Auditory brainstem responses after ovariectomy and estrogen replacement in rat.

Previous work has suggested possible influences of ovarian hormones on evoked potentials in the auditory system. The aim of this project was to study the effects of ovariectomy and subsequent administration of estrogen replacement on the auditory brainstem response and the middle latency response. Groups of 90 day-old Long-Evans hooded rats were anesthetized for bilateral ovariectomies (ovex) and recordings made 3 weeks later. During the week prior to recordings some ovariectomized groups received subcutaneous injections of 10, 100 or 500 micrograms/kg Premarin in peanut oil, and other unoperated animals received vehicle injections. Recordings from vertex/chin using needle electrodes and pure tone stimulus parameters were made under Rompun/Ketamine. The results using 40 kHz tone stimuli showed that mean latencies for ovex animals were longer than animals in the 100 micrograms/kg Premarin group for waves 1a, 1an, 1b, 11, 111, 111n, and 1V/V. Other posthoc comparisons at 40 kHz stimulation revealed differences between control and 100 micrograms/kg Premarin groups for latencies of waves 1b, 1bn, 11 and 111. Latency reduction appeared for waves 1b, 1bn, 11 and 111 for the 10 ovex group, but only at wave 11 for the 500 ovex group, compared to ovex-only animals. Data from 8 kHz stimulation also demonstrated significant differences between the ovex and ovex 100 groups at waves 1bn and Vn. Observations of interpeak latency differences, especially between waves 1a and 11, suggested central as well as cochlear involvement in hormone action.(ABSTRACT TRUNCATED AT 250 WORDS)

Current methodologies for the study of pineal morphophysiology.

Light and electron microscopes, with or without the use of immunohistochemical techniques, have been the instruments of choice for study of the pineal complex even up to recent times. Other morphological technologies have become available during the past decade that, if applied to current questions concerning pineal morphophysiology, could add considerably to our understanding of this complex system. Those technologies discussed include confocal scanning laser microscopy (in conjunction with other techniques including immunohistochemistry and three-dimensional reconstruction), tissue culture methodologies, carbocyanine dyes (i.e., DiI), in situ hybridization, and application of microinjection methodologies. It is suggested that these technologies will be necessary for morphophysiologists to not only collaborate with molecular biologists and biochemists who study the pineal complex, but to corroborate the molecular and biochemical results of our colleagues.

Third ventricular pineal gland grafts in the gerbil: an electron microscopical and immunohistochemical investigation.

The superficial pineal gland was grafted into the third ventricle of adult Mongolian gerbils. Donor pineal glands from both neonatal and 3-4 week old gerbils were able to survive for at least 6 months. The pinealocytes of the grafted superficial pineal glands maintained the morphology and the S-antigen immunoreactivity of the in situ pineal complex. Synaptic ribbons and spherules were present but rare. Unlike the in situ pinealocytes, glycogen accumulations were common in the graft pinealocytes. Site specific modulation of structure was indicated as the ventricular surface of the grafts became covered with cerebrospinal fluid (CSF)-contacting pinealocytes typical of those seen in the deep pineal. The CSF-contacting pinealocytes of the graft had numerous processes that extended along the ventricular surface of the graft. The blood vessels of the grafts had non-fenestrated endothelium and wide perivascular areas typical of those seen in the in situ pineal complex. Tyrosine hydroxylase-immunopositive nerve fibers were present in the grafted tissue indicating reinnervation of the graft. The source of the fibers was not determined. The nerve fibers were present both within the perivascular area and within the parenchyma where they were associated with pinealocytes. The results demonstrate that the cerebral ventricles are an ideal location for the survival of superficial pineal gland grafts. It is suggested that pineal grafts may be a means to further study pineal development and innervation.

S-antigen and glial fibrillary acidic protein immunoreactivity in the in situ pineal gland of hamster and gerbil and in pineal grafts: developmental expression of pinealocyte and glial markers.

Postnatal development of S-Ag and GFAP immunoreactivity in the in situ pineal glands of golden hamsters and gerbils was examined using the avidin-biotin-peroxidase immunohistochemical technique. S-Ag was present in the gerbil pineal gland on the first postnatal day (P1), whereas it did not appear in the hamster pineal until P6. GFAP-immunoreactive astrocytes were first observed in the hamster pineal gland on P7 and in the gerbil pineal gland on P10. The number of S-Ag-immunoreactive pinealocytes and GFAP-immunoreactive astrocytes in the pineal glands of hamsters and gerbils increased with increasing age from P7 to 3 weeks. By 4 weeks, strong S-Ag and GFAP immunoreactivity was observed in both hamster and gerbil pineal glands. GFAP-immunoreactive stellate astrocytes were distributed evenly throughout the gerbil superficial pineal gland, but they were more often located in the peripheral region of the hamster superficial pineal. For the pineal grafts, pineal glands from neonatal (3-5 day old) hamsters were transplanted into the third cerebral ventricle (infundibular recess or posterior third ventricle) or beneath the renal capsule of adult male hamsters. S-Ag immunoreactivity appeared in the pineal grafts within 1 week following transplantation. By 4 weeks the pineal grafts showed strong S-Ag immunoreactivity which was maintained until at least 12 weeks after transplantation. The time course of glial cell maturation in the cerebroventricular pineal grafts is generally parallel to the hamster pineal gland in situ before 4 weeks. By 12 weeks, however, more astrocytes differentiated and developed GFAP-immunoreactivity in the pineal grafts than in the in situ pineals. These studies have described the postnatal development of S-Ag and GFAP immunoreactivity in in situ pineal glands and in neonatal pineal grafts.

Application of confocal laser scanning microscopy to the deep pineal gland and other neural tissues.

The study of the deep pineal gland of the Mongolian gerbil and other neuronal tissue from the rat by means of confocal laser scanning microscopy (CLSM) is described. Opical serial sectioning was performed on thick (100-200 microns) sections of the deep pineal gland of the Mongolian gerbil stained immunohistochemically using antisera to S-antigen and tyrosine hydroxylase (TH). Both dual-stained and single-stained material was examined using the fluorochromes fluorescein isothiocyanate (FITC) and Texas Red. High resolution images were obtained showing that pinealocytes have 1-3 processes that extend primarily to other pinealocytes or presumptive pinealocytes. Pinealocytes are located within the deep pineal gland as well as adjacent to the posterior aspect of the medial habenular nuclei. Pinealocyte processes were not seen extending into the habenular nuclei, but rather ended within the deep pineal gland a significant distance from their perikarya. The TH-immunopositive fibers were distributed throughout the deep pineal gland, often forming "baskets" of fibers around pinealocytes rather than being associated primarily with blood vessels. Other uses of the confocal microscope are demonstrated on rat neural tissue reacted with peroxidase/diaminobenzidine (DAB) immunohistochemistry and FITC fluorescence immunohistochemistry (paraventricular nucleus) as well as Golgi-stained neuronal tissue (cerebral cortex). The HRP/DAB and Golgi-stained images were visualized using the reflected image mode of the confocal system.(ABSTRACT TRUNCATED AT 250 WORDS)

Tyrosine hydroxylase and neuropeptide-Y immunoreactivity in pineal glands developing in situ and in pineal grafts.

Postnatal development of the innervation of the pineal gland in situ as well as the reinnervation of pineal grafts by tyrosine hydroxylase (TH)- and neuropeptide Y (NPY)-immunoreactive nerve fibers were examined using the avidin-biotin-peroxidase immunohistochemical technique. TH-immunoreactive nerve fibers appeared in the pineal gland on the second postnatal day (P2) in both hamsters and gerbils. NPY-immunoreactive nerve fibers first appeared in the pineal gland of gerbils on P2 and in the hamsters on P3. By the seventh postnatal day (P7), the pineal glands of both hamsters and gerbils were richly innervated by TH- and NPY-fibers that appeared as smooth fibers or fibers with sporadic varicosities. By the age of 4 weeks, the innervation of the pineal glands of hamsters and gerbils by TH- and NPY-fibers was fully developed. Abundant TH- and NPY-fibers formed a dense meshwork in the parenchyma of the superficial and deep pineals. The great majority of the fibers bore a large number of varicosities. More NPY-fibers were found in the pineal glands of gerbils than hamsters. NPY fibers were distributed evenly throughout the pineal glands of the gerbil, but they were more often located in the central region of the superficial pineal of the hamster. For the pineal grafts, superficial pineals from neonatal and 4-week-old hamsters were transplanted to different sites in the third cerebral ventricle (infundibular recess, posterior third ventricle) or beneath the renal capsule. The pineal grafts from 4-week-old donors appeared to undergo severe degeneration and eventually disappeared. The pineal grafts from neonatal hamsters, however, successfully survived and became well integrated into their new locations. Abundant TH- and NPY-fibers in the host brain were found surrounding the pineal grafts placed in the third cerebral ventricle, but were only rarely seen entering the parenchyma of the grafts. A few TH-fibers were demonstrated in the renal grafts 4 weeks after transplantation. These studies describe the postnatal development of the innervation of the pineal glands in situ by TH- and NPY-nerve fibers, and demonstrate a lack of reinnervation of cerebroventricular pineal grafts by TH and NPY fibers from adjacent host brain.

Timing of Silastic tubing removal after intubation for congenital nasolacrimal duct obstruction.

One thousand five hundred twenty-one patients (2,038 eyes) with congenital nasolacrimal duct obstruction were reviewed at The Children's Hospital of Philadelphia. Of these, 174 patients with congenital dacryostenosis involving 192 eyes underwent polymeric silicone (Silastic) intubation to treat the dacryostenosis. All patients had undergone at least several months of conservative management consisting of topical antibiotics and massage. All had undergone at least one probing and irrigation. Congenital dacryostenosis as well as resolution of symptoms were confirmed by clinical examination and use of a modified dye disappearance test. In 192 eyes the overall success rate was 83.33%. When broken down into age group, progression of success rates were from 100% in the 6-13 month age group to 79.6% in the over 24-month age group. Success rates differed significantly according to how long the Silastic tubing remained in position, especially in older age groups. The data suggest that Silastic intubation is a successful means of treating congenital dacryostenosis and that one should consider leaving the silastic in place for 6 months when possible.

Cerebrospinal fluid-contacting area of the deep pineal: effects of photoperiod.

The surface of the pineal recess of the Syrian hamster demonstrates three morphologically distinct zones that are classified as the peripheral, transitional, and central zones. The central zone is the most remarkable because of the number of distinguishable morphological specializations in this region that appear to indicate interaction between the cerebrospinal fluid (CSF) and associated ventricular structures and the deep pineal gland. CSF-contacting pinealocytes are present in the central zone and have a relatively indistinct ventricular surface except for the presence of surface blebs and pinealocyte processes that course on the surface of the deep pineal. Supraependymal neurons and neuronal processes appear to converge on the central zone, occasionally having presumptive terminals that are associated with the cells of the central zone. When the hamsters were maintained in a short photoperiod (LD 8:16), the CSF-contacting area of the pineal recess was significantly larger in those hamsters killed 2 hours before lights off compared to those killed 2 hours before lights on (P less than 0.01). There were no significant differences in the CSF-contacting area when comparing two groups of hamsters maintained in a long photoperiod (LD 14:10, killed 2 hours before lights on and lights off, respectively). There was statistically significant interaction (P less than 0.05) between the lighting cycle and the time of day of death on the appearance of CSF-contacting pinealocytes. The hamsters maintained in LD 8:16 had significantly reduced testicular weights when compared to those maintained in LD 14:10. The plasticity of the central zone and the associated CSF-contacting pinealocytes of the pineal recess of the hamster are evidence that this region demonstrates morphological changes that are dependent upon the physiological state of the animal.

Intraventricular blood vessels associated with the deep pineal gland of the Mongolian gerbil, Meriones unguiculatus.

Intraventricular blood vessels and choroidal-like cells were studied using scanning electron microscopy and correlative light microscopy. The intraventricular blood vessels were covered on their ependymal surface with a layer of cells essentially identical to the ependyma of the choroid plexus in the gerbil. Similar choroidal-like cells were seen either singly or in clusters associated with the cerebrospinal fluid-contacting pinealocytes of the suprapineal recess. Processes of the cerebrospinal fluid-contacting pinealocytes were seen extending to and making contact with the choroidal-like cells. The intraventricular blood vessels appeared to be derived from the choroid plexus, and typically took one of three courses in and around the surface of the deep pineal: (1) the vessels or their equivalent were located in the suprapineal recess with no indication of penetration into the substance of the deep pineal; (2) the vessels coursed from the suprapineal recess around the anterior surface of the habenular commissure to enter the ventral surface of the deep pineal; or (3) the vessels entered the parenchyma of the deep pineal from its dorsal surface and could be seen coursing through the substance of the gland. The close association between the choroidal-like cells and the intraventricular blood vessels with the deep pineal gland add morphological support for the possibility of interaction between the cerebrospinal fluid, or perhaps the choroid plexus, and the deep pineal gland.

An ultrastructural examination of murine alveolar macrophages following intranasal administration of propionibacterium acnes.

Light and electron microscopic analysis of murine lungs or isolated pulmonary cells was performed three days after intranasal administration of the bacterial immunostimulant, Propionibacterium acnes (P. acnes). Our observations indicated that pulmonary alveolar and airway macrophages (PAMs) were the only cells with P. acnes bacilli in their cytoplasm. Bacilli were not observed in pulmonary interstitial macrophages, granulocytes, lymphocytes or pulmonary parenchymal cells such as type I and type II pneumocytes. Because of the morphological heterogeneity of PAMs observed in control and experimental animals, it was not possible from these studies to be certain about the relative abundance or complexity of lysosomes, endoplasmic reticulum, Golgi and other organelles in the two groups. However, we noted that it was not uncommon to observe in the same PAM, profiles of P. acnes and a well developed Golgi complex and endoplasmic reticulum. These P. acnes--associated morphological alterations occurred at a time when functional activities (e.g., phagocytosis, cytostasis) of PAMs were enhanced.

Timing of initial probing and irrigation in congenital nasolacrimal duct obstruction.

A series of 427 patients with congenital dacryostenosis involving 572 eyes was seen at the Children's Hospital of Philadelphia. All patients were treated conservatively with antibiotics and massage prior to decision by the parents to request probing. Congenital dacryostenosis, as well as resolution of symptoms, were confirmed by clinical examination and use of a modified dye disappearance test. In 572 eyes, the success rate of initial probing was found to be 97% under 13 months of age. Over 13 months, however, the mean success rate was found to be 54.7%. When broken down into smaller age categories, a stepwise progression was observed from 76.4% between 13 and 18 months to 33.3% for patients probed after 24 months. In addition, the number and complexity of subsequent procedures appeared to increase along with the age at which the initial probing was performed. These data suggest that initial probing should be done prior to 13 months of age depending on the severity of symptoms and parent compliance with medical management.

Ocular and adnexal complications of unilateral orbital advancement for plagiocephaly.

Strabismus, ptosis, lateral canthal dystopia, nasolacrimal obstruction, and cranial nerve palsy were noted preoperatively in 32%, 21%, 14%, 12%, and 9% of 34 patients, respectively, undergoing ophthalmologic evaluation prior to unilateral orbital advancement for plagiocephaly. Thirty-two percent of the patients had normal preoperative ocular and adnexal examination results. Ptosis, strabismus, and amblyopia were frequently acquired postoperative abnormalities in 29%, 18%, and 18% of the patients, respectively. Forty-four percent of the patients had no new abnormalities following craniofacial surgery.

Three-dimensional computed tomographic imaging.

Recent developments in imaging techniques now allow reconstruction of actual three-dimensional images from computed tomographic data. This article discusses the basic concepts involved in three-dimensional imaging and reviews its potential as a diagnostic and management tool for the clinical ophthalmologist. New computer techniques allow review of actual three-dimensional images in both static and dynamic formats. This can allow the clinician to define more accurately a normal and pathologic anatomy involving skeletal structures in particular.

Pseudallescheria boydii (Petriellidium boydii) infection of the orbit.

A 10-year-old male developed a chronic orbital infection following penetrating trauma and retention of an orbital foreign body. Diagnosis of infection with Pseudallescheria boydii (Petriellidium boydii) was made by fungal smear and culture. Sensitivity tests indicated the organism was resistant to amphotericin B. Surgical debridement of the inferior orbit and removal of the foreign body was followed by a six-week course of intravenous miconazole. The patient has shown no signs of recurrence in a two-year follow-up period. To our knowledge, this is the first reported case of orbital infection with Pseudallescheria boydii, although the organism has been reported in cornea, ocular, and peri-orbital sinus infections.

Cytochemical analysis of calcium distribution in the superficial pineal gland of the Mongolian gerbil.

The potassium pyroantimonate-osmium method was employed to determine the distribution of cations in the superficial pineal gland of the Mongolian gerbil. The reaction product in the glands was presumed to be calcium following the use of both the chelator EGTA and x-ray microanalysis. A gradient of reaction product was found in the pineal with the highest concentrations occurring in and around the pineal concretions (PC). The periphery of mature PC demonstrated a heavy precipitate as did the surrounding pinealocytes. PC-associated pinealocytes contained reaction product in many organelles, including small vesicles that appeared to be opening in the direction of the concretions. The vacuoles of the pinealocytes contained various concentrations of precipitate. The results obtained in the present investigation have led to a hypothesis on the formation of pineal concretions: a pinealocyte vacuole is formed, calcium is transported to the vacuole, the cation content of the vacuole increases, and the cations precipitate into an immature concretion. Fibrillar material and an amorphous substance located within the pinealocyte vacuole appear to form cation containing vesicles that contribute to the periphery of the developing PC, resulting in the continued growth of the concretion.

Effect of acute light exposure upon melatonin content, NAT activity, and nuclear volume in the gerbil pineal complex.

This report describes the response of both the superficial and deep components of the gerbil pineal gland to a 30-min pulse of fluorescent light at the time of the nocturnal peak in pineal activity. When gerbils were maintained in a 14 h light:10 h dark photoperiod, mean melatonin concentrations in the superficial pineal gland ranged between 72 and 108 pg/gland during the day and first 4 h of darkness, rose to a peak of 399 pg/gland 7 h after lights out, then returned to basal levels at the expected time of light onset. Pineal melatonin contents were reduced to daytime values within 30 min after exposure of gerbils to fluorescent light at the time of the nocturnal peak. These changes in superficial pineal melatonin content reflected the circadian pattern in serotonin N-acetyltransferase (NAT) activity, as would be expected if NAT controls melatonin synthesis. In addition to the reductions in NAT and melatonin content induced by nocturnal photic stimulation, there was a 30% reduction in mean pinealocyte nuclear volume. A nocturnal elevation in melatonin content but not in NAT activity occurred in the deep pineal gland. Unlike the superficial pineal gland, the deep pineal gland did not demonstrate a response in melatonin content, NAT activity, or pinealocyte nuclear volumes upon exposure of gerbils to light at the time of the nocturnal peak in superficial pineal activity.

Recurrence of sebaceous carcinoma of the eyelid after radiation therapy.

Sebaceous carcinoma originating in the meibomian gland recurred in six patients (four women, 61, 68, 71, and 88 years old, and two men, 52 and 65 years old) who had undergone radiation therapy. The patients had received radiation dosages ranging from 3,300 to 11,900 rads. The tumors recurred two months to two years after treatment. All six patients then underwent surgical excision of the tumors and have remained tumor-free for follow-up periods of as long as 42 months. These data indicated that radiation therapy of sebaceous carcinoma of the eyelid should be considered palliative rather than curative.

CSF-contacting pinealocytes in the pineal recess of the Mongolian gerbil: a correlative scanning and transmission electron microscope study.

The pineal recess of the Mongolian gerbil was studied using correlative scanning and transmission electron microscopy. The surface of the pineal recess can be subdivided into three distinct zones: (1) central, (2) transitional, and (3) peripheral. In the gerbil, the deep pineal gland is located deep to the central and transitional zones. The ependyma of the peripheral zone is densely ciliated and resembles that of the main ventricular lining. Ependymal cells of the transitional zone are sparsely ciliated but possess numerous microvilli on their apical surfaces. Supraependymal neurons were identified in the transitional zones. These cells appear to make a synaptic-like contact with the underlying ependymal cells. Of the three zones, the central zone demonstrated the greatest amount of morphological variability. Although a number of supraependymal structures could be identified in the central zone, the most remarkable feature was the presence of protruding cells that possessed no significant surface features. Employing correlative transmission electron microscopy, the protruding cells were shown to be CSF-contacting pinealocytes. The number of CSF-contacting pinealocytes present in the central zone varied from one cell to large clusters that covered the entire zone. The results of this investigation demonstrate the presence of a direct contact and the potential for interaction between the deep pineal gland and the CSF of the pineal recess in the gerbil.

Enhancement of natural resistance to influenza virus in lipopolysaccharide-responsive and -nonresponsive mice by Propionibacterium acnes.

Lipopolysaccharide-responsive C3H/HeN mice were rendered resistant to a mouse-adapted strain of influenza (Aichi, H(3)N(2)) virus when Propionibacterium acnes was given either intranasally or intraperitoneally several days before virus infection. The time of P. acnes treatment was important since no protection was demonstrated when this agent was given either on the same day as or several days after virus challenge. In contrast, lipopolysaccharide-nonresponsive C3H/HeJ mice were not protected when P. acnes was administered intranasally at any time before infection; however, protection was demonstrated when P. acnes was given by the intraperitoneal route. Depending on the route of inoculation, P. acnes induced several distinctive immunological responses in the lungs of both C3H/HeN and C3H/HeJ mice. Intranasal inoculation was more effective in activating pulmonary macrophages in C3H/HeN than in C3H/HeJ mice. In contrast, intraperitoneal inoculation activated pulmonary natural killer cells in both mouse lines but did not activate pulmonary macrophages.