Inhibition of rat cerebral mitochondrial respiration by cyclosporins A, D, and G and restoration with trimetazidine

The aim of this work was to investigate possible inhibitory effects of Ca+ and different cyclosporins (Cs) on the rat brain mitochondrial respiratory control ratio (RCR) and whether or not these effects could be antagonized by trimetazidine (TMZ). The RCR was evaluated as the state 3/state 4 ratio of oxidative phosphorylation. CsA, D, and G inhibited about 10% of RCR in a concentration-dependent manner with EC50 of 57, 19 and 7 nM, respectively, whereas CsH did not modify RCR. TMZ was able to fully antagonize this inhibitory effect in a concentration-dependent manner with EC50 of 5,200, 180, and 1 nM, respectively. The Ca2+ added to the mitochondrial preparation decreased RCR in a concentration-dependent manner with a maximal effect of 46% obtained with 100 microM Ca2+. In the presence of TMZ (100 microM), the inhibitory effect of Ca2+ was partly reversed (9%). TMZ alone showed no inhibitory or stimulant effect on RCR. These results show that restoration of RCR by TMZ is due to a Ca(2+)-dependent mechanism, promoting Ca2+ efflux from the mitochondrial matrix. However, Ca2+ efflux is only partial in case of Ca2+ overload. These data suggest that TMZ may restore ATP synthesis in circumstances where neither Ca2+ overload, nor a prooxidant have generated a RCR decrease.

[Telephonic advice by an emergency department given in a simulated pediatric case]

BACKGROUND

Emergency departments (ED) are requested everyday to dispense medical telephone advice for children. To evaluate the quality of telephone management, a mock scenario simulating a febrile 4 month-old-girl with signs compatible with septicemia was used.

METHODS

One hundred randomly selected French emergency departments were called on. Half of the hospitals had a pediatric department with more than 20 beds; the other half did not have a pediatric department. A research technician called and said: "My baby has got fever and I do not know what to do". Additional information was given only on request.

RESULTS

Ninety-four ED gave medical advice by telephone: 65% of the cases by a physician, 24.5% by a nurse, 9.5% by a nurse technician and 1% by a secretary. In hospitals without a pediatric department, physicians took calls in 76.5% of the cases, whereas in hospitals with a pediatric department they only took calls in 53% of the cases. The mean number of questions asked per ED was 3.1. The age of the child was requested by 87.2% of the respondents. Advice was given by 36.1% of the ED without asking either the age of the patient or grade of the fever. The advice given by the respondents was: come to the ED immediately (30.9%), see a community physician immediately (51%), come to the ED tomorrow (2.1%), see a community physician tomorrow (8.5%), and manage at home (7.5%).

CONCLUSIONS

This study has shown important inadequacies in pediatric telephone advice given by some ED. It suggests that the respondents do not use a protocol to handle the calls; development of such protocols to guide the histories taken and advice given for the most common telephone queries is urged.

[Evaluation of pediatric advise asked by telephone in emergency units]

BACKGROUND

Telephone calls for advice are common in pediatric emergency departments. This study was conducted to determine the nature of these calls and the answers provided.

METHODS

From 24 April through 24 July 1994, all telephone calls requesting pediatric advice in the emergency department of the Poissy Hospital were independently analysed by two pediatricians from forms prospectively filled in for each call by the resident or the attending people who answered the call.

RESULTS

Of the 239 registered calls, 186 could be analysed. They represented, in number, 15.25% of the children seen at the same emergency department during the study period. Weekend and holiday calls accounted for 35.5% of calls. 7.8% of calls were received from 0.01 am to 8.00 am, 28.7% from 8.01 am to 4.00 pm, and 63.5% from 4.01 pm to 12.00 pm. Thirty-seven percent concerned children under one year of age. The caller was one of the parents in 93% of cases. The four most frequent complaints were fever (26.5%), requests for information (17.2%), rash (12.3%), and vomiting (10.2%). The review of calls by two pediatricians determined that 67% of children did not need to be seen by a physician within six hours; 28% needed to be seen within 6 hours, and 5% needed to be seen within one hour. The advice given was followed in 88% of cases; 96% of callers were satisfied with their calls management.

CONCLUSIONS

Telephone advice constitutes an important part of the activity in the pediatric emergency department. Instructional programs in telephone management are necessary for physicians. These programs should include communication skills and familiarization with protocols concerning the most frequent complaints, especially those regarding children under one year of age.

Early inflammatory response correlates with the severity of injury

OBJECTIVE

To determine if the early inflammatory response correlates with the severity of injury in a blunt trauma model in rats.

DESIGN

Prospective, randomized, controlled trial.

SETTING

Research laboratory.

SUBJECTS

Male Sprague-Dawley rats, weighing 250 to 400 g.

INTERVENTIONS

Twenty-two male Sprague-Dawley rats were divided randomly into single hindlimb fracture, bilateral hindlimb fracture, and no fracture groups. At 90 mins, all animals underwent midline laparotomy and aspiration of blood from the inferior vena cava. Venous blood gas, plasma lactate, and plasma concentrations of tumor necrosis factor (TNF), prostaglandin F(6-keto-PGF1 alpha), and interleukin (IL)-6 were sampled. Statistical analysis was done via one-way analysis of variance and Scheffé post hoc analysis. In a second part of this experiment, the effect of hemorrhage on the release of IL-6 was evaluated. Animals in this group were compared with control and bilateral hindlimb fracture animals, using the Student's t-test.

MEASUREMENTS AND MAIN RESULTS

There were no significant differences in venous pH or base deficit among the groups. Oxygen saturation was significantly decreased in the bilateral hindlimb fracture group when compared with the control group. In the hemorrhage plus bilateral fracture group, oxygen saturation was significantly decreased when compared with the bilateral fracture group. lactate concentrations in plasma were increased in both fracture groups as well as the hemorrhaged groups. Plasma TNF concentrations were increased in the injured groups but there was no significant difference between single and bilateral hindlimb fracture groups. The 6-keto-PGF1 alpha concentrations were increased in both of the fracture groups when compared with the control group and there was a significant difference between single and bilateral hindlimb fracture groups. Similarly, circulating IL-6 concentrations were significantly higher in the bilateral fracture group than in the single fracture group; both fracture groups were significantly higher than the control group. Hemorrhaged animals had even higher IL-6 concentrations.

CONCLUSIONS

Plasma lactate and TNF concentrations were affected by injury, however their concentrations did not correlate with degree of injury. IL-6 concentrations were increased early postinjury and correlated with severity of injury. The 6-keto-PGF1 alpha concentrations in plasma also correlated with the severity of injury and this phenomenon may represent early endothelial activation which may be the source of IL-6 release.

[Sedation and analgesia in children]

This article describes the most current and effective means for providing sedation and analgesia for the pediatric patient. Three basic levels for sedation can be defined: conscious sedation, deep sedation and general anesthesia. Treatment of pain is also established according to an analgesic ladder. Providing safe and effective sedation and analgesia to children requires appropriate selection of drugs and dosage, proper monitoring, knowledge of potential side effects, and adequate airway management equipment and personnel. Agents available for sedation and analgesia of children and therapeutic options according to different clinical situations are described.

[Hepatitis C virus infection in hemodialysis]

The surveillance of HCV infections is now a must in the clinical management of hemodialysis patients. The natural history of HCV has shown acute hepatitis to be a constant feature although rarely symptomatic. Progression to chronicity occurs in 90% of the cases with detectable viremia in 80% of the cases. The long-term impact of the liver disease in chronic hemodialyzed patients remains to be defined. HCV is responsible for more than 90% of the non-A, non-B hepatitis case diagnosed among hemodialyzed patients. The transmission is either transfusional or nosocomial. Following recent transfusion safety regulations, the nosocomial risk became the predominant residual risk. Thus, all efforts should target HCV eradication. In the absence of specific prophylaxis, this can only be achieved by enforcement of very stringent precautions.

Fluorescent in situ hybridization with rRNA-targeted oligonucleotide probes to identify small phytoplankton by flow cytometry

Because of their tiny size (0.2 to 2 microns), oceanic picophytoplanktonic cells (either cultured strains or natural communities) are difficult to identify, and some basic questions concerning their taxonomy, physiology, and ecology are still largely unanswered. The present study was designed to test the suitability of in situ hybridization with rRNA fluorescent probes detected by flow cytometry for the identification of small photosynthetic eukaryotes. Oligonucleotide probes targeted against regions of the 18S rRNAs of Chlorophyta lineage (CHLO probe) and of non-Chlorophyta (NCHLO probe) algal species were designed. The CHLO and NCHLO probes, which differed by a single nucleotide, allowed discrimination of chlorophyte from nonchlorophyte cultured strains. The sensitivity of each probe was dependent upon the size of the cells and upon their growth stage. The mean fluorescence was 8 to 80 times higher for specifically labeled than for nonspecifically labeled cells in exponential growth phase, but it decreased sharply in stationary phase. Such taxon-specific probes should increase the applicability of flow cytometry for the rapid identification of cultured pico- and nanoplanktonic strains, especially those that lack taxonomically useful morphological features.

Utilization of exogenous siderophores and natural catechols by Listeria monocytogenes

Listeria monocytogenes does not produce siderophores for iron acquisition. We demonstrate that a number of microbial siderophores and natural iron-binding compounds are able to promote the growth of iron-starved L. monocytogenes. We suggest that the ability of L. monocytogenes to use a variety of exogenous siderophores and natural catechols accounts for its ubiquitous character.

[Intraosseous infusion in children]

BACKGROUND

Intravenous access in critically ill patients may be very difficult to obtain. The intraosseous route is an alternate way to administer fluids and drugs.

CASE REPORT

A five month old infant was brought to the emergency department in profound hypovolemia requiring immediate tracheal intubation. A peripheral venous access was established and 35 ml of colloid were rapidly infused. Unfortunately, fluid extravasated and the intravenous line had to be removed. As further attempts to gain intravenous access were unsuccessful, an intraosseous needle was inserted into the left tibia 1 cm below the tibial tuberosity, and colloid and human albumin solution were infused rapidly, followed by 1.4% sodium bicarbonate. After ninety minutes of intraosseous rehydration, 2 peripheral venous lines were inserted, and the intraosseous needle was removed. Bacteriological and viral cultures were negative. Four days after admission, the child was discharged in good condition.

CONCLUSIONS

Intraosseous infusion provides safe, rapid and reliable access to the circulation for administration of fluids and drugs in the critically ill child or during cardiac arrest.

HCV-associated liver cancer without cirrhosis

Chronic infection with hepatitis C virus (HCV) is regarded as a risk factor for hepatocellular cancer, mostly in patients with liver cirrhosis. We looked for HCV genomes in the livers of patients with hepatocellular cancer who did not have cirrhosis to see whether HCV was directly oncogenic. Cancerous and non-cancerous liver tissue, and serum samples from 19 patients negative for hepatitis B surface antigen were analysed by polymerase chain reaction for the presence of HCV genome, HCV replication, HCV genotyping, and HBV genome. 13 of 19 patients were HCV RNA-positive in cancerous and non-cancerous liver tissue; 8 of 17 tested were anti-HCV positive. Among the 13 HCV RNA-positive patients, 11 had genotype 1b and 2 had genotype 2a. 7 of 13 serum samples were HCV RNA positive. 7 of 19 patients were HBV DNA positive in cancerous and non-cancerous liver tissue, 5 of them anti-HBc positive. 4 patients were both HCV RNA and HBV DNA positive and 3 were both HCV RNA and HBV DNA negative. Our results provide evidence for the association of HCV, mostly genotype 1b, with hepatocellular cancer without the intermediate step of cirrhosis.

Landscape patterns of abundance of Ixodes scapularis (Acari: Ixodidae) on Shelter Island, New York

Nymphal Ixodes scapularis Say, the vector of Lyme borreliosis, was most common in forested areas across Shelter Island, Suffolk County, New York, and least common in xeric habitats such as beach and grassland. At the scale of individual house yards, nymphs were most common at wooded edges of property and least common on lawns. The abundance of ticks at yard edges was positively correlated with numbers on lawns and in landscaping, suggesting that tick abundance in woods affects abundances in adjacent yards. Because 57% of all yard area is adjacent to woodlands on Shelter Island, public health efforts to reduce tick populations in wooded areas should supplement efforts by individual yard owners to decrease risk. Methods of tick control for woodlands should also be evaluated for their effect on tick populations in adjacent yard habitats.

Anti-hepatitis C virus (anti-HCV) seroconversion in patients undergoing hemodialysis: comparison of second- and third-generation anti-HCV assays

BACKGROUND

The results obtained in sequential specimens from recently infected subjects generally provide the best means of comparing the sensitivity of assays.

STUDY DESIGN AND METHODS

The sensitivity of second- and third-generation assays for antibody to hepatitis C virus (HCV) was compared on sequential specimens, generally collected at monthly intervals from 45 patients undergoing hemodialysis who seroconverted for HCV between 1980 and 1990.

RESULTS

Fifteen patients (33%) were positive earlier in the third-generation enzyme-linked immunosorbent assay (ELISA), with a mean difference of 17 days (range, 7-30) between the last negative and the first positive specimens. At the first rise in alanine aminotransferase, and at its peak, 63 and 91 percent of the patients, respectively, were anti-HCV positive in the third-generation ELISA. Third-generation recombinant immunoblot assay (RIBA) reacted at the same time as third-generation ELISA. Of the first specimens that were positive in second-generation ELISA, 44 percent reacted and 56 percent were indeterminate in third-generation RIBA, while 10 percent reacted, 72 percent were indeterminate, and 18 percent did not react in second-generation RIBA. From the beginning to the end of the follow-up, antibody to c33c was the most prevalent, followed in descending order by antibody to c22-3, antibody to c100-3, and antibody to NS5: 56, 54, 26, and 18 percent, respectively, at time 0, and 100, 86, 83, and 31 percent, respectively, 12 months later.

CONCLUSION

Third-generation assays (both ELISA and RIBA) were more sensitive than second-generation assays in the diagnosis of HCV infection, in that positive results were obtained earlier and a higher proportion of specimens were confirmed positive in RIBA testing.

A twelve year natural history of hepatitis C virus infection in hemodialyzed patients

A prospective non-A, non-B follow-up program, implemented in a hepatitis B surface antigen-free dialysis unit, enabled us to report on the natural history of hepatitis C virus (HCV) infection in hemodialyzed patients between 1980 and 1992. For this program, every patient was prospectively monitored every two weeks for alanine amino transferase (ALT) activity, and every month for gammaglutamyl transpeptidase (GGT) activity and systematic collection of frozen sera. Sequences of stored sera from 217 patients were repeatedly tested for anti-HCV antibodies using second generation assays. Eighty-six of the 217 patients (39.6%), including 61 of the 67 patients with non-A, non-B hepatitis (91%), had HCV infection repeatedly evidenced by positive ELISA in all, and confirmed by RIBA in 84 of 86 (97.5%). In addition, 19 out of 23 patients (82.6%) were positive for HCV RNA by the polymerase chain reaction (PCR). Of the 86 anti-HCV positive patients, 41 had previously acquired HCV infection, and 45 seroconverted during chronic dialysis. Of these, all but one patient developed hepatitis with raised ALT activity which lasted for at least six months in all. Only 29 of 45 patients (64.5%) had a history of blood transfusion. Seventy-eight of the 86 patients (91%) who were followed up for one to 11.5 years (median 5) retained anti-HCV for several years. Nineteen liver biopsies performed in 16 patients showed chronic active hepatitis in 8 (50%) and hepatocellular carcinoma without cirrhosis in one patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Fetal weight-cerebellar diameter discordance as an indicator of asymmetrical fetal growth impairment

In this study on the effect of fetal growth impairment < or = 25th percentile on the transverse cerebellar diameter and its relationship with other fetal biometric parameters, the sample comprised 50 women with singleton pregnancies referred for ultrasound evaluation because of clinically suspected intrauterine growth retardation. The cerebellar diameter of asymmetrically growth-impaired fetuses remained within the normal range although it was found to be reduced when compared with that of normal fetuses (4.4 +/- 0.9 versus 4.8 +/- 0.7, P < .05). Although other biometric parameters (biparietal diameter, femur length and abdominal and head circumferences) were also reduced in growth-impaired fetuses, the ratios of these biometric parameters to cerebellar diameter were similar to those of unaffected fetuses. Fetal weight was affected to a greater extent than the cerebellar diameter, leading to discordance between the two parameters. This discordance identified almost all asymmetrically growth-impaired fetuses with a sensitivity of 95.6% and specificity of 96.3%. In contrast, the ratio of head circumference to abdominal circumference remained normal in more than half of the fetuses. Fetal weight-to-cerebellar diameter discordance is a very sensitive and specific indicator of asymmetrical fetal growth impairment.

Erythrocyte uroporphyrinogen decarboxylase activity in 80 unrelated patients with porphyria cutanea tarda

To estimate the prevalence of the subgroups of porphyria cutanea tarda (PCT), erythrocyte uroporphyrinogen decarboxylase (UD) activity was measured in 80 unrelated patients with PCT, and in 45 of their relatives by using pentacarboxyl-porphyrinogen III as substrate. The subgroups were differentiated by analysis of the urinary porphyrins of the patients and 119 of their relatives. Of the patients, 77.5% were found to be suffering from the sporadic form of PCT (type I PCT), and 22.5% from the familial form (type II PCT). Every patient with PCT had previously been affected by alcohol, oestrogen or some other liver-damaging factor. The relative frequency of familial PCT was higher in females (nine of 15) than in males (nine of 65), which suggests that inheritance of the gene for type II PCT may predispose to oestrogen-precipitated PCT. The onset of type II PCT occurred at a lower age than that of type I (42.6 vs. 47.0 years). The findings suggest an increased risk of precipitating factors in carriers of an inherited UD deficiency.

Basement membrane components (matrigel) promote the tumorigenicity of human breast adenocarcinoma MCF7 cells and provide an in vivo model to assess the responsiveness of cells to estrogen

The ability to transplant human tumors into athymic nude mice allows studies of tumor cells in vivo. However, after s.c. injection the incidence of tumor and metastases in nude mice is frequently low. We have studied the tumorigenicity in nude mice of estradiol (E2)-sensitive breast adenocarcinoma MCF7 cells. Matrigel, an extract of basement membrane proteins, induces rapid tumor development after s.c. injection of MCF7 cells. In the absence of this matrice, MCF7 cells failed to induce tumor growth. In this in vivo model, MCF7 cells were analysed for their E2 sensitivity. Two weeks after inoculation in the presence of matrigel, cells formed growing tumors in intact mice supplemented with E2. In ovariectomized or untreated mice, tumor appearance was delayed and the growth level was very low. Thus, MCF7 cells formed tumors in the absence of E2 but retained in vivo their responsiveness to estrogen. Growing human tumors in nude mice provides a rapid and useful model for testing the sensitivity of cells to hormone.

Cisplatin, carboplatin, and cyclophosphamide combination chemotherapy in advanced-stage ovarian carcinoma: an Eastern Cooperative Oncology Group pilot study

Cyclophosphamide (CTX) 600 mg/m2, carboplatin 280 mg/m2, and cisplatin 50 mg/m2 were administered on day 1 every 4 weeks to 41 previously untreated ovarian cancer patients with residual disease greater than 2.0 cm after primary laparotomy. Of 22 patients with measurable disease treated with up to eight cycles of therapy, the overall clinical response rate was 73% (exact 95% confidence interval [CI], 50% to 89%), with 50% complete response (CR). Six of 11 clinical CR (cCR) patients underwent surgical restaging; three pathologic CRs (pCRs) and three pathologic partial responses (pPRs) with residual disease less than 2.0 cm were documented. Fourteen patients had nonmeasurable but assessable disease; the clinical response rate was 57% (Cl, 29% to 82%) with two (14%) CRs. Second-look surgery was performed in one of the two cCR patients; a pPR was documented. Five patients with nonassessable disease were stable during chemotherapy; two underwent surgery and had pCRs. The median time to treatment failure (TTF) was 14.8 months, and median survival for the 41 patients is 26.7 months. Overall, 37% of the patients had progression-free intervals of at least 2 years, and 27% have survival times in excess of 3 years. Hematologic toxicity was substantial but manageable, with 58% and 66% experiencing a granulocyte nadir less than 500/microL and a platelet nadir less than 50,000/microL, respectively. One treatment-associated fatality occurred as a result of leukopenic sepsis and renal failure in the setting of progressive disease and ureteral obstruction. Mild to moderate nausea and vomiting occurred in most patients, but none experienced severe ototoxicity or peripheral neuropathy. Over all courses, 73% of the projected dose intensity of CTX and carboplatin and 86% of cisplatin were delivered. Since granulocytopenia and thrombocytopenia were dose-limiting, the addition of colony-stimulating factors that support both myeloid and megakaryocyte precursors may permit further dose intensification.

Infantile autism and Wernicke's encephalopathy

In this paper I discuss evidence that brain damage in infantile autism may involve the same complex of brainstem nuclei that are damaged by alcohol abuse, thiamine deficiency, and asphyxia. These are metabolically the most active structures in the brain, which makes them vulnerable to many injurious factors. It is my belief that the high metabolic rate in the brainstem nuclei could support a control function for multiplexing of neural pathways, and that if this control is lost it may result in the defects of awareness and responsiveness seen in autistic children.

Uroporphyrinogen decarboxylase deficiency in hepatoerythropoietic porphyria: further evidence for genetic heterogeneity

Catalytic and immunoreactive erythrocyte uroporphyrinogen decarboxylase was measured in a woman with hepatoerythropoietic porphyria (HEP). The uroporphyrinogen decarboxylase activity was 24% of the mean value for normal controls and the concentration of the immunoreactive enzyme (106 ng/mgHb), measured with the rocket immunoelectrophoresis technique, did not differ from that of healthy controls. Consequently, catalytically inactive, cross-reactive immunological material (CRIM) was present, and the patient was CRIM-positive. This enzyme activity and immunoreactive enzyme concentration differs from those for previously known HEP patients, and represents a new mutation, evidence for heterogeneity in inherited uroporphyrinogen decarboxylase deficiency.

Maternal-fetal transport of vitamin K1 and its effects on coagulation in premature infants

We conducted a prospective study to determine (1) the maternal-fetal vitamin K1 transport in premature infants after vitamin K1 was given to the mothers antenatally and (2) the vitamin K1 effects on blood coagulation in the babies. Women in labor at less than or equal to 34 weeks of gestation were randomly selected to receive antenatal vitamin K1, 5 mg given intramuscularly (vitamin K1 group), or no vitamin K1 (control group). Eight infants, including one set of twins, were in the vitamin K1 group and six in the control group. Vitamin K1 concentrations were higher in the vitamin K1 group than in the control group (p = 0.06). Activated partial thromboplastin time was prolonged, and factor II coagulation activity and factor II antigen were proportionately decreased in cord plasma in both groups. The average ratio of factor II coagulation activity to antigen was not decreased in either group. Protein induced by vitamin K absence-II (PIVKA-II) was not detectable in any cord plasma sample in either group. These findings support previous reports that the decreased vitamin K-dependent coagulation activity in premature infants is the result of reduced synthesis of precursor proteins, rather than the result of vitamin K deficiency, and suggest that additional vitamin K1 is not likely to improve coagulation activity. Among those infants who underwent cranial ultrasonography, all four in the vitamin K1 group and one of five in the control group had mild intraventricular hemorrhage. Studies of a larger number of patients are necessary before it can be established that maternal antenatal administration of vitamin K1 results in improvement of coagulation and the prevention of intraventricular hemorrhage in premature infants.