Biomedical subjects

T Steffen

Publications and source records attributed to T Steffen.

At least 19 recordsLinked to original sources

PubMed2001

Feasibility, safety, and efficacy of injectable heroin prescription for refractory opioid addicts: a follow-up study.

BACKGROUND: Heroin-assisted substitution treatment for severely opioid-dependent drug users has been available in Switzerland since 1994. Our aim was to ascertain the feasibility, safety, and efficacy of this treatment. METHODS: We did a cohort study in 21 community outpatient treatment centres. We assessed 1969 opioid-dependent drug users, who began heroin-assisted substitution treatment between January, 1994, and December, 2000, to ascertain admission and discharge patterns, and patient characteristics. We also followed up a subset of 237 patients who began treatment between Jan 1, 1994, and March 31, 1995, and who stayed with the programme for at least 18 months. We used questionnaires, interviews, and medical examinations done at entry and after 6, 12, and 18 months to assess somatic and mental health, social integration, and treatment outcomes. FINDINGS: More than 70% (1378) of patients remained in treatment for more than a year. Treatment showed positive effects with respect to health and social outcomes. A long stay in treatment was related to a higher chance of starting abstinence-oriented therapy than a short stay. INTERPRETATION: Heroin-assisted substitution treatment might be an effective option for chronically addicted patients for whom other treatments have failed.

Adult↗

PubMed2001

Porous tricalcium phosphate and transforming growth factor used for anterior spine surgery.

Harvesting autologous bone graft from the iliac crest is associated with considerable secondary morbidity. Bone graft substitutes such as porous ceramics are increasingly used for spinal surgery. This paper presents the results of an animal study in which beta-tricalcium phosphate (beta-TCP) bone substitutes were used for anterior spinal surgery in sheep and baboons. The presented baboon study also investigated the effect of impregnating the ceramic material with transforming growth factor (TGF). In the first study, using the sheep model, a stand-alone instrumented anterior fusion was performed. The animals were randomized into three treatment groups: autologous bone, beta-TCP granules, and sham group. The results were analyzed biomechanically and histologically at three survival intervals: 8, 16 and 32 weeks. An additional animal group was added later, with ceramic pre-filled implants. In the second study, a baboon model was used to assess the osteointegration of a 15-mm-diameter porous beta-TCP block into the vertebral body. The experiment was partially motivated by a new surgical procedure proposed for local bone graft harvest. Three treatment groups were used: beta-TCP plug, beta-TCP plug impregnated with TGF-beta3, and a sham group with empty defect. The evaluation for all animals included computer tomograms at 3 and 6 months, as well as histology at 6 months. In the sheep model, the mechanical evaluation failed to demonstrate differences between treatment groups. This was because massive anterior bone bridges formed in almost all the animals, masking the effects of individual treatments. Histologically, beta-TCP was shown to be a good osteoconductor. While multiple signs of implant micromotion were documented, pre-filling the cages markedly improved the histological fusion outcomes. In the baboon study, the beta-TCP plugs were completely osteointegrated at 6 months. For the group that used ceramic plugs impregnated with TGF-beta3, no incremental advantage was seen as a result of this particular application. However, TGF-beta3 is a potent growth factor at a very low dose. Not only does it speed up the ceramic material resorption, but it is also responsible for massive regional new bone formation. More experiments are required to better understand the biological effects of this growth factor in relation to bone formation, and to be able to take clinical advantage of them.

Animals↗

PubMed2001

Infectious diseases and public health: risk-taking behavior during participation in the Swiss program for a medical prescription of narcotics (PROVE).

The medically controlled prescription of narcotics program (PROVE) followed a uniform protocol from January 1, 1994 until December 31, 1996. The program included 800 slots for heroin prescription, 200 slots for intravenous methadone prescription, and 200 slots for intraveneous morphine. Admission criteria were age 20 and above, minimum 2-year duration of daily heroin consumption, failure in at least two previous treatments, and documented social and/or health deficits. There was a very high seroprevalence of hepatitis B (73%) and hepatitis C (82%) among the 1035 entrants. The rate of HIV (15%) was also high compared with prevalence of infection in other therapy programs (methadone program, inpatient therapy). The prevalence of HIV and hepatitis B/C increased with the duration of drug dependence and cocaine use. During treatment, use of street heroin and cocaine could be reduced substantially. After 18 months of continued participation in the program, 74% of patients reported no illegal heroin consumption, and the rate of cocaine abstinence increased from 15% at entry to 41%. Significant declines in visits to the drug scene, illegal income, and needle sharing were also observed. The high prevalence of HIV and hepatitis B and C confirm that a group of drug dependence with severe medical problems was reached in accordance with the admission criteria for the studies. During treatment, a significant reduction in risk-taking behavior was observed in a target population of heroin-dependent persons who failed in previous treatments.

Adult↗

PubMed2001

HIV and hepatitis virus infections among injecting drug users in a medically controlled heroin prescription programme.

BACKGROUND: In Switzerland, 1,035 patients were accepted for admission to the medically controlled prescription of narcotics programme (PROVE) from 1 January 1994 until 31 December 1996. Heroin, methadone, and morphine were prescribed. This paper presents the prevalence and incidence of HIV and hepatitis B/C infections in the sociomedical context of the participants. METHODS: Admission criteria were a minimum age of 20 years, at least a two-year duration of daily heroin consumption, a negative outcome of at least two previous treatments, and documented social and health deficits as a consequence of their heroin dependence. The patients were examined at admission and every six months. A serological test was carried out at the same time for HIV and hepatitis B/C. RESULTS: Serological testing on admission could be performed in more than 80% of the entrants and documented a very high seroprevalence of antibodies against HBcore (73%) and HCV (82%). The prevalence of HIV and hepatitis B/C increased with duration of drug intake. In the follow-up analysis of seronegative individuals, a halving of the risk of viral hepatitis infection was shown when comparing the first six months with the period greater then six months after PROVE entry. CONCLUSION: The tests conducted showed high prevalence and incidence rates of HIV and hepatitis B/C among patients who had consumed intravenous drugs for years. The descriptive analysis in heroin-assisted treatment showed a reduction in infection risk for viral hepatitis corresponding to the lower risk behaviour of patients.

Adult↗

PubMed2000

[Development of skin diseases in intravenous drug dependent patients treated with heroin substitution].

Drug addiction is linked with increased prevalence of various illnesses. Of major importance are skin diseases which often have a powerful influence on the health. Analysis of the situation in Switzerland at the outset of the 1990s showed that not all drug addicts could be reached with the existing range of treatments. For this reason, heroin-supported treatment was examined as a new therapy option from 1994 on. The influence on the skin's health are examined in this study. The minimum age of those admitted was set at age 20. Heroin addiction had to date back at least two years, and several treatment efforts had to have failed. Data of 1,035 patients was based on tests at admission and after six, 12, and 18 months of treatment. Some 18% of drug consumers indicated abcesses at admission, and almost 30% showed phlegmones. The prevalence of all skin diseases examined show significant declines over the 18 months of treatment. The relative risk resulting from puncture points fell to 0.35 (SD: 0.26-0.47), from phlegmones to 0.24 (SD: 0.14-0.41), from absesses to 0.31 (SD: 0.15-0.60). This study shows that skin diseases are a frequent and important complication among intravenous drug addicts. Heroin-supported treatment led to favourable progress of the dermatological situation among patients.

Abscess↗

PubMed2000

Segmental stability and compressive strength of posterior lumbar interbody fusion implants.

STUDY DESIGN: Human cadaveric study on initial segmental stability and compressive strength of posterior lumbar interbody fusion implants. OBJECTIVES: To compare the initial segmental stability and compressive strength of a posterior lumbar interbody fusion construct using a new cortical bone spacer machined from allograft to that of titanium threaded and nonthreaded posterior lumbar interbody fusion cages, tested as stand-alone and with supplemental pedicle screw fixation. SUMMARY OF BACKGROUND DATA: Cages were introduced to overcome the limitations of conventional allografts. Radiodense cage materials impede radiographic assessment of the fusion, however, and may cause stress shielding of the graft. METHODS: Multisegmental specimens were tested intact, with posterior lumbar interbody fusion implants inserted into the L4/L5 interbody space and with supplemental pedicle screw fixation. Three posterior lumbar interbody fusion implant constructs (Ray Threaded Fusion Cage, Contact Fusion Cage, and PLIF Allograft Spacer) were tested nondestructively in axial rotation, flexion-extension, and lateral bending. The implant-specimen constructs then were isolated and compressed to failure. Changes in the neutral zone, range of motion, yield strength, and ultimate compressive strength were analyzed. RESULTS: None of the stand-alone implant constructs reduced the neutral zone. Supplemental pedicle screw fixation decreased the neutral zone in flexion-extension and lateral bending. Stand-alone implant constructs decreased the range of motion in flexion and lateral bending. Differences in the range of motion between stand-alone cage constructs were found in flexion and extension (marginally significant). Supplemental posterior fixation further decreased the range of motion in all loading directions with no differences between implant constructs. The Contact Fusion Cage and PLIF Allograft Spacer constructs had a higher ultimate compressive strength than the Ray Threaded Fusion Cage. CONCLUSIONS: The biomechanical data did not suggest any implant construct to behave superiorly either as a stand-alone or with supplemental posterior fixation. The PLIF Allograph Spacer is biomechanically equivalent to titanium cages but is devoid of the deficiencies associated with other cage technologies. Therefore, the PLIF Allograft Spacer is a valid alternative to conventional cages.

Bone Screws↗

PubMed2000

Harvesting the intact cadaveric cervical spine (C0-Th1).

STUDY DESIGN: Technical report on harvesting method for human cadaveric cervical spine. OBJECTIVES: Description of a new method for harvesting the intact cervical spine during routine autopsies, including the atlanto-occipital and cervico-thoracic joints, without visible disfigurement above the suprasternal notch. SUMMARY OF BACKGROUND DATA: Despite the need for cervical spine specimens, there are only few articles describing procedures for harvesting an intact cervical spine. Presently available techniques either do not preserve the atlanto-occipital joint or leave visible disfigurement. METHODS: The body was placed in a prone position with the head flexed, and a posterior midline incision was performed. The spine was separated from surrounding tissue, then the caudal end was cut off through the Th1/Th2 disc space. A circular craniotomy provided access to the cranial base. A square window surrounding the foramen magnum was cut at the cranial base (through the sella turcica, the internal occipital protuberance, and 5 cm parasagittal on either side), and the entire cervical spine extracted through the posterior incision. The defect was reconstructed using wood and plaster materials. RESULTS: Eighteen specimens were harvested to date using this method. The average time of harvesting the cervical spine was less than 30 minutes. Reconstruction using wood and plaster resulted in a nearly normal appearance of the neck. CONCLUSIONS: Using this technique, the nuchal ligament providing stability to the cervical spine can be preserved. The suggested method was found simple, efficient, and reproducible for harvesting the intact cervical spine, including the atlanto-occipital and cervico-thoracic joints, from any routine autopsy.

Atlanto-Occipital Joint↗

PubMed2000

The efficacy of interconnected porous hydroxyapatite in achieving posterolateral lumbar fusion in sheep.

STUDY DESIGN: An animal study was performed to evaluate lumbar spinal fusion radiologically and mechanically. OBJECTIVES: To assess the efficacy of interconnected porous hydroxyapatite in achieving posterolateral lumbar arthrodesis in sheep. SUMMARY OF BACKGROUND DATA: Posterolateral spinal arthrodesis with autologous bone graft is the gold standard procedure for lumbar fusion. The procedure for harvesting bone from the iliac crest increases morbidity. Interconnected porous hydroxyapatite has been used effectively as an alternative to cancellous bone graft material in metaphyseal bone defects. Little is known about the efficacy of interconnected porous hydroxyapatite in achieving lumbar spinal fusion. METHODS: Four groups of seven sheep underwent bisegmental posterolateral lumbar fusion with instrumentation using different intertransverse graft material. In group 1, no graft material was used. In group 2, autologous bone was used. Group 3 had interconnected porous hydroxyapatite. Group 4 had an equip of interconnected porous hydroxyapatite and autologous bone. The animals were killed at 20 weeks after surgery. Radiographs and computed tomography images were obtained. The fusion masses were graded for bone resorption and trabecular connectivity on the computed tomography images. Mechanical testing of the specimens was performed, and the three-dimensional segmental motion was measured in flexion/extension, axial rotation, and lateral bending. RESULTS: The radiographic images were difficult to interpret because of the radiodense interconnected porous hydroxyapatite granules. According to mechanical stability criteria, the fusion rate for the different groups was as follows: 100% (14/14) for the autologous bone group, 72% (10/14) for the bone/interconnected porous hydroxyapatite group, 50% (7/14) for the pure interconnected porous hydroxyapatite group, and 15% (2/14) for the sham group. CONCLUSIONS: Spinal arthrodesis using interconnected porous hydroxyapatite alone or mixed with bone as graft material reduced segmental motion. It was not, however, as effective as autologous bone graft material in achieving spinal arthrodesis. The sheep model using autologous bone achieved a 100% fusion rate. Because the nonunion rate for a single level in humans may be as high as 40%, the fusion rate with bone/interconnected porous hydroxyapatite in humans may be lower than the 72% found in the sheep model. The little resorption of the radiodense interconnected porous hydroxyapatite granules made the radiologic evaluation of the fusion masses difficult.

Animals↗

PubMed2000

Effect of implant design and endplate preparation on the compressive strength of interbody fusion constructs.

STUDY DESIGN: A human cadaveric study on the compressive strength of different lumbar interbody fusion implants and endplate preparation techniques was performed. OBJECTIVES: To assess the axial compressive strength of an implant with peripheral endplate contact as opposed to full surface contact, and to assess whether removal of the central bony endplate affects the axial compressive strength. SUMMARY OF BACKGROUND DATA: The compressive strength of interbody fusion constructs has been compared between implants and bone grafts. Neither implant design nor endplate preparation has been shown to affect strength. Removal of the central bony endplate for bone grafts was noted to improve graft incorporation but also to facilitate subsidence. METHODS: A total of 44 vertebrae were tested in four experimental groups by combining two interbody implants (full-surface vs peripheral surface support) with two endplate preparation techniques (intact bony endplate vs removal of the central bony endplate). Specimens were tested to ultimate compressive failure using a 50 N/second ramped load. Yield strength and ultimate compressive strength were compared between groups using two-factor analysis of covariance. A P value less than 0.05 was considered significant. Stepwise linear regressions assessed the predictive power of age, bone mineral content, and the implant's normalized endplate coverage on yield strength and ultimate compressive strength. RESULTS: Neither implant design nor endplate preparation technique affected yield strength or ultimate compressive strength. Age, bone mineral content, and the normalized endplate coverage were strong predictors of yield strength (P < 0. 0001; r2 = 0.459) and ultimate compressive strength (P < 0.0001; r2 = 0.510). CONCLUSIONS: An implant with only peripheral support resting on the apophyseal ring offers axial mechanical strength similar to that of an implant with full support. Neither supplementary struts nor a solid implant face has any additional mechanical advantage, but reduces graft-host contact area. Removal of the central bony endplate is recommended because it does not affect the compressive strength and promotes graft incorporation.

Adolescent↗

PubMed2000

Minimally invasive bone harvesting tools.

The most readily available source for autologous bone graft used in spinal fusion (the gold standard) is the iliac crest. However, the open surgical approach for harvesting corticocancellous iliac bone is associated with a marked increase in morbidity. This study suggests two alternatives to the traditional open harvesting procedure. For anterior interbody fusion procedures using a cage, the autologous bone is harvested regionally from a neighboring vertebral body. Alternatively, using minimally invasive techniques, a custom bone graft harvester with a flexible tube and cutting tip allows harvesting of autologous bone from a single entry point at the iliac crest. The effect on the mechanical strength of a lumbar vertebra of removing a cylindrical regional bone graft was studied in a cadaveric model. The bone defect was filled using three different filler materials: a porous tri-calcium phosphate plug, a porous tantalum plug, and a self-setting calcium phosphate cement. After plug removal, the vertebral body's strength in flexion/compression loading was reduced significantly, but could be restored to at least intact values with any of the three filler materials. The minimally invasive bone graft harvester was tested in three cadaveric pelves. With the cutting tip being guided within the cortical boundaries of the pelvis, cancellous bone volumes of 10-20 cc could be harvested from each iliac bone. Regional bone graft harvest in anterior spine surgery is suggested to be anatomically safe and biomechanically acceptable. Any of the three filler materials can restore the vertebral body's mechanical strength, but the filler's long-term resorption/remodeling or osteointegration behavior is unknown. The minimally invasive bone graft harvester is a novel tool, which performed satisfactorily under laboratory conditions, but clinical results are still missing.

Bone Transplantation↗

PubMed2000

Synframe: a preliminary report.

Both endoscopic lumbar spinal surgery and the non-standardized and unstable retractor systems for the lumbar spine presently on the market have disadvantages and limitations in relation to the minimally invasive surgical concept, which have been gradually recognized in the last few years. In an attempt to resolve some of these issues, we have developed a highly versatile retractor system, which allows access to and surgery at the lumbar, thoracic and even cervical spine. This retractor system - Synframe - is based on a ring concept allowing 360 degrees access to a surgical opening in anterior as well as posterior surgery. The ring is concentrically laid over the surgical opening for the approach and is used as a carrier for retractor arms, which are instrumented with either different sizes or types of blades and/or different sizes of Hohmann hooks. In posterior surgery, nerve root retractors can also be installed. This ring also functions as a carrier for fiberoptic illumination devices and different sizes of endoscopes, used to transmit the surgical procedure out of the depth of the surgical exposure for both teaching purposes and for the surgical team when it has no longer direct visual access to the procedure. The ring is stable, being fixed onto the operating table, allowing precise minimally open approaches and surgical procedures under direct vision with optimal illumination. This ring system also opens perspectives for an integrated minimally open surgical concept, where the ring may be used as a reference platform in computer-navigated surgery.

Equipment Design↗

PubMed2000

Cages: designs and concepts.

Many new interbody fusion cages have been recently developed, but clinical studies analyzing fusion outcome are still scarce. Radiological methods to assess fusion are not standardized and are often unreliable. Cages have been stated to provide good segmental distraction, provide axial load support and reduce segmental mobility, but there have been reports of failed fusions because of implant failure. This paper presents a critical opinion on current cage designs, stressing their clinical and biomechanical implications. Threaded cage designs compromise endplate integrity, and when placed in pairs have inherent limitations for distraction. Non-threaded cage designs usually preserve endplate integrity, but geometry may be inadequate to provide a good surface match to the endplate. The concept of an open frame type cage is believed to have biological advantages, because large graft volumes inside the cage can be in direct contact with host bone. Cadaveric tests suggest that open frame constructs have compressive strength similar to that of full surface contact cages. Restoration of segmental height, sagittal balance and increased neuroforaminal clearance are all functions of disc space distraction. The effect of cage instrumentation on axial load distribution, however, is not well understood. Biomechanical experiments strongly suggest supplementing cage instrumentation with posterior fixation, to achieve a marked increase in initial segmental stability. In the absence of gross segmental instability, micromotion at the host graft interface may still exist. As a result, fusion will never occur, instead a pseudoarthrosis will develop. For monitoring fusion, the use of non-metallic cages has distinct advantages, because no metal artifacts will disturb radiological assessment.

Equipment Design↗

PubMed2000

A surgical approach to the ventral aspect of the lumbar vertebrae in the sheep model.

The sheep model is frequently used for pre-clinical trials of spinal implants and vertebral interbody fusion devices. The lack of a well-documented multisegmental approach to the ventral aspect of the lumbar vertebrae has limited these trials to a posterior approach to the spine. A retroperitoneal approach to the sheep lumbar vertebrae was established and tested. One hundred and five sheep underwent the surgery. No major complications are reported. Major anatomical differences between sheep and humans were observed and documented. Anatomical variations in the sheep segmental vessel anatomy were also observed. Comprehensive knowledge of the retroperitoneal approach in sheep will facilitate pre-clinical studies testing ventral spinal implants or fusion techniques.

Animals↗

PubMed2000

Biomechanical stability of five stand-alone anterior lumbar interbody fusion constructs.

Anterior lumbar interbody fusion (ALIF) cages are expected to reduce segmental mobility. Current ALIF cages have different designs, suggesting differences in initial stability. The objective of this study was to compare the effect of different stand-alone ALIF cage constructs and cage-related features on initial segmental stability. Human multisegmental specimens were tested intact and with an instrumented L3/4 disc level. Five different ALIF cages (I/F, BAK, TIS, SynCage, and ScrewCage) were tested non-destructively in axial rotation, flexion/extension and lateral bending. A cage 'pull-out' concluded testing. Changes in neutral zone (NZ) and range of motion (ROM) were analyzed. Cage-related measurements normalized to vertebral dimensions were used to predict NZ and ROM. No cage construct managed to reduce NZ. The BAK and TIS cages had the largest NZ increase in flexion/extension and lateral bending, respectively. Cages did reduce ROM in all loading directions. The TIS cage was the least effective in reducing the ROM in lateral bending. Cages with sharp teeth had higher 'pull-out' forces. Antero-posterior and mediolateral cage dimensions, cage height and wedge angle were found to influence initial stability. The performance of stand-alone ALIF cage constructs generally increased the NZ in any loading direction, suggesting potential directions of initial segmental instability that may lead to permanent deformity. Differences between cages in flexion/extension and lateral bending NZ are attributed to the severity of geometrical cage-endplate surface mismatch. Stand-alone cage constructs reduced ROM effectively, but the residual ROM present indicates the presence of micromotion at the cage-endplate interface.

Adult↗

PubMed2000

[Tobacco prevention in apprentices--evaluation of a general practice project "not smoking is cool!"].

PURPOSE: In recent years the incidence of adolescent smokers has increased steeply. Taking this into account, current anti-smoker campaigns should be reconsidered. Great importance must be attached to the apprentice group, since adolescents in professional training have frequently not been reached sufficiently by the preventive efforts. This study presents a tobacco prevention campaign among adolescents which was conducted in a large Swiss industrial company in 1998. METHODS AND SAMPLE: A total of 430 apprentices took part in the prevention campaign which intentionally targeted adolescent behaviour. Of these, 40 apprentices were trained as mediators for tobacco prevention in advance. On the prevention day, the mediators communicated their know-how and experiences to their working groups. To evaluate the campaign, the apprentices were surveyed via standardised questionnaires on their smoking habits before the prevention campaign began. One month after the prevention day they were surveyed again on their current smoking habits and how the campaign had affected them. RESULTS: The study showed that apprentices smoke heavily despite high awareness of the negative consequences. Some 30% of the trainees admitted smoking regularly. Another 11% said they were occasional tobacco consumers. No significant gender difference was noticeable. Especially striking was that the adolescents often justified their own smoking as habit and dependence on tobacco. The prevention campaign was well received by the adolescents. It set about half of the smokers thinking over their smoking habits. No change in smoking habits, however, could be demonstrated one month after the campaign. CONCLUSIONS: Prevention among adolescents beyond the mandatory school period is a special challenge, since one cannot take advantage of the school's network. Within the scope of the campaign described here, it was possible to reach 430 apprentices of a major company. The study shows a great need for on-target smoking prevention in this sector. In the future, studies should examine whether tobacco prevention campaigns for apprentices should already contain secondary prevention elements from the outset. They should also assess if the effects could be further improved by introducing structural and other ongoing health-promotion measures.

Adolescent↗

PubMed2000

Posterolateral and anterior interbody spinal fusion models in the sheep.

Posterolateral and anterior interbody spinal arthrodesis is a frequent procedure, but high nonunion rates are reported and harvesting autologous bone graft from the iliac crest significantly increases morbidity. Bone graft substitutes are an alternative, but to date clinical results are not conclusive. Bone substitutes can be organic or inorganic, biologic or synthetic. They can have osteoconductive properties, inductive properties or both. Animal experiments are essential to investigating bone substitutes using biomechanical and histologic methods not available in clinical studies. Few authors reported on instrumented anterior fusion models, but none used the sheep model. In the current study posterolateral and anterior interbody fusion models in sheep are described. Both models used instrumented fusions, applying porous mineral scaffolds, alone or mixed with bone. The surgical techniques are described step-by-step and potential difficulties are highlighted. Preliminary results are reported for the posterolateral fusion model using coralline graft substitutes. The coral granules mixed with locally harvested bone had fusion outcomes similar to pure autologous bone. The graft substitute showed marked resorption between 12 and 20 weeks. All fusions had bone cortex and good trabecular connectivity. Histologic evaluation suggests after 20 weeks nearly the entire surface of the substitute is covered with new bone. Porous mineral bone substitutes mixed with locally harvested autologous bone are thought to be a valid alternative for posterolateral fusions.

Animals↗

PubMed1999

[Hepatitis B and C in intravenous drug abusers in Switzerland].

Since the 1980s hepatitis B and C have spread greatly among intravenous drug consumers. This shows up today in a high prevalence for both pathogens. It is striking that many patients who have only consumed drugs intravenously for a few years have already been infected with hepatitis B or C. The clear reduction in the spread of HIV within the drug-using community achieved by targeted measures during recent years has not had a similar impact on hepatitis B and C. Given this background, optimising preventive efforts among intravenous drug users is of great importance. Structural steps for therapy and damage-reduction should be optimised even more. Moreover, individual protective behaviour among patients should be improved. Medical advice and care is of great importance in this case. New studies show that many intravenous drug consumers are insufficiently informed on the risks of infection from shared use of injection utensils (spoons, filters, etc.) or drug sharing with used needles. Moreover, many drug consumers are not vaccinated against hepatitis B. Medical advice on protective behaviour should address these problems more directly. In the future, other sustainable intervention programmes based on this approach will need to be developed.

Adolescent↗

PubMed1999

[New treatment concepts in smoking cessation].

Although the smoking rate in Switzerland had declined during the 1970s and 1980s, it has not continued to decrease during the 1990s. About one third of the population in Switzerland smoked in 1997. Striking is a sharp increase in young female smokers during recent years. The portion of 15- to 25-year-old female smokers rose from 26% (1992) to 41% (1997). This undesirable development calls for making the most of preventive initiatives to date. Beside primary prevention steps, the range of assistance for smokers also needs to be extended. In addition to the smoking withdrawal counselling introduced, development of a range of programmes should also be expanded to assist smokers who have currently been unable to quit. Reduction in the number of cigarettes smoked within the framework of intensive specialist care can make sense in this situation. In the near future, pharmacological aids (nicotine substitute preparations) are also anticipated for this purpose. The most important resources for such smoker counselling will be presented. Future studies should focus on optimising reduction treatment as a new approach toward treatment.

Adolescent↗