Marbofloxacin for the treatment of experimentally induced Mycoplasma haemofelis infection in cats.

BACKGROUND: Administration of tetracyclines or fluoroquinolones is associated with improvement in clinical and laboratory abnormalities in cats infected with Mycoplasma haemofelis. No treatment protocol has consistently eliminated the organism, and antimicrobial susceptibility may vary among M. haemofelis isolates. Continued search for effective therapies is warranted. HYPOTHESIS: Marbofloxacin administered at the onset of clinical illness will be safe and effective for the treatment of M. haemofelis. ANIMALS: Fourteen young adult, laboratory-reared cats housed together in a specific pathogen-free facility. METHODS: Twelve cats were inoculated IV with 2.0 mL of blood from 2 M. haemofelis positive cats. Clinical parameters were assessed daily. CBC and hemoplasma polymerase chain reaction (PCR) assay were performed before inoculation, weekly for 1-3 weeks postinoculation (PI) and twice weekly 3-6 weeks PI. Treatment with marbofloxacin (2.75 mg/kg PO daily for 14 days) was initiated in 6 randomly selected cats when PCV was <30% or fever was >102.5 degrees F (39.2 degrees C). Cats that were PCR positive on day 7 of therapy were treated for 28 days. Cats that were PCR negative on day 42 PI were treated with 20 mg/kg methylprednisolone acetate IM on day 50 PI. RESULTS: Significant differences between groups on some days after inoculation included higher PCV and red blood cell counts, lower mean cell volume, and higher mean cell hemoglobin content in marbofloxacin-treated cats. No differences in PCR assay results were noted between groups. CONCLUSIONS AND CLINICAL IMPORTANCE: Marbofloxacin was safe and resulted in more rapid hematologic improvement in M. haemofelis-infected cats, but did not change clinical scores and did not consistently eliminate infection.

Inoculation with Bartonella henselae followed by feline herpesvirus 1 fails to activate ocular toxoplasmosis in chronically infected cats.

Infection by Toxoplasma gondii is very common in cats although most remain disease free. The factors that trigger development of uveitis in some cats infected with T gondii have not been elucidated, but infection by more than one organism may be contributory. In this study, cats chronically infected with T gondii were inoculated with Bartonella henselae followed by FHV-1 to test the hypothesis that immune stimulation by multiple infections will reactivate ocular toxoplasmosis. Anterior uveitis and chorioretinitis were not detected in the cats with chronic T gondii infection thus allowing rejection of the hypothesis using this experimental design.

Detection of Toxoplasma gondii in the milk of experimentally infected lactating cats.

Tachyzoites of Toxoplasma gondii have been found in the milk of sheep, goats, cows and mice and infection by ingestion of raw goat milk has been documented in humans. Lactational transmission from infected cats to their kittens is suspected but the organism has not been detected in the milk. The purpose of this study was to demonstrate the presence of T. gondii in the milk of experimentally infected cats. Pregnant specific pathogen free cats were inoculated orally with T. gondii at various times prior to parturition. Feces were examined for oocyst shedding after sugar solution centrifugation. Milk was collected for polymerase chain reaction (PCR) and bioassay in mice. T. gondii was detected in the milk of five of six cats by either bioassay or PCR.

Analysis of aqueous humor obtained from normal eyes of llamas and alpacas.

OBJECTIVE: To evaluate composition of aqueous humor obtained from normal eyes of llamas (Lama glama) and alpacas (Lama pacos). SAMPLE POPULATION: Aqueous humor obtained from 10 male llamas and 10 male alpacas. PROCEDURE: All animals had normal eyes, as determined by ocular examination. Aqueous humor samples were obtained via paracentesis of the anterior chamber of animals that were heavily sedated. Chemical analysis included measurement of concentrations of sodium, potassium, magnesium, chloride, bicarbonate, phosphorus, and glucose as well as osmolality and pH. RESULTS: With the exception of potassium concentrations, values for aqueous humor composition did not differ significantly between llamas and alpacas. Mean +/- SD values for llamas and alpacas, respectively, were: sodium, 154.7 +/- 2.1 and 152.7 +/- 2.1 mEq/L; potassium, 5.3 +/- 0.4 and 4.6 +/- 0.4 mEq/L; magnesium, 1.8 +/- 0.1 and 1.7 +/- 0.1 mg/dl; chloride, 130.0 +/- 1.6 and 127.0 +/- 3.3 mEq/L; bicarbonate, 19.2 +/- 1.5 and 20.2 +/- 2.3 mEq/L; phosphorous, 2.7 +/- 0.3 and 2.5 +/- 0.4 mg/dl; glucose, 80.3 +/- 3.9 and 80.8 +/- 7.3 mg/dl; total protein, 29.0 +/- 8.6 and 31.5 +/- 10.1 mg/dl; and osmolality, 305.8 +/- 11.8 and 306.2 +/- 4.9 mOsm. The pH ranged from 7.5 to 8.0 for both species. Potassium concentrations were significantly higher in llamas than alpacas. CONCLUSIONS AND CLINICAL RELEVANCE: Except for potassium, composition of aqueous humor did not differ significantly between llamas and alpacas. Aqueous humor composition of llamas and alpacas is similar to that of other species that have been examined.

Clinical ocular toxoplasmosis in neonatal kittens.

OBJECTIVE: To describe ocular findings in kittens with congenital or early neonatal infection by Toxoplasma gondii and to determine if there are detectable differences in disease caused by three strains. ANIMALS STUDIED: Six adult female cats and the offspring from seven litters. METHODS: Four kittens from uninfected specific pathogen-free (SPF) queens and 21 kittens from SPF queens inoculated at various times late in gestation with Mozart, Maggie, or ME-49 strain of T. gondii were used. Ocular examinations were performed on queens prior to and after delivery, and on kittens weekly to bi-weekly for up to 27 weeks. Whole blood for serology was collected from all kittens at 5(1/2) to 8 weeks of age and again at 12 weeks of age or later. RESULTS: No kittens from noninfected queens developed ocular lesions or antibody to T. gondii. Three of the 24 kittens from infected queens died or were euthanized early in the study. Chorioretinitis was detected in 15 of 21 living kittens from infected queens. Two developed concurrent anterior uveitis that resolved within 1 week. Posterior segment lesions varied ophthalmoscopically between strains. Of 21 kittens from T. gondii-infected queens, six developed positive antibody titers to T. gondii during the study. All seropositive kittens were born to queens infected with Mozart strain of T. gondii. CONCLUSION: Results of this study suggest that ocular toxoplasmosis can occur without other evidence of clinical illness in kittens infected in utero or in the neonatal period, and that T. gondii strains may have varying degrees of ocular pathogenicity in cats.

Comorbidities and exercise capacity in older patients with intermittent claudication.

Patients with peripheral arterial disease (PAD) and intermittent claudication often have coronary artery disease (CAD) and other comorbid medical problems. There is a paucity of information on the impact of coexistent medical conditions on exercise capacity and functional status in patients with PAD. This study examined the impact of CAD, diabetes, cigarette smoking, prior peripheral surgical revascularization and other medical conditions on claudication pain times and peak oxygen capacity (VO2) during maximal effort treadmill testing in 119 male outpatient volunteers (ankle-brachial index (ABI) of 0.65 +/- 0.2, mean +/- SEM) with a history of Fontaine Stage II PAD. Smoking status was significantly related to ambulatory function. Current smokers had a lower peak VO2 expressed in l/min than either former or never smokers (ANCOVA adjusted for age, p = 0.003). However, after adjustment for body weight, there was only a trend for a difference in peak VO2 between current (13.2 +/- 0.5 ml/kg per min), former (14.2 +/- 0.4 ml/kg per min) and never (15.4 +/- 1.0 ml/kg per min) smokers (ANCOVA, p = 0.10). Current smokers had a shorter time to onset of claudication pain (p = 0.023) and shorter maximal claudication pain times (p = 0.029) than former or never smokers (p = 0.023). The ABI 1 min after cessation of exercise was also lower in smokers compared to former and never smokers (p = 0.018). There were no significant differences in functional performance measures or time to recovery from maximal claudication pain when patients were categorized on the presence or absence of CAD, diabetes, peripheral revascularization, arthritis, hypertension or dyslipidemia. Therefore, smoking adversely affected exercise capacity in these PAD patients, whereas the presence of CAD, diabetes and other medical problems had a relatively minor impact on exercise capacity. In conclusion, the relatively minor impact of comorbid medical conditions on walking ability in patients with PAD reflects the overwhelming limitation in ambulatory function due to the claudication pain.

A new device to limit extravasation during contrast-enhanced CT.

OBJECTIVE: The extravasation detection accessory (EDA) is designed for use during contrast-enhanced CT studies performed with a power injector. The EDA detects the changes in soft-tissue impedance that occur with enhanced extravasation and halts the further infusion of contrast material via a feedback circuit to the injector. We tested the sensitivity of this device in a model of contrast extravasation. MATERIALS AND METHODS: Study subjects had an extravasation of 5% dextrose in water (nonionic contrast equivalent) in one arm and 0.9% sodium chloride solution (ionic contrast equivalent) in the other. An EDA was placed over the site of infusion and connected to a power injector. Injections were performed at 0.25 ml/sec (n = 40), 2.5 ml/sec (n = 62), or 5 ml/sec (n = 20). RESULTS: At infusion rates of 2.5 and 5 ml/sec, the device halted the injector in every subject after an average volume of 12.5 +/- 1.6 ml was delivered. At 0.25 ml/sec, the device failed to halt the injector in 11 of 20 events. After reprogramming the algorithm, 10 more subjects were tested at the lowest injection rate. The device halted 18 of 20 extravasation events with an average volume of 3.7 +/- 0.5 ml. CONCLUSION: In our model of contrast extravasation, the EDA halted a power injector with reliability and reproducibility before a large volume of contrast material was delivered. The sensitivity of the device approached, but did not reach, 100%. This device may serve to diminish the morbidity of extravasation events.

Intraocular pressure in normal llamas (Lama glama) and alpacas (Lama pacos).

OBJECTIVE: To determine the mean intraocular pressure in llamas (Lama glama) and alpacas (Lama pacos) using applanation tonometry.Animals studied: Ten llamas and 10 alpacas.Procedures: Intraocular pressure (IOP) was measured with a Tono-Pentrade mark XL (Mentor Ophthalmics, Inc., Norwell, MA, USA). Three values, with 5% variance, were recorded for each eye. Least-squares means were determined for IOP for each eye of llamas and alpacas. Controlling for age, differences between left and right eye were analyzed using ANOVA. Two age groups were established, less than 5 years and greater than 5 years. The effect of age on IOP within each group was analyzed by linear regression. Probability values of less than 0.05 were considered significant. RESULTS: Comparison of mean IOP between right (n = 20) and left eyes (n = 20), independent of species type, showed no differences in IOPs for llamas and alpacas. Mean IOP declined with increasing age in llamas and alpacas. Mean IOPs for 20 eyes in 10 llamas was 16.96 +/- 3.51 mmHg. Mean IOP for 20 eyes in 10 alpacas was 16.14 +/- 3.74 mmHg. Mean IOP for all eyes (n = 40), independent of species, was 16.55 +/- 3.55 mmHg. The range of IOP in normal llamas and alpacas within 2 SD (95% of the population) was 14.89+/-18.21 mmHg. CONCLUSIONS: There was no significant difference in IOP between alpacas and llamas. Mean IOP in both species decreased with increased age.

Effects of exercise rehabilitation on cardiovascular risk factors in older patients with peripheral arterial occlusive disease.

OBJECTIVE: The purpose of this study was to determine whether a 6-month exercise rehabilitation program can improve cardiovascular risk factors in patients with peripheral arterial occlusive disease (PAOD). METHODS: Thirty-four patients (mean age, 68 +/- 8 years; range 54-84 years) with PAOD with intermittent claudication (Fontaine stage II) and 14 longitudinal controls of comparable age with stage II PAOD enrolled in an exercise intervention at the University Medical Center and Veterans Affairs Medical Center at Baltimore, Maryland. The main outcome measures were lipid profile (total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol [LDL-C]), fasting glucose, blood pressure, body mass index, treadmill times to onset and maximal claudication pain, cardiopulmonary function (peak oxygen uptake), and ankle/brachial index. RESULTS: With exercise rehabilitation, treadmill times to onset and maximal claudication pain increased by 106% and 64% (P <.0001), whereas peak oxygen uptake increased 7% (P <.05). Exercise rehabilitation lowered total cholesterol and LDL-C levels by 5.2% (P <.005) and 8% (P <.01), respectively. Systolic blood pressure declined by 5.7% (P <.05) with no change in diastolic blood pressure. These changes in cholesterol and LDL-C concentrations were related to their initial values. All other cardiovascular risk factors measured did not change. There was no correlation between improvement of cardiovascular risk factors and functional performance measurements. None of the variables measured changed significantly in the control group. CONCLUSIONS: Exercise rehabilitation not only improves functional performance, but also results in favorable alterations in cardiovascular risk factor profile, which is an important element in the management of PAOD.

Chronic venous insufficiency is associated with increased platelet and monocyte activation and aggregation.

PURPOSE: This study assessed whether the increased numbers of platelet-monocyte aggregates observed in patients with venous stasis ulceration (VSU) represent a response to dermal ulceration or if it is a condition associated with underlying chronic venous insufficiency (CVI). We also analyzed the expression of CD11b in patients with CVI to determine whether leukocyte activation, known to occur in VSU, is a precursor of or a response to ulceration. METHODS: Patients with varying classes of CVI (n = 24) and healthy control subjects (n = 15), whose status was documented by means of duplex scanning, stood upright and stationary for 10 minutes. Two aliquots of blood, drawn from a distal leg vein and an antecubital fossa vein, were incubated with either buffer or one of three platelet agonists. After fixation, these samples were further incubated with fluorescent-labeled monoclonal antibodies (f-MoAb) specific for CD14 (monocytes) and CD61 (platelets). The activated leukocyte assay was performed by incubating another aliquot of the blood samples with f-MoAb specific for CD11b and CD14. All samples were evaluated by means of flow cytometry. RESULTS: We observed significantly more platelet-monocyte aggregates throughout the circulation in patients with CVI than in control subjects (29% vs. 8%; P <.0002). Furthermore, patients with CVI formed significantly more of these aggregates in response to all platelet agonists than did control subjects. There were no significant differences between baseline numbers of aggregates or response to agonists in patients who had CVI with (n = 10) or without (n = 14) ulceration. Patients with CVI had more circulating platelet-neutrophil aggregates than control subjects (7.2% vs. 3.6%; P =.05). The addition of platelet agonists to the blood of patients with CVI resulted in more platelet-neutrophil aggregates than in control subjects. Monocyte CD11b expression was higher in patients with CVI than in control subjects (7.5 vs. 3.7; P <.01), with no differences noted in CD11b expression between patients with or without ulceration. Neutrophil CD11b expression was low and similar in control subjects and patients with CVI. CONCLUSION: All classes of CVI are associated with significantly increased percentages of platelet-monocyte aggregates and increased percentages of platelet-neutrophil aggregates throughout the circulation. The presence of more of these aggregates and the increased propensity to form aggregates in the presence of platelet agonists in all classes of CVI suggests an underlying state of platelet activation and increased reactivity that is independent of the presence of ulceration. The increased expression of monocyte CD11b throughout the circulation in all classes of CVI suggests that although systemic monocyte activation occurs in CVI, its presence is independent of VSU as well.

The prevalence of carotid artery stenosis in patients undergoing aortic reconstruction.

BACKGROUND: Coronary artery disease occurs frequently in patients undergoing aortic reconstruction, and it has been presumed that internal carotid artery occlusive disease is also common. This has led to the practice of screening for and repairing significant carotid lesions in asymptomatic patients prior to aortic reconstruction. The purpose of this study was to determine the true prevalence of internal carotid artery disease in these patients. METHODS: The records of 240 patients who underwent duplex ultrasound screening for carotid artery disease prior to aortic reconstruction were reviewed. Surgery was performed for aortic aneurysm (AA) or aorto-iliac occlusive disease (AO). The prevalence of hyperlipidemia and coronary artery disease was similar between the two groups, but tobacco use, hypertension, and diabetes mellitus differed. RESULTS: Internal carotid artery stenosis > or = 50% occurred in 26.7% of the total group (64 of 240 cases). Stenosis > or = 50% was more common in the AO group (40 of 101 cases, 39.6%) than the AA group (24 of 139 cases, 17.3%, P = 0.0001). Severe disease (70% to 99%) was also more common in the AO group than the AA group (9.9% versus 3.6%, P = 0.0464). CONCLUSION: Internal carotid artery disease occurs commonly in patients undergoing aortic reconstruction, and screening is worthwhile. Significant disease is more common in patients with aorto-iliac occlusive disease than in those with aortic aneurysm, although atherosclerotic risk factors occur with varying frequency in the two groups. These findings suggest that additional factors may contribute to the higher prevalence of internal carotid artery stenosis in aorto-iliac occlusive disease.

Sequencing and characterization of the citrus weevil, Diaprepes abbreviatus, trypsin cDNA. Effect of Aedes trypsin modulating oostatic factor on trypsin biosynthesis.

Trypsin mRNA from the citrus weevil, Diaprepes abbreviatus, was reverse transcribed and amplified by PCR. A cDNA species of 513 bp was cloned and sequenced. The 3' and 5' ends of the gene (262 bp and 237 bp, respectively) were amplified by rapid amplification of cDNA ends, cloned and sequenced. The deduced sequence of the trypsin cDNA (860 bp) encodes for 250 amino acids including 11 amino acids of activation and signal peptides and exhibited 16.8% identity to trypsin genes of selected Lepidoptera and Diptera. A three-dimensional model of Diaprepes trypsin contained two domains of beta-barrel sheets as has been found in Drosophila and Neobellieria. The catalytic active site is composed of the canonical triad of His41, Asp92 and Ser185 and a specificity pocket occupied by Asp179 with maximal activity at pH 10.4. Southern blot analysis indicated that at least two copies of the gene are encoded by Diaprepes midgut. Northern blot analysis detected a single RNA band below 1.35 kb at different larval ages (28-100 days old). The message increased with age and was most abundant at 100 days. Trypsin activity, on the other hand, reached a peak at 50 days and fell rapidly afterwards indicating that the trypsin message is probably regulated translationally. Feeding of soybean trypsin inhibitor and Aedes aegypti trypsin modulating oostatic factor affected trypsin activity and trypsin biosynthesis, respectively. These results indicate that Diaprepes regulates trypsin biosynthesis with a trypsin modulating oostatic factor-like signal.

Adenosine A2a receptors increase arterial endothelial cell nitric oxide.

BACKGROUND: Adenosine is a potent vasodilator of vascular smooth muscle. Endothelium-derived nitric oxide (NO) elicits vasodilation. We have previously reported that adenosine stimulates the production of NO from porcine carotid arterial endothelial cells (PCAEC) via a receptor-mediated mechanism. This study was to determine whether adenosine also enhances NO production from human arterial endothelium and to define the involvement of adenosine A1 and A2 receptors. MATERIALS AND METHODS: Human iliac arterial endothelial cells (HIAEC) and PCAEC were harvested and cultured in dishes. NO production was evaluated with a NO electrode sensor which measured continuously real-time NO production. RESULTS: NO content of the medium bathing HIAEC and PCAEC was significantly increased with adenosine (100 micromol/L). Ethylcarboxamidoadenosine (NECA), a nonselective adenosine receptor agonist, and carboxyethyl-phenethylamino-ethylcarboxamidoadenosine (CGS-21680), a selective adenosine A2a receptor agonist, increased NO production by HIAEC and PCAEC with respective EC50 values of 3.32 and 6.96 nmol/L for NECA and 30.97 and 29.47 nmol/L for CGS-21680. Chlorofuryl-triazolo-quinazolinamine (CGS-15943; 1 micromol/L), an adenosine A1 and A2 receptor antagonist, and aminofuryltriazolotriazinyl-aminoethylphenol (ZM-241385; 1 micromol/L), a selective adenosine A2a receptor antagonist, inhibited the effect of CGS-21680. Chlorocyclopentyl-adenosine (CCPA; 1 micromol/L), an adenosine A1 receptor agonist, significantly depressed NO production by both HIAEC and PCAEC: This effect was inhibited by cyclopentyl-dipropylxanthine (DPCPX), a selective adenosine A1 receptor antagonist. CONCLUSIONS: The results demonstrate that adenosine A2a receptors increase, and adenosine A1 receptors decrease, the production of NO by human and porcine arterial endothelial cells.

Diaspirin crosslinked hemoglobin (DCLHb): more effective than lactated Ringer's solution in restoring central venous oxygen saturation after hemorrhagic shock in rats.

Central venous oxygen saturation (ScvO2) has been shown to reflect tissue oxygen consumption in hemorrhagic shock. The purpose of this study was to test whether the "blood substitute" diaspirin crosslinked hemoglobin (DCLHb, Baxter Healthcare, Round Lake, IL) might be more effective than lactated Ringer's solution (LR) at restoring tissue oxygenation, as measured by ScvO2, when used as a resuscitative fluid following hemorrhage. Conscious male Sprague-Dawley rats (250-350 gm) were bled through a jugular venous catheter to a target central venous base deficit of 15 +/- 2 mmol/L. Animals were immediately resuscitated with either 10% DCLHb (1:1) or LR (3:1), based on shed blood volume, followed by a maintenance infusion of LR until completion of the experiment. Central venous blood was sampled at baseline, prior to resuscitation and every 15 minutes for the first hour following resuscitation. While the baseline and pre-resuscitation ScvO2 values were not significantly different between groups, ScvO2 values were greater (P < or = 0.01) in the DCLHb group at all times following resuscitation. Furthermore, DCLHb restored SvO2 to baseline by 15 minutes after resuscitation, whereas LR resuscitation never restored ScvO2 to baseline. Since venous desaturation is one of the major compensatory mechanisms by which oxygen consumption is maintained under conditions of limited oxygen supply, these data suggest that animals resuscitated with DCLHb had a more rapid restoration of tissue oxygenation than those resuscitated with LR in this model of hemorrhagic shock.

Subcutaneous oxygen tension: a useful adjunct in assessment of perfusion status.

OBJECTIVES: Using a new fluorescence-quenching optode which, unlike earlier oximeters, neither consumes oxygen nor generates heat, we sought to determine the effects of hemorrhage and resuscitation on subcutaneous PO2. Additionally, we compared the effects of resuscitation with diaspirin crosslinked hemoglobin, an oxygen-carrying solution, on subcutaneous PO2 to that of traditional resuscitative fluids. We also compared mean arterial pressure and central venous oxygen saturation, indirect indices of perfusion, to subcutaneous PO2, a direct index of perfusion. DESIGN: Prospective trial, randomized for selection of treatment regimen. SETTING: Shock-trauma laboratory of a medical university. SUBJECTS: Male Sprague-Dawley rats, weighing 260 to 380 g. INTERVENTIONS: Rats were bled 22 mL/kg and resuscitated, 1 min later, with either 66 mL/kg of lactated Ringer's solution, 22 mL/kg of human serum albumin, 22 mL/kg of blood, or 22 mL/kg of diaspirin crosslinked hemoglobin. A fifth group of animals was not resuscitated after hemorrhage. Subcutaneous PO2 and mean arterial pressure were monitored continuously throughout the experiment, while central venous oxygen saturation was measured intermittently. MEASUREMENTS AND MAIN RESULTS: Subcutaneous PO2 decreased in response to hemorrhage and, although it did increase after resuscitation with each fluid, no treatment was able to restore subcutaneous PO2 to baseline within 2 hrs postresuscitation. Subcutaneous PO2 continued to decrease after hemorrhage in the unresuscitated animals. In contrast, mean arterial pressure was restored to baseline values in only blood- and diaspirin crosslinked hemoglobin-treated animals, although this effect was lost within 30 mins in the blood-treated group. Only blood restored the central venous oxygen saturation to baseline values in the early postresuscitation period. CONCLUSIONS: The fluorescence-quenching optode consistently followed changes in subcutaneous PO2 during hemorrhage and after resuscitation. Diaspirin crosslinked hemoglobin performed as well as blood in restoring peripheral perfusion, as measured by subcutaneous PO2, while both of these fluids were superior to either lactated Ringer's solution or albumin. Both whole blood and diaspirin crosslinked hemoglobin restored mean arterial pressure to baseline, although the effect of the latter was of a longer duration. The pressor effect of the crosslinked hemoglobin did not affect peripheral perfusion, as reflected by the values for subcutaneous PO2. Subcutaneous PO2 is a useful adjunct in assessment of the adequacy of peripheral perfusion and may help redefine targets for resuscitation.

Diaspirin crosslinked hemoglobin (DCLHb) attenuates bacterial translocation in rats.

Intestinal barrier function is compromised following severe hemorrhage which may allow bacterial translocation (BT) to occur and subsequently initiate a systemic response leading to multiple system organ failure (MSOF). This study compared BT following hemorrhage and resuscitation with lactated Ringer's solution (LR) or diaspirin crosslinked hemoglobin solution (DCLHb). Rats (250-350 grams) were hemorrhaged to a base deficit of 15 +/- 2 mmol/L and immediately resuscitated with either 3:1 LR or 1:1 DCLHb based on shed blood volume. Four hours following resuscitation, the mesenteric lymph node complex was harvested, homogenized and plated onto MacConkey and Columbia CNA agar culture media. Facultative anaerobic and obligate aerobic bacteria were identified 48 hours later in 11/22 (50%) LR-treated rats and in 4/21 (19%) DCLHb-treated rats (p < or = 0.05). Following resuscitation, base excess (BE) and central venous oxygen saturation (SvO2) were not only restored to baseline but were significantly greater (p < or = 0.05) in DCLHb-treated rats than in LR-treated rats. In a separate group of rats subjected to the same hemorrhage and resuscitation protocol, mean arterial pressure in DCLHb-treated rats, but not LR-treated rats, was restored to baseline by 15 minutes and remained at or above baseline for up to 4 hrs. Twenty-four hour survival was 50% in LR-treated rats and 77% in DCLHb-treated rats (p > 0.05). These data suggest that DCLHb is superior to LR in restoring tissue oxygen delivery, as judged by BE and SvO2. Furthermore, since DCLHb restores oxygen delivery and attenuates BT, early resuscitation with DCLHb may limit gut ischemia and subsequent gut barrier failure and hence prevent the development of sepsis, MSOF and subsequent death.

The efficacy of diaspirin crosslinked hemoglobin solution resuscitation in a model of uncontrolled hemorrhage.

Controversy exists whether early aggressive fluid therapy in the setting of uncontrolled hemorrhage worsens outcome by increasing blood loss from injured vessels. Since diaspirin crosslinked hemoglobin (DCLHb) is a vasoactive, oxygen-carrying solution, we compared the effects of DCLHb with other resuscitative fluids on blood loss, hemodynamics, and tissue oxygen delivery in a model of uncontrolled hemorrhage. Anesthetized rats (250-350 g) were subjected to a 50% tail transection and resuscitated 15 minutes later with 1:1 DCLHb, 3:1 lactated Ringer's solution (LR), 1:1 hypertonic saline (7.5% HTS), or 1:1 human serum albumin (8.3% HSA) based on initial volume of blood loss (average 4.7 +/- 0.3 mL/kg). An unresuscitated group served as a control. Cumulative blood loss was measured at 5 hours postresuscitation. By 15 minutes after tail transection, mean arterial pressure (MAP) decreased 19.2 +/- 3.8 mm Hg from the baseline value (102 +/- 5 mm Hg). The DCLHb solution restored and maintained MAP and subcutaneous tissue oxygen tension at baseline values better than all other resuscitative fluids. Although blood loss in DCLHb-treated animals was greater than in unresuscitated animals, it was no different from other resuscitative fluids and less than with HSA. There was no difference in 24-hour survival between all treatment groups. In conclusion, DCLHb elevates MAP but does not exacerbate blood loss or compromise tissue oxygen delivery compared with other resuscitative fluids in this model of uncontrolled hemorrhage.

Toxoplasma gondii-specific antibodies in the aqueous humor of cats with toxoplasmosis.

We decided to determine whether Toxoplasma gondii-specific IgM or IgG is produced locally or is deposited in the aqueous humor of T gondii-naive cats after primary or secondary inoculation with T gondii. Cats were orally inoculated with T gondii tissue cysts during weeks 0 and 36. Aqueous humor and serum T gondii-specific IgM and IgG were measured, using ELISA, during weeks 0, 2, 4, 6, 8, 12, 16, 20, 26, 34, 38, 40, 42, 44, 48, 56, 62, 66, and 72 after primary oral inoculation. Total immunoglobulin-based Goldmann-Witmer coefficients were calculated to verify intraocular antibody production. Toxoplasma gondii-specific IgM was not detected in the aqueous humor of any cat. Data indicate that cats have transient local production of T gondii-specific IgG in the aqueous humor after primary and secondary oral inoculations with T gondii tissue cysts. The intraocular immune response to systemic T gondii infection may signal ocular recruitment of antigen-specific lymphocytes that function independently from the general humoral response to T gondii infection. Cautious interpretation of results that suggest intraocular production of T gondii-specific IgG in cats with uveitis is warranted.