Physiological and clinical outcome of anterior sphincteroplasty

A total of 55 women underwent sphincteroplasty for the treatment of faecal incontinence related to anterior defects. Patients were followed prospectively for a mean of 29 months to evaluate the outcome overall and according to age. All patients were evaluated clinically by means of a questionnaire and graded using an incontinence scoring system ranging from 0 (perfect continence) to 20 (complete incontinence). Some 52 patients (95 per cent) had had a previous vaginal delivery and 30 (55 per cent) had a history of previous anal sphincter repair. Physiological and functional parameters in patients with a successful outcome (n = 39) were compared with those in patients with a poor outcome (n = 16). The results were also compared in patients under (n = 39) and over (n = 16) 60 years of age. Overall, patients with a successful outcome had a significant change in mean and maximal resting and squeeze pressures. These changes correlated well with the increase in the high-pressure zone (HPZ) length from 1.0-2.2 cm (P = 0.0002) and with functional outcome (change in incontinence score from 15.3 to 5.8; P < 0.0001). In patients over 60 years of age, a significant change in mean squeeze pressure (P = 0.03) and HPZ length (P = 0.01) was noted and correlated with functional outcome (change in incontinence score from 14.3 to 6.4; P < 0.0001). A successful outcome after anterior sphincteroplasty is related to improvement in sphincter function even in an older population. These results demonstrate that age itself does not seem to be a predictor of poor outcome. Patients should not be denied a repair exclusively on grounds of age.

Characterization of clinical mastitis occurring in cows on 50 large dairy herds in Wisconsin

In recent years, the US dairy industry has experienced significant demographic changes, with an increase in the number of large herds. The objectives of the present study were to characterize clinical mastitis occurring in cows on large dairy herds in Wisconsin. Participating herds (n=50) were required to have a minimum of 200 lactating animals, participate in monthly DHI testing (including monthly individual cow somatic cell count), use computerized herd records, use a milking routine that included fore-stripping quarters for detection of mastitis, and use antimicrobials to treat affected cows. After study personnel visited the farm, each herd was instructed to enroll the next 17 cows that experienced clinical mastitis, regardless of severity. At detection of clinical mastitis and 14 to 21 d after treatment ended, duplicate quarter milk samples were collected from all affected quarters and used for microbiological analysis. Treatments of affected cows were performed according to existing individual farm protocols. Cow level follow-up data was collected for 90 d after enrollment. Microbiological diagnoses at enrollment included gram-negative (35.6%), no growth (27.3%), gram-positive (27.5%), and other (9.6%). Of the 741 cases, the most prevalent pathogens were Escherichia coli (22.5%), followed by environmental streptococci (12.8%), Klebsiella spp. (6.9%), and coagulase-negative staphylococci (6.1%). Bacteriological cure was 75.0% for cases caused by gram-negative pathogens (n=136), 50.8% for cases caused by gram-positive pathogens (n=128), 47.5% for cases caused by other pathogens (n=40), and 73.2% for cases which did not result in microbial growth (n=123). Of the 583 cases with severity recorded, the distribution of mild, moderate, and severe symptoms was 47.8, 36.9, and 15.3%, respectively. The majority of cases presenting with severe symptoms were caused by gram-negative pathogens. Treatment cure was greater for gram-negative pathogens and cases for which no pathogens were recovered as compared with cases caused by other etiologies. Cows experiencing severe cases were more likely to receive multiple antimicrobial treatments.

Autosomal recessive retinitis pigmentosa caused by mutations in the alpha subunit of rod cGMP phosphodiesterase

Retinitis pigmentosa (RP) constitutes a group of genetically heterogeneous progressive photoreceptor degenerations leading to blindness and affecting 50,000-100,000 people in the U.S. alone. Over 20 different RP loci have been mapped, of which six have been identified. Three of these encode members of the rod photoreceptor visual transduction cascade: rhodopsin, the rod cGMP-gated cation channel alpha subunit, and the beta subunit of cGMP-phosphodiesterase (PDEB). As null mutations in PDEB cause some cases of RP and since both alpha and beta subunits are required for full phosphodiesterase activity, we examined the gene encoding the alpha subunit of cGMP phosphodiesterase (PDEA) in 340 unrelated patients with RP. We found three point mutations in PDEA in affected members of two pedigrees with recessive RP. Each mutation alters an essential functional domain of the encoded protein and likely disrupts its catalytic function. PDEA is the seventh RP gene identified, highlighting the extensive genetic heterogeneity of the disorder and encouraging further investigation into the role of other members of the phototransduction cascade in RP.

Mechanical bowel preparation for elective colorectal surgery. A prospective, randomized, surgeon-blinded trial comparing sodium phosphate and polyethylene glycol-based oral lavage solutions

AIM

The aim of this study was to compare the cleansing ability, patient compliance, and safety of two oral solutions for elective colorectal surgery.

METHODS

All eligible patients were prospectively randomized to receive either 4 l of standard polyethylene glycol (PEG) solution or 90 ml of sodium phosphate (NaP) as mechanical bowel preparation for colorectal surgery. A detailed questionnaire was used to assess patient compliance. In addition, the surgeons, blinded to the preparation, intraoperatively evaluated its quality. Postoperative septic complications were also assessed. The calcium serum level was monitored before and after bowel preparation. Statistical analysis was performed using the Wilcoxon's rank-sum test and Fisher's exact test.

RESULTS

Two hundred patients, well matched for age, gender, and diagnosis, were prospectively randomized to receive either PEG or NaP solutions for elective colorectal surgery. All patients completed all phases of the trial. There was a significant decrease in serum calcium levels after administration of both NaP (mean, 9.3-8.8 mg/dl) and PEG (9.2-8.9 mg/dl), respectively (P < 0.0001), with no clinical sequelae. However, patient tolerance to NaP was superior to PEG: less trouble drinking the preparation (17 vs. 32 percent; P < 0.0002), less abdominal pain (12 vs. 22 percent; P = 0.004), less bloating (7 vs. 28 percent), and less fatigue (8 vs. 17 percent), respectively. Additionally, 65 percent of patients who received the NaP preparation stated they would repeat this preparation again compared with only 25 percent for the PEG group (P < 0.0001). Ninety-five percent of patients who received the NaP solution tolerated 100 percent of the solution compared with only 37 percent of the PEG group (P < 0.0001). For quality of cleansing, surgeons scored NaP as "excellent" or "good" in 87 compared with 76 percent after PEG (P = not significant). Rates of septic and anastomotic complications were 1 percent and 1 percent for NaP and 4 percent and 1 percent for PEG, respectively (P = not significant).

CONCLUSION

Both oral solutions proved to be equally effective and safe. However, patient tolerance of the small volume of NaP demonstrated a clear advantage over the traditional PEG solution.

Pudendal neuropathy is predictive of failure following anterior overlapping sphincteroplasty

PURPOSE

This study assessed the efficacy of anterior overlapping sphincteroplasty and parameters predictive of a successful outcome.

METHODS

Clinical findings and physiologic investigations of female patients who underwent anterior overlapping sphincteroplasty for fecal incontinence between 1988 and 1996 were reviewed. The extent of sphincter damage was assessed at needle electromyography as the number of quadrants exhibiting decreased motor unit potentials. Prolonged pudendal nerve terminal motor latencies were those of greater than 2.2 ms. The size of the endoanal ultrasound defect was assessed as degrees circumference of the external sphincter in which viable muscle was absent. Patients were reviewed by telephone questionnaire and were asked to grade the outcome of their surgery as excellent or good (success) or fair or poor (failure). Incontinence was graded using a scoring system of 0 (perfect continence) to 20 (complete incontinence).

RESULTS

There were 100 patients who had an overlapping sphincteroplasty; complete follow-tip information was obtained for 77 patients at a median of 24 (range, 2-96) months. The median age was 47 (range, 25-80) years and they had a median duration of incontinence of four (range, 0.1-39) years. Prior sphincteroplasty had been performed in 30 patients with a median of one (range, 1-7) operations. Investigations performed included electromyography (n = 49), pudendal nerve terminal motor latency (n = 71), endoanal ultrasound (n = 49), and manometry (n = 67). Sixty percent of patients had improved continence and 42 (55 percent) considered their surgery to have been successful as attested to by a significant decrease in their incontinence score (from 15.1 +/- 4.5 to 4.3 +/- 4.2; P < 0.0001). Neither patient age, parity, prior sphincteroplasty, cause or duration of incontinence, extent of electromyography damage, size of the endoanal ultrasound defect, nor any manometric parameter correlated with outcome. However, 62 percent of 59 patients with bilaterally normal pudendal nerve terminal motor latencies had a successful outcome compared with only 16.7 percent of 12 patients with unilateral or bilateral prolonged pudendal nerve terminal motor latencies (P < 0.01).

CONCLUSION

Bilateral normal pudendal nerve terminal motor latencies are the only factors predictive of long-term success after overlapping sphincteroplasty.

Treatments of clinical mastitis occurring in cows on 51 large dairy herds in Wisconsin

Antimicrobials are frequently used for treatment of bovine mastitis and few studies have examined modern treatment strategies on large US dairy farms. The objective of this study was to describe treatment practices for clinical mastitis occurring in cows on large dairy herds in Wisconsin. Treatments performed on 747 cows experiencing cases of mild, moderate, or severe symptoms of clinical mastitis were recorded on 51 Wisconsin dairy farms. Duplicate milk samples were collected from the affected quarter for microbiological analysis at the onset of clinical mastitis and 14 to 21 d after treatment ended. Cows were treated according to individual farm protocol. Drugs and doses used for treatments were recorded for each case. Among all herds, 5 intramammary (IMM) antimicrobials (amoxicillin, hetacillin, pirlimycin, ceftiofur, and cephapirin) were used to treat cows for clinical mastitis. Of 712 cows with complete treatment data, 71.6% were treated with IMM ceftiofur either solely or combined with other antimicrobials (administered either IMM or systemically). Of cows experiencing severe symptoms of clinical mastitis, 43.8% received IMM treatment concurrent with systemic antimicrobials. Of all cows treated, 23.1% received an additional secondary treatment (either IMM, systemic, or both) because of perceived lack of response to the initial treatment. The majority of IMM treatments were administered to cows with a microbiological diagnosis of no growth (34.9%) or Escherichia coli (27.2%). Half of the cows experiencing cases caused by E. coli were treated using systemic antimicrobials in contrast to only 6.8% of cows experiencing cases caused by coagulase-negative staphylococci. In conflict with FDA regulations, which do not allow extra-label treatments using sulfonamides, a total of 22 cows from 8 farms were treated with systemic sulfadimethoxine either solely or in combination with oxytetracycline. Antimicrobial drugs were used on all herds and many cows received extra-label treatments. Great opportunity exists to improve mastitis therapy on large dairy herds, but use of more diagnostic methodologies is necessary to guide treatments. Farmers and veterinarians should work together to create protocols based on the herd needs considering reduced inappropriate and excessive use of antimicrobials.

Contributions of stimulus valence and arousal to visual activation during emotional perception

Neuroimaging experiments have revealed that the visual cortex is involved in the processing of affective stimuli: seeing emotional pictures leads to greater activation than seeing neutral ones. It is unclear, however, whether such differential activation is due to stimulus valence or whether the results are confounded by arousal level. In order to investigate the contributions of valence and arousal to visual activation, we created a new category of "interesting" stimuli designed to have high arousal, but neutral valence, and employed standard neutral, unpleasant, and pleasant picture categories. Arousal ratings for pleasant and neutral pictures were equivalent, as were valence ratings for interesting and neutral pictures. Differential activation for conditions matched for arousal (pleasant vs neutral) as well as matched for valence (interesting vs neutral) indicated that both stimulus valence and arousal contributed to visual activation.

Comparative study of the whisky aroma profile based on headspace solid phase microextraction using different fibre coatings

A dynamic headspace solid-phase microextraction (HS-SPME) and gas chromatography coupled to ion trap mass spectrometry (GC-(IT)MS) method was developed and applied for the qualitative determination of the volatile compounds present in commercial whisky samples which alcoholic content was previously adjusted to 13% (v/v). Headspace SPME experimental conditions, such as fibre coating, extraction temperature and extraction time, were optimized in order to improve the extraction process. Five different SPME fibres were used in this study, namely, poly(dimethylsiloxane) (PDMS), poly(acrylate) (PA), Carboxen-poly(dimethylsiloxane) (CAR/PDMS), Carbowax-divinylbenzene (CW/DVB) and Carboxen-poly(dimethylsiloxane)-divinylbenzene (CAR/PDMS/DVB). The best results were obtained using a 75 microm CAR/PDMS fibre during headspace extraction at 40 degrees C with stirring at 750 rpm for 60 min, after saturating the samples with salt. The optimised methodology was then applied to investigate the volatile composition profile of three Scotch whisky samples--Black Label, Ballantines and Highland Clan. Approximately seventy volatile compounds were identified in the these samples, pertaining at several chemical groups, mainly fatty acids ethyl esters, higher alcohols, fatty acids, carbonyl compounds, monoterpenols, C13 norisoprenoids and some volatile phenols. The ethyl esters form an essential group of aroma components in whisky, to which they confer a pleasant aroma, with "fruity" odours. Qualitatively, the isoamyl acetate, with "banana" aroma, was the most interesting. Quantitatively, significant components are ethyl esters of caprilic, capric and lauric acids. The highest concentration of fatty acids, were observed for caprilic and capric acids. From the higher alcohols the fusel oils (3-methylbutan-1-ol and 2.phenyletanol) are the most important ones.

Laparoscopic creation of stomas

BACKGROUND

Some indications for laparoscopic bowel surgery are still controversial. However, the use of laparoscopic techniques for the treatment of benign disorders is less often challenged. Moreover, the morbidity of nonresectional procedures is less than that encountered with resectional cases. Therefore, stoma creation seems ideally suited to laparoscopy. The aim of our study was to assess the outcome of laparoscopic stoma creation.

METHODS

All patients who underwent laparoscopic intestinal diversion were evaluated; parameters included age, gender, indication for the procedure, history of previous surgery, operative time, length of hospitalization, recovery of bowel function, and postoperative complications.

RESULTS

Between March 1993 and January 1996, 32 patients of a mean age of 42.2 (range 19-72) years (14 males, 18 females) underwent elective laparoscopic fecal diversion (25 loop ileostomy, four loop colostomy, three end colostomy). Indications for fecal diversion were fecal incontinence (n = 11), Crohn's disease (n = 6), unresectable rectal cancer (n = 4), pouch vaginal fistula (n = 3), rectovaginal fistula (n = 2), colonic inertia (n = 2), radiation proctitis (n = 1), anal stenosis (n = 1), Kaposi's sarcoma of the rectum (n = 1), and tuberculous fistula (n = 1). Conversion was required in five patients (15.6%) due to the presence of adhesions (three), enterotomy (one), or colotomy (one). All of these five patients had undergone previous abdominal surgery and were operated on early in our experience. Major postoperative complications occurred in two patients (6%) and in both cases consisted of stoma outlet obstruction after construction of a loop ileostomy. One of the two patients had undergone prior surgery. This patient required reoperation, at which time a rotation of the terminal ileum at the stoma site was found. The other patient had a narrow fascial opening which was successfully managed with 2 weeks of self-intubation of the stoma. The mean operative time was 76 (range 30-210) min; mean length of hospitalization was 6.2 (range 2-13) days; stoma function started after a mean of 3.1 (range 1-6) days. Patients with previous abdominal surgery had a longer mean operative time (14/32; 117 min) compared to patients who had no previous surgery (18/32; 55 min) (p < 0.0002). These longer operative times and hospital stay were attributable to extensive enterolysis, which was required in some cases.

CONCLUSION

In conclusion, laparoscopic creation of intestinal stomas is safe, feasible, and effective. Although the length of the procedure is longer in patients who have had prior surgery, previous surgery is not a contraindication, and even in these cases, a laparotomy can be avoided in the majority of patients. Lastly, care must be taken to ensure adequate fascial opening and correct limb orientation.

Effects of age and physical activity on the autonomic control of heart rate in healthy men

The effects of the aging process and an active life-style on the autonomic control of heart rate (HR) were investigated in nine young sedentary (YS, 23 +/- 2.4 years), 16 young active (YA, 22 +/- 2.1 years), 8 older sedentary (OS, 63 +/- 2.4 years) and 8 older active (OA, 61 +/- 1.1 years) healthy men. Electrocardiogram was continuously recorded for 15 min at rest and for 4 min in the deep breathing test, with a breath rate of 5 to 6 cycles/min in the supine position. Resting HR and RR intervals were analyzed by time (RMSSD index) and frequency domain methods. The power spectral components are reported in normalized units (nu) at low (LF) and high (HF) frequency, and as the LF/HF ratio. The deep breathing test was analyzed by the respiratory sinus arrhythmia indices: expiration/inspiration ratio (E/I) and inspiration-expiration difference (deltaIE). The active groups had lower HR and higher RMSSD index than the sedentary groups (life-style condition: sedentary vs active, P < 0.05). The older groups showed lower HFnu, higher LFnu and higher LF/HF ratio than the young groups (aging effect: young vs older, P < 0.05). The OS group had a lower E/I ratio (1.16) and deltaIE (9.7 bpm) than the other groups studied (YS: 1.38, 22.4 bpm; YA: 1.40, 21.3 bpm; OA: 1.38, 18.5 bpm). The interaction between aging and life-style effects had a P < 0.05. These results suggest that aging reduces HR variability. However, regular physical activity positively affects vagal activity on the heart and consequently attenuates the effects of aging in the autonomic control of HR.

Validation of an Immunoassay for Detection and Quantitation of a Genetically Modified Soybean in Food and Food Fractions Using Reference Materials: Interlaboratory Study

An immunoassay for detection of a specific genetically modified soybean (Roundup-Ready®) was validated on dried soybean powder in an interlaboratory study. Different percentages of genetically modified soybeans in nonmodified soybean matrix were evaluated in a blind study. Thirty-eight laboratories from 13 countries participated. The immunoassay was evaluated for 2 endpoints: (1) To give a semiquantitative result, i.e., determination of a given sample above or below a given threshold, or (2) to compute a quantitative result, i.e., percentage of genetically modified soybeans in the sample. Semiquantitative results showed that a given sample which contained &lt;2% genetically modified soybeans was identified as below 2% with a 99% confidence level. Quantitative use of the assay resulted in a repeatability (r) and reproducibility (R) that were computed to be RSDr = 7% and RSDR = 10%, respectively, for a sample containing 2% genetically modified soybeans. Application of this method depends on availability of appropriate reference materials for a specific food matrix. Only matrix-matched reference materials can be used for analysis of food or food fractions.

Resilience and vagal tone predict cardiac recovery from acute social stress

Previous studies showed that heart period decreases during and recovers after an acute stress. We investigated if individual predispositions and emotional priming influence heart period recovery after a speech stress task. Psychometric scales and resting cardiac vagal tone were used to measure individual traits. The presentation of a sequence of either pleasant or unpleasant pictures, as emotional primers, preceded the speech stress. Heart period was measured throughout the experiment. Stress induced tachycardia irrespective of emotional priming or traits. In the recovery period, participants with higher resting cardiac vagal tone or presenting higher resilience significantly reduced the heart acceleration. Furthermore, these traits interacted synergistically in the promotion of the recovery of heart period. Pleasant priming also improved recovery for participants with lower negative affect. In conclusion, the stress recovery measured through heart period seemed dependent upon individual predispositions and emotional priming. These findings further strengthen previous observations on the association between greater cardiac vagal tone and the ability to regulate emotion.

Anomalies of the CD8+ T cell pool in haemochromatosis: HLA-A3-linked expansions of CD8+CD28- T cells

The present study consists of a phenotypic and functional characterization of peripheral blood T lymphocytes in a group of 21 patients with hereditary haemochromatosis (HH), an MHC class I-linked genetic disease resulting in iron overload, and a group of 30 healthy individuals, both HLA-phenotyped. The HH patients studied showed an increased percentage of CD8+ CD28- T cells with a corresponding reduction in the percentage of CD8+ CD28+ T cells in peripheral blood relative to healthy blood donors. No anomalies of CD28 expression were found in the CD4+ subset. The presence of the HLA-A3 antigen but not age accounted for these imbalances. Thus, an apparent failure of the CD8+ CD28+ T cell population 'to expand', coinciding with an 'expansion' of CD8+ CD28- T cells in peripheral blood of HLA-A3+ but not HLA-A3- HH patients was observed when compared with the respective HLA-A3-matched control group. A significantly higher percentage of HLA-DR+ but not CD45RO+ cells was also found within the peripheral CD8+ T cell subset in HH patients relative to controls. Phytohaemagglutinin (PHA) stimulation of peripheral blood mononuclear cells (PBMC) for 5 days showed: (i) that CD8+ CD28+ T cells both in controls and HH were able to expand in vitro; (ii) that CD8+ CD28- T cells decreased markedly after activation in controls but not in HH patients. Moreover, functional studies showed that CD8+ cytotoxic T lymphocytes (CTL) from HH patients exhibited a diminished cytotoxic activity (approx. two-fold) in standard 51Cr-release assays when compared with CD8+ CTL from healthy controls. The present results provide additional evidence for the existence of phenotypic and functional anomalies of the peripheral CD8+ T cell pool that may underlie the clinical heterogeneity of this iron overload disease. They are of particular relevance given the recent discovery of a novel mutated MHC class I-like gene in HH.

Correlated mutation analyses on very large sequence families

The 'omics era' (the era of genomics, proteomics, and so forth) is marked by a flood of data that need to be interpreted to become useful information. Thanks to genome sequencing projects, large numbers of sequence families with more than a thousand members each are now available. Novel analytical techniques are needed to deal with this avalanche of sequence data. Sequence entropy is a measure of the information present in an alignment, whereas sequence variability represents the mutational flexibility at a particular position. Entropy versus variability plots can reveal the roles of groups of residues in the overall function of a protein. Such roles can be as part of the main active site, part of a modulator binding site, or transduction of a signal between those sites. Residues that are involved in a common function tend to stay conserved as a group, but when they mutate, they tend to mutate together. Correlated mutation analysis can detect groups of residue positions that show this behaviour. The combination of entropy, variability and correlation is a powerful tool to convert sequence data into useful information. This analysis can, for example, detect the key residues involved in cooperativity in globins, the switch regions in ras-like proteins and the calcium binding and signalling residues in serine proteases. We have extrapolated from these three classes of structurally and functionally well-described proteins to G-protein-coupled receptors (GPCRs). We can detect the residues in the main functional site in GPCRs that are responsible for G-protein coupling, the residues in the endogenous agonist binding site, and the residues in between that transduce the signal to and fro between these sites. The results are discussed in the light of a simple two-step evolutionary model for the development of functional proteins.

A low resolution model for the interaction of G proteins with G protein-coupled receptors

A model is presented for the interaction between G proteins and G protein-coupled receptors. The model is based on the fact that this interaction shows little specificity and thus conserved parts of the G proteins have to interact with conserved parts of the receptors. These parts are a conserved negative residue in the G protein, a fully conserved arginine in the receptor and a series of residues that are not conserved but always hydrophobic like the hydrophobic side of the C-terminal helix of the G protein and the hydrophobic side of a helix in the C-terminal domain of the receptor. Other, mainly cytosolic, factors determine the specificity and regulation of this interaction. The relation between binding and activation will be shown. A large body of experimental evidence supports this model. Despite the fact that the model does not provide atomic resolution, it can be used to explain some experimental data that would otherwise seem inexplicable, and it suggests experiments for its falsification or verification.

Converse modulation of IRP1 and IRP2 by immunological stimuli in murine RAW 264.7 macrophages

Iron regulatory proteins (IRP1 and IRP2) are two cytoplasmic RNA-binding proteins that control iron metabolism in mammalian cells. Both IRPs bind to specific sequences called iron-responsive elements (IREs) located in the 3' or 5' untranslated regions of several mRNAs, in particular mRNA encoding ferritin and transferrin receptor. In this study, we followed in parallel the in vivo regulation of the two IRPs in physiologically stimulated macrophages. We show that stimulation of mouse RAW 264.7 macrophage-like cells increased IRP1 IRE binding activity 4-fold, whereas IRP2 activity decreased 2-fold 8 h after interferon-gamma/lipopolysaccharide treatment. Decrease in IRP2 was not due to nitric oxide (NO) production and did not require de novo protein synthesis. Our data therefore indicate that the two IRPs can be conversely regulated in response to the same stimulus. In addition, the effect of endogenously produced NO on IRP1 was further characterized in an activated macrophage/target cell system. We show that NO acts as an intercellular signal to increase IRP1 activity in adjacent cells. As the effect was detectable within 1 h and did not require de novo protein synthesis, this result supports a direct action of NO on IRP1.

Immobility reactions under threat: A contribution to human defensive cascade and PTSD

Violence exacts a burden on public health. Gun violence is a major trigger for motor defensive reactions in humans and post-traumatic stress disorder (PTSD) is its main psychiatric sequela. However, studies of the human defensive cascade, especially the motor reactions, are at an early stage. This review focuses on studies that employ stabilometry, a methodology that assesses whole body motor reactions, to address defensive behaviors to violence-related threats. Special attention is given to three reactions: "attentive immobility", "immobility under attack" and "tonic immobility", with emphasis on the latter - a peritraumatic reaction which has been strongly associated with the severity of PTSD. These reactions are characterized by reduced body sway and bradycardia, except tonic immobility that presents robust tachycardia. The advances made by investigations into the immobility reactions of the human defensive cascade contribute to helping to bridge the gap between human and non-human species. Furthermore, progresses in basic research to objectively monitor motor defensive reactions under threat can help to develop a dimensional, trans-diagnostic approach to PTSD.

Postanal repair for fecal incontinence--is it worthwhile?

PURPOSE

Patients with idiopathic or neurogenic incontinence without an isolated sphincter defect may be suitable candidates for a postanal repair. The aim of this study was to assess the results of postanal repair in patients with idiopathic or neurogenic fecal incontinence and to evaluate the role of various parameters, including preoperative physiologic testing on outcome.

METHODS

Postanal repair was offered by a single surgeon to patients meeting the following criteria: incontinence score of at least 12 of 20, absence of an isolated anterior external anal sphincter defect, and failed conservative, medical, and biofeedback management. Physiologic investigation and clinical findings of female patients who had postanal repair for fecal incontinence between 1992 and 1998 were reviewed. Physiologic investigation included anorectal manometry, pudendal nerve terminal motor latency, concentric needle electromyography, and endoanal ultrasonography. Follow-up was obtained by telephone questionnaire; moreover, patients were asked to grade the outcome of their surgery as excellent or good (success) or as fair or poor (failure).

RESULTS

Twenty-one patients of median age 68 (range, 40-80) years had a mean duration of fecal incontinence before postanal repair of 6.8 (range, 0.5-22) years. Twenty patients (95 percent) were available for at least one year of follow-up. Seventeen patients (80.9 percent) had at least one prior vaginal delivery, and prior sphincteroplasty had been performed in 10 patients (47.6 percent). The morbidity and mortality rates were 5 and 0 percent, respectively. After a mean follow-up period of three (range, 1-7.5) years, seven patients (35 percent) considered surgery to be successful and had a statistically significant decrease in their incontinence score. Neither prolongation of pudendal nerve terminal motor latency nor external sphincter damage as noted on electromyography or any of the preoperative manometric parameters correlated with outcome. Furthermore, patients' ages at surgery did not correlate with the degree of postoperative improvement in continence scores nor did the duration of the patients' symptoms, number of vaginal deliveries, or a history of previous surgery for fecal incontinence.

CONCLUSION

None of the factors assessed was demonstrated to be predictive of outcome after postanal repair; moreover, the currently available preoperative testing has not altered the success rate, which remains low (35 percent). Despite the low success rate, the absence of any mortality and the low morbidity suggest that postanal repair may be a valid therapeutic approach. However, it should be offered only to selected patients with persistent, severe fecal incontinence despite an anatomically intact external anal sphincter who are not candidates for or refuse all other operative modalities.

Thioredoxin activation of iron regulatory proteins. Redox regulation of RNA binding after exposure to nitric oxide

Iron regulatory proteins (IRP1 and IRP2) are redox-sensitive RNA-binding proteins that modulate the expression of several genes encoding key proteins of iron metabolism. IRP1 can also exist as an aconitase containing a [4Fe-4S] cluster bound to three cysteines at the active site. We previously showed that biosynthesis of nitric oxide (NO) induces the transition of IRP1 from aconitase to apoprotein able to bind RNA. This switch is also observed when cytosolic extracts are exposed to NO donors. However, the activation of IRP1 under these conditions is far from maximal. In this study we examined the capacity of physiological reducing systems to cooperate with NO in the activation of IRP1. Cytosolic extracts from the macrophage cell line RAW 264.7 or purified IRP1 were incubated with NO donors and subsequently exposed to glutathione or to thioredoxin (Trx), a strong protein disulfide reductase. Trx was the most effective, inducing a 2-6-fold enhancement of the RNA binding activity of NO-treated IRP1. Furthermore, the effect of NO on IRP1 from cytosolic extracts was abolished in the presence of anti-Trx antibodies. We also studied the combined effect of NO and Trx on IRP2, which exhibits constitutive RNA binding activity. We observed an inhibition of IRP2 activity following exposure to NO donors which was restored by Trx. Collectively, these results point to a crucial role of Trx as a modulator of IRP activity in situations of NO production.

Heavier-than-air flying machines are impossible

Many G protein-coupled receptor (GPCR) models have been built over the years. The release of the structure of bovine rhodopsin in August 2000 enabled us to analyze models built before that period to learn more about the models we build today. We conclude that the GPCR modelling field is riddled with 'common knowledge' similar to Lord Kelvin's remark in 1895 that "heavier-than-air flying machines are impossible", and we summarize what we think are the (im)possibilities of modelling GPCRs using the coordinates of bovine rhodopsin as a template. Associated WWW pages: www.gpcr.org/articles/2003_mod

Are interpretations of video defecographies reliable and reproducible?

Video defecography is a dynamic investigation which can influence surgical decision making in constipated patients. A study was therefore undertaken to assess the inter and intraobserver variability in video defecography. Specifically, we sought to assess the interpretation of video defecographies by a group of observers with the same training, guidelines and standards. To determine interobserver variation, four independent observers, two blinded to the patient's history, reviewed 100 randomly sequenced video defecographies performed in constipated patients. The presence or absence of sigmoidocele, rectocele, intussusception or prolapse was noted. Adequate or improper function of the puborectalis, anal canal opening, anorectal angle (ARA) and grade of emptying of the rectum were also assessed. Two weeks after the initial assessment, intraobserver variation was determined by a repeat blinded review of unlabelled randomly sequenced studies. The results of interobserver accuracy for sigmoidoceles, rectoceles, intussusception, rectal prolapse, rectal emptying, opening of the anal canal, puborectalis contraction and straightening of the ARA and rectal emptying were 89.5%, 46.0%, 87.5%, 97.5%, 86.5%, 88.5%, 83.0%, and 80.0%, respectively. The intraobserver variations were 88.5%, 83.8%, 80.5%, 94.5%, 77.0%, 84.8%, 80.5% and 85.5%, respectively. Prior knowledge of the patient's history did not significantly influence the outcome. In summery, video defecography has an overall accuracy of 83.3% and as such is a valid tool in assessing constipated patients.