Bioavailability and pharmacokinetics of lorazepam after intranasal, intravenous, and intramuscular administration.

The purpose of this study was to evaluate the pharmacokinetic profile of intranasal lorazepam in comparison to currently established administration routes. Eleven healthy volunteers completed this randomized crossover study. On three occasions, each separated by a 1-week washout, subjects received a 2 mg dose of lorazepam via the intranasal, intravenous, or intramuscular route. Blood samples were collected serially from 0 to 36 hours. Noncompartmental methods were used to determine pharmacokinetic parameters. Lorazepam was well absorbed following intranasal administration with a mean (%CV) bioavailability of 77.7(11.1). Intranasal administration resulted in a faster absorption rate than intramuscular administration. Elimination profiles were comparable between all three routes. The concentration-time profile for intranasal delivery demonstrated evidence of a double peak in several subjects, suggesting partial oral absorption. Females were found to have significantly higher AUC values than males for all three delivery routes. Overall, this study demonstrated favorable pharmacokinetics of intranasal lorazepam in relation to standard administration methods. Intranasal delivery could provide an alternative, noninvasive delivery route for lorazepam.

Localization of the gene for familial laryngeal abductor paralysis to chromosome 6q16.

BACKGROUND: Vocal fold paralysis is a common cause of neonatal stridor. Although it is usually classified as idiopathic or iatrogenic in origin, a small subset of patients have a family history of this disorder, indicating a possible genetic cause. OBJECTIVE: To identify the genetic locus of the gene that causes familial laryngeal abductor paralysis. DESIGN: A standard nonorganic protocol was used to extract DNA from whole-blood samples. The DNA samples were quantified by DNA fluorometry, and the concentration of all samples was standardized at 40 ng/microL. A pooled DNA strategy was used to facilitate rapid polymerase chain reaction screening of markers in the Weber v8.0 genome screening set. Polymerase chain reaction screening of individual DNA samples was performed using possible linked markers initially identified as having an allele that appeared with a higher incidence in the affected DNA pools. Statistical analysis of possible linkage was performed using the LINKAGE 5.1 set of linkage analysis computer programs. SUBJECTS: A family in which a form of familial laryngeal abductor paralysis segregates was ascertained. Whole blood samples were drawn from 40 participating individuals within this family after the subjects' fully informed consent was obtained. RESULTS: Initial screening of the pooled DNA specimens revealed a band pattern for D6S1021 on chromosome 6q16, indicating an allele with a higher incidence in the affected vs the nonaffected pool. Two-point analysis of individual allele patterns confirmed linkage to D6S1021 with an lod score of 3.86 (straight theta = 0.0) at a penetrance value of 0.8. Haplotype analysis with flanking markers defined a 5-centiray critical region between D6S283 and AFMA047YG1. CONCLUSION: An autosomal dominant form of familial laryngeal abductor paralysis is linked to a 5-centiray region on chromosome 6q16 surrounding D6S1021.

Tracheal agenesis: diagnosis and management.

Tracheal agenesis (TA) is a rare congenital anomaly that typically has fatal consequences. Its rarity, lack of prenatal symptoms, and emergent presentation usually lead to a failure to arrive at the correct diagnosis and manage the airway properly before the onset of irreversible cerebral anoxia. We report the case history of an infant born with immediate respiratory failure who was diagnosed with tracheal agenesis. The clinical features, embryology, classification schemes and surgical management are discussed with the hope that increased awareness and earlier diagnosis may lead to better chances of survival for affected individuals.

Age-related mitochondrial DNA mutations in the human larynx.

OBJECTIVE: To determine whether age-related mitochondrial DNA mutations occur in the human larynx. STUDY DESIGN: Genetic study of cadaveric larynx specimens. METHODS: Vocal fold mucosa, thyroarytenoid muscle, and cricoarytenoidjoint tissue were harvested from 13 fresh postmortem larynges (age range, 2 d-82 y). DNA was extracted from each sample, and the polymerase chain reaction (PCR) was used to amplify a target DNA sequence resulting from the common age-associated, 4977-base-pair (bp) mitochondrial DNA deletion. PCR products were visualized by agarose gel electrophoresis. Automated sequencing determined the sequence of identified PCR products. SUBJECTS: Thirteen cadaveric larynges were obtained through the University of Kentucky Medical Center (Lexington, KY). Specimens from patients with a history of head and neck cancer, previous laryngeal trauma, or surgery were excluded. RESULTS: Strongly positive bands were identified in samples from three individuals. Weaker bands were seen in samples from four other samples. No band was noted from the two pediatric larynges. Different band patterns were seen among the three different tissue sites in the larynges with positive PCR products, but no consistent pattern was seen. Sequencing of the identified PCR products from selected samples confirmed that they were products of the age-associated, 4977-bp mitochondrial DNA deletion. CONCLUSIONS: An age-associated mitochondrial DNA deletion was detected in several post-mortem human larynges. Its presence seemed to increase in appearance with age. In the larynges in which the deletion occurred, there were individual regional differences in the occurrence of the deletion, but no consistent pattern was noted across all individuals who carried the deletion.

Otolaryngologic aspects of oral-facial-digital syndrome.

The oral-facial-digital (OFD) syndromes are a heterogeneous group of hereditary disorders which have in common the findings of oral abnormalities, facial dysmorphism, and hand/feet malformations. We report the case history of an 18-month-old male with cerebellar cysts, hydrocephalus, tongue hamartomas, and polydactyly. These findings are most consistent with OFD VI. The clinical features of eight different types of OFD are discussed, with particular attention to the characteristics of the most interest to the otolaryngologist.

Variations in end-expiratory pressure during partial liquid ventilation: impact on gas exchange, lung compliance, and end-expiratory lung volume.

STUDY OBJECTIVES: To determine the effects of different levels of positive end-expiratory pressure (PEEP) during partial liquid ventilation (PLV) on gas exchange, lung compliance, and end-expiratory lung volume (EELV). DESIGN: Prospective animal study. SETTING: Animal physiology research laboratory. SUBJECTS: Nine piglets. INTERVENTIONS: Animals underwent saline solution lavage to produce lung injury. Perflubron was instilled via the endotracheal tube in a volume estimated to represent functional residual capacity. The initial PEEP setting was 4 cm H(2)O, and stepwise changes in PEEP were made. At 30-min intervals, the PEEP was increased to 8, then 12, then decreased back down to 8, then 4 cm H(2)O. MEASUREMENTS AND RESULTS: After 30 min at each level of PEEP, arterial blood gases, aortic and central venous pressures, heart rates, dynamic lung compliance, and changes in EELV were recorded. Paired t tests with Bonferroni correction were used to evaluate the data. There were no differences in heart rate or mean BP at the different PEEP levels. CO(2) elimination and oxygenation improved directly with the PEEP level and mean airway pressure (Paw). Compliance did not change with increasing PEEP, but did increase when PEEP was lowered. EELV changes correlated directly with the level of PEEP. CONCLUSIONS: As previously reported during gas ventilation, oxygenation and CO(2) elimination vary directly with PEEP and proximal Paw during PLV. EELV also varies directly with PEEP. Dynamic lung compliance, however, improved only when PEEP was lowered, suggesting an alteration in the distribution of perflubron due to changes in pressure-volume relationships.

Cervical vertebral anomalies in patients with anomalies of the head and neck.

Congenital head and neck anomalies can occur in association with vertebral anomalies, particularly of the cervical vertebrae. While the former are easily recognized, especially when part of a syndrome, the latter are often occult, thereby delaying their diagnosis. The presence of vertebral anomalies must be considered in pediatric patients with head and neck abnormalities to expedite management of select cases and to prevent neurologic injury. We present our experience with 5 pediatric patients who were referred to the Department of Otolaryngology-Head and Neck Surgery at the University of Iowa with a variety of syndromic anomalies of the head and neck. Each patient was subsequently also found to have a vertebral anomaly. The relevant embryogenesis of the anomalous structures is discussed, with highlighting of potential causes such as teratogenic agents and events and germ-line mutations. A review of syndromes having both head and neck and vertebral anomalies is presented to heighten awareness of otolaryngologists evaluating children with syndromic disorders. Finally, the findings on radiographic imaging studies, particularly computed tomography, are discussed to facilitate the prompt diagnosis of vertebral anomalies.

Familial laryngeal paralysis.

Vocal fold paralysis (VFP) is the second most frequent cause of congenital stridor. Although often due to birth trauma, infection, and brainstem abnormalities, most cases are idiopathic. Infrequently, a family history of VFP is elicited, identifying a role for genetic factors in laryngeal function. This study describes a family in which an autosomal dominant form of familial laryngeal abductor paralysis segregates. The typical physical findings, diagnostic and therapeutic considerations, and possible molecular mechanisms of this disorder are discussed in detail.

Presymptomatic diagnosis of nonsyndromic hearing loss by genotyping.

BACKGROUND: Nonsyndromic hearing loss (NSHL) is the most common type of hereditary hearing impairment (HHI). It is genetically heterogeneous, and although the exact number of genes is not known, 38 loci have been identified. By cloning the relevant genes and studying the function of the encoded proteins at the molecular level, it may be possible to impact the habitation of persons at risk for HHI. Currently, for select families, presymptomatic diagnosis of NSHL by genotyping is possible. OBJECTIVE: To provide presymptomatic diagnosis of HHI to individuals in select families who have participated in linkage studies. DESIGN: In 2 large families with autosomal dominant HHI, genes for NSHL were mapped to chromosomes 6 (DFNA10) and 19 (DFNA4). In each family, the phenotype is one of progressive sensorineural hearing loss that begins in the individual's mid-30s and progresses to a severe-to-profound loss requiring amplification. Presymptomatic diagnosis was requested by, and provided to, 19 at-risk persons in these kindreds. RESULTS: By reconstructing haplotypes through the use of short tandem repeat polymorphisms tightly linked to the disease gene, risk calculations and genetic counseling were provided to these persons. CONCLUSIONS: By simple Mendelian genetics, the risk of inheriting a fully penetrant autosomal dominant NSHL gene from a single affected parent is 50% for each offspring. However, by reconstructing haplotypes in families in which an HHI gene has been localized, this risk can be changed substantially.

Construction of P1-derived artificial chromosome and yeast artificial chromosome contigs encompassing the DFNB7 and DFNB11 region of chromosome 9q13-21.

DFNB7 and DFNB11, two loci for autosomal recessive nonsyndromic hearing loss (ARNSHL), have been mapped to chromosome 9q13-21 in separate consanguineous families. Using a radiation hybrid map, we have determined the correct marker order in the DFNB7/11 region and have demonstrated that the DFNB11 locus resides within a redefined DFNB7 interval. The gene(s) responsible for ARNSHL at these loci resides within an approximately 1 cM interval bounded by markers D9S1806 (centromeric) and D9S769 (telomeric). A recently discovered Indian family confirms the new telomeric boundary. To assist in the identification and cloning of candidate genes, YAC and PAC contigs were constructed. A total of 19 YAC and 23 PAC clones were utilized to span the affected region and ensure double coverage throughout. Twenty-two previously published STSs and 21 new STSs were used to determine marker order and confirm the integrity of the contig. Using a positional cloning strategy we have identified three cochlear expressed genes that map to the DFNB7/11 interval.

Sequential muscle biopsy changes in a case of congenital myopathy.

Muscle biopsies at age 7 months in a set of dizygotic male twins born floppy showed typical features of congenital fiber-type disproportion (CFTD). One of the twins died at age 1 year due to respiratory complications. The second one subsequently developed facial diplegia and external ophthalmoplegia. He never walked, remained wheelchair bound, and required continuous ventilatory support. He underwent repeat biopsies at ages 2 and 4, which showed many atrophic type 1 muscle fibers containing central nuclei and severe type 2 fiber deficiency compatible with centronuclear myopathy (CNM). Two-dimensional gel electrophoresis of muscle showed decreases of type II myosin light chains 2 and 3, suggestive of histochemical type I fiber deficiency. The progressive nature of morphological changes in one of our patients cannot be explained by maturational arrest. Repeat biopsies in cases of CFTD with rapid clinical deterioration may very well show CNM.

The role of magnetic resonance angiography in head and neck surgery.

Magnetic resonance angiography (MRA) is a recently developed, noninvasive vascular imaging technique. The authors of this investigation assessed the diagnostic value of MRA, along with its influence on therapeutic decisions, in 11 patients with a variety of head and neck disorders. In 5 patients, MRA diagnosed or ruled out an intrinsic vascular lesion. MRA was used to evaluate 5 of 8 patients with cancer for evidence of direct tumor involvement of vascular structures. Other uses of MRA included preoperative determination of tumor vascularity and delineation of anatomic relationships between normal vessels and head and neck pathology. Overall, MRA results guided management in 10 patients, and in some cases it determined the extent of surgical intervention. Because MRA is safer and more practical than traditional angiography, the authors recommend more frequent use of this imaging technique in the practice of head and neck surgery.

Prognostic significance of nucleolar organizer regions (NORS) in malignant melanoma.

Nucleolar organizer regions (NORs) are loops of ribosomal DNA (rDNA) in the nucleolus and are associated with acidic proteins. They are seen in routinely processed paraffin sections by using a one-step colloidal silver (Ag) staining method; they appear as black dots termed "AgNORs". The quantitative assay of AgNORs has been used to differentiate benign from malignant neoplasms. Melanocytic lesions differ significantly in AgNOR counts between malignant melanoma and nevi. However, conflicting results have been reported as to AgNORs' prognostic value in melanoma. A recent study showed AgNOR counts to be a more accurate prognostic indicator than Breslow's thickness. In this study, we counted the AgNORs in 26 patients with primary cutaneous melanomas (CMM) between 2.0 mm and 2.5 mm thick. Of these, 14 are alive without disease (AN) at 5 years after diagnosis (group 1) and 12 are dead of disease (DD) in less than 5 years (group 2). The AgNORs were scored in 30 nuclei per tumor, and the means were calculated. For group 1, the mean number of AgNORs per nucleus was 6.88, ranging from 3.73 to 12.70. For group 2, the mean number was 6.97, ranging from 3.63 to 11.67. Statistical analysis using analysis of variance (ANOVA) showed no significant difference between the groups (p = 0.33). In our study, AgNOR counts did not prove to be of prognostic value in malignant melanoma.

Primary cutaneous phaeohyphomycosis: report of seven cases.

We report seven cases of primary cutaneous phaeohyphomycosis. There were five males and two females, ranging in age from 42-65 years (mean 57.7 years). Two patients were otherwise healthy, but five were immunocompromised. One patient had rheumatoid arthritis and was on oral prednisone; two were renal transplant recipients, one was a heart transplant recipient, and the fifth had dermatomyositis. No history of trauma was elicited from any of the patients, but in two cases, foreign material was seen in the tissue sections. All lesions were on the extremities. In two cases, tissues were cultured, and these grew Exophiala jeanselmei. The others were not cultured because fungal infection was not clinically suspected. No systemic disease developed in any of the cases, and all were cured by the simple, complete excision of the lesions.

Inherited congenital adrenal hyperplasia in the rabbit: absent cholesterol side-chain cleavage cytochrome P450 gene expression.

We investigated adrenal steroidogenic enzymes, their activity and mRNA expression, and in vitro biosynthesis of an enzyme in rabbits with congenital adrenal hyperplasia (CAH; weight: CAH, 19 +/- 5 mg/adrenal; normal, 2.7 +/- 1.0 mg/adrenal). Serum pregnenolone (delta 5-P) levels in CAH newborn rabbits (12-36 h) were normal (mean/range, 438/51-2191 ng/dl), but corticosterone levels were low [0.05 +/- 0.05 microgram/dl; P less than 0.001 vs. normal (0.66 +/- 0.57)]. Serum Na+ levels in CAH newborn rabbits were in the normal range (143 +/- 30 meq/liter), but K+ levels were elevated [7 +/- 1.1 meq/liter; P less than 0.05 vs. normal (5.9 +/- 0.6 meq/liter)]. Minced normal adrenal tissue incubated with [3H] cholesterol (30-100 pmol/flask) and ACTH (100 mU/flask) produced [3H]delta 5-P (newborn, 21 and 45 fmol/100 mg; adult, 3 and 5 fmol/100 mg) and [3H]corticosterone (newborn, 23 fmol/100 mg; adult, 11.3 fmol/100 mg), but CAH adrenals produced no product (less than 1.3 fmol/100 mg). Adrenal mitochondria from normal newborn rabbits produced delta 5-P (4.4-7 nmol/mg protein), but CAH adrenals did not, while CAH adrenal mitochondria demonstrated over 4 times greater 11 beta-hydroxylase activity. A Western blot of adrenal homogenate from normal newborn rabbits revealed a cholesterol side-chain cleavage cytochrome P450 (P450scc)-immunoreactive species (mol wt, 53 x 10(3), but this species was absent in CAH adrenals; CAH adrenals had a normal adrenodoxin and intensified 17 alpha-hydroxylase cytochrome P450 (P450(17)alpha) band compared to normal adrenals. In vitro translation of RNA in a cell-free rabbit reticulocyte lysate system containing [35S] methionine yielded a precursor P450scc protein (mol wt, 58.5 x 10(3)) with normal adrenal RNA, but not with CAH adrenal RNA. P450scc mRNA was detected in all normal adrenals, but was not detected in all CAH adrenals. 21-Hydroxylase cytochrome P450 mRNA expression was detected at a similar level in both normal and CAH adrenals. We conclude that CAH in the rabbit is caused by inherited absent P450scc gene expression. The clinical, pathological, and biochemical manifestations of P450scc deficiency in the rabbit are nearly identical to the human disorder. Increased 11 beta-hydroxylase activity and increased P450(17)alpha on Western blot of CAH adrenals indicate altered gene expression of other steroidogenic enzymes due to CAH. Further molecular analysis of the P450scc gene in this animal CAH model will facilitate understanding of P450scc deficiency CAH.