Estimation of blood flow in transcutaneous PO2 measurements

A method for estimation of the cutaneous blood flow in transcutaneous PO2 measurements is presented. Recordings of electrode and skin temperature make it possible to compute the effect dissipated to the circulating blood. Eighteen measurements were performed on three healthy volunteers at electrode temperature settings from 37.0 degrees C to 45.0 degrees C. The blood-flow estimates ranged from 0.07 to 0.19 ml . cm-2 . min-1. At an electrode temperature of 45.0 degrees C the investigations showed a tc-PO2 value as low as 7 mmHg (0.9 kPa) which, however, corresponded well to the lowest blood-flow estimate determined. The temperature-corrected (37 degrees C) a-PO2-tc-PO2 gradient ranged from 50 mmHg to 95 mmHg (6.7-12.6 kPa). The investigations confirm the importance of simultaneous determinations of cutaneous blood flow, capillary temperature and cutaneous oxygen consumption in order to describe the connection between arterial and cutaneous oxygen tension. The cutaneous blood flow seems in this connection to be the most important parameter.     

Treatment of cutaneous sporotrichosis with one daily dose of potassium iodide

BACKGROUND: Recommended treatment for cutaneous sporotrichosis consists of a saturated solution of potassium iodide (SSKI) administered in three daily doses (tid). Because compliance with this regimen has been a problem in our previous experience, we evaluated the use of one daily (qd) full dose of SSKI. METHODS: Patients with culture-confirmed cutaneous sporotrichosis were entered in a randomized, nonblinded study to compare the safety and efficacy of qd vs. tid dosage of SSKI. RESULTS: Fifty-seven patients were enrolled to receive either qd (29) or tid (28) SSKI. Three (1 in the qd and 2 in the tid group) were not compliant with the assigned regimen. Side effects were common but mild in both treatment groups (61% in the qd and 42% in the tid group, P = 0.17); treatment had to be discontinued because of side effects in 3 cases (2 in the qd and 1 in the tid group). Overall 26 (89.6%) and 25 (89.2%) of the individuals initially assigned to the qd and tid dosing schedule, respectively, were cured by the treatment. No relapse was detected after 45 days of follow-up. CONCLUSION: These findings suggest that a single daily full dose of SSKI appears to be appropriate therapy for cutaneous sporotrichosis; further studies with larger numbers of patients are required.     

Severe encephalopathy in a child: an uncommon cause

We report the unusual fixed cutaneous variety of sporotrichosis in a patient hailing from Uttarkashi (Uttar Pradesh) in the north-western part of India.     

Fine-needle aspiration cytologic diagnosis of lymphocutaneous sporotrichosis: a case report

A case of lymphocutaneous sporotrichosis initially diagnosed by fine-needle aspiration (FNA) cytology and confirmed by tissue biopsy and culture study is presented. Asteroid bodies and yeast cells with budding, highly suggestive of the disease, were seen in the cytologic and histologic preparations. The pathology of this unusual fungal disease and the role of cytology in the diagnosis are discussed. This is the first case of lymphocutaneous sporotrichosis reported in the cytologic literature as diagnosed by FNA cytology.     

A pediatric case of atypical Mycobacterium avium infection of the skin

We report a case of cutaneous atypical mycobacteriosis in a 12-year-old healthy girl due to Mycobacterium avium. The cutaneous symptoms were three well-defined subcutaneous nodules on both buttocks and on the posterior surface of the left thigh. One had a fistulous opening on the skin surface. Histopathological examination revealed epithelioid cell granulomas surrounded by dense lymphocytic infiltration and acid-fast bacteria were seen with modified periodic acid-carbol fuchsin staining. Using Ogawa's medium at 37 degrees C, acid-fast bacteria were isolated from the biopsied specimen and identified by the DNA-DNA hybridization method as Mycobacterium avium. In drug susceptibility test, these were resistant to all antituberculous drugs. Oral administration of minocycline 100 mg/day for two months had little effect on the two remaining lesions, which were therefore excised. Based upon reported cases of Mycobacterium avium complex, we considered that our pediatric patient with multiple intradermal or subcutaneous nodules on the buttocks and the thigh exhibited the characteristic symptoms of M. avium infection.     

Responses of cutaneous A-fiber nociceptors to noxious cold

Responses of cutaneous nociceptors to natural stimuli, particularly mechanical and heat stimuli, have been well documented. Although nociceptors are excited by noxious cold stimuli, there have been few studies of their stimulus-response functions for cold stimuli over a wide range of stimulus temperatures. Furthermore, the proportion of nociceptors excited by noxious cold is not clear. In the present study, we examined responses of mechanosensitive A delta-nociceptors and low-threshold mechanoreceptors to a wide range of cold stimuli that included stimulus temperatures <0 degrees C. Electrophysiological recordings were made from single primary afferent fibers in the saphenous nerves of anesthetized rats. Cutaneous sensory receptors were classed according to their conduction velocity and subgrouped functionally according to their responses evoked by mechanical, heat, and cold stimuli (0 degrees C). Responses evoked by a wide range of cold stimulus intensities that included stimuli considered innocuous and noxious (painful) were then assessed. Stimuli of 20 to -20 degrees C were delivered to the receptive field via a 1-cm2 contact thermode from a base temperature of 32 degrees C. Stimuli were applied in descending order of 2 degrees C decrements. Stimulus ramp rate was 5 degrees C/s, and stimulus temperatures were applied for a duration of 10 s. A total of 90 A fibers was studied, of which 61 were nociceptors and had conduction velocity in the A delta-range (2-30 m/s). Nociceptors were classed initially as mechanical, mechanoheat, and mechanocold nociceptors. The remaining 29 fibers were low-threshold mechanoreceptors with conduction velocity in the A delta- or A beta-range (>30 m/s). These were subgrouped according to their adaptive properties as slowly or rapidly adapting, and according to whether they were excited by hair movement (hair follicle afferent fibers). All nociceptors were excited by noxious cold. Only 30% of nociceptors were considered sensitive to cold on initial classification with the use of a cold stimulus of 0 degrees C. However, all nociceptors were excited by stimulus intensities <0 degreesC. Response thresholds for cold ranged from 14 to -18 degrees C (-4.6 +/- 1.07 degrees C, mean +/- SE). The total number of impulses, discharge rate, and peak discharge increased monotonically as intensity of cold stimuli increased. Power functions were used to determine the rate at which the number of impulses increased as stimulus intensity increased. The slopes of power funcions ranged from 0.12 to 2.28 (mean 1.07 +/- 0.13). Most mechanoreceptors were not excited by cold stimuli. The only types of mechanoreceptors that responded reliably to cold stimuli were the slowly adapting mechanoreceptors. Responses usually occurred during the temperature ramp when the skin temperature was decreasing. There was no evidence that mechanoreceptors encoded the intensity of cold stimuli at intensities above or below 0 degrees C, because evoked responses did not increase with intensity of cold stimuli. It is concluded that the proportion of cutaneous A delta-nociceptors excited by noxious cold stimuli has been underestimated in previous studies. All nociceptors were excited by stimulus temperatures <0 degrees C and encoded the intensity of cold stimuli. It is therefore likely that cutaneous A delta-nociceptors contribute to the sensation of cold pain, particularly pain produced by stimulus temperatures <0 degrees C.     

Candida parapsilosis infection in a rose thorn wound

Candida parapsilosis should be recognized by primary care physicians as an important nosocomial pathogen, which is also frequently associated with sporadic skin and appendage infections. Its association with environmentally acquired skin ulcers can mimic fixed cutaneous sporotrichosis.     

Cutaneous cryosurgery in family medicine: dimethyl ether-propane spray versus liquid nitrogen

OBJECTIVE: To compare the efficacy, tolerance and safety of two types of cryotherapy, performed by family physicians, for benign cutaneous lesions: low freezing (-59 degrees C) with dimethyl either-propane cryogenic spray (DMEP) and intense freezing (196 degrees C) with conventional liquid nitrogen (LN). DESIGN: A randomised, multi-centered, controlled clinical trial, with single-blind assessment. SETTING: Three primary care teaching teams in the Community of Madrid. PATIENTS AND OTHER PARTICIPANTS: Ten MIR from family & community medicine intervened. There were 124 patients, who had 174 benign cutaneous lesions, suitable for cryotherapy. There were 3 voluntary withdrawals, none because of an adverse reaction. Interventions, in each case there was local application for a standard time of the randomised agent. Control-group intervention, 81 cases: swab soaked in LN. Study-group intervention, 93 cases: swab saturated with DMEP spray. Maximum of three freezings per case, at weekly intervals. MEASUREMENTS AND MAIN RESULTS: A doctor made a blind assessment of the results (elimination, adverse reaction, aesthetic result) 15 days after treatment. CONCLUSIONS: No clinically relevant differences between the efficacy, tolerance and safety of the two cryogenic agents used in primary care were found. The low freezing of DMEP was sufficient for the cryotherapy of benign lesions.     

Spontaneous transfer of GM3 ganglioside between vesicles

The spontaneous transfer between membranes of GM3, a ganglioside present in a vesicular form of aggregation instead of micellar form like the majority of gangliosides in aqueous medium, has been studied. Upon incubation of GM3 in the presence of dipalmitoylphosphatidylcholine (DPPC) large unilamellar vesicles at 50 degrees C, mixed GM3/DPPC vesicles are formed. The maximum amount of GM3 that can be inserted into vesicles is about 8%. The temperature dependence of the kinetics has been followed by the excimer formation technique, using the fluorescent analogue pyrenyldodecanoyl-GM3. The transfer of ganglioside from its vesicles to DPPC vesicles depends on the physicochemical characteristics of both the donor and of the acceptor vesicles and increases with the temperature (k = 0.006 0.012, 0.037 at 30, 41 and 50 degrees C, respectively), with a major break point at 41 degrees C and a minor one at 35 degrees C. These temperatures correspond to the gel- to liquid-crystalline transition of DPPC (Tm = 41.3 degrees C), and to a temperature transition displayed by GM3 ganglioside. Similar experiments performed with erythrocyte ghosts yielded a rate constant of 0.04 at 37 degrees C. For the transfer of ganglioside from DPPC (donor) to DMPC (acceptor) the rate constants were 0 at 15 degrees C (both phospholipids in the gel phase), 0.005 at 37 degrees C (donor in the gel phase, acceptor in the fluid phase) and 0.04 at 50 degrees C (both phospholipids in the fluid phase).(ABSTRACT TRUNCATED AT 250 WORDS)     

Temperature requirements of Chrysomya albiceps (Wiedemann, 1819) (Diptera, Calliphoridae) under laboratory conditions

Chrysomya albiceps specimens were obtained from colonies established with larvae and adults collected at the Federal Rural University in Rio de Janeiro, Seropédica, State of Rio de Janeiro. The larval stage of C. albiceps was allowed to develop in climatic chambers at temperatures of 18, 22, 27 and 32 degrees C, and the pupal stage was allowed to develop at 22, 27 and 32 degrees C (60 +/- 10% RH and 14 hr photoperiod). The duration and viability of the larval stage of C. albiceps at 18, 22, 27 and 32 degrees C were 21.30, 10.61, 5.0 and 4.0 days and 76.5, 88.5, 98.5 and 99.5%, respectively, with mean mature larval weights of 45.16, 81.86, 84.35 and 70.53 mg, respectively. Mean duration and viability of the pupal stage at 22, 27 and 32 degrees C were 9.36, 4.7 and 3.0 days and 93.8, 100 and 100%, respectively. The basal temperature for the larval and pupal stage and for the larval and adult phase were 15.04, 17.39 and 15.38 degrees C, corresponding to 65.67, 44.15 and 114.23 DD.     

Cooling effects on nitric oxide production by rabbit ear and femoral arteries during cholinergic stimulation

1. Ear (cutaneous) and femoral (deep) arteries from rabbit were perfused at 37 degrees C and 24 degrees C (cooling) and the production of nitrite, as an index of nitric oxide production, was measured under basal conditions and cholinergic stimulation. 2. In both types of arteries under control conditions, the basal production of nitrite was similar at 24 degrees C and 37 degrees C. Compared with the control conditions, the basal production of nitrite was significantly lower in ear and femoral arteries without endothelium or treated with NG-nitro-L-arginine methyl ester (L-NAME, 10(-4) M) but it was similar in those treated with atropine (10(-6) M). 3. At 37 degrees C, methacholine (10(-7)-10(-5) M) increased the production of nitrite in ear and femoral arteries; this increase persisted during 30-60 min and was practically abolished by L-NAME (10(-4) M), atropine (10(-6) M), or removal of the endothelium. In ear arteries the total nitrite production to activation with methacholine was higher at 24 degrees C than at 37 degrees C due to this production persisted increased for a longer period (> 150 min), whereas in femoral arteries it was lower at 24 degrees C than at 37 degrees C. 4. It is suggested that: (a) the endothelium of rabbit ear and femoral arteries produce nitric oxide under basal conditions, which is increased by cholinergic stimulation, and (b) cooling potentiates endothelial nitric oxide production to cholinergic stimulation in cutaneous arteries, whereas it inhibits this production in deep arteries.     

Cutaneous granulomatous cladosporiosis

The case of a 41 year old man with a tumorlike cutaneous cladosporiosis on the fifth right finger is described. Histologically seen there was an unspecific granulomatous inflammatory cellular infiltrate in the upper and middle corium, whereas in the deeper corium there were found big macrophages phagocytizing fungical elements pointing to cladosporiosis. The fungi grew up very slowly at a temperature of 30 degrees C. Since 1971 the patient was suffering from a "symptomatic" epilepsy medicamentally controlled. Though a neurotropic action of some cladosporion species is well known there could not be found any hint for a cerebral abscess.     

Modification of venous stasis thrombosis in the rat by platelet-active drugs and by heparin

Incubation of adenovirus type 2 infected cells at 42 degrees C resulted in an inhibition of assembly of virus particles although all the major viral structural polypeptides and virus-induced cellular polypeptides so far identified were detected by electrophoretic analysis. Selective high salt-acid-urea extraction of low mol. wt. polypeptides revealed the absence of protein VII at 42 degrees C whereas precursor polypeptide P-VII and core protein V were found. Pulse-chase and temperature shift experiments indicated that cleavage of P-VII into VII was a reversible thermosensitive process, requiring de novo protein synthesis after shift-down to 37 degrees C. Virus particles assembled at 37 degrees C after transfer from 42 to 37 degrees C contained both viral DNA and polypeptides pre-labelled during the eclipse phase at 42 degrees C, including core protein VII.     

A highly adherent phenotype associated with virulent Bvg+-phase swine isolates of Bordetella bronchiseptica grown under modulating conditions

The ability of Bvg(-)-phase and Bvg(+)-phase Bordetella bronchiseptica swine isolates, grown under modulating or nonmodulating conditions, to adhere to swine ciliated nasal epithelial cells was determined. When virulent strains were cultivated at 37 degrees C in the Bvg+ phase, numerous adherent bacteria (approximately eight per cell, depending on the strain used) were observed. However, when such strains were grown under modulating conditions (23 degrees C), a significant increase in the level of attachment was seen, suggesting that B. bronchiseptica produces a Bvg-repressed adhesin under these conditions. bvg mutant strains, including an isogenic bvgS mutant, adhered minimally. Western blots indicated that two putative B. bronchiseptica adhesins, filamentous hemagglutinin and pertactin, were not detectable in cultures displaying the highly adherent phenotype. Several proteins apparent in Western blots obtained by using bacterial extracts enriched in outer membrane proteins derived from B. bronchiseptica grown at 23 degrees C were not present in similar extracts prepared from an isogenic bvgS mutant grown at 23 degrees C or from the parent strain grown at 37 degrees C. Adherence of bacteria cultivated at 23 degrees C was almost completely abolished by pretreatment of organisms at 60 degrees C; adherence was reduced by 57% when bacteria were pretreated with pronase E. Temperature shift experiments revealed that the heightened level of adhesion that occurs following growth at 23 degrees C was maintained for up to 18 h when bacteria were subsequently incubated at 37 degrees C. We propose that a Bvg-repressed adhesin, expressed only by modulated bvg+ strains of B. bronchiseptica, may play a key role in the initial colonization of naturally infected swine.     

Synergetic interpretation of patterned vasomotor activity in microvascular perfusion: discrete effects of myogenic and neurogenic vasoconstriction as well as arterial and venous pressure fluctuations

Synergetic concepts allow to identify emergent coordination phenomena between interacting physiological systems, for example between the cutaneous microcirculation, the sympathetic nervous system and the cardiac and pulmonary systems. The temporal patterns (oscillations of various frequencies) that are found in the data obtained with laser-Doppler anemometers (LDA; e.g. Periflux 2 used in the study) can be investigated by simultaneous recording of photoplethysmographic data obtained in the identical region of interest, as well as in cutaneous regions treated with vasoparalytic procedures which permit to record the dynamics of the arterial system. These strategies were applied to studies in the cutaneous microcirculation (volar side of the index fingers) as well as to mucosal microcirculation (maxillar gingiva) in healthy subjects and in patients suffering from autonomic dysfunction (cutaneous microcirculation) or gingivitis. By this procedure, it could be corroborated that - contrary to popular notions - the temporal fluctuations in the LDA records do not necessarily reflect myogenic vasomotion, but can have multiple causes. In a confirming recent study [Schmid-Sch?nbein et al., J Auton Nerv Syst, 57, 136-140, 1996], we have demonstrated that the LDA fluctuations under conditions of normal ambient temperature and hand position most likely reflect neurogenic vasoconstriction. Under exceptional conditions, different patterns emerge. Prolonged exposure to ambient temperature (18 degrees C) leads to marked vasoconstriction, with occasional vasodilator escape ('miniature hunting reaction'). Normal subjects under gravitational load and in warm environment (28 degrees C ambient) silence their neurogenetic vasoconstriction reactions, which allows sinusoidal vasomotion to dominate. A similar phenomenon is seen in neuropathic patients at 21-24 degrees C (presumably due to structural defects). Fluctuations in LDA signal taken from the healthy gingiva are entrained to arterial, those taken from inflamed gingiva to respiratory activity. The theory and practice of nonlinear analysis is discussed, and data compression procedures allowing to portray characteristic temporal patterns for future diagnostic procedures are presented.     

Increased yields of Japanese encephalitis virus in heat shocked cell cultures

Monolayers of porcine stable kidney (PS) and baby hamster kidney (BHK-21) cell lines were exposed to 43 degrees C and 41 degrees C, respectively, for 4 hrs and infected with Japanese encephalitis virus (JEV) Nakayama strain at low and high multiplicity of infection. Virus yields were increased by 0.2-2.5 log PFU/ml in heat shocked cultures compared to control cultures at 37 degrees C. This phenomenon was detected in the late phase of replication after 16 hrs post infection. The progeny virus obtained from heat shocked cultures was more thermostable.     

Characterization of nitric oxide synthase in the cerebellum of the chicken

We investigated the effect of a temperature shift from 37 degrees C to 17 degrees C on the steady-state diffusion rate of imipenem and cephalothin by evaluating periplasmic drug concentrations in intact cells of Pseudomonas aeruginosa, which overexpresses the extended spectrum beta-lactamase. We found that the ratio of periplasmic imipenem concentration at 17 degrees C relative to that of 37 degrees C was 1.03+/-0.1, whereas that of cephalothin was 0.43+/- 0.09. Accumulation rates of cell-associated tetracycline and fluoroquinolone at 17 degrees C were roughly 1/16 and 1/8, respectively, compared with that at 37 degrees C. We concluded from these data that cephalothin and possibly most other antibiotics excepting carbapenems cross the outer membrane of P. aeruginosa mainly by dissolving in the lipid phase but probably not passing through the porin channel. This may explain why the outer membrane of P. aeruginosa is a tight barrier against the penetration of antibiotics.     

Short- and long-term variations in non-linear dynamics of heart rate variability

Since in humans, skin temperature is lower than internal temperature, the temperature sensitivity of Leishmania may influence the tropism of Leishmania in the human host; temperature-sensitive parasites may remain in the skin, temperature-resistant parasites may go to the viscera. In order to pursue the genetic factors controlling Leishmania tropism, we have developed an in vitro promastigote temperature model. Promastigote growth is measured at 30, 32, and 34 degrees C and compared with growth at the control temperature (25 degrees C). The results from tests of the promastigote temperature sensitivity of eight species (33 different strains) show that visceral species (L. donovani and L. chagasi) are more temperature resistant than cutaneous species (L. major, L. tropica, L. mexicana, L. braziliensis, L. panamensis, and L. amazonensis), that Old World species are more temperature-resistant than New World species, and that within the New World cutaneous species there are three distinct temperature sensitivity groupings (L. mexicana > L. braziliensis and L. panamensis > L. amazonensis). Interestingly, viscerotropic L. tropica from Operation Desert Storm and L. donovani complex strains isolated from cutaneous lesions are more and less temperature-sensitive, respectively, than strains of the same species with the expected tropism in vivo.     

Exercise and extracorporeal blood cooling during hemodialysis

Intradialytic exercise may improve hemodialysis efficiency. Because exercise interferes with thermal energy and fluid balance, relative blood volume changes (deltaBV%), arterial blood temperatures (T(art)), mean arterial blood pressures, and heart rates (HR) were measured using different dialysate temperatures (Tdia). Four stable patients (age, 49.9 +/- 7.7 years) were studied during 22 treatments that either maintained Tdia at 35.9 degrees C +/- 0.1 degrees C (standard) or provided maximum extracorporeal cooling (cool, Tdia = 34.8 degrees C +/- 0.8 degrees C) in attempts to maintain a constant T(art). Patients exercised for 1 hr at a resistance of 21 +/- 5 W on a stationary bicycle ergometer. Energy expenditure monitored by indirect calorimetry increased from 117 +/- 38 W (baseline) to 338 +/- 116 W (exercise). Mean arterial blood pressures increased by 7 +/- 7 mmHg with cool Tdia, but remained unchanged (-1 +/- 4 mmHg) with standard Tdia (p < 0.05). However, the increase in T(art) was smaller with cool (0.1 degrees C +/- 0.3 degrees C) than with standard (0.3 degrees C +/- 0.2 degrees C) Tdia (p < 0.05). The larger increase in O2 uptake per change in HR (68 +/- 56 vs 38 +/- 17 ml/beat) indicated an increase in stroke volume when cool dialysate was used (p = NS). Exercise produced a small (0.95% +/- 0.95%), but significant, decrease in deltaBV% that reversed at the end of exercise. Intradialytic exercise was well tolerated, especially when Tdia was lowered such that hemodynamic stress to dissipate excess heat through the cutaneous circulation was reduced and blood pressure stability was improved.