Reactions of Living Polytetrahydrofuran with Amines V - Tertiary Amine Terminated Polybutadienes; The Synthesis of Novel Ionically Linked Block Copolymers

The reactions of mono- and difunctional tertiary amine ended polybutadienes with mono- and difunctional living cationic poly THF have been studied. It is shown that the reaction to form quaternary ammonium linking groups takes place rapidly in all cases, and AB. ABA, BAB and (AB) block copolymers have been prepared. The efficiency of the process is extremely high and the degree of conversion is essentially controlled by the efficiency with which the terminal tertiary amine groups can be introduced on to the polybutadiene. The block copolymers show anomalous behaviour on gel permeation chromatography columns and this has been related to a specific interaction of the created ionic groups with polar species on the column packing. This effect is greatest with (AB) block copolymers where substantial proportions are retained indefinitely on the columns.     

Nutritional evaluation of soya beans (glycine max): Nitrogen balance and fractionation studies

The poor nutritional performance of rats fed raw soya-bean-containing diets appeared to be due to reduced apparent digestion and absorption of dietary protein, coupled to changes in systemic metabolism leading to a poor overall nitrogen balance. Aqueous heat treatment greatly reduced but did not eliminate the antinutritional effect. Heat treatment with aqueous ethanol was more effective. The whey protein (pH 4.8 soluble extract) fraction contained the bulk of the trypsin inhibitor and haemagglutination activity and gave the poorest net protein utilisation value. However, an eight-fold increase in trypsin inhibitor content did not significantly effect apparent nitrogen digestibility. Therefore inhibition of gut proteolytic enzyme activity in vivo by soya bean trypsin inhibitors did not account fully for the poor nutritional performance. The problems elicited by soya bean are not transitory and thus there was a cumulative deterioration in overall performance for 16 weeks as a result of continuous exposure to soya bean.     

Endoscopic therapy of esophageal cancer

In the management of esophageal cancer, endoscopy has evolved from a tool used to provide biopsy confirmation of suspected tumor to an integral part of the staging and ongoing treatment of patients. Endoscopic ultrasound is currently the most accurate means for T and N staging. Improved endoscopic techniques like dye staining and aggressive biopsy protocols can identify very early stage tumors in high-risk groups and allow curative surgery. Patients with early-stage tumors who are not surgical candidates can also be treated with endoscopic mucosectomy, photodynamic therapy, or Nd:YAG laser and still have a chance of long-term cure. Palliation of advanced tumors remains the major role of endoscopy in patients with esophageal cancer. A variety of techniques have proven effective over the years, including dilatation, laser, and rigid prostheses. Newer developments like bipolar probes, injection therapy, photodynamic therapy, and brachytherapy offer potential applications. The development and continuing improvements in both coated and uncoated expandable metal stents have been perhaps the greatest recent advance in endoscopic palliation of malignant dysphagia and esophagorespiratory fistulas. With the increasing array of endoscopic treatments and palliative techniques, emphasis must be placed on considering functional status; tumor characteristics like stage, location, and shape; patient wishes; and local expertise in tailoring treatment plans for each situation.     

Computed tomography-guided biopsy of the spine. A review of 103 patients

PURPOSE: This study was performed to evaluate relations among neutrophil count (including its course), type of lesion, treatment, and prognosis in patients with leukemia and perianal infection. METHODS: Medical records of patients with acute and chronic leukemia who were followed during the last five years were reviewed retrospectively. RESULTS: The incidence of perianal infections was found to be 7.3 percent in 259 patients with acute leukemia. Only 1 of 108 patients with chronic leukemia suffered from this problem. Twenty percent of all patients with this complication died as a result of sepsis. Perianal abscess was the sole and obligatory indication for surgical treatment in our patients. There were ten patients in each treatment group. The operative group had better results (9 cures, 1 complication vs. 3 cures, 7 complications). However, median neutrophil count at diagnosis was notably higher in the operative group 1,280/mm3 vs. 96/mm3; P = 0.075). Also, significantly more frequent abscess formations and, consequently, operative treatments were performed in patients with a period of normal neutrophil counts during the infection compared with continuously neutropenic patients (9 operative, 4 nonoperative vs. 1 operative, 6 nonoperative; P = 0.057). Ten cures, three complications vs. two cures, five complications (3 mortalities) were present in patients with and without normal neutrophil counts, respectively (P = 0.062). When only severely neutropenic patients were considered, four patients in the surgery group had normal neutrophil counts before or shortly after surgery. However, only two of eight patients with perianal cellulitis had normal counts during full-course infection (P = 0.06). CONCLUSIONS: The course of the neutrophil count during infection was an important factor affecting the perianal lesion, and indirectly, choice of treatment and prognosis. A period of normal counts during infection usually led to well bordered and fluctuant lesions, and the prognosis was acceptable with operative treatment. However, continuously neutropenic patients developed nonfluctuating indurations. We found disappointing results with nonoperative treatment of such patients. In all studies, regarding treatment of perianal infections in neutropenic patients, the course of the neutrophil count and indications for surgery should be clarified to get reliable results.     

Expression and localization in the fish retina of a homologue of the Alzheimer's related PS1 gene

Early-onset familial Alzheimer's disease (early-onset FAD) has been linked with mutations in the presenilin gene, PS1. Mutations in PS1 may affect the processing/trafficking of b-amyloid precursor-protein (bAPP) and favour the production of toxic amyloid-b fragments that are associated with neural degeneration. This study reports the expression of a PS1-like cDNA in the carp (Cyprinus carpio) retina (the encoded protein shows 76% identity to the human PS1 protein). Carp PS1 mRNA was localized by in situ hybridization to the photoreceptor cell, inner nuclear and ganglion cell layers. Expression of the PS1 gene in the rat retina was also confirmed. The retinal expression of PS1 raises the possibility that PS1 mutations also lead to neural degeneration in the retina.     

Infant feeding and weaning practices in some semi-arid rural areas of Rajasthan

The paper contains information on infant feeding and weaning practices in the rural communities of a semi-arid district of Rajasthan. The findings have been drawn from a recent survey of 328 rural mothers. The rural women of this area are found to believe in old deep seated beliefs and customs, which in turn deprive their infants from advantages of colostrum (77% discarded colostrum) and nutritionally rich supplements, which otherwise should be supplemented to them at any cost in order to keep them healthy. The practices of prolonged breast feeding and delayed supplementation to infants are rampant in this area. Mean age at weaning (27.1 months) again not only affects the health status of mothers and their children but also leads to the undernutrition among both. The findings of the study necessitate to evolve an exhaustive educative programme dealing with various aspects of infant feeding and weaning practices, keeping in view their traditions, so that the useful practices can be encouraged and harmful ones be prohibited.