Galactose-induced cataract formation in guinea pigs: morphologic changes and accumulation of galactitol

PURPOSE

To develop and characterize a new model of galactose-induced cataract formation in young, 3- to 4-week-old Hartley guinea pigs.

METHODS

Experimental animals were fed 50% galactose in powdered guinea pig chow containing 0.5 g ascorbate/kg diet. Control animals were fed normal powdered guinea pig chow (0.5 g ascorbate/kg diet). Lenses from all animals were subjected to photo-slit-lamp examination, light microscopic analysis, and high-pressure liquid chromatography (HPLC) analysis of polyol content.

RESULTS

Photo-slit-lamp examination indicated initial opacities in equatorial subcapsular region between 3 and 5 days in all galactose-fed animals (20/20); opacities progressed toward the anterior pole when diet was extended to 14 days. Histologic analysis of the equatorial changes confirmed progressive cataract formation consisting of small intra-fibrillar vacuoles in the pre-equatorial region (3 days), an increased number of enlarged and coalesced vacuoles (6 days), and progressive tissue swellings with cellular disruption and signs of epithelial multilayering (14 days). The anterior epithelium showed increased cell height and swelling after 3 days of the galactose diet. HPLC analysis of lens tissue indicated progressive accumulation of galactitol, 18 mM after 3 days, which plateaued to about 30 mM between 6 and 14 days. The level of myo-inositol dropped from a control value of 2.8 +/- 0.7 mM to 1.5 +/- 0.7 mM after 3 days, and was nearly undetectable after 14 days of the galactose diet.

CONCLUSIONS

The current study suggests that the guinea pig model may serve as a valuable new tool to study sugar-induced cataract formation and to characterize the early morphologic and biochemical events in cataractogenesis.

Otitis media with effusion in head and neck cancer patients

Fifty-two patients who had otitis media with effusion associated with head and neck malignancies were identified and studied retrospectively. Forty-three of the patients underwent myringotomy and tube for treatment of the effusion. Ten (23%) of the 43 patients had either multiple infections or continuous otorrhea necessitating tube removal. The patients identified as having the highest rate of serious complications following myringotomy and tube were those individuals who had nasopharyngeal carcinoma, with 6 (55%) of 11 patients in this group having suffered major infections during the study. Myringotomy and tube is a satisfactory treatment for most patients who have effusions as a result of non-malignant etiologies; however, infections were more common and more severe in the study group than those anticipated in noncancer patients. Expectant management and the use of amplification in selected cases may prove to be a viable alternative in patients with unilateral effusion and/or relatively mild symptoms.

Blood-brain barrier transport of circulating Alzheimer's amyloid beta

The origin of amyloid beta (A beta) deposited in brain and cerebral blood vessels of patients with Alzheimer's Disease (AD) is not known. In this study, we tested whether soluble A beta (sA beta) can cross the blood-brain barrier (BBB). An in vivo vascular brain perfusion model and capillary depletion technique in guinea-pigs were used to determine cerebral capillary sequestration and blood-brain transport of a synthetic peptide identical with residues 1-40 (SP-40) of A beta. A saturable, specific binding of SP-40 has been demonstrated at the luminal side of the BBB, with the Kd of 25 +/- 2 nM, and Bmax of 188 +/- 11 fmol/min/g of isolated microvessels. A specific transcellular BBB transport of SP-40 into brain parenchyma exhibited the Km of 49 +/- 10 nM, and Vmax of 111 +/- 19 fmol/min/g of capillary depleted brain. We concluded that the BBB has the capability to control the cerebrovascular sequestration and blood-to-brain transport of circulating sA beta. Hence, sA beta can contribute to both cerebrovascular and parenchymal amyloid formation.

Subdural empyema of the cervical spine: clinicopathological correlates and magnetic resonance imaging. Report of three cases

A paucity of formally described information is available in the scientific literature regarding spinal subdural empyema. Patients presenting with neurological deterioration associated with subdural empyema are rarely identified, and treatment is often based upon anecdotal cases. The authors contribute three cases of primary cervical spinal subdural empyema and review the seven found in the literature. All patients had clinical evidence of neurological compromise, cervical tenderness, cervical pain, and leukocytosis upon admission. Cervical involvement ranged from C-2 to C-7. All patients underwent laminectomy with durotomy and drainage. The authors recommend prompt surgical decompressive laminectomy, copious irrigation, and drainage, followed with appropriate adjunctive antibiotic therapy for treatment of these patients.

Penetrating craniocerebral injury resultant from gunshot wounds: gang-related injury in children and adolescents

We prospectively and retrospectively reviewed a series of 780 patients who presented to the University of Southern California/Los Angeles County Medical Center with a diagnosis of gunshot wound to the brain during an 8-year period. Of these, 105 were children ranging in age from 6 months to 17 years. Injuries were gang related in 76 (72%) children and adolescents. Stepwise linear regression analysis was used to formulate a predictive model of outcome in this population. Patient age (F = 10.92), sex (F = 9.32), occipital entry site (F = 8.17), bihemispheric injury (F = 8.50), and admission Glasgow Coma Scale (F = 69.91) were all found to correlate with outcome (P < 0.05). Significant differences between pediatric and adult populations were noted in transit time, entrance site, and age-related outcome. Occipital or assassination-type wounds were most common in children. In addition, a younger age was associated with poor outcome (P < 0.0001). We describe both the economic and racial trends in our population of patients in addition to weapon type and toxicological evaluation. The Department of Neurological Surgery is becoming directly involved in providing information to children at the junior high school level regarding gang activity and brain and spinal cord injury. In conjunction with the Community Youth Gang Services Organization and Think First Organization, we are attempting to integrate prevention through education and community mobilization. This is a plan aimed at informing and recovering the youth affected by gangs.

Development of neurosurgery in southern California and the Los Angeles county/University of Southern California Medical Center

The Los Angeles County General Hospital has played an integral role in the development of medicine and neurosurgery in Southern California. From its fledgling beginnings, the University of Southern California School of Medicine has been closely affiliated with the hospital, providing the predominant source of clinicians to care for and to utilize as a teaching resource the immense and varied patient population it serves.

The significance of subarachnoid hemorrhage after penetrating craniocerebral injury: correlations with angiography and outcome in a civilian population

Certain clinical factors are considered to have an effect on patient outcome after penetrating missile injury. These include bilateral hemispheric injury, ventricular hemorrhage, intracerebral hemorrhage, mass effect, and missile or bony fragmentation. The relationship of subarachnoid hemorrhage (SAH) after penetrating craniocerebral injury and outcome is unknown. In addition, controversy exists regarding the role of angiography and the incidence of traumatic intracranial aneurysm in this population. Finally, can we assume that the incidence of traumatic intracranial aneurysm is equal in military and civilian populations, given the absence of penetrating shrapnel injury in civilian populations? Now that computed tomography has supplanted angiography as the primary diagnostic modality, increasing vigilance on the part of the physician and examination of angiography in high-risk patients should allow for enhanced outcome. We evaluated 100 patients with a diagnosis of cerebral gunshot wound over a 12-month period. All patients were evaluated neurologically at the time of admission and had imaging studies. Thirty-one patients with radiological evidence of SAH on computed tomography underwent angiography. Angiograms were limited to the side of the injury in patients with single-lobe or unilateral multilobe injuries and were bilateral in patients with bilateral hemispheric involvement. One intracranial aneurysm (3.2%) was documented and treated surgically. In those patients who died within 48 hours of admission, 68% had SAH as compared with only 17% of those surviving. Outcome was based upon neurological evaluation at the time of discharge and at the time of clinical follow-up at 3 and 6 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical and radiographic response in a minority of patients with recurrent malignant gliomas treated with high-dose tamoxifen

Previous work has demonstrated the importance of the Protein Kinase C (PKC) signal transduction system in regulating the growth rate of malignant gliomas in vitro. Tamoxifen inhibits PKC in a minority of malignant gliomas within the micromolar concentration range in vitro, a property distinct from its estrogen receptor blockade effect. Tamoxifen was administered orally in very high dosages to 11 patients (9 males:2 females, age range 26-73, mean 45 years) with malignant gliomas (anaplastic astrocytoma or glioblastoma multiforme) who had failed treatment with external beam radiation therapy (and additional chemotherapy in 2). The dosage administered was estimated to be that necessary to achieve tissue concentrations within the low micromolar range, shown necessary to inhibit PKC in these tumors in vitro, and is approximately 5 times that used for standard antiestrogen therapy. Tumor reduction on radiographic images (MRI and PET [18FdG uptake]) with clinical improvement occurred in 3 patients; halting of tumor progression clinically and radiographically occurred in an additional patient. Of the remaining seven patients, three patients had marked and rapid progression of their disease despite treatment (dead after 3, 4, and 6 months respectively). Complications of treatment included a deep venous thrombosis requiring anticoagulation in one patient, nausea in one patient, and "hot-flashes" in a third patient. Tumor biopsy and measurement of tamoxifen and its active metabolite within the tumor of one patient (non-responder) showed levels within the middle of the in vitro therapeutic range. Follow-up of alive patients ranges from 4-18 months (mean 10 months). These encouraging preliminary results in a minority of these patients suggests some potential for this type of therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Magnetic resonance imaging and pathological correlates of meningiomas

We examined the relationships between specific magnetic resonance imaging features and certain gross and microscopic characteristics of meningiomas, including vascularity, gross texture (consistency), and venous sinus involvement. Magnetic resonance imaging scans, surgery reports, and the histopathological findings of tumors were examined retrospectively in 54 patients. Sinus involvement was accurately predicted on T1-weighted images in 9 of 10 cases (P = 0.001) and tumors with cystic changes in 3 of 3 cases. T1-weighted images were not useful for predicting vascularity unless actual flow voids could be visualized (five of six cases). There was no correlation between T1 signal intensity, tumor consistency, or histological findings. In tumors without detectable vascularity on T1-weighted images, hyperintensity relative to gray matter on T2-weighted images was correlated with increased vascularity (P = 0.004). Tumors with soft consistency (P = 0.007), cellular atypia, invasion, angioblastic, or melanocytic components were also hyperintense, compared with gray matter on T2-weighted images (P = 0.0266). Aggressive meningiomas were found to be more vascular (P = 0.045). No correlation was found between the degree of surrounding edema or contrast enhancement with histopathological findings, vascularity, or consistency.

An in situ perfused guinea-pig eye model for blood-ocular transport studies: application to amino acids

A technique for in situ vascular eye perfusion (VEP) in the guinea-pig has been developed for measurements of the blood-ocular transport kinetics of substrates under controlled conditions of arterial inflow. The blood-aqueous and blood-vitreous barriers remained intact to the vascular space marker [3H]dextran (MW 70 kDa) with the perfusion pressure maintained between 80 and 100 mmHg. Several 3H-, 14C- or 35S-labeled amino acids, and 3H- or 14C-labeled sucrose (extracellular space marker) were used to validate the VEP model for transport kinetic studies. Multiple time-point graphic analysis was used to estimate the compartmental unidirectional blood-ocular transport constants, K(in), within the 20 min period of the VEP experiment. Blood-to-aqueous humor K(in) values for [3H]serine, [14C]N-methyl-alpha-aminoisobutyric acid (MeAIB) and [3H] or ]14C]sucrose were 3.57 +/- 0.38, 1.21 +/- 0.13 and 1.13 +/- 0.17 microliters min-1 g-1, respectively. The respective blood-to-lens K(in) values for labeled serine, MeAIB and sucrose were 1.71 +/- 0.19, 0.09 +/- 0.03 and 0.03 +/- 0.002 microliters min-1 g-1. The uptake of newly secreted amino acids from the aqueous humor in the lens followed the order: [35S]methionine greater than [3H]serine greater than or equal to [35S]cysteine greater than or equal to [3H]alanine greater than [14C]cycloleucine greater than or equal to [14C]MeAIB greater than or equal to [3H] or [14C]sucrose. The data indicate lack of a rapid blood-to-lens uptake of two model amino acids defining the A and L amino acid carriers.(ABSTRACT TRUNCATED AT 250 WORDS)

Surgery for recurrent and residual cholesteatoma

One hundred twelve patients (116 ears) were treated for recurrent and residual cholesteatoma. A retrospective review revealed that 66% had undergone canal wall down mastoidectomy at the previous surgery. The surgical procedure at revision was selected on the basis of an intraoperative assessment of the extent of disease, and clinical prediction of eustachian tube function. The average period of follow-up was 3.4 years. Revision surgery was successful in providing the patient with a safe, dry ear in 105 (91%) of 116 cases. Surgical principles and hearing results are presented.

Compulsive polydipsia following meningioma resection: an epileptic phenomenon? Case report

The authors report the case of an individual who developed compulsive polydipsia following resection of a left sphenoidal ridge meningioma. The episodic, stereotyped nature of his symptoms, response to treatment, and electroencephalographic and magnetic resonance imaging findings are all highly consistent with temporal lobe-onset epilepsy. The pathophysiology of this underrecognized phenomenon is discussed.

Monostotic fibrous dysplasia of the clivus. Case report

A case report of monostotic fibrous dysplasia of the clivus in a postadolescent woman is described. Although fibrous dysplasia of craniofacial structures is well documented, involvement of the clivus has not been reported. Diagnosis by clinical, radiographic, and histopathological features is detailed. Implications for the role of surgery and management are discussed.

Sixth nerve schwannomas. Report of two cases

Two cases of sixth cranial nerve schwannoma are presented with a review of four other cases from the literature. The clinical spectrum, neuroradiological findings, and surgical outcome of the six cases are discussed. There are two distinct clinical presentations for sixth cranial nerve schwannomas. Type I sixth nerve schwannomas present with sixth nerve palsy and diplopia and arise from the cavernous sinus. In contrast, type II sixth nerve schwannomas have a more severe presentation with obstructive hydrocephalus, raised intracranial pressure, sixth nerve palsy, and diplopia. This type arises along the course of the sixth cranial nerve in the prepontine area. Cavernous sinus involvement in either type may preclude total surgical excision and indicate an increase possibility for recurrence.

Choanal atresia and lymphedema

The coexistence of bilateral bony choanal atresia and lower-extremity lymphedema was observed in a family with several consanguineous marriages. The combination of these two rare anomalies, in a hereditary form, has not been described before.

Recidivism in congenital cholesteatoma surgery

Forty-four cases of congenital cholesteatoma in the pediatric age group have been treated surgically. There have been three residual cholesteatomas, which were localized to the anterior aspect of the malleus and were easily excised. Two cases of postero-superior retraction pockets developed post-operatively, and these were treated by conventional tympanomastoid surgery with excision of the retraction pocket and grafting. All five of the patients with recidivism have experienced no further difficulty.

Treatment of unresectable meningiomas with the antiprogesterone agent mifepristone

The possibility that meningioma growth may be related to female sex hormone levels is suggested by several lines of evidence. Meningiomas are twice as common in women as in men, have been observed to wax and wane with pregnancy, and are positively associated with breast cancer. A physiological explanation for these phenomena is provided by the finding of steroid hormone receptors in meningiomas. However, unlike breast cancer, meningiomas are much more commonly positive for progesterone receptors than for estrogen receptors. The authors initiated a study on long-term oral therapy of unresectable meningiomas with the antiprogesterone mifepristone (RU486). Fourteen patients received mifepristone in daily doses of 200 mg for periods ranging from 2 to 31+ months (greater than or equal to 6 months in 12 patients). Five patients have shown signs of objective response (reduced tumor measurement on computerized tomography scan or magnetic resonance image, or improved visual field examination). Three have also experienced subjective improvement (improved extraocular muscle function or relief from headache). The side effects of long-term mifepristone therapy have been mild. Fatigue was noted in 11 of the 14 patients. Other side effects included hot flashes in five patients, gynecomastia in three, partial alopecia in two, and cessation of menses in two. Long-term therapy with mifepristone is a new therapeutic option that may have efficacy in cases of unresectable benign meningioma.

Vasopressin uptake by hypothalamopituitary axis and pineal gland in guinea pigs

The uptake of circulating arginine vasopressin (AVP) by the pituitary gland (anterior lobe), pineal gland, and hypothalamus (ventromedial part) was investigated in an isolated in situ perused brain of anesthetized guinea pig. Kinetic experiments revealed saturable AVP uptake in all studied regions with Km values of 0.79, 0.19, and 0.76 microM and maximum velocity values of 22, 2.1, and 1.6 pmol.min-1.g-1 for the pituitary gland, pineal gland, and hypothalamus, respectively. The nonsaturable components (diffusion constants) were not significantly different from zero. Peptide fragments, L-phenylalanine, and Bestatin (an aminopeptidase inhibitor) did not interfere with AVP uptake. However, uptake of AVP was strongly inhibited in the presence of the V1 antagonist [1-(beta-mercapto-beta-beta-cyclopentamethylenepropionic acid), 2-(O-methyl)tyrosine]AVP at 2.7 microM, and regional Ki values, assuming that the observed inhibitions were purely competitive, ranged between 0.32 and 2.23 microM. The V2 agonist 1-desamino-8-D-AVP at 2.7 microM produced only a weak inhibition of AVP uptake, and regional Ki values ranged between 9.56 and 21.3 microM. It is concluded that specific uptake mechanisms in the hypothalamopituitary axis and pineal gland are sensitive enough to detect blood-borne AVP under the physiological hormonal state. It is suggested that AVP binding in situ is primarily related to V1 receptors, which may be involved in mediating the central effects of this circulating peptide.

Kinetics of circulating vasopressin uptake by choroid plexus

Uptake of circulating arginine vasopressin (AVP) by choroid plexus was studied by means of the in situ brain perfusion technique in anesthetized guinea pig and by means of single-circulation paired-tracer dilution technique in isolated perfused sheep choroid plexus. Kinetic analysis revealed saturable AVP uptake with Michaelis constant (Km) values of 32 +/- 4 and 31 +/- 5 nM and maximal saturable influx rate (Vmax) of 0.45 +/- 0.06 and 12.1 +/- 0.67 pmol.min-1.g-1 in guinea pig and sheep choroid plexus, respectively. The peptide fragments AVP-(1-8) and [pGlu4,Cyt6]AVP-(4-9), the amino acids L-phenylalanine, L-tyrosine, and 2-aminobicyclo(2,2,1)heptane-2-carboxylic acid, and the aminopeptidase inhibitors Bestatin and bacitracin did not influence hormone kinetics. However, the V1 antagonist [(1-beta-mercapto-beta,beta-cyclo-pentamethylenepropionic acid)-O-methyl-Tyr2]AVP significantly inhibited AVP uptake with inhibitor constant (Ki) values of 0.19 +/- 0.03 (guinea pig) and 0.07 +/- 0.01 microM (sheep). The V2 agonist 1-desamino-8-D-AVP and pressinoic acid produced weak inhibitions only in guinea pig choroid plexus, and Ki/Km ratios indicated 220 and 310 times lower affinities than for AVP, respectively. It is suggested that the membrane mechanism responsible for AVP uptake in choroid plexus has a binding site with properties similar to those of V1 receptor.

Management of labyrinthine fistulas caused by cholesteatoma

The surgical management of labyrinthine fistulas caused by cholesteatoma remains controversial. Forty cases (41 ears) of labyrinthine fistulas were reviewed. This represented 10% of our total series of cholesteatomas in adults and children (426 ears). Clinical presentation, extent of disease, results of fistula testing and audiometric studies, and radiographic findings were analyzed. A canal wall-down procedure was performed in all but one patient. Generally an attempt was made to completely remove the cholesteatoma, to graft the fistulous area, and to reconstruct the middle ear mechanism in one stage. The matrix was preserved in patients with large fistulas where the involved ear was the only hearing one, when the matrix was adherent to the underlying optic duct, and in selected elderly persons. Long-term followup did not reveal a significant difference in hearing, degree of vertigo, or incidence of recidivism when those patients in whom the matrix was removed were compared with those in whom the matrix was preserved. The importance of recognizing the presence of a labyrinthine fistula preoperatively is stressed, along with the need to be prepared for an unexpected fistula. Operative management is described.

Predictive value of brainstem evoked response in the diagnosis of acoustic neuroma

Predictive value positive is the probability that a positive test result represents a true positive finding. Twenty-six patients with brainstem evoked response findings characteristic of retrocochlear hearing loss were studied. Four acoustic neuromas were diagnosed in this group after radiologic workup. The predictive value in this population was 15%. Statistical considerations are presented.

Cochlear implant flap complications

In a series of 52 patients who received cochlear implants, 4 patients suffered flap complications (7.7%). The problems encountered involved the postauricular flap and were usually minor in nature. None required explantation as a direct result of these complications. Flap ischemia in a patient with Cogan's syndrome and vasculitis, two cases of suture extrusion with one having exposure of the implant, and a case of receiver unit magnet extrusion repaired with a vascularized pericranial flap based upon temporalis muscle are presented. Flap design in patients who have had postauricular incisions demands special consideration. Principles useful for avoiding complications as well as their management are discussed.

Lack of efficacy of megestrol acetate in the treatment of unresectable meningioma

The detection of hormone receptors on meningiomas raises the possibility of hormonal manipulation as a form of therapy. Since progesterone receptors are found on meningiomas more frequently and in greater amounts than estrogen receptors, manipulation of progesterone levels would be most promising. A trial of the oral progesterone agonist megestrol acetate for the treatment of unresectable meningioma was therefore performed. Megestrol acetate was administered at a dose of 40 mg four times daily which could be escalated to 80 mg four times daily. Nine patients (six meningothelial, two fibrous, and one anaplastic meningiomas) were treated for 1 to 12 months. No tumor responses were seen. However three patients required discontinuation of therapy due to deteriorating vision within 2 1/2 months. The major systemic toxicity of megestrol acetate was weight gain with a median weight gain of 14 kg for patients treated for at least 6 months. Due to the lack of efficacy and the significant toxicity noted, megestrol acetate is not recommended for the treatment of meningioma. However clinical trials of progesterone antagonists would still be of interest.

Pituitary gland metastasis from adenocarcinoma of the prostate. Case report

A case of prostatic carcinoma metastasis to the pituitary gland is reported. The presentation and rarity of such a lesion is addressed. The literature review yielded only isolated case reports of symptomatic brain metastases unassociated with bone disease from adenocarcinoma of the prostate. The management options of such a lesion are discussed.

Ultrastructure of the orbital pathway for cerebrospinal fluid drainage in rabbits

An increasing number of physiological and morphological studies indicate that cerebrospinal fluid (CSF) drains via nonarachnoidal pathways in several mammalian species. Ultrastructural tracer studies were undertaken to examine the orbital route for CSF absorption in the rabbit. At the termination of the optic nerve subarachnoid space, an area of connective tissue containing numerous small tortuous channels is present. Ferritin (molecular weight 400,000) infused into the ventricles at normal and increased intraventricular pressure was present in these channels by 15 minutes postinfusion, and subsequently reached the intraorbital connective tissue. Elevating the intraventricular pressure did not noticeably alter the morphological appearance of this region or change the gross distribution pattern of the ferritin. Ferritin did not penetrate the scleral barrier to reach the choriocapillaris, nor did it breach the arachnoid barrier layer proximal to the transitional zone at the optic subarachnoid space to reach the dura mater. These results are very similar to those described for the hamster orbital region and the rabbit cribriform region. These experiments support the concept that macromolecules exit the subarachnoid space at the termination of the optic nerve via open channels, and that no significant barrier to drainage of macromolecules in CSF is present at this location.

Computed tomography after skull base resection

We have obtained serial CT scans in the evaluation and follow-up of 80 patients with lesions of the skull base. CT scanning has been useful for assessment of recurrence in this group of patients, many of whom underwent complex ablative and reconstructive procedures.

Dysphagia in infants and children

The evaluation of dysphagia in pediatric patients involves many special considerations. A diagnostic approach to this problem is presented.

Flow cytometric analysis of pituitary tumors. Correlation of nuclear antigen p105 and DNA content with clinical behavior

Flow cytometric quantitation of the proliferation-associated nuclear antigen p105 and DNA content was performed on nuclear suspensions from 12 paraffin-embedded pituitary macroadenomas and one pituitary carcinoma and correlated with clinical outcome. Median follow-up was 41 months (range, 33 to 48 months). Three of the 13 tumors (23%) had an identifiable aneuploid peak. Of the four tumors that recurred or metastasized, only one was aneuploid. Nuclear antigen analysis of all diploid tumors showed enhanced p105 expression in G2M phase cells compared to G0G1 cells. The G2M/G0G1 fluorescence ratio for p105 was consistently higher (P less than 0.05) for the three diploid tumors that recurred (median, 1.32 arbitrary fluorescence units; range, 1.27 to 1.80) than for the seven nonrecurrent diploid tumors (median, 1.20 arbitrary fluorescent units; range 1.14 to 1.22). These findings indicate a low incidence of DNA aneuploidy among pituitary tumors and suggest that for diploid adenomas, measurement of p105 may provide information useful in predicting prognosis and directing postoperative adjuvant therapy.

Metastatic carcinoma to pituitary adenomas: a report of two cases

Two cases of carcinoma metastatic to pituitary adenomas are reported. One patient had a prostatic adenocarcinoma, giving rise to metastases in an adenoma found incidentally at autopsy; clinically and immunohistochemically, the adenoma showed lack of endocrine activity. The second patient had symptoms of cortisol excess. A corticotroph adenoma associated with a malignant neoplasm was diagnosed ante mortem; at autopsy a pancreatic endocrine neoplasm was found. Immunohistochemistry and electron microscopy were important in elucidating the primary tumor. The formation of extraportal vascular channels and altered blood flow may have importance in the pathogenesis of cancer metastases to pituitary adenomas.

May children with otitis media with effusion safely fly?

This study addresses the question of whether patients who fly with otitis media with effusion (OME) are at risk for the development of barotitis. Fourteen patients with otitis media with effusion were followed before and after air travel. No ear with OME became symptomatic, though two contralateral, previously "normal" ears did become symptomatic. An analysis of the physiology of this phenomenon is presented.

Blood-cerebrospinal fluid barrier alteration following intraventricularly administered cholera toxin

Cholera toxin (CT) has been reported to double cerebrospinal fluid (CSF) formation following its introduction into the ventricular system of cats and dogs. In our laboratory we noted that CT used in a similar fashion in rabbits and cats resulted in only a slight increase in CSF formation and was associated with a steadily rising protein content in the cisterna magna effluent. To further investigate this finding, rabbits and cats underwent ventriculo-cisternal perfusions, one group with CT introduced into the ventricles and the other without. In the rabbit only, radioiodinated serum albumin (125I-RISA) was given i.v. Other groups of rabbits had 125I-RISA or 125I-CT injected into the ventricles. The group of rabbits receiving intraventricular CT experienced a 4-10-fold elevation in the amount of both protein and 125I-RISA in the cisterna magna effluent compared with the control group. Electrophoretic pattern of the protein present in the effluent was similar to that of rabbit plasma. Autoradiography of the brains of those animals given intraventricular 125I-CT were found to have a very high uptake of 125I-CT in the choroid plexus and along all exposed ventricular surfaces, a finding not evident when 125I-RISA alone was given intraventricularly. It is concluded that CT altered the blood-CSF barriers allowing the reference marker to penetrate these barriers and plasma to leak into the CSF. These findings appear to account for most if not all of what was thought to be an increase in CSF formation in response to intraventricular CT.

Rhabdomyosarcoma in the region of the sella turcica

Intracranial extension of rhabdomyosarcoma from the face, nasopharynx or middle ear is rare. A 16-year-old boy presented with deterioration of vision and headache. CT scan revealed a soft tissue mass occupying the sphenoid and ethmoid sinuses, extending to the suprasellar fossa and impinging on the optic chiasm. The tumour, mimicking pituitary carcinoma, was removed by transsphenoidal craniotomy. Morphologic studies, including immunohistochemistry and electron microscopy, revealed that the tumour was a rhabdomyosarcoma. This case stresses the value of immunohistochemical and ultrastructural studies in the diagnosis of tumours occurring in the region of the sella turcica. The origin of this tumour was thought to be the sphenoid or ethmoid sinus. The pituitary gland appeared intact.

Correlation of meningioma hormone receptor status with hormone sensitivity in a tumor stem-cell assay

Several investigators have detected progesterone receptors in a high percentage of meningioma specimens and have noted progesterone receptors to be more common than estrogen receptors in these specimens. However, a functional significance of such hormone receptor positivity in control of meningioma growth has not been described. This paper describes a paired test of the estrogen and progesterone receptor assay as the biochemical assay and of the human tumor stem-cell clonogenic assay (HTSCCA) as the functional assay in 17 meningioma specimens. Only one (6%) of the 17 specimens was estrogen receptor-positive, while 11 (69%) of 16 specimens were progesterone receptor-positive. The HTSCCA revealed that only two (15%) of 13 specimens were sensitive to estradiol while five (31%) of 16 specimens were sensitive to progesterone. Comparison of progesterone results for the 15 specimens on which both hormone receptor assay and HTSCCA were performed revealed correlation in a majority of cases; four specimens were positive for both assays and five specimens were negative for both assays. No specimen that was negative for progesterone receptors was sensitive to progesterone by HTSCCA. These results suggest that the hormone receptor and sensitivity pattern of meningiomas may differ from that of breast cancer, and that progesterone addition or ablation may be a reasonable therapeutic approach for meningiomas.

Ultrastructural morphology of the olfactory pathway for cerebrospinal fluid drainage in the rabbit

Previous physiological studies indicate that the olfactory region serves as a major pathway for cerebrospinal fluid (CSF) drainage into the lymphatic system. The present study was undertaken to determine the ultrastructural characteristics of this egress route. New Zealand White rabbits received a single bolus injection of the tracer ferritin (MW 400,000) into both lateral ventricles in such a manner as not to raise the intraventricular pressure above the normal level. The animals were sacrificed via intracardiac perfusion of fixative between less than 12 minutes and 4 hours following injection. The cribriform region was removed en bloc, decalcified, sectioned coronally, and prepared for light and electron microscopic examination. The arachnoid, dura, and periosteum surrounding the fila olfactoria passing through the cribriform plate merge together and form the perineurium, which consists of multiple layers of loosely overlapping cells with widely separated junctions and few vesicles. The perineurium surrounding the olfactory filaments at the superficial submucosal level is only one cell thick. The subarachnoid space freely communicates with the perineural space surrounding each filament. No morphological barrier between the perineural space and the loose submucosal connective tissue was identified. Whether or not the perineurium was multi- or single-layered, ferritin was noted in abundance between the loosely overlapping perineural cells and in the submucosal connective tissue. The distribution of ferritin at 12 minutes was similar to that at 4 hours; however, the quantity of ferritin was increased at 4 hours. These results indicate that no significant barrier to CSF drainage is present at the rabbit cribriform region and that CSF reaches the submucosal region rapidly via open pathways.

Cavernous sinus invasion by pituitary adenomas

One hundred ninety-eight surgically explored pituitary adenomas were evaluated preoperatively by high-resolution computed tomography (CT). At surgery, evidence of direct cavernous sinus invasion was demonstrated in 19. CT findings in these cases included cavernous sinus expansion (17 patients) and visible encasement of the internal carotid artery (14 patients). The invasive tumor often enhanced to a lesser degree than the cavernous sinuses and ipsilateral internal carotid artery. Intracavernous cranial nerve compression, obliteration, or displacement (14 patients), invasion of the lateral wall of the cavernous sinus (seven patients), and diffuse bone destruction (seven cases) were other findings. Magnetic resonance imaging in three patients provided excellent demonstration of intracavernous internal carotid artery encasement, but displacement and obliteration of intracavernous cranial nerves was not shown as well as it was with CT. Histologically, only three patients showed anaplastic features and only one of them had distant metastases. There was no correlation between histologic features, hormone assays, and invasiveness. This experience indicates any type of pituitary adenoma, regardless of its endocrinologic activity, can invade the cavernous sinus. Cavernous sinus involvement makes complete surgical removal difficult. Preoperative recognition of invasive behavior of these tumors has prognostic value and aids in designing appropriate management. CT is the most useful technique generally available for evaluation and follow-up.

Fascicular conduction disturbances and ischemic heart disease: adverse prognosis despite coronary revascularization

In patients with ischemic heart disease, fascicular conduction disturbances are associated with increased mortality. This study reveals that increased mortality also exists for certain types of fascicular conduction disturbances after myocardial revascularization. In 227 consecutive patients undergoing bypass surgery, 24 had preoperative and an additional 52 developed at surgery a fascicular conduction disturbance. At 66 +/- 14 months of follow-up, 6 (4%) of 148 control patients without pre- or postoperative fascicular conduction disturbances had died from cardiac causes. Although right bundle branch block and left hemifascicular block were the most common form of fascicular conduction disturbance, only 1 of 55 of these patients died (p = NS). Mortality rates were much higher for patients with left bundle branch block or an intraventricular conduction defect; 8 (38%) of 21 died from cardiac causes (p less than 0.05). A high risk subgroup was identified by comparing 14 consecutive patients with left bundle branch block or an intraventricular conduction defect who survived more than 1 year postoperatively with 21 consecutive patients with these same conduction defects who died within 1 year of surgery. The following variables were significantly (p less than 0.05) different (survivors versus nonsurvivors): age (58 +/- 7 versus 65 +/- 9 years); class IV angina (2 of 14 versus 16 of 21), prior myocardial infarction (9 of 14 versus 21 of 21), left ventricular ejection fraction (53 +/- 18 versus 41 +/- 15%), three vessel disease (9 of 14 versus 20 of 21) and left ventricular aneurysm (2 of 14 versus 13 of 21).(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of cerebrospinal fluid rhinorrhea by metrizamide computed tomographic cisternography

Seven interesting and instructive cases of cerebrospinal fluid rhinorrhea evaluated by metrizamide computed tomographic cisternography are presented. The rhinorrhea was spontaneous in three patients and was related to previous head trauma or surgical procedures in four patients. The anatomical site and the extent of the fistula were demonstrated precisely by directly showing metrizamide passing through the bony defect. A combination of bone dehiscence and metrizamide within the adjacent paranasal sinuses or the nasal cavity is also useful in localization. Distortion of the interhemispheric fissure, sylvian fissure, or basal sulci indicates the probability of brain herniation through the defect.