Extent Of Pigmentation Research Articles

Relation of graded ocular anterior chamber pigmentation to phenothiazine intake in schizophrenics--quantification procedures.

The fact that larger doses of phenothiazine medications cause more anterior chamber (lens and cornea) pigmentation in schizophrenics has been apparent since the introduction of these neuroleptic drugs nearly 30 years ago. The present study relates the extent of pigmentation to the dose and duration of phenothiazine administration in long-term schizophrenics. An investigation and analysis of the medication records of 272 pigmented schizophrenics show a statistically significant correlation between most of the pigmentation grades and the associated dose of medication. The results indicate that regular biomicroscopy examinations for pigmentation can help confirm medication history and classify schizophrenics.

Study of two forms of the adult Stenocranus minutus

SUMMARY In studies on Stenocranus minutus, two winged forms of adults have been observed, macropterous and sub‐macropterous. Macropterous individuals, with extra‐long wings, have not been previously observed or described. Probably only the macropterous form disperses by flight. The two forms differ in their wing lengths, intensity and extent of pigmentation. The rate of maturation differs in the two forms. In macropters, maturation is delayed; the period of oviposition is shorter and they are less fecund. Macropters do not live as long as sub‐macropters. The macropters weigh less than the sub‐macropters. Under laboratory conditions, both forms can hop but the macropterous forms fly for a longer time than the sub‐macropters. At 25°C, more macropterous forms were produced on wilting Dactylis than on green, succulent Dactylis. Dispersal of field population was inferred from changes in proportions of the two forms and by simultaneous occurrence of macropters in aerial suction traps. The macropterous forms of S.minutus migrate a few weeks after emergence while still immature and migration coincides with drying up of host plant, Dactylis glomerata L. Relatively high temperature, low wind speeds and a small number of hours of sunlight seem to favour dispersal by flight in S.minutus.

Pigmentation and Retinal Breaks

Of 260 patients with primary, nontraumatic, rhegmatogenous retinal separation analyzed for the presence of retinal or subretinal pigmentation associated with the retinal breaks, some 48.5% of all patients had significant pigmentary changes, especially occurring with lattice degeneration and nonlattice horseshoe tears. Critical analysis of the age of the patient, type of retinal break, vitreoretinal degeneration, and type and extent of pigmentation is essential before ascribing a protective effect of the pigment in the prevention of subsequent retinal separation.

Prognostic factors in cutaneous malignant melanoma: A comparative study of long term and short term survivors

The clinical presentation and histologic characteristics of primary melanomas of a consecutive series of 100 short term (fatal within five years) and 100 long term survivors (disease-free for ten years or longer) were studied. The clinical parameters analyzed included the history of pre-existent mole, duration of changes before diagnosis, site, elevation, ulceration, extent of pigmentation, and satellitosis around the primary lesion. Study of histologic features included analysis of exact measurements of the primary melanoma, depth of dermal invasion, tumor cell morphology, mitotic rate, intracellular pigmentation, presence or absence of giant tumor cells, blood vessel or lymphatic invasion, lateral junctional activity, and presence and extent of lymphoid response to the primary lesion. Statistically significant differences were found between the long term and short term survivors with respect to several variables. It is one of the conclusions of this study that an elective node dissection would seem to be indicated in all patients with stage I melanoma who present with poor prognostic signs, that is, patients who belong to any combination of the following categories: male, primary lesions>1 cm., which has ulcerated, with a deeper level of dermal penetration, with dermal lymphatic or blood vessel invasion, and a lack of lymphoid reaction around the primary lesion.

Extent of Pigmentation in Autopsied Human Lungs as an Indicator of Particulate Environmental Air Pollution

Preparation of lung specimens in inflation permits quantification of many aspects of morphology. In a study of some 250 non-emphysematous inflated lungs from adult men, the extent of pigmentation has been measured by a point-counting procedure. Using a grid of intersecting lines superimposed on a lung piece, all points which touch lung tissue and those which touch pigmented tissue are counted and the ratio is a measure of extent of pigmentation.

Colour Variation in Two Mesopelagic Fishes and its Correlation with Ambient Light Conditions

LITTLE is known about colour variation in mesopelagic fishes. In her observations on Valencienellus tripunctulatus (Esmark), Grey1,2 noted two pigment forms. On some specimens, “the back and tail (were) whitish or translucent, with a lengthwise series of 14–18 black chromatophores standing out in bold relief”. On others, “the back and tail (were) brownish, the lateral series of chromatophores being diffuse and obscure”. Such differences in the extent of pigmentation have now been shown to be related to the light conditions prevailing at the time of capture.

The effect of humidity and temperature on the extent of abdominal pigmentation inGlossina pallidipesAusten

The extent of pigmentation of the abdominal bands ofGlossina pallidipesAust. was studied in specimens emerging in the laboratory from puparia maintained at constant temperature and a range of relative humidities and derived from females collected in the field at Shinyanga, Tanganyika. An index of pigmentation was obtained by regarding the bands as consisting in all of 15 zones, each carrying a score of 1.The index was closely dependent on the humidity experienced during pupal development, almost full pigmentation being produced in saturated air and almost complete suppression of it in dry air; it is inversely related to size and little affected in nearly saturated air by temperatures below 28°C. during pupal development, although still higher temperatures reduce it quite sharply.In flies collected in the field throughout the year, most of those taken towards the end of the rains (March and April) fell into the darker pigment categories; as the dry season advanced the distribution tended to become bimodal, with the darker mode relatively steady at an index of about 12 and the paler mode moving progressively down the scale, reaching an index of about 5 in October and then disappearing. December and January collections (rainy season) were again unimodal, resembling those of March. It is suggested that these changes reflect the use of two types of larviposition site, the darker mode representing pupae from the evergreen thickets along the drainage lines and the lighter mode those from semi-deciduous thickets on the eluvial slopes, and that during the dry season the soil-space humidity in the latter sites may reach levels inimical to survival.The depth to which larvae ofG. pallidipesburrow appears to be related to the temperature, and perhaps the humidity, obtaining at the time of larviposition.The possible effect of humidity on coloration was tested in four other species of tsetse fly, namelyG. swynnertoniAust.,G. morsitansWestw.,G. palpalis fuscipesNewst. andG. longipennisCorti. OnlyG. swynnertonigave indications of some slight effect.