Microscopic examination in vivo and in vitro of natural and cross-linked polyunsaturated mclPHA

Pseudomonas aeruginosa 42A2 produces a polyunsaturated polyhydroxyalkanoates (PHA-L) when grown on linseed oil as a substrate. Its high unsaturation content (36.5%) provides highly reactive PHA-L, generating a cross-linked biopolymer after ultraviolet (UV) irradiation. Both PHAs (PHA-L and uvPHA-L) were characterized by nuclear magnetic resonance, Fourier transform infrared spectroscopy, gel permeation chromatography, gas chromatography-mass spectrometry and differential scanning calorimetry-thermogravimetric analysis. The structural analysis of the new polymer revealed a dramatic decrease in unsaturated monomer content (8.5%), due to the complete disappearance of the polyunsaturated monomers (C(12:2), C(14:2), and C(14:3)). The cross-linking reaction was also confirmed by atomic force microscopy (AFM) and transmission electron microscopy. AFM showed morphological changes in bacteria cells with and without PHA granules. The microscope techniques provided us with micrographs of the native and cross-linked polymers, showing the formation of a reticular structure as the consequence of the cross-linking reaction.

Estimation of individual evoked potential components using iterative independent component analysis

Independent component analysis (ICA) has been successfully employed in the study of single-trial evoked potentials (EPs). In this paper, we present an iterative temporal ICA methodology that processes multielectrode single-trial EPs, one channel at a time, in contrast to most existing methodologies which are spatial and analyze EPs from all recording channels simultaneously. The proposed algorithm aims at enhancing individual components in an EP waveform in each single trial, and relies on a dynamic template to guide EP estimation. To quantify the performance of this method, we carried out extensive analyses with artificial EPs, using different models for EP generation, including the phase-resetting and the classical additive-signal models, and several signal-to-noise ratios and EP component latency jitters. Furthermore, to validate the technique, we employed actual recordings of the auditory N100 component obtained from normal subjects. Our results with artificial data show that the proposed procedure can provide significantly better estimates of the embedded EP signals compared to plain averaging, while with actual EP recordings, the procedure can consistently enhance individual components in single trials, in all subjects, which in turn results in enhanced average EPs. This procedure is well suited for fast analysis of very large multielectrode recordings in parallel architectures, as individual channels can be processed simultaneously on different processors. We conclude that this method can be used to study the spatiotemporal evolution of specific EP components and may have a significant impact as a clinical tool in the analysis of single-trial EPs.

Phenobarbital: effects of long-term administration on behavior and brain of artificially reared rats

Two doses of phenobarbital were given daily for 2 weeks to infant rats fed by intragastric cannulas. The larger dose (60 milligrams per kilogram of body weight) resulted in decreased spontaneous activity and increased responses to novel stimuli. The smaller dose (15 milligrams per kilogram) resulted in increased spontaneous activity and also an increase of responses to novel stimuli. The larger dose produced a 12 percent reduction in brain growth, while the smaller dose was associated with a 3 percent reduction in brain growth.

Autochthonous transmission of Trypanosoma cruzi, Louisiana

Autochthonous transmission of the Chagas disease parasite, Trypanosoma cruzi, was detected in a patient in rural New Orleans, Louisiana. The patient had positive test results from 2 serologic tests and hemoculture. Fifty-six percent of 18 Triatoma sanguisuga collected from the house of the patient were positive for T. cruzi by PCR.

The effect of internal DC shocks on the atrial fibrillation frequency

The objective of this study, was to investigate the effect of internal DC shocks on the atrial fibrillation frequency (AFF). AFF has previously been shown to predict the success and energy requirements in patients undergoing internal cardioversion (IC) of atrial fibrillation (AF). However the possibility that unsuccessful shocks during IC may influence the AFF has not been before studied. Thirty eight patients with AF, suggested for DC cardioversion at the Royal Victoria Hospital in Belfast, were included in our study. Two catheters were positioned in the right atrial appendage (RAA) and the coronary sinus (CS), to deliver a biphasic shock waveform, synchronized with the R wave of the electrocardiogram (ECG) signal. A voltage step-up protocol (50-300 V) was used for patient cardioversion. The ECG was analyzed for a mean of 52,8+/-10.1 seconds (corresponding to segments before and after nonsuccessful shocks). Atrial fibrillatory activity was extracted by means of bandpass filtering and ventricular activity (QRST) cancellation. QRST complexes were cancelled using a recursive least squared (RLS) adaptive filter. FFT was applied to the residual atrial fibrillatory signal. AFF was estimated from the dominant frequency within the 3-12 Hz band of the power spectrum. R-R intervals during the segments were also analyzed. A total of 26 patients were successfully cardioverted, employing 167 shocks (141 nonsuccessful). AFF, computed with 10 s of signal, showed significant reduction (mean 0.3052 +/- 1.1055 Hz, P=0.028) comparing segments immediately before and after shocks, and AFF significantly increases (mean 0.2582 +/- 0.609 Hz, P=0.007) between segments immediately after shocks and those 35 s after. AFF showed distinct behavior according to the energy level of the shocks. In conclusion, intracardiac electric shocks could cause transitory changes in the AFF of patients with atrial fibrillation.

First 100 liver transplants at the medico-surgical research center (CIMEQ)

In July 1999 we began a liver transplant program that to October 2005 has included 100 liver transplants in 92 patients, eight retransplants, and two combined liver and kidney grafts. Twelve transplants were in pediatric patients, who showed a 92% survival rate in the first year. Fifty-four percent of the patients were male and 46% female. The most frequent etiologies of cirrhosis were 27% hepatitis virus C, 18% alcoholic, 13% cryptogenic, and 11% autoimmune. In 95% of the patients, we preserved the retrohepatic vena cava. The bile duct was reconstructed with a Kehr tube in 46% of patients with 31% using end-to-end suture with a tutor and 15% an end-to-end suture without a tutor. A hepaticojejunostomy was performed in 8%. The immunosuppression included cyclosporine (Neoral) or Prograf combined with mycophenolate mofetil or mycophenolate sodium and steroids. The most frequent biliary complications were local anastomosis leaks (6%) and stenosis (10%). The overall 1-year survival rate was 72%.

In vitro and in vivo biological responses to a novel radiopacifying agent for bone cement

Iodixanol (IDX) and iohexol (IHX) have been investigated as possible radiopacification agents for polymethylmethacrylate (PMMA) bone cement, to replace the currently used barium sulphate and zirconia. IDX and IHX are both water-soluble iodine-based contrast media and for the last 20 years have been used extensively in clinical diagnostic procedures such as contrast media enhanced computed tomography, angiography and urography. One of the major reasons to remove the current radiopacifying agents is their well-documented cytotoxicity and their potential to increase bone resorption. Using in vitro bone resorption assays, the effect of PMMA particles plus IDX or IHX to induce osteoclast formation and lacunar resorption on dentine slices has been investigated. These responses have been compared with the in vitro response to PMMA particles containing the conventional radiopacifying agents, that is, barium sulphate and zirconia. In parallel, the in vivo reaction, in terms of new bone formation, to particles of these materials has been tested using a bone harvest chamber in rabbit tibiae. In vitro cell culture showed that PMMA containing IHX resulted in significantly less bone resorption than PMMA containing the conventional opacifiers. In vivo testing, however, showed no significant differences between the amounts of new bone formed around cement samples containing the two iodine-based opacifying agents in particulate form, although both led to fewer inflammatory cells than particles of PMMA containing zirconia. Our results suggest that a non-ionic radiopacifier could be considered as an alternative to the conventional radiopacifying agents used in biomaterials in orthopaedic surgery.

Influence of first line treatment in the 5 (5yS) and 10-year (10yS) survival outcomes of patients with gastroenteropancreatic neuroendocrine tumors (GNETs): 2001–2005 Spanish task force GNET group

14058

Background: Data on incidence, morbidity and mortality of GNETs is limited due to the low frequency of these tumors. However this survival data is critical to design studies with new agents. Methods: Data was obtained from medical records of 262 patients with GNETs and centralized in an online registry at www.retegep.net . Among the study parameters were histology, localization, stage, diagnostic workup, 1st line and subsequent treatments, 5yS and 10yS for the whole dataset and for different stages, tumor types and 1st line systemic treatment. Results: Mean age 58, 58% male. Primary tumors: 49% Carcinoids (C), 19% non-functioning pancreatic tumors (PT), 9% insulinomas, 6% gastrinomas and 8% unknown primary. Localizations: midgut (36%), head (17%) and body of pancreas (10%). Functioning symptoms led to diagnosis in 38% of cases. 4% were associated to MEN1. Stage at diagnosis was advanced (Adv) in 46%, localised (L) in 30% and locorregional (LR) in 13% (unknown in 11%). Diagnostic workup were CT Scan (84%), Octreoscan (52%) and US (52%) and serum hormone tests (65%). Treatments for Adv disease included somatostatin analogues (SA) (47%), surgery (S) (43%), chemotherapy (CT) (35%) and interferon (IFN) (34%), embolization (7%) and radiofrequency ablation (3%). 5yS and 10yS for the whole group was 61.6% (SD: 5.2%) and 49.8% (SD: 7.7%) respectively. 5yS and 10yS for the L/LR and Adv stages were 78.1% (SD: 7.3%) and 71% (SD: 10%), and 48.9% (SD: 7.7%) and 29% (SD: 12.4%), respectively. LR PT and C had similar 5 and 10yS but Adv PT did worse than Adv C (5yS of 36.2% and 61.1%, respectively). 1st line systemic treatment for LR and Adv disease (n=90) included SA (39%), CT (34.4%), IFN (5.6%), combinations of SA+IFN (13.3%), A+CT (4.4%) and other combinations (3.3%), with a 10yS rate of 69%, 79%, 50%, 89%, 66% and 50%, respectively. Adv PT perform worse than C regardless of treatment choice. As second line systemic treatment (n=43) 30% received SA, 30% CT, 26% inmunotherapy and 14% combinations. Conclusions: An extensive use of systemic therapy and a scarce use of non-surgical LR treatments is observed in the Adv stages. Choice of 1st line systemic treatment does not seem to influence survival outcomes.

No significant financial relationships to disclose.

A novel apical midpiece defect in the spermatozoa of a bull without an apparent decrease in motility and fertility. A case study

Despite some limitations as predictors of fertility, evaluation of sperm morphology and progressive motility is the commonest method to assess viability of frozen/thawed semen. In this article we describe by light and transmission electron microscopy a novel midpiece structural defect observed in 24-36% of frozen/thawed sperm cells from a Charolais bull, used in artificial insemination programs without any apparent ill effect to the fertility. After thawing, the sperm progressive motility ranged from 65 to 80% and the pregnancy rate for all artificial inseminations performed (43%) did not differ (p>0.05) from results obtained with insemination with semen of other bulls (40%). The defect consisted in mitochondrial aplasia at the neck region, mitochondrial segmental elongation and gaps and thickening of the outer dense fibers at the apical region of the midpiece, and loss of the cementing substance and development of plasma membrane extensions in the entire midpiece. No structural abnormalities were found in the capitulum, proximal centriole, striated columns, axoneme, annulus and fibrous sheath. The thickness of the outer fibers returned to normal at the distal region of the midpiece. Based on the examination it is suggested that the alterations might be originally caused by loss of the cementing substance that links mitochondria to the plasma membrane in association with mitochondrial aplasia at the neck region of the midpiece. The abnormality appeared not related to other described sperm defect syndromes, although it shared particular characteristics with the dag defect, segmental aplasia of the mitochondrial sheath, corkscrew defect and pseudodroplet defect.

Morbidity of laparoscopic surgery for complicated appendicitis: an international study

BACKGROUND

Although laparoscopic appendectomy has some advantages over open appendectomy, some reports do show more postoperative intraabdominal abscesses.

METHODS

A retrospective review of complicated appendicitis managed surgically by eight surgical groups from six countries was undertaken. Among 3,433 patients with appendicitis, 1,017 (29.5%) had complicated appendicitis, which included perforated or gangrenous appendicitis with or without localized or disseminated peritonitis. There were 74 preoperative abscesses (7.4%) and 5 small bowel obstructions.

RESULTS

One patient died. There were 29 postoperative intraabdominal abscesses (2.8%) and 112 mostly minor complications. Conversion to laparotomy was necessary for 28 patients (2.7%). The surgical time ranged from 32 to 132 min (mean, 62 min), and the hospital stay ranged from 1 to 18 days (mean, 3.5 days).

CONCLUSIONS

The morbidity rates, particularly for intraabdominal abscesses, were less for laparoscopic appendectomy in complicated appendicitis than those reported in the literature for open appendectomy, whereas operating times and hospital stays were similar.

Negative cell cycle regulator 14-3-3sigma stabilizes p27 Kip1 by inhibiting the activity of PKB/Akt

The 14-3-3sigma (sigma) protein is a human cancer marker downregulated in various tumors, but its function has not been fully established. 14-3-3sigma is a negative regulator of cell cycle when overexpressed, but it is not clear whether 14-3-3sigma regulates cyclin-dependent kinase inhibitor p27(Kip1) to negatively affect cell cycle progression. Protein kinase B/Akt is a crucial regulator of oncogenic signal and can phosphorylate p27(Kip1) to enhance p27(Kip1)degradation, thereby promoting cell growth. Here, we show that 14-3-3sigma-mediated cell cycle arrest concurred with p27(Kip1) upregulation and Akt inactivation. We show that 14-3-3sigma blocks Akt-mediated acceleration of p27(Kip1) turnover rate. 14-3-3sigma inhibits Akt-mediated p27(Kip1) phosphorylation that targets p27(Kip1) for nuclear export and degradation. 14-3-3sigma inhibits cell survival and tumorigenicity of Akt-activating breast cancer cell. Low expression of 14-3-3sigma in human primary breast cancers correlates with cytoplasmic location of p27(Kip1). These data provide an insight into 14-3-3sigma activity and rational cancer gene therapy by identifying 14-3-3sigma as a positive regulator of p27 and as a potential anticancer agent.

The Dopamine D3 Receptor: A Therapeutic Target for the Treatment of Neuropsychiatric Disorders

The role of the D(3) receptor has remained largely elusive before the development of selective research tools, such as selective radioligands, antibodies, various highly specific pharmacological agents and knock-out mice. The data collected so far with these tools have removed some of the uncertainties regarding the functions mediated by the D(3) receptor. The D(3) receptor is an autoreceptor that controls the phasic, but not tonic activity of dopamine neurons. The D(3) receptor, via regulation of its expression by the brain-derived neurotrophic factor (BDNF), mediates sensitization to dopamine indirect agonists. This process seems responsible for side-effects of levodopa (dyskinesia) in the treatment of Parkinson's disease (PD), as well as for some aspects of conditioning to drugs of abuse. The D(3) receptor mediates behavioral abnormalities elicited by glutamate/NMDA receptor blockade, which suggests D(3) receptor-selective antagonists as novel antipsychotic drugs. These data allow us to propose novel treatment options in PD, schizophrenia and drug addiction, which are awaiting evaluation in clinical trials.

An algorithm for the treatment of type 2 diabetes in Latin America

Diabetes is a principal and growing health concern in Latin America, accounting for significant mortality and morbidities. Large, randomized, prospective trials of various interventional therapies in patients with both type 1 and type 2 diabetes have demonstrated that reductions in hyperglycaemia and management of diabetes-related risk factors can significantly reduce the micro- and macrovascular complications of diabetes. Therefore, patients with type 2 diabetes will benefit from more aggressive treatment regimens to help decrease the occurrence and rate of progression of diabetic complications. Given the many complexities of diabetes management, it is often difficult for general practice physicians to stay abreast of emerging treatment strategies and therapies. Owing to the high prevalence of type 2 diabetes in Latin America, the majority of patients with diabetes are treated by generalists rather than specialists. This article was intended to assist physicians and other healthcare professionals in developing and using effective treatment strategies to stem the growing epidemic of diabetes and its complications in Latin America.

Sustainable sludge management in developing countries

Worldwide, unsanitary conditions are responsible for more than three million deaths annually. One of the reasons is the low level of sanitation in developing countries. Particularly, sludge from these regions has a high parasite concentration and low heavy metal content even though the available information is limited. Different issues needed to achieve a sustainable sludge management in developing nations are analysed. Based on this analysis some conclusions arise: sludge management plays an important role in sanitation programs by helping reduce health problems and associated risks; investments in sanitation should consider sludge management within the overall projects; the main restriction for reusing sludge is the high microbial concentration, which requires a science-based decision on the treatment process, while heavy metals are generally low; adequate sludge management needs the commitment of those sectors involved in the development and enforcement of the regulations as well as those that are directly related to its generation, treatment, reuse or disposal; current regulations have followed different approaches, based mainly on local conditions, but they favour sludge reuse to fight problems like soil degradation, reduced crop production, and the increased use of inorganic fertilizers. This paper summarises an overview of these issues.

Dopamine and glutamate dysfunctions in schizophrenia: role of the dopamine D3 receptor

Symptoms of schizophrenia are improved by dopamine antagonists and exacerbated by dopamine-releasing agents, suggesting hyperactivity of dopamine. However, chronic blockade of glutamate neurotransmission by antagonists at the N-methyl-D-aspartate (NMDA) receptor subtype produces a pathophysiological state resembling schizophrenia. A link between cortical glutamate/NMDA deficiency and subcortical dopamine hyperactivity, particularly in the mesolimbic pathway, has been hypothesized in schizophrenia. Here we show that hyperactivity produced by NMDA receptor blockade is dependent upon stimulation of the dopamine D3 receptor subtype. Since D3 receptor antagonists and antipsychotics produced very similar effects, our results add to the growing evidence suggesting that D3 receptor blockade might produce antipsychotic effects.

Louisiana State University School of Public Health

On July 1, 2003, the Louisiana State University School of Public Health became the 6th School at LSU Health Sciences Center in New Orleans joining the Schools of Medicine, Nursing, Dentistry, Allied Health Professions, and Graduate Studies. Its primary mission will be to improve the health of the people of Louisiana and their families and communities through education, research, and community service, with special emphasis on the health and healthcare of underserved people and on the industries of importance to the state. Its programs and faculty will be developed primarily in collaboration with other components of the LSU system.

The transplantation donation process in the Centro de Investigaciones Medico Quirurgicas of Cuba: 1999-2002

OBJECTIVE

In 1998 in the Centro de Investigaciones Medico Quirurgicas the Transplant Coordination Office (TCO) was created, with the aim to organize a system to support a hepatic transplantation program. This organization, which changed the transplantation-donation process not only in our center but in the whole country, is described in this article.

METHOD

The files of donors generated in our hospital were studied together with the transplant coordination records, from 1999 till the first half of 2002.

RESULTS

In the period studied, 21 potential donors were diagnosed with brain death, yielding a donation rate of 71.4%. Brain death was most frequently caused by vascular brain disease; however, in the realized donor group, the cranioencephalic trauma predominated. The typical donor was a man of average age 39.2 years (range, 18-86 years). Among the potential donors, 24% were excluded based on medical criteria, and 5% due to family objections. Forty liver transplantation were performed in 36 patients including 1 liver-kidney simultaneous procedure. The principal etiologies for transplant included hepatitis C virus cirrhosis, 22%; alcoholic, 19%; and acute hepatic failure, 13%. Kidney transplantations were performed in 70 patients, including 41 from cadaveric donors (53.6%) and 29 from living related donors (41.4%). In 2001, a pancreas-kidney transplantation program was started.

CONCLUSION

The creation of the TCO has been of paramount importance to optimize transplantation program functions.

Anapsos (Polypodium leucotomos) modulates lymphoid cells and the expression of adhesion molecules

Anapsos is a medical prescription registered in the Health Ministry of Spain, that is obtained from the rhizomes of the fern Polypodium leucotomos. An immunomodulating effect of Anapsos on certain lymphocyte subsets and cytokines has already been described in the literature. The current study extends and supports part of the aforementioned results of the product on the immune system, showing the ability of Anapsos to stimulate proliferation and activation of T and natural killer lymphocytes, as well as an important down-regulating effect on CD11, CD18 and CD62-L adhesion molecules, both on peripheral blood mononuclear cells and on U-937 and HL-60 cell lines.

Simultaneous PAGE, immunoblotting, and immunohistochemical analysis of differentiation associated keratins in lesions of the oral mucosa

The expression of differentiation associated high PM Keratin polypeptides of the oral mucosa lesions were studied by immunohistochemical and immunoblotting techniques applied to adjacent sections of each biopsy specimen. The material studied included specimens of leukoplakia, verrucous carcinoma, squamous cell carcinoma, adenocarcinoma and keratoacanthoma. Little or no expression of 65-67 Kd keratins was evident in squamous cell carcinoma and adenocarcinoma. Hyperkeratotic (both benign and dysplastic) lesions such as verrucous carcinoma, leukoplakia, and keratoacanthoma, showed great variations in the intensity of 65-67 bands and a very irregular immunohistochemical staining pattern. Increased amounts of horny substance was usually accompanied by absence of, or decreased expression of 65-67 Kd keratins, thus indicating a change in the polypeptide composition of the horny layer in pathological conditions of the oral epithelium.

Wheat germ supplement reduces cyst and trophozoite passage in people with giardiasis

The protozoan parasite Giardia lamblia is a major cause of waterborne enteric disease worldwide. Lectins are proteins that bind to carbohydrate (sugar) moieties. Potential targets for lectins are found on the surface of most single-celled organisms. Modest concentrations of wheat germ agglutinin (WGA) have been shown to inhibit G. lamblia excystation and trophozoite growth in vitro and can reduce cyst passage in mice infected with the closely related protozoan parasite, G. muris. Commercial preparations of wheat germ (WG) contain 13-53 microg of WGA per gram. We performed a double-masked, placebo-controlled study of dietary supplementation with WG in 63 subjects with giardiasis in Montreal and Lima (25 asymptomatic patients passing cysts; 38 patients with symptoms). Asymptomatic subjects received WG (2 g, 3 times a day) or placebo (cornstarch, 2 g, 3 times a day) for 10 days, followed by metronidazole (250 mg 3 times a day) for 7 days. Symptomatic subjects received metronidazole (250 mg 3 times a day) plus either WG or placebo for 7 days. Stool specimens were collected every day (Montreal) or every other day (Lima) for 10 days and on Day 35 for microscopic examination and coproantigen determination. Subjects kept a diary of symptoms for 10 days after recruitment. In asymptomatic subjects, both cyst passage and coproantigen levels were reduced by approximately 50% in those taking WG compared with the placebo group (P < 0.01 and P = 0.06, respectively). In symptomatic subjects, cyst passage and coproantigen levels fell precipitously in response to metronidazole therapy, and there were no clinically important differences between those receiving supplemental WG or placebo. However, symptoms appear to have resolved more rapidly in the subjects taking WG in addition to metronidazole. The WG supplement was well tolerated in both symptomatic and asymptomatic subjects. These data suggest that components of WG, possibly WGA, either alone or in combination with antiprotozoal agents, can influence the course of human giardiasis.

Autologous Schwann cells drive regeneration through a 6-cm autogenous venous nerve conduit

Peripheral nerve regeneration is a complex series of events, involving bi-directional interactions between regenerating axons and Schwann cells. These authors have demonstrated in their laboratory that nerves will regenerate through a 3-cm autogenous venous nerve conduit (AVNC) in an animal model and, with Dr. David Chiu, a similar distance in the human. They have shown that the upper limit of nerve regeneration in an empty AVNC was 3 cm, with no evidence of nerve growth at the 6-cm mark (no-growth model). Most recently, they have demonstrated rapid growth at 1 month in a 3-cm AVNC filled with Schwann cells, compared to poor-to-no-regrowth at 1 month in controls. While, in theory, Schwann-cell-derived growth factor should be sufficient to supplant the requirement for Schwann cells, in practice, therapies with growth factors have failed in clinical trials, with some resulting in severe morbidity and mortality for the subjects. The present study showed excellent nerve regeneration through a 6-cm AVNC with the addition of autologous Schwann cells, breaking the barrier in the previous no-growth model. In the first stage, autologous Schwann cells were harvested from the contralateral peroneal nerve of the rabbit and expanded in culture. The Schwann cells were purified to >99 percent homogeneity using differential adhesion and antibody-compliment-mediated cytolysis. In the second stage, 6 cm of gluteal vein were harvested and used as a conduit that was filled with either Matrigel or a slurry of Matrigel and 10(6)/ml autologous Schwann cells (n=6 control and 6 experimental animals). The non-donor side peroneal was exposed and transected, leaving a gap of 6 cm. The filled gluteal vein graft (AVNC) was then anastomosed to the proximal and distal peroneal nerve stumps, and the rabbits were allowed to recover. Four months postoperatively, the animals were subjected to transcardiac perfusion with EM grade fixative. The grafts were analyzed at the light and electronmicroscopic levels, and showed excellent growth of nerve at 6 cm, the distal end of the AVNC.

Prospective comparison of admission computed tomographic scan and plain films of the upper cervical spine in trauma patients with altered mental status

OBJECTIVE

The accurate evaluation of patients with multiple injuries is logistically complex and time sensitive, and must be cost-effective. We hypothesize that computed tomographic (CT) scan of the upper cervical spine (occiput to C3 [Co-C3]) would add little to the initial evaluation of patients with multiple injuries who have altered mental status.

METHODS

The study consisted of a prospective, unblinded, consecutive series. Patients met entry criteria if they had sustained a blunt mechanism of injury and had an altered mental status requiring CT scan of two or more body systems. All patients received CT scan of Co-C3 with 2-mm cuts and subsequent reconstructions as well as five-view cervical spine plain films. Cervical spine injury was defined as any radiographically identified fracture or subluxation that required treatment. Patients were excluded if they died or were cleared clinically before plain film series were obtained. CT scan of Co-C3 and cervical spine films were reviewed by two different attending radiologists.

RESULTS

Of the 2,690 consecutive admissions between December 1998 and November 1999, 1,356 patients met entry criteria. Seventy patients (5.2%) had a total of 95 injuries to the upper cervical spine. CT scan of Co-C3 identified 67 of 70 patients and plain films identified 38 of 70 patients with injuries to the upper cervical spine. Twelve patients (17%) had neurologic deficits attributable to Co-C3 injuries. Three patients had false-negative CT scans of Co-C3, and one patient was quadriplegic. There were 32 patients with false-negative plain films, including four patients with motor deficits (one with quadriplegia). Use of the guidelines developed by the Eastern Association for the Surgery of Trauma identified all patients with upper cervical spine injuries; to date, no patient in the study group was readmitted or has initiated a lawsuit for missed injury of the upper cervical spine.

CONCLUSION

CT scan of Co-C3 was superior to plain films in the early identification of upper cervical spine injury. Plain films failed to identify 45% of upper cervical spine injuries; four of these missed injuries resulted in motor deficits. Our study supports the practice guidelines developed by the Eastern Association for the Surgery of Trauma for clearance of the upper cervical spine in patients with altered mental status, as all patients with injuries were identified using these guidelines.

Coincident linkage of fasting plasma insulin and blood pressure to chromosome 7q in hypertensive hispanic families

BACKGROUND

Insulin resistance (IR) and hyperinsulinemia are phenotypically associated with hypertension. We have previously provided evidence that blood pressure (BP) and IR cosegregate in Hispanic families, suggesting that this association has a genetic component. In the present study, we provide further support for the hypothesis of a genetic basis for the BP-IR relationship from a genetic linkage study.

METHODS AND RESULTS

A 10-cM genome scan was conducted in 390 Hispanic family members of 77 hypertensive probands. Detailed measurements of BP, glucose, insulin levels, and insulin sensitivity (euglycemic clamp) were performed in adult offspring of probands. Multipoint variance component linkage analysis was used. A region on chromosome 7q seemed to influence both IR and BP. The greatest evidence for linkage was found for fasting insulin (lod score=3.36 at 128 cM), followed by systolic BP (lod score=2.06 at 120 cM). Fine mapping with greater marker density in this region increased the maximum lod score for fasting insulin to 3.94 at 125 cM (P=0.00002); lod score for systolic BP was 2.51 at 112 cM. Coincident mapping at this locus also included insulin sensitivity measured by the homeostasis assessment model (HOMA) and serum leptin concentrations. Insulin sensitivity by euglycemic clamp did not map to the same locus.

CONCLUSIONS

Our results demonstrate that a major gene determining fasting insulin is located on chromosome 7q. Linkage of BP, HOMA, and leptin levels to the same region suggests this locus may broadly influence traits associated with IR and supports a genetic basis for phenotypic associations in IR syndrome.

The Fanconi anemia complementation group C gene product: structural evidence of multifunctionality

The Fanconi anemia (FA) group C gene product (FANCC) functions to protect cells from cytotoxic and genotoxic effects of cross-linking agents. FANCC is also required for optimal activation of STAT1 in response to cytokine and growth factors and for suppressing cytokine-induced apoptosis by modulating the activity of double-stranded RNA-dependent protein kinase. Because not all FANCC mutations affect STAT1 activation, the hypothesis was considered that cross-linker resistance function of FANCC depends on structural elements that differ from those required for the cytokine signaling functions of FANCC. Structure-function studies were designed to test this notion. Six separate alanine-substituted mutations were generated in 3 highly conserved motifs of FANCC. All mutants complemented mitomycin C (MMC) hypersensitive phenotype of FA-C cells and corrected aberrant posttranslational activation of FANCD2 in FA-C mutant cells. However, 2 of the mutants, S249A and E251A, failed to correct defective STAT1 activation. FA-C lymphoblasts carrying these 2 mutants demonstrated a defect in recruitment of STAT1 to the interferon gamma (IFN-gamma) receptor and GST-fusion proteins bearing S249A and E251A mutations were less efficient binding partners for STAT1 in stimulated lymphoblasts. These same mutations failed to complement the characteristic hypersensitive apoptotic responses of FA-C cells to tumor necrosis factor-alpha (TNF-alpha) and IFN-gamma. Cells bearing a naturally occurring FANCC mutation (322delG) that preserves this conserved region showed normal STAT1 activation but remained hypersensitive to MMC. The conclusion is that a central highly conserved domain of FANCC is required for functional interaction with STAT1 and that structural elements required for STAT1-related functions differ from those required for genotoxic responses to cross-linking agents. Preservation of signaling capacity of cells bearing the del322G mutation may account for the reduced severity and later onset of bone marrow failure associated with this mutation.

Localized amyloid deposition in trigger finger

Trigger finger is due to degeneration and thickening of the proximal portion (A1 pulley) of the flexor tendon sheath, which causes constriction of the flexor tendon. This study reports the presence of localized amyloid deposition in the tendon sheath of 11 of 47 cases (23%) of idiopathic primary trigger finger. Amyloid deposits were only found in patients aged over 46 years old and were present around cells and at sites of mucinous and fibrinoid degeneration which contained highly sulphated glycosaminoglycans. The pathogenic significance of these deposits is uncertain but their small size and presence only in middle-aged and elderly adults suggests that they represent a form of age-associated amyloid deposition.

Functional correction of FA-C cells with FANCC suppresses the expression of interferon gamma-inducible genes

Because hematopoietic cells derived from Fanconi anemia (FA) patients of the C-complementation group (FA-C) are hypersensitive to the inhibitory effects of interferon gamma (IFNgamma), the products of certain IFNgamma-inducible genes known to influence hematopoietic cell survival were quantified. High constitutive expression of the IFNgamma-inducible genes, IFN-stimulated gene factor 3 gamma subunit (ISGF3gamma), IFN regulatory factor-1 (IRF-1), and the cyclin-dependent kinase inhibitor p21(WAF1) was found in FANCC mutant B lymphoblasts, low-density bone marrow cells, and murine embryonic fibroblasts. Paradoxically, these cells do not activate signal transducer and activator of transcription (STAT) 1 properly. In an attempt to clarify mechanisms by which FA-C cells overexpress IFNgamma-inducible genes in the face of defective STAT1 phosphorylation, it was reasoned that decreased levels of activated STAT1 might result in reduced expression of a hematopoietic IFNgamma-responsive protein that normally modulates expression of other IFNgamma-responsive genes. Levels of the IFNgamma-inducible factor IFN consensus sequence binding protein (ICSBP), a negative trans-acting regulator of some IFNgamma-inducible genes, were quantified. ICSBP levels were reduced in FA-C B lymphoblasts and MEFs. However, enforced expression of ICSBP failed to down-regulate IRF-1, ISGF3gamma, and p21(WAF1). Thus, the FANCC protein functions to modulate expression of a family of genes that in normal cells are inducible only by specific environmental cues for apoptosis or mitogenic inhibition, but it does so independently of the classic IFN-STAT1 pathway and is not the direct result of reduced ICSBP expression.

BDNF controls dopamine D3 receptor expression and triggers behavioural sensitization

Brain-derived neurotrophic factor (BDNF), like other neurotrophins, is a polypeptidic factor initially regarded to be responsible for neuron proliferation, differentiation and survival, through its uptake at nerve terminals and retrograde transport to the cell body. A more diverse role for BDNF has emerged progressively from observations showing that it is also transported anterogradely, is released on neuron depolarization, and triggers rapid intracellular signals and action potentials in central neurons. Here we report that BDNF elicits long-term neuronal adaptations by controlling the responsiveness of its target neurons to the important neurotransmitter, dopamine. Using lesions and gene-targeted mice lacking BDNF, we show that BDNF from dopamine neurons is responsible for inducing normal expression of the dopamine D3 receptor in nucleus accumbens both during development and in adulthood. BDNF from corticostriatal neurons also induces behavioural sensitization, by triggering overexpression of the D3 receptor in striatum of hemiparkinsonian rats. Our results suggest that BDNF may be an important determinant of pathophysiological conditions such as drug addiction, schizophrenia or Parkinson's disease, in which D3 receptor expression is abnormal.

Late-onset mitochondrial DNA depletion: DNA copy number, multiple deletions, and compensation

Through a report of 4 late-onset cases with mitochondrial DNA (mtDNA) depletion, we address the specificity of the clinical entities associated with a very low residual amount of mtDNA. Three of the patients met the diagnostic criteria of Kearns Sayre syndrome, which has never been associated with mtDNA depletion. The fourth patient had an isolated skeletal myopathy. Deleted mtDNA molecules were found by long-range polymerase chain reaction (PCR) only in the Kearns Sayre syndromes, which strengthens the clinical differences between the two types of patients. All patients had extremely low residual amounts of mtDNA as shown by Southern blot analysis. Using an original method based on competitive PCR, we were able to measure the number of mtDNA copies per diploid genome. These results demonstrated the severity of the depletion in the patients by comparison not only to normal controls but also to patients with mtDNA disorders. Despite the severity of the depletion, in situ hybridization using two mtDNA transcripts revealed a normal steady-state level of transcription. Such compensation provides clues to the striking contrast between the severity of mtDNA depletion and the late onset and slowly progressive disease.

Assessing the acceptability, service delivery requirements, and use-effectiveness of the diaphragm in Colombia, Philippines, and Turkey

The diaphragm is not available in many countries, despite the recommendations of numerous authors that it has important advantages as a woman-controlled method that offers some protection against sexually transmitted diseases, and one that is safe and free of side effects. An interagency team collaborated to introduce the diaphragm in Colombia, the Philippines, and Turkey, using the same protocol to assess the acceptability, service delivery requirements and use-effectiveness of the method. Eighteen public and private sector service delivery sites were involved and a total of 550 women were enrolled in the study. Provider training aimed to improve the quality of care with which all methods were delivered and included counseling about sexuality and reproductive health risks. The cumulative 12-month pregnancy rate of 10.1 (SE 1.7) per 100 woman-years is on the low end of previous studies of the diaphragm, and the 12-month continuation rate (57.2 [SE 2.4] per 100) compares favorably with that for oral contraceptives and the intrauterine device. Focus group discussions conducted with clients and providers indicated that the method was an important alternative for some women, particularly those who had experienced health problems with other methods or were unable to negotiate condom use with their partners. Provider biases diminished as they observed the strategic niche that the diaphragm filled for their clients. While providing the diaphragm requires training and good client-provider interaction, the requirements are consistent with those called for in the Programme of Action of the International Conference on Population and Development (ICPD, 1994). With proper attention to quality of care, the diaphragm can be successfully offered in resource-poor settings.

Role of double-stranded RNA-dependent protein kinase in mediating hypersensitivity of Fanconi anemia complementation group C cells to interferon gamma, tumor necrosis factor-alpha, and double-stranded RNA

Hematopoietic cells bearing inactivating mutations of Fanconi anemia group C (FANCC) are excessively apoptotic and demonstrate hypersensitivity not only to cross-linking agents but also to interferon gamma (IFN-gamma) and tumor necrosis factor-alpha. Seeking essential signaling pathways for this phenotype, this study quantified constitutive and induced RNA-dependent protein kinase (PKR) activation in Fanconi anemia cells of the C complementation group (FA-C). PKR was constitutively phosphorylated and exhibited an increased binding affinity for double-stranded RNA (dsRNA) in FANCC(-/-) cells. FANCC(-/-) cells were hypersensitive to both dsRNA and the combination of dsRNA and IFN-gamma in that these agents induced a higher fraction of apoptosis in FANCC(-/-) cells than in normal cells. Overexpression of wild-type PKR-sensitized FANCC(-/-) cells to apoptosis induced by IFN-gamma and dsRNA. Conversely, inhibition of PKR function by enforced expression of a dominant-negative inhibitory mutant of PKR (PKRDelta6) substantially reduced the IFN and dsRNA hypersensitivity of FANCC(-/-) cells. Two PKR target molecules, IkappaB-alpha and IRF-1, were not differentially activated in FANCC(-/-) cells, but enforced expression of a nonphosphorylatable form of eukaryotic translation initiation factor-2alpha reversed the PKR-mediated block of messenger RNA translation and partially abrogated the PKR-mediated apoptosis in FANCC(-/-) cells. Because no evidence was found of a PKR/FANCC complex in normal cells, it was concluded that an essential function of FANCC is to suppress, indirectly, the activity of PKR and that FANCC inactivation results in IFN hypersensitivity, at least in part, because this function of FANCC is abrogated.

The effect of chronic cocaine administration on hemodynamic stability and neurohumoral mediators during isoflurane anesthesia and shock in rats

BACKGROUND

The aim of this investigation was to determine whether chronic cocaine administration altered endogenous vasoconstrictor secretion in response to hypotension from isoflurane anesthesia and blood loss in rats.

METHODS

Rats received continuous intravenous infusions of saline (n=11), or cocaine 6 mg kg(-1) d(-1) (n=13) or 18 mg kg(-1) d(-1) (n=12) for 13 days. On day 14, rats were anesthetized with intraperitoneal ketamine and xylazine and a femoral artery catheter and a tracheotomy performed to allow lung ventilation (PaCO2, 30-40 mmHg). After baseline parameters were noted, isoflurane was introduced to end-tidal concentrations of 0.7% for 10 min (1/2 MAC), 1.4% for 10 min (MAC) and again 0.7% for 10 min (1/2 MAC-2) when 5 ml of blood was withdrawn (SHOCK). Blood samples were drawn to assess arterial blood gas indices at various time points as well as plasma epinephrine, angiotensin II and vasopressin at MAC, 1/2 MAC-2 and SHOCK.

RESULTS

Rats administered cocaine had higher oxygen extraction, required higher minute ventilation and had lower PaO2 values than rats administered saline despite similar body temperatures and hematocrits. Isoflurane administration resulted in significant dose dependent but similar blood pressure decreases in all study groups. Plasma epinephrine, angiotensin II and vasopressin concentrations were not different in saline or cocaine treated animals at any time point.

CONCLUSION

These data suggest that chronic cocaine treatment in rats does not impair endogenous vasoconstrictor secretion nor alter the heart rate and blood pressure response to isoflurane and blood loss.

Evidence for joint genetic control of insulin sensitivity and systolic blood pressure in hispanic families with a hypertensive proband

BACKGROUND

The clustering of hypertension, insulin resistance, and obesity remains unexplained. We tested for genetic and nongenetic influences on the association among these traits in Hispanic families with hypertension.

METHODS AND RESULTS

Blood pressure and body mass index (BMI) were measured in 331 members of 73 Hispanic families in which an index case (proband) had hypertension. Insulin sensitivity (S(I)) was measured by euglycemic clamp in 287 probands and their spouses (parents' generation) or their adult offspring. Correlation analysis examined relationships among traits within and between generations. Path analysis estimated genetic and nongenetic contributions to variability in systolic blood pressure (SBP), S(I), and the correlation between them. In the offspring, there was a significant correlation between individuals for each trait, as well as significant correlations within and between individuals for all possible pairs of traits. Between generations, SBP, S(I), and BMI in parents correlated with the same traits in their offspring; BMI in parents correlated with S(I) and SBP in offspring; and S(I) in parents correlated with SBP in offspring. Path analysis estimated that among offspring, genetic effects unrelated to BMI accounted for 60.8% of the variation in SBP, 36.8% of the variation in S(I), and 31.5% of the correlation between SBP and S(I) after adjustment for age and sex. Heritable effects related to BMI accounted for an additional 14.0% of variation in SBP, 26.8% of variation in S(I), and 56.3% of variation in their correlation.

CONCLUSIONS

Clustering of hypertension and insulin resistance in Hispanic Americans is accounted for in part by heritable factors both associated with and independent of BMI.

Dopamine D3 receptors expressed by all mesencephalic dopamine neurons

A polyclonal antibody was generated using synthetic peptides designed in a specific sequence of the rat D(3) receptor (D(3)R). Using transfected cells expressing recombinant D(3)R, but not D(2) receptor, this antibody labeled 45-80 kDa species in Western blot analysis, immunoprecipitated a soluble fraction of [(125)I]iodosulpride binding, and generated immunofluorescence, mainly in the cytoplasmic perinuclear region of the cells. In rat brain, the distribution of immunoreactivity matched that of D(3)R binding, revealed using [(125)I]R(+)trans-7-hydroxy-2-[N-propyl-N-(3'-iodo-2'-propenyl)amino] tetralin ([(125)I]7-trans-OH-PIPAT), with dense signals in the islands of Calleja and mammillary bodies, and moderate to low signals in the shell of nucleus accumbens (AccSh), frontoparietal cortex, substantia nigra (SN), ventral tegmental area (VTA) and lobules 9 and 10 of the cerebellum. Very low or no signals could be detected in other rat brain regions, including dorsal striatum, or in D(3)R-deficient mouse brain. Labeling of perikarya of AccSh and SN/VTA appeared with a characteristic punctuate distribution, mostly at the plasma membrane where it was not associated with synaptic boutons, as revealed by synaptophysin immunoreactivity. In SN/VTA, D(3)R immunoreactivity was found on afferent terminals, arising from AccSh, in which destruction of intrinsic neurons by kainate infusions produced a loss of D(3)R binding in both AccSh and SN/VTA. D(3)R-immunoreactivity was also found in all tyrosine hydroxylase (TH)-positive neurons observed in SN, VTA and A8 retrorubral fields, where it could represent D(3) autoreceptors controlling dopamine neuron activities, in agreement with the elevated dopamine extracellular levels in projection areas of these neurons found in D(3)R-deficient mice.