Left multicystic dysplastic kidney with contralateral ureteropelvic obstruction: report of one case

PURPOSE: The technique of administration and the resulting volume and concentration of the dye delivered to the eye via dye-impregnated paper strips are not standardized or known. The purpose of this study was to use a standard technique for preparation of rose bengal dye from commercially available paper strips to determine the variability in concentration based upon soak time, and to determine the volume delivered by such a technique to a model eye. METHODS: Rose bengal filter paper strips were wetted for either 15, 30, or 45 s, and the resulting concentration of dye eluted was determined by spectrophotometry. With the same preparation technique and a 15-s soak time, the strip was applied to wetted filter paper, as a model for the moist surface of the eye. The volume of solution delivered was calculated by weight. RESULTS: Concentrations of rose bengal for the various soak times were: 15 s: 7.64 (+/- 1.11) by 10(-6) g/ml; 30 s: 9.70 (+/- 1.79) by 10(-6) g/ml; and 45 s: 10.27 (+/- 0.66) by 10(-6) g/ml. The volume delivered to the eye model with this technique was 17.43 microliters (+/- 3.09). CONCLUSIONS: The concentration of rose bengal dye delivered to the ocular surface by means of a wetted strip is relatively low and soak time/technique-dependent. This suggests a possibility that results in clinical studies with rose bengal strip application may be different than if controlled volume applications of commercially available 1% liquid rose bengal dye are used.     

The use of intravital microscopy in surgical research. 26-years of experience analyzed by studies presented at the Surgical Forum of the Annual Congress of the German Society of Surgery

Recent developments in intravital microscopy make this technique an attractive approach to studying microvascular, cellular, and molecular mechanisms of distinct surgical diseases. We investigated the value of this technique in surgical research laboratories by analyzing the studies presented during the past 26 years (1972-1997) at the Surgical Forum of the Annual Congress of the German Society of Surgery. From a total of 2279 papers 188 contributions (8.3%) presented data which derived from the analysis of the microcirculation using techniques, such as H2 and 133Xe clearance, autoradiography, thermodiffusion, laser Doppler fluxmetry, laser speckle, radioactive and fluorescent microspheres, polarographic oximetry, and intravital microscopy. There were 72 presentations (3.2% of all contributions) reporting the use of intravital microscopy, thus reflecting 38.3% of all microcirculatory analyses. Although these numbers may be considered quite small, analysis over time revealed a significant (P<0.05) increase in the number of microcirculatory studies (11.4%) and in particular of those using intravital microscopy (6.3%) in the 1990s when compared to the 1970s (5.3%; 0.1%) and 80th (7.1 %; 1.3%). In 1997, 27 of 165 contributions (16.4%) included microcirculatory analyses, and 18 of the 165 contributions (10.9%) reported results analyzed by intravital microscopy. Thus our analysis reflects an increasing interest of surgical researchers to study in vivo the microcirculation, and by doing so to use intravital microscopy for the elucidation of mechanisms of surgical disease.     

Condition of the microcirculatory bed of cat ventricular myocardium following exposure to gravitational stress]

The status of microcirculatory bed in the cat ventricular myocardium was studied after a single (10 units for 3 min) and repeated effect (6 units for 3 min every other day for a month) of overloading in the cranio-caudal direction (+Qz). The material to examine was taken in 20 min, 1, 3, 7 and 30 days after the completion of the experiment. The myocardial vessels were injected with water emulsion of Indian ink and studied by routine histological methods, amino nitrogen silver impregnation and electron microscopy. A single overloading was stated to result in changes of capillary permiability which was evident in the increasing amount of pinocyte vesicles, polysoma and endothelial plasmic processes. The effect of repeated overloadings produces more severe disorders in the walls of different components of the myocardial microcirculatory bed.     

Prevention of health status impairment in children under conditions of the Extreme North

Normally the rat gingival microcirculatory bed is represented by superficial capillaries, postcapillaries, arterioles, and venules of different diameters. The major changes characterizing microcirculation disorders in experimental periodontitis are edema, arteriolar constriction and dilatation, stasis, and thrombosis, which undergo variously directed shifts in different periods of pathological process.     

Sarthran preserves cochlear microcirculation and reduces temporary threshold shifts after noise exposure

The cause of noise-induced hearing loss remains unclear despite years of both epidemiologic and experimental investigation. Among the many possible pathophysiologic mechanisms that may contribute to noise-induced temporary or permanent threshold shifts are insufficiencies in cochlear blood flow. Although the literature is inconsistent, several histologic and physiologic studies demonstrate signs of reduced circulation in the cochlea after noise exposure. Recent studies using computer-enhanced intravital microscopy complement these earlier findings. Evidence suggests that these microcirculatory events are mediated in part by several circulating factors, including the potent vasoactive peptide angiotensin. This study investigated this possibility by pretreating with the angiotensin receptor antagonist sarthran during noise exposure and examining both cochlear microcirculation and auditory sensitivity. The results of these experiments show noise-induced ischemia in the lateral wall of the cochlea and temporary threshold shifts. Treatment with sarthran prevented this noise-induced microcirculatory ischemia and preserved auditory sensitivity at the low frequencies tested. These findings support a role for the angiotensinergic system during noise exposure and suggest that preservation of cochlear blood flow is functionally related to auditory sensitivity.     

Time course of the endocochlear potential in the isolated cochlea of the guinea pig

The temperature of Hanks' solution changed its potential (-0.48 mV/degrees C in Na(+)-Hanks' and -0.23 mV/degrees C in K(+)-Hanks' solution), but the pH had no clear effect on the potential. The time course of the endocochlear potential (EP) in the isolated cochlea of the guinea pig was measured under some different conditions. When the cochlea was moistened with Hanks' solution, negative EP increased gradually toward 0 mV at 124 min after death. When the cochlea was immersed in Hanks' solution, positive EP was obtained but it depended on the oxygen and the circulation of Hanks' solution. Moderate cooling (5 degrees C) of Hanks' solution had no significant effect on the EP of the isolated cochlea immersed in oxygen-saturated Hanks' solution circulated by oxygen bubbles. The space constant and the amplitude of the displacement responses were independent of the EP in the isolated cochlea. Thus, the positive EP might not show the physiological condition of the isolated cochlea.     

Evaluation of subjective assessments and objective diagnostic tests for diagnosing tear-film disorders known to cause ocular irritation

PURPOSE: To determine which subjective assessments and objective tests have clinical utility as diagnostic tools in ocular irritation associated with Sj?gren's syndrome-related aqueous tear deficiency (ATD), non-Sj?gren ATD, inflammatory meibomian gland disease (MGD) associated with rosacea, and atrophic MGD. METHODS: Forty adults with ocular irritation and 10 with normal ocular surfaces were enrolled in a nonrandomized, nonblinded clinical trial. Symptoms were evaluated. Tests included biomicroscopy; evaluation of tear-film integrity, production, and clearance; fluorescein and rose bengal staining; and serum autoantibody screening. RESULTS: Symptoms were similar among groups and most severe in the Sj?gren's group. Fluorescein tear break-up time was significantly faster in the ATD and MGD groups than that in controls. Schirmer scores were significantly lower in the ATD group than those in MGD and control groups. Tear clearance was delayed in the ATD and atrophic MGD groups. Xeroscope grid distortion was noted only with ATD. The Sj?gren's group had greater loss of naso-lacrimal reflex, slower fluorescein clearance, and greater ocular-surface fluorescein and rose bengal staining than did the others. More MGD subjects had meibomian gland orifice metaplasia and acinar dropout than did those with Sj?gren-related ATD and controls. Schirmer scores correlated inversely with rose bengal staining, corneal fluorescein staining, and grid distortion. Rose bengal staining correlated with grid distortion and loss of nasal-lacrimal reflex, but not with MGD. CONCLUSION: Subjective assessments and objective diagnostic tests have clinical utility as diagnostic tools in tear-film disorders. ATD is correlated with ocular-surface disease. An algorithm summarizing the diagnostic utility of these tests is included.     

The diagnosis of microcirculatory-rheological disorders and their correction in patients with the initial manifestations of insufficiency of the cerebral blood supply

An evaluation was done of the state of bulbar microcirculation and aggregability of blood platelets in 47 patients presenting with early manifestations of cerebral circulatory insufficiency. A correlation was established between the revealed disturbances in the microcirculatory bed and augmentation of aggregational activity of thrombocytes. Computation of the integrative guide, microcirculatory-rheologic index, reflecting objectively the degree of intravascular hemocirculatory disorders has been performed. Treatment with calcium antagonist corinfar, antihypoxic agent actovegin was of particular benefit for the patients when administered in combination; more than half of the parameters characterizing microcirculation, rheologic properties of blood, microcirculatory-rheologic index have all returned to normal.     

Microcirculation in systemic hypertension

In 40 patients with idiopathic systemic hypertension, skin blood flow was evaluated with laser-Doppler flowmetry, transcutaneous measurements of partial pressure of oxygen (PO2) and partial pressure of carbon dioxide (PCO2), and determination of capillary permeability before and after treatment with nifedipine (10 mg tid for four weeks). Also 35 normal subjects matched for age and sex distribution were studied. Before treatment, microcirculatory studies showed a significant decrease in skin flow and venoarteriolar response in hypertensive patients in comparison with normal subjects. Moreover, PO2, PCO2, and capillary permeability were significantly lower in hypertensives. All these microcirculatory parameters significantly increased after nifedipine treatment while both systolic and diastolic pressures decreased. In conclusion, laser-Doppler flowmetry used with other microcirculatory techniques was able to discriminate between normal subjects and hypertensive patients, and it was able to show the improvement in the microcirculation after nifedipine treatment.     

Character of changes in the microcirculatory bed of the mesentery of the small intestine in experimental acute myocardial infarct

On the first day of the development of acute coronary insufficiency there appears a spastic state of all the vascular system of the small intestine mesentery and a deceleration of the blood flow. On the third day after ligation of the coronary artery branch against the background of spasmed arterioles the alternation of sites of constricted and dilated capillaries, postcapillaries and venules was observed, i.e., there was a well pronounced spasticatonical state of the microcirculation bed vessels. On the fifth and seventh day the characteristic features were dilatation and decreased tonus of the venous part of the microcirculatory bed, redistribution of blood and more considerable disorders in microcirculation with aggregation and diapedesis of erythrocytes.     

Low-volume resuscitation with a hemoglobin-based oxygen carrier after hemorrhage improves gut microvascular oxygenation in swine

Using palladium-porphyrin quenching of phosphorescence, we investigated the influence of diaspirin cross-linked hemoglobin (DCLHb) on gut microvascular oxygen pressure (microPO2) in anesthetized pigs. Values of gut microPO2 were studied in correlation with regional intestinal as well as global metabolic and circulatory parameters. A controlled hemorrhagic shock (blood withdrawal of 40 mL/kg) was followed by resuscitation with either a combination of lactated Ringer's solution (75 mL/kg) and modified gelatin (15 mL/kg)(lactR/Gel) or 10% DCLHb (5 mL/kg). After resuscitation, gut microPO2 was similarly improved in the lactR/Gel group (from 25 +/- 10 mm Hg to 53 +/- 8 mm Hg) and the DCLHb group (from 23 +/- 9 mm Hg to 46 +/- 6 mm Hg), which was associated with increased gut oxygen delivery. However, the improvement after resuscitation with DCLHb was sustained for longer periods of time (75 vs 30 min). Mesenteric venous PO2 was increased after resuscitation with lactated Ringer's solution and modified gelatin but not with DCLHb, which was associated with an increased gut oxygen consumption in the latter group. We conclude that measurement of microPO2 by the palladium-porphyrin phosphorescence technique revealed DCLHb to be an effective carrier of oxygen to the microcirculation of the gut. Also, this effect can be achieved with a lower volume than is currently used in resuscitation procedures.     

Effect of focal cochlear vascular lesion on endocochlear potential in guinea pigs

The alteration endocochlear potential (EP) in response to total cochlear ischemia induced by various experimental manipulations has been studied. However, the effect of restricted areal damage to the microvessels (restricted to small area in the lateral wall of a cochlear turn) on the EP value is still unknown. In the current investigation we adopted a photochemical method to produce a focal (i.e., restricted area) microvessel injury in the lateral wall of the guinea pig cochlea and examined the effect of these insults on EP recorded in the same region. The small area of the microvessel lesion (small fenestra: approximately 0.2 x 0.4 mm2) induced by photoactivation did not yield significant EP changes, suggesting that damage to such a small area of microcirculation in the lateral wall of the cochlea has no statistically significant effects on EP values. In subjects with a large area of the microvessel lesion (large fenestra: approximately 0.2 x 0.8 mm2), a decrease in the EP value (mean +/- SEM 7.9 +/- 0.8 mV) was noted. However, the control group animals with a large fenestra but without microvessel lesion also displayed a decrease (8.6 +/- 0.8 mV) in EP. In the current study we were unable to differentiate whether the EP changes in animals with the large fenestra microvessel lesions were caused by the cochlear blood flow decrease or by the surgical preparation. However, the results of this study indicated if the EP value was affected by the large area of the microvessel lesion, the level of decrease would not be large. That is, the EP decrease was less than the EP change in the control group (mean: 8.6 mV). Considering the dependence of EP on blood flow, the data of this study suggest that compensatory mechanisms in the cochlea may maintain the EP following a focal lesion in the lateral wall of the cochlea. This study also indicates that the photochemical method provides a reliable approach to produce the animal model with the focal microvessel lesion in the lateral wall of the cochlea.     

Defining the critical limit of oxygen extraction in the human small intestine

Although animal models have been used to characterize the relation between oxygen consumption and blood flow, reliable data have not been generated in the human small intestine. We perfused segments of human small intestine by using an ex vivo perfusion circuit that allowed precise manipulation of blood flow and perfusion pressure. Our goal was to define the critical level of intestinal blood flow necessary to maintain the metabolic needs of the tissue. Human small intestine (n = 5) tissue obtained at transplantation harvest was transported on ice to the laboratory. A 40-cm mid-jejunal segment was selected for perfusion, and appropriate inflow and outflow vessels were identified and cannulated. Perfusion with an autologous blood solution was initiated through an extracorporeal membrane oxygenation circuit. After a 30-minute equilibration period, arterial and venous blood gases were measured at varying flow rates while maintaining a constant hematocrit level. Arterial and venous oxygen content, arteriovenous oxygen difference (A-VO2 diff), and oxygen consumption (VO2) were then calculated. Our results demonstrated that at blood flows > 30 ml/min/100 g, VO2 is independent of blood flow (1.6 +/- 0.06 ml/min/100 g), and oxygen extraction is inversely related to flow. Below this blood flow rate of 30 ml/min/100 g, oxygen extraction does not increase further (6.3 +/- 0.3 vol%), and VO2 becomes flow dependent. This ex vivo preparation defines for the first time a threshold value of blood flow for small intestine below which oxygen consumption decreases (30 ml/min/100 g). Previous animal studies have correlated such a decrease in oxygen consumption with functional and histologic evidence of tissue injury. This "critical" flow rate in human intestine is similar to that found previously in canine and feline intestine, but lower than that of rodent species.     

The nitric oxide donor sodium nitroprusside protects against hepatic microcirculatory dysfunction in early endotoxaemia

OBJECTIVE: Endotoxin rapidly inhibits the activity of the constitutive endothelial nitric oxide synthase (ecNOS); this precedes the production of NO from inducible NOS (iNOS). This leaves a period in early endotoxaemia with a supposed scarcity of NO. The present study was conducted to examine the effects of external supplementation of NO on liver microcirculation and function. MATERIAL: 13 male Sprague Dawley rats. INTERVENTIONS: The rats underwent laparotomy, and the left liver lobe was exteriorised. All animals were given a bolus dose of endotoxin (LPS) 5 mg/kg intraportally. One group (n = 6) had a continuous infusion of sodium nitroprusside (SNP) 1.4 microg/kg per min started concurrently, the other group (n = 7) was treated with normal saline. The study was terminated after 3 h LPS. MEASUREMENTS AND RESULTS: Intravital microscopy was performed at baseline, at 2 h and 3 h LPS. Hepatic function was assessed by arterial ketone body ratio, acid base values, and bile flow. At baseline 1% of the sinusoids were without perfusion. After 2 h LPS this figure had risen to 9.8+/-1.5% in the SNP group versus 16.9+/-1.4% in the controls (p < 0.05 vs controls). The corresponding values after 3 h LPS were 13.5+/-1.5 versus 19.3+/-1.5% (p < 0.05 vs controls). The leukocyte count in sinusoids and venules had a similar development. Functional parameters were all slightly better preserved in the SNP group, but with no individual significance versus controls. CONCLUSIONS: Infusion of the NO donor SNP in early endotoxaemia attenuates the detrimental effects of LPS on liver microcirculation, most probably by alleviating a relative deficit of NO at the microcirculatory level.     

The tonic sympathetic input to the cochlear vasculature in guinea pig

Vascular tones is an essential component in maintaining steady regional blood flow and dynamic responsiveness of a vascular bed. Sympathetic innervation can contribute to vascular tone. Although certain studies have reported evoked changes in cochlear blood flow (CBF) with activation of the sympathetic fibers to the cochlear vasculature, other studies have failed to show evidence of sympathetic contribution to CBF regulation when the cervical sympathetic fibers were unilaterally sectioned. We hypothesized that the bilateral 'sympathectomy of the stellate ganglia' would remove sufficient sympathetic input to the cochlea to yield a change in CBF resting level. To test this hypothesis a new technique was used to expose the stellate ganglia (SG) bilaterally and induce a chemical sympathectomy. We observed that unilateral SG blockade with 2 microliters of 4 mM lidocaine hydrochloride on either side produced a 5-10% increase in CBF, which recovered to baseline during the following 2 min. A subsequent blockade of the contralateral SG produced a rapid 25-35% increase, which then recovered partially during the following 3-4 min, remaining 5-15% above the baseline over a 20 min measurement period. Superior cervical ganglion transection did not affect CBF. Our results provide evidence for the existence of a tonic sympathetic component in the control of vascular tone in guinea pig cochlea. This neural effect is derived bilaterally from SG. This result is consistent with previous anatomical studies showing the bilateral innervation of the cochlea by the SG sympathetic fibers and with previous physiological studies on the bilaterality of evoked changes in CBF due to electric stimulation of SG.     

The face of Job

PURPOSE: To describe the microcirculation architecture of metastatic choroidal and ciliary body melanoma. METHOD: Histologic sections of 35 metastases from 19 primary melanomas were stained to demonstrate microcirculation. RESULT: The appearance of microcirculatory networks in metastases is independent of the target organ but associated with the size of the metastatic deposit (estimated coefficient = 0.5959; SE = 0.3024; P = .0488). CONCLUSION: The microcirculatory patterns of primary uveal melanomas that are associated with metastatic behavior appear in foci of metastasis, regardless of the site of dissemination.     

Functional evaluation of an experimental model of cutaneous microcirculation and pO2 after surgical excision: traditional method vs laser CO2

Within an experimental study project about the interaction between Laser and biological tissues, the authors utilized a Laser Doppler Flowmeter device and a Polarographic method to study the cutaneous microcirculation and the tissue pO2. Under standardized conditions, the experimental model considered the microcirculation measurement and the ptiO2 before and after the exsection of a cutaneous lozenge on the animals back realized with traditional surgical methods (scalpel and electrotome) or with a last generation CO2 Laser in continuous and in pulsed mode. The Laser Doppler Flowmeter showed that the largest perturbation of the microcirculatory flux occurred after the exsection realized with the scalpel and the electrotome. The CO2 Laser utilized in continuous mode showed an influence slightly lower on the microcirculation while in pulsed mode the perturbation was absent. The ptiO2 measurement showed similar results emphasizing that the CO2 surgical Laser technique is less invasive than the traditional. To sum up, these functional methods allowed a careful microcirculation an ptiO2 evaluation and provided useful information about vasal and metabolic alterations, showing that the CO2 surgical Laser utilized in pulsed mode appears to be the less harmful surgical technique for the tissues surrounding the exsection site.     

Human nasal blood vessels after permanent tracheostomy. Electron-microscopic study

The influence of Dopamine on microcirculation during hemorrhagic shock was investigated by means of the pancreas chamber technique (HEISIG, 1967). Parameter of microcirculation was the corpuscular flow velocity measured with the "flying spot" method. Simultaneously arterial and venous blood pressure, heart rate, blood gases and pH-status were registered. While a Dopamine-dosage of 5 mug/kg/min did not markedly effect perfusion of the pancreas, application of 10 as well as 20 mug/kg/min Dopamine caused a significant improvement of microcirculation. There was no difference between 10 and 20 mug/kg/min Dopamine. The increase of capillary perfusion can certainly not be explained by the small rise of blood pressure that was found under treatment with Dopamine. The results support the statement of the existence of Dopamine-specific receptors in pancreatic vessels. Compared to a group of animals treated with 5 mug/kg/min Dopamine and an untreated control group, survival rate of animals treated with 10 as well as 20 mug/kg/min Dopamine was significantly increased.     

Gabexate mesilate improves pancreatic microcirculation and reduces lung edema in a rat model of acute pancreatitis

We evaluated the effects of a protease inhibitor on the progression of acute pancreatitis in rats. The model was selected and modified to mimic an intermediate stage of the disease. The degree of microcirculatory derangement in the pancrease and of lung edema was determined to assess the effects of gabexate mesilate (ethyl-4-(6-guanidinohexanoyloxy) benzoate methane sulfonate), a synthetic antiprotease, in acute pancreatitis. Male Sprague-Dawley rats (225-275 g) were used. Experimental pancreatitis was established by four intramuscular injections of cerulein (50 micrograms/kg) at 1 hour intervals. Lipopolysaccharide (10 mg/kg) was injected intraperitoneally as an acute septic challenge. Gabexate mesilate was infused intravenously 6 hours after the initiation of induction of acute pancreatitis at doses of 0.01, 0.1, 1, or 10 mg/kg/h. Microcirculatory changes in the pancreas were studied using in vivo microscopy. All animals survived until the end of the experiments. Gabexate mesilate significantly improved pathologic criteria and decreased serum lipase levels at doses of 1 and 10 mg/kg/h. It significantly lessened the severity of lung edema and improved the microcirculatory environment in the pancreas by increasing flow velocity and reducing leukocyte sticking. These results indicate the beneficial effects of gabexate mesilate on pancreatic microcirculation and lung edema in the progression of acute pancreatitis with septic challenge in rats.     

Vessel size, antioxidants, and restenosis: never too small, not too little, but often too late

BACKGROUND: Diagnostic laparoscopy has been used in abdominal trauma patients, although its role is not well defined. The safety of laparoscopic evaluation in trauma patients with severe intraabdominal hemorrhage has not yet been analyzed. The purpose of this study is to evaluate the hemodynamic and metabolic effects of CO2 pneumoperitoneum (COI) in hemorrhaged animals through a retroperitoneal hematoma (RH). METHODS: Twenty-two 15-20-kg mongrel dogs were monitored for systemic and pulmonary hemodynamics, inferior vena cava pressure, and arterial blood gases. After 1 h of baseline, all animals were submitted to a RH. After 45 min the dogs were randomized into two groups. Control (CTR): dogs were submitted only to a RH; pneumoperitoneum (PN): dogs were submitted to a RH and 45 min later they were insufflated to an intraabdominal pressure of 10 mmHg with medical-grade CO2 gas for 30 min. Echocardiography was performed, only in PN animals, at baseline, 45 and 60 min after RH. RESULTS: RH induced a shock condition with low, sustained levels of arterial pressure, cardiac index, left ventricular stroke index, base excess, and oxygen delivery which were further depressed following COI. Three deaths occurred in the PN group, all of them toward the end of COI. During COI, hypercapnia was observed in one animal. COI did not impair systolic function or ejection fraction. CONCLUSIONS: COI with an IAP of 10 mmHg may be deleterious in animals with hemorrhagic shock due to an intraabdominal lesion. These findings could be clinically significant in abdominal trauma patients.