Perforated synapses on double-headed dendritic spines: a possible structural substrate of synaptic plasticity

Examination of axospinous synapses in serial sections obtained from the middle molecular layer of the rat dentate gyrus has revealed that some of them involve double-healed dendritic spines. Each spine head is apposed by a separate axon terminal with which it always forms a perforated synaptic contact distinguished by a discontinuous postsynaptic density. The number of perforated synapses on double-headed spines was estimated as a synapse-to-neuron ratio with the aid of the disector technique and found to be significantly increased in rats kindled via medial perforant path stimulation. These results support the notion that perforated synapses involving double-headed dendritic spines represent a structural modification related to enhanced synaptic efficacy.     

Perceived efficacy of herbal remedies by users accessing primary healthcare in Trinidad

Background  

The increasing global popularity of herbal remedies requires further investigation to determine the probable factors driving this burgeoning phenomenon. We propose that the users' perception of efficacy is an important factor and assessed the perceived efficacy of herbal remedies by users accessing primary health facilities throughout Trinidad. Additionally, we determined how these users rated herbal remedies compared to conventional allopathic medicines as being less, equally or more efficacious.     

Methods of treatment of exterior eye neoplasms

The difficulty in the choice of the optimal treatment strategy is explained by a great variety of the cellular composition, site, size, type, and growth rate of tumors of the eyelids, conjunctiva, cornea, and lacrimal duct; a good choice of effective treatment modalities, such as surgical or laser excision, ionization, cold or coagulation destruction does not simplify this task. The author suggests an algorithm, facilitating the choice of the treatment strategy, with due consideration for some specific features of each case.     

Results of a thirty-year study of familial adenomatous polyposis coli

PURPOSE: This study was designed to estimate the efficiency of the various methods used to treat familial adenomatous polyposis coli. METHODS: Three hundred ninety patients (219 males) underwent surgery for familial adenomatous polyposis coli; postoperative follow-up was from 1 to 30 years. RESULTS: Coloproctectomy with preservation of the anal sphincter and coloproctectomy with ileoanal pull-through procedures resulted in development of anal canal cancer in 3 (4.1 percent) of 74 patients. Follow-up revealed development of cancer in the large bowel in 26 (10.7 percent) of 242 patients, in whom colectomy with preservation of various colonic segments was performed. CONCLUSIONS: The occurrence rate of cancer is not significantly related to patients' gender, age, length of preserved colonic segment, presence of cancer in the removed colonic segment, or postoperative follow-up period; however, presence of polyps in the colonic segments preserved during surgery significantly increased the risk of development of cancer at a later time.