Secondary syphilis presenting as a pruritic dermatosis

Three patients had secondary syphilis with severely pruritic skin lesions. This presentation contradicts several modern medical texts in which the lesions of secondary syphilis are described as nonpruitic.     

Induction of swimming in the high spinal stingray by L-DOPA

Stingrays with high spinal transections, which do not spontaneously locomote, can be induced to swim by intravenous injection of L-DOPA. The L-DOPA-induced swim of the spinal animal is associated with patterns of EMG activity that appear similar to those of the spontaneous swim of the decerebrate preparation. However, in contrast to the decerebrate condition, the L-DOPA-induced cycles of swimming are slower and less vigorous. Furthermore, secondary periodicites and altered intersegmental timing relationships are also evident.     

RNA secondary structure as a reusable interface to biological information resources

The dissemination of biological information has become critically dependent on the Internet and World Wide Web (WWW), which enable distributed access to information in a platform independent manner. The mode of interaction between biologists and on-line information resources, however, has been mostly limited to simple interface technologies such has hypertext links, tables and forms. The introduction of platform-independent runtime environments facilitates the development of more sophisticated WWW-based user interfaces. Until recently, most such interfaces have been tightly coupled to the underlying computation engines, and not separated as reusable components. We believe that many subdisciplines of biology have intuitive and familiar graphical representations of knowledge that can serve as multipurpose user interface elements. We call such graphical idioms "domain graphics". In order to illustrate the power of such graphics, we have built a reusable interface based on the standard two dimensional (2D) layout of RNA secondary structure. The interface can be used to represent any pre-computed layout of RNA, and takes as a parameters the sets of actions to be performed as a user interacts with the interface. It can provide to any associated application program information about the base, helix, or subsequence selected by the user. We show the versatility of this interface by using it as a special purpose interface to BLAST, Medline and the RNA MFOLD search/compute engines. These demonstrations are available at: http://www-smi.stanford.edu/projects/helix/pubs/ gene-combis-96/     

Low prevalence of HTLV-II in Mayan Indians in the Yucatan Peninsula, Mexico

Infection with HTLV-II is endemic in Amerindians, with prevalence ranging from 0.89% - 33%. To determine the prevalence of HTLV-II among indigenous Mayans in the Yucatan Peninsula of Mexico, 440 indigenous Mayans were recruited, all native to and residents of one of six Mayan communities in the Yucatan Peninsula, (Xohuayan n=144, Yaxachen n=101, Kanxoc n=84, Xocen n=40, Nabalan n=46 and X'calot n=25) between May, 1992 and June, 1993. All of the above are pre-Hispanic settlements located in tropical forest with no immigrations for over 50 years. Of the 440 indigenous Mayans, only one woman from the X'calot tribe (0.23%) was shown to be infected with HTLV-II. A high percentage of indeterminate results was found (22/439, 5%), three of which were accounted for by the husband and two children of the positive female case. PCR analysis followed by specific restriction digestion demonstrated the virus to be of the HTLV-IIb subtype, similar to that described in the Guaymi Indians from Panama. The presence of HTLV-II in the Mayan ethnos, and in other Amerindian populations supports the idea that HTLV-II is an ancestral virus in America and that it has been sustained in "closed" communities.     

Prognostic value of a hand symptom diagram in surgery for carpal tunnel syndrome

OBJECTIVE: To evaluate symptom patterns on a hand diagram as predictors of surgical outcome in carpal tunnel syndrome (CTS). METHODS: 202 patients with CTS enrolled in a prospective, community based cohort study in Maine completed a hand symptom diagram before surgery and at 6 month followup. They were asked to mark on the hand diagram the location of 3 symptoms: pain, numbness/tingling (NT), and "other" symptoms. The diagram was first divided into 6 regions following a standardized procedure. For the 6 regions, symptom patterns were identified separately for each of the 3 symptoms. Outcomes 6 months after surgery were expressed as the percentage of change on the Symptom Severity Scale and Function Status Scale of the Carpal Tunnel Syndrome Assessment Questionnaire, and the satisfaction with the results of the surgery. RESULTS: Several distinct symptom patterns were associated with the 3 principal outcomes in univariate and multivariate analysis. In linear regression models controlling for the baseline severity of symptoms and function, as well as other predictors, the hand symptom pattern variables accounted for 30, 14, and 24%, respectively, of the total explained variance in satisfaction, symptom severity, and functional status. Patients receiving Workers' Compensation (37% of the cohort) had more wrist pain and NT of the arm, and less pain involving the arm and upper palm. This group also had worse outcomes and were less satisfied with surgery. Drawing expansion was associated with a low score on the SF-36 mental health subscale. However, psychological impairment was not associated with a worse outcome. CONCLUSION: Symptom patterns identified preoperatively with a hand symptom diagram help to predict the outcome of carpal tunnel release.     

Management of chronic medical conditions in children and adolescents

The care of children and adolescents with chronic medical conditions is an area of great interest for primary care physicians. With longer lives and more "mainstreaming" of care, the primary care physician often finds an increased role in the management of children and adolescents with chronic conditions such as mental retardation, Down syndrome, and diabetes mellitus. This article discusses familiarity with the most common chronic conditions and common pitfalls of management.     

Neurodevelopmental consequences of early exposure to phencyclidine and related drugs

In the early development of the central nervous system, stimulation of N-methyl-D-aspartate (NMDA) receptors may be critical for neuronal cell survival and differentiation, as well as the establishment of neural networks resulting from "experience-dependent plasticity." The trophic influence of NMDA receptor stimulation may be present only during a certain critical period of development. There are, therefore, major concerns associated with the administration of noncompetitive NMDA receptor antagonists (such as MK-801 [dizocilpine]) as neuroprotective and anticonvulsant agents to pregnant women, neonates, infants, and young children. Several studies showing disruptive effects of noncompetitive NMDA receptor antagonists on normal neurobehavioral development are reviewed in this article. This research has important public health implications because phencyclidine (PCP), a noncompetitive NMDA receptor antagonist, is a frequently-abused drug that may disrupt brain development in utero when abused by pregnant women. The article also reviews studies of neonatal blockade of the NMDA receptor complex in animals; studies that may lead to useful models of human neurodevelopmental disorders. These models may even mimic the relevant neurodevelopmental aspects of at least some forms of schizophrenia, especially the early developmental disconnection of circuits between the hippocampus and frontal cortex.