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In Italy, no national data on tuberculosis (TB) treatment results were available. In 1995, the AIPO (Italian Association of Hospital Pneumologists) TB Study Group, in collaboration with the Istituto Superiore di Sanità (technical branch of the Ministry of Health), started a prospective monitoring activity based on World Health Organization (WHO) and International Union against Tuberculosis and Lung Disease (IUATLD) recommendations. Data were collected from a nationwide network of 41 TB units, managing a significant proportion of all the TB cases notified in Italy each year. The aim of this study was to analyse the case findings and treatment results for the year 1996. Eight hundred and thirty eight TB cases were reported (56% males; 26% immigrants), 708 (84%) being new cases. Of these cases, 565 (67%) were pulmonary, 235 (28%) extrapulmonary and 38 (5%) both pulmonary and extrapulmonary. The main risk factors for TB were a history of recent contact and diabetes among native Italians and recent contact and human immunodeficiency virus-seropositive status among immigrants. The majority of immigrants were from Africa and Asia, and had been in Italy > 24 months before diagnosis of TB. Thirty-six per cent of patients had a positive direct sputum smear examination for alcohol acid-fast bacilli; 37% were resistant to any drug (monoresistance to isoniazid 4.4%; multidrug resistance 10.4%). In 96% of cases, the duration of treatment was < 12 months. The overall success rate (cured plus treatment completed) was 84.1%. A significantly higher percentage of deaths was found in native Italians (being age-related), whereas immigrants had a higher default rate.

In anaesthetized cats, reflex respiratory responses were evoked by electrically stimulating proximal ends of cut nerves to gastrocnemius-soleus muscles of the left hindlimb. The direction of these responses, in the excitatory or inhibitory sense, depended on the types of afferent fibres stimulated and on the mode of stimulation. Continuous stimulation, delivered with stimuli of 0.1 ms at 200 or 300 Hz, in all cases induced excitatory responses, consisting of increases in pulmonary ventilation, mainly caused by increases in tidal volume. Intermittent stimulation, which consisted of brief trains of stimuli repeated at 2-3 Hz, induced excitatory responses when afferent fibres with conduction velocities higher than 20 m/s were stimulated, while it induced inhibitory responses, consisting of decreases in pulmonary ventilation, tidal volume and respiratory frequency, when fibres with conduction velocities below 20 m/s were simultaneously stimulated with the high-conduction velocity fibres.

Experiments were done on anesthetized and curarized cats to see whether the increase in blood pressure caused by electrical stimulation of group I afferent fibers is related to a direct reflex effect on the heart. The reflex effect of electrical stimulation of group I afferent fibers from the gastrocnemius-soleus muscles on the arterial pressure, the left ventricular pressure, the inotropic state of the left ventricle (dP50/dt) and the heart rate were compared before and after beta-blockade with propranolol (0.1 mg/kg intravenously) to reduce a possible direct effect on the heart. The same comparison was made before and after alpha-blockade with phentolamine (2.5 mg/kg intravenously) to keep the peripheral resistance constant. Electrical stimulation of group I afferent fibers caused an increase in the blood pressure, the left ventricular pressure and, to some extent, the inotropic state of the left ventricle and the heart rate. The beta-blockade had no significant effect on these increases, while the alpha-blockade abolished the increase in blood pressure. It is concluded that the effect of stimulation of group I afferent fibers on the blood pressure is not dependent on a direct reflex effect on the heart, but can be better explained by a reflex increase in the peripheral resistance.

The authors describe the microscopic and ultrastructural changes in the synovial membrane and femoral growth cartilage in experimentally induced chronic anemia. The reiterated anoxic stimulus is responsible for premature morphologic changes which become progressively worse and then appear to stabilize after 30 days. The series of events at the completion of the experiment are characterized by the following: 1) villous hyperplasia-hypertrophy with an increase of the secretory vesicles of type B synoviocytes in the intima and lymphoplasmacellular infiltrates in the sub-intima of the synovial membrane with fragmentation of the bony trabeculae, 2) areas of premature closure of the growth cartilage, 3) irregularity of the profile, thickness, and structure of the articular cartilage. The authors propose a biologic correlation between the above osteoarticular changes and the typical features of certain disorders of this anatomical region (hemopathies, Legg-Calvé-Perthes disease).

We have investigated the various sensory modalities represented in the laryngeal nerves of the guinea pig. In addition, we have examined the defensive responses to mechanical stimuli and capsaicin instillation into the laryngeal lumen of the same species. Recording from both the whole superior laryngeal nerve and from single units of the same nerve revealed the presence of afferent activity related (1) to the contraction of laryngeal muscles and/or the 'tracheal tug', (2) to transmural pressure changes, either positive or negative and (3) to mechanical and chemical irritants. The irritant type receptors of this species, when challenged with water solutions, show two distinct patterns of activation: some behave as osmoreceptors, some respond to the lack of chloride ions. Challenges with capsaicin solutions activated one ending with the characteristics of a C-fiber receptor that failed to respond to a subsequent trial. This behavior is consistent with the reflex apnea, dependent on an intact laryngeal innervation, induced by capsaicin instillation that was not elicitable on repeating the challenge. Cough to mechanical probing of the supraglottic area depended on an intact SLN, whereas cough elicited from the subglottic area depended on an intact RLN. Cough to mechanical stimulation could not be desensitized by capsaicin. These findings suggest the presence of two independent afferent pathways for defensive responses.

Experiments were performed on cats to see whether stimulation of group I afferent fibers from gastrocnemius-soleus muscles induced changes in cardiac activity, in addition to the increase in systemic arterial pressure already established. The results show that the increase in arterial pressure is accompanied by an increase in systolic left ventricular pressure, without any significant changes in cardiac inotropism and chronotropism. It is concluded that the cardiac innervation is not an important efferent pathway of the pressor reflex evoked by stimulating group I afferent fibers, and that the reflex increase in arterial pressure depends mainly on an increase in peripheral vascular resistance.

Although constant airflow through the upper airway has been shown to induce ventilatory depression in anesthetized newborn animals, the role of laryngeal temperature in this response has not been studied. Experiments were performed in fourteen 1-5 day-old anesthetized puppies breathing through a tracheostomy. Tidal volume and laryngeal temperature were recorded while a constant stream of air (15-25 ml/sec) at room temperature was passed in the expiratory direction for 20 sec through the isolated upper airway. Warm (35-37 degrees C), humidified air at the same flow served as control. When laryngeal temperature was decreased by 7.5 +/- 0.9 degrees C, a marked change in breathing pattern was observed (VT = 54 +/- 5, TI = 187 +/- 33, TE = 636 +/- 179, VT/TI = 45 +/- 10% of control; n = 9). Warm air at the same flow induced no significant changes. Superior laryngeal nerve section abolished the effects of cooling on breathing pattern. In 5 puppies we compared the effect of 'fast' and 'slow' laryngeal cooling. Fast trials altered breathing pattern earlier than slow trials. We conclude that the depressant effect of airflow through the upper airway is entirely due to a decrease in laryngeal temperature and is mediated by superior laryngeal nerve afferents.

The purpose of this study was to relate the carbon dioxide (CO2) response of laryngeal receptors to their behavior during the breathing cycle (i.e. their response to transmural pressure changes, laryngeal movement or decreases in temperature) or during exposure to irritant stimuli (water or cigarette smoke). In 9 anesthetized mongrel dogs breathing spontaneously through a tracheostomy, unit activity from the superior laryngeal nerve was recorded while warmed and humidified gas mixtures (air or 10% CO2 in O2) were passed, for 1 min, through the functionally isolated upper airway in the expiratory direction. None of the 10 cold receptors studied were affected by CO2. Eleven of 20 laryngeal non-modulated mechano-receptors were stimulated (from 0.3 to 1.6 imp/sec) by exposure to CO2. These CO2-responsive receptors were also stimulated by known irritant stimuli (cigarette smoke, water), although not all receptors which responded to these irritants were stimulated by CO2. Twelve of 33 respiratory-modulated receptors were affected by CO2; 4 were stimulated and 8 inhibited. Receptors inhibited by CO2 were also inhibited by negative pressure while receptors stimulated by CO2 were also stimulated by negative pressure. These results show that CO2-responsive laryngeal receptors are not specialized endings. Although it is not clear to what extent each separate group of laryngeal receptors is involved, each may contribute to the reflex bradypnea which has been observed during exposure of the upper airway to elevated levels of CO2. However, the importance of CO2-responsive laryngeal receptors in physiological conditions remains unclear.

Both respiratory and cardiodynamic parameters were analyzed (the latter non invasively by means of a computerized impedance cardiograph) in 6 subjects at the start of voluntary dorsal ankle flexions. Increased mean inspiratory flow with a slow reduction in end tidal PCO2 was shown in the breath following the start of movements, and these findings indicate the nervous origin of this hyperventilation. Within the same breath, left cardiac output, stroke volume and ventricular ejection time remained unchanged, and the same is true of heart rate and ventricular performance indexes depending on both the first derivative of the base thoracic electrical bioimpedance and on the mean left ventricle ejection flow, as well as in the systemic venous return index depending on the basal value of the thoracic impedance. These results, indicating that no cardiodynamic intervention in the neurogenic hyperventilation was seen, show that nervous stimuli elicited at the start of voluntary exercise may exert a direct action on respiratory control structures.

Experiments were carried out in anaesthetized and curarized cats to study the effects of the alpha-blocker phentolamine on arterial pressor response to stimulation of group I afferent fibers from gastrocnemius-soleus muscles. It has been found that increasing doses of phentolamine given i.v. cause a decreasing pressor response until complete disappearance occurs at 2.5 mg/Kg. It is concluded that pressor response is present only when the adrenergic control system is effective and, therefore, it is due mainly to an increase in peripheral vascular resistances.

In a series of isotonic muscle contractions induced by repetitive stimulation at frequencies higher than 0.1 Hz the pause in the afferent discharge of the muscle spindles tends to decrease as a function of time and as a function of frequency, while the afferent discharge of the Golgi tendon organs, as measured in the same experimental conditions, remains constant. The results support the hypothesis that the changes in the spindle are due to changes in the visco-elastic properties of the intrafusal muscle fibers (1). Since no muscolar tissue is present within the Golgi tendon organs (4) their afferent discharge and the pause, which occurs during the relaxation phase (3) do not change as seen in the spindles.