Improved P1/P1' substituents for cyclic urea based HIV-1 protease inhibitors: synthesis, structure-activity relationship, and X-ray crystal structure analysis

We present several novel P1/P1' substituents that can replace the characteristic benzyl P1/P1' moiety of the cyclic urea based HIV protease inhibitor series. These substituents typically provide 5-10-fold improvements in binding affinity compared to the unsubstituted benzyl analogs. The best substituent was the 3,4-(ethylenedioxy)benzyl group. Proper balancing of the molecule's lipophilicity facilitated the transfer of this improved binding affinity into a superior cellular antiviral activity profile. Several analogs were evaluated further for protein binding and resistance liabilities. Compound 18 (IC90 = 8.7 nM) was chosen for oral bioavailability studies based on its log P and solubility profile. A 10 mg/kg dose in dogs provided modest bioavailability with Cmax = 0.22 microg/mL. X-ray crystallographic analysis of two analogs revealed several interesting features responsible for the 3,4-(ethylenedioxy)benzyl-substituted analog's potency: (1) Comparing the two complexes revealed two distinct binding modes for each P1/P1' substituent; (2) The ethylenedioxy moieties are within 3.6 A of Pro 81 providing additional van der Waals contacts missing from the parent structure; (3) The enzyme's Arg 8 side chain moves away from the P1 substituent to accommodate the increased steric volume while maintaining a favorable hydrogen bond distance between the para oxygen substituent and the guanidine NH.

Moderate peripheral neuropathy impairs weight transfer and unipedal balance in the elderly

OBJECTIVE

To quantitatively assess the performance of elderly with and without moderate, electrodiagnostically confirmed peripheral neuropathy (PN) on tasks of weight shifting and maintenance of unipedal balance.

PATIENTS AND METHODS

A case control study with PN subjects selected from a computerized data bank of all patients who had undergone electrodiagnostic studies at a university-based referral center. Control subjects of similar age and same gender were selected from the same source. Clinical examination included neurological and gross motor components. Quantitative evaluation included testing while the subjects stood with a force plate under each foot. Center of reaction (CR) excursions and ground reaction forces were quantified in: (1) six trials as subjects transferred their weight from bipedal stance to unipedal stance, on command, and attempted to maintain it for at least 3 seconds; and (2) in two additional trials in which subjects held unipedal stance for as long as possible.

RESULTS

No subjects in either group had difficulty with level gait, a 180-degree turn, or required examiner assistance during an eyes-closed Romberg test. Biomechanical testing revealed that although the PN group used the same time to transfer their weight onto one foot as the C group, they achieved a significantly (1) lower rate of success in reliably maintaining 3 seconds of unipedal stance (.12 vs .58, p = .021), and (2) shorter mean maximum unipedal stance time (3.8 vs 32.3sec, p < .001). Furthermore, the PN group experienced greater difficulty in maintaining unipedal stance, as evidenced by significantly greater fluctuations in their ground reaction forces.

CONCLUSIONS

The demonstrated impairment in reliability of unipedal stance in elderly with PN likely contributes to their known high rate of falls. Furthermore, unipedal stance testing serves to sharpen the physical examination by verifying the functional significance of impaired distal sensation-a common finding in the elderly.

The stroke syndrome of cortical vein thrombosis

Cortical vein thrombosis without sinus involvement is rarely diagnosed, although it may commonly be overlooked. We report four cases of cerebral venous thrombosis limited to the cortical veins. The diagnosis was made on surgical intervention in one patient and by angiography in three patients. Together with a survey of the published cases, the clinical and neuroimaging patterns of our patients allow delineation of several features suggestive of cortical venous stroke. Focal or generalized seizures followed by hemiparesis, aphasia, hemianopia, or other focal neurologic dysfunction in the absence of signs of increased intracranial pressure should suggest this possibility. Neuroimaging (CT, MRI) shows an ischemic lesion that does not follow the boundary of arterial territories and often has a hemorrhagic component, without signs of venous sinus thrombosis. Conventional angiography demonstrates no arterial occlusion but may show cortical vein thrombosis corresponding to the infarct, although these may also be nonspecific findings. The role of MR angiography, which is well-established in sinus thrombosis, remains to be assessed in patients with brain ischemia due to isolated cortical vein occlusion.

The CTLA-4 gene region of chromosome 2q33 is linked to, and associated with, type 1 diabetes. Belgian Diabetes Registry

Susceptibility to autoimmune insulin-dependent (type 1) diabetes mellitus is determined by a combination of environmental and genetic factors, which include variation in MHC genes on chromosome 6p21 (IDDM1) and the insulin gene on chromosome 11p15 (IDDM2). However, linkage to IDDM1 and IDDM2 cannot explain the clustering of type 1 diabetes in families, and a role for other genes is inferred. In the present report we describe linkage and association of type 1 diabetes to the CTLA-4 gene (cytotoxic T lymphocyte associated-4) on chromosome 2q33 (designated IDDM12). CTLA-4 is a strong candidate gene for T cell-mediated autoimmune disease because it encodes a T cell receptor that mediates T cell apoptosis and is a vital negative regulator of T cell activation. In addition, we provide supporting evidence that CTLA-4 is associated with susceptibility to Graves' disease, another organ-specific autoimmune disease.

Preparation and structure-activity relationship of novel P1/P1'-substituted cyclic urea-based human immunodeficiency virus type-1 protease inhibitors

A series of novel P1/P1'-substituted cyclic urea-based HIV-1 protease inhibitors was prepared. Three different synthetic schemes were used to assemble these compounds. The first approach uses amino acid-based starting materials and was originally used to prepare DMP 323. The other two approaches use L-tartaric acid or L-mannitol as the starting material. The required four contiguous R,S,S,R centers of the cyclic urea scaffold are introduced using substrate control methodology. Each approach has specific advantages based on the desired P1/P1' substituent. Designing analogs based on the enzyme's natural substrates provided compounds with reduced activity. Attempts at exploiting hydrogen bond sites in the S1/S1' pocket, suggested by molecular modeling studies, were not fruitful. Several analogs had better binding affinity compared to our initial leads. Modulating the compound's physical properties led to a 10-fold improvement in translation resulting in better overall antiviral activity.

The corporatization of health care: an evaluation and an alternative

The corporatization of health care organizations has become a significant international trend. This paper examines that trend, comparing the development of corporate health care in the USA with the impact of the New Zealand health reforms. The paper traces the evolution of the organizations of health care systems and explains the emergence of the corporate form. We argue that the corporate model of work organization is unsuited to the complex and ambiguous nature of the medical task as it ignores inherent interdependencies. An alternative is needed which addresses work practices rather than just participation in decision making and is based on a concept of mutual interdependence and support in the execution of work.

Comparisons of wrist postures in VDT operators using wrist rests and forearm supports

OBJECTIVE

The purpose of this study was to examine wrist motions in video display terminal (VDT) workers using the Greenleaf Medical WristSystem. This study was developed because of the limited research about the effectiveness of ergonomic equipment for VDT operators, as well as the recent increase in cumulative trauma disorders (CTDs) among these workers.

STUDY DESIGN

Twenty adult VDT operators with no history of CTD were recruited from Boston University and surrounding businesses. WristSensorTM gloves containing dual-axis sensors for detection of dynamic wrist movements were worn by participants. Calibrations were then performed through the Movement Analysis System (MAS) software, after which participants were requested to type using a wrist rest (condition A), using forearm supports (condition B), using the wrist rest and forearm supports together (condition C), and finally using no form of wrist or forearm support (condition D). It was assumed by the investigators that wrist extension and ulnar deviation would decrease when using the wrist rest or forearm support, with the greatest change occurring when using both types of support. Questionnaires requesting demographic information were completed by each participant. Contrast scores were also calculated and converted into t -tests and their corresponding P -values.

RESULTS

The average degrees of motion for both right and left hands were: flexion 4.5°, extension 18.9°, ulnar deviation 15.3°, and radial deviation 2.0°. P-values for all four conditions in the left hand were found to be significant and are as follows: extension t(19) = 2.35, P < 0.025, flexion t(19) = 2.17, P < 0.025, ulnar deviation t(19) = 3.41, P < 0.0025, and radial deviation t(19) = 2.5, P < 0.025. The only significant P-value in the right hand was during ulnar deviation: t(19) = 2.7, P < 0.01.

DISCUSSION

Research suggests that wrist extension greater than 15° and ulnar deviation greater than 20° can be predisposing factors to the development of CTDs. In this study, all four wrist motions remained under 20° during the three conditions using the wrist rest and forearm supports. A trend of continued decreases in ulnar deviation and wrist extension from using no supports to that requiring both types of supports was also observed. Specifically, the smallest degree of wrist extension appeared when participants used only the wrist rest; ulnar deviation was smallest when both supports were used. Right hand degree values were found to be generally larger than those for the left hand. It is hoped that these results can serve as a foundation for future investigation into the effectiveness of wrist and forearm supports in reducing CTDs.

Isometric cervical extension strength of recreational and experienced cyclists

The effect for cyclists of the typical forward sitting position on neck strength and its possible relationship to neck pain have not been examined. The purpose of this study was to measure the peak isometric cervical extension strength (PICES) of both recreational and experienced road cyclists and to compare these values to those of noncyclists. Subjects, 45 men between the ages of 18 and 40, were tested for voluntary PICES through a 126 degrees range of motion on a MedX cervical extension machine. No significant differences were found between the three groups in PICES at any angle. When expressed relative to body weight, significant differences in PICES were found at 126 degrees between the control group and the recreational cyclist group (p < 0.05), and between the control group and the experienced cyclist group (p < 0.01), but not at any other angle. Furthermore, no significant differences in strength were found between cyclists experiencing neck pain and those who did not. These data indicate that the cervical muscles of cyclists have not adapted by increasing maximal isometric strength above that of noncyclists, and that the neck pain frequently reported may be due to fatigue from sustained muscular contractions associated with time spent cycling, rather than from muscle weakness.

Swedish use and validation of Valpar work samples for patients with musculoskeletal neck and shoulder pain

I studien beskrivs vad e bedömning av arbetskapacitet (BAK) innehåller Vid en bedömning av arbetskapacitet jämförs kraven för att utföra ett specifikt arbete, definierat i "The dictionary of Occupational Titles" (DOT), och patientens förmåga att utföra ett arbote vilket definieras med hjälp av sju variabler. Allmän utbildnings nivä. Speciella yrkesförberedelser. Anlag, Intresseområden, Personlig läggning. Fysiska drav och Miljöpåverkan. En bedömning av arbetskapaciteten kan ske antingen genom att observera patienten under arbete påarbetsplatsen eller under simulerat arbete tex genom att använda Valpar systemets arbetsprover.Vid Rehabiliteringsmedicinska kliniken, Karolinska Sjukhuset har tvä av de standardiserade arbetsprovema använts. VCWS 8 "Simulerad moontering" och VCWS 9 "Simulerade rorelser for hela kroppen" for att förbättra bedömningen av patientens arbetskapacitet. VCWS 8 mäter "en persons förmaga att utföra ett monteringsarbete som kräver repetetiva fysiska manipulationer" och VCWS 9 mäter "en persons formåga att röra på bålen, nacken, armarna, händerna och fingrama när de relaterar till funktionellt utförande av ett arbete". Valideringen av arbetsprovema för Svensk anvandning gjordes på en grupp patienter (n = 97) med muskuloskelettal nack- och skulder smärta som deltog i ett rehabiliteringsprogram. VCWS 9 utfördes av åttiofem patienter och VCWS 9 av sextionic patienter.Medelvärdet for patienterna som slutförde VCWS 8 var 83.1% av industriell standard nivå (mätt enligt MTM-Method-Time-Measurement) där den lä gsta gränsen är 87.5% för ett godkännt utförende. Detta innebär att de "inte moter" kraven för detta specifika arbete. I motsats till detta sä nädde patientema som utförde VCWS 9 ett medelvärde pä 108.6% vilket overstiger kravet (87.5%) för industriell standard. Det oväntade resultatet kan kanske förklaras av att patienternas intresseområden vad gäller arbetsfalt endast sammanfoll med iintresseområdena för VCWS 8 och yeWS 9 i 32% av fallen. En retrospective jämförelse mellan att vara sjukskriven eller inte vara sjukskriven och deras förmåga att utföra ett arbetsprov och uppnå minimi kravet for industriell standard visade inte på något samband. Mänga faktorer kan ha påverkat resultatet som tex patientens motivation, andra psyko-sociala omstandigheter och arbetsterapeutemas beslut att endast använda sig av två stycken av ett flertal arbetsprov.Konklusiionen ar att en bedörning av patientens arbetskapacitet skall utföras prospektivt och bör ta i beräknng de krav arbetet ställer enligt DOT och därefter bör rätt arbetsprov väijas för den individuella patienten. Sker detta på ett riktigt sätt så år Valpars arbetsprover valida och till stor hjälp vid en medicinsk bedomning och för beslut när det gäller fortsatt sjukskrivning eller vid yrkesrådgivning.

In vivo sensitivity of Plasmodium falciparum to chloroquine in rural areas of Côte d'Ivoire

In vivo testing of Plasmodium falciparum sensitivity to chloroquine was carried out in four rural sites of differing socio-geographical environment in Côte d'Ivoire. Of a total of 1282 patients of all ages with fever or previous history of fever, 649 were slide positive, with 435 patients with a pure P. falciparum infection; 191 fulfilled all the criteria for inclusion in this study, and 113 completed it. Treatment failure rates ranged from 9.7% (Djébonoua) to 38.1% (Tiéviéssou), and were most often associated with higher degrees of resistance (RII = 54.2%; RIII = 37.5%). Blood chloroquine levels measured by ELISA test suggest that many people take chloroquine routinely; furthermore 37.5% of resistance cases occurred in subjects who had high blood chloroquine concentrations on day 0. Twenty-three out of 24 cases of resistance were found in children under 7 years of age. Nearly all children with persisting parasitaemia were afebrile on day 7, even those (7/8) with RIII resistance. Children aged < 7 years represent the the best sentinel group for monitoring P. falciparum sensitivity to chloroquine in Côte d'Ivoire.

Flow and the occupational therapy practitioner

OBJECTIVE

This study examined optimal flow experience, a form of job satisfaction in occupational therapy practitioners employed at physical rehabilitation facilities in New England.

METHOD

Factors associated with flow were measured over a 5-day work week with the Experience Sampling Method. Ninety-seven percent of the 90 subjects' responses were analyzed and 43% of the subjects participated in the debriefing interview.

RESULTS

Subjects experienced flow a relatively small amount of the time--an average of 5.24 times in a 5-day work week, with a range of 1 to 12 experiences. Flow was experienced most often (23.6%) when subjects were working with a client in some type of intervention. Perceived autonomy and self-esteem were high during a flow experience. Subjects described their flow experiences as including such moods and attitudes as "alert," "happy," "involved," creative," "excited," "productive," "accomplished," "proud," "good," "confident," "positive," and "challenged." Conversely, subjects in flow also tended to describe their mood as "tense."

CONCLUSION

Retaining occupational therapy practitioners is critical to meeting and increasing the unprecedented demand for health care services. Understanding what causes occupational therapy practitioners to experience flow and how to transform an activity into a flow experience may ultimately improve job satisfaction, productivity, and the retention of practitioners.

Human dento-gnathic metric variation in mesolithic/neolithic Ukraine: possible evidence of demic diffusion in the Dnieper Rapids region

Dental and gnathic metrics from a series of Mesolithic and Neolithic cemetery samples in the Dnieper River valley (Ukraine) are compared. Both male and female Neolithic samples have larger dental dimensions, wider dental arcades, and a more robust mandibular corpus than do the Mesolithic samples. In addition, the relative variances (RVs) of bucco-lingual dental breadths (as measured by modified Levene's Tests) show an intriguing pattern of change from the Mesolithic into and through the Neolithic. Female RVs show a clear tenency to increase through time, while male RVs show more mixed tendencies. Such a pattern indicates that the increases in Ukrainian Neolithic dento-gnathic dimensions are plausibly attributable to low intensity gene flow (demic diffusion). Seen in the light of new chronometric, paleodietary, and paleolinguistic information, as well as in the context of recent archaeological models for agro-pastoralist origins in the North Pontic, these data suggest that gene flow via population interactions originating in or transient through the circum-Caucasus may have played an important role in producing the Ukrainian Neolithic dental increase.

The management of health care: a model of control

This paper is aimed primarily at those involved in managing and implementing management structures in health services. It is concerned with the replacement of historical management structures with 'proven' private sector structures. It is argued that a major problem with the private sector models introduced in New Zealand is that they fail to recognise the levels of uncertainty inherent in the diagnosis and treatment of illness. The Gibbs Report criticisms of existing management practices are discussed, criticisms that were based strongly on the Griffiths Report. A model of organisational control is outlined, based on Ouchi's concepts of market, bureaucracy and clan. This model is used to evaluate two major structural changes: the introduction of general management and the involvement of clinicians in clinical directorates. It is argued that success or failure of health service management reform depends on a greater recognition of the underlying uncertainties involved in medical practice.

Immunohistologic and electron microscopic abnormalities of desmin and dystrophin in familial cardiomyopathy and myopathy

A 52-year-old man had a cardiomyopathy for 22 years as had his brother. Both required pacemakers. For the past 12 years, he also suffered from increasing muscle weakness. His muscle fibres contained granulo-filamentous material as previously seen in muscle fibres of a French family with myopathy and cardiomyopathy. It was rich in desmin, alpha-B crystallin, and dystrophin, the connotation, pathogenesis, and common denominator of which, however, remain unexplained.