Dependence of the Molecular Mobility and Protein Stability of Freeze-Dried γ-Globulin Formulations on the Molecular Weight of Dextran

Purpose. The effect of the molecular weight of dextran on the molecular mobility and protein stability of freeze-dried serum -globulin (BGG) formulations was studied. The stabilizing effect of higher molecular weight dextran is discussed in relation to the molecular mobility of the formulations. Methods. The molecular mobility of freeze-dried BGG formulations containing dextrans of various molecular weights was determined based on the free induction decay of dextran and water protons measured by proton NMR. The protein stability of the formulations was determined at temperatures ranging from 20 to 70°C by size exclusion chromatography. Results. Changes in the molecular mobility of freeze-dried formulations that occurred at temperatures below the glass transition temperature could be detected as the molecular mobility-changing temperature (T_mc), at which dextran protons started to exhibit a Lorentzian relaxation decay due to higher mobility in addition to a Gaussian relaxation decay. T_mc increased as the molecular weight of dextran increased. The proportion of dextran protons which exhibited the higher mobility relaxation process (P_hm) at temperatures above T_mc decreased as the molecular weight of dextran increased. Protein stability was closely related to molecular mobility. The temperature dependence of the denaturation rate changed at around T_mc, and denaturation in the microscopically liquidized state decreased as P_hm decreased with increasing molecular weight of dextran. Conclusions. The effect of the molecular weight of dextran on the protein stability of freeze-dried BGG formulations could be explained in terms of the parameters obtained by ¹H-NMR such as T_mc and P_hm. These parameters appear to be useful in preformulation and stability prediction of freeze-dried formulations.     

Tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2) stimulate osteoclastic bone resorption

As both tissue inhibitor of metalloproteinases-1 (TIMP-1) and TIMP-2 have been reported to inhibit bone resorption, we examined whether TIMP-1 or TIMP-2 in fetal calf serum (FCS), with which culture media were supplemented, affected osteoclastic bone resorption in vitro. Contrary to our expectation, almost complete suppression of osteoclastic bone resorption was observed when both TIMP-1 and TIMP-2 were removed from the FCS. Bone resorption was, however, almost fully restored by the addition of recombinant TIMPs. TIMPs stimulate bone resorption at significantly lower concentrations (∼ng/ml) than those (∼μg/ml) required to inhibit bone resorption. To understand the mechanism of TIMP-dependent bone resorption, we counted and compared the number of tartrate-resistant acid phosphatase-(TRAP-) positive and multinuclear cells in cultures containing either 10% FCS or TIMP-1-free and/or TIMP-2-free FCS. There was essentially no difference in number among these, suggesting that the TIMP role seems to be related to the functional expression of osteoclasts. Metallo-proteinase inhibitors, either BE16627B[l-N-(N-hydroxy-2-isobutylsuccinynamoyl)-seryl-l-valine] or R94138 {N-methyl-(3S)-2-[(2R)-2-hydroxycarbamoylmethylundecanoyl] hexahydropyridazine-3-carboxamide}, could not replace TIMPs, suggesting that the osteoclast-stimulating activity of TIMPs cannot be ascribed to merely their inhibitory effect on matrix metalloproteinases. Received: Oct. 15, 1998 / Accepted: April 5, 1999     

Study on allergic rhinitis in workers exposed to methyltetrahydrophthalic anhydride

Methylterahydrophthalic anhydride (MTHPA) is used as a hardening agent in an epoxy resin system. Because work-related nasal symptoms were observed in some workers exposed toMTHPA at two condenser plants, a cross-sectional survey was performed to improve their work environment. MeanMTHPA levels in the manufacturing processes to which the workers were routinely assigned were extremely low (1.09-22.4 μg/m3). However, specific IgE antibody (S-IgE) was detected in 9 (32%) of 28 workers. Of these, 8 (89%) had nasal symptoms. An IgE-mediated mechanism seems to be associated with at least some of the cases of work-related nasal symptoms. This indicates that the occupational health administration ofMTHPA cannot be controlled simply by limiting exposure in the work environment. Total IgE (T-IgE) levels were significantly higher in S-IgE-positive workers than in S-IgE-negative workers (geometric mean, 200.5 and 51.3 IU/ml, respectively; p<0.002, unpaired t test). These findings demonstrate that workers in whom S-IgE is less likely to be produced, i.e., those in whom the T-IgE level is 80 IU/ml or less, should be assigned to work in these manufacturing processes.     

Membrane structures of human oligodendroglioma

Summary Two cases of McArdle's syndrome are reported. One is a classical exaple; the other is unusual because of the in vitro presence of muscle phosphorylase activity. In the latter case. the electronmicroscopic investigation confirmed the diagnosis.The fine structural changes characteristic of this disease are summarized and it is concluded that histochemical studies alone are insufficient to exclude the diagnosis of McArdle's myopathy.     

Serum fluoride as an indicator of occupational hydrofluoric acid exposure

Summary To define the relationship between ionic fluoride concentration in the serum of workers and the amount of hydrofluoric acid (HF) in the work environment, pre-and postshift serum and urine samples of 142 HF workers and 270 unexposed workers were examined. The maximum and minimum concentrations of HF in the air in each workshop varied from the mean by less than 30%. The pre-exposure levels of serum and urinary fluoride in HF workers were higher (P < 0.001) than the control values. This suggests that fluoride excretion from the body continues for at least 12 h. The postshift serum and urinary fluoride concentrations of these workers were significantly higher (P < 0.001) than the preshift concentrations. A good correlation (r = 0.64) was obtained between postshift serum fluoride and postshift urine fluoride. There was a linear relationship between mean serum fluoride concentration and HF concentration in the workshop. A mean fluoride concentration of 82.3 g/l with a lower fiducial limit (95%, P = 0.05) of 57.9 g/l was estimated to correspond to an atmospheric HF concentration of 3 ppm. This is the maximum allowable environmental concentration recommended by the Japanese Association of Industrial Health, and it is also the threshold limit value suggested by the American Conference of Governmental Industrial Hygienists. The results demonstrate that exposure to HF can be monitored by determining the serum fluoride concentration.     

Small follicular lymphoma arising near the ampulla of vater

A 49-yr-old Japanese woman underwent upper gastrointestinal endoscopy because of nonspecific dyspepsia. Endoscopy revealed a flat elevated lesion about 15 mm in diameter adjacent to the duodenal papilla, the surface of which was uneven and covered with whitish granules. Based on the results of histological examination with immunohistochemistry (positive for CD10, CD20, CD79a, and bcl-2 protein, negative for CD5 and cyclin D1), a diagnosis of grade 1/3 follicular lymphoma was established. Systemic staging examinations suggested the lymphoma was restricted to the mucosa and superficial portion of the submucosa in the duodenal wall. The patient was treated with a combination of CHOP chemotherapy (cyclophosphamide, doxorubicin, vincristine, and prednisolone) and monoclonal anti-CD20 antibody (rituximab), in addition to radiotherapy. After six courses of this combination chemotherapy, complete regression of the lymphoma was observed. Although reports of small duodenal lymphoma (<20 mm or localized to the mucosa or submucosa) are extremely rare, the features of this case are characteristic of small duodenal lymphoma in terms of evolution around the ampulla of Vater, low-grade follicular type, occurrence in a women, occurrence in the fourth decade of life, and favorable outcome, and this type of tumor may need to be distinguished by pathogenesis and clinical behavior from various other gastrointestinal lymphomas.