Foreign body neonatal otitis media in infants.

HYPOTHESIS: An influx of amniotic fluid cellular content (AFCC) into the middle ears during birth may lead to the development of a chronic inflammatory process in the form of varying amounts of granulation tissue even if signs of otitis media are absent. This foreign body neonatal otitis media may predispose the child to recurrent otitis media. BACKGROUND: Foreign body neonatal otitis media caused by AFCC was described by Aschoff and elaborated by Wittmaack 100 years ago. Recent studies have shown how AFCC spreads to various middle ear compartments and causes histologic changes, the severity of which is related to the amount of AFCC. Specific elements become phagocytized after the first months of life but have caused the formation of inflammatory polyps and granulation tissue with round cell secretions in the meantime. METHODS: Ten temporal bones from the Temporal Bone Foundation, derived from infants aged 5 months to 1 year 11 months, were serially sectioned at 20 microm, saved at 0.2-mm intervals, numbered, and stained with hematoxylin and eosin. Every slide was studied for the presence, nature, and stage of pathologic tissue changes of the middle ear and the mastoid antrum. RESULTS: Pseudocystic granulation tissue was massive in the temporal bone of the 8-month-old child born through thick meconium. Severe changes were present in the temporal bones of two infants aged 5 months, one of which showed traces of AFCC. In the temporal bones of two older children, long-standing changes were minor, one of them still showed traces of AFCC. Fresh acute changes and long-standing histologic changes occurred side by side. CONCLUSIONS: Neonatal otitis media caused by AFCC can give rise to extensive granulation tissue and round cell secretion, which is likely to make the ear susceptible to infectious otitis media. Cumulative development of granulation tissue as a result of infection may lead to blockage of attic aeration and drainage pathways, causing irreversible adhesive otitis media. A data base should be formed of all neonates born through meconium-stained amniotic fluid to allow a comparison with those born through clear fluids. Surgery with the creation of auxiliary aeration pathways becomes advisable in the treatment of ears with massive development of granulation tissue.

Selective inner hair cell loss in premature infants and cochlea pathological patterns from neonatal intensive care unit autopsies.

BACKGROUND: Deafness and handicapping sensorineural hearing impairment occur frequently in neonatal intensive care unit survivors for unknown reasons. PATIENTS AND METHODS: Hearing was tested early and repeatedly in neonatal intensive care unit patients with an auditory brainstem response (ABR) screener. The temporal bones of 15 nonsurvivors (30 ears) were fixed promptly (average, 5 hours) after death for histological evaluation. RESULTS: Among these patients, 12 failed the ABR screen bilaterally, 1 passed unilaterally, and 2 passed bilaterally. Cochlear histopathologic conditions that could contribute to hearing loss included bilateral selective outer hair cell loss in 2 patients, bilateral selective inner hair cell loss in 3 (all premature), and a combination of both outer and inner hair cell loss in 2. Other hair cell abnormalities were noted; the 2 infants who had passed the ABR screen demonstrated normal histological features. Neuronal counts were normal. CONCLUSIONS: Auditory brainstem response failure among these neonatal intensive care unit infants who died was extremely common in part owing to an unexpected histological alteration, selective inner hair cell loss among premature newborns, that should be detectable uniquely by the ABR testing method. Additional histological patterns suggest more than one cause for neonatal intensive care unit hearing loss. Hair cell loss patterns seem frequently compatible with in utero damage.

Spread and fate of amniotic fluid cellular content in the middle ear.

In this study, 24 temporal bones with an age range from neonates to 23-month-old infants were serially sectioned and studied for the spread and fate of amniotic fluid cellular content (AFCC) in the middle ear and mastoid. Most children had had either a moderate or massive contamination. AFCC clusters were found to spread to all compartments, with the sites of predilection being the stapes region, the lower lateral attic and the tympanic isthmus. AFCC created an intensive foreign body giant cell reaction and the foreign material practically dissolved in 5 months as a result of the organization process. Tiny remnants of AFCC appeared as late as 15 months after birth. It seems likely that AFCC contamination predisposes the ears to recurring otitis media. The sequalae of the massive granulation tissue development involves obliteration of Prussak's space and its aeration routes, as well as blockage of the tympanic isthmus, leading to extensive disease in the major attic compartments.

Aeration and drainage pathways of Prussak's space.

OBJECTIVE: the purpose of this study was to document the aeration and drainage pathways of Prussak's space. METHODS: 55 temporal bones with an age range from neonate to 11 years of age were serially sectioned to 20 microns, every 10th section was saved and stained by Hematoxylin eosin. Each consecutive section was studied as to the connections of Prussak's space to adjacent compartments and measurements of the dimensions were made for both Prussak's space and its aeration pathways. RESULTS: the classic aeration pathway via the posterior pouch, as described by Prussak in 1867, was found in 34 ears (62%). In 19 (36%), aeration occurred superior to the posterior pouch in the region of the lower lateral attic and the upper mesotympanum. In these ears the posterior pouch had formed, but its superior limit ended blindly in the tympanic membrane. In two temporal bones the aeration pathway was from the anterior pouch and in these cases also a blind posterior pouch had developed. In one temporal bone an auxiliary pathway in addition to the route via the posterior pouch was through the roof (the lateral malleal ligamental fold) of Prussak's space to the overlying lateral malleal space. The height of the posterior pouch varied with a range from 0.5 to 2.4 mm, and the greatest width, which was towards the posterior tympanic spine, varied from 1.6 to 3.2 mm. The superiorly blind posterior pouch was shorter, ranging from 0.4 to 1.2 mm in height. The most frequent route of the chorda tympani nerve was running from 0.5 to 1 mm medial to the posterior malleal ligament in the anterior half of the pouch, joining it posteriorly, or it was connected to it by a short fold, 37 ears (67%). In 18 cases (33%) the chorda was surrounded by its own fold, thus entirely separate from the posterior malleal ligamental fold during its entire course across the tympanum. CONCLUSIONS: we have made a detailed documentation of the aeration and drainage pathways of Prussak's space and the findings concur, with important modifications, with Prussak's original description. There is no evidence for contemporary claims that Prussak's space would be aerated superiorly between the lateral incudal and malleal folds. Prussak's space and its aeration pathway is an unit of its own, entirely separate of the major epitympanic compartments which are aerated via the tympanic isthmus. Due to frequent disease processes in the lower lateral attic and posterior mesotympanum, Prussak's space and its aeration pathway are likely to become blocked. This may lead to obliteration of Prussak's space and to the development of retraction pocket or papillary ingrowth cholesteatoma.

Effect of amniotic fluid cellular content on attic aeration pathways: histologic observations of infants aged 2 to 4 months.

HYPOTHESIS: The tissue-fixed amniotic fluid cellular content (AFCC) in the middle ear and mastoid antrum causes foreign body type reactions that may later severely restrict the aeration pathways to the main attic and to Prussak's space. BACKGROUND: It was shown by Aschoff 100 years ago that AFCC remained in the neonate ears and caused sterile otitis media. Recent data show that children born through thick meconium are at risk for large quantities of AFCC entering the middle ear cleft, the ensuing inflammatory reaction being related to the amount of AFCC. Spread of AFCC in the neonate occurred along the aeration pathways with corresponding tissue fixation but further systematic data in young infants are lacking. METHODS: Five temporal bones of three infants aged 2 to 4 months were embedded in celloidin, serially sectioned at 20 microns, and every 10th section stained with Hematoxylin and eosin and mounted on slides. All slides were studied and relevant details of aeration pathways and all compartments photographed. RESULTS: The histologic changes were characterized by the development of masses of pseudocystic granulation tissue, with some remnants of the original AFCC, mainly in the form of fragments of hair. The tympanic isthmus was involved to varying extent, maximally to half of its size. Posterior tympanum and the stapes region had masses of fresh granulation tissue, the maturing of which might cause marked indrawing of the posterior pars tensa and further reduction of the tympanic isthmus. Aeration of Prussak's space was severely involved in two bones, favored by the narrow pathway through the posterior pouch. Features of recent acute or secretory otitis media were associated with the early changes caused by AFCC. CONCLUSIONS: The granulation tissue in this age group is immature and its final fate is decided by the nature of the future ear disease. If the AFCC contamination is slight, the granulation tissue after maturing may appear only in the form of thin cords and sheets, a frequent chance finding in ear surgery. Large amount of AFCC may lead to chronic inflammation, which may predispose the child to recurring middle ear infections during infancy. Further histologic and clinical studies in older infants and young children are needed to find out the final outcome after a massive AFCC contamination of the new-born middle ear.

Supratubal recess in neonates and infants.

OBJECTIVE: The fetal development of the supratubal recess and of the tensor fold was described by Hammar in 1902. Recent studies claim that neither structure is regularly present in neonates and controversial views have been presented of the separation of the anterior attic and supratubal recess. The objective of this study is to clarify these issues. METHODS: Twenty temporal bones, 13 neonate and seven infant, were studied either by microdissection of fresh (five bones) or formalin stored (two) specimens, or by serial sectioning after formalin fixation and decalcification (13 bones). The serial sections were cut to 20 microm, every tenth section saved and stained by hematoxylin eosin. RESULTS: In all specimens the separating structure between the anterior attic and supratubal recess was the tensor fold. It was intact in 15 bones while five showed a membrane defect. In vertically oriented folds the recess was deep and in horizontally oriented folds shallow. In 19 bones the tensor fold inserted superiorly to a soft tissue insertion ring of varying thickness and only once directly to a shallow transverse crest. The breadth of the tensor fold near the tensor tendon showed only little variation, whereas its height, and the distance from the tensor tendon to the supratubal tegmen varied in larger limits. CONCLUSIONS: The tensor fold and the supratubal recess are present already in the neonate and thus develop during the fetal period. The shape of the recess is determined by the fold direction and its size grows in conjunction with the other middle ear spaces. The transverse crest has no apparent influence on the position of the tensor fold. The easiest method to study the integrated whole of the anterior attic and supratubal recess is to view them alternatively from the anterior and superior microdissection approaches. Clinically, removal of the tensor fold creates an efficient additional aeration route from the supratubal recess to the anterior attic.

Spread of amniotic fluid cellular content within the neonate middle ear.

Six full-term neonatal temporal bones, with meconium contaminated amniotic fluid aspiration of varying degrees, were serially sectioned at 20 microm and every tenth section was stained by hematoxylin eosin and mounted on slides. All stained sections were studied, the data recorded and relevant details of all compartments photographed. In addition, four normal neonate temporal bones were studied, one by serial sectioning and three by microdissection. The lateral incudomalleal and tensor folds were present in all, membrane defects in the tensor fold were seen in two normal ears. Three ears in the aspiration group had much fetal tissue present rendering Prussak's space small. Four ears with aspiration had remnants of incus intercrural (medial) folds. The amniotic fluid cellular content (AFCC) was sparse or nonexistent in the supratubal recess, Prussak's space and hypotympanum. It concentrated to the areas around the stapes, to sinus tympani and round window niche, to lower lateral attic and posterior pouch, medial attic and in lesser amounts to superior attic, mastoid antrum and air cells. Massive amounts of AFCC in tympanic isthmus and posterior pouch may lead to formation of granulation tissue and blockage of the aeration pathways to attic proper and to Prussak's space. These changes may initiate the development of chronic secretory otitis media in infants.

Embryonic middle ear mesenchyme disappears by redistribution.

OBJECTIVE: The fate of embryonic middle ear mesenchyme from a postgestational infant ear has been speculative. Recently a volume analysis of human neonatal temporal bones demonstrated that embryonic mesenchyme disappeared by redistribution and thinning to surface a growing middle ear space. If this model is accurate, interaction with amniotic fluid and the gestational environment should not influence mesenchymal behavior. Therefore an opossum marsupial model was compared with human data. METHODS: The temporal bones of opossum pups (20 to 36 days of age) were sectioned for histologic analysis. Computations were made for the volume of the middle ear air cavity (VAC), volume of the bone cavity (VBC), volume of mesenchyme (VM), and percentage of the middle ear occupied by mesenchyme (%M), which were plotted against height using regression statistics. These data were compared with human neonatal (0 to 30 days of age) temporal bones. RESULTS: In both the opossum and the human the VAC and the VBC increased in parallel with growth of the body. In the opossum the VAC and VBC both grew at 0.148 mm3/mm of body length. In humans, both the VAC and VBC grew 6.1 mm3/cm of body length. The VM in the opossum remained constant at 0.98 mm3, regardless of body length. In humans the VM remained constant at 71.7 mm3, regardless of body length. Therefore the %M proportionately decreased inversely with increasing ear size in both the opossum and the human neonate. CONCLUSION: This study supports a simple and credible explanation for the illusion of mesenchymal disappearance in the neonatal middle ear. The mesenchymal connective tissue redistributes to cover a larger surface area in a persistently enlarging cavity. These findings occur in different species, whether gestation is completed in an intrauterine or an extrauterine environment.

The origin of congenital cholesteatoma.

OBJECTIVE: This study aimed to document histologically the origin of congenital cholesteatoma in neonatal temporal bones. STUDY DESIGN: The study design was a systematic analysis of pediatric temporal bones. SETTING: The study was performed at the temporal bone laboratory, Tufts University School of Medicine and New England Medical Center, Boston, Massachusetts. RESULTS: We describe histologic findings of a congenital cholesteatoma and a squamous epithelial rest in two postpartum patients. In both patients, the masses were asymptomatic and occurred in the anterosuperior quadrant of the middle ear cleft. This is the first histologic documentation of postpartum congenital cholesteatoma. CONCLUSIONS: We believe that these cases represent the first clear histologic documentation of the origin of congenital cholesteatoma.

Juvenile keratin inoculation induces chronic ear pathology.

OBJECTIVE: Human neonatal temporal bones frequently show the formation of granulation tissue provoked by amniotic fluid keratin contents, desquamated keratinized epithelial cells and lanugo hair. Similar histopathologic findings have been produced previously in a short-term animal model. To test the hypothesis that those short-term pathologic observations could have theoretical relevance for ear disease in older patients, a longer term animal model study was necessary. METHODS: Into the right bulla of 10 chinchilla pups was placed an aliquot of autogenous, nonviable epidermal scrapings and hair. Into the left bulla was placed 1 mm2 viable autogenous epidermal tissue. Animals were killed at intervals up to 11 months and then studied by light microscopy. RESULTS: Chronic ear histopathologic changes such as granulation tissue, osteoneogenesis, adhesions, and cholesteatoma were present. Over time, these secondary pathologic changes became more obvious than the initial keratin implant. CONCLUSIONS: The authors conclude that chronic pathologic changes resembling human ear disorders persist and that this model further extends the hypothesis that prenatally acquired keratin eventually could account for some cases of human ear disease.

Sulfonamide-induced iritis.

Anterior uveitis is a relatively rare adverse drug reaction when the prescription rate of sulfonamides is considered. Current medications should be included in the differential diagnosis of patients who present with uveitis, because discontinuation of the offending agent is mandatory to resolution of the problem. Lack of recognition and failure to discontinue the medication will increase the patient's risk of ocular injury.

Neonatal mesenchyme temporal bone study: typical receding pattern versus increase in Potter's sequence.

The fate of mesenchyme, which lines the fetal and newborn bony middle ear, is not well understood. The authors wished to test previous observations that a greater amount of mesenchyme was found in Potter's sequence (renal anomalies, pulmonary hypoplasia, and oligohydramnios). Using celloidin-embedded neonatal temporal bones (68 cases, 123 ears), with clinical and autopsy information, middle ear volumes were compared among diagnostic groups using analysis of variance. In 16 ears of Potter's sequence cases the volume of mesenchyme increased in proportion to the size of the middle ear. Conversely, in all other cases the volume of mesenchyme remained constant compared to increasing middle ear size. Both the volume of the bony middle ear and the volume of the air cavity increased at 15 mm3/500 g of body weight (gbw). Mesenchyme percentage decreased by 2%/500 gbw. Middle ear mesenchyme appears to recede rather than reabsorb. However, in Potter's sequence cases the volume of mesenchyme increases, raising issues of a missing renal signal that inhibits mesenchymal growth under normal circumstances.

What high school students think of a nursing career: a survey of Dade County senior high schools.

Using a cross-sectional design, we surveyed 700 10th and 11th-grade students in Dade County, Florida, to examine high school students' opinions of a nursing career and the relationships among students' opinions and several variables. Of a possible range of opinion scores from 14 to 56, the mean opinion score for the sample was 40.92 (SD = 7.8). While age had no significant correlation with nursing opinion scores, they were influenced significantly by gender, the students' desired occupation, and the opinions of parents, friends, and guidance counselors. Although only 28 (7%) of the students selected nursing as their desired occupation, 119 (24.5%) considered nursing one of their alternatives prior to making a decision. These findings have important implications for the recruitment of high school graduates into nursing.

Chronic ear pathology in a model of neonatal amniotic fluid ear inoculation.

Human histopathologic studies have demonstrated that amniotic fluid cellular contents, keratinized squamous epithelial cells and lanugo hair, induce an intense inflammatory reaction including granulation tissue in the neonatal temporal bone. To investigate this reaction over a prolonged period, an animal model was studied. An aliquot of sterilized autologous hair and keratinized epithelial cells was placed into 14 gerbil bullae; saline was used as a contralateral control. The animals were sacrificed at intervals up to 6 months and the temporal bones were studied by light microscopy. All animals demonstrated nonpurulent inflammatory changes on the experimental side including granulation tissue, osteoneogenesis, tympanosclerosis, and cholesteatoma; the control side demonstrated minimal middle ear changes. We conclude that in this model autologous keratinized tissue provokes a foreign body response similar to the granulation tissue observed in human infants and, further, that over a prolonged period the middle ear demonstrates more severe pathologic consequences.

Automated enzymatic assays for the determination of intestinal permeability probes in urine. 1. Lactulose and lactose.

Lactulose is becoming the disaccharide of choice in the dual sugar assessment of passive permeability of the small intestinal mucosa. However its more widespread use is hampered by current analytical methods which are tedious and time consuming. An automated spectrophotometric technique for the assay of this sugar in urine is presented in which lactulose is linked by a series of enzyme reactions to the equimolar production of NADPH. In addition to lactulose, the procedure also gives accurate values for lactose, glucose and fructose in the urine sample. The assay has been shown to be highly specific for lactulose and lactose and was not affected by high concentrations of other sugars or other urinary constituents. Within assay and between assay precision were similar with the coefficient of variation for both sugars in the range 0.4-1.6%. The technique represents a significant improvement in time, simplicity and precision on existing methods of analysis.