Basing policy on evidence: low HIV, STIs, and risk behaviour in Dili, East Timor argue for more focused interventions.

BACKGROUND: East Timor is a newly independent, poor nation with many internally displaced people and foreign peace keeping forces. Similarities with Cambodia, which now has Asia's worst HIV epidemic, caused donors to earmark money for HIV prevention in East Timor, but no data were available to plan appropriate programmes. OBJECTIVES: To determine levels of infection with HIV and other sexually transmitted infections (STIs) and associated risk behaviours in Dili, East Timor, in order to guide resource allocation and appropriate prevention and care strategies. METHODS: In mid-2003, a cross sectional survey of female sex workers, men who have sex with men (MSM), taxi drivers, and soldiers was conducted. Participants provided biological specimens and all answered structured questionnaires. RESULTS: HIV prevalence was 3% among female sex workers (3/100), 0.9% among MSM (1/110), and zero in the other groups. All the HIV infected sex workers reported sex with foreign clients. Partner turnover reported by all groups was among the lowest in Asia, so was condom use. Access to basic HIV prevention services, including condoms and STI services, was extremely low in all groups. CONCLUSIONS: A few sex workers are infected with HIV in East Timor, but the virus is not circulating widely among their clients, and sexual networking is limited. The risk of a generalised HIV epidemic in East Timor is minimal. HIV can be contained by the provision of basic services to the small minority of the population at highest risk, preserving resources for other health and development needs.

[Current aspects of facelift surgery]. / Aktuelle Aspekte der Facelift-Chirurgie.

In the care of the aging face, the facelift procedure occupies the center of attention. Of the many techniques available, only a few procedures fulfill the justifiable expectations that both patient and physician should have of such an intervention to reach the four goals of a facelift operation: create a natural, nonoperated appearance, obtain long-term durability, ensure a minimal complication rate, and restore or maintain a youthful vibrancy. This can especially be achieved with the so-called super-extended face lift with SMAS dissection, rotation, and refixation. Besides possessing surgical skill, every surgeon working in the field of aesthetic surgery must have a "concept of beauty" as defined by Connell and Levy, i.e., the surgeon must recognize the entirety of the face as an aesthetic unit and plan each intervention on an individual basis. Thus, in many cases it is not only necessary to correct the cheek and neck area, but also to take the forehead/eyebrow section into consideration.

[Differential diagnosis and treatment of cheilognathopalatoschises]. / Differenzialdiagnostik und Therapie der Lippen-Kiefer-Gaumen-Spalten.

Cleft lip, alveolous and palate is the second frequent malformation in Europe with an incidence of 1 : 500. Pertaining to ontogeny it must be differentiated between cleft lip and alveolous and cleft palate. Cleft lip and cleft lip and alveolous can occur unilateral, right or left, or bilateral. Cleft bony palate can also occur unilateral, right or left, or bilateral, but cleft velum only in the median plane. Diagnostic and treatment of cleft lip and palate call for interdisciplinary cooperation between gynecologist/obstetrician, cranio-maxillo-facial surgeon, pediatrician, otorhinolaryngologist, orthodontist and logopedist. The schedule of primary cleft surgery in Germany is marked by a more-stage concept, in which at the end of the second year of life cleft lip and palate except cleft alveolous should be closed up. Despite of most careful surgery patients with cleft lip and palate can show functional and aesthetic disturbances. The functional disorders can affected masticatory function, speech, hearing and nasal breathing. Aesthetics disorders can be concerned to skeletal or soft tissue deformities of lip and nose. Operative corrections of bone and soft tissue can rehabilitate these patients entirely from functional and aesthetic view.

Acid phosphatases.

Acid phosphatases (APs) are a family of enzymes that are widespread in nature, and can be found in many animal and plant species. Mystery surrounds the precise functional role of these molecular facilitators, despite much research. Yet, paradoxically, human APs have had considerable impact as tools of clinical investigation and intervention. One particular example is tartrate resistant acid phosphatase, which is detected in the serum in raised amounts accompanying pathological bone resorption. This article seeks to explore the identity and diversity of APs, and to demonstrate the relation between APs, human disease, and clinical diagnosis.

Stationary-phase mutation in the bacterial chromosome: recombination protein and DNA polymerase IV dependence.

Several microbial systems have been shown to yield advantageous mutations in slowly growing or nongrowing cultures. In one assay system, the stationary-phase mutation mechanism differs from growth-dependent mutation, demonstrating that the two are different processes. This system assays reversion of a lac frameshift allele on an F' plasmid in Escherichia coli. The stationary-phase mutation mechanism at lac requires recombination proteins of the RecBCD double-strand-break repair system and the inducible error-prone DNA polymerase IV, and the mutations are mostly -1 deletions in small mononucleotide repeats. This mutation mechanism is proposed to occur by DNA polymerase errors made during replication primed by recombinational double-strand-break repair. It has been suggested that this mechanism is confined to the F plasmid. However, the cells that acquire the adaptive mutations show hypermutation of unrelated chromosomal genes, suggesting that chromosomal sites also might experience recombination protein-dependent stationary-phase mutation. Here we test directly whether the stationary-phase mutations in the bacterial chromosome also occur via a recombination protein- and pol IV-dependent mechanism. We describe an assay for chromosomal mutation in cells carrying the F' lac. We show that the chromosomal mutation is recombination protein- and pol IV-dependent and also is associated with general hypermutation. The data indicate that, at least in these male cells, recombination protein-dependent stationary-phase mutation is a mechanism of general inducible genetic change capable of affecting genes in the bacterial chromosome.

Adenovirus L4-100K assembly protein is a granzyme B substrate that potently inhibits granzyme B-mediated cell death.

Cytotoxic lymphocytes kill virus-infected target cells and play a critical role in host recovery from viral infections. Granzyme B (GrB) is a cytotoxic lymphocyte granule protease that plays a critical role in mediating cytotoxicity. In these studies, we demonstrate that the adenovirus assembly protein L4--100K (100K) is a GrB substrate that prevents cytotoxic lymphocyte granule-induced apoptosis in infected target cells by potently inhibiting GrB. This inhibition is absolutely dependent on Asp-48 in 100K, found within a classic GrB consensus motif. 100K is the first viral protein described that exclusively targets the GrB pathway. It represents a novel class of viral protease inhibitor, in which an essential, multifunctional viral protein, which is vulnerable to specific proteolysis by GrB, expresses inhibitory function against that protease.

The three-dimensional structure of human granzyme B compared to caspase-3, key mediators of cell death with cleavage specificity for aspartic acid in P1.

BACKGROUND: Granzyme B, one of the most abundant granzymes in cytotoxic T-lymphocyte (CTL) granules, and members of the caspase (cysteine aspartyl proteinases) family have a unique cleavage specificity for aspartic acid in P1 and play critical roles in the biochemical events that culminate in cell death. RESULTS: We have determined the three-dimensional structure of the complex of the human granzyme B with a potent tetrapeptide aldehyde inhibitor. The Asp-specific S1 subsite of human granzyme B is significantly larger and less charged than the corresponding Asp-specific site in the apoptosis-promoting caspases, and also larger than the corresponding subsite in rat granzyme B. CONCLUSIONS: The above differences account for the variation in substrate specificity among granzyme B, other serine proteases and the caspases, and enable the design of specific inhibitors that can probe the physiological functions of these proteins and the disease states with which they are associated.

Adaptive amplification: an inducible chromosomal instability mechanism.

Adaptive mutation is an induced response to environmental stress in which mutation rates rise, producing permanent genetic changes that can adapt cells to stress. This contrasts with neo-Darwinian views of genetic change rates blind to environmental conditions. DNA amplification is a flexible, reversible genomic change that has long been postulated to be adaptive. We report the discovery of adaptive amplification at the lac operon in Escherichia coli. Additionally, we find that adaptive amplification is separate from, and does not lead to, adaptive point mutation. This contradicts a prevailing alternative hypothesis whereby adaptive mutation is normal mutability in amplified DNA. Instead, adaptive mutation and amplification are parallel routes of inducible genetic instability allowing rapid evolution under stress, and escape from growth inhibition.

Viscocanalostomy for primary open-angle glaucoma: the Gross Pankow experience.

PURPOSE: To assess the pressure-lowering effect and postoperative complications of the viscocanalostomy nonpenetrating filtering procedure. SETTING: A private practice ophthalmic surgery referral center. METHODS: Fifty-six eyes of 41 patients with medically uncontrolled primary open-angle glaucoma had a viscocanalostomy. After a superficial scleral flap was raised, a deep sclerectomy was performed in the scleral bed with deroofing of Schlemm's canal and preparation of a window of Descemet's membrane. The ostia of Schlemm's canal were probed and stretched with sodium hyaluronate 1.4% (Healon GV(R)), and the scleral flap and conjunctiva were sutured. Examinations were performed before surgery and 1, 3, and 14 days and 1, 3, 6, and 12 months postoperatively. RESULTS: Mean preoperative intraocular pressure (IOP) was 28.1 mm Hg +/- 7.4 (SD) with a mean of 2.4 +/- 0.7 medications. Mean postoperative IOP was 18.6 +/- 7.5 mm Hg with 0 medications at 1 day, 17.4 +/- 5.2 mm Hg with 0.1 medications at 3 days, 19.1 +/- 4. 3 mm Hg with 0.1 medications at 14 days, 19.4 +/- 4.3 mm Hg with 0.4 medications at 1 month, 18.3 +/- 3.6 mm Hg with 0.6 medications at 3 months, 18.0 +/- 2.6 mm Hg with 0.6 medications at 6 months, and 17. 8 +/- 3.8 mm Hg with 0.7 medications at 1 year. After 1 year, IOP was lower than 21 mm Hg without medication in 36% of patients and lower than 21 mm Hg with medication in 79%. Five patients (9%) required a second operation for pressure control. The following postoperative complications occurred: hyphema (2%); postoperative hypotony less than 10 mm Hg (2%); positive Seidel test (17%); further surgery to lower IOP (12%). Cataract surgery was performed in 1 patient (2%) at 4 months. Despite an attempt to close the scleral flap watertight, 26 patients had evidence of subconjunctival drainage (conjunctival microcysts or filtration bleb) at 1 year. CONCLUSION: Viscocanalostomy lowered IOP and reduced the need for pressure-controlling medications with a low postoperative complication rate. The high success rates of earlier publications were not reproduced.

[Esthetic facial surgery]. / Asthetische Gesichtschirurgie.

In the last few years, aesthetic facial surgery--especially soft-tissue surgery--has received increasing attention, not only from the medical profession but also particularly from the media. This is due, in part, to the growing level of general acceptance of the formerly stigmatized issue of aesthetic surgery, and in part to increasing patient expectations. Moreover, the introduction of less invasive procedures with outstanding long-term results have brought about a considerable change in aesthetic surgery. A comprehensive account of face lifting, forehead lifting, brow lifting, blepharoplasty, cervical liposuction and adjuvant techniques of skin rejuvenation will be given and discussed.

Evidence that stationary-phase hypermutation in the Escherichia coli chromosome is promoted by recombination.

Adaptive (or stationary-phase) mutation is a group of phenomena in which mutations appear to occur more often when selected than when not. They may represent cellular responses to the environment in which the genome is altered to allow survival. The best-characterized assay system and mechanism is reversion of a lac allele on an F' sex plasmid in Escherichia coli, in which the stationary-phase mutability requires homologous recombination functions. A key issue has concerned whether the recombination-dependent mutation mechanism is F' specific or is general. Hypermutation of chromosomal genes occurs in association with adaptive Lac(+) mutation. Here we present evidence that the chromosomal hypermutation is promoted by recombination. Hyperrecombinagenic recD cells show elevated chromosomal hypermutation. Further, recG mutation, which promotes accumulation of recombination intermediates proposed to prime replication and mutation, also stimulates chromosomal hypermutation. The coincident mutations at lac (on the F') and chromosomal genes behave as independent events, whereas coincident mutations at lac and other F-linked sites do not. This implies that transient covalent linkage of F' and chromosomal DNA (Hfr formation) does not underlie chromosomal mutation. The data suggest that recombinational stationary-phase mutation occurs in the bacterial chromosome and thus can be a general strategy for programmed genetic change.

Mechanisms of genome-wide hypermutation in stationary phase.

Stationary-phase mutation (a subset of which was previously called adaptive mutation) occurs in apparently nondividing, stationary-phase cells exposed to a nonlethal genetic selection. In one experimental system, stationary-phase reversion of an Escherichia coli F'-borne lac frameshift mutation occurs by a novel molecular mechanism that requires homologous recombination functions of the RecBCD system. Chromosomal mutations at multiple loci are detected more frequently in Lac+ stationary-phase revertants than in cells that were also exposed to selection but did not become Lac+. Thus, mutating cells represent a subpopulation that experiences hypermutation throughout the genome. This paper summarizes current knowledge regarding stationary-phase mutation in the lac system. Hypotheses for the mechanism of chromosomal hypermutation are discussed, and data are presented that exclude one hypothetical mechanism in which chromosomal mutations result from Hfr formation.

[Augmentation of the extremely atrophied maxilla and mandible by autologous calvarial bone transplantation]. / Aufbau des extrem atrophierten Ober- und Unterkiefers durch autologe Kalottenknochentransplantate.

Rehabilitation in patients with severe alveolar ridge atrophy of the maxilla or mandible is problematic and can often only be achieved by long-term treatment. In most cases, autologous bone grafting with iliac crest bone has been used to augment severely atrophied upper jaws. In our experience, iliac bone grafts are less useful, since iliac bone appears to be of inferior quality; in elderly osteoporotic women, the bone is soft, indentable, and of poor osteogenic potency. In our department, we have been using only autologous calvarial bone grafts for augmentation of alveolar ridge atrophy since 1993. The bone is removed from the outer table of the skull only, trimmed to the alveolar ridge, und fixed with titanium lag scews. The skull defect created is covered with crushed bone or a titanium mesh to avoid aesthetic problems. Insertion of dental implants follows after a healing period of the bone grafts of 5-6 months. A total of 63 patients underwent calvarial split-graft augmentation; augmentation of the maxilla and mandible was carried out in 15 of these patients, of the maxilla only in eight, and of the mandible only in 40. The investigations 1 year later showed a resorption rate of approximately 10%. This is lower than when using iliac bone grafting. The resorption results were stable between 6 and 12 months after augmentation. Using dental implants (12 patients with 32 implants), the resorption rate was low and constant. We have never seen total loss of bone grafts or intracranial complications. All patients were pleased with the treatment. In our opinion, severe alveolar atrophy of the maxilla or mandible should be compensated for by augmentation with autologous calvarial bone grafts to obtain good long-term results.

Translational frameshift sites within bacteriophage lambda genes rexA and cI.

Phage lambda's cI-rexA-rexB operon displays an intriguing example of regulation by an unexplained mechanism of polarity. We have identified three potential -1 translational frameshift sites and present a model for translational frameshift suppression by lambda's CI repressor as a mechanism of regulating operon polarity, implying an additional role for CI self-regulation.

Reactivity and assay restriction profiles of monoclonal and polyclonal antibodies to acid phosphatases: a preliminary study.

The development of secure diagnostic immunoassays requires, among others, rigorous characterisation of potential antibody reagents. The reactivity profiles of seven antibodies (six monoclonal [MAb] and one polyclonal [PAb]) with putative specificity for tartrate-resistant acid phosphatase (TRAP) and/or osteoclasts were evaluated in enzyme-linked immunosorbent assay (ELISA) and/or immunocytochemistry. MAbs 2H1, 4E6 and 5Cl demonstrated assay restriction: exhibiting reactivity only in ELISA. The remaining three MAbs (G211D, G312G and V35B) and the PAb 8023 recognised recombinant TRAP (rTRAP) in ELISA and native acid phosphatases in selected tissues and cell lines. The latter were cytochemically assessed for both tartrate-sensitive acid phosphatase (TSAP) and TRAP. V35B showed reactivity against the monocytic leukaemia cell line U937 and guinea pig kidney tissue (both TSAP+ and TRAP+) and ECV304 (TSAP+) cells. Interestingly, the reactivity of MAb G211D co-localised with TRAP activity in the membrane of osteoclasts but also detected cytoplasmic components in U937 cells and human embryonic lung fibroblasts (TRAP+ and TRAP+). G211D exhibited immunoreactivity against placental trophoblasts (positive for total AP). Intriguingly, MAbs 2H1, 4E6, 5Cl and PAb 8023 cross-reacted with potato acid phosphatase in ELISA, suggesting reactivity to conformationally similar epitopes. Thus, some of these reagents could be used in the development of standardised diagnostic immunoassays or as drug-targeting agents for conditions in which the pathological process involves bone resorption, the MAbs G211D, 2H1, 4E6, 5Cl and PAb 8023 being useful in ELISA but not immunocytochemical detection of TRAP.

[Significance of hemodynamic parameters of blood loss in orthognathic surgery]. / Bedeutung hämodynamischer Parameter für den Blutverlust in der Dysgnathiechirurgie.

INTRODUCTION: The hemodynamic parameters of 95 patients undergoing maxillary or bimaxillary orthognathic surgery in 1996 and 1997 at the Department of OMF Surgery/Plastic Surgery, Krefeld, Germany, were analyzed retrospectivly to study the effect of intraoperative blood loss. MATERIALS AND METHODS: The parameters included the blood loss volume, age, weight and sex of the patients, the mode of osteotomy and the operation time, the surgeon, the average blood pressure, the infusion volume, the anesthesiologist, the thrombocyte counts and their function, the activity of the coagulation factors II, V, VII, VIII, IX, X, XI, XII, XIII and von-Willebrand-factor, and the pathological coagulation factor counts of each patient, the rate of autologous blood donation and the rate of retransfusion. Statistical analysis was done using the Speraman-Rhotest. RESULTS: The average blood loss during maxillary osteotomy was 670 +/- 380 ml and during bimaxillary surgery 1120 +/- 510 ml. Men lost about 300 ml more than women. Operations of more than 3.5 h in length led to a blood loss of 1200 +/- 520 ml as opposed to 670 +/- 310 ml. The average blood loss among various surgeons was between 670 ml and 1180 ml of various anesthesiologists between 730 ml and 1200 ml, without statistical evidence. Some 17.9% of patients showed pathological thrombocytic function concerning medication with aspirin; 34.7% had pathological activities of coagulation factors, but only 2.1% with clinical significance. CONCLUSION: Mode of operation, maxillary or bimaxillary, und length of operation were the most significant factors of intraoperative blood loss. Patients with pathological coagulation had nearly the same rate of blood loss as patients with physiological coagulation. In most cases this was determined by restriction of aspirin. Analysis of the rate of autologous blood retransfusion showed a significant correlation to blood loss in bimaxillary surgery. Maxillary osteotomy led to a retransfusion of only 14.2% of autologous blood unit. This should be reviewed critically especially concerning costs.

Acquired mutations in phage lambda genes O or P that enable constitutive expression of a cryptic lambdaN+cI[Ts]cro- prophage in E. coli cells shifted from 30 degreesC to 42 degreesC, accompanied by loss of immlambda and Rex+ phenotypes and emergence of a non-immune exclusion-state.

The majority of bacteria, which carry the N+-cI857[Ts]-cro--O+-P+ fragment of lambda genome, are killed when derepressed by shifting from 30 degreesC to 42 degreesC. Among rare survivors, we observed a proportion of colony-forming units (cfu) that retained the typical immlambda-immunity phenotype when grown at 30 degreesC; however, when shifted from 30 degreesC to 42 degreesC, they lost lambda immunity and acquired a non-immune exclusion-state (Nie phenotype). We also found that the immlambda survivor cfu quickly lost their Rex+ exclusion phenotype (as measured by T4rII plating inhibition) when shifted from 30 degreesC to 42 degreesC, even though they produced CII, which stimulates pE-cI-rexA-rexB transcription. The Nie phenotype was characterized by an inhibition of plating of the homoimmune phage, lambdawt, and the heteroimmune phage, lambdaimm434. However, lambdavir and spontaneous mutants of lambdawt (lambdase mutations localized within oR) escaped the Nie exclusion-state and plated efficiently on lawns of Nie cfu at 42 degreesC. Thus, we examined the scope of the Nie exclusion-state toward lambda mutants blocked for lysogeny, and lambda hybrids substituted for immunity or replication genes. Phage like lambdawt, competent for lysogeny, were severely excluded compared to some mutants of lambda defective for lysogeny. Among this latter type, there was high variance in the Nie exclusion of various cI mutants; some of which were not excluded. The Nie exclusion-state was attributed to the constitutive expression of the defective lambda fragment in the survivor cfu, made possible by the acquired replication defect(s). We characterized, both genetically and physically, the mutations in the defective integrated lambda prophage that permitted growth of the survivor cfu at 42 degreesC. In five of seven survivor cfu, we identified IS2 insertions within lambda genes O and P that can block replication initiation from the lambda fragment. The remaining survivor cfu had multiple base substitutions within the C-terminal end of O and N-terminal half of P, the majority of which were silent. In some of these mutants, either an ochre nonsense mutation or a single-base frameshift deletion inactivated P.

Cloning, expression and characterization of rhesus macaque types 1 and 2 5alpha-reductase: evidence for mechanism-based inhibition by finasteride.

The rhesus macaque types 1 and 2 5alpha-reductase (5aR1 and 5aR2) were cloned and expressed in COS cells to facilitate comparison of rhesus and human 5aRs. The deduced protein sequences of the rhesus SaRs shared 94% and 96% identity with the human type 1 and 2 isozymes, respectively. Despite a four amino acid insertion at the N-terminal region of rhesus 5aR1, the biochemical properties of rhesus and human homologs are very similar with respect to pH optimum, Km values for testosterone and progesterone, and inhibition by a variety of inhibitors. As expected, the biochemical properties of the human and rhesus 5aR2 are also very similar. The mechanism of inhibition of the rhesus 5aR1 and 5aR2 by finasteride was investigated in more detail. Finasteride displays time dependent inhibition of the rhesus 5aR1 and 5aR2 with second order rate constants of 4 x 10(3) M(-1) s(-1) and 5.2 x 10(5) M(-1)s(-1). Inhibition of rhesus 5aR2 with 3H-finasteride resulted in 3H bound to the enzyme which is not released by dialysis. Heat denaturation of the [rhesus SaR2:inhibitor] complex releases dihydrofinasteride, a breakdown product presumably related to the NADP+-adduct previously identified with the human SaRs (Bull et al., Mechanism-based inhibition of human steroid 5alpha-reductase by finasteride: Enzyme catalyzed formation of NADP-dihydrofinasteride, a potent bisubstrate analog inhibitor. J. Amer. Chem. Soc., 1996, 118, 2359-2365). Taken together, these results provide good evidence that the rhesus macaque is a suitable model to evaluate the pharmacological properties of finasteride and other 5aR inhibitors.

Rustmicin, a potent antifungal agent, inhibits sphingolipid synthesis at inositol phosphoceramide synthase.

Rustmicin is a 14-membered macrolide previously identified as an inhibitor of plant pathogenic fungi by a mechanism that was not defined. We discovered that rustmicin inhibits inositol phosphoceramide synthase, resulting in the accumulation of ceramide and the loss of all of the complex sphingolipids. Rustmicin has potent fungicidal activity against clinically important human pathogens that is correlated with its sphingolipid inhibition. It is especially potent against Cryptococcus neoformans, where it inhibits growth and sphingolipid synthesis at concentrations <1 ng/ml and inhibits the enzyme with an IC50 of 70 pM. This inhibition of the membrane-bound enzyme is reversible; moreover, rustmicin is nearly equipotent against the solubilized enzyme. Rustmicin was efficacious in a mouse model for cryptococcosis, but it was less active than predicted from its in vitro potency against this pathogen. Stability and drug efflux were identified as two factors limiting rustmicin's activity. In the presence of serum, rustmicin rapidly epimerizes at the C-2 position and is converted to a gamma-lactone, a product that is devoid of activity. Rustmicin was also found to be a remarkably good substrate for the Saccharomyces cerevisiae multidrug efflux pump encoded by PDR5.

Cutaneous responses to endothelin-1 and histamine in patients with vibration white finger.

Vibration white finger (VWF) is the episodic blanching of the fingers that occurs in response to cold in those who work with hand-held vibrating tools. Clinically the condition differs from primary Raynaud's phenomenon as persistent pain and paresthesia are common in the hands and arms and occur independently of the "white attacks." We have previously reported a decrease in protein gene product 9.5 and calcitonin gene-related peptide-immunoreactive nerve fibers in the digital skin of individuals with VWF. In this study, we have sought to determine whether this deficit of immunoreactive sensory-motor nerves has a functional counterpart in vivo. Histamine produces a rapid wheal and flare response following intradermal injection, whereas endothelin-1 (ET-1) produces a central area of pallor with a surrounding neurogenic flare. In contrast, calcitonin gene-related peptide produces a non-neurogenic erythema. In this study, histamine and ET-1 were injected into the dorsum of the middle phalanx and the local neurovascular response was assessed by measuring the area of the visible flare or pallor. Basal finger blood flow was also measured by laser Doppler flowmetry in each of the digits prior to intradermal injection. The experiments were performed at 21 degrees C and 4 degrees C. Patients with VWF and asymptomatic vibration-exposed workers had significantly lower resting skin blood flow at both 21 degrees C and 4 degrees C than heavy manual workers with no vibration exposure. The size of the histamine- and ET-1-induced flares at both 21 degrees C and 4 degrees C was significantly smaller in patients with VWF when compared with the asymptomatic vibration-exposed workers and heavy manual workers. The size of the ET-1-induced pallor was smaller in patients with VWF when compared with the heavy manual workers at both 21 degrees C and 4 degrees C. In contrast, the area of erythema induced by intradermal injection of calcitonin gene-related peptide at both 21 degrees C and 4 degrees C was of a similar size in patients with VWF and in heavy manual workers. These results indicate that the neuroneal deficit identified by immunohistochemistry in the digital skin of patients with VWF has a functional counterpart in vivo and is evident as a reduced ability to propagate an axon-reflex vasodilator response when challenged with histamine and ET-1. Furthermore, these results enable patients with VWF to be differentiated from both asymptomatic vibration-exposed workers, in whom the histamine- and ET-1-induced flares are normal, and those with primary Raynaud's disease, in whom the ET-1 flare is reduced and the histamine-induced flare is normal.