Serum concentrations of beta-melanocyte-stimulating hormone in human pregnancy

Surgical treatment of malignant melanoma: practical guidelines

Melanoma is currently the fifth and sixth most common solid malignancy diagnosed in men and women, respectively. Although accounting for only 4% of cases of all cutaneous malignancies, melanoma accounts for more than 75% of all deaths from skin cancer. This article discusses epidemiology and risk factors, proper biopsy technique, advanced histologic evaluation of biopsy material, assessment of tumor thickness and staging, preoperative metastatic evaluation, excision margin, treatment of regional lymph nodes, treatment of recurrence, and some special clinical situations.

Surgical approaches to malignant melanoma. Practical guidelines

Practical guidelines for the surgical approach to malignant melanoma are discussed in detail. Topics include diagnosis and proper biopsy technique; the appropriate preoperative metastatic workup; width of excision margins; treatment of the regional lymph nodes including cutaneous lymphoscintigraphy, intraoperative lymphatic mapping, and sentinel lymphadenectomy; postoperative follow-up schedules; management of local recurrence including surgical resection, isolated limb perfusion, intralesional therapy, adjuvant immunotherapy; management of special clinical situations including subungal melanoma, plantar melanoma, melanoma on the face, melanoma in pregnancy, and the treatment of lesions of uncertain diagnosis.

Spatiotemporal expression, distribution, and processing of POMC and POMC-derived peptides in murine skin

In murine skin, after depilation-induced anagen, there was a differential spatial and temporal expression of pro-opiomelanocortin (POMC) mRNA, of the POMC-derived peptides beta-endorphin, ACTH, beta-MSH, and alpha-MSH, and of the prohormone convertases PC1 and PC2 in epidermal and hair follicle keratinocytes and in the cells of sebaceous units. Using a combination of in situ hybridization histochemistry and immunohistochemistry, we found cell-specific variations in the expression of POMC mRNA that were consistent with immunoreactivities for POMC-derived peptides. Cells that contained POMC peptide immunoreactivity (IR) also expressed POMC mRNA, and where the IR increased there was a parallel increase in mRNA. The levels of PC1-IR and PC2-IR also showed cell-specific variations and were present in the same cells that contained the POMC peptides. Based on the cleavage specificities of these convertases and on the spatial and temporal expression of the convertases and of ACTH, beta-endorphin, beta-MSH, and alpha-MSH, we can infer that the activities of PC1 and PC2 are responsible for the cell-specific differential processing of POMC in murine skin.

POMC and fibroblast biology

We evidenced in vitro proopiomelanocortin (POMC) mRNA-transcription in human dermal fibroblasts using Northern blot hybridization. Modulation of POMC gene expression by cytokines (transforming growth factor-beta, TGF-beta, and tumor necrosis factor-alpha, TNF-alpha) was investigated by incubating human normal fibroblasts with 1 and 10 ng/ml cytokines, either alone or in combination, for 24 hours. Our results show that dermal fibroblasts express POMC at significant levels under unstimulated conditions. POMC steady-state levels were significantly reduced by addition of TGF-beta. On the other hand, TNF-alpha exerted a stimulatory effect on POMC mRNA transcription, partially counteracting the effect of TGF-beta. These data provide the first demonstration of POMC gene expression in cultured skin fibroblasts. The opposite regulatory effect of TGF-beta and TNF-alpha, two cytokines primarily involved in extracellular matrix regulation, suggests a possible role for POMC-derived peptides in fibroblast activity. We also investigated POMC mRNA expression in keloid-derived fibroblasts in culture, and its regulation by TGF-beta added at the highest concentration documented for inhibition. Keloid-derived fibroblasts showed clearly detectable levels of POMC mRNA in basal conditions, and no alteration of POMC gene expression was observed when TGF-beta was added in culture. The altered TGF-beta regulation of POMC mRNA levels suggest that POMC-derived peptides may play a role in the pathogenesis of keloid formation through an autocrine/paracrine network, resulting in modulation of extracellular matrix synthesis.

Central serous retinopathy associated with adrenocorticotrophic hormone therapy. A case report and a hypothesis

BACKGROUND

Central serous retinopathy (CSR) has been linked by several authors to the therapeutic use of adrenocorticotrophic hormone (ACTH) or corticosteroids or to endogenous ACTH hypersecretion. Various pathogenic mechanisms have been suggested to explain this phenomenon; all relate to the steroids as the causative agents.

CASE REPORT

A simultaneous, bilateral central serous retinopathy developed in a woman treated by intramuscular injections of a synthetic ACTH analog for arthritis. The condition resolved 2 months after stopping the use of this drug.

DISCUSSION

Many investigators consider CSR to be either a disorder of the retinal pigment epithelium (RPE) ion-pump function or a result of choroidal vascular hyperpermeability. ACTH has a melanotrophic part, melanocyte-stimulating hormone (MSH), that may affect RPE cells, which are melanin-pigmented cells of neuroectoderm origin, and alter their ionic pumping properties. This is supported by evidence in the literature for the effect of MSH on animal RPE cells, as well as on other secreting epithelia. MSH is known to act through increasing intracellular cAMP levels. Based on the current concepts regarding the pathogenesis of CSR, two possible mechanisms for ACTH/MSH-associated CSR are suggested. In the first, MSH increases intracellular cAMP levels in RPE cells, thereby inducing pump dysfunction and a reversal of ionic current direction, leading to subretinal fluid accumulation. An alternative mechanism is based on the known ability of MSH to increase the permeability of blood-aqueous and blood-brain barriers. It is hypothesized that MSH disrupts the outer blood-retinal barrier or causes leakage from choroidal vessels.

Propiomelanocortin (POMC) gene expression by normal skin and keloid fibroblasts in culture: modulation by cytokines

Originally described as a product of the pituitary gland, propiomelanocortin (POMC) has recently been identified in other tissues, such as in human skin, where it may accumulate in response to various stimuli. Thus far, epidermal keratinocytes, as well as melanocytes and macrophages, have been shown to express POMC. This study investigated the expression of POMC mRNA in cultured dermal fibroblasts derived from either normal skin or keloids. Using Northern blot hybridization with a POMC cDNA generated by RT-PCR of mRNA isolated from cardiac muscle, we demonstrated that dermal fibroblasts express POMC, as significant levels of mRNA were detected in unstimulated cells in culture. POMC transcript steady-state levels were strongly reduced by transforming growth factor-beta (TGF-beta), whereas tumor necrosis factor-alpha (TNF-alpha) counteracted the effect of TGF-beta and exerted a stimulatory activity on POMC mRNA levels. Reduction of POMC transcript levels by TGF-beta was also observed in cultured keratinocytes. Clearly detectable levels of POMC mRNA were detected in cultured keloid-derived fibroblasts; however, little, if any, regulation by TGF-beta was observed. These data represent the first demonstration of POMC expression by fibroblasts and down-regulation by TGF-beta. Furthermore, our results indicate altered TGF-beta regulation of POMC gene expression in keloid-derived fibroblasts, suggesting that POMC may play a role in the pathogenesis of keloid formation.

Increased thickness of pregnancy-associated melanoma

The effects of pregnancy on the pathophysiology of melanoma remain unclear. Although a gender-specific advantage for women vs. men is seen for characteristics such as stage at presentation, site of primary tumour, and survival time, an adverse effect of pregnancy on melanoma development and progression has been reported. In a retrospective study, we investigated the tumour characteristics of women who developed pregnancy-associated melanoma, and compared them with melanomas arising in non-pregnant women of child-bearing age. The patient records of the Massachusetts General Hospital Pigmented Lesion Clinic were reviewed, and 465 women of reproductive age (16-45 years) who developed melanoma were identified. Of these, in 45 women (age 21-42 years) there was a close temporal relationship between diagnosis of the tumour and pregnancy. Clinical and histological characteristics of the primary tumours were recorded. Differences in tumour thickness, site and histological type were analysed. The mean thickness of pregnancy-associated melanomas was significantly greater than that of non-pregnancy-associated tumours (2.28 vs. 1.22 mm, respectively; P < 0.007). No differences in histological type (P = 0.64) or site (P = 0.74) of the primary tumours were found between the two patient groups. Not surprisingly, multivariate analysis revealed that tumour thickness was a statistically significant variable in determining prognosis (P = 0.001). An unexpected finding, on multivariate analysis, was a possible pregnancy-associated prognostic advantage (P = 0.08). Melanomas arising during pregnancy are thicker, but are not necessarily associated with a less favourable prognosis than tumours arising in non-pregnant women of child-bearing age.(ABSTRACT TRUNCATED AT 250 WORDS)

An epidemiological study of posterior uveal melanoma in Israel, 1961-1989

Trends in the incidence rate of uveal melanoma in Israel during the period 1961-1989 among Jews of various geographical origins and among non-Jews were examined, and found to be stable over time. Based on data of the Israel Cancer Registry, 515 cases were included in the final study population after an independent case-finding ascertainment survey. The average annual incidence rate per million for all Jews was 5.7 for both males and females; the rates for non-Jews were: males 1.6, females 1.3. Incidence rates within the Jewish sub-populations show significant differences. The highest rates by sub-population were for Jews born in Europe or America (7.5 for males and for females), followed by Jews born in Israel (males 6.8, females 6.7); and lowest in Jews born in Africa (males 2.1, females 2.3) and Asia (males 1.6, females 2.8). Jews born in Israel had rates lower than Jews born in Europe and America during the 1960s, but in the 1980s the situation was reversed. Results suggest that rate differences between population groups and over time stem from constitutional factors or from the direct or indirect effect of sunlight radiation, whether early in life or from cumulative exposure.

Does pregnancy influence the prognosis of malignant melanoma?

The effect of pregnancy on the clinical course of malignant melanoma (MM) is unclear. Early clinical and laboratory evidence suggested a relation between hormones and MM and subsequently between pregnancy and MM. We reviewed the literature on MM and pregnancy to address three questions: What is the effect on prognosis if an MM is diagnosed during pregnancy? What is the effect of previous pregnancies on the prognosis of MM? What effect does a subsequent pregnancy have on the prognosis of MM? On the basis of a limited number of controlled studies, it does not appear that being pregnant before, after, or at the time of diagnosis of stage I MM influences the 5-year survival rate. However, caution in interpreting these data must be taken because it is possible that the duration of follow-up and size of the study populations are not sufficient to observe a true effect.

An evaluation of the influence of reproductive factors on the risk of metastases from uveal melanoma

BACKGROUND

There is a paucity of data concerning the possible role played by hormonal factors in the risk of metastases from intraocular melanomas.

METHODS

The authors studied the influence of post-diagnosis pregnancy and oral contraceptive use in a group of women of reproductive age (45 or younger) who were treated for uveal melanoma by proton beam irradiation. A baseline reproductive history had been collected before irradiation for all women, and interim reproductive data were collected by mailed questionnaire.

RESULTS

In this age group, the overall rate of metastasis among women was similar to that of men treated during the same interval (adjusted rate ratio: 1.28; 95% confidence interval: 0.62-2.67). A total of 24 full-term pregnancies were reported among the 139 women still menstruating at diagnosis. Twenty-three women reported regular oral contraceptive use. Metastases developed in 15 of the 139 women. Compared with other women in the series, rates of metastases were not higher among the women who reported pregnancies (P = 0.932) or oral contraceptive use (P = 0.424) after diagnosis.

CONCLUSION

Although based on limited numbers, results suggest that the hormonal environment has no appreciable influence on risk of metastases in younger women with uveal melanoma.

Epidemiologic aspects of uveal melanoma

Although the underlying cause or causes of uveal melanoma have yet to be elucidated, important insights may be gained by examining the epidemiologic features of the disease. Uveal melanoma is an uncommon cancer with an incidence of only six cases per million population per year. It is most often diagnosed in the sixth decade and is somewhat more common in males. Apart from sporadic reports of family clusters, uveal melanoma is not considered an inherited disease. Whether some environmental exposure triggers the development of uveal melanoma remains an open question. Sunlight has been proposed as an environmental risk factor because sunlight is known to cause melanoma of the skin and both diseases are rare in nonwhite races. Unlike cutaneous melanoma, however, rates have not been increasing over time and do not vary by latitude. This paper evaluates the available evidence for sunlight and other potential risk factors for uveal melanoma, highlighting areas requiring further research.

Multiple primary melanoma in pregnancy: a case report

A case is reported of three primary superficial spreading melanomas presenting in one patient in the space of 12 months. On each occasion the patient was pregnant at the time of definitive treatment. Local excision was performed for each tumour on the basis that this is appropriate for melanomas of less than 0.76 mm in depth (Breslow, 1975). The second primary had been biopsied between pregnancies and reported as benign. It is difficult to escape the inference that, in this patient, initiation of malignant transformation during pregnancy was not coincidental.

Maternal plasma adrenocorticotropin and cortisol relationships throughout human pregnancy

Adrenocorticotropin (ACTH) and cortisol in plasma were measured weekly from early in gestation through delivery in five women whose pregnancies were normal. During the twelfth week of pregnancy, the concentration of ACTH in plasma of blood samples obtained between 0800 and 0900 hours was 23 +/- 4.6 pg/ml (mean and SEM) and rose progressively to 59 +/- 16 pg/ml at 37 weeks. The levels of ACTH in plasma were significantly lower throughout pregnancy than those found in nonpregnant women. During labor and delivery, ACTH levels rose strikingly to values of 301 +/- 137 pg/ml. As pregnancy advanced, the concentration of cortisol in plasma increased progressively from 149 +/- 34 ng/ml (mean and SEM) at 12 weeks to 352 +/- 90 ng/ml at 26 weeks' gestation but changed minimally thereafter until labor commenced, during which values of 706 +/- 148 ng/ml were achieved. ACTH and cortisol secretory patterns over a 24-hour period were also investigated in one subject during each trimester of pregnancy. Diurnal variations were observed that were qualitatively similar to those seen in nonpregnant women. From the results of these studies, we conclude that ACTH levels are suppressed in plasma of normal pregnant women but are higher in late pregnancy than in early pregnancy. The rise in plasma ACTH concentrations, as pregnancy advances, in spite of increasing levels of plasma cortisol, estrogens, and progesterone, is suggestive of the possibility that a source of ACTH exists that is not subject to negative feedback control, that the clearance of free cortisol increases as pregnancy advances, or that there is an alteration in the metabolism of the ACTH precursor protein produced by the pituitary and/or placenta.

Adverse effect of pregnancy on melanoma: a reappraisal

The influence of pregnancy on the prognosis of cutaneous melanoma in women of childbearing age was examined in a retrospective review of 251 surgically treated cases. There was no statistical difference in survival at five years, free of disease, for Stage I melanoma between nulliparous, parous nonpregnant, and pregnant women. For Stage II melanoma, however, a significantly lower survival rate was observed for pregnant patients (29%) and parous women who had experienced activation of the lesion in a previous pregnancy (22%), as compared with that of nulliparous patients (55%) and other patients in the parous group (51%); p less than 0.05. This discrepancy in survival, together with the observed higher frequencies of Stage II cases, melanomas occurring on the trunk, and symptoms such as bleeding, ulceration, irritation, and elevation of the lesion, strongly suggest an adverse influence of pregnancy on women with Stage II melanoma.

Tyrosinase activity in human skin. Influence of race and age in newborns

Tyrosinase has been measured in homogenates of foreskins from newborn babies. The tyrosine hydroxylation reaction is dependent upon 3,4-dihydroxyphenylalanine as a cosubstrate, and the Km for tyrosine is 0.15 mM, similar to the value observed for other mammalian tyrosinases. The mean enzyme activity for black babies (n = 169) is about two and one-fourth times that for white babies (n = 82). For white babies there is a significant correlation between age at circumcision and tyrosinase activity. For black babies this correlation becomes significant when four individuals with extremely high tyrosinase activities are omitted from the series.