The value of grooming to female primates

Current socioecological models suggest that the structure of female-bonded primate groups is predicated on the need for coalitionary support in competitive interactions. Social grooming is thought to be the means by which females ensure support from other individuals, either by the direct exchange of grooming for aid or by using grooming as a means of strengthening social bonds. Since these relationships are valuable, they must be regularly serviced and must be repaired if they become damaged. We question this position and show that empirical evidence to support these theoretical arguments is lacking. We then go on to present a new framework in which the inconsistencies regarding grooming and relationship negotiation are interpreted in the context of individual decision-making processes. In this framework, primate groups represent biological markets in which individuals either trade grooming in a reciprocal manner for the direct benefits that grooming itself offers, or exchange it for tolerance by more powerful animals. A number of testable predictions are derived from this hypotheses. The need for socioecological studies to focus on the dynamics of individual relationships rather than using summary measures is emphasized since only a detailed knowledge of serial interaction will provide the key to understanding the complexities of individual decision-making processes.

Treponema pallidum major sheath protein homologue Tpr K is a target of opsonic antibody and the protective immune response

We have identified a family of genes that code for targets for opsonic antibody and protective immunity in T. pallidum subspecies pallidum using two different approaches, subtraction hybridization and differential immunologic screening of a T. pallidum genomic library. Both approaches led to the identification of a polymorphic multicopy gene family with predicted amino acid homology to the major sheath protein of Treponema denticola. One of the members of this gene family, tpr K, codes for a protein that is predicted to have a cleavable signal peptide and be located in the outer membrane of the bacterium. Reverse transcription polymerase chain reaction analysis of T. pallidum reveals that Tpr K is preferentially transcribed in the Nichols strain of T. pallidum. Antibodies directed to purified recombinant variable domain of Tpr K can opsonize T. pallidum, Nichols strain, for phagocytosis, supporting the hypothesis that this portion of the protein is exposed at the surface of the treponeme. Immunization of rabbits with the purified recombinant variable domain of Tpr K provides significant protection against infection with the Nichols strain of T. pallidum. This gene family is hypothesized to be central to pathogenesis and immunity during syphilis infection.

Poly-L-glutamic acid derivatives as vectors for gene therapy

This paper describes the synthesis and evaluation of biodegradable derivatives of poly-L-glutamic acid as suitable vectors for gene therapy. When mixed with DNA the new polymers self assemble and form polyelectrolyte complexes. The formation of the complexes and determination of their stability towards disruption by serum albumin was monitored by Ethidium bromide (EtBr) fluorescence spectroscopy. All polymers were able to form complexes and their size, determined by photon correlation spectroscopy, was between 84.5+/-2 nm and 96. 7+/-1.6 nm, depending on the type of polymer and the charge ratio. All complexes were stable towards serum albumin. The results from the biodegradability tests, using tritosomes, show that the polymers are biodegradable and the rate of degradation is influenced by the number of charged groups in the side chains. Haemolysis and red blood cell (RBC) agglutination were assessed and compared to poly(L-lysine) (pLL) and polyethyleneimine (pEI). RBC agglutination was monitored with optical microscopy. Results show that the new polymers are less toxic than pLL and pEI. Preliminary transfection studies show that the polymers are suitable vectors for gene delivery.

RNA splicing capability of live neuronal dendrites

Dendrites are specialized extensions of the neuronal soma that contain components of the cellular machinery involved in RNA and protein metabolism. Several dendritically localized proteins are associated with the precursor-mRNA (pre-mRNA) splicing complex, or spliceosome. Although some spliceosome-related, RNA-binding proteins are known to subserve separate cytoplasmic functions when moving between the nucleus and cytoplasm, little is known about the pre-mRNA splicing capacity of intact dendrites. Here, we demonstrate the presence and functionality of pre-mRNA-splicing components in dendrites. When isolated dendrites are transfected with a chicken delta-crystallin pre-mRNA or luciferase reporter pre-mRNA, splicing junctions clustered at or near expected splice sites are observed. Additionally, in vitro synaptoneurosome experiments show that this subcellular fraction contains a similar complement of splicing factors that is capable of splicing chicken delta-crystallin pre-mRNA. These observations suggest that pre-mRNA-splicing factors found in the dendroplasm retain the potential to promote pre-mRNA splicing.

Optic nerve dysfunction in thyroid eye disease: CT

Optic nerve dysfunction in thyroid eye disease is thought to be due to compression of the optic nerve by enlarged extraocular muscles near the orbital apex. High-resolution computed tomography (CT) scans of 78 orbits of 31 patients with thyroid eye disease were reviewed. Axial scans alone were inadequate for demonstrating compression of the optic nerve. With a coronal reformatted scan from the axial scans, a muscular index was devised and measured to reflect extraocular muscle impingement on the optic nerve. Orbits with optic nerve dysfunction had significantly higher muscular indices than those without optic nerve dysfunction, supporting the hypothesis that optic nerve dysfunction is usually secondary to compression by enlarged extraocular muscles. Muscular indices of 67% or greater in patients with optic nerve dysfunction were diagnostic of compressive optic neuropathy, while muscular indices of less than 50% appeared to exclude optic nerve compression. A single case of optic nerve dysfunction without muscular compression is also discussed.

A prospective, randomized, parallel group, controlled study of the effect of intensity of speech and language therapy on early recovery from poststroke aphasia

Objective: To examine whether the amount of speech and language therapy influences the recovery from poststroke aphasia.

Setting: A hospital stroke unit and community.

Design: A prospective, randomized controlled trial.

Intervention: Aphasic stroke patients were randomly allocated to receive 5 hours (intensive therapy group, n=51) or 2 hours (standard therapy group) of speech and language therapy per week for 12 consecutive weeks starting as soon as practicable after the stroke. Another 19 patients were recruited for 2 hours per week of therapy and were treated by National Health Service (NHS) staff (NHS group).

Outcome measure and assessment: The Western Aphasia Battery. Assessments were made blind to randomization at baseline and 4, 8, 12 and 24 weeks after the start of therapy. Data were analysed by intention to treat.

Results: The mean (SD) Western Aphasia Battery score at week 12 for the intensive, standard and NHS groups was 70.3 (26.9), 66.2 (26.2) and 58.1 (33.7), respectively. There was no treatment effect of intensive therapy (P > 0.05), but there was a statistically significant difference between the standard study and the NHS groups (P = 0.002 at week 12 and 0.01 at week 24).

Conclusions: Intensive speech and language therapy (as delivered in this study) did not improve the language impairment significantly more than the `standard' therapy which averaged 1.6 hours/week. The improvement in aphasia was least in patients who were in the NHS group. These patients received 0.57 (0.49) hours of therapy per week.

Sustained effects of gene-activated matrices after CNS injury

We show that when gene-activated matrices (GAM) are placed between the proximal and distal stumps of severed rat optic nerves, DNA is retained within the GAM, promoting sustained transgene expression in the optic nerve, in the GAM itself, and, more importantly, in axotomized retinal ganglion cells (RGC). Plasmids that encode basic fibroblast growth factor (FGF2), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT3) promote sustained survival of RGC for over 3 months after the initial injury. These findings suggest that immobilized DNA implanted into a CNS lesion will be delivered by axon terminal uptake and retrograde transport to axotomized neurons. GAM may therefore be a useful agent for promoting sustained neuron survival and axon regeneration. Whether further optimization of the matrices, plasmids, promoters, and genes present in the GAM will promote even more survival or, alternatively, axon regeneration remains to be determined.

Primary sciatic nerve lymphoma: a case report and review of the literature

A patient with primary B cell non-Hodgkin's lymphoma of the sciatic nerve is described. He presented with neuropathic symptoms in the left leg, initially diagnosed as tarsal tunnel syndrome. Magnetic resonance imaging (MRI) identified the abnormality in the sciatic nerve. A fascicular biopsy of the sciatic nerve showed a diffuse large B cell non-Hodgkin's lymphoma. The patient was treated with chemotherapy and rituximab (anti-CD20 monoclonal antibody). Four months later he was in remission, and remains so 48 months from presentation. Primary lymphoma of single peripheral nerves may be a unique subtype of extranodal lymphoma, which usually follows an aggressive course and has a variable response to current therapeutic strategies. MRI is useful, alongside electrophysiological studies, in patients with atypical peripheral nerve symptoms.

FL-160 proteins of Trypanosoma cruzi are expressed from a multigene family and contain two distinct epitopes that mimic nervous tissues

The partial sequence of a gene encoding the COOH terminus of a protein of apparent molecular weight of 160 kD associated with the flagellum of trypomastigotes of Trypanosoma cruzi (FL-160 now renamed to FL-160-1) has been previously reported. The COOH terminus of FL-160-1 has an epitope, defined by 12 amino acids, which molecularly miMics a nervous tissue antigen of 48 kD found in myenteric plexus, sciatic nerve, and a subset of cells in the central nervous system. We now report that FL-160 is a family of highly related genes. The sequence has been determined for the entire open reading frame (ORF) of one of the members of the FL-160 gene family (FL-160-2) and three other partial ORFs. Sequence analysis reveals the various members of the FL-160 gene family to be approximately 80% homologous in the predicted amino acid sequence, but all retain the 12-amino acid molecular mimicry epitope on the COOH terminus. Comparison of the sequence of FL-160-2 to other sequences demonstrates amino acid homology to bacterial sialidase (27%), members of the SA85 gene family (25-30%) and the shed acute-phase antigen/neuraminidase/trans-sialidase gene family (25-30%). Quantitative hybridization at high stringency suggests 750 copies of FL-160 are present in the DNA of each parasite. Reverse transcription and sequence analysis demonstrates that at least five of the members of the FL-160 gene family are transcribed. The NH2 terminus of one of the FL-160 gene products was expressed and antibodies prepared. Antibodies directed to either the COOH or the NH2 terminus of FL-160 bind a 160-kD T. cruzi protein. Both antibodies bind the surface membrane in the flagellar pocket of the trypomastigote. Antibodies to the NH2 terminus bind epineurium and scattered linear densities in sciatic nerve in a pattern distinct from the pattern with antibodies to the COOH terminus. Thus, there are at least two distinct molecular mimicry epitopes on the FL-160 molecule and both mimic epitopes found in nervous tissues. FL-160 may be involved in the generation of autoimmunity to nervous tissues by molecular mimicry, observed in chronic Chagas' disease.

Extending ventilator circuit change interval beyond 2 days reduces the likelihood of ventilator-associated pneumonia

OBJECTIVE

To determine the risk of acquiring ventilator-associated pneumonia (VAP) and the impact on costs when extending ventilator circuit change intervals beyond 2 days to 7 and 30 days.

DESIGN

Prospective 4-year review of mechanically ventilated patients.

SETTING

The respiratory and medical ICUs of an 800-bed tertiary teaching Veterans Affairs hospital.

PATIENTS

All adult patients receiving mechanical ventilation from January 1991 through December 1994.

INTERVENTIONS

Ventilator circuits with active heated water humidifiers were changed at 2-day intervals during a 2-year control period, followed by 7-day and 30-day intervals (for 1 year each). Heated wire circuits were adopted with the 30-day interval. The rate of VAP per 1,000 ventilator days was calculated for each circuit change interval group. Survival analysis was used to model VAP with ventilator circuit change to determine risk.

RESULTS

During the study period, 637 patients received mechanical ventilation. During the 2 years with 2-day change intervals, the VAP per 1,000 ventilator days was 11.88 (n=343), compared with 3.34 (n=137) and 6.28 (n=157) for 7-day and 30-day change intervals, respectively. The risk of acquiring a VAP for those with a circuit change every 2 days was significantly greater (relative risk, 3.1; p=0.0004; 95% confidence interval, 1.662, 5.812) than those with the 7- and 30-day circuit changes. Extending circuit change intervals reduced supply and labor costs averaging $4,231/yr for each ventilator in use.

CONCLUSIONS

Circuit change intervals of 7 and 30 days have lower risks for VAP than the 2-day intervals, yielding substantial reductions in morbidity as well labor and supply costs.

Habitual cave use and thermoregulation in chacma baboons (Papio hamadryas ursinus)

The willingness to utilise caves as shelters is held to have been important to early humans but dependent on pyrotechnology. Despite anecdotal evidence that non-human primates will also exploit caves there has as yet been no detailed account of such exploitation or of the reasons underlying it. Here we provide the first such data, on the frequency and patterning of the use of an underground cave system by baboons (Papio hamadryas)-and show that usage is determined, at least in part, by above-ground temperatures.

Prevalence of intestinal parasitic and bacterial pathogens in diarrhoeal and non-diarroeal human stools from Vhembe district, South Africa

In the present study, a cross-sectional survey of intestinal parasitic and bacterial infections in relation to diarrhoea in Vhembe district and the antimicrobial susceptibility profiles of isolated bacterial pathogens was conducted. Stool samples were collected from 528 patients attending major public hospitals and 295 children attending two public primary schools and were analyzed by standard microbiological and parasitological techniques. Entamoeba histolytica/E. dispar (34.2%) and Cryptosporidium spp. (25.5%) were the most common parasitic causes of diarrhoea among the hospital attendees while Giardia lamblia (12.8%) was the most common cause of diarrhoea among the primary school children (p < 0.05). Schistosoma mansoni (14.4%) was more common in non-diarrhoeal samples at both hospitals (16.9%) and schools (17.6%). Campylobacter spp. (24.9%), Aeromonas spp. (20.8%), and Shigella spp. (8.5%) were the most common bacterial causes of diarrhoea among the hospital attendees while Campylobacter (12.8%) and Aeromonas spp. (12.8%) were most common in diarrhoeal samples from school children. Vibrio spp. was less common (3% in the hospitals) and were all associated with diarrhoea. Antimicrobial resistance was common among the bacterial isolates but ceftriaxone (91%) and ciprofloxacin (88.6%) showed stronger activities against all the organisms. The present study has demonstrated that E. histolytica/dispar, Cryptosporidium, Giardia, and Cyclospora are common parasitic causes of diarrhoea in Vhembe district while Campylobacter spp. and Aeromonas are the most common bacterial causes of diarrhoea in Vhembe district of South Africa.

Female baboons do not raise the stakes but they give as good as they get

We used data from four chacma baboon, Papio cynocephalus ursinus, troops, living in two populations, to test the raise the stakes (RTS) strategy of reciprocity. Female baboons did not raise the stakes either within or across grooming bouts. Instead they time-matched grooming contributions and divided grooming into short episodes. In addition, analysis of the grooming behaviour of frequently versus infrequently grooming dyads did not reveal differences in grooming patterns predicted by the RTS strategy. We suggest time constraints preclude the escalation of grooming bout length as required by RTS; the data were more consistent with a strategy of give as good as you get. However, this strategy could not explain all the patterns observed, and we conclude that biological market theory represents a more appropriate framework for investigating female grooming dynamics than dyadic games based on the iterated prisoner's dilemma. We suggest that competitive altruism among individuals acts as a market force influencing an individual's value as a grooming partner. Copyright 2000 The Association for the Study of Animal Behaviour.

Magnetic resonance imaging and computed tomography in a model of wooden foreign bodies in the orbit

Wooden foreign bodies in the orbit are not detectable by standard roentgenography. Reports in the literature on the ability of computed tomography (CT) to detect orbital wooden foreign bodies have varied. To evaluate whether magnetic resonance imaging (MRI) would offer any advantage over CT in detecting wood in the orbit. MRI and CT were performed on an in vitro model of wooden foreign bodies in the orbit. Woods of different types and sizes were studied in vegetable fat backgrounds chosen to simulate orbital fat. On CT, most types of wood were hypodense to fat. Appropriate window settings were critical in the detection of wood by CT: in this model, a window width of 1000 Hounsfield units was optimal. On MRI, all types of wood were hypointense to fat. Small pieces of wood were surrounded by an MRI truncation artifact consisting of hyperintense spots. T1-weighted images demonstrated wood better than T2-weighted images and required less scanning time than either proton density or T2-weighted images, MRI was superior to CT in detecting the smallest pieces of wood. The role of MRI in the detection of orbital wooden foreign bodies in clinical practice remains to be determined.

Evaluation of dacryocystorhinostomy failure with computed tomography and computed tomographic dacryocystography

Five patients with dacryocystorhinostomy failures were examined with computed tomography or computed tomographic dacryocystography. In computed tomographic dacryocystography, radiopaque dye was instilled into the lacrimal sac before computed tomography to show its shape, location, and relation to surrounding structures. Problems with the bony ostium were detected in all five patients. Recurrent nasal polyposis, a retained metallic clip, and an unresected ethmoid air cell were also identified. Computed tomography and computed tomographic dacryocystography provided important information that facilitated reoperation after dacryocystorhinostomy failure.

Genomic diversity of "Norwalk like viruses" (NLVs): pediatric infections in a Brazilian shantytown

"Norwalk-like viruses" (NLVs) are a common cause of epidemic gastroenteritis in adults and children in developed countries. However, little is known about the role of NLVs in endemic pediatric gastroenteritis in developing countries. We sequenced Genogroup I and II NLV reverse transcription-polymerase chain reaction (RT-PCR) products from an 81-nucleotide region of the viral RNA polymerase gene to examine the molecular epidemiology of NLV infection in children younger than 5 years of age in Forteleza, Ceará, Brazil. NLV-positive PCR products were obtained from stool specimens collected over a 16-month period (1990-1991) from diarrhea cases and controls in a cohort of 120 children in an urban shantytown and from a study in the same city of hospitalized children with persistent diarrhea. Eight unique strains were detected in 15 specimens from 10 cohort children and in two hospital specimens. Nucleotide identity between the strains (5 Genogroup I, 3 Genogroup II) ranged from 63% to 88%. We designated these strains BraV1-8, for Brazil virus 1-8. The degree of genomic diversity of NLV strains we identified in this cohort during a short time period suggests multiple foci of infection within the community. Furthermore, sequence analysis of strains from two children with multiple symptomatic NLV infections indicates that infection with one strain was not protective against subsequent infection with a different strain in the same genogroup. These findings have implications for vaccine development and the prevention of pediatric gastroenteritis in developing countries.

Early-onset Alzheimer's disease: an analysis of CT findings

Brain computed tomographic scans of 60 patients with early-onset Alzheimer's disease (mean age, 60.7 years) were compared with those of age- and sex-matched control subjects. Computed tomographic analysis included standard ventricular measurements as well as subjective ratings of ventricular and sulcal size. These indices were correlated with the results of a battery of neuropsychological tests and electroencephalographic findings. Linear measurements of ventricular size were significantly greater in the patients with Alzheimer's disease than in the age-matched control group (p less than 0.0005). Using subjective appraisal of ventricular and sulcal size, the neuroradiologist noted abnormalities significantly more often in patients than in controls (p less than 0.0005). Linear measurements of ventricular size correlated significantly (p less than 0.05) with the severity of aphasia and dementia and the presence of electroencephalographic abnormalities. There was, however, no correlation between the subjective judgment of cortical atrophy and the degree of impairment as measured by neuropsychological tests. The findings in this study demonstrate the usefulness of computed tomographic imaging in Alzheimer's disease of early onset.

Complement C1q does not bind monomeric beta-amyloid

The tendency of both labeled and unlabeled beta-amyloid to bind in solution to C1q, the recognition species in the complement cascade, was examined using both hydrodynamic and spectroscopic methods. Potential binding interactions were evaluated using a purified synthetic beta-amyloid 1-40 sequence, alone, and selectively labeled at the amino terminus with spectroscopic probes. The probes permitted both absorbance and fluorescence analyses of beta-amyloid binding interactions. Under conditions used for the analyses beta-amyloid exists exclusively as a monomer in solution, and C1q retains an intact quaternary structure and is capable of binding to IgM. When mixed together the monomeric beta-amyloid does not bind to, or interact with, the complement C1q at concentrations below approximately 100 microM. The data suggest that if beta-amyloid toxicity is associated with complement activation in Alzheimer's disease then monomeric beta-amyloid is likely not responsible for activation through the classical complement pathway.

Success breeds success in mating male reed frogs (Hyperolius marmoratus)

Studies of the distribution of mating success among males in frog choruses typically seek to identify specific phenotypic attributes that confer a higher mating success on certain individual males. These attributes invariably relate to competition among males: either direct competition in the form of aggression, or competition to attract and be chosen by females. In this paper, we present evidence that an additional factor may operate in frog choruses. We show that individual males who mate on a given night enjoy a higher probability of being successful on the next night, and we suggest that this is because successful mating enables males to conserve energy.

Meaning and misunderstanding in occupational forms: a study of therapeutic goal setting

OBJECTIVE

This study examined occupational therapists' use of the occupational form of goal setting as therapy and its impact on clients.

METHOD

The study method was qualitative, using participant observation and interviewing as the main source of data.

RESULTS

The findings illustrated that therapists work both to give substance to the occupational form and to create the context of an implied narrative that imbues it with particular meanings. Simultaneously, clients' experience of meaning is influenced by a personal volitional narrative. When the two narratives do not coincide, therapists' efforts to maintain the occupational form intensify as they encourage clients toward attitudes and performances that do not resonate with the clients' experience of reality.

CONCLUSION

The findings underscore the importance of recognizing that occupational forms are embedded in social processes and perspectives that inevitably come into play when occupational forms are used as therapy.