Surgical training on rectal cancer surgery: do supervised senior residents differ from consultants in outcomes?

INTRODUCTION

The present work is a comparative study to investigate the independent effect of tutored senior residents on rectal cancer surgery in an academic university hospital. The variable "surgeon" is held to be a major determinant of outcome following total mesorectal excision (TME) for rectal cancer.

OBJECTIVE

We hypothesized that TME can be tutored to senior surgical residents without compromising surgical and oncological outcomes.

METHODS

Demographics, preoperative characteristics, and surgical data from consecutive patients undergoing elective TME in an academic center over the last decade were retrospectively reviewed from a prospectively collected database. Outcomes were compared in the two cohorts by a principal surgeon (senior resident or staff) and supervised in all cases by a senior colorectal consultant. Association of outcome variables with the type of surgeon was determined by univariate and multivariate analyses and results were corrected by tumor's height.

RESULTS

A total of 230 patients were treated over the study period; 136 (59 %) surgeries were performed by staff surgeons (group S) and 94 (41 %) by residents (group R). Both groups were comparable except for distance to anal verge; staff surgeons operated on lower tumors and performed a high percentage of coloanal anastomosis. There were no statistical differences between groups in terms of surgical and oncological outcomes when tumors were located over 7 cm from the anal verge.

CONCLUSIONS

Rectal surgery can be performed by senior residents with equal results to staff surgeons when there is direct supervision by a senior consultant and when the tumor is located in the mid-upper rectum (>7 cm from the anal verge). For lower tumors, a careful selection must be made as the operation may require a higher level of training.

Preliminary outcome of a treatment strategy based on perioperative chemotherapy and surgery in patients with locally advanced colon cancer

AIM

Preoperative chemotherapy followed by radical surgery is an attractive treatment for locally advanced colon cancer (LACC) given the promising results of this approach in other locally advanced tumours. The study evaluates the outcome and treatment-related complications of perioperative oxaliplatin- and capecitabine-based chemotherapy and surgery for clinical Stage III colon cancer.

METHOD

Twenty-two consecutive patients with a CT-staged LACC were included. All were staged at baseline and before surgery. Surgery-related complications and oncological outcome were determined.

RESULTS

Toxicity was manageable, with 19/22 patients completing the planned chemotherapy protocol. The median time from initial diagnosis to surgery was 65.5 days. The median time from the end of chemotherapy to surgery was 22 days. After neoadjuvant treatment, tumour reduction of 69.5% was observed by CT scan and a 59.9% decrease of SUVmax (standard uptake value) was achieved on positron emission tomography/CT. No progressive disease was reported during preoperative chemotherapy and surgery was performed in all 22 patients. Four patients developed postoperative complications. After a median postoperative follow-up of 14.4 months, the actuarial overall and disease-free survival rates were 100 and 90%.

CONCLUSION

Neoadjuvant chemotherapy followed by surgery and chemotherapy for LACC is safe without apparent increase of early and medium-term complications.

[Giant duodenal ulcer perforation: a case of innovative repair with an antrum gastric patch]

BACKGROUNDS

the treatment of a perforated giant duodenal ulcer (GUDs) represents a formidable surgical challenge regarding the duodenal wall defect repair in severe peritonitis setting. A high incidence of dehiscence and hospital mortality (15-40%- has been reported with the majority of the techniques). We report a case of GUDs perforation successfully treated with a subtotal gastrectomy and a gastric patch with the remnant antrum, for repairing the duodenal defect.

CASE REPORT

a 63-years-old man with antecedents of peptic ulcer disease presents a large duodenal ulcer perforation with 48 hrs delay and associated with severe peritonitis and a retroperitoneal collection. A subtotal gastrectomy with Billroth II reconstruction and reconstruction of the duodenal defect with a patch of the remnant antrum was carried out. The patient was discharged at 17th postoperative day with good tolerance.

DISCUSSION

the duodenal defect repair with a patch of the remant antrum, represents a valid alternative in similar circumstances. To our knowledge, it appears to be the first clinical description of this technique.

Exome sequencing detection of two untranslated GFPT1 mutations in a family with limb-girdle myasthenia

The term 'limb-girdle myasthenia' (LGM) was first used to describe three siblings with proximal limb weakness without oculobulbar involvement, but with EMG decrement and responsiveness to anticholinesterase medication. We report here that exome sequencing in the proband of this family revealed several sequence variations in genes linked to proximal limb weakness. However, the only mutations that cosegregated with disease were an intronic IVS7-8A>G mutation and the previously reported 3'-UTR c.*22C>A mutation in GFPT1, a gene linked to LGM. A minigene assay showed that IVS7-8A>G activates an alternative splice acceptor that results in retention of the last seven nucleotides of intron 7 and a frameshift leading to a termination codon 13 nucleotides downstream from the new splice site. An anconeus muscle biopsy revealed mild reduction of the axon terminal size and postsynaptic fold simplification. The amplitudes of miniature endplate potentials and quantal release were also diminished. The DNA of the mildly affected father of the proband showed only the intronic mutation along with sequence variations in other genes potentially relevant to LGM. Thus, this study performed in the family originally described with LGM showed two GFPT1 untranslated mutations, which may cause disease by reducing GFPT1 expression and ultimately impairing protein glycosylation.

Cobblestone lissencephaly in Schinzel-Giedion syndrome

The brain of a 5-year-old boy with Schinzel-Giedion syndrome displayed a cobblestone appearance of orbital and lateral aspects of frontal lobes due to widespread glioneuronal meningeal heterotopia. Meningeal heterotopia consisted of scattered neurons, neurofilament positive axons, and myelinated fibers accompanied by striking astrocytic gliosis. The underlying cortex showed gaps in the pial basal lamina, distorted neuronal layering, and focal polymicrogyria. The number of capillaries appeared increased throughout the brain. Mild hydrocephalus was associated with a slight atrophy of corpus callosum as well as villous hyperplasia and marked stromal degeneration of the choroid plexus. Our findings suggest that Schinzel-Giedion syndrome may represent One more entity within enlarging spectrum of lissencephalic cortical dysplasia syndromes.

Anatomy of the temporomandibular joint in the cat: a study by microdissection, cryosection and vascular injection

The minute anatomy of the temporomandibular joint (TMJ) is of great clinical relevance in cats owing to a high number of lesions involving this articulation. However, the precise anatomy is poorly documented in textbooks and scientific articles. The aim of this study was to describe, in detail, the TMJ anatomy and its relationship with other adjacent anatomical structures in the cat. Different anatomical preparations, including vascular and articular injection, microdissection, cryosection and plastination, were performed in 12 cadaveric cats. All TMJ anatomical structures were identified and described in detail. A thorough understanding of the TMJ anatomy is essential to understand the clinical signs associated with TMJ disorders, to locate lesions precisely and to accurately interpret the results in all diagnostic imaging techniques.

Congenital myasthenic syndrome associated with epidermolysis bullosa caused by homozygous mutations in PLEC1 and CHRNE

Mutations in the plectin gene (PLEC1) cause epidermolysis bullosa simplex (EBS), which may associate with muscular dystrophy (EBS-MD) or pyloric atresia (EBS-PA). The association of EBS with congenital myasthenic syndrome (CMS) is also suspected to result from PLEC1 mutations. We report here a consanguineous patient with EBS and CMS for whom mutational analysis of PLEC1 revealed a homozygous 36 nucleotide insertion (1506_1507ins36) that results in a reduced expression of PLEC1 mRNA and plectin in the patient muscle. In addition, mutational analysis of CHRNE revealed a homozygous 1293insG, which is a well-known low-expressor receptor mutation. A skin biopsy revealed signs of EBS, and an anconeus muscle biopsy showed signs of a mild myopathy. Endplate studies showed fragmentation of endplates, postsynaptic simplification, and large collections of thread-like mitochondria. Amplitudes of miniature endplate potentials were diminished, but the endplate quantal content was actually increased. The complex phenotype presented here results from mutations in two separate genes. While the skin manifestations are because of the PLEC1 mutation, footprints of mutations in PLEC1 and CHRNE are present at the neuromuscular junction of the patient indicating that abnormalities in both genes contribute to the CMS phenotype.

Effect of cold storage on larval and adult Anastrepha ludens (Diptera: Tephritidae) viability in commercially ripe, artificially infested Persea americana 'Hass'

Commercially ripe 'Hass' avocados, Persea americana Mill, artificially exposed to wild Anastrepha ludens (Loew) (Diptera: Tephritidae) females 24 h after harvest were placed in a cold storage facility to determine the effect of low temperature on larval survival and adult viability. Fruit were left for 3, 6, 9, and 12 d in a cold room at 5 degrees C followed by a 20-25-d period at ambient temperature to allow for larval development and pupation. Hass avocados and grapefruit, Citrus paradisi Macfadyen, maintained at ambient temperature served as controls. Overall, only 0.23% of the Hass avocados and 19.30% of the grapefruit were infested. The number of infested fruit increased with decreasing exposure time to cold. Puparia from cold-treated Hass avocados were significantly smaller than those stemming from cold-treated grapefruit. Hass avocados exposed for 12 d to 5 degrees C yielded no puparia, and those exposed for 6 and 9 d yielded 22 and two puparia, respectively, but no adults. Although Hass avocados exposed to cold temperature for 3 d yielded adults that reached sexual maturity (N = 16), females laid inviable eggs. Grapefruit exposed to cold for 12 d yielded normal-sized puparia (but no adults), whereas those exposed over 9 d yielded females able to lay viable eggs. We conclude that exposing fruit to cold storage after packing and during transport represents an effective risk-mitigating procedure in the highly improbable event that a gravid A. ludens female might lay eggs in a commercially ripe Hass avocado that had been left unprotected in a packinghouse.

Peutz-Jeghers syndrome and duodeno-jejunal adenocarcinoma--therapeutic implications

The Peutz-Jeghers syndrome (PJS) is an autosomal dominant hamartomatous poliposis describred in 1921. Hemminki in 1997 described the presence of LKB-1 mutation tumor-suppressor gen.The patients with PJS develop a higher cumulative incidence of gastrointestinal, pancreas and extraintestinal tumors, being occasion of a renew interest on hamartomatous polyposis syndromes regarding the clinical care, cancer surveillance treatment and long term follow-up.We report the case of a 38 years old male, diagnosed of PJS who developed a multiple adenocarcinoma in duodenum and yeyunum. Surgically treated and with a long-term free disease survival of 11 years represents the sixth case reported in the spanish literature of PJS associated with a gastrointestinal tumor.A critical review, molecular alterations and the established criteria of tumor screening and surveillance are reviewed.

[Analysis of postoperative morbidity in patients with gastric adenocarcinoma treated using a protocol of preoperative chemoradiotherapy and surgery]

INTRODUCTION

The impact of neoadjuvant treatment on the postoperative complications in stomach cancer is a subject of controversy. The aim of this study is to analyse the post-surgical morbidity and mortality in a group of patients who were treated using a chemoradiotherapy protocol before surgery, as well as to identify the possible risk factors that may be associated with the development of complications.

MATERIAL AND METHODS

Patients diagnosed with locally advanced gastric adenocarcinoma between June 2005 and June 2008 were operated on in our Centre after having followed a preoperative chemoradiotherapy protocol. Data on postoperative morbidity and mortality were collected retrospectively and the dependent variables associated with the patients, the type of intervention and the tumour characteristics were analysed.

RESULTS

A total of 40 patients were evaluated. The overall morbidity and mortality was 32.5% (13 patients) and 2.5% (1 patient), respectively. The most frequent complications were pneumonia in 12.9% and sepsis due to the catheter in 9.7% of the patients. The risk factors for the development of complications were the body mass index (BMI 25 kg/m(2)) and the inclusion of the pancreas and/or spleen in the resection.

CONCLUSIONS

Preoperative treatment with chemoradiotherapy in patients with locally advanced stomach cancer does not increase the incidence of post-surgical complication. The preoperative condition of the patient (BMI) and extending the surgery to the spleen and pancreas are prognostic factors of early postoperative complications.

Mutations in LAMB2 causing a severe form of synaptic congenital myasthenic syndrome

Background:

We describe a severe form of congenital myasthenic syndrome (CMS) associated with congenital nephrosis and ocular malformations caused by two truncating mutations in the gene encoding the laminin β2 subunit (LAMB2).

Methods and results:

Mutational analysis in the affected patient, who has a history of a serious untoward reaction to treatment with acetylcholinesterase inhibition, revealed two frame-shifting heteroallelic mutations, a maternally inherited 1478delG and a paternally inherited 4804delC. An anconeus muscle biopsy demonstrated a profound distortion of the architecture and function of the neuromuscular junction, which was strikingly similar to that seen in mice lacking laminin β2 subunit. The findings included: pronounced reduction of the axon terminal size with encasement of the nerve endings by Schwann cells, severe widening of the primary synaptic cleft and invasion of the synaptic space by the processes of Schwann cells, and moderate simplification of postsynaptic folds and intact expression of the endplate acetylcholinesterase. The endplate potential quantal content was notably reduced, while the frequencies and amplitudes of miniature endplate potentials were only moderately diminished and the decay phases of miniature endplate potentials were normal. Western blot analysis of muscle and kidney tissue and immunohistochemistry of kidney tissue showed no laminin β2 expression.

Conclusion:

This case, which represents a new type of synaptic CMS, exemplifies the wide variability of phenotypes associated with LAMB2 mutations and underscores the fundamental role that laminin β2 plays in the development of the human neuromuscular junction.

Structure and function of the nicotinic arm of acetylcholine regulatory axis in human leukemic T cells

Although acetylcholine (ACh) is widely known as a neurotransmitter, it also functions as a local humoral factor translating environmental stimuli into alterations in T cell development and function. The cholinergic components present in neurons are expressed in T cells where they constitute an independent cholinergic system. Both non-immunologic and immunologic stimulations can alter expression and function of cholinergic elements in T cells. Recent studies have convincingly demonstrated regulation of immune system by auto/paracrine ACh, which provides a basis for development of new immunomodulatory therapies with nicotinic agonists. The purpose of our research is to integrate information about the structure and activity of the ACh regulatory axis with the phenotypic and functional alterations of T cells during their development and commitment. In this study, we used the Ach producing human leukemic T cell line CCRF-CEM (CEM) to investigate auto/paracrine mechanisms of T cell regulation through the nicotinic class of ACh receptors (nAChRs). The intact CEM expressed alpha3, alpha5, alpha6, alpha7, alpha 9, beta2 and beta4 nAChR subunits. Stimulation of CEM with 10 microg/ml of phytohemagglutinin (PHA) for 16 h upregulated expression of the alpha3, alpha5, alpha7, alpha9 and beta2 and downregulated that of alpha6 and beta4 subunits, indicating that TCR activation leads to overexpression of high Ca2+-permeable ACh-gated ion channels. Activation of alpha7- and alpha3 AChRs predominantly abrogated PHA-dependent upregulation of the pro-inflammatory cytokine TNF-alpha and IFN-gamma receptors, respectively, at the mRNA and protein levels. Signaling through alpha7 and alpha3 nAChRs also significantly (p<0.05) altered expression of the cell state regulators p21 and Bcl-2, respectively, suggesting that downregulation of inflammation via nAChRs includes effects on the T cell cycle progression and apoptosis. These findings indicate that constant stimulation of alpha7 and alpha3 nAChRs by endogenously released ACh controls T cell activation and that signaling downstream of distinct nAChR subtypes targets specific inflammatory and cell cycle genes. Learning the cholinergic pharmacology of inflammation should allow to regulate specific types of immune reactions by selectively activating or blocking the types of nAChRs expressed by the immune cells mediating specific immune reactions.

[Medical students' knowledge of cardiovascular risk factors]

OBJECTIVES

To evaluate cardiovascular risk factor awareness among medical students at the University of Navarra.

MATERIAL AND METHODS

A descriptive cross-sectional study including 334 students of the 1st, 4th and 6th year. They answered an anonymous structured questionnaire, and the results were analyzed using SPSS 11.0.

RESULTS

Most 4th and 6th year students correctly identified the cardiovascular risk factors (CVRF). The 4th year students obtained better results on lipid values while the 6th year students performed better on body mass index and arterial hypertension. 97.8% of the sample considered the Mediterranean diet to be a protective factor.

CONCLUSION

University of Navarra's medical students are well informed about CVRF and their knowledge increases along the degree course.

Women's attitudes towards mechanisms of action of family planning methods: survey in primary health centres in Pamplona, Spain

Background

Informed consent in family planning includes knowledge of mechanism of action. Some methods of family planning occasionally work after fertilization. Knowing about postfertilization effects may be important to some women before choosing a certain family planning method. The objective of this survey is to explore women's attitudes towards postfertilization effects of family planning methods, and beliefs and characteristics possibly associated with those attitudes.

Methods

Cross-sectional survey in a sample of 755 potentially fertile women, aged 18–49, from Primary Care Health Centres in Pamplona, Spain. Participants were given a 30-item, self-administered, anonymous questionnaire about family planning methods and medical and surgical abortion. Logistic regression was used to identify variables associated with women's attitudes towards postfertilization effects.

Results

The response rate was 80%. The majority of women were married, held an academic degree and had no children. Forty percent of women would not consider using a method that may work after fertilization but before implantation and 57% would not consider using one that may work after implantation. While 35.3% of the sample would stop using a method if they learned that it sometimes works after fertilization, this percentage increased to 56.3% when referring to a method that sometimes works after implantation. Women who believe that human life begins at fertilization and those who consider it is important to distinguish between natural and induced embryo loss were less likely to consider the use of a method with postfertilization effects.

Conclusion

Information about potential postfertilization effects of family planning methods may influence women's acceptance and choice of a particular family planning method. Additional studies in other populations are necessary to evaluate whether these beliefs are important to those populations.

Oviposition deterrents for the Mediterranean fruit fly, Ceratitis capitata (Diptera: Tephritidae) from fly faeces extracts

After oviposition, females of the Mediterranean fruit fly Ceratitis capitata Wiedemann deposit a host-marking pheromone on the fruit surface that deters oviposition by conspecifics. Methanolic extracts of fruit fly faeces elicit a similar deterrent effect. The results of laboratory and field experiments using raw methanolic extracts of C. capitata faeces as an oviposition deterrent are reported. Laboratory bioassays revealed a significant positive relationship between concentration of faeces and the inhibition of oviposition responses by C. capitata. Treatment of halves of coffee bushes with methanolic extracts containing 0.1, 1.0 and 10 mg faeces ml(-1) resulted in a significant reduction of infestation only at the highest concentration (P=0.03). Treatment of blocks of coffee bushes with an extract of 10 mg faeces ml(-1) resulted in an 84% reduction in infestation by C. capitata in sprayed plants and a 56% reduction in adjacent untreated coffee bushes surrounding treated plots, probably due to the deterrent effect of host-marking pheromone on fly oviposition. We conclude that faeces contain oviposition deterrent substances that effectively reduce fruit infestations by C. capitata, suggesting a clear potential for the use of this infochemical in integrated management programmes targeted at this pest.

Muscarinic acetylcholine receptors regulating cell cycle progression are expressed in human gingival keratinocytes

We have previously reported the presence in human gingival keratinocytes (GKC) of choline acetyltransferase, the acetylcholine (ACh) synthesizing enzyme, acetylcholinesterase, the ACh degrading enzyme, and alpha 3, alpha 5, alpha 7, beta 2 as well as alpha 9 nicotinic ACh receptor subunits. To expand the knowledge about the role of ACh in oral biology, we investigated the presence of the muscarinic ACh receptor (mAChR) subtypes in GKC. RT-PCR demonstrated the presence of m2, m3, m4, and m5 mRNA transcripts. Synthesis of the respective proteins was verified by immunoblotting with the subtype-specific antibodies that revealed receptor bands at the expected molecular weights. The antibodies mapped mAChR subtypes in the epithelium of human attached gingiva and also visualized them on the cell membrane of cultured GKC. The whole cell radioligand binding assay revealed that GKC have specific binding sites for the muscarinic ligand [3H]quinuclidinyl benzilate, Bmax = 222.9 fmol/106 cells with a Kd of 62.95 pM. The downstream coupling of the mAChRs to regulation of cell cycle progression in GKC was studied using quantitative RT-PCR and immunoblotting assays. Incubation of GKC for 24 h with 10 micro m muscarine increased relative amounts of Ki-67, PCNA and p53 mRNAs and PCNA, cyclin D1, p21 and p53 proteins. These effects were abolished in the presence of 50 micro m atropine. The finding in GKC of mAChRs coupled to regulation of the cell cycle progression demonstrate further the structure/function of the non-neuronal cholinergic system operating in human oral epithelium. The results obtained in this study help clarify the role for keratinocyte ACh axis in the physiologic control of oral gingival homeostasis.

Identification and characterization of muscarinic acetylcholine receptor subtypes expressed in human skin melanocytes

The present study was designed to identify and characterize muscarinic acetylcholine receptors in normal human melanocytes. We used subtype-specific oligonucleotide primers to localize the five genetically defined mAChR mRNAs (ml through m5) by reverse transcription-polymerase chain reaction. These experiments showed that all five mAChR subtype mRNAs are expressed in melanocytes. The PCR products were verified by restriction analysis and Southern blotting. Receptors were visualized in cultures of normal human melanocytes and specimens of normal human skin by subtype-specific rabbit anti-receptor polyclonal antibodies. Radioligand binding assays with the lipophilic drug [3H]quinuclidinyl benzilate demonstrated approximately 9,000 high affinity binding sites/cell. Micromolar concentrations of muscarine or carbachol transiently increased intracellular Ca2+, which could be attenuated by atropine, demonstrating coupling of the receptors to mobilization of intracellular free Ca2+. Lower concentrations of muscarine induced spontaneous repetitive spike-like increases of intracellular Ca2+ which is characteristic for the activation of muscarinic receptors. These results indicate that normal human skin melanocytes express the ml, m2, m3, m4, and m5 subtypes of classic muscarinic acetylcholine receptors on their cell membrane and that these receptors regulate the concentration of intracellular free Ca2+, which may play an important physiologic role in melanocyte behavior and skin pigmentation.

A receptor-mediated mechanism of nicotine toxicity in oral keratinocytes

Smoking and smokeless tobacco cause morbidity that originates from the epithelium lining of the skin and upper digestive tract. Oral keratinocytes (OKC) express nicotinic acetylcholine receptors (nAChRs) that bind nicotine (Nic). We studied the mechanism of the receptor-mediated toxicity of tobacco products on OKC. Preincubation of normal human OKC with Nic altered the ligand-binding kinetics of their nAChRs, suggesting that the nAChRs underwent structural changes. This hypothesis was confirmed by the finding that exposure of OKC to Nic causes transcriptional and translational changes. Through RT-PCR and immunoblotting, we found a 1.5- to 2.9-fold increase in the mRNA and protein levels of alpha3, alpha5, alpha7, beta2, and beta4 nAChR subunits. Exposure of OKC to Nic also changed the mRNA and protein levels of the cell cycle and cell differentiation markers Ki-67, PCNA, p21, cyclin D1, p53, filaggrin, loricrin, and cytokeratins 1 and 10. The nicotinic antagonist mecamylamine prevented these changes, which indicates that the Nic-induced changes in the expression of both the nAChR and the cell cycle and cell differentiation genes resulted from pharmacologic stimulation of nAChRs with Nic. To establish the relevance of these findings to the pathobiologic effects of tobacco products in vivo, we studied the above parameters in the oral tissue of rats and mice after their exposure for 3 weeks to environmental cigarette smoke or drinking water containing equivalent concentrations of Nic that are pathophysiologically relevant. The changes of the nAChRs and the cell cycle and cell differentiation genes were similar to those found in vitro. The results of indirect immunofluorescence assay of tissue specimens validated these findings. Thus, some pathobiologic effects of tobacco products in oral tissues may stem from Nic-induced alterations of the structure and function of keratinocyte nAChRs responsible for the physiologic regulation of the cell cycle by the cytotransmitter acetylcholine.

Programmed cell death of keratinocytes culminates in apoptotic secretion of a humectant upon secretagogue action of acetylcholine

The programmed cell death of the stratified squamous epithelial cells comprising human epidermis culminates in abrupt transition of viable granular keratinocytes (KC) into dead corneocytes sloughed by the skin. The granular cell-corneocyte transition is associated with a loss in volume and dry cell weight but the mechanism for and biological significance of this form of keratinocyte apoptosis remain obscure. We show that terminally differentiated KC extrude into the intercellular spaces of living epidermis the cytoplasmic buds containing randomly congregated components of the cytosol as well as filaggrin, a precursor of the natural moisturizing factor. The discharge of secretory product is reminiscent of holocrine secretion, suggesting the term ‘apoptotic secretion’ for this novel, essential step in the process of cornification. The secretory product may become a part of the glycocalyx (a.k.a. ‘intercellular cement substance’ of epidermis) and serve as a humectant that counterbalances the osmotic pressure imposed by the natural moisturizing factor located in the stratum corneum comprised by corneocytes. The apoptotic secretion commences upon secretagouge action of acetylcholine which is synthesized and released by KC. A combination of a cholinergic nicotinic agonist and a muscarinic antagonist which increases intracellular calcium levels is required to trigger the apoptotic secretion. Analysis of the relative amounts of cholinergic enzymes and receptors expressed by KC capable of secretion and the pharmacological profiles of secretion regulation revealed an upward concentration gradient of free acetylcholine in epidermis which may provide for its unopposed secretagogue action via the m1 muscarinic and the (α)7, and (α)9 nicotinic receptor types expressed by KC at the latest stage of their development in the epidermis.

Antigen-dependent cytokine mRNA expression by individual rhesus macaque T helper cells by flow cytometry

Specific patterns of cytokine secretion by CD4(+) T helper (Th) cells determine the nature of immune effector responses. Using a multiparameter, flow cytometric fluorescent in situ hybridization (FISH) assay that detected cytoplasmic mRNA within intact cells, we assessed antigen-specific cytokine expression in rhesus macaque Th cells. In the peripheral lymphocytes of immunized rhesus macaques, FISH detected antigen-induced cytokine gene expression in single Th cells. Analysis of simultaneous cytokine expression by single cells demonstrated that the recall immune response consisted of Th cells expressing either a Th1 (IL-2(+)/IFN-gamma(+)) or a Th2 (IL-4(+)/IL-6(+)) cytokine pattern. In addition to the classic Th subsets, Th cells expressing only one of two Th1 or Th2 defining cytokines were common following antigen restimulation. The data gathered with the FISH assay suggest that, in primates, the immune response to recall antigens consists of nonclassic Th cells, as well as a mixture of polarized Th1 and Th2 T cells.

Periprosthetic humeral fractures: management and classification

Six patients (67 to 94 years of age) sustained a periprosthetic humeral fracture at an average of 43 months after shoulder arthroplasty (range 13 to 85 months). These fractures were classified depending on fracture anatomy and implant stability. Type A fractures occur about the tuberosities. Type B fractures occur about the stem and are subclassified by fracture anatomy and implant stability: B1 fractures are spiral fractures with a stable implant, B2 fractures are transverse or short oblique fractures about the tip of the stem with a stable implant, and B3 fractures are those fractures about the stem with an unstable implant. Type C fractures occur well distal to the tip of the stem. Five of the 6 fractures required surgery, 4 with revision to a long-stemmed component. All fractures united with restoration of range of motion and function. Satisfactory results may be anticipated if these fractures are managed in an appropriate fashion.

Bipolar shoulder arthroplasty in patients with osteoarthritis: short-term clinical results and evaluation of birotational head motion

To determine the clinical outcome and evaluate the biomechanical properties (persisting birotational head motion) of the bipolar shoulder system in patients with primary osteoarthritis, a prospective study of 48 shoulders in 43 patients was undertaken. Patients were monitored for a mean of 3. 1 years (range 2 to 6 years). Pain relief was achieved in 92% of cases. Forty-one (96%) patients were satisfied with the result of the surgery, and satisfactory results were obtained in 92% of shoulders (with The University of California at Los Angeles rating system). Prosthetic birotational motion (head-shell and shell-glenoid motion) persisted in all shoulders. Bipolar shoulder arthroplasty is a low-friction device with persisting birotational head motion that offers excellent pain relief, eliminates glenoid component loosening concerns, and represents an adequate alternative to shoulder arthroplasty. Early results have been promising.

Repair of massive rotator cuff tears in patients older than 70 years

Major ruptures of the rotator cuff are common in elderly patients, and their management has been a challenge for orthopaedic surgeons. This study was undertaken to evaluate the results obtained in patients older than 70 years who were treated with open surgical repair for massive ruptures of the rotator cuff tendons and to correlate the functional outcomes with the quality of the repairs. Between January 1991 and November 1994, 69 patients older than 70 years of age underwent rotator cuff repairs of massive tears with a minimum follow-up of 2 years (mean of 3 years). These patients were evaluated before and after surgery with the University of California at Los Angeles score. The mean age was 75 years (range 70 to 90 years), and female sex and right shoulder were predominant. A good bone-tendon repair was achieved in 55 patients, a fair bone-tendon repair in 5 patients, a poor bone tendon-repair in 8 patients, and 1 patient had no repair. The mean University of California at Los Angeles rating score before surgery was 9.4 points, and the mean postoperative score at final follow-up was 30.9 points, with an average improvement of 21.5 points (P = .0001). Satisfactory results were achieved in 78.2% of the patients (University of California at Los Angeles score equal or over 28). The patients' clinical results and postoperative arthrograms are evaluated with regard to the quality of cuff repair. Painful massive rotator cuff tears can be repaired in patients older than 70 years with satisfactory results.

Non-Hodgkin's lymphoma as an unexpected diagnosis in a shoulder arthroplasty

Shoulder arthroplasty (SA) is commonly performed in patients with rheumatoid arthritis (RA) who have been treated with long-term immunosuppressive medication. RA is associated with an increased risk of neoplasms of the immune system. A case of non-Hodgkin's lymphoma as an unexpected diagnosis after the routine pathologic examination of the soft tissues after SA was detected in a 54-year-old woman with long-standing RA and prolonged immunosuppressive therapy. Although this case does not support the cost-effectiveness of routine specimen evaluation during SA, we suggest that histological analysis of the surgical tissues is appropriate and should be performed in all patients who have been treated with prolonged immunosuppressive medication, especially RA patients as well as patients who have suspicious surgical findings.

Nonunion after a tibial shaft fracture complicating tibial tubercule osteotomy

Tibial shaft fracture after tibial tubercle osteotomy in total knee replacement is a rare complication. We report on a 67-year-old man who had a knee revision arthroplasty in which a long tubercle osteotomy was performed to facilitate exposure. Three weeks after surgery, he presented with a transverse shaft fracture, which became a nonunion requiring surgical management. This shaft nonunion and its solution after tibial tubercle osteotomy is discussed as well as relevant literature.

Home continuous passive motion machine versus professional physical therapy following total knee replacement

A vigorous rehabilitation program following discharge from the hospital is necessary for patients having a total knee arthroplasty to maintain and improve range of motion and function. To compare the effectiveness of the continuous passive motion (CPM) machine as a home therapy program versus professional physical therapy, a prospective, comparative, randomized clinical study of 103 consecutive primary total knee arthroplasties in 80 patients (23 bilateral) was performed. The CPM group consisted of 37 patients (49 knees), and the physical therapy group consisted of 43 patients (54 knees). At 2 weeks, knee flexion was similar in the two groups, but a flexion contracture was noted in the CPM group (4.2 degrees). This difference is felt by the authors to be clinically insignificant. At 6 months, there were no differences in knee scores, knee flexion, presence of flexion contracture, or extensor lag between the two groups. The cost for the CPM machine group was $10,582 ($286 per patient), and the cost for professional therapy was $23,994 ($558 per patient). We conclude that the CPM machine after the hospital discharge of patients having total knee replacement is an adequate rehabilitation alternative with lower cost and with no difference in results compared with professional therapy.

Bipolar shoulder arthroplasty for painful conditions of the shoulder

Between April 1991 and March 1997, 182 bipolar shoulder replacements were implanted in 174 patients (8 bilateral) for painful conditions of the shoulder. The study group comprises 108 patients who were followed for an average of 2.9 years (range, 2-6 years). Diagnoses included osteoarthritis (51), rotator cuff arthropathy (27), avascular necrosis (3), revisions (8), rheumatoid arthritis (2), and fractures--both old and recent (17). A satisfactory rating (University of California at Los Angeles shoulder rating score greater than or equal to 28 points of 35) was achieved by 72% of the patients (including rotator cuff arthropathy patients). Patients with osteoarthritis obtained 90.2% of satisfactory results (46 of 51). The overall pain score after surgery was 8.8 points (of 10), meaning that none or occasional pain was present. Five patients required prosthetic revision, and 102 (94.4%) were satisfied with the surgical procedure.

Scintigraphic evaluation in total knee failure secondary to severe metallosis

The scintigraphic findings are described for a patient with severe metallosis in a failed noninfected total knee arthroplasty secondary to metal-metal friction between the femoral and tibial components as a result of polyethylene wear. Technetium-99m phosphate and gallium-67 citrate scans were positive in incongruent uptake areas. This uptake is classically associated with septic loosening. The recommendation is made that metallosis be suspected before surgery as a possible cause of a false positive scan where sequential technetium-gallium scans are employed.

Thigh pain following tourniquet application in simultaneous bilateral total knee replacement arthroplasty

Thigh pain following tourniquet application is a common patient complaint in the early postoperative period following total knee arthroplasty. Postoperative thigh pain was evaluated in 28 consecutive simultaneous bilateral total knee arthroplasty patients between April 1996 and October 1996. A prospective, double-blind, randomized clinical trial was performed. Tourniquet pressure of 350 mmHg was used on 1 thigh (thigh 1) and 100 mmHg plus systolic blood pressure on the other (thigh 2). A scale of pain (no pain, mild, moderate, or severe) was applied on the first, second, and third days, as well as 2 and 6 weeks after surgery. There were 16 men and 12 women with a mean age of 72 years (range, 55-85 years). The mean tourniquet time was similar in both groups (thigh 1 = 23 minutes, thigh 2 = 22 minutes). The mean tourniquet pressure in thigh 2 was 230 mmHg (range, 212-260 mmHg). There was a statistically significant difference in thigh pain on the first (P = .01), second (P = .01), and third (P = .001) postoperative days between both groups, with more thigh pain on the 350 mmHg side. At 6 weeks after surgery, the difference in thigh pain was gone. For total knee arthroplasty, using the tourniquet at a pressure of 100 mmHg above the systolic blood pressure is recommended. This is adequate to provide a bloodless field and will result in a less unpleasant postoperative period.

Bipolar shoulder arthroplasty for rotator cuff arthropathy

Between July 1991 and February 1995, 33 patients underwent bipolar shoulder arthroplasty for painful rotator cuff arthropathy of the shoulder. Twenty-two of these patients have been followed for an average of 28 months (range 24 to 48 months) and comprised the study group. All patients had massive, irreparable rotator cuff tears and presented with preserved passive motion, good deltoid function, and obliterated glenohumeral joint surfaces. Function and comfort were dramatically improved in all patients, with an average increase in active forward elevation of 29 degrees and a gain in active external rotation of 39 degrees. There was one complication requiring reoperation at 4 years. Utilizing the UCLA and Swanson scoring systems, all patients were rated fair or better.

Midterm results in metal-backed patella revisions for metallosis

Nine patients underwent isolated patellar revisions and synovectomies for metallosis secondary to the mechanical failure of metal-backed patellar components. These patients were followed for an average of 5 years (range, 2 to 8 years). In all cases, the femoral and tibial components were left in place, and in one patient the patellar bone was deemed too thin to resurface. Two patients (22%) developed deep infection. One infection (enterococcal) required arthrodesis, and the other (staphylococcal) was successfully managed with a two-staged reimplantation. A third patient sustained an inferior patella pole fracture that was treated conservatively. The remaining six patients are functioning satisfactorily. Metallosis is a serious complication in knee arthroplasty, and these patients merit close follow-up.

Restoration of limb alignment in total knee arthroplasty: evaluation and methods

Obtaining adequate alignment is critical in the proper performance of total knee arthroplasty (TKA). This study prospectively evaluates 350 patients who had previous TKA. Its goals are to establish the best method of measuring limb alignment as well as the best method of restoring ideal alignment. Intramedullary alignment techniques were compared with extramedullary, and alignment of each limb was evaluated by both long (scanogram) and short films (14 inches x 17 inches). Conclusions reached were (1) that only data obtained from full limb radiographs are accurate for determining and reporting limb alignment in TKA, (2) that alignment values should be reported relative to the mechanical axis of the limb because of the variability of the femoral anatomic angle, (3) that intramedullary femoral guides are required to make accurate femoral bone cuts, (4) that extramedullary tibial guides permit accurate cuts of the proximal end of the tibia, and (5) that tibial intramedullary guides are not only unnecessary but also potentially misleading.

Drosophila paramyosin/miniparamyosin gene products show a large diversity in quantity, localization, and isoform pattern: a possible role in muscle maturation and function

The Drosophila paramyosin/miniparamyosin gene expresses two products of different molecular weight transcriptionally regulated from two different promoters. Distinct muscle types also have different relative amounts of myosin, paramyosin, and miniparamyosin, reflecting differences in the organization of their thick filaments. Immunofluorescence and EM data indicate that miniparamyosin is mainly located in the M line and at both ends of the thick filaments in Drosophila indirect flight muscles, while paramyosin is present all along the thick filaments. In the tergal depressor of the trochanter muscle, both proteins are distributed all along the A band. In contrast, in the waterbug, Lethocerus, both paramyosin and miniparamyosin are distributed along the length of the indirect flight and leg muscle thick filaments. Two-dimensional and one-dimensional Western blot analyses have revealed that miniparamyosin has several isoforms, focusing over a very wide pH range, all of which are phosphorylated in vivo. The changes in isoform patterns of miniparamyosin and paramyosin indicate a direct or indirect involvement of these proteins in muscle function and flight. This wide spectrum of potential regulatory characteristics underlines the key importance of paramyosin/miniparamyosin and its complex isoform pattern in the organization of the invertebrate thick filament.