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Biomedical subjects

G Capasso

Publications and source records attributed to G Capasso.

At least 19 recordsLinked to original sources
PubMed1995

Bicarbonate transport along the loop of Henle effects of adrenal steroids.

The role of adrenal steroids in the regulation of bicarbonate absorption in the loop of Henle was studied by in vivo microperfusion. Bicarbonate transport (JHCO3) was measured by microcalorimetry and fluid reabsorption by [14C]inulin, 7-10 days after surgery, in 1) sham-operated control rats, 2) adrenalectomized (Adx) rats, 3) Adx rats receiving dexamethasone (1.2 micrograms.100 g body wt-1.24 h-1) and a low dose of aldosterone (0.5 micrograms.100 g body wt-1.24 h-1), 4) Adx rats receiving dexamethasone, 5) Adx rats receiving a low dose of aldosterone, and 6) Adx rats receiving a high dose of aldosterone (1.0 micrograms.100 g body wt-1.24 h-1). JHCO3 along the loop of Henle was decreased by 40% in Adx rats. JHCO3 was increased by dexamethasone alone and by dexamethasone plus a low dose of aldosterone to rates observed in fully supplemented Adx rats. Aldosterone given alone at a low physiological dose had no effect, but, when administered at a high dose, returned JHCO3 to normal.

Absorption↗
PubMed1994

The effect of acute metabolic alkalosis on bicarbonate transport along the loop of Henle. The role of active transport processes and passive paracellular backflux.

The loop of Henle (LOH) reabsorbs approximately 15% of filtered HCO3- via a luminal Na(+)-H+ exchanger and H+ATPase. During acute metabolic alkalosis (AMA) induced by i.v. HCO3- infusion, we have observed previously inhibition of LOH net HCO3- reabsorption (JHCO3-), which contributes to urinary elimination of the HCO3- load and correction of the systemic alkalosis. To determine whether the activities of the Na(+)-H+ exchanger and/or H(+)-ATPase are reduced during AMA, two inhibitors believed to be sufficiently specific for each transporter were delivered by in vivo LOH microperfusion during AMA. AMA reduced LOH JHCO3- from 205.0 +/- 10.8 to 96.2 +/- 11.8 pmol.min-1 (P < 0.001). Luminal perfusion with bafilomycin A1 (10(-4) mol.l-1) caused a further reduction in JHCO3- by 83% and ethylisopropylamiloride (EIPA; 5.10(-4) mol.l-1) completely abolished net HCO3- reabsorption. The combination of bafilomycin A1 and EIPA in the luminal perfusate was additive, resulting in net HCO3- secretion (-66.6 +/- 20.8 pmol.min-1; P < 0.001) and abolished net fluid reabsorption (from 5.0 +/- 0.6 during AMA to 0.2 +/- 1.1 nl.min-1; P < 0.001). To establish whether HCO3- secretion via luminal stilbene-sensitive transport mechanism participates in LOH adaptation to AMA, we added diisothiocyanato-2,2'-stilbenedisulphonate (DIDS; 10(-4) mol.l-1) to the perfusate. No effect was found.(ABSTRACT TRUNCATED AT 250 WORDS)

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1994

Potassium and sodium transport along the loop of Henle: effects of altered dietary potassium intake.

We assessed the effects of changes in potassium (K+) balance on the function of the loop of Henle by a combination of renal clearance and microperfusion experiments. Rat superficial cortical nephrons were perfused in vivo at 20 nl.min-1 from late proximal to early distal tubule with an artificial end-proximal solution containing either 3.8 or 1.8 mM potassium. Rats were fed a control diet, a low-potassium diet for at least three weeks, or a high-potassium diet for 10 to 14 days. When compared with the appropriate end-proximal potassium concentration in the perfusion fluid, potassium absorption along the loop of Henle (JK) increased in potassium-depletion whereas sodium (JNa) and fluid (Jv) absorption decreased. In rats fed a high-potassium diet, absorption of potassium, sodium and fluid was depressed. We propose that changes of external potassium balance affect the transport of electrolytes and fluid along the loop of Henle in vivo by modulating the transport of potassium and sodium primarily in the thick ascending limb. Changes in potassium reabsorption may also be affected by alterations of potassium-recycling.

Animals↗
PubMed1994

Joseph Jacob Plenck (1735-1807).

Joseph Jacob Plenck (1735-1807) is considered to be the forerunner of modern European dermatology, who also compiled a list of about 800 plants with medicinal uses. Of these about 115 have diuretic properties and are currently included in various pharmacopeias. They were traditionally used to cure ascites of various causes, in urolithiasis, nephritis, cystitis, bladder ulcers, strangury, urinary retention and incontinence. Few of these plants have been fully investigated by modern medicinal chemists, and many are worthy of further study.

Austria↗
PubMed1994

A history of salt.

The medical history of salt begins in ancient times and is closely related to different aspects of human history. Salt may be extracted from sea water, mineral deposits, surface encrustations, saline lakes and brine springs. In many inland areas, wood was used as a fuel source for evaporation of brine and this practice led to major deafforestation in central Europe. Salt played a central role in the economies of many regions, and is often reflected in place names. Salt was also used as a basis for population censuses and taxation, and salt monopolies were practised in many states. Salt was sometimes implicated in the outbreak of conflict, e.g. the French Revolution and the Indian War of Independence. Salt has also been invested with many cultural and religious meanings, from the ancient Egyptians to the Middle Ages. Man's innate appetite for salt may be related to his evolution from predominantly vegetarian anthropoids, and it is noteworthy that those people who live mainly on protein and milk or who drink salty water do not generally salt their food, whereas those who live mainly on vegetables, rice and cereals use much more salt. Medicinal use tended to emphasize the positive aspects of salt, e.g. prevention of putrefaction, reduction of tissue swelling, treatment of diarrhea. Evidence was also available to ancient peoples of its relationship to fertility, particularly in domestic animals. The history of salt thus represents a unique example for studying the impact of a widely used dietary substance on different important aspects of man's life, including medical philosophy.

Africa↗
PubMed1994

Renal synthesis of prostaglandins and thromboxane has no causative role for protein-induced glomerular hyperfiltration in healthy humans.

The study was devised to establish the role of prostaglandin E2, prostaglandin1 alpha and thromboxane A2 in the genesis of glomerular hyperfiltration response to a meat meal in healthy humans. To this end, a group of 8 healthy women was studied 4 times: in the control state (study 1), after a meat meal (study 2), following a meat meal associated with intravenous aspirin (study 3) and finally after a meat meal associated with intravenous aspirin following 2-day pretreatment with oral aspirin (study 4). Urinary excretion of prostaglandins and thromboxane increased during the glomerular hyperfiltration response to a meat meal and was suppressed by aspirin administration which did not suppress the renal hemodynamic response to the meat meal. The data do not support a causal role for prostaglandins and thromboxane A2 in the hemodynamic response to acute protein loading.

6-Ketoprostaglandin F1 alpha↗
PubMed1994

Bicarbonate transport along the loop of Henle. II. Effects of acid-base, dietary, and neurohumoral determinants.

The loop of Henle contributes to renal acidification by reabsorbing about 15% of filtered bicarbonate. To study the effects on loop of Henle bicarbonate transport (JHCO3) of acid-base disturbances and of several factors known to modulate sodium transport, these in vivo microperfusion studies were carried out in rats during: (a) acute and chronic metabolic acidosis, (b) acute and chronic (hypokalemic) metabolic alkalosis, (c) a control sodium diet, (d) a high-sodium diet, (e) angiotensin II (AII) intravenous infusion, (f) simultaneously intravenous infusion of both AII and the AT1 receptor antagonist DuP 753, (g) acute ipsilateral mechanicochemical renal denervation. Acute and chronic metabolic acidosis increased JHCO3; acute metabolic alkalosis significantly reduced JHCO3, whereas chronic hypokalemic alkalosis did not alter JHCO3. Bicarbonate transport increased in animals on a high-sodium intake and following AII administration, and the latter was inhibited by the AII (AT1) receptor antagonist DuP 753; acute renal denervation lowered bicarbonate transport. These data indicate that bicarbonate reabsorption along the loop of Henle in vivo is closely linked to systemic acid-base status and to several factors known to modulate sodium transport.

Acid-Base Imbalance↗
PubMed1994

Anaerobic threshold determination in master endurance runners.

Twenty middle aged endurance runners underwent physiological testing to determine their maximal oxygen uptake (VO2max), lactate threshold, ventilatory threshold, the slope variation point (SVP) of the linear relationship between running speed (RS) and heart rate (HR) both on the treadmill and during a field test, and the onset of blood lactate accumulation point. The RS, HR, VO2 and blood lactate concentration at which the different thresholds occurred were highly correlated (0.70 < r < 0.95; p < 0.01). The various indices of aerobic-anaerobic transition in the master athletes examined were shown to occur at a comparable percentage of their VO2max as compared to their younger counterparts. The tests developed for, and commonly used in adult athletes, are equally valid in this age group.

Aged↗
PubMed1994

Molded arthroplasty and transfer of the extensor hallucis brevis tendon. A modification of the Keller-Lelievre operation.

The Keller-Lelievre technique for hallux valgus correction was modified by detaching the extensor hallucis brevis tendon from the proximal phalanx, and reattaching it on the medial sesamoid. Thirty-five consecutive patients were assigned randomly to 1 of 2 groups. Patients in Group 1 received the modified operation, and the original Keller-Lelievre technique was used for the control group. The only significant radiographic difference at 6 months was the distance between the first and the fifth metatarsal heads. There were only slightly significant differences in function and in pain relief between the 2 groups at the 6th postoperative month. At 3 years, these differences were greater, with the group treated by the modification described herein, retaining significant correction and showing better functional results.

Aged↗
PubMed1994

Proteases and antiproteases in cartilage homeostasis. A brief review.

Among other factors, articular cartilage degeneration is caused by proteolytic enzymes. Different cell types of the synovial fluid and/or the synovial membrane and cartilage release specific proteases. Normally, these are finely tuned with their inhibitors. When this balance is altered, the proteolytic action may prevail, producing tissue damage, cartilage disruption, and ultimately a full osteoarthritic picture. The protease antiprotease mechanism opens new perspectives in the diagnosis and pharmacologic management of osteoarthritis. Early diagnosis and improved monitoring of the evolution of the disease are made possible, and a more rational therapy against cartilage disruption becomes feasible.

Cartilage, Articular↗
PubMed1994

[Current diagnostic-therapeutic trends in treatment of pediatric appendicitis].

Acute appendicitis is the first cause of emergency surgery in children. Actually, emergency abdominal sonography has evolved in differential diagnosis of acute appendicitis in children to differentiate it from other causes of acute abdomen as mesenteric lymphoadenitis, acute right pyelonephritis, acute diverticulitis in Meckel's diverticulum, intestinal intussusception, regional enterits, primary peritonitis, anaphylactoid purpura of Henoch-Schonlein. The aim of this study is the evaluation of the usefulness of abdominal sonography in diagnosing acute appendicitis in our current series of pediatric patients. We have operated 102 patients afflicted by appendicitis admitted to the pediatric department of Ospedale San Raffaele, Milano in a period of 5 years and operated on for appendectomy. In the last 2 years 36 patients were evaluated with abdominal sonography. This diagnostic tool showed in 34 (94.4%) a liquid effusion, sometimes thick of the right iliac fossa. In 2 patients the appendix had thickened layers, was edematous and the lumen was clearly filled with debris. Abdominal sonography has given a clear cut picture of the acute inflammatory process of the appendix. None of these patients has suffered from septic or obstructive complications. Mean duration of hospital stay was 6.35 days (3-15 days). Differential diagnosis of acute appendicitis can be extremely variable, from simple, paradigmatic situations to the most intriguing ones. This concept is well emphasized by William Silen when he says that "differential diagnosis of acute appendicits is an encyclopedic compendium of every abdominal disease that causes pain" in the 11th edition of Harrison's Principles of Internal Medicine.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdomen↗
PubMed1993

Post-viral fatigue syndrome. A longitudinal assessment in varsity athletes.

Maximal oxygen uptake, anaerobic threshold (AT), isometric strength of the elbow flexor and knee extensor muscles, isometric strength endurance exhaustion time (prolonged contraction at 66% of maximal isometric strength), uphill sprinting exhaustion time were longitudinally studied in eight varsity endurance runners with post-viral fatigue syndrome (PVFS). Prolonged impairment of exercise performance is evident during the course of PVFS. Although maximal oxygen uptake (VO2max) had returned to pre-infection values 13 months after the viral illness (4.160 vs 4.0 L.min-1), AT was still significantly reduced [52 ml.kg-1.min-1, 18.6 km.hr-1, 176 bpm, and 82% of VO2max vs. 49.1 ml.kg-1.min-1 (p < 0.05), 175 bpm (NS), 17.2 km.hr-1 (p < 0.01) and 79% of VO2max (NS)]. Maximal isometric contraction strength of the upper limb remained constant (282 N vs. 274 N), while knee extensor muscles strength decreased significantly (730 N vs. 701 N, p < 0.05). Strength endurance was still significantly reduced by the end of the study (arm average pre-infection: 46.2 sec; end of study: 29.3 sec, p < 0.001; leg average pre-infection: 66.4 sec; end of study: 49.1 sec, p < 0.01). Up hill sprinting time was similarly reduced by the end of the study period (29.3 sec vs. 16.2 sec, p < 0.01). Both aerobic and anaerobic exercise variables are seriously affected by post-viral fatigue syndrome, and one year may not be sufficient to fully recover.

Adult↗
PubMed1993

[Liver transplant in children: comments and legislative proposal].

Having examined the literature on this subject, the authors raise the problem of segmentary liver transplant from a liver donor to a pediatric patient. They evaluate the current Italian legislation regarding the donation of organs and on the basis of foreign experience they draft a possible amendment to the law currently in force.

Child↗