Increased expression of inducible nitric oxide synthase and cyclooxygenase-2 in Barrett's esophagus and associated adenocarcinomas

Barrett's esophagus is a premalignant condition arising in response to chronic reflux esophagitis. Inducible nitric oxide synthase (iNOS; NOS-2) and cyclooxygenase-2 (COX-2) are mediators of inflammation and regulators of epithelial cell growth. Expression levels of iNOS and COX-2 are high in colorectal adenomas and carcinomas, and COX-2 expression is elevated in gastric cancers. To determine the involvement of iNOS and COX-2 in Barrett's-associated neoplasia, we measured expression of these genes in metaplastic Barrett's and esophageal adenocarcinomas. We detected elevated iNOS and COX-2 mRNA levels in Barrett's mucosa compared with paired gastric control tissues in 16 of 21 (76%) and 17 of 21 (80%) patients, respectively (P < 0.001 for both genes). In esophageal adenocarcinomas, iNOS and COX-2 mRNA levels were increased in four of five and five of five cases, respectively. Furthermore, in 10 of 10 Barrett's patients, immunohistochemical staining for iNOS and COX-2 expression was strongly positive and higher than in matched gastric controls. Increased COX-2 expression was confirmed by Western blotting. These findings support the hypothesis that iNOS and COX-2 are involved early and often in Barrett's-associated neoplastic progression.

[Endovascular treatment of intracranial aneurysms with GDC: report of 8 cases]

OBJECTIVE

To assess the usefulness and practical experience in intracranial aneurysm embolization with guglielmi detachable coil (GDC) applied firstly in China.

METHOD

Under general anesthesia and systematic anticoagulation, eight cases of intracranial aneurysms were embolized with GDC which was introduced by tracker micro-catheter, combined remodeling technique (RT) if necessary.

RESULT

100% occlusion was achieved in 5 cases, 95% in 2 and 90% in 1, without any complication. Among these cases, 4 failed in the previous attempts of endovascular treatment with mechanical detachable system (MDS), because MDS could not be safely and totally placed inside the aneurysms and Mag 3F/2F micro-catheter could not be navigated into the aneurysms.

CONCLUSION

Embolization of intracranial aneurysms with GDC is safe, effective and reliable, and it may offer the cure opportunity to those enearysms which are very dangerous to embolize or can not be embolized with MDS.

Determination of polyamines in human prostate by high-performance liquid chromatography with fluorescence detection

A high-performance liquid chromatographic method for the determination of polyamines in human prostate has been developed. This method is based on pre-column derivatization with dansyl chloride (Dns-Cl). The derivatives were separated on a muBondapak C18 column (250x4.6 mm I.D.; 10 microm), and eluted with methanol and distilled water using a one-step linear gradient. The column eluate was monitored by fluorescence detection (excitation, 370 nm; emission, 506 nm). The within-assay precision of the study (C.V.) was as follows: putrescine (PUT) 2.88%, spermidine (SPD) 2.94% and spermine (SP) 1.17%. The between-assay precision (C.V.) was: PUT 2.66%, SPD 3.06%, SP 2.79%. The recovery was greater than 97%. The detection limit for PUT, SPD and SP were 0.05, 0.08 and 0.06 nmol/ml, respectively. In contrast to other studies, sample or polyamine derivatives did not require extraction with an organic solvent such as ethanol, evaporation under vacuum or other condensation procedures. This is a simple, rapid and sensitive method that can be applied to the determination of polyamines in nearly all biological tissues and body fluids, such as urine and serum.

Interleukin-10 gene transfer inhibits murine mammary tumors and elevates nitric oxide

Transfection of cDNA for IL-10 into line 66.1 murine mammary tumor cells results in marked suppression of tumor growth and metastasis. Others have reported that nitric oxide has potent antitumor activity and IL-10 is known to regulate the inducible isoform of nitric oxide synthase (iNOS) expressed in macrophages. We identified nitric oxide production in mammary tumors as indicated by electron paramagnetic resonance detection of nitric oxide-hemoglobin (NO-Hb). IL-10 expression resulted in elevated levels of NO-Hb in mammary tumors. Immunohistochemical examination of mammary tumors for iNOS protein revealed few positively staining cells in parental or control neo-transfected tumors but strong iNOS staining in all IL-10 transfected tumors, consistent with the NO-Hb data. To determine if mammary epithelial tumor cells themselves, express nitric oxide synthase activity, cultured tumor cells were treated with pro-inflammatory cytokines and nitrite accumulation was assessed in the conditioned medium. All IL-10 producing cell lines accumulated uM concentrations of nitrite in response to short term (24 hr) cytokine stimulation. Cells not expressing IL-10 (parental and neo-transfectants) accumulated no nitrite under similar culture conditions. After longer stimulation (48 hr), parental and 66-neo cells accumulated lower amounts of nitrite. IL-10 gene transfer is associated with increased iNOS protein expression and enzymatic activity detected both in vitro and in vivo. Our findings suggest that the antimetastatic and antitumor activity of IL-10 is related to enhanced production of nitric oxide.

Presence of dopa and amino acid hydroperoxides in proteins modified with advanced glycation end products (AGEs): amino acid oxidation products as a possible source of oxidative stress induced by AGE proteins

Glycation and subsequent Maillard or browning reactions of glycated proteins, leading to the formation of advanced glycation end products (AGEs), are involved in the chemical modification of proteins during normal aging and have been implicated in the pathogenesis of diabetic complications. Oxidative conditions accelerate the browning of proteins by glucose, and AGE proteins also induce oxidative stress responses in cells bearing AGE receptors. These observations have led to the hypothesis that glycation-induced pathology results from a cycle of oxidative stress, increased chemical modification of proteins via the Maillard reaction, and further AGE-dependent oxidative stress. Here we show that the preparation of AGE-collagen by incubation with glucose under oxidative conditions in vitro leads not only to glycation and formation of the glycoxidation product Nepsilon-(carboxymethyl)lysine (CML), but also to the formation of amino acid oxidation products on protein, including m-tyrosine, dityrosine, dopa, and valine and leucine hydroperoxides. The formation of both CML and amino acid oxidation products was prevented by anaerobic, anti-oxidative conditions. Amino acid oxidation products were also formed when glycated collagen, prepared under anti-oxidative conditions, was allowed to incubate under aerobic conditions that led to the formation of CML. These experiments demonstrate that amino acid oxidation products are formed in proteins during glycoxidation reactions and suggest that reactive oxygen species formed by redox cycling of dopa or by the metal-catalysed decomposition of amino acid hydroperoxides, rather than by redox activity or reactive oxygen production by AGEs on protein, might contribute to the induction of oxidative stress by AGE proteins.

[Suppression of metastatic phenotype of cloned mouse lung adenocarcinoma cells by transfer of human genomic DNA]

OBJECTIVE

To isolate and identify human sequences with metastatic suppression ability.

METHODS

Genomic DNA fragments isolated from normal human lung tissue were transfected into cloned highly metastatic mouse lung adenocarcinoma cells together with PSV2neo as selectable marker.

RESULTS

25 transfectants were cloned in medium containing G418 and Ouabain. Eight morphologically flat revertants exhibited a more normal phenotype, six clones containing human DNA were identified by a sensitive Inter Alu-PCR method. The rate of cell growth and colony formation in agar were detected in vitro. Clone 12, 20 and 32 showed a lower ratio than maternal untransfected cells. In vivo clone 12 showed more significent less spontaneous metastases in nude mice and syngeneic T739 mouse than control group.

CONCLUSION

The results indicated that the inserted human DNA may be responsible for suppression of metastatic phenotype of mouse lung adenocarcinoma cells.

Hyperfractionated accelerated radiation therapy for non-small cell lung cancer: clinical phase I/II trial

PURPOSE

In an attempt to improve local control and survival of nonsmall cell lung cancer (NSCLC), hyperfractionated accelerated radiation therapy (HART) was carried out as a clinical phase I/II trial.

METHODS AND MATERIALS

HART was delivered by 1.1 Gy/fraction, three fractions per day with intervals of 4 h and five treatment days per week. The clinical tumors were irradiated to 74.3 Gy (72.6-75.9)/66-69 fx, 33 days (29-40) (not corrected for lung density), and the subclinical lesions, to 50.0 Gy (48.4-50.6)/44-46 fx, 33 days (29-40). Sixty-nine patients with NSCLC were enrolled in this study. Nine patients were withdrawn from the study during HART due to different reasons. Sixty patients formed the study for outcome analyses. They were 57 males and 3 females with median age of 61 years (21-77). There were 41 cases of squamous cell carcinoma, 15 cases of adenocarcinoma, and 4 cases of large cell carcinoma. Overall, favorable patients (KPS > or = 70, weight loss < 5% and Stages I, II, IIIa) accounted for 73% (44 of 60) of all patients. Forty-four patients (73%) received adjuvant chemotherapy (DDP + VP16) with median cycles of 1.8 before and/or after HART. In order to compare the outcome of HART with conventional irradiation, 50 NSCLC patients treated by conventional fractionated irradiation (CFI) during the same period were chosen as the basis to evaluate relative effects of HART. They derived from the control group of another clinical trial of hyperfractionated irradiation for NSCLC in the same department. They received median tumor dose of 63.9 Gy (62.8-65.0)/34 fx (32-36), 48 days (45-53).

RESULTS

1. Acute and late complications: (a) In HART, 87% of patients (52 cases) developed acute radiation esophagitis: Grade 1-2, 46 cases (77%) and Grade 3, 6 cases (10%), at 2.5 weeks (2-3.5 weeks) after HART began. Five patients with Grade 3 esophagitis had their HART interrupted for <7 days. In CFI, esophagitis was much less (44%,p < 0.05) with 38% of Grade 1-2 and 6% of Grade 3. (b) In HART, acute pulmonary symptoms (RTOG Grade 1-2) occurred in 17% (10 cases), and acute radiation pneumonitis (Grade 3), in 8% (5 cases), while in CFI, they were 24% and 2% (p > 0.05), respectively. Late lung fibrosis (RTOG Grade 1-2) appeared in 20% (12 cases), whereas 18% in CFI (p > 0.05). (c), No other severe acute or late complications have been observed so far in HART. 2. Immediate response. In HART, 20% of patients (12 cases) achieved CR, 60% (36 cases), PR and 20% (12 cases), NR or PD. In CFI, the above three percentages were 10, 28, and 62%, respectively (p < 0.001). 3. Follow-up. The 1-, 2-, and 3-year actuarial survivals were 72, 47, and 28% for HART, and 60, 18, and 6% for CFI, respectively (p < 0.001). Better local control was seen in HART than in CFI with 1-, 2-, and 3-year local control rates being 71, 44, 29%, and 60, 20, and 5%, respectively (p = 0.001). Distant metastases developed less in HART than in CFI. The 1-, 2-, and 3-year distant metastasis rates were 23, 36, and 50% in HART, but 30, 48, and 80% in CFI (p = 0.021).

CONCLUSION

1. HART could be tolerated by most of the favorable NSCLC patients. The predominant complication was acute esophagitis. No other severe acute or late complications have been observed so far. 2. HART resulted in better survivals and local controls, and less distant metastases than CFI.

[Histomorphometric study of the effect of nylestriol on bone turnover in ovariectomized rabbits]

OBJECTIVE

To assess the effect of Nylestriol on postmenopausal osteoporosis in an attempt to reveal its mechanism.

METHODS

Thirty-seven month-old female New Zealand white rabbits were randomized into 3 groups (10 rabbits per group): treatment group [ovariectomized (OVX) + nylestriol (2 mg, monthly)], OVX control group (OVX + vehicle) and normal control group (sham operation + vehicle). Six months later, all rabbits were subjected to tetracycline labelling and then were killed. Under VIDAS system, bone turnover was assessed by bone histomorphometry.

RESULTS

Bone volume trabecular (BV/TV), relative osteoid volume (OV/BV), osteoblastic index (OBI) and bone formation rate at tissue level [BFR(T)] increased in treatment group compared with OVX control group and (or) sham control group.

CONCLUSIONS

Nylestriol can increase the number of osteoblast, which resulted in more bone matrix production and consequently converted the bone turnover of OVX rabbits to a positive balance situation. It indicated that Nylestriol was probably a stimulator for osteoblast recruitment and (or) proliferation.

Use of the cosmid adenoviral vector cloning system for the in vitro construction of recombinant adenoviral vectors

The large size of the adenoviral genome unfortunately precludes there being many unique, useful restriction sites available for in vitro manipulation. Two methods have been developed for the construction of recombinant adenoviral vectors to date: in vivo homologous recombination or direct ligation in vitro. The efficiency of either the direct ligation method or the homologous recombination method is low because of the large size of the recombinant adenoviral vectors. To circumvent these problems, we have chosen to use the cosmid vector system to facilitate the assembly of recombinant adenoviral vectors. In this paper, we demonstrate for the first time that recombinant adenoviral vectors can be efficiently constructed in vitro by the cosmid vector system. With this method, it is possible to amplify the recombinant adenoviral vector DNA sufficiently to transfect 293 cells. The cosmid adenoviral vector cloning method for in vitro construction of the full-length recombinant adenoviral vectors represented here is simple and efficient and should facilitate the development of recombinant adenoviral vectors for human gene therapy.

[Relationship between umbilical blood lead level and neonatal neurobehavioral development]

Umbilical blood lead level, as an indicator for intrauterine exposure to lead, and neurobehavioral score, as an effect indicator, were determined in 101 neonates in Beijing area to explore the relationship between intrauterine lead exposure and neonatal neurobehavioral development. Results revealed that there was a negative relationship between neonatal umbilical blood lead level and their neurobehavioral score and behavioral ability. With umbilical blood lead level of 0.48 mumol/L as a cutoff value, there was a significant difference in neonatal behavioral ability score between groups of high and low blood lead levels. There also were significant differences in nonbiologically auditory and biological visual and auditory orientation reaction. It suggests that intrauterine lead exposure can cause adverse effects on neonatal neurobehavioral development, especially on their visual and auditory function.

Biochemistry and pathology of radical-mediated protein oxidation

Radical-mediated damage to proteins may be initiated by electron leakage, metal-ion-dependent reactions and autoxidation of lipids and sugars. The consequent protein oxidation is O2-dependent, and involves several propagating radicals, notably alkoxyl radicals. Its products include several categories of reactive species, and a range of stable products whose chemistry is currently being elucidated. Among the reactive products, protein hydroperoxides can generate further radical fluxes on reaction with transition-metal ions; protein-bound reductants (notably dopa) can reduce transition-metal ions and thereby facilitate their reaction with hydroperoxides; and aldehydes may participate in Schiff-base formation and other reactions. Cells can detoxify some of the reactive species, e.g. by reducing protein hydroperoxides to unreactive hydroxides. Oxidized proteins are often functionally inactive and their unfolding is associated with enhanced susceptibility to proteinases. Thus cells can generally remove oxidized proteins by proteolysis. However, certain oxidized proteins are poorly handled by cells, and together with possible alterations in the rate of production of oxidized proteins, this may contribute to the observed accumulation and damaging actions of oxidized proteins during aging and in pathologies such as diabetes, atherosclerosis and neurodegenerative diseases. Protein oxidation may also sometimes play controlling roles in cellular remodelling and cell growth. Proteins are also key targets in defensive cytolysis and in inflammatory self-damage. The possibility of selective protection against protein oxidation (antioxidation) is raised.

[The simultaneous analysis of substance P, somatostatin, neurokinin and neurotensin by capillary zone electrophoresis]

Neuropeptides play an important part in several different areas of neurochemistry. Recently, capillary electrophoresis (CE) was developed for analysis of neuropeptides. This paper reports a capillary zone electrophoretic method for the simultaneous separation and quantitative determination of the substance P (SP), somatostatin (SS), neurokinin (NKA) and neurotensin (NT). The separation was performed on a 50microm x 60cm fused-silica capillary using 0.1mol/L at pH 2.7 phosphate as buffer. The eluted fractions were detected at 214nm.

[Effect of light colours and illumination intensity on the sexual behaviour of Hepialus gonggaensis Fu et Huang]

The sexual behaviour of Hepialus gonggaensis has close relations with ecological environment and varies with its ecotypes. The more intense the illumination, the faster the sexual drive of Hepialus gonggaensis begins and the longer its sexual intercourse continues, light colours have a bearing on its sexual intercourse time. This study has provided an evidence for the artificial cultivation of Hepialus gonggaensis.

[Simultaneous analysis of theophylline, phenobarbital, amobarbital and carbamazepine in serum by high performance liquid chromatography]

Theophylline, phenobarbital, amobarbital and carbamazepine are the chief therapeutic drugs in clinical practice. Because of the differences among inter-individuals in the metabolic clearance of these drugs and their toxicity at certain levels of concentration in serum, the dosage should be regulated to maintain a therapeutic blood drugs level. To achieve this a rapid and accurate assay method for drugs in blood is necessary. This paper reports that a reversed phase high performance liquid chromatographic (HPLC) method had been established for the simultaneous separation and quantitative determination of the four drugs in serum. The separation was performed on RP-C18 column using methanol:water (1:1) as mobile phase and 4-aminoantipyrime as internal standard. The eluted substances were detected at 210nm.

Effect of the photoperiod in modulating the androgenic control of 1-alkyl-2,3-diacylglycerol composition in the harderian gland of the golden hamster, Mesocricetus auratus

The golden hamster Harderian gland produces a lipid secretion consisting mainly of 1-alkyl-2,3-diacylglycerol. We investigated the composition of alkyl and acyl groups in male and female hamster Harderian alkyldiacylglycerol, in animals kept in long and short photoperiods. Female hamsters in long days have alkyl groups with long saturated straight chains (C18:0 and C20:0) and methyl-branched chains (even and odd chain length iso-branched and odd chain length anteiso-branched chains). Acyl groups in females in long days are mostly long straight chains (C16:0) and methyl-branched chains. In females, short photoperiods led to reductions in the proportions of methyl-branched chains and changes in the proportions of straight chain alkyl and acyl groups; these changes were prevented by pinealectomy. Male hamsters with intact gonads, maintained in long days, had no methyl-branched chain alkyl or acyl groups; saturated straight chains were generally shorter than those of females and the odd chain length saturated C15:0 acyl group was common. Short photoperiods did not significantly alter the composition of male alkyldiacylglycerol. Castrated male hamsters in long days showed a distinctively female phenotype, with long straight chains and methyl-branched alkyl and acyl groups. Castrated males in short days showed a mixture of male and female characteristics: shorter straight chain alkyl and acyl groups, a total absence of methyl-branched alkyl groups, and the presence of methyl-branched acyl groups. These results and those of other studies suggest that testosterone controls the enzymes isovaleryl acyl-CoA dehydrogenase and 2-methyl branched-chain acyl-CoA dehydrogenase; in the absence of these enzymes, the primers for the synthesis of methyl-branched chain fatty acids are produced. Our results indicate that this control is modulated by short photoperiods (perhaps due to reduced prolactin levels). It is also suggested that characteristics of male-type alkyldiacylglycerol are better adapted to conditions of autumn and winter than are those of female-type alkyldiacylglycerol.

[Intestinal flora in renal allograft recipients]

OBJECTIVE

To explore the change of 10 kinds of intestinal flora in renal allograft recipients and its significance.

METHODS

Ten kinds of intestinal flora in faeces were investigated in 30 renal allograft recipients by Kang Bai's classification of flora, and compared with 100 patients with diarrhea and 30 normal controls.

RESULTS

The number of enteric bacilli in renal allograft recipients (8.5 +/- 1.0 CFU/g) was increased more markely than in the diarrhea patients (7.7 +/- 1.1 CFU/g, P < 0.01). The number of bacteroid (7.8 +/- 0.6 CFU/g), bifidobactercium (7.7 +/- 0.3 CFU/g), eubaclerium (7.2 +/- 0.6 CFU/g), and clostridium (7.8 +/- 0.5 CFU/g) in renal allograft recipients were decreased more markedly in than normal control (8.2 +/- 0.7 CFU/g, P < 0.01, 8.3 +/- 0.7 CFU/g, P < 0.01, 8.1 +/- 0.9 CFU/g, P < 0.01, 8.0 +/- 0.8 CFU/g, P < 0.01), but the number of Bifidobactercum was higher than that is the diarrhea patients (7.3 +/- 0.6 CFU/g, P < 0.01). The number of eubacterium was Lower than that in the diarrhea patients (7.7 +/- 0.8 CFU/g, P < 0.01). Among 30 renal allograft recipients 3 had constipation and 20 diarrhea. Two cases died of toxic shock with serious diarrhea because of imbalance of intestinal flora.

CONCLUSION

The imbalance of intestinal flora existes in the early stage of renal transplantation. It is characterized by anaerobic bacilli imabalance such as bifidobacteriam and may be a direct cause of intestinal infection as diarrhea.

Approaches and reconstruction in skull base operation

OBJECTIVE

To design convenient lateronasal and infrafrontal approaches or lateronasal subvolution approach to radically resect skull base tumors involving cranial cavity.

METHODS

From 1987 through 1994, 22 patients with malignant tumors, 6 with benign tumors, one with a giant sphenoid sinus cyst and one with intranasal meningoencephalocele underwent the operation. Twenty-three cases had anterocranial fossa involved; 4, midcranial fossa; 2, anteromedial cranial fossa; and 1 case, posteromedial cranial fossa. Among the patients with malignant tumors, 11 underwent expansive maxillectomy and 10 had orbital contents resected. The intracranial approaches through lateronasal and infrafront (21 cases), nasal columella lateral subvolution (3 cases) and other approaches were used.

RESULTS

The reconstruction of bony skull base defect in excess of 3.00 cm x 3.00 cm with total front musculocutaneous flap (8 cases), galeal and pericranial flap (5 cases) or other tissues (3 cases) has effectively prevented meningoencephalocele. Twelve cases had the dura resected in a range of 2.00 cm x 2.00 cm to 7.00 cm x 6.00 cm. Reconstruction of the dura defect with autofascia lata in 9 cases and other tissues in 3 cases effectively prevented the cerebrospinal fluid leak. Eight of 22 (36.4%) patients with malignant tumors have been alive and free of disease for 3-7 years after the operation. Six patients with benign tumors, one patient with giant sphenoid sinus cyst and one with meningoencephalocele were cured with this reconstructing method.

CONCLUSIONS

Frontal musculocutaneous and pericranial flaps have advantages over free bone because of easy surviving and easy operating without occurrence of osteonecrosis and exclusive reaction.

Primary structure of trypsin inhibitors from Sicyos australis

Three trypsin inhibitors from Sicyos australis, have been isolated, purified and sequenced. Following protein extraction with ammonium sulphate, the mixture of inhibitors was separated from other proteins by trypsin-affinity chromatography. Subsequent purification of the individual inhibitors was accomplished by reversed-phase HPLC. The primary structures of each inhibitor were elucidated by a combination of protein sequencing and electrospray ionization mass spectrometry (ESI-MS) and tandem mass spectrometry (MS-MS) on both the untreated and the reduced and S-carboxymethylated inhibitors. All three inhibitors show extensive sequence similarity with inhibitors from cultivated Cucurbitaceae species, although there are a number of novel residues present. One of the inhibitors has a blocked N-terminus (pyroglutamic acid) and the use of MS-MS was crucial to the elucidation of its primary structure. ESI-MS was further used to characterize the non-covalent complex between one of the inhibitors and trypsin.

[Comparison on the chemical constituents of chuanhonghua I with jianyang honghua]

Based on the qualitative reaction of chemical constituents and TLC, the chemical constituents of Chuanhonghua-I were found similar to those Jianyang honghua. The effective constituents, safflower haematochrome and safflower yellow contents of Chuanhonghua-I, meet the standards of Chinese Pharmacopoeia (Ed. 1990).

Lack of X inactivation associated with maternal X isodisomy: evidence for a counting mechanism prior to X inactivation during human embryogenesis

We have previously reported functional disomy for X-linked genes in females with tiny ring X chromosomes and a phenotype significantly more abnormal than Turner syndrome. In such cases the disomy results from failure of these X chromosomes to inactivate because they lack DNA sequences essential for cis X inactivation. Here we describe a novel molecular mechanism for functional X disomy that is associated with maternal isodisomy. In this case, the severe mental retardation and multiple congenital abnormalities in a female with a mosaic 45,X/ 46,X,del(X)(q21.3-qter)/ 46X,r(X) karyotype are associated with overexpression of the genes within Xpter to Xq21.31 in many of her cells. Her normal X, ring X, and deleted linear X chromosomes originate from the same maternal X chromosome, and all are transcriptionally active. None expresses X inactive specific transcript (XIST), although the locus and region of the putative X inactivation center (XIC) are present on both normal and linear deleted X chromosomes. To our knowledge, this is the first report of a functional maternal X isodisomy, and the largest X chromosome to escape inactivation. In addition, these results (1) show that cis inactivation does not invariably occur in human females with two X chromosomes, even when the XIC region is present on both of them; (2) provide evidence for a critical time prior to the visible onset of X inactivation in the embryo when decisions about X inactivation are made; and (3) support the hypothesis that the X chromosome counting mechanism involves chromosomal imprinting, occurs prior to the onset of random inactivation, and is required for subsequent inactivation of the chromosome.

Biological fate of amino acid, peptide and protein hydroperoxides

In the course of searching for a suitable marker for studying protein oxidation, we have successfully elucidated the structures of three valine hydroperoxides, i.e. beta-hydroperoxyvaline, (2S,3S)-gamma-hydroperoxyvaline and (2S,3R)-gamma-hydroperoxyvaline, which are novel products of protein oxidation. The corresponding valine hydroxides were obtained by sodium borohydride reduction [Fu, Hick, Sheil and Dean (1995) Free Rad. Biol. Med. 19, 281-292]. We hypothesized that valine hydroxides might be the major biological degradation products of valine hydroperoxides and, as such, could be useful markers for the study of protein oxidation in vivo. The aim of this study was to investigate the fate of valine hydroperoxide in selected biological systems by the use of chemiluminescence detection of hydroperoxides and HPLC analysis of O-phthaldialdehyde derivatives of amino acid residues. The degradation of hydroperoxides present on gamma-radiolysed solutions of valine, Pro-Val-Gly, or BSA occurred in the presence of: (1) transition metals (Fe2+, Fe3+, or Cu2+), (2) the detoxifying enzyme GSH peroxidase, (3) human plasma, and (4) J774 mouse monocyte macrophage cells. The major degradation product of valine hydroperoxide recovered in each case was found to be a valine hydroxide. These results suggest that valine hydroxide (derived from the hydroperoxide) may well be a useful in vivo marker for studying protein damage under oxidative stress.

Clinical and pathologic studies on idiopathic uveal effusion

In order to investigate the clinical features, pathology and treatment of idiopathic uveal effusion syndrome, ten eyes of seven patients with the syndrome had been studied. In addition to general clinical examinations, indirect opthalmoscopy, fundus fluorescein angiography and (FFA) ultrasonography were used to make definite diagnoses. The findings of these examinations indicate four key features of the idiopathic uveal effusion syndrome. They are: annular cilio-choroidal detachment, shifting non-rhegmatogenous retinal detachment, unremarkable inflammation in the anterior segment, and normal intraocular pressure. The fundus change is characterized by the "leopard-spot". All patients were treated by sclerectomy and sclerotomy, ciliochoroidal detachments disappeared soon after surgery, and retinal detachments resolved later on. Patients' visual acuity recovered well. The histochemical and electron microscopic examinations of excised tissues from five eyes showed thickened sclera, a general increase of the scleral fibril width compared to normal scleral, the disruption of normal lamellar arrangement of the scleral fibers and the deposition of glycosaminoglycans in the interfibrillar spaces. All these indicate that a congenital scleral abnormality seems to be the basic pathophysiology of the idiopathic uveal effusion syndrome.

Structural identification of valine hydroperoxides and hydroxides on radical-damaged amino acid, peptide, and protein molecules

We have previously demonstrated the formation of two reactive moieties on proteins during free radical attack: hydroperoxides, and 3,4-dihydroxyphenylalanine (DOPA). Here we have undertaken the structural elucidation of the hydroperoxides of valine, the amino acid which is most susceptible to peroxidation. Exposure of L-valine to free radicals generated by radiolysis in an oxygen-saturated system produced three valine hydroperoxides. Upon treatment with sodium borohydride these were reduced to their corresponding hydroxides, which can be separated and purified by high performance liquid chromatography (HPLC). Based on spectroscopic data from high resolution chemical ionization (CI) mass spectrometry (MS), electrospray (ES) MS, electron impact (EI) MS, proton (1H) nuclear magnetic resonance (NMR) and carbon-13 (13C) NMR studies, the three valine hydroxides have been identified as beta-hydroxyvaline [(2S)-2-amino-3-hydroxy-3-methyl-butanoic acid], (2S,3S)-gamma-hydroxyvaline [(2S,3S)-2-amino-3-hydroxymethyl-butanoic acid], and (2S,3R)-gamma-hydroxyvaline [(2S,3R)-2-amino-3-hydroxymethyl-butanoic acid]. HPLC analysis of O-phthaldialdehyde (OPA) derivatives of the hydroxyvalines provides a sensitive and accurate method for quantitative measurement. This method enabled hydroxyvalines to be detected in the hydrolysates of a tripeptide (glutamyl-valinyl-phenylalanine) and a protein (bovine serum albumin) that had been gamma-radiolysed and treated with sodium borohydride. Hydroxyvaline may be useful as a marker in studying protein oxidation in some biological systems under oxidative stress.

Transduction of MDR1 into human and mouse haemopoietic progenitor cells: use of rhodamine (Rh123) to determine transduction frequency and in vivo selection

The MDR1 gene product P-glycoprotein (P-gp) extrudes several anticancer drugs including taxol and fluorescent dyes such as rhodamine (Rh123). Modulation of the level of P-gp expression has the potential of overcoming multidrug resistance. One possible approach is the retroviral transfer of the human MDR1 gene into murine and human bone marrow (BM) progenitor cells. The rationale for this approach is increased chemoprotection, which allows chemotherapy of a greater level of intensity to be delivered. In this study, flow cytometric measurement of Rh123 extrusion was used to test P-gp function in human and mouse haemopoietic progenitor cells, which had been transduced with a virus containing the human MDR1 transcription unit. Human CD34+ selected cells were analysed immediately following transduction. In two successive experiments MDR1 cDNA transduction resulted in a 7% and 11% increase of P-gp expressing Rh123 dull cells. To monitor transduction efficiency over time as well as the possibility of in vivo selection of drug-resistant BM cells in mice treated with increasing numbers of taxol cycles, the assay was also successfully applied to peripheral blood lymphocytes of mice transplanted with MDR1 transduced BM cells, demonstrating increased Rh123 efflux in transduced cells. Analysis of another fluorescence assay using fluorescein di-beta galactopyranoside as a substrate for beta-galactosidase in cells transduced with a MDR1: beta-gal activity. We conclude that the Rh123 efflux assay is a sensitive method to monitor P-gp function in MDR1 cDNA transduced cells, and may be used to enrich transduced cells via flow cytometric cell sorting for Rh123 dull cells.

[The experimental observation on the procedure of atherosclerotic restenosis following PTCA]

Angioplasty of stenotic iliac artery was performed in 23 Japanese white rabbits. Angiography and histopathology examinations were performed one day (6 rabbits), 3 days (5 rabbits), one week (5 rabbits) and one month (7 rabbits) after dilation. TXB/PGF in blood was analyzed with radio-immunologic method. TXB/6-K-PGF increased at 1st day, began to reduce at 3rd day, became almost normal after one week and returned to normal level week after one month. Restenosis occurred in all animals. Platelet aggregation and mural thrombi were observed at 1st and 3rd day. New endothelial cells covered the surface of denuded endothelium at 3rd day. At 7th day, repairing of endothelium was completed and proliferation of smooth muscle cells were prominent in new intimia. Stenosis of lumen occurred again after 1 month. The results suggested that intimia injury during the procedure initiates the process of restenosis and aggregation of platelets, imbalance of between TXA and PGI is and proliferation of smooth muscle cells play important roles in the formation of restenosis.

Resistance to taxol chemotherapy produced in mouse marrow cells by safety-modified retroviruses containing a human MDR-1 transcription unit

We used an animal model system to transplant lethally-irradiated mice with one million marrow cells which had been: (1) collected from 5-fluorouracil (5-FU) treated mice; and (2) transduced with retroviruses containing a multiple drug resistance-1 (MDR-1) gene transcription unit. Following recovery from the transplant, we exposed these mice to doses of taxol ranging from 7 mg/kg to 30 mg/kg, which corresponds to doses of 68 to 268 mg/m2 in man. The median white blood cell count by 5 days after taxol (expressed as the percentage of the white blood cell count before taxol) was 83% (range 46-100%) in 11 courses of taxol in mice transplanted once with MDR-1 transduced marrow immediately after transplant, whereas the median white blood cell count by 5 days after taxol in mice not transplanted with MDR-1 marrow was 41% in nine courses of taxol (range 11-66%). This difference is statistically different at the P < 0.001 level (Wilcoxon test). One million marrow cells from the MDR-1 transplanted mice were harvested and serially transplanted through five additional cohorts of mice, and tested with taxol after each cohort. The white blood cell count (expressed as the percentage of pre-taxol white blood cell count) after each cohort ranged from 94-146% in the 29 mice transplanted with the transduced MDR-1 marrow, which had been through more than one transplant. This is statistically different from the median white blood cell count recovery after taxol in mice which have no human MDR-1 modified marrow (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

PML/RARalpha, a fusion protein in acute promyelocytic leukemia, prevents growth factor withdrawal-induced apoptosis in TF-1 cells

A unique mRNA produced by the t(15;17) (q22-24;q11-21) translocation in the leukemic cells of acute promyelocytic leukemia patients encodes a chimeric protein, PML/RARalpha, which is formed by the fusion of the retinoic acid receptor alpha (RARalpha) and the promyelocytic locus gene (PML). This translocation is often the only visible karyotypic aberration present which is detected in almost 100% of acute promyelocytic leukemia patients. As an initial step to study the role of PML/RARalpha in leukemogenesis, we attempted to express the fusion protein in hematopoietic cells through retrovirus-mediated gene transfer of the retroviral vector, pGPRCHT, which contains the PML/RARalpha cDNA. Transduction of the PML/RARalpha cDNA fragment used in this vector, which extends from the position 31 bp to the position 2638 bp in a transcription unit driven by the Moloney murine sarcoma virus LTR, was found to abrogate the growth factor dependence of TF-1 cells. In addition, introduction of PML/RARalpha into TF-1 cells can protect these cells from the apoptosis usually induced in TF-1 cells by growth factor withdrawal, as measured by three assays for apoptosis: morphology, DNA ladder formation, and end labeling of nicked DNA with fluorescent-conjugated nucleotide precursors followed by a fluorescence-activated cell sorting assay. These data suggest that the PML/RARalpha fusion protein may inhibit programmed cell death in myeloid cells.

Chemotherapy resistance to taxol in clonogenic progenitor cells following transduction of CD34 selected marrow and peripheral blood cells with a retrovirus that contains the MDR-1 chemotherapy resistance gene

A retrovirus containing the multiple drug resistance (MDR-1) cDNA, was used to transduce cultures of CD34 selected human marrow cells, on stromal monolayers in the presence of hematopoietic growth factors IL-3 and IL-6, following collection from patients recently recovered from chemotherapy-induced myelosuppression. In one experiment, these CD34 selected cells were grown in Dexter cultures for 35 days or more following MDR-1 transduction, and then plated in methylcellulose. Polymerase chain reaction (PCR) analysis of colonies picked after 10-14 days of methylcellulose culture, using a set of primers that are specific for the endogenous or the retrovirally transduced MDR-1, showed that the long-term culture initiating cells (LTCICs) were transduced by the MDR-1 virus. Analysis of the colonies from the CD34 selected MDR-1 transduced cells, with a reverse transcription (RT) PCR assay that could distinguish viral MDR-1 mRNA from endogenous MDR-1 mRNA, showed that the viral MDR-1 mRNA levels were much higher than that of the MDR-1 mRNA from the endogenous MDR-1 gene in the transduced CD34 selected cells. Fluorescence activated cell sorting (FACS) analysis of the CD34 selected transduced marrow cells within 48 h after the transduction, using the C219 and UIC2 monoclonal antibodies for p-glycoprotein, showed that the transduction frequency under these conditions varied from 7 to 20%. Rhodamine efflux studies showed that this additional p-glycoprotein was functional and that the frequency of cells with high p-glycoprotein levels was higher in the transduced cells than in the non-transduced cells. The resistance to taxol of the CD34 selected transduced cells, as judged by the plating efficiency of clonogenic progenitor cells derived from these cells by growth in methylcellulose supplemented with taxol was much higher in the transduced cells than in untransduced cells. In order to test the reproducibility of the transduction frequency of the retroviral supernatants from PA317 MDR-1 viral producer cells on CD34 selected cells, the virus produced from 12 different lots of supernatants from the PA317 MDR-1 producer cell line was used to transduce CD34 selected marrow cells from four different patients, and to transduce the peripheral blood cells of two additional patients collected following chemotherapy-induced myelosuppression. The supernatant lots used for these transduction experiments were tested by Microbiological Associates (Rockville, MD, USA), by the Mus dunni co-cultivation and amplification tests in the S+L-assay and found to be negative for replication-competent retrovirus, and later approved for human use by the Food and Drug Administration.(ABSTRACT TRUNCATED AT 400 WORDS)

Suppression of tumorigenesis by transcription units expressing the antisense E6 and E7 messenger RNA (mRNA) for the transforming proteins of the human papilloma virus and the sense mRNA for the retinoblastoma gene in cervical carcinoma cells

Human cervical carcinoma cell lines that harbor human papilloma virus (HPV) have been reported to express HPV E6 and E7 proteins at least in the beginning stages if not at all stages of the disease. The HPV E6 and E7 proteins bind to and inactivate the products of the p53 and retinoblastoma (Rb) tumor suppressor genes, which thereby allow the cervical carcinoma cells to circumvent the action of these tumor suppressor genes. We observed that the introduction of the antisense HPV 18 E6 and E7 sequences, as well as a sense cDNA for the human wild-type Rb gene into a human cervical carcinoma cell line (HeLa), which is positive for the HPV 18 provirus, decreased the in vitro and in vivo growth rate of the transfected cells if both antisense transcripts for the HPV 18 E6 and E7 and sense transcripts for human Rb were expressed. In addition, overexpression of a complementary DNA (cDNA) for the Rb messenger RNA was sufficient to slow the proliferation of HeLa cells, and the level of Rb cDNA expression was correlated with the degree to which the rate of growth of the tumor was slowed. The results of our experiments show that the presence of HPV E6 and E7 proteins and the resultant inactivation of Rb in cervical carcinoma cells contributes to the neoplastic phenotype even in highly evolved cervical carcinoma cell lines such as HeLa, which have been derived from a cervical carcinoma patient at an advanced stage of the disease process. These data suggest that the HPV proteins play a role not only at the beginning of cervical cancer, but also at advanced stages of this disease. These experiments may lead to genetic approaches to the control of this disease that involve antisense sequences that downregulate the E6 and E7 genes or lead to expression of the Rb gene.

Protein hydroperoxides can give rise to reactive free radicals

Proteins damaged by free-radical-generating systems in the presence of oxygen yield relatively long-lived protein hydroperoxides. These hydroperoxides have been shown by e.p.r. spectroscopy to be readily degraded to reactive free radicals on reaction with iron(II) complexes. Comparison of the observed spectra with those obtained with free amino acid hydroperoxides had allowed identification of some of the protein-derived radical species (including a number of carbon-centred radicals, alkoxyl radicals and a species believed to be the CO2 radical anion) and the elucidation of novel fragmentation and rearrangement processes involving amino acid side chains. In particular, degradation of hydroperoxide functions on the side chain of glutamic acid is shown to result in decarboxylation at the side-chain carboxy group via the formation of the CO2 radical anion; the generation of an identical radical from hydroperoxide groups on proteins suggests that a similar process occurs with these molecules. In a number of cases these fragmentation and rearrangement reactions give rise to further reactive free radicals (R., O2-./HO2., CO2-.) which may act as chain-carrying species in protein oxidations. These studies suggest that protein hydroperoxides are capable of initiating further radical chain reactions both intra- and inter-molecularly, and provide information on some of the fundamental mechanisms of protein alteration and side-chain fragmentation.

[Hyperfractionated irradiation for non-small cell lung cancer (NSCLC)--a phase III clinical trial]

From Dec. 1990 to Aug. 1991, 109 patients with NSCLC were randomized into two groups. The first was treated by hyperfractionated irradiation (HF) with 1.15-1.25Gy per fraction, twice daily (interval > or = 6 hrs between fractions), and total doses of 69.6 +/- 2.1Gy. The other was conventional irradiation (CF) with 1.8-2.0Gy per fraction, once a day, and total doses of 63.9 +/- 1.1Gy. All but 11 was included in the analysis. The results showed that HF, compared to CF, could improve immediate response rates in patients with squamous cell carcinoma or with tumor size of 3-6cm (P < 0.05). The comparison of 1 and 2 year survivals did not show significant difference, but 1 year local control rate was 47.3% in HF and 29.1% in CF, P < 0.05. Further stratified analysis showed that the 1 and 2 year local control rates in patients of HF in stage I-IIIa were 54%, 28%; 39%, 13% in patients of CF in stage I-IIIa, P < 0.05. The 1 and 2 year survival rates in patients in stage I-IIIa were 64%, 32% in HF; 18%, 6% in CF, (P < 0.05). An assessment of acute and late toxicity showed no significant difference in incidences between the two groups. It is concluded that HF, compared to CF, can improve 1 and 2 year survival and local control rates of patients in stage I-IIIa.

Differential effects of thermal injury on circulating insulin-like growth factor binding proteins in burn patients

The results of this report provide evidence that insulin-like growth factor-1 binding proteins (IGFBPs) in human sera are differentially regulated as a result of severe burn injury. Using the ligand binding technique, 125I-IGF-1 visualizes 5 different protein bands corresponding to those previously reported for IGFBP-1 to 4 with apparent sizes of 23-42 kd in serum samples prepared from severely burned patients and healthy individuals. The level of IGFBP-3 was significantly decreased within 3-5 days of injury and remained depressed for up to 20 days post injury. The average level of this binding protein reached its lowest value within 3-5 days of the injury (3.8 +/- 1.48% relative to day 0-1 value, n = 4, p < 0.01). Serum samples from 3 of 4 patients showed no recovery within 20 days post injury and the level of IGFBP-3 remained significantly depressed (p < 0.01). In contrast, the levels of IGFBP-2 and IGFBP-4 increased 2 and 3 fold in the same serum samples within 3-5 days of the burn injury, respectively. This increase returns to normal (day 0-1 value) within 7-10 days for IGFBP-2, but the level of IGFBP-4 remained elevated 4 fold relative to the day 0-1 (p < 0.01). However, the abundance of IGFBP-1 in these serum samples was not significantly altered by the burn injury. By controlling for protein loading, these apparent alterations of IGFBPs in the sera of burned patients were not due to hemodilution. Similarly, significant reductions in IGFBP-3 were not likely due to IGFBP-3 specific protease activity in the sera of burn patients since incubation of sera from burn patients and normal individuals at 37 degrees C did not alter the pattern of IGFBPs in sera obtained from normal individuals. Of interest, the level of IGF-1 protein in these samples was also markedly reduced following severe burn injury similar to IGFBP-3. The results of this study suggest that a marked reduction of serum IGF-1 seen in burn patients is associated with a significant reduction of IGFBP-3, a major IGF-1 binding protein in human serum.

Genetic marking shows that Ph+ cells present in autologous transplants of chronic myelogenous leukemia (CML) contribute to relapse after autologous bone marrow in CML

Relapse after autologous bone marrow transplantation for chronic myelogenous leukemia (CML) can be due either to the persistence of leukemia cells in systemic tissues following preparative therapy, or due to the persistence of leukemia cells in the autologous marrow used to restore marrow function after intensive therapy. To help distinguish between these two possible causes of relapse, we used safety-modified retroviruses, which contain the bacterial resistance gene NEO, to mark autologous marrow cells that had been collected from patients early in the phase of hematopoietic recovery after in vivo chemotherapy. The cells were then subjected to ex vivo CD34 selection following collection and 30% of the bone marrow were exposed to a safety-modified virus. This marrow was infused after delivery of systemic therapy, which consisted of total body irradiation (1,020 cGy), cyclophosphamide (120 mg/kg), and VP-16 (750 mg/m2). RT PCR assays specific for the bacterial NEO mRNA, which was coded for by the virus, and the bcr-abl mRNA showed that in two evaluable CML patients transplanted with marked cells, sufficient numbers of leukemia cells remained in the infused marrow to contribute to systemic relapse. In addition, both normal and leukemic cells positive for the retroviral transgenome persisted in the systemic circulation of the patients for at least 280 days posttransplant showing that the infused marrow was responsible for the return of hematopoiesis following the preparative therapy. This observation shows that it is possible to use a replication-incompetent safety-modified retrovirus in order to introduce DNA sequences into the hematopoietic cells of patients undergoing autologous bone marrow transplantation. Moreover, this data suggested that additional fractionation procedures will be necessary to reduce the probability of relapse after bone marrow transplantation in at least the advanced stages of the disease in CML patients undergoing autologous bone marrow transplantation procedures.

Molecular approaches to the diagnosis and treatment of cancer

We have used autologous bone marrow transplantation (ABMT) as a setting to develop the genetic therapy of cancer in hematopoietic neoplasms based on the use of the bone marrow as a conduit through which to introduce regulatory molecules into the patient. This has involved three developmental phases: 1) learning how to develop genetic modification techniques; 2) learning how to develop in vivo selection techniques for the genetically modified cells; and 3) developing molecular vectors for modification of hematopoietic cells for therapy of cancer. These programs will be summarized in terms of their progress at the conference.

The effect of laminin on molecular motion in the cell membrane and on cell motility

We have studied the variation of lateral diffusion of proteins in the cell membrane, of membrane lipid fluidity and of the electrophoretic motility (EPM) of macrophages after treatment with extrinsic laminin. The results showed that the lateral diffusion coefficient D value of membrane proteins, the fluidity of membrane lipids and the EPM of macrophages were decreased after laminin had bound to its membrane receptor on the macrophages. These results are important for developing an understanding of the early reaction of plasma membranes and cells in the presence of laminin.

Genetic therapy of human neoplastic disease

Molecular biology has provided clinical investigators and basic scientists with the tools to identify those changes present within neoplastic hematopoietic and epithelial cells that lead to the evolution of unregulated patterns of cell growth. This information has made possible the development of therapy that involves genetic modification of either the normal hematopoietic cells (for chemoprotection), or the tumor cells themselves to suppress the growth of these cells. This article will summarize the clinical and laboratory data that is evolving in this area.

Molecular cytogenetic study of short arm aberrations in human D, G group chromosomes

Six cases of Dp+/Gp+, 10 cases of D/G translocation, 1 case of supernumerary marker chromosome, and 1 case of Yqs were studied using molecular and cytogenetic techniques. The Ag-NOR frequencies of the Dp+ and Gp+ groups were found to be higher than those of normal controls, while their satellite association frequencies were lower. Autoradiographic silver grains were not significantly distributed along the p+ part of the marker chromosome as revealed by chromosomal in situ hybridization using an rRNA probe. This result differs from our previous report. It is suggested that there might be different mechanisms for the formation of p+ on acrocentric chromosomes. D/G translocation cases were found to have lost their NOR. A study of supernumerary marker chromosomes and Yqs cases suggested that the marker chromosome and Yqs exerted no phenotypic effect. The mechanism of their formation is discussed.

Pyronaridine: A new antimalarial drug

The worldwide spread of strains of Plasmodium falciparum that are resistant to chloroquine has highlighted the urgent need for new antimalarial drugs, particularly in less developed tropical countries. However, in the current economic climate the pharmaceutical giants in the developed world are withdrawing from tropical disease research. Consequently, the following article from Fu Sui and Xiao Shuhuo is of particular interest, not only because it summarizes work on on alternative antimalarial drug that is efficacious against multiply resistant Plasmodium but also because this drug has been developed primarily from Chinese research efforts, the results of which have largely only been published in the Chinese scientific literature. The drug under scrutiny is pyronaridine, and is the product of 30 years of chemistry that began with the mepacrine nucleus. This nucleus was selected as the starting point in the search for a chloroquine alternative because the various derivatives synthesized were active against chloroquine-resistant parasites. However, mepacrine itself also needed replacing as it is too toxic for mass use. After synthesizing and screening a huge series of substitutions, the addition of an amodiaquine side-chain to this nucleus was found to give the greatest activity for fewest adverse effects. Being aware of the rapid selection of pyronaridine-resistant Plasmodium strains that occurs in the laboratory, the Chinese efforts have also investigated the use of drug combinations to circumvent or delay the development of drug resistance. In addition to the triple combination described here, pyronaridine and primaquine combinations are under trial against both P. vivax and P. falciparum. Pyronaridine is a highly active blood schizonticide like chloroquine and amodiaquine. It has already undergone extensive trials in humans against both P. falciparum and P. vivax. However, nothing is known of its mode of action, nor the basis for the development of resistance and although it is active against chloroquine-resistant strains of parasite, paradoxically, pyronaridine-resistant Plasmodium is resistant to chloroquine.

A modified electrode plate for low energy electric conversion of atrial fibrillation

Fifty-six patients with atrial fibrillation associated with heart disease were treated with a modified electrode plate for low energy electric conversion. Fifty-four (96%) of these cases were successfully converted into sinus rhythm using the modified electrode plates, a new site and low energy discharge (an average of about 50 J). To construct the new-style electrode plates, a 2 cm arc segment was cut from each of two electrodes (10 cm in diameter each). As for the site of application, the cut-edge of the anterior chest electrode, which has a concave diameter of 150 cm, is placed close to the right of the sterum over the fourth to sixth intercostal spaces, and the cut-edge of the other electrode is placed to the left of the spinal column at the level of the seventh to ninth thoracic vertebrae. The safe-effective period for the appearance of the first post-discharge QRS complex was found to be 1.4-5.0 s.

Clinical use of praziquantel in China

Praziquantel, a broad-spectrum anthelmintic developed by E. Merck and Bayer AG in Germany in the early 1970s, was synthesized in the People's Republic of China in 1977 and given the Chinese name Pyquiton. After a series of pharmacological and toxicological studies in China, praziquantel was released for clinical use in 1978. The drug is now available for treatment of human schistosome and other trematode infections as well as the treatment of cestode infections including cysticercosis. However, much of the clinical work has been published in Chinese journals that may not be universally familiar. This article summarizes some of the key aspects of these reports, dealing with the clinical use of praziquantel against schistosomiasis japonica and other helminth infections in China.

In situ hybridization and immunocytochemistry for improved assessment of human immunodeficiency virus cultures

The authors characterized the early intracellular events involved in human immunodeficiency virus (HIV) replication after in vitro inoculation into cultures of susceptible human T-cell lines and phytohemagglutinin-stimulated peripheral-blood mononuclear cells (PMCs). Within 24 hours of infection, in situ hybridization with HIV DNA probe detected cytoplasmic viral RNA. Viral core antigen was detected in infected cells over the subsequent two to ten days by means of an immunocytochemical assay employing monoclonal antibodies. Several days later, cell-free virus was detected by both reverse transcriptase assay and a p25gag antigen-capture assay. When these methods were applied to monitor cultures of ten sero-positive persons' PMCs, a similar progression of virus replication was apparent: cytoplasmic viral RNA was detected in infected PMCs by day 3, with the subsequent appearance of intracellular viral proteins (days 6-9) and cell-free virus (days 12-21). In situ hybridization and immunocytochemistry offer complementary, sensitive, and specific approaches for monitoring the early stages of acquired immune deficiency syndrome virus replication in vitro.

In vitro activity of chloroquine, the two enantiomers of chloroquine, desethylchloroquine and pyronaridine against Plasmodium falciparum

A 48 h in vitro test was conducted to compare the susceptibility of two strains of Plasmodium falciparum to chloroquine, the two enantiomers of chloroquine, desethylchloroquine and the new antimalarial drug pyronaridine. The five compounds similarly inhibited the chloroquine sensitive strain. However, desethylchloroquine was less active and pyronaridine was much more active than chloroquine and its enantiomers against the chloroquine resistant strain.

Clinical trial on furapyrimidone in filariasis

A clinical trial was carried out with furapyrimidone in treating 51 patients with B. malayi, 159 with W. bancrofti and eight with D. perstans using different dosage schedules. Two hundred and fifty-seven cases of Malayan and bancroftian filariasis were treated with hetrazan for comparison. The results based on the microfilaricidal effects suggest that furapyrimidone possesses similar therapeutic effects of hetrazan on Malayan filariasis at eight-month follow-up, and higher incidences of microfilarial disappearance of W. bancrofti infection (81.3%) at six-month follow-up. The drug was also effective against D. perstans. The side effects consisted of fever and irritation of the digestive tract. Fever may be related to allergic reaction of foreign protein from the dead or dying parasites. The side reactions are similar to those of hetrazan and usually not serious. Comparing the efficacies and side effects of furapyrimidone with different dosage schedules the authors recommend regimens of 15 to 20 mg/kg/day for six days in treating Malayan filariasis and 20 mg/kg/day for seven days in treating bancroftian filariasis.