Is cysteamine use effective in the treatment of melasma? A systematic review and meta-analysis

Melasma is a recurrent hypermelanosis disorder characterized by the appearance of brownish and symmetrical spots on the skin. It affects the quality of life and is resistant to available treatment approaches. Cysteamine has been reported as a promising depigmenting agent for melasma treatment and following formulation enhancement, its use is being reported. This review aimed to evaluate the efficacy of the use of depigmenting formulations containing 5% cysteamine in the treatment of patients with melasma. A systematic search was performed in PubMed, Science Direct, and Scielo databases until December 27, 2021, based on criteria selected by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Statistical analysis was performed with Review Manager 5.4 software. The risk of bias was assessed using the Cochrane Risk of Bias Tool for Randomized Trials. A total of six studies containing 120 melasma patients treated with 5% cysteamine were included in this meta-analysis. The meta-analysis demonstrated that 5% cysteamine is effective for the treatment of patients with melasma (MD 6.26 [95% CI 3.68-8.83], p < 0.0001, I²  = 86%). In this review, through meta-analysis allows concluding that 5% cysteamine is effective in the treatment of melasma and presents a low probability of side or adverse effects.

Acute Toxicity and Sub-lethal Effects of the Essential Oil of Aristolochia trilobata and Its Major Constituents on Nasutitermes corniger (Termitidae: Nasutitermitinae)

Nasutitermes corniger (Motschulsky, 1855) (Termitidae: Nasutitermitinae) is an important pest in urban environments and bioinsecticides can be an alternative to its control. Here, we determined the toxicity and repellence of the essential oil (EO) prepared from stems of Aristolochia trilobata L. (Aristolochiaceae) and its major constituents on N. corniger. We also investigated behavioral changes of individuals exposed to limonene. The lethal dose required to kill 50% of N. corniger population (LD₅₀) of EO of A. trilobata was 2.44 μg mg^-1. Limonene was the most toxic compound to N. corniger followed by linalool (LD₅₀ = 1.02 and 1.29 μg mg^-1, respectively). In addition, all treatments presented median lethal time (LT₅₀) less than 11 h. A. trilobata EO and its constituents showed irritability activity, but only limonene repelled soldiers more than workers. The negative behaviors of N. corniger groups were higher in individuals treated with limonene. A. trilobata EO and its constituents, especially the limonene, are promising for the control of N. corniger due the high toxicity, repellence, and possible disturbance in the colonies.

Lethal Effect and Behavioral Responses of Leaf-Cutting Ants to Essential Oil of Pogostemon cablin (Lamiaceae) and Its Nanoformulation

Leaf-cutting ants belonging to the genus Atta (Formicidae: Myrmicinae) are important pests in agricultural and forest environments. In the present study, we evaluated the formicidal activity of the essential oil of Pogostemon cablin and its nanoformulation on the leaf-cutting ants: Atta opaciceps (Borgmeier, 1939), Atta sexdens (Linnaeus, 1758), and Atta sexdens rubropilosa Forel, 1908. The nanoformulation was developed by magnetic stirring using polyoxyethylene (36%), pure ethanol (36%), essential oil of P. cablin (18%), and water (10%). Bioassays of acute toxicity by fumigation and behavioral bioassays in treated arenas, with and without choice, were performed. The essential oil of P. cablin and its nanoformulation demonstrated efficient insecticidal activity and irritability to ant species. The concentration required to kill 50% of workers varied from 1.06 to 2.10 μL L^-1, with a mean time to death of less than or equal to 42 h. The essential oil of P. cablin and its nanoformulation reduced the displacement and velocity speed of the workers of A. opaciceps and A. sexdens rubropilosa in totally treated arenas. In the bioassays with choices, the three species of ants walked less and at a greater speed on the treated side of arena. This work demonstrates the potential of the essential oil of P. cablin and its nanoformulation to the generation of new formicidal products.

Sub-lethal effects of essential oil of Lippia sidoides on drywood termite Cryptotermes brevis (Blattodea: Termitoidea)

The drywood termite Cryptotermes brevis (Walker, 1853) (Kalotermitidae) is one of the most important wood structural pest in the world. Substances from the secondary metabolism of plants (e.g., essential oils) have been considered an environmentally safer form of control for urban pests, such as termites. In the present study, we analyzed the lethal and sub-lethal effects of essential oil of Lippia sidoides and its major components on C. brevis pseudergates in two routes of exposure (contact and fumigation). The essential oil of L. sidoides and thymol were more toxic to C. brevis pseudergates when applied by contact (LD₅₀ = 9.33 and 8.20µgmg^-1, respectively) and by fumigation (LC₅₀ = 9.10 and 23.6µLL^-1, respectively). In general, treatments changed the individual and collective behaviors of C. brevis pseudergates, as well as the displacement and walking speed. The essential oil of L. sidoides and its major components showed a high potential to control C. brevis pseudergates, due to the bioactivity in the two routes of exposure and the sub-lethal effects on the behavior and walking, important activities for the cohesion of C. brevis colonies.

Plasmacytoma of the urethra treated by excisional biopsy

Plasmacytoma is an unusual disease of plasma cells, its presentation in the urethra is rare. We report the sixth known case of primary urethral plasmacytoma, which was treated by surgical excision, without recurrence for 3 years of follow-up.

Neurochemical effects of L-pyroglutamic acid

The effect of L-pyroglutamic acid, a metabolite that accumulates in pyroglutamic aciduria, on different neurochemical parameters was investigated in adult male Wistar rats. Glutamate binding, adenylate cyclase activity and G protein coupling to adenylate cyclase were assayed in the presence of the acid. L-pyroglutamic acid decreased Na(+)-dependent and Na(+)-independent glutamate binding. Basal and GMP-PNP stimulated adenylate cyclase activity were not affected by the acid. Furthermore, rats received unilateral intrastriatal injections of 10-300 nmol of buffered L-pyroglutamic acid. Vehicle (0.25 M Tris-Cl, pH 7.35-7.4) was injected into the contralateral striatum. Neurotoxic damage was assessed seven days after the injection by histological examination and by weighing both cerebral hemispheres. No difference in histology or weight could be identified between hemispheres. These results suggest that, although capable of interfering with glutamate binding, pyroglutamate did not cause a major lesion in the present model of neurotoxicity.

Multicentric granular cell tumor of the colon: report of a patient with 52 tumors

Granular cell myoblastoma is an uncommon benign tumor that can be located anywhere in the body. Multiple tumors of the gastrointestinal tract are quite rare, having been reported infrequently in the English literature. The histologic, immunohistochemical, and electron microscopic findings in our case, as well as in others reported, suggest that its histogenesis may be related to Schwann cells. One case of multifocal granular cell tumor presenting 52 tumors from the cecum to the sigmoid is described, and the previously reported cases with similar presentation are reviewed. We suggest that in such cases, a long period of observation with repeated colonoscopy may be more appropriate than an aggressive approach.

Small cell carcinoma of the esophagus. Clinicopathological and immunohistochemical findings in four cases

Small cell carcinoma of the esophagus is an uncommon neoplasm. The authors report the clinicopathologic and immunohistochemical findings in four cases. Dysphagia was the most frequent symptom at presentation. Only one patient was treated by surgery; the other did not receive any treatment. Histologically, three were oat-cell type tumors with areas of intermediate cell type. Combined cell type was not present. Immunohistochemistry demonstrated positivity for neuron-specific enolase and for chromogranin in all four cases. One case was a double primary carcinoma, a squamous cell carcinoma and a small cell carcinoma.

Pancreatic metastasis from renal cell carcinoma

We report a case of renal cell carcinoma that metastasized to the pancreas 7 years after the initial excision. The primary and the metastatic tumors were histologically similar. Upper gastrointestinal bleeding was the leading symptom in the present case and the cause of the patient's death.

[Prevalence of the various types of gastritis in patients with upper dyspeptic symptoms]

Multiple site biopsy specimens from 153 patients were examined retrospectively for the presence of gastritis and Helicobacter-like organisms (HLO). Chronic gastritis was classified as superficial gastritis, diffuse antral gastritis, postgastrectomy (reflux) gastritis, diffuse corporal atrophic gastritis, and multifocal atrophic gastritis. In some cases technical problems did not make possible to define the type of chronic gastritis and we introduce the terms unclassified gastritis and minimal inflammatory changes to name those cases. In our opinion they represent superficial biopsies from cases of diffuse antral gastritis. Diffuse antral gastritis was found in 60% of patients followed by multifocal atrophic gastritis found in 20% of patients. HLO was searched in histological sections stained by a modified Giemsa stain. The typical curved bacilli were seen in the gastric mucus or closely attached to the top of superficial or foveolar epithelial cells in 83% of patients. Although we have noted high correlation between activity of chronic gastritis and infection by HLO such correlation was not possible between the degree of activity and the degree of infection.

Carcinoma cuniculatum originating from intertriginous lesions

Three cases of long-standing carcinoma cuniculatum originating from intertriginous lesions, which resembled athlete's foot in their initial stages, were reported. The authors suggest cutaneous malignancy to be considered in the differential diagnosis of intertriginous lesions unresponsive to usual therapeutic measures.

[Aortic-esophageal fistula caused by inflammatory pseudotumor of the esophagus]

A 56-year-old, otherwise healthy man died in operative room from a massive esophageal hemorrhage, one week after a single episode of postprandial odynophagia. Surgical specimen of the esophagus and the aorta showed a fistulous tract extending from an esophageal tumoral mass to the aorta. Histological examination disclosed the microscopic finding of the so-called inflammatory pseudotumor of the esophagus (IPT). To our knowledge, this is the first reported case of such unusual complication of IPT, resulting in fatal gastrointestinal bleeding.

[Hepatic cell adenoma and peliosis hepatis in women using oral contraceptives]

A case of hepatic cell adenoma associated with peliosis hepatis is reported. Both these conditions developed in a 41 year-old woman after the patient was under oral contraceptive therapy for 13 years. The relation between the use of oral contraceptives and these hepatic conditions are briefly discussed.

[Epidermoid carcinoma of the stomach]

A case of pure squamous cell carcinoma of the stomach in a 63-year-old woman has been reported. The tumor was located in pyloric antrum and histologic examination disclosed a well differentiated squamous cell carcinoma, with many horn pearls. Histogenesis of similar cases of this unusual tumor have been briefly discussed.

Epithelioma cuniculatum, a verrucous carcinoma of the foot. Report of 2 cases

Epithelioma cuniculatum, a rare form of squamous cell carcinoma affecting the sole of the foot, was observed in 2 male patients aged 62 and 69 years, respectively. In each case the lesion consisted of a fungating mass with sinuses draining foul-smelling fluid with keratin debris.