Estimating 3-dimensional surface areas of small scleractinian corals.

Stressor-response research on stony corals in the laboratory relies on detecting relatively small changes in the size of coral fragments throughout the course of an experiment. Coral colonies are complex, three-dimensional (3D) communities of organisms, so small changes in size are best detected by changes in 3D surface area. Traditional methods to estimate 3D coral surface area commonly require destruction of the sample, thereby eliminating repeat measurements and the ability to calculate growth rate. However, non-destructive two-dimensional (2D) photogrammetry can be used if defensible relationships with 3D surface area can be established. In this study, 165 coral skeletons representing four stony coral species (Pocillopora damicornis, Madracis mirabilis, Orbicella faveolata, Porites porites) were photographed in 2D (top and side views) and then imaged with 3D laser scanning. Significant linear relationships were found between the 3D surface areas (laser) and the sum of various combinations of top and side view surface areas captured by 2D digital photography. The relationships were very strong for simple colony shapes and more variable as coral fragments increased in size and complexity. This study demonstrates an efficient method for obtaining estimates of 3D coral surface area from non-destructive 2D photogrammetry, allowing measurement of growth rate throughout experimental exposure periods.

Assessing land use, sedimentation, and water quality stressors as predictors of coral reef condition in St. Thomas, U.S. Virgin Islands.

Coral reef condition on the south shore of St. Thomas, U.S. Virgin Islands, was assessed at various distances from Charlotte Amalie, the most densely populated city on the island. Human influence in the area includes industrial activity, wastewater discharge, cruise ship docks, and impervious surfaces throughout the watershed. Anthropogenic activity was characterized using a landscape development intensity (LDI) index, sedimentation threat (ST) estimates, and water quality (WQ) impairments in the near-coastal zone. Total three-dimensional coral cover, reef rugosity, and coral diversity had significant negative coefficients for LDI index, as did densities of dominant species Orbicella annularis, Orbicella franksi, Montastraea cavernosa, Orbicella faveolata, and Porites porites. However, overall stony coral colony density was not significantly correlated with stressors. Positive relationships between reef rugosity and ST, between coral diversity and ST, and between coral diversity and WQ were unexpected because these stressors are generally thought to negatively influence coral growth and health. Sponge density was greater with higher disturbance indicators (ST and WQ), consistent with reports of greater resistance by sponges to degraded water quality compared to stony corals. The highest FoRAM (Foraminifera in Reef Assessment and Monitoring) indices indicating good water quality were found offshore from the main island and outside the harbor. Negative associations between stony coral metrics and LDI index have been reported elsewhere in the Caribbean and highlight LDI index potential as a spatial tool to characterize land-based anthropogenic stressor gradients relevant to coral reefs. Fewer relationships were found with an integrated stressor index but with similar trends in response direction.

Repeat gamma knife stereotactic radiosurgery in the treatment of trigeminal neuralgia: A single-center experience and focused review of the literature.

OBJECTIVES: Repeat Gamma Knife stereotactic radiosurgery (GKSR) for refractory trigeminal neuralgia (TGN) is an increasingly common practice. Prior studies have reported varying success rates and incidence of trigeminal nerve dysfunction following repeated GKSR. We report treatment outcomes and toxicity in patients following repeat GKSR for TGN at the University of Alabama at Birmingham (UAB) with a focused review of the literature. METHODS: We retrospectively reviewed medical records of 55 TGN patients re-treated with radiosurgery using the Leksell Gamma Knife® at the University of Alabama at Birmingham between 1996 and 2012. Outcomes were defined using the Modified Marseille Scale. Demographics, prior treatments and symptom duration were correlated with outcomes. RESULTS: Eighteen patients (33%) achieved Marseille Class I or II, 14 (25%) Class III or IV, and 23 (42%) Class V at a mean follow-up of 14.4 months. Twenty-five patients (45%) developed new trigeminal nerve dysfunction after re-treatment. Of these, four (16%) did not develop dysfunction until subsequent microvascular decompression (MVD) for inadequate symptom relief. CONCLUSIONS: Although more than half of the patients undergoing repeat GKSR for refractory TGN maintained excellent or good outcomes (Marseille classes I-IV) at an average follow-up of 14.4 months, neither age, gender, nor pre-treatment duration of symptoms or interval between treatments had a statistically significant effect on outcomes. Following repeat GKSR, patients have increased risk for new-onset trigeminal nerve dysfunction and those undergoing MVD after repeat GKSR may have an increased risk for new-onset trigeminal nerve dysfunction.

Low-grade astrocytomas: treatment results and prognostic variables.

Low-grade astrocytomas in adults are uncommon malignant neoplasms of the central nervous system which are fatal in the great majority of patients despite a lack of aggressive histologic features. Several series of such patients have been previously reported, but prognostic factors have not been fully identified. Between 1960 and 1986, 50 patients with low-grade astrocytomas have been treated with megavoltage radiation at the Naval Hospital, Bethesda, MD, following surgical biopsy or excision. Overall actuarial survival at 10 years for the entire treated group was 32%, similar to other series. The most significant prognostic factor was patient age, with decreasing survival for each age decade and a highly significant difference in survival between patients less than age 40 compared to older patients (p = .0017). The era of treatment (before or after 1978) was also an important prognostic indicator (p = .057), largely due to an effect of dose, although better tumor localization in the CT era may also have played a role. There was a trend toward increasing survival with increasing dose of radiation, although not reaching statistical significance at the p = .05 level on multivariate analysis. Patient sex, extent of surgical resection, use of whole brain irradiation, and tumor grade did not significantly affect survival. In comparison, in a separate group of 10 patients who received surgery without radiation during the same period, all patients who were completely resected were long-term survivors, whereas none of those with incomplete resections survived longer than 6 years.

In vitro binding of parasites (Bonamia ostreae) and latex particles by hemocytes of susceptible and insusceptible oysters.

Bonamia ostreae is a protozoan parasite that has caused severe losses in the flat oyster (Ostrea edulis) industry in Europe. The cupped oyster (Crassostrea gigas), recently introduced and cultured in Europe, is not infected by the disease. In vitro tests were conducted to determine whether there was a difference in the ability of hemocytes from each species to recognize and bind inert foreign particles (fluorescent latex beads) and purified, infective B. ostreae. The results indicated no difference in their ability to bind latex beads, but C. gigas were able to bind more B. ostreae than were O. edulis. The relative inability of the O. edulis hemocytes to recognize the parasite is discussed as a possible factor in flat oyster susceptibility.

Visual loss and a suprasellar mass complicated by pregnancy.

A 43-year-old woman who was 12 weeks pregnant presented with a one-month history of visual loss in the right eye. Neuroimaging studies revealed multiple intracranial aneurysms, one of which compressed the right optic nerve. Her pregnancy raised many issues concerning her management. Evidence of aneurysm enlargement and the increased risk of aneurysm rupture as gestation progressed led to early, successful surgical intervention.

Cerebrospinal fluid fistula: detection with MR cisternography.

PURPOSE: Our goal was to assess the role of MR cisternography in the examination of patients with suspected CSF rhinorrhea. METHODS: MR cisternography was performed as a heavily T2-weighted fast spin-echo study with fat suppression and video reversal of the images in 37 patients over a 3-year interval. Twenty-four of the patients subsequently had exploratory surgery for fistula. Statistical analysis of the surgical results was compared with the findings at MR cisternography. RESULTS: MR cisternography showed significant correlation with surgical findings, with sensitivity, specificity, and accuracy of 0.87, 0.57, and 0.78, respectively. CONCLUSION: MR cisternography proved to be an accurate diagnostic imaging technique in the evaluation of suspected CSF rhinorrhea.

Computer-aided intelligence: application of an expert system to brachial plexus injuries.

When confronted with a patient with a brachial plexus injury, how often as neurosurgeons do we consult an atlas to confirm the anatomy of the brachial plexus and then attempt to establish the location of the lesion? Similar difficulties are encountered with lumbar and sacral plexus lesions. In a project organized to assist the neurosurgeon in this time-consuming task, a computer program that can rapidly determine the site of a lesion in a brachial, lumbar, or sacral plexus injury was created. Using known anatomical pathways (37 clinically relevant upper and 20 lower extremity muscle innervations), and relying solely upon the neurological motor examination, rapid computer-assisted diagnosis is possible. When more than one final common pathway lesion occurs (for example, multiple root avulsions of the brachial plexus), possible lesion sites can be obtained. An interactive dialogue between the user and the program helps to determine the location of the lesion. The program can be run on any IBM-compatible personal computer and is presented as an instrument that provides assistance in cases of complex peripheral nerve injuries, when expert consultants are unavailable. In addition, it can be used as an aid to learning and as a review of basic neuroanatomy.

Decision analysis: a tool of the future: an application to unruptured arteriovenous malformations.

Overwhelming and confusing data regarding the natural history of arteriovenous malformations can confound physicians attempting to advise patients whether surgery of unruptured arteriovenous malformations is indicated. Decision analysis is a new mathematical tool that allows physicians to compare options in such patients. With the use of a simple office computer, a software program was devised to compare surgical versus conservative options in a hypothetical 25-year-old man. The computer model weighs the important considerations of patient age, mortality and morbidity rates of the physician performing the surgery, rebleeding from the arteriovenous malformation, and patient desires, using the Markov process. When mortality and morbidity rates are reasonable, the mathematical process supports surgical intervention in the hypothetical patient. Patient guidelines for older patients and future plans for the model using grading systems are discussed.

Cure, morbidity, and mortality associated with embolization of brain arteriovenous malformations: a review of 1246 patients in 32 series over a 35-year period.

Published reports of cure, morbidity, and mortality associated with the embolization of 1246 brain arteriovenous malformations during the last 35 years were reviewed. Embolization resulted in cure in 5% of arteriovenous malformations. The cure rates of embolization were 4% in reports of 708 patients published before 1990 and 5% in reports of 538 patients published since 1990 (P = not significant). Temporary morbidity from embolization was 10%, and permanent morbidity was 8%. Permanent morbidity was 9% before 1990 and 8% since 1990 (P = not significant). Death after embolization of brain arteriovenous malformations occurred in 1% of patients. Mortality associated with the embolization was 2% before 1990 and 1% since 1990 (P = not significant). Long-term morbidity associated with the use of neurotoxic embolization materials is worrisome but has never been proven.

Cervical myelopathy from dural substitute.

A case report of cervical spinal cord compression by infolding of a silicone-coated Dacron graft is presented. The possible complications of synthetic dural substitutes are discussed.

Thoracic chordoma in a patient with paraparesis and ivory vertebral body.

Chordoma arising in the thoracic region is uncommon. Its presentation roentgenographically as an ivory vertebra has not been previously reported. Such a case is described, and a brief review of the incidence and location of spinal chordomas is given.

Screening for ocular hemorrhages in patients with ruptured cerebral aneurysms: a prospective study of 99 patients.

BACKGROUND: Terson's syndrome (vitreous hemorrhage) and other ocular hemorrhages (retinal hemorrhages) have been reported to occur in up to 40% of patients with ruptured cerebral aneurysms. Because microsurgical vitrectomy can safely restore vision in patients with visual loss secondary to Terson's syndrome, we hypothesized that prospectively screening a selected group of patients with aneurysms would result in a higher rate of vitrectomy in patients with more extensive subarachnoid hemorrhage. METHODS: Ninety-nine patients with ruptured cerebral aneurysms were prospectively screened for Terson's syndrome and other forms of ocular hemorrhage by an ophthalmologist. Follow-up data were obtained for seven of eight cases of Terson's syndrome, and vitrectomy was performed for visual restoration when indicated. RESULTS: Ocular hemorrhages were present in 17% of patients with ruptured cerebral aneurysms, and Terson's syndrome was present in 8% of patients. Screening of patients with histories of transient or prolonged comas sensitively identified patients with ocular hemorrhages in 100% of the patients with Terson's syndrome and 89% of the patients with other ocular hemorrhages. Fifty-five percent of the patients in the overall series had histories of transient or prolonged comas, and 53% (specificity) of those patients had ocular hemorrhages. Two of the eight patients with Terson's syndrome underwent vitrectomy, with dramatic improvement in vision. No other ocular hemorrhages required surgery. CONCLUSIONS: Ophthalmological screening of patients with histories of transient or prolonged comas after ruptured cerebral aneurysms very sensitively identifies patients with ocular hemorrhages, which are relatively common in patients with subarachnoid hemorrhage treated in an academic neurosurgical practice. The present study underestimates the true incidence of Terson's syndrome in that patients who died shortly after their subarachnoid hemorrhage were not included. Vitrectomy for patients who do not exhibit spontaneous improvement in vision results in a dramatic reversal of blindness.

Treatment of a bacterial (mycotic) intracranial aneurysm using an endovascular approach.

The case of a patient with a bacterial intracranial aneurysm treated with antibiotics and endovascular obliteration is reported. The patient presented with dysphasia and right hemiparesis. A medical workup revealed endocarditis and associated heart valve dysfunction with no evidence of congestive heart failure. Computed tomography demonstrated subarachnoid hemorrhage, and a subsequent cerebral arteriogram showed a distal left middle cerebral aneurysm, which, as demonstrated by angiography, did not change in size in 2 weeks. An endovascular approach was used to obliterate the aneurysm and its parent vessel. Endovascular techniques may be used to obliterate certain bacterial intracranial aneurysms, particularly in patients who harbor distal aneurysms.

The relationship of subarachnoid hemorrhage and the need for postoperative shunting.

The incidence of chronic hydrocephalus requiring shunting after aneurysmal subarachnoid hemorrhage (SAH) is not precisely known. The authors investigated whether the need for ventriculoperitoneal (VP) shunting can be predicted by initial Hunt and Hess grade or Fisher computerized tomography score. One hundred eight patients who presented with SAH and underwent 116 surgical procedures for aneurysm clipping were evaluated retrospectively to determine the incidence of chronic hydrocephalus. Chronic hydrocephalus was defined as clinically and radiographically demonstrated hydrocephalus that lasted 2 weeks or longer after the original hemorrhage and that required shunting. All SAH patients were managed in a similar fashion with induced hypervolemia, relative hemodilution, and hypertension complemented by a course of calcium channel blockers. The majority of patients underwent perioperative extracranial ventricular drainage to allow intraoperative brain relaxation and to assist intracranial pressure management. The overall mortality rate of the study group was 17%. Of the surviving patients, 20% underwent VP shunt placement secondary to chronic hydrocephalus. There were no statistically significant relationships between chronic hydrocephalus and patient age or gender, aneurysm type and size, or use of a perioperative drain. There was a high clinical correlation between chronic hydrocephalus and admission Hunt and Hess grades and Fisher grades (p < 0.05). All of the patients who survived a second bleeding episode and almost 46% of the patients who presented with intraventricular hemorrhage required placement of a VP shunt. The authors present predictive tables of chronic hydrocephalus based on the patient's admission Hunt and Hess grade and Fisher classification.

Trilateral retinoblastoma: ocular and pineal retinoblastomas.

Trilateral retinoblastomas, the syndrome of bilateral retinoblastoma associated with ectopic retinoblastoma in the pineal gland, is rare but well recognized. In contrast to bilateral retinoblastomas alone, the ocular retinoblastomas in trilateral retinoblastoma develop before the age of 6 months, and a family history positive for retinoblastoma is usually obtained. The retinal tumors are often quiescent at the time that the pineal tumor is discovered, and show no evidence of metastatic spread after enucleation of the globes. Pathologically, the pineal tumor is indistinguishable from the ocular retinoblastoma. The pathophysiology of this syndrome is not well understood, but a germinal mutation is thought to target photoreceptor tissue for further postzygotic mutation. Eventual expression depends on the inherited host resistance to the carcinogenic manifestation of these genes. The low host resistance of trilateral retinoblastoma is evident by the early age of presentation, the multicentric occurrence of the tumor, and the high early mortality rate despite aggressive management.

Carotid endarterectomy performed after progressive carotid stenosis following angioplasty and stent placement. Case report.

Carotid endarterectomy (CEA) is the treatment of choice for asymptomatic and symptomatic disease causing greater than 60% internal carotid artery (ICA) stenosis. Recently, percutaneous transluminal angioplasty (PTA) with stent placement has been investigated as a therapeutic option for the treatment of ICA stenosis. In this report the authors document CEA performed after PTA with stent placement and describe the pathological findings. A standard CEA was performed. The surgical intervention was more difficult secondary to the following variables: the length of the exposure necessary to dissect out the metallic stent, the difficulty with opening and cutting the artery, and the care required to remove the stent to avoid vessel wall perforation. Pathological examination of the specimen demonstrated classic atherosclerotic changes revealing persistence of native disease. The metallic stent was embedded within the plaque. Many questions remain unanswered regarding the physiological and biological changes that occur in the carotid vessel wall after PTA with stent placement. It is concluded that CEA of a stent-containing carotid artery is feasible and should be considered as an alternative when recurrent stenosis occurs after PTA.

Tethered cord syndrome in the adult postoperative myelomeningocele patient. A case report.

Tethered cord syndrome in the post-myelomeningocele repair pediatric patient has been previously described. The common presentation is unexplained progressive spasticity and a history of urinary dysfunction. Two series, in particular, looked at the onset of tethered cord following myelomeningocele repair in childhood. We have described delayed presentation in an adult with evidence of the tethered spinal cord syndrome following myelomeningocele repair. This patient's presenting complaints are similar to that of the childhood variety, despite many earlier symptom-free years. Further studies of adults who have had low-level myelomeningocele repair early in life may delineate a more common problem than is realized at present.

A survey of oysters Crassostrea virginica from Tampa Bay, Florida: associations of internal defense measurements with contaminant burdens.

Oysters from 16 sites in Tampa Bay, Florida, were collected during a 6-week period in winter 1993 and analyzed for both biological characteristics and tissue chemical concentrations. Using previous sediment contamination and toxicity data, oyster tissues from the selected sites were expected to exhibit a wide range in both quantity and type of chemicals. Chemical analysis showed tissue concentrations at some of these sites to be greater than national averages, as reported by the National Status and Trends Mussel Watch Program, for total PAH, total PCB, total chlordanes, DDT, Cu, Pb and Zn. Measures of oyster internal defense, including hemocyte density, rate of locomotion and superoxide generation, varied significantly among sites and were generally higher at sites with higher tissue concentrations of xenobiotic chemicals. Potential associations between oyster defense characteristics and accumulated chemical contaminants, either singly or in chemical classes, were explored using correlation analysis and a composited ranking procedure. Positive relationships were found for hemocyte characteristics with certain trace metal (Cu, Sn and Zn) and PAH analytes, whereas negative relationships were found with certain PCB and pesticide analytes. Heightened defenses in contaminated conditions may reflect a hemocyte process for sequestration and detoxification of environmental contaminants. Oysters from four of the 16 sites were additionally collected in June and September 1993 and site-related differences did not closely parallel those obtained in winter. Seasonal environmental factors may have altered contaminant-related differences among sites.

Relationships between tissue contaminants and defense-related characteristics of oysters (Crassostrea virginica) from five Florida bays.

Evidence linking bivalve defense responses with pollutant exposure is increasing. Contaminant effects on immune or defense responses could influence the ability of an organism to resist infectious disease. This study explored relationships between xenobiotic chemicals accumulated in oyster (Crassostrea virginica) tissue and various measures of putative oyster internal defense activities and physiological condition. Defense-related and physiological measurements were made on individual oysters collected from 22 sites at five Florida bays and pooled oyster tissue from each site was analyzed for polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), metals and certain pesticides. Chemical concentrations, physiological condition, and hemocyte and hemolymph characteristics varied across bays and among sites within a bay. Within-bay comparisons showed that sites with high oyster defense-related activities often had accompanying high tissue concentrations of one or more classes of xenobiotic chemicals. Correlation analysis performed across bays demonstrated significant positive relationships between most defense-related characteristics and at least one contaminant, including various PAH, PCB and trace metal analytes. In combination with other recent studies, these results strengthen the hypothesis that certain xenobiotic chemicals may be associated with elevated oyster hemocyte activities, even though the ultimate influence on disease resistance remains unknown.