Metalloproteinase activity is present in rat urine and derived from the renal cortex

Summary: Matrix metalloproteinases (MP) are important candidates for the degradation of extracellular matrix, but the role of MP in the diseased kidney remains poorly understood. to examine the significance of urinary MP, we first investigated the characteristics of MP in normal rat urine and renal cortex, and then evaluated the urinary MP activity in anti-thymocyte induced glomerulonephritis (Thy.1 GN). Metalloproteinase activity was measured as the EDTA-inhibitable degradation of [³H] gelatin. the enzyme was purified from urine and the renal cortex homogenate in normal Wistar rats by using several chromatographic and gel filtration methods. Both materials contained the identical molecular weight (Mr 126 kDa by gel permeation method) of gelatin-degrading enzymes, the activity of which was inhibited by metal chelating agents and reactivated by ZnC1₂ but not by other proteinase inhibitors. Thy.1 GN was induced by intravenous injection of rabbit anti-thymocyte serum into rats, and daily urine was collected at sequential time points. Urinary MP activity was markedly reduced soon after the serum injection, and returned to the control level in 9 weeks. Conversely, urinary MP-inhibitor activity (Mr 30 kDa), determined as inhibiting activity against MP derived from renal cortex, showed serial changes strikingly reflected as urinary MP activity. These findings suggested that rat urine contained the MP which seemed to be derived from the renal cortex, and the urinary MP activity was decreased in Thy.1 GN model, probably due to the presence of MP-inhibitor. As urinary MP is likely to reflect intra-renal MP, the evaluation of urinary MP may be useful to search metabolic alteration of extracellular matrix in the diseased kidney.     

Abnormalities in visceral evoked potentials from the anal canal in children with chronic constipation

The integrity of the sensory nervous system in the anal canals of chronically constipated children was investigated using evoked potential techniques examining cerebral and spinal evoked potentials from the lower extremities and anal canal. Stimulation of the posterior tibial nerve produced no significant difference in the parameters of spinal and cerebral evoked potentials between 18 controls and 12 chronically constipated chidren. However, stimulation of the anal canal resulted in evoked potentials related to the age and/or consciousness level of the control children. Reproducible cerebral responses were obtained only from nine of these control children, all aged over 4 years, who were examined while awake without sedatives. A typical response was characterized by a polyphasic wave occurring with an onset latency of 79.4± 27.7ms (mean ±SD). In the 12 chronically constipated children, the 5 sedated patients examined while asleep did not show any reproducible potential, as in the controls. However, in the remaining 7 children examined while awake, the occurrence of the anal canal evoked potential was significantly reduced, and only two exhibited a cerebral response. These findings suggest that rectal mucosal perception of the intraluminal stimuli might be disturbed in some children with chronic constipation.     

Application and usefulness of flowcytometry in the haematology laboratory

Recent technological advances, in both hardware and software, and availability of various monoclonal antibodies (MoAb) for membrane antigens of blood cells have expanded the application of flow cytometry (FCM) in medicine. In the haematology laboratory, FCM has been used mainly for assessment of leukemia and lymphoma and for determination of lymphocyte subsets. In acute leukemia, FCM is useful to classify ALL accurately, particularly for bi phenotypic or mixed lineage leukemia. In lymphocyte subset determination, we found that the use of magnetic beads to remove contaminating monocytes and some granulocytes to purify the lymphocyte-population is helpful in clarify the subsets. We present data describing the age dependent variation in lymphocyte subsets in the pediatric population. In early life (up to 2 years old), CD4 (+) 2H4 (+) lymphocyte overwhelmed CD4 (+) 2H4 (-) cells, implying predominance of suppressor-inducer activity. We also presented some cases of markedly increased double negative T cells (gamma/delta TCR) and a rare case of double positive (CD4+, CD8+) T cells.     

Anorectal pressure monitoring during surgery on sacral lipomeningocele. Case report

Intraoperative monitoring of anorectal pressure was used in a case of sacral lipomeningocele accompanied by congenital dermal sinus to protect the physiological function of the anorectal sphincters. This monitoring system consists of a manometric anorectal balloon and neural electrical stimulation. The system was able to differentiate functioning neural structures from surrounding tissues during the operation.     

Middle-ear pressure variations during total intravenous anesthesia with propofol, fentanyl, and ketamine

Purpose As the middle-ear cavity is one of the noncompliant gas-filled cavities, an increase in middle-ear pressure (MEP) instead of volume expansion is observed with inhalation of nitrous oxide (N₂O). Changes in MEP cause many complications, such as ear pain, temporary hearing impairment, and postoperative emesis. Therefore, we investigated changes in MEP during total intravenous anesthesia (TIVA) with propofol, fentanyl, and ketamine (PFK) and inhalation of N₂O. Methods Twelve patients were anesthetized with PFK until 60 min after the induction of anesthesia, and then N₂O (60%) inhalation was started. MEP was measured by impedance audiometry (ranging from −300 daPa to +200 daPa) at 10-min intervals during PFK, and at 2-min intervals after the inhalation of N₂O. Results MEP gradually but significantly increased from the preanesthetic value of 16±8 to 34±12 (SEM) daPa 50 min after the induction of PFK. However, MEP did not exceed the normal limit. The values of MEP in all patients were more than 200 daPa within 36 min after the start of inhalation of N₂O in oxygen. Conclusion PFK had a minimal effect on MEP, whereas addition of N₂O to PFK increased MEP dramatically. Therefore, TIVA, or at least PFK, would be a better choice for patients with middle-ear or upper-airway diseases.     

Activity-dependent survival and enhanced turnover of calcium in cultured rat cerebellar granule neurons

Neurons survive when their activity is maintained. An influential hypothesis on the cellular mechanism underlying this phenomenon is that there is an appropriate range of intracellular Ca²⁺ concentration ([Ca²⁺]i) for survival. The rat cerebellar granule neuron in culture serves as the most often used model system for the analysis of activity-dependent survival, since it does not survive unless an excitant (KCl or glutamate) is added to the culture medium. Against the above-mentioned hypothesis, we found in our previous examination no difference between steady-state [Ca²⁺]i in granule neurons cultured under high KCl (i.e., survival) and low KCl (i.e., death) conditions. In this report, we present the quantitative background of unchanged [Ca²⁺]i between the two culture conditions. Influx of Ca²⁺ due predominantly to L-type voltage-dependent calcium channels was higher in high KCl cultures than in low KCl cultures. At the same time, efflux of Ca²⁺ due to the activity of Ca²⁺/Na⁺ antiport was also higher in high KCl cultures. Additionally, we found that the endocytotic activity was greater in high KCl cultures than in low KCl cultures, as monitored by the rate of uptake of horseradish peroxidase added to medium. Since the uptake was blocked by an internal Ca²⁺ chelator, the increased endocytotic activity in high KCl cultures might be a consequence of the enhanced Ca²⁺ turnover.     

Malacoplakia of the bladder: Efficacy of enoxacine therapy

Malacoplakia of the urinary bladder was seen in a 69-year-old woman with haematuria. We firstly treated her with distigmine bromide, ascorbic acid and trimethroprim-sulfamethoxazole. Haematuria subsided but the lesion did not change after 6 weeks. Thereafter we tried enoxacine therapy. Eight weeks after the medication the tumorous leson disappeared. Bladder biopsy performed 4 months after the initiation of the treatment revealed predominantly granulation tissue. We can find no previous case treated successfully with long-term enoxacine.     

Acute kindling: interstimulation interval effects and spontaneous interictal or ictal epileptiform discharges

With regard to "acute kindling" that signifies progressive changes in various epileptiform discharges produced with repeated electrical stimulations in a brief time span in acute experiments, the interstimulation interval effect was examined. Kindling developments produced respectively with 3 and 30-minute interval stimulations to the visual cortex of rabbits were compared with each other. Eventually, in kindling with a longer interstimulation interval, after-discharges induced in every trial of stimulation were often lengthened in duration more prominently than those with the shorter interstimulation interval and, furthermore, occasional slight relapses in the afterdischarge duration occurred more infrequently in the former than in the latter. These results suggest that the interstimulation interval plays an important role in the development of acute kindling, presumably in relation to postictal inhibition. In addition, spontaneous interictal or ictal epileptiform discharges occasionally arising during the 3-minute interstimulation intervals were reported. These spontaneous discharges may suggest a high epileptogenicity in acute kindling.