PubMed Health⌕ Search

Biomedical subjects

S Bello

Publications and source records attributed to S Bello.

At least 37 records · Page 2Linked to original sources
PubMed1991

The squirrel monkey vestibulo-ocular reflex and adaptive plasticity in yaw, pitch, and roll.

The vestibulo-ocular reflex (VOR) was studied in adult squirrel monkeys before and after adaptation to magnifying and minifying viewing conditions. Monkeys were subjected to broadband (0.05-0.71 Hz) conditioning rotation for six hours in head yaw, pitch, and roll on separate occasions, and the VORs in these three planes were studied in darkness to assess adaptive plasticity in the reflexes. The gain of the horizontal VOR (H-VOR) averaged 0.8 across the frequency bandwidth studied (0.025-4 Hz). Phase was near 0 degrees from 4 to around 0.1 Hz, but developed a progressive lead as frequency declined further. Normal vertical VOR (V-VOR) gain climbed from 0.6 at 0.025 Hz to near 1 as frequency increased to 4 Hz. Phase lead was more pronounced at low frequencies than in the H-VOR. The normal torsional VOR (T-VOR) qualitatively resembled the V-VOR, showing similar phase but lower gains (0.3-0.7) across the frequency bandwidth. These findings suggest that the dynamics of the V-VOR and T-VOR resemble canal characteristics more closely than does the H-VOR. After adaptation to visual minification and conditioning rotation (0.5X for yaw and pitch, 0X for roll), gain decreased in each of the planes of conditioning. Similarly, gain increased in the plane of conditioning after adaptation to visual magnification (2X). The adaptive changes were greater at low (0.025-1 Hz) than at high (2.5-4 Hz) frequencies, and were more robust when gain was driven downward than upward. However, control (sham) adaptation experiments showed that VOR gain tended to drop slightly over 6 h in the absence of adaptive drive to do so, suggesting that the gain modifications may be more symmetric when referenced to the control. Adaptive VOR gain enhancement or decrement in the plane of conditioning did not result in systematic and parallel changes in orthogonal VOR planes.

Acclimatization↗
PubMed1991

[Treatment of smoking].

Smoking is difficult to treat, since addiction to tobacco is very strong and a deprivation syndrome may follow cessation of nicotine consumption. The ultimate goal of treatment is smoking cessation. Anti-smoking counseling and self teaching manuals are used as public health strategies, while nicotine chewing gum, clonidine, hypnosis, acupuncture and negative conditioning are individual strategies. Success rates in treatment of smoking vary between 5 and 40% at 1 to 2 years. Individualized therapy including care for the smoker as a person, family and labor support are needed to increase the chance of success.

Adolescent↗
PubMed1975

Epileptogenic properties of folic acid and N5 methyltetrahydrofolate in cat.

The epileptogenic properties of folic acid and N5-methyltetrahydrofolate applied locally on the cortex were compared in cats. Neither substance was epileptogenic except in very high concentration, on the order of 10(-3) M. N5-Methyltetrahydrofolate, the folate derivative most widely distributed in the central nervous system and CSF of mammals, was not more epileptogenic than folic acid. Because the level of N5-methyltetrahydrofolate is only slightly diminished in patients treated with anticonvulsants, the change cannot account for the therapeutic effect of the drugs.

Animals↗
PubMedDate not supplied

[Videothoracoscopy versus thoracotomy in the diagnosis of diffuse interstitial disease].

Histopathology plays an important role in the diagnosis of diffuse interstitial lung disease. New endoscopic techniques allow performance of sampling procedures that have the same diagnostic accuracy and fewer complications that open lung biopsy (OLB). We evaluated our experience with video thoracoscopic lung biopsy (VTLB) in comparison with OLB in terms of diagnostic accuracy, duration of pleural drainage and hospital stay, number and size of samples and complications. Thirty patients who underwent VTLB from March 1987 to January 1995, and 28 patients who underwent OLB from May 1987 to January 1995 were studied retrospectively. Diagnosis was achieved in the VLTB group in 96.66% of cases and in the OLB group in 92.85%. The number of specimens obtained was 1.5 (SD 0.5) in the VTLB group (p = 0.47). Overall specimen size expressed in cm3 was 13.3 (SD-15.4) in the VTLB group and 18.5 (SD 21) in the OLB group (p = 0.284). Length of pleural drainage in hours was 52 (SD 39.9) in the VTLB group and 89.1 (SD 47) in the OLB group (p = 0.002). Length of hospital stay in days was 3.5 (SD 2) in the VTLB group and 8.7 (3.5) in the OLB group (p = 0.001). Complications were fewer and less severe after VLTB. VLTB is as useful as OLD for obtaining lung biopsies in diffuse interstitial lung disease. VLTB also causes fewer complications and is less expensive because drainage times and hospital stays are shorter.

Adult↗