Parathyroid hormone-related peptide in the human fetal uro-genital tract.

Using a polyclonal antiserum raised against the first 34 amino acids of human parathyroid hormone-related peptide (PTHrP), we have localized PTHrP throughout the uro-genital tract of the human fetus aged between 8 and 40 weeks. Staining was present in the developing mesonephros, metanephros, gonads and in both the adrenal cortex and medulla. In particular, the developing mesonephric and metanephric renal tubules were intensely positive. Using Northern hybridization analysis we have detected a complex pattern of PTHrP mRNA transcripts ranging in size from 1.4 to 4.5 kb in early second trimester human fetal kidney. The presence of PTHrP in the mesonephros and metanephros provides evidence for a role for PTHrP in the regulation of fetal calcium metabolism. However, its presence in the gonad and adrenal gland invites the possibility of a wider role for PTHrP.

Detection of sex-specific proteins in chick embryo gonads and mesonephros: effects of estradiol benzoate or tamoxifen on their expression.

Gonadal and mesonephric protein patterns from 19 day old normal chick embryos were investigated by two-dimensional polyacrylamide gel electrophoresis. Under these conditions, several sex-specific polypeptides were detected. As concerns gonadal extracts, four sex-specific polypeptides, all restricted to the cytosol, were present in the testis, whereas three sex-specific polypeptides, two localized in the cytosol, the other being membrane-bound, were identified in the ovary. Among the ovary-specific polypeptides two proved to be estrogen-dependent. They appeared in the left testis of embryos after early estradiol benzoate treatment and their expression was reduced in the ovary after early exposure to the antiestrogen, tamoxifen. Mesonephros extracts of both sexes also differed in their protein composition since three additional polypeptides (one in both the cytosolic and membrane fractions, the others in the cytosol) not found in females were found to be present in males. None appeared to be affected after either estradiol or tamoxifen treatment.

Mesonephric duct hyperplasia of the uterus. Report of two cases and three other cases of mesonephric duct remnant with findings of mucin histochemistry and lectin binding immunohistochemistry.

Two cases of mesonephric duct hyperplasia of the uterus, together with three cases of uterine mesonephric duct remnant, are reported. The latter cases were identified by serial transverse sectioning of 42 surgically resected uteri, yielding a frequency of approximately 7%. Histochemical studies showed no mucin in the cytoplasm of cells lining the mesonephric duct remnant, as well as mesonephric duct hyperplasia. In contrast, the endocervical epithelium had abundant neutral mucin, sialomucin and sulfomucin. Immunohistochemical studies on lectin binding showed positive binding of PNA and SBA lectins only to the lining cells of mesonephric duct hyperplasia.

Widespread distribution of type II collagen during embryonic chick development.

Type II collagen is a major component of hyaline cartilage, and has been suggested to be causally involved in promoting chondrogenesis during embryonic development. In the present study we have performed an immunohistochemical analysis of the distribution of type II collagen during several early stages of embryonic chick development. Unexpectedly, we have found that type II collagen is widely distributed in a temporally and spatially regulated fashion in basement membranes throughout the trunk of the embryo at stages 14 through 19, including regions with no apparent relationship to chondrogenesis. Immunohistochemical staining with two different monoclonal antibodies against type II collagen, as well as with an affinity-purified polyclonal antibody, is detectable in the basement membranes of the neural tube, notochord, auditory vesicle, dorsal/lateral surface ectoderm, lateral/ventral gut endoderm, mesonephric duct, and basal surface of the splanchnic mesoderm subjacent to the dorsal aorta, and at the interface between the epimyocardium and endocardium of the developing heart. In contrast, immunoreactive type IX collagen is detectable only in the perinotochordal sheath in the trunk of the embryo at these stages of development. Thus type II collagen is much more widely distributed during early development than previously thought, and may be fulfilling some as yet undefined function, unrelated to chondrogenesis, during early embryogenesis.

Lectin activity and distribution of chicken lactose lectin I in the extracellular matrix of the chick developing kidney.

A lectin activity inhibitable by thiodigalactose, N-acetyllactosamine, lactulose, lactose and by an antibody raised against CLL I (chicken-lactose lectin I) has been investigated in the chick embryo developing kidney. At post-induction stages this activity was found in both mesonephros and metanephros. In immunofluorescence and immunoelectron microscopy, the extracellular distribution of CLL I was similar in the mesonephros and the metanephros. The lectin was never found intracellularly; cultured kidney cells did not express any endogenous lectin but were rich in lectin-receptor sites, which led to the hyphothesis that CLL I is not produced in situ but could be adsorbed on renal cells. Potential physiological roles for embryonic lectins are discussed.

[Immunohistochemistry of the human fetal mesonephros with anti-human N-myc protein antibody].

Expression of a N-myc gene has been found in Wilms' tumor. N-myc protein, which is a N-myc gene product, can be detected using an anti-N-myc antibody. Paraffin sections of the fetal tissues at the seventh week of gestation were prepared for immunohistochemistry, stained by PAP method. The N-myc gene product was observed in the cells consisting of the mesonephric ductular wall. This result may suggest that Wilms' tumor is originated from the mesonephric tissue.

Immunocytochemical demonstration of insulin in the mesonephros and metanephros of the Brazilian opossum Didelphis albiventris).

The presence of insulin the brush border and apical pole of the cells lining the pouch opossum mesonephric and metanephric proximal tubules was demonstrated by immunofluorescence and immunoperoxidase techniques. Positive result for insulin was also observed in the tufts of capillaries of some metanephric corpuscles.

Nephrogenic adenoma and embryonic kidney tubules share PNA receptor sites.

Nephrogenic adenoma a rare bladder, ureter, or urethral lesion, is of disputed pathogenesis, metaplastic and congenital etiologies both being implicated in its development. Since light and electron microscopy have been unable to fully resolve the lesion's pathogenesis, the authors used biotinylated lectins as probes and avidin-biotin peroxidase complex (ABC) as a visualant to study cases of nephrogenic adenomas and compared their lectin binding patterns with those of normal transitional epithelium, human embryonic kidneys, and cases of cystitis cystica and glandularis and squamous metaplasia of the bladder in an effort to clarify this issue. Only the epithelial lining of the luminal surface and tubuli in nephrogenic adenoma and tubules in embryonic kidney exhibited free PNA receptor sites. The striking staining similarities between the epithelial components of nephrogenic adenomas and mesonephric and metanephric tubules complement previous findings concerning the origin of nephrogenic adenoma.

Glycogen accumulations in differentiating mesonephric ducts and tubuli in male human embryos.

Human mesonephric duct epithelial cells contained empty appearing regions in the infranuclear cytoplasm when prepared for transmission electron microscopy using glutaraldehyde and osmium fixation. The same regions stained positively with PAS in Epon sections for light microscopy suggesting that glycogen was present. Incubation with saliva abolished the reaction. For electron microscopy the glycogen stained very intensely if a mixture of osmium tetroxide and potassium ferrocyanide was used instead of osmium alone. Glycogen accumulations were present between the ages of 5 to 10 weeks and absent at the age of 15 weeks. Reports by others indicate that glycogen may be present in different reactive forms in relation to its staining behaviour after various fixatives. The present results, and similar studies in other tissues, indicate that osmium tetroxide-potassium ferrocyanide fixative should be used routinely for preservation of embryos and fetuses and where indicated, for ultrastructural identification of glycogen and cytoplasmic filaments in clinical specimens.