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PubMed1993

A comparison of the ultrastructure of pigment granules in melanosis ilei and pulmonary lymph nodes.

Two cases of melanosis ilei were studied, in which grossly visible blackish pigmentation of the ileal mucosa was incidentally discovered at autopsy. Light microscopy showed that the pigment granules lay within macrophages in atrophic Peyer's patches. Ultrastructural studies showed that the pigment granules were heterolysosomes containing crystalline material, particles, granules and, occasionally, lipid droplets. The morphological similarity between these pigment granules and granules in pulmonary macrophages was established through ultrastructural studies of pulmonary lymph nodes obtained during routine autopsies. These data, plus results of past electron-probe X-ray analytic studies by us and others, leads us to conclude that the pigment granules in melanosis ilei contain exogenous material derived from inspired and ingested materials.

Adult↗

PubMed1982

Pigment mutations in the mouse which also affect lysosomal functions lead to suppressed natural killer cell activity.

The impact of five pigment mutations in the mouse on natural killer (NK) activity was examined in inbred strains congenic for the respective mutation. Whereas the nature of pigmentation disorder was similar in the five mutant strains (beige, pallid, reduced pigmentation, pale ear, and sepia), all mutations except sepia also led to a significant change in lysosomal enzyme activities in the kidney. A significant reduction in NK activity was observed in the four strains with lysosomal impact, whereas homozygous sepia mice displayed normal NK activity. The pigment mutations analysed are located on different chromosomes and fail to cross-interact negatively with each other in the heterozygous mice. This would indicate that pigment mutations with a parallel impact on lysosomal enzyme activities probably always result in a reduction in natural killer cell activity.

Animals↗

PubMed1975

Isolation and identification of the urinary pigment uroerythrin.

The red pigment uroerythrin, a chromophore known to be adsorbed by the amorphous urate sediments (sedimentum lateritium), has been isolated from human urine and further purified as its trimethyl derivative. Urine was applied to a column of Amberlite XAD-2 resin on which uroerythrin and other pigments were adsorbed. The pigments were eluted with methanol and uroerythrin was further purified by extraction with ether at pH 4.0, repeated chromatography on lipophilic Sephadex LH-20 and thin-layer chromatography on silica gel. For optimal purification uroerythrin was converted into the trimethyl derivative and chromatographed on silical gel thin-layer plates. The structure of the pigment has been studied by chromate degradation followed by identification of the imide products by thin-layer chromatography. From these results and from infrared, mass spectral and nuclear magnetic resonance data a tripyrrole structure for uroerythrin is concluded. The proposed structure for the chromophore is related to that of the bile pigment biliverdin consisting, however, only of the rings A, B and C.

Chromatography, Ion Exchange↗

PubMedDate not supplied

Significance of different conjugate forms of bilirubin in the formation of pigment gallstones.

The aim of the present study was to analyse bile samples from cases with gallstones by high performance liquid chromatography according to the type of stones present, with special reference to the glucoside and xyloside conjugates of bilirubin, and to investigate their deconjugation. The composition of bilirubin conjugates in bile was similar between cholesterol and black pigment stones except that the total bilirubin concentration was about 5 times higher in black pigment stone cases with haemolysis. Unconjugated bilirubin was higher in brown pigment stone cases than in cholesterol stone cases, although total bilirubin concentration was lower in the former. In addition, in brown pigment stone cases, bile contained statistically less bilirubin diglucuronide and more bilirubin diglucoside and monoglucoside than in bile with cholesterol stones (P less than 0.05). Glucoside and xyloside conjugates are also major components, regardless of the types of gallstones present, accounting for as much as 18 to 25%. Incubation experiment revealed that bilirubin diglucuronide was more readily deconjugated than bilirubin diglucoside or bilirubin monoglucoside monoxyloside. Therefore, glucuronide conjugates were likely to be the main source of unconjugated bilirubin in the formation of pigment gallstones.

Bile↗

PubMed1993

Retinal projections to the pretectum, accessory optic system and superior colliculus in pigmented and albino ferrets.

Retinal projections to the pretectal nuclei, accessory optic system and superior colliculus in pigmented and albino ferrets were studied using anterograde tracing techniques. Both Nissl- and myelin-stained material was used to identify the pretectal nuclei, nuclei of the accessory optic system and the layers of the superior colliculus. Following monocular injection of either horseradish peroxidase or rhodamine-B-isothiocyanate, four pretectal nuclei, including the nucleus of the optic tract, posterior pretectal nucleus, anterior pretectal nucleus and the olivary pretectal nucleus, could be identified to receive direct retinal input in both pigmented and albino strains. In the accessory optic system, retinal terminals were observed in the dorsal, lateral and medial terminal nuclei as well as in the interstitial nucleus of the superior fasciculus, posterior fibres. The retinal projection to the superior colliculus was found to innervate the three superficial layers. The retinal projections to the pretectal nuclei and nuclei of the accessory optic system in the pigmented animals were bilateral, although the label was most dense contralateral to the injected eye. Ipsilateral retinal projections to the pretectal nuclei and nuclei of the accessory optic system appeared to be absent in albino ferrets, i.e. they were invisible with our methods. In both pigmented and albino ferrets retinal terminals in the contralateral superior colliculus densely innervated the three superficial layers. In both strains the ipsilateral projection appeared as clusters which were absent in rostral and caudal poles. In pigmented animals the ipsilateral projection was much denser and more extensive than in albinos. Following injection of retrograde tracers into the brainstem at the level of the dorsal cap of the inferior olive, retrogradely labelled neurons in the pretectum were found in the ipsilateral nucleus of the optic tract. Their somata overlapped mainly with scattered retinal terminals close to the pretectal surface and rarely or not all with the deeper prominent terminal clusters. In the accessory optic system, inferior olive projecting neurons were observed in all four ipsilateral nuclei and fully coincided with the retino-recipient zones. In the superior colliculus, retrogradely labelled neurons were found contralateral to the injection site in the deep layers.

Albinism↗

PubMed1997

Pigmented epithelium sustains cell proliferation and decreases expression of opsins and acetylcholinesterase in reaggregated chicken retinospheroids.

We investigated the effect of the retinal pigmented epithelium on cell proliferation and differentiation in rosetted retinospheroids, which are retina-like spheres reaggregated in the complete absence of retinal pigmented epithelium from dissociated retinal cells of 6-day-old chick embryos in a rotation culture system. In spheroids raised in the absence of retinal pigmented epithelium (controls), acetylcholinesterase was expressed in cells of an inner nuclear-like layer and their neuropil matrices. Moreover, the ratio between rods and cones was found to be approximately normal throughout the spheroid. When spheroids were cultured in the presence of retinal pigmented epithelium monolayers, cell proliferation in spheroids as determined by BrdU labelling was significantly increased and extended for 1 week, while acetylcholinesterase protein levels and specific activities in homogenates were decreased to approximately 30%. At the same time, opsin immunoreactivity was completely suppressed within the spheroid and appeared slowly in cells around its periphery; i.e. the proportion of rhodopsin-positive cells decreased from 14 to 3%. This study reveals that the retinal pigmented epithelium in vitro sustains cell proliferation but inhibits the differentiation of acetylcholinesterase-positive cells and of photoreceptors.

Acetylcholinesterase↗

PubMedDate not supplied

Fundus pigment distribution in rhesus monkeys.

There is growing evidence for an interaction among fundus pigmentation, character, geography and the function and structure of the outer retina. We examined three inbred groups of rhesus macaques (132 eyes) including all ages. One was a smaller (18 eyes) group. Coat colors were variations of brown-tan however, the smaller group had lighter 'golden' coats and colors. Fundus images were classified for pigmentation and its geographic distribution. In golden-coated animals there was bias toward nasal fundus hypopigmentation with the optic disk as a watershed demarcation zone, which extended in the superior-inferior direction. Temporal fundus hypopigmentation did not occur in the absence of nasal hypopigmentation. More common, darker coated samples showed a characteristic diffuse fundus pigmentation. There was no evidence for albinism or large variations in macular pigmentation. Rhesus monkeys can exhibit geographically controlled genetic development of fundus pigmentation. Hypopigmentation provides for access to the choroidal infrastructure.

Animals↗

PubMed1993

Purified human neuromelanin, synthetic dopamine melanin as a potential model pigment, and the normal human substantia nigra: characterization by electron paramagnetic resonance spectroscopy.

Neuromelanin is a poorly understood pigment that accumulates in catecholaminergic neurons during normal aging. Electron paramagnetic resonance spectroscopy, an especially effective technique for investigating melanins, is used in the present study to show unambiguously that neuromelanin is a melanin; however, it is not well modeled by synthetic dopamine melanin and thus is an atypical melanin. Some of the unusual features of neuromelanin can be explained by postulating two distinct sources for its free radicals, the dominant one possibly derived from a precursor containing sulfur. Examination of human substantia nigra by electron paramagnetic resonance spectroscopy during the purification of neuromelanin also demonstrates, contrary to some other studies, that a portion of the paramagnetic metal ions in this tissue are bound to the pigment in situ. Combined with previous histochemical data, these observations have implications for the mechanism through which neuromelanin accumulates in vivo and are consistent with its having a cytoprotective function under normal conditions, but a cytotoxic role at advanced ages and in patients with Parkinson's disease. Other results of this study show that homogenizing tissues during the purification of any natural pigment may cause contamination of the pigment by extraneous metal ions and that subsequent incubation in hot acid, though most effective in removing metal ions and hydrolyzing proteins, leads to degradation of melanin. A purification procedure using incubation in acid at room temperature, however, is well suited for identifying and characterizing unknown natural pigments by electron paramagnetic resonance spectroscopy.

Animals↗

PubMed1990

Pigmented streaks in melanoma scars.

Fifty consecutive patients from our melanoma clinic were examined for the presence of transverse pigmented streaks in their melanoma surgical scars. Thirty-four (68%) patients were noted to have pigmented streaks in their melanoma scars. Ten of these 34 patients also had similar pigmented streaks in their nonmelanoma surgical scars. Long-term follow-up (mean 81.7 +/- 14.5 months, minimum 36 months) of these patients with the melanoma-scar pigmented streaks indicates that the streaks are benign. Histologic examination of a representative pigmented streak revealed basal layer hyperpigmentation without melanocytic hyperplasia. These streaks are frequently associated with the presence of freckles. However, this association may simply be coincidental.

Adult↗

PubMed1995

Allergic reactions to tattoo pigment after laser treatment.

BACKGROUND: Cutaneous allergic reactions to pigments found in tattoos are not infrequent. Cinnabar (mercuric sulfide) is the most common cause of allergic reactions in tattoos and is probably related to a cell-mediated (delayed) hypersensitivity reaction. OBJECTIVE: The purpose of these case presentations is to describe a previously unreported complication of tattoo removal with two Q-switched lasers. RESULTS: Two patients without prior histories of skin disease experienced localized as well as widespread allergic reactions after treatment of their tattoos with two Q-switched lasers. CONCLUSION: The Q-switched ruby and neodymium:yttrium-aluminum-garnet lasers target intracellular tattoo pigment, causing rapid thermal expansion that fragments pigment-containing cells and causes the pigment to become extracellular. This extracellular pigment is then recognized by the immune system as foreign.

Adult↗

PubMed1996

The treatment of benign pigmented lesions and tattoos with the Q-switched ruby laser. A comparative study using the 5.0- and 6.5-mm spot size.

BACKGROUND: The Q-switched ruby laser (QSRL) is useful in the treatment of benign pigmented lesions and tattoos. Two spot sizes are available in the QSRL (5 and 6.5 mm). It has not been shown if one spot size is more efficacious in the treatment of benign pigmented lesions and tattoos. OBJECTIVE: The purpose of this study is to compare the clinical lightening and side effects observed with the 5.0- and 6.5-mm spot sizes of the QSRL in the treatment of benign pigmented lesions and tattoos. METHODS: Eleven patients with 12 benign pigmented lesions or tattoos were prospectively studied with the QSRL. Half of the lesion was treated with the 5.0-mm spot size while the other half was treated with the 6.5-mm spot size. Clinical lightening of the lesion was assessed using pretreatment and posttreatment photographs. RESULTS: No significant clinical difference in the lightening of lesions or in the side effect profile was observed with either spot size. CONCLUSIONS: The 5.0- and 6.5-mm spot sizes of the QSRL are equally efficacious in the removal of benign pigmented lesions and tattoos. It seems prudent to use the 6.5-mm spot size when treating large lesions to reduce treatment time, patient discomfort, and treatment cost.

Adolescent↗

PubMed1977

Pigmentation and musculoskeletal abnormalities in an aged state hospital population.

In a State hospital population, 686 patients (mean age, 65 years) were examined for patterned pigmentation on unexposed areas of the body. Of these patients, 285 (41.5 percent) met the criteria for pigmentation. There were no sex or age differences. Psychosis had been diagnosed in 96 percent of the pigmented group. All of the 239 patients examined orthopedically had vertebral malalignment greater than 15 degrees and often had other bony deformities. Nearly all of the pigmented group displayed dyskinetic activity. A possible mechanism for the production of the pigmentation-psychosis-skeletal deformity triad could be an alteration in the concentration of available melatonin. Continued research along these lines may lead to an effective means of pharmacologic treatment as well as better psychologic and physical care.

Adult↗

PubMed1995

The amount of lens exfoliation and chamber-angle pigmentation in exfoliation syndrome with or without glaucoma.

Correlations of the amount of chamber-angle pigmentation and exfoliation material with IOP and with image analysis of the optic discs are reported in the paired eyes of 63 persons with unilateral exfoliation syndrome, and 35 patients with unilateral capsular glaucoma. The effect on IOP of phenylephrine-induced pigmentary dispersion is examined. Chamber-angle pigmentation was more pronounced in capsular glaucoma than in the nonglaucomatous exfoliation eyes (p < 0.01), although the amount of lens exfoliation was the same. In nonglaucomatous exfoliative eyes IOP correlated significantly with the amount of chamber-angle pigmentation (p < 0.01) and exfoliation material (p < 0.05). The nonglaucomatous exfoliative eyes with grade > or = 2 trabecular pigmentation and those with reduction of IOP on phenylephrine provocation had smaller rim areas and rim/disc area ratios than the fellow eyes (p < 0.05). Rather than the amount of exfoliation, the main risk factor for glaucoma seems to be the degree of chamber-angle pigmentation.

Aged↗

PubMed1996

Pattern dystrophies of the retinal pigment epithelium.

Pattern dystrophies of the retinal pigment epithelium are infrequent fundus abnormalities arranged in various patterns of dots, lines and branches. The basic lesion appears to be yellow deposits of abnormal lipofuscin accumulated within degenerated retinal pigment epithelium cells. Examinations were carried out on two families who had developed different patterned alterations in the retinal pigment epithelium. The proband of family 1 had diffuse changes associated with equatorial folds. One sister had a macular alteration. A daughter was normal; a son had bilateral atrophy of the temporal retinal pigment epithelium. The proband of family 2 had bilateral, symmetrical retinal pigment epithelium lesions that simulated fundus flavimaculatus. His first daughter had a central lesion in her right eye. The second daughter, a peripapillary crescent of hyperpigmentation in her right eye, and circumpapillary chorioretinal atrophy associated with foveolar abnormalities in the left. This report provides further evidence that variable types of pattern dystrophy can occur within a single family pedigree and support the current opinion that all forms of pattern dystrophies are variants of a single pathogenic mechanism.

Adult↗

PubMed1984

Physiologic pigmentation of the oral mucosa in Israeli Jews of different ethnic origin.

The prevalence of oral physiologic pigmentation in three ethnic groups of a total of 2465 Israeli Jews was determined, and the relationship of oral pigmentation to age and sex within the groups was noted. Results showed the presence of oral pigmentation in 63.6% of the Eastern group, 54.8% of the Sephardic group, and 24.9% of the Ashkenazi group. No indication was found of sex predilection, and no significant trend was evident in the prevalence of pigmentation with relation to age. The leading site of pigmentation among the entire sample was the gingiva, and this finding did not vary with ethnicity.

Adolescent↗

PubMed1977

Pigmented cells in adenolymphoma (Warthin's tumor).

A study of a series of adenolymphomas showed the presence of pigmented cells in the lymphoid stroma in 85% of the cases. The pigmented cells contained light brown cytoplasmic pigment and manifested sudanophila, acid-fastness, silver reduction capacity, PAS positivity and yellow autofluorescence in ultraviolet light. The morphology, histochemical reactions and autofluorescence suggest that the pigmented cells are macrophages containing ceroid derived from breakdown of damaged organelles of the epithelial tumor cells. It is possible that these cells play a role in the elimination of undigestable pigment material present in the cystic spaces of the tumor.

Adenolymphoma↗

PubMed1991

Oral melanin pigmentation in 467 Thai and Malaysian people with special emphasis on smoker's melanosis.

At the faculties of dentistry in Chiang Mai, Thailand (CM), and Kuala Lumpur, Malaysia (KL), 234 and 233 consecutive out-patients were interviewed concerning tobacco and chewing habits and examined for the presence of oral melanin pigmentation. Tobacco was regularly used by 32% and 28% of the studied populations in CM and KL. Cigarette smoking was the predominant habit, but the chewing of betel and tea leaves (miang) and the smoking of banana leaf cigars (khi yo) was also registered. The genetically acquired pigmentation dominated. Although nearly all non-tobacco users in the Malay and Indian populations had oral melanin pigmentation, it was found that tobacco smokers had significantly more oral surfaces pigmented than non-tobacco users. Among Thais, the percentage of pigmented individuals was significantly higher among tobacco smokers. It was concluded that tobacco smoking stimulates oral melanocytes to a higher melanin production also in dark-skinned ethnic groups.

Adult↗

PubMed1991

Primary structure and relative potency of an analog of beta-PDH (pigment-dispersing hormone) from the crayfish Procambarus clarkii.

A pigment-dispersing hormone (PDH) from eyestalks of the crayfish Procambarus clarkii was purified by gel filtration, cation-exchange chromatography, partition chromatography, and reversed-phase HPLC. Based on automated sequencing and by the identical chromatographic behavior of the native PDH and the synthetic amidated form of the deduced sequence, the primary structure of Procambarus PDH has been established as: Asn-Ser-Glu-Leu-Ile-Asn-Ser-Ile-Leu-Gly-Leu-Pro-Lys-Val-Met-Asn-Glu-Ala- NH2. This peptide differs from beta-PDH of the fiddler crab Uca pugilator at a single position, Glu17 in place of Asp17. Because of this substitution, Procambarus PDH was 4 to 7-fold less potent than beta-PDH in causing pigment dispersion in the erythrophores, leucophores, and melanophores of Uca. In contrast, Procambarus PDH was 4-fold more potent than beta-PDH in eliciting pigment dispersion in the erythrophores of Procambarus. These peptides displayed less marked differences in potency in triggering leucophore pigment dispersion and light-adaptational distal eye pigment movement in Procambarus. These findings indicate that the structural requirements for PDH-receptor interactions vary with the species and with the target cell type within a given species.

Amino Acid Sequence↗