We reviewed our experience with combined approaches to lesions that transcend the bones of the skull base. Seventy-seven skull base procedures were performed on 73 patients during a 10-year period from 1982 to 1992. There were 34 patients (44%) with region lesions (anterior), seven patients (9%) with region II lesions (anterior-lateral), 25 patients (32%) with region III lesions (lateral-posterior), and 11 patients (14%) with lesions that invaded more than one anatomic site. The histopathology in this series was quite variable, with 22 patients (29%) having squamous cell carcinoma and eight patients (10%) having basal cell carcinoma. Forty-one patients had surgery by an anterior approach and 38 patients had lateral approaches, with 18 undergoing an infratemporal approach and 29 undergoing temporal bone resections. Overall, 44% of the patients had a postoperative complication. Survival of this heterogeneous group of patients is 79% at 2 years and 71% at 4 years, with those patients with region II disease having a statistically significant poorer prognosis with no survivors at 4 years.

Adolescent↗

PubMedDate not supplied

Inducer and suppressor T-cells in hepatitis B virus-induced liver disease.

During acute type B hepatitis, the proportion of inducer to cytotoxic/suppressor T-cells is decreased due to an increase in the concentration of suppressor cells. Similar changes are seen in chronically infected subjects with evidence of active viral replication (HBeAg positive) and chronic hepatitis of varying severity. This imbalance of the regulatory cells returns to normal when viral replication decreases during the recovery phase of acute hepatitis and in patients who become chronic carriers with minimal liver disease (HBeAb positive patient). Patients in whom viral replication has subsided (HBeAb positive) but who continue to exhibit chronic active liver disease have increased inducer to cytotoxic/suppressor cell ratios due to a decrease in the concentration of the cytotoxic/suppressor cell population. Further studies are needed to determine whether these alterations of the regulatory cells of the immune system are a causal factor influencing the duration of active hepatitis B virus replication and the degree of inflammatory liver damage, or merely changes secondary to the presence of a replicating virus.

Acute Disease↗

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HLA class I antigens on the hepatocyte membrane during recovery from acute hepatitis B virus infection and during interferon therapy in chronic hepatitis B virus infection.

In a chimpanzee model of acute type B hepatitis, at the time of onset of hepatitis B virus replication and before the development of immunity to hepatitis B virus, interferon is present in the plasma. This is followed by an increase in the display of HLA class I, but not class II proteins, on the hepatocyte membrane. In chronic hepatitis B virus infection, there is a low density of HLA class I protein display on the infected hepatocyte. Administration of alpha-interferon enhances HLA display and in many cases is followed by a transaminase elevation, seroconversion of HBe antigen to antibody and disappearance of hepatitis B virus DNA from serum, changes implying clearance of infected hepatocytes. Successful response to interferon therapy may be predicted by a rapidly rising serum beta 2-microglobulin, a component of the HLA class I molecule, during the first 2 weeks of therapy, before the rise in transaminases.

Acute Disease↗

PubMedDate not supplied

Early loss of neurons and axon terminals in scrapie-affected mice revealed by morphometry and immunocytochemistry.

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Animals↗

PubMedDate not supplied

Loss of the airway during tracheostomy: rescue oxygenation and re-establishment of the airway.

PURPOSE: To describe loss of the airway during tracheostomy and suggest a method for re-establishment of the airway and providing rescue oxygenation. CLINICAL FEATURES: A 22-yr-old female diagnosed with encephalomyelopathy was admitted to the intensive care unit with a progressively deteriorating level of consciousness and respiratory failure requiring intubation and ventilation. Several weeks later, an elective tracheostomy was performed under anesthesia. The surgeon made an anterior tracheal wall incision and inserted a cuffed #6 Shiley tracheostomy tube. No end-tidal CO(2) was detected and the patient could not be ventilated. After another failed attempt at insertion of a second tracheostomy tube, the diagnosis was made of a false passage within the trachea. The Shiley tracheostomy tube was removed and a #6 regular endotracheal tube was introduced in the trachea through the tracheostomy incision. The patient now could be ventilated with difficulty and low readings of end-tidal CO(2) were noted. Despite all efforts to further ventilate the patient, the arterial oxygen saturation never recovered, resulting in cardiac arrest. CONCLUSION: To restore a lost airway during tracheostomy, we recommend that a jet ventilation airway exchange catheter (JVAE) be inserted in the endotracheal tube through a bronchoscope port attachment prior to surgical entry into the trachea. The JVAE will also ensure continued ability to oxygenate the patient.

Adult↗

PubMedDate not supplied

Prevalence of measles antibody among children under 15 years of age in Santa Cruz, Bolivia: implications for vaccination strategies.

We conducted a community-based survey in Santa Cruz city, Bolivia, to determine the age-specific prevalence of measles antibodies, determine factors associated with absence of detectable measles antibodies, and to compare results of salivary and serum measles immunoglobulin G (IgG) antibody assays. Serum samples from 1654 children were assayed for measles IgG antibody using the haemagglutination inhibition (HI) assay, and salivary samples were also obtained from 187 children and tested for measles IgG antibody using an antibody capture radioimmunoassay. Reported measles vaccine coverage in children aged 12-35 months was 77% (95% confidence interval [CI], 72-81%). Eighty-seven percent (95% CI 85-89%) had detectable HI antibody, but a high proportion had antibody levels below 200 miu (30-40% of 2-14 years old children). Measles seronegativity was associated with not being vaccinated against measles, a negative history of measles disease, living in the inner city, being a lifetime resident of Santa Cruz, and young age. Of 212 children without detectable measles antibody, 58% had a positive history of vaccination or measles disease, so that historical information was not sufficiently reliable to identify susceptibles. The salivary measles antibody assay was not sufficiently sensitive to be used for population screening; only 54% of 171 salivary samples from children who had detectable serum HI antibody were positive. A mass measles vaccination campaign of all children under 15 years of age is planned in Bolivia in 1994. Although only 7% of school-age children in Santa Cruz were seronegative, the effectiveness of a mass campaign in this age group depends in part on the response to revaccination of children with low, but detectable, antibody levels.

Adolescent↗

PubMedDate not supplied

Diffuse malignant melanoma of iris with metastases.

A 66-year-old man had decreased visual acuity in the left eye. Slit-lamp examination showed hyperpigmentation of the periphery of the iris from 2:30 to 9 o'clock. Gonioscopy disclosed an ill-defined mass involving the angle and extending from 5 to 7:30 o'clock with diffuse pigmentation of the meshwork for 360 degrees. A sector iridectomy was performed inferiorly in his left eye. Histopathologic examination disclosed a diffuse malignant melanoma of the iris, mixed cell type. The patient was free of recurrence when examined at 18, 24 and 30 months following surgery. Two years and ten months following the iridectomy, the patient developed multiple metastatic bony lesions and a mass in the liver. Bone marrow aspiration from the sternum and biopsy from the iliac crest, respectively, showed metastatic malignant melanoma. He died shortly thereafter and an autopsy was not performed. The remote possibility of an occult, intraocular tumor such as a ciliary body melanoma or an internally located melanoma cannot be excluded. Assuming that this is indeed an iris melanoma, as our studies indicate, the rarity of this metastatic iris neoplasm is emphasized by noting that only 37 cases of iris melanomas with presumed metastases have been reported in the literature.

Aged↗

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Quantitative electrocardiography during extended space flight.

To assess the effects of prolonged space flight on the electrophysiological properties of the heart, vectorcardiograms (VCG) were obtained on the Skylab crews at regular intervals during flight and the pre- and postflight periods. The VCG signals were telemetered from Skylab and analyzed by digital computer. Conventional 12-lead electrocardiograms were derived from the VCG signals by a lead transformation program. Standardized exercise loads were incorporated into the experiment protocol to increase the sensitivity of the VCG for effects of deconditioning and to detect susceptibility for arrhythmias. In Skylab II, 24 preflight, 21 inflight, and 19 postflight experiments were analyzed. Statistically significant inflight changes observed in two or more crew members included: decreased resting heart rate, increased QRS duration, anterior shift QRS vector, increased QRS vector magnitude, anterior shift T vector, and increased T vector magnitude. One astronaut had occasional premature ventricular contractions (PVC) during the pre- and postflight phases. He had a single episode of multiple PVC's during heavy-load exercise testing in flight. A second astronaut had no arrhythmia during pre- or inflight testing. On postflight day 21 he had multiple PVC's and salvos of ectopic ventricular beats. He has had no recurrence of the arrhythmia. With the exception of the cardiac arrhythmias, no deleterious electrophysiological changes were observed during Skylab II.

Arrhythmias, Cardiac↗

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Villous oedema of the placenta: a clinicopathological study.

Villous oedema was observed in 259 placentae among 1925 consecutive singleton pregnancies of greater than 19 weeks gestation. It was present in 11 per cent of term placentae in which significant associations with fetal and neonatal death (P less than 0.03), and absence of maternal cigarette smoking (P less than 0.002) were found. In preterm placentae, the oedema was usually more severe, and its prevalence increased from 20 per cent for 33-37 weeks to 40 per cent for less than 33 weeks. Our analysis showed that for a given gestational age, villous oedema was not significantly related to chorioamnionistis, Apgar scores of less than 7 at 1 and 5 min, or neonatal death, an exception was for 33-37 weeks gestation, in the absence of chorioamnionitis, villous oedema was associated with low 1 min Apgar score. Immature intermediate villi are present in premature placentae as a normal developmental stage and in dysmature placentae as a result of villous maldevelopment. Since villous oedema closely resembles the 'stromal channels' in this villous type and shows significant association with prematurity and villous dysmaturity, we postulate that villous oedema is a lesion primarily of the immature intermediate villi. Both fetal and maternal factors are involved in its pathogenesis.

Chorionic Villi↗

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Hypokalemia, hypophosphatemia, and compartment syndrome of the leg after downhill skiing on moguls.

Any process that increases intracompartmental pressure may precipitate compartment syndrome. We report the case of a patient with hypokalemia and hypophosphatemia who presented with compartment syndrome of the legs after a day of downhill skiing on moguls. The presentation is followed by a review of the pathophysiology, etiology, clinical presentation, and management of compartment syndrome, as well as the relationship between hypokalemia, hypophosphatemia, and the development of muscle injury.

Adult↗