Surgery of spinal nerve sheath tumors with special reference to neurofibromatosis

OBJECTIVE: We conducted a retrospective study of 87 patients with spinal nerve sheath tumors to determine the overall clinical outcome and specific features in 20 patients affected with neurofibromatosis Types 1 and 2 (NF-1 and NF-2, respectively). METHODS: Case records, operation notes, outpatient files, and radiological examinations were analyzed for all patients treated between September 1977 and August 1994. Additional follow-up data were obtained using outpatient examinations, questionnaires, and telephone calls. RESULTS: During the study period, 128 spinal neuromas (i.e., schwannomas) and 6 neurofibromas in 87 patients were treated. Fifty-seven neuromas were associated with NF-2 in 17 patients and six neurofibromas with NF-1 in 3 patients. Patients with NF-2 and symptomatic neuromas presented with more severe neurological deficits compared to patients without NF-2. Eighty-six percent of the neuromas were removed completely. On average, most preoperative deficits or symptoms improved in patients without NF-2, whereas neurological symptoms remained unchanged in patients with NF-2. Multiple regression analysis revealed that partial removal, surgery of a recurrent tumor, NF-2, and old age predisposed for tumor recurrence. No increased risk of recurrence was observed for patients with NF-1. For patients without NF-2, we observed overall recurrence rates of 10.7% after 5 years and 28.2% after 10 and 15 years, respectively, as determined by Kaplan-Meier analysis. For NF-2, the recurrence rate at 5 years was 39.2%, and all tumors had recurred by 9 years. CONCLUSION: Spinal nerve sheath tumors carry an excellent prognosis in patients with NF-1 and in patients without neurofibromatosis. Symptomatic neuromas occurring in association with NF-2 present with more severe neurological deficits, demonstrate little postoperative improvement, and have a very high recurrence rate.     

The structure of bovine periodontal ligament with special reference to the epithelial cell rests

The aim of this study was to determine the structure of the bovine periodontal ligament, with special reference to epithelial cell rests (ECR) and their cytokeratin content. Periodontal ligament was obtained from bovine molar teeth and studied at both the light microscopic and electron microscopic levels. Cytokeratin content was determined using immunohistochemistry against a number of cytokeratin antibodies and specificity tested against bovine and human oral mucosa. Collagen fibril diameters and the area of a fiber bundle occupied by collagen were determined using a digital planimeter with a digitizing tablet. The majority of periodontal fibroblasts possessed considerable quantities of roughened endoplasmic reticulum, indicating rapid synthesis and secretion of collagen, but no intracellular collagen profiles were present. Endothelial cells showed Weibel-Palade bodies. Collagen fibril diameters showed a unimodal distribution with a mean collagen fibril diameter of 55.3 nm. The mean percentage area of the extracellular matrix occupied by collagen was 42%. Structurally, ECR were unusual in exhibiting large numbers of microvilli and conspicuous amounts of cytokeratin filaments. Bovine ECR showed a positive reaction to the pancytokeratin MNF116 (which reacts with the cytokeratins 5, 6, 8, 17, and probably 19), to PCK-26 (which reacts with the type II cytokeratins 1, 5, 6, and 8) and to cytokeratin 13. There was no reaction for cytokeratins 1, 4, 10, 11 and 18. Structurally, bovine periodontal ligament showed features common to other species. However, ECR in terms of both structure and cytokeratin content showed features indicative of important species differences which may have relevance when considering the etiology of radicular cysts.     

Dorso-ventral patterning of the vertebrate limb and dermatoglyphs with special reference to the pad pattern of mice]

The contributions were determined in primary cultures of bovine corneal epithelial cells (BCEC) of Na:H exchange (NHE) and vacuolar H+-ATPase (i.e. V-type) activity to the regulation of intracellular pH (pHi). Furthermore, we characterized the effects on pHi regulation of exposure to 1 microM ET-1 under control and acid loaded conditions. With the pH sensitive dye, 2',7' Bis (carboxyethyl)-5,6-carboxyfluorescein acetoxymethyl ester (BCECF-AM), the control pHi was 7.1 in NaCl (nominally HCO3-free) Ringers. Inhibition of NHE with 100 microM dimethylamiloride (DMA) rapidly decreased pHi by 0.37 units. Similarly, selective inhibition of V-type H+-ATPase with 10 microM bafilomycin A1 decreased pHi by 0.22 units. Following acid loading in NaCl Ringers with a 20 mm NH4Cl prepulse, pHi recovery was partially inhibited by exposure to either Na-free (NMGCl) Ringers, 100 microM DMA or 20 microM bafilomycin A1. Based on decreases in H+ efflux resulting from selective inhibition of NHE and V-type H+ pump activity, NHE activity accounts for 76% of the pHi recovery following acid loading. Under control conditions, ET-1 (1 microM) had no effect on pHi whereas ET-1 completely suppressed pHi recovery following acid loading in NaCl or NMGCl Ringers. This inhibitory effect was largely due to stimulation of ETA because in the presence of BQ-123 (10 microM), a selective ETA receptor antagonist, pHi recovery was completely restored. Suppression of pHi recovery also occurred following stimulation of protein kinase C (PKC) with 10(-7) m phorbol myristate (PMA) whereas 10(-7) m 4 alpha phorbol 12,13 didecanoate (PDD) had no effect. ET-1 failed to suppress pHi recovery after inhibition of PKC with 0.5 microM calphostin C suggesting that the inhibition of pHi recovery by ET-1 is a consequence of PKC stimulation. Similarly, inhibition of Ca2+-dependent calmodulin stimulated CaM II kinase with KN-62 (10 microM) reversed the suppression of pHi recovery by ET-1. Preinhibition of either protein phosphatase (PP), PP-1, PP-2A or PP-2B activity with 1 microM phenylarsine oxide, 10 nm okadaic acid, 10 microM cyclosporin A1 or 20 microM BAPTA, also obviated the suppression of pHi recovery by ET-1. Therefore ETA receptor mediated inhibition of pHi regulation following acid loading could be a consequence of either PKC or CaMII kinase stimulation. Each one of these kinases may in turn phosphorylate and thereby stimulate the activities of PP-1, PP-2A or PP-2B. An increase in the activity of any one of these protein phosphatases could lead to dephosphorylation of the NHE and V-type H+ pump. This alteration may prevent them from becoming adequately stimulated to elicit pHi recovery in response to acid loading.     

The perception of bodily sensations, with special reference to hypochondriasis

Bodily sensations are relevant to problems such as hypochondriasis, but the issue of whether people are accurate in their perception remains unclear. The accuracy of perception of bodily sensations was analysed in 20 male and 20 female volunteers using two methods: a heart beat tracking procedure and the within-S correlational approach described by Steptoe and V?gele (1992, Behaviour Research and Therapy, 30, 597-607). The correlational approach involved monitoring of heart rate, skin conductance level and total respiratory resistance during relaxation and task periods, and computing correlations between appropriate physiological parameters and ratings of heart rate, sweaty hands and difficulty with breathing. In general, subjective ratings of bodily sensations were tied more closely with feelings of distress than with objective physiological state. Error scores on the heart beat tracking procedure showed no association with hypochondriacal concerns or with vigilant and avoidant coping styles measured with the Mainz Coping Inventory. Individuals varied considerably in accuracy as assessed with the correlational approach. However, there was a significant negative association between hypochondriacal concerns and accuracy of perception of sweat gland activity. The results are discussed in relation to measures of somatic perception and the experience of bodily sensations.     

Injuries to the phrenic nerve resulting in diaphragmatic paralysis with special reference to stretch trauma

The effectiveness of purines and purine analogues as inducers of erythroid differentiation in cultured murine erythroleukemia cells has been investigated. These cell lines have previously been shown to differentiate in vitro in response to dimethylsulfoxide (DMSO) and a number of other polar solvents. Two purine analogues, 6-thioguanine and 6-mercaptopurine, as well as the naturally occuring purine, purine, hypoxanthine, are shown to be extremely potent inducers. 6-Thioguanine is effective at a concentration of 0.06 mM, 750 fold lower than the DMSO concentration required for equivalent induction. 6-Mercaptopurine and hypoxanthine are effective inducers at a concentration of approximately 2 mM. Accumulation of globin mRNA was monitored during induction with purine inducers and shown to be similar in amount to globin mRNA levels reached in DMSO-induced cultures. Induction of differentiation by all three compounds follows a similar time course to induction with DMSO. All three compounds are potent inducers of HGPRT (hypoxanthine-guanine phosphoribosyltransferase)-negative cell lines; hence incorporation of purines into DNA is not required for induction of differentiation. Comparison of these compounds with other purines and purine analogues suggests a high degree of specificity in their interaction with a cellular target.     

Atherosclerosis, with special reference to vitamin E

The relationship between atherosclerosis and fat soluble vitamin, especially vitamin E is reviewed on the basis of oxidised modification of low density lipoprotein (LDL). Data now support the notion that the oxidised LDL is present in the blood and arterial wall and antioxidant drugs such as probucol and vitamin E, beta-carotene, may prevent the progression of atherosclerosis. LDL alpha-tocopherol levels are generally correlated to the plasma concentrations and supplementation with alpha-tocopherol increases its content in LDL. There is a significant correlation between the LDL alpha-tocopherol level and the resistance to oxidative modification. Epidemiological data also shows the relation between low levels of plasma vitamin E and the increased incidence of coronary heart disease. Clinical application of vitamin E should be clarified in detail to inhibit the progression of atherosclerosis.     

Experimental mouse models of susceptible and resistant pneumococcal pneumonia with special reference to the cause of bacteremia

The popularity of submental suctioning, platysmaplasty neck lifts, and now Botulinum A exotoxin injections into the neck has increased dramatically. A detailed working knowledge of clinical platysma and lip depressor muscle anatomy is of paramount importance to successfully anesthetize and block the treated areas, to avoid injury to important vessels, nerves, and deeper cervical structures, and to optimally treat the problem areas. A simple, user-friendly knowledge can be obtained by remembering simple mnemonics relating to (1) specific target areas, (2) anatomic relationships, and (3) topographic clinical landmarks.     

The quality of vital perinatal statistics data, with special reference to prenatal care

OBJECTIVES: Most patients with severe pulmonary emphysema referred for lung volume reduction surgery (LVRS) have a long-standing history of cigarette smoking. Coronary artery disease (CAD) predisposes to perioperative cardiac complications. Since symptoms and signs of myocardial ischemia are often absent in patients with severe ventilatory impairment even during exercise, we investigated the prevalence of CAD in candidates for LVRS by angiography. DESIGN: We prospectively studied the prevalence of CAD by angiography and assessed the CAD risk factor profile in 41 candidates for LVRS (26 men, 15 women; mean age, 66+/-6.8 years; range, 52 to 76 years), who had no current symptoms or a history of myocardial ischemia. RESULTS: In six patients (15%), asymptomatic but significant coronary lesions (> 70% stenosis) were detected. In five patients, these findings altered the clinical management. Patients with CAD had significant higher cholesterol levels, tended to have smoked more, and had more often additional vascular risk factors. CONCLUSIONS: We found a high prevalence of angiographically significant but clinically silent CAD in this particular population of heavy smokers with advanced emphysema.     

Neuronal control of mammalian vocalization, with special reference to the squirrel monkey

Squirrel monkey vocalization can be considered as a suitable model for the study in humans of the neurobiological basis of nonverbal emotional vocal utterances, such as laughing, crying, and groaning. Evaluation of electrical and chemical brain stimulation data, lesioning studies, single-neurone recordings, and neuroanatomical tracing work leads to the following conclusions: The periaqueductal gray and laterally bordering tegmentum of the midbrain represent a crucial area for the production of vocalization. This area collects the various vocalization-triggering stimuli, such as auditory, visual, and somatosensory input from diverse sensory-processing structures, motivation-controlling input from some limbic structures, and volitional impulses from the anterior cingulate cortex. Destruction of this area causes mutism. It is still under dispute whether the periaqueductal region harbors the vocal pattern generator or merely couples vocalization-triggering information to motor-coordinating structures further downward in the brainstem. The periaqueductal region is connected with the phonatory motoneuron pools indirectly via one or several interneurons. The nucleus retroambiguus represents a crucial relay station for the laryngeal and expiratory component of vocalization. The articulatory component reaches the orofacial motoneuron pools via the parvocellular reticular formation. Essential proprioceptive feedback from the larynx and lungs enter the vocal-controlling network via the solitary tract nucleus.     

Cerebral abscess with special reference to the angiographic changes

From 1961 to 1973 forty patients with surgically confirmed intracranial abscesses had preoperative cerebral angiography. The findings were abnormal in all cases but one. In 20 patients (50%) the primary diagnosis was a space-occupying lesion. In 19 patients (47.5%) an abscess was suggested by the presence of a capsule, the only finding definitely diagnostic of an abscess. Subtraction technique provided essential information in detecting the capsule. Angiography proved indispensable in suggesting the nature of the lesion.     

The treatment of staphylococcal infections with special reference to pharmacokinetic, pharmacodynamic and pharmacoeconomic considerations

Children with inborn errors of metabolism form an important group of children at risk of oral pathology. Their management includes dietary therapies which aim to promote normal growth and development but which are often highly cariogenic. It is important for paediatricians, dietitians and paediatric dentists to liaise closely in the management of these children. This paper reviews these disorders and the limited literature that exists on the oral health implications of those conditions that rely on dietary manipulation for their management, and presents suggestions for their dental care.     

The risk of non-Hodgkin's lymphoma after Hodgkin's disease, with special reference to splenic treatment

BACKGROUND AND OBJECTIVE: One of the consequences of the enormous improvement in survival rates of patients treated for Hodgkin's disease (HD) is the emergence in the long term of treatment-related complications, particularly secondary cancers. This study was undertaken to observe the occurrence of non-Hodgkin's lymphoma (NHL) in patients treated for HD and to identify the etiological role of various risk factors, especially spleen irradiation, in the pathogenesis of this illness. DESIGN AND METHODS: From 1972 to 1996, the Department of Radiation Oncology and the Hematology Section of "La Sapienza" University of Rome observed and analyzed the occurrence of NHL in 1,391 patients treated for HD. The average follow-up period was 84 months. For a more accurate calculation of the risk of the occurrence of NHL, the patients were first divided into 3 groups according to their initial treatment and also according to the total treatment they had received. Then, in order to establish the possible connection between NHL and splenic treatment the patients were also divided into 3 subgroups according to whether they had undergone splenectomy, splenic irradiation or neither of these. Two different methods of statistical analysis were used: (a) the cumulative risk (confidence interval) was evaluated in relation to treatment (initial and at the time of salvage) and (b) the Cox model was applied to identify the variables which play a role in the appearance of NHL. The cumulative risk of developing NHL was assessed using the Kaplan and Meier method. A multivariate analysis was performed using the Cox Proportional Hazard Model. RESULTS: A total of 20 cases of NHL were observed, appearing between 17 and 206 months after initial treatment. The cumulative risk was 0.8%, 1.8%, 2.6% and 3.5% at 5, 10, 15 and 20 years respectively. According to the multivariate analysis, significant risk factors were splenic irradiation and age (> 40 years). Splenic irradiation (vs no splenectomy/no splenic irradiation) showed a relative risk of 5.69, p = 0.0280, while age over 40 showed a relative risk of 3.05, p = 0.0152. INTERPRETATION AND CONCLUSIONS: From the results of this study, if appears that there is a possibility that splenic irradiation and age over 40 increase the risk of NHL in HD patients. Further studies are needed to investigate in greater depth the role of spleen irradiation in the occurrence of this illness.