). It was not significantly different between patients with and without enhancing lesions at the baseline MRI or between patients with and without lesion dissemination in time. No correlation was found between WBNAA concentrations and lesion volumes. Widespread axonal pathology, largely independent of MRI-visible inflammation and too extensive to be completely reversible, occurs in patients even at the earliest clinical stage of multiple sclerosis. This finding lessens the validity of the current concept that the axonal pathology of multiple sclerosis is the end-stage result of repeated inflammatory events, and argues strongly in favour of early neuroprotective intervention.

Adult↗

Effect of glatiramer acetate on MS lesions enhancing at different gadolinium doses.

This baseline-vs-treatment study of 20 patients with relapsing-remitting MS investigated whether glatiramer acetate (GA) has a graduated effect on MS inflammatory activity, which was measured using monthly, standard, and triple dose gadolinium (Gd)-enhanced MRI. GA significantly reduced the mean numbers of enhancing lesions/patient/month on both standard dose and triple dose scans, without interactions with the Gd dose. GA is effective in reducing MS activity, independent of the severity of the MRI-detectable inflammatory process.

Adolescent↗

Evidence for widespread movement-associated functional MRI changes in patients with PPMS.

BACKGROUND: Previous work has suggested that functional reorganization of cortical motor areas might have a role in limiting the motor deficits in patients with MS. OBJECTIVE: To test whether movement-associated cortical changes in MS might extend beyond the "classic" motor areas and involve sites for multimodal integration. METHODS: fMRI was used to assess patterns of brain activations associated with 3 different motor tasks in 30 right-handed patients with primary progressive MS (PPMS) and variable degrees of motor impairment, which were compared with those from 15 right-handed, sex- and age-matched control subjects. RESULTS: Compared with control subjects, patients with MS showed increased activation of brain regions within both traditional motor planning and execution regions (including the supplementary motor area and the cingulate motor area), the insula (a region implicated in sensory processing), and several multimodal cortical regions in the temporal, parietal, and occipital lobes. In patients, the extent of the fMRI activations was strongly correlated with MR lesion burden (r ranging from 0.70 to 0.86, p < 0.001). CONCLUSIONS: This study shows that movement-associated cortical activation in patients with PPMS is widely distributed and also involves multimodal "nonmotor" cortical networks. It also suggests that adaptive cortical reorganization might be one of the mechanisms limiting the clinical impact of MS in the progressive phases of the disease.

Adult↗

Correlations between structural CNS damage and functional MRI changes in primary progressive MS.

In patients with primary progressive multiple sclerosis (PPMS), we investigated whether brain and cervical cord structural changes in lesions and normal-appearing brain tissue (NABT), measured using conventional, magnetization transfer (MT), and diffusion tensor (DT) MRI, are correlated with movement-associated cortical activations measured using functional magnetic resonance imaging (fMRI). From 26 right-handed PPMS patients and 15 right-handed, sex- and age-matched healthy controls, we obtained: (a) brain and cervical cord dual-echo scans and MT ratio (MTR) maps; (b) brain mean diffusivity (D(-)) maps, and (c) f-MRI (flexion-extension of the last four fingers of the right hand). All PPMS patients had no previous symptoms affecting their right upper limbs, which were functionally normal. Healthy volunteers showed more significant activation in the ipsilateral cerebellar hemisphere than PPMS patients. PPMS patients showed greater activation bilaterally in the superior temporal gyrus, ipsilaterally in the middle frontal gyrus, and, contralaterally in the insula/claustrum. In PPMS patients, moderate to strong correlations (r values ranging from 0.59 to 0.68) were found between relative activations of cortical areas located in a widespread network for sensory-motor and multimodal integration and the severity of structural changes of the NABT (as measured using MT and DT MRI) and the severity of cervical cord damage (as measured using MT MRI). This study shows that the pattern of cortical activation of PPMS patients is different from that of normal controls even when performing a motor task with clinically unaffected limbs. It also suggests that cortical reorganization might be able to limit the consequences of MS injury in the brain and cervical cord.

Adult↗

Effect of hydrogen peroxide on antioxidant enzymes and metallothionein level in the digestive gland of Mytilus galloprovincialis. cavalett@unipmn.it.

The pro-oxidant effect of H2O2 at a concentration of 20 microM was examined in the digestive gland of Mytilus galloprovincialis, a bivalve mollusc frequently used in biomonitoring programs. The oxidative stress caused by H2O2 has been evaluated in terms of lipid peroxidation and lysosomal system alteration. Complex cellular antioxidant defence mechanisms of the mussel were investigated at the enzymatic and non-enzymatic level in order to explain their relative role in reducing the risk of oxidative injury. Metallothionein, glutathione, superoxide dismutase, catalase and glutathione peroxidase were assayed after 1, 4 and 7 days of exposure to H2O2. The metallothionein content showed an increase by 43% after 4 days of exposure, followed by a decrease back to control values at 7 days. Antioxidant enzyme activities followed a similar pattern with a moderate increase after 1 or 4 days of treatment and a return to control values at 7 days. All data indicate a 'transient' oxidative stress response, after which mussel cells restore the redox balance.

Animals↗

Autoantibodies in multiple sclerosis patients before and during IFN-beta 1b treatment: are they correlated with the occurrence of autoimmune diseases?

Autoimmune side effects, namely autoantibody (autoAb) occurrence and thyroid function alteration, have been described during interferon-beta (IFN-beta) treatment for multiple sclerosis (MS). AutoAb occurrence and autoimmune thyroid diseases are also frequently detected in MS patients free of any treatment. The aim of this study was to evaluate the relationship between IFN-beta 1b treatment, autoAb occurrence, and autoimmune diseases in MS. Thyroid and liver function and serum autoAb (antithyroid, antinuclear, anti-liver, anti-kidney microsomes, anti-smooth muscle and parietal cell antigens) occurrence were evaluated in 156 relapsing-remitting MS (RRMS) patients before and every 3 months after starting IFN-beta 1b treatment (8 MIU subcutaneously [s.c.] on alternate days). The probability of having liver or thyroid function alteration or autoAb occurrence was analyzed longitudinally with the generalized estimating equations (GEE) approach. At baseline, 16.1% of patients had autoAb. During treatment, autoAb occurred de novo in 7.2% of patients. GEE analysis showed that the probability of having autoAb at any time during IFN-beta 1b treatment did not change significantly compared with baseline. AutoAb occurring de novo rarely persisted during treatment and significantly less than those already present at baseline. Positivity for autoAb at baseline or during treatment was not correlated with the development of thyroid or liver function alteration during IFN-beta 1b treatment. Our study indicates that IFN-beta treatment is a safe treatment for MS patients, free of risk of autoimmunity and of associated liver or thyroid function alteration.

Adjuvants, Immunologic↗

Prospective study of multiple sclerosis with early onset.

Fifty-four subjects (36 females and 18 males) affected by clinically definite multiple sclerosis (MS) and with onset of the disease at 15 years of age or before were prospectively studied in five Italian MS centres. Female/male ratio was 4.7 in subjects with age > or = 12 years, suggesting a role of hormonal changes in triggering MS onset The mean follow-up duration was 10.9+/-5.6 years. The functional systems more frequently involved at onset were the pyramidal and brainstem (both in 28% of cases). The onset was monosymptomatic in 31 subjects (57%). The course was relapsing-remitting in 39 subjects (72%) and relapsing-progressive in 15 (28%). Disability was assessed by the Expanded Disability Status Scale (EDSS): the mean score after 8 years of follow up was 3.5 (+/-2.5). The score was <4 in 68% of cases, between 4 and 6 in 8% of cases, >6 in 24% of cases. Disability after 8 years was highly predicted by disability in the first year (p=0.008). There was a tendency to a worse prognosis in relation to the number of relapses in the first 2 years (p=0.08). The outcome was not influenced by the characteristics of symptoms at onset age and gender.

Adolescent↗

Liver and thyroid function and autoimmunity during interferon-beta 1b treatment for MS.

BACKGROUND: The occurrence or recurrence of autoimmune diseases or of autoantibodies (autoAb) has been reported during type I interferon (IFN) treatment. OBJECTIVE: To define the frequency of thyroid and liver dysfunction and of autoimmunity during IFN-beta 1b (IFNB) treatment of MS. METHODS: Prospective 1-year multicenter follow-up of 156 patients with MS recruited by 18 centers was conducted. Thyroid-stimulating hormone and anti-thyroid autoAb were measured by an immunoradiometric method, thyroid hormones by chromatographic assay, and non-organ-specific autoAb by indirect immunofluorescence. Tests were repeated every 3 months. The probability of having liver, thyroid, or autoAb alterations was analyzed longitudinally with the generalized estimating equations (GEE) method. RESULTS: Thyroid dysfunction was observed in 5.3% of cases at baseline and 8.3% de novo during IFNB treatment. GEE analysis showed that the probability of having thyroid alteration did not change significantly during treatment compared with baseline. Liver alteration was observed in 4.6% of cases at baseline and 37.5% de novo during IFNB treatment (p < 0.0001). GEE analysis showed that the probability of having liver alteration was higher (p < 0.002) at months 3 and 6 compared with baseline, returning to values similar to baseline by month 9. AutoAb were detected in 16.1% of patients at baseline and in 20% during IFNB. GEE analysis showed that the probability of having autoAb did not change significantly during treatment compared with baseline. Thyroid or liver alteration or autoAb occurring de novo during IFNB were usually transient. CONCLUSIONS: Differently from the frequency of liver function alteration (which significantly increased during the first months of IFNB treatment, suggesting a probable causal relationship with IFNB), the frequency of thyroid dysfunction or of autoimmunity showed random and insignificant changes over time, probably not related to IFNB treatment.

Adjuvants, Immunologic↗

Differential diagnosis of acute myelopathies.

Diagnosis of acute myelopathy applies to subjects with acute motor involvement, segmental sensory loss and sphincter dysfunction, reaching a maximum no later than 4 weeks after onset. Among the different causes of acute myelopathy (e.g. compressive, vascular, traumatic or toxic lesions, paraneoplastic involvement and electrical injury), acute myelitis due to infective agents or to an autoimmune-inflammatory process frequently causes problems relating to the differential diagnosis of multiple sclerosis (MS) and its potential risk of developing MS.

Acute Disease↗

Cranial nerve, brainstem and cerebellar syndromes in the differential diagnosis of multiple sclerosis.

A clinically isolated syndrome indicating a pathological process involving the cranial nerves or the posterior fossa may constitute a hard diagnostic challenge for the clinician. Whereas internuclear ophthalmoplegia, for example, is almost pathognomonic of multiple sclerosis (MS), other clinical presentations are often puzzling. The main alternative causes of symptoms that may suggest a clinical onset of MS are reviewed here, grouped in principal clinical syndromes, with particular attention to some rare, recently recognised conditions.

Brain Stem↗

Neurological manifestations of gastrointestinal disorders, with particular reference to the differential diagnosis of multiple sclerosis.

Neurological manifestations of gastrointestinal disorders are described, with particular reference to those resembling multiple sclerosis (MS) on clinical or MRI grounds. Patients with celiac disease can present cerebellar ataxia, progressive myoclonic ataxia, myelopathy, or cerebral, brainstem and peripheral nerve involvement. Antigliadin antibodies can be found in subjects with neurological dysfunction of unknown cause, particularly in sporadic cerebellar ataxia ("gluten ataxia"). Patients with Whipple's disease can develop mental and psychiatric changes, supranuclear gaze palsy, upper motoneuron signs, hypothalamic dysfunction, cranial nerve abnormalities, seizures, ataxia, myorhythmia and sensory deficits. Neurological manifestations can complicate inflammatory bowel disease (e.g. ulcerative colitis and Crohn's disease) due to vascular or vasculitic mechanisms. Cases with both Crohn's disease and MS or cerebral vasculitis are described. Epilepsy, chronic inflammatory polyneuropathy, muscle involvement and myasthenia gravis are also reported. The central nervous system can be affected in patients with hepatitis C virus (HCV) infection because of vasculitis associated with HCV-related cryoglobulinemia. Mitochondrial neurogastrointestinal encephalopathy (MNGIE) is a disease caused by multiple deletions of mitochondrial DNA. It is characterized by peripheral neuropathy, ophthalmoplegia, deafness, leukoencephalopathy, and gastrointestinal symptoms due to visceral neuropathy. Neurological manifestations can be the consequence of vitamin B1, nicotinamide, vitamin B12, vitamin D, or vitamin E deficiency and from nutritional deficiency states following gastric surgery.

Celiac Disease↗

In vivo assessment of the brain and cervical cord pathology of patients with primary progressive multiple sclerosis.

In patients with primary progressive (PP) multiple sclerosis, brain MRI lesion activity and burden are low, despite the presence of severe neurological impairment. On the contrary, the degree of cord atrophy and diffuse tissue damage in the brain and cervical cord have been found to be associated with clinical disability. Against this background, this study aimed at providing an in vivo indirect assessment of brain and cervical cord pathology in a large cohort of PP multiple sclerosis patients, using conventional MRI and magnetization transfer imaging (MTI). Ninety-one PP multiple sclerosis patients, 36 secondary progressive (SP) multiple sclerosis patients and 30 healthy controls underwent brain and cervical cord MRI scans, using dual echo (brain) or fast short-tau inversion recovery (cervical cord) MTI and T(1)-weighted sequences. For the brain, T(2) hyperintense and T(1) hypointense lesion volumes were calculated and the volume of the whole of the brain tissue measured. For the cervical cord, the number and burden of lesions and the cross-sectional area were assessed. MTI scans were post-processed and analysed to obtain magnetization transfer ratio (MTR) histograms from the whole of the brain and cervical cord tissue and from the normal-appearing brain tissue in isolation. In PP multiple sclerosis patients, brain, normal-appearing brain tissue and cervical cord MTR histogram-derived metrics revealed the presence of diffuse tissue damage whose characteristics did not significantly differ from those of SP multiple sclerosis patients, even though SP multiple sclerosis patients had higher MRI-visible lesion burdens. None of the correlations between MRI or MTI measures obtained from the brain and the cord were significant. PP multiple sclerosis patients' disability was significantly, albeit weakly associated with a composite MR model including measures of loss and intrinsic damage of cervical cord tissue. Our data indicate the presence of a diffuse tissue damage undetectable by conventional MRI in PP multiple sclerosis patients, whose extent seems to match that of SP multiple sclerosis patients with similar levels of disability. They also suggest that the severity of multiple sclerosis pathology in the cervical cord is one of the factors contributing to neurological impairment in PP multiple sclerosis.

Adult↗

Magnetic resonance imaging, magnetisation transfer imaging, and diffusion weighted imaging correlates of optic nerve, brain, and cervical cord damage in Leber's hereditary optic neuropathy.

OBJECTIVES: Leber's hereditary optic neuropathy (LHON) is a mitochondrial disease leading to bilateral loss of central vision and severe optic nerve atrophy. A subtype of LHON presents additional clinical and MRI aspects indistinguishable from those of multiple sclerosis (MS) (LHON-MS). In patients with LHON or LHON-MS, an assessment was made of (a) the severity of optic nerve damage, using MRI and magnetisation transfer imaging (MTI), and (b) the presence and extent of macroscopic and microscopic pathology in the brain and cervical cord, using MRI and MT ratio (MTR) and mean diffusivity (D) histogram analysis. METHODS: Ten patients with LHON, four with LHON-MS, and 20 age and sex matched healthy controls were studied. For the optic nerve and the brain, dual-echo turbo spin echo (TSE), T1 weighted spin echo, and MT images were obtained. For the brain, fast fluid attenuated inversion recovery (fast FLAIR) and diffusion weighted images were also obtained. For the cervical cord, fast short tau inversion recovery (STIR) and MT images were obtained. The volume and the average MTR value of both the optic nerves were measured. MTR and histograms of the normal appearing brain tissue (NABT) and MTR histograms of the whole cervical cord tissue were created. RESULTS: The mean values of optic nerve volumes and MTR were significantly lower in patients with LHON than in healthy controls. Mean NABT-MTR histogram peak height was significantly lower in patients with LHON than in controls, whereas no significant difference was found for any of the cervical cord MTR histogram derived measures. Average diffusivity (D) was higher in patients with LHON than in controls. Optic nerve volume and MTR value and mean NABT-MTR were lower in patients with LHON-MS than in those with LHON. CONCLUSIONS: The severity of optic nerve pathology in LHON is measurable in vivo using MRI and MTI. MTR and histogram analysis suggests that microscopic brain damage occurs in LHON and that it is more severe in the MS-like form of the disease.

Adult↗

Thyroid function and autoimmunity during interferon beta-1b treatment: a multicenter prospective study.

Thyroid dysfunction and autoimmunity have been reported during type I interferon therapy, namely interferon-alpha for chronic hepatitis or interferon-beta for multiple sclerosis. To define the frequency of thyroid dysfunction and autoimmunity during interferon-beta treatment, 156 multiple sclerosis patients were prospectively followed up by 18 centers for 1 yr after starting interferon-beta-1b treatment. Serial clinical assessments and tests of thyroid and liver function and antithyroid autoantibodies (all performed by the same centralized laboratory) were conducted every 3 months. TSH and antithyroid autoantibodies against human TG or thyroid microsomal antigens were measured by immunoradiometric methods; free T3 and T4 were measured by chromatographic assays. Longitudinal occurrence of thyroid or liver alterations or of autoantibodies was analyzed with the generalized estimating equations method, correcting for the correlation of repeated measurements of the same subject over time. Pretreatment comparison with a control group of 437 healthy blood donors did not show significant differences in the frequency of thyroid dysfunction or antithyroid autoantibody positivity. During interferon-beta treatment, the de novo frequency of thyroid alteration was 8.3%, that of liver alteration was 37.5%, and that of antithyroid autoantibody was 4.5%. Generalized estimating equations analysis demonstrated that the frequency of liver alteration significantly increased during treatment compared with the baseline value (odds ratio, 7.03; confidence interval, 2.49-19.9), whereas that of thyroid alteration or of antithyroid autoantibodies did not. The frequency of thyroid dysfunction during interferon-beta treatment showed random, nonsignificant changes over time and, in addition, was not correlated to antithyroid autoantibody positivity.

Adolescent↗

Mortality for liver disease in patients with HIV infection: a cohort study.

We undertook this study to assess the association between the various potential causes of liver disease in HIV-seropositive patients and mortality due to liver failure. Three hundred and eight in-hospital deaths were observed from 1987 to December 1995 in a prospectively followed cohort of 1894 HIV-seropositive patients. For each study subject, clinical data were evaluated to assess whether liver failure had substantially contributed to mortality. A case control study nested in the cohort was then performed, which compared demographic and clinical variables observed at enrollment and during follow-up between patients who died for liver disease as the main or concurrent cause of death (cases) and those who died as a result of illness related to AIDS or other causes (controls). Among 308 in-hospital deaths, liver failure was found the cause of death in 35 patients (12%); in 16 cases, it was the primary cause and in 19 cases it was concurrent. Multivariate analysis showed that in-hospital liver-disease-related mortality was independently associated with hepatitis B surface antigen reactivity (odds ratio [OR], 9; 95% confidence interval [CI], 3.8-21.7) and history of alcohol abuse (OR, 2.3; 95% CI, 1-5.2). Prevention and treatment of hepatitis B virus infection and alcohol intake are management priorities in HIV-seropositive patients.

Acquired Immunodeficiency Syndrome↗

The prognostic value of age, gender, pregnancy and endocrine factors in multiple sclerosis.

The evolution of multiple sclerosis at the time of diagnosis remains unpredictable since a reliable prognostic marker is not yet available. Nevertheless, a series of useful prognostic indicators have been singled out from epidemiological studies. Young age at onset, female gender, relapsing/remitting course, and sensitive or visual disturbances as initial symptoms are considered favourable prognostic factors. Conversely, late age at onset, male gender, progressive course, and pyramidal or cerebellar symptoms at the first episode predict an unfavourable evolution. Another prognostic indicator has been recognized in pregnancy: although the overall effect of pregnancy on short-term MS course is neutral, in the long-term it seems to protect from disease progression. Most prognostic indicators seem to act through the neuro-endocrine-immune network, modulating the immune response in the context of the Th1/Th2 paradigm.

Adult↗