Skeletal muscle reperfusion injury: reversal by controlled limb reperfusion--a case report

Despite successful surgical revascularization of ischemic limbs, a local and systemic reperfusion injury may occur after normal blood reperfusion. Recent experimental and clinical application of controlled limb reperfusion in Europe has demonstrated superior results, with lower morbidity and mortality. This new surgical technique includes modification of the reperfusate (calcium, pH, substrates, osmolarity, free radical scavenger) and the circumstances of initial reperfusion (time, temperature, pressure). This report describes the first application of controlled limb reperfusion after reperfusion injury. A 16-year-old boy underwent femoral access cardiopulmonary bypass for repeat cardiac repair with an ischemic time of 245 minutes. Postoperatively, severe ischemia/reperfusion syndrome developed with muscle contracture, immobility, and anesthesia of the right leg with a second ischemic time of about 6 hours. The systemic creatine phosphokinase level was 88,000 U/L; myoglobin was 27,000 ng/mL. He underwent controlled limb reperfusion by withdrawing blood from the aorta and mixing it with a crystalloid solution (calcium-reduced, hyperosmolar, hyperglycemic, alkalotic, glutamate- and aspartate-enriched, and containing a free radical scavenger) under controlled conditions (blood:crystalloid solution 6:1, for 30 minutes, reperfusion pressure < 50 mm Hg, and normothermia) before establishing normal blood reperfusion. Metabolic data from the central and femoral vein demonstrated a significant reduction of all previous elevated enzyme levels, avoidance of hyperkalemia, normalization of acidosis, and avoidance of systemic reperfusion injury with no multiorgan failure. Limb salvage was accomplished and functional recovery almost complete. To the authors' knowledge, this is the first application of controlled limb reperfusion reported in North America. With this surgical technique we were able to prevent metabolic local and systemic reperfusion changes after prolonged ischemia and also reduced previous reperfusion changes. This report confirms former experimental data, and further clinical studies are warranted.

Visits to home environments by emergency medical services: a statewide study

Understanding out-of-hospital transport demographics would clarify the opportunities for injury surveillance and prevention.

OBJECTIVE

To test the hypotheses that there are demographic differences in home vs. non-home emergency medical services (EMS) scene transports and that among age groups there are differences in demographics.

METHODS

Data were extracted from the EMS State Ambulance Transport database of all reported during 1995. Transports from patient homes were compared with transports from all non-home scenes. Data extracted included age, gender, race, and type of complaint. Subgroup analysis was performed based on age groups in nonvehicular cases, safety problems, and interpersonal violence. Results were compared using a two-tailed chi-square with significance at p<0.05. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated for significant differences.

RESULTS

The study included 118,131 transported patients: 13% were children, 49% were adult between 18 and 64 years, and 38% were elder; 13% were African American, 82% were white, and 5% were other; 47% were male and 53% were female. Fifty-eight percent of the transports were for safety problems, and 17% were for interpersonal violence. Of the 118,131 transports, 56,812 (48%) were from patients' homes and 61,319 were not. Compared with EMS transports from non-home scenes, fewer home EMS transports were for injury (p<0.01, OR = 0.18, 95% CI = 0.17-0.19) and more home EMS transports were for illness (p<0.01, OR = 5.64, 95% CI = 5.49-5.79). There was no clinically significant difference in age, race, or gender. For all non-vehicular injury transports, the reason was more likely safety problems than interpersonal violence (58% vs. 17%); however, there was no difference in the percentages of type of call between the home and non-home transports. Home EMS transports were more likely interpersonal violence problems among adult patients less than 65 years old; however, among the old and young, the problems were more likely to be safety-related.

CONCLUSION

Forty-eight percent of all EMS transports are from the home. Only 18% of these EMS home transports are for injury-related problems. In general, EMS injury transports are more likely related to safety than to interpersonal violence. Among the home EMS transports, more than 50% of transports for young and old patients are safety-related. A large proportion of the home EMS transports for adults less than 65 years of age, however, are for interpersonal violence.

The course of the marriage of Elizabeth Montagu: an ambitious and talented woman without means

Based on a study of the Montagu Collection of letters housed in the Huntington Library, this article analyzes the apparent motives behind the marriage between Elizabeth and Edward Montagu and the slow but sure emergence of evidence of her growing dissatisfaction with it. It reveals the various ways in which she sought distraction from her marriage and her attempts to compensate for it. Behind her growing restlessness and frustration, there lie aspects of her character—her obsession with money, her urgent need to be constantly admired and lauded, and her need to be in control of both people and things.

Combined molecular ecological and confocal laser scanning microscopic analysis of peat bog methanogen populations

Confocal laser scanning microscopy, using fluorescently labelled oligonucleotide probes targeting the 16S rRNA of different physiological groups of methanogens, was used to identify which methanogenic genera were present and to describe their in situ spatial locations in samples taken at different depths from blanket peat bog cores. Total bacterial DNA was also extracted and purified from the samples and used as template for amplification of 16S rRNA and regions of methyl CoM reductase-encoding genes using the polymerase chain reaction, as well as for oligonucleotide hybridisation experiments. These techniques, used in concert, demonstrated that methanogens of several physiological groups were present in highest numbers in the mid regions of 25 cm deep peat cores. Some discrepancies were apparent in the findings of the microscopic and molecular methods, though these may be partially accounted for by the different sensitivities of the techniques employed. The combined approaches used in this study gave an insight into the diversity and distribution of methanogens in peat environments not possible using molecular ecological methods alone.

Gender differences in state-wide EMS transports

There are gender differences in emergency medical services (EMS) transports and management based on diagnosis. Data were extracted from the EMS State Ambulance Transport database. This database exists because of a legal requirement that all EMS transports generated by 911 calls and all interhospital transports be reported to the State EMS Bureau. All ambulance transports reported to the State EMS Division during 1995 were evaluated. Cases were excluded if they were aborted, admission or discharge transports, outpatient transports, or cases listed as "other" without a diagnosis. Gender-related treatment differences were determined for problems for which EMTs have specific treatment options. These were cardiac arrest, chest pain, allergic reactions, and extremity fractures. Results were compared using a two-tailed Chi squared or Fischer's Exact with significance at P < .05. Odds Ratios (OR) and 95% confidence intervals (CIs) were calculated. There were a total of 164,595 ambulance transports reported to the State EMS Division. Of these 76,074 (46%) were men and 88,521 (54%) were women. Of these, 50,211 were excluded. This left 52,607 injury transport and 61,777 illnesses transport. Men were significantly more likely than women to have injuries related to all-terrain vehicle accidents, motorcycle accidents, RV accidents, burns, gunshot wounds, and stab wounds. Men were significantly more likely than women to have illnesses related to cardiac arrest, dead on arrivals (DOAs), drowning, and smoke inhalation. For cardiac arrest transports, significantly more male patients presented ventricular fibrillation, more males received defibrillation, lidocaine, and bicarbonate, but more women received atropine. Male chest pain patients were more likely to receive oxygen and morphine and less likely to receive nitroglycerin. Male allergic reaction patients were more likely to receive an i.v. and subcutaneous epinephrine. Male extremity fracture patients were more likely to get an i.v. line, but there was no difference in morphine use or splinting. There are numerous disease-specific gender differences in the demographics of illness and injury transported by EMS. The use of various medications and procedures may also be related to gender. Understanding these differences may help in preparing EMS professionals for patient management.

Addition of the human interferon beta scaffold attachment region to retroviral vector backbones increases the level of in vivo transgene expression among progeny of engrafted human hematopoietic stem cells

Absence of durable high-level expression of transgenes from Moloney murine leukemia (Mo-MuLV) retroviral vectors has been a hurdle in bringing effective gene therapy to the clinic. In this study we have analyzed transgene expression among the progeny of mobilized hematopoietic stem cells (HSCs), comparing Mo-MuLV and mouse stem cell virus (MSCV) vectors, with or without addition of a scaffold attachment region (SAR) from the human interferon beta gene. Retroviral (RV) vector supernatant quality was assessed by comparing NGFR transgene expression by HEL cells, and transgene delivery and expression by CD34(+) cells 72 hr after transduction, using real-time PCR and FACS analysis. This is the first description of the effect of SAR within both Mo-MuLV and MSCV vector backbones on long-term RV transgene expression among in vivo HSC progeny in HSC repopulation assays (SCID-hu bone and NOD/SCID). After transduction of mobilized CD34(+) cells with MSCV-SAR vector, transgene expression was observed among a mean of 10% of donor HSC progeny in the SCID-hu bone (range, 0.6-43%). The predominant effect of SAR was to increase the mean fluorescence intensity (MFI) of transgene expression among HSC progeny in both in vivo bone repopulation models (three- to fourfold), and after long-term stromal cultures (twofold).

College students with dyslexia: persistent linguistic deficits and foreign language learning

The first of these two studies compared college students with dyslexia enrolled in modified Latin and Spanish classes and non-dyslexic students enrolled in regular foreign language classes on measures of foreign language aptitude, word decoding, spelling, phonological awareness and word repetition. The groups did not differ on age or grade point average. Analyses indicated that students with dyslexia performed significantly poorer on the foreign language aptitude measures as well as on both phonological tasks, reading and spelling. In the second study, students with learning disabilities who were enrolled in a modified Latin class were not significantly different from their peers in a regular Latin class on grade point average or on performance on a proficiency examination at the end of the second semester. The data suggest that while phonological processing deficits persist into adulthood, students with dyslexia are able to acquire appropriate skills and information to successfully complete the University's foreign language requirement in classes modified to meet their needs.

Rubiginoside, a farnesyl glycoside from Lepisanthes rubiginosa

Chemical investigation of the methanolic fraction of Lepisanthes rubiginosa bark has led to the isolation and characterisation of a new tetrasaccharide derivative of farnesol named rubiginoside along with known triterpenoid saponins.

Optimization of retroviral gene transduction of mobilized primitive hematopoietic progenitors by using thrombopoietin, Flt3, and Kit ligands and RetroNectin culture

We have investigated the ability of several cytokine combinations to improve retrovirus-mediated transduction of human primitive hematopoietic progenitors (PHPs) from mobilized peripheral blood (MPB). Retroviral infection of CD34+ cells was performed by culture on fibronectin fragment CH-296 (RetroNectin, RN), using the truncated human nerve growth factor receptor (NGFR) as the transgene reporter. Transgene expression among progeny of PHPs was assayed by FACS analysis after long-term stromal culture (LTC). Transgene delivery to PHPs was assessed by PCR of individual stromal culture-derived methylcellulose colonies (LTC-CFCs). Compared with interleukin 3 (IL-3), IL-6, and leukemia inhibitory factor (LIF), the combination of thrombopoietin (TPO), Flt3 ligand (FL), and Kit ligand (KL) effected a 73-fold increase in NGFR expression among CD34+ cells (to 14%) and a 14-fold increase in NGFR expression among total cells (to 10%) after LTC. In addition, a 2.4-fold increase in neo gene marking of LTC-CFCs was observed. A preclinical study comparing the effect of high-speed centrifugation ("spinoculation") or culture on RN during exposure to retroviral particles in teflon cell culture bags showed no difference in the efficiency of transduction of PHPs between these two methods.

The use of the Fogarty catheter in 1998

Catheter-mediated thromboembolectomy has evolved over the last three decades along with changes in vascular disease patterns. As in situ arterial thrombosis has become more common both in natural arteries and prosthetic grafts, changes in mechanical thromboembolectomy have been necessary to optimize treatment strategies. A variety of devices and techniques are now available for transluminal clot removal including the original thromboembolectomy catheter, newer adherent clot catheters, graft thrombectomy catheters, thru-lumen balloon catheters and methods that involve fragmentation and removal of fresh thrombus by hydrodynamic means.

The emergence of decreased susceptibility to vancomycin in Staphylococcus epidermidis

BACKGROUND

Coagulase-negative staphylococci (CNS) are the major cause of nosocomial bloodstream infection. Emergence of vancomycin resistance among CNS is a serious public health concern, because CNS usually are multidrug-resistant, and glycopeptide antibiotics, among which only vancomycin is available in the United States, are the only remaining effective therapy. In this report, we describe the first bloodstream infection in the United States associated with a Staphylococcus epidermidis strain with decreased susceptibility to vancomycin.

METHODS

We reviewed the hospital's microbiology records for all CNS strains, reviewed the patient's medical and laboratory records, and obtained all available CNS isolates with decreased susceptibility to vancomycin. Blood cultures were processed and CNS isolates identified by using standard methods; antimicrobial susceptibility was determined by using minimum inhibitory concentration (MIC) and disk-diffusion methods. Nares cultures were obtained from exposed healthcare workers (HCWs) to identify possible colonization by CNS with decreased susceptibility to vancomycin.

RESULTS

The bloodstream infection by an S. epidermidis strain with decreased susceptibility to vancomycin occurred in a 49-year-old woman with carcinoma. She had two blood cultures positive for CNS; both isolates were S. epidermidis. Although susceptible to vancomycin by the disk-diffusion method (16-17 mm), the isolates were intermediate by MIC (8-6 microg/mL). The patient had received an extended course of vancomycin therapy; she died of her underlying disease. No HCW was colonized by CNS with decreased susceptibility to vancomycin.

CONCLUSIONS

This is the first report in the United States of bloodstream infection due to S. epidermidis with decreased susceptibility to vancomycin. Contact precautions likely played a role in preventing nosocomial transmission of this strain, and disk-diffusion methods may be inadequate to detect CNS with decreased susceptibility to vancomycin.

Quantitation of the proliferative potential of highly enriched human primitive hematopoietic progenitor cells using a stroma-free limiting dilution assay with automated scoring

BACKGROUND

Increasing use of phenotypically-enriched stem cell populations for clinical hematopoietic transplants has led to an urgent demand for a reliable, rapid and simple functional assay which would provide an estimation of the reconstituting potential of cells prior to transplantation.

METHODS

We have developed a 2-week quantitative, stroma-free assay to measure the frequency of primitive progenitors within hematopoietic cell samples. This relatively short-term assay provides frequency information which correlates with that measured by a 5-week stroma-dependent CAFC assay. Cells with the phenotype CD34+Thy-1+ were purified by fluorescence-activated cell sorting from peripheral blood apheresis products of multiple myeloma patients mobilized with cytoxan and GM-CSF. CD34+Thy-1+ cells were plated at limiting dilution into microtiter wells and cultured in an Iscove's based serum-deprived culture medium, supplemented with the cytokines, interleukin (IL)-3, IL-6, G-CSF, Flk2/Flt3 ligand (FL) and Kit ligand (KL). After 2 weeks, cell proliferation in individual wells was quantified by microscopy and bright-field imaging, or by using a fluorescent nucleic acid-binding dye and fluorimetry. Poisson statistics were used to calculate the frequency of wells containing cells with high proliferative potential (wells containing > or = 500 cells).

RESULTS

Progenitor cell frequencies generated using this assay were compared by linear regression analysis to those generated from 32 parallel CAFC and CFU-C assays performed on the same patient samples. Correlations were r = 0.80, r2 = 0.65, and r = 0.76, r2 = 0.58, respectively; these correlations were highly significant (p < 10(-7)).

DISCUSSION

This limiting dilution assay should more directly quantitate the potential of primitive hematopoietic cells than a CFU-C assay. It also has advantages over both the CAFC and the CFU-C assay, in that scoring has been automated, making it simple, rapid, and objective compared with manual cobblestone area or colony counting. The described limiting dilution assay may provide a useful alternative to assays currently used to evaluate the viability and proliferative potential of purified hematopoietic cells intended for transplant.

Comparative study of BacT/Alert FAN bottles and standard BacT/Alert bottles

A total of 5,230 paired blood cultures were studied. One sample was divided between aerobic and anaerobic BacT/Alert standard bottles, and the other divided between aerobic and anaerobic BacT/Alert FAN bottles. There were 44 occasions where Staphylococcus aureus was recovered only from the FAN bottles, compared to six where only the standard bottles were positive (p < 0.001), and 21 occasions where Escherichia coli was isolated only from FAN bottles, compared to eight occasions where only the standard bottles were positive for this organism (p < 0.05). In 21 of 28 cases reviewed where S. aureus was isolated from FAN bottles only the patient had been receiving anti-staphylococcal antibiotics. However, only 2 of 30 cases where Gram-negative bacilli were isolated from FAN bottles had documented recent appropriate antibiotic therapy. Patients in whom FAN bottles are more likely to recover organisms cannot be selected on the basis of documented antibiotic treatment.