Risk of skin cancer after ultraviolet phototherapy in patients with vitiligo: a systematic review and meta-analysis.

BACKGROUND: Although ultraviolet (UV) phototherapy is an effective treatment for vitiligo, its effect on the risk of skin cancer remains controversial. AIM: To investigate the association between UV phototherapy and skin cancer risk in patients with vitiligo. METHODS: A systematic review was performed for studies published before 5 May 2021 in the PubMed, Embase, Web of Science and Cochrane Library databases. The primary outcome was the association of UV phototherapy with the risk of skin cancer in patients with vitiligo. A meta-analysis with a random-effects model was conducted. RESULTS: Five retrospective cohort studies covering a total of 228 607 patients with vitiligo (110 038 who had been treated with UV phototherapy and 118 569 patients who had not) were included in the meta-analysis. The risk of nonmelanoma skin cancer [Mantel-Haenszel risk ratio (MHRR) = 0.95; 95% CI 0.44-2.05] and melanoma (MHRR = 1.11; 95% CI 0.33-3.82) did not significantly increase after phototherapy in patients with vitiligo. In the subgroup analysis, we also found no significant association between phototherapy with narrowband UVB phototherapy specifically and risk of skin cancer in patients with vitiligo. There was no significant difference in risk of skin cancer between patients from Europe and those from East Asia and the risk was not affected by the number of narrowband UVB phototherapy sessions. CONCLUSIONS: The findings of this systematic review and meta-analysis suggest that UV phototherapy is a safe treatment for vitiligo with no significant risk of skin cancer.

Distribution of contaminants in biota and sediments in the Musquash Estuary, Atlantic Canada, marine protected area site initiative and contaminant exclusion zone.

The Musquash Estuary, one of the last ecologically intact estuaries in New Brunswick, has been designated an area of interest for a marine protected area (MPA) under the Oceans Act. The area has been assessed for contaminant background levels as required for establishing MPA environmental quality. American lobster (Homarus americanus), blue mussel (Mytilus edulis) and sediments were collected for assessing contaminant levels and distribution in the harbour. Levels of contaminants from the indicator species and the abiotic component have shown: (1) two extremes of high and low Cu and Ag in lobster from the area; and (2) lower metal levels in inner Musquash Harbour sediments and mussels than in those from the harbour mouth. These suggest that deposition of contaminants into the Musquash MPA site was due to transport of contaminants by coastal currents from upstream coastal industrial activities. This reverse trend with higher contaminant levels in the biotic and abiotic components in the outer harbour than in the inner harbour differs from a contaminated harbour and suggests that a contaminant exclusion zone should be considered for controlling contamination from nearby coastal and estuarine industrial sites to protect the sensitive habitats within the marine protected area.

Selection of bioindicators for monitoring marine environmental quality in the Bay of Fundy, Atlantic Canada.

Distribution of metals, PAH's and PCB's in lobsters, mussels, and sediments were used to assess marine environmental quality of the Bay of Fundy. This study demonstrates that the lobster (Homarus americanus) is a better bioindicator for monitoring contaminants in the marine environment and has a greater capacity for the uptake and accumulation of contaminants than the mussel (Mytilus edulis) and sediments. A definite pattern in the spatial distribution of lobster Cu, Cd, and Ag was evident. The distribution of organic contaminants for both mussels and lobsters in the Bay of Fundy lacked a spatial trend, and organic contaminants were undetectable in sediments from all sites. The Gulf Watch Programme, which monitors chemicals in mussels in the Bay of Fundy, did not indicate a problem with high levels of Cu, Cd, and Zn in the ecosystem. Analytes below the detection limit, such as in mussels and sediments, increase the difficulties of chemical analysis and detection for environmental monitoring. Deficiencies of mussels in monitoring the Bay of Fundy were discussed.

Metal contaminants for modelling lobster (Homarus americanus) migration patterns in the Inner Bay of Fundy, Atlantic Canada.

A method, which uses metal compositions in lobster digestive glands as natural environmental tags, has been developed to trace lobster movements. Lobsters were collected from three selected sites, Minas Channel, Minas Basin, and Cobequid Bay, Inner Bay of Fundy, New Brunswick, Canada, that were known to be contaminated with Cu. Five metal variables (Ag, Cd, Cu, Mn and Zn) were processed for principal component analysis (PCA). Metal concentration and burden models were investigated and PCA was able to differentiate lobsters from the respective catch sites. The method was applied to investigate the May and June lobsters collected at the three sites to determine the migration rate during this period of the fishing season. The results show a high level of mixing at Minas Basin and Cobequid Bay in June, and lobster movement inward toward the inner reaches of the bay, with very limited movement outward from the inner bay.

Aquaculture-related trace metals in sediments and lobsters and relevance to environmental monitoring program ratings for near-field effects.

The study was undertaken to assess the marine environmental effects from feed and waste associated with aquaculture activities. Metal compositions of sediment, lobster, and feed were used to evaluate the extent of detectable effects at 0 m (under the cage) and 50 m distance. Sediments that were collected under the cages and were characterised as hypoxic or anoxic, showed elevated levels of Cu, Zn, organic carbon, and % <63 microm particles, and low Mn and Fe. At 50 m there was a major reduction in waste chemical impact. Using lobster, a bioindicator species, as a tool for detecting near-field impacts, showed accumulations of high Cu associated with active aquaculture sites. Chemical compositions and metal ratios normalised with organic carbon, were used to assess the sediment conditions associated with environmental monitoring program ratings (EMP--normal, hypoxic, and anoxic). Principal component analysis (PCA) was used to explore chemical data at all sites for differentiating normal, hypoxic and anoxic sediment conditions. Selected variables (Cu, Zn, Fe, Mn, organic carbon, and particles <63 microm) were sufficient for the PCA approach with >90% explainable variance of first two components. The groupings based on PCA and cluster analysis were similar to EMP classifications with some exceptions of mis-identification by EMP. The sediment chemistry components were valid indicators for evaluating marine environmental conditions and for assessing aquaculture operating sites. The developed techniques, using chemical variables in combination with EMP and the statistical approach should be useful to predict the effects of aquaculture practices and the suitability of aquaculture operations.

Effects of a continuous infusion of dopamine on the ventilatory and carotid body responses to hypoxia in cats.

1. We investigated how a continuous infusion of dopamine (DA; 5 micrograms/kg per min), which is often used clinically, would affect the ventilation and carotid chemoreceptor neural activity in anaesthetized cats. 2. In anaesthetized, spontaneously breathing cats, tidal volume (VT) and respiratory frequency (f) were continuously monitored at five levels of inspired oxygen (PIO2 = 110, 130, 150, 170, 760 mmHg) during Da or saline infusion. VT and f were sampled for 1 min after 3 min exposure to each level of PIO2. Time control study was also performed. 3. DA infusion significantly lowered VT under both normoxia and hypoxia in seven of eight cats. Respiratory frequency was not affected by DA infusion. Depression of ventilation during post-hypoxic hyperoxia was augmented by DA infusion. Chemodenervation abolished the ventilatory response to hypoxia and DA did not further affect the ventilatory response to hypoxia. 4. In a second group of artificially ventilated cats, carotid chemoreceptor neural activity was recorded at five levels of arterial oxygen tension. DA infusion significantly depressed carotid chemoreceptor neural activity during normoxia and hypoxia in six of seven cats. 5. These findings suggest that changes in ventilation during low dosage of DA infusion closely correlate with carotid body neural output. A predominant effect of this dosage of DA (5 micrograms/kg per min) was depression in the ventilatory response to hypoxia due to an inhibition of carotid body neural output.

Isolation and characterization of metal-binding proteins (metallothioneins) from lobster digestive gland (Homarus americanus).

Two metallothionein (low-molecular-weight, metal-binding proteins) preparations, MT-1 and MT-2, have been isolated from the digestive gland of American lobster (Homarus americanus) contaminated with Cd. MT-1 contains Cd- and Cu-binding proteins, whereas MT-2 is a reasonably pure Cd-binding protein. The properties of MT-1 and MT-2 with respect to amino acid and elemental compositions, heat stabilities, polarographic, high-performance liquid chromatography (HPLC), and isoelectric focussing behaviors are reported. Lobster metallothioneins share a number of similarities with mammalian metallothioneins with respect to the presence of Cd and Cu, apparent molecular weights, amino acid compositions, UV absorption spectra at various pH, and polarographic behavior, but differ substantially in their electrophoretic behavior.

The reactivity of EDTA, copper ion, and copper citrate with metallothioneins isolated from the digestive gland of cadmium-contaminated lobster (Homarus americanus).

The reactivity of EDTA, Cu2+, and copper citrate with two metallothionein preparations (MT-1 and MT-2) isolated from the digestive gland of Cd-contaminated American lobster (Homarus americanus) was studied. Under pseudo-first-order conditions, metallothioneins reacted with EDTA for removal of Cd2+ in a multiphasic manner. Cadmium(+II) removal by Cu2+ was complex and non-stoichiometric, suggesting different binding sites. Rabbit liver metallothionein reacted similarly. Cadmium removal from lobster metallothionein by copper citrate was slow and triphasic in nature. EDTA removed Cu2+ from lobster metallothionein very slowly.

Dimethylthiourea decreases acute pulmonary edema induced by phorbol myristate acetate in isolated blood-perfused lung of the rat.

Acute pulmonary edema can be induced by phorbol myristate acetate (PMA). Oxygen radicals released from the neutrophils have been considered to play an important role in the pathogenesis of PMA-induced pulmonary edema. In the present experiment, we studied the effect of dimethylthiourea (DMTU) on PMA-induced pulmonary injuries in isolated perfused lungs of rats. DMTU is a potent scavenger of the hydroxyl radical and hydrogen peroxide. PMA infusion into the isolated lung increased pulmonary arterial pressure (delta PAP) by 37.8 +/- 3.9 mmHg. The lung weight gain (LWG) and lavage albumin concentration (LAC) amounted to 6.2 +/- 1.2 g and 102.0 +/- 22.9 mg/dl, respectively. DMTU (100 mM) pretreatment significantly reduced the PAP increase (delta PAP = 4.6 +/- 0.8 mmHg, p less than 0.001), LWG (0.3 +/- 0.1 g, p less than 0.01) and LAC (25.3 +/- 1.7 mg/dl, p less than 0.01). Additional in vitro experiments demonstrated that DMTU depressed the chemiluminescence released from neutrophils activated by PMA (17.9 +/- 2.6 mV.min to 2.6 +/- 0.5 mV.min, p less than 0.01). The results suggest that DMTU, a scavenger of toxic radicals, decreases the lung edema through both attenuation of pulmonary hypertension and protection of vascular permeability from PMA injury.