Middle ear and inner ear effects on clinical bone-conduction threshold

The measurement of bone-conduction thresholds is an integral part of audiologic evaluation. The relationship between bone-conduction and air-conduction thresholds is the differentiating diagnostic indicator between conductive and sensorineural hearing loss. At the same time, the influence of middle ear and inner ear structures upon the bone-conduction response has been well documented. We present two cases illustrating this influence and attempt to explain the clinical bone-conduction thresholds with operative findings.

The complete nucleotide sequence of RNA 3 of citrus leaf rugose and citrus variegation ilarviruses

Complete sequence data for the RNA 3 of both citrus leaf rugose (CiLRV) and citrus variegation (CVV) ilarviruses have been determined. The RNAs are 2289 nt (CiLRV) and 2309 nt (CVV) in length and both contain the typical Bromoviridae arrangement of two open reading frames (ORFs) which, when translated, code for proteins that correspond to the Mr 32,000 (32K) putative movement proteins (ORF 1) and the coat proteins (ORF 2) of the respective viruses. The 3' termini of both viruses can be folded to form a secondary structure similar to those reported for other ilarviruses. These are the first complete nucleotide sequences for RNA 3 of members of subgroup 2 of the ilarviruses. The two viruses share substantial homology in nucleic acid sequence, code for identically sized coat proteins and share high levels of identity in the translated products of both ORFs. Although related, these viruses differ sufficiently to be considered distinct. The RNA 3s of CiLRV and CVV appear to be distinct from those of other ilarviruses for which comparable sequence data are available and also from the closely related alfalfa mosaic virus.

Scanning electron microscopic observation of dark cells after streptomycin perfusion of the vestibule in guinea pigs

Hearing has been stabilized in the majority of patients studied in the treatment of Meniére's disease with streptomycin. This observation suggests that effects of streptomycin may ameliorate endolymphatic hydrops, possibly by attenuating the activity of secretory tissue. The purpose of this study is to observe the dark cells of the utricle in guinea pigs after streptomycin perfusion of the vestibule. Twelve pigmented guinea pigs weighing 250-350 grams were used in this study. The vestibules in five guinea pigs were perfused monolaterally with 150 micrograms of streptomycin in artificial perilymph and, in seven, the vestibules were perfused only with artificial perilymph as a control group. Specimens were processed for observation with a scanning electron microscope. After streptomycin perfusion, the margin of the dark cells became indistinct. The luminal surface of the cells bulged out like a dome. The microvilli decreased or were absent, and some debris was deposited on the surface. In four of the five animals, the luminal membrane of the dark cell ruptured. The cytoplasm and organelle extruded into the endolymphatic space. After the cellular debris moved out into the endolymph, either a vanished cell or a nucleus in an empty nest was observed. These cells appeared damaged and destroyed. The results indicate that the dark cells in the membranous wall of the utricle were affected by streptomycin. The results lead to the assumption that streptomycin may reduce the volume of endolymph by damaging the dark cells of the utricle.

Traumatic endolymphatic hydrops

Traumatic endolymphatic hydrops is an accumulation of endolymph in the cochlear duct caused by traumatic insult. The causative mechanisms are: (1) fistulization of the bony labyrinth, which causes a disturbance in the normal perilymph-endolymph pressure relationship; (2) direct injury to the membranous labyrinth, which may be just a collection of fluid in the cochlear duct from irritation, resulting in endolymphatic hydrops that may not be progressive and may subside in a short period of time after injury and hearing loss may occur; and (3) injury to the endolymphatic fluid drainage system, including a temporal bone fracture in which the fissure happens to extend through the vestibular aqueduct, causing fibro-osseous blockage of the endolymphatic duct and surgical injury to the saccule with obstruction of the longitudinal flow of endolymph, resulting in endolymphatic hydrops that may be delayed in onset and is usually persistent. The diagnosis of traumatic endolymphatic hydrops is made by a history of trauma, such as barotrauma, a blow to the head, or perhaps a previous ear operation, such as stapedectomy; the presence of typical symptoms of endolymphatic hydrops, including fullness, tinnitus, fluctuant hearing loss, and episodic vertigo; and an elevated negative summating potential and an increased summating potential:action potential ratio by electrocochleography. Three patients are presented to demonstrate this clinical entity.

It takes two to replicate: a mediational model for the impact of parents' stress on adolescent adjustment

In this study of parental stress and adolescent adjustment, experiences of negative life events during the recent past were used to generate a measure of acute stress. In addition, multiple indicators based on reports from various informants were used to estimate latent constructs for parental depression, discipline practices, and adolescent adjustment. Employing 2 independent samples of families from 2 different regions of the country (rural Iowa and a medium-sized city in Oregon), structural equation models were used to test the hypothesis that in intact families acute stress experienced by parents is linked to boys' adjustment (average age equaled 11.8 years in the Oregon sample, 12.7 years in the Iowa sample) through 2 different causal mechanisms. The findings showed that parental stress was related to adjustment through stress-related parental depression that is, in turn, correlated with disrupted discipline practices. Poor discipline appears to provide the direct link with developmental outcomes. The structural equation model (SEM) used to test the proposed mediational process was consistent with the data for mothers and boys from both the Oregon and the Iowa samples. The similarity in results was less clear for fathers and boys. Implications of these results for future replication studies are discussed.

The nucleotide sequence of citrus leaf rugose ilarvirus RNA-2

The nucleotide sequence of citrus leaf rugose ilarvirus (CiLRV) RNA-2 consists of 2990 nucleotides and contains one open reading frame (ORF) which encodes a deduced translation product of 832 amino acids with a calculated M(r) of 95,501 (95K). The 5' terminus of the RNA has a m7Gppp cap. Both the nucleotide sequence of CiLRV RNA-2 and its translated polypeptide share homologies with the nucleotide sequence and translated polypeptide, respectively, of RNA-2 of alfalfa mosaic virus (AlMV). The homology occurs in the central region of both the nucleic acid sequence and the polypeptide. Homologies between either CiLRV or AlMV and other Bromoviridae (cucumber mosaic virus--CMV, brome mosaic virus--BMV and cowpea chlorotic mottle virus--CCMV) were far less. Alignment of the 104 amino acid region (polymerase signature) of the 95K protein against 10 other 'alpha-like' plant viral polymerase signatures showed that CiLRV and AlMV are more closely related to each other than to CMV, BMV or CCMV. This is the first report of the full-length sequence of RNA-2 of an ilarvirus.

Long-term results of low dose intramuscular streptomycin for Menière's disease

The initial results of partial ablation of vestibular function are evident to control vertigo attacks and stabilize hearing as well as to reduce the severity of ataxia. The purpose of this study is to observe the long-term results of low dose intramuscular streptomycin in the treatment of bilateral Menière's disease. Eleven patients with disabling bilateral Menière's disease were treated with low doses of intramuscular streptomycin (20-40 g, mean = 25 g). Follow-up was 5-12 years (mean = 8 yr). All 11 patients achieved relief of their disabling vertigo. One patient had recurrent vertigo 1 year after treatment and streptomycin perfusion of the labyrinth was performed subsequently. Four patients reported feeling slightly off balance during follow-up. None experienced oscillopsia in this series. In the entire group of 11 patients (22 ears), hearing was unchanged in 17 ears, improved in two and worse in three. A hearing threshold of < 30 dB was found in two ears before and two after treatment; 30-60 dB was found in seven ears before and six after treatment; and > 60 dB was found in 13 ears before and 14 after treatment. The mean PTA of the 22 ears was 58 dB before and 65.5 dB after treatment. The mean speech discrimination scores were 61.4 percent before and 51.3 percent after treatment. The long-term results suggest that partial ablation of vestibular function by streptomycin has long-lasting effects of controlling vertigo attacks, stabilizing hearing, and reducing the severity of ataxia. Administration of low doses of intramuscular streptomycin is the treatment of choice for bilateral Menière's disease.

Endolymphatic hydrops associated with otosclerosis

Endolymphatic hydrops (EH) associated with otosclerosis has been noted for many years. However, the causal relationship of these two entities remains controversial. Having reviewed the records of patients with otosclerosis describing fluctuant hearing loss and vertiginous symptoms, the authors found the EH may coexist with otosclerosis preoperatively; they may be two separate diseases that exist coincidentally; or EH may be caused by the otosclerotic process. Secondly, EH may occur with a fistula after surgery. Occurring after stapedectomy, EH may be caused by fistulization of the bony labyrinth, which is effectively treated by surgery to seal the fistula, which may cause EH to subside and hearing to improve. Thirdly, delayed EH may occur months or years after stapedectomy, possibly as a result of otosclerotic foci or surgical insult to the labyrinth. Dexamethasone, diuretics, and a room air rebreather can be used in the treatment of delayed EH. Hearing may be maintained or may deteriorate, but there usually is no dizziness. The clinical manifestations of EH associated with otosclerosis include a conductive or mixed type of hearing loss; the presence of fullness, tinnitus, fluctuation of hearing, episodic vertigo, an elevated negative summating potential (SP), and an increased summating potential:action potential (SP:AP) ratio shown by ECoG. This report presents five cases of EH associated with otosclerosis.

Streptomycin perfusion of the labyrinth through the round window plus intravenous streptomycin

Streptomycin perfusion of the labyrinth through the round window membrane in the middle ear is a simple, safe, and effective way to stop the dizzy spells, fullness, and tinnitus of Ménière's disease without making the hearing worse. My results with 24 patients in the last 8 months are presented. Although the long-term effect of this operation remains to be seen, my experience with streptomycin perfusion of the labyrinth through the lateral semicircular canal leads me to believe these good results will be maintained in the future. Although the caloric response is not usually eliminated completely in the operated ear, it is reduced enough that the patient no longer has dizzy spells. Because the vestibular receptors are not completely destroyed, and the afferent and efferent nerves coming to and from them are undamaged, the patient compensates after this operation more quickly than when the vestibular receptors are completely destroyed by intramuscular or middle ear aminoglycoside, or when the afferent and efferent nerves of the vestibular receptors are cut as in labyrinthectomy or vestibular neurectomy. Hyaluronan is used to carry the streptomycin into the inner ear because it is known to penetrate the round window easily, and because being hygroscopic, it may reduce the amount of endolymph by osmosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Economic stress, coercive family process, and developmental problems of adolescents

We propose a model of family conflict and coercion that links economic stress in family life to adolescent symptoms of internalizing and externalizing emotions and behaviors. The 180 boys and 198 girls in the study were living in intact families in the rural Midwest, an area characterized by economic decline and uncertainty. Theoretical constructs in the model were measured using both trained observer and family member reports. These adolescents and their parents were interviewed each year for 3 years during the seventh, eighth, and ninth grades. Our theoretical model proposes that economic pressure experienced by parents increases parental dysphoria and marital conflict as well as conflicts between parents and children over money. High levels of spousal irritability, coupled with coercive exchanges over money matters, were expected to be associated with greater hostility in general by parents toward their children. These hostile/coercive exchanges were expected to increase the likelihood of adolescent emotional and behavioral problems. Overall, results were consistent with the proposed model. Moreover, the hypothesized processes applied equally well to the behavior of mothers and fathers, as well as sons and daughters.

Parents' stressful life events and adolescent depressed mood

The present study of 451 families living in the rural Midwest examines a mediational model of the relationship between the stressful life events experienced by parents and adolescent depressed mood. This model is intended to overcome two limitations in previous research on the relationship between parents' stressful events and adolescent depressed mood by 1) examining a mediating process involving parental mood and parenting behavior, and 2) using multiple informants to assess the theoretical constructs. Findings from the present study indicate that stressful life events experienced by parents are first related to parents' depressed mood which operates to disrupt skillful parenting practices. The disrupted parenting practices in turn place adolescents at increased risk for developing depressive symptoms. The results show that inclusion of these mediating processes represents a significant improvement over the bivariate model and that the hypothesized mediational model generalizes to four parent-adolescent dyads: fathers and sons, fathers and daughters, mothers and sons, and mothers and daughters. Moreover, parents' stressful life events are related directly to adolescent boys' depressed mood only when parents' reports are included in both theoretical constructs. When parents' reports are removed as an indicator for the adolescent depressed mood construct, the effects of parental stress on adolescent depressed mood are largely accounted for by stress-related parental depressed mood and harsh/inconsistent parenting.

Factors influencing results with streptomycin perfusion of the labyrinth

Streptomycin perfusion of the labyrinth is the logical choice of treatment for the third stage of Meniere's disease with intractable vertigo. The results of streptomycin perfusion of the labyrinth are comparable to those of other treatments, including endolymphatic shunt and vestibular nerve section. Refinements must be made in the process of selecting candidates for the operation. To study the factors influencing the results of streptomycin perfusion of the labyrinth, 144 patients who had streptomycin perfusion of the labyrinth and were followed for 1 year were studied using the 1972 AAOO classification of results. The findings of this study indicate that only a low dosage of streptomycin and a small volume of perfusate are required to obtain good results. Patients who have long lasting severe endolymphatic hydrops with poor hearing preoperatively are less likely to achieve good results.

Ossification patterns of the tympanic facial canal in the human fetus and neonate

Dehiscences in the bony facial canal are comparatively common in the human adult. The highest incidence occurs in the tympanic segment of the facial nerve near the region of the oval window. Thirty-three fetal temporal bones, ranging from 16 to 40 weeks' gestation, and four from 1, 2, 4 and 12 weeks' postpartum neonates, were studied to evaluate the normal patterns of ossification of the fallopian canal of the tympanic facial nerve segment in the human. The tympanic facial nerve segment elongates three-fold during this period (from 1 mm to 3 mm). The ossification starts at 21 weeks' gestation anteriorly from apical otic ossification centers and at 26 weeks from canalicular ossification centers near the stapedius muscle. The ossification proceeds in an anterior-to-posterior direction as two periosteal shelves of bone surround the facial nerve. The superior periosteal bony ledge contributes 75% of the circumference of the fallopian canal. The anterior ossification center forms over 83% of the fallopian canal length. The two centers fuse post partum near the region of the oval window. The anatomic location of the facial nerve, nerve branching, and neural vasculature precede ossification. In 80% of the paired temporal bones, this ossification pattern appears to be symmetrical. The patterns and incidence of bony dehiscences within the tympanic fallopian canal segment can be explained by these observations. This study demonstrates that fallopian canal dehiscences are not congenital anomalies, but variations of normal developmental anatomic processes.

trans-activation of the alpha 1-acid glycoprotein gene acute phase responsive element by multiple isoforms of C/EBP and glucocorticoid receptor

alpha 1-Acid glycoprotein (AGP) is a major acute phase protein synthesized primarily by the liver. The AGP gene is transcriptionally activated in hepatocytes during the acute phase response to bacterial lipopolysaccharide. In this study, we analyzed an acute phase responsive element (APRE) located between nucleotide residues -127 to -104 relative to the transcription initiation site of the mouse AGP gene. Binding studies show that several trans-acting factors interact with the APRE. Using monospecific antibodies we demonstrate that three isoforms of the CCAAT/enhancer-binding protein (C/EBP) family, namely C/EBP alpha, C/EBP beta, and C/EBP delta, bind to the APRE. Furthermore, with liver nuclear protein from control animals, C/EPB alpha is the predominant form that binds to the APRE, whereas with nuclear proteins from acute phase-induced animals, C/EBP alpha is replaced by C/EBP beta. The mechanism of activation of the AGP gene during the acute phase response appears to involve an exchange of C/EBP alpha by C/EBP beta. C/EBP delta does not play a role in this reaction. Interestingly, the C/EBP binding site of the APRE partially overlaps a functional glucocorticoid responsive element. We present evidence that both purified C/EBP alpha and glucocorticoid receptor bind strongly to the APRE. By site-specific mutation, we have identified the C/EBP and glucocorticoid receptor binding sites in the APRE. These mutants were used in expression vectors to demonstrate that both C/EBP and glucocorticoid receptor are essential for maximal response to interleukin-6 and dexamethasone. These results demonstrate that the APRE is a composite binding site for multiple factors that are responsible for the transcriptional control of the mouse AGP. Finally, functional analyses indicate that C/EBP alpha, C/EBP beta, and C/EBP delta are strong transcriptional trans-activators of the AGP APRE in hepatoma cells. These data suggest that the regulatory activity of the C/EBP with the APRE in the liver may require interactions with adjacent proteins.

Transtympanic electrocochleography in Menière's disease using clicks and tone-bursts

Transtympanic electrocochleography (ECoG), using clicks and tone-bursts at 500, 1000, and 2000 Hz, was employed to study 80 patients with Meniere's disease and 25 non-Meniere's patients. The magnitude of the negative summating potential and the summating potential:action potential ratio (SP:AP) were examined in both groups. Groups were further divided based upon degree of hearing loss and audiometric configuration. An elevated SP:AP ratio was found in 83.7 percent of the Meniere's ears and 12 percent of the non-Meniere's. The likelihood of obtaining a positive ECoG in Meniere's patients was strongly related to degree of hearing loss but not audiometric configuration.

Effect on endocochlear potential of streptomycin perfusion of the cochlea in guinea pigs

Perilymphatic perfusion of the cochlea with streptomycin was performed on 17 guinea pigs. The first and second group, consisting of five animals each, received streptomycin 150 micrograms and 1500 micrograms respectively. In a control group, consisting of seven animals, the perilymph was perfused with artificial perilymph only. The endocochlear potential (EP) was recorded from the second turn of the cochlea in each animal. The results indicate that streptomycin in a low dosage that will destroy the vestibular receptors was not harmful to the function of either the stria vascularis or the hair cells in the cochlea, as measured by changes in the EP after streptomycin perfusion of the cochlea.

Husband and wife differences in response to undesirable life events

In the present study of 451 married couples living in the rural midwest, gender differences were examined in reports of exposure and vulnerability to specific types of undesirable life events. Consistent with expectations derived from either a social structural or identity perspective, the results demonstrated that men are more likely than women to report exposure to and to be distressed by work and financial events. Women, on the other hand, are more strongly influenced by exposure to negative events within the family but not within their network of friends. Outcomes vary according to the type of emotional distress. Financial stress, for example, increases hostility among men more than among women, but wives are more likely than husbands to report somatic complaints in response to the same stressor. The findings demonstrate the need for future research that more directly investigates the intraindividual and social mechanisms which account for gender differences in a broad range of emotional and behavioral responses to varying types of significant life changes.

Intramuscular streptomycin effect on dark cells of utricle in guinea pigs

Streptomycin has been used in the treatment of Meniere's disease for almost half a century. Clinical studies showed that streptomycin may eliminate vertigo attacks and stabilize or improve hearing in the majority of patients. Animal experiments have demonstrated severe damage to the vestibular hair cells after streptomycin treatment. This study is to observe the effect of intramuscular streptomycin on dark cells of utricle. Guinea pigs that had received intramuscular injections of streptomycin sulfate 400 mg/kg per day for 1 and 2 weeks were studied. The dark cells of utricle were observed under transmission electron microscope. The pinocytotic vesicles and rough endoplasmic reticula markedly decreased and the plasmalemma infoldings in the lower part of the cell reduced in the 1-week group. The luminal membrane of the cells bulged out on the surface. After the cell membrane ruptured, the cytoplasmic organelle moved into the endolymphatic space and the cell dissolved. The morphologic changes indicated that streptomycin damaged the cytoplasmic granules and the plasma membrane infoldings of the dark cells. These cytologic characteristics are engaged in fluid secretion. The damage of secretory function of the dark cells may reduce the volume of endolymph.

Functional analysis of the trans-acting factor binding sites of the mouse alpha-fetoprotein proximal promoter by site-directed mutagenesis

The trans-acting factors of the mouse alpha-fetoprotein proximal promoter (-202 base pairs) are aligned as follows: regions Ia (HNF-1), Ib (C/EBP), II (NF-1 or C/EBP), II' (NF-1 or HNF-1), III (NP-III), IV (NP-IV), Va (NP-Va), and Vb (C/EBP). Site-specific mutation abolished protein binding to the corresponding mutated site with the exception of the NF-1 site, in which mutation causes partial protection. Transient expression analyses indicate that chloramphenicol acetyl-transferase (CAT) activity is reduced by mutations in regions Ia, II', Ib, II, and IV. Mutation of region III causes an increased activity and mutation of regions Va and Vb shows a slight inhibitory effect. Linking alpha-fetoprotein enhancer I to the wild type promoter resulted in a 12-fold stimulation of CAT activity. The activity of promoters with mutated C/EBP-binding sites (Ib, II, and Vb), was slightly above controls, indicating that enhancer I can reverse the effect of these mutations. Inhibition or stimulation of promoter activity resulting from mutations of the HNF-1 or NP-III binding sites, respectively, persisted when enhancer I was linked to the promoters, indicating that enhancer I cannot rescue these mutations. Mutation of both HNF-1-binding sites resulted in greater than 90% inhibition of CAT expression with and without enhancer I, indicating these sites are essential for promoter activity. The stimulation of promoter activity by mutation of the NP-III site suggests that this site may be essential for repression or attenuation of the alpha-fetoprotein gene. Our studies indicate that regulation of the alpha-fetoprotein gene requires the combinatorial effect of multiple cis- and trans-acting elements in the proximal promoter and that enhancer I may provide a factor(s) that specifically rescue the promoter from the inhibitory effect of mutation in the C/EBP-binding sites.

Induction of several acute-phase protein genes by heavy metals: a new class of metal-responsive genes

Acute-phase reactants, metallothioneins, and heat-shock proteins are the products of three families of genes that respond to glucocorticoids and cytokines. Metallothioneins and heat-shock proteins, however, are also stimulated by heavy metals, whereas very little is known about the effect of heavy metals on acute-phase-reactant genes. We have studied the effect of heavy metals (Hg, Cd, Pb, Cu, Ni, and Zn) and Mg on the acute-phase reactants alpha 1-acid glycoprotein, C-reactive protein, alpha 1-antitrypsin and alpha 1-antichymotrypsin. alpha 1-Acid glycoprotein and C-reactive protein mRNA levels were increased severalfold in livers of heavy-metal-treated Balb/c mice. The strongest induction was mediated by Hg, followed in order of response by Cd greater than Pb greater than Cu greater than Ni greater than Zn greater than Mg. None of the metals affected the mRNA levels of albumin, alpha 1-antitrypsin, and alpha 1-antichymotrypsin. Furthermore, failure to repress albumin, a negative acute-phase reactant, indicated that the induction of these genes was not due to a metal-mediated inflammatory response. The metals also induced alpha 1-acid glycoprotein and C-reactive protein in adrenalectomized animals, indicating that induction by the heavy metals is not mediated by the glucocorticoid induction pathway. Sequence analysis has revealed a region of homology to metal-responsive elements in the alpha 1-acid glycoprotein and C-reactive protein promoters. Additionally, an alpha 1-acid glycoprotein expression vector, pAGP(-595)CAT, responded to Hg and Cd when transfected into human HepG2 cells.(ABSTRACT TRUNCATED AT 250 WORDS)

[Short-term curative effect of cultured Cordyceps sinensis (Berk.) Sacc. Mycelia in chronic hepatitis B]

33 cases of chronic hepatitis B. patients treated with cultured Cordyceps sinensis mycelia have shown that the drug improves the liver function, promotes negative transfer HBsAg, and markedly helps to raise plasma albumin, resist high gamma globulin and to adjust body immunocompetence. It is therefore suggested that cultured Cordyceps sinensis mycelia may be used as a medicine for chronic hepatitis B. patients in adjusting protein metabolism and correcting inversion of albumin and globulin.