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Biomedical subjects

O L Cruz

Publications and source records attributed to O L Cruz.

7 recordsLinked to original sources
PubMed2001

Morphological and functional study of the cochlea after administration of estrogen and progesterone in the guinea pig.

The aim of this study was to analyze the morphological cochlear changes and auditory function observed after the administration of estrogen or progesterone or both. Sixty-two guinea pigs were divided into four groups that received estrogen (group 1), progesterone (group 2), estrogen and progesterone (group 3), and saline solution (controls, group 4), respectively. The auditory evaluation consisted of brainstem evoked response audiometry, performed before and after drug administration. Structural analysis was based on histological hematoxylin and eosin staining preparations. Our results showed changes in latency and amplitude of waves in the study groups that received estrogen or progesterone. The main histological changes observed were inflammatory infiltrate and vacuolization of the stria vascularis. Our results suggest that both estrogen and progesterone lead to morphological and physiological lesions of the cochlea, the degree of the observed lesions depending not only on the presence of these hormones but also on the proportion between them.

Animals↗
PubMed1994

Results and prognostic factors in skull base surgery.

The charts of 81 patients who underwent skull base surgery between 1982 and 1993 were reviewed retrospectively. Data relative to demographic aspects, clinical stage, previous treatment, surgical approach, type of reconstruction, histology, extent of disease, complications, and follow-up were analyzed. The craniofacial approach for the anterior fossa was used in 53% of patients, the lateral skull base approach in 12%, and a combination of both in 17. Malignant tumors were diagnosed in 58 patients (72%), and histologically benign tumors in the remaining 23 (28%). Forty-one patients (51%) had skin cancer. There was dural invasion in 31 patients (38%), and 32 (40%) underwent microsurgical flap reconstruction. From the malignant group, 31 (53%) were alive with no evidence of disease (NED), and 6 (10%) were alive with disease. From the benign group, 19 (83%) were alive NED. The most common complications were cerebrospinal-fluid fistula (10%) and flap necrosis (9%). Statistical analyses of survival showed significantly different rates associated with histologic types (P = 0.0002), type of reconstruction (P = 0.0039), and previous treatment (P = 0.0018).

Adolescent↗
PubMed1992

Sensorineural hearing loss associated to gonadal dysgenesis in sisters: Perrault's syndrome.

Genetic alterations that involve the inner ear and other systems may present well-defined clinical differences. We present two oriental sisters, age 34 and 26 years, with a picture of primary amenorrhea and "infantile" uterus associated with progressive hearing loss begun in infancy in the older sister, and after 20 years of age in the younger sister. The gynecologic evaluation showed uterine hypoplasia and gonadal dysgenesis in both sisters. The audiologic study showed bilateral sensorineural hearing loss with a flat-type curve in both cases, with an average threshold of 500, 1000 and 2000 Hz (PTA) in 80 dB (older sister) and 60 dB (younger sister), with recruitment measured by stapedial reflex in the second case. Vocal discrimination was 30 percent and 80 percent, respectively. The clinical picture fits Perrault's syndrome: recessive autosomal genetic alteration, with XX gonadal dysgenesis and sensorineural hearing loss.

Abnormalities, Multiple↗
PubMed1991

Reversible hearing loss from cerebellopontine angle tumors.

We report two patients who presented with a dramatic recovery from severe sensorineural hearing loss after total surgical removal of cerebellopontine angle tumors (meningioma and jugular foramen neurinoma). The factors that differentiate these "non-acoustic tumors" in relation to the prognosis for hearing are discussed. A surgical approach that maintains the labyrinthine structure and preserves the arachnoid membrane of the superior cerebellopontine angle cistern during tumor removal is stressed.

Adult↗
PubMed1990

Autoimmune sensorineural hearing loss: a preliminary experimental study.

The aim of this study was to compare cochlear alterations produced by induction of anti-type II collagen antibodies with alterations produced by passive transfer of anticochlear antibodies. Guinea pigs (GP) were used. The anticochlear antibodies were obtained by injecting GP membranous cochlea plus Freund's adjuvant into rabbits. After partial purification of the immunoglobulins, the antibodies (20 mg) were injected intramuscularly into 10 normal GP. A second group of 10 normal GP received intramuscular injections of purified chicken type II collagen (1 mg) plus Freund's adjuvant. A control group of 10 normal GP was studied under the same conditions without any stimulus. The cochlea function was analysed with brainstem evoked audiometry (BERA). The structural study was carried out by immunofluorescent and hematoxylin preparations. The results showed structural alterations in both experimental groups (loss of nucleus in the spiral ganglion); however, significant changes in the BERA were not found. Only increase of the latency of wave I could be seen. These preliminary results support the hypothesis that antibodies to collagen type II may play an important role in human autoimmune sensorineural hearing loss, but the possible existence of other cochlear antigens is discussed.

Animals↗
PubMed1990

Clinical and surgical aspects of cholesteatomas in children.

A review of 101 charts of pediatric patients who underwent surgery for cholesteatoma in the Hospital das Clínicas, São Paulo, Brazil, showed that the peak incidence was in the 10- to 15-year-old age group (mean age, 10.7 years). A high incidence of complications (45.5%) and a significant functional impairment (air-bone gap greater than 40 dB in 49% of patients) were some of the particular features of our patients. Radical or modified radical mastoidectomies were performed in 75 cases (74.3% of cases). The open technique was chosen primarily to eradicate cholesteomatous disease, but the satisfactory functional results also achieved support our preference for this technique.

Adolescent↗