Per‐oral transgastric abdominal surgery

Laparoscopic surgery has several advantages over traditional surgery because it has been shown to be less invasive. The next logical step in the evolution of minimally invasive surgery may be to eliminate all abdominal incisions. The natural orifices provide a port of entry via the gastrointestinal tract to the peritoneal cavity. This approach would require the creation of a perforation, which is considered to be a major complication of endoscopy with significant morbidity and mortality. However, there are several recent studies that have described the technical feasibility and safety of a per‐oral transgastric approach to the peritoneal cavity using conventional endoscopes. Theoretically, this approach could reduce postoperative abdominal wall pain, wound infection, hernia formation, and adhesions. This article aims to summarize the current status of transgastric surgery, currently referred to as natural orifice transluminal endoscopic surgery (NOTES), and to address some of its future challenges.     

Iotrol versus metrizamide in lumbar myelography: a double-blind study

In a prospective, randomized, double-blind study, 49 patients underwent lumbar myelography using iotrol (24 patients) or metrizamide (25 patients). The diagnostic imaging adequacy of iotrol was comparable with that of metrizamide. After iotrol myelography, adverse reactions were fewer, less severe, and of shorter duration than were those following metrizamide myelography. Thirteen of 24 patients (54%) receiving iotrol reported some adverse reactions compared with 24 of 25 patients (96%) receiving metrizamide. Five moderate and one severe adverse reaction occurred in the group receiving iotrol. Fourteen moderate and eight severe adverse reactions occurred in the group receiving metrizamide. Thirty-eight patients underwent electroencephalography both before and after myelography (19 iotrol and 19 metrizamide). None of the EEGs obtained after iotrol myelography changed from baseline, while seven of the EEGs obtained after metrizamide myelography showed changes from baseline. Iotrol was judged superior to metrizamide as a contrast medium in this patient population.     

Optic chiasm glioma associated with inappropriate secretion of antidiuretic hormone,cerebral ischemia,nonobstructive hydrocephalus and chronic ascites following ventriculoperitoneal shunting

An optic chiasm glioma may cause loss of vision, endocrine disturbances, hydrocephalus and cerebral ischemia due to its proximity to the pituitary, hypothalamus, III ventricle and internal carotids. A 3-month-old infant with optic chiasm glioma developed hypopituitarism and inappropriate secretion of antidiuretic hormone with plasma hypo-osmolality. The cerebrospinal fluid (CSF) protein concentration was markedly elevated. The impairment of fluid absorption via arachnoid villi and peritoneum by the high protein content, and reversed osmotic gradient between protein-rich CSF and hypo-osmolar plasma may have contributed to both nonobstructive hydrocephalus and recurrent ascites following ventriculoperitoneal shunting. Cerebral ischemia from carotid compression may have led to cerebral atrophy.     

Plasma Ratios of Tryptophan and Tyrosine to Other Large Neutral Amino Acids in Manic-Depressive Patients

Abstract: The plasma ratio of each neutral amino acid (tryptophan (TRP), tyrosine (TYR), valine, isoleucine, leucine (LEU) or phenylalanine) to the sum of the other neutral amino acids was measured in 16 : manic and 14 : depressed patients. In the manics, there was a correlation between the psychomotor activity and the plasma TRP and LEU ratios. In the depressives, the depressed mood, retardation and global severity were correlated with the TRP ratio. The zotepine responders showed an increase in the TRP ratio after treatment. In the mianserin responders, the TYR ratio, which was high before the treatment, decreased to the normal range after the treatment. But, the plasma amino acid ratios remained unchanged in the patients treated with lithium carbonate or amitriptyhe. These results suggest that, in manic-depressive illness, there might be abnormalities in the metabolism of neutral amino acids, mainly of TRP and TYR, and that the plasma TRP and TYR ratios might be important indicators for determining the efflcacy of some drugs.     

Magnetic resonance imaging of rabbit brain after intracarotid injection of large multivesicular liposomes containing paramagnetic metals and DTPA

A procedure has been developed for the preparation of large (10- to 80-microns-diameter) multivesicular liposomes that contain magnetic resonance contrast agent (DTPA and either manganese or gadolinium). Blue dextran was observed to induce the formation of the large liposomes with dioleoylphosphatidylcholine and cholesterol (1:1 molar ratio) and with dipalmitoylphosphatidylcholine and cholesterol (1:1 molar ratio). The formation of the large liposomes is dependent upon mixing the blue dextran with the lipid films at temperatures above the transition point of the lipids. Tracer amounts of 153Gd were added to the aqueous phase to permit quantitation of the recovery of encapsulated materials. Liposomes that were prepared using equimolar ratios of phospholipid and cholesterol were stable in serum for more than 12 h. The ultrastructure of the large multivesicular liposomes reveals the existence of individual vesicles (greater than 2 micron diameter) bound together by a multilamellar coating. When injected into the internal carotid artery of the rabbit, the large liposomes became entrapped in the vascular bed primarily in the frontal and occipital regions of brain. The resulting emboli may provide a means to deliver drugs to a specific site in brain, such as a tumor, if the vascular bed of the site can be cannulated precisely.     

Stability of regional cerebral glucose metabolism in the normal brain measured by positron emission tomography

Cerebral glucose utilization (LCMRGI) was measured using the [18F]fluorodeoxyglucose method with PET in two groups of ten healthy young volunteers, each scanned in a resting state under different methodological conditions. In addition, five subjects had a second scan within 48 hr. Mean hemispheric values averaged 45.8 +/- 3.3 mumol/100 g/min in the right cerebral hemisphere and 47.0 +/- 3.7 mumol/100 g/min in the left hemisphere. A four-way analysis of variance (group, sex, region, hemisphere) was carried out on the results using three different methods of data manipulation: (a) the raw values of glucose utilization, (b) LCMRGI values "normalized" by the mean hemispheric gray matter LCMRGI value, and (c) log transformed LCMRGI values. For all analysis techniques, significantly higher LCMRGI values were consistently seen in the left mid and posterior temporal area and caudate nucleus relative to the right, and in the right occipital region relative to the left. The coefficient of variation of intrasubject regional differences (9.9%) was significantly smaller than the coefficient of variation for regions between subjects (16.5%). No differences were noted between the sexes and no effect of repeat procedures was seen in subjects having multiple scans. In addition, inter-regional LCMRGI correlations were examined both in values from the 20 normal subjects, as well as in a set of hypothetical "abnormal" values. Results were compared with those reported from other PET centers; despite certain methodological differences, the intersubject and inter-regional variation of LCMRGI is fairly constant.     

Molecular epidemiology of Mycobacterium avium subsp. paratuberculosis isolates recovered from wild animal species

Mycobacterial isolates were obtained by radiometric culture from 33 different species of captive or free-ranging animals (n = 106) and environmental sources (n = 3) from six geographic zones within the United States. The identities of all 109 isolates were confirmed by using mycobactin J dependence and characterization of five well-defined molecular markers, including two integration loci of IS900 (loci L1 and L9), one Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis)-specific sequence (locus 251), and one M. avium subsp. avium-specific marker (IS1245), as well as hsp65 and IS1311 restriction endonuclease analyses. Seventy-six acid-fast isolates were identified as M. paratuberculosis, 15 were identified as belonging to the M. avium-M. intracellulare complex (but not M. paratuberculosis), and the remaining 18 were identified as mycobacteria outside the M. avium-M. intracellulare complex. Fingerprinting by multiplex PCR for IS900 integration loci clustered 67 of the 76 M. paratuberculosis strains into a single clade (designated clade A18) and had a Simpson's diversity index (D) of 0.53. In contrast, sequence-based characterization of a recently identified M. paratuberculosis short sequence repeat (SSR) region enabled the differentiation of the M. paratuberculosis isolates in clade A18 into seven distinct alleles (D = 0.75). The analysis revealed eight subtypes among the 33 species of animals, suggesting the interspecies transmission of specific strains. Taken together, the results of our analyses demonstrate that SSR analysis enables the genetic characterization of M. paratuberculosis isolates from different host species and provide evidence for the host specificity of some M. paratuberculosis strains as well as sharing of strains between wild and domesticated animal species.     

Expression of the 5.1 H11 antigen, a fetal muscle surface antigen, in normal and neoplastic tissue

The monoclonal antibody 5.1 H11 recognizes an antigen on human fetal muscle and on rhabdomyosarcoma cell lines and xenografts that has been shown to be homologous to the neural cell adhesion molecule. To evaluate its range of expression, we used immunoperoxidase staining of fresh frozen-tissue sections to determine monoclonal antibody 5.1 H11 reactivity in normal and neoplastic tissue. Among normal tissue specimens, intense antibody staining was seen in brain and peripheral nerve, and weaker staining in ganglionic elements of colon. In addition to 26 of 29 rhabdomyosarcoma specimens, 5.1 H11 antibody showed reactivity to 9 of 10 Wilms' tumors, 6 of 6 neural tumors, and 4 of 4 gliomas, and with single specimens of ectomesenchymoma, clear-cell sarcoma of kidney, undifferentiated sarcoma of liver, ovarian fibroma, and neurofibroma. We conclude that the monoclonal antibody 5.1 H11 recognizes an antigen present not only on fetal muscle but on normal brain and nerve as well. In addition to rhabdomyosarcoma, a variety of other tumors, most of which have been previously shown to express neural cell adhesion molecule, also appear to express the antigen recognized by 5.1 H11. Our results thus offer additional confirmatory evidence that an epitope of neural cell adhesion molecule is the antigen for 5.1 H11.