Keratinocyte conditioned medium abrogates the modulatory effects of IGF-1 and TGF-β1 on collagenase expression in dermal fibroblasts

Overexpression of wound healing-promoting factors such as transforming growth factor-1 (TGF-beta1) and insulin-like growth factor-1 (IGF-1) during the healing process has been implicated in the development of dermal fibrosis in patients following thermal injury, surgical incision, and deep trauma. However, the mechanism through which the expression of these two fibrogenic factors is slowed down and/or abrogated in the late stages of the healing process is not known. Here, we hypothesize that keratinocyte-releasable factors counteract the fibrogenic role of both IGF-1 and TGF-beta1 in fibroblasts. To test this hypothesis, the levels of collagenase (MMP-1), as an index for extracellular matrix degradation, in dermal fibroblasts in response to either keratinocyte-conditioned medium (KCM) or our recently identified keratinocyte-releasable stratifin in the presence and absence of either IGF-1, TGF-beta1, or both were evaluated. The results of Northern analysis showed a significant increase in collagenase mRNA expression in cells treated with KCM in the presence of both IGF-1 and TGF-beta1. The effect was, at least in part, due to keratinocyte-derived stratifin that was present in KCM. This was ascertained as the levels of MMP-1 mRNA were markedly reduced when cells were treated with stratifin-immuno-depleted KCM. The results of Western blot analysis showed an increase in the level of MMP-1 protein in stratifin-treated fibroblasts and this was consistent with the level of MMP-1 mRNA expression detected by Northern analysis. However, in contrast to KCM, whose efficacy on MMP-1 expression was modestly reduced by either IGF-1 and TGF-beta1, or a combination of both, these factors abrogated the MMP-1 stimulatory effect of stratifin in fibroblasts. In summary, the results of this study revealed that both stratifin and KCM stimulate the expression of MMP-1-in fibroblasts and this effect can be abrogated by either IGF-1, TGF-beta1, or a combination of both.     

Ameloblastic fibrosarcoma of the jaws--report of three cases. Clinico-pathologic, histoenzymological and ultrastructural study

The ameloblastic fibrosarcoma is a rare variety of neoplasm. Three new cases reported here occurred within preexistent benign odontogenic tumors (ameloblastic fibroma or fibro-odontoma). These large, osteolytic tumors, spreading to adjacent soft parts, recurred after surgical treatment in two cases. One of them had a lethal course, with pleuro-pulmonary, mediastinal lymph node and hepatic metastases. Histologically, these sarcomas show a malignant mesenchymal component and few benign ameloblastic islands, which often disappear after one or several recurrences. Histoenzymologically, a high level of alkaline phosphatase and ATPase activities is always present, a feature not present in common fibrosarcomas. The ultrastructural study demonstrates, in analogy with odontogenic myxomas, clear cells provided with numerous microfilaments, secretory cells and also some fibroblasts and myofibroblast-like cells. In addition to these pleomorphic cells, a great number of peculiar granular cells with numerous lysosomal bodies were also found. The histogenesis of these tumors in unknown. Perhaps the epithelial component, being unable to assume its functions of organization, may initiate the malignant transformation of its odontogenic mesenchyme.     

Female and male partner age and menotrophin requirements influence pregnancy rates with human menopausal gonadotrophin therapy in combination with intrauterine insemination

This study analyses the influence of female and male patient age and human menopausal gonadotrophin (HMG) requirements on clinical pregnancy rates and live birth rates with ovulation stimulation using HMG in combination with intrauterine insemination (IUI). In this study, 363 consecutive HMG/IUI treatment cycles in 184 patients carried out at a university fertility centre were analysed in a retrospective fashion. The main outcomes measured were clinical pregnancy rates and live birth rates. Increased female partner age (> or = 35) and male partner age (> or = 40) were found to negatively influence pregnancy rates with HMG/ IUI therapy. In addition, this study demonstrated a critical threshold of HMG requirements beyond which pregnancy did not occur. No pregnancies occurred in treatment cycles requiring > 25 ampoules (1875 IU) of menotrophins to achieve follicular maturity, irrespective of patient age. In conclusion, female partner age, male partner age, and HMG requirements all significantly influence pregnancy rates with HMG/IUI therapy.      

Modulation of receptors for the colony-stimulating factor, CSF-1, by bacterial lipopolysaccharide and CSF-1

The ability of the mononuclear phagocyte-specific colony-stimulating factor, CSF-1, to down-regulate its receptor on peritoneal exudate macrophages (PEM) was examined. Because of the essentially irreversible binding of CSF-1 to its receptor at 2 degrees C, unoccupied cell surface receptors could be measured by rapidly cooling PEM to 2 degrees C and determining the amount of 125I-CSF-1 bound at this temperature. On incubation with 125I-CSF-1 at 37 degrees C more receptors were lost than could be accounted for by 125I-CSF-1 binding. This receptor loss, apparently caused by CSF-1 itself, was shown to be due in large part to the presence of contaminating lipopolysaccharide (LPS), which at 10 ng/ml was by itself able to cause complete loss of the CSF-1 receptors. LPS also induced loss of the insulin receptor by PEM. LPS did not cause apparent CSF-1 receptor loss by binding to the receptor or by stimulating the release of CSF-1 or substances which compete for the binding of 125I-CSF-1 to the receptor. However, LPS did stimulate release of factors by LPS responsive (C3H/HeN) PEM which caused CSF-1 receptor loss by LPS non-responsive (C3H/HeJ) PEM. In the absence of LPS induced effects, incubation of 125I-CSF-1 with PEM at 37 degrees C resulted in down-regulation of the CSF-1 receptors. The number of CSF-1 receptor sites down-regulated corresponded to the number of CSF-1 molecules that were cell-associated plus the number that were intracellularly degraded and released.     

Paramagnetic macrocyclic complexes as contrast agents for MR imaging: proton nuclear relaxation rate enhancement in aqueous solution and in rat tissues

Paramagnetic macrocyclic chelates show promise as magnetic resonance (MR) imaging contrast agents due to stability and relaxivity comparable to those of DTPA-type chelates. For the three copper and manganese macrocyclic complexes studied in aqueous solution, T1 and T2 relaxivities ranged from 0.14 to 5.88 mM-1sec-1 at 6.25 MHz. In rats, the intravenous administration of 16 mumol/kg of Mn(cyclam) caused the liver T1 relaxation rate to double at 15 minutes after injection. T1 measurements by pulsed MR imaging and manganese analyses on excised tissue showed that both relaxation rate (1/T1) and manganese content of liver and kidney increase linearly with the dosage of Mn(cyclam). The linear relationship between 1/T1 and manganese content can be considered an "in tissue" relaxivity plot for the agent. The resulting relaxivity is 54 mM-1sec-1 in liver, compared with 3.1 mM-1sec-1 in aqueous solution. Although this work is preliminary, the implication for medical MR imaging applications is that macrocyclic contrast agents can be effective at approximately one-tenth the current typical dose used for gadolinium DTPA.