Effects of fluid restriction on measures of circulatory efficacy in adults with septic shock.

BACKGROUND: The haemodynamic consequences of fluid resuscitation in septic shock have not been fully elucidated. Therefore, we assessed circulatory effects in the first 24 h of restriction of resuscitation fluid as compared to standard care in intensive care unit (ICU) patients with septic shock. METHODS: This was a post-hoc analysis of the multicentre CLASSIC randomised trial in which patients with septic shock, who had received the initial fluid resuscitation, were randomised to a protocol restricting resuscitation fluid or a standard care protocol in nine ICUs. The highest plasma lactate, highest dose of noradrenaline, and the urinary output were recorded in five time frames in the first 24 h after randomisation. We used multiple linear mixed effects models to compare the two groups. RESULTS: We included all 151 randomised patients; the cumulated fluid resuscitation volume in the first 24 h after randomisation was median 500 ml (Interquartile range (IQR) 0-1500) and 1250 ml (500-2500) in the fluid restriction group and standard care group, respectively. The estimated differences in the fluid restriction group vs. the standard care group were 0.1 mM (95% confidence interval -0.7 to 0.9; P = 0.86) for lactate, 0.01 µg/kg/min (-0.02 to 0.05; P = 0.48) for dose of noradrenaline, and -0.1 ml/kg/h (-0.3 to 0.2; P = 0.70) for urinary output during the first 24 h after randomisation. CONCLUSIONS: We observed no indications of worsening of measures of circulatory efficacy in the first 24 h of restriction of resuscitation fluid as compared with standard care in adults with septic shock who had received initial resuscitation.

Typical patterns of expiratory flow and carbon dioxide in mechanically ventilated patients with spontaneous breathing.

Incomplete expiration of tidal volume can lead to dynamic hyperinflation and auto-PEEP. Methods are available for assessing these, but are not appropriate for patients with respiratory muscle activity, as occurs in pressure support. Information may exist in expiratory flow and carbon dioxide measurements, which, when taken together, may help characterize dynamic hyperinflation. This paper postulates such patterns and investigates whether these can be seen systematically in data. Two variables are proposed summarizing the number of incomplete expirations quantified as a lack of return to zero flow in expiration (IncExp), and the end tidal CO2 variability (varETCO2), over 20 breaths. Using these variables, three patterns of ventilation are postulated: (a) few incomplete expirations (IncExp < 2) and small varETCO2; (b) a variable number of incomplete expirations (2 ≤ IncExp ≤ 18) and large varETCO2; and (c) a large number of incomplete expirations (IncExp > 18) and small varETCO2. IncExp and varETCO2 were calculated from data describing respiratory flow and CO2 signals in 11 patients mechanically ventilated at 5 levels of pressure support. Data analysis showed that the three patterns presented systematically in the data, with periods of IncExp < 2 or IncExp > 18 having significantly lower variability in end-tidal CO2 than periods with 2 ≤ IncExp ≤ 18 (p < 0.05). It was also shown that sudden change in IncExp from either IncExp < 2 or IncExp > 18 to 2 ≤ IncExp ≤ 18 results in significant, rapid, change in the variability of end-tidal CO2 p < 0.05. This study illustrates that systematic patterns of expiratory flow and end-tidal CO2 are present in patients in supported mechanical ventilation, and that changes between these patterns can be identified. Further studies are required to see if these patterns characterize dynamic hyperinflation. If so, then their combination may provide a useful addition to understanding the patient at the bedside.

Clinical significance of aberrant vimentin expression in oral premalignant lesions and carcinomas.

OBJECTIVE: To investigate the clinical significance of vimentin expression at early and late events of tobacco/areca nut-associated oral tumorigenesis. MATERIALS AND METHODS: Immunohistochemistry (IHC) was carried out on paraffin-embedded tissues of oral mucosa normal (n = 10), inflammatory lesions (n = 19), leukoplakia (n = 52), submucous fibrosis (n = 71) and tumours/cut margins (n = 227 each), using anti-vimentin antibody, and the expression profile was correlated with patients' clinical parameters. Immunofluorescence, Western blot and RT-PCR analysis were also carried out wherever adequate and fresh tissues were available. RESULTS: Aberrant vimentin expression was seen in hyperplastic, dysplastic and fibrotic tissues, which showed statistically significant correlation with the histopathological grade of dysplasia (P = 0.001) and fibrosis (P = 0.009). Vimentin expression also showed statistically significant correlation with tumour size (P = 0.048), clinical stage (P = 0.013), regional lymph node metastases (P = 0.001), local recurrence (P = 0.001) and survival (P = 0.021) of patients with oral squamous cell carcinoma (OSCC). Its expression in invasive fronts statistically correlated with development of nodal metastasis and local recurrence. CONCLUSIONS: Our results suggest possible role of vimentin in early events of tobacco/areca nut-associated oral tumorigenesis, which may prove useful to predict the malignant potential of high-risk oral lesions. Further, association between vimentin expression in invasive fronts and aggressive phenotype of tumours may help clinicians to choose the appropriate treatment modality for OSCC management.

Exploring distribution and genomic diversity of begomoviruses associated with yellow mosaic disease of legume crops from India, highlighting the dominance of mungbean yellow mosaic India virus.

Yellow mosaic disease (YMD) caused by several begomoviruses is one of the major constraints of over a dozen leguminous crops worldwide, particularly in Asian and Southeast Asian countries. The present study aimed to investigate the distribution, diversity and prevalence of begomoviruses associated with YMD in leguminous hosts in five agro-climatic zones of India, to assess the extent of their geographical presence and develop location and crop-specific distribution maps. One hundred and seventy-four leguminous plant samples were tested from 32 locations in India to detect YMD-causing viruses. Additionally, publicly available data were incorporated into this study to provide a comprehensive overview of their distribution in India. This resulted in 581 reports on the DNA-A component representing 119 locations, which were also utilized to depict the distribution of YMD-causing viruses on a map of India. In this study, 117 full-length DNA-A and 103 DNA-B components were successfully characterized, representing the detected mungbean yellow mosaic India virus (MYMIV), mungbean yellow mosaic virus (MYMV), and horsegram yellow mosaic virus in the collected samples. Phylogenetic analysis of isolates of these species showed no differentiation based on location in India. Diversity indices revealed the abundance (55.9%) and dominance (0.56) of MYMIV across 119 locations. These findings hold significant implications for legume researchers, offering insights into disease prevalence and geographic distribution. Furthermore, the distribution of YMD-causing viruses in different agro-climatic zones will help researchers in developing zone-specific YMD-resistant cultivars of the legume crops and would facilitate effective disease management options.

Endovascular Aneurysm Repair for Infrarenal Abdominal Aortic Aneurysm: New Horizon in Endovascular Surgery in Bangladesh.

Abdominal aortic aneurysm remains mostly asymptomatic. It is usually detected incidentally with imaging studies. Here we present a 55 years old hypertensive, non smoker, non diabetic, male patient who was diagnosed as a case of infrarenal abdominal aortic aneurysm. He was treated by endovascular means using endograft without laparatomy. Endografts were deployed through bilateral femoral artery cut down technique under general anesthesia. Completion angiogram following this endovascular aneurysm repair (EVAR) technique revealed good technical success with no endoleak. This hybrid procedure was performed in a cathlab having surgical instruments in hand. Three years after the procedure, patient is doing well.

Antioxidative responses of Salvinia (Salvinia natans Linn.) to aluminium stress and it's modulation by polyamine.

Antioxidative stress response of free-floating aquatic fern (Salvinia natans Linn.) was studied under increasing toxic amount of aluminium (Al) and its modulation by exogenous application of polymaine. Increased levels of superoxide (O2 (-)) and hydrogen peroxide (H2O2) species from affected tissues suggested that plants were undergoing oxidative stress and it was concominant with increased accumulation of Al in a dose dependent manner. Application of polyamine like putrescine (Put) led to a decrease in oxidative stress as revealed by reduced level of O2 (-) and H2O2. Al toxicity resulted into decreased biomass that was ameliorated by the application of Put. The changes observed in lipid peroxidation (MDA) and protein oxidation also indicated that plats are undergoing Al induced oxidative stress. In order to circumvent the oxidative stress resulting from Al toxicity, plants enzymatic and nonenzymatic antioxidant pathways were active. The ratio of both oxidized and reduced cellular glutathione exhibited significant variation in response to Al stress and was improved upon Put treatment. Peroxidase and glutathione were upregulated whereas catalse was downregulated under varying doses of Al. Isozyme profile of above enzymes also showed a trend with increasing amount of Al. The nuclear disintegration study using comet assay was indicative of Al induced oxidative stress. In the present study, we have explored the antioxidative response of aquatic fern Salvinia natans Linn in response to Al toxicity. The application of polyamine Put improved the overall antioxidative response and thus would make it a better candidate to be used as hyper accumulator of Al and other toxic metals.

Role of Intra-arterial Nitroglycerin (Post Procedural, Prehemostasis) to Reduce Radial Artery Occlusion after Transradial Catheterisation: A Doppler-guided Study.

The study was intended to evaluate efficacy of Intra-arterial nitroglycerin through the sheath at the end of a transradial procedure to preserve the patency of the radial artery. This prospective observational study was done in the Department of Cardiology, National Institute of Cardiovascular Diseases (NICVD), Dhaka, Bangladesh from May 2017 to April 2018, by including a total 200 patients undergoing coronary procedures (CAG and / or PCI) through TRA. RAO was defined as an absence of antegrade flow or monophasic flow or invert flow on Doppler study. In this study 102 patients (Group I) received 200 mcg intra-arterial nitroglycerine, prior to trans-radial sheath removal. Another 98 patients (Group II) did not receive intra-arterial nitroglycerine prior to trans-radial sheath removal. Conventional haemostatic compression methods were applied (average 2 hours) in both groups of patients. Evaluation of radial arterial arterial blood flow by colour Doppler study was done on next day after the procedure in both groups. Results of this study in which RAO was determined by vascular doppler study showed that frequency of radial artery occlusion were 13.5% one day after transradial coronary procedures. We found the incidence was 8.8% vs. 18.4%, (p=0.04) in Group I and Group II respectively. The incidence of RAO was significantly lower in post procedural nitroglycerine group. From multivariate logistic regression analysis diabetes mellitus (p = 0.02), hemostatic compression time for more than 02 hours after sheath removal (p = <0.001) and procedure time (p = 0.02) was predictors of RAO. So, the administration of nitroglycerin at the end of a transradial catheterization reduced the incidence of RAO, as shown by 1 day after the radial procedure by doppler ultrasound.

Variations of antioxidative responses in two rice cultivars with polyamine treatment under salinity stress.

The rice varieties viz. Nonabokra and Swarna were evaluated on the basis of their responses for oxidative stress induced by sodium chloride (NaCl) and the effects of exogenously applied polyamine thereon. Rice seedlings were treated with 200 mM of NaCl supplemented with two dosages: 1 mM and 2 mM putrescine. Following treatments, plants were evaluated for accumulation of reactive oxygen species (ROS) like O2 (-), H2O2 etc. in tissues, lipid peroxidation, protein carbonylation, accumulation of flavonoids and anthocyanin, activities of different oxidative enzymes like guaiacol peroxidase (GPX), catalase (CAT) and glutathione reductase (GR). Preliminary, oxidative stress out of salinity was ensured by plants from significantly higher accumulation of O2 (-) and H2O2 in the tissues of the NaCl treated varieties. Irrespective of varieties, there recorded a significant variation of the endogenous polyamine profiles under NaCl stress. Interestingly, exogenous application of putrescine had a close relationship on O2 (-) and H2O2 content for both the varieties. However, Nonabokra was evident as more respondent than Swarna to applied putrescine. The other effects of oxidative stress was impacted on plants as higher values of MDA content, enhanced rate of protein oxidation and putrescine recorded as an alleviating agent regardless of varieties with dose dependant manner. The generation of ROS and cellular disintegration was accompanied by up regulation of non-enzymatic and enzymatic antioxidation pathways with exogenous application of putrescine. For non-enzymatic antioxidant, it revealed that putrescine was highly effective for sustaining the anthocyanin and flavonoid content in both the varieties under salinity. Whereas, antioxidative enzyme, CAT showed its diminished activity; but activity of GPX and GR were significantly induced under salinity and it was according to the concentration of applied putrescine.

Melanocyte-Keratinocyte Transplantation in Post-Burn Leukoderma Scars: Preliminary Experience Using a Modified Technique.

Post-burn leukoderma, commonly affecting the African and Asian communities, results from deep dermal burns. The associated stigma exacerbates the condition and significantly affects the rehabilitation and reintegration of post-burn survivors into society. Melanocyte-keratinocyte transplantation (MKTP) is a promising single-stage treatment for repigmentation in vitiligo. However, its use in post-burn leukoderma is undetermined. This study aims to evaluate the MKTP treatment in post-burn leukoderma patches. Six patients (five males and one female, mean age = 29±5.51 years) with ten patches of post-burn leukoderma underwent single-stage MKTP without adjuvant pigmentation therapy. The postoperative follow-up period ranged from twelve to twenty-four months for all the patients. The average size of leukoderma treated was 16.25±9 cm2. Repigmentation was observed in 92.16±11.05% of the total treated area by the end of one year after MKTP application. All six patients were satisfied with the treatment outcome. MKTP without adjuvant therapy is an effective surgical treatment to treat post-burn leukoderma patches. Future studies should cover a larger sample over a longer follow-up period.

Le vitiligo cicatriciel après brûlure est fréquent dans les populations africaines et asiatiques, affectant significativement la réintégration sociale des patients. La TMK est une technique en 1 temps de repigmentation du vitiligo, prometteuse, qui n'a pas été évaluée dans ce contexte. Nous l'avons utilisée, sans traitement adjuvant, chez 6 patients (5 hommes et 1 femme de 29 +/- 5,51 ans) sur 10 zones dépigmentées (surface de 16,25 +/- 9 cm2), avec un recul de 12 à 32 mois. À un an, une repigmentation a été observée sur 92,16 +/- 11,05% de la surface traitée et tous les patients étaient satisfaits du résultat. La TMK isolée semble donc être efficace pour traiter le vitiligo cicatriciel après brûlures, des études sur des zones plus étendues et avec un suivi à plus long terme restant nécessaires.

Conservative Management Of Partial-Thickness Scald Burns In Children Using Cultured Allogenic Keratinocyte Spray: Initial Experience Of 18 Patients Treated In An Outpatient Setting.

The objective of this study was to describe our clinical experience with the use of cultured allogeneic keratinocyte (CAK) using a simplified cell delivery method in the treatment of pediatric partial-thickness scald burns treated as outpatients in a Burn Unit. An actuator fitted onto a 3ml syringe was used for cell spray. Eighteen patients having active mixed partial-thickness burn wound areas of <10% total body surface area (TBSA), treated between 2017 and 2019, were included in the study. The wounds were managed conservatively with a combination of burn dressings using hydrogels and CAK application. The timing of the CAK application was decided by the treating plastic surgeon based on his clinical judgment and the clinical status of the wound. The primary study endpoints were the number of days and dressing changes required for complete wound reepithelialization. All of the eighteen patients' wounds reepithelialized completely with CAK application, with a mean reepithelialization time of 10.33 (±4.95) days after the application of CAK. The median value for the number of CAK applications and total dressing sessions required to achieve complete healing were 3 and 4 times, respectively. Wounds treated with CAK application between 8-21 days after burn injury required fewer cell application sessions and fewer dressing changes than wounds treated within seven days and after 21 days from the burn injury. None of the patients reported any adverse reaction related to CAK use. The present study suggests that non-extensive mixed partial-thickness scald burn in children can be successfully treated conservatively using CAK as an adjunct in addition to standard dressing in the outpatient setting.

Le but de cette étude est de décrire notre expérience clinique avec l'utilisation de kératinocytes allogéniques de culture (KAC), en utilisant une méthode simplifiée d'application cellulaire pour le traitement des brûlures intermédiaires de l'enfant par eau chaude, traitées en ambulatoire dans notre unité de brûlés. Un embout, fixé à une seringue de 3 ml, a été utilisé pour la vaporisation cellulaire. 18 patients présentant des brûlures de profondeur intermédiaire au stade aigu, de surface <10% de la surface corporelle totale (SCT) et pris en charge entre 2017 et 2019, ont été inclus dans cette étude. Les plaies ont reçu un traitement conservateur combinant des pansements à base d'hydrogel et l'application de KAC. Le moment pour appliquer les KAC a été choisi par le chirurgien plasticien référent en fonction de son appréciation clinique et du stade de la plaie. Les critères principaux d'évaluation de l'étude ont été le nombre de jours et le nombre de réfections de pansements nécessaires à une réépithélialisation complète. Les plaies des 18 patients ont été totalement réépithélialisées par l'application de KAC, avec un délai moyen de 10,33 (+/-4,95) jours après la vaporisation cellulaire. La valeur médiane du nombre d'applications de KAC d'une part et de réfections de pansements d'autre part, nécessaires pour obtenir une cicatrisation complète a été respectivement de trois applications de KAC et de quatre pansements. Les plaies traitées par l'application de KAC dans un délai de 8 à 21 jours après la brûlure ont nécessité moins de séances d'application cellulaire et de pansements que les plaies traitées dans les sept premiers jours ou au-delà du 21e jour après la brûlure. Aucun des patients n'a présenté d'effets secondaires rapportés à l'utilisation de KAC. Cette étude suggère que les brûlures peu étendues intermédiaires par ébouillantement chez l'enfant peuvent être menées à cicatrisation par un traitement conservateur utilisant la vaporisation de KAC en complément de pansements standards en traitement ambulatoire.

A Pilot Study To Compare Nutrition Screening Tools: Customized Nutrition Screening Tool for Burn Patients (Nstb) and Malnutrition Universal Screening Tool (Must).

Nutrition screening is an initial procedure in which the risk of malnutrition is identified. It plays a role in and can incur costs to health systems and patients. A customized nutrition screening tool for burn patients (NSTB) was formulated and the nutritional risk score of 22 patients from a burn unit in Bahrain using NSTB and MUST was compared. The samples selected were adult patients aged 18 years or over; pregnant and mentally retarded patients were excluded. Mean age of the total sample was 29.40, and 90.9% were male. Mean BMI was 26.96. The mean and SD for NSTB was 2.18±1.65, and for MUST 2.0±0.0. A difference in the nutritional screening risk score of the same group of patients was observed. In the MUST group, 100% patients were classified as high risk, while in the NSTB group 50% patients were classified as high risk, 36.36% as moderate risk and 13.63% as low risk respectively. The variability of the risk score in the NSTB group helps prioritize the patients based on high, medium, and low risk, whereas MUST categorizes all patients as high risk. A unique screening tool for burns will be more effective in determining risk patients due to tailor-made characteristics. Even though the data sample is small, the difference gives scope for extensive study.

L'évaluation du risque de dénutrition est nécessaire chez les patients brûlés, chez qui elle joue un rôle majeur dans l'évolution initiale. NSTB a été développé afin de ne pas passer à côté, et a été comparé à MUST au moyen d'une étude piloté réalisé auprès de 22 patients adultes (femmes enceintes et handicapés mentaux exclus) hospitalisés dans un CTB de Bahreïn. L'âge moyen était de 24,9 ans ; 90,9% étaient des hommes, le BMI moyen était de 29,96. Tous les patients de MUST était classés à haut risque quand était variable en utilisant NSTB. En effet, il classait 50% des patients à haut risque; 36,36% à risque modéré et 13,63% à risque faible. Ainsi, NSTB pourrait être plus précis que MUST pour évaluer le risque nutritionnel chez les brûlés, ce qui devrait être validé sur une série plus longue.

Stimulatory lipids accumulate in the mouse liver within 30 min of contact sensitization to facilitate the activation of Naïve iNKT cells in a CD1d-dependent fashion.

Natural killer T cells with invariant αß-T cell receptors (TCRs) (iNKT cells) constitute a lipid-responsive arm of the innate immune system that has been implicated in the regulation or promotion of various immune, infectious and neoplastic processes. Contact sensitivity (CS), also known as contact hypersensitivity or allergic contact dermatitis, is one such immune process that begins with topical sensitization to an allergen and culminates in a localized cutaneous inflammatory response after challenge with the same allergen. CS depends on events initiated early in sensitization by hepatic iNKT cells. We have shown previously that these iNKT cells release IL-4 early after skin sensitization to activate B-1 B cells to produce IgM antibodies that aid in local recruitment of the effector T cells. Here, we utilize adoptive transfer techniques in several strains of knockout mice to demonstrate that hepatic lipids isolated 30 min after sensitization are significantly more stimulatory to naïve hepatic iNKT cells than hepatic lipids isolated after sham sensitization. These stimulatory hepatic lipids specifically affect iNKT cells and not B-1 B cells. The downstream CS response is abrogated with anti-CD1d-blocking antibodies, suggesting a critical role of CD1d in the activation of hepatic iNKT cells with these lipids. Hepatocytes may not be essential, as donor hepatic iNKT cells can reconstitute CS without migrating to the recipient mouse liver. Rather, CD1d-expressing liver mononuclear cells are sufficient for activation of iNKT cells. In conclusion, stimulatory lipids accumulate in the liver soon after sensitization and facilitate iNKT cell activation in a CD1d-dependent yet potentially hepatocyte-independent manner.

Differential expression of non-muscle myosin heavy chain genes during Xenopus embryogenesis.

Class II non-muscle myosins are implicated in diverse biological processes such as cytokinesis, cellularization, cell shape changes and gastrulation. Two distinct non-muscle myosin heavy chain genes have been reported in all vertebrates: non-muscle myosin heavy chain-A (NMHC-A) and -B (NMHC-B). We report here the isolation of the Xenopus homolog of NMHC-A and present a comparative analysis of the developmental and spatial expression patterns of NMHC-A and the previously isolated NMHC-B to address the role of NMHCs in Xenopus development. A 7.5 kb NMHC-A mRNA is present, maternally in unfertilized eggs and throughout embryogenesis, as well as in all adult tissues examined. An additional 8.3 kb zygotic transcript for NMHC-A is also detected, but only during embryonic stages. Whole mount in situ hybridization with tailbud stage embryos shows that NMHC-A mRNA is predominantly expressed in the epidermis, whereas NMHC-B mRNA is expressed in the somites, brain, eyes and branchial arches. Interestingly, the expression of NMHC-B in developing somites is gradually restricted to the center of each somite as differentiation proceeds. DAPI nuclear staining demonstrated that NMHC-B mRNA is colocalized with the nuclei or perinuclear area. In animal cap experiments, treatment with activin A or ectopic expression of Xbra and an activated form of Xlim1 markedly up-regulates NMHC-B as well as muscle actin mRNAs and slightly down-regulates NMHC-A mRNA, consistent with NMHC-B expression in the somitic muscle and NMHC-A expression in the epidermis.

Fox (forkhead) genes are involved in the dorso-ventral patterning of the Xenopus mesoderm.

Fox (forkhead/winged helix) genes encode a family of transcription factors that are involved in embryonic pattern formation, regulation of tissue specific gene expression and tumorigenesis. Several of them are transcribed during Xenopus embryogenesis and are important for the patterning of ectoderm, mesoderm and endoderm. We have isolated three forkhead genes that are activated during gastrulation and play an important role in the dorso-ventral patterning of the mesoderm. XFKH1 (FoxA4b), the first vertebrate forkhead gene to be implicated in embryonic pattern formation, is expressed in the Spemann-Mangold organizer region and later in the embryonic notochord. XFKH7, the Xenopus orthologue of the murine Mfh1(Foxc2), is expressed in the presomitic mesoderm, but not in the notochord or lateral plate mesoderm. Finally, XFD-13'(FoxF1b)1 is expressed in the lateral plate mesoderm, but not in the notochord or presomitic mesoderm. Expression pattern and functional experiments indicate that these three forkhead genes are involved in the dorso-ventral patterning of the mesoderm.

A mathematical model approach quantifying patients' response to changes in mechanical ventilation: Evaluation in pressure support.

PURPOSE: This article evaluates how mathematical models of gas exchange, blood acid-base status, chemical respiratory drive, and muscle function can describe the respiratory response of spontaneously breathing patients to different levels of pressure support. METHODS: The models were evaluated with data from 12 patients ventilated in pressure support ventilation. Models were tuned with clinical data (arterial blood gas measurement, ventilation, and respiratory gas fractions of O2 and CO2) to describe each patient at the clinical level of pressure support. Patients were ventilated up to 5 different pressure support levels, for 15 minutes at each level to achieve steady-state conditions. Model-simulated values of respiratory frequency (fR), arterial pH (pHa), and end-tidal CO2 (FeCO2) were compared to measured values at each pressure support level. RESULTS: Model simulations compared well to measured data with Bland-Altman bias and limits of agreement of fR of 0.7 ± 2.2 per minute, pHa of -0.0007 ± 0.019, and FeCO2 of -0.001 ± 0.003. CONCLUSION: The models describe patients' fR, pHa, and FeCO2 response to changes in pressure support with low bias and narrow limits of agreement.

A mathematical model approach quantifying patients' response to changes in mechanical ventilation: evaluation in volume support.

This paper presents a mathematical model-approach to describe and quantify patient-response to changes in ventilator support. The approach accounts for changes in metabolism (V̇O2, V̇CO2) and serial dead space (VD), and integrates six physiological models of: pulmonary gas-exchange; acid-base chemistry of blood, and cerebrospinal fluid; chemoreflex respiratory-drive; ventilation; and degree of patients' respiratory muscle-response. The approach was evaluated with data from 12 patients on volume support ventilation mode. The models were tuned to baseline measurements of respiratory gases, ventilation, arterial acid-base status, and metabolism. Clinical measurements and model simulated values were compared at five ventilator support levels. The models were shown to adequately describe data in all patients (χ(2), p > 0.2) accounting for changes in V̇CO2, VD and inadequate respiratory muscle-response. F-ratio tests showed that this approach provides a significantly better (p < 0.001) description of measured data than: (a) a similar model omitting the degree of respiratory muscle-response; and (b) a model of constant alveolar ventilation. The approach may help predict patients' response to changes in ventilator support at the bedside.

Bone-marrow-derived mesenchymal stem cells attenuate cognitive deficits in an endothelin-1 rat model of stroke.

PURPOSE: Stroke is the third leading cause of death and permanent disability in the United States, often producing long-term cognitive impairments, which are not easily recapitulated in animal models. The goals of this study were to assess whether: (1) the endothelin-1 (ET-1) model of chronic stroke produced discernable cognitive deficits; (2) a spatial operant reversal task (SORT) would accurately measure memory deficits in this model; and (3) bone-marrow-derived mesenchymal stem cells (BMMSCs) could reduce any observed deficits. METHODS: Rats were given unilateral intracerebral injections of vehicle or ET-1, a stroke-inducing agent, near the middle cerebral artery. Seven days later, they were given intrastriatal injections of BMMSCs or vehicle, near the ischemic penumbra. The cognitive abilities of the rats were assessed on a novel SORT, which was designed to efficiently distinguish cognitive deficits from potential motoric confounds. RESULTS: Rats given ET-1 had significantly more cognitive errors at six weeks post-stroke on the SORT, and that these deficits were attenuated by BMMSC transplants. CONCLUSIONS: These findings indicate that: (1) the ET-1 model produces chronic cognitive deficits; (2) the SORT efficiently measures cognitive deficits that are not confounded by motoric impairment; and (3) BMMSCs may be a viable treatment for stroke-induced cognitive dysfunction.

Isolation and expression of a rat liver cDNA encoding phosphoglucomutase.

A cDNA encoding phosphoglucomutase (PGM) has been isolated from a rat liver cDNA library following screening with a polymerase chain reaction product. The cDNA was found to contain a 53-base-pair (bp) 5' untranslated region (5' UTR), a single start codon and consensus initiation sequence, an open reading frame (ORF) of 1686 bp, and a 3' untranslated tail. A comparison to the rabbit and human muscle PGM cDNAs [Whitehouse et al., Proc. Natl. Acad. Sci. USA 89 (1992) 411-415] showed 90% identity of rat cDNA to both, while a comparison to the deduced amino acid sequences showed 97 and 96% identity, respectively. Northern blot analyses determined that PGM was encoded by a single mRNA in rat liver, of approximately 2.2 kb. Following transfection of COS-7 cells with a plasmid containing the entire PGM ORF, indirect immunofluorescence analyses using a PGM-specific monoclonal antibody determined that approximately 5% of the cells displayed 50-100 times greater fluorescence than that seen in the remainder of the cells or in mock transfects. The enhanced production of PGM was also demonstrated by Western blotting and by enzymatic activity assays.