Insights into DNA substrate selection by APOBEC3G from structural, biochemical, and functional studies

Human apolipoprotein B mRNA-editing enzyme-catalytic polypeptide-like 3 (A3) proteins are a family of cytidine deaminases that catalyze the conversion of deoxycytidine (dC) to deoxyuridine (dU) in single-stranded DNA (ssDNA). A3 proteins act in the innate immune response to viral infection by mutating the viral ssDNA. One of the most well-studied human A3 family members is A3G, which is a potent inhibitor of HIV-1. Each A3 protein prefers a specific substrate sequence for catalysis-for example, A3G deaminates the third dC in the CCCA sequence motif. However, the interaction between A3G and ssDNA is difficult to characterize due to poor solution behavior of the full-length protein and loss of DNA affinity of the truncated protein. Here, we present a novel DNA-anchoring fusion strategy using the protection of telomeres protein 1 (Pot1) which has nanomolar affinity for ssDNA, with which we captured an A3G-ssDNA interaction. We crystallized a non-preferred adenine in the -1 nucleotide-binding pocket of A3G. The structure reveals a unique conformation of the catalytic site loops that sheds light onto how the enzyme scans substrate in the -1 pocket. Furthermore, our biochemistry and virology studies provide evidence that the nucleotide-binding pockets on A3G influence each other in selecting the preferred DNA substrate. Together, the results provide insights into the mechanism by which A3G selects and deaminates its preferred substrates and help define how A3 proteins are tailored to recognize specific DNA sequences. This knowledge contributes to a better understanding of the mechanism of DNA substrate selection by A3G, as well as A3G antiviral activity against HIV-1.

Ambivalence Toward the Body: Death, Neuroticism, and the Flight From Physical Sensation

Based on terror management theory, the authors suggest that ambivalent reactions to the human body are partially rooted in the association of the physical body with inescapable death and that individuals high in neuroticism are particularly vulnerable to such difficulties. Three experiments demonstrated that priming thoughts about one’s death leads individuals high in neuroticism to flee from physical sensations, including pleasurable ones. In response to mortality salience, highly neurotic individuals spent less time submerging their arm in ice-cold water and using an electric foot massager but did not avoid stimulation in nontactile modalities (i.e., listening to music). The discussion highlights the role of existentially motivated self-repression in inhibitions surrounding the body.

Ranolazine-induced myopathy in a patient on chronic statin therapy

We present a case demonstrating clinical, electrophysiological, serological, and radiological evidence of a myopathy induced by ranolazine, in a patient otherwise asymptomatic on chronic statin therapy. The patient developed proximal weakness, serum creatine kinase levels of 1875 U/L, electromyography with muscle membrane instability and small short-duration motor unit potentials, and magnetic resonance imaging evidence of muscle edema. The manifestations began within one week of initiation of ranolazine and improved within days after discontinuation. Ranolazine is a weak inhibitor of CYP3A4 known to increase the serum level of simvastatin and its active metabolite 2-fold. We postulate that the addition of ranolazine to a medical regimen that included atorvastatin induced a myoncecrotic myopathy.

Reduced models for unidirectional block conduction and their geometrical setting

This article revisits a reduced model of cardiac electro-physiology which was proposed to understand the genesis of unidirectional block pathology and of ectopic foci. We underline some specificities of the model from the viewpoint of dynamical systems and bifurcation theory. We point out that essentially the same properties are shared by a simpler system more accessible to analysis. With this simpler system, it becomes possible to give a new presentation of the phenomenon in a phase plane with time moving slow manifolds. This presentation can be of interest both for cardiac electro-physiologists and for mathematicians.

Characterization of a pigment-dispersing hormone in eyestalks of the fiddler crab Uca pugilator

A pigment-dispersing hormone (PDH) from eyestalks of the fiddler crab Uca pugilator has been purified by gel filtration, ion-exchange chromatography, partition chromatography, and reversed-phase liquid chromatography. Based on automated gas-phase sequencing and subsequent identification of carboxyl-terminal amide, we have assigned the primary structure of this peptide as Asn-Ser-Glu-Leu-Ile-Asn-Ser-Ile-Leu-Gly-Leu-Pro-Lys-Val-Met-Asn-Asp-Ala-NH (2). We have confirmed the sequence by synthesizing this peptide and demonstrating that the synthetic PDH and the native PDH display identical chromatographic behavior and biological activity. This hormone is a member of a family of invertebrate neuropeptides that includes a light-adapting/pigment-dispersing octadecapeptide hormone from the prawn Pandalus borealis. In assays for melanophore pigment dispersion in destalked fiddler crabs, Uca PDH was 21-fold more potent than Pandalus PDH. These two hormones share a hexapeptide core sequence (residues 5-10: -Ile-Asn-Ser-Ile-Leu-Gly-) as well as the amino- and carboxyl-terminal residues but differ at positions 3, 4, 11, 13, 16, and 17. These results point to speciesrelated or group-specific structural differences among crustacean PDHs.

Three residues at the interface of factor XI (FXI) monomers augment covalent dimerization of FXI

BACKGROUND

Human plasma factor XI is a homodimer, with each monomer comprising a catalytic domain and four homologous 'apple' domains. The monomers bind to each other through non-covalent bonds and through a disulfide bond between Cys321 residues in apple 4 domains.

OBJECTIVE

To identify residues essential for dimerization in the FXI monomer interface.

METHODS

Specificity-determining residues in apple 4 domains were sought by sequence alignment of FXI and prekallikrein apple domains in different species. Specific residues identified in apple 4 domains were mutagenized and expressed in baby hamster kidney (BHK) cells for evaluation of their effect on FXI dimerization, analyzed by non-reduced sodium dodecylsulfate polyacrylamide gel electrophoresis and size-exclusion chromatography.

RESULTS

Among the 19 residues of the FXI monomer interface, Leu284, Ile290 and Tyr329 were defined as specificity-determining residues. Substitutions of these residues or pairs of residues did not affect FXI synthesis and secretion from transfected BHK cells, but did impair dimerization, despite the presence of cysteine at position 321. The double mutant 284A/290A yielded predominantly a monomer, whereas all other single or double mutants yielded monomers as well as disulfide-bonded dimers.

CONCLUSIONS

The data suggest that Leu284, Ile290 and Tyr329 in the interface of FXI monomers are essential for forming non-covalently bonded dimers that facilitate formation of a disulfide-bonded stable FXI dimer.

Trp207Gly in platelet glycoprotein Ibalpha is a novel mutation that disrupts the connection between the leucine-rich repeat domain and the disulfide loop structure and causes Bernard-Soulier syndrome

BACKGROUND

Bernard-Soulier syndrome (BSS) is a severe inherited bleeding disorder that is caused by a defect in glycoprotein (GP)Ib-IX-V complex, the platelet membrane receptor for von Willebrand factor.

PATIENTS

The diagnosis of BSS was made in two members of a Bukharian Jewish family who had life-long thrombocytopenia associated with mucocutaneous bleeding manifestations.

METHODS AND RESULTS

Flow cytometry and Western blot analyses showed only trace amounts of GPIb and GPIX on the patients' platelets. Sequence analysis of the GPIbalpha gene revealed a homozygous T > G transversion at nucleotide 709 predicting Trp207Gly substitution in the mature protein. Introduction of the mutation into a mammalian expression construct abolished the surface expression of GPIbalpha in transfected baby hamster kidney cells. The crystal structure of the N-terminus of GPIbalpha (PDB: 1SQ0) indicates that Trp207 is completely buried and located in a disulfide loop structure that interacts with the leucine-rich repeat (LRR) domain.

CONCLUSION

A novel mutation, Trp207Gly, causes BSS and predicts disruption of the interaction between a disulfide loop and the LRR domain that is essential for the integrity of GPIbalpha structure.

Severe factor XI deficiency caused by a Gly555 to Glu mutation (factor XI-Glu555): a cross-reactive material positive variant defective in factor IX activation

During normal hemostasis, the coagulation protease factor (F)XIa activates FIX. Hereditary deficiency of the FXIa precursor, FXI, is usually associated with reduced FXI protein in plasma, and circulating dysfunctional FXI variants are rare. We identified a patient with < 1% normal plasma FXI activity and normal levels of FXI antigen, who is homozygous for a FXI Gly555 to Glu substitution. Gly555 is two amino acids N-terminal to the protease active site serine residue, and is highly conserved among serine proteases. Recombinant FXI-Glu555 is activated normally by FXIIa and thrombin, and FXIa-Glu555 binds activated factor IX similarly to wild type FXIa (FXIa(WT)). When compared with FXIa(WT), FXIa-Glu555 activates factor IX at a greatly reduced rate ( approximately 400-fold), and is resistant to inhibition by antithrombin. Interestingly, FXIa(WT) and FXIa-Glu555 cleave the small tripeptide substrate S-2366 with comparable k(cat)s. Modeling indicates that the side chain of Glu555 significantly alters the electrostatic charge around the active site, and would sterically interfere with the interaction between the FXIa S2' site and the P2' residues on factor IX and antithrombin. FXI-Glu555 is the first reported example of a naturally occurring FXI variant with a significant defect in FIX activation.

Characterization of mutations causing factor VII deficiency in 61 unrelated Israeli patients

Inherited factor (F)VII deficiency is rare in most populations but relatively common in Israel. The aim of this study was to characterize the molecular and functional defect in unrelated Israeli patients with FVII deficiency. Mutations were identified by direct sequencing of PCR-amplified genomic DNA fragments. Selected mutations were expressed in baby hamster kidney (BHK) cells and tested for binding to tissue factor (TF), activation by FXa and activation of FX. In 61 patients with FVII deficiency, the causative mutation in the FVII gene was discerned. The predominant mutation found in this and a previously reported cohort of 27 unrelated patients in Israel was Ala244Val substitution; of 121 independent mutant alleles defined in all 88 patients ascertained in Israel, 102 (84%) bore this alteration. Eleven additional mutations were identified of which one, Cys22Arg, is novel. Expression of the mutations in BHK cells revealed that four (Ala244Val, 11128delC, Leu300Pro and Cys22Arg) were cross-reacting material (CRM)- negative, and three (Ala294Val, Cys310Phe and Phe24del) were CRM-positive. As predicted by modeling, we observed no binding to TF of FVII Phe24del, diminished binding of FVII Cys310Phe and normal binding of FVII Ala294Val. The main defect of FVII Ala294Val was its inability to activate FX in the presence of TF. Coexpression of Ala294Val and Arg353Gln, a polymorphism known to affect FVII secretion, did not reveal an additive effect on FVII secretion, while coexpression of Ala244Val and Arg353Gln did yield an additive effect.

Seven novel mutations in the factor XIII A-subunit gene causing hereditary factor XIII deficiency in 10 unrelated families

BACKGROUND

Hereditary factor (F)XIII deficiency is a rare bleeding disorder mostly due to mutations in FXIII A subunit.

OBJECTIVES

We studied the molecular basis of FXIII deficiency in patients from 10 unrelated families originating from Israel, India and Tunisia.

METHODS

Exons 2-15 of genomic DNA consisting of coding regions and intron/exon boundaries were amplified and sequenced. Structural analysis of the mutations was undertaken by computer modeling.

RESULTS

Seven novel mutations were identified in the FXIIIA gene. The propositus from the Ethiopian-Jewish family was found to be a compound heterozygote for two novel mutations: a 10-bp deletion in exon 12 at nucleotides 1652-1661 (followed by 22 altered amino acids and termination codon) and Ala318Val mutation. The propositus of the Tunisian family was homozygous for C insertion after nucleotide 863 within a stretch of six cytosines of exon 7. This insertion results in generation of eight altered amino acids followed by a termination codon downstream. The propositus from Indian-Jewish origin was found to be homozygous for G to T substitution at IVS 11 [+1] resulting in skipping of exons 10 and 11. In addition to the Ala318Val mutation, three of the novel mutations identified are missense mutations: Arg260Leu, Thr398Asn and Gly210Arg each occurring in a homozygous state in an Israeli-Arab and two Indian families, respectively.

CONCLUSIONS

Structure-function correlation analysis by computer modeling of the new missense mutations predicted that Gly210Arg will cause protein misfolding, Ala318Val and Thr398Asn will interfere with the catalytic process or protein stability, and Arg260Leu will impair dimerization.

A novel Phe171Cys mutation in integrin alpha causes Glanzmann thrombasthenia by abrogating alphabeta complex formation

BACKGROUND

Glanzmann thrombasthenia (GT) is an autosomal recessive bleeding disorder characterized by lack of platelet aggregation induced by most agonists. The disease is caused by mutations in either alpha(IIb)[glycoprotein (GP) IIb] or beta(3) (GPIIIa) genes that lead to a lack or dysfunction of the integrin alpha(IIb)beta(3) which serves as a fibrinogen receptor.

PATIENTS

Mucocutaneous bleeding manifestations and platelet dysfunction consistent with GT were observed in three members of a Cypriot family: a 3-year-old proband, her father and her paternal uncle.

OBJECTIVE

To determine the molecular basis of GT in this family and to characterize possible biochemical and structural defects.

RESULTS

Analysis of the patients' platelets by fluorescence-activated cell sorting demonstrated trace amounts of beta(3), no alpha(IIb) and no alpha(IIb)beta(3) on the membrane. Sequence analysis revealed a novel T607G transversion in exon 5 of the alpha(IIb) gene predicting a Phe171Cys alteration that created a PstI recognition site. All three patients were homozygous for the mutation, the mother and paternal grandparents of the proband were heterozygous, whereas 110 healthy subjects lacked this transversion. Chinese hamster ovary cells cotransfected with cDNAs of mutated alpha(IIb) and wild-type beta(3) failed to express alpha(IIb)beta(3) as shown by immunoprecipitation and immunohistochemistry experiments. Structural analysis of the alpha(IIb)beta(3) model, which was based on the crystal structure of alpha(v)beta(3), indicated that Phe171 plays an essential role in the interface between the beta-propeller domain of alpha(IIb) and the betaA domain of beta(3).

CONCLUSIONS

A novel Phe171Cys mutation in the alpha(IIb) gene of patients with GT is associated with abrogation of alpha(IIb)beta(3) complex formation.

[Hypophysis metastasis of a hypernephroma tumor revealed by a chiasma syndrome]

In a 45-year-old man with a hypernephroma tumor of the right kidney, a metastasis in the pituitary gland of this neoplasm was diagnosed 9 years after removal of this kidney. He complained of bitemporal hemianopsia and slight impairment of vision. A hypernephroma metastasis in the pituitary gland is very rare and few have been reported to date. In general, these metastases occur in cases with multiple metastasis to many organs, which suggests that the appearance of pituitary metastasis represents extensive disease. Many of these patients present diabetes insipidus. Visual defects are frequently associated. The Goldmann perimeter is important to detect visual field anomalies. MRI is the key radiological exam to localize the tumor. Surgery is the preferred treatment and should be undertaken quickly if visual function is affected. The histological exam should be made to confirm the diagnosis.

Melanocyte-associated T cell epitopes can function as autoantigens for transfer of alopecia areata to human scalp explants on Prkdc(scid) mice

Alopecia areata is a tissue restricted autoimmune condition affecting the hair follicle, resulting in hair loss. The goal of this study was to test the hypothesis that the autoantigen of alopecia areata is melanocyte associated. Potential autoantigens were tested in the human scalp explant/Prkd(scid) CB-17 mouse transfer system. Scalp T cells from lesional (bald) alopecia areata scalp were cultured with antigen-presenting cells, and antigen, along with interleukin-2. The T cells were then injected into autologous lesional scalp grafts on SCID mice, and hair regrowth was measured. Hair follicle homogenate was used as an autoantigen control. T cells cultured with melanoma homogenate induced statistically significant reduction in hair growth (p <0.01 by ANOVA). HLA-A2-restricted melanocyte peptide epitopes were then tested with lesional scalp T cells from HLA-A2-positive alopecia areata patients. Melanocyte-peptide-activated T cells significantly reduced the number of hairs regrowing in two experiments with six patients (p <0.001 by ANOVA). Injected scalp grafts showed histologic and immunochemical changes of alopecia areata. The most consistent peptide autoantigens were the Gp100-derived G9-209 and G9-280 peptides, as well as MART-1 (27-35). Melanocyte peptide epitopes can function as autoantigens for alopecia areata. Multiple peptides were recognized, suggesting epitope spreading.

Clinical significance of markedly elevated serum creatine kinase levels in patients with acne on isotretinoin

Muscle-related complaints and high creatine kinase (CK) blood levels have been reported in 16-51% of patients with acne treated with isotretinoin. It has been suggested that this retinoid and exercise have a synergistic effect on muscle. The presence of marked hyperCKemia during the treatment raises concern about rhabdomyolysis. The objective of this report was to evaluate the incidence, course and clinical significance of severe hyperCKemia in isotretinoin therapy for acne. Out of 442 patients on isotretinoin, we reviewed 7 patients (1.58%) with CK values above 5,000 IU/l. Only two of them had myalgia. Physical activity or intramuscular injection prior to blood testing was reported in 6 patients. CK values returned to normal within 2 weeks and all subjects except 2, completed treatment. In conclusion, marked hyperCKemia with or without muscle-related complaints in isotretinoin-treated patients with acne is a benign phenomenon.

Sweet's syndrome in association with Crohn's disease: report of a case and review of the literature

A 41-year-old woman developed a skin rash as part of Sweet's syndrome concurrent with the first episode of Crohn's disease of the colon. Sweet's syndrome, acute febrile neutrophilic dermatosis, may be associated with inflammatory, infectious, or neoplastic diseases. Its association with Crohn's disease is very rare, and when reported it has been mainly associated with Crohn's colitis. This association has been described in various stages of the disease. Sweet's syndrome may be considered one of the extraintestinal manifestations of Crohn's disease. Early diagnosis of this dermatosis may be important because of the prompt response to treatment with corticosteroids. The value of metronidazole should be considered because this medication may enhance response to treatment.

Application of the IDSA guidelines for the use of antimicrobial agents in neutropenic patients: impact on reducing the use of glycopeptides

We evaluated the impact of applying the Infectious Diseases Society of America guidelines for febrile neutropenic patients in reducing the use of glycopeptides. Forty-five prior episodes of febrile neutropenia were compared to 97 episodes seen after application of the guidelines. Glycopeptide use was reduced from 73% to 43% of episodes (P=.0008), without changes in outcome.

Adolescent-onset ichthyosiform-like erythroderma with lichenoid tissue reaction: a new entity?

A patient with severe ichthyosiform erythroderma and lichenoid histological changes is presented. We discuss the clinical and histological differential diagnosis, including lupus erythematosus, lichenoid drug eruption, lichen planus, graft-versus-host disease, lymphoma, keratosis lichenoides chronica, Netherton's syndrome and ichthyosiform erythroderma. None of these is consistent with the features in our case, which may represent either a hitherto unreported form of ichthyosiform erythroderma or possibly a new entity.

Analysis of laboratory data in acne patients treated with isotretinoin: is there really a need to perform routine laboratory tests?

INTRODUCTION

Isotretinoin has been used to treat acne since 1982. Its current indications in the package insert are limited and many physicians still feel uncomfortable prescribing it because of its side effects. Serum levels of liver enzymes and lipids are carried out as a routine in most clinics both before and during treatment.

AIMS

Our objective was to evaluate the effect of isotretinoin on serum lipids, liver function and other laboratory parameters in order to assess the necessity to perform routine laboratory tests.

METHODS

Computerized medical files of 1292 patients in private practice that received isotretinoin for acne were analyzed.

RESULTS

907 patients completed a treatment course of 5 to 9 months. Serum levels of liver enzymes were not elevated to a degree necessitating discontinuation of treatment. Only 1.5% of the patients had serum triglyceride levels above 400 mg%. No laboratory abnormalities were a cause for discontinuation of treatment. During a 6-year follow up only 3.5% of patients received a second course of therapy with isotretinoin.

CONCLUSIONS

Aside from its teratogenic effect, isotretinoin is a safe and excellent drug for acne therapy. It should be prescribed for any inflammatory acne and in our opinion there is no need for a routine laboratory follow-up in young, healthy patients aside from a pregnancy test in females. At present, isotretinoin should be considered as the drug of choice for moderate to severe acne.

Idiopathic palmoplantar eccrine hidradenitis in children

Idiopathic palmoplantar eccrine hidradenitis (IPPH) is a recently described disorder characterized by painful erythematous plantar nodules and in three cases, showed a typical neutrophilic infiltrate around and within the eccrine sweat apparatus. Five cases of IPPH on the soles of the feet in healthy children are reported. The disorder presented after intense physical activity in four cases. The course was benign and self-limiting. Complete bed rest for several days without any medical therapy led to alleviation of the pain and disappearance of all the lesions. Conclusion. Idiopathic palmoplantar eccrine hidradenitis may be more common than reported. Paediatricians should be aware of it in order to avoid unnecessary diagnostic tests and treatments.

Thallium poisoning in Israel

We report the first case of thallium poisoning in Israel in almost 30 years. A 40-year-old man was apparently poisoned by a business associate when, on several occasions, he unknowingly drank an alcoholic beverage containing the toxic substance. Delayed admission and recurrent thallium ingestion resulted in both acute and chronic symptoms being present concomitantly. Conventional treatment modalities (Prussian blue and forced diuresis) were employed. The patient survived, although neurological sequelae ensued. The problems encountered in diagnosis and treatment of this relatively uncommon entity are discussed.

Contact dermatitis with systemic symptoms from Agave americana

BACKGROUND

Twelve cases of contact dermatitis provoked by Agave americana are described, 10 with systemic signs and symptoms and 8 with abnormal laboratory results.

RESULTS

Patient history revealed a background of intentional exposure among soldiers seeking sick leave. Treatment with oral antihistamines and topical saline compresses resulted in subsidence of the systemic symptoms within 24 h of hospitalization and regression of cutaneous manifestations in 7-10 days.

CONCLUSION

The importance that dermatologists be alert to the possibility of self-inflicted contact dermatitis induced by exposure to plants is stressed, especially to A. americana. Systemic signs are not rare accompanying findings with this plant.

[Dermatitis from contact with Agave americana]

Various plants induce dermatitis in man. There have been only a few published cases of contact dermatitis caused by Agave americana (AA). We report intentional exposure to AA in a soldier seeking sick leave, and review our previously reported cases. Treatment with oral antihistamines and topical saline compresses resulted in subsidence of the systemic symptoms within 24 h and regression of cutaneous manifestations in 7-10 days. Physicians should be alert to the possibility of self-inflicted contact dermatitis induced by exposure to plants, especially to A. americana. Systemic signs may accompany the cutaneous lesions.

Two p16 (CDKN2A) germline mutations in 30 Israeli melanoma families

Germline mutations in the p16 (CDKN2A) tumour suppressor gene have been linked to inherited predisposition to malignant melanoma (MM). Variable frequencies of p16 germline mutations were reported in different collections of melanoma families but it can be as high as 50%. Here we describe the results of p16 mutation screening in 30 melanoma kindreds in Israel. The entire coding region of the p16 gene, including exons 1, 2 and 3, flanking exon/intron junctions, and a portion of the 3' untranslated (UTR) region of the gene were examined by single-stranded conformation polymorphism (SSCP) analysis and direct sequencing. Two p16 germline mutations were identified: G101W, which has been previously observed in a number of melanoma kindreds, and G122V, a novel missense mutation. Thus, the frequency of mutations identified in this collection of Israeli families was 7%. Functional analysis indicated that the novel G122V variant retained some capacity to interact with cyclin dependent kinases (CDKs) in vitro, yet it was significantly impaired in its ability to cause a G1 cell cycle arrest in human diploid fibroblasts. This partial loss of function is consistent with the predicted impact of G122V substitution on the 3-dimensional structure of the p16 protein.

Plantar hidradenitis in children induced by exposure to wet footwear

Painful erythematous papules and nodules involving either the palms of the hands, or, more commonly, the soles of the feet, characterize palmoplantar eccrine hidradenitis or palmoplantar hidradenitis (PH). The younger pediatric population is predominately affected. Histologically, the eccrine gland apparatus is the target of inflammatory neutrophilic infiltrates. This entity has been reported under a variety of names, including traumatic plantar urticaria, neutrophilic eccrine hidradenitis, plantar erythema nodosum, and idiopathic recurrent palmoplantar hidradenitis. All are essentially the same process, described in different forms. Despite the growing number of reported cases, the pathogenesis remains obscure. We present four children with PH of the soles of the feet, who shared a common recent history of exposure to cold, damp, footwear. The temporal relationship between exposure to dampness and cold and the appearance of the skin lesions suggest a possible pathogenetic mechanism.

Unusual eruption as a presenting symptom of cat scratch disease

Cat scratch disease (CSD) is a common infectious cause of subacute regional lymphadenopathy. Bartonella henselae is the principal etiologic agent. About 10% of CSD patients experience atypical manifestations, including rashes. The most common cutaneous manifestation of CSD is a papule at the inoculation site. We report a case of CSD presenting with an eruption on the upper trunk, reminiscent of Sweet's syndrome, accompanied by lymphadenopathy, arthralgia, and fever. Response to systemic corticosteroids was remarkable. Histopathologic findings refuted the diagnosis of Sweet's syndrome. Identification of anti-B henselae antibodies and B henselae DNA in the affected lymph node confirmed the diagnosis of CSD. This is a first report of extensive papuloedematous eruption as a cutaneous manifestation of CSD. Accurate diagnosis is possible due to the availability of serological tests and DNA amplification techniques.

Sicca syndrome and HTLV-I-associated myelopathy/tropical spastic paraparesis

PURPOSE

The objective of this study is to describe the clinical and immunological aspects observed in patients with both human T-cell lymphotropic virus type I-associated myelopathy/tropical spastic paraparesis and ocular dryness.

METHODS

In 15 such patients, clinical and biological examinations completed with a biopsy of secondary salivary glands were performed to assess the etiology of the ocular dryness.

RESULTS

Histological study of the biopsy specimens indicated that 80% of the patients had grade 3 or grade 4 lesions, according to the Chisholm scale. Polyclonal hypergammaglobulinemia was found in 60% of patients and lymphocytic alveolitis in 80%. Three patients had past medical history of chronic uveitis.

CONCLUSIONS

All findings in these patients were compatible with Sjögren's syndrome; however, no immunological disorders characteristic of the syndrome were found. Tests for antinuclear antibodies and rheumatoid factor proved negative in all cases.

Effects of psychotropic drugs on cell proliferation and differentiation

Some of the psychotropic agents widely used for the amelioration of anxiety, depression, and psychosis also show an effect at the cellular proliferation level. Surprisingly little research, however, has been directed to the antitumoral potential of these drugs, alone or in combination with established cancer treatments. Our review of the literature to date has yielded some promising early findings. Ligands active at the benzodiazepine (BZ) receptors have been studied the most extensively and were found to have differential, concentration-dependent effects on the growth and proliferation of both normal and cancer cells. Of the phenothiazines tested, chlorpromazine (CPZ) and perphenazine (PPZ) had the most potent cytotoxic action on fibroblasts and glioma cells. Antiproliferative effects also were noted by these and other agents in leukemic and breast cancer cell lines. Additional psychotropic drugs studied include the atypical antipsychotics, antidepressants, and mood stabilizers, especially lithium. Most of the reported activities were observed in in vitro studies and were achieved at high pharmacological concentrations. Further in vivo studies in well-designed animal models are warranted to determine whether these well-tolerated, relatively inexpensive, and widely available drugs or their derivatives may be added in the future to the armamentarium of cancer pharmacotherapy.

Computerized system to enhance the clinical diagnosis of pigmented cutaneous malignancies

BACKGROUND

An increase in the incidence of cutaneous malignant melanoma in recent years has not been accompanied by satisfactory progress in diagnostic methods. This study was carried out to evaluate a specially designed computerized image analysis system, called Derma Vision, to aid in the differentiation between malignant and benign cutaneous pigmented lesions.

METHODS

Seventy-one lesions were photographed with a digital camera and the data were analyzed by the Derma Vision system. The system assessed the variation of hues in each image, calculated the mean standard deviation of the hues, and produced a value that expressed the range of hues in the lesion. The lesions were then excised and examined histologically. The computer-assisted clinical diagnosis was correlated with the histologic diagnosis to determine the accuracy of the former.

RESULTS

Derma Vision predicted the malignant character of a lesion with 92% precision, compared with 87% accuracy based only on the clinical features.

CONCLUSIONS

This simple, inexpensive device can boost the accuracy of clinical diagnosis and provide a useful tool to the physician faced increasingly with having to determine whether pigmented lesions are malignant or benign.