Neglect and constructive disorder

A 61 year-old right handed man, who suffered from right cerebral infarction with evidences of visual-spatial neglect and constructive disorder, was reported. When copying simple geometric designs, he omitted to copy figures on the left side of the page; he tended to bisect the line to the right of the line's real center; after memorizing the familiar pictures he mainly mentioned the pictures on the right side of the page; when copying the "Rey Complex" he also ignored the structures on the left side. The relations of the neglect and construction disorder are discussed.

Apparent blood stream origin of endothelial and smooth muscle cells in the neointima of long, impervious carotid-femoral grafts in the dog

The purpose of this study was to determine whether endothelial and smooth muscle cells originating from the blood stream contribute to the endothelialization of impervious, small-caliber, long Dacron grafts used as extraanatomical bypasses in dogs. We implanted silicone-rubber-coated, permanently impervious grafts 64 to 77 cm long and 6 mm in diameter, made of externally supported knitted Dacron as unilateral carotid-femoral bypasses with distal femoral arteriovenous fistulae in 10 dogs for 3 months; sides were alternated between cases. Subjects received 162 mg/day of aspirin, and its effectiveness on platelet aggregation (PA) was evaluated and expressed as a PA score. Graft healing was studied by stereomicroscopy with silver nitrate staining, by light microscopy with hematoxylin-eosin and immunocytochemical staining for endothelial and smooth muscle cells, and by scanning and transmission electron microscopy. Five grafts were patent for 3 months and could be included in the healing study; the five occluded grafts thrombosed within 14 days. Although there was no transinterstitial tissue ingrowth from perigraft tissues into the impervious Dacron grafts, scattered islands of endothelial cells were conclusively demonstrated on graft flow surfaces 3 months after implantation. Average endothelial-like cell coverage of the flow surfaces was 15.6% +/- 3.8%, and alpha-actin-positive smooth muscle cells and microvessels were found beneath some of the endothelial islands. These findings suggest that blood stream-derived endothelial and smooth muscle cells play a role in the healing of the inner wall of Dacron grafts in the dog.

Continued risky injection subsequent to syringe exchange use among injection drug users in New York City

Although the vast majority of injection drug users (IDUs) attending syringe exchange programs in New York City have stopped risky injection (injecting with syringes used by someone else), there remains a subgroup of IDUs who continue to engage in high-risk injecting behaviors despite access to sterile syringes. Subjects were randomly recruited from five legally authorized syringe exchange programs in New York City between October 1992 and August 1994. Participants were asked about drug and sexual risk behavior 30 days prior to their first use of the syringe exchange as well as during the 30-day period prior to the interview while using the exchange. Of the 2,465 participants, 77.4% reported no risky injection during the 30 days prior to using syringes exchange. For this analysis we included only those who reported risky injection for the 30-day period prior to using syringe exchange (N = 556). We compared sociodemographics and behavioral characteristics of a group who continued risky injection while using the syringe exchange, "continuers," N = 158 (28.8%) with a group who reported risky injection prior to using the exchange and then ceased risky injection while using the exchange, "stoppers," N = 391(71.2%). Continuers were significantly more likely to report passing on dirty syringes to social network members and to inject cocaine at least daily. We present other predictors of continued risk and discuss the implications for interventions and make recommendations for syringe exchange programs.

Antitumor agents--CLXXV. Anti-tubulin action of (+)-thiocolchicine prepared by partial synthesis

(+)-Thiocolchicine (2b) was prepared from (+/-)-colchicine (1) in a five-step reaction sequence that included chromatographic separation of appropriate camphanylated diastereomers. Acid hydrolysis of the (+)-diastereomer, followed by acetylation, yielded the desired product 2b. (+)-Thiocolchicine has 15-fold lower inhibitory activity against tubulin polymerization than (-)-thiocolchicine, and is 29-fold less potent for inhibiting growth of human Burkitt lymphoma cells. The enantiomer 2a, prepared from the (-)-camphanylated diastereomer, had potent activity in all assays comparable to that of (-)-thiocolchicine prepared by other methods. These results support the hypothesis that the proper configuration of colchicine-related compounds is an important requirement for their anti-tubulin action.

[Cloning and expression in Escherichia coli of an alkaline and thermostable exolipase from Pseudomonas pseudoalcaligenes]

A gene coding for an alkaline and thermostable exolipase of Pseudomonas pseudoalcaligenes was cloned into Escherichia coli LE392 by inserting Sau3 AI-generated DNA fragments into the BamHI site of pIJ285. Four colonies with esterase and lipase activities on the tributyrin agar plate were isolated by screening the constructed pseudomonas pseudoalcaligenes genomic library. Only one out of the four positive colonies showed lipase activity on the agar plate contatining olive oil and Rhodamine-B. Subclones of the 45 kb insert carrying lipase gene was obtained in E. coli HB101 using pUC118 as a vector, two of which (HB101 (pHZ1402) and HB101 (pHZ1403)), retained lipase activity, but the level seems to be different. They carried 3.0 kb and 2.9 kb inserts with a 2 kb overlapping sequence. The lipase activity of HB101 (pHZ1403) is about 4 times higher than that of HB101 (pHZ1402), as 5 times as that of original strain P. pseudoalcaligenes.

Early presence of endothelial-like cells on the flow surface of porous arterial prostheses implanted in the descending thoracic aorta of the dog

The purpose of this study was to investigate early arterial graft healing and its sources in porous Dacron prostheses after very short implantation periods in the dog, using extensive histologic examination of serial sections. Preclotted Dacron prostheses 6 cm long and 8 mm in diameter were implanted in the descending thoracic aorta (DTA) of 14 dogs, and retrieved at 7 days (n = 6), 10 days (n = 4), and 14 days (n = 4). The flow surface was assessed for thrombus coverage, endothelial-like cell (ELC) coverage, and the number of microvessel ostia. Where an ELC island was identified under the stereomicroscope, full-wall longitudinal tissue samples were taken, and embedded in resin for light microscopy study of 6-microns, H&E-stained serial sections to determine general healing and interstitial tissue presence. If there was more than one ELC island, another full-wall sample was taken and embedded in paraffin for staining with laminin, collagen IV, and smooth muscle alpha-actin antibodies, and PTAH. All grafts were patent with very little thrombus. Islands of endothelial-like cells were found for each time period, and on all 14-day grafts. Endothelial-like cell coverage was highest at 14 days. On 7- and 10-day grafts, cells proved to be endothelium were found in the middle of the flow surface, unconnected to either pannus or perigraft tissue ingrowth. Healing occurs as early as 7 days in porous knitted Dacron grafts. The source at periods earlier than 10 days appears to be cells from the blood stream.

[Studies of bone marrow T lymphocytes in patients with aplastic anemia]

OBJECTIVE

To study the role of immunological factors in the pathogenesis of aplastic anemia(AA).

METHODS

Phenotype of T lymphocytes in bone marrow and CFU-GM yields of bone marrow mononuclear cells with or without T cells were assayed with APAAP and semi-solid culture method, respectively.

RESULTS

The percentage of lymphocytes in bone marrow of AA patients was higher than that of normal controls, and the lymphocytes were mainly CD8 and CD25 positive cells. Changes of T lymphocyte subsets in peripheral blood of AA patients did not completely reflect the changes in the bone marrow. In some AA patients, increased percentage of CD8+ cells was found in bone marrow, while it was normal in peripheral blood. The CFU-GM yields of bone marrow cells of AA patients were much lower than that of normal controls, and were markedly improved by removing T cells before culture.

CONCLUSION

The abnormalities of cell-mediated immune response played important roles in the pathogenesis of AA. The changes of T lymphocytes in bone marrow were more meaningful than that in peripheral blood. It is suggested that bone marrow T lymphocyte and its subsets should be routinely examined in all of the AA patients diagnosed so as to assess the indication and predict the effectiveness of immunosuppresive therapy.

Analytical performance and clinical utility of a sensitive immunoassay for determination of human cardiac troponin I

OBJECTIVES

To determine the serum and plasma level of human cardiac troponin I (cTnI) resulting from myocardial damage, we have developed a sensitive and specific one-step enzyme immunoassay to measure cardiac troponin I.

DESIGN AND METHODS

The COBAS cTnI assay is a semi-automated one-step solid phase immunoassay compatible with the COBAS Core. The assay is performed in a sandwich type format using a polyclonal goat antibody capture and two highly specific horseradish peroxidase conjugated monoclonal antibody detectors directed against different epitopes of the cTnI molecule. Calibrators were made with purified recombinant cTnI.

RESULTS

The level of cTnI was determined in 84 healthy donors with no evidence of myocardial injury, resulting in a lower limit of detection (LLD) of 0.09 microgram/L. The upper reference limit (URL) of the normal reference range was calculated as 0.20 microgram/L. The dynamic range of the consequent EIA was between 0.09 and 6.0 micrograms/L with a total assay time of 45 min. Intra-assay and inter-assay variances (CVs) were < or = 4%. Cross-reactivity with fast and slow skeletal troponin I was absent in concentrations up to 2.0 mg/L. Common interferents yielded negative results in the cTnI assay. Clinical utility was confirmed by measuring the circulating serum or plasma levels of cardiac troponin I in serial samples from marathon runners, clinical samples from trauma patients, and patients presenting to the Emergency Department with complaints of chest pain. Results were further evaluated using clinical diagnosis at discharge and quantified concentrations of other cardiac markers by a Stratus analyzer and ELISA procedures.

CONCLUSIONS

Results from normal and clinical samples assayed in house for cTnI concentrations indicate that the Spectral EIA is a highly sensitive means of quantifying cTnI levels in serum and plasma for acute cardiac syndrome. The cardiac specificity of cTnI over other well-known cardiac markers is reflected in experimental results and parallel clinical diagnosis.

Removal of endotoxin from recombinant protein preparations

OBJECTIVES

To develop an effective method to remove endotoxin from large scale E. coli recombinant protein purifications.

DESIGN AND METHODS

Triton X-114 phase separation, affinity chromatography utilizing immobilized polymyxin B or immobilized histidine, were used to remove endotoxin from purified preparations of recombinant CK-BB, CK-MB, CK-MM, myoglobin, and cardiac troponin I. Endotoxin levels were measured by a Limulus Amebocyte Lysate gel-clot assay. The immunoactivity of these protein preparations was determined by BIAcore analysis using a panel of in-house generated monoclonal antibodies and by a Stratus Fluorometric Analyzer. In the case of troponin I, the BIAcore was also utilized to measure troponin C interactions.

RESULTS

Phase separation with Triton X-114 was the most effective method in reducing the amount of endotoxin present in the protein preparations compared to either polymyxin B or histidine affinity chromatography. With Triton X-114, the reduction in endotoxin levels was greater than 99% and recovery of the proteins after endotoxin removal was greater than 90%. All three procedures for removing endotoxin had no deleterious effects on the immunoactivity of majority proteins when tested with a panel of monoclonal antibodies. Troponin I also retained its ability to bind to troponin C in the presence of Ca2+. Recombinant CK-BB and CK-MM which were expressed in the soluble fraction of E. coli cell lysates, contained significantly higher endotoxin levels than recombinant CK-MB, myoglobin and cardiac troponin I which were expressed in the form of inclusion bodies.

CONCLUSION

Of the three methods tested, Triton X-114 phase separation was the most effective way of removing endotoxin from recombinant proteins.

Regulation of the biological activity of glucagon-like peptide 2 in vivo by dipeptidyl peptidase IV

Species-specific differences in the enzymatic inactivation of peptides is an important consideration in the evaluation of therapeutic efficacy. We demonstrate that glucagon-like peptide 2 (GLP-2), shown to be highly intestinotrophic in mice, promotes an increase in intestinal villus height but has no trophic effect on small bowel weight in rats. The reduced intestinotrophic activity of GLP-2 in rats is attributable to inactivation by the enzyme dipeptidyl peptidase IV (DPP-IV). GLP-2(1-33) was degraded to GLP-2(3-33) following incubation with human placental DPP-IV or rat serum but not by serum from DPP-IV-deficient rats. Administration of rat GLP-2 to DPP-IV-deficient rats was associated with markedly increased bioactivity of rat GLP-2 resulting in a significant increase in small bowel weight. A synthetic GLP-2 analog, r[Gly2]GLP-2, with an alanine to glycine substitution at position 2, was resistant to cleavage by both DPP-IV and rat serum in vitro. Treatment of wild-type rats with r[Gly2]GLP-2 produced a statistically significant increase in small bowel mass. DPP-IV-mediated inactivation of GLP-2 is a critical determinant of the growth factor-like properties of GLP-2.

[Technological study on the supercritical-CO2 fluid extraction of Curcuma longa oils]

This paper first reports technological study on the extraction of Curcuma longa oils by supercritical-CO2 fluid, mainly studies the influence of pressure, temperature, flow rate of CO2 and time on the yield of the oils, determines optimum technology of extracting the oils, analyzes chemical constituents extracted, compares the oils from SFE-CO2 and SD technology, studies industrial test on the SF-CO2 extraction. The results shows pressure and temperature are more important factors of influence; the optimum technological condition is the extracted pressure 25 MPa and temperature 45 degrees C, isolated pressure I 12.5 MPa and temperature I 60 degrees C, isolated pressure II 6MPa and temperature II 38 degrees C, CO2 flow rate 9 Kg/Kg.h, and extracted time 2 h; the constituents from SFE-CO2 and SD methods are identical, but their content has some difference; SFE-CO2 technology is better than that of SD, which is high yield shorter time, etc.; the industrial production of the oils with SFE-CO2 method is available.

[Determination of composition of electronic material by fundamental parameter method of XRF]

The fundamental parameters (FP) method of XRF in determination of the composition of electronic ceramic materials is studied. The fundamental parameters needed in calculation are developed by math calculation and the program is developed in C language. The method can also be used in determination of the composition of alloy. Some samples are analysed by this method and the relative derivation is less than 3%.

[Study of supercritical-CO2 fluid extraction in extracting essential oils of Amomun tsao-ko]

Essential oils from Amomum tsao-ko are extracted by supercritical-CO2 fluid and the oils are analyzed by GC-MS. 1, 8-cineole, trans-geraniol eicosatrienoic acid methylester and d-nerolidol of them are the major constitutents, 12 constitutents of them are first obtained from the plant.

Endothelium on the flow surface of human aortic Dacron vascular grafts

PURPOSE

We have previously observed endothelium on two human vascular prostheses explanted under optimal conditions for flow surface preservation. In this study we sought to further verify the hypothesis that endothelialization can occur on clinical grafts and that it can be detected in specimens that have been promptly removed and properly preserved in a timely manner.

METHODS

We studied 29 aortic grafts. Of these, 11 Dacron bypass grafts were in a condition suitable for analysis with light microscopy and immunocytochemistry staining, and scanning and transmission electron microscopy.

RESULTS

Three grafts had endothelium beyond the pannus, identified by factor VIII/ vWF, Ulex europaeus agglutinin, and collagen IV positivity. Specimen A, a knitted 6-year implant, was preserved by embalming 3 hours after the patient's death and had a firmly attached outer capsule with fibroblasts, collagen, giant cells, and microvessels in the interstices. Specimen B, a woven 18-year implant, was retrieved at reoperation and immediately fixed in 10% formalin; it had no outer capsule and no tissue ingrowth. Specimen C, a woven 7-year implant, was removed and fixed 5 hours after the patient's death; it had a firmly attached outer capsule but no tissue ingrowth beyond the outer portion of the wall.

CONCLUSIONS

The rapidity with which the specimens were fixed probably enabled identification of endothelium. These findings suggest that endothelialization of synthetic arterial grafts may occur more frequently in human beings than previously recognized.

[Supercritical-CO2 fluid extraction of natural VE and fatty oil from the oil foot of Brassica campestris and GC-MS analysis]

Natural VE and fatty oil from the oil foot of Brassica campestris are extracted by supercritical-CO2. After saponification and esterification these acidesters and natural VE in the extraction are analyzed by GC-MS. The results show that the fatty acids from SFE-CO2 contain 10 components which of oleic acid, linodeic acid and linolenic acid are main components, linodenic acid and linoleic acid of them are increased signifantly, at the same time, natural VE can be extracted from the materials and the rate of extraction gets to 95%.

Antitumor agents. 172. Synthesis and biological evaluation of novel deacetamidothiocolchicin-7-ols and ester analogs as antitubulin agents

A series of novel 7-O-substituted deacetamidothiocolchicine derivatives has been synthesized and evaluated for their inhibitory activity against tubulin polymerization, the binding of [3H]-colchicine to tubulin, and the growth of human Burkitt lymphoma cells. Of these new derivatives, thiocolchicone (8), wherein an acetamido group in thiocolchicine is replaced by a carbonyl oxygen at C(7), was obtained from deacetythiocolchicine (6) by Schiffs base equilibration and acid hydrolysis. Reduction of thiocolchiocone with sodium borohydride yielded the racemic alcohol 9, the structure of which was verified by X-ray crystallographic analysis. Optically pure alcohols 9a,b were obtained by treatment of 9 with the optically pure reagent (1S)-(-)-camphanic chloride followed by chromatographic separation of the camphanate esters and hydrolysis of the diastereomers. X-ray crystallographic analysis established the aS,7S-configuration of 9a. Racemic and optically active esters 11-15, 11a,b, 12a, 14a, and 15a were obtained by esterification of the corresponding alcohols. The compounds showing activity equivalent to or greater than (-)-thiocolchicione (2a) in all the biological assays were three (-)-aS,7S optically pure enantiomers: the alcohol 9a, the acetate 11a (an oxygen isostere of thiocolchicine), and the isonicotinoate 15a. In addition, the ketone 8 and two (-)-aS,7S enantiomers (12a, 14a) had high activity in the biochemical assays with tubulin but reduced antiproliferative activity. In all cases, optically pure isomers with the (-)-aS,7S configuration exhibited greater biological activity than racemic mixtures or isomers or isomers with the (+)-aR,7R configuration.

Modulation of the specificity and activity of a cellular promoter in an adenoviral vector

Most gene therapy studies with recombinant adenoviruses employ viral promoters and lack tissue specificity. To determine whether a tissue-specific cellular promoter inserted into the adenoviral genome can direct the expression of a reporter gene in a tissue-specific manner, recombinant adenoviruses containing a nuclear lacZ gene driven by a human ventricular/slow muscle myosin light chain 1 promoter with and without a muscle creatine kinase enhancer were constructed. The ability of these viruses to express the reporter genes in infected myogenic and nonmyogenic cell lines was studied. Intramuscular injection of these viruses into mice showed that little or no reporter gene expression occurred in muscle fibers, although a relatively high level of lacZ gene expression was observed in surrounding connective tissue. Insertion of adenovirus sequences from the 5' inverted terminal repeat (ITR) region and/or the protein IX region into plasmids resulted in decreased reporter gene expression from myosin light chain 1 promoter in transfected C2C12 myotubes and 293 cells, as well as in injected muscles. These results suggested that negative elements are present in the adenoviral genome. This negative effect seems neither tissue nor species specific. Adenovirus cis-elements that may affect the specificity and activity of a cellular promoter are discussed.

Accelerated endothelialization model for the study of Dacron graft healing

Accelerated endothelialization was studied by creating a vascular tissue environment around porous Dacron grafts. Three study groups, each containing 10 dogs, were divided equally into 2- and 4-week implant periods, with 8 mm x 6 cm knitted Dacron grafts implanted in the abdominal aorta. Grafts in group 1, the control group, were implanted conventionally. In group 2 each implanted graft was completely wrapped in a resected segment of the autogenous inferior vena cava, with its intima against the wall. In group 3 the adventitial side of the vein was wrapped against the wall. The vein wrap produced accelerated endothelialization as follows: endothelial-like cell coverage scores at 2 and 4 weeks were, respectively, 78% and 98% for group 2 and 80% and 95% for group 3, compared to only 14% and 50% for group 1 (p < 0.05). The neointima, which contained smooth muscle cells, was formed as early as 2 weeks in the vein-wrapped grafts. There were no differences in the speed of healing or in healing patterns according to whether the intimal or the adventitial side of the inferior vena cava was placed against the graft. Histologic findings did not support the hypothesis that accelerated flow surface endothelialization results in direct migration of endothelial cells from the intima of the vein wrap, and there was no clear correlation between the surface endothelial-like cell coverage and microostia. To gain further insight into why accelerated healing occurs in this model, earlier observations accompanied by molecular biology analysis are needed, and vein wrap studies provide a method of comparison for this work.

Implant site influence on arterial prosthesis healing: a comparative study with a triple implantation model in the same dog

PURPOSE

The purpose of this study was to develop a cost-effective canine graft healing model that gives information on various implant sites and controls for variable factors between graft locations and between animals and to compare the influence of implant site (retropleural, retroperitoneal, and subcutaneous areas) on arterial graft healing in the same subject under such controlled study conditions.

METHODS

Five mongrel dogs were studied for 8 weeks, and one was studied for 3 years. Each received three porous Dacron grafts during the same surgery: a carotid-femoral bypass (C-FB) and interposition grafts in the descending thoracic aorta and abdominal aorta. To produce comparable shear stress calibers of the C-FB and abdominal aorta grafts were 2 mm less than those of the descending thoracic aorta, and a distal arterio-venous fistula was created to further increase the C-FB flow. For comparable blood aggregation status platelet aggregation was preevaluated and adjusted with antiplatelet agents. Graft flow surfaces were assessed for thrombus-free surface and endothelial-like cell coverage scores. Tissue samples were studied with hematoxylin-eosin, factor VIII/ von Willebrand factor, smooth muscle alpha-actin staining, and scanning electron microscopy and transmission electron microscopy.

RESULTS

All grafts were patent. Shear stress for the three grafts and platelet aggregation among the study subjects were comparable. Healing of descending thoracic aorta and abdominal aorta grafts was similar, but C-FB healing was slow, incomplete, and uneven, with a high incidence of seroma. Eight-week and 3-year results were comparable.

CONCLUSIONS

This model gives broad healing information about the areas where grafts are often implanted in humans. Eight weeks appears to be a sufficient period to reflect basic and general healing characteristics. Grafts heal better in the retropleural and retroperitoneal areas than in the subcutaneous tissues.

[Hodgkin's disease with concurrent infection of toxoplasmosis]

Hodgkin's disease (HD) is a specific type of malignant lymphoma characteristic of local and general lymphadenectasis. Aquired toxoplasmosis (AT) is one kind of lymphoadenopathy without fever and fatigue. When the two diseases coexist, clinical and pathological misdiagnosis may be made. This is the first male case of toxoplasmosis and Hodgkin's disease in China, diagnosed by surgical removal of the major part of the cervical and supraclavicular masses, detection of blood anti-toxoplasma gondii antibody, PCR analysis of toxoplasma gondii DNA, and pathological, ultrastructural and immunohistochemical studies of the tumour tissues. The patient treated by radiation and chemotherapy was abated.

Effect of altered blood flow on the caliber and morphology of the internal thoracic artery in the dog

OBJECTIVE

The purpose of this study was to evaluate in dogs the effect of blood flow alteration on caliber and morphology of in situ internal thoracic arteries.

METHODS

Six dogs underwent creation of a unilateral distal arteriovenous fistula between the internal thoracic artery and vein at the sixth rib to create high flow, and in six others the internal thoracic artery was unilaterally skeletonized and dissected. For both groups the contralateral internal thoracic artery served as the control; sides were alternated among cases. Blood flow was measured for shear stress calculation before and after surgical alteration. After 2 months, internal thoracic arteries were harvested with the entire anterior chest plate, which was dynamically inflated and fixed with 10% formalin at a controlled pressure of 120 mm Hg after angiography had been done at the same pressure. The luminal diameters were then measured at eight levels on the angiograms. Arterial tissue samples were taken at three levels and embedded, sectioned, and treated with hematoxylin-eosin and Verhoeff-van Gieson stains. Digital imaging analysis was used for quantitative morphometric studies.

RESULTS

All fistulas remained patent. In comparison with control arteries, high-flow internal thoracic arteries dilated and low-flow internal thoracic arteries narrowed, which was associated with significant change in shear stress for both groups. There were no substantial structural changes in the walls of either group.

CONCLUSION

In the dog, the luminal diameter of the internal thoracic artery responds to altered blood flow without intimal thickening or other undesirable wall changes.

[Study on the inflation pressure of air tourniquets in surgery of the upper extremities]

52 patients were studied under two different inflation pressure so as to find out the proper inflation pressure in the upper extremity operation. Analyzing the hemostasis effect and EMG of the upper extremity under different inflation pressre, it suggested that when the air tourniquet is used in the upper extremity operation the traditionally used pressure (33.3-40.0 kPa) of the air tourniquet should be changed according to the patient's condition. Usually good hemotasis effect could be obtained under the pressure of 4.0-6.6 kPa, which is more than the systolic pressure of the brachial artery.

Structure and stereochemistry of pseudolarolide J, a novel nortriterpene lactone from Pseudolarix kaempferi

Pseudolarolide J (1), a novel nortriterpene lactone, has been isolated from the seeds of Pseudolarix kaempferi and structurally characterized from spectral data and X-ray crstallographic analysis.

HIV incidence among injecting drug users in New York City syringe-exchange programmes

BACKGROUND

There have been no studies showing that participation in programmes which provide legal access to drug-injection equipment leads to individual-level protection against incident HIV infection. We have compared HIV incidence among injecting drug users participating in syringe-exchange programmes in New York City with that among non-participants.

METHODS

We used meta-analytic techniques to combine HIV incidence data from injecting drug users in three studies: the Syringe Exchange Evaluation (n = 280), in which multiple interviews and saliva samples were collected from participants at exchange sites; the Vaccine Preparedness initiative cohort (n = 133 continuing exchanges and 188 non-exchangers, in which participants were interviewed and tested for HIV every 3 months; and very-high-seroprevalence cities in the National AIDS Demonstration Research (NADR) programme (n = 1029), in which street-recruited individuals were interviewed and tested for HIV every 6 months. In practice, participants in the NADR study had not used syringe exchanges.

FINDINGS

HIV incidence among continuing exchange-users in the Syringe Exchange Evaluation was 1.58 per 100 person-years at risk (95% CI 0.54, 4.65) and among continuing exchange-users in the Vaccine Preparedness Initiative it was 1.38 per 100 person-years at risk (0.23, 4.57). Incidence among non-users of the exchange in the Vaccine Preparedness Initiative was 5.26 per 100 person-years at risk (2.41, 11.49), and in the NADR cities, 6.23 per 100 person-years at risk (4.4, 8.6). In a pooled-data, multivariate proportional-hazards analysis, not using the exchanges was associated with a hazard ratio of 3.35 (95% CI 1.29, 8.65) for incident HIV infection compared with using the exchanges.

INTERPRETATION

We observed an individual-level protective effect against HIV infection associated with participation in a syringe-exchange programme. Sterile injection equipment should be legally provided to reduce the risk of HIV infection in persons who inject illicit drugs.