Sixth nerve palsies in children

The causes of sixth nerve palsies in 75 children, all of whom had undergone modern neuroimaging, were reviewed. Neoplasms or their neurosurgical removal was the most common cause (n = 34 [45%]); elevated intracranial pressure (nontumor) (15%), traumatic (12%), congenital (11%), inflammatory (7%), miscellaneous (5%), and idiopathic (5%) causes represented other categories but were less commonly present. Isolated sixth nerve palsies were relatively uncommon (9%). On the basis of the relatively high risk of neoplasm, the authors suggest neuroimaging early in the clinical course of children with sixth nerve palsies, even if the palsy is isolated.

Acute effects of chundosunbup qi-training on blood concentrations of TSH, calcitonin, PTH and thyroid hormones in elderly subjects

The present study investigated how the systemic treatment of a programmed exercise, ChunDoSunBup (CDSB) Qi-training, affects the secretion of thyroid and parathyroid hormones in elderly subjects (10 male and 5 female). Plasma concentrations of thyroid stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), parathyroid hormone (PTH), ionized calcium, and calcitonin were determined. CDSB Qi-training induces a slight increase in TSH. Both T4 and T3 were increased at the mid-time of CDSB Qi-training (p < 0.05). There were significant correlations only between T3 and T4 at mid-training. This shows that increase in the plasma level of T3 was associated with the secretion of T4. The plasma concentrations of calcitonin and PTH were increased at mid-time and post-time of CDSB Qi-training. But ionized calcium was decreased slightly by CDSB Qi-training. These results suggest that Qi-training modulates the secretion of thyroid hormones, calcium metabolism, and parathyroid hormones in the elderly. However, whether the long-term practice of CDSB Qi-training might change bone metabolism and have longitudinal effects on the thyroid hormone of the elderly need further investigation.

Dietary fiber content and composition of fruits in Taiwan

Forty-one fresh fruits frequently consumed in the Taiwan area were analysed for their dietary fiber content by an enzymatic-gravimetric method. Total dietary fiber (TDF) of these fruits ranged from 0.2 g (per 100 g edible weight) in grapes to 8.6 g in eggfruit. In citrus fruit, the proportion of soluble fiber in TDF was more than 50%. However, in some fruits like guavas and waxapple, soluble fiber took less than 30% of TDF. Soluble fiber in almost all fruit was comprised of a large amount of uronic acids, while the composition of insoluble non-cellulose polysaccharides (INCP) varied a great deal. Mangos and pummelos of different varieties were different in their sugar composition of INCP. Insoluble non-cellulose polysaccharides of a crisp type of persimmon had more arabinose and galactose, but those of soft persimmon contained mainly xylose. These results show that different types of fruit are distinct in their composition and hence, the properties of their dietary fiber. These data are useful for dietary assessments in Taiwan and South-East Asia.

Co-administration of sertraline and haloperidol

Along with recent increased interest in the selective serotonin reuptake inhibitors, a number of studies has been undertaken to observe interactions with different drugs. When selective serotonin reuptake inhibitor was administered together with antipsychotics to schizophrenics showing depressive or obsessive symptoms and negative symptoms, meaningful results were observed. The objective of our research was to identify the changes in the concentration of plasma haloperidol when sertraline was administered to patients who already were being treated with haloperidol. Sixteen patients who did not respond to the traditional antipsychotics after 2 weeks of treatment with a certain dosage of haloperidol were administered with 50 mg of sertraline for a period of 2 weeks. The concentration changes between plasma haloperidol and the reduced haloperidol were observed using high-powered liquid chromatography equipped with a UV detector. There was a significant increase (P < 0.01) in the concentration of haloperidol, the change being from 8.52 +/- 4.22 to 10.91 +/- 5.38 ng/mL. However, the change in the concentration of reduced haloperidol was from 7.41 +/- 7.93 to 5.22 +/- 6.10 ng/mL, showing a significant decrease. The concentrations of total plasma haloperidol showed no significant changes at all. In comparing the ratio of the reduced haloperidol and the haloperidol, the reduction ratio was down to 0.39 +/- 0.27 from 0.94 +/- 0.65 showing a significant decrease. There seems to be few studies done on interactions using serotonergic drugs together with antipsychotics in spite of their clinically applicable possibility. According to similar studies done in the past, co-administering of such drugs not only increases the plasma concentration of antipsychotics, but it also results in clinical improvement of negative symptoms and aggravation of extrapyramidal symptoms. Changes in clinical symptoms and adverse effects were not observed in our study. However, we think these observations need to be included in upcoming larger scale studies.

Insertion-duplication mutagenesis in Streptococcus pneumoniae: targeting fragment length is a critical parameter in use as a random insertion tool

To examine whether insertion-duplication mutagenesis with chimeric DNA as a transformation donor could be valuable as a gene knockout tool for genomic analysis in Streptococcus pneumoniae, we studied the transformation efficiency and targeting specificity of the process by using a nonreplicative vector with homologous targeting inserts of various sizes. Insertional recombination was very specific in targeting homologous sites. While the recombination rate did not depend on which site or region was targeted, it did depend strongly on the size of the targeting insert in the donor plasmid, in proportion to the fifth power of its length for inserts of 100 to 500 bp. The dependence of insertion-duplication events on the length of the targeting homology was quite different from that for linear allele replacement and places certain limits on the design of mutagenesis experiments. The number of independent pneumococcal targeting fragments of uniform size required to knock out any desired fraction of the genes in a model genome with a defined probability was calculated from these data by using a combinatorial theory with simplifying assumptions. The results show that efficient and thorough mutagenesis of a large part of the pneumococcal genome should be practical when using insertion-duplication mutagenesis.

Effects of chundosunbup Qi-training on psychological adjustments: a cross-sectional study

This cross-sectional investigation evaluated the trend of psychological changes by ChunDoSunBup (CDSB) Qi-training using a self-report inventory of emotional distress, Symptom Check List-90-Revision (SCL-90-R). 41 normal healthy subjects (mean age = 20.98 +/- 5.39) and 123 CDSB Qi-trainees (divided into three groups, Q1, Q2 and Q3) participated in this study. Group Q1 has received 1-4 months CDSB Qi-training (age 21.95 +/- 7.82, n = 41); Q2 has 5-12 months Qi-training (age 20.0 +/- 7.75, n = 41); and Q3 has more than 13 months Qi-training (age 22.68 +/- 6.72, n = 41). Our results show that Qi-trainees over 13 months had significantly lower scores compared to controls. A significant negative correlation was found between the Qi-training period and all SCL-90-R subscales except phobic anxiety. These results suggest that CDSB Qi-training is effective in protection as well as reduction of psychological symptomatology.

Immunoglobulin E-dependent active fatal anaphylaxis in mast cell-deficient mice

Mast cells have long been believed to be the central effector cells in the development of immunoglobulin (Ig)E-dependent anaphylaxis. In this study, we investigated the role of mast cells in IgE-dependent hapten-induced active fatal anaphylaxis using mast cell-deficient WBB6F1- W/Wv (W/Wv) and congenic normal (+/+) mice. Although a 5-min delay in shock signs and death were observed in W/Wv mice, 100% fatal reactions to penicillin V (Pen V) occurred in both +/+ and W/Wv mice. Administration of monoclonal anti-IL-4 antibody completely prevented the fatal reactions, and the effect of anti-IL-4 was associated with its suppressive activity on Pen V-specific serum levels of IgE, but not IgG. The platelet-activating factor (PAF) antagonist, BN 50739, completely prevented the fatal reactions in both strains of mice. Our kinetic study revealed, in contrast to no elevation of plasma histamine level in W/Wv mice, high levels of PAF in the circulation after challenge in both +/+ and W/Wv mice, albeit to a lesser degree in the latter case. These data indicate that cells other than mast cells are sufficient to induce an IgE-dependent active fatal anaphylaxis by elaborating PAF, which is the critical mediator for fatal murine anaphylaxis.

Oblique medial malleolar osteotomy for the management of talar dome lesions

The purpose of this retrospective study was to determine the efficacy of the oblique medial malleolar osteotomy for the management of medial talar dome lesions. Arthroscopy remains a viable option for the management of these lesions; however, the central and posteromedial lesions are often difficult to gain access to with arthroscopy and may require open arthrotomy. Fourteen oblique medial malleolar osteotomies were performed for the surgical management of medial talar dome lesions. Subjective data were collected through the process of questionnaire. Objective criteria consisted of radiographic evaluation and retrospective medical record review. Seven of the 14 patients related a history of trauma preoperatively. The oblique medial malleolar osteotomy demonstrated osseous union at an average of 6.6 weeks. There were no delayed unions or nonunions. None of the patients required a second operative procedure. Nine patients reported excellent postoperative results, two patients had good results, two had fair results, and one patient related a poor postoperative outcome with only 50% relief of pain. Patients greater than the age of 30 were found to have less favorable results. Follow-up ranged from 6 to 72 months, with a mean follow-up of 34 months.

Colonoscopic diagnosis of whipworm infection

Trichuriasis is an intestinal infection found in human beings which is caused by Trichuris trichiura, more commonly known as whipworm because of its whip-like appearance. It is characterized by the invasion of the colonic mucosa by the adult Trichuris and produces minor inflammatory changes at the sites of localization. It is prevalent throughout the world, especially in tropical areas. Its diagnosis is usually made by identification of the typical eggs in the stool; adult whipworm is rarely seen during colonoscopy. Colonoscopy can directly diagnose trichuriasis, confirming the threadlike form of worms with an attenuated end. The worms can be overlooked, particularly if colon preparation is imperfect. Attenuated whip-like ends of whipworms, which are embedded in the colonic mucosa, were removed with biopsy forceps. We report on 5 cases of whipworm infection that were diagnosed on total colonoscopy.

Maternal or paternal exposure to radiation increases susceptibility to the induction of glutathione S-transferase-positive hepatic foci in offspring rats

Experiments were conducted to determine whether gamma-ray-induced genetic damage in parental rats can lead to the development of cancer in their offspring rats using glutathione S-transferase-positive (GST-P+) hepatic foci with or without the addition of diethylnitrosamine (DEN), a carcinogen. A single 1 Gy whole-body exposure of gamma-rays was given to pregnant rats at day 14 and during postnatal week 3, DEN was intraperitoneally injected twice in 1 week. Female pups from irradiated maternal and paternal rats were also used. Twelve weeks after birth, the rats were sacrificed. GST-P+ foci in animals subjected only to radiation were not different to those of normal control pups, but the incidence of GST-P+ foci was 2.4 times higher in pups treated with DEN alone at 3 weeks after birth than in those irradiated after the onset of pregnancy. In DEN-combined groups, irradiation of post-pregnant or maternal and paternal rats with gamma-rays before mating significantly increased both the incidence and area of GST-P+ foci when compared to those of rats treated with DEN alone. The proliferating cell nuclear antigen (PCNA) labeling index was significantly higher in the offspring of rats subjected to radiation alone or radiation combined with DEN than in normal control pups. Using a rat-liver model, the results of this study indicate that although the dose did not induce phenotypic malformation, exposure to radiation during the embryonic or pre-embryonic stage increases susceptibility to carcinogens.

A double-blind study of adjunctive sertraline in haloperidol-stabilized patients with chronic schizophrenia

We conducted a placebo-controlled, randomized, double-blind, 8-week trial of sertraline added to haloperidol treatment in patients with schizophrenia to evaluate changes in clinical measures and pharmacokinetic interactions with haloperidol. In addition to their haloperidol regimen, 36 inpatients with chronic schizophrenia were randomly assigned to receive capsulized sertraline (50 mg/day; N = 18) or identically capsulized placebo (N = 18) for 8 weeks. The results from the Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression (CGI) Scale, Simpson-Angus Extrapyramidal Effects (S-A) Scale, and plasma concentration levels of haloperidol and reduced haloperidol were examined at baseline and 2, 4, 6, and 8 weeks of treatment. No significant differences between the three PANSS factors (positive, negative, general psychopathology) scores, CGI Scale scores, or S-A Scale scores were recorded at any point during sertraline and placebo treatment. Neither plasma haloperidol or reduced haloperidol concentrations was changed significantly at any point during the sertraline and placebo treatments. In this study, the addition of sertraline 50 mg to the treatment regimen of inpatients did not differ significantly from the placebo effect on positive and negative symptoms and extrapyramidal side effects. The results further indicate that the pharmacokinetics of haloperidol are seemingly unaffected by sertraline.

Molecular cloning and analysis of the argC gene from Corynebacterium glutamicum

The argC gene encoding N-acetylglutamate 5-semialdehyde dehydrogenase has been cloned from Corynebacterium glutamicum by transforming Escherichia coli arginine auxotroph with the genomic DNA library. Based on the restriction map of the cloned DNA, we have subcloned and sequenced the minimal DNA fragment complementing the E. coli argC mutant. The coding region of the cloned gene is 1041 nucleotides long with a predicted molecular mass of about 38 kDa polypeptide. Enzyme activity and size of the expressed protein in the E. coli auxotroph carrying the recombinant argC gene revealed that the cloned gene indeed codes for N-acetylglutamate 5-semialdehyde dehydrogenase. Computer analysis of the amino acid sequences of the predicted protein revealed a strong similarity to the corresponding protein of other bacteria.

Solution structure of the cellular factor BAF responsible for protecting retroviral DNA from autointegration

The solution structure of the human barrier-to-autointegration factor, BAF, a 21,000 Mr dimer, has been solved by NMR, including extensive use of dipolar couplings which provide a priori long range structural information. BAF is a highly evolutionarily conserved DNA binding protein that is responsible for inhibiting autointegration of retroviral DNA, thereby promoting integration of retroviral DNA into the host chromosome. BAF is largely helical, and each subunit is composed of five helices. The dimer is elongated in shape and the dimer interface comprises principally hydrophobic contacts supplemented by a single salt bridge. Despite the absence of any sequence similarity to any other known protein family, the topology of helices 3-5 is similar to that of a number of DNA binding proteins, with helices 4 and 5 constituting a helix-turn-helix motif. A model for the interaction of BAF with DNA that is consistent with structural and mutagenesis data is proposed.

Giant hidradenocarcinoma: a report of malignant transformation from nodular hidradenoma

A giant hidradenocarcinoma presented by a 75-year-old female is reported. The patient had a malignant transformation within a nodular hidradenoma involving the right postauricular area, which was treated by mass removal and a right radical neck dissection with a free-flap covering. Malignant hidradenocarcinoma is the least common adnexal tumor of uncertain origin. They are usually malignant from their inception, but some develop from a benign counterpart. To the authors' knowledge, only three cases have been reported previously. Two histologically distinct components were seen in this tumor: (i) typical nodular hidradenoma, which constituted a small part of the tumor; and (ii) carcinoma with areas of transition. The secretory cells of hidradenocarcinoma showed decapitation secretion on light and electron microscopic observations, which is evidence of apocrine differentiation. Histologically, this case was concluded as a hidradenocarcinoma arising from a long-standing nodular hidradenoma. A literature review is presented and the histological, immunohistochemical and ultrastructural features are described.

Skin necrosis due to photodynamic action of benzoporphyrin depends on circulating rather than tissue drug levels: implications for control of photodynamic therapy

In an ideal world, photodynamic therapy (PDT) of abnormal tissue would reliably spare the surrounding normal tissue. Normal tissue responses set the limits for light and drug dosimetry. The threshold fluence for necrosis (TFN) was measured in normal skin following intravenous infusion with a photosensitizer, benzoporphyrin derivative monoacid ring A (BPD-MA) Verteporin as a function of drug dose (0.25-2.0 mg/kg), wavelength of irradiation (458 and 690 nm) and time interval (0-5 h) between drug administration and irradiation. The BPD-MA levels were measured in plasma and skin tissue to elucidate the relationship between TFN, drug kinetics and biodistribution. The PDT response of normal skin was highly reproducible. The TFN for 458 and 690 nm wavelengths was nearly identical and the estimated quantum efficiency for skin response was equal at these two wavelengths. Skin phototoxicity, quantified in terms of 1/TFN, closely correlated with the plasma pharmacokinetics rather than the tissue pharmacokinetics and was quadratically dependent on the plasma drug concentration regardless of the administered drug dose or time interval between drug and light exposure. This study strongly suggests that noninvasive measurements of the circulating drug level at the time of light treatment will be important for setting optimal light dosimetry for PDT with liposomal BPD-MA, a vascular photosensitizer.

The effects of surgical and chemical delay procedures on the survival of arterialized venous flaps in rabbits

The aim of this study was to investigate the efficacy of a surgical delay procedure and a combined surgical and chemical delay procedure on the survival of arterialized venous flaps. Experimental groups included (1) a control group, (2) a surgical delay (4-day and 7-day delay) group, and (3) a combined surgical and chemical (doxazosin mesylate, nitroglycerine patch) delay group. These groups were further divided into subgroups (n = 10) depending on the delay period and the chemical agents. An arterialized venous flap was created on one ear of each rabbit. In the arterialized venous flap, arterial inflow was provided by anastomosis of the central auricular artery to the anterior branch of the central auricular vein and a venous outflow through the anterior marginal vein. In the control group, the arterialized venous flaps without any delay procedure showed complete necrosis of all flaps. In the surgical delay group, the mean percentage survival of arterialized venous flaps was 36.6 percent in the 4-day delay group and 59.7 percent in the 7-day delay group. In the combined surgical and chemical delay group, a 3-day chemical delay followed by a 4-day simultaneous surgical and chemical delay resulted in mean percentage survival of the arterialized venous flaps of 81.1 percent in the doxazosin mesylate group, 72.8 percent in the nitroglycerine patch group, and 92.9 percent in a combination group of doxazosin mesylate and nitroglycerine patch. A 3-day chemical delay followed by a 7-day simultaneous surgical and chemical delay resulted in mean percentage survival of the arterialized venous flaps of 94 percent in the doxazosin mesylate group, 90.2 percent in the nitroglycerine patch group, and 99 percent in a combination group of doxazosin mesylate and nitroglycerine patch. In conclusion, the surgical delay procedure increased the percentage survival of the arterialized venous flaps in proportion to the delay period. The combination group of surgical and chemical delay procedures had a significantly greater percentage survival than that of the surgical delay group (p < 0.001), and the delay period could be shortened.

Induction of growth inhibition of 293 cells by downregulation of the cyclin E and cyclin-dependent kinase 4 proteins due to overexpression of TIS21

We earlier reported that TIS21 mRNA expression was markedly decreased in A549 and NCIH69 human lung cancer cells and in thymic carcinoma tissues obtained from transgenic mice containing simian virus 40 large T antigen (J Cancer Res Clin Oncol 121:279-284, 1995). To determine how TIS21 inhibits growth, we made 293 cells that constitutively expressed TIS21 protein. The constitutive TIS21 expresser lines C9 and C11 grew to a lower saturation density than did those in the vector-transfected clones (V7 and V10) and antisense-transfected clones (AS1 and AS4), and the size of the C9 and C11 cells increased significantly after transfection with TIS21 cDNA. The serum-stimulated cell cycle was analyzed by fluorescence-activated cell sorting after double thymidine treatment; V10 progressed normally through the cell division cycle, but C9 and C11 cells accumulated continuously in G1 phase until 36 h after treatment. On the other hand, the progression of cells that had already entered to S or G2/M phase was not inhibited. When cell-cycle regulatory proteins were measured, C9 and C11 cells showed significantly reduced synthesis of cyclin E and cyclin-dependent kinase (cdk) 4 as well as a decrease in cyclin E-associated cdk activity. These observations led us to conclude that TIS21 overexpression in G1 phase decreased the amounts of cyclin E and cdk4, thereby decreasing the activity of cdks at the G1-S transition.

Cytokinetic pattern in the thoracic spinal cord of chick embryos (incubation day 5-13) using PCNA staining and TUNEL method

For the cytokinetic studies using spinal cords of chick embryos, chronological patterns of cell proliferation and programmed cell death (apoptosis) should be known. Information in the early stages of chick embryos is available while data on later stages are seldom available. To investigate the chronological patterns of cell proliferation and apoptosis in the thoracic spinal cord of normal chick embryos on incubation day 5, 6, 8, 10 and 13 (Hamburger and Hamilton stage 26-40), proliferating cell nuclear antigen (PCNA) staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method were used. Cell proliferation was active at the germinal layer on days 5 and 6. It markedly declined on day 8 and became negligible on day 13. TUNEL-positive cells were mainly found in the germinal layer, the ventrolateral part of the mantle layer and the dorsal root ganglion. Compared to PCNA-positive cells, TUNEL-positive cells were sparse, especially after day 10, when only a few positive cells were scattered. These results will be used as a control data for the studies such as an experimental research for neural tube defects.

The effects of diffusion blur on Snellen and grating acuity and foveal function in amblyopia

In order to verify that the effects of diffusion blur on Snellen and grating acuity in amblyopic eyes resemble those obtained from the peripheral or central retina in normal controls, we conducted the following experiment using a liquid crystal window (Edmund Scientific Co.) to produce diffusion blur on Snellen and grating acuity. Spatial frequencies used for a Snellen chart and Teller acuity card were 3.2, 6.5, 13.0, 26.0 cyc/cm at a working distance of 55 cm. The values of diffusive blur on central and peripheral visual acuity obtained from 20 normal healthy control eyes were compared with those values of central visual acuity in 26 amblyopic eyes. The diffusion blur had a strong negative effect on both Snellen and grating acuity in amblyopic eyes, but it had more potent effects on grating acuity (p < 0.05). The diffusion blur values obtained from the central amblyopic retina were more compatible with those of the central retina than with those of the peripheral retina in the control group (p > 0.05). Snellen acuity obtained from diffusion blur overestimated grating acuity in the normal central acuity group and amblyopic central acuity group. The result of this investigation demonstrated that the liquid crystal diffusion blur had a strong negative effect on both Snellen and grating acuity and suggested that the visual function of an amblyopic retina resembled that of a normal central retina.

Localization of atrial natriuretic peptide receptors in the rat tongue and hard palate

Atrial natriuretic peptide (ANP) receptors were characterized in rat oral mucosa using quantitative in vitro autoradiography and activation of particulate guanylyl cyclase (GC) by natriuretic peptides. Competition-binding analysis performed by quantitative in vitro autoradiography demonstrated specific [125I]rANP(1-28) binding sites in the tongue and hard palate. The precise location of this binding was revealed on the basal and parabasal cells of the epithelia by microautoradiography. The dissociation constant (Kd) and maximal binding capacity (Bmax) of these sites were 3.34+/-1.35 nM and 2.71+/-2.21 fmol/mm2 on the epithelium of the tongue, and 4.09+/-1.52 nM and 3.45+/-3.01 fmol/mm2 on the epithelium of the hard palate, respectively. Receptor subtypes were characterized by competition with des [Gln18, Ser19, Gly20, Leu21, Gly22] ANP(4-23) (C-ANP), a specific ligand for the clearance receptor (NPR-C). These binding sites were displaced by C-ANP with inhibition constant (Ki) of 8.96+/-3.18 nM and Bmax of 2.89+/-2.45 fmol/mm2 on the epithelium of the tongue, and Ki of 9.12+/-2.71 nM and Bmax of 3.08+/-2.94 fmol/mm2 on the epithelium of the hard palate, respectively. Production of cyclic GMP by particulate GC in the epithelial membranes of the tongue and hard palate was stimulated by rANP(1-28), porcine brain natriuretic peptide (BNP)(1-26), and C-type natriuretic peptide (CNP)(1-22) in a dose-dependent manner. These results indicate that ANP-binding sites in the epithelium of the tongue and hard palate are mainly clearance receptors (NPR-C) but biological receptors (NPR-A and/or NPR-B) with GC activity are also present, and suggest that ANP may have a role in the proliferation of the oral epithelial cells, especially in the tongue and hard palate.

Mutations of ret proto-oncogene in 3 Korean families with MEN 2A: clinical use of new restriction sites for genetic diagnosis

Abnormalities in the ret proto-oncogene are found in several disorders such as multiple endocrine neoplasia (MEN) 2, sporadic medullary thyroid cancer, congenital megacolon and papillary thyroid cancer. In MEN 2A or 2B, early genetic diagnosis before the development of clinical tumors is crucial for the cure of the disease. We studied mutations of ret proto-oncogene in 3 Korean families with MEN 2A and searched for new restriction sites that could be used for genetic diagnosis. By direct sequencing of exon 10 and 11 harboring 'hot' spots, heterozygous point mutation was detected at positions translating cysteine codon in all 3 families. In 2 families, mutations at codon 634 in exon 11 were found (from TGC to CGC or TAC), yielding a new CfoI or RsaI restriction site. In one family, a mutation was located at codon 618 in exon 10 (from TGC to CGC), generating a new CfoI restriction site. These new restriction sites were used in detecting 2 undiagnosed family members without clinical symptoms or signs. In one of them, thyroidectomy was performed to disclose a small medullary thyroid cancer. These results indicate that Korean MEN 2A patients have germ-line mutations in the ret protooncogene at the cysteine residues like patients of other races, and the strategy employing direct sequencing to find mutations at 'hot spot' and search for ensuing new restriction sites could be a useful approach for the molecular diagnosis of genetic diseases accompanied by mutations in restricted areas of disease genes such as MEN 2.

Use of affinity capillary electrophoresis for the study of protein and drug interactions

Protein-drug interactions were studied using affinity capillary electrophoresis (ACE). The initial study was performed using a model system, fibronectin-heparin interaction. Two distinct binding constants, 21 and 641 nM, were derived from the Scatchard plots. The results are consistent with reported data obtained using other analytical techniques. The ACE binding assay was applied for studying molecular interactions between kedarcidin chromophore and apoprotein. Conditions with an organic solvent as buffer component were examined to establish a suitable binding assay. It appears that the electrophoretic behavior of the protein shows little distortion in the presence of either dimethyl sulfoxide (up to 10%) or acetonitrile (ACN) (up to 30%). The binding assay was initially conducted in aqueous buffer phase. The saturation concentration of chomophore was found to be around 15 microM. A linear Scatchard plot was derived from binding data with a correlation coefficient of 0.94. The binding constant was determined as Kd = 5.6 microM. The effects of organic solvent content ranging from 0 to 30% ACN on the constant were examined. The binding constants were determined as Kd = 11, 12.5 and 16.2 microM for 5, 10 and 30% ACN, respectively. It appeared that the binding affinity between kedarcidin chromophore and apoprotein is reduced as the organic solvent content in the aqueous phase is increased.

Cloning of the histidine biosynthetic genes of Corynebacterium glutamicum: organization and sequencing analysis of the hisA, impA, and hisF gene cluster

The hisA and hisF genes of Corynebacterium glutamicum were cloned by transforming histidine auxotrophic Escherichia coli with the genomic DNA library. They are two of the eight genes that participate in the histidine biosynthetic pathway. Cloned DNA fragments containing the genes can also complement hisH and hisI auxotrophs of Escherichia coli, suggesting that the four genes are clustered in the genome. We determined the nucleotide sequences of the minimal fragment containing the hisA and hisF genes, which are separated by the impA gene. The coding regions of the hisA and hisF genes are 245 and 257 amino acids in length with a predicted size of about 26 and 27 kDa, respectively. These are in good agreement with the sizes of proteins expressed in E. coli. A high similarity was observed in comparison of nucleotide sequences of each protein between C. glutamicum and other species, as well as those between hisA and hisF genes of C. glutamicum.

Stabilization of the receptor protein tyrosine phosphatase-like protein ICA512 in GH4C1 cells upon treatment with estradiol, insulin, and epidermal growth factor

Treatment with 1 nM estradiol, 300 nM insulin, and 5 nM epidermal growth factor induces secretory granule accumulation and prolactin storage in GH4C1 rat pituitary tumor cells. The same triple treatment induced more than 6-fold accumulation of both the precursor (100 kDa, pro-ICA512) and the mature forms (60-70 kDa, ICA512 transmembrane fragment) of ICA512, a receptor protein tyrosine phosphatase-like protein that is preferentially localized in secretory granule membranes. Accumulation of ICA512 resembles that of prolactin storage, for the combination of all three, estradiol, insulin, and epidermal growth factor, gave the greatest induction, which was maximal at 4 days. This effect was specific, as the levels of the small GTP-binding protein Rab3, which is also associated with secretory granule membranes, were unaffected by the triple hormone/growth factor treatment. Increased transcription and translation of ICA512 could only partially account for its 6-fold accumulation, as ICA512 messenger RNA and ICA512 synthesis levels were 1.8 +/- 0.35- and 1.6 +/- 0.17-fold in triple treated GH4C1 cells compared with those in untreated cells, respectively. Pulse-chase procedures showed that pro-ICA512 was more stable in treated cells. These results indicate that the enlargement of the secretory granule compartment results in the stabilization of ICA512 and raise the possibility that trafficking of secretory granules may affect ICA512's function and vice versa.