Purification and chemical modification of porcine bone morphogenetic protein

Implantation of porcine bone morphogenetic protein (pBMP) in the muscle induces differentiation of mesenchymal-type cells and results in endochondral bone formation. pBMP was isolated from porcine demineralized bone matrix and purified by hydroxyapatite chromatography, Sephadex G75 gel filtration, preparative sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), preparative isoelectric focusing (IEF), and chromatofocusing fast protein liquid chromatography (FPLC). Porcine BMP has an MW of 26 K and a range of pI from 4.65 to 4.73 determined by SDS-PAGE and IEF, respectively. Reconstitution with the citrate buffer supernatant fraction enables as little as 50 micrograms of the soluble pBMP fractions to induce osteogenesis in an in vivo assay. Chemical modification studies indicate that the osteoinductive potential of the pBMP molecule depends on tyrosine, carboxyl groups, and disulfide bonds and can be increased by modification of sulfhydryl groups. Modification of arginine and tryptophan has no effect on bioactivity. By pepsin-limited proteolysis, fragments of pBMP with an MW of 6-14 K show definite, although reduced, BMP activity.     

Selective intra-arterial methylene blue injection: a novel method of localizing gastrinoma.

A 40-year-old woman had persistent Zollinger-Ellison syndrome despite excision of a 4-cm duodenal gastrinoma. Localizing studies including ultrasonography, computed tomography, magnetic resonance imaging, duodenal endoscopy, endoscopic ultrasonography, and intraoperative endoscopic transillumination of the duodenum failed to detect a tumor. Selective intra-arterial methylene blue injection was used to identify a 6-mm gastrinoma in the duodenum, which was locally excised. Postoperatively, the patient had a negative secretin provocative test result. This novel method uses selective arterial secretin injection with hepatic venous gastrin sampling to identify the vessel feeding the gastrinoma. An angiographic catheter is then positioned in this artery. At laparotomy, methylene blue is injected through this catheter to selectively stain the gastrinoma, facilitating its identification. Selective intra-arterial methylene blue injection can enhance intraoperative detection of small gastrinomas and may improve the rate of curative resection in the Zollinger-Ellison syndrome. Further evaluation of this novel localizing technique is warranted.     

Effects of posts on dentin stress distribution in pulpless teeth.

A finite element analysis was carried out to study the roles of posts in reducing dentin stress in pulpless teeth. Two-dimensional plane strain models of the midlabiolingual section of a human maxillary central incisor were first analyzed. The results showed that the gold alloy post reduced maximal dentin stress by as much as 30%. However, the integrity of the dentin was compromised and the effects of the post were likely to be exaggerated in such models. In an effort to correct for these problems, plane stress models with side plates and axisymmetric models were analyzed. Posts were found to reduce maximal dentin stress by only 3% to 8% when the teeth were subjected to masticatory and traumatic loadings in these latter models. Although posts reduced maximal dentin stress by as much as 20% when the teeth were loaded vertically, teeth such as incisors and canines normally are not subjected to vertical loadings. Thus the reinforcement effects of posts seem to be doubtful in these teeth.     

Restriction fragment length polymorphism analysis to study the genetic origin of complete hydatidiform mole.

To determine the genetic origin of the complete hydatidiform mole, 20 abnormal pregnancies were studied with restriction fragment length polymorphism with five genomic probes: EJ 6.6, beta-globin gene, 3'alpha-hypervariable region, J-Bir, and St14. In the 12 cases of molar pregnancy, pure paternal origin was proved in 11 cases, but both maternal and paternal inheritance were shown in only one case. In the cases with pure paternal origin, all of the restriction fragment length polymorphisms were homozygous, although those of the fathers were heterozygous at 15 loci. In the four cases that mimicked hydatidiform mole but were diagnosed as hydropic change of villi, both paternal and maternal inheritance were noted. In the four pregnancies with blighted ovum, both paternal and maternal inheritance were shown in three cases; and in one case with a balanced translocation between chromosomes 13 and 14, only paternal inheritance was noted. This study showed that most of the complete hydatidiform moles were caused by fertilization of an empty egg by a duplicated haploid sperm, but rare exceptions may exist.     

The value of ventilation scintigraphy after single lung transplantation.

BACKGROUND: A decrease in forced expiratory volume in 1 second (FEV(1)) as a diagnostic criterion for bronchiolitis obliterans syndrome (BOS) after single lung transplantation may be influenced significantly by the presence of the native lung. To quantify and to discriminate between the relative contribution of graft and native lung to the FEV(1), we retrospectively investigated the diagnostic value of combined FEV(1) measurements and ventilation scintigraphy in pulmonary dysfunction after single lung transplantation in 11 recipients with pulmonary vascular disease, 3 with obstructive lung disease, and 3 with restrictive lung disease. METHODS: We assessed function of the native lung and the graft, and subsequently calculated an adjusted grading of BOS by correcting routine FEV(1) measurements using linear interpolation of bi-annual lung ventilation scans. RESULTS: The contribution of the native lung to the total FEV(1) was slight (median, 9%) in recipients with obstructive disease compared with recipients with vascular (38%) or restrictive lung diseases (27%). Adjusted BOS grading was not useful in patients with obstructive disease. In the other patient groups, the onset of adjusted BOS Grade 1 and standard BOS Grade 1 was at a median of 220 days (range, 127-1146 days) and 836 days (184-3065 days), respectively. CONCLUSION: Ventilation scintigraphy is a useful adjunct in the (early) diagnosis of BOS in recipients of single lung transplants who have vascular and restrictive lung diseases.     

Status and trend of HIV-1 infection and AIDS in Taiwan, December, 1991.

From May 1, 1985 to December 31, 1991, a total of 4,962,707 serum samples from 8 population groups in Taiwan were tested for anti-human immunodeficiency virus type 1 (anti-HIV-1). In total, 256 samples were seropositive; of these individuals, 43 developed acquired immunodeficiency syndrome (AIDS): 29 were homosexuals; 5 were hemophiliacs; 8 were heterosexuals and 1 was of unknown risk. Although the prevalence of HIV-1 infection and AIDS remains low compared with other countries, since 1988 the increase has been rapid. Before 1977 the majority were homosexuals and hemophiliacs; thereafter the risk groups diversified, with a trend away from homosexuals and hemophiliacs towards heterosexuals and intravenous drug abusers (IVDAs). A few patients have caused serious social problems for the public, health care workers and families. Active community efforts are needed to achieve future success in the control of HIV-1 infection and AIDS in Taiwan.     

Evaluation of the visual system in people having extended contact with fluorine

Presented are the results of examination of 75 men, workers of the Chemical Works in Police, in whom in the scheme of complex clinical examinations detailed ophthalmological examinations have been carried out. The period of a professional contact with fluor amounted 6-15 years. The examined persons showed a variety of changes; the most important were opacities of the lens capsule, attenuation of the retinal arteries and a pathological record of the ERG.     

Mechanisms of the inhibition by neostigmine of tetanic contraction in the mouse diaphragm.

Neostigmine (0.5-2 microM) caused fade of tetanic contractions (Wedensky inhibition) evoked by repetitive nerve stimulation. The mechanism underlying this action was studied in intact and cut isolated phrenic nerve-diaphragm preparations of mice. The fade was brought about by failure to elicit muscle action potentials. During fade, the muscle was unable to conduct directly evoked action potentials across the central endplate zone. Recovery of excitability occurred in 5 s with continued stimulation. In the presence of neostigmine, the resting membrane potential at endplate areas during repetitive stimulation decreased from -80 mV to less than -50 mV within the first 10 pulses at 75-200 Hz and thereafter recovered gradually to about -60 mV in the following 5 s during continuous stimulation. The quantal content of endplate potentials evoked by single stimulation was not reduced by neostigmine whereas that evoked by high frequency stimuli (75 Hz) was reduced to about 1/3 in 10 pulses. It is concluded that the fade of tetanic contraction caused by inhibition of acetylcholinesterase is induced by the inactivation of sodium channels in the area surrounding the endplates and that the sustained fade is due to a decrease of transmitter release. Both effects are the result of acetylcholine accumulation.     

Comparison of glomerular and mesangial prostaglandin synthesis and glomerular contraction in two rat models of diabetes mellitus

Enhanced prostaglandin production is postulated to contribute to altered vascular reactivity and glomerular hyperfiltration in early insulin-deficient diabetes mellitus. Rats with streptozocin-induced diabetes (STZ-D) show glomerular hyperfiltration and develop renal disease. BB rats with genetic diabetes (BB-D) also hyperfilter but have only minor renal lesions. We therefore compared glomerular and mesangial prostaglandin E2 (PGE2) production and glomerular contractility in response to pressors as a reflection of in vitro vascular reactivity in these models. Glomeruli isolated from rats with 3 wk of STZ-D produced significantly more PGE2 under basal and ionophore A23187-stimulated conditions than those from control rats. Glomeruli from BB-D rats under basal and stimulated conditions, however, generated amounts of PGE2 that were comparable to either those of nondiabetic littermates or of normal Wistar rats. Mesangial cells cultured from glomeruli of STZ-D, BB-D, and control rats all had identical prostaglandin profiles judged by conversion of [14 C]arachidonic acid. They also produced comparable amounts of PGE2 under basal conditions and after stimulation with angiotensin II or A23187, as determined by radioimmunoassay. Planar surface area of glomeruli isolated from control rats showed a dose-dependent decrease in response to angiotensin II (10(-11)-10(-9) M). This response to angiotensin II was at least as great in glomeruli from STZ-D rats. Contraction of glomeruli from control and STZ-D rats was also comparable after vasopressin or norepinephrine. Similarly, glomeruli from BB-D and BB control rats contracted in a comparable fashion to angiotensin II and norepinephrine.(ABSTRACT TRUNCATED AT 250 WORDS)