Single nephron glomerular filtration rate ratios of superficial,intercortical and juxtamedullary nephrons in rats during development

Summary In 20, 40 and 60-day-old rats the filtration rate was studied, using Baines modification of Hanssen's Na₄Fe(¹⁴CN)₆ method enabeling the determination of single nephron glomerular filtration rate (SNGFR) ratio between superficial (S), intercortical (I) and juxtamedullary (J) nephrons. The proximal tubule lengths were determined as well. A close correlation was obtained between age and S/I, I/J and S/J of proximal tubule lengths and between age and I/J, S/J¹⁴C-activities of ferrocyanide. Presented findings confirm the data on the increasing role of superficial nephrons in the course of postnatal development of rat.     

Comparison of hen egg lysozyme immunoassays based on different labels

To check the concentrations of hen egg lysozyme in foodstuffs, added as a bacteriostatic agent, immunoassays based on different labels have been developed. The following detection limits (defined as non‐specific binding increased by three standard deviations) were achieved using antibody labelled with either peroxidase ¹²⁵ I or a biotin‐streptavidin system: 0–8; 0–75 and 0–13 ng/ml, respectively. Only the most sensitive lysozyme immunoassay was likely to be suitable for application to analysis of cheese because matrix interference effects mean that sample extracts need to be diluted prior to assay.     

Partial purification and characterization of anhydrotetracycline oxygenase of Streptomyces aureofaciens

Anhydrotetracycline oxygenase was purified both by affinity chromatography and by hydrophobic interaction chromatography. Molecular weight of anhydrotetracycline oxygenase was determined to be 115,000 by Sephadex G-200 gel filtration. Using preparative isoelectric focusing the isoelectric point of the enzyme was estimated to be 5.3. The enzyme showed a sensitivity to thiol-specific inhibitors. During the hydrophobic interaction purification step, the activity dropped considerably. Reactivation occurred when a heat treated crude extract was added to the reaction mixture.     

Lysosomal and energy enzyme activities in hypertrophied rat soleus muscle after denervation

Muscle hypertrophy was induced in the soleus muscle of young rats by tenotomy of the gastrocnemius and plantaris muscles. Three and 7 days afterwards the sciatic nerve was sectioned. The loss of weight of muscles subjected to this combined procedure three days after denervation was 30–40%. Lysosomal enzyme activities (acid phosphatase, -glucosidase, -galactosidase and N-acetyl--d-glucosaminidase) and energy enzyme activities (lactate dehydrogenase, LDH, triose-3-phosphate dehydrogenase, TPDH,d-hexokinase, HK and citrate synthase, CS) were determined 3 days after denervation, 3, 7 and 10 days after hypertrophy had been induced and 3 days after denervation of hypertrophying muscles on day 3 and 7. Normal non-operated rats of corresponding body wieght served as controls and their enzyme activities were estimated on the same day. In the course of muscle hypertrophy, the 4 lysosomal enzyme activities increased progressively. Although 3 days' denervation of control muscles did not alter lysomal enzyme activities, denervation of hypertrophying muscles greatly enhanced the activity of these enzymes. Enzymes of energy metabolism were affected to a lesser degree. The results suggest that denervation of hypertrophying muscles causes more extreme changes in muscle weight and lysosomal enzyme activities than denervation alone. The possible implications of this finding are discussed in relation to the rapid atrophy.     

Effects of high doses of testosterone propionate and testosterone enanthate on rat seminiferous tubules — a stereological and cytological study

The effects of exogenous testosterone on various testicular variables has become of increasing significance because of its potential use in male contraception. For this reason, high doses of two testosterone esters [testosterone propionate (TP) and testosterone enanthate (TE)] were used in a study of their influence on the morphology, length and curvature of the seminiferous tubules of the rat testis, and on cytological smears of the seminiferous tubules epithelium. TP was given for 14 days (3 mg/100 g body weight, i. m.) to assess the acute effects of testosterone on the seminiferous tubules. TE was administered for 60 days (in the same manner as TP) to study possible chronic effects on the rat testis. After TP and TE treatment the seminiferous tubule epithelium showed disorganization and desquamation of spermatogenic cells. In the TP-treated testes the tubules lined with Sertoli cells only were observed. The values for the length and curvature of seminiferous tubules of the TP- and TE-treated rats were significantly reduced (p<0.001). All these changes were observed earlier in the TP-treated than in the TE-treated animals. In cytological smears of the testis of the TP- and TE-treated rats an increase of vacuoles and residual bodies in Sertoli cell cytoplasm was noted. In addition, a reduction of spermatogenic cells, particularly sperms, was manifest in the smears after treatment. Large groups of Sertoli cells were seen in the smears from these testes.The study was supported by a Grant for Scientific Research No. 3-01-041 from the Ministry of Science, Technology and Informatics of the Republic of Croatia     

Increased muscle stiffness after anterior cruciate ligament reconstruction – memory on injury?

Residual impairment of knee function was tested in 25 patients 6 to 12 months after successful unilateral reconstruction of the anterior cruciate ligament. The control group comprised 25 healthy individuals. Jumping onto one foot from a height of 20 cm was taken as a prototype of similar everyday activities. We measured maximum flexion of the knee during the landing phase of the jump, and the degree of knee flexion at the time of maximum deceleration of the knee against gravity during jumping using the three-dimensional optical motion analysis system-ELITE. In the group of patients, measured parametres were significantly smaller on the operated side than on the unaffected side. These two measured values were significantly smaller on both legs in group of patients as compared to the values in the control group. The results of our study indicate that functional disturbance persisted for 6 to 12 months after anterior cruciate reconstruction. This may be due to the changed muscle activation pattern of the knee causing increased stiffness of knee muscles. It seems that re-programming of the central nervous system occurred in order to protect the injured lower extremities from another injury.     

Clinical and epidemiological aspects of respiratory syncytial virus lower respiratory tract infections

This paper has analyzed respiratory syncytial virus lower respiratory tract infections in 201 hospitalized children. In children with wheezing, erythrocyte sedimentation rate (ESR) was significantly higher in those with pneumonia than with syndroma pertussis, while the white blood cell (WBC) count was significantly lower in patients with bronchitis than in those with bronchiolitis and syndroma pertussis. Bronchodilatators were applied in 75.6% and corticosteroids in 20% of patients. Ten patients were ventilated. Fatal disease outcome was observed in one infant. Twelve consecutive-year study of respiratory syncytial virus (RSV) infections showed that 27.3% of these diseases were bronchiolitis and pneumonia.     

Cystoid macular edema in anterior chamber lens implantation following posterior capsule rupture

By comparing the incidence of cystoid macular edema (CME) in three groups of patients having different surgical procedures, we attempted to assess the role of vitreous loss as a risk factor for CME development. In the first group (n = 470), the surgical procedure was extracapsular cataract extraction followed by implantation of posterior chamber lens (EC-CE + PC-IOL). The second group (n = 42) had extracapsular cataract extraction which was complicated by posterior capsule rupture, and therefore anterior vitrectomy followed by implantation of anterior chamber lens had to be performed (ECCE + anterior vitrectomy + AC-IOL). In the third group (n = 22) the surgery was intracapsular cataract extraction followed by anterior chamber lens implantation (ICCE + AC-IOL). The third group was included in this follow up study to assess the role of AC-IOL as a possible causative factor for development of CME in uncomplicated cases of ICCE and AC-IOL. The difference of incidences of CME in the second and third group would therefore depend mostly on the vitreous loss. The incidence of CME diagnosed by fluorescein angiography in the first, second and third group was 1.5% (7/470), 35.7% (15/42) and 9.0% (2/22), respectively. All patients who developed CME were treated with combination of corticosteroid-antibiotic drops, dexamethasone retrobulbarly (40 mg/day) and peroral indomethacine (25 mg/day/6 weeks). This therapeutic regime resulted in only moderate improvement of visual acuity.Abbreviations AC-IOL anterior chamber intraocular lens - CME cystoid macular edema - ECCE extracapsular cataract extraction - ICCE intracapsular cataract extraction - IOL intraocular lens - PC-IOL posterior chamber intraocular lens     

The pharmacology of aggressive behavioural phenomena elicited by muscarine injected into the cerebral ventricles of conscious cats

Atropine and scopolamine, injected intraventricularly, abolished typical emotional behaviour with aggression and autonomic and motor phenomena, as well as with clonic-tonic convulsions of intraventricularly injected muscarine. On the other hand, adrenergic and dopaminergic blocking agents, antihistamines, 5-hydroxytryptamine antagonists, antiepileptic drugs, and 5-hydroxytryptamine, administered intraventricularly, failed to antagonize the gross behavioural effects of intraventricular muscarine. However, ganglionic and sometimes neuromuscular blocking agents, as well as catecholamines and histamine injected intraventricularly, antagonized the emotional behaviour with aggression and depressed the autonomic and motor phenomena of small doses of intraventricular muscarine. In addition, emotional behaviour with aggression and autonomic and motor phenomena evoked by high doses of intraventricular muscarine were resistant to these antagonists administered intraventricularly. From these experiments it is concluded that the sites activated by muscarine in the CNS producing aggressive behaviour have the following characteristics: in high doses muscarine acted on muscarinic cholinoceptive sites, while in small doses it activated the cholinoceptive sites having muscarinic and nicotinic characteristics. Finally, the ability of single intraventricular injections of muscarine to trigger and to maintain the long-lasting gross behavioural effects cannot be ascribed to a rapid detonator transmission, but rather to an action that differs from a conventional transmitter function.