Neurologic Evaluation of Infant and Adult Rats before and after Sciatic Nerve Blockade

Background: Only limited data exist comparing differences in sensory function and responses to neural blockade in infant and adult rats. Therefore, the authors sought (1) to compare baseline thermal, proprioceptive, and postural responses in infant, adolescent, and adult rats; and (2) to compare the effects of sciatic nerve blockade on thermal, proprioceptive, and postural responses in infant, adolescent, and adult rats.

Methods: Infant, adolescent, and adult rats were evaluated for proprioceptive, thermal, and mechanical nociceptive and motor function before and after sciatic blockade using a detailed neurologic examination.

Results: Mechanical and thermal nociception were present in all rats, starting from age 1 day. The withdrawal reflex latency to pinch was rapid at all ages, whereas that reaction to thermal stimulus depended on both age and temperature. In contrast, the tactile placing response and hopping response were absent at birth and developed completely during the first 10 days of life. The extensor postural thrust was absent in the first 2 weeks of life and developed variably during the first 50 days of life. Sciatic blockade duration is shorter in infant rats than in adult rats receiving the same dose per kilogram. A brief halothane general anesthetic at the time of sciatic injection in infant or adult rats does not alter the duration of blockade.     

Traumatic aneurysm of the internal carotid artery: a late finding presenting as a mass in the sphenoid sinus.

We describe a case of a traumatic aneurysm of the cavernous portion of the internal carotid artery in a patient who had had craniofacial trauma 12 years before. MR and CT revealed a mass in the sphenoid sinus thought to be unrelated to the patient''s symptoms. Carotid angiography gave the correct diagnosis.     

Perinatal 'TORCH' infections identified by serology: correlation with abnormalities in the children through 7 years of age.

A matched case-control methodology was used to assess the risk for a wide range of abnormalities in children associated with serological evidence for 'TORCH' infections in the mothers. Specimens were selected from the large bank of sera from the approximately 54,000 pregnant women who participated in the Collaborative Perinatal Project. There was no clear association between any of the antigens studied and any specific damage to the child. These 'negative' findings are consistent with the absence of frequent significant effects due to these agents in the second and third trimesters of pregnancy.     

The “suffocation alarm” theory of panic attacks: A critical commentary

In 1993 Klein proposed a “false suffocation alarm” theory of panic attacks, claiming that many spontaneous panic attacks are due to a “suffocation monitor” in the brain erroneously signaling a lack of useful air, and triggering an evolved “suffocation alarm system”. He proposed that carbon dioxide acts as a panic stimulus because rising arterial CO₂ suggests suffocation may be imminent. The present paper provides a critical analysis of Klein's theory and concludes that there is neither empirical evidence nor compelling argument to support the assumptions or the proposed neurological mechanism of a “suffocation alarm”, true or false, or a CO₂ “suffocation monitor”. Data relevant to the role of breathing in the phenomenon of panic can be parsimoniously subsumed within the domain of dyspnea.     

Lectin-like cell adhesion molecule 1 mediates leukocyte rolling in mesenteric venules in vivo

During the inflammatory response, granulocytes and other leukocytes adhere to and emigrate from small venules. Before firm attachment, leukocytes are observed rolling slowly along the endothelium in venules of most tissues accessible to intravital microscopy. The molecular mechanism underlying this early type of leukocyte-endothelial interaction is unknown. Leukocyte rolling was investigated in venules (diameter, 40 microns) of the exposed rat mesentery. Micro-infusion of a recombinant soluble chimera (LEC-IgG) of the murine homing receptor lectin-like cell adhesion molecule 1 (LEC-CAM 1; gp90MEL) into individual venules reduced the number of rolling leukocytes by 89% +/- 2% (mean +/- SEM, n = 20 venules), while a similar CD4 chimera (CD4-IgG) had no effect (inhibition 14% +/- 7%, n = 25). Rolling was also greatly reduced by a polyclonal serum against LEC-CAM 1 (inhibition 84% +/- 3%, n = 35); preimmune serum was ineffective (11% +/- 13% inhibition, n = 28). These findings indicate that LEC-CAM 1 mediates the adhesive interaction underlying leukocyte rolling and thus may play an important role in inflammation and in pathologic conditions involving leukocytes.     

Medulloblastoma in adulthood: Prognostic factors influencing survival and recurrence

Summary Thirty adult patients presenting with medulloblastoma between 1974 and 1991 were studied and treated at Puerta de Hierro Clinic. After diagnosis, all patients were treated by surgery followed by radiotherapy and eight of them received adjuvant chemotherapy. We have studied the influence of some factors such as age, sex, location of tumour in the cerebellum, amount of surgical resection and histological variants on survival and recurrence of the disease. Only the histological type has a statistically significant influence on survival and recurrence: we have found that patients presenting classic medulloblastoma have a long survival and a long relapse-free interval.     

High frequency of precancerous lesions of gastric cancer associated with Helicobacter pylori and response to treatment,in Chiapas,Mexico

Stomach cancer is the second cause of death in Mexico in patients with malignant tumors. This disease represents a public health problem. A strong association has been described between chronic infection with Helicobacter pylori and gastric cancer. This malignancy is preceded by a series of preneoplastic conditions, including chronic atrophic gastritis (CAG), intestinal metaplasia (IM), and dysplasia. The objective of this study was to establish the prevalence of preneoplastic conditions associated with infection of Helicobacter pylori in the state of Chiapas and its eradication with antibiotics. Persons infected with Helicobacter pylori and with CAG were identified by serology against CagA protein and serologic levels of gastrin. An endoscopy with biopsy was performed at the beginning of the study, and at 6 weeks and 1 year thereafter. A total of 281 people were enrolled and randomly assigned to treatment or placebo group. CAG was found in 59%, IM in 51%, and dysplasia in 13%. In intent-to-treat and per-protocol analysis, Helicobacter pylori was eliminated in 70 and 76%, respectively. These results indicate high frequency of preneoplastic conditions associated with Helicobacter pylori and an excellent eradication rate. They also offer a possible alternative for preventing gastric cancer.     

The effect of antigen deprivation on thymus-dependent and thymus-independent lymphocytes in the small intestine of the mouse

Isografts of foetal small intestine, implanted under the kidney capsules of adult mice grow normally and, despite the lack of intraluminal antigenic stimulation, are populated by thymus-dependent and thymus-independent lymphocytes. The Peyer's patches in these grafts are very small, lack germinal centres and can be shown to have small thymus-dependent areas.

Quantitative intraepithelial lymphocyte counts were carried out in normally sited small intestine of immunologically intact and thymus-deprived mice, and in grafts implanted in intact and thymus-deprived mice. Counts were also performed in a group of neonatally thymectomized and control mice. The results show a significant depletion of intraepithelial lymphocytes in neonatally thymectomized mice, and a profound reduction in numbers of intraepithelial lymphocytes in grafts, deprived of antigen, when compared with normally sited intestine of the same age.