Malignant fibrous histiocytoma: an uncommon sarcoma with pathological fracture of mandible.

BACKGROUND: Tumors composed of cells differentiating as both fibroblasts and histiocytes have been designated fibrous histiocytomas. Only a small percentage of these lesions behave in a malignant fashion, they are called malignant fibrous histiocytoma (MFH).The occurrence of MFH in membranous bones including the mandible is quite unusual. Involvement of the mandible accounts for only 3 % of all MFH bone lesions. Recent literature revealed only a few (30) cases of MFH involving the mandible but not a single case of MFH associated with pathological fracture of the mandible, probably the first such kind of case to support antecedent trauma as an initial proliferative response for its occurence. CASE REPORT: A rare case of MFH involving the mandible and submandibular glands with pathological fracture in a 14-year-old boy is presented with special emphasis on the poor prognosis even after prompt therapy, its controversial histogenesis, high malignant potential, high recurrence rate and tendency to metastasise. The patient was regularly followed up for 11 months post-operatively, during which patient complained of pain in the operated region after 8 to 9 months. Though there was no clinically obvious abnormality seen, the young boy died after 11 months. The clinical, surgical, radiographic and pathological features of this lesion are discussed. DISCUSSION: Malignant fibrous histiocytoma, the most frequent soft tissue sarcoma of adulthood, was first described as a new malignant tumour by O'Brian and Stout in the 1960s and the details of the histopathological features of MFH were first described by Kempson and Kyriakos. Despite the frequency of diagnosis, MFH has remained an enigma as no true cell of origin has ever been identified. Treatment consists of surgical excision and in some cases chemotherapy and radiation. Early and complete surgical removal using wide or radical resection is indicated because of the aggressive nature of the tumor. The combination of infrequent occurrence, varied pathologic features, uncertain histogenesis, numerous subtypes and the many potential sites of presentation makes these tumors a challenge for the diagnostician, surgeon and oncologist. Close follow-up after treatment is important, as local recurrence is common and early metastasis to the lungs is also frequent, which are the reasons for high mortality rate in MFH.

Unusual intramaxillary plexiform schwannoma.

BACKGROUND: Neoplasms of peripheral nerve in the head and neck region are of common occurrence, but origin in the oral and para-oral tissues is uncommon and they rarely occur centrally within the jaws. Schwannoma is a benign neoplasm originating from the neural sheath of peripheral soft tissues, but its occurrence within the jaw bones is most unusual. Plexiform schwannoma is a unique variant of Schwann cell tumours having plexiform pattern. Literature revealed only one case of plexiform schwannoma of the jaw bones, i.e. involving the mandible. CASE REPORT: In this report, we present the first documented case of intraosseous plexiform schwannoma of the maxilla, an extremely rare benign neurogenic tumour treated surgically. DISCUSSION: Schwannoma is a benign neoplasm originating from the neural sheath of peripheral soft tissues, but to occur within the jaw bones is exceptional. Plexiform schwannoma is a rare variant of Schwann cell tumour having plexiform pattern of intraneural growth with multinodularity. Plexiform schwannoma is a benign neoplasm with no malignant potential, but recurrences are evident if excised incompletely. Plexiform schwannoma has similar clinical and histopathological features as that of plexiform neurofibroma which has high malignant potential; hence, it is imperative to correctly diagnose and differentiate this lesion as treatment modality of these two lesions differs.

A Zinc(II)/poly(gamma-glutamic acid) complex as an oral therapeutic for the treatment of type-2 diabetic KKAy mice.

In developing new insulin-mimetic zinc(II) complexes with various ligands including a biodegradable polymer, we prepared and characterized a Zn(gamma-pga) complex in solution as well as in solid, and investigated its in vitro insulin-mimetic activity and in vivo antidiabetic effect in type-2 diabetic KKA(y) mice. The in vitro insulin-mimetic activity of the Zn(gamma-pga) complex was considerable better than that of ZnSO(4). The Zn(gamma-pga) complex normalized the hyperglycemia in KKA(y) mice within 21 d when administrated orally at doses of 10-20 mg (0.15-0.31 mmol) Zn per kg body mass for 30 d. In addition, the impaired glucose tolerance, elevated HbA(1c) levels and metabolic syndromes were significantly improved in Zn(gamma-pga)-treated KKA(y) mice relative to those administrated with saline and ZnSO(4).

Chelation of vanadium(IV) by a natural and edible biopolymer poly(gamma-glutamic acid) in aqueous solution: structure and binding constant of complex.

The naturally occurring edible biopolymer poly(gamma-glutamic acid) (gamma-PGA) is shown to be an efficient chelating agent of vanadium(IV). The structure of poly(gamma-glutamic acid)oxovanadium(IV) (VO-gamma-PGA) complex in solution has been analyzed by electron spin resonance and UV-visible absorption spectra. The equatorial coordination sphere of vanadium(IV) is proposed to be [2 x carboxylate (2O)-VO-(OH2)2]. The binding isotherm is determined for suspensions of gamma-PGA in vanadium(IV) oxide sulfate (VS) solutions of different concentrations, and the data have been adjusted to fit the modified Langmuir equation. The maximum amount of vanadium bound per gram of gamma-PGA is estimated to be 141 mmol . g(-1) with a binding constant of 22 L . g(-1) at pH 3.

Amelioration of hyperglycemia and metabolic syndromes in type 2 diabetic KKA(y) mice by poly(gamma-glutamic acid)oxovanadium(IV) complex.

Recently, we found that poly(gamma-glutamic acid)oxovanadium(IV) complex (VO(gamma-pga)) exhibits a potent antidiabetic activity in streptozotocin (STZ)-induced type 1 diabetic mice. This result prompted us to examine its ability to treat the type 2 diabetic model KKA(y) mice with insulin resistance. We studied the in vivo antidiabetic activity of VO(gamma-pga), compared with that of vanadium(IV) oxide sulfate (VS) as control. Both compounds were orally administered at doses of 5-10 mg (0.1-0.2 mmol) V kg(-1) body mass to the KKA(y) mice for 30 days. VO(gamma-pga) normalized the hyperglycemia within 21 days, whereas VS lowered the blood glucose concentration only by a small degree. In addition, the glucose intolerance, HbA(1c) level, hyperinsulinemia, hypercholesterolemia, and hyperleptinemia were significantly improved in VO(gamma-pga)-treated KKA(y) mice compared with those treated with VS. Based on these observations, VO(gamma-pga) is proposed to be the first orally active oxovanadium(IV)-polymer complex for the efficacious treatment of not only type 2 diabetes but also metabolic syndrome in animals.

Investigation of a Cu(II)-poly(gamma-glutamic acid) complex in aqueous solution and its insulin-mimetic activity.

The complexation between cupric ions (Cu(II)) and poly(gamma-glutamic acid) (gamma-PGA) in aqueous solutions (pH 3-11) has been studied by UV-visible absorption and electron spin resonance (ESR) techniques. Formation of the Cu(II)-gamma-PGA complex is confirmed by the observation of the blue shift of the absorption band in the visible region, anisotropic line shapes in the ESR spectrum at room temperature, and a computer simulation of the visible absorption spectrum of the complex. The structure of the Cu(II)-gamma-PGA complex, depending on the pH, has been determined. The in vitro insulin-mimetic activity of the Cu(II)-gamma-PGA complex is examined by determining both inhibition of free fatty acid release and glucose uptake in isolated rat adipocytes treated with epinephrine, in which the concentration of the Cu(II)-gamma-PGA complex for 50% inhibition of free fatty acid release is very similar to that of CuSO4. However, it is significantly lower than that of a previously reported insulin-mimetic bis(3-hydroxypicolinato)copper(II), [Cu(3hpic)2], complex.

A [meso-tetrakis(4-sulfonatophenyl)porphyrinato]zinc(ii) complex as an oral therapeutic for the treatment of type 2 diabetic KKA(y) mice.

We prepared and characterized [meso-tetrakis(4-sulfonatophenyl)porphyrinato]zinc(II) ([Zn(tpps)]), and investigated its in vitro insulin-mimetic activity and in vivo hypoglycemic effect in type 2 diabetic KKA(y) mice. The results were compared with those of previously proposed insulin-mimetic zinc(II) complexes and zinc sulfate (ZnSO(4)). The in vitro insulin-mimetic activity of [Zn(tpps)] was considerably better than that of bis(allixinato)zinc(II) ([Zn(alx)(2)]), bis(maltolato)zinc(II) ([Zn(mal)(2)]), bis(2-aminomethylpyridinato)zinc(II) ([Zn(2-ampy)(2)](2+)), and ZnSO(4). In particular, the order of in vitro insulin-mimetic activity of the complexes was determined to be: [Zn(tpps)]>[Zn(alx)(2)]>[Zn(mal)(2)]>[Zn(2-ampy)](2+)>ZnSO(4). [Zn(tpps)] normalized the hyperglycemia of KKA(y) mice within 21 days when administered orally at doses of 10-20 mg (0.15-0.31 mmol) Zn per kg body mass for 28 days. In addition, metabolic syndromes such as insulin resistance, the degree of renal disturbance, and the degree of liver disturbance were significantly improved in [Zn(tpps)]-treated KKA(y) mice relative to those administered with saline and ZnSO(4). The improvement in diabetes was validated by the results of oral glucose-tolerance tests and the decrease in the HbA(1c) level observed. In contrast, ZnSO(4) and the ligand H(2)tpps did not lower the elevated blood glucose level under the same experimental conditions. Based on these observations, [Zn(tpps)] is proposed to be the first orally active zinc(II)-porphyrin complex for the efficacious treatment of not only type 2 diabetes but also metabolic syndromes in animals.

A novel drug delivery system for type 1 diabetes: insulin-mimetic vanadyl-poly(gamma-glutamic acid) complex.

Insulin-mimetic vanadyl-poly(gamma-glutamic acid) complex, VO-gamma-PGA, is proposed as a novel drug delivery system for treating type 1 diabetic animals. The structure of VO-gamma-PGA in solution as well as in solid state was analyzed by electronic absorption, infra-red, and electron spin resonance spectra, and proposed that the equatorial coordination mode of VO(2+) is in either carboxylate(O)-VO-(OH(2))(3) or 2 carboxylate(O(2))-VO-(OH(2))(2). In vitro insulin-mimetic activity, metallokinetic feature in the blood of healthy rats, and in vivo normoglycemic effect of the complex prepared in solution were evaluated in streptozotocin(STZ)-induced type 1 diabetic mice, and these effects were compared with those of a solution containing only VOSO(4) as a positive control. The in vitro insulin-mimetic activity of VO-gamma-PGA was examined by determining both inhibition of free fatty acid (FFA) release and glucose uptake in isolated rat adipocytes, in which the concentration of VO-gamma-PGA for 50% inhibition of FFA release was significantly lower than that of VOSO(4). Metallokinetic study suggested that the bioavailability of VO-gamma-PGA complex was much higher than that of VOSO(4). The complex showed a significant hypoglycemic activity within at least 4h after a single oral administration, the effect being sustained for at least 24h. Furthermore, VO-gamma-PGA normalized the hyperglycemia in STZ-mice within 3 days when it was given orally at doses of 5-10mgVkg(-1) body mass for 16 days. The improvement in diabetes was also supported by the results on oral glucose tolerance test, HbA(1c) levels, and blood pressure.