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Biomedical subjects

M Jordan

Publications and source records attributed to M Jordan.

At least 19 recordsLinked to original sources
PubMed1992

Association between growth indicators and volume of lesions in lungs from pigs at slaughter.

Conflicting findings exist among studies on the effect of pneumonia on growth in pigs. We determined the extent of pneumonia in market-weight pigs by use of an objective, volumetric method and linear regression analyses of mean daily gain and days-to-slaughter weight on the percentage of pneumonic lung. In a range of extent of pneumonia between 1.33 and 70.44%, a 10% increase in the volume of pneumonic lung was associated with a decrease in mean daily gain by 41.1 g and a 16.7-day increase in number of days to a slaughter weight of 104.5 kg.

Animals↗
PubMed1992

Conservative management of splenic subcapsular hematoma in the third trimester of pregnancy. A case report.

A delayed splenic hemorrhage from a subcapsular hematoma occurred in association with pregnancy. That rare complication carries a high mortality rate, is rarely diagnosed preoperatively and is correctly diagnosed only 20% of the time. The clinical setting and a high index of suspicion led us to investigate for the presence of a splenic hematoma. A computed tomographic scan was invaluable in establishing the diagnosis. We adopted a conservative approach and followed the patient's clinical course from 28 to 40 weeks' gestation, until she delivered vaginally. In general, patient management (conservative vs. splenectomy) and mode of delivery will depend on how close one is to the initial event, on the patient's and fetus's clinical condition and on the gestational age.

Accidents, Traffic↗
PubMed1991

[Do ulcerogenic pepsins exist? Characterization of polymorphism of human pepsins].

Studies on the role of pepsin in the pathogenesis of peptic ulcer are hampered by lack of suitable methods for the separation, characterization and quantification of different forms of pepsin. As a contribution toward solving this problem, we have developed several electrophoretic systems which exhibit a high resolving power for pepsins and their precursors, pepsinogens. When human gastric juices were fractionated by discontinuous electrophoresis at pH 3.7 in polyacrylamide gel, pepsin was resolved into as many as 20 distinct forms: 3 major isoenzymes (C, A4, A3), 4 less abundant isoforms (C', A6, A4', A3' or A2), 8-10 minor isoforms of pepsin A1 and at least 3 dimeric isoforms of pepsin A (Ad). All the pepsin components were identified by means of bidimensional electrophoresis. Pepsinogens from gastric mucosa were separated by discontinuous electrophoresis at pH 5.5 in the first dimension, then converted to pepsins in the gel by acidification and resolved by electrophoresis at pH 3.7 in the second dimension. Based on discontinuous electrophoresis at low pH, a much needed method was elaborated for the quantification of different forms of pepsin(ogen) within the stomach. This technique will allow detailed clinical studies which may provide insight into the question whether or not there are specific forms of pepsin that are associated with peptic ulcer.

Electrophoresis, Gel, Two-Dimensional↗
PubMed1991

Interneurones of the lumbar cord related to spontaneous locomotor activity in the rabbit. I. Rhythmically active interneurones.

In decorticate, unanaesthetized and curarized rabbit preparations displaying spontaneous fictive locomotor sequences, the firing pattern of neurones was recorded extracellularly in the L6-S1 spinal cord. These neurones, located in the intermediate part of the cord, were not invaded by antidromic stimulation of the hindlimb muscle nerves and thus were considered as interneurones (or propriospinal or tract cells ascending to the brain). When compared to the output from the ipsilateral muscle nerves, these neurones were classified as flexor (F INs) or extensor (E INs) according to the phase of the locomotor cycle when they displayed their maximal firing rate. Among 69 F INs, 33 maintained tonic firing during the periods between episodes of locomotor activity. Their maximal firing rate was in phase with the flexor efferent bursts of the locomotor sequence; during the extensor phase, they maintained an instantaneous frequency (i.f.) that was clearly above the resting i.f. Of these neurones, six became completely silent during the initial flexorextensor coactivation that opened the sequence (F1 neurones) whereas the 27 others increased their firing rate at that time (F2 neurones). The other neurones (36 F3) were silent between the locomotor episodes. Although most of them had a rhythmic activity limited to the flexor bursts, some fired throughout locomotor sequence with a maximal rate during flexor bursts. All the 123 E neurones completely stopped firing during the flexor phase. As was the case for F3 neurone firing, E3 neurone firing (34 neurones) occurred only during periods of locomotor activity. Among the neurones that displayed tonic activity between locomotor episodes, the E2 neurones (24 from 123) remained at this resting value during the extensor phase whereas the E1 neurones (65 neurones) showed an increased i.f. for all or part of this phase. These data, which suggest an asymmetrical genesis of the flexor and extensor activities in locomotion, need to be supported by further analysis.

Animals↗
PubMed1991

Specialization in low vision rehabilitation and visual therapy.

A questionnaire was mailed to members of the Low Vision Section (LVS) of the American Optometric Association (AOA) and the Council on Visual Development (COVD) to determine the practice patterns of low vision clinicians, amount and source of specialty training and the extent of dual specialization in both low vision rehabilitation and visual training by members of COVD. Results indicate that 61.1 percent of AOA/LVS members and 20.9 percent of COVD members examine more than four patients per month who require low vision services. Yet, only 2.1 percent of COVD respondents and 32.2 percent of AOA/LVS respondents spend more than 20 percent of their practice time providing low vision services.

Humans↗
PubMed1991

Evidence for the entrainment of breathing by locomotor pattern in human.

In human, it has been shown that interactions between locomotor and respiratory patterns may lead to locomotor-respiratory couplings termed entrainment. In order to prove that this coupling is really an entrainment, we tried to show that it obeys one of the expected rules, i.e. that it evolves and is not present for all imposed locomotor frequencies. For that purpose, seventeen healthy volunteers were asked to run on a treadmill at 14 different locomotor rates (instead of 2 or 3 in previous works) for 40 s. All the subjects did not exhibit the same coupling and different relationships could be obtained: the most commonly observed was 2:1 (2 locomotor activities for a respiratory one) but other forms could appear (4:1 and even 5:2 or 3:2). When the coupling evolution was followed in the same subject, it did not appear for all locomotor frequencies but only for locomotor periods close to harmonics of respiratory ones (absolute coordination). On both sides of these values, it progressively evolved to relative coordination and to the lack of coordination. When two forms of absolute coordination were observed in a same subject, the phase relationships followed the rules of the entrainment. Compared to data obtained in quadrupeds, these results suggest that the entrainment of breathing frequency by the locomotor activity is due to central interactions between the respiratory and locomotor pattern generators and does not depend on a chemical regulation avoided here by short locomotor sequences.

Breathing Exercises↗
PubMed1990

Kidney transplantation under FK 506.

The experimental immunosuppressive drug FK 506 was given to 36 renal transplant recipients, many of whom were highly sensitized. Ten were undergoing kidney retransplantation, 10 also underwent liver transplantation at an earlier time (6 patients) or concomitantly (4 patients), and 2 patients received a third organ (heart or pancreas) in addition to a liver and kidney. With follow-ups of 4 to 13 months, all but 2 of the 36 patients are alive, 29 (81%) are dialysis free, and most have good renal function. Twenty of the 29 dialysis-free patients are receiving no or low-dose (2.5 to 5.0 mg/d) prednisone therapy. Only one kidney was lost to cellular rejection. However, patients who had antidonor cytotoxic antibodies in current or historical serum samples had a high rate (3 of 9) of irreversible humoral rejection. A low incidence of posttransplant hypertension was noteworthy. Hirsutism and gingival hyperplasia were not observed. Serum cholesterol levels in patients who took FK 506 were unexpectedly low, and the effect on the level of uric acid was minimal. The side effects of FK 506 therapy include nephrotoxicity, neurotoxicity, and potential induction of a diabetic state. These are similar to the side effects of cyclosporine use, but probably less severe. The seeming safety, efficacy, and relative freedom from side effects of FK 506 encourage further trials in kidney transplantation.

Adult↗
PubMed1990

Biological effects of shock waves: effect of shock waves on the liver and gallbladder wall of dogs--administration rate dependence.

The effect of extracoporeal shock waves on the liver and the gallbladder wall was compared in two groups of dogs exposed to 1500 shock waves generated in an electrohydraulic lithotripter with 15 kV and 80 nF. The waves were focused on the gallbladder wall. In the experimental group, a shock wave burst of 10 consecutive waves with an interval of 10 ms between the waves was administered each second; in the control group, single shocks were released each second. The day following shock wave exposure, the dogs were anaesthetized, killed and then dissected. In the liver, subcapsular and intraparenchymal focal haemorrhages occurred in the high pressure field and venous thrombi in portal veins. There was a nonsignificant trend towards an increased number of venous thrombi after burst application. The gallbladder wall was haemorrhagic and oedematous, the mucosa was ulcerated in the focal area; blood clots were found in nearly all gallbladders. No differences were detected between the groups. The free plasma haemoglobin was only increased after fast shock wave administration. Increased haemolysis and the trend towards an increased number of thrombi favour cavitation as a mechanism of shock wave damage. The similar extent of tissue damage suggests that shock wave bursts can be applied for gallstone destruction in humans if the major liver vessels are kept out of the high pressure field.

Animals↗
PubMed1990

Biological effects of shock waves: cavitation by shock waves in piglet liver.

Shock waves are known to generate cavitation in vitro. In vivo, extracorporeal shock waves may cause haemorrhages in tissues. Two types of changes were detected by conventional, real-time B-scan ultrasound when shock waves were administered to 5 piglet livers in vivo: transient changes consisting of bright signals in intrahepatic branches of the portal vein and tributaries of the hepatic vein, presumed to originate from gas bubbles, and stationary changes consisting of brightening of the area along the long axis of the high pressure field, presumed to indicate an increased number of gas-filled bubbles in this area. Transient changes appeared from the start of shock wave administration; bright signals were seen in liver vessels for several hundred microseconds before they were flushed away with the blood flow. Stationary changes appeared later, increased in intensity over several hundred shock waves and persisted for minutes after cessation of shock wave administration. Both types of signals were interpreted as direct evidence that lithotripter shock waves generated cavitation in vivo. Similar signals were received in the partly degassed water of the lithotripter tub. At autopsy of the piglets, focal intralobular haemorrhages and thrombi of portal veins were detected in the shock wave path. The occurrence of cavitation and tissue damage in the same gross area suggests that cavitation might be involved in the generation of tissue damage by shock waves.

Animals↗