Pectoralis major muscle of turkey displays divergent function as correlated with meat quality.

Fresh turkey meat color is determined by many factors that include muscle fiber type composition and heme protein concentrations. These factors either are affected by or influence biochemical events occurring postmortem. Deviations in the processing environment also can result in aberrant fresh meat quality and may ultimately change the quality characteristics of further processed products. Our objective was to describe the underlying cause and significance of the two-toning color defect in fresh turkey breast. In the first experiment, pectoralis major muscles were collected, classified as single- or two-toned, and analyzed using image processing to characterize fresh turkey color. Samples from the large and small lobes of the pectoralis major muscle were collected for pH, glycolytic intermediates, protein abundance, mRNA expression, and quality characteristics. In the second experiment, time from stun to exsanguination was tested as a promoter of fresh turkey color. Results from the first experiment showed that the turkey breast possesses two distinct lobes. The large lobe had greater (P < 0.05) glycolytic potential, lactate content, lactate dehydrogenase (LDH) abundance, and centrifugal drip loss, while pH, myoglobin mRNA expression, and soluble protein levels were lower (P < 0.05) compared to the small lobe. Results from the second experiment showed that reducing time from stun to exsanguination enhanced (P < 0.05) fresh turkey color by mitigating the differences between the two lobes. Our results also showed that birds exsanguinated first had greater (P < 0.05) muscle pH values and body temperatures. These results show inherent differences in breast muscle and processing conditions interact to establish variations in fresh turkey color.

Putative immunodominant human immunodeficiency virus-specific CD8(+) T-cell responses cannot be predicted by major histocompatibility complex class I haplotype.

Recent studies of human immunodeficiency virus (HIV)-specific CD8(+) T cells have focused on responses to single, usually HLA-A2-restricted epitopes as surrogate measures of the overall response to HIV. However, the assumption that a response to one epitope is representative of the total response is unconfirmed. Here we assess epitope immunodominance and HIV-specific CD8(+) T-cell response complexity using cytokine flow cytometry to examine CD8(+) T-cell responses in 11 HLA-A2(+) HIV(+) individuals. Initial studies demonstrated that only 4 of 11 patients recognized the putative immunodominant HLA-A2-restricted p17 epitope SLYNTVATL, suggesting that the remaining subjects might lack significant HIV-specific CD8(+) T-cell responses. However, five of six SLYNTVATL nonresponders recognized other HIV epitopes, and two of four SLYNTVATL responders had greater responses to HIV peptides restricted by other class I alleles. In several individuals, no HLA-A2-restricted epitopes were recognized, but CD8(+) T-cell responses were detected to epitopes restricted by other HLA class I alleles. These data indicate that an individual's overall CD8(+) T-cell response to HIV is not adequately represented by the response to a single epitope and that individual major histocompatibility complex class I alleles do not predict an immunodominant response restricted by that allele. Accurate quantification of total HIV-specific CD8(+) T-cell responses will require assessment of the response to all possible epitopes.

Detection of benzene and other gases with an open-path, static Fourier-transform UV spectrometer.

Releases of benzene and other gases have been detected and quantified using a novel optical, open-path instrument based on a deuterium light source and a static Fourier-transform spectrometer. The spectrometer uses Wollaston prisms to form an interferogram in the spatial domain that is recorded by use of a detector array. The instrument is designed to operate in the ultraviolet region of the spectrum between 200 and 270 nm, which coincides with strong absorption features in the spectra of many gases of environmental and health interest. Using the instrument with a 5-s measurement period provides a path-integrated concentration sensitivity to benzene of 2 parts in 10(6) times meter, which corresponds to a 20-parts in 10(9) detection limit over a typical path length of 100 m.

Static Fourier-transform ultraviolet spectrometer for gas detection.

We report the design, construction, and evaluation of a static Fourier-transform ultraviolet spectrometer. The spectrometer is based on Wollaston prisms that form an interferogram in the spatial domain, which is recorded with a detector array. We demonstrate the application of the spectrometer to gas detection. Using a deuterium light source, we measured a detection limit, with a 1-s integration time, for hydrogen sulfide and sulfur dioxide, corresponding to 0.2 ppm over a 5-m path length.

Design of a static Fourier-transform spectrometer with increased field of view.

We present several novel designs of static Fourier-transform spectrometers based on Wollaston prisms. By numerical modeling we show the increased field of view that can be obtained when an achromatic half-wave plate is included between the prisms or when prisms fabricated from positive and negative birefringent materials are combined. In addition, we model how a single Wollaston prism with an inclined optic axis produces a fringe plane localized behind its exit face, thus enabling the design of a static Fourier-transform spectrometer based on a single Wollaston prism.

Epidemiology of Hymenolepis nana infections in primary school children in urban and rural communities in Zimbabwe.

Fecal specimens were obtained on 3 occasions at 10-12 wk intervals from 315 children in 3 rural villages in Zimbabwe and from 351 children in the high-density suburbs of an adjacent small town. Specimens were examined qualitatively and quantitatively for eggs of Hymenolepis nana, and these were found in 142 (21%) children. Infections occurred more frequently in younger children in the urban area but in older children in rural areas. The prevalence in urban areas (24%) was higher than in rural areas (18%), and in urban areas infection correlated with low "hygiene scores" (determined by observation) and with the presence in the household of an infected sibling. The prevalence of infection in the 3 rural communities did not correlate with availability of water, number of households per toilet, with low "hygiene scores," or with the presence of an infected sibling. Treatment with a single oral dose of 15 mg/kg praziquantel cured 84% of the infected children. New or reinfections occurred more frequently in households that had an infected sibling in an urban but not rural setting. The study demonstrates distinct differences in the transmission of H. nana infection in rural and urban communities. The data suggest intrafamily transmission in urban areas, particularly in households with poor hygiene behavior, leading to primary infection early in life. In rural areas, the prevalence of infection and the incidence of reinfection were highest in children of school age, and there was little evidence for intrafamily transmission of the parasite.

Effects of fibrin sealant on the fixation of porous titanium and pyrolytic carbon implants.

The authors investigated the potential role the fibrin sealant system may portray in the fixation of osseous implants. The application of a layer of fibrin did not interfere with the fixation of osseous implants of either pyrolytic carbon or Biolite-coated porous titanium. A greater percentage of tissue ingrowth was observed in the porous titanium implants in the presence of the fibrin sealant system; however, no significant difference in the ultimate interfacial shear stress was observed.

Motion of the first metatarsophalangeal joint.

The analysis of motion of the first metatarsophalangeal joint in this study demonstrates the character of motion about this joint. Four instantaneous centers of rotation were calculated in the first metatarsal head that formed an arc encircling an area of increased stress patterns. The joint motion is made up of rolling, sliding, and compression. The fact that there is more than one center of motion contradicts the theory of a simple hinge joint. The joint is a dynamic acetabulum or "hammock," as described by Kelikian. That is, the first metatarsal head moves within a stable support comprised of the base of the proximal phalanx, the sesamoids, soft tissue, and muscle tendons. The nature of first metatarsophalangeal joint motion must be considered when contemplating surgical procedures of the first metatarsophalangeal joint.

Epidemiology of Giardia lamblia infection in children: cross-sectional and longitudinal studies in urban and rural communities in Zimbabwe.

Stool specimens from 3,038 children in rural and urban areas near Harare were examined for Giardia lamblia cysts. Preliminary studies, using specimens collected on three consecutive days from 157 known cyst passers, showed that over 89% of infections could be diagnosed on single stool specimens by examination of Gomori-stained smears. The overall prevalence of giardial infection was 19.4% with significantly more urban children (21.1%) passing cysts than rural children (16.7%). In urban areas the highest prevalence was in young (5-6 year) children, while in rural areas, the highest prevalence was in older (9-10 year) children. Of 132 children treated with Entamizole a metronidazole-diloxanide combination, 127 (96.2%) had ceased excreting cysts by the fifth treatment day. Follow-up examination of these children showed a high rate of reinfection, with 29.6% excreting cysts during the year following treatment. During the same period 13.3% of previously uninfected children had started passing cysts, while over half of infected, but untreated, children had undergone apparent "self-cure." Younger children were more likely to be reinfected than older children, and continued excreting cysts for a longer period of time.

Giardiasis and the nutritional status of Zimbabwean schoolchildren.

Stool specimens, obtained from 1813 schoolchildren from communal lands, commercial farms and urban areas in Zimbabwe, were examined for helminth and protozoan parasites. The findings were collated with anthropometric data on the same children to investigate the relationship between intestinal parasitism and nutritional status. Protozoan infections were common with Giardia lamblia being identified in 17.4% of children. There was a strong association between giardial infection and undernutrition, wasting and stunting in these children. There was no evidence of an association between helminth infection and undernutrition. In view of the known impairment of absorption from the gut in giardiasis, it is suggested that giardial infection may be an important factor contributing to the low nutritional status of many primary schoolchildren in Zimbabwe.

Piped water supply and intestinal parasitism in Zimbabwean schoolchildren.

The prevalence of intestinal parasitism in primary schoolchildren in three areas, communal (peasant farm) lands, commercial farms and urban townships, was assessed by examination of concentrated and stained stool specimens to determine the effect of water supply on intestinal parasitism. Piped water in communal lands was associated with decreased frequency of schistosomiasis and hymenolepiasis, but not with decreased frequency of protozoa. Schistosomiasis was very common in commercial farm labour communities, particularly on farms adjoining the local river, despite the availability of stored borehole water supplied through communal taps. The prevalence of intestinal parasitism in children from urban areas with municipal water supplied to taps in each household was similar to that of children in communal areas who obtained water from surface streams. The frequency of Giardia lamblia infection was higher in urban than in rural schoolchildren, and within communal areas was higher in children with access to protected borehole water. The provision of piped water was, therefore, not found to be associated with reduced prevalence of intestinal parasitism, though additional factors such as frequency of contact with infected water, the provision of ancillary improvements and the actual usage of available water supplies would need to be more closely assessed.

Proliferative response of human lymphocytes to secretory and cellular antigens of Trichomonas vaginalis.

Lymphocytes from patients with active trichomoniasis showed a proliferative response when incubated in the presence of secretory and cellular products of either pathogenic or non-pathogenic Trichomonas vaginalis. Maximal responses were detected using 50 micrograms per ml protein after 5 days incubation. Lymphocytes from non-infected laboratory workers showed no response to these antigens. This indicates that delayed hypersensitivity reactions may act to modulate inflammatory responses in trichomoniasis.

Muscarinic receptors and [3H]inositol incorporation in a rat sympathetic ganglion.

[3H]Inositol incorporation into phosphatidylinositol was accelerated in rat superior cervical ganglia treated with 4-aminopyridine or Bethanechol. The inositol response to these drugs occurred in intact and denervated ganglia and was prevented by atropine. The possibility that muscarinic receptor subtypes are present in the ganglia is considered because bethanechol, but not 4-aminopyridine, is known to increase cGMP in rat superior cervical ganglia by an atropine-sensitive process.

Regulation of cyclic AMP accumulation in a rat sympathetic ganglion: effects of vasoactive intestinal polypeptide.

Cyclic AMP accumulation in rat superior cervical ganglia during synaptic activity occurs by a noncholinergic, nonadrenergic process. Both preganglionic nerve stimulation and 4-aminopyridine increase ganglion cyclic AMP levels in the presence of atropine or phentolamine. Of the polypeptides tested as putative transmitters, vasoactive intestinal polypeptide (10(-6) M) causes ganglion cyclic AMP accumulation comparable to that produced by preganglionic nerve stimulation.

The regulation of cyclic nucleotides in a sympathetic ganglion.

Preganglionic nerve terminal stimulation in rat superior cervical ganglia causes marked increases in the levels of cyclic nucleotides. Results are similar when preganglionic nerve stimulation is compared with elevated [K+]0 or 4-aminopyridine. Although intact nerve terminals and Ca2+ are required for the response to occur, pharmacological studies indicate that acetylcholine and adrenergic transmitters are not involved in the cyclic nucleotide response. It is suggested that cyclic nucleotide accumulation occurs in the nerve terminals or an unknown transmitter or substance participates in the postsynaptic accumulation of the cyclic nucleotides. Polypeptides tested thus far do not seem to be implicated. Interrelationships among phospholipid turnover, Ca2+-exchange and cyclic nucleotide accumulation in rat sympathetic ganglia are considered, but are difficult to establish.

Cyclic guanosine 3':5'-monophosphate accumulation and 45Ca-uptake by rat superior cervical ganglia during preganglionic stimulation.

Repetitive preganglionic nerve stimulation increases cyclic guanosine 3':5'-monophosphate (cGMP) content in rat superior cervical ganglia by a mechanism requiring Ca++ but resistant to blockade by cholinergic receptor antagonists. Similarly, 45Ca-uptake during prolonged preganglionic nerve stimulation is unaffected by hexamethonium or atropine. These findings indicate that nerve stimulation increases cGMP accumulation and 45Ca-uptake by a noncholinergic mechanism Substance P, met-enkephalin and luteinizing hormone-releasing factor have little or no effect on cGMP content. By contrast, bethanechol causes a 3-fold increase in cGMP content and postganglionic cell firing. Thus, as reported by others, muscarinic receptor activation increases ganglionic cGMP[. 4-Aminopyridine causes an increase in cGMP of resting ganglia that requires Ca++ and the nerve terminal is blocked by tetrodotoxin but unaffected by atropine or hexamethonium. Ouabain also increases ganglionic cGMP content by a process that requires Ca++ and the nerve terminals. Like preganglionic nerve stimulation, 4-aminopyridine and ouabain cause cGMP accumulation in the nerve terminals or in the ganglion cells as a consequence of releasing a noncholinergic transmitter. The uptake of Ca++ by ganglion cells is not an adequate stimulus for cGMP accumulation because the nicotinic receptor agonist dimethylphenylpiperazinium increases 45Ca-uptake but has no effect on cGMP formation in ganglia.