Biomedical subjects

M Hassouna

Publications and source records attributed to M Hassouna.

39 records · Page 3Linked to original sources

PubMed1983

[Vesicourethral physiology during continence and urination in cats. In vivo and in vitro studies].

The mechanisms implicated in the opening of the bladder neck during voiding are still controversial. We present a study of the reflexes of bladder, urethra and periurethral striated muscles in the cat. The study in vivo shows that a passive muscle tonus of the urethra is able to maintain the continence. During voiding, opening of the bladder outlet is done actively: contraction of the longitudinal and relaxation of the circular muscle layers of the urethra associated with detrusor contraction. There is a local reflex between the urethra, bladder and periurethral striated muscles that completes emptying of the bladder with an interrupted stream. The study in vitro confirms that the 2 muscle layers of the urethra have different innervation: the parasympathomimetic agents act on the longitudinal layer and very weakly on the circular. Both layers react to adrenergic stimulation.

Animals↗

PubMedDate not supplied

Investigation of the spread of human visceral leishmaniasis in central Tunisia.

The epidemiology, clinical patterns, and spatial spread of Mediterranean visceral leishmaniasis were retrospectively studied in central Tunisia. The clinical profile of the disease was typical of the Mediterranean infantile form. Malnutrition and associated infectious diseases were observed in 62.5% and 55% of cases, respectively. The case-fatality rate was 6.2% and resistance to meglumine antimonate was observed in 1.6% of patients. The annual incidence of cases increased from approximately 10 cases per year before 1991 to approximately 50 cases per year between 1992 and 1994. The cumulative incidence was 133.7/100,000 among children aged < 15 years. This increase was preceded by 3 years of high mean annual rainfall in the region. The spatial distribution of the incidence of the infection through time showed an aggregation of cases in the northern part of the area where intensive agriculture projects took place during the last 10 years, leading to the establishment of a stable Leishmania infantum transmission cycle below the Atlas mountain chains, and an evident tendency to a progressive extension to the south.

Adolescent↗

PubMedDate not supplied

A new bladder stimulator--hand-held controller and miniaturized implant: preliminary results in dogs.

A new urinary-tract stimulator that is intended to restore normal bladder function to patients who have spinal-cord injuries is described. The system is composed of two principal parts. The first, which is external, consists of a hand-held device based on an inductive-coupling technique. This controller incorporates all the circuitry necessary to transmit data transdermally. The second, a fully programmable implantable device, includes a complementary metal oxide semiconductor gate-array integrated circuit controlling eight monopolar (or four bipolar) stimulation channels. To protect the tissues and the device, three different biocompatible polymers encapsulate the implant. In the experimental phase, the authors investigated the effect of early electrical stimulation of the bladder during the spinal-shock phase in paraplegic dogs. In addition, using the stimulator, they localized the parameters of stimulation that give the best results in terms of effective bladder pressure and voiding a high volume of urine.

Animals↗