Absence of processing enzymes for inactive renin in mouse blood but polymorphonuclear neutrophils contain active renin

The possible role of enzymes in plasma and blood cells for the conversion of inactive renin was investigated in mice of the Balb C strain. The concentrations of both inactive and active renin were unchanged in unfractionated plasma and whole blood during incubation at 37 degrees C for 5 h, indicating, that inactive renin had not been activated. Purified platelets, mononuclear cells (monocytes and lymphocytes), and polymorphonuclear leukocytes were incubated separately with partially purified inactive renin at 37 degrees C for 1 h. Inactive renin was neither activated nor degraded by whole blood cells. Polymorphonuclear neutrophils were also obtained in mice after i.p. injection of fluid thioglycollate medium. Extracts of the polymorphonuclear neutrophils were incubated with partially purified, inactive renin. During incubation at pH 7.5 for 1 h at 37 degrees C, inactive renin was stable and no activation was registered, whereas degradation, without a concomitant increase in active renin, occurred at pH 4.5. Extracts of polymorphonuclear neutrophils were found to contain active, but no inactive renin. The mean amount of renin per cell was 0.5 X 10(-11) Goldblatt units (GU) (range 0.3 X 10(-11) GU - 0.9 X 10(-11) GU; n = 6). These findings argue against a role for the blood cells and plasma in a physiological activation of inactive renin, and do not support the concept that activation of inactive renin in the circulation may participate in homeostasis.     

Herniation pits of the femoral neck: appearance at MR imaging

Herniation pits of the femoral neck are benign lesions recognized because of their characteristic appearance and location on plain radiographs. The appearance of this lesion in seven magnetic resonance (MR) examinations of the hips in five patients is described. MR revealed a well-marginated, round to oval defect in the superior lateral quadrant of the femoral neck with anterior cortical extension in all cases. With T1 weighting the signal intensity within each lesion was uniformly low. All but one case revealed a peripheral margin of absent signal intensity on T2-weighted and out-of-phase images. The MR appearance and location are sufficiently characteristic to allow identification of this lesion and aid in differentiating it from pathologic processes such as avascular necrosis, with which it may be confused.     

Clonidine treatment of neonatal narcotic abstinence syndrome

Clonidine hydrochloride, an alpha 2-adrenergic agonists, was used to treat seven infants who were passively addicted to narcotics because of maternal methadone maintenance. In six of seven infants, the major symptoms of narcotic withdrawal were ameliorated after a total daily oral dose of 3-4 micrograms/kg/day was achieved. One infant failed to respond. No toxic side effects of clonidine were observed at the dosage level used. The results of this pilot study suggest that clonidine may be a safe therapeutic agent for the treatment of neonatal narcotic abstinence syndrome (NNAS). Clonidine treatment of NNAS remains strictly investigational at this time. The relative efficacy and safety of clonidine versus other currently used drug regimens for NNAS also remains to be determined.     

BOOKS

WHO Expert Committee on Drug Dependence: Eighteenth Report. World Health Organization Technical Report Series 1970 Measurements of man at work. An appraisal of physiological and psychological criteria in man-machine systems. Proceedings of a symposium held in Amsterdam in 1969. Edited by Singleton Pletscher, A., & A. Marino (eds.): Psychotropic Drugs in Internal Medicine. The Theoretic, Experimental and Clinical Bases for a Rational Application of Psychopharmacotherapy in Internal Diseases. International Congress Series Schwarz, B., K. Weise & A. Thom: Sozialpsychiatrie in der sozialistischen Gesellschaft. W. J. C. Verhaart: Studies in Neuro-Anatomy No. 8: Comparative Anatomical Aspects of the Mammalian Brain Stem and the Cord.     

The intraprostatic spiral: clinical results in 150 consecutive patients.

The clinical results of treatment of infravesical prostatic obstruction with an intraurethral coil in 150 consecutive patients are reported. A total of 80 patients had urinary retention and 70 had severe prostatism. Median observation time was 8.2 months, with a range of 0 to 40 months. In 75 patients the spiral was removed after a median of 4 months (range 0 to 30 months) because of planned prostatectomy in 17, urinary retention in 16, incontinence in 10, local discomfort in 7, no symptomatic improvement in 13 and causes not related to the spiral (stroke and so forth) in 7. Migration occurred 55 times in 42 patients but this only led to coil removal in 5. A total of 23 patients died with the coil in situ. Voiding symptoms improved considerably in the majority of the patients. Approximately two-thirds of the patients had no or few symptoms, while a fourth had moderate symptoms, leaving only approximately 10% with severe prostatism. Chronic bacteriuria was noted in 52 patients but was not a clinical problem. Calcification on the top and inside of the coil was noted mainly after long-term treatment, and probably necessitated exchange of the coil after 2 to 3 years. We conclude that the prostatic spiral is a useful alternative to an indwelling catheter. However, life-long followup is necessary in most patients.     

Pharmacologically induced erection in patients with multiple sclerosis

Intracavernous injection of papaverine was tested in a group of 29 patients with multiple sclerosis and erectile dysfunction. Acceptable rigidity was obtained in 27 patients of whom 23 started to use self-injections as treatment. During an observation period of 5-12 months (mean 8.5 months) a total of 297 injections (3-35 per patient) were reported and 272 injections (92%) produced rigidity in 8-480 min. One case of priapism was seen. Minor haematomas or ecchymoses were reported in 16 cases. Two patients developed penile indurations after 6 and 19 injections respectively; one of these indurations resolved spontaneously. Self-injection with papaverine was found to be a safe and well-accepted treatment of erectile dysfunction in multiple sclerosis but long term side effects need further elucidation before the treatment is to be used as a routine procedure.     

Antimicrobials for the treatment of aggressive periodontitis

Aggressive periodontitis is characterized by a considerable attachment loss over a relatively short period of time. It may be the consequence of either the presence of highly aggressive pathogens or a highly susceptible host. In the first case, the use of antimicrobials should be beneficial in the treatment of those patients. However, due to the organization of the micro-organisms as a biofilm, the increasing incidence of allergies and resistance against antimicrobials and their side-effects, there is still controversy about their benefit in the treatment of periodontal disease. This paper discusses indications for the use of antimicrobials, the substances prescribed and the type of application under the conditions of aggressive periodontitis.     

Pseudarthrosis following lumbar fusion: detection by direct coronal CT scanning

Twenty patients with fusions of the lumbar spine (seven with pseudarthrosis, 11 with solid bony fusions, and two with fusions that appeared solid but assessment was complicated by the presence of surgical hardware) underwent computed tomographic (CT) scanning in the supine position in the axial plane and, employing a specially designed seat, in the coronal plane. Three-millimeter contiguous sections were acquired. The direct coronal images were compared with those reformated from the axial images. The higher-resolution direct coronal images facilitated the diagnosis of pseudarthrosis and increased confidence in interpretation of normal studies. Direct coronal imaging is easy to perform and in many cases requires fewer scans and less radiation than reformations. Because it provides more useful diagnostic information, direct coronal imaging should replace current methods for evaluating fusions of the lumbar spine.